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* [PATCH v2 0/3] convert tree to get_random_u32_{below,above,between}()
@ 2022-11-14 16:45 Jason A. Donenfeld
  2022-11-14 16:45 ` [PATCH v2 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
                   ` (3 more replies)
  0 siblings, 4 replies; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-14 16:45 UTC (permalink / raw)
  To: linux-kernel, patches
  Cc: Jason A. Donenfeld, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Theodore Ts'o,
	Andreas Dilger, Jaegeuk Kim, Richard Weinberger,
	Darrick J . Wong, SeongJae Park, Thomas Gleixner, Andrew Morton,
	Michael Ellerman, Helge Deller, netdev, linux-crypto,
	linux-block, linux-fsdevel, linux-media, linux-arm-kernel,
	loongarch, linux-mips, linuxppc-dev, linux-mmc, linux-parisc

Hey everyone,

[Changes v1->v2: Jakub asked me to send a v2 around now in the current
 cycle to minimize potential conflicts with the net tree. So this is
 rebased and stripped down to just the treewide parts. As well, the
 removal function is deferred until the end of 6.2 in a separate pull so
 that we don't have merge issues.]

This series is the second tranche of tree-wide conversions to get random
integer handling a bit tamer. It's another Coccinelle-based patchset.

First we s/prandom_u32_max/get_random_u32_below/, since the former is
just a deprecated alias for the latter. Then later, we can remove
prandom_u32_max all together. I'm quite happy about finally being able
to do that. It means that prandom.h is now only for deterministic and
repeatable randomness, not non-deterministic/cryptographic randomness.
That line is no longer blurred.

In order to clean up a bunch of inefficient patterns, we use two simple
helper functions built on top of get_random_u32_below:
get_random_u32_above and get_random_u32_between. The next two patches
convert some gnarly open-coded number juggling to use these helpers.

I've used Coccinelle for these three treewide patches, so hopefully
review is rather uneventful. I didn't accept all of the changes that
Coccinelle proposed, though, as these tend to be somewhat
context-specific. I erred on the side of just going with the most
obvious cases, at least this time through. And then we can address more
complicated cases through actual maintainer trees.

Since get_random_u32_below() and others sits in my random.git tree,
these patches too will flow through that same tree.

Regards,
Jason

Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Helge Deller <deller@gmx.de>
Cc: netdev@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-block@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: loongarch@lists.linux.dev
Cc: linux-mips@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-parisc@vger.kernel.org

Jason A. Donenfeld (3):
  treewide: use get_random_u32_below() instead of deprecated function
  treewide: use get_random_u32_{above,below}() instead of manual loop
  treewide: use get_random_u32_between() when possible

 arch/arm/kernel/process.c                     |  2 +-
 arch/arm64/kernel/process.c                   |  2 +-
 arch/loongarch/kernel/process.c               |  2 +-
 arch/loongarch/kernel/vdso.c                  |  2 +-
 arch/mips/kernel/process.c                    |  2 +-
 arch/mips/kernel/vdso.c                       |  2 +-
 arch/parisc/kernel/vdso.c                     |  2 +-
 arch/powerpc/crypto/crc-vpmsum_test.c         |  4 +-
 arch/powerpc/kernel/process.c                 |  2 +-
 arch/s390/kernel/process.c                    |  2 +-
 arch/s390/kernel/vdso.c                       |  2 +-
 arch/sparc/vdso/vma.c                         |  2 +-
 arch/um/kernel/process.c                      |  2 +-
 arch/x86/entry/vdso/vma.c                     |  2 +-
 arch/x86/kernel/module.c                      |  2 +-
 arch/x86/kernel/process.c                     |  2 +-
 arch/x86/mm/pat/cpa-test.c                    |  4 +-
 crypto/rsa-pkcs1pad.c                         |  2 +-
 crypto/testmgr.c                              | 86 +++++++++----------
 drivers/block/drbd/drbd_receiver.c            |  4 +-
 drivers/bus/mhi/host/internal.h               |  2 +-
 drivers/dma-buf/st-dma-fence-chain.c          |  6 +-
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  2 +-
 .../drm/i915/gt/intel_execlists_submission.c  |  2 +-
 drivers/gpu/drm/i915/intel_memory_region.c    |  4 +-
 drivers/infiniband/core/cma.c                 |  2 +-
 drivers/infiniband/hw/cxgb4/id_table.c        |  4 +-
 drivers/infiniband/hw/hns/hns_roce_ah.c       |  5 +-
 drivers/infiniband/ulp/rtrs/rtrs-clt.c        |  2 +-
 drivers/md/bcache/request.c                   |  2 +-
 drivers/media/common/v4l2-tpg/v4l2-tpg-core.c |  8 +-
 .../media/test-drivers/vidtv/vidtv_demod.c    |  8 +-
 .../test-drivers/vivid/vivid-kthread-cap.c    |  2 +-
 .../test-drivers/vivid/vivid-kthread-out.c    |  2 +-
 .../media/test-drivers/vivid/vivid-radio-rx.c |  4 +-
 .../media/test-drivers/vivid/vivid-sdr-cap.c  |  2 +-
 .../test-drivers/vivid/vivid-touch-cap.c      |  2 +-
 drivers/mmc/core/core.c                       |  4 +-
 drivers/mmc/host/dw_mmc.c                     |  2 +-
 drivers/mtd/nand/raw/nandsim.c                |  4 +-
 drivers/mtd/tests/mtd_nandecctest.c           | 10 +--
 drivers/mtd/tests/stresstest.c                |  8 +-
 drivers/mtd/ubi/debug.c                       |  2 +-
 drivers/mtd/ubi/debug.h                       |  6 +-
 drivers/net/ethernet/broadcom/cnic.c          |  2 +-
 .../chelsio/inline_crypto/chtls/chtls_io.c    |  4 +-
 drivers/net/phy/at803x.c                      |  2 +-
 drivers/net/team/team_mode_random.c           |  2 +-
 drivers/net/wireguard/selftest/allowedips.c   | 20 ++---
 drivers/net/wireguard/timers.c                |  4 +-
 .../broadcom/brcm80211/brcmfmac/p2p.c         |  2 +-
 .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c |  2 +-
 drivers/pci/p2pdma.c                          |  2 +-
 drivers/s390/scsi/zfcp_fc.c                   |  2 +-
 drivers/scsi/fcoe/fcoe_ctlr.c                 |  4 +-
 drivers/scsi/qedi/qedi_main.c                 |  2 +-
 drivers/scsi/scsi_debug.c                     |  6 +-
 fs/ceph/inode.c                               |  2 +-
 fs/ceph/mdsmap.c                              |  2 +-
 fs/ext2/ialloc.c                              |  2 +-
 fs/ext4/ialloc.c                              |  2 +-
 fs/ext4/mmp.c                                 |  8 +-
 fs/ext4/super.c                               |  5 +-
 fs/f2fs/gc.c                                  |  2 +-
 fs/f2fs/segment.c                             |  8 +-
 fs/ubifs/debug.c                              |  8 +-
 fs/ubifs/lpt_commit.c                         | 14 +--
 fs/ubifs/tnc_commit.c                         |  2 +-
 fs/xfs/libxfs/xfs_alloc.c                     |  2 +-
 fs/xfs/libxfs/xfs_ialloc.c                    |  2 +-
 fs/xfs/xfs_error.c                            |  2 +-
 include/linux/damon.h                         |  2 +-
 include/linux/nodemask.h                      |  2 +-
 kernel/bpf/core.c                             |  4 +-
 kernel/kcsan/selftest.c                       |  4 +-
 kernel/locking/test-ww_mutex.c                |  4 +-
 kernel/time/clocksource.c                     |  2 +-
 lib/fault-inject.c                            |  2 +-
 lib/find_bit_benchmark.c                      |  4 +-
 lib/kobject.c                                 |  2 +-
 lib/reed_solomon/test_rslib.c                 |  6 +-
 lib/sbitmap.c                                 |  4 +-
 lib/test-string_helpers.c                     |  2 +-
 lib/test_fprobe.c                             |  5 +-
 lib/test_hexdump.c                            | 10 +--
 lib/test_kprobes.c                            |  5 +-
 lib/test_list_sort.c                          |  2 +-
 lib/test_printf.c                             |  2 +-
 lib/test_rhashtable.c                         |  6 +-
 lib/test_vmalloc.c                            |  8 +-
 mm/kasan/kasan_test.c                         |  6 +-
 mm/kfence/core.c                              |  4 +-
 mm/kfence/kfence_test.c                       |  4 +-
 mm/slub.c                                     |  2 +-
 mm/swapfile.c                                 |  5 +-
 net/802/garp.c                                |  2 +-
 net/802/mrp.c                                 |  2 +-
 net/batman-adv/bat_iv_ogm.c                   |  4 +-
 net/batman-adv/bat_v_elp.c                    |  2 +-
 net/batman-adv/bat_v_ogm.c                    |  4 +-
 net/batman-adv/network-coding.c               |  2 +-
 net/bluetooth/mgmt.c                          |  5 +-
 net/can/j1939/socket.c                        |  2 +-
 net/can/j1939/transport.c                     |  2 +-
 net/ceph/mon_client.c                         |  2 +-
 net/ceph/osd_client.c                         |  2 +-
 net/core/neighbour.c                          |  4 +-
 net/core/pktgen.c                             | 37 ++++----
 net/core/stream.c                             |  2 +-
 net/ipv4/icmp.c                               |  2 +-
 net/ipv4/igmp.c                               |  6 +-
 net/ipv4/inet_connection_sock.c               |  2 +-
 net/ipv4/inet_hashtables.c                    |  2 +-
 net/ipv4/route.c                              |  4 +-
 net/ipv4/tcp_bbr.c                            |  2 +-
 net/ipv4/tcp_input.c                          |  3 +-
 net/ipv6/addrconf.c                           |  8 +-
 net/ipv6/mcast.c                              | 10 +--
 net/ipv6/output_core.c                        |  8 +-
 net/ipv6/route.c                              |  2 +-
 net/netfilter/ipvs/ip_vs_twos.c               |  4 +-
 net/netfilter/nf_conntrack_core.c             |  4 +-
 net/netfilter/nf_nat_helper.c                 |  2 +-
 net/netlink/af_netlink.c                      |  2 +-
 net/packet/af_packet.c                        |  4 +-
 net/sched/act_gact.c                          |  2 +-
 net/sched/act_sample.c                        |  2 +-
 net/sched/sch_choke.c                         |  2 +-
 net/sched/sch_netem.c                         |  4 +-
 net/sctp/socket.c                             |  2 +-
 net/sctp/transport.c                          |  2 +-
 net/sunrpc/cache.c                            |  2 +-
 net/sunrpc/xprtsock.c                         |  2 +-
 net/tipc/socket.c                             |  2 +-
 net/vmw_vsock/af_vsock.c                      |  3 +-
 net/xfrm/xfrm_state.c                         |  2 +-
 136 files changed, 286 insertions(+), 313 deletions(-)

-- 
2.38.1


^ permalink raw reply	[flat|nested] 24+ messages in thread

* [PATCH v2 1/3] treewide: use get_random_u32_below() instead of deprecated function
  2022-11-14 16:45 [PATCH v2 0/3] convert tree to get_random_u32_{below,above,between}() Jason A. Donenfeld
@ 2022-11-14 16:45 ` Jason A. Donenfeld
  2022-11-14 17:35   ` Russell King (Oracle)
  2022-11-14 16:45 ` [PATCH v2 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop Jason A. Donenfeld
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-14 16:45 UTC (permalink / raw)
  To: linux-kernel, patches
  Cc: Jason A. Donenfeld, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Theodore Ts'o,
	Andreas Dilger, Jaegeuk Kim, Richard Weinberger,
	Darrick J . Wong, SeongJae Park, Thomas Gleixner, Andrew Morton,
	Michael Ellerman, Helge Deller, netdev, linux-crypto,
	linux-block, linux-fsdevel, linux-media, linux-arm-kernel,
	loongarch, linux-mips, linuxppc-dev, linux-mmc, linux-parisc

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
  (E)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 arch/arm/kernel/process.c                     |  2 +-
 arch/arm64/kernel/process.c                   |  2 +-
 arch/loongarch/kernel/process.c               |  2 +-
 arch/loongarch/kernel/vdso.c                  |  2 +-
 arch/mips/kernel/process.c                    |  2 +-
 arch/mips/kernel/vdso.c                       |  2 +-
 arch/parisc/kernel/vdso.c                     |  2 +-
 arch/powerpc/crypto/crc-vpmsum_test.c         |  4 +-
 arch/powerpc/kernel/process.c                 |  2 +-
 arch/s390/kernel/process.c                    |  2 +-
 arch/s390/kernel/vdso.c                       |  2 +-
 arch/sparc/vdso/vma.c                         |  2 +-
 arch/um/kernel/process.c                      |  2 +-
 arch/x86/entry/vdso/vma.c                     |  2 +-
 arch/x86/kernel/module.c                      |  2 +-
 arch/x86/kernel/process.c                     |  2 +-
 arch/x86/mm/pat/cpa-test.c                    |  4 +-
 crypto/rsa-pkcs1pad.c                         |  2 +-
 crypto/testmgr.c                              | 86 +++++++++----------
 drivers/block/drbd/drbd_receiver.c            |  4 +-
 drivers/bus/mhi/host/internal.h               |  2 +-
 drivers/dma-buf/st-dma-fence-chain.c          |  6 +-
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  2 +-
 .../drm/i915/gt/intel_execlists_submission.c  |  2 +-
 drivers/gpu/drm/i915/intel_memory_region.c    |  4 +-
 drivers/infiniband/core/cma.c                 |  2 +-
 drivers/infiniband/hw/cxgb4/id_table.c        |  4 +-
 drivers/infiniband/hw/hns/hns_roce_ah.c       |  4 +-
 drivers/infiniband/ulp/rtrs/rtrs-clt.c        |  2 +-
 drivers/md/bcache/request.c                   |  2 +-
 drivers/media/common/v4l2-tpg/v4l2-tpg-core.c |  8 +-
 .../media/test-drivers/vidtv/vidtv_demod.c    |  8 +-
 .../test-drivers/vivid/vivid-kthread-cap.c    |  2 +-
 .../test-drivers/vivid/vivid-kthread-out.c    |  2 +-
 .../media/test-drivers/vivid/vivid-radio-rx.c |  4 +-
 .../media/test-drivers/vivid/vivid-sdr-cap.c  |  2 +-
 .../test-drivers/vivid/vivid-touch-cap.c      |  2 +-
 drivers/mmc/core/core.c                       |  4 +-
 drivers/mmc/host/dw_mmc.c                     |  2 +-
 drivers/mtd/nand/raw/nandsim.c                |  4 +-
 drivers/mtd/tests/mtd_nandecctest.c           | 10 +--
 drivers/mtd/tests/stresstest.c                |  8 +-
 drivers/mtd/ubi/debug.c                       |  2 +-
 drivers/mtd/ubi/debug.h                       |  6 +-
 drivers/net/ethernet/broadcom/cnic.c          |  2 +-
 .../chelsio/inline_crypto/chtls/chtls_io.c    |  4 +-
 drivers/net/phy/at803x.c                      |  2 +-
 drivers/net/team/team_mode_random.c           |  2 +-
 drivers/net/wireguard/selftest/allowedips.c   | 20 ++---
 drivers/net/wireguard/timers.c                |  4 +-
 .../broadcom/brcm80211/brcmfmac/p2p.c         |  2 +-
 .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c |  2 +-
 drivers/pci/p2pdma.c                          |  2 +-
 drivers/s390/scsi/zfcp_fc.c                   |  2 +-
 drivers/scsi/fcoe/fcoe_ctlr.c                 |  4 +-
 drivers/scsi/qedi/qedi_main.c                 |  2 +-
 drivers/scsi/scsi_debug.c                     |  6 +-
 fs/ceph/inode.c                               |  2 +-
 fs/ceph/mdsmap.c                              |  2 +-
 fs/ext2/ialloc.c                              |  2 +-
 fs/ext4/ialloc.c                              |  2 +-
 fs/ext4/super.c                               |  5 +-
 fs/f2fs/gc.c                                  |  2 +-
 fs/f2fs/segment.c                             |  8 +-
 fs/ubifs/debug.c                              |  8 +-
 fs/ubifs/lpt_commit.c                         | 14 +--
 fs/ubifs/tnc_commit.c                         |  2 +-
 fs/xfs/libxfs/xfs_alloc.c                     |  2 +-
 fs/xfs/libxfs/xfs_ialloc.c                    |  2 +-
 fs/xfs/xfs_error.c                            |  2 +-
 include/linux/damon.h                         |  2 +-
 include/linux/nodemask.h                      |  2 +-
 kernel/bpf/core.c                             |  4 +-
 kernel/kcsan/selftest.c                       |  4 +-
 kernel/locking/test-ww_mutex.c                |  4 +-
 kernel/time/clocksource.c                     |  2 +-
 lib/fault-inject.c                            |  2 +-
 lib/find_bit_benchmark.c                      |  4 +-
 lib/kobject.c                                 |  2 +-
 lib/reed_solomon/test_rslib.c                 |  6 +-
 lib/sbitmap.c                                 |  4 +-
 lib/test-string_helpers.c                     |  2 +-
 lib/test_hexdump.c                            | 10 +--
 lib/test_list_sort.c                          |  2 +-
 lib/test_printf.c                             |  2 +-
 lib/test_rhashtable.c                         |  6 +-
 lib/test_vmalloc.c                            |  8 +-
 mm/kasan/kasan_test.c                         |  6 +-
 mm/kfence/core.c                              |  4 +-
 mm/kfence/kfence_test.c                       |  4 +-
 mm/slub.c                                     |  2 +-
 mm/swapfile.c                                 |  4 +-
 net/802/garp.c                                |  2 +-
 net/802/mrp.c                                 |  2 +-
 net/batman-adv/bat_iv_ogm.c                   |  4 +-
 net/batman-adv/bat_v_elp.c                    |  2 +-
 net/batman-adv/bat_v_ogm.c                    |  4 +-
 net/batman-adv/network-coding.c               |  2 +-
 net/bluetooth/mgmt.c                          |  4 +-
 net/can/j1939/socket.c                        |  2 +-
 net/can/j1939/transport.c                     |  2 +-
 net/ceph/mon_client.c                         |  2 +-
 net/ceph/osd_client.c                         |  2 +-
 net/core/neighbour.c                          |  4 +-
 net/core/pktgen.c                             | 28 +++---
 net/core/stream.c                             |  2 +-
 net/ipv4/icmp.c                               |  2 +-
 net/ipv4/igmp.c                               |  6 +-
 net/ipv4/inet_connection_sock.c               |  2 +-
 net/ipv4/inet_hashtables.c                    |  2 +-
 net/ipv4/route.c                              |  4 +-
 net/ipv4/tcp_bbr.c                            |  2 +-
 net/ipv4/tcp_input.c                          |  3 +-
 net/ipv6/addrconf.c                           |  8 +-
 net/ipv6/mcast.c                              | 10 +--
 net/ipv6/route.c                              |  2 +-
 net/netfilter/ipvs/ip_vs_twos.c               |  4 +-
 net/netfilter/nf_conntrack_core.c             |  4 +-
 net/netfilter/nf_nat_helper.c                 |  2 +-
 net/netlink/af_netlink.c                      |  2 +-
 net/packet/af_packet.c                        |  4 +-
 net/sched/act_gact.c                          |  2 +-
 net/sched/act_sample.c                        |  2 +-
 net/sched/sch_choke.c                         |  2 +-
 net/sched/sch_netem.c                         |  4 +-
 net/sctp/socket.c                             |  2 +-
 net/sctp/transport.c                          |  2 +-
 net/sunrpc/cache.c                            |  2 +-
 net/sunrpc/xprtsock.c                         |  2 +-
 net/tipc/socket.c                             |  2 +-
 net/vmw_vsock/af_vsock.c                      |  2 +-
 net/xfrm/xfrm_state.c                         |  2 +-
 132 files changed, 280 insertions(+), 280 deletions(-)

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index a2b31d91a1b6..f811733a8fc5 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -371,7 +371,7 @@ static unsigned long sigpage_addr(const struct mm_struct *mm,
 
 	slots = ((last - first) >> PAGE_SHIFT) + 1;
 
-	offset = prandom_u32_max(slots);
+	offset = get_random_u32_below(slots);
 
 	addr = first + (offset << PAGE_SHIFT);
 
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 044a7d7f1f6a..1395a1638427 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -591,7 +591,7 @@ unsigned long __get_wchan(struct task_struct *p)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
 
diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/process.c
index 2526b68f1c0f..77952d814bad 100644
--- a/arch/loongarch/kernel/process.c
+++ b/arch/loongarch/kernel/process.c
@@ -293,7 +293,7 @@ unsigned long stack_top(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 
 	return sp & STACK_ALIGN;
 }
diff --git a/arch/loongarch/kernel/vdso.c b/arch/loongarch/kernel/vdso.c
index 8c9826062652..eaebd2e0f725 100644
--- a/arch/loongarch/kernel/vdso.c
+++ b/arch/loongarch/kernel/vdso.c
@@ -78,7 +78,7 @@ static unsigned long vdso_base(void)
 	unsigned long base = STACK_TOP;
 
 	if (current->flags & PF_RANDOMIZE) {
-		base += prandom_u32_max(VDSO_RANDOMIZE_SIZE);
+		base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
 		base = PAGE_ALIGN(base);
 	}
 
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index bbe9ce471791..093dbbd6b843 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -711,7 +711,7 @@ unsigned long mips_stack_top(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 
 	return sp & ALMASK;
 }
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index 5fd9bf1d596c..f6d40e43f108 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -79,7 +79,7 @@ static unsigned long vdso_base(void)
 	}
 
 	if (current->flags & PF_RANDOMIZE) {
-		base += prandom_u32_max(VDSO_RANDOMIZE_SIZE);
+		base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
 		base = PAGE_ALIGN(base);
 	}
 
diff --git a/arch/parisc/kernel/vdso.c b/arch/parisc/kernel/vdso.c
index 47e5960a2f96..c5cbfce7a84c 100644
--- a/arch/parisc/kernel/vdso.c
+++ b/arch/parisc/kernel/vdso.c
@@ -75,7 +75,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
 
 	map_base = mm->mmap_base;
 	if (current->flags & PF_RANDOMIZE)
-		map_base -= prandom_u32_max(0x20) * PAGE_SIZE;
+		map_base -= get_random_u32_below(0x20) * PAGE_SIZE;
 
 	vdso_text_start = get_unmapped_area(NULL, map_base, vdso_text_len, 0, 0);
 
diff --git a/arch/powerpc/crypto/crc-vpmsum_test.c b/arch/powerpc/crypto/crc-vpmsum_test.c
index 273c527868db..c61a874a3a5c 100644
--- a/arch/powerpc/crypto/crc-vpmsum_test.c
+++ b/arch/powerpc/crypto/crc-vpmsum_test.c
@@ -77,8 +77,8 @@ static int __init crc_test_init(void)
 
 		pr_info("crc-vpmsum_test begins, %lu iterations\n", iterations);
 		for (i=0; i<iterations; i++) {
-			size_t offset = prandom_u32_max(16);
-			size_t len = prandom_u32_max(MAX_CRC_LENGTH);
+			size_t offset = get_random_u32_below(16);
+			size_t len = get_random_u32_below(MAX_CRC_LENGTH);
 
 			if (len <= offset)
 				continue;
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 67da147fe34d..fcf604370c66 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2303,6 +2303,6 @@ void notrace __ppc64_runlatch_off(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 42af4b3aa02b..3f5d2db0b854 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -224,7 +224,7 @@ unsigned long __get_wchan(struct task_struct *p)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
 
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 3105ca5bd470..119328e1e2b3 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -227,7 +227,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned long len)
 	end -= len;
 
 	if (end > start) {
-		offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
+		offset = get_random_u32_below(((end - start) >> PAGE_SHIFT) + 1);
 		addr = start + (offset << PAGE_SHIFT);
 	} else {
 		addr = start;
diff --git a/arch/sparc/vdso/vma.c b/arch/sparc/vdso/vma.c
index ae9a86cb6f3d..136c78f28f8b 100644
--- a/arch/sparc/vdso/vma.c
+++ b/arch/sparc/vdso/vma.c
@@ -354,7 +354,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned int len)
 	unsigned int offset;
 
 	/* This loses some more bits than a modulo, but is cheaper */
-	offset = prandom_u32_max(PTRS_PER_PTE);
+	offset = get_random_u32_below(PTRS_PER_PTE);
 	return start + (offset << PAGE_SHIFT);
 }
 
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 010bc422a09d..e38f41444721 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -356,7 +356,7 @@ int singlestepping(void * t)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(8192);
+		sp -= get_random_u32_below(8192);
 	return sp & ~0xf;
 }
 #endif
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 311eae30e089..d45c5fcfeac2 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -327,7 +327,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
 	end -= len;
 
 	if (end > start) {
-		offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
+		offset = get_random_u32_below(((end - start) >> PAGE_SHIFT) + 1);
 		addr = start + (offset << PAGE_SHIFT);
 	} else {
 		addr = start;
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index c032edcd3d95..c09ae279ef32 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -53,7 +53,7 @@ static unsigned long int get_module_load_offset(void)
 		 */
 		if (module_load_offset == 0)
 			module_load_offset =
-				(prandom_u32_max(1024) + 1) * PAGE_SIZE;
+				(get_random_u32_below(1024) + 1) * PAGE_SIZE;
 		mutex_unlock(&module_kaslr_mutex);
 	}
 	return module_load_offset;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index c21b7347a26d..62671ccf0404 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -965,7 +965,7 @@ early_param("idle", idle_setup);
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(8192);
+		sp -= get_random_u32_below(8192);
 	return sp & ~0xf;
 }
 
diff --git a/arch/x86/mm/pat/cpa-test.c b/arch/x86/mm/pat/cpa-test.c
index 423b21e80929..3d2f7f0a6ed1 100644
--- a/arch/x86/mm/pat/cpa-test.c
+++ b/arch/x86/mm/pat/cpa-test.c
@@ -136,10 +136,10 @@ static int pageattr_test(void)
 	failed += print_split(&sa);
 
 	for (i = 0; i < NTEST; i++) {
-		unsigned long pfn = prandom_u32_max(max_pfn_mapped);
+		unsigned long pfn = get_random_u32_below(max_pfn_mapped);
 
 		addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
-		len[i] = prandom_u32_max(NPAGES);
+		len[i] = get_random_u32_below(NPAGES);
 		len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
 
 		if (len[i] == 0)
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index 3285e3af43e1..0f722f8f779b 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -253,7 +253,7 @@ static int pkcs1pad_encrypt(struct akcipher_request *req)
 	ps_end = ctx->key_size - req->src_len - 2;
 	req_ctx->in_buf[0] = 0x02;
 	for (i = 1; i < ps_end; i++)
-		req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
+		req_ctx->in_buf[i] = 1 + get_random_u32_below(255);
 	req_ctx->in_buf[ps_end] = 0x00;
 
 	pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index bcd059caa1c8..079923d43ce2 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -855,9 +855,9 @@ static int prepare_keybuf(const u8 *key, unsigned int ksize,
 /* Generate a random length in range [0, max_len], but prefer smaller values */
 static unsigned int generate_random_length(unsigned int max_len)
 {
-	unsigned int len = prandom_u32_max(max_len + 1);
+	unsigned int len = get_random_u32_below(max_len + 1);
 
-	switch (prandom_u32_max(4)) {
+	switch (get_random_u32_below(4)) {
 	case 0:
 		return len % 64;
 	case 1:
@@ -874,14 +874,14 @@ static void flip_random_bit(u8 *buf, size_t size)
 {
 	size_t bitpos;
 
-	bitpos = prandom_u32_max(size * 8);
+	bitpos = get_random_u32_below(size * 8);
 	buf[bitpos / 8] ^= 1 << (bitpos % 8);
 }
 
 /* Flip a random byte in the given nonempty data buffer */
 static void flip_random_byte(u8 *buf, size_t size)
 {
-	buf[prandom_u32_max(size)] ^= 0xff;
+	buf[get_random_u32_below(size)] ^= 0xff;
 }
 
 /* Sometimes make some random changes to the given nonempty data buffer */
@@ -891,15 +891,15 @@ static void mutate_buffer(u8 *buf, size_t size)
 	size_t i;
 
 	/* Sometimes flip some bits */
-	if (prandom_u32_max(4) == 0) {
-		num_flips = min_t(size_t, 1 << prandom_u32_max(8), size * 8);
+	if (get_random_u32_below(4) == 0) {
+		num_flips = min_t(size_t, 1 << get_random_u32_below(8), size * 8);
 		for (i = 0; i < num_flips; i++)
 			flip_random_bit(buf, size);
 	}
 
 	/* Sometimes flip some bytes */
-	if (prandom_u32_max(4) == 0) {
-		num_flips = min_t(size_t, 1 << prandom_u32_max(8), size);
+	if (get_random_u32_below(4) == 0) {
+		num_flips = min_t(size_t, 1 << get_random_u32_below(8), size);
 		for (i = 0; i < num_flips; i++)
 			flip_random_byte(buf, size);
 	}
@@ -915,11 +915,11 @@ static void generate_random_bytes(u8 *buf, size_t count)
 	if (count == 0)
 		return;
 
-	switch (prandom_u32_max(8)) { /* Choose a generation strategy */
+	switch (get_random_u32_below(8)) { /* Choose a generation strategy */
 	case 0:
 	case 1:
 		/* All the same byte, plus optional mutations */
-		switch (prandom_u32_max(4)) {
+		switch (get_random_u32_below(4)) {
 		case 0:
 			b = 0x00;
 			break;
@@ -959,24 +959,24 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
 		unsigned int this_len;
 		const char *flushtype_str;
 
-		if (div == &divs[max_divs - 1] || prandom_u32_max(2) == 0)
+		if (div == &divs[max_divs - 1] || get_random_u32_below(2) == 0)
 			this_len = remaining;
 		else
-			this_len = 1 + prandom_u32_max(remaining);
+			this_len = 1 + get_random_u32_below(remaining);
 		div->proportion_of_total = this_len;
 
-		if (prandom_u32_max(4) == 0)
-			div->offset = (PAGE_SIZE - 128) + prandom_u32_max(128);
-		else if (prandom_u32_max(2) == 0)
-			div->offset = prandom_u32_max(32);
+		if (get_random_u32_below(4) == 0)
+			div->offset = (PAGE_SIZE - 128) + get_random_u32_below(128);
+		else if (get_random_u32_below(2) == 0)
+			div->offset = get_random_u32_below(32);
 		else
-			div->offset = prandom_u32_max(PAGE_SIZE);
-		if (prandom_u32_max(8) == 0)
+			div->offset = get_random_u32_below(PAGE_SIZE);
+		if (get_random_u32_below(8) == 0)
 			div->offset_relative_to_alignmask = true;
 
 		div->flush_type = FLUSH_TYPE_NONE;
 		if (gen_flushes) {
-			switch (prandom_u32_max(4)) {
+			switch (get_random_u32_below(4)) {
 			case 0:
 				div->flush_type = FLUSH_TYPE_REIMPORT;
 				break;
@@ -988,7 +988,7 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
 
 		if (div->flush_type != FLUSH_TYPE_NONE &&
 		    !(req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) &&
-		    prandom_u32_max(2) == 0)
+		    get_random_u32_below(2) == 0)
 			div->nosimd = true;
 
 		switch (div->flush_type) {
@@ -1035,7 +1035,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 
 	p += scnprintf(p, end - p, "random:");
 
-	switch (prandom_u32_max(4)) {
+	switch (get_random_u32_below(4)) {
 	case 0:
 	case 1:
 		cfg->inplace_mode = OUT_OF_PLACE;
@@ -1050,12 +1050,12 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 		break;
 	}
 
-	if (prandom_u32_max(2) == 0) {
+	if (get_random_u32_below(2) == 0) {
 		cfg->req_flags |= CRYPTO_TFM_REQ_MAY_SLEEP;
 		p += scnprintf(p, end - p, " may_sleep");
 	}
 
-	switch (prandom_u32_max(4)) {
+	switch (get_random_u32_below(4)) {
 	case 0:
 		cfg->finalization_type = FINALIZATION_TYPE_FINAL;
 		p += scnprintf(p, end - p, " use_final");
@@ -1071,7 +1071,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 	}
 
 	if (!(cfg->req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) &&
-	    prandom_u32_max(2) == 0) {
+	    get_random_u32_below(2) == 0) {
 		cfg->nosimd = true;
 		p += scnprintf(p, end - p, " nosimd");
 	}
@@ -1084,7 +1084,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 					  cfg->req_flags);
 	p += scnprintf(p, end - p, "]");
 
-	if (cfg->inplace_mode == OUT_OF_PLACE && prandom_u32_max(2) == 0) {
+	if (cfg->inplace_mode == OUT_OF_PLACE && get_random_u32_below(2) == 0) {
 		p += scnprintf(p, end - p, " dst_divs=[");
 		p = generate_random_sgl_divisions(cfg->dst_divs,
 						  ARRAY_SIZE(cfg->dst_divs),
@@ -1093,13 +1093,13 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 		p += scnprintf(p, end - p, "]");
 	}
 
-	if (prandom_u32_max(2) == 0) {
-		cfg->iv_offset = 1 + prandom_u32_max(MAX_ALGAPI_ALIGNMASK);
+	if (get_random_u32_below(2) == 0) {
+		cfg->iv_offset = 1 + get_random_u32_below(MAX_ALGAPI_ALIGNMASK);
 		p += scnprintf(p, end - p, " iv_offset=%u", cfg->iv_offset);
 	}
 
-	if (prandom_u32_max(2) == 0) {
-		cfg->key_offset = 1 + prandom_u32_max(MAX_ALGAPI_ALIGNMASK);
+	if (get_random_u32_below(2) == 0) {
+		cfg->key_offset = 1 + get_random_u32_below(MAX_ALGAPI_ALIGNMASK);
 		p += scnprintf(p, end - p, " key_offset=%u", cfg->key_offset);
 	}
 
@@ -1652,8 +1652,8 @@ static void generate_random_hash_testvec(struct shash_desc *desc,
 	vec->ksize = 0;
 	if (maxkeysize) {
 		vec->ksize = maxkeysize;
-		if (prandom_u32_max(4) == 0)
-			vec->ksize = 1 + prandom_u32_max(maxkeysize);
+		if (get_random_u32_below(4) == 0)
+			vec->ksize = 1 + get_random_u32_below(maxkeysize);
 		generate_random_bytes((u8 *)vec->key, vec->ksize);
 
 		vec->setkey_error = crypto_shash_setkey(desc->tfm, vec->key,
@@ -2218,13 +2218,13 @@ static void mutate_aead_message(struct aead_testvec *vec, bool aad_iv,
 	const unsigned int aad_tail_size = aad_iv ? ivsize : 0;
 	const unsigned int authsize = vec->clen - vec->plen;
 
-	if (prandom_u32_max(2) == 0 && vec->alen > aad_tail_size) {
+	if (get_random_u32_below(2) == 0 && vec->alen > aad_tail_size) {
 		 /* Mutate the AAD */
 		flip_random_bit((u8 *)vec->assoc, vec->alen - aad_tail_size);
-		if (prandom_u32_max(2) == 0)
+		if (get_random_u32_below(2) == 0)
 			return;
 	}
-	if (prandom_u32_max(2) == 0) {
+	if (get_random_u32_below(2) == 0) {
 		/* Mutate auth tag (assuming it's at the end of ciphertext) */
 		flip_random_bit((u8 *)vec->ctext + vec->plen, authsize);
 	} else {
@@ -2249,7 +2249,7 @@ static void generate_aead_message(struct aead_request *req,
 	const unsigned int ivsize = crypto_aead_ivsize(tfm);
 	const unsigned int authsize = vec->clen - vec->plen;
 	const bool inauthentic = (authsize >= MIN_COLLISION_FREE_AUTHSIZE) &&
-				 (prefer_inauthentic || prandom_u32_max(4) == 0);
+				 (prefer_inauthentic || get_random_u32_below(4) == 0);
 
 	/* Generate the AAD. */
 	generate_random_bytes((u8 *)vec->assoc, vec->alen);
@@ -2257,7 +2257,7 @@ static void generate_aead_message(struct aead_request *req,
 		/* Avoid implementation-defined behavior. */
 		memcpy((u8 *)vec->assoc + vec->alen - ivsize, vec->iv, ivsize);
 
-	if (inauthentic && prandom_u32_max(2) == 0) {
+	if (inauthentic && get_random_u32_below(2) == 0) {
 		/* Generate a random ciphertext. */
 		generate_random_bytes((u8 *)vec->ctext, vec->clen);
 	} else {
@@ -2321,8 +2321,8 @@ static void generate_random_aead_testvec(struct aead_request *req,
 
 	/* Key: length in [0, maxkeysize], but usually choose maxkeysize */
 	vec->klen = maxkeysize;
-	if (prandom_u32_max(4) == 0)
-		vec->klen = prandom_u32_max(maxkeysize + 1);
+	if (get_random_u32_below(4) == 0)
+		vec->klen = get_random_u32_below(maxkeysize + 1);
 	generate_random_bytes((u8 *)vec->key, vec->klen);
 	vec->setkey_error = crypto_aead_setkey(tfm, vec->key, vec->klen);
 
@@ -2331,8 +2331,8 @@ static void generate_random_aead_testvec(struct aead_request *req,
 
 	/* Tag length: in [0, maxauthsize], but usually choose maxauthsize */
 	authsize = maxauthsize;
-	if (prandom_u32_max(4) == 0)
-		authsize = prandom_u32_max(maxauthsize + 1);
+	if (get_random_u32_below(4) == 0)
+		authsize = get_random_u32_below(maxauthsize + 1);
 	if (prefer_inauthentic && authsize < MIN_COLLISION_FREE_AUTHSIZE)
 		authsize = MIN_COLLISION_FREE_AUTHSIZE;
 	if (WARN_ON(authsize > maxdatasize))
@@ -2342,7 +2342,7 @@ static void generate_random_aead_testvec(struct aead_request *req,
 
 	/* AAD, plaintext, and ciphertext lengths */
 	total_len = generate_random_length(maxdatasize);
-	if (prandom_u32_max(4) == 0)
+	if (get_random_u32_below(4) == 0)
 		vec->alen = 0;
 	else
 		vec->alen = generate_random_length(total_len);
@@ -2958,8 +2958,8 @@ static void generate_random_cipher_testvec(struct skcipher_request *req,
 
 	/* Key: length in [0, maxkeysize], but usually choose maxkeysize */
 	vec->klen = maxkeysize;
-	if (prandom_u32_max(4) == 0)
-		vec->klen = prandom_u32_max(maxkeysize + 1);
+	if (get_random_u32_below(4) == 0)
+		vec->klen = get_random_u32_below(maxkeysize + 1);
 	generate_random_bytes((u8 *)vec->key, vec->klen);
 	vec->setkey_error = crypto_skcipher_setkey(tfm, vec->key, vec->klen);
 
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index ee69d50ba4fd..3eccc6cd5004 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -781,7 +781,7 @@ static struct socket *drbd_wait_for_connect(struct drbd_connection *connection,
 
 	timeo = connect_int * HZ;
 	/* 28.5% random jitter */
-	timeo += prandom_u32_max(2) ? timeo / 7 : -timeo / 7;
+	timeo += get_random_u32_below(2) ? timeo / 7 : -timeo / 7;
 
 	err = wait_for_completion_interruptible_timeout(&ad->door_bell, timeo);
 	if (err <= 0)
@@ -1004,7 +1004,7 @@ static int conn_connect(struct drbd_connection *connection)
 				drbd_warn(connection, "Error receiving initial packet\n");
 				sock_release(s);
 randomize:
-				if (prandom_u32_max(2))
+				if (get_random_u32_below(2))
 					goto retry;
 			}
 		}
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 01fd10a399b6..c73621aabbd1 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -129,7 +129,7 @@ enum mhi_pm_state {
 #define PRIMARY_CMD_RING				0
 #define MHI_DEV_WAKE_DB					127
 #define MHI_MAX_MTU					0xffff
-#define MHI_RANDOM_U32_NONZERO(bmsk)			(prandom_u32_max(bmsk) + 1)
+#define MHI_RANDOM_U32_NONZERO(bmsk)			(get_random_u32_below(bmsk) + 1)
 
 enum mhi_er_type {
 	MHI_ER_TYPE_INVALID = 0x0,
diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c
index 0a9b099d0518..9fbad7317d9b 100644
--- a/drivers/dma-buf/st-dma-fence-chain.c
+++ b/drivers/dma-buf/st-dma-fence-chain.c
@@ -400,7 +400,7 @@ static int __find_race(void *arg)
 		struct dma_fence *fence = dma_fence_get(data->fc.tail);
 		int seqno;
 
-		seqno = prandom_u32_max(data->fc.chain_length) + 1;
+		seqno = get_random_u32_below(data->fc.chain_length) + 1;
 
 		err = dma_fence_chain_find_seqno(&fence, seqno);
 		if (err) {
@@ -429,7 +429,7 @@ static int __find_race(void *arg)
 		dma_fence_put(fence);
 
 signal:
-		seqno = prandom_u32_max(data->fc.chain_length - 1);
+		seqno = get_random_u32_below(data->fc.chain_length - 1);
 		dma_fence_signal(data->fc.fences[seqno]);
 		cond_resched();
 	}
@@ -637,7 +637,7 @@ static void randomise_fences(struct fence_chains *fc)
 	while (--count) {
 		unsigned int swp;
 
-		swp = prandom_u32_max(count + 1);
+		swp = get_random_u32_below(count + 1);
 		if (swp == count)
 			continue;
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 845023c14eb3..29d2459bcc90 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2424,7 +2424,7 @@ gen8_dispatch_bsd_engine(struct drm_i915_private *dev_priv,
 	/* Check whether the file_priv has already selected one ring. */
 	if ((int)file_priv->bsd_engine < 0)
 		file_priv->bsd_engine =
-			prandom_u32_max(num_vcs_engines(dev_priv));
+			get_random_u32_below(num_vcs_engines(dev_priv));
 
 	return file_priv->bsd_engine;
 }
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index c718e6dc40b5..45b605e32c87 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -3689,7 +3689,7 @@ static void virtual_engine_initial_hint(struct virtual_engine *ve)
 	 * NB This does not force us to execute on this engine, it will just
 	 * typically be the first we inspect for submission.
 	 */
-	swp = prandom_u32_max(ve->num_siblings);
+	swp = get_random_u32_below(ve->num_siblings);
 	if (swp)
 		swap(ve->siblings[swp], ve->siblings[0]);
 }
diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index 9a4a7fb55582..b9a164efd6ae 100644
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -38,7 +38,7 @@ static int __iopagetest(struct intel_memory_region *mem,
 			u8 value, resource_size_t offset,
 			const void *caller)
 {
-	int byte = prandom_u32_max(pagesize);
+	int byte = get_random_u32_below(pagesize);
 	u8 result[3];
 
 	memset_io(va, value, pagesize); /* or GPF! */
@@ -92,7 +92,7 @@ static int iopagetest(struct intel_memory_region *mem,
 static resource_size_t random_page(resource_size_t last)
 {
 	/* Limited to low 44b (16TiB), but should suffice for a spot check */
-	return prandom_u32_max(last >> PAGE_SHIFT) << PAGE_SHIFT;
+	return get_random_u32_below(last >> PAGE_SHIFT) << PAGE_SHIFT;
 }
 
 static int iomemtest(struct intel_memory_region *mem,
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 26d1772179b8..dd1c703b10df 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3807,7 +3807,7 @@ static int cma_alloc_any_port(enum rdma_ucm_port_space ps,
 
 	inet_get_local_port_range(net, &low, &high);
 	remaining = (high - low) + 1;
-	rover = prandom_u32_max(remaining) + low;
+	rover = get_random_u32_below(remaining) + low;
 retry:
 	if (last_used_port != rover) {
 		struct rdma_bind_list *bind_list;
diff --git a/drivers/infiniband/hw/cxgb4/id_table.c b/drivers/infiniband/hw/cxgb4/id_table.c
index 280d61466855..e2188b335e76 100644
--- a/drivers/infiniband/hw/cxgb4/id_table.c
+++ b/drivers/infiniband/hw/cxgb4/id_table.c
@@ -54,7 +54,7 @@ u32 c4iw_id_alloc(struct c4iw_id_table *alloc)
 
 	if (obj < alloc->max) {
 		if (alloc->flags & C4IW_ID_TABLE_F_RANDOM)
-			alloc->last += prandom_u32_max(RANDOM_SKIP);
+			alloc->last += get_random_u32_below(RANDOM_SKIP);
 		else
 			alloc->last = obj + 1;
 		if (alloc->last >= alloc->max)
@@ -85,7 +85,7 @@ int c4iw_id_table_alloc(struct c4iw_id_table *alloc, u32 start, u32 num,
 	alloc->start = start;
 	alloc->flags = flags;
 	if (flags & C4IW_ID_TABLE_F_RANDOM)
-		alloc->last = prandom_u32_max(RANDOM_SKIP);
+		alloc->last = get_random_u32_below(RANDOM_SKIP);
 	else
 		alloc->last = 0;
 	alloc->max = num;
diff --git a/drivers/infiniband/hw/hns/hns_roce_ah.c b/drivers/infiniband/hw/hns/hns_roce_ah.c
index 480c062dd04f..b37d2a81584d 100644
--- a/drivers/infiniband/hw/hns/hns_roce_ah.c
+++ b/drivers/infiniband/hw/hns/hns_roce_ah.c
@@ -41,8 +41,8 @@ static inline u16 get_ah_udp_sport(const struct rdma_ah_attr *ah_attr)
 	u16 sport;
 
 	if (!fl)
-		sport = prandom_u32_max(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX + 1 -
-					IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
+		sport = get_random_u32_below(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX +
+					     1 - IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
 			IB_ROCE_UDP_ENCAP_VALID_PORT_MIN;
 	else
 		sport = rdma_flow_label_to_udp_sport(fl);
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index 8546b8816524..ab75b690ad08 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -1517,7 +1517,7 @@ static void rtrs_clt_err_recovery_work(struct work_struct *work)
 	rtrs_clt_stop_and_destroy_conns(clt_path);
 	queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork,
 			   msecs_to_jiffies(delay_ms +
-					    prandom_u32_max(RTRS_RECONNECT_SEED)));
+					    get_random_u32_below(RTRS_RECONNECT_SEED)));
 }
 
 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt,
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 3427555b0cca..32e21ba64357 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -401,7 +401,7 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
 	}
 
 	if (bypass_torture_test(dc)) {
-		if (prandom_u32_max(4) == 3)
+		if (get_random_u32_below(4) == 3)
 			goto skip;
 		else
 			goto rescale;
diff --git a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
index 303d02b1d71c..a366566f22c3 100644
--- a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
+++ b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
@@ -872,7 +872,7 @@ static void precalculate_color(struct tpg_data *tpg, int k)
 	} else if (tpg->pattern == TPG_PAT_NOISE) {
 		r = g = b = get_random_u8();
 	} else if (k == TPG_COLOR_RANDOM) {
-		r = g = b = tpg->qual_offset + prandom_u32_max(196);
+		r = g = b = tpg->qual_offset + get_random_u32_below(196);
 	} else if (k >= TPG_COLOR_RAMP) {
 		r = g = b = k - TPG_COLOR_RAMP;
 	}
@@ -2286,7 +2286,7 @@ static void tpg_fill_params_extras(const struct tpg_data *tpg,
 		params->wss_width = tpg->crop.width;
 	params->wss_width = tpg_hscale_div(tpg, p, params->wss_width);
 	params->wss_random_offset =
-		params->twopixsize * prandom_u32_max(tpg->src_width / 2);
+		params->twopixsize * get_random_u32_below(tpg->src_width / 2);
 
 	if (tpg->crop.left < tpg->border.left) {
 		left_pillar_width = tpg->border.left - tpg->crop.left;
@@ -2495,9 +2495,9 @@ static void tpg_fill_plane_pattern(const struct tpg_data *tpg,
 		linestart_newer = tpg->black_line[p];
 	} else if (tpg->pattern == TPG_PAT_NOISE || tpg->qual == TPG_QUAL_NOISE) {
 		linestart_older = tpg->random_line[p] +
-				  twopixsize * prandom_u32_max(tpg->src_width / 2);
+				  twopixsize * get_random_u32_below(tpg->src_width / 2);
 		linestart_newer = tpg->random_line[p] +
-				  twopixsize * prandom_u32_max(tpg->src_width / 2);
+				  twopixsize * get_random_u32_below(tpg->src_width / 2);
 	} else {
 		unsigned frame_line_old =
 			(frame_line + mv_vert_old) % tpg->src_height;
diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.c b/drivers/media/test-drivers/vidtv/vidtv_demod.c
index e7959ab1add8..d60c6d16beea 100644
--- a/drivers/media/test-drivers/vidtv/vidtv_demod.c
+++ b/drivers/media/test-drivers/vidtv/vidtv_demod.c
@@ -188,11 +188,11 @@ static void vidtv_demod_update_stats(struct dvb_frontend *fe)
 	 * Also, usually, signal strength is a negative number in dBm.
 	 */
 	c->strength.stat[0].svalue = state->tuner_cnr;
-	c->strength.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50);
+	c->strength.stat[0].svalue -= get_random_u32_below(state->tuner_cnr / 50);
 	c->strength.stat[0].svalue -= 68000; /* Adjust to a better range */
 
 	c->cnr.stat[0].svalue = state->tuner_cnr;
-	c->cnr.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50);
+	c->cnr.stat[0].svalue -= get_random_u32_below(state->tuner_cnr / 50);
 }
 
 static int vidtv_demod_read_status(struct dvb_frontend *fe,
@@ -213,11 +213,11 @@ static int vidtv_demod_read_status(struct dvb_frontend *fe,
 
 		if (snr < cnr2qual->cnr_ok) {
 			/* eventually lose the TS lock */
-			if (prandom_u32_max(100) < config->drop_tslock_prob_on_low_snr)
+			if (get_random_u32_below(100) < config->drop_tslock_prob_on_low_snr)
 				state->status = 0;
 		} else {
 			/* recover if the signal improves */
-			if (prandom_u32_max(100) <
+			if (get_random_u32_below(100) <
 			    config->recover_tslock_prob_on_good_snr)
 				state->status = FE_HAS_SIGNAL  |
 						FE_HAS_CARRIER |
diff --git a/drivers/media/test-drivers/vivid/vivid-kthread-cap.c b/drivers/media/test-drivers/vivid/vivid-kthread-cap.c
index 690daada7db4..ee65d20314d3 100644
--- a/drivers/media/test-drivers/vivid/vivid-kthread-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-kthread-cap.c
@@ -693,7 +693,7 @@ static noinline_for_stack void vivid_thread_vid_cap_tick(struct vivid_dev *dev,
 
 	/* Drop a certain percentage of buffers. */
 	if (dev->perc_dropped_buffers &&
-	    prandom_u32_max(100) < dev->perc_dropped_buffers)
+	    get_random_u32_below(100) < dev->perc_dropped_buffers)
 		goto update_mv;
 
 	spin_lock(&dev->slock);
diff --git a/drivers/media/test-drivers/vivid/vivid-kthread-out.c b/drivers/media/test-drivers/vivid/vivid-kthread-out.c
index 0833e021bb11..fac6208b51da 100644
--- a/drivers/media/test-drivers/vivid/vivid-kthread-out.c
+++ b/drivers/media/test-drivers/vivid/vivid-kthread-out.c
@@ -51,7 +51,7 @@ static void vivid_thread_vid_out_tick(struct vivid_dev *dev)
 
 	/* Drop a certain percentage of buffers. */
 	if (dev->perc_dropped_buffers &&
-	    prandom_u32_max(100) < dev->perc_dropped_buffers)
+	    get_random_u32_below(100) < dev->perc_dropped_buffers)
 		return;
 
 	spin_lock(&dev->slock);
diff --git a/drivers/media/test-drivers/vivid/vivid-radio-rx.c b/drivers/media/test-drivers/vivid/vivid-radio-rx.c
index 8bd09589fb15..79c1723bd84c 100644
--- a/drivers/media/test-drivers/vivid/vivid-radio-rx.c
+++ b/drivers/media/test-drivers/vivid/vivid-radio-rx.c
@@ -94,8 +94,8 @@ ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
 
 		if (data_blk == 0 && dev->radio_rds_loop)
 			vivid_radio_rds_init(dev);
-		if (perc && prandom_u32_max(100) < perc) {
-			switch (prandom_u32_max(4)) {
+		if (perc && get_random_u32_below(100) < perc) {
+			switch (get_random_u32_below(4)) {
 			case 0:
 				rds.block |= V4L2_RDS_BLOCK_CORRECTED;
 				break;
diff --git a/drivers/media/test-drivers/vivid/vivid-sdr-cap.c b/drivers/media/test-drivers/vivid/vivid-sdr-cap.c
index 0ae5628b86c9..a81f26b76988 100644
--- a/drivers/media/test-drivers/vivid/vivid-sdr-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-sdr-cap.c
@@ -90,7 +90,7 @@ static void vivid_thread_sdr_cap_tick(struct vivid_dev *dev)
 
 	/* Drop a certain percentage of buffers. */
 	if (dev->perc_dropped_buffers &&
-	    prandom_u32_max(100) < dev->perc_dropped_buffers)
+	    get_random_u32_below(100) < dev->perc_dropped_buffers)
 		return;
 
 	spin_lock(&dev->slock);
diff --git a/drivers/media/test-drivers/vivid/vivid-touch-cap.c b/drivers/media/test-drivers/vivid/vivid-touch-cap.c
index 6cc32eb54f9d..c7f6e23df51e 100644
--- a/drivers/media/test-drivers/vivid/vivid-touch-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-touch-cap.c
@@ -221,7 +221,7 @@ static void vivid_fill_buff_noise(__s16 *tch_buf, int size)
 
 static inline int get_random_pressure(void)
 {
-	return prandom_u32_max(VIVID_PRESSURE_LIMIT);
+	return get_random_u32_below(VIVID_PRESSURE_LIMIT);
 }
 
 static void vivid_tch_buf_set(struct v4l2_pix_format *f,
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 95fa8fb1d45f..a1efda85c6f2 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -97,8 +97,8 @@ static void mmc_should_fail_request(struct mmc_host *host,
 	    !should_fail(&host->fail_mmc_request, data->blksz * data->blocks))
 		return;
 
-	data->error = data_errors[prandom_u32_max(ARRAY_SIZE(data_errors))];
-	data->bytes_xfered = prandom_u32_max(data->bytes_xfered >> 9) << 9;
+	data->error = data_errors[get_random_u32_below(ARRAY_SIZE(data_errors))];
+	data->bytes_xfered = get_random_u32_below(data->bytes_xfered >> 9) << 9;
 }
 
 #else /* CONFIG_FAIL_MMC_REQUEST */
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index c78bbc22e0d1..6ef410053037 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1858,7 +1858,7 @@ static void dw_mci_start_fault_timer(struct dw_mci *host)
 	 * Try to inject the error at random points during the data transfer.
 	 */
 	hrtimer_start(&host->fault_timer,
-		      ms_to_ktime(prandom_u32_max(25)),
+		      ms_to_ktime(get_random_u32_below(25)),
 		      HRTIMER_MODE_REL);
 }
 
diff --git a/drivers/mtd/nand/raw/nandsim.c b/drivers/mtd/nand/raw/nandsim.c
index 672719023241..274a31b93100 100644
--- a/drivers/mtd/nand/raw/nandsim.c
+++ b/drivers/mtd/nand/raw/nandsim.c
@@ -1405,9 +1405,9 @@ static void ns_do_bit_flips(struct nandsim *ns, int num)
 	if (bitflips && get_random_u16() < (1 << 6)) {
 		int flips = 1;
 		if (bitflips > 1)
-			flips = prandom_u32_max(bitflips) + 1;
+			flips = get_random_u32_below(bitflips) + 1;
 		while (flips--) {
-			int pos = prandom_u32_max(num * 8);
+			int pos = get_random_u32_below(num * 8);
 			ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
 			NS_WARN("read_page: flipping bit %d in page %d "
 				"reading from %d ecc: corrected=%u failed=%u\n",
diff --git a/drivers/mtd/tests/mtd_nandecctest.c b/drivers/mtd/tests/mtd_nandecctest.c
index 440988562cfd..824cc1c03b6a 100644
--- a/drivers/mtd/tests/mtd_nandecctest.c
+++ b/drivers/mtd/tests/mtd_nandecctest.c
@@ -47,7 +47,7 @@ struct nand_ecc_test {
 static void single_bit_error_data(void *error_data, void *correct_data,
 				size_t size)
 {
-	unsigned int offset = prandom_u32_max(size * BITS_PER_BYTE);
+	unsigned int offset = get_random_u32_below(size * BITS_PER_BYTE);
 
 	memcpy(error_data, correct_data, size);
 	__change_bit_le(offset, error_data);
@@ -58,9 +58,9 @@ static void double_bit_error_data(void *error_data, void *correct_data,
 {
 	unsigned int offset[2];
 
-	offset[0] = prandom_u32_max(size * BITS_PER_BYTE);
+	offset[0] = get_random_u32_below(size * BITS_PER_BYTE);
 	do {
-		offset[1] = prandom_u32_max(size * BITS_PER_BYTE);
+		offset[1] = get_random_u32_below(size * BITS_PER_BYTE);
 	} while (offset[0] == offset[1]);
 
 	memcpy(error_data, correct_data, size);
@@ -71,7 +71,7 @@ static void double_bit_error_data(void *error_data, void *correct_data,
 
 static unsigned int random_ecc_bit(size_t size)
 {
-	unsigned int offset = prandom_u32_max(3 * BITS_PER_BYTE);
+	unsigned int offset = get_random_u32_below(3 * BITS_PER_BYTE);
 
 	if (size == 256) {
 		/*
@@ -79,7 +79,7 @@ static unsigned int random_ecc_bit(size_t size)
 		 * and 17th bit) in ECC code for 256 byte data block
 		 */
 		while (offset == 16 || offset == 17)
-			offset = prandom_u32_max(3 * BITS_PER_BYTE);
+			offset = get_random_u32_below(3 * BITS_PER_BYTE);
 	}
 
 	return offset;
diff --git a/drivers/mtd/tests/stresstest.c b/drivers/mtd/tests/stresstest.c
index 75b6ddc5dc4d..8062098930d6 100644
--- a/drivers/mtd/tests/stresstest.c
+++ b/drivers/mtd/tests/stresstest.c
@@ -46,7 +46,7 @@ static int rand_eb(void)
 
 again:
 	/* Read or write up 2 eraseblocks at a time - hence 'ebcnt - 1' */
-	eb = prandom_u32_max(ebcnt - 1);
+	eb = get_random_u32_below(ebcnt - 1);
 	if (bbt[eb])
 		goto again;
 	return eb;
@@ -54,12 +54,12 @@ static int rand_eb(void)
 
 static int rand_offs(void)
 {
-	return prandom_u32_max(bufsize);
+	return get_random_u32_below(bufsize);
 }
 
 static int rand_len(int offs)
 {
-	return prandom_u32_max(bufsize - offs);
+	return get_random_u32_below(bufsize - offs);
 }
 
 static int do_read(void)
@@ -118,7 +118,7 @@ static int do_write(void)
 
 static int do_operation(void)
 {
-	if (prandom_u32_max(2))
+	if (get_random_u32_below(2))
 		return do_read();
 	else
 		return do_write();
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index 908d0e088557..fcca6942dbdd 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -590,7 +590,7 @@ int ubi_dbg_power_cut(struct ubi_device *ubi, int caller)
 
 		if (ubi->dbg.power_cut_max > ubi->dbg.power_cut_min) {
 			range = ubi->dbg.power_cut_max - ubi->dbg.power_cut_min;
-			ubi->dbg.power_cut_counter += prandom_u32_max(range);
+			ubi->dbg.power_cut_counter += get_random_u32_below(range);
 		}
 		return 0;
 	}
diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h
index dc8d8f83657a..23676f32b681 100644
--- a/drivers/mtd/ubi/debug.h
+++ b/drivers/mtd/ubi/debug.h
@@ -73,7 +73,7 @@ static inline int ubi_dbg_is_bgt_disabled(const struct ubi_device *ubi)
 static inline int ubi_dbg_is_bitflip(const struct ubi_device *ubi)
 {
 	if (ubi->dbg.emulate_bitflips)
-		return !prandom_u32_max(200);
+		return !get_random_u32_below(200);
 	return 0;
 }
 
@@ -87,7 +87,7 @@ static inline int ubi_dbg_is_bitflip(const struct ubi_device *ubi)
 static inline int ubi_dbg_is_write_failure(const struct ubi_device *ubi)
 {
 	if (ubi->dbg.emulate_io_failures)
-		return !prandom_u32_max(500);
+		return !get_random_u32_below(500);
 	return 0;
 }
 
@@ -101,7 +101,7 @@ static inline int ubi_dbg_is_write_failure(const struct ubi_device *ubi)
 static inline int ubi_dbg_is_erase_failure(const struct ubi_device *ubi)
 {
 	if (ubi->dbg.emulate_io_failures)
-		return !prandom_u32_max(400);
+		return !get_random_u32_below(400);
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/broadcom/cnic.c b/drivers/net/ethernet/broadcom/cnic.c
index 2198e35d9e18..74bc053a2078 100644
--- a/drivers/net/ethernet/broadcom/cnic.c
+++ b/drivers/net/ethernet/broadcom/cnic.c
@@ -4105,7 +4105,7 @@ static int cnic_cm_alloc_mem(struct cnic_dev *dev)
 	for (i = 0; i < MAX_CM_SK_TBL_SZ; i++)
 		atomic_set(&cp->csk_tbl[i].ref_count, 0);
 
-	port_id = prandom_u32_max(CNIC_LOCAL_PORT_RANGE);
+	port_id = get_random_u32_below(CNIC_LOCAL_PORT_RANGE);
 	if (cnic_init_id_tbl(&cp->csk_port_tbl, CNIC_LOCAL_PORT_RANGE,
 			     CNIC_LOCAL_PORT_MIN, port_id)) {
 		cnic_cm_free_mem(dev);
diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
index a4256087ac82..ae6b17b96bf1 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
@@ -919,8 +919,8 @@ static int csk_wait_memory(struct chtls_dev *cdev,
 	current_timeo = *timeo_p;
 	noblock = (*timeo_p ? false : true);
 	if (csk_mem_free(cdev, sk)) {
-		current_timeo = prandom_u32_max(HZ / 5) + 2;
-		vm_wait = prandom_u32_max(HZ / 5) + 2;
+		current_timeo = get_random_u32_below(HZ / 5) + 2;
+		vm_wait = get_random_u32_below(HZ / 5) + 2;
 	}
 
 	add_wait_queue(sk_sleep(sk), &wait);
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 349b7b1dbbf2..b07513c61c35 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -1758,7 +1758,7 @@ static int qca808x_phy_fast_retrain_config(struct phy_device *phydev)
 
 static int qca808x_phy_ms_random_seed_set(struct phy_device *phydev)
 {
-	u16 seed_value = prandom_u32_max(QCA808X_MASTER_SLAVE_SEED_RANGE);
+	u16 seed_value = get_random_u32_below(QCA808X_MASTER_SLAVE_SEED_RANGE);
 
 	return at803x_debug_reg_mask(phydev, QCA808X_PHY_DEBUG_LOCAL_SEED,
 			QCA808X_MASTER_SLAVE_SEED_CFG,
diff --git a/drivers/net/team/team_mode_random.c b/drivers/net/team/team_mode_random.c
index f3f8dd428402..53d0ce34b8ce 100644
--- a/drivers/net/team/team_mode_random.c
+++ b/drivers/net/team/team_mode_random.c
@@ -16,7 +16,7 @@ static bool rnd_transmit(struct team *team, struct sk_buff *skb)
 	struct team_port *port;
 	int port_index;
 
-	port_index = prandom_u32_max(team->en_port_count);
+	port_index = get_random_u32_below(team->en_port_count);
 	port = team_get_port_by_index_rcu(team, port_index);
 	if (unlikely(!port))
 		goto drop;
diff --git a/drivers/net/wireguard/selftest/allowedips.c b/drivers/net/wireguard/selftest/allowedips.c
index 19eac00b2381..78a916f30c82 100644
--- a/drivers/net/wireguard/selftest/allowedips.c
+++ b/drivers/net/wireguard/selftest/allowedips.c
@@ -285,8 +285,8 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 4);
-		cidr = prandom_u32_max(32) + 1;
-		peer = peers[prandom_u32_max(NUM_PEERS)];
+		cidr = get_random_u32_below(32) + 1;
+		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v4(&t, (struct in_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
 			pr_err("allowedips random self-test malloc: FAIL\n");
@@ -300,7 +300,7 @@ static __init bool randomized_test(void)
 		for (j = 0; j < NUM_MUTATED_ROUTES; ++j) {
 			memcpy(mutated, ip, 4);
 			get_random_bytes(mutate_mask, 4);
-			mutate_amount = prandom_u32_max(32);
+			mutate_amount = get_random_u32_below(32);
 			for (k = 0; k < mutate_amount / 8; ++k)
 				mutate_mask[k] = 0xff;
 			mutate_mask[k] = 0xff
@@ -311,8 +311,8 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = prandom_u32_max(32) + 1;
-			peer = peers[prandom_u32_max(NUM_PEERS)];
+			cidr = get_random_u32_below(32) + 1;
+			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v4(&t,
 						    (struct in_addr *)mutated,
 						    cidr, peer, &mutex) < 0) {
@@ -329,8 +329,8 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 16);
-		cidr = prandom_u32_max(128) + 1;
-		peer = peers[prandom_u32_max(NUM_PEERS)];
+		cidr = get_random_u32_below(128) + 1;
+		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v6(&t, (struct in6_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
 			pr_err("allowedips random self-test malloc: FAIL\n");
@@ -344,7 +344,7 @@ static __init bool randomized_test(void)
 		for (j = 0; j < NUM_MUTATED_ROUTES; ++j) {
 			memcpy(mutated, ip, 16);
 			get_random_bytes(mutate_mask, 16);
-			mutate_amount = prandom_u32_max(128);
+			mutate_amount = get_random_u32_below(128);
 			for (k = 0; k < mutate_amount / 8; ++k)
 				mutate_mask[k] = 0xff;
 			mutate_mask[k] = 0xff
@@ -355,8 +355,8 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = prandom_u32_max(128) + 1;
-			peer = peers[prandom_u32_max(NUM_PEERS)];
+			cidr = get_random_u32_below(128) + 1;
+			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v6(&t,
 						    (struct in6_addr *)mutated,
 						    cidr, peer, &mutex) < 0) {
diff --git a/drivers/net/wireguard/timers.c b/drivers/net/wireguard/timers.c
index d54d32ac9bc4..b5706b6718b1 100644
--- a/drivers/net/wireguard/timers.c
+++ b/drivers/net/wireguard/timers.c
@@ -147,7 +147,7 @@ void wg_timers_data_sent(struct wg_peer *peer)
 	if (!timer_pending(&peer->timer_new_handshake))
 		mod_peer_timer(peer, &peer->timer_new_handshake,
 			jiffies + (KEEPALIVE_TIMEOUT + REKEY_TIMEOUT) * HZ +
-			prandom_u32_max(REKEY_TIMEOUT_JITTER_MAX_JIFFIES));
+			get_random_u32_below(REKEY_TIMEOUT_JITTER_MAX_JIFFIES));
 }
 
 /* Should be called after an authenticated data packet is received. */
@@ -183,7 +183,7 @@ void wg_timers_handshake_initiated(struct wg_peer *peer)
 {
 	mod_peer_timer(peer, &peer->timer_retransmit_handshake,
 		       jiffies + REKEY_TIMEOUT * HZ +
-		       prandom_u32_max(REKEY_TIMEOUT_JITTER_MAX_JIFFIES));
+		       get_random_u32_below(REKEY_TIMEOUT_JITTER_MAX_JIFFIES));
 }
 
 /* Should be called after a handshake response message is received and processed
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 10d9d9c63b28..23c971b77965 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -1128,7 +1128,7 @@ static void brcmf_p2p_afx_handler(struct work_struct *work)
 	if (afx_hdl->is_listen && afx_hdl->my_listen_chan)
 		/* 100ms ~ 300ms */
 		err = brcmf_p2p_discover_listen(p2p, afx_hdl->my_listen_chan,
-						100 * (1 + prandom_u32_max(3)));
+						100 * (1 + get_random_u32_below(3)));
 	else
 		err = brcmf_p2p_act_frm_search(p2p, afx_hdl->peer_listen_chan);
 
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
index de0c545d50fd..1696fbf1009a 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@@ -1099,7 +1099,7 @@ static void iwl_mvm_mac_ctxt_cmd_fill_ap(struct iwl_mvm *mvm,
 			iwl_mvm_mac_ap_iterator, &data);
 
 		if (data.beacon_device_ts) {
-			u32 rand = prandom_u32_max(64 - 36) + 36;
+			u32 rand = get_random_u32_below(64 - 36) + 36;
 			mvmvif->ap_beacon_time = data.beacon_device_ts +
 				ieee80211_tu_to_usec(data.beacon_int * rand /
 						     100);
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 88dc66ee1c46..5565f67d6537 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -673,7 +673,7 @@ struct pci_dev *pci_p2pmem_find_many(struct device **clients, int num_clients)
 	}
 
 	if (dev_cnt)
-		pdev = pci_dev_get(closest_pdevs[prandom_u32_max(dev_cnt)]);
+		pdev = pci_dev_get(closest_pdevs[get_random_u32_below(dev_cnt)]);
 
 	for (i = 0; i < dev_cnt; i++)
 		pci_dev_put(closest_pdevs[i]);
diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index 77917b339870..f21307537829 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -48,7 +48,7 @@ unsigned int zfcp_fc_port_scan_backoff(void)
 {
 	if (!port_scan_backoff)
 		return 0;
-	return prandom_u32_max(port_scan_backoff);
+	return get_random_u32_below(port_scan_backoff);
 }
 
 static void zfcp_fc_port_scan_time(struct zfcp_adapter *adapter)
diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c
index ddc048069af2..5c8d1ba3f8f3 100644
--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -2233,7 +2233,7 @@ static void fcoe_ctlr_vn_restart(struct fcoe_ctlr *fip)
 
 	if (fip->probe_tries < FIP_VN_RLIM_COUNT) {
 		fip->probe_tries++;
-		wait = prandom_u32_max(FIP_VN_PROBE_WAIT);
+		wait = get_random_u32_below(FIP_VN_PROBE_WAIT);
 	} else
 		wait = FIP_VN_RLIM_INT;
 	mod_timer(&fip->timer, jiffies + msecs_to_jiffies(wait));
@@ -3125,7 +3125,7 @@ static void fcoe_ctlr_vn_timeout(struct fcoe_ctlr *fip)
 					  fcoe_all_vn2vn, 0);
 			fip->port_ka_time = jiffies +
 				 msecs_to_jiffies(FIP_VN_BEACON_INT +
-					prandom_u32_max(FIP_VN_BEACON_FUZZ));
+					get_random_u32_below(FIP_VN_BEACON_FUZZ));
 		}
 		if (time_before(fip->port_ka_time, next_time))
 			next_time = fip->port_ka_time;
diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
index df2fe7bd26d1..f2ee49756df8 100644
--- a/drivers/scsi/qedi/qedi_main.c
+++ b/drivers/scsi/qedi/qedi_main.c
@@ -618,7 +618,7 @@ static int qedi_cm_alloc_mem(struct qedi_ctx *qedi)
 				sizeof(struct qedi_endpoint *)), GFP_KERNEL);
 	if (!qedi->ep_tbl)
 		return -ENOMEM;
-	port_id = prandom_u32_max(QEDI_LOCAL_PORT_RANGE);
+	port_id = get_random_u32_below(QEDI_LOCAL_PORT_RANGE);
 	if (qedi_init_id_tbl(&qedi->lcl_port_tbl, QEDI_LOCAL_PORT_RANGE,
 			     QEDI_LOCAL_PORT_MIN, port_id)) {
 		qedi_cm_free_mem(qedi);
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 629853662b82..a86db9761d00 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -5702,16 +5702,16 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 			u64 ns = jiffies_to_nsecs(delta_jiff);
 
 			if (sdebug_random && ns < U32_MAX) {
-				ns = prandom_u32_max((u32)ns);
+				ns = get_random_u32_below((u32)ns);
 			} else if (sdebug_random) {
 				ns >>= 12;	/* scale to 4 usec precision */
 				if (ns < U32_MAX)	/* over 4 hours max */
-					ns = prandom_u32_max((u32)ns);
+					ns = get_random_u32_below((u32)ns);
 				ns <<= 12;
 			}
 			kt = ns_to_ktime(ns);
 		} else {	/* ndelay has a 4.2 second max */
-			kt = sdebug_random ? prandom_u32_max((u32)ndelay) :
+			kt = sdebug_random ? get_random_u32_below((u32)ndelay) :
 					     (u32)ndelay;
 			if (ndelay < INCLUSIVE_TIMING_MAX_NS) {
 				u64 d = ktime_get_boottime_ns() - ns_from_boot;
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 4af5e55abc15..fb255988dee8 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -362,7 +362,7 @@ static int ceph_fill_fragtree(struct inode *inode,
 	if (nsplits != ci->i_fragtree_nsplits) {
 		update = true;
 	} else if (nsplits) {
-		i = prandom_u32_max(nsplits);
+		i = get_random_u32_below(nsplits);
 		id = le32_to_cpu(fragtree->splits[i].frag);
 		if (!__ceph_find_frag(ci, id))
 			update = true;
diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
index 3fbabc98e1f7..7dac21ee6ce7 100644
--- a/fs/ceph/mdsmap.c
+++ b/fs/ceph/mdsmap.c
@@ -29,7 +29,7 @@ static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
 		return -1;
 
 	/* pick */
-	n = prandom_u32_max(n);
+	n = get_random_u32_below(n);
 	for (j = 0, i = 0; i < m->possible_max_rank; i++) {
 		if (CEPH_MDS_IS_READY(i, ignore_laggy))
 			j++;
diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
index f4944c4dee60..78b8686d9a4a 100644
--- a/fs/ext2/ialloc.c
+++ b/fs/ext2/ialloc.c
@@ -277,7 +277,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
 		int best_ndir = inodes_per_group;
 		int best_group = -1;
 
-		parent_group = prandom_u32_max(ngroups);
+		parent_group = get_random_u32_below(ngroups);
 		for (i = 0; i < ngroups; i++) {
 			group = (parent_group + i) % ngroups;
 			desc = ext2_get_group_desc (sb, group, NULL);
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index e9bc46684106..9fc1af8e19a3 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -465,7 +465,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent,
 			ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
 			parent_group = hinfo.hash % ngroups;
 		} else
-			parent_group = prandom_u32_max(ngroups);
+			parent_group = get_random_u32_below(ngroups);
 		for (i = 0; i < ngroups; i++) {
 			g = (parent_group + i) % ngroups;
 			get_orlov_stats(sb, g, flex_size, &stats);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7cdd2138c897..63ef74eb8091 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3778,7 +3778,7 @@ static int ext4_lazyinit_thread(void *arg)
 			}
 			if (!progress) {
 				elr->lr_next_sched = jiffies +
-					prandom_u32_max(EXT4_DEF_LI_MAX_START_DELAY * HZ);
+					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
 			}
 			if (time_before(elr->lr_next_sched, next_wakeup))
 				next_wakeup = elr->lr_next_sched;
@@ -3925,8 +3925,7 @@ static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
 	 * spread the inode table initialization requests
 	 * better.
 	 */
-	elr->lr_next_sched = jiffies + prandom_u32_max(
-				EXT4_DEF_LI_MAX_START_DELAY * HZ);
+	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
 	return elr;
 }
 
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 4546e01b2ee0..536d332d9e2e 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -282,7 +282,7 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 
 	/* let's select beginning hot/small space first in no_heap mode*/
 	if (f2fs_need_rand_seg(sbi))
-		p->offset = prandom_u32_max(MAIN_SECS(sbi) * sbi->segs_per_sec);
+		p->offset = get_random_u32_below(MAIN_SECS(sbi) * sbi->segs_per_sec);
 	else if (test_opt(sbi, NOHEAP) &&
 		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 		p->offset = 0;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index acf3d3fa4363..334415d946f8 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2534,7 +2534,7 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
 
 	sanity_check_seg_type(sbi, seg_type);
 	if (f2fs_need_rand_seg(sbi))
-		return prandom_u32_max(MAIN_SECS(sbi) * sbi->segs_per_sec);
+		return get_random_u32_below(MAIN_SECS(sbi) * sbi->segs_per_sec);
 
 	/* if segs_per_sec is large than 1, we need to keep original policy. */
 	if (__is_large_section(sbi))
@@ -2588,7 +2588,7 @@ static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
 	curseg->alloc_type = LFS;
 	if (F2FS_OPTION(sbi).fs_mode == FS_MODE_FRAGMENT_BLK)
 		curseg->fragment_remained_chunk =
-				prandom_u32_max(sbi->max_fragment_chunk) + 1;
+				get_random_u32_below(sbi->max_fragment_chunk) + 1;
 }
 
 static int __next_free_blkoff(struct f2fs_sb_info *sbi,
@@ -2625,9 +2625,9 @@ static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
 			/* To allocate block chunks in different sizes, use random number */
 			if (--seg->fragment_remained_chunk <= 0) {
 				seg->fragment_remained_chunk =
-				   prandom_u32_max(sbi->max_fragment_chunk) + 1;
+				   get_random_u32_below(sbi->max_fragment_chunk) + 1;
 				seg->next_blkoff +=
-				   prandom_u32_max(sbi->max_fragment_hole) + 1;
+				   get_random_u32_below(sbi->max_fragment_hole) + 1;
 			}
 		}
 	}
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 3f128b9fdfbb..9c9d3f0e36a4 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -2467,7 +2467,7 @@ int dbg_check_nondata_nodes_order(struct ubifs_info *c, struct list_head *head)
 
 static inline int chance(unsigned int n, unsigned int out_of)
 {
-	return !!(prandom_u32_max(out_of) + 1 <= n);
+	return !!(get_random_u32_below(out_of) + 1 <= n);
 
 }
 
@@ -2485,13 +2485,13 @@ static int power_cut_emulated(struct ubifs_info *c, int lnum, int write)
 			if (chance(1, 2)) {
 				d->pc_delay = 1;
 				/* Fail within 1 minute */
-				delay = prandom_u32_max(60000);
+				delay = get_random_u32_below(60000);
 				d->pc_timeout = jiffies;
 				d->pc_timeout += msecs_to_jiffies(delay);
 				ubifs_warn(c, "failing after %lums", delay);
 			} else {
 				d->pc_delay = 2;
-				delay = prandom_u32_max(10000);
+				delay = get_random_u32_below(10000);
 				/* Fail within 10000 operations */
 				d->pc_cnt_max = delay;
 				ubifs_warn(c, "failing after %lu calls", delay);
@@ -2571,7 +2571,7 @@ static int corrupt_data(const struct ubifs_info *c, const void *buf,
 	unsigned int from, to, ffs = chance(1, 2);
 	unsigned char *p = (void *)buf;
 
-	from = prandom_u32_max(len);
+	from = get_random_u32_below(len);
 	/* Corruption span max to end of write unit */
 	to = min(len, ALIGN(from + 1, c->max_write_size));
 
diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c
index cfbc31f709f4..c4d079328b92 100644
--- a/fs/ubifs/lpt_commit.c
+++ b/fs/ubifs/lpt_commit.c
@@ -1970,28 +1970,28 @@ static int dbg_populate_lsave(struct ubifs_info *c)
 
 	if (!dbg_is_chk_gen(c))
 		return 0;
-	if (prandom_u32_max(4))
+	if (get_random_u32_below(4))
 		return 0;
 
 	for (i = 0; i < c->lsave_cnt; i++)
 		c->lsave[i] = c->main_first;
 
 	list_for_each_entry(lprops, &c->empty_list, list)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = lprops->lnum;
 	list_for_each_entry(lprops, &c->freeable_list, list)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = lprops->lnum;
 	list_for_each_entry(lprops, &c->frdi_idx_list, list)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = lprops->lnum;
 
 	heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
 	for (i = 0; i < heap->cnt; i++)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = heap->arr[i]->lnum;
 	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
 	for (i = 0; i < heap->cnt; i++)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = heap->arr[i]->lnum;
 	heap = &c->lpt_heap[LPROPS_FREE - 1];
 	for (i = 0; i < heap->cnt; i++)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = heap->arr[i]->lnum;
 
 	return 1;
 }
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
index 01362ad5f804..a55e04822d16 100644
--- a/fs/ubifs/tnc_commit.c
+++ b/fs/ubifs/tnc_commit.c
@@ -700,7 +700,7 @@ static int alloc_idx_lebs(struct ubifs_info *c, int cnt)
 		c->ilebs[c->ileb_cnt++] = lnum;
 		dbg_cmt("LEB %d", lnum);
 	}
-	if (dbg_is_chk_index(c) && !prandom_u32_max(8))
+	if (dbg_is_chk_index(c) && !get_random_u32_below(8))
 		return -ENOSPC;
 	return 0;
 }
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index de79f5d07f65..989cf341779b 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1516,7 +1516,7 @@ xfs_alloc_ag_vextent_lastblock(
 
 #ifdef DEBUG
 	/* Randomly don't execute the first algorithm. */
-	if (prandom_u32_max(2))
+	if (get_random_u32_below(2))
 		return 0;
 #endif
 
diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index 94db50eb706a..5118dedf9267 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -636,7 +636,7 @@ xfs_ialloc_ag_alloc(
 	/* randomly do sparse inode allocations */
 	if (xfs_has_sparseinodes(tp->t_mountp) &&
 	    igeo->ialloc_min_blks < igeo->ialloc_blks)
-		do_sparse = prandom_u32_max(2);
+		do_sparse = get_random_u32_below(2);
 #endif
 
 	/*
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index c6b2aabd6f18..822e6a0e9d1a 100644
--- a/fs/xfs/xfs_error.c
+++ b/fs/xfs/xfs_error.c
@@ -279,7 +279,7 @@ xfs_errortag_test(
 
 	ASSERT(error_tag < XFS_ERRTAG_MAX);
 	randfactor = mp->m_errortag[error_tag];
-	if (!randfactor || prandom_u32_max(randfactor))
+	if (!randfactor || get_random_u32_below(randfactor))
 		return false;
 
 	xfs_warn_ratelimited(mp,
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 620ada094c3b..84525b9cdf6e 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -21,7 +21,7 @@
 /* Get a random number in [l, r) */
 static inline unsigned long damon_rand(unsigned long l, unsigned long r)
 {
-	return l + prandom_u32_max(r - l);
+	return l + get_random_u32_below(r - l);
 }
 
 /**
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index efef68c9352a..bb0ee80526b2 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -516,7 +516,7 @@ static inline int node_random(const nodemask_t *maskp)
 		bit = first_node(*maskp);
 		break;
 	default:
-		bit = find_nth_bit(maskp->bits, MAX_NUMNODES, prandom_u32_max(w));
+		bit = find_nth_bit(maskp->bits, MAX_NUMNODES, get_random_u32_below(w));
 		break;
 	}
 	return bit;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 25a54e04560e..38159f39e2af 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1032,7 +1032,7 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 	hdr->size = size;
 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
 		     PAGE_SIZE - sizeof(*hdr));
-	start = prandom_u32_max(hole) & ~(alignment - 1);
+	start = get_random_u32_below(hole) & ~(alignment - 1);
 
 	/* Leave a random number of instructions before BPF code. */
 	*image_ptr = &hdr->image[start];
@@ -1094,7 +1094,7 @@ bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
 
 	hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
 		     BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
-	start = prandom_u32_max(hole) & ~(alignment - 1);
+	start = get_random_u32_below(hole) & ~(alignment - 1);
 
 	*image_ptr = &ro_header->image[start];
 	*rw_image = &(*rw_header)->image[start];
diff --git a/kernel/kcsan/selftest.c b/kernel/kcsan/selftest.c
index 1740ce389e7f..7b619f16a492 100644
--- a/kernel/kcsan/selftest.c
+++ b/kernel/kcsan/selftest.c
@@ -31,8 +31,8 @@ static bool __init test_encode_decode(void)
 	int i;
 
 	for (i = 0; i < ITERS_PER_TEST; ++i) {
-		size_t size = prandom_u32_max(MAX_ENCODABLE_SIZE) + 1;
-		bool is_write = !!prandom_u32_max(2);
+		size_t size = get_random_u32_below(MAX_ENCODABLE_SIZE) + 1;
+		bool is_write = !!get_random_u32_below(2);
 		unsigned long verif_masked_addr;
 		long encoded_watchpoint;
 		bool verif_is_write;
diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
index 43efb2a04160..29dc253d03af 100644
--- a/kernel/locking/test-ww_mutex.c
+++ b/kernel/locking/test-ww_mutex.c
@@ -399,7 +399,7 @@ static int *get_random_order(int count)
 		order[n] = n;
 
 	for (n = count - 1; n > 1; n--) {
-		r = prandom_u32_max(n + 1);
+		r = get_random_u32_below(n + 1);
 		if (r != n) {
 			tmp = order[n];
 			order[n] = order[r];
@@ -538,7 +538,7 @@ static void stress_one_work(struct work_struct *work)
 {
 	struct stress *stress = container_of(work, typeof(*stress), work);
 	const int nlocks = stress->nlocks;
-	struct ww_mutex *lock = stress->locks + prandom_u32_max(nlocks);
+	struct ww_mutex *lock = stress->locks + get_random_u32_below(nlocks);
 	int err;
 
 	do {
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 8058bec87ace..9cf32ccda715 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -310,7 +310,7 @@ static void clocksource_verify_choose_cpus(void)
 	 * CPUs that are currently online.
 	 */
 	for (i = 1; i < n; i++) {
-		cpu = prandom_u32_max(nr_cpu_ids);
+		cpu = get_random_u32_below(nr_cpu_ids);
 		cpu = cpumask_next(cpu - 1, cpu_online_mask);
 		if (cpu >= nr_cpu_ids)
 			cpu = cpumask_first(cpu_online_mask);
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index 96e092de5b72..9f53408c545d 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -139,7 +139,7 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
 			return false;
 	}
 
-	if (attr->probability <= prandom_u32_max(100))
+	if (attr->probability <= get_random_u32_below(100))
 		return false;
 
 	if (!fail_stacktrace(attr))
diff --git a/lib/find_bit_benchmark.c b/lib/find_bit_benchmark.c
index 7c3c011abd29..d3fb09e6eff1 100644
--- a/lib/find_bit_benchmark.c
+++ b/lib/find_bit_benchmark.c
@@ -174,8 +174,8 @@ static int __init find_bit_test(void)
 	bitmap_zero(bitmap2, BITMAP_LEN);
 
 	while (nbits--) {
-		__set_bit(prandom_u32_max(BITMAP_LEN), bitmap);
-		__set_bit(prandom_u32_max(BITMAP_LEN), bitmap2);
+		__set_bit(get_random_u32_below(BITMAP_LEN), bitmap);
+		__set_bit(get_random_u32_below(BITMAP_LEN), bitmap2);
 	}
 
 	test_find_next_bit(bitmap, BITMAP_LEN);
diff --git a/lib/kobject.c b/lib/kobject.c
index a0b2dbfcfa23..af1f5f2954d4 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -694,7 +694,7 @@ static void kobject_release(struct kref *kref)
 {
 	struct kobject *kobj = container_of(kref, struct kobject, kref);
 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
-	unsigned long delay = HZ + HZ * prandom_u32_max(4);
+	unsigned long delay = HZ + HZ * get_random_u32_below(4);
 	pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
 		 kobject_name(kobj), kobj, __func__, kobj->parent, delay);
 	INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
diff --git a/lib/reed_solomon/test_rslib.c b/lib/reed_solomon/test_rslib.c
index 848e7eb5da92..75cb1adac884 100644
--- a/lib/reed_solomon/test_rslib.c
+++ b/lib/reed_solomon/test_rslib.c
@@ -183,7 +183,7 @@ static int get_rcw_we(struct rs_control *rs, struct wspace *ws,
 
 		do {
 			/* Must not choose the same location twice */
-			errloc = prandom_u32_max(len);
+			errloc = get_random_u32_below(len);
 		} while (errlocs[errloc] != 0);
 
 		errlocs[errloc] = 1;
@@ -194,12 +194,12 @@ static int get_rcw_we(struct rs_control *rs, struct wspace *ws,
 	for (i = 0; i < eras; i++) {
 		do {
 			/* Must not choose the same location twice */
-			errloc = prandom_u32_max(len);
+			errloc = get_random_u32_below(len);
 		} while (errlocs[errloc] != 0);
 
 		derrlocs[i] = errloc;
 
-		if (ewsc && prandom_u32_max(2)) {
+		if (ewsc && get_random_u32_below(2)) {
 			/* Erasure with the symbol intact */
 			errlocs[errloc] = 2;
 		} else {
diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index 7280ae8ca88c..58de526ff051 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -21,7 +21,7 @@ static int init_alloc_hint(struct sbitmap *sb, gfp_t flags)
 		int i;
 
 		for_each_possible_cpu(i)
-			*per_cpu_ptr(sb->alloc_hint, i) = prandom_u32_max(depth);
+			*per_cpu_ptr(sb->alloc_hint, i) = get_random_u32_below(depth);
 	}
 	return 0;
 }
@@ -33,7 +33,7 @@ static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb,
 
 	hint = this_cpu_read(*sb->alloc_hint);
 	if (unlikely(hint >= depth)) {
-		hint = depth ? prandom_u32_max(depth) : 0;
+		hint = depth ? get_random_u32_below(depth) : 0;
 		this_cpu_write(*sb->alloc_hint, hint);
 	}
 
diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c
index 86fadd3ba08c..41d3447bc3b4 100644
--- a/lib/test-string_helpers.c
+++ b/lib/test-string_helpers.c
@@ -587,7 +587,7 @@ static int __init test_string_helpers_init(void)
 	for (i = 0; i < UNESCAPE_ALL_MASK + 1; i++)
 		test_string_unescape("unescape", i, false);
 	test_string_unescape("unescape inplace",
-			     prandom_u32_max(UNESCAPE_ANY + 1), true);
+			     get_random_u32_below(UNESCAPE_ANY + 1), true);
 
 	/* Without dictionary */
 	for (i = 0; i < ESCAPE_ALL_MASK + 1; i++)
diff --git a/lib/test_hexdump.c b/lib/test_hexdump.c
index 0927f44cd478..efc50fd30a44 100644
--- a/lib/test_hexdump.c
+++ b/lib/test_hexdump.c
@@ -149,7 +149,7 @@ static void __init test_hexdump(size_t len, int rowsize, int groupsize,
 static void __init test_hexdump_set(int rowsize, bool ascii)
 {
 	size_t d = min_t(size_t, sizeof(data_b), rowsize);
-	size_t len = prandom_u32_max(d) + 1;
+	size_t len = get_random_u32_below(d) + 1;
 
 	test_hexdump(len, rowsize, 4, ascii);
 	test_hexdump(len, rowsize, 2, ascii);
@@ -208,11 +208,11 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len,
 static void __init test_hexdump_overflow_set(size_t buflen, bool ascii)
 {
 	unsigned int i = 0;
-	int rs = (prandom_u32_max(2) + 1) * 16;
+	int rs = (get_random_u32_below(2) + 1) * 16;
 
 	do {
 		int gs = 1 << i;
-		size_t len = prandom_u32_max(rs) + gs;
+		size_t len = get_random_u32_below(rs) + gs;
 
 		test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, ascii);
 	} while (i++ < 3);
@@ -223,11 +223,11 @@ static int __init test_hexdump_init(void)
 	unsigned int i;
 	int rowsize;
 
-	rowsize = (prandom_u32_max(2) + 1) * 16;
+	rowsize = (get_random_u32_below(2) + 1) * 16;
 	for (i = 0; i < 16; i++)
 		test_hexdump_set(rowsize, false);
 
-	rowsize = (prandom_u32_max(2) + 1) * 16;
+	rowsize = (get_random_u32_below(2) + 1) * 16;
 	for (i = 0; i < 16; i++)
 		test_hexdump_set(rowsize, true);
 
diff --git a/lib/test_list_sort.c b/lib/test_list_sort.c
index 19ff229b9c3a..cc5f335f29b5 100644
--- a/lib/test_list_sort.c
+++ b/lib/test_list_sort.c
@@ -71,7 +71,7 @@ static void list_sort_test(struct kunit *test)
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, el);
 
 		 /* force some equivalencies */
-		el->value = prandom_u32_max(TEST_LIST_LEN / 3);
+		el->value = get_random_u32_below(TEST_LIST_LEN / 3);
 		el->serial = i;
 		el->poison1 = TEST_POISON1;
 		el->poison2 = TEST_POISON2;
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 4bd15a593fbd..6d10187eddac 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -126,7 +126,7 @@ __test(const char *expect, int elen, const char *fmt, ...)
 	 * be able to print it as expected.
 	 */
 	failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
-	rand = 1 + prandom_u32_max(elen+1);
+	rand = 1 + get_random_u32_below(elen + 1);
 	/* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 	failed_tests += do_test(rand, expect, elen, fmt, ap);
 	failed_tests += do_test(0, expect, elen, fmt, ap);
diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
index f2ba5787055a..6a8e445c8b55 100644
--- a/lib/test_rhashtable.c
+++ b/lib/test_rhashtable.c
@@ -368,8 +368,8 @@ static int __init test_rhltable(unsigned int entries)
 
 	pr_info("test %d random rhlist add/delete operations\n", entries);
 	for (j = 0; j < entries; j++) {
-		u32 i = prandom_u32_max(entries);
-		u32 prand = prandom_u32_max(4);
+		u32 i = get_random_u32_below(entries);
+		u32 prand = get_random_u32_below(4);
 
 		cond_resched();
 
@@ -396,7 +396,7 @@ static int __init test_rhltable(unsigned int entries)
 		}
 
 		if (prand & 2) {
-			i = prandom_u32_max(entries);
+			i = get_random_u32_below(entries);
 			if (test_bit(i, obj_in_table)) {
 				err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
 				WARN(err, "cannot remove element at slot %d", i);
diff --git a/lib/test_vmalloc.c b/lib/test_vmalloc.c
index cf7780572f5b..104f09ea5fcc 100644
--- a/lib/test_vmalloc.c
+++ b/lib/test_vmalloc.c
@@ -151,7 +151,7 @@ static int random_size_alloc_test(void)
 	int i;
 
 	for (i = 0; i < test_loop_count; i++) {
-		n = prandom_u32_max(100) + 1;
+		n = get_random_u32_below(100) + 1;
 		p = vmalloc(n * PAGE_SIZE);
 
 		if (!p)
@@ -291,12 +291,12 @@ pcpu_alloc_test(void)
 		return -1;
 
 	for (i = 0; i < 35000; i++) {
-		size = prandom_u32_max(PAGE_SIZE / 4) + 1;
+		size = get_random_u32_below(PAGE_SIZE / 4) + 1;
 
 		/*
 		 * Maximum PAGE_SIZE
 		 */
-		align = 1 << (prandom_u32_max(11) + 1);
+		align = 1 << (get_random_u32_below(11) + 1);
 
 		pcpu[i] = __alloc_percpu(size, align);
 		if (!pcpu[i])
@@ -391,7 +391,7 @@ static void shuffle_array(int *arr, int n)
 
 	for (i = n - 1; i > 0; i--)  {
 		/* Cut the range. */
-		j = prandom_u32_max(i);
+		j = get_random_u32_below(i);
 
 		/* Swap indexes. */
 		swap(arr[i], arr[j]);
diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c
index 0d59098f0876..640f9c7f8e44 100644
--- a/mm/kasan/kasan_test.c
+++ b/mm/kasan/kasan_test.c
@@ -1299,7 +1299,7 @@ static void match_all_not_assigned(struct kunit *test)
 	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
 
 	for (i = 0; i < 256; i++) {
-		size = prandom_u32_max(1024) + 1;
+		size = get_random_u32_below(1024) + 1;
 		ptr = kmalloc(size, GFP_KERNEL);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
@@ -1308,7 +1308,7 @@ static void match_all_not_assigned(struct kunit *test)
 	}
 
 	for (i = 0; i < 256; i++) {
-		order = prandom_u32_max(4) + 1;
+		order = get_random_u32_below(4) + 1;
 		pages = alloc_pages(GFP_KERNEL, order);
 		ptr = page_address(pages);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
@@ -1321,7 +1321,7 @@ static void match_all_not_assigned(struct kunit *test)
 		return;
 
 	for (i = 0; i < 256; i++) {
-		size = prandom_u32_max(1024) + 1;
+		size = get_random_u32_below(1024) + 1;
 		ptr = vmalloc(size);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 141788858b70..6cbd93f2007b 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -360,9 +360,9 @@ static void *kfence_guarded_alloc(struct kmem_cache *cache, size_t size, gfp_t g
 	unsigned long flags;
 	struct slab *slab;
 	void *addr;
-	const bool random_right_allocate = prandom_u32_max(2);
+	const bool random_right_allocate = get_random_u32_below(2);
 	const bool random_fault = CONFIG_KFENCE_STRESS_TEST_FAULTS &&
-				  !prandom_u32_max(CONFIG_KFENCE_STRESS_TEST_FAULTS);
+				  !get_random_u32_below(CONFIG_KFENCE_STRESS_TEST_FAULTS);
 
 	/* Try to obtain a free object. */
 	raw_spin_lock_irqsave(&kfence_freelist_lock, flags);
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index a97bffe0cc3e..20028c179796 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -532,8 +532,8 @@ static void test_free_bulk(struct kunit *test)
 	int iter;
 
 	for (iter = 0; iter < 5; iter++) {
-		const size_t size = setup_test_cache(test, 8 + prandom_u32_max(300), 0,
-						     (iter & 1) ? ctor_set_x : NULL);
+		const size_t size = setup_test_cache(test, 8 + get_random_u32_below(300),
+						     0, (iter & 1) ? ctor_set_x : NULL);
 		void *objects[] = {
 			test_alloc(test, size, GFP_KERNEL, ALLOCATE_RIGHT),
 			test_alloc(test, size, GFP_KERNEL, ALLOCATE_NONE),
diff --git a/mm/slub.c b/mm/slub.c
index 157527d7101b..7cd2c657030a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1881,7 +1881,7 @@ static bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
 		return false;
 
 	freelist_count = oo_objects(s->oo);
-	pos = prandom_u32_max(freelist_count);
+	pos = get_random_u32_below(freelist_count);
 
 	page_limit = slab->objects * s->size;
 	start = fixup_red_left(s, slab_address(slab));
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 5fc1237a9f21..e9318305a24a 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -773,7 +773,7 @@ static void set_cluster_next(struct swap_info_struct *si, unsigned long next)
 		if (si->highest_bit <= si->lowest_bit)
 			return;
 		next = si->lowest_bit +
-			prandom_u32_max(si->highest_bit - si->lowest_bit + 1);
+			get_random_u32_below(si->highest_bit - si->lowest_bit + 1);
 		next = ALIGN_DOWN(next, SWAP_ADDRESS_SPACE_PAGES);
 		next = max_t(unsigned int, next, si->lowest_bit);
 	}
@@ -3089,7 +3089,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 		 */
 		for_each_possible_cpu(cpu) {
 			per_cpu(*p->cluster_next_cpu, cpu) =
-				1 + prandom_u32_max(p->highest_bit);
+				1 + get_random_u32_below(p->highest_bit);
 		}
 		nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
 
diff --git a/net/802/garp.c b/net/802/garp.c
index fc9eb02a912f..77aac2763835 100644
--- a/net/802/garp.c
+++ b/net/802/garp.c
@@ -407,7 +407,7 @@ static void garp_join_timer_arm(struct garp_applicant *app)
 {
 	unsigned long delay;
 
-	delay = prandom_u32_max(msecs_to_jiffies(garp_join_time));
+	delay = get_random_u32_below(msecs_to_jiffies(garp_join_time));
 	mod_timer(&app->join_timer, jiffies + delay);
 }
 
diff --git a/net/802/mrp.c b/net/802/mrp.c
index 155f74d8b14f..8c6f0381023b 100644
--- a/net/802/mrp.c
+++ b/net/802/mrp.c
@@ -592,7 +592,7 @@ static void mrp_join_timer_arm(struct mrp_applicant *app)
 {
 	unsigned long delay;
 
-	delay = prandom_u32_max(msecs_to_jiffies(mrp_join_time));
+	delay = get_random_u32_below(msecs_to_jiffies(mrp_join_time));
 	mod_timer(&app->join_timer, jiffies + delay);
 }
 
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 7f6a7c96ac92..114ee5da261f 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -280,7 +280,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
 	unsigned int msecs;
 
 	msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
-	msecs += prandom_u32_max(2 * BATADV_JITTER);
+	msecs += get_random_u32_below(2 * BATADV_JITTER);
 
 	return jiffies + msecs_to_jiffies(msecs);
 }
@@ -288,7 +288,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
 /* when do we schedule a ogm packet to be sent */
 static unsigned long batadv_iv_ogm_fwd_send_time(void)
 {
-	return jiffies + msecs_to_jiffies(prandom_u32_max(BATADV_JITTER / 2));
+	return jiffies + msecs_to_jiffies(get_random_u32_below(BATADV_JITTER / 2));
 }
 
 /* apply hop penalty for a normal link */
diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c
index f1741fbfb617..f9a58fb5442e 100644
--- a/net/batman-adv/bat_v_elp.c
+++ b/net/batman-adv/bat_v_elp.c
@@ -51,7 +51,7 @@ static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
 	unsigned int msecs;
 
 	msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
-	msecs += prandom_u32_max(2 * BATADV_JITTER);
+	msecs += get_random_u32_below(2 * BATADV_JITTER);
 
 	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
 			   msecs_to_jiffies(msecs));
diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
index 033639df96d8..addfd8c4fe95 100644
--- a/net/batman-adv/bat_v_ogm.c
+++ b/net/batman-adv/bat_v_ogm.c
@@ -90,7 +90,7 @@ static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
 	unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
 
 	/* msecs * [0.9, 1.1] */
-	msecs += prandom_u32_max(msecs / 5) - (msecs / 10);
+	msecs += get_random_u32_below(msecs / 5) - (msecs / 10);
 	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
 			   msecs_to_jiffies(msecs / 1000));
 }
@@ -109,7 +109,7 @@ static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
 		return;
 
 	msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
-	msecs += prandom_u32_max(2 * BATADV_JITTER);
+	msecs += get_random_u32_below(2 * BATADV_JITTER);
 	queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 			   msecs_to_jiffies(msecs));
 }
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 5f4aeeb60dc4..bf29fba4dde5 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -1009,7 +1009,7 @@ static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
 static u8 batadv_nc_random_weight_tq(u8 tq)
 {
 	/* randomize the estimated packet loss (max TQ - estimated TQ) */
-	u8 rand_tq = prandom_u32_max(BATADV_TQ_MAX_VALUE + 1 - tq);
+	u8 rand_tq = get_random_u32_below(BATADV_TQ_MAX_VALUE + 1 - tq);
 
 	/* convert to (randomized) estimated tq again */
 	return BATADV_TQ_MAX_VALUE - rand_tq;
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index a92e7e485feb..b2f9679066c4 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -7374,8 +7374,8 @@ static int get_conn_info(struct sock *sk, struct hci_dev *hdev, void *data,
 	 * calculate conn info age as random value between min/max set in hdev.
 	 */
 	conn_info_age = hdev->conn_info_min_age +
-			prandom_u32_max(hdev->conn_info_max_age -
-					hdev->conn_info_min_age);
+			get_random_u32_below(hdev->conn_info_max_age -
+					     hdev->conn_info_min_age);
 
 	/* Query controller to refresh cached values if they are too old or were
 	 * never read.
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index b670ba03a675..7e90f9e61d9b 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -189,7 +189,7 @@ static void j1939_sk_queue_activate_next_locked(struct j1939_session *session)
 		int time_ms = 0;
 
 		if (err)
-			time_ms = 10 + prandom_u32_max(16);
+			time_ms = 10 + get_random_u32_below(16);
 
 		j1939_tp_schedule_txtimer(first, time_ms);
 	}
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 55f29c9f9e08..67d36776aff4 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1168,7 +1168,7 @@ static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
 		if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
 			session->tx_retry++;
 			j1939_tp_schedule_txtimer(session,
-						  10 + prandom_u32_max(16));
+						  10 + get_random_u32_below(16));
 		} else {
 			netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
 				     __func__, session);
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index db60217f911b..faabad6603db 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -222,7 +222,7 @@ static void pick_new_mon(struct ceph_mon_client *monc)
 				max--;
 		}
 
-		n = prandom_u32_max(max);
+		n = get_random_u32_below(max);
 		if (o >= 0 && n >= o)
 			n++;
 
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 4e4f1e4bc265..11c04e7d928e 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1479,7 +1479,7 @@ static bool target_should_be_paused(struct ceph_osd_client *osdc,
 
 static int pick_random_replica(const struct ceph_osds *acting)
 {
-	int i = prandom_u32_max(acting->size);
+	int i = get_random_u32_below(acting->size);
 
 	dout("%s picked osd%d, primary osd%d\n", __func__,
 	     acting->osds[i], acting->primary);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index a77a85e357e0..ba92762de525 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -111,7 +111,7 @@ static void neigh_cleanup_and_release(struct neighbour *neigh)
 
 unsigned long neigh_rand_reach_time(unsigned long base)
 {
-	return base ? prandom_u32_max(base) + (base >> 1) : 0;
+	return base ? get_random_u32_below(base) + (base >> 1) : 0;
 }
 EXPORT_SYMBOL(neigh_rand_reach_time);
 
@@ -1652,7 +1652,7 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 		    struct sk_buff *skb)
 {
 	unsigned long sched_next = jiffies +
-			prandom_u32_max(NEIGH_VAR(p, PROXY_DELAY));
+			get_random_u32_below(NEIGH_VAR(p, PROXY_DELAY));
 
 	if (p->qlen > NEIGH_VAR(p, PROXY_QLEN)) {
 		kfree_skb(skb);
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index c3763056c554..95da2ddc1c20 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2324,7 +2324,7 @@ static inline int f_pick(struct pktgen_dev *pkt_dev)
 				pkt_dev->curfl = 0; /*reset */
 		}
 	} else {
-		flow = prandom_u32_max(pkt_dev->cflows);
+		flow = get_random_u32_below(pkt_dev->cflows);
 		pkt_dev->curfl = flow;
 
 		if (pkt_dev->flows[flow].count > pkt_dev->lflow) {
@@ -2380,8 +2380,8 @@ static void set_cur_queue_map(struct pktgen_dev *pkt_dev)
 	else if (pkt_dev->queue_map_min <= pkt_dev->queue_map_max) {
 		__u16 t;
 		if (pkt_dev->flags & F_QUEUE_MAP_RND) {
-			t = prandom_u32_max(pkt_dev->queue_map_max -
-					    pkt_dev->queue_map_min + 1) +
+			t = get_random_u32_below(pkt_dev->queue_map_max -
+						 pkt_dev->queue_map_min + 1) +
 			    pkt_dev->queue_map_min;
 		} else {
 			t = pkt_dev->cur_queue_map + 1;
@@ -2411,7 +2411,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		__u32 tmp;
 
 		if (pkt_dev->flags & F_MACSRC_RND)
-			mc = prandom_u32_max(pkt_dev->src_mac_count);
+			mc = get_random_u32_below(pkt_dev->src_mac_count);
 		else {
 			mc = pkt_dev->cur_src_mac_offset++;
 			if (pkt_dev->cur_src_mac_offset >=
@@ -2437,7 +2437,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		__u32 tmp;
 
 		if (pkt_dev->flags & F_MACDST_RND)
-			mc = prandom_u32_max(pkt_dev->dst_mac_count);
+			mc = get_random_u32_below(pkt_dev->dst_mac_count);
 
 		else {
 			mc = pkt_dev->cur_dst_mac_offset++;
@@ -2469,16 +2469,16 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 	}
 
 	if ((pkt_dev->flags & F_VID_RND) && (pkt_dev->vlan_id != 0xffff)) {
-		pkt_dev->vlan_id = prandom_u32_max(4096);
+		pkt_dev->vlan_id = get_random_u32_below(4096);
 	}
 
 	if ((pkt_dev->flags & F_SVID_RND) && (pkt_dev->svlan_id != 0xffff)) {
-		pkt_dev->svlan_id = prandom_u32_max(4096);
+		pkt_dev->svlan_id = get_random_u32_below(4096);
 	}
 
 	if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
 		if (pkt_dev->flags & F_UDPSRC_RND)
-			pkt_dev->cur_udp_src = prandom_u32_max(
+			pkt_dev->cur_udp_src = get_random_u32_below(
 				pkt_dev->udp_src_max - pkt_dev->udp_src_min) +
 				pkt_dev->udp_src_min;
 
@@ -2491,7 +2491,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 
 	if (pkt_dev->udp_dst_min < pkt_dev->udp_dst_max) {
 		if (pkt_dev->flags & F_UDPDST_RND) {
-			pkt_dev->cur_udp_dst = prandom_u32_max(
+			pkt_dev->cur_udp_dst = get_random_u32_below(
 				pkt_dev->udp_dst_max - pkt_dev->udp_dst_min) +
 				pkt_dev->udp_dst_min;
 		} else {
@@ -2508,7 +2508,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		if (imn < imx) {
 			__u32 t;
 			if (pkt_dev->flags & F_IPSRC_RND)
-				t = prandom_u32_max(imx - imn) + imn;
+				t = get_random_u32_below(imx - imn) + imn;
 			else {
 				t = ntohl(pkt_dev->cur_saddr);
 				t++;
@@ -2530,7 +2530,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 				if (pkt_dev->flags & F_IPDST_RND) {
 
 					do {
-						t = prandom_u32_max(imx - imn) +
+						t = get_random_u32_below(imx - imn) +
 						    imn;
 						s = htonl(t);
 					} while (ipv4_is_loopback(s) ||
@@ -2578,8 +2578,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 	if (pkt_dev->min_pkt_size < pkt_dev->max_pkt_size) {
 		__u32 t;
 		if (pkt_dev->flags & F_TXSIZE_RND) {
-			t = prandom_u32_max(pkt_dev->max_pkt_size -
-					    pkt_dev->min_pkt_size) +
+			t = get_random_u32_below(pkt_dev->max_pkt_size -
+						 pkt_dev->min_pkt_size) +
 			    pkt_dev->min_pkt_size;
 		} else {
 			t = pkt_dev->cur_pkt_size + 1;
@@ -2589,7 +2589,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		pkt_dev->cur_pkt_size = t;
 	} else if (pkt_dev->n_imix_entries > 0) {
 		struct imix_pkt *entry;
-		__u32 t = prandom_u32_max(IMIX_PRECISION);
+		__u32 t = get_random_u32_below(IMIX_PRECISION);
 		__u8 entry_index = pkt_dev->imix_distribution[t];
 
 		entry = &pkt_dev->imix_entries[entry_index];
diff --git a/net/core/stream.c b/net/core/stream.c
index 75fded8495f5..5b1fe2b82eac 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -123,7 +123,7 @@ int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 
 	if (sk_stream_memory_free(sk))
-		current_timeo = vm_wait = prandom_u32_max(HZ / 5) + 2;
+		current_timeo = vm_wait = get_random_u32_below(HZ / 5) + 2;
 
 	add_wait_queue(sk_sleep(sk), &wait);
 
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index d5d745c3e345..46aa2d65e40a 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -263,7 +263,7 @@ bool icmp_global_allow(void)
 		/* We want to use a credit of one in average, but need to randomize
 		 * it for security reasons.
 		 */
-		credit = max_t(int, credit - prandom_u32_max(3), 0);
+		credit = max_t(int, credit - get_random_u32_below(3), 0);
 		rc = true;
 	}
 	WRITE_ONCE(icmp_global.credit, credit);
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 81be3e0f0e70..c920aa9a62a9 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -213,7 +213,7 @@ static void igmp_stop_timer(struct ip_mc_list *im)
 /* It must be called with locked im->lock */
 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
 {
-	int tv = prandom_u32_max(max_delay);
+	int tv = get_random_u32_below(max_delay);
 
 	im->tm_running = 1;
 	if (!mod_timer(&im->timer, jiffies+tv+2))
@@ -222,7 +222,7 @@ static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
 
 static void igmp_gq_start_timer(struct in_device *in_dev)
 {
-	int tv = prandom_u32_max(in_dev->mr_maxdelay);
+	int tv = get_random_u32_below(in_dev->mr_maxdelay);
 	unsigned long exp = jiffies + tv + 2;
 
 	if (in_dev->mr_gq_running &&
@@ -236,7 +236,7 @@ static void igmp_gq_start_timer(struct in_device *in_dev)
 
 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
 {
-	int tv = prandom_u32_max(delay);
+	int tv = get_random_u32_below(delay);
 
 	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
 		in_dev_hold(in_dev);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 4e84ed21d16f..f22051219b50 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -314,7 +314,7 @@ inet_csk_find_open_port(const struct sock *sk, struct inet_bind_bucket **tb_ret,
 	if (likely(remaining > 1))
 		remaining &= ~1U;
 
-	offset = prandom_u32_max(remaining);
+	offset = get_random_u32_below(remaining);
 	/* __inet_hash_connect() favors ports having @low parity
 	 * We do the opposite to not pollute connect() users.
 	 */
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index d3dc28156622..a879ec1a267d 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -1037,7 +1037,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 	 * on low contention the randomness is maximal and on high contention
 	 * it may be inexistent.
 	 */
-	i = max_t(int, i, prandom_u32_max(8) * 2);
+	i = max_t(int, i, get_random_u32_below(8) * 2);
 	WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2);
 
 	/* Head lock still held and bh's disabled */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index cd1fa9f70f1a..de6e3515ab4f 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -471,7 +471,7 @@ static u32 ip_idents_reserve(u32 hash, int segs)
 	old = READ_ONCE(*p_tstamp);
 
 	if (old != now && cmpxchg(p_tstamp, old, now) == old)
-		delta = prandom_u32_max(now - old);
+		delta = get_random_u32_below(now - old);
 
 	/* If UBSAN reports an error there, please make sure your compiler
 	 * supports -fno-strict-overflow before reporting it that was a bug
@@ -689,7 +689,7 @@ static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr,
 	} else {
 		/* Randomize max depth to avoid some side channels attacks. */
 		int max_depth = FNHE_RECLAIM_DEPTH +
-				prandom_u32_max(FNHE_RECLAIM_DEPTH);
+				get_random_u32_below(FNHE_RECLAIM_DEPTH);
 
 		while (depth > max_depth) {
 			fnhe_remove_oldest(hash);
diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index 54eec33c6e1c..d2c470524e58 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -618,7 +618,7 @@ static void bbr_reset_probe_bw_mode(struct sock *sk)
 	struct bbr *bbr = inet_csk_ca(sk);
 
 	bbr->mode = BBR_PROBE_BW;
-	bbr->cycle_idx = CYCLE_LEN - 1 - prandom_u32_max(bbr_cycle_rand);
+	bbr->cycle_idx = CYCLE_LEN - 1 - get_random_u32_below(bbr_cycle_rand);
 	bbr_advance_cycle_phase(sk);	/* flip to next phase of gain cycle */
 }
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 0640453fce54..3b076e5ba932 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3646,7 +3646,8 @@ static void tcp_send_challenge_ack(struct sock *sk)
 		u32 half = (ack_limit + 1) >> 1;
 
 		WRITE_ONCE(net->ipv4.tcp_challenge_timestamp, now);
-		WRITE_ONCE(net->ipv4.tcp_challenge_count, half + prandom_u32_max(ack_limit));
+		WRITE_ONCE(net->ipv4.tcp_challenge_count,
+			   half + get_random_u32_below(ack_limit));
 	}
 	count = READ_ONCE(net->ipv4.tcp_challenge_count);
 	if (count > 0) {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 9c3f5202a97b..daf89a2eb492 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -104,7 +104,7 @@ static inline u32 cstamp_delta(unsigned long cstamp)
 static inline s32 rfc3315_s14_backoff_init(s32 irt)
 {
 	/* multiply 'initial retransmission time' by 0.9 .. 1.1 */
-	u64 tmp = (900000 + prandom_u32_max(200001)) * (u64)irt;
+	u64 tmp = (900000 + get_random_u32_below(200001)) * (u64)irt;
 	do_div(tmp, 1000000);
 	return (s32)tmp;
 }
@@ -112,11 +112,11 @@ static inline s32 rfc3315_s14_backoff_init(s32 irt)
 static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
 {
 	/* multiply 'retransmission timeout' by 1.9 .. 2.1 */
-	u64 tmp = (1900000 + prandom_u32_max(200001)) * (u64)rt;
+	u64 tmp = (1900000 + get_random_u32_below(200001)) * (u64)rt;
 	do_div(tmp, 1000000);
 	if ((s32)tmp > mrt) {
 		/* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
-		tmp = (900000 + prandom_u32_max(200001)) * (u64)mrt;
+		tmp = (900000 + get_random_u32_below(200001)) * (u64)mrt;
 		do_div(tmp, 1000000);
 	}
 	return (s32)tmp;
@@ -3967,7 +3967,7 @@ static void addrconf_dad_kick(struct inet6_ifaddr *ifp)
 	if (ifp->flags & IFA_F_OPTIMISTIC)
 		rand_num = 0;
 	else
-		rand_num = prandom_u32_max(idev->cnf.rtr_solicit_delay ?: 1);
+		rand_num = get_random_u32_below(idev->cnf.rtr_solicit_delay ? : 1);
 
 	nonce = 0;
 	if (idev->cnf.enhanced_dad ||
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 7860383295d8..1c02160cf7a4 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1050,7 +1050,7 @@ bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
 /* called with mc_lock */
 static void mld_gq_start_work(struct inet6_dev *idev)
 {
-	unsigned long tv = prandom_u32_max(idev->mc_maxdelay);
+	unsigned long tv = get_random_u32_below(idev->mc_maxdelay);
 
 	idev->mc_gq_running = 1;
 	if (!mod_delayed_work(mld_wq, &idev->mc_gq_work, tv + 2))
@@ -1068,7 +1068,7 @@ static void mld_gq_stop_work(struct inet6_dev *idev)
 /* called with mc_lock */
 static void mld_ifc_start_work(struct inet6_dev *idev, unsigned long delay)
 {
-	unsigned long tv = prandom_u32_max(delay);
+	unsigned long tv = get_random_u32_below(delay);
 
 	if (!mod_delayed_work(mld_wq, &idev->mc_ifc_work, tv + 2))
 		in6_dev_hold(idev);
@@ -1085,7 +1085,7 @@ static void mld_ifc_stop_work(struct inet6_dev *idev)
 /* called with mc_lock */
 static void mld_dad_start_work(struct inet6_dev *idev, unsigned long delay)
 {
-	unsigned long tv = prandom_u32_max(delay);
+	unsigned long tv = get_random_u32_below(delay);
 
 	if (!mod_delayed_work(mld_wq, &idev->mc_dad_work, tv + 2))
 		in6_dev_hold(idev);
@@ -1130,7 +1130,7 @@ static void igmp6_group_queried(struct ifmcaddr6 *ma, unsigned long resptime)
 	}
 
 	if (delay >= resptime)
-		delay = prandom_u32_max(resptime);
+		delay = get_random_u32_below(resptime);
 
 	if (!mod_delayed_work(mld_wq, &ma->mca_work, delay))
 		refcount_inc(&ma->mca_refcnt);
@@ -2574,7 +2574,7 @@ static void igmp6_join_group(struct ifmcaddr6 *ma)
 
 	igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
 
-	delay = prandom_u32_max(unsolicited_report_interval(ma->idev));
+	delay = get_random_u32_below(unsolicited_report_interval(ma->idev));
 
 	if (cancel_delayed_work(&ma->mca_work)) {
 		refcount_dec(&ma->mca_refcnt);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2f355f0ec32a..e74e0361fd92 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1713,7 +1713,7 @@ static int rt6_insert_exception(struct rt6_info *nrt,
 	net->ipv6.rt6_stats->fib_rt_cache++;
 
 	/* Randomize max depth to avoid some side channels attacks. */
-	max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH);
+	max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH);
 	while (bucket->depth > max_depth)
 		rt6_exception_remove_oldest(bucket);
 
diff --git a/net/netfilter/ipvs/ip_vs_twos.c b/net/netfilter/ipvs/ip_vs_twos.c
index f2579fc9c75b..3308e4cc740a 100644
--- a/net/netfilter/ipvs/ip_vs_twos.c
+++ b/net/netfilter/ipvs/ip_vs_twos.c
@@ -71,8 +71,8 @@ static struct ip_vs_dest *ip_vs_twos_schedule(struct ip_vs_service *svc,
 	 * from 0 to total_weight
 	 */
 	total_weight += 1;
-	rweight1 = prandom_u32_max(total_weight);
-	rweight2 = prandom_u32_max(total_weight);
+	rweight1 = get_random_u32_below(total_weight);
+	rweight2 = get_random_u32_below(total_weight);
 
 	/* Pick two weighted servers */
 	list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index f97bda06d2a9..8703812405eb 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -906,7 +906,7 @@ nf_conntrack_hash_check_insert(struct nf_conn *ct)
 					   nf_ct_zone_id(nf_ct_zone(ct), IP_CT_DIR_REPLY));
 	} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 
-	max_chainlen = MIN_CHAINLEN + prandom_u32_max(MAX_CHAINLEN);
+	max_chainlen = MIN_CHAINLEN + get_random_u32_below(MAX_CHAINLEN);
 
 	/* See if there's one in the list already, including reverse */
 	hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode) {
@@ -1227,7 +1227,7 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 		goto dying;
 	}
 
-	max_chainlen = MIN_CHAINLEN + prandom_u32_max(MAX_CHAINLEN);
+	max_chainlen = MIN_CHAINLEN + get_random_u32_below(MAX_CHAINLEN);
 	/* See if there's one in the list already, including reverse:
 	   NAT could have grabbed it without realizing, since we're
 	   not in the hash.  If there is, we lost race. */
diff --git a/net/netfilter/nf_nat_helper.c b/net/netfilter/nf_nat_helper.c
index a95a25196943..bf591e6af005 100644
--- a/net/netfilter/nf_nat_helper.c
+++ b/net/netfilter/nf_nat_helper.c
@@ -223,7 +223,7 @@ u16 nf_nat_exp_find_port(struct nf_conntrack_expect *exp, u16 port)
 		if (res != -EBUSY || (--attempts_left < 0))
 			break;
 
-		port = min + prandom_u32_max(range);
+		port = min + get_random_u32_below(range);
 	}
 
 	return 0;
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a662e8a5ff84..7a401d94463a 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -835,7 +835,7 @@ static int netlink_autobind(struct socket *sock)
 		/* Bind collision, search negative portid values. */
 		if (rover == -4096)
 			/* rover will be in range [S32_MIN, -4097] */
-			rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN);
+			rover = S32_MIN + get_random_u32_below(-4096 - S32_MIN);
 		else if (rover >= -4096)
 			rover = -4097;
 		portid = rover--;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 6ce8dd19f33c..51a47ade92e8 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1350,7 +1350,7 @@ static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
 		if (READ_ONCE(history[i]) == rxhash)
 			count++;
 
-	victim = prandom_u32_max(ROLLOVER_HLEN);
+	victim = get_random_u32_below(ROLLOVER_HLEN);
 
 	/* Avoid dirtying the cache line if possible */
 	if (READ_ONCE(history[victim]) != rxhash)
@@ -1386,7 +1386,7 @@ static unsigned int fanout_demux_rnd(struct packet_fanout *f,
 				     struct sk_buff *skb,
 				     unsigned int num)
 {
-	return prandom_u32_max(num);
+	return get_random_u32_below(num);
 }
 
 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index 62d682b96b88..be267ffaaba7 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -25,7 +25,7 @@ static struct tc_action_ops act_gact_ops;
 static int gact_net_rand(struct tcf_gact *gact)
 {
 	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
-	if (prandom_u32_max(gact->tcfg_pval))
+	if (get_random_u32_below(gact->tcfg_pval))
 		return gact->tcf_action;
 	return gact->tcfg_paction;
 }
diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index 7a25477f5d99..4194480746b0 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -168,7 +168,7 @@ static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
 	psample_group = rcu_dereference_bh(s->psample_group);
 
 	/* randomly sample packets according to rate */
-	if (psample_group && (prandom_u32_max(s->rate) == 0)) {
+	if (psample_group && (get_random_u32_below(s->rate) == 0)) {
 		if (!skb_at_tc_ingress(skb)) {
 			md.in_ifindex = skb->skb_iif;
 			md.out_ifindex = skb->dev->ifindex;
diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index 3ac3e5c80b6f..19c851125901 100644
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -183,7 +183,7 @@ static struct sk_buff *choke_peek_random(const struct choke_sched_data *q,
 	int retrys = 3;
 
 	do {
-		*pidx = (q->head + prandom_u32_max(choke_len(q))) & q->tab_mask;
+		*pidx = (q->head + get_random_u32_below(choke_len(q))) & q->tab_mask;
 		skb = q->tab[*pidx];
 		if (skb)
 			return skb;
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index fb00ac40ecb7..6ef3021e1169 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -513,8 +513,8 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			goto finish_segs;
 		}
 
-		skb->data[prandom_u32_max(skb_headlen(skb))] ^=
-			1<<prandom_u32_max(8);
+		skb->data[get_random_u32_below(skb_headlen(skb))] ^=
+			1<<get_random_u32_below(8);
 	}
 
 	if (unlikely(sch->q.qlen >= sch->limit)) {
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 83628c347744..cfe72085fdc4 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -8319,7 +8319,7 @@ static int sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
 
 		inet_get_local_port_range(net, &low, &high);
 		remaining = (high - low) + 1;
-		rover = prandom_u32_max(remaining) + low;
+		rover = get_random_u32_below(remaining) + low;
 
 		do {
 			rover++;
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index f8fd98784977..ca1eba95c293 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -199,7 +199,7 @@ void sctp_transport_reset_hb_timer(struct sctp_transport *transport)
 	if ((time_before(transport->hb_timer.expires, expires) ||
 	     !timer_pending(&transport->hb_timer)) &&
 	    !mod_timer(&transport->hb_timer,
-		       expires + prandom_u32_max(transport->rto)))
+		       expires + get_random_u32_below(transport->rto)))
 		sctp_transport_hold(transport);
 }
 
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index f075a9fb5ccc..95ff74706104 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -677,7 +677,7 @@ static void cache_limit_defers(void)
 
 	/* Consider removing either the first or the last */
 	if (cache_defer_cnt > DFR_MAX) {
-		if (prandom_u32_max(2))
+		if (get_random_u32_below(2))
 			discard = list_entry(cache_defer_list.next,
 					     struct cache_deferred_req, recent);
 		else
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 915b9902f673..2e4987dcba29 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1619,7 +1619,7 @@ static int xs_get_random_port(void)
 	if (max < min)
 		return -EADDRINUSE;
 	range = max - min + 1;
-	rand = prandom_u32_max(range);
+	rand = get_random_u32_below(range);
 	return rand + min;
 }
 
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index e902b01ea3cb..b35c8701876a 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3010,7 +3010,7 @@ static int tipc_sk_insert(struct tipc_sock *tsk)
 	struct net *net = sock_net(sk);
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	u32 remaining = (TIPC_MAX_PORT - TIPC_MIN_PORT) + 1;
-	u32 portid = prandom_u32_max(remaining) + TIPC_MIN_PORT;
+	u32 portid = get_random_u32_below(remaining) + TIPC_MIN_PORT;
 
 	while (remaining--) {
 		portid++;
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 884eca7f6743..ff38c5a4d174 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -627,7 +627,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
 
 	if (!port)
 		port = LAST_RESERVED_PORT + 1 +
-			prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
+			get_random_u32_below(U32_MAX - LAST_RESERVED_PORT);
 
 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 3d2fe7712ac5..40f831854774 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2072,7 +2072,7 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
 	} else {
 		u32 spi = 0;
 		for (h = 0; h < high-low+1; h++) {
-			spi = low + prandom_u32_max(high - low + 1);
+			spi = low + get_random_u32_below(high - low + 1);
 			x0 = xfrm_state_lookup(net, mark, &x->id.daddr, htonl(spi), x->id.proto, x->props.family);
 			if (x0 == NULL) {
 				newspi = htonl(spi);
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v2 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop
  2022-11-14 16:45 [PATCH v2 0/3] convert tree to get_random_u32_{below,above,between}() Jason A. Donenfeld
  2022-11-14 16:45 ` [PATCH v2 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
@ 2022-11-14 16:45 ` Jason A. Donenfeld
  2022-11-14 16:45 ` [PATCH v2 3/3] treewide: use get_random_u32_between() when possible Jason A. Donenfeld
  2022-11-17 20:29 ` [PATCH v3 0/3] convert tree to get_random_u32_{below,above,inclusive}() Jason A. Donenfeld
  3 siblings, 0 replies; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-14 16:45 UTC (permalink / raw)
  To: linux-kernel, patches
  Cc: Jason A. Donenfeld, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Theodore Ts'o,
	Andreas Dilger, Jaegeuk Kim, Richard Weinberger,
	Darrick J . Wong, SeongJae Park, Thomas Gleixner, Andrew Morton,
	Michael Ellerman, Helge Deller, netdev, linux-crypto,
	linux-block, linux-fsdevel, linux-media, linux-arm-kernel,
	loongarch, linux-mips, linuxppc-dev, linux-mmc, linux-parisc

These cases were done with this Coccinelle:

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I > E);
+   I = get_random_u32_below(E + 1);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I >= E);
+   I = get_random_u32_below(E);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I < E);
+   I = get_random_u32_above(E - 1);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I <= E);
+   I = get_random_u32_above(E);

@@
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (!I);
+   I = get_random_u32_above(0);

@@
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I == 0);
+   I = get_random_u32_above(0);

@@
expression E;
@@
- E + 1 + get_random_u32_below(U32_MAX - E)
+ get_random_u32_above(E)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 fs/ext4/mmp.c            | 8 +-------
 lib/test_fprobe.c        | 5 +----
 lib/test_kprobes.c       | 5 +----
 net/ipv6/output_core.c   | 8 +-------
 net/vmw_vsock/af_vsock.c | 3 +--
 5 files changed, 5 insertions(+), 24 deletions(-)

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 588cb09c5291..4681fff6665f 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -262,13 +262,7 @@ void ext4_stop_mmpd(struct ext4_sb_info *sbi)
  */
 static unsigned int mmp_new_seq(void)
 {
-	u32 new_seq;
-
-	do {
-		new_seq = get_random_u32();
-	} while (new_seq > EXT4_MMP_SEQ_MAX);
-
-	return new_seq;
+	return get_random_u32_below(EXT4_MMP_SEQ_MAX + 1);
 }
 
 /*
diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c
index e0381b3ec410..1fb56cf5e5ce 100644
--- a/lib/test_fprobe.c
+++ b/lib/test_fprobe.c
@@ -144,10 +144,7 @@ static unsigned long get_ftrace_location(void *func)
 
 static int fprobe_test_init(struct kunit *test)
 {
-	do {
-		rand1 = get_random_u32();
-	} while (rand1 <= div_factor);
-
+	rand1 = get_random_u32_above(div_factor);
 	target = fprobe_selftest_target;
 	target2 = fprobe_selftest_target2;
 	target_ip = get_ftrace_location(target);
diff --git a/lib/test_kprobes.c b/lib/test_kprobes.c
index eeb1d728d974..1c95e5719802 100644
--- a/lib/test_kprobes.c
+++ b/lib/test_kprobes.c
@@ -339,10 +339,7 @@ static int kprobes_test_init(struct kunit *test)
 	stacktrace_target = kprobe_stacktrace_target;
 	internal_target = kprobe_stacktrace_internal_target;
 	stacktrace_driver = kprobe_stacktrace_driver;
-
-	do {
-		rand1 = get_random_u32();
-	} while (rand1 <= div_factor);
+	rand1 = get_random_u32_above(div_factor);
 	return 0;
 }
 
diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c
index 2685c3f15e9d..b5205311f372 100644
--- a/net/ipv6/output_core.c
+++ b/net/ipv6/output_core.c
@@ -15,13 +15,7 @@ static u32 __ipv6_select_ident(struct net *net,
 			       const struct in6_addr *dst,
 			       const struct in6_addr *src)
 {
-	u32 id;
-
-	do {
-		id = get_random_u32();
-	} while (!id);
-
-	return id;
+	return get_random_u32_above(0);
 }
 
 /* This function exists only for tap drivers that must support broken
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index ff38c5a4d174..d593d5b6d4b1 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -626,8 +626,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
 	struct sockaddr_vm new_addr;
 
 	if (!port)
-		port = LAST_RESERVED_PORT + 1 +
-			get_random_u32_below(U32_MAX - LAST_RESERVED_PORT);
+		port = get_random_u32_above(LAST_RESERVED_PORT);
 
 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-14 16:45 [PATCH v2 0/3] convert tree to get_random_u32_{below,above,between}() Jason A. Donenfeld
  2022-11-14 16:45 ` [PATCH v2 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
  2022-11-14 16:45 ` [PATCH v2 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop Jason A. Donenfeld
@ 2022-11-14 16:45 ` Jason A. Donenfeld
  2022-11-16 22:43   ` Kees Cook
  2022-11-17 20:29 ` [PATCH v3 0/3] convert tree to get_random_u32_{below,above,inclusive}() Jason A. Donenfeld
  3 siblings, 1 reply; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-14 16:45 UTC (permalink / raw)
  To: linux-kernel, patches
  Cc: Jason A. Donenfeld, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Theodore Ts'o,
	Andreas Dilger, Jaegeuk Kim, Richard Weinberger,
	Darrick J . Wong, SeongJae Park, Thomas Gleixner, Andrew Morton,
	Michael Ellerman, Helge Deller, netdev, linux-crypto,
	linux-block, linux-fsdevel, linux-media, linux-arm-kernel,
	loongarch, linux-mips, linuxppc-dev, linux-mmc, linux-parisc

These cases were done with this Coccinelle:

@@
expression H;
expression L;
@@
- (get_random_u32_below(H) + L)
+ get_random_u32_between(L, H + L)

@@
expression H;
expression L;
expression E;
@@
  get_random_u32_between(L,
  H
- + E
- - E
  )

@@
expression H;
expression L;
expression E;
@@
  get_random_u32_between(L,
  H
- - E
- + E
  )

@@
expression H;
expression L;
expression E;
expression F;
@@
  get_random_u32_between(L,
  H
- - E
  + F
- + E
  )

@@
expression H;
expression L;
expression E;
expression F;
@@
  get_random_u32_between(L,
  H
- + E
  + F
- - E
  )

And then subsequently cleaned up by hand, with several automatic cases
rejected if it didn't make sense contextually.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 arch/x86/kernel/module.c                      |  2 +-
 crypto/rsa-pkcs1pad.c                         |  2 +-
 crypto/testmgr.c                              | 10 ++++----
 drivers/bus/mhi/host/internal.h               |  2 +-
 drivers/dma-buf/st-dma-fence-chain.c          |  2 +-
 drivers/infiniband/core/cma.c                 |  2 +-
 drivers/infiniband/hw/hns/hns_roce_ah.c       |  5 ++--
 drivers/mtd/nand/raw/nandsim.c                |  2 +-
 drivers/net/wireguard/selftest/allowedips.c   |  8 +++---
 .../broadcom/brcm80211/brcmfmac/p2p.c         |  2 +-
 .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c |  2 +-
 fs/f2fs/segment.c                             |  6 ++---
 kernel/kcsan/selftest.c                       |  2 +-
 lib/test_hexdump.c                            | 10 ++++----
 lib/test_printf.c                             |  2 +-
 lib/test_vmalloc.c                            |  6 ++---
 mm/kasan/kasan_test.c                         |  6 ++---
 mm/kfence/kfence_test.c                       |  2 +-
 mm/swapfile.c                                 |  5 ++--
 net/bluetooth/mgmt.c                          |  5 ++--
 net/core/pktgen.c                             | 25 ++++++++-----------
 net/ipv4/tcp_input.c                          |  2 +-
 net/ipv6/addrconf.c                           |  6 ++---
 net/netfilter/nf_nat_helper.c                 |  2 +-
 net/xfrm/xfrm_state.c                         |  2 +-
 25 files changed, 56 insertions(+), 64 deletions(-)

diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index c09ae279ef32..9f74b7d71a50 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -53,7 +53,7 @@ static unsigned long int get_module_load_offset(void)
 		 */
 		if (module_load_offset == 0)
 			module_load_offset =
-				(get_random_u32_below(1024) + 1) * PAGE_SIZE;
+				get_random_u32_between(1, 1024 + 1) * PAGE_SIZE;
 		mutex_unlock(&module_kaslr_mutex);
 	}
 	return module_load_offset;
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index 0f722f8f779b..f31c94855a09 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -253,7 +253,7 @@ static int pkcs1pad_encrypt(struct akcipher_request *req)
 	ps_end = ctx->key_size - req->src_len - 2;
 	req_ctx->in_buf[0] = 0x02;
 	for (i = 1; i < ps_end; i++)
-		req_ctx->in_buf[i] = 1 + get_random_u32_below(255);
+		req_ctx->in_buf[i] = get_random_u32_between(1, 256);
 	req_ctx->in_buf[ps_end] = 0x00;
 
 	pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 079923d43ce2..b09b9408ec44 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -962,11 +962,11 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
 		if (div == &divs[max_divs - 1] || get_random_u32_below(2) == 0)
 			this_len = remaining;
 		else
-			this_len = 1 + get_random_u32_below(remaining);
+			this_len = get_random_u32_between(1, remaining + 1);
 		div->proportion_of_total = this_len;
 
 		if (get_random_u32_below(4) == 0)
-			div->offset = (PAGE_SIZE - 128) + get_random_u32_below(128);
+			div->offset = get_random_u32_between(PAGE_SIZE - 128, PAGE_SIZE);
 		else if (get_random_u32_below(2) == 0)
 			div->offset = get_random_u32_below(32);
 		else
@@ -1094,12 +1094,12 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 	}
 
 	if (get_random_u32_below(2) == 0) {
-		cfg->iv_offset = 1 + get_random_u32_below(MAX_ALGAPI_ALIGNMASK);
+		cfg->iv_offset = get_random_u32_between(1, MAX_ALGAPI_ALIGNMASK + 1);
 		p += scnprintf(p, end - p, " iv_offset=%u", cfg->iv_offset);
 	}
 
 	if (get_random_u32_below(2) == 0) {
-		cfg->key_offset = 1 + get_random_u32_below(MAX_ALGAPI_ALIGNMASK);
+		cfg->key_offset = get_random_u32_between(1, MAX_ALGAPI_ALIGNMASK + 1);
 		p += scnprintf(p, end - p, " key_offset=%u", cfg->key_offset);
 	}
 
@@ -1653,7 +1653,7 @@ static void generate_random_hash_testvec(struct shash_desc *desc,
 	if (maxkeysize) {
 		vec->ksize = maxkeysize;
 		if (get_random_u32_below(4) == 0)
-			vec->ksize = 1 + get_random_u32_below(maxkeysize);
+			vec->ksize = get_random_u32_between(1, maxkeysize + 1);
 		generate_random_bytes((u8 *)vec->key, vec->ksize);
 
 		vec->setkey_error = crypto_shash_setkey(desc->tfm, vec->key,
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index c73621aabbd1..cfb85d00ab6e 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -129,7 +129,7 @@ enum mhi_pm_state {
 #define PRIMARY_CMD_RING				0
 #define MHI_DEV_WAKE_DB					127
 #define MHI_MAX_MTU					0xffff
-#define MHI_RANDOM_U32_NONZERO(bmsk)			(get_random_u32_below(bmsk) + 1)
+#define MHI_RANDOM_U32_NONZERO(bmsk)			(get_random_u32_between(1, bmsk + 1))
 
 enum mhi_er_type {
 	MHI_ER_TYPE_INVALID = 0x0,
diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c
index 9fbad7317d9b..bb46b57cc230 100644
--- a/drivers/dma-buf/st-dma-fence-chain.c
+++ b/drivers/dma-buf/st-dma-fence-chain.c
@@ -400,7 +400,7 @@ static int __find_race(void *arg)
 		struct dma_fence *fence = dma_fence_get(data->fc.tail);
 		int seqno;
 
-		seqno = get_random_u32_below(data->fc.chain_length) + 1;
+		seqno = get_random_u32_between(1, data->fc.chain_length + 1);
 
 		err = dma_fence_chain_find_seqno(&fence, seqno);
 		if (err) {
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index dd1c703b10df..b5983b19513d 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3807,7 +3807,7 @@ static int cma_alloc_any_port(enum rdma_ucm_port_space ps,
 
 	inet_get_local_port_range(net, &low, &high);
 	remaining = (high - low) + 1;
-	rover = get_random_u32_below(remaining) + low;
+	rover = get_random_u32_between(low, remaining + low);
 retry:
 	if (last_used_port != rover) {
 		struct rdma_bind_list *bind_list;
diff --git a/drivers/infiniband/hw/hns/hns_roce_ah.c b/drivers/infiniband/hw/hns/hns_roce_ah.c
index b37d2a81584d..02481487b203 100644
--- a/drivers/infiniband/hw/hns/hns_roce_ah.c
+++ b/drivers/infiniband/hw/hns/hns_roce_ah.c
@@ -41,9 +41,8 @@ static inline u16 get_ah_udp_sport(const struct rdma_ah_attr *ah_attr)
 	u16 sport;
 
 	if (!fl)
-		sport = get_random_u32_below(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX +
-					     1 - IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
-			IB_ROCE_UDP_ENCAP_VALID_PORT_MIN;
+		sport = get_random_u32_between(IB_ROCE_UDP_ENCAP_VALID_PORT_MIN,
+					       IB_ROCE_UDP_ENCAP_VALID_PORT_MAX + 1);
 	else
 		sport = rdma_flow_label_to_udp_sport(fl);
 
diff --git a/drivers/mtd/nand/raw/nandsim.c b/drivers/mtd/nand/raw/nandsim.c
index 274a31b93100..d4d7c6dac001 100644
--- a/drivers/mtd/nand/raw/nandsim.c
+++ b/drivers/mtd/nand/raw/nandsim.c
@@ -1405,7 +1405,7 @@ static void ns_do_bit_flips(struct nandsim *ns, int num)
 	if (bitflips && get_random_u16() < (1 << 6)) {
 		int flips = 1;
 		if (bitflips > 1)
-			flips = get_random_u32_below(bitflips) + 1;
+			flips = get_random_u32_between(1, bitflips + 1);
 		while (flips--) {
 			int pos = get_random_u32_below(num * 8);
 			ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
diff --git a/drivers/net/wireguard/selftest/allowedips.c b/drivers/net/wireguard/selftest/allowedips.c
index 78a916f30c82..34d5981f4513 100644
--- a/drivers/net/wireguard/selftest/allowedips.c
+++ b/drivers/net/wireguard/selftest/allowedips.c
@@ -285,7 +285,7 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 4);
-		cidr = get_random_u32_below(32) + 1;
+		cidr = get_random_u32_between(1, 32 + 1);
 		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v4(&t, (struct in_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
@@ -311,7 +311,7 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = get_random_u32_below(32) + 1;
+			cidr = get_random_u32_between(1, 32 + 1);
 			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v4(&t,
 						    (struct in_addr *)mutated,
@@ -329,7 +329,7 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 16);
-		cidr = get_random_u32_below(128) + 1;
+		cidr = get_random_u32_between(1, 128 + 1);
 		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v6(&t, (struct in6_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
@@ -355,7 +355,7 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = get_random_u32_below(128) + 1;
+			cidr = get_random_u32_between(1, 128 + 1);
 			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v6(&t,
 						    (struct in6_addr *)mutated,
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 23c971b77965..0e6bf5e5c8a9 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -1128,7 +1128,7 @@ static void brcmf_p2p_afx_handler(struct work_struct *work)
 	if (afx_hdl->is_listen && afx_hdl->my_listen_chan)
 		/* 100ms ~ 300ms */
 		err = brcmf_p2p_discover_listen(p2p, afx_hdl->my_listen_chan,
-						100 * (1 + get_random_u32_below(3)));
+						100 * get_random_u32_between(1, 4));
 	else
 		err = brcmf_p2p_act_frm_search(p2p, afx_hdl->peer_listen_chan);
 
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
index 1696fbf1009a..f0b94633834e 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@@ -1099,7 +1099,7 @@ static void iwl_mvm_mac_ctxt_cmd_fill_ap(struct iwl_mvm *mvm,
 			iwl_mvm_mac_ap_iterator, &data);
 
 		if (data.beacon_device_ts) {
-			u32 rand = get_random_u32_below(64 - 36) + 36;
+			u32 rand = get_random_u32_between(36, 64);
 			mvmvif->ap_beacon_time = data.beacon_device_ts +
 				ieee80211_tu_to_usec(data.beacon_int * rand /
 						     100);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 334415d946f8..8319fdc59fb4 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2588,7 +2588,7 @@ static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
 	curseg->alloc_type = LFS;
 	if (F2FS_OPTION(sbi).fs_mode == FS_MODE_FRAGMENT_BLK)
 		curseg->fragment_remained_chunk =
-				get_random_u32_below(sbi->max_fragment_chunk) + 1;
+				get_random_u32_between(1, sbi->max_fragment_chunk + 1);
 }
 
 static int __next_free_blkoff(struct f2fs_sb_info *sbi,
@@ -2625,9 +2625,9 @@ static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
 			/* To allocate block chunks in different sizes, use random number */
 			if (--seg->fragment_remained_chunk <= 0) {
 				seg->fragment_remained_chunk =
-				   get_random_u32_below(sbi->max_fragment_chunk) + 1;
+				   get_random_u32_between(1, sbi->max_fragment_chunk + 1);
 				seg->next_blkoff +=
-				   get_random_u32_below(sbi->max_fragment_hole) + 1;
+				   get_random_u32_between(1, sbi->max_fragment_hole + 1);
 			}
 		}
 	}
diff --git a/kernel/kcsan/selftest.c b/kernel/kcsan/selftest.c
index 7b619f16a492..eed30ad29796 100644
--- a/kernel/kcsan/selftest.c
+++ b/kernel/kcsan/selftest.c
@@ -31,7 +31,7 @@ static bool __init test_encode_decode(void)
 	int i;
 
 	for (i = 0; i < ITERS_PER_TEST; ++i) {
-		size_t size = get_random_u32_below(MAX_ENCODABLE_SIZE) + 1;
+		size_t size = get_random_u32_between(1, MAX_ENCODABLE_SIZE + 1);
 		bool is_write = !!get_random_u32_below(2);
 		unsigned long verif_masked_addr;
 		long encoded_watchpoint;
diff --git a/lib/test_hexdump.c b/lib/test_hexdump.c
index efc50fd30a44..f4ff3041ec10 100644
--- a/lib/test_hexdump.c
+++ b/lib/test_hexdump.c
@@ -149,7 +149,7 @@ static void __init test_hexdump(size_t len, int rowsize, int groupsize,
 static void __init test_hexdump_set(int rowsize, bool ascii)
 {
 	size_t d = min_t(size_t, sizeof(data_b), rowsize);
-	size_t len = get_random_u32_below(d) + 1;
+	size_t len = get_random_u32_between(1, d + 1);
 
 	test_hexdump(len, rowsize, 4, ascii);
 	test_hexdump(len, rowsize, 2, ascii);
@@ -208,11 +208,11 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len,
 static void __init test_hexdump_overflow_set(size_t buflen, bool ascii)
 {
 	unsigned int i = 0;
-	int rs = (get_random_u32_below(2) + 1) * 16;
+	int rs = get_random_u32_between(1, 3) * 16;
 
 	do {
 		int gs = 1 << i;
-		size_t len = get_random_u32_below(rs) + gs;
+		size_t len = get_random_u32_between(gs, rs + gs);
 
 		test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, ascii);
 	} while (i++ < 3);
@@ -223,11 +223,11 @@ static int __init test_hexdump_init(void)
 	unsigned int i;
 	int rowsize;
 
-	rowsize = (get_random_u32_below(2) + 1) * 16;
+	rowsize = get_random_u32_between(1, 3) * 16;
 	for (i = 0; i < 16; i++)
 		test_hexdump_set(rowsize, false);
 
-	rowsize = (get_random_u32_below(2) + 1) * 16;
+	rowsize = get_random_u32_between(1, 3) * 16;
 	for (i = 0; i < 16; i++)
 		test_hexdump_set(rowsize, true);
 
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 6d10187eddac..da5efc8b8543 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -126,7 +126,7 @@ __test(const char *expect, int elen, const char *fmt, ...)
 	 * be able to print it as expected.
 	 */
 	failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
-	rand = 1 + get_random_u32_below(elen + 1);
+	rand = get_random_u32_between(1, elen + 2);
 	/* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 	failed_tests += do_test(rand, expect, elen, fmt, ap);
 	failed_tests += do_test(0, expect, elen, fmt, ap);
diff --git a/lib/test_vmalloc.c b/lib/test_vmalloc.c
index 104f09ea5fcc..7a2caf4596c5 100644
--- a/lib/test_vmalloc.c
+++ b/lib/test_vmalloc.c
@@ -151,7 +151,7 @@ static int random_size_alloc_test(void)
 	int i;
 
 	for (i = 0; i < test_loop_count; i++) {
-		n = get_random_u32_below(100) + 1;
+		n = get_random_u32_between(1, 101);
 		p = vmalloc(n * PAGE_SIZE);
 
 		if (!p)
@@ -291,12 +291,12 @@ pcpu_alloc_test(void)
 		return -1;
 
 	for (i = 0; i < 35000; i++) {
-		size = get_random_u32_below(PAGE_SIZE / 4) + 1;
+		size = get_random_u32_between(1, PAGE_SIZE / 4 + 1);
 
 		/*
 		 * Maximum PAGE_SIZE
 		 */
-		align = 1 << (get_random_u32_below(11) + 1);
+		align = 1 << get_random_u32_between(1, 12);
 
 		pcpu[i] = __alloc_percpu(size, align);
 		if (!pcpu[i])
diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c
index 640f9c7f8e44..6167e19056f0 100644
--- a/mm/kasan/kasan_test.c
+++ b/mm/kasan/kasan_test.c
@@ -1299,7 +1299,7 @@ static void match_all_not_assigned(struct kunit *test)
 	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
 
 	for (i = 0; i < 256; i++) {
-		size = get_random_u32_below(1024) + 1;
+		size = get_random_u32_between(1, 1024 + 1);
 		ptr = kmalloc(size, GFP_KERNEL);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
@@ -1308,7 +1308,7 @@ static void match_all_not_assigned(struct kunit *test)
 	}
 
 	for (i = 0; i < 256; i++) {
-		order = get_random_u32_below(4) + 1;
+		order = get_random_u32_between(1, 5);
 		pages = alloc_pages(GFP_KERNEL, order);
 		ptr = page_address(pages);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
@@ -1321,7 +1321,7 @@ static void match_all_not_assigned(struct kunit *test)
 		return;
 
 	for (i = 0; i < 256; i++) {
-		size = get_random_u32_below(1024) + 1;
+		size = get_random_u32_between(1, 1024 + 1);
 		ptr = vmalloc(size);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index 20028c179796..99abe86fc9b1 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -532,7 +532,7 @@ static void test_free_bulk(struct kunit *test)
 	int iter;
 
 	for (iter = 0; iter < 5; iter++) {
-		const size_t size = setup_test_cache(test, 8 + get_random_u32_below(300),
+		const size_t size = setup_test_cache(test, get_random_u32_between(8, 308),
 						     0, (iter & 1) ? ctor_set_x : NULL);
 		void *objects[] = {
 			test_alloc(test, size, GFP_KERNEL, ALLOCATE_RIGHT),
diff --git a/mm/swapfile.c b/mm/swapfile.c
index e9318305a24a..08f0152c32da 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -772,8 +772,7 @@ static void set_cluster_next(struct swap_info_struct *si, unsigned long next)
 		/* No free swap slots available */
 		if (si->highest_bit <= si->lowest_bit)
 			return;
-		next = si->lowest_bit +
-			get_random_u32_below(si->highest_bit - si->lowest_bit + 1);
+		next = get_random_u32_between(si->lowest_bit, si->highest_bit + 1);
 		next = ALIGN_DOWN(next, SWAP_ADDRESS_SPACE_PAGES);
 		next = max_t(unsigned int, next, si->lowest_bit);
 	}
@@ -3089,7 +3088,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 		 */
 		for_each_possible_cpu(cpu) {
 			per_cpu(*p->cluster_next_cpu, cpu) =
-				1 + get_random_u32_below(p->highest_bit);
+				get_random_u32_between(1, p->highest_bit + 1);
 		}
 		nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
 
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index b2f9679066c4..bab37a529db5 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -7373,9 +7373,8 @@ static int get_conn_info(struct sock *sk, struct hci_dev *hdev, void *data,
 	/* To avoid client trying to guess when to poll again for information we
 	 * calculate conn info age as random value between min/max set in hdev.
 	 */
-	conn_info_age = hdev->conn_info_min_age +
-			get_random_u32_below(hdev->conn_info_max_age -
-					     hdev->conn_info_min_age);
+	conn_info_age = get_random_u32_between(hdev->conn_info_min_age,
+					       hdev->conn_info_max_age);
 
 	/* Query controller to refresh cached values if they are too old or were
 	 * never read.
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 95da2ddc1c20..5eb401003368 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2380,9 +2380,8 @@ static void set_cur_queue_map(struct pktgen_dev *pkt_dev)
 	else if (pkt_dev->queue_map_min <= pkt_dev->queue_map_max) {
 		__u16 t;
 		if (pkt_dev->flags & F_QUEUE_MAP_RND) {
-			t = get_random_u32_below(pkt_dev->queue_map_max -
-						 pkt_dev->queue_map_min + 1) +
-			    pkt_dev->queue_map_min;
+			t = get_random_u32_between(pkt_dev->queue_map_min,
+						   pkt_dev->queue_map_max + 1);
 		} else {
 			t = pkt_dev->cur_queue_map + 1;
 			if (t > pkt_dev->queue_map_max)
@@ -2478,9 +2477,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 
 	if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
 		if (pkt_dev->flags & F_UDPSRC_RND)
-			pkt_dev->cur_udp_src = get_random_u32_below(
-				pkt_dev->udp_src_max - pkt_dev->udp_src_min) +
-				pkt_dev->udp_src_min;
+			pkt_dev->cur_udp_src = get_random_u32_between(pkt_dev->udp_src_min,
+								      pkt_dev->udp_src_max);
 
 		else {
 			pkt_dev->cur_udp_src++;
@@ -2491,9 +2489,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 
 	if (pkt_dev->udp_dst_min < pkt_dev->udp_dst_max) {
 		if (pkt_dev->flags & F_UDPDST_RND) {
-			pkt_dev->cur_udp_dst = get_random_u32_below(
-				pkt_dev->udp_dst_max - pkt_dev->udp_dst_min) +
-				pkt_dev->udp_dst_min;
+			pkt_dev->cur_udp_dst = get_random_u32_between(pkt_dev->udp_dst_min,
+								      pkt_dev->udp_dst_max);
 		} else {
 			pkt_dev->cur_udp_dst++;
 			if (pkt_dev->cur_udp_dst >= pkt_dev->udp_dst_max)
@@ -2508,7 +2505,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		if (imn < imx) {
 			__u32 t;
 			if (pkt_dev->flags & F_IPSRC_RND)
-				t = get_random_u32_below(imx - imn) + imn;
+				t = get_random_u32_between(imn, imx);
 			else {
 				t = ntohl(pkt_dev->cur_saddr);
 				t++;
@@ -2530,8 +2527,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 				if (pkt_dev->flags & F_IPDST_RND) {
 
 					do {
-						t = get_random_u32_below(imx - imn) +
-						    imn;
+						t = get_random_u32_between(imn, imx);
 						s = htonl(t);
 					} while (ipv4_is_loopback(s) ||
 						ipv4_is_multicast(s) ||
@@ -2578,9 +2574,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 	if (pkt_dev->min_pkt_size < pkt_dev->max_pkt_size) {
 		__u32 t;
 		if (pkt_dev->flags & F_TXSIZE_RND) {
-			t = get_random_u32_below(pkt_dev->max_pkt_size -
-						 pkt_dev->min_pkt_size) +
-			    pkt_dev->min_pkt_size;
+			t = get_random_u32_between(pkt_dev->min_pkt_size,
+						   pkt_dev->max_pkt_size);
 		} else {
 			t = pkt_dev->cur_pkt_size + 1;
 			if (t > pkt_dev->max_pkt_size)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3b076e5ba932..1a348298a99e 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3647,7 +3647,7 @@ static void tcp_send_challenge_ack(struct sock *sk)
 
 		WRITE_ONCE(net->ipv4.tcp_challenge_timestamp, now);
 		WRITE_ONCE(net->ipv4.tcp_challenge_count,
-			   half + get_random_u32_below(ack_limit));
+			   get_random_u32_between(half, ack_limit + half));
 	}
 	count = READ_ONCE(net->ipv4.tcp_challenge_count);
 	if (count > 0) {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index daf89a2eb492..3f750e6d0ac3 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -104,7 +104,7 @@ static inline u32 cstamp_delta(unsigned long cstamp)
 static inline s32 rfc3315_s14_backoff_init(s32 irt)
 {
 	/* multiply 'initial retransmission time' by 0.9 .. 1.1 */
-	u64 tmp = (900000 + get_random_u32_below(200001)) * (u64)irt;
+	u64 tmp = get_random_u32_between(900000, 1100001) * (u64)irt;
 	do_div(tmp, 1000000);
 	return (s32)tmp;
 }
@@ -112,11 +112,11 @@ static inline s32 rfc3315_s14_backoff_init(s32 irt)
 static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
 {
 	/* multiply 'retransmission timeout' by 1.9 .. 2.1 */
-	u64 tmp = (1900000 + get_random_u32_below(200001)) * (u64)rt;
+	u64 tmp = get_random_u32_between(1900000, 2100001) * (u64)rt;
 	do_div(tmp, 1000000);
 	if ((s32)tmp > mrt) {
 		/* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
-		tmp = (900000 + get_random_u32_below(200001)) * (u64)mrt;
+		tmp = get_random_u32_between(900000, 1100001) * (u64)mrt;
 		do_div(tmp, 1000000);
 	}
 	return (s32)tmp;
diff --git a/net/netfilter/nf_nat_helper.c b/net/netfilter/nf_nat_helper.c
index bf591e6af005..a12c3470f7fd 100644
--- a/net/netfilter/nf_nat_helper.c
+++ b/net/netfilter/nf_nat_helper.c
@@ -223,7 +223,7 @@ u16 nf_nat_exp_find_port(struct nf_conntrack_expect *exp, u16 port)
 		if (res != -EBUSY || (--attempts_left < 0))
 			break;
 
-		port = min + get_random_u32_below(range);
+		port = get_random_u32_between(min, range + min);
 	}
 
 	return 0;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 40f831854774..c118476f73ae 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2072,7 +2072,7 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
 	} else {
 		u32 spi = 0;
 		for (h = 0; h < high-low+1; h++) {
-			spi = low + get_random_u32_below(high - low + 1);
+			spi = get_random_u32_between(low, high + 1);
 			x0 = xfrm_state_lookup(net, mark, &x->id.daddr, htonl(spi), x->id.proto, x->props.family);
 			if (x0 == NULL) {
 				newspi = htonl(spi);
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 1/3] treewide: use get_random_u32_below() instead of deprecated function
  2022-11-14 16:45 ` [PATCH v2 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
@ 2022-11-14 17:35   ` Russell King (Oracle)
  0 siblings, 0 replies; 24+ messages in thread
From: Russell King (Oracle) @ 2022-11-14 17:35 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: linux-kernel, patches, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc

On Mon, Nov 14, 2022 at 05:45:56PM +0100, Jason A. Donenfeld wrote:
> This is a simple mechanical transformation done by:
> 
> @@
> expression E;
> @@
> - prandom_u32_max
> + get_random_u32_below
>   (E)
> 
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
> Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> ---
>  arch/arm/kernel/process.c                     |  2 +-

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-14 16:45 ` [PATCH v2 3/3] treewide: use get_random_u32_between() when possible Jason A. Donenfeld
@ 2022-11-16 22:43   ` Kees Cook
  2022-11-16 23:55     ` Jason A. Donenfeld
  0 siblings, 1 reply; 24+ messages in thread
From: Kees Cook @ 2022-11-16 22:43 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc

On Mon, Nov 14, 2022 at 05:45:58PM +0100, Jason A. Donenfeld wrote:
> -				(get_random_u32_below(1024) + 1) * PAGE_SIZE;
> +				get_random_u32_between(1, 1024 + 1) * PAGE_SIZE;

I really don't like "between". Can't this be named "inclusive" (and
avoid adding 1 everywhere, which seems ugly), or at least named
something less ambiguous?

> -		n = get_random_u32_below(100) + 1;
> +		n = get_random_u32_between(1, 101);

Because I find this much less readable. "Below 100" is clear: 0-99
inclusive, plus 1, so 1-100 inclusive. "Between 1 and 101" is not obvious
to me to mean: 1-100 inclusive.

These seem so much nicer:
	get_random_u32_inclusive(1, 1024)
	get_random_u32_inclusive(1, 100)

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-16 22:43   ` Kees Cook
@ 2022-11-16 23:55     ` Jason A. Donenfeld
  2022-11-17  0:03       ` Jason A. Donenfeld
  2022-11-17  2:05       ` Jason A. Donenfeld
  0 siblings, 2 replies; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-16 23:55 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On Wed, Nov 16, 2022 at 02:43:13PM -0800, Kees Cook wrote:
> On Mon, Nov 14, 2022 at 05:45:58PM +0100, Jason A. Donenfeld wrote:
> > -				(get_random_u32_below(1024) + 1) * PAGE_SIZE;
> > +				get_random_u32_between(1, 1024 + 1) * PAGE_SIZE;
> 
> I really don't like "between". Can't this be named "inclusive" (and
> avoid adding 1 everywhere, which seems ugly), or at least named
> something less ambiguous?
> 
> > -		n = get_random_u32_below(100) + 1;
> > +		n = get_random_u32_between(1, 101);
> 
> Because I find this much less readable. "Below 100" is clear: 0-99
> inclusive, plus 1, so 1-100 inclusive. "Between 1 and 101" is not obvious
> to me to mean: 1-100 inclusive.
> 
> These seem so much nicer:
> 	get_random_u32_inclusive(1, 1024)
> 	get_random_u32_inclusive(1, 100)

Yann pointed out something similar -- the half-closed interval being
confusing -- and while I was initially dismissive, I've warmed up to
doing this fully closed after sending a diff of that:

https://lore.kernel.org/lkml/Y3Qt8HiXj8giOnZy@zx2c4.com/

So okay, let's say that I'll implement the inclusive version instead. We
now have two problems to solve:

1) How/whether to make f(0, UR2_MAX) safe,
   - without additional 64-bit arithmetic,
   - minimizing the number of branches.
   I have a few ideas I'll code golf for a bit.

2) What to call it:
   - between I still like, because it mirrors "I'm thinking of a number
     between 1 and 10 and..." that everybody knows,
   - inclusive I guess works, but it's not a preposition,
   - bikeshed color #3?

I think I can make progress with (1) alone by fiddling around with
godbolt enough, like usual. I could use some more ideas for (2) though.

Jason

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-16 23:55     ` Jason A. Donenfeld
@ 2022-11-17  0:03       ` Jason A. Donenfeld
  2022-11-17  0:31         ` Kees Cook
  2022-11-17  2:05       ` Jason A. Donenfeld
  1 sibling, 1 reply; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17  0:03 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote:
> 2) What to call it:
>    - between I still like, because it mirrors "I'm thinking of a number
>      between 1 and 10 and..." that everybody knows,
>    - inclusive I guess works, but it's not a preposition,
>    - bikeshed color #3?

- between
- ranged
- spanning

https://www.thefreedictionary.com/List-of-prepositions.htm
- amid

Sigh, names.


^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-17  0:03       ` Jason A. Donenfeld
@ 2022-11-17  0:31         ` Kees Cook
  2022-11-17  0:43           ` Jason A. Donenfeld
  0 siblings, 1 reply; 24+ messages in thread
From: Kees Cook @ 2022-11-17  0:31 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On Thu, Nov 17, 2022 at 01:03:14AM +0100, Jason A. Donenfeld wrote:
> On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote:
> > 2) What to call it:
> >    - between I still like, because it mirrors "I'm thinking of a number
> >      between 1 and 10 and..." that everybody knows,
> >    - inclusive I guess works, but it's not a preposition,
> >    - bikeshed color #3?
> 
> - between
> - ranged
> - spanning
> 
> https://www.thefreedictionary.com/List-of-prepositions.htm
> - amid
> 
> Sigh, names.

I think "inclusive" is best. The other words still don't provide
unambiguous language. It's the language used in formal math, e.g.
sigma-notation, etc. It's an adjective for "get random" (verb, noun).

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-17  0:31         ` Kees Cook
@ 2022-11-17  0:43           ` Jason A. Donenfeld
  2022-11-17  0:47             ` Kees Cook
  0 siblings, 1 reply; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17  0:43 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On Wed, Nov 16, 2022 at 04:31:18PM -0800, Kees Cook wrote:
> On Thu, Nov 17, 2022 at 01:03:14AM +0100, Jason A. Donenfeld wrote:
> > On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote:
> > > 2) What to call it:
> > >    - between I still like, because it mirrors "I'm thinking of a number
> > >      between 1 and 10 and..." that everybody knows,
> > >    - inclusive I guess works, but it's not a preposition,
> > >    - bikeshed color #3?
> > 
> > - between
> > - ranged
> > - spanning
> > 
> > https://www.thefreedictionary.com/List-of-prepositions.htm
> > - amid
> > 
> > Sigh, names.
> 
> I think "inclusive" is best.

I find it not very descriptive of what the function does. Is there one
you like second best? Or are you convinced they're all much much much
worse than "inclusive" that they shouldn't be considered?

Jason

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-17  0:43           ` Jason A. Donenfeld
@ 2022-11-17  0:47             ` Kees Cook
  2022-11-17 15:42               ` Theodore Ts'o
  0 siblings, 1 reply; 24+ messages in thread
From: Kees Cook @ 2022-11-17  0:47 UTC (permalink / raw)
  To: Jason A. Donenfeld, Kees Cook
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On November 16, 2022 4:43:54 PM PST, "Jason A. Donenfeld" <Jason@zx2c4.com> wrote:
>On Wed, Nov 16, 2022 at 04:31:18PM -0800, Kees Cook wrote:
>> On Thu, Nov 17, 2022 at 01:03:14AM +0100, Jason A. Donenfeld wrote:
>> > On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote:
>> > > 2) What to call it:
>> > >    - between I still like, because it mirrors "I'm thinking of a number
>> > >      between 1 and 10 and..." that everybody knows,
>> > >    - inclusive I guess works, but it's not a preposition,
>> > >    - bikeshed color #3?
>> > 
>> > - between
>> > - ranged
>> > - spanning
>> > 
>> > https://www.thefreedictionary.com/List-of-prepositions.htm
>> > - amid
>> > 
>> > Sigh, names.
>> 
>> I think "inclusive" is best.
>
>I find it not very descriptive of what the function does. Is there one
>you like second best? Or are you convinced they're all much much much
>worse than "inclusive" that they shouldn't be considered?

Right, I don't think any are sufficiently descriptive. "Incluisve" with two arguments seems unambiguous and complete to me. :)


-- 
Kees Cook

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-16 23:55     ` Jason A. Donenfeld
  2022-11-17  0:03       ` Jason A. Donenfeld
@ 2022-11-17  2:05       ` Jason A. Donenfeld
  2022-11-17 10:32         ` Russell King (Oracle)
  1 sibling, 1 reply; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17  2:05 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote:
> 1) How/whether to make f(0, UR2_MAX) safe,
>    - without additional 64-bit arithmetic,
>    - minimizing the number of branches.
>    I have a few ideas I'll code golf for a bit.
> I think I can make progress with (1) alone by fiddling around with
> godbolt enough, like usual.

The code gen is definitely worse.

Original half-open interval:

    return floor + get_random_u32_below(ceil - floor);

Suggested fully closed interval:
	
    ceil = ceil - floor + 1;
    return likely(ceil) ? floor + get_random_u32_below(ceil) : get_random_u32();

Is the worse code gen actually worth it? Options:

 a) Decide worse codegen is worth it.
 b) Declare f(0, U32_MAX) undefined and just not handle it.
 c) Stick with original half-open interval that doesn't have this problem.

Jason

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-17  2:05       ` Jason A. Donenfeld
@ 2022-11-17 10:32         ` Russell King (Oracle)
  0 siblings, 0 replies; 24+ messages in thread
From: Russell King (Oracle) @ 2022-11-17 10:32 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: Kees Cook, linux-kernel, patches, Greg Kroah-Hartman,
	Jakub Kicinski, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On Thu, Nov 17, 2022 at 03:05:14AM +0100, Jason A. Donenfeld wrote:
> On Thu, Nov 17, 2022 at 12:55:47AM +0100, Jason A. Donenfeld wrote:
> > 1) How/whether to make f(0, UR2_MAX) safe,
> >    - without additional 64-bit arithmetic,
> >    - minimizing the number of branches.
> >    I have a few ideas I'll code golf for a bit.
> > I think I can make progress with (1) alone by fiddling around with
> > godbolt enough, like usual.
> 
> The code gen is definitely worse.
> 
> Original half-open interval:
> 
>     return floor + get_random_u32_below(ceil - floor);
> 
> Suggested fully closed interval:
> 	
>     ceil = ceil - floor + 1;
>     return likely(ceil) ? floor + get_random_u32_below(ceil) : get_random_u32();

How many of these uses are going to have ceil and floor as a variable?
If they're constants (e.g. due to being in an inline function with
constant arguments) then the compiler will optimise all of the above
and the assembly code will just be either:

1. a call to get_random_u32()
2. a call to get_random_u32_below() and an addition.

If one passes ceil or floor as a variable, then yes, the code gen is
going to be as complicated as you suggest above.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-17  0:47             ` Kees Cook
@ 2022-11-17 15:42               ` Theodore Ts'o
  2022-11-17 16:19                 ` Jason A. Donenfeld
  2022-11-17 22:15                 ` David Laight
  0 siblings, 2 replies; 24+ messages in thread
From: Theodore Ts'o @ 2022-11-17 15:42 UTC (permalink / raw)
  To: Kees Cook
  Cc: Jason A. Donenfeld, Kees Cook, linux-kernel, patches,
	Greg Kroah-Hartman, Jakub Kicinski, Russell King,
	Catalin Marinas, Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On Wed, Nov 16, 2022 at 04:47:27PM -0800, Kees Cook wrote:
> >> > - between
> >> > - ranged
> >> > - spanning
> >> > 
> >> > https://www.thefreedictionary.com/List-of-prepositions.htm
> >> > - amid
> >> > 
> >> > Sigh, names.
> >> 
> >> I think "inclusive" is best.
> >
> >I find it not very descriptive of what the function does. Is there one
> >you like second best? Or are you convinced they're all much much much
> >worse than "inclusive" that they shouldn't be considered?
> 
> Right, I don't think any are sufficiently descriptive. "Incluisve"
> with two arguments seems unambiguous and complete to me. :)

The problem with "between", "ranged", "spanning" is that they don't
tell the reader whether we're dealing with an "open interval" or a
"closed interval".  They are just different ways of saying that it's a
range between, say, 0 and 20.  But it doesn't tell you whether it
includes 0 or 20 or not.

The only way I can see for making it ambiguous is either to use the
terminology "closed interval" or "inclusive".  And "open" and "closed"
can have other meanings, so get_random_u32_inclusive() is going to be
less confusing than get_random_u32_closed().

Cheers,

					- Ted

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-17 15:42               ` Theodore Ts'o
@ 2022-11-17 16:19                 ` Jason A. Donenfeld
  2022-11-17 22:15                 ` David Laight
  1 sibling, 0 replies; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17 16:19 UTC (permalink / raw)
  To: Theodore Ts'o
  Cc: Kees Cook, Kees Cook, linux-kernel, patches, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

On Thu, Nov 17, 2022 at 10:42:37AM -0500, Theodore Ts'o wrote:
> On Wed, Nov 16, 2022 at 04:47:27PM -0800, Kees Cook wrote:
> > >> > - between
> > >> > - ranged
> > >> > - spanning
> > >> > 
> > >> > https://www.thefreedictionary.com/List-of-prepositions.htm
> > >> > - amid
> > >> > 
> > >> > Sigh, names.
> > >> 
> > >> I think "inclusive" is best.
> > >
> > >I find it not very descriptive of what the function does. Is there one
> > >you like second best? Or are you convinced they're all much much much
> > >worse than "inclusive" that they shouldn't be considered?
> > 
> > Right, I don't think any are sufficiently descriptive. "Incluisve"
> > with two arguments seems unambiguous and complete to me. :)
> 
> The problem with "between", "ranged", "spanning" is that they don't
> tell the reader whether we're dealing with an "open interval" or a
> "closed interval".  They are just different ways of saying that it's a
> range between, say, 0 and 20.  But it doesn't tell you whether it
> includes 0 or 20 or not.
> 
> The only way I can see for making it ambiguous is either to use the
> terminology "closed interval" or "inclusive".  And "open" and "closed"
> can have other meanings, so get_random_u32_inclusive() is going to be
> less confusing than get_random_u32_closed().

Alright, that about settles it then. I'll re-roll.

Jason

^ permalink raw reply	[flat|nested] 24+ messages in thread

* [PATCH v3 0/3] convert tree to get_random_u32_{below,above,inclusive}()
  2022-11-14 16:45 [PATCH v2 0/3] convert tree to get_random_u32_{below,above,between}() Jason A. Donenfeld
                   ` (2 preceding siblings ...)
  2022-11-14 16:45 ` [PATCH v2 3/3] treewide: use get_random_u32_between() when possible Jason A. Donenfeld
@ 2022-11-17 20:29 ` Jason A. Donenfeld
  2022-11-17 20:29   ` [PATCH v3 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
                     ` (2 more replies)
  3 siblings, 3 replies; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17 20:29 UTC (permalink / raw)
  To: linux-kernel, patches
  Cc: Jason A. Donenfeld, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Theodore Ts'o,
	Andreas Dilger, Jaegeuk Kim, Richard Weinberger,
	Darrick J . Wong, SeongJae Park, Thomas Gleixner, Andrew Morton,
	Michael Ellerman, Helge Deller, netdev, linux-crypto,
	linux-block, linux-fsdevel, linux-media, linux-arm-kernel,
	loongarch, linux-mips, linuxppc-dev, linux-mmc, linux-parisc

Hey everyone,

[Changes v2->v3: rename get_random_u32_between() to
 get_random_u32_inclusive(), and implement with closed interval.]

This series is the second tranche of tree-wide conversions to get random
integer handling a bit tamer. It's another Coccinelle-based patchset.

First we s/prandom_u32_max/get_random_u32_below/, since the former is
just a deprecated alias for the latter. Then later, we can remove
prandom_u32_max all together. I'm quite happy about finally being able
to do that. It means that prandom.h is now only for deterministic and
repeatable randomness, not non-deterministic/cryptographic randomness.
That line is no longer blurred.

In order to clean up a bunch of inefficient patterns, we use two simple
helper functions built on top of get_random_u32_below:
get_random_u32_above and get_random_u32_inclusive. The next two patches
convert some gnarly open-coded number juggling to use these helpers.

I've used Coccinelle for these three treewide patches, so hopefully
review is rather uneventful. I didn't accept all of the changes that
Coccinelle proposed, though, as these tend to be somewhat
context-specific. I erred on the side of just going with the most
obvious cases, at least this time through. And then we can address more
complicated cases through actual maintainer trees.

Since get_random_u32_below() and others sits in my random.git tree,
these patches too will flow through that same tree.

Regards,
Jason

Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Helge Deller <deller@gmx.de>
Cc: netdev@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-block@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: loongarch@lists.linux.dev
Cc: linux-mips@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-parisc@vger.kernel.org

Jason A. Donenfeld (3):
  treewide: use get_random_u32_below() instead of deprecated function
  treewide: use get_random_u32_{above,below}() instead of manual loop
  treewide: use get_random_u32_inclusive() when possible

 arch/arm/kernel/process.c                     |  2 +-
 arch/arm64/kernel/process.c                   |  2 +-
 arch/loongarch/kernel/process.c               |  2 +-
 arch/loongarch/kernel/vdso.c                  |  2 +-
 arch/mips/kernel/process.c                    |  2 +-
 arch/mips/kernel/vdso.c                       |  2 +-
 arch/parisc/kernel/vdso.c                     |  2 +-
 arch/powerpc/crypto/crc-vpmsum_test.c         |  4 +-
 arch/powerpc/kernel/process.c                 |  2 +-
 arch/s390/kernel/process.c                    |  2 +-
 arch/s390/kernel/vdso.c                       |  2 +-
 arch/sparc/vdso/vma.c                         |  2 +-
 arch/um/kernel/process.c                      |  2 +-
 arch/x86/entry/vdso/vma.c                     |  2 +-
 arch/x86/kernel/module.c                      |  2 +-
 arch/x86/kernel/process.c                     |  2 +-
 arch/x86/mm/pat/cpa-test.c                    |  4 +-
 crypto/rsa-pkcs1pad.c                         |  2 +-
 crypto/testmgr.c                              | 86 +++++++++----------
 drivers/block/drbd/drbd_receiver.c            |  4 +-
 drivers/bus/mhi/host/internal.h               |  2 +-
 drivers/dma-buf/st-dma-fence-chain.c          |  6 +-
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  2 +-
 .../drm/i915/gt/intel_execlists_submission.c  |  2 +-
 drivers/gpu/drm/i915/intel_memory_region.c    |  4 +-
 drivers/infiniband/core/cma.c                 |  2 +-
 drivers/infiniband/hw/cxgb4/id_table.c        |  4 +-
 drivers/infiniband/hw/hns/hns_roce_ah.c       |  5 +-
 drivers/infiniband/ulp/rtrs/rtrs-clt.c        |  2 +-
 drivers/md/bcache/request.c                   |  2 +-
 drivers/media/common/v4l2-tpg/v4l2-tpg-core.c |  8 +-
 .../media/test-drivers/vidtv/vidtv_demod.c    |  8 +-
 .../test-drivers/vivid/vivid-kthread-cap.c    |  2 +-
 .../test-drivers/vivid/vivid-kthread-out.c    |  2 +-
 .../media/test-drivers/vivid/vivid-radio-rx.c |  4 +-
 .../media/test-drivers/vivid/vivid-sdr-cap.c  |  2 +-
 .../test-drivers/vivid/vivid-touch-cap.c      |  2 +-
 drivers/mmc/core/core.c                       |  4 +-
 drivers/mmc/host/dw_mmc.c                     |  2 +-
 drivers/mtd/nand/raw/nandsim.c                |  4 +-
 drivers/mtd/tests/mtd_nandecctest.c           | 10 +--
 drivers/mtd/tests/stresstest.c                |  8 +-
 drivers/mtd/ubi/debug.c                       |  2 +-
 drivers/mtd/ubi/debug.h                       |  6 +-
 drivers/net/ethernet/broadcom/cnic.c          |  2 +-
 .../chelsio/inline_crypto/chtls/chtls_io.c    |  4 +-
 drivers/net/phy/at803x.c                      |  2 +-
 drivers/net/team/team_mode_random.c           |  2 +-
 drivers/net/wireguard/selftest/allowedips.c   | 20 ++---
 drivers/net/wireguard/timers.c                |  4 +-
 .../broadcom/brcm80211/brcmfmac/p2p.c         |  2 +-
 .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c |  2 +-
 drivers/pci/p2pdma.c                          |  2 +-
 drivers/s390/scsi/zfcp_fc.c                   |  2 +-
 drivers/scsi/fcoe/fcoe_ctlr.c                 |  4 +-
 drivers/scsi/qedi/qedi_main.c                 |  2 +-
 drivers/scsi/scsi_debug.c                     |  6 +-
 fs/ceph/inode.c                               |  2 +-
 fs/ceph/mdsmap.c                              |  2 +-
 fs/ext2/ialloc.c                              |  2 +-
 fs/ext4/ialloc.c                              |  2 +-
 fs/ext4/mmp.c                                 |  8 +-
 fs/ext4/super.c                               |  5 +-
 fs/f2fs/gc.c                                  |  2 +-
 fs/f2fs/segment.c                             |  8 +-
 fs/ubifs/debug.c                              |  8 +-
 fs/ubifs/lpt_commit.c                         | 14 +--
 fs/ubifs/tnc_commit.c                         |  2 +-
 fs/xfs/libxfs/xfs_alloc.c                     |  2 +-
 fs/xfs/libxfs/xfs_ialloc.c                    |  2 +-
 fs/xfs/xfs_error.c                            |  2 +-
 include/linux/damon.h                         |  2 +-
 include/linux/nodemask.h                      |  2 +-
 kernel/bpf/core.c                             |  4 +-
 kernel/kcsan/selftest.c                       |  4 +-
 kernel/locking/test-ww_mutex.c                |  4 +-
 kernel/time/clocksource.c                     |  2 +-
 lib/fault-inject.c                            |  2 +-
 lib/find_bit_benchmark.c                      |  4 +-
 lib/kobject.c                                 |  2 +-
 lib/reed_solomon/test_rslib.c                 |  6 +-
 lib/sbitmap.c                                 |  4 +-
 lib/test-string_helpers.c                     |  2 +-
 lib/test_fprobe.c                             |  5 +-
 lib/test_hexdump.c                            | 10 +--
 lib/test_kprobes.c                            |  5 +-
 lib/test_list_sort.c                          |  2 +-
 lib/test_printf.c                             |  2 +-
 lib/test_rhashtable.c                         |  6 +-
 lib/test_vmalloc.c                            |  8 +-
 mm/kasan/kasan_test.c                         |  6 +-
 mm/kfence/core.c                              |  4 +-
 mm/kfence/kfence_test.c                       |  4 +-
 mm/slub.c                                     |  2 +-
 mm/swapfile.c                                 |  5 +-
 net/802/garp.c                                |  2 +-
 net/802/mrp.c                                 |  2 +-
 net/batman-adv/bat_iv_ogm.c                   |  4 +-
 net/batman-adv/bat_v_elp.c                    |  2 +-
 net/batman-adv/bat_v_ogm.c                    |  4 +-
 net/batman-adv/network-coding.c               |  2 +-
 net/bluetooth/mgmt.c                          |  5 +-
 net/can/j1939/socket.c                        |  2 +-
 net/can/j1939/transport.c                     |  2 +-
 net/ceph/mon_client.c                         |  2 +-
 net/ceph/osd_client.c                         |  2 +-
 net/core/neighbour.c                          |  4 +-
 net/core/pktgen.c                             | 37 ++++----
 net/core/stream.c                             |  2 +-
 net/ipv4/icmp.c                               |  2 +-
 net/ipv4/igmp.c                               |  6 +-
 net/ipv4/inet_connection_sock.c               |  2 +-
 net/ipv4/inet_hashtables.c                    |  2 +-
 net/ipv4/route.c                              |  4 +-
 net/ipv4/tcp_bbr.c                            |  2 +-
 net/ipv4/tcp_input.c                          |  3 +-
 net/ipv6/addrconf.c                           |  8 +-
 net/ipv6/mcast.c                              | 10 +--
 net/ipv6/output_core.c                        |  8 +-
 net/ipv6/route.c                              |  2 +-
 net/netfilter/ipvs/ip_vs_twos.c               |  4 +-
 net/netfilter/nf_conntrack_core.c             |  4 +-
 net/netfilter/nf_nat_helper.c                 |  2 +-
 net/netlink/af_netlink.c                      |  2 +-
 net/packet/af_packet.c                        |  4 +-
 net/sched/act_gact.c                          |  2 +-
 net/sched/act_sample.c                        |  2 +-
 net/sched/sch_choke.c                         |  2 +-
 net/sched/sch_netem.c                         |  4 +-
 net/sctp/socket.c                             |  2 +-
 net/sctp/transport.c                          |  2 +-
 net/sunrpc/cache.c                            |  2 +-
 net/sunrpc/xprtsock.c                         |  2 +-
 net/tipc/socket.c                             |  2 +-
 net/vmw_vsock/af_vsock.c                      |  3 +-
 net/xfrm/xfrm_state.c                         |  2 +-
 136 files changed, 286 insertions(+), 313 deletions(-)

-- 
2.38.1

^ permalink raw reply	[flat|nested] 24+ messages in thread

* [PATCH v3 1/3] treewide: use get_random_u32_below() instead of deprecated function
  2022-11-17 20:29 ` [PATCH v3 0/3] convert tree to get_random_u32_{below,above,inclusive}() Jason A. Donenfeld
@ 2022-11-17 20:29   ` Jason A. Donenfeld
  2022-11-17 21:59     ` Kees Cook
  2022-11-17 20:29   ` [PATCH v3 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop Jason A. Donenfeld
  2022-11-17 20:29   ` [PATCH v3 3/3] treewide: use get_random_u32_inclusive() when possible Jason A. Donenfeld
  2 siblings, 1 reply; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17 20:29 UTC (permalink / raw)
  To: linux-kernel, patches
  Cc: Jason A. Donenfeld, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Theodore Ts'o,
	Andreas Dilger, Jaegeuk Kim, Richard Weinberger,
	Darrick J . Wong, SeongJae Park, Thomas Gleixner, Andrew Morton,
	Michael Ellerman, Helge Deller, netdev, linux-crypto,
	linux-block, linux-fsdevel, linux-media, linux-arm-kernel,
	loongarch, linux-mips, linuxppc-dev, linux-mmc, linux-parisc,
	Russell King, Ulf Hansson

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
  (E)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 arch/arm/kernel/process.c                     |  2 +-
 arch/arm64/kernel/process.c                   |  2 +-
 arch/loongarch/kernel/process.c               |  2 +-
 arch/loongarch/kernel/vdso.c                  |  2 +-
 arch/mips/kernel/process.c                    |  2 +-
 arch/mips/kernel/vdso.c                       |  2 +-
 arch/parisc/kernel/vdso.c                     |  2 +-
 arch/powerpc/crypto/crc-vpmsum_test.c         |  4 +-
 arch/powerpc/kernel/process.c                 |  2 +-
 arch/s390/kernel/process.c                    |  2 +-
 arch/s390/kernel/vdso.c                       |  2 +-
 arch/sparc/vdso/vma.c                         |  2 +-
 arch/um/kernel/process.c                      |  2 +-
 arch/x86/entry/vdso/vma.c                     |  2 +-
 arch/x86/kernel/module.c                      |  2 +-
 arch/x86/kernel/process.c                     |  2 +-
 arch/x86/mm/pat/cpa-test.c                    |  4 +-
 crypto/rsa-pkcs1pad.c                         |  2 +-
 crypto/testmgr.c                              | 86 +++++++++----------
 drivers/block/drbd/drbd_receiver.c            |  4 +-
 drivers/bus/mhi/host/internal.h               |  2 +-
 drivers/dma-buf/st-dma-fence-chain.c          |  6 +-
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  2 +-
 .../drm/i915/gt/intel_execlists_submission.c  |  2 +-
 drivers/gpu/drm/i915/intel_memory_region.c    |  4 +-
 drivers/infiniband/core/cma.c                 |  2 +-
 drivers/infiniband/hw/cxgb4/id_table.c        |  4 +-
 drivers/infiniband/hw/hns/hns_roce_ah.c       |  4 +-
 drivers/infiniband/ulp/rtrs/rtrs-clt.c        |  2 +-
 drivers/md/bcache/request.c                   |  2 +-
 drivers/media/common/v4l2-tpg/v4l2-tpg-core.c |  8 +-
 .../media/test-drivers/vidtv/vidtv_demod.c    |  8 +-
 .../test-drivers/vivid/vivid-kthread-cap.c    |  2 +-
 .../test-drivers/vivid/vivid-kthread-out.c    |  2 +-
 .../media/test-drivers/vivid/vivid-radio-rx.c |  4 +-
 .../media/test-drivers/vivid/vivid-sdr-cap.c  |  2 +-
 .../test-drivers/vivid/vivid-touch-cap.c      |  2 +-
 drivers/mmc/core/core.c                       |  4 +-
 drivers/mmc/host/dw_mmc.c                     |  2 +-
 drivers/mtd/nand/raw/nandsim.c                |  4 +-
 drivers/mtd/tests/mtd_nandecctest.c           | 10 +--
 drivers/mtd/tests/stresstest.c                |  8 +-
 drivers/mtd/ubi/debug.c                       |  2 +-
 drivers/mtd/ubi/debug.h                       |  6 +-
 drivers/net/ethernet/broadcom/cnic.c          |  2 +-
 .../chelsio/inline_crypto/chtls/chtls_io.c    |  4 +-
 drivers/net/phy/at803x.c                      |  2 +-
 drivers/net/team/team_mode_random.c           |  2 +-
 drivers/net/wireguard/selftest/allowedips.c   | 20 ++---
 drivers/net/wireguard/timers.c                |  4 +-
 .../broadcom/brcm80211/brcmfmac/p2p.c         |  2 +-
 .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c |  2 +-
 drivers/pci/p2pdma.c                          |  2 +-
 drivers/s390/scsi/zfcp_fc.c                   |  2 +-
 drivers/scsi/fcoe/fcoe_ctlr.c                 |  4 +-
 drivers/scsi/qedi/qedi_main.c                 |  2 +-
 drivers/scsi/scsi_debug.c                     |  6 +-
 fs/ceph/inode.c                               |  2 +-
 fs/ceph/mdsmap.c                              |  2 +-
 fs/ext2/ialloc.c                              |  2 +-
 fs/ext4/ialloc.c                              |  2 +-
 fs/ext4/super.c                               |  5 +-
 fs/f2fs/gc.c                                  |  2 +-
 fs/f2fs/segment.c                             |  8 +-
 fs/ubifs/debug.c                              |  8 +-
 fs/ubifs/lpt_commit.c                         | 14 +--
 fs/ubifs/tnc_commit.c                         |  2 +-
 fs/xfs/libxfs/xfs_alloc.c                     |  2 +-
 fs/xfs/libxfs/xfs_ialloc.c                    |  2 +-
 fs/xfs/xfs_error.c                            |  2 +-
 include/linux/damon.h                         |  2 +-
 include/linux/nodemask.h                      |  2 +-
 kernel/bpf/core.c                             |  4 +-
 kernel/kcsan/selftest.c                       |  4 +-
 kernel/locking/test-ww_mutex.c                |  4 +-
 kernel/time/clocksource.c                     |  2 +-
 lib/fault-inject.c                            |  2 +-
 lib/find_bit_benchmark.c                      |  4 +-
 lib/kobject.c                                 |  2 +-
 lib/reed_solomon/test_rslib.c                 |  6 +-
 lib/sbitmap.c                                 |  4 +-
 lib/test-string_helpers.c                     |  2 +-
 lib/test_hexdump.c                            | 10 +--
 lib/test_list_sort.c                          |  2 +-
 lib/test_printf.c                             |  2 +-
 lib/test_rhashtable.c                         |  6 +-
 lib/test_vmalloc.c                            |  8 +-
 mm/kasan/kasan_test.c                         |  6 +-
 mm/kfence/core.c                              |  4 +-
 mm/kfence/kfence_test.c                       |  4 +-
 mm/slub.c                                     |  2 +-
 mm/swapfile.c                                 |  4 +-
 net/802/garp.c                                |  2 +-
 net/802/mrp.c                                 |  2 +-
 net/batman-adv/bat_iv_ogm.c                   |  4 +-
 net/batman-adv/bat_v_elp.c                    |  2 +-
 net/batman-adv/bat_v_ogm.c                    |  4 +-
 net/batman-adv/network-coding.c               |  2 +-
 net/bluetooth/mgmt.c                          |  4 +-
 net/can/j1939/socket.c                        |  2 +-
 net/can/j1939/transport.c                     |  2 +-
 net/ceph/mon_client.c                         |  2 +-
 net/ceph/osd_client.c                         |  2 +-
 net/core/neighbour.c                          |  4 +-
 net/core/pktgen.c                             | 28 +++---
 net/core/stream.c                             |  2 +-
 net/ipv4/icmp.c                               |  2 +-
 net/ipv4/igmp.c                               |  6 +-
 net/ipv4/inet_connection_sock.c               |  2 +-
 net/ipv4/inet_hashtables.c                    |  2 +-
 net/ipv4/route.c                              |  4 +-
 net/ipv4/tcp_bbr.c                            |  2 +-
 net/ipv4/tcp_input.c                          |  3 +-
 net/ipv6/addrconf.c                           |  8 +-
 net/ipv6/mcast.c                              | 10 +--
 net/ipv6/route.c                              |  2 +-
 net/netfilter/ipvs/ip_vs_twos.c               |  4 +-
 net/netfilter/nf_conntrack_core.c             |  4 +-
 net/netfilter/nf_nat_helper.c                 |  2 +-
 net/netlink/af_netlink.c                      |  2 +-
 net/packet/af_packet.c                        |  4 +-
 net/sched/act_gact.c                          |  2 +-
 net/sched/act_sample.c                        |  2 +-
 net/sched/sch_choke.c                         |  2 +-
 net/sched/sch_netem.c                         |  4 +-
 net/sctp/socket.c                             |  2 +-
 net/sctp/transport.c                          |  2 +-
 net/sunrpc/cache.c                            |  2 +-
 net/sunrpc/xprtsock.c                         |  2 +-
 net/tipc/socket.c                             |  2 +-
 net/vmw_vsock/af_vsock.c                      |  2 +-
 net/xfrm/xfrm_state.c                         |  2 +-
 132 files changed, 280 insertions(+), 280 deletions(-)

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index a2b31d91a1b6..f811733a8fc5 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -371,7 +371,7 @@ static unsigned long sigpage_addr(const struct mm_struct *mm,
 
 	slots = ((last - first) >> PAGE_SHIFT) + 1;
 
-	offset = prandom_u32_max(slots);
+	offset = get_random_u32_below(slots);
 
 	addr = first + (offset << PAGE_SHIFT);
 
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 044a7d7f1f6a..1395a1638427 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -591,7 +591,7 @@ unsigned long __get_wchan(struct task_struct *p)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
 
diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/process.c
index 2526b68f1c0f..77952d814bad 100644
--- a/arch/loongarch/kernel/process.c
+++ b/arch/loongarch/kernel/process.c
@@ -293,7 +293,7 @@ unsigned long stack_top(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 
 	return sp & STACK_ALIGN;
 }
diff --git a/arch/loongarch/kernel/vdso.c b/arch/loongarch/kernel/vdso.c
index 8c9826062652..eaebd2e0f725 100644
--- a/arch/loongarch/kernel/vdso.c
+++ b/arch/loongarch/kernel/vdso.c
@@ -78,7 +78,7 @@ static unsigned long vdso_base(void)
 	unsigned long base = STACK_TOP;
 
 	if (current->flags & PF_RANDOMIZE) {
-		base += prandom_u32_max(VDSO_RANDOMIZE_SIZE);
+		base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
 		base = PAGE_ALIGN(base);
 	}
 
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index bbe9ce471791..093dbbd6b843 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -711,7 +711,7 @@ unsigned long mips_stack_top(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 
 	return sp & ALMASK;
 }
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index 5fd9bf1d596c..f6d40e43f108 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -79,7 +79,7 @@ static unsigned long vdso_base(void)
 	}
 
 	if (current->flags & PF_RANDOMIZE) {
-		base += prandom_u32_max(VDSO_RANDOMIZE_SIZE);
+		base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
 		base = PAGE_ALIGN(base);
 	}
 
diff --git a/arch/parisc/kernel/vdso.c b/arch/parisc/kernel/vdso.c
index 47e5960a2f96..c5cbfce7a84c 100644
--- a/arch/parisc/kernel/vdso.c
+++ b/arch/parisc/kernel/vdso.c
@@ -75,7 +75,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
 
 	map_base = mm->mmap_base;
 	if (current->flags & PF_RANDOMIZE)
-		map_base -= prandom_u32_max(0x20) * PAGE_SIZE;
+		map_base -= get_random_u32_below(0x20) * PAGE_SIZE;
 
 	vdso_text_start = get_unmapped_area(NULL, map_base, vdso_text_len, 0, 0);
 
diff --git a/arch/powerpc/crypto/crc-vpmsum_test.c b/arch/powerpc/crypto/crc-vpmsum_test.c
index 273c527868db..c61a874a3a5c 100644
--- a/arch/powerpc/crypto/crc-vpmsum_test.c
+++ b/arch/powerpc/crypto/crc-vpmsum_test.c
@@ -77,8 +77,8 @@ static int __init crc_test_init(void)
 
 		pr_info("crc-vpmsum_test begins, %lu iterations\n", iterations);
 		for (i=0; i<iterations; i++) {
-			size_t offset = prandom_u32_max(16);
-			size_t len = prandom_u32_max(MAX_CRC_LENGTH);
+			size_t offset = get_random_u32_below(16);
+			size_t len = get_random_u32_below(MAX_CRC_LENGTH);
 
 			if (len <= offset)
 				continue;
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 67da147fe34d..fcf604370c66 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2303,6 +2303,6 @@ void notrace __ppc64_runlatch_off(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 42af4b3aa02b..3f5d2db0b854 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -224,7 +224,7 @@ unsigned long __get_wchan(struct task_struct *p)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
 
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 3105ca5bd470..119328e1e2b3 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -227,7 +227,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned long len)
 	end -= len;
 
 	if (end > start) {
-		offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
+		offset = get_random_u32_below(((end - start) >> PAGE_SHIFT) + 1);
 		addr = start + (offset << PAGE_SHIFT);
 	} else {
 		addr = start;
diff --git a/arch/sparc/vdso/vma.c b/arch/sparc/vdso/vma.c
index ae9a86cb6f3d..136c78f28f8b 100644
--- a/arch/sparc/vdso/vma.c
+++ b/arch/sparc/vdso/vma.c
@@ -354,7 +354,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned int len)
 	unsigned int offset;
 
 	/* This loses some more bits than a modulo, but is cheaper */
-	offset = prandom_u32_max(PTRS_PER_PTE);
+	offset = get_random_u32_below(PTRS_PER_PTE);
 	return start + (offset << PAGE_SHIFT);
 }
 
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 010bc422a09d..e38f41444721 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -356,7 +356,7 @@ int singlestepping(void * t)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(8192);
+		sp -= get_random_u32_below(8192);
 	return sp & ~0xf;
 }
 #endif
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 311eae30e089..d45c5fcfeac2 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -327,7 +327,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
 	end -= len;
 
 	if (end > start) {
-		offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
+		offset = get_random_u32_below(((end - start) >> PAGE_SHIFT) + 1);
 		addr = start + (offset << PAGE_SHIFT);
 	} else {
 		addr = start;
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index c032edcd3d95..c09ae279ef32 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -53,7 +53,7 @@ static unsigned long int get_module_load_offset(void)
 		 */
 		if (module_load_offset == 0)
 			module_load_offset =
-				(prandom_u32_max(1024) + 1) * PAGE_SIZE;
+				(get_random_u32_below(1024) + 1) * PAGE_SIZE;
 		mutex_unlock(&module_kaslr_mutex);
 	}
 	return module_load_offset;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index c21b7347a26d..62671ccf0404 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -965,7 +965,7 @@ early_param("idle", idle_setup);
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(8192);
+		sp -= get_random_u32_below(8192);
 	return sp & ~0xf;
 }
 
diff --git a/arch/x86/mm/pat/cpa-test.c b/arch/x86/mm/pat/cpa-test.c
index 423b21e80929..3d2f7f0a6ed1 100644
--- a/arch/x86/mm/pat/cpa-test.c
+++ b/arch/x86/mm/pat/cpa-test.c
@@ -136,10 +136,10 @@ static int pageattr_test(void)
 	failed += print_split(&sa);
 
 	for (i = 0; i < NTEST; i++) {
-		unsigned long pfn = prandom_u32_max(max_pfn_mapped);
+		unsigned long pfn = get_random_u32_below(max_pfn_mapped);
 
 		addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
-		len[i] = prandom_u32_max(NPAGES);
+		len[i] = get_random_u32_below(NPAGES);
 		len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
 
 		if (len[i] == 0)
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index 3285e3af43e1..0f722f8f779b 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -253,7 +253,7 @@ static int pkcs1pad_encrypt(struct akcipher_request *req)
 	ps_end = ctx->key_size - req->src_len - 2;
 	req_ctx->in_buf[0] = 0x02;
 	for (i = 1; i < ps_end; i++)
-		req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
+		req_ctx->in_buf[i] = 1 + get_random_u32_below(255);
 	req_ctx->in_buf[ps_end] = 0x00;
 
 	pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index bcd059caa1c8..079923d43ce2 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -855,9 +855,9 @@ static int prepare_keybuf(const u8 *key, unsigned int ksize,
 /* Generate a random length in range [0, max_len], but prefer smaller values */
 static unsigned int generate_random_length(unsigned int max_len)
 {
-	unsigned int len = prandom_u32_max(max_len + 1);
+	unsigned int len = get_random_u32_below(max_len + 1);
 
-	switch (prandom_u32_max(4)) {
+	switch (get_random_u32_below(4)) {
 	case 0:
 		return len % 64;
 	case 1:
@@ -874,14 +874,14 @@ static void flip_random_bit(u8 *buf, size_t size)
 {
 	size_t bitpos;
 
-	bitpos = prandom_u32_max(size * 8);
+	bitpos = get_random_u32_below(size * 8);
 	buf[bitpos / 8] ^= 1 << (bitpos % 8);
 }
 
 /* Flip a random byte in the given nonempty data buffer */
 static void flip_random_byte(u8 *buf, size_t size)
 {
-	buf[prandom_u32_max(size)] ^= 0xff;
+	buf[get_random_u32_below(size)] ^= 0xff;
 }
 
 /* Sometimes make some random changes to the given nonempty data buffer */
@@ -891,15 +891,15 @@ static void mutate_buffer(u8 *buf, size_t size)
 	size_t i;
 
 	/* Sometimes flip some bits */
-	if (prandom_u32_max(4) == 0) {
-		num_flips = min_t(size_t, 1 << prandom_u32_max(8), size * 8);
+	if (get_random_u32_below(4) == 0) {
+		num_flips = min_t(size_t, 1 << get_random_u32_below(8), size * 8);
 		for (i = 0; i < num_flips; i++)
 			flip_random_bit(buf, size);
 	}
 
 	/* Sometimes flip some bytes */
-	if (prandom_u32_max(4) == 0) {
-		num_flips = min_t(size_t, 1 << prandom_u32_max(8), size);
+	if (get_random_u32_below(4) == 0) {
+		num_flips = min_t(size_t, 1 << get_random_u32_below(8), size);
 		for (i = 0; i < num_flips; i++)
 			flip_random_byte(buf, size);
 	}
@@ -915,11 +915,11 @@ static void generate_random_bytes(u8 *buf, size_t count)
 	if (count == 0)
 		return;
 
-	switch (prandom_u32_max(8)) { /* Choose a generation strategy */
+	switch (get_random_u32_below(8)) { /* Choose a generation strategy */
 	case 0:
 	case 1:
 		/* All the same byte, plus optional mutations */
-		switch (prandom_u32_max(4)) {
+		switch (get_random_u32_below(4)) {
 		case 0:
 			b = 0x00;
 			break;
@@ -959,24 +959,24 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
 		unsigned int this_len;
 		const char *flushtype_str;
 
-		if (div == &divs[max_divs - 1] || prandom_u32_max(2) == 0)
+		if (div == &divs[max_divs - 1] || get_random_u32_below(2) == 0)
 			this_len = remaining;
 		else
-			this_len = 1 + prandom_u32_max(remaining);
+			this_len = 1 + get_random_u32_below(remaining);
 		div->proportion_of_total = this_len;
 
-		if (prandom_u32_max(4) == 0)
-			div->offset = (PAGE_SIZE - 128) + prandom_u32_max(128);
-		else if (prandom_u32_max(2) == 0)
-			div->offset = prandom_u32_max(32);
+		if (get_random_u32_below(4) == 0)
+			div->offset = (PAGE_SIZE - 128) + get_random_u32_below(128);
+		else if (get_random_u32_below(2) == 0)
+			div->offset = get_random_u32_below(32);
 		else
-			div->offset = prandom_u32_max(PAGE_SIZE);
-		if (prandom_u32_max(8) == 0)
+			div->offset = get_random_u32_below(PAGE_SIZE);
+		if (get_random_u32_below(8) == 0)
 			div->offset_relative_to_alignmask = true;
 
 		div->flush_type = FLUSH_TYPE_NONE;
 		if (gen_flushes) {
-			switch (prandom_u32_max(4)) {
+			switch (get_random_u32_below(4)) {
 			case 0:
 				div->flush_type = FLUSH_TYPE_REIMPORT;
 				break;
@@ -988,7 +988,7 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
 
 		if (div->flush_type != FLUSH_TYPE_NONE &&
 		    !(req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) &&
-		    prandom_u32_max(2) == 0)
+		    get_random_u32_below(2) == 0)
 			div->nosimd = true;
 
 		switch (div->flush_type) {
@@ -1035,7 +1035,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 
 	p += scnprintf(p, end - p, "random:");
 
-	switch (prandom_u32_max(4)) {
+	switch (get_random_u32_below(4)) {
 	case 0:
 	case 1:
 		cfg->inplace_mode = OUT_OF_PLACE;
@@ -1050,12 +1050,12 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 		break;
 	}
 
-	if (prandom_u32_max(2) == 0) {
+	if (get_random_u32_below(2) == 0) {
 		cfg->req_flags |= CRYPTO_TFM_REQ_MAY_SLEEP;
 		p += scnprintf(p, end - p, " may_sleep");
 	}
 
-	switch (prandom_u32_max(4)) {
+	switch (get_random_u32_below(4)) {
 	case 0:
 		cfg->finalization_type = FINALIZATION_TYPE_FINAL;
 		p += scnprintf(p, end - p, " use_final");
@@ -1071,7 +1071,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 	}
 
 	if (!(cfg->req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) &&
-	    prandom_u32_max(2) == 0) {
+	    get_random_u32_below(2) == 0) {
 		cfg->nosimd = true;
 		p += scnprintf(p, end - p, " nosimd");
 	}
@@ -1084,7 +1084,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 					  cfg->req_flags);
 	p += scnprintf(p, end - p, "]");
 
-	if (cfg->inplace_mode == OUT_OF_PLACE && prandom_u32_max(2) == 0) {
+	if (cfg->inplace_mode == OUT_OF_PLACE && get_random_u32_below(2) == 0) {
 		p += scnprintf(p, end - p, " dst_divs=[");
 		p = generate_random_sgl_divisions(cfg->dst_divs,
 						  ARRAY_SIZE(cfg->dst_divs),
@@ -1093,13 +1093,13 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 		p += scnprintf(p, end - p, "]");
 	}
 
-	if (prandom_u32_max(2) == 0) {
-		cfg->iv_offset = 1 + prandom_u32_max(MAX_ALGAPI_ALIGNMASK);
+	if (get_random_u32_below(2) == 0) {
+		cfg->iv_offset = 1 + get_random_u32_below(MAX_ALGAPI_ALIGNMASK);
 		p += scnprintf(p, end - p, " iv_offset=%u", cfg->iv_offset);
 	}
 
-	if (prandom_u32_max(2) == 0) {
-		cfg->key_offset = 1 + prandom_u32_max(MAX_ALGAPI_ALIGNMASK);
+	if (get_random_u32_below(2) == 0) {
+		cfg->key_offset = 1 + get_random_u32_below(MAX_ALGAPI_ALIGNMASK);
 		p += scnprintf(p, end - p, " key_offset=%u", cfg->key_offset);
 	}
 
@@ -1652,8 +1652,8 @@ static void generate_random_hash_testvec(struct shash_desc *desc,
 	vec->ksize = 0;
 	if (maxkeysize) {
 		vec->ksize = maxkeysize;
-		if (prandom_u32_max(4) == 0)
-			vec->ksize = 1 + prandom_u32_max(maxkeysize);
+		if (get_random_u32_below(4) == 0)
+			vec->ksize = 1 + get_random_u32_below(maxkeysize);
 		generate_random_bytes((u8 *)vec->key, vec->ksize);
 
 		vec->setkey_error = crypto_shash_setkey(desc->tfm, vec->key,
@@ -2218,13 +2218,13 @@ static void mutate_aead_message(struct aead_testvec *vec, bool aad_iv,
 	const unsigned int aad_tail_size = aad_iv ? ivsize : 0;
 	const unsigned int authsize = vec->clen - vec->plen;
 
-	if (prandom_u32_max(2) == 0 && vec->alen > aad_tail_size) {
+	if (get_random_u32_below(2) == 0 && vec->alen > aad_tail_size) {
 		 /* Mutate the AAD */
 		flip_random_bit((u8 *)vec->assoc, vec->alen - aad_tail_size);
-		if (prandom_u32_max(2) == 0)
+		if (get_random_u32_below(2) == 0)
 			return;
 	}
-	if (prandom_u32_max(2) == 0) {
+	if (get_random_u32_below(2) == 0) {
 		/* Mutate auth tag (assuming it's at the end of ciphertext) */
 		flip_random_bit((u8 *)vec->ctext + vec->plen, authsize);
 	} else {
@@ -2249,7 +2249,7 @@ static void generate_aead_message(struct aead_request *req,
 	const unsigned int ivsize = crypto_aead_ivsize(tfm);
 	const unsigned int authsize = vec->clen - vec->plen;
 	const bool inauthentic = (authsize >= MIN_COLLISION_FREE_AUTHSIZE) &&
-				 (prefer_inauthentic || prandom_u32_max(4) == 0);
+				 (prefer_inauthentic || get_random_u32_below(4) == 0);
 
 	/* Generate the AAD. */
 	generate_random_bytes((u8 *)vec->assoc, vec->alen);
@@ -2257,7 +2257,7 @@ static void generate_aead_message(struct aead_request *req,
 		/* Avoid implementation-defined behavior. */
 		memcpy((u8 *)vec->assoc + vec->alen - ivsize, vec->iv, ivsize);
 
-	if (inauthentic && prandom_u32_max(2) == 0) {
+	if (inauthentic && get_random_u32_below(2) == 0) {
 		/* Generate a random ciphertext. */
 		generate_random_bytes((u8 *)vec->ctext, vec->clen);
 	} else {
@@ -2321,8 +2321,8 @@ static void generate_random_aead_testvec(struct aead_request *req,
 
 	/* Key: length in [0, maxkeysize], but usually choose maxkeysize */
 	vec->klen = maxkeysize;
-	if (prandom_u32_max(4) == 0)
-		vec->klen = prandom_u32_max(maxkeysize + 1);
+	if (get_random_u32_below(4) == 0)
+		vec->klen = get_random_u32_below(maxkeysize + 1);
 	generate_random_bytes((u8 *)vec->key, vec->klen);
 	vec->setkey_error = crypto_aead_setkey(tfm, vec->key, vec->klen);
 
@@ -2331,8 +2331,8 @@ static void generate_random_aead_testvec(struct aead_request *req,
 
 	/* Tag length: in [0, maxauthsize], but usually choose maxauthsize */
 	authsize = maxauthsize;
-	if (prandom_u32_max(4) == 0)
-		authsize = prandom_u32_max(maxauthsize + 1);
+	if (get_random_u32_below(4) == 0)
+		authsize = get_random_u32_below(maxauthsize + 1);
 	if (prefer_inauthentic && authsize < MIN_COLLISION_FREE_AUTHSIZE)
 		authsize = MIN_COLLISION_FREE_AUTHSIZE;
 	if (WARN_ON(authsize > maxdatasize))
@@ -2342,7 +2342,7 @@ static void generate_random_aead_testvec(struct aead_request *req,
 
 	/* AAD, plaintext, and ciphertext lengths */
 	total_len = generate_random_length(maxdatasize);
-	if (prandom_u32_max(4) == 0)
+	if (get_random_u32_below(4) == 0)
 		vec->alen = 0;
 	else
 		vec->alen = generate_random_length(total_len);
@@ -2958,8 +2958,8 @@ static void generate_random_cipher_testvec(struct skcipher_request *req,
 
 	/* Key: length in [0, maxkeysize], but usually choose maxkeysize */
 	vec->klen = maxkeysize;
-	if (prandom_u32_max(4) == 0)
-		vec->klen = prandom_u32_max(maxkeysize + 1);
+	if (get_random_u32_below(4) == 0)
+		vec->klen = get_random_u32_below(maxkeysize + 1);
 	generate_random_bytes((u8 *)vec->key, vec->klen);
 	vec->setkey_error = crypto_skcipher_setkey(tfm, vec->key, vec->klen);
 
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index ee69d50ba4fd..3eccc6cd5004 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -781,7 +781,7 @@ static struct socket *drbd_wait_for_connect(struct drbd_connection *connection,
 
 	timeo = connect_int * HZ;
 	/* 28.5% random jitter */
-	timeo += prandom_u32_max(2) ? timeo / 7 : -timeo / 7;
+	timeo += get_random_u32_below(2) ? timeo / 7 : -timeo / 7;
 
 	err = wait_for_completion_interruptible_timeout(&ad->door_bell, timeo);
 	if (err <= 0)
@@ -1004,7 +1004,7 @@ static int conn_connect(struct drbd_connection *connection)
 				drbd_warn(connection, "Error receiving initial packet\n");
 				sock_release(s);
 randomize:
-				if (prandom_u32_max(2))
+				if (get_random_u32_below(2))
 					goto retry;
 			}
 		}
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 01fd10a399b6..c73621aabbd1 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -129,7 +129,7 @@ enum mhi_pm_state {
 #define PRIMARY_CMD_RING				0
 #define MHI_DEV_WAKE_DB					127
 #define MHI_MAX_MTU					0xffff
-#define MHI_RANDOM_U32_NONZERO(bmsk)			(prandom_u32_max(bmsk) + 1)
+#define MHI_RANDOM_U32_NONZERO(bmsk)			(get_random_u32_below(bmsk) + 1)
 
 enum mhi_er_type {
 	MHI_ER_TYPE_INVALID = 0x0,
diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c
index 0a9b099d0518..9fbad7317d9b 100644
--- a/drivers/dma-buf/st-dma-fence-chain.c
+++ b/drivers/dma-buf/st-dma-fence-chain.c
@@ -400,7 +400,7 @@ static int __find_race(void *arg)
 		struct dma_fence *fence = dma_fence_get(data->fc.tail);
 		int seqno;
 
-		seqno = prandom_u32_max(data->fc.chain_length) + 1;
+		seqno = get_random_u32_below(data->fc.chain_length) + 1;
 
 		err = dma_fence_chain_find_seqno(&fence, seqno);
 		if (err) {
@@ -429,7 +429,7 @@ static int __find_race(void *arg)
 		dma_fence_put(fence);
 
 signal:
-		seqno = prandom_u32_max(data->fc.chain_length - 1);
+		seqno = get_random_u32_below(data->fc.chain_length - 1);
 		dma_fence_signal(data->fc.fences[seqno]);
 		cond_resched();
 	}
@@ -637,7 +637,7 @@ static void randomise_fences(struct fence_chains *fc)
 	while (--count) {
 		unsigned int swp;
 
-		swp = prandom_u32_max(count + 1);
+		swp = get_random_u32_below(count + 1);
 		if (swp == count)
 			continue;
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 845023c14eb3..29d2459bcc90 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2424,7 +2424,7 @@ gen8_dispatch_bsd_engine(struct drm_i915_private *dev_priv,
 	/* Check whether the file_priv has already selected one ring. */
 	if ((int)file_priv->bsd_engine < 0)
 		file_priv->bsd_engine =
-			prandom_u32_max(num_vcs_engines(dev_priv));
+			get_random_u32_below(num_vcs_engines(dev_priv));
 
 	return file_priv->bsd_engine;
 }
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index c718e6dc40b5..45b605e32c87 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -3689,7 +3689,7 @@ static void virtual_engine_initial_hint(struct virtual_engine *ve)
 	 * NB This does not force us to execute on this engine, it will just
 	 * typically be the first we inspect for submission.
 	 */
-	swp = prandom_u32_max(ve->num_siblings);
+	swp = get_random_u32_below(ve->num_siblings);
 	if (swp)
 		swap(ve->siblings[swp], ve->siblings[0]);
 }
diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index 9a4a7fb55582..b9a164efd6ae 100644
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -38,7 +38,7 @@ static int __iopagetest(struct intel_memory_region *mem,
 			u8 value, resource_size_t offset,
 			const void *caller)
 {
-	int byte = prandom_u32_max(pagesize);
+	int byte = get_random_u32_below(pagesize);
 	u8 result[3];
 
 	memset_io(va, value, pagesize); /* or GPF! */
@@ -92,7 +92,7 @@ static int iopagetest(struct intel_memory_region *mem,
 static resource_size_t random_page(resource_size_t last)
 {
 	/* Limited to low 44b (16TiB), but should suffice for a spot check */
-	return prandom_u32_max(last >> PAGE_SHIFT) << PAGE_SHIFT;
+	return get_random_u32_below(last >> PAGE_SHIFT) << PAGE_SHIFT;
 }
 
 static int iomemtest(struct intel_memory_region *mem,
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 26d1772179b8..dd1c703b10df 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3807,7 +3807,7 @@ static int cma_alloc_any_port(enum rdma_ucm_port_space ps,
 
 	inet_get_local_port_range(net, &low, &high);
 	remaining = (high - low) + 1;
-	rover = prandom_u32_max(remaining) + low;
+	rover = get_random_u32_below(remaining) + low;
 retry:
 	if (last_used_port != rover) {
 		struct rdma_bind_list *bind_list;
diff --git a/drivers/infiniband/hw/cxgb4/id_table.c b/drivers/infiniband/hw/cxgb4/id_table.c
index 280d61466855..e2188b335e76 100644
--- a/drivers/infiniband/hw/cxgb4/id_table.c
+++ b/drivers/infiniband/hw/cxgb4/id_table.c
@@ -54,7 +54,7 @@ u32 c4iw_id_alloc(struct c4iw_id_table *alloc)
 
 	if (obj < alloc->max) {
 		if (alloc->flags & C4IW_ID_TABLE_F_RANDOM)
-			alloc->last += prandom_u32_max(RANDOM_SKIP);
+			alloc->last += get_random_u32_below(RANDOM_SKIP);
 		else
 			alloc->last = obj + 1;
 		if (alloc->last >= alloc->max)
@@ -85,7 +85,7 @@ int c4iw_id_table_alloc(struct c4iw_id_table *alloc, u32 start, u32 num,
 	alloc->start = start;
 	alloc->flags = flags;
 	if (flags & C4IW_ID_TABLE_F_RANDOM)
-		alloc->last = prandom_u32_max(RANDOM_SKIP);
+		alloc->last = get_random_u32_below(RANDOM_SKIP);
 	else
 		alloc->last = 0;
 	alloc->max = num;
diff --git a/drivers/infiniband/hw/hns/hns_roce_ah.c b/drivers/infiniband/hw/hns/hns_roce_ah.c
index 480c062dd04f..b37d2a81584d 100644
--- a/drivers/infiniband/hw/hns/hns_roce_ah.c
+++ b/drivers/infiniband/hw/hns/hns_roce_ah.c
@@ -41,8 +41,8 @@ static inline u16 get_ah_udp_sport(const struct rdma_ah_attr *ah_attr)
 	u16 sport;
 
 	if (!fl)
-		sport = prandom_u32_max(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX + 1 -
-					IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
+		sport = get_random_u32_below(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX +
+					     1 - IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
 			IB_ROCE_UDP_ENCAP_VALID_PORT_MIN;
 	else
 		sport = rdma_flow_label_to_udp_sport(fl);
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index 8546b8816524..ab75b690ad08 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -1517,7 +1517,7 @@ static void rtrs_clt_err_recovery_work(struct work_struct *work)
 	rtrs_clt_stop_and_destroy_conns(clt_path);
 	queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork,
 			   msecs_to_jiffies(delay_ms +
-					    prandom_u32_max(RTRS_RECONNECT_SEED)));
+					    get_random_u32_below(RTRS_RECONNECT_SEED)));
 }
 
 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt,
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 3427555b0cca..32e21ba64357 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -401,7 +401,7 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
 	}
 
 	if (bypass_torture_test(dc)) {
-		if (prandom_u32_max(4) == 3)
+		if (get_random_u32_below(4) == 3)
 			goto skip;
 		else
 			goto rescale;
diff --git a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
index 303d02b1d71c..a366566f22c3 100644
--- a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
+++ b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c
@@ -872,7 +872,7 @@ static void precalculate_color(struct tpg_data *tpg, int k)
 	} else if (tpg->pattern == TPG_PAT_NOISE) {
 		r = g = b = get_random_u8();
 	} else if (k == TPG_COLOR_RANDOM) {
-		r = g = b = tpg->qual_offset + prandom_u32_max(196);
+		r = g = b = tpg->qual_offset + get_random_u32_below(196);
 	} else if (k >= TPG_COLOR_RAMP) {
 		r = g = b = k - TPG_COLOR_RAMP;
 	}
@@ -2286,7 +2286,7 @@ static void tpg_fill_params_extras(const struct tpg_data *tpg,
 		params->wss_width = tpg->crop.width;
 	params->wss_width = tpg_hscale_div(tpg, p, params->wss_width);
 	params->wss_random_offset =
-		params->twopixsize * prandom_u32_max(tpg->src_width / 2);
+		params->twopixsize * get_random_u32_below(tpg->src_width / 2);
 
 	if (tpg->crop.left < tpg->border.left) {
 		left_pillar_width = tpg->border.left - tpg->crop.left;
@@ -2495,9 +2495,9 @@ static void tpg_fill_plane_pattern(const struct tpg_data *tpg,
 		linestart_newer = tpg->black_line[p];
 	} else if (tpg->pattern == TPG_PAT_NOISE || tpg->qual == TPG_QUAL_NOISE) {
 		linestart_older = tpg->random_line[p] +
-				  twopixsize * prandom_u32_max(tpg->src_width / 2);
+				  twopixsize * get_random_u32_below(tpg->src_width / 2);
 		linestart_newer = tpg->random_line[p] +
-				  twopixsize * prandom_u32_max(tpg->src_width / 2);
+				  twopixsize * get_random_u32_below(tpg->src_width / 2);
 	} else {
 		unsigned frame_line_old =
 			(frame_line + mv_vert_old) % tpg->src_height;
diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.c b/drivers/media/test-drivers/vidtv/vidtv_demod.c
index e7959ab1add8..d60c6d16beea 100644
--- a/drivers/media/test-drivers/vidtv/vidtv_demod.c
+++ b/drivers/media/test-drivers/vidtv/vidtv_demod.c
@@ -188,11 +188,11 @@ static void vidtv_demod_update_stats(struct dvb_frontend *fe)
 	 * Also, usually, signal strength is a negative number in dBm.
 	 */
 	c->strength.stat[0].svalue = state->tuner_cnr;
-	c->strength.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50);
+	c->strength.stat[0].svalue -= get_random_u32_below(state->tuner_cnr / 50);
 	c->strength.stat[0].svalue -= 68000; /* Adjust to a better range */
 
 	c->cnr.stat[0].svalue = state->tuner_cnr;
-	c->cnr.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50);
+	c->cnr.stat[0].svalue -= get_random_u32_below(state->tuner_cnr / 50);
 }
 
 static int vidtv_demod_read_status(struct dvb_frontend *fe,
@@ -213,11 +213,11 @@ static int vidtv_demod_read_status(struct dvb_frontend *fe,
 
 		if (snr < cnr2qual->cnr_ok) {
 			/* eventually lose the TS lock */
-			if (prandom_u32_max(100) < config->drop_tslock_prob_on_low_snr)
+			if (get_random_u32_below(100) < config->drop_tslock_prob_on_low_snr)
 				state->status = 0;
 		} else {
 			/* recover if the signal improves */
-			if (prandom_u32_max(100) <
+			if (get_random_u32_below(100) <
 			    config->recover_tslock_prob_on_good_snr)
 				state->status = FE_HAS_SIGNAL  |
 						FE_HAS_CARRIER |
diff --git a/drivers/media/test-drivers/vivid/vivid-kthread-cap.c b/drivers/media/test-drivers/vivid/vivid-kthread-cap.c
index 690daada7db4..ee65d20314d3 100644
--- a/drivers/media/test-drivers/vivid/vivid-kthread-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-kthread-cap.c
@@ -693,7 +693,7 @@ static noinline_for_stack void vivid_thread_vid_cap_tick(struct vivid_dev *dev,
 
 	/* Drop a certain percentage of buffers. */
 	if (dev->perc_dropped_buffers &&
-	    prandom_u32_max(100) < dev->perc_dropped_buffers)
+	    get_random_u32_below(100) < dev->perc_dropped_buffers)
 		goto update_mv;
 
 	spin_lock(&dev->slock);
diff --git a/drivers/media/test-drivers/vivid/vivid-kthread-out.c b/drivers/media/test-drivers/vivid/vivid-kthread-out.c
index 0833e021bb11..fac6208b51da 100644
--- a/drivers/media/test-drivers/vivid/vivid-kthread-out.c
+++ b/drivers/media/test-drivers/vivid/vivid-kthread-out.c
@@ -51,7 +51,7 @@ static void vivid_thread_vid_out_tick(struct vivid_dev *dev)
 
 	/* Drop a certain percentage of buffers. */
 	if (dev->perc_dropped_buffers &&
-	    prandom_u32_max(100) < dev->perc_dropped_buffers)
+	    get_random_u32_below(100) < dev->perc_dropped_buffers)
 		return;
 
 	spin_lock(&dev->slock);
diff --git a/drivers/media/test-drivers/vivid/vivid-radio-rx.c b/drivers/media/test-drivers/vivid/vivid-radio-rx.c
index 8bd09589fb15..79c1723bd84c 100644
--- a/drivers/media/test-drivers/vivid/vivid-radio-rx.c
+++ b/drivers/media/test-drivers/vivid/vivid-radio-rx.c
@@ -94,8 +94,8 @@ ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
 
 		if (data_blk == 0 && dev->radio_rds_loop)
 			vivid_radio_rds_init(dev);
-		if (perc && prandom_u32_max(100) < perc) {
-			switch (prandom_u32_max(4)) {
+		if (perc && get_random_u32_below(100) < perc) {
+			switch (get_random_u32_below(4)) {
 			case 0:
 				rds.block |= V4L2_RDS_BLOCK_CORRECTED;
 				break;
diff --git a/drivers/media/test-drivers/vivid/vivid-sdr-cap.c b/drivers/media/test-drivers/vivid/vivid-sdr-cap.c
index 0ae5628b86c9..a81f26b76988 100644
--- a/drivers/media/test-drivers/vivid/vivid-sdr-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-sdr-cap.c
@@ -90,7 +90,7 @@ static void vivid_thread_sdr_cap_tick(struct vivid_dev *dev)
 
 	/* Drop a certain percentage of buffers. */
 	if (dev->perc_dropped_buffers &&
-	    prandom_u32_max(100) < dev->perc_dropped_buffers)
+	    get_random_u32_below(100) < dev->perc_dropped_buffers)
 		return;
 
 	spin_lock(&dev->slock);
diff --git a/drivers/media/test-drivers/vivid/vivid-touch-cap.c b/drivers/media/test-drivers/vivid/vivid-touch-cap.c
index 6cc32eb54f9d..c7f6e23df51e 100644
--- a/drivers/media/test-drivers/vivid/vivid-touch-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-touch-cap.c
@@ -221,7 +221,7 @@ static void vivid_fill_buff_noise(__s16 *tch_buf, int size)
 
 static inline int get_random_pressure(void)
 {
-	return prandom_u32_max(VIVID_PRESSURE_LIMIT);
+	return get_random_u32_below(VIVID_PRESSURE_LIMIT);
 }
 
 static void vivid_tch_buf_set(struct v4l2_pix_format *f,
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 95fa8fb1d45f..a1efda85c6f2 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -97,8 +97,8 @@ static void mmc_should_fail_request(struct mmc_host *host,
 	    !should_fail(&host->fail_mmc_request, data->blksz * data->blocks))
 		return;
 
-	data->error = data_errors[prandom_u32_max(ARRAY_SIZE(data_errors))];
-	data->bytes_xfered = prandom_u32_max(data->bytes_xfered >> 9) << 9;
+	data->error = data_errors[get_random_u32_below(ARRAY_SIZE(data_errors))];
+	data->bytes_xfered = get_random_u32_below(data->bytes_xfered >> 9) << 9;
 }
 
 #else /* CONFIG_FAIL_MMC_REQUEST */
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index c78bbc22e0d1..6ef410053037 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1858,7 +1858,7 @@ static void dw_mci_start_fault_timer(struct dw_mci *host)
 	 * Try to inject the error at random points during the data transfer.
 	 */
 	hrtimer_start(&host->fault_timer,
-		      ms_to_ktime(prandom_u32_max(25)),
+		      ms_to_ktime(get_random_u32_below(25)),
 		      HRTIMER_MODE_REL);
 }
 
diff --git a/drivers/mtd/nand/raw/nandsim.c b/drivers/mtd/nand/raw/nandsim.c
index 672719023241..274a31b93100 100644
--- a/drivers/mtd/nand/raw/nandsim.c
+++ b/drivers/mtd/nand/raw/nandsim.c
@@ -1405,9 +1405,9 @@ static void ns_do_bit_flips(struct nandsim *ns, int num)
 	if (bitflips && get_random_u16() < (1 << 6)) {
 		int flips = 1;
 		if (bitflips > 1)
-			flips = prandom_u32_max(bitflips) + 1;
+			flips = get_random_u32_below(bitflips) + 1;
 		while (flips--) {
-			int pos = prandom_u32_max(num * 8);
+			int pos = get_random_u32_below(num * 8);
 			ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
 			NS_WARN("read_page: flipping bit %d in page %d "
 				"reading from %d ecc: corrected=%u failed=%u\n",
diff --git a/drivers/mtd/tests/mtd_nandecctest.c b/drivers/mtd/tests/mtd_nandecctest.c
index 440988562cfd..824cc1c03b6a 100644
--- a/drivers/mtd/tests/mtd_nandecctest.c
+++ b/drivers/mtd/tests/mtd_nandecctest.c
@@ -47,7 +47,7 @@ struct nand_ecc_test {
 static void single_bit_error_data(void *error_data, void *correct_data,
 				size_t size)
 {
-	unsigned int offset = prandom_u32_max(size * BITS_PER_BYTE);
+	unsigned int offset = get_random_u32_below(size * BITS_PER_BYTE);
 
 	memcpy(error_data, correct_data, size);
 	__change_bit_le(offset, error_data);
@@ -58,9 +58,9 @@ static void double_bit_error_data(void *error_data, void *correct_data,
 {
 	unsigned int offset[2];
 
-	offset[0] = prandom_u32_max(size * BITS_PER_BYTE);
+	offset[0] = get_random_u32_below(size * BITS_PER_BYTE);
 	do {
-		offset[1] = prandom_u32_max(size * BITS_PER_BYTE);
+		offset[1] = get_random_u32_below(size * BITS_PER_BYTE);
 	} while (offset[0] == offset[1]);
 
 	memcpy(error_data, correct_data, size);
@@ -71,7 +71,7 @@ static void double_bit_error_data(void *error_data, void *correct_data,
 
 static unsigned int random_ecc_bit(size_t size)
 {
-	unsigned int offset = prandom_u32_max(3 * BITS_PER_BYTE);
+	unsigned int offset = get_random_u32_below(3 * BITS_PER_BYTE);
 
 	if (size == 256) {
 		/*
@@ -79,7 +79,7 @@ static unsigned int random_ecc_bit(size_t size)
 		 * and 17th bit) in ECC code for 256 byte data block
 		 */
 		while (offset == 16 || offset == 17)
-			offset = prandom_u32_max(3 * BITS_PER_BYTE);
+			offset = get_random_u32_below(3 * BITS_PER_BYTE);
 	}
 
 	return offset;
diff --git a/drivers/mtd/tests/stresstest.c b/drivers/mtd/tests/stresstest.c
index 75b6ddc5dc4d..8062098930d6 100644
--- a/drivers/mtd/tests/stresstest.c
+++ b/drivers/mtd/tests/stresstest.c
@@ -46,7 +46,7 @@ static int rand_eb(void)
 
 again:
 	/* Read or write up 2 eraseblocks at a time - hence 'ebcnt - 1' */
-	eb = prandom_u32_max(ebcnt - 1);
+	eb = get_random_u32_below(ebcnt - 1);
 	if (bbt[eb])
 		goto again;
 	return eb;
@@ -54,12 +54,12 @@ static int rand_eb(void)
 
 static int rand_offs(void)
 {
-	return prandom_u32_max(bufsize);
+	return get_random_u32_below(bufsize);
 }
 
 static int rand_len(int offs)
 {
-	return prandom_u32_max(bufsize - offs);
+	return get_random_u32_below(bufsize - offs);
 }
 
 static int do_read(void)
@@ -118,7 +118,7 @@ static int do_write(void)
 
 static int do_operation(void)
 {
-	if (prandom_u32_max(2))
+	if (get_random_u32_below(2))
 		return do_read();
 	else
 		return do_write();
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index 908d0e088557..fcca6942dbdd 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -590,7 +590,7 @@ int ubi_dbg_power_cut(struct ubi_device *ubi, int caller)
 
 		if (ubi->dbg.power_cut_max > ubi->dbg.power_cut_min) {
 			range = ubi->dbg.power_cut_max - ubi->dbg.power_cut_min;
-			ubi->dbg.power_cut_counter += prandom_u32_max(range);
+			ubi->dbg.power_cut_counter += get_random_u32_below(range);
 		}
 		return 0;
 	}
diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h
index dc8d8f83657a..23676f32b681 100644
--- a/drivers/mtd/ubi/debug.h
+++ b/drivers/mtd/ubi/debug.h
@@ -73,7 +73,7 @@ static inline int ubi_dbg_is_bgt_disabled(const struct ubi_device *ubi)
 static inline int ubi_dbg_is_bitflip(const struct ubi_device *ubi)
 {
 	if (ubi->dbg.emulate_bitflips)
-		return !prandom_u32_max(200);
+		return !get_random_u32_below(200);
 	return 0;
 }
 
@@ -87,7 +87,7 @@ static inline int ubi_dbg_is_bitflip(const struct ubi_device *ubi)
 static inline int ubi_dbg_is_write_failure(const struct ubi_device *ubi)
 {
 	if (ubi->dbg.emulate_io_failures)
-		return !prandom_u32_max(500);
+		return !get_random_u32_below(500);
 	return 0;
 }
 
@@ -101,7 +101,7 @@ static inline int ubi_dbg_is_write_failure(const struct ubi_device *ubi)
 static inline int ubi_dbg_is_erase_failure(const struct ubi_device *ubi)
 {
 	if (ubi->dbg.emulate_io_failures)
-		return !prandom_u32_max(400);
+		return !get_random_u32_below(400);
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/broadcom/cnic.c b/drivers/net/ethernet/broadcom/cnic.c
index 2198e35d9e18..74bc053a2078 100644
--- a/drivers/net/ethernet/broadcom/cnic.c
+++ b/drivers/net/ethernet/broadcom/cnic.c
@@ -4105,7 +4105,7 @@ static int cnic_cm_alloc_mem(struct cnic_dev *dev)
 	for (i = 0; i < MAX_CM_SK_TBL_SZ; i++)
 		atomic_set(&cp->csk_tbl[i].ref_count, 0);
 
-	port_id = prandom_u32_max(CNIC_LOCAL_PORT_RANGE);
+	port_id = get_random_u32_below(CNIC_LOCAL_PORT_RANGE);
 	if (cnic_init_id_tbl(&cp->csk_port_tbl, CNIC_LOCAL_PORT_RANGE,
 			     CNIC_LOCAL_PORT_MIN, port_id)) {
 		cnic_cm_free_mem(dev);
diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
index a4256087ac82..ae6b17b96bf1 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
@@ -919,8 +919,8 @@ static int csk_wait_memory(struct chtls_dev *cdev,
 	current_timeo = *timeo_p;
 	noblock = (*timeo_p ? false : true);
 	if (csk_mem_free(cdev, sk)) {
-		current_timeo = prandom_u32_max(HZ / 5) + 2;
-		vm_wait = prandom_u32_max(HZ / 5) + 2;
+		current_timeo = get_random_u32_below(HZ / 5) + 2;
+		vm_wait = get_random_u32_below(HZ / 5) + 2;
 	}
 
 	add_wait_queue(sk_sleep(sk), &wait);
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 349b7b1dbbf2..b07513c61c35 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -1758,7 +1758,7 @@ static int qca808x_phy_fast_retrain_config(struct phy_device *phydev)
 
 static int qca808x_phy_ms_random_seed_set(struct phy_device *phydev)
 {
-	u16 seed_value = prandom_u32_max(QCA808X_MASTER_SLAVE_SEED_RANGE);
+	u16 seed_value = get_random_u32_below(QCA808X_MASTER_SLAVE_SEED_RANGE);
 
 	return at803x_debug_reg_mask(phydev, QCA808X_PHY_DEBUG_LOCAL_SEED,
 			QCA808X_MASTER_SLAVE_SEED_CFG,
diff --git a/drivers/net/team/team_mode_random.c b/drivers/net/team/team_mode_random.c
index f3f8dd428402..53d0ce34b8ce 100644
--- a/drivers/net/team/team_mode_random.c
+++ b/drivers/net/team/team_mode_random.c
@@ -16,7 +16,7 @@ static bool rnd_transmit(struct team *team, struct sk_buff *skb)
 	struct team_port *port;
 	int port_index;
 
-	port_index = prandom_u32_max(team->en_port_count);
+	port_index = get_random_u32_below(team->en_port_count);
 	port = team_get_port_by_index_rcu(team, port_index);
 	if (unlikely(!port))
 		goto drop;
diff --git a/drivers/net/wireguard/selftest/allowedips.c b/drivers/net/wireguard/selftest/allowedips.c
index 19eac00b2381..78a916f30c82 100644
--- a/drivers/net/wireguard/selftest/allowedips.c
+++ b/drivers/net/wireguard/selftest/allowedips.c
@@ -285,8 +285,8 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 4);
-		cidr = prandom_u32_max(32) + 1;
-		peer = peers[prandom_u32_max(NUM_PEERS)];
+		cidr = get_random_u32_below(32) + 1;
+		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v4(&t, (struct in_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
 			pr_err("allowedips random self-test malloc: FAIL\n");
@@ -300,7 +300,7 @@ static __init bool randomized_test(void)
 		for (j = 0; j < NUM_MUTATED_ROUTES; ++j) {
 			memcpy(mutated, ip, 4);
 			get_random_bytes(mutate_mask, 4);
-			mutate_amount = prandom_u32_max(32);
+			mutate_amount = get_random_u32_below(32);
 			for (k = 0; k < mutate_amount / 8; ++k)
 				mutate_mask[k] = 0xff;
 			mutate_mask[k] = 0xff
@@ -311,8 +311,8 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = prandom_u32_max(32) + 1;
-			peer = peers[prandom_u32_max(NUM_PEERS)];
+			cidr = get_random_u32_below(32) + 1;
+			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v4(&t,
 						    (struct in_addr *)mutated,
 						    cidr, peer, &mutex) < 0) {
@@ -329,8 +329,8 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 16);
-		cidr = prandom_u32_max(128) + 1;
-		peer = peers[prandom_u32_max(NUM_PEERS)];
+		cidr = get_random_u32_below(128) + 1;
+		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v6(&t, (struct in6_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
 			pr_err("allowedips random self-test malloc: FAIL\n");
@@ -344,7 +344,7 @@ static __init bool randomized_test(void)
 		for (j = 0; j < NUM_MUTATED_ROUTES; ++j) {
 			memcpy(mutated, ip, 16);
 			get_random_bytes(mutate_mask, 16);
-			mutate_amount = prandom_u32_max(128);
+			mutate_amount = get_random_u32_below(128);
 			for (k = 0; k < mutate_amount / 8; ++k)
 				mutate_mask[k] = 0xff;
 			mutate_mask[k] = 0xff
@@ -355,8 +355,8 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = prandom_u32_max(128) + 1;
-			peer = peers[prandom_u32_max(NUM_PEERS)];
+			cidr = get_random_u32_below(128) + 1;
+			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v6(&t,
 						    (struct in6_addr *)mutated,
 						    cidr, peer, &mutex) < 0) {
diff --git a/drivers/net/wireguard/timers.c b/drivers/net/wireguard/timers.c
index d54d32ac9bc4..b5706b6718b1 100644
--- a/drivers/net/wireguard/timers.c
+++ b/drivers/net/wireguard/timers.c
@@ -147,7 +147,7 @@ void wg_timers_data_sent(struct wg_peer *peer)
 	if (!timer_pending(&peer->timer_new_handshake))
 		mod_peer_timer(peer, &peer->timer_new_handshake,
 			jiffies + (KEEPALIVE_TIMEOUT + REKEY_TIMEOUT) * HZ +
-			prandom_u32_max(REKEY_TIMEOUT_JITTER_MAX_JIFFIES));
+			get_random_u32_below(REKEY_TIMEOUT_JITTER_MAX_JIFFIES));
 }
 
 /* Should be called after an authenticated data packet is received. */
@@ -183,7 +183,7 @@ void wg_timers_handshake_initiated(struct wg_peer *peer)
 {
 	mod_peer_timer(peer, &peer->timer_retransmit_handshake,
 		       jiffies + REKEY_TIMEOUT * HZ +
-		       prandom_u32_max(REKEY_TIMEOUT_JITTER_MAX_JIFFIES));
+		       get_random_u32_below(REKEY_TIMEOUT_JITTER_MAX_JIFFIES));
 }
 
 /* Should be called after a handshake response message is received and processed
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 10d9d9c63b28..23c971b77965 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -1128,7 +1128,7 @@ static void brcmf_p2p_afx_handler(struct work_struct *work)
 	if (afx_hdl->is_listen && afx_hdl->my_listen_chan)
 		/* 100ms ~ 300ms */
 		err = brcmf_p2p_discover_listen(p2p, afx_hdl->my_listen_chan,
-						100 * (1 + prandom_u32_max(3)));
+						100 * (1 + get_random_u32_below(3)));
 	else
 		err = brcmf_p2p_act_frm_search(p2p, afx_hdl->peer_listen_chan);
 
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
index de0c545d50fd..1696fbf1009a 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@@ -1099,7 +1099,7 @@ static void iwl_mvm_mac_ctxt_cmd_fill_ap(struct iwl_mvm *mvm,
 			iwl_mvm_mac_ap_iterator, &data);
 
 		if (data.beacon_device_ts) {
-			u32 rand = prandom_u32_max(64 - 36) + 36;
+			u32 rand = get_random_u32_below(64 - 36) + 36;
 			mvmvif->ap_beacon_time = data.beacon_device_ts +
 				ieee80211_tu_to_usec(data.beacon_int * rand /
 						     100);
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 88dc66ee1c46..5565f67d6537 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -673,7 +673,7 @@ struct pci_dev *pci_p2pmem_find_many(struct device **clients, int num_clients)
 	}
 
 	if (dev_cnt)
-		pdev = pci_dev_get(closest_pdevs[prandom_u32_max(dev_cnt)]);
+		pdev = pci_dev_get(closest_pdevs[get_random_u32_below(dev_cnt)]);
 
 	for (i = 0; i < dev_cnt; i++)
 		pci_dev_put(closest_pdevs[i]);
diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index 77917b339870..f21307537829 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -48,7 +48,7 @@ unsigned int zfcp_fc_port_scan_backoff(void)
 {
 	if (!port_scan_backoff)
 		return 0;
-	return prandom_u32_max(port_scan_backoff);
+	return get_random_u32_below(port_scan_backoff);
 }
 
 static void zfcp_fc_port_scan_time(struct zfcp_adapter *adapter)
diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c
index ddc048069af2..5c8d1ba3f8f3 100644
--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -2233,7 +2233,7 @@ static void fcoe_ctlr_vn_restart(struct fcoe_ctlr *fip)
 
 	if (fip->probe_tries < FIP_VN_RLIM_COUNT) {
 		fip->probe_tries++;
-		wait = prandom_u32_max(FIP_VN_PROBE_WAIT);
+		wait = get_random_u32_below(FIP_VN_PROBE_WAIT);
 	} else
 		wait = FIP_VN_RLIM_INT;
 	mod_timer(&fip->timer, jiffies + msecs_to_jiffies(wait));
@@ -3125,7 +3125,7 @@ static void fcoe_ctlr_vn_timeout(struct fcoe_ctlr *fip)
 					  fcoe_all_vn2vn, 0);
 			fip->port_ka_time = jiffies +
 				 msecs_to_jiffies(FIP_VN_BEACON_INT +
-					prandom_u32_max(FIP_VN_BEACON_FUZZ));
+					get_random_u32_below(FIP_VN_BEACON_FUZZ));
 		}
 		if (time_before(fip->port_ka_time, next_time))
 			next_time = fip->port_ka_time;
diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
index df2fe7bd26d1..f2ee49756df8 100644
--- a/drivers/scsi/qedi/qedi_main.c
+++ b/drivers/scsi/qedi/qedi_main.c
@@ -618,7 +618,7 @@ static int qedi_cm_alloc_mem(struct qedi_ctx *qedi)
 				sizeof(struct qedi_endpoint *)), GFP_KERNEL);
 	if (!qedi->ep_tbl)
 		return -ENOMEM;
-	port_id = prandom_u32_max(QEDI_LOCAL_PORT_RANGE);
+	port_id = get_random_u32_below(QEDI_LOCAL_PORT_RANGE);
 	if (qedi_init_id_tbl(&qedi->lcl_port_tbl, QEDI_LOCAL_PORT_RANGE,
 			     QEDI_LOCAL_PORT_MIN, port_id)) {
 		qedi_cm_free_mem(qedi);
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 629853662b82..a86db9761d00 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -5702,16 +5702,16 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 			u64 ns = jiffies_to_nsecs(delta_jiff);
 
 			if (sdebug_random && ns < U32_MAX) {
-				ns = prandom_u32_max((u32)ns);
+				ns = get_random_u32_below((u32)ns);
 			} else if (sdebug_random) {
 				ns >>= 12;	/* scale to 4 usec precision */
 				if (ns < U32_MAX)	/* over 4 hours max */
-					ns = prandom_u32_max((u32)ns);
+					ns = get_random_u32_below((u32)ns);
 				ns <<= 12;
 			}
 			kt = ns_to_ktime(ns);
 		} else {	/* ndelay has a 4.2 second max */
-			kt = sdebug_random ? prandom_u32_max((u32)ndelay) :
+			kt = sdebug_random ? get_random_u32_below((u32)ndelay) :
 					     (u32)ndelay;
 			if (ndelay < INCLUSIVE_TIMING_MAX_NS) {
 				u64 d = ktime_get_boottime_ns() - ns_from_boot;
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 4af5e55abc15..fb255988dee8 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -362,7 +362,7 @@ static int ceph_fill_fragtree(struct inode *inode,
 	if (nsplits != ci->i_fragtree_nsplits) {
 		update = true;
 	} else if (nsplits) {
-		i = prandom_u32_max(nsplits);
+		i = get_random_u32_below(nsplits);
 		id = le32_to_cpu(fragtree->splits[i].frag);
 		if (!__ceph_find_frag(ci, id))
 			update = true;
diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
index 3fbabc98e1f7..7dac21ee6ce7 100644
--- a/fs/ceph/mdsmap.c
+++ b/fs/ceph/mdsmap.c
@@ -29,7 +29,7 @@ static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
 		return -1;
 
 	/* pick */
-	n = prandom_u32_max(n);
+	n = get_random_u32_below(n);
 	for (j = 0, i = 0; i < m->possible_max_rank; i++) {
 		if (CEPH_MDS_IS_READY(i, ignore_laggy))
 			j++;
diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
index f4944c4dee60..78b8686d9a4a 100644
--- a/fs/ext2/ialloc.c
+++ b/fs/ext2/ialloc.c
@@ -277,7 +277,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
 		int best_ndir = inodes_per_group;
 		int best_group = -1;
 
-		parent_group = prandom_u32_max(ngroups);
+		parent_group = get_random_u32_below(ngroups);
 		for (i = 0; i < ngroups; i++) {
 			group = (parent_group + i) % ngroups;
 			desc = ext2_get_group_desc (sb, group, NULL);
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index e9bc46684106..9fc1af8e19a3 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -465,7 +465,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent,
 			ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
 			parent_group = hinfo.hash % ngroups;
 		} else
-			parent_group = prandom_u32_max(ngroups);
+			parent_group = get_random_u32_below(ngroups);
 		for (i = 0; i < ngroups; i++) {
 			g = (parent_group + i) % ngroups;
 			get_orlov_stats(sb, g, flex_size, &stats);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7cdd2138c897..63ef74eb8091 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3778,7 +3778,7 @@ static int ext4_lazyinit_thread(void *arg)
 			}
 			if (!progress) {
 				elr->lr_next_sched = jiffies +
-					prandom_u32_max(EXT4_DEF_LI_MAX_START_DELAY * HZ);
+					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
 			}
 			if (time_before(elr->lr_next_sched, next_wakeup))
 				next_wakeup = elr->lr_next_sched;
@@ -3925,8 +3925,7 @@ static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
 	 * spread the inode table initialization requests
 	 * better.
 	 */
-	elr->lr_next_sched = jiffies + prandom_u32_max(
-				EXT4_DEF_LI_MAX_START_DELAY * HZ);
+	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
 	return elr;
 }
 
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 4546e01b2ee0..536d332d9e2e 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -282,7 +282,7 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 
 	/* let's select beginning hot/small space first in no_heap mode*/
 	if (f2fs_need_rand_seg(sbi))
-		p->offset = prandom_u32_max(MAIN_SECS(sbi) * sbi->segs_per_sec);
+		p->offset = get_random_u32_below(MAIN_SECS(sbi) * sbi->segs_per_sec);
 	else if (test_opt(sbi, NOHEAP) &&
 		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 		p->offset = 0;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index acf3d3fa4363..334415d946f8 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2534,7 +2534,7 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
 
 	sanity_check_seg_type(sbi, seg_type);
 	if (f2fs_need_rand_seg(sbi))
-		return prandom_u32_max(MAIN_SECS(sbi) * sbi->segs_per_sec);
+		return get_random_u32_below(MAIN_SECS(sbi) * sbi->segs_per_sec);
 
 	/* if segs_per_sec is large than 1, we need to keep original policy. */
 	if (__is_large_section(sbi))
@@ -2588,7 +2588,7 @@ static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
 	curseg->alloc_type = LFS;
 	if (F2FS_OPTION(sbi).fs_mode == FS_MODE_FRAGMENT_BLK)
 		curseg->fragment_remained_chunk =
-				prandom_u32_max(sbi->max_fragment_chunk) + 1;
+				get_random_u32_below(sbi->max_fragment_chunk) + 1;
 }
 
 static int __next_free_blkoff(struct f2fs_sb_info *sbi,
@@ -2625,9 +2625,9 @@ static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
 			/* To allocate block chunks in different sizes, use random number */
 			if (--seg->fragment_remained_chunk <= 0) {
 				seg->fragment_remained_chunk =
-				   prandom_u32_max(sbi->max_fragment_chunk) + 1;
+				   get_random_u32_below(sbi->max_fragment_chunk) + 1;
 				seg->next_blkoff +=
-				   prandom_u32_max(sbi->max_fragment_hole) + 1;
+				   get_random_u32_below(sbi->max_fragment_hole) + 1;
 			}
 		}
 	}
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 3f128b9fdfbb..9c9d3f0e36a4 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -2467,7 +2467,7 @@ int dbg_check_nondata_nodes_order(struct ubifs_info *c, struct list_head *head)
 
 static inline int chance(unsigned int n, unsigned int out_of)
 {
-	return !!(prandom_u32_max(out_of) + 1 <= n);
+	return !!(get_random_u32_below(out_of) + 1 <= n);
 
 }
 
@@ -2485,13 +2485,13 @@ static int power_cut_emulated(struct ubifs_info *c, int lnum, int write)
 			if (chance(1, 2)) {
 				d->pc_delay = 1;
 				/* Fail within 1 minute */
-				delay = prandom_u32_max(60000);
+				delay = get_random_u32_below(60000);
 				d->pc_timeout = jiffies;
 				d->pc_timeout += msecs_to_jiffies(delay);
 				ubifs_warn(c, "failing after %lums", delay);
 			} else {
 				d->pc_delay = 2;
-				delay = prandom_u32_max(10000);
+				delay = get_random_u32_below(10000);
 				/* Fail within 10000 operations */
 				d->pc_cnt_max = delay;
 				ubifs_warn(c, "failing after %lu calls", delay);
@@ -2571,7 +2571,7 @@ static int corrupt_data(const struct ubifs_info *c, const void *buf,
 	unsigned int from, to, ffs = chance(1, 2);
 	unsigned char *p = (void *)buf;
 
-	from = prandom_u32_max(len);
+	from = get_random_u32_below(len);
 	/* Corruption span max to end of write unit */
 	to = min(len, ALIGN(from + 1, c->max_write_size));
 
diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c
index cfbc31f709f4..c4d079328b92 100644
--- a/fs/ubifs/lpt_commit.c
+++ b/fs/ubifs/lpt_commit.c
@@ -1970,28 +1970,28 @@ static int dbg_populate_lsave(struct ubifs_info *c)
 
 	if (!dbg_is_chk_gen(c))
 		return 0;
-	if (prandom_u32_max(4))
+	if (get_random_u32_below(4))
 		return 0;
 
 	for (i = 0; i < c->lsave_cnt; i++)
 		c->lsave[i] = c->main_first;
 
 	list_for_each_entry(lprops, &c->empty_list, list)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = lprops->lnum;
 	list_for_each_entry(lprops, &c->freeable_list, list)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = lprops->lnum;
 	list_for_each_entry(lprops, &c->frdi_idx_list, list)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = lprops->lnum;
 
 	heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
 	for (i = 0; i < heap->cnt; i++)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = heap->arr[i]->lnum;
 	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
 	for (i = 0; i < heap->cnt; i++)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = heap->arr[i]->lnum;
 	heap = &c->lpt_heap[LPROPS_FREE - 1];
 	for (i = 0; i < heap->cnt; i++)
-		c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;
+		c->lsave[get_random_u32_below(c->lsave_cnt)] = heap->arr[i]->lnum;
 
 	return 1;
 }
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
index 01362ad5f804..a55e04822d16 100644
--- a/fs/ubifs/tnc_commit.c
+++ b/fs/ubifs/tnc_commit.c
@@ -700,7 +700,7 @@ static int alloc_idx_lebs(struct ubifs_info *c, int cnt)
 		c->ilebs[c->ileb_cnt++] = lnum;
 		dbg_cmt("LEB %d", lnum);
 	}
-	if (dbg_is_chk_index(c) && !prandom_u32_max(8))
+	if (dbg_is_chk_index(c) && !get_random_u32_below(8))
 		return -ENOSPC;
 	return 0;
 }
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index de79f5d07f65..989cf341779b 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1516,7 +1516,7 @@ xfs_alloc_ag_vextent_lastblock(
 
 #ifdef DEBUG
 	/* Randomly don't execute the first algorithm. */
-	if (prandom_u32_max(2))
+	if (get_random_u32_below(2))
 		return 0;
 #endif
 
diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index 94db50eb706a..5118dedf9267 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -636,7 +636,7 @@ xfs_ialloc_ag_alloc(
 	/* randomly do sparse inode allocations */
 	if (xfs_has_sparseinodes(tp->t_mountp) &&
 	    igeo->ialloc_min_blks < igeo->ialloc_blks)
-		do_sparse = prandom_u32_max(2);
+		do_sparse = get_random_u32_below(2);
 #endif
 
 	/*
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index c6b2aabd6f18..822e6a0e9d1a 100644
--- a/fs/xfs/xfs_error.c
+++ b/fs/xfs/xfs_error.c
@@ -279,7 +279,7 @@ xfs_errortag_test(
 
 	ASSERT(error_tag < XFS_ERRTAG_MAX);
 	randfactor = mp->m_errortag[error_tag];
-	if (!randfactor || prandom_u32_max(randfactor))
+	if (!randfactor || get_random_u32_below(randfactor))
 		return false;
 
 	xfs_warn_ratelimited(mp,
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 620ada094c3b..84525b9cdf6e 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -21,7 +21,7 @@
 /* Get a random number in [l, r) */
 static inline unsigned long damon_rand(unsigned long l, unsigned long r)
 {
-	return l + prandom_u32_max(r - l);
+	return l + get_random_u32_below(r - l);
 }
 
 /**
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index efef68c9352a..bb0ee80526b2 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -516,7 +516,7 @@ static inline int node_random(const nodemask_t *maskp)
 		bit = first_node(*maskp);
 		break;
 	default:
-		bit = find_nth_bit(maskp->bits, MAX_NUMNODES, prandom_u32_max(w));
+		bit = find_nth_bit(maskp->bits, MAX_NUMNODES, get_random_u32_below(w));
 		break;
 	}
 	return bit;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 25a54e04560e..38159f39e2af 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1032,7 +1032,7 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 	hdr->size = size;
 	hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
 		     PAGE_SIZE - sizeof(*hdr));
-	start = prandom_u32_max(hole) & ~(alignment - 1);
+	start = get_random_u32_below(hole) & ~(alignment - 1);
 
 	/* Leave a random number of instructions before BPF code. */
 	*image_ptr = &hdr->image[start];
@@ -1094,7 +1094,7 @@ bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
 
 	hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
 		     BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
-	start = prandom_u32_max(hole) & ~(alignment - 1);
+	start = get_random_u32_below(hole) & ~(alignment - 1);
 
 	*image_ptr = &ro_header->image[start];
 	*rw_image = &(*rw_header)->image[start];
diff --git a/kernel/kcsan/selftest.c b/kernel/kcsan/selftest.c
index 1740ce389e7f..7b619f16a492 100644
--- a/kernel/kcsan/selftest.c
+++ b/kernel/kcsan/selftest.c
@@ -31,8 +31,8 @@ static bool __init test_encode_decode(void)
 	int i;
 
 	for (i = 0; i < ITERS_PER_TEST; ++i) {
-		size_t size = prandom_u32_max(MAX_ENCODABLE_SIZE) + 1;
-		bool is_write = !!prandom_u32_max(2);
+		size_t size = get_random_u32_below(MAX_ENCODABLE_SIZE) + 1;
+		bool is_write = !!get_random_u32_below(2);
 		unsigned long verif_masked_addr;
 		long encoded_watchpoint;
 		bool verif_is_write;
diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
index 43efb2a04160..29dc253d03af 100644
--- a/kernel/locking/test-ww_mutex.c
+++ b/kernel/locking/test-ww_mutex.c
@@ -399,7 +399,7 @@ static int *get_random_order(int count)
 		order[n] = n;
 
 	for (n = count - 1; n > 1; n--) {
-		r = prandom_u32_max(n + 1);
+		r = get_random_u32_below(n + 1);
 		if (r != n) {
 			tmp = order[n];
 			order[n] = order[r];
@@ -538,7 +538,7 @@ static void stress_one_work(struct work_struct *work)
 {
 	struct stress *stress = container_of(work, typeof(*stress), work);
 	const int nlocks = stress->nlocks;
-	struct ww_mutex *lock = stress->locks + prandom_u32_max(nlocks);
+	struct ww_mutex *lock = stress->locks + get_random_u32_below(nlocks);
 	int err;
 
 	do {
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 8058bec87ace..9cf32ccda715 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -310,7 +310,7 @@ static void clocksource_verify_choose_cpus(void)
 	 * CPUs that are currently online.
 	 */
 	for (i = 1; i < n; i++) {
-		cpu = prandom_u32_max(nr_cpu_ids);
+		cpu = get_random_u32_below(nr_cpu_ids);
 		cpu = cpumask_next(cpu - 1, cpu_online_mask);
 		if (cpu >= nr_cpu_ids)
 			cpu = cpumask_first(cpu_online_mask);
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index 96e092de5b72..9f53408c545d 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -139,7 +139,7 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
 			return false;
 	}
 
-	if (attr->probability <= prandom_u32_max(100))
+	if (attr->probability <= get_random_u32_below(100))
 		return false;
 
 	if (!fail_stacktrace(attr))
diff --git a/lib/find_bit_benchmark.c b/lib/find_bit_benchmark.c
index 7c3c011abd29..d3fb09e6eff1 100644
--- a/lib/find_bit_benchmark.c
+++ b/lib/find_bit_benchmark.c
@@ -174,8 +174,8 @@ static int __init find_bit_test(void)
 	bitmap_zero(bitmap2, BITMAP_LEN);
 
 	while (nbits--) {
-		__set_bit(prandom_u32_max(BITMAP_LEN), bitmap);
-		__set_bit(prandom_u32_max(BITMAP_LEN), bitmap2);
+		__set_bit(get_random_u32_below(BITMAP_LEN), bitmap);
+		__set_bit(get_random_u32_below(BITMAP_LEN), bitmap2);
 	}
 
 	test_find_next_bit(bitmap, BITMAP_LEN);
diff --git a/lib/kobject.c b/lib/kobject.c
index a0b2dbfcfa23..af1f5f2954d4 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -694,7 +694,7 @@ static void kobject_release(struct kref *kref)
 {
 	struct kobject *kobj = container_of(kref, struct kobject, kref);
 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
-	unsigned long delay = HZ + HZ * prandom_u32_max(4);
+	unsigned long delay = HZ + HZ * get_random_u32_below(4);
 	pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
 		 kobject_name(kobj), kobj, __func__, kobj->parent, delay);
 	INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
diff --git a/lib/reed_solomon/test_rslib.c b/lib/reed_solomon/test_rslib.c
index 848e7eb5da92..75cb1adac884 100644
--- a/lib/reed_solomon/test_rslib.c
+++ b/lib/reed_solomon/test_rslib.c
@@ -183,7 +183,7 @@ static int get_rcw_we(struct rs_control *rs, struct wspace *ws,
 
 		do {
 			/* Must not choose the same location twice */
-			errloc = prandom_u32_max(len);
+			errloc = get_random_u32_below(len);
 		} while (errlocs[errloc] != 0);
 
 		errlocs[errloc] = 1;
@@ -194,12 +194,12 @@ static int get_rcw_we(struct rs_control *rs, struct wspace *ws,
 	for (i = 0; i < eras; i++) {
 		do {
 			/* Must not choose the same location twice */
-			errloc = prandom_u32_max(len);
+			errloc = get_random_u32_below(len);
 		} while (errlocs[errloc] != 0);
 
 		derrlocs[i] = errloc;
 
-		if (ewsc && prandom_u32_max(2)) {
+		if (ewsc && get_random_u32_below(2)) {
 			/* Erasure with the symbol intact */
 			errlocs[errloc] = 2;
 		} else {
diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index 7280ae8ca88c..58de526ff051 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -21,7 +21,7 @@ static int init_alloc_hint(struct sbitmap *sb, gfp_t flags)
 		int i;
 
 		for_each_possible_cpu(i)
-			*per_cpu_ptr(sb->alloc_hint, i) = prandom_u32_max(depth);
+			*per_cpu_ptr(sb->alloc_hint, i) = get_random_u32_below(depth);
 	}
 	return 0;
 }
@@ -33,7 +33,7 @@ static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb,
 
 	hint = this_cpu_read(*sb->alloc_hint);
 	if (unlikely(hint >= depth)) {
-		hint = depth ? prandom_u32_max(depth) : 0;
+		hint = depth ? get_random_u32_below(depth) : 0;
 		this_cpu_write(*sb->alloc_hint, hint);
 	}
 
diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c
index 86fadd3ba08c..41d3447bc3b4 100644
--- a/lib/test-string_helpers.c
+++ b/lib/test-string_helpers.c
@@ -587,7 +587,7 @@ static int __init test_string_helpers_init(void)
 	for (i = 0; i < UNESCAPE_ALL_MASK + 1; i++)
 		test_string_unescape("unescape", i, false);
 	test_string_unescape("unescape inplace",
-			     prandom_u32_max(UNESCAPE_ANY + 1), true);
+			     get_random_u32_below(UNESCAPE_ANY + 1), true);
 
 	/* Without dictionary */
 	for (i = 0; i < ESCAPE_ALL_MASK + 1; i++)
diff --git a/lib/test_hexdump.c b/lib/test_hexdump.c
index 0927f44cd478..efc50fd30a44 100644
--- a/lib/test_hexdump.c
+++ b/lib/test_hexdump.c
@@ -149,7 +149,7 @@ static void __init test_hexdump(size_t len, int rowsize, int groupsize,
 static void __init test_hexdump_set(int rowsize, bool ascii)
 {
 	size_t d = min_t(size_t, sizeof(data_b), rowsize);
-	size_t len = prandom_u32_max(d) + 1;
+	size_t len = get_random_u32_below(d) + 1;
 
 	test_hexdump(len, rowsize, 4, ascii);
 	test_hexdump(len, rowsize, 2, ascii);
@@ -208,11 +208,11 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len,
 static void __init test_hexdump_overflow_set(size_t buflen, bool ascii)
 {
 	unsigned int i = 0;
-	int rs = (prandom_u32_max(2) + 1) * 16;
+	int rs = (get_random_u32_below(2) + 1) * 16;
 
 	do {
 		int gs = 1 << i;
-		size_t len = prandom_u32_max(rs) + gs;
+		size_t len = get_random_u32_below(rs) + gs;
 
 		test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, ascii);
 	} while (i++ < 3);
@@ -223,11 +223,11 @@ static int __init test_hexdump_init(void)
 	unsigned int i;
 	int rowsize;
 
-	rowsize = (prandom_u32_max(2) + 1) * 16;
+	rowsize = (get_random_u32_below(2) + 1) * 16;
 	for (i = 0; i < 16; i++)
 		test_hexdump_set(rowsize, false);
 
-	rowsize = (prandom_u32_max(2) + 1) * 16;
+	rowsize = (get_random_u32_below(2) + 1) * 16;
 	for (i = 0; i < 16; i++)
 		test_hexdump_set(rowsize, true);
 
diff --git a/lib/test_list_sort.c b/lib/test_list_sort.c
index 19ff229b9c3a..cc5f335f29b5 100644
--- a/lib/test_list_sort.c
+++ b/lib/test_list_sort.c
@@ -71,7 +71,7 @@ static void list_sort_test(struct kunit *test)
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, el);
 
 		 /* force some equivalencies */
-		el->value = prandom_u32_max(TEST_LIST_LEN / 3);
+		el->value = get_random_u32_below(TEST_LIST_LEN / 3);
 		el->serial = i;
 		el->poison1 = TEST_POISON1;
 		el->poison2 = TEST_POISON2;
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 4bd15a593fbd..6d10187eddac 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -126,7 +126,7 @@ __test(const char *expect, int elen, const char *fmt, ...)
 	 * be able to print it as expected.
 	 */
 	failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
-	rand = 1 + prandom_u32_max(elen+1);
+	rand = 1 + get_random_u32_below(elen + 1);
 	/* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 	failed_tests += do_test(rand, expect, elen, fmt, ap);
 	failed_tests += do_test(0, expect, elen, fmt, ap);
diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
index f2ba5787055a..6a8e445c8b55 100644
--- a/lib/test_rhashtable.c
+++ b/lib/test_rhashtable.c
@@ -368,8 +368,8 @@ static int __init test_rhltable(unsigned int entries)
 
 	pr_info("test %d random rhlist add/delete operations\n", entries);
 	for (j = 0; j < entries; j++) {
-		u32 i = prandom_u32_max(entries);
-		u32 prand = prandom_u32_max(4);
+		u32 i = get_random_u32_below(entries);
+		u32 prand = get_random_u32_below(4);
 
 		cond_resched();
 
@@ -396,7 +396,7 @@ static int __init test_rhltable(unsigned int entries)
 		}
 
 		if (prand & 2) {
-			i = prandom_u32_max(entries);
+			i = get_random_u32_below(entries);
 			if (test_bit(i, obj_in_table)) {
 				err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
 				WARN(err, "cannot remove element at slot %d", i);
diff --git a/lib/test_vmalloc.c b/lib/test_vmalloc.c
index cf7780572f5b..104f09ea5fcc 100644
--- a/lib/test_vmalloc.c
+++ b/lib/test_vmalloc.c
@@ -151,7 +151,7 @@ static int random_size_alloc_test(void)
 	int i;
 
 	for (i = 0; i < test_loop_count; i++) {
-		n = prandom_u32_max(100) + 1;
+		n = get_random_u32_below(100) + 1;
 		p = vmalloc(n * PAGE_SIZE);
 
 		if (!p)
@@ -291,12 +291,12 @@ pcpu_alloc_test(void)
 		return -1;
 
 	for (i = 0; i < 35000; i++) {
-		size = prandom_u32_max(PAGE_SIZE / 4) + 1;
+		size = get_random_u32_below(PAGE_SIZE / 4) + 1;
 
 		/*
 		 * Maximum PAGE_SIZE
 		 */
-		align = 1 << (prandom_u32_max(11) + 1);
+		align = 1 << (get_random_u32_below(11) + 1);
 
 		pcpu[i] = __alloc_percpu(size, align);
 		if (!pcpu[i])
@@ -391,7 +391,7 @@ static void shuffle_array(int *arr, int n)
 
 	for (i = n - 1; i > 0; i--)  {
 		/* Cut the range. */
-		j = prandom_u32_max(i);
+		j = get_random_u32_below(i);
 
 		/* Swap indexes. */
 		swap(arr[i], arr[j]);
diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c
index 0d59098f0876..640f9c7f8e44 100644
--- a/mm/kasan/kasan_test.c
+++ b/mm/kasan/kasan_test.c
@@ -1299,7 +1299,7 @@ static void match_all_not_assigned(struct kunit *test)
 	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
 
 	for (i = 0; i < 256; i++) {
-		size = prandom_u32_max(1024) + 1;
+		size = get_random_u32_below(1024) + 1;
 		ptr = kmalloc(size, GFP_KERNEL);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
@@ -1308,7 +1308,7 @@ static void match_all_not_assigned(struct kunit *test)
 	}
 
 	for (i = 0; i < 256; i++) {
-		order = prandom_u32_max(4) + 1;
+		order = get_random_u32_below(4) + 1;
 		pages = alloc_pages(GFP_KERNEL, order);
 		ptr = page_address(pages);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
@@ -1321,7 +1321,7 @@ static void match_all_not_assigned(struct kunit *test)
 		return;
 
 	for (i = 0; i < 256; i++) {
-		size = prandom_u32_max(1024) + 1;
+		size = get_random_u32_below(1024) + 1;
 		ptr = vmalloc(size);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 141788858b70..6cbd93f2007b 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -360,9 +360,9 @@ static void *kfence_guarded_alloc(struct kmem_cache *cache, size_t size, gfp_t g
 	unsigned long flags;
 	struct slab *slab;
 	void *addr;
-	const bool random_right_allocate = prandom_u32_max(2);
+	const bool random_right_allocate = get_random_u32_below(2);
 	const bool random_fault = CONFIG_KFENCE_STRESS_TEST_FAULTS &&
-				  !prandom_u32_max(CONFIG_KFENCE_STRESS_TEST_FAULTS);
+				  !get_random_u32_below(CONFIG_KFENCE_STRESS_TEST_FAULTS);
 
 	/* Try to obtain a free object. */
 	raw_spin_lock_irqsave(&kfence_freelist_lock, flags);
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index a97bffe0cc3e..20028c179796 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -532,8 +532,8 @@ static void test_free_bulk(struct kunit *test)
 	int iter;
 
 	for (iter = 0; iter < 5; iter++) {
-		const size_t size = setup_test_cache(test, 8 + prandom_u32_max(300), 0,
-						     (iter & 1) ? ctor_set_x : NULL);
+		const size_t size = setup_test_cache(test, 8 + get_random_u32_below(300),
+						     0, (iter & 1) ? ctor_set_x : NULL);
 		void *objects[] = {
 			test_alloc(test, size, GFP_KERNEL, ALLOCATE_RIGHT),
 			test_alloc(test, size, GFP_KERNEL, ALLOCATE_NONE),
diff --git a/mm/slub.c b/mm/slub.c
index 157527d7101b..7cd2c657030a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1881,7 +1881,7 @@ static bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
 		return false;
 
 	freelist_count = oo_objects(s->oo);
-	pos = prandom_u32_max(freelist_count);
+	pos = get_random_u32_below(freelist_count);
 
 	page_limit = slab->objects * s->size;
 	start = fixup_red_left(s, slab_address(slab));
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 5fc1237a9f21..e9318305a24a 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -773,7 +773,7 @@ static void set_cluster_next(struct swap_info_struct *si, unsigned long next)
 		if (si->highest_bit <= si->lowest_bit)
 			return;
 		next = si->lowest_bit +
-			prandom_u32_max(si->highest_bit - si->lowest_bit + 1);
+			get_random_u32_below(si->highest_bit - si->lowest_bit + 1);
 		next = ALIGN_DOWN(next, SWAP_ADDRESS_SPACE_PAGES);
 		next = max_t(unsigned int, next, si->lowest_bit);
 	}
@@ -3089,7 +3089,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 		 */
 		for_each_possible_cpu(cpu) {
 			per_cpu(*p->cluster_next_cpu, cpu) =
-				1 + prandom_u32_max(p->highest_bit);
+				1 + get_random_u32_below(p->highest_bit);
 		}
 		nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
 
diff --git a/net/802/garp.c b/net/802/garp.c
index fc9eb02a912f..77aac2763835 100644
--- a/net/802/garp.c
+++ b/net/802/garp.c
@@ -407,7 +407,7 @@ static void garp_join_timer_arm(struct garp_applicant *app)
 {
 	unsigned long delay;
 
-	delay = prandom_u32_max(msecs_to_jiffies(garp_join_time));
+	delay = get_random_u32_below(msecs_to_jiffies(garp_join_time));
 	mod_timer(&app->join_timer, jiffies + delay);
 }
 
diff --git a/net/802/mrp.c b/net/802/mrp.c
index 155f74d8b14f..8c6f0381023b 100644
--- a/net/802/mrp.c
+++ b/net/802/mrp.c
@@ -592,7 +592,7 @@ static void mrp_join_timer_arm(struct mrp_applicant *app)
 {
 	unsigned long delay;
 
-	delay = prandom_u32_max(msecs_to_jiffies(mrp_join_time));
+	delay = get_random_u32_below(msecs_to_jiffies(mrp_join_time));
 	mod_timer(&app->join_timer, jiffies + delay);
 }
 
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 7f6a7c96ac92..114ee5da261f 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -280,7 +280,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
 	unsigned int msecs;
 
 	msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
-	msecs += prandom_u32_max(2 * BATADV_JITTER);
+	msecs += get_random_u32_below(2 * BATADV_JITTER);
 
 	return jiffies + msecs_to_jiffies(msecs);
 }
@@ -288,7 +288,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
 /* when do we schedule a ogm packet to be sent */
 static unsigned long batadv_iv_ogm_fwd_send_time(void)
 {
-	return jiffies + msecs_to_jiffies(prandom_u32_max(BATADV_JITTER / 2));
+	return jiffies + msecs_to_jiffies(get_random_u32_below(BATADV_JITTER / 2));
 }
 
 /* apply hop penalty for a normal link */
diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c
index f1741fbfb617..f9a58fb5442e 100644
--- a/net/batman-adv/bat_v_elp.c
+++ b/net/batman-adv/bat_v_elp.c
@@ -51,7 +51,7 @@ static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
 	unsigned int msecs;
 
 	msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
-	msecs += prandom_u32_max(2 * BATADV_JITTER);
+	msecs += get_random_u32_below(2 * BATADV_JITTER);
 
 	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
 			   msecs_to_jiffies(msecs));
diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
index 033639df96d8..addfd8c4fe95 100644
--- a/net/batman-adv/bat_v_ogm.c
+++ b/net/batman-adv/bat_v_ogm.c
@@ -90,7 +90,7 @@ static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
 	unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
 
 	/* msecs * [0.9, 1.1] */
-	msecs += prandom_u32_max(msecs / 5) - (msecs / 10);
+	msecs += get_random_u32_below(msecs / 5) - (msecs / 10);
 	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
 			   msecs_to_jiffies(msecs / 1000));
 }
@@ -109,7 +109,7 @@ static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
 		return;
 
 	msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
-	msecs += prandom_u32_max(2 * BATADV_JITTER);
+	msecs += get_random_u32_below(2 * BATADV_JITTER);
 	queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 			   msecs_to_jiffies(msecs));
 }
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 5f4aeeb60dc4..bf29fba4dde5 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -1009,7 +1009,7 @@ static struct batadv_nc_path *batadv_nc_get_path(struct batadv_priv *bat_priv,
 static u8 batadv_nc_random_weight_tq(u8 tq)
 {
 	/* randomize the estimated packet loss (max TQ - estimated TQ) */
-	u8 rand_tq = prandom_u32_max(BATADV_TQ_MAX_VALUE + 1 - tq);
+	u8 rand_tq = get_random_u32_below(BATADV_TQ_MAX_VALUE + 1 - tq);
 
 	/* convert to (randomized) estimated tq again */
 	return BATADV_TQ_MAX_VALUE - rand_tq;
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index a92e7e485feb..b2f9679066c4 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -7374,8 +7374,8 @@ static int get_conn_info(struct sock *sk, struct hci_dev *hdev, void *data,
 	 * calculate conn info age as random value between min/max set in hdev.
 	 */
 	conn_info_age = hdev->conn_info_min_age +
-			prandom_u32_max(hdev->conn_info_max_age -
-					hdev->conn_info_min_age);
+			get_random_u32_below(hdev->conn_info_max_age -
+					     hdev->conn_info_min_age);
 
 	/* Query controller to refresh cached values if they are too old or were
 	 * never read.
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index b670ba03a675..7e90f9e61d9b 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -189,7 +189,7 @@ static void j1939_sk_queue_activate_next_locked(struct j1939_session *session)
 		int time_ms = 0;
 
 		if (err)
-			time_ms = 10 + prandom_u32_max(16);
+			time_ms = 10 + get_random_u32_below(16);
 
 		j1939_tp_schedule_txtimer(first, time_ms);
 	}
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 55f29c9f9e08..67d36776aff4 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1168,7 +1168,7 @@ static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
 		if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
 			session->tx_retry++;
 			j1939_tp_schedule_txtimer(session,
-						  10 + prandom_u32_max(16));
+						  10 + get_random_u32_below(16));
 		} else {
 			netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
 				     __func__, session);
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index db60217f911b..faabad6603db 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -222,7 +222,7 @@ static void pick_new_mon(struct ceph_mon_client *monc)
 				max--;
 		}
 
-		n = prandom_u32_max(max);
+		n = get_random_u32_below(max);
 		if (o >= 0 && n >= o)
 			n++;
 
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 4e4f1e4bc265..11c04e7d928e 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1479,7 +1479,7 @@ static bool target_should_be_paused(struct ceph_osd_client *osdc,
 
 static int pick_random_replica(const struct ceph_osds *acting)
 {
-	int i = prandom_u32_max(acting->size);
+	int i = get_random_u32_below(acting->size);
 
 	dout("%s picked osd%d, primary osd%d\n", __func__,
 	     acting->osds[i], acting->primary);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index a77a85e357e0..ba92762de525 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -111,7 +111,7 @@ static void neigh_cleanup_and_release(struct neighbour *neigh)
 
 unsigned long neigh_rand_reach_time(unsigned long base)
 {
-	return base ? prandom_u32_max(base) + (base >> 1) : 0;
+	return base ? get_random_u32_below(base) + (base >> 1) : 0;
 }
 EXPORT_SYMBOL(neigh_rand_reach_time);
 
@@ -1652,7 +1652,7 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
 		    struct sk_buff *skb)
 {
 	unsigned long sched_next = jiffies +
-			prandom_u32_max(NEIGH_VAR(p, PROXY_DELAY));
+			get_random_u32_below(NEIGH_VAR(p, PROXY_DELAY));
 
 	if (p->qlen > NEIGH_VAR(p, PROXY_QLEN)) {
 		kfree_skb(skb);
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index c3763056c554..95da2ddc1c20 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2324,7 +2324,7 @@ static inline int f_pick(struct pktgen_dev *pkt_dev)
 				pkt_dev->curfl = 0; /*reset */
 		}
 	} else {
-		flow = prandom_u32_max(pkt_dev->cflows);
+		flow = get_random_u32_below(pkt_dev->cflows);
 		pkt_dev->curfl = flow;
 
 		if (pkt_dev->flows[flow].count > pkt_dev->lflow) {
@@ -2380,8 +2380,8 @@ static void set_cur_queue_map(struct pktgen_dev *pkt_dev)
 	else if (pkt_dev->queue_map_min <= pkt_dev->queue_map_max) {
 		__u16 t;
 		if (pkt_dev->flags & F_QUEUE_MAP_RND) {
-			t = prandom_u32_max(pkt_dev->queue_map_max -
-					    pkt_dev->queue_map_min + 1) +
+			t = get_random_u32_below(pkt_dev->queue_map_max -
+						 pkt_dev->queue_map_min + 1) +
 			    pkt_dev->queue_map_min;
 		} else {
 			t = pkt_dev->cur_queue_map + 1;
@@ -2411,7 +2411,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		__u32 tmp;
 
 		if (pkt_dev->flags & F_MACSRC_RND)
-			mc = prandom_u32_max(pkt_dev->src_mac_count);
+			mc = get_random_u32_below(pkt_dev->src_mac_count);
 		else {
 			mc = pkt_dev->cur_src_mac_offset++;
 			if (pkt_dev->cur_src_mac_offset >=
@@ -2437,7 +2437,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		__u32 tmp;
 
 		if (pkt_dev->flags & F_MACDST_RND)
-			mc = prandom_u32_max(pkt_dev->dst_mac_count);
+			mc = get_random_u32_below(pkt_dev->dst_mac_count);
 
 		else {
 			mc = pkt_dev->cur_dst_mac_offset++;
@@ -2469,16 +2469,16 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 	}
 
 	if ((pkt_dev->flags & F_VID_RND) && (pkt_dev->vlan_id != 0xffff)) {
-		pkt_dev->vlan_id = prandom_u32_max(4096);
+		pkt_dev->vlan_id = get_random_u32_below(4096);
 	}
 
 	if ((pkt_dev->flags & F_SVID_RND) && (pkt_dev->svlan_id != 0xffff)) {
-		pkt_dev->svlan_id = prandom_u32_max(4096);
+		pkt_dev->svlan_id = get_random_u32_below(4096);
 	}
 
 	if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
 		if (pkt_dev->flags & F_UDPSRC_RND)
-			pkt_dev->cur_udp_src = prandom_u32_max(
+			pkt_dev->cur_udp_src = get_random_u32_below(
 				pkt_dev->udp_src_max - pkt_dev->udp_src_min) +
 				pkt_dev->udp_src_min;
 
@@ -2491,7 +2491,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 
 	if (pkt_dev->udp_dst_min < pkt_dev->udp_dst_max) {
 		if (pkt_dev->flags & F_UDPDST_RND) {
-			pkt_dev->cur_udp_dst = prandom_u32_max(
+			pkt_dev->cur_udp_dst = get_random_u32_below(
 				pkt_dev->udp_dst_max - pkt_dev->udp_dst_min) +
 				pkt_dev->udp_dst_min;
 		} else {
@@ -2508,7 +2508,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		if (imn < imx) {
 			__u32 t;
 			if (pkt_dev->flags & F_IPSRC_RND)
-				t = prandom_u32_max(imx - imn) + imn;
+				t = get_random_u32_below(imx - imn) + imn;
 			else {
 				t = ntohl(pkt_dev->cur_saddr);
 				t++;
@@ -2530,7 +2530,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 				if (pkt_dev->flags & F_IPDST_RND) {
 
 					do {
-						t = prandom_u32_max(imx - imn) +
+						t = get_random_u32_below(imx - imn) +
 						    imn;
 						s = htonl(t);
 					} while (ipv4_is_loopback(s) ||
@@ -2578,8 +2578,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 	if (pkt_dev->min_pkt_size < pkt_dev->max_pkt_size) {
 		__u32 t;
 		if (pkt_dev->flags & F_TXSIZE_RND) {
-			t = prandom_u32_max(pkt_dev->max_pkt_size -
-					    pkt_dev->min_pkt_size) +
+			t = get_random_u32_below(pkt_dev->max_pkt_size -
+						 pkt_dev->min_pkt_size) +
 			    pkt_dev->min_pkt_size;
 		} else {
 			t = pkt_dev->cur_pkt_size + 1;
@@ -2589,7 +2589,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		pkt_dev->cur_pkt_size = t;
 	} else if (pkt_dev->n_imix_entries > 0) {
 		struct imix_pkt *entry;
-		__u32 t = prandom_u32_max(IMIX_PRECISION);
+		__u32 t = get_random_u32_below(IMIX_PRECISION);
 		__u8 entry_index = pkt_dev->imix_distribution[t];
 
 		entry = &pkt_dev->imix_entries[entry_index];
diff --git a/net/core/stream.c b/net/core/stream.c
index 75fded8495f5..5b1fe2b82eac 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -123,7 +123,7 @@ int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 
 	if (sk_stream_memory_free(sk))
-		current_timeo = vm_wait = prandom_u32_max(HZ / 5) + 2;
+		current_timeo = vm_wait = get_random_u32_below(HZ / 5) + 2;
 
 	add_wait_queue(sk_sleep(sk), &wait);
 
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index d5d745c3e345..46aa2d65e40a 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -263,7 +263,7 @@ bool icmp_global_allow(void)
 		/* We want to use a credit of one in average, but need to randomize
 		 * it for security reasons.
 		 */
-		credit = max_t(int, credit - prandom_u32_max(3), 0);
+		credit = max_t(int, credit - get_random_u32_below(3), 0);
 		rc = true;
 	}
 	WRITE_ONCE(icmp_global.credit, credit);
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 81be3e0f0e70..c920aa9a62a9 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -213,7 +213,7 @@ static void igmp_stop_timer(struct ip_mc_list *im)
 /* It must be called with locked im->lock */
 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
 {
-	int tv = prandom_u32_max(max_delay);
+	int tv = get_random_u32_below(max_delay);
 
 	im->tm_running = 1;
 	if (!mod_timer(&im->timer, jiffies+tv+2))
@@ -222,7 +222,7 @@ static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
 
 static void igmp_gq_start_timer(struct in_device *in_dev)
 {
-	int tv = prandom_u32_max(in_dev->mr_maxdelay);
+	int tv = get_random_u32_below(in_dev->mr_maxdelay);
 	unsigned long exp = jiffies + tv + 2;
 
 	if (in_dev->mr_gq_running &&
@@ -236,7 +236,7 @@ static void igmp_gq_start_timer(struct in_device *in_dev)
 
 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
 {
-	int tv = prandom_u32_max(delay);
+	int tv = get_random_u32_below(delay);
 
 	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
 		in_dev_hold(in_dev);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 4e84ed21d16f..f22051219b50 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -314,7 +314,7 @@ inet_csk_find_open_port(const struct sock *sk, struct inet_bind_bucket **tb_ret,
 	if (likely(remaining > 1))
 		remaining &= ~1U;
 
-	offset = prandom_u32_max(remaining);
+	offset = get_random_u32_below(remaining);
 	/* __inet_hash_connect() favors ports having @low parity
 	 * We do the opposite to not pollute connect() users.
 	 */
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index d3dc28156622..a879ec1a267d 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -1037,7 +1037,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 	 * on low contention the randomness is maximal and on high contention
 	 * it may be inexistent.
 	 */
-	i = max_t(int, i, prandom_u32_max(8) * 2);
+	i = max_t(int, i, get_random_u32_below(8) * 2);
 	WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2);
 
 	/* Head lock still held and bh's disabled */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index cd1fa9f70f1a..de6e3515ab4f 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -471,7 +471,7 @@ static u32 ip_idents_reserve(u32 hash, int segs)
 	old = READ_ONCE(*p_tstamp);
 
 	if (old != now && cmpxchg(p_tstamp, old, now) == old)
-		delta = prandom_u32_max(now - old);
+		delta = get_random_u32_below(now - old);
 
 	/* If UBSAN reports an error there, please make sure your compiler
 	 * supports -fno-strict-overflow before reporting it that was a bug
@@ -689,7 +689,7 @@ static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr,
 	} else {
 		/* Randomize max depth to avoid some side channels attacks. */
 		int max_depth = FNHE_RECLAIM_DEPTH +
-				prandom_u32_max(FNHE_RECLAIM_DEPTH);
+				get_random_u32_below(FNHE_RECLAIM_DEPTH);
 
 		while (depth > max_depth) {
 			fnhe_remove_oldest(hash);
diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index 54eec33c6e1c..d2c470524e58 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -618,7 +618,7 @@ static void bbr_reset_probe_bw_mode(struct sock *sk)
 	struct bbr *bbr = inet_csk_ca(sk);
 
 	bbr->mode = BBR_PROBE_BW;
-	bbr->cycle_idx = CYCLE_LEN - 1 - prandom_u32_max(bbr_cycle_rand);
+	bbr->cycle_idx = CYCLE_LEN - 1 - get_random_u32_below(bbr_cycle_rand);
 	bbr_advance_cycle_phase(sk);	/* flip to next phase of gain cycle */
 }
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 0640453fce54..3b076e5ba932 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3646,7 +3646,8 @@ static void tcp_send_challenge_ack(struct sock *sk)
 		u32 half = (ack_limit + 1) >> 1;
 
 		WRITE_ONCE(net->ipv4.tcp_challenge_timestamp, now);
-		WRITE_ONCE(net->ipv4.tcp_challenge_count, half + prandom_u32_max(ack_limit));
+		WRITE_ONCE(net->ipv4.tcp_challenge_count,
+			   half + get_random_u32_below(ack_limit));
 	}
 	count = READ_ONCE(net->ipv4.tcp_challenge_count);
 	if (count > 0) {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 9c3f5202a97b..daf89a2eb492 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -104,7 +104,7 @@ static inline u32 cstamp_delta(unsigned long cstamp)
 static inline s32 rfc3315_s14_backoff_init(s32 irt)
 {
 	/* multiply 'initial retransmission time' by 0.9 .. 1.1 */
-	u64 tmp = (900000 + prandom_u32_max(200001)) * (u64)irt;
+	u64 tmp = (900000 + get_random_u32_below(200001)) * (u64)irt;
 	do_div(tmp, 1000000);
 	return (s32)tmp;
 }
@@ -112,11 +112,11 @@ static inline s32 rfc3315_s14_backoff_init(s32 irt)
 static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
 {
 	/* multiply 'retransmission timeout' by 1.9 .. 2.1 */
-	u64 tmp = (1900000 + prandom_u32_max(200001)) * (u64)rt;
+	u64 tmp = (1900000 + get_random_u32_below(200001)) * (u64)rt;
 	do_div(tmp, 1000000);
 	if ((s32)tmp > mrt) {
 		/* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
-		tmp = (900000 + prandom_u32_max(200001)) * (u64)mrt;
+		tmp = (900000 + get_random_u32_below(200001)) * (u64)mrt;
 		do_div(tmp, 1000000);
 	}
 	return (s32)tmp;
@@ -3967,7 +3967,7 @@ static void addrconf_dad_kick(struct inet6_ifaddr *ifp)
 	if (ifp->flags & IFA_F_OPTIMISTIC)
 		rand_num = 0;
 	else
-		rand_num = prandom_u32_max(idev->cnf.rtr_solicit_delay ?: 1);
+		rand_num = get_random_u32_below(idev->cnf.rtr_solicit_delay ? : 1);
 
 	nonce = 0;
 	if (idev->cnf.enhanced_dad ||
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 7860383295d8..1c02160cf7a4 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1050,7 +1050,7 @@ bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
 /* called with mc_lock */
 static void mld_gq_start_work(struct inet6_dev *idev)
 {
-	unsigned long tv = prandom_u32_max(idev->mc_maxdelay);
+	unsigned long tv = get_random_u32_below(idev->mc_maxdelay);
 
 	idev->mc_gq_running = 1;
 	if (!mod_delayed_work(mld_wq, &idev->mc_gq_work, tv + 2))
@@ -1068,7 +1068,7 @@ static void mld_gq_stop_work(struct inet6_dev *idev)
 /* called with mc_lock */
 static void mld_ifc_start_work(struct inet6_dev *idev, unsigned long delay)
 {
-	unsigned long tv = prandom_u32_max(delay);
+	unsigned long tv = get_random_u32_below(delay);
 
 	if (!mod_delayed_work(mld_wq, &idev->mc_ifc_work, tv + 2))
 		in6_dev_hold(idev);
@@ -1085,7 +1085,7 @@ static void mld_ifc_stop_work(struct inet6_dev *idev)
 /* called with mc_lock */
 static void mld_dad_start_work(struct inet6_dev *idev, unsigned long delay)
 {
-	unsigned long tv = prandom_u32_max(delay);
+	unsigned long tv = get_random_u32_below(delay);
 
 	if (!mod_delayed_work(mld_wq, &idev->mc_dad_work, tv + 2))
 		in6_dev_hold(idev);
@@ -1130,7 +1130,7 @@ static void igmp6_group_queried(struct ifmcaddr6 *ma, unsigned long resptime)
 	}
 
 	if (delay >= resptime)
-		delay = prandom_u32_max(resptime);
+		delay = get_random_u32_below(resptime);
 
 	if (!mod_delayed_work(mld_wq, &ma->mca_work, delay))
 		refcount_inc(&ma->mca_refcnt);
@@ -2574,7 +2574,7 @@ static void igmp6_join_group(struct ifmcaddr6 *ma)
 
 	igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
 
-	delay = prandom_u32_max(unsolicited_report_interval(ma->idev));
+	delay = get_random_u32_below(unsolicited_report_interval(ma->idev));
 
 	if (cancel_delayed_work(&ma->mca_work)) {
 		refcount_dec(&ma->mca_refcnt);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2f355f0ec32a..e74e0361fd92 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1713,7 +1713,7 @@ static int rt6_insert_exception(struct rt6_info *nrt,
 	net->ipv6.rt6_stats->fib_rt_cache++;
 
 	/* Randomize max depth to avoid some side channels attacks. */
-	max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH);
+	max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH);
 	while (bucket->depth > max_depth)
 		rt6_exception_remove_oldest(bucket);
 
diff --git a/net/netfilter/ipvs/ip_vs_twos.c b/net/netfilter/ipvs/ip_vs_twos.c
index f2579fc9c75b..3308e4cc740a 100644
--- a/net/netfilter/ipvs/ip_vs_twos.c
+++ b/net/netfilter/ipvs/ip_vs_twos.c
@@ -71,8 +71,8 @@ static struct ip_vs_dest *ip_vs_twos_schedule(struct ip_vs_service *svc,
 	 * from 0 to total_weight
 	 */
 	total_weight += 1;
-	rweight1 = prandom_u32_max(total_weight);
-	rweight2 = prandom_u32_max(total_weight);
+	rweight1 = get_random_u32_below(total_weight);
+	rweight2 = get_random_u32_below(total_weight);
 
 	/* Pick two weighted servers */
 	list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index f97bda06d2a9..8703812405eb 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -906,7 +906,7 @@ nf_conntrack_hash_check_insert(struct nf_conn *ct)
 					   nf_ct_zone_id(nf_ct_zone(ct), IP_CT_DIR_REPLY));
 	} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 
-	max_chainlen = MIN_CHAINLEN + prandom_u32_max(MAX_CHAINLEN);
+	max_chainlen = MIN_CHAINLEN + get_random_u32_below(MAX_CHAINLEN);
 
 	/* See if there's one in the list already, including reverse */
 	hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode) {
@@ -1227,7 +1227,7 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 		goto dying;
 	}
 
-	max_chainlen = MIN_CHAINLEN + prandom_u32_max(MAX_CHAINLEN);
+	max_chainlen = MIN_CHAINLEN + get_random_u32_below(MAX_CHAINLEN);
 	/* See if there's one in the list already, including reverse:
 	   NAT could have grabbed it without realizing, since we're
 	   not in the hash.  If there is, we lost race. */
diff --git a/net/netfilter/nf_nat_helper.c b/net/netfilter/nf_nat_helper.c
index a95a25196943..bf591e6af005 100644
--- a/net/netfilter/nf_nat_helper.c
+++ b/net/netfilter/nf_nat_helper.c
@@ -223,7 +223,7 @@ u16 nf_nat_exp_find_port(struct nf_conntrack_expect *exp, u16 port)
 		if (res != -EBUSY || (--attempts_left < 0))
 			break;
 
-		port = min + prandom_u32_max(range);
+		port = min + get_random_u32_below(range);
 	}
 
 	return 0;
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a662e8a5ff84..7a401d94463a 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -835,7 +835,7 @@ static int netlink_autobind(struct socket *sock)
 		/* Bind collision, search negative portid values. */
 		if (rover == -4096)
 			/* rover will be in range [S32_MIN, -4097] */
-			rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN);
+			rover = S32_MIN + get_random_u32_below(-4096 - S32_MIN);
 		else if (rover >= -4096)
 			rover = -4097;
 		portid = rover--;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 6ce8dd19f33c..51a47ade92e8 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1350,7 +1350,7 @@ static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
 		if (READ_ONCE(history[i]) == rxhash)
 			count++;
 
-	victim = prandom_u32_max(ROLLOVER_HLEN);
+	victim = get_random_u32_below(ROLLOVER_HLEN);
 
 	/* Avoid dirtying the cache line if possible */
 	if (READ_ONCE(history[victim]) != rxhash)
@@ -1386,7 +1386,7 @@ static unsigned int fanout_demux_rnd(struct packet_fanout *f,
 				     struct sk_buff *skb,
 				     unsigned int num)
 {
-	return prandom_u32_max(num);
+	return get_random_u32_below(num);
 }
 
 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index 62d682b96b88..be267ffaaba7 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -25,7 +25,7 @@ static struct tc_action_ops act_gact_ops;
 static int gact_net_rand(struct tcf_gact *gact)
 {
 	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
-	if (prandom_u32_max(gact->tcfg_pval))
+	if (get_random_u32_below(gact->tcfg_pval))
 		return gact->tcf_action;
 	return gact->tcfg_paction;
 }
diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index 7a25477f5d99..4194480746b0 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -168,7 +168,7 @@ static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
 	psample_group = rcu_dereference_bh(s->psample_group);
 
 	/* randomly sample packets according to rate */
-	if (psample_group && (prandom_u32_max(s->rate) == 0)) {
+	if (psample_group && (get_random_u32_below(s->rate) == 0)) {
 		if (!skb_at_tc_ingress(skb)) {
 			md.in_ifindex = skb->skb_iif;
 			md.out_ifindex = skb->dev->ifindex;
diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index 3ac3e5c80b6f..19c851125901 100644
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -183,7 +183,7 @@ static struct sk_buff *choke_peek_random(const struct choke_sched_data *q,
 	int retrys = 3;
 
 	do {
-		*pidx = (q->head + prandom_u32_max(choke_len(q))) & q->tab_mask;
+		*pidx = (q->head + get_random_u32_below(choke_len(q))) & q->tab_mask;
 		skb = q->tab[*pidx];
 		if (skb)
 			return skb;
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index fb00ac40ecb7..6ef3021e1169 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -513,8 +513,8 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			goto finish_segs;
 		}
 
-		skb->data[prandom_u32_max(skb_headlen(skb))] ^=
-			1<<prandom_u32_max(8);
+		skb->data[get_random_u32_below(skb_headlen(skb))] ^=
+			1<<get_random_u32_below(8);
 	}
 
 	if (unlikely(sch->q.qlen >= sch->limit)) {
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 83628c347744..cfe72085fdc4 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -8319,7 +8319,7 @@ static int sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
 
 		inet_get_local_port_range(net, &low, &high);
 		remaining = (high - low) + 1;
-		rover = prandom_u32_max(remaining) + low;
+		rover = get_random_u32_below(remaining) + low;
 
 		do {
 			rover++;
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index f8fd98784977..ca1eba95c293 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -199,7 +199,7 @@ void sctp_transport_reset_hb_timer(struct sctp_transport *transport)
 	if ((time_before(transport->hb_timer.expires, expires) ||
 	     !timer_pending(&transport->hb_timer)) &&
 	    !mod_timer(&transport->hb_timer,
-		       expires + prandom_u32_max(transport->rto)))
+		       expires + get_random_u32_below(transport->rto)))
 		sctp_transport_hold(transport);
 }
 
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index f075a9fb5ccc..95ff74706104 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -677,7 +677,7 @@ static void cache_limit_defers(void)
 
 	/* Consider removing either the first or the last */
 	if (cache_defer_cnt > DFR_MAX) {
-		if (prandom_u32_max(2))
+		if (get_random_u32_below(2))
 			discard = list_entry(cache_defer_list.next,
 					     struct cache_deferred_req, recent);
 		else
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 915b9902f673..2e4987dcba29 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1619,7 +1619,7 @@ static int xs_get_random_port(void)
 	if (max < min)
 		return -EADDRINUSE;
 	range = max - min + 1;
-	rand = prandom_u32_max(range);
+	rand = get_random_u32_below(range);
 	return rand + min;
 }
 
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index e902b01ea3cb..b35c8701876a 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3010,7 +3010,7 @@ static int tipc_sk_insert(struct tipc_sock *tsk)
 	struct net *net = sock_net(sk);
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	u32 remaining = (TIPC_MAX_PORT - TIPC_MIN_PORT) + 1;
-	u32 portid = prandom_u32_max(remaining) + TIPC_MIN_PORT;
+	u32 portid = get_random_u32_below(remaining) + TIPC_MIN_PORT;
 
 	while (remaining--) {
 		portid++;
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 884eca7f6743..ff38c5a4d174 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -627,7 +627,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
 
 	if (!port)
 		port = LAST_RESERVED_PORT + 1 +
-			prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
+			get_random_u32_below(U32_MAX - LAST_RESERVED_PORT);
 
 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 3d2fe7712ac5..40f831854774 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2072,7 +2072,7 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
 	} else {
 		u32 spi = 0;
 		for (h = 0; h < high-low+1; h++) {
-			spi = low + prandom_u32_max(high - low + 1);
+			spi = low + get_random_u32_below(high - low + 1);
 			x0 = xfrm_state_lookup(net, mark, &x->id.daddr, htonl(spi), x->id.proto, x->props.family);
 			if (x0 == NULL) {
 				newspi = htonl(spi);
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v3 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop
  2022-11-17 20:29 ` [PATCH v3 0/3] convert tree to get_random_u32_{below,above,inclusive}() Jason A. Donenfeld
  2022-11-17 20:29   ` [PATCH v3 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
@ 2022-11-17 20:29   ` Jason A. Donenfeld
  2022-11-17 21:58     ` Kees Cook
  2022-11-17 20:29   ` [PATCH v3 3/3] treewide: use get_random_u32_inclusive() when possible Jason A. Donenfeld
  2 siblings, 1 reply; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17 20:29 UTC (permalink / raw)
  To: linux-kernel, patches
  Cc: Jason A. Donenfeld, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Theodore Ts'o,
	Andreas Dilger, Jaegeuk Kim, Richard Weinberger,
	Darrick J . Wong, SeongJae Park, Thomas Gleixner, Andrew Morton,
	Michael Ellerman, Helge Deller, netdev, linux-crypto,
	linux-block, linux-fsdevel, linux-media, linux-arm-kernel,
	loongarch, linux-mips, linuxppc-dev, linux-mmc, linux-parisc

These cases were done with this Coccinelle:

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I > E);
+   I = get_random_u32_below(E + 1);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I >= E);
+   I = get_random_u32_below(E);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I < E);
+   I = get_random_u32_above(E - 1);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I <= E);
+   I = get_random_u32_above(E);

@@
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (!I);
+   I = get_random_u32_above(0);

@@
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I == 0);
+   I = get_random_u32_above(0);

@@
expression E;
@@
- E + 1 + get_random_u32_below(U32_MAX - E)
+ get_random_u32_above(E)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 fs/ext4/mmp.c            | 8 +-------
 lib/test_fprobe.c        | 5 +----
 lib/test_kprobes.c       | 5 +----
 net/ipv6/output_core.c   | 8 +-------
 net/vmw_vsock/af_vsock.c | 3 +--
 5 files changed, 5 insertions(+), 24 deletions(-)

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 588cb09c5291..4681fff6665f 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -262,13 +262,7 @@ void ext4_stop_mmpd(struct ext4_sb_info *sbi)
  */
 static unsigned int mmp_new_seq(void)
 {
-	u32 new_seq;
-
-	do {
-		new_seq = get_random_u32();
-	} while (new_seq > EXT4_MMP_SEQ_MAX);
-
-	return new_seq;
+	return get_random_u32_below(EXT4_MMP_SEQ_MAX + 1);
 }
 
 /*
diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c
index e0381b3ec410..1fb56cf5e5ce 100644
--- a/lib/test_fprobe.c
+++ b/lib/test_fprobe.c
@@ -144,10 +144,7 @@ static unsigned long get_ftrace_location(void *func)
 
 static int fprobe_test_init(struct kunit *test)
 {
-	do {
-		rand1 = get_random_u32();
-	} while (rand1 <= div_factor);
-
+	rand1 = get_random_u32_above(div_factor);
 	target = fprobe_selftest_target;
 	target2 = fprobe_selftest_target2;
 	target_ip = get_ftrace_location(target);
diff --git a/lib/test_kprobes.c b/lib/test_kprobes.c
index eeb1d728d974..1c95e5719802 100644
--- a/lib/test_kprobes.c
+++ b/lib/test_kprobes.c
@@ -339,10 +339,7 @@ static int kprobes_test_init(struct kunit *test)
 	stacktrace_target = kprobe_stacktrace_target;
 	internal_target = kprobe_stacktrace_internal_target;
 	stacktrace_driver = kprobe_stacktrace_driver;
-
-	do {
-		rand1 = get_random_u32();
-	} while (rand1 <= div_factor);
+	rand1 = get_random_u32_above(div_factor);
 	return 0;
 }
 
diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c
index 2685c3f15e9d..b5205311f372 100644
--- a/net/ipv6/output_core.c
+++ b/net/ipv6/output_core.c
@@ -15,13 +15,7 @@ static u32 __ipv6_select_ident(struct net *net,
 			       const struct in6_addr *dst,
 			       const struct in6_addr *src)
 {
-	u32 id;
-
-	do {
-		id = get_random_u32();
-	} while (!id);
-
-	return id;
+	return get_random_u32_above(0);
 }
 
 /* This function exists only for tap drivers that must support broken
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index ff38c5a4d174..d593d5b6d4b1 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -626,8 +626,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
 	struct sockaddr_vm new_addr;
 
 	if (!port)
-		port = LAST_RESERVED_PORT + 1 +
-			get_random_u32_below(U32_MAX - LAST_RESERVED_PORT);
+		port = get_random_u32_above(LAST_RESERVED_PORT);
 
 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v3 3/3] treewide: use get_random_u32_inclusive() when possible
  2022-11-17 20:29 ` [PATCH v3 0/3] convert tree to get_random_u32_{below,above,inclusive}() Jason A. Donenfeld
  2022-11-17 20:29   ` [PATCH v3 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
  2022-11-17 20:29   ` [PATCH v3 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop Jason A. Donenfeld
@ 2022-11-17 20:29   ` Jason A. Donenfeld
  2022-11-17 21:57     ` Kees Cook
  2 siblings, 1 reply; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17 20:29 UTC (permalink / raw)
  To: linux-kernel, patches
  Cc: Jason A. Donenfeld, Kees Cook, Greg Kroah-Hartman,
	Jakub Kicinski, Russell King, Catalin Marinas,
	Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Theodore Ts'o,
	Andreas Dilger, Jaegeuk Kim, Richard Weinberger,
	Darrick J . Wong, SeongJae Park, Thomas Gleixner, Andrew Morton,
	Michael Ellerman, Helge Deller, netdev, linux-crypto,
	linux-block, linux-fsdevel, linux-media, linux-arm-kernel,
	loongarch, linux-mips, linuxppc-dev, linux-mmc, linux-parisc

These cases were done with this Coccinelle:

@@
expression H;
expression L;
@@
- (get_random_u32_below(H) + L)
+ get_random_u32_inclusive(L, H + L - 1)

@@
expression H;
expression L;
expression E;
@@
  get_random_u32_inclusive(L,
  H
- + E
- - E
  )

@@
expression H;
expression L;
expression E;
@@
  get_random_u32_inclusive(L,
  H
- - E
- + E
  )

@@
expression H;
expression L;
expression E;
expression F;
@@
  get_random_u32_inclusive(L,
  H
- - E
  + F
- + E
  )

@@
expression H;
expression L;
expression E;
expression F;
@@
  get_random_u32_inclusive(L,
  H
- + E
  + F
- - E
  )

And then subsequently cleaned up by hand, with several automatic cases
rejected if it didn't make sense contextually.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 arch/x86/kernel/module.c                      |  2 +-
 crypto/rsa-pkcs1pad.c                         |  2 +-
 crypto/testmgr.c                              | 10 ++++----
 drivers/bus/mhi/host/internal.h               |  2 +-
 drivers/dma-buf/st-dma-fence-chain.c          |  2 +-
 drivers/infiniband/core/cma.c                 |  2 +-
 drivers/infiniband/hw/hns/hns_roce_ah.c       |  5 ++--
 drivers/mtd/nand/raw/nandsim.c                |  2 +-
 drivers/net/wireguard/selftest/allowedips.c   |  8 +++---
 .../broadcom/brcm80211/brcmfmac/p2p.c         |  2 +-
 .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c |  2 +-
 fs/f2fs/segment.c                             |  6 ++---
 kernel/kcsan/selftest.c                       |  2 +-
 lib/test_hexdump.c                            | 10 ++++----
 lib/test_printf.c                             |  2 +-
 lib/test_vmalloc.c                            |  6 ++---
 mm/kasan/kasan_test.c                         |  6 ++---
 mm/kfence/kfence_test.c                       |  2 +-
 mm/swapfile.c                                 |  5 ++--
 net/bluetooth/mgmt.c                          |  5 ++--
 net/core/pktgen.c                             | 25 ++++++++-----------
 net/ipv4/tcp_input.c                          |  2 +-
 net/ipv6/addrconf.c                           |  6 ++---
 net/netfilter/nf_nat_helper.c                 |  2 +-
 net/xfrm/xfrm_state.c                         |  2 +-
 25 files changed, 56 insertions(+), 64 deletions(-)

diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index c09ae279ef32..a98687642dd0 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -53,7 +53,7 @@ static unsigned long int get_module_load_offset(void)
 		 */
 		if (module_load_offset == 0)
 			module_load_offset =
-				(get_random_u32_below(1024) + 1) * PAGE_SIZE;
+				get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
 		mutex_unlock(&module_kaslr_mutex);
 	}
 	return module_load_offset;
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index 0f722f8f779b..e75728f87ce5 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -253,7 +253,7 @@ static int pkcs1pad_encrypt(struct akcipher_request *req)
 	ps_end = ctx->key_size - req->src_len - 2;
 	req_ctx->in_buf[0] = 0x02;
 	for (i = 1; i < ps_end; i++)
-		req_ctx->in_buf[i] = 1 + get_random_u32_below(255);
+		req_ctx->in_buf[i] = get_random_u32_inclusive(1, 255);
 	req_ctx->in_buf[ps_end] = 0x00;
 
 	pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 079923d43ce2..e669acd2ebdd 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -962,11 +962,11 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
 		if (div == &divs[max_divs - 1] || get_random_u32_below(2) == 0)
 			this_len = remaining;
 		else
-			this_len = 1 + get_random_u32_below(remaining);
+			this_len = get_random_u32_inclusive(1, remaining);
 		div->proportion_of_total = this_len;
 
 		if (get_random_u32_below(4) == 0)
-			div->offset = (PAGE_SIZE - 128) + get_random_u32_below(128);
+			div->offset = get_random_u32_inclusive(PAGE_SIZE - 128, PAGE_SIZE - 1);
 		else if (get_random_u32_below(2) == 0)
 			div->offset = get_random_u32_below(32);
 		else
@@ -1094,12 +1094,12 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
 	}
 
 	if (get_random_u32_below(2) == 0) {
-		cfg->iv_offset = 1 + get_random_u32_below(MAX_ALGAPI_ALIGNMASK);
+		cfg->iv_offset = get_random_u32_inclusive(1, MAX_ALGAPI_ALIGNMASK);
 		p += scnprintf(p, end - p, " iv_offset=%u", cfg->iv_offset);
 	}
 
 	if (get_random_u32_below(2) == 0) {
-		cfg->key_offset = 1 + get_random_u32_below(MAX_ALGAPI_ALIGNMASK);
+		cfg->key_offset = get_random_u32_inclusive(1, MAX_ALGAPI_ALIGNMASK);
 		p += scnprintf(p, end - p, " key_offset=%u", cfg->key_offset);
 	}
 
@@ -1653,7 +1653,7 @@ static void generate_random_hash_testvec(struct shash_desc *desc,
 	if (maxkeysize) {
 		vec->ksize = maxkeysize;
 		if (get_random_u32_below(4) == 0)
-			vec->ksize = 1 + get_random_u32_below(maxkeysize);
+			vec->ksize = get_random_u32_inclusive(1, maxkeysize);
 		generate_random_bytes((u8 *)vec->key, vec->ksize);
 
 		vec->setkey_error = crypto_shash_setkey(desc->tfm, vec->key,
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index c73621aabbd1..2e139e76de4c 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -129,7 +129,7 @@ enum mhi_pm_state {
 #define PRIMARY_CMD_RING				0
 #define MHI_DEV_WAKE_DB					127
 #define MHI_MAX_MTU					0xffff
-#define MHI_RANDOM_U32_NONZERO(bmsk)			(get_random_u32_below(bmsk) + 1)
+#define MHI_RANDOM_U32_NONZERO(bmsk)			(get_random_u32_inclusive(1, bmsk))
 
 enum mhi_er_type {
 	MHI_ER_TYPE_INVALID = 0x0,
diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c
index 9fbad7317d9b..c0979c8049b5 100644
--- a/drivers/dma-buf/st-dma-fence-chain.c
+++ b/drivers/dma-buf/st-dma-fence-chain.c
@@ -400,7 +400,7 @@ static int __find_race(void *arg)
 		struct dma_fence *fence = dma_fence_get(data->fc.tail);
 		int seqno;
 
-		seqno = get_random_u32_below(data->fc.chain_length) + 1;
+		seqno = get_random_u32_inclusive(1, data->fc.chain_length);
 
 		err = dma_fence_chain_find_seqno(&fence, seqno);
 		if (err) {
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index dd1c703b10df..aacd6254df77 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3807,7 +3807,7 @@ static int cma_alloc_any_port(enum rdma_ucm_port_space ps,
 
 	inet_get_local_port_range(net, &low, &high);
 	remaining = (high - low) + 1;
-	rover = get_random_u32_below(remaining) + low;
+	rover = get_random_u32_inclusive(low, remaining + low - 1);
 retry:
 	if (last_used_port != rover) {
 		struct rdma_bind_list *bind_list;
diff --git a/drivers/infiniband/hw/hns/hns_roce_ah.c b/drivers/infiniband/hw/hns/hns_roce_ah.c
index b37d2a81584d..e77fcc74f15c 100644
--- a/drivers/infiniband/hw/hns/hns_roce_ah.c
+++ b/drivers/infiniband/hw/hns/hns_roce_ah.c
@@ -41,9 +41,8 @@ static inline u16 get_ah_udp_sport(const struct rdma_ah_attr *ah_attr)
 	u16 sport;
 
 	if (!fl)
-		sport = get_random_u32_below(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX +
-					     1 - IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
-			IB_ROCE_UDP_ENCAP_VALID_PORT_MIN;
+		sport = get_random_u32_inclusive(IB_ROCE_UDP_ENCAP_VALID_PORT_MIN,
+						 IB_ROCE_UDP_ENCAP_VALID_PORT_MAX);
 	else
 		sport = rdma_flow_label_to_udp_sport(fl);
 
diff --git a/drivers/mtd/nand/raw/nandsim.c b/drivers/mtd/nand/raw/nandsim.c
index 274a31b93100..c21abf748948 100644
--- a/drivers/mtd/nand/raw/nandsim.c
+++ b/drivers/mtd/nand/raw/nandsim.c
@@ -1405,7 +1405,7 @@ static void ns_do_bit_flips(struct nandsim *ns, int num)
 	if (bitflips && get_random_u16() < (1 << 6)) {
 		int flips = 1;
 		if (bitflips > 1)
-			flips = get_random_u32_below(bitflips) + 1;
+			flips = get_random_u32_inclusive(1, bitflips);
 		while (flips--) {
 			int pos = get_random_u32_below(num * 8);
 			ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
diff --git a/drivers/net/wireguard/selftest/allowedips.c b/drivers/net/wireguard/selftest/allowedips.c
index 78a916f30c82..78ebe2892a78 100644
--- a/drivers/net/wireguard/selftest/allowedips.c
+++ b/drivers/net/wireguard/selftest/allowedips.c
@@ -285,7 +285,7 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 4);
-		cidr = get_random_u32_below(32) + 1;
+		cidr = get_random_u32_inclusive(1, 32);
 		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v4(&t, (struct in_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
@@ -311,7 +311,7 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = get_random_u32_below(32) + 1;
+			cidr = get_random_u32_inclusive(1, 32);
 			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v4(&t,
 						    (struct in_addr *)mutated,
@@ -329,7 +329,7 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 16);
-		cidr = get_random_u32_below(128) + 1;
+		cidr = get_random_u32_inclusive(1, 128);
 		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v6(&t, (struct in6_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
@@ -355,7 +355,7 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = get_random_u32_below(128) + 1;
+			cidr = get_random_u32_inclusive(1, 128);
 			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v6(&t,
 						    (struct in6_addr *)mutated,
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 23c971b77965..c704ca752138 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -1128,7 +1128,7 @@ static void brcmf_p2p_afx_handler(struct work_struct *work)
 	if (afx_hdl->is_listen && afx_hdl->my_listen_chan)
 		/* 100ms ~ 300ms */
 		err = brcmf_p2p_discover_listen(p2p, afx_hdl->my_listen_chan,
-						100 * (1 + get_random_u32_below(3)));
+						100 * get_random_u32_inclusive(1, 3));
 	else
 		err = brcmf_p2p_act_frm_search(p2p, afx_hdl->peer_listen_chan);
 
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
index 1696fbf1009a..3a7a44bb3c60 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@@ -1099,7 +1099,7 @@ static void iwl_mvm_mac_ctxt_cmd_fill_ap(struct iwl_mvm *mvm,
 			iwl_mvm_mac_ap_iterator, &data);
 
 		if (data.beacon_device_ts) {
-			u32 rand = get_random_u32_below(64 - 36) + 36;
+			u32 rand = get_random_u32_inclusive(36, 63);
 			mvmvif->ap_beacon_time = data.beacon_device_ts +
 				ieee80211_tu_to_usec(data.beacon_int * rand /
 						     100);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 334415d946f8..b304692c0cf5 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2588,7 +2588,7 @@ static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
 	curseg->alloc_type = LFS;
 	if (F2FS_OPTION(sbi).fs_mode == FS_MODE_FRAGMENT_BLK)
 		curseg->fragment_remained_chunk =
-				get_random_u32_below(sbi->max_fragment_chunk) + 1;
+				get_random_u32_inclusive(1, sbi->max_fragment_chunk);
 }
 
 static int __next_free_blkoff(struct f2fs_sb_info *sbi,
@@ -2625,9 +2625,9 @@ static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
 			/* To allocate block chunks in different sizes, use random number */
 			if (--seg->fragment_remained_chunk <= 0) {
 				seg->fragment_remained_chunk =
-				   get_random_u32_below(sbi->max_fragment_chunk) + 1;
+				   get_random_u32_inclusive(1, sbi->max_fragment_chunk);
 				seg->next_blkoff +=
-				   get_random_u32_below(sbi->max_fragment_hole) + 1;
+				   get_random_u32_inclusive(1, sbi->max_fragment_hole);
 			}
 		}
 	}
diff --git a/kernel/kcsan/selftest.c b/kernel/kcsan/selftest.c
index 7b619f16a492..8679322450f2 100644
--- a/kernel/kcsan/selftest.c
+++ b/kernel/kcsan/selftest.c
@@ -31,7 +31,7 @@ static bool __init test_encode_decode(void)
 	int i;
 
 	for (i = 0; i < ITERS_PER_TEST; ++i) {
-		size_t size = get_random_u32_below(MAX_ENCODABLE_SIZE) + 1;
+		size_t size = get_random_u32_inclusive(1, MAX_ENCODABLE_SIZE);
 		bool is_write = !!get_random_u32_below(2);
 		unsigned long verif_masked_addr;
 		long encoded_watchpoint;
diff --git a/lib/test_hexdump.c b/lib/test_hexdump.c
index efc50fd30a44..bcfff9cbc6dd 100644
--- a/lib/test_hexdump.c
+++ b/lib/test_hexdump.c
@@ -149,7 +149,7 @@ static void __init test_hexdump(size_t len, int rowsize, int groupsize,
 static void __init test_hexdump_set(int rowsize, bool ascii)
 {
 	size_t d = min_t(size_t, sizeof(data_b), rowsize);
-	size_t len = get_random_u32_below(d) + 1;
+	size_t len = get_random_u32_inclusive(1, d);
 
 	test_hexdump(len, rowsize, 4, ascii);
 	test_hexdump(len, rowsize, 2, ascii);
@@ -208,11 +208,11 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len,
 static void __init test_hexdump_overflow_set(size_t buflen, bool ascii)
 {
 	unsigned int i = 0;
-	int rs = (get_random_u32_below(2) + 1) * 16;
+	int rs = get_random_u32_inclusive(1, 2) * 16;
 
 	do {
 		int gs = 1 << i;
-		size_t len = get_random_u32_below(rs) + gs;
+		size_t len = get_random_u32_inclusive(gs, rs + gs - 1);
 
 		test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, ascii);
 	} while (i++ < 3);
@@ -223,11 +223,11 @@ static int __init test_hexdump_init(void)
 	unsigned int i;
 	int rowsize;
 
-	rowsize = (get_random_u32_below(2) + 1) * 16;
+	rowsize = get_random_u32_inclusive(1, 2) * 16;
 	for (i = 0; i < 16; i++)
 		test_hexdump_set(rowsize, false);
 
-	rowsize = (get_random_u32_below(2) + 1) * 16;
+	rowsize = get_random_u32_inclusive(1, 2) * 16;
 	for (i = 0; i < 16; i++)
 		test_hexdump_set(rowsize, true);
 
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 6d10187eddac..f098914a48d5 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -126,7 +126,7 @@ __test(const char *expect, int elen, const char *fmt, ...)
 	 * be able to print it as expected.
 	 */
 	failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
-	rand = 1 + get_random_u32_below(elen + 1);
+	rand = get_random_u32_inclusive(1, elen + 1);
 	/* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 	failed_tests += do_test(rand, expect, elen, fmt, ap);
 	failed_tests += do_test(0, expect, elen, fmt, ap);
diff --git a/lib/test_vmalloc.c b/lib/test_vmalloc.c
index 104f09ea5fcc..f90d2c27675b 100644
--- a/lib/test_vmalloc.c
+++ b/lib/test_vmalloc.c
@@ -151,7 +151,7 @@ static int random_size_alloc_test(void)
 	int i;
 
 	for (i = 0; i < test_loop_count; i++) {
-		n = get_random_u32_below(100) + 1;
+		n = get_random_u32_inclusive(1, 100);
 		p = vmalloc(n * PAGE_SIZE);
 
 		if (!p)
@@ -291,12 +291,12 @@ pcpu_alloc_test(void)
 		return -1;
 
 	for (i = 0; i < 35000; i++) {
-		size = get_random_u32_below(PAGE_SIZE / 4) + 1;
+		size = get_random_u32_inclusive(1, PAGE_SIZE / 4);
 
 		/*
 		 * Maximum PAGE_SIZE
 		 */
-		align = 1 << (get_random_u32_below(11) + 1);
+		align = 1 << get_random_u32_inclusive(1, 11);
 
 		pcpu[i] = __alloc_percpu(size, align);
 		if (!pcpu[i])
diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c
index 640f9c7f8e44..54181eba3e24 100644
--- a/mm/kasan/kasan_test.c
+++ b/mm/kasan/kasan_test.c
@@ -1299,7 +1299,7 @@ static void match_all_not_assigned(struct kunit *test)
 	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
 
 	for (i = 0; i < 256; i++) {
-		size = get_random_u32_below(1024) + 1;
+		size = get_random_u32_inclusive(1, 1024);
 		ptr = kmalloc(size, GFP_KERNEL);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
@@ -1308,7 +1308,7 @@ static void match_all_not_assigned(struct kunit *test)
 	}
 
 	for (i = 0; i < 256; i++) {
-		order = get_random_u32_below(4) + 1;
+		order = get_random_u32_inclusive(1, 4);
 		pages = alloc_pages(GFP_KERNEL, order);
 		ptr = page_address(pages);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
@@ -1321,7 +1321,7 @@ static void match_all_not_assigned(struct kunit *test)
 		return;
 
 	for (i = 0; i < 256; i++) {
-		size = get_random_u32_below(1024) + 1;
+		size = get_random_u32_inclusive(1, 1024);
 		ptr = vmalloc(size);
 		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 		KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index 20028c179796..b5d66a69200d 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -532,7 +532,7 @@ static void test_free_bulk(struct kunit *test)
 	int iter;
 
 	for (iter = 0; iter < 5; iter++) {
-		const size_t size = setup_test_cache(test, 8 + get_random_u32_below(300),
+		const size_t size = setup_test_cache(test, get_random_u32_inclusive(8, 307),
 						     0, (iter & 1) ? ctor_set_x : NULL);
 		void *objects[] = {
 			test_alloc(test, size, GFP_KERNEL, ALLOCATE_RIGHT),
diff --git a/mm/swapfile.c b/mm/swapfile.c
index e9318305a24a..4ee31056d3f8 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -772,8 +772,7 @@ static void set_cluster_next(struct swap_info_struct *si, unsigned long next)
 		/* No free swap slots available */
 		if (si->highest_bit <= si->lowest_bit)
 			return;
-		next = si->lowest_bit +
-			get_random_u32_below(si->highest_bit - si->lowest_bit + 1);
+		next = get_random_u32_inclusive(si->lowest_bit, si->highest_bit);
 		next = ALIGN_DOWN(next, SWAP_ADDRESS_SPACE_PAGES);
 		next = max_t(unsigned int, next, si->lowest_bit);
 	}
@@ -3089,7 +3088,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 		 */
 		for_each_possible_cpu(cpu) {
 			per_cpu(*p->cluster_next_cpu, cpu) =
-				1 + get_random_u32_below(p->highest_bit);
+				get_random_u32_inclusive(1, p->highest_bit);
 		}
 		nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
 
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index b2f9679066c4..81ce668b0b77 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -7373,9 +7373,8 @@ static int get_conn_info(struct sock *sk, struct hci_dev *hdev, void *data,
 	/* To avoid client trying to guess when to poll again for information we
 	 * calculate conn info age as random value between min/max set in hdev.
 	 */
-	conn_info_age = hdev->conn_info_min_age +
-			get_random_u32_below(hdev->conn_info_max_age -
-					     hdev->conn_info_min_age);
+	conn_info_age = get_random_u32_inclusive(hdev->conn_info_min_age,
+						 hdev->conn_info_max_age - 1);
 
 	/* Query controller to refresh cached values if they are too old or were
 	 * never read.
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 95da2ddc1c20..760238196db1 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2380,9 +2380,8 @@ static void set_cur_queue_map(struct pktgen_dev *pkt_dev)
 	else if (pkt_dev->queue_map_min <= pkt_dev->queue_map_max) {
 		__u16 t;
 		if (pkt_dev->flags & F_QUEUE_MAP_RND) {
-			t = get_random_u32_below(pkt_dev->queue_map_max -
-						 pkt_dev->queue_map_min + 1) +
-			    pkt_dev->queue_map_min;
+			t = get_random_u32_inclusive(pkt_dev->queue_map_min,
+						     pkt_dev->queue_map_max);
 		} else {
 			t = pkt_dev->cur_queue_map + 1;
 			if (t > pkt_dev->queue_map_max)
@@ -2478,9 +2477,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 
 	if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
 		if (pkt_dev->flags & F_UDPSRC_RND)
-			pkt_dev->cur_udp_src = get_random_u32_below(
-				pkt_dev->udp_src_max - pkt_dev->udp_src_min) +
-				pkt_dev->udp_src_min;
+			pkt_dev->cur_udp_src = get_random_u32_inclusive(pkt_dev->udp_src_min,
+									pkt_dev->udp_src_max - 1);
 
 		else {
 			pkt_dev->cur_udp_src++;
@@ -2491,9 +2489,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 
 	if (pkt_dev->udp_dst_min < pkt_dev->udp_dst_max) {
 		if (pkt_dev->flags & F_UDPDST_RND) {
-			pkt_dev->cur_udp_dst = get_random_u32_below(
-				pkt_dev->udp_dst_max - pkt_dev->udp_dst_min) +
-				pkt_dev->udp_dst_min;
+			pkt_dev->cur_udp_dst = get_random_u32_inclusive(pkt_dev->udp_dst_min,
+									pkt_dev->udp_dst_max - 1);
 		} else {
 			pkt_dev->cur_udp_dst++;
 			if (pkt_dev->cur_udp_dst >= pkt_dev->udp_dst_max)
@@ -2508,7 +2505,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 		if (imn < imx) {
 			__u32 t;
 			if (pkt_dev->flags & F_IPSRC_RND)
-				t = get_random_u32_below(imx - imn) + imn;
+				t = get_random_u32_inclusive(imn, imx - 1);
 			else {
 				t = ntohl(pkt_dev->cur_saddr);
 				t++;
@@ -2530,8 +2527,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 				if (pkt_dev->flags & F_IPDST_RND) {
 
 					do {
-						t = get_random_u32_below(imx - imn) +
-						    imn;
+						t = get_random_u32_inclusive(imn, imx - 1);
 						s = htonl(t);
 					} while (ipv4_is_loopback(s) ||
 						ipv4_is_multicast(s) ||
@@ -2578,9 +2574,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
 	if (pkt_dev->min_pkt_size < pkt_dev->max_pkt_size) {
 		__u32 t;
 		if (pkt_dev->flags & F_TXSIZE_RND) {
-			t = get_random_u32_below(pkt_dev->max_pkt_size -
-						 pkt_dev->min_pkt_size) +
-			    pkt_dev->min_pkt_size;
+			t = get_random_u32_inclusive(pkt_dev->min_pkt_size,
+						     pkt_dev->max_pkt_size - 1);
 		} else {
 			t = pkt_dev->cur_pkt_size + 1;
 			if (t > pkt_dev->max_pkt_size)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3b076e5ba932..23cf418efe4f 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3647,7 +3647,7 @@ static void tcp_send_challenge_ack(struct sock *sk)
 
 		WRITE_ONCE(net->ipv4.tcp_challenge_timestamp, now);
 		WRITE_ONCE(net->ipv4.tcp_challenge_count,
-			   half + get_random_u32_below(ack_limit));
+			   get_random_u32_inclusive(half, ack_limit + half - 1));
 	}
 	count = READ_ONCE(net->ipv4.tcp_challenge_count);
 	if (count > 0) {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index daf89a2eb492..d720f6f5de3f 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -104,7 +104,7 @@ static inline u32 cstamp_delta(unsigned long cstamp)
 static inline s32 rfc3315_s14_backoff_init(s32 irt)
 {
 	/* multiply 'initial retransmission time' by 0.9 .. 1.1 */
-	u64 tmp = (900000 + get_random_u32_below(200001)) * (u64)irt;
+	u64 tmp = get_random_u32_inclusive(900000, 1100000) * (u64)irt;
 	do_div(tmp, 1000000);
 	return (s32)tmp;
 }
@@ -112,11 +112,11 @@ static inline s32 rfc3315_s14_backoff_init(s32 irt)
 static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
 {
 	/* multiply 'retransmission timeout' by 1.9 .. 2.1 */
-	u64 tmp = (1900000 + get_random_u32_below(200001)) * (u64)rt;
+	u64 tmp = get_random_u32_inclusive(1900000, 2100000) * (u64)rt;
 	do_div(tmp, 1000000);
 	if ((s32)tmp > mrt) {
 		/* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
-		tmp = (900000 + get_random_u32_below(200001)) * (u64)mrt;
+		tmp = get_random_u32_inclusive(900000, 1100000) * (u64)mrt;
 		do_div(tmp, 1000000);
 	}
 	return (s32)tmp;
diff --git a/net/netfilter/nf_nat_helper.c b/net/netfilter/nf_nat_helper.c
index bf591e6af005..67e56456615f 100644
--- a/net/netfilter/nf_nat_helper.c
+++ b/net/netfilter/nf_nat_helper.c
@@ -223,7 +223,7 @@ u16 nf_nat_exp_find_port(struct nf_conntrack_expect *exp, u16 port)
 		if (res != -EBUSY || (--attempts_left < 0))
 			break;
 
-		port = min + get_random_u32_below(range);
+		port = get_random_u32_inclusive(min, range + min - 1);
 	}
 
 	return 0;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 40f831854774..d63a3644ee1a 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2072,7 +2072,7 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
 	} else {
 		u32 spi = 0;
 		for (h = 0; h < high-low+1; h++) {
-			spi = low + get_random_u32_below(high - low + 1);
+			spi = get_random_u32_inclusive(low, high);
 			x0 = xfrm_state_lookup(net, mark, &x->id.daddr, htonl(spi), x->id.proto, x->props.family);
 			if (x0 == NULL) {
 				newspi = htonl(spi);
-- 
2.38.1


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* Re: [PATCH v3 3/3] treewide: use get_random_u32_inclusive() when possible
  2022-11-17 20:29   ` [PATCH v3 3/3] treewide: use get_random_u32_inclusive() when possible Jason A. Donenfeld
@ 2022-11-17 21:57     ` Kees Cook
  2022-11-17 22:10       ` Jason A. Donenfeld
  0 siblings, 1 reply; 24+ messages in thread
From: Kees Cook @ 2022-11-17 21:57 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc

On Thu, Nov 17, 2022 at 09:29:06PM +0100, Jason A. Donenfeld wrote:
> These cases were done with this Coccinelle:
> 
> @@
> expression H;
> expression L;
> @@
> - (get_random_u32_below(H) + L)
> + get_random_u32_inclusive(L, H + L - 1)
> 
> @@
> expression H;
> expression L;
> expression E;
> @@
>   get_random_u32_inclusive(L,
>   H
> - + E
> - - E
>   )
> 
> @@
> expression H;
> expression L;
> expression E;
> @@
>   get_random_u32_inclusive(L,
>   H
> - - E
> - + E
>   )
> 
> @@
> expression H;
> expression L;
> expression E;
> expression F;
> @@
>   get_random_u32_inclusive(L,
>   H
> - - E
>   + F
> - + E
>   )
> 
> @@
> expression H;
> expression L;
> expression E;
> expression F;
> @@
>   get_random_u32_inclusive(L,
>   H
> - + E
>   + F
> - - E
>   )
> 
> And then subsequently cleaned up by hand, with several automatic cases
> rejected if it didn't make sense contextually.
> 
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> ---
>  arch/x86/kernel/module.c                      |  2 +-
>  crypto/rsa-pkcs1pad.c                         |  2 +-
>  crypto/testmgr.c                              | 10 ++++----
>  drivers/bus/mhi/host/internal.h               |  2 +-
>  drivers/dma-buf/st-dma-fence-chain.c          |  2 +-
>  drivers/infiniband/core/cma.c                 |  2 +-
>  drivers/infiniband/hw/hns/hns_roce_ah.c       |  5 ++--
>  drivers/mtd/nand/raw/nandsim.c                |  2 +-
>  drivers/net/wireguard/selftest/allowedips.c   |  8 +++---
>  .../broadcom/brcm80211/brcmfmac/p2p.c         |  2 +-
>  .../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c |  2 +-
>  fs/f2fs/segment.c                             |  6 ++---
>  kernel/kcsan/selftest.c                       |  2 +-
>  lib/test_hexdump.c                            | 10 ++++----
>  lib/test_printf.c                             |  2 +-
>  lib/test_vmalloc.c                            |  6 ++---
>  mm/kasan/kasan_test.c                         |  6 ++---
>  mm/kfence/kfence_test.c                       |  2 +-
>  mm/swapfile.c                                 |  5 ++--
>  net/bluetooth/mgmt.c                          |  5 ++--
>  net/core/pktgen.c                             | 25 ++++++++-----------
>  net/ipv4/tcp_input.c                          |  2 +-
>  net/ipv6/addrconf.c                           |  6 ++---
>  net/netfilter/nf_nat_helper.c                 |  2 +-
>  net/xfrm/xfrm_state.c                         |  2 +-
>  25 files changed, 56 insertions(+), 64 deletions(-)

Even the diffstat agrees this is a nice clean-up. :)

Reviewed-by: Kees Cook <keescook@chromium.org>

The only comment I have is that maybe these cases can just be left as-is
with _below()?

> -             size_t len = get_random_u32_below(rs) + gs;
> +             size_t len = get_random_u32_inclusive(gs, rs + gs - 1);

It seems like writing it in the form of base plus [0, limit) is clearer?

		size_t len = gs + get_random_u32_below(rs);

But there is only a handful, so *shrug*

All the others are much cleaner rewritten as _inclusive().

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v3 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop
  2022-11-17 20:29   ` [PATCH v3 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop Jason A. Donenfeld
@ 2022-11-17 21:58     ` Kees Cook
  0 siblings, 0 replies; 24+ messages in thread
From: Kees Cook @ 2022-11-17 21:58 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc

On Thu, Nov 17, 2022 at 09:29:05PM +0100, Jason A. Donenfeld wrote:
> These cases were done with this Coccinelle:
> 
> @@
> expression E;
> identifier I;
> @@
> -   do {
>       ... when != I
> -     I = get_random_u32();
>       ... when != I
> -   } while (I > E);
> +   I = get_random_u32_below(E + 1);
> 
> @@
> expression E;
> identifier I;
> @@
> -   do {
>       ... when != I
> -     I = get_random_u32();
>       ... when != I
> -   } while (I >= E);
> +   I = get_random_u32_below(E);
> 
> @@
> expression E;
> identifier I;
> @@
> -   do {
>       ... when != I
> -     I = get_random_u32();
>       ... when != I
> -   } while (I < E);
> +   I = get_random_u32_above(E - 1);
> 
> @@
> expression E;
> identifier I;
> @@
> -   do {
>       ... when != I
> -     I = get_random_u32();
>       ... when != I
> -   } while (I <= E);
> +   I = get_random_u32_above(E);
> 
> @@
> identifier I;
> @@
> -   do {
>       ... when != I
> -     I = get_random_u32();
>       ... when != I
> -   } while (!I);
> +   I = get_random_u32_above(0);
> 
> @@
> identifier I;
> @@
> -   do {
>       ... when != I
> -     I = get_random_u32();
>       ... when != I
> -   } while (I == 0);
> +   I = get_random_u32_above(0);
> 
> @@
> expression E;
> @@
> - E + 1 + get_random_u32_below(U32_MAX - E)
> + get_random_u32_above(E)
> 
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v3 1/3] treewide: use get_random_u32_below() instead of deprecated function
  2022-11-17 20:29   ` [PATCH v3 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
@ 2022-11-17 21:59     ` Kees Cook
  0 siblings, 0 replies; 24+ messages in thread
From: Kees Cook @ 2022-11-17 21:59 UTC (permalink / raw)
  To: Jason A. Donenfeld
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, Russell King, Ulf Hansson

On Thu, Nov 17, 2022 at 09:29:04PM +0100, Jason A. Donenfeld wrote:
> This is a simple mechanical transformation done by:
> 
> @@
> expression E;
> @@
> - prandom_u32_max
> + get_random_u32_below
>   (E)
> 
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
> Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v3 3/3] treewide: use get_random_u32_inclusive() when possible
  2022-11-17 21:57     ` Kees Cook
@ 2022-11-17 22:10       ` Jason A. Donenfeld
  0 siblings, 0 replies; 24+ messages in thread
From: Jason A. Donenfeld @ 2022-11-17 22:10 UTC (permalink / raw)
  To: Kees Cook
  Cc: linux-kernel, patches, Greg Kroah-Hartman, Jakub Kicinski,
	Russell King, Catalin Marinas, Thomas Bogendoerfer,
	Heiko Carstens, Herbert Xu, Christoph Böhmwalder,
	Jani Nikula, Jason Gunthorpe, Sakari Ailus, Martin K . Petersen,
	Theodore Ts'o, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc

On Thu, Nov 17, 2022 at 01:57:13PM -0800, Kees Cook wrote:
> The only comment I have is that maybe these cases can just be left as-is
> with _below()?
> 
> > -             size_t len = get_random_u32_below(rs) + gs;
> > +             size_t len = get_random_u32_inclusive(gs, rs + gs - 1);
> 
> It seems like writing it in the form of base plus [0, limit) is clearer?
> 
> 		size_t len = gs + get_random_u32_below(rs);
> 
> But there is only a handful, so *shrug*

Okay, I'll drop that one.

Jason

^ permalink raw reply	[flat|nested] 24+ messages in thread

* RE: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible
  2022-11-17 15:42               ` Theodore Ts'o
  2022-11-17 16:19                 ` Jason A. Donenfeld
@ 2022-11-17 22:15                 ` David Laight
  1 sibling, 0 replies; 24+ messages in thread
From: David Laight @ 2022-11-17 22:15 UTC (permalink / raw)
  To: 'Theodore Ts'o', Kees Cook
  Cc: Jason A. Donenfeld, Kees Cook, linux-kernel, patches,
	Greg Kroah-Hartman, Jakub Kicinski, Russell King,
	Catalin Marinas, Thomas Bogendoerfer, Heiko Carstens, Herbert Xu,
	Christoph Böhmwalder, Jani Nikula, Jason Gunthorpe,
	Sakari Ailus, Martin K . Petersen, Andreas Dilger, Jaegeuk Kim,
	Richard Weinberger, Darrick J . Wong, SeongJae Park,
	Thomas Gleixner, Andrew Morton, Michael Ellerman, Helge Deller,
	netdev, linux-crypto, linux-block, linux-fsdevel, linux-media,
	linux-arm-kernel, loongarch, linux-mips, linuxppc-dev, linux-mmc,
	linux-parisc, ydroneaud

From: Theodore Ts'o
> Sent: 17 November 2022 15:43
...
> The problem with "between", "ranged", "spanning" is that they don't
> tell the reader whether we're dealing with an "open interval" or a
> "closed interval".  They are just different ways of saying that it's a
> range between, say, 0 and 20.  But it doesn't tell you whether it
> includes 0 or 20 or not.
> 
> The only way I can see for making it ambiguous is either to use the
> terminology "closed interval" or "inclusive".  And "open" and "closed"
> can have other meanings, so get_random_u32_inclusive() is going to be
> less confusing than get_random_u32_closed().

It has to be said that removing the extra function and requiring
the callers use 'base + get_random_below(high [+1] - base)' is
likely to be the only way to succinctly make the code readable
and understandable.

Otherwise readers either have to look up another function to see
what it does or waste variable brain cells on more trivia.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


^ permalink raw reply	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2022-11-17 22:16 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-11-14 16:45 [PATCH v2 0/3] convert tree to get_random_u32_{below,above,between}() Jason A. Donenfeld
2022-11-14 16:45 ` [PATCH v2 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
2022-11-14 17:35   ` Russell King (Oracle)
2022-11-14 16:45 ` [PATCH v2 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop Jason A. Donenfeld
2022-11-14 16:45 ` [PATCH v2 3/3] treewide: use get_random_u32_between() when possible Jason A. Donenfeld
2022-11-16 22:43   ` Kees Cook
2022-11-16 23:55     ` Jason A. Donenfeld
2022-11-17  0:03       ` Jason A. Donenfeld
2022-11-17  0:31         ` Kees Cook
2022-11-17  0:43           ` Jason A. Donenfeld
2022-11-17  0:47             ` Kees Cook
2022-11-17 15:42               ` Theodore Ts'o
2022-11-17 16:19                 ` Jason A. Donenfeld
2022-11-17 22:15                 ` David Laight
2022-11-17  2:05       ` Jason A. Donenfeld
2022-11-17 10:32         ` Russell King (Oracle)
2022-11-17 20:29 ` [PATCH v3 0/3] convert tree to get_random_u32_{below,above,inclusive}() Jason A. Donenfeld
2022-11-17 20:29   ` [PATCH v3 1/3] treewide: use get_random_u32_below() instead of deprecated function Jason A. Donenfeld
2022-11-17 21:59     ` Kees Cook
2022-11-17 20:29   ` [PATCH v3 2/3] treewide: use get_random_u32_{above,below}() instead of manual loop Jason A. Donenfeld
2022-11-17 21:58     ` Kees Cook
2022-11-17 20:29   ` [PATCH v3 3/3] treewide: use get_random_u32_inclusive() when possible Jason A. Donenfeld
2022-11-17 21:57     ` Kees Cook
2022-11-17 22:10       ` Jason A. Donenfeld

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