[PATCH AUTOSEL 5.0 010/317] tools/bpf: fix perf build error with uClibc (seen on ARC)

[PATCH AUTOSEL 5.0 010/317] tools/bpf: fix perf build error with uClibc (seen on ARC)

[Sasha Levin]

From: Vineet Gupta <Vineet.Gupta1@synopsys.com>

[ Upstream commit ca31ca8247e2d3807ff5fa1d1760616a2292001c ]

When build perf for ARC recently, there was a build failure due to lack
of __NR_bpf.

| Auto-detecting system features:
|
| ...                     get_cpuid: [ OFF ]
| ...                           bpf: [ on  ]
|
| #  error __NR_bpf not defined. libbpf does not support your arch.
    ^~~~~
| bpf.c: In function 'sys_bpf':
| bpf.c:66:17: error: '__NR_bpf' undeclared (first use in this function)
|  return syscall(__NR_bpf, cmd, attr, size);
|                 ^~~~~~~~
|                 sys_bpf

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/lib/bpf/bpf.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 88cbd110ae580..ddeb46c9eef2f 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -45,6 +45,8 @@
 #  define __NR_bpf 349
 # elif defined(__s390__)
 #  define __NR_bpf 351
+# elif defined(__arc__)
+#  define __NR_bpf 280
 # else
 #  error __NR_bpf not defined. libbpf does not support your arch.
 # endif
-- 
2.20.1

[PATCH AUTOSEL 5.0 011/317] selftests/bpf: set RLIMIT_MEMLOCK properly for test_libbpf_open.c

[Sasha Levin]

From: Yonghong Song <yhs@fb.com>

[ Upstream commit 6cea33701eb024bc6c920ab83940ee22afd29139 ]

Test test_libbpf.sh failed on my development server with failure
  -bash-4.4$ sudo ./test_libbpf.sh
  [0] libbpf: Error in bpf_object__probe_name():Operation not permitted(1).
      Couldn't load basic 'r0 = 0' BPF program.
  test_libbpf: failed at file test_l4lb.o
  selftests: test_libbpf [FAILED]
  -bash-4.4$

The reason is because my machine has 64KB locked memory by default which
is not enough for this program to get locked memory.
Similar to other bpf selftests, let us increase RLIMIT_MEMLOCK
to infinity, which fixed the issue.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/test_libbpf_open.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_libbpf_open.c b/tools/testing/selftests/bpf/test_libbpf_open.c
index 8fcd1c076add0..cbd55f5f8d598 100644
--- a/tools/testing/selftests/bpf/test_libbpf_open.c
+++ b/tools/testing/selftests/bpf/test_libbpf_open.c
@@ -11,6 +11,8 @@ static const char *__doc__ =
 #include <bpf/libbpf.h>
 #include <getopt.h>
 
+#include "bpf_rlimit.h"
+
 static const struct option long_options[] = {
 	{"help",	no_argument,		NULL, 'h' },
 	{"debug",	no_argument,		NULL, 'D' },
-- 
2.20.1

[PATCH AUTOSEL 5.0 012/317] bpftool: exclude bash-completion/bpftool from .gitignore pattern

[Sasha Levin]

From: Masahiro Yamada <yamada.masahiro@socionext.com>

[ Upstream commit a7d006714724de4334c5e3548701b33f7b12ca96 ]

tools/bpf/bpftool/.gitignore has the "bpftool" pattern, which is
intended to ignore the following build artifact:

  tools/bpf/bpftool/bpftool

However, the .gitignore entry is effective not only for the current
directory, but also for any sub-directories.

So, from the point of .gitignore grammar, the following check-in file
is also considered to be ignored:

  tools/bpf/bpftool/bash-completion/bpftool

As the manual gitignore(5) says "Files already tracked by Git are not
affected", this is not a problem as far as Git is concerned.

However, Git is not the only program that parses .gitignore because
.gitignore is useful to distinguish build artifacts from source files.

For example, tar(1) supports the --exclude-vcs-ignore option. As of
writing, this option does not work perfectly, but it intends to create
a tarball excluding files specified by .gitignore.

So, I believe it is better to fix this issue.

You can fix it by prefixing the pattern with a slash; the leading slash
means the specified pattern is relative to the current directory.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/bpf/bpftool/.gitignore | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/.gitignore b/tools/bpf/bpftool/.gitignore
index 67167e44b7266..8248b8dd89d4b 100644
--- a/tools/bpf/bpftool/.gitignore
+++ b/tools/bpf/bpftool/.gitignore
@@ -1,5 +1,5 @@
 *.d
-bpftool
+/bpftool
 bpftool*.8
 bpf-helpers.*
 FEATURE-DUMP.bpftool
-- 
2.20.1

[PATCH AUTOSEL 5.0 048/317] x86/modules: Avoid breaking W^X while loading modules

[Sasha Levin]

From: Nadav Amit <namit@vmware.com>

[ Upstream commit f2c65fb3221adc6b73b0549fc7ba892022db9797 ]

When modules and BPF filters are loaded, there is a time window in
which some memory is both writable and executable. An attacker that has
already found another vulnerability (e.g., a dangling pointer) might be
able to exploit this behavior to overwrite kernel code. Prevent having
writable executable PTEs in this stage.

In addition, avoiding having W+X mappings can also slightly simplify the
patching of modules code on initialization (e.g., by alternatives and
static-key), as would be done in the next patch. This was actually the
main motivation for this patch.

To avoid having W+X mappings, set them initially as RW (NX) and after
they are set as RO set them as X as well. Setting them as executable is
done as a separate step to avoid one core in which the old PTE is cached
(hence writable), and another which sees the updated PTE (executable),
which would break the W^X protection.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lkml.kernel.org/r/20190426001143.4983-12-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/kernel/alternative.c | 28 +++++++++++++++++++++-------
 arch/x86/kernel/module.c      |  2 +-
 include/linux/filter.h        |  1 +
 kernel/module.c               |  5 +++++
 4 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index ebeac487a20c7..2db985513917a 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -666,15 +666,29 @@ void __init alternative_instructions(void)
  * handlers seeing an inconsistent instruction while you patch.
  */
 void *__init_or_module text_poke_early(void *addr, const void *opcode,
-					      size_t len)
+				       size_t len)
 {
 	unsigned long flags;
-	local_irq_save(flags);
-	memcpy(addr, opcode, len);
-	local_irq_restore(flags);
-	sync_core();
-	/* Could also do a CLFLUSH here to speed up CPU recovery; but
-	   that causes hangs on some VIA CPUs. */
+
+	if (boot_cpu_has(X86_FEATURE_NX) &&
+	    is_module_text_address((unsigned long)addr)) {
+		/*
+		 * Modules text is marked initially as non-executable, so the
+		 * code cannot be running and speculative code-fetches are
+		 * prevented. Just change the code.
+		 */
+		memcpy(addr, opcode, len);
+	} else {
+		local_irq_save(flags);
+		memcpy(addr, opcode, len);
+		local_irq_restore(flags);
+		sync_core();
+
+		/*
+		 * Could also do a CLFLUSH here to speed up CPU recovery; but
+		 * that causes hangs on some VIA CPUs.
+		 */
+	}
 	return addr;
 }
 
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index b052e883dd8cc..cfa3106faee42 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -87,7 +87,7 @@ void *module_alloc(unsigned long size)
 	p = __vmalloc_node_range(size, MODULE_ALIGN,
 				    MODULES_VADDR + get_module_load_offset(),
 				    MODULES_END, GFP_KERNEL,
-				    PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
+				    PAGE_KERNEL, 0, NUMA_NO_NODE,
 				    __builtin_return_address(0));
 	if (p && (kasan_module_alloc(p, size) < 0)) {
 		vfree(p);
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 3358646a8e7a7..42513fa6846c9 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -709,6 +709,7 @@ static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
 {
 	set_memory_ro((unsigned long)hdr, hdr->pages);
+	set_memory_x((unsigned long)hdr, hdr->pages);
 }
 
 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
diff --git a/kernel/module.c b/kernel/module.c
index 2ad1b52399109..ae1b77da6a200 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1950,8 +1950,13 @@ void module_enable_ro(const struct module *mod, bool after_init)
 		return;
 
 	frob_text(&mod->core_layout, set_memory_ro);
+	frob_text(&mod->core_layout, set_memory_x);
+
 	frob_rodata(&mod->core_layout, set_memory_ro);
+
 	frob_text(&mod->init_layout, set_memory_ro);
+	frob_text(&mod->init_layout, set_memory_x);
+
 	frob_rodata(&mod->init_layout, set_memory_ro);
 
 	if (after_init)
-- 
2.20.1

[PATCH AUTOSEL 5.0 068/317] libbpf: fix samples/bpf build failure due to undefined UINT32_MAX

[Sasha Levin]

From: "Daniel T. Lee" <danieltimlee@gmail.com>

[ Upstream commit 32e621e55496a0009f44fe4914cd4a23cade4984 ]

Currently, building bpf samples will cause the following error.

    ./tools/lib/bpf/bpf.h:132:27: error: 'UINT32_MAX' undeclared here (not in a function) ..
     #define BPF_LOG_BUF_SIZE (UINT32_MAX >> 8) /* verifier maximum in kernels <= 5.1 */
                               ^
    ./samples/bpf/bpf_load.h:31:25: note: in expansion of macro 'BPF_LOG_BUF_SIZE'
     extern char bpf_log_buf[BPF_LOG_BUF_SIZE];
                             ^~~~~~~~~~~~~~~~

Due to commit 4519efa6f8ea ("libbpf: fix BPF_LOG_BUF_SIZE off-by-one error")
hard-coded size of BPF_LOG_BUF_SIZE has been replaced with UINT32_MAX which is
defined in <stdint.h> header.

Even with this change, bpf selftests are running fine since these are built
with clang and it includes header(-idirafter) from clang/6.0.0/include.
(it has <stdint.h>)

    clang -I. -I./include/uapi -I../../../include/uapi -idirafter /usr/local/include -idirafter /usr/include \
    -idirafter /usr/lib/llvm-6.0/lib/clang/6.0.0/include -idirafter /usr/include/x86_64-linux-gnu \
    -Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm -c progs/test_sysctl_prog.c -o - | \
    llc -march=bpf -mcpu=generic  -filetype=obj -o /linux/tools/testing/selftests/bpf/test_sysctl_prog.o

But bpf samples are compiled with GCC, and it only searches and includes
headers declared at the target file. As '#include <stdint.h>' hasn't been
declared in tools/lib/bpf/bpf.h, it causes build failure of bpf samples.

    gcc -Wp,-MD,./samples/bpf/.sockex3_user.o.d -Wall -Wmissing-prototypes -Wstrict-prototypes \
    -O2 -fomit-frame-pointer -std=gnu89 -I./usr/include -I./tools/lib/ -I./tools/testing/selftests/bpf/ \
    -I./tools/  lib/ -I./tools/include -I./tools/perf -c -o ./samples/bpf/sockex3_user.o ./samples/bpf/sockex3_user.c;

This commit add declaration of '#include <stdint.h>' to tools/lib/bpf/bpf.h
to fix this problem.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/lib/bpf/bpf.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 8f09de482839e..64762a62c008d 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -26,6 +26,7 @@
 #include <linux/bpf.h>
 #include <stdbool.h>
 #include <stddef.h>
+#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {
-- 
2.20.1

[PATCH AUTOSEL 5.0 081/317] ssb: Fix possible NULL pointer dereference in ssb_host_pcmcia_exit

[Sasha Levin]

From: YueHaibing <yuehaibing@huawei.com>

[ Upstream commit b2c01aab9646ed8ffb7c549afe55d5349c482425 ]

Syzkaller report this:

kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN PTI
CPU: 0 PID: 4492 Comm: syz-executor.0 Not tainted 5.0.0-rc7+ #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:sysfs_remove_file_ns+0x27/0x70 fs/sysfs/file.c:468
Code: 00 00 00 41 54 55 48 89 fd 53 49 89 d4 48 89 f3 e8 ee 76 9c ff 48 8d 7d 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 2d 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 8b 6d
RSP: 0018:ffff8881e9d9fc00 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffffffff900367e0 RCX: ffffffff81a95952
RDX: 0000000000000006 RSI: ffffc90001405000 RDI: 0000000000000030
RBP: 0000000000000000 R08: fffffbfff1fa22ed R09: fffffbfff1fa22ed
R10: 0000000000000001 R11: fffffbfff1fa22ec R12: 0000000000000000
R13: ffffffffc1abdac0 R14: 1ffff1103d3b3f8b R15: 0000000000000000
FS:  00007fe409dc1700(0000) GS:ffff8881f1200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d721000 CR3: 00000001e98b6005 CR4: 00000000007606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 sysfs_remove_file include/linux/sysfs.h:519 [inline]
 driver_remove_file+0x40/0x50 drivers/base/driver.c:122
 pcmcia_remove_newid_file drivers/pcmcia/ds.c:163 [inline]
 pcmcia_unregister_driver+0x7d/0x2b0 drivers/pcmcia/ds.c:209
 ssb_modexit+0xa/0x1b [ssb]
 __do_sys_delete_module kernel/module.c:1018 [inline]
 __se_sys_delete_module kernel/module.c:961 [inline]
 __x64_sys_delete_module+0x3dc/0x5e0 kernel/module.c:961
 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x462e99
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe409dc0c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe409dc16bc
R13: 00000000004bccaa R14: 00000000006f6bc8 R15: 00000000ffffffff
Modules linked in: ssb(-) 3c59x nvme_core macvlan tap pata_hpt3x3 rt2x00pci null_blk tsc40 pm_notifier_error_inject notifier_error_inject mdio cdc_wdm nf_reject_ipv4 ath9k_common ath9k_hw ath pppox ppp_generic slhc ehci_platform wl12xx wlcore tps6507x_ts ioc4 nf_synproxy_core ide_gd_mod ax25 can_dev iwlwifi can_raw atm tm2_touchkey can_gw can sundance adp5588_keys rt2800mmio rt2800lib rt2x00mmio rt2x00lib eeprom_93cx6 pn533 lru_cache elants_i2c ip_set nfnetlink gameport tipc hampshire nhc_ipv6 nhc_hop nhc_udp nhc_fragment nhc_routing nhc_mobility nhc_dest 6lowpan silead brcmutil nfc mt76_usb mt76 mac80211 iptable_security iptable_raw iptable_mangle iptable_nat nf_nat_ipv4 nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_gre sit hsr veth vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon vcan bridge stp llc ip6_gre ip6_tunnel tunnel6 tun joydev mousedev serio_raw ide_pci_generic piix floppy ide_core sch_fq_codel ip_tables x_tables ipv6
 [last unloaded: 3c59x]
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace 3913cbf8011e1c05 ]---

In ssb_modinit, it does not fail SSB init when ssb_host_pcmcia_init failed,
however in ssb_modexit, ssb_host_pcmcia_exit calls pcmcia_unregister_driver
unconditionally, which may tigger a NULL pointer dereference issue as above.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 399500da18f7 ("ssb: pick PCMCIA host code support from b43 driver")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/ssb/bridge_pcmcia_80211.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/ssb/bridge_pcmcia_80211.c b/drivers/ssb/bridge_pcmcia_80211.c
index f51f150307dfb..ffa379efff83c 100644
--- a/drivers/ssb/bridge_pcmcia_80211.c
+++ b/drivers/ssb/bridge_pcmcia_80211.c
@@ -113,16 +113,21 @@ static struct pcmcia_driver ssb_host_pcmcia_driver = {
 	.resume		= ssb_host_pcmcia_resume,
 };
 
+static int pcmcia_init_failed;
+
 /*
  * These are not module init/exit functions!
  * The module_pcmcia_driver() helper cannot be used here.
  */
 int ssb_host_pcmcia_init(void)
 {
-	return pcmcia_register_driver(&ssb_host_pcmcia_driver);
+	pcmcia_init_failed = pcmcia_register_driver(&ssb_host_pcmcia_driver);
+
+	return pcmcia_init_failed;
 }
 
 void ssb_host_pcmcia_exit(void)
 {
-	pcmcia_unregister_driver(&ssb_host_pcmcia_driver);
+	if (!pcmcia_init_failed)
+		pcmcia_unregister_driver(&ssb_host_pcmcia_driver);
 }
-- 
2.20.1