[PATCH AUTOSEL 4.14 1/8] of/fdt: Don't calculate initrd size from DT if start > end

[PATCH AUTOSEL 4.14 1/8] of/fdt: Don't calculate initrd size from DT if start > end

[Sasha Levin]

From: Marek Bykowski <marek.bykowski@gmail.com>

[ Upstream commit d5e3050c0feb8bf7b9a75482fafcc31b90257926 ]

If the properties 'linux,initrd-start' and 'linux,initrd-end' of
the chosen node populated from the bootloader, eg. U-Boot, are so that
start > end, then the phys_initrd_size calculated from end - start is
negative that subsequently gets converted to a high positive value for
being unsigned long long. Then, the memory region with the (invalid)
size is added to the bootmem and attempted being paged in paging_init()
that results in the kernel fault.

For example, on the FVP ARM64 system I'm running, the U-Boot populates
the 'linux,initrd-start' with 8800_0000 and 'linux,initrd-end' with 0.
The phys_initrd_size calculated is then ffff_ffff_7800_0000
(= 0 - 8800_0000 = -8800_0000 + ULLONG_MAX + 1). paging_init() then
attempts to map the address 8800_0000 + ffff_ffff_7800_0000 and oops'es
as below.

It should be stressed, it is generally a fault of the bootloader's with
the kernel relying on it, however we should not allow the bootloader's
misconfiguration to lead to the kernel oops. Not only the kernel should be
bullet proof against it but also finding the root cause of the paging
fault spanning over the bootloader, DT, and kernel may happen is not so
easy.

  Unable to handle kernel paging request at virtual address fffffffefe43c000
  Mem abort info:
    ESR = 0x96000007
    EC = 0x25: DABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
  Data abort info:
    ISV = 0, ISS = 0x00000007
    CM = 0, WnR = 0
  swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000080e3d000
  [fffffffefe43c000] pgd=0000000080de9003, pud=0000000080de9003
  Unable to handle kernel paging request at virtual address ffffff8000de9f90
  Mem abort info:
    ESR = 0x96000005
    EC = 0x25: DABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
  Data abort info:
    ISV = 0, ISS = 0x00000005
    CM = 0, WnR = 0
  swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000080e3d000
  [ffffff8000de9f90] pgd=0000000000000000, pud=0000000000000000
  Internal error: Oops: 96000005 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.51-yocto-standard #1
  Hardware name: FVP Base (DT)
  pstate: 60000085 (nZCv daIf -PAN -UAO)
  pc : show_pte+0x12c/0x1b4
  lr : show_pte+0x100/0x1b4
  sp : ffffffc010ce3b30
  x29: ffffffc010ce3b30 x28: ffffffc010ceed80
  x27: fffffffefe43c000 x26: fffffffefe43a028
  x25: 0000000080bf0000 x24: 0000000000000025
  x23: ffffffc010b8d000 x22: ffffffc010e3d000
  x23: ffffffc010b8d000 x22: ffffffc010e3d000
  x21: 0000000080de9000 x20: ffffff7f80000f90
  x19: fffffffefe43c000 x18: 0000000000000030
  x17: 0000000000001400 x16: 0000000000001c00
  x15: ffffffc010cef1b8 x14: ffffffffffffffff
  x13: ffffffc010df1f40 x12: ffffffc010df1b70
  x11: ffffffc010ce3b30 x10: ffffffc010ce3b30
  x9 : 00000000ffffffc8 x8 : 0000000000000000
  x7 : 000000000000000f x6 : ffffffc010df16e8
  x5 : 0000000000000000 x4 : 0000000000000000
  x3 : 00000000ffffffff x2 : 0000000000000000
  x1 : 0000008080000000 x0 : ffffffc010af1d68
  Call trace:
   show_pte+0x12c/0x1b4
   die_kernel_fault+0x54/0x78
   __do_kernel_fault+0x11c/0x128
   do_translation_fault+0x58/0xac
   do_mem_abort+0x50/0xb0
   el1_da+0x1c/0x90
   __create_pgd_mapping+0x348/0x598
   paging_init+0x3f0/0x70d0
   setup_arch+0x2c0/0x5d4
   start_kernel+0x94/0x49c
  Code: 92748eb5 900052a0 9135a000 cb010294 (f8756a96) 

Signed-off-by: Marek Bykowski <marek.bykowski@gmail.com>
Link: https://lore.kernel.org/r/20220909023358.76881-1-marek.bykowski@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/of/fdt.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index cc9b8c699da4..253680c84c8c 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -957,6 +957,8 @@ static void __init early_init_dt_check_for_initrd(unsigned long node)
 	if (!prop)
 		return;
 	end = of_read_number(prop, len/4);
+	if (start > end)
+		return;
 
 	__early_init_dt_declare_initrd(start, end);
 
-- 
2.35.1

[PATCH AUTOSEL 4.14 2/8] objtool,x86: Teach decode about LOOP* instructions

[Sasha Levin]

From: Peter Zijlstra <peterz@infradead.org>

[ Upstream commit 7a7621dfa417aa3715d2a3bd1bdd6cf5018274d0 ]

When 'discussing' control flow Masami mentioned the LOOP* instructions
and I realized objtool doesn't decode them properly.

As it turns out, these instructions are somewhat inefficient and as
such unlikely to be emitted by the compiler (a few vmlinux.o checks
can't find a single one) so this isn't critical, but still, best to
decode them properly.

Reported-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Yxhd4EMKyoFoH9y4@hirez.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/objtool/arch/x86/decode.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 540a209b78ab..faaf2820e932 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -440,6 +440,12 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
 		*type = INSN_CONTEXT_SWITCH;
 		break;
 
+	case 0xe0: /* loopne */
+	case 0xe1: /* loope */
+	case 0xe2: /* loop */
+		*type = INSN_JUMP_CONDITIONAL;
+		break;
+
 	case 0xe8:
 		*type = INSN_CALL;
 		break;
-- 
2.35.1

[PATCH AUTOSEL 4.14 3/8] gfs2: Check sb_bsize_shift after reading superblock

From: Andrew Price <anprice@redhat.com>

[ Upstream commit 670f8ce56dd0632dc29a0322e188cc73ce3c6b92 ]

Fuzzers like to scribble over sb_bsize_shift but in reality it's very
unlikely that this field would be corrupted on its own. Nevertheless it
should be checked to avoid the possibility of messy mount errors due to
bad calculations. It's always a fixed value based on the block size so
we can just check that it's the expected value.

Tested with:

    mkfs.gfs2 -O -p lock_nolock /dev/vdb
    for i in 0 -1 64 65 32 33; do
        gfs2_edit -p sb field sb_bsize_shift $i /dev/vdb
        mount /dev/vdb /mnt/test && umount /mnt/test
    done

Before this patch we get a withdraw after

[   76.413681] gfs2: fsid=loop0.0: fatal: invalid metadata block
[   76.413681]   bh = 19 (type: exp=5, found=4)
[   76.413681]   function = gfs2_meta_buffer, file = fs/gfs2/meta_io.c, line = 492

and with UBSAN configured we also get complaints like

[   76.373395] UBSAN: shift-out-of-bounds in fs/gfs2/ops_fstype.c:295:19
[   76.373815] shift exponent 4294967287 is too large for 64-bit type 'long unsigned int'

After the patch, these complaints don't appear, mount fails immediately
and we get an explanation in dmesg.

Reported-by: syzbot+dcf33a7aae997956fe06@syzkaller.appspotmail.com
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/gfs2/ops_fstype.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 0b5c37ceb3ed..2bc1226a0bd9 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -172,7 +172,10 @@ static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
 		pr_warn("Invalid superblock size\n");
 		return -EINVAL;
 	}
-
+	if (sb->sb_bsize_shift != ffs(sb->sb_bsize) - 1) {
+		pr_warn("Invalid block size shift\n");
+		return -EINVAL;
+	}
 	return 0;
 }
 
-- 
2.35.1

[Cluster-devel] [PATCH AUTOSEL 4.14 3/8] gfs2: Check sb_bsize_shift after reading superblock

[Sasha Levin]

From: Andrew Price <anprice@redhat.com>

[ Upstream commit 670f8ce56dd0632dc29a0322e188cc73ce3c6b92 ]

Fuzzers like to scribble over sb_bsize_shift but in reality it's very
unlikely that this field would be corrupted on its own. Nevertheless it
should be checked to avoid the possibility of messy mount errors due to
bad calculations. It's always a fixed value based on the block size so
we can just check that it's the expected value.

Tested with:

    mkfs.gfs2 -O -p lock_nolock /dev/vdb
    for i in 0 -1 64 65 32 33; do
        gfs2_edit -p sb field sb_bsize_shift $i /dev/vdb
        mount /dev/vdb /mnt/test && umount /mnt/test
    done

Before this patch we get a withdraw after

[   76.413681] gfs2: fsid=loop0.0: fatal: invalid metadata block
[   76.413681]   bh = 19 (type: exp=5, found=4)
[   76.413681]   function = gfs2_meta_buffer, file = fs/gfs2/meta_io.c, line = 492

and with UBSAN configured we also get complaints like

[   76.373395] UBSAN: shift-out-of-bounds in fs/gfs2/ops_fstype.c:295:19
[   76.373815] shift exponent 4294967287 is too large for 64-bit type 'long unsigned int'

After the patch, these complaints don't appear, mount fails immediately
and we get an explanation in dmesg.

Reported-by: syzbot+dcf33a7aae997956fe06 at syzkaller.appspotmail.com
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/gfs2/ops_fstype.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 0b5c37ceb3ed..2bc1226a0bd9 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -172,7 +172,10 @@ static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
 		pr_warn("Invalid superblock size\n");
 		return -EINVAL;
 	}
-
+	if (sb->sb_bsize_shift != ffs(sb->sb_bsize) - 1) {
+		pr_warn("Invalid block size shift\n");
+		return -EINVAL;
+	}
 	return 0;
 }
 
-- 
2.35.1

[PATCH AUTOSEL 4.14 4/8] m68knommu: fix non-specific 68328 choice interrupt build failure

[Sasha Levin]

From: Greg Ungerer <gerg@linux-m68k.org>

[ Upstream commit 750321ace9107e103f254bf46900629ff347eb7b ]

Compiling for a classic m68k non-MMU target with no specific CPU
selected fails with the following error:

   arch/m68k/68000/ints.c: In function 'process_int':
>> arch/m68k/68000/ints.c:82:30: error: 'ISR' undeclared (first use in this function)
      82 |         unsigned long pend = ISR;
         |                              ^~~

This interrupt handling code is specific to the 68328 family of 68000
parts. There is a couple of variants (68EZ328, 68VZ328) and the common
ancestor of them the strait 68328.

The code here includes a specific header for each variant type. But if
none is selected then nothing is included to supply the appropriate
register and bit flags defines.

Rearrange the includes so that at least one type is always included.
At the very least the 68328 base type should be the fallback, so make
that true.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/m68k/68000/ints.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/m68k/68000/ints.c b/arch/m68k/68000/ints.c
index cda49b12d7be..f9a5ec781408 100644
--- a/arch/m68k/68000/ints.c
+++ b/arch/m68k/68000/ints.c
@@ -18,12 +18,12 @@
 #include <asm/io.h>
 #include <asm/machdep.h>
 
-#if defined(CONFIG_M68328)
-#include <asm/MC68328.h>
-#elif defined(CONFIG_M68EZ328)
+#if defined(CONFIG_M68EZ328)
 #include <asm/MC68EZ328.h>
 #elif defined(CONFIG_M68VZ328)
 #include <asm/MC68VZ328.h>
+#else
+#include <asm/MC68328.h>
 #endif
 
 /* assembler routines */
-- 
2.35.1

[PATCH AUTOSEL 4.14 5/8] m68knommu: fix non-mmu classic 68000 legacy timer tick selection

[Sasha Levin]

From: Greg Ungerer <gerg@linux-m68k.org>

[ Upstream commit 18011e50c497f04a57a8e00122906f04922b30b4 ]

The family of classic 68000 parts supported when in non-mmu mode all
currently use the legacy timer support. Move the selection of that config
option, LEGACY_TIMER_TICK, into the core CPU configuration.

This fixes compilation if no specific CPU variant is selected, since
the LEGACY_TIMER_TICK option was only selected in the specific CPU
variant configurations.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/m68k/Kconfig.cpu | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index 6f13c53c8dc7..3f5b92f567dc 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -43,6 +43,7 @@ config M68000
 	select GENERIC_CSUM
 	select CPU_NO_EFFICIENT_FFS
 	select HAVE_ARCH_HASH
+	select LEGACY_TIMER_TICK
 	help
 	  The Freescale (was Motorola) 68000 CPU is the first generation of
 	  the well known M68K family of processors. The CPU core as well as
-- 
2.35.1

[PATCH AUTOSEL 4.14 6/8] 9p: trans_fd/p9_conn_cancel: drop client lock earlier

[Sasha Levin]

From: Dominique Martinet <asmadeus@codewreck.org>

[ Upstream commit 52f1c45dde9136f964d63a77d19826c8a74e2c7f ]

syzbot reported a double-lock here and we no longer need this
lock after requests have been moved off to local list:
just drop the lock earlier.

Link: https://lkml.kernel.org/r/20220904064028.1305220-1-asmadeus@codewreck.org
Reported-by: syzbot+50f7e8d06c3768dd97f3@syzkaller.appspotmail.com
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Tested-by: Schspa Shi <schspa@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/9p/trans_fd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 1b56b22c5c5d..acb5b5f15a33 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -219,6 +219,8 @@ static void p9_conn_cancel(struct p9_conn *m, int err)
 		list_move(&req->req_list, &cancel_list);
 	}
 
+	spin_unlock(&m->client->lock);
+
 	list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
 		p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
 		list_del(&req->req_list);
@@ -226,7 +228,6 @@ static void p9_conn_cancel(struct p9_conn *m, int err)
 			req->t_err = err;
 		p9_client_cb(m->client, req, REQ_STATUS_ERROR);
 	}
-	spin_unlock(&m->client->lock);
 }
 
 static int
-- 
2.35.1

[PATCH AUTOSEL 4.14 7/8] 9p/trans_fd: always use O_NONBLOCK read/write

[Sasha Levin]

From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

[ Upstream commit ef575281b21e9a34dfae544a187c6aac2ae424a9 ]

syzbot is reporting hung task at p9_fd_close() [1], for p9_mux_poll_stop()
 from p9_conn_destroy() from p9_fd_close() is failing to interrupt already
started kernel_read() from p9_fd_read() from p9_read_work() and/or
kernel_write() from p9_fd_write() from p9_write_work() requests.

Since p9_socket_open() sets O_NONBLOCK flag, p9_mux_poll_stop() does not
need to interrupt kernel_read()/kernel_write(). However, since p9_fd_open()
does not set O_NONBLOCK flag, but pipe blocks unless signal is pending,
p9_mux_poll_stop() needs to interrupt kernel_read()/kernel_write() when
the file descriptor refers to a pipe. In other words, pipe file descriptor
needs to be handled as if socket file descriptor.

We somehow need to interrupt kernel_read()/kernel_write() on pipes.

A minimal change, which this patch is doing, is to set O_NONBLOCK flag
 from p9_fd_open(), for O_NONBLOCK flag does not affect reading/writing
of regular files. But this approach changes O_NONBLOCK flag on userspace-
supplied file descriptors (which might break userspace programs), and
O_NONBLOCK flag could be changed by userspace. It would be possible to set
O_NONBLOCK flag every time p9_fd_read()/p9_fd_write() is invoked, but still
remains small race window for clearing O_NONBLOCK flag.

If we don't want to manipulate O_NONBLOCK flag, we might be able to
surround kernel_read()/kernel_write() with set_thread_flag(TIF_SIGPENDING)
and recalc_sigpending(). Since p9_read_work()/p9_write_work() works are
processed by kernel threads which process global system_wq workqueue,
signals could not be delivered from remote threads when p9_mux_poll_stop()
 from p9_conn_destroy() from p9_fd_close() is called. Therefore, calling
set_thread_flag(TIF_SIGPENDING)/recalc_sigpending() every time would be
needed if we count on signals for making kernel_read()/kernel_write()
non-blocking.

Link: https://lkml.kernel.org/r/345de429-a88b-7097-d177-adecf9fed342@I-love.SAKURA.ne.jp
Link: https://syzkaller.appspot.com/bug?extid=8b41a1365f1106fd0f33 [1]
Reported-by: syzbot <syzbot+8b41a1365f1106fd0f33@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+8b41a1365f1106fd0f33@syzkaller.appspotmail.com>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
[Dominique: add comment at Christian's suggestion]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/9p/trans_fd.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index acb5b5f15a33..9b23bf0e278c 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -834,11 +834,14 @@ static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
 		goto out_free_ts;
 	if (!(ts->rd->f_mode & FMODE_READ))
 		goto out_put_rd;
+	/* prevent workers from hanging on IO when fd is a pipe */
+	ts->rd->f_flags |= O_NONBLOCK;
 	ts->wr = fget(wfd);
 	if (!ts->wr)
 		goto out_put_rd;
 	if (!(ts->wr->f_mode & FMODE_WRITE))
 		goto out_put_wr;
+	ts->wr->f_flags |= O_NONBLOCK;
 
 	client->trans = ts;
 	client->status = Connected;
-- 
2.35.1

[PATCH AUTOSEL 4.14 8/8] virtio_pci: don't try to use intxif pin is zero

[Sasha Levin]

From: Angus Chen <angus.chen@jaguarmicro.com>

[ Upstream commit 71491c54eafa318fdd24a1f26a1c82b28e1ac21d ]

The background is that we use dpu in cloud computing,the arch is x86,80
cores. We will have a lots of virtio devices,like 512 or more.
When we probe about 200 virtio_blk devices,it will fail and
the stack is printed as follows:

[25338.485128] virtio-pci 0000:b3:00.0: virtio_pci: leaving for legacy driver
[25338.496174] genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer)
[25338.503822] CPU: 20 PID: 5431 Comm: kworker/20:0 Kdump: loaded Tainted: G           OE    --------- -  - 4.18.0-305.30.1.el8.x86_64
[25338.516403] Hardware name: Inspur NF5280M5/YZMB-00882-10E, BIOS 4.1.21 08/25/2021
[25338.523881] Workqueue: events work_for_cpu_fn
[25338.528235] Call Trace:
[25338.530687]  dump_stack+0x5c/0x80
[25338.534000]  __setup_irq.cold.53+0x7c/0xd3
[25338.538098]  request_threaded_irq+0xf5/0x160
[25338.542371]  vp_find_vqs+0xc7/0x190
[25338.545866]  init_vq+0x17c/0x2e0 [virtio_blk]
[25338.550223]  ? ncpus_cmp_func+0x10/0x10
[25338.554061]  virtblk_probe+0xe6/0x8a0 [virtio_blk]
[25338.558846]  virtio_dev_probe+0x158/0x1f0
[25338.562861]  really_probe+0x255/0x4a0
[25338.566524]  ? __driver_attach_async_helper+0x90/0x90
[25338.571567]  driver_probe_device+0x49/0xc0
[25338.575660]  bus_for_each_drv+0x79/0xc0
[25338.579499]  __device_attach+0xdc/0x160
[25338.583337]  bus_probe_device+0x9d/0xb0
[25338.587167]  device_add+0x418/0x780
[25338.590654]  register_virtio_device+0x9e/0xe0
[25338.595011]  virtio_pci_probe+0xb3/0x140
[25338.598941]  local_pci_probe+0x41/0x90
[25338.602689]  work_for_cpu_fn+0x16/0x20
[25338.606443]  process_one_work+0x1a7/0x360
[25338.610456]  ? create_worker+0x1a0/0x1a0
[25338.614381]  worker_thread+0x1cf/0x390
[25338.618132]  ? create_worker+0x1a0/0x1a0
[25338.622051]  kthread+0x116/0x130
[25338.625283]  ? kthread_flush_work_fn+0x10/0x10
[25338.629731]  ret_from_fork+0x1f/0x40
[25338.633395] virtio_blk: probe of virtio418 failed with error -16

The log :
"genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer)"
was printed because of the irq 0 is used by timer exclusive,and when
vp_find_vqs call vp_find_vqs_msix and returns false twice (for
whatever reason), then it will call vp_find_vqs_intx as a fallback.
Because vp_dev->pci_dev->irq is zero, we request irq 0 with
flag IRQF_SHARED, and get a backtrace like above.

According to PCI spec about "Interrupt Pin" Register (Offset 3Dh):
"The Interrupt Pin register is a read-only register that identifies the
 legacy interrupt Message(s) the Function uses. Valid values are 01h, 02h,
 03h, and 04h that map to legacy interrupt Messages for INTA,
 INTB, INTC, and INTD respectively. A value of 00h indicates that the
 Function uses no legacy interrupt Message(s)."

So if vp_dev->pci_dev->pin is zero, we should not request legacy
interrupt.

Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20220930000915.548-1-angus.chen@jaguarmicro.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/virtio/virtio_pci_common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 924554b7010d..9f2f215a69b6 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -405,6 +405,9 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, desc);
 	if (!err)
 		return 0;
+	/* Is there an interrupt pin? If not give up. */
+	if (!(to_vp_device(vdev)->pci_dev->pin))
+		return err;
 	/* Finally fall back to regular interrupts. */
 	return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx);
 }
-- 
2.35.1

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[PATCH AUTOSEL 4.14 8/8] virtio_pci: don't try to use intxif pin is zero

[Sasha Levin]

From: Angus Chen <angus.chen@jaguarmicro.com>

[ Upstream commit 71491c54eafa318fdd24a1f26a1c82b28e1ac21d ]

The background is that we use dpu in cloud computing,the arch is x86,80
cores. We will have a lots of virtio devices,like 512 or more.
When we probe about 200 virtio_blk devices,it will fail and
the stack is printed as follows:

[25338.485128] virtio-pci 0000:b3:00.0: virtio_pci: leaving for legacy driver
[25338.496174] genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer)
[25338.503822] CPU: 20 PID: 5431 Comm: kworker/20:0 Kdump: loaded Tainted: G           OE    --------- -  - 4.18.0-305.30.1.el8.x86_64
[25338.516403] Hardware name: Inspur NF5280M5/YZMB-00882-10E, BIOS 4.1.21 08/25/2021
[25338.523881] Workqueue: events work_for_cpu_fn
[25338.528235] Call Trace:
[25338.530687]  dump_stack+0x5c/0x80
[25338.534000]  __setup_irq.cold.53+0x7c/0xd3
[25338.538098]  request_threaded_irq+0xf5/0x160
[25338.542371]  vp_find_vqs+0xc7/0x190
[25338.545866]  init_vq+0x17c/0x2e0 [virtio_blk]
[25338.550223]  ? ncpus_cmp_func+0x10/0x10
[25338.554061]  virtblk_probe+0xe6/0x8a0 [virtio_blk]
[25338.558846]  virtio_dev_probe+0x158/0x1f0
[25338.562861]  really_probe+0x255/0x4a0
[25338.566524]  ? __driver_attach_async_helper+0x90/0x90
[25338.571567]  driver_probe_device+0x49/0xc0
[25338.575660]  bus_for_each_drv+0x79/0xc0
[25338.579499]  __device_attach+0xdc/0x160
[25338.583337]  bus_probe_device+0x9d/0xb0
[25338.587167]  device_add+0x418/0x780
[25338.590654]  register_virtio_device+0x9e/0xe0
[25338.595011]  virtio_pci_probe+0xb3/0x140
[25338.598941]  local_pci_probe+0x41/0x90
[25338.602689]  work_for_cpu_fn+0x16/0x20
[25338.606443]  process_one_work+0x1a7/0x360
[25338.610456]  ? create_worker+0x1a0/0x1a0
[25338.614381]  worker_thread+0x1cf/0x390
[25338.618132]  ? create_worker+0x1a0/0x1a0
[25338.622051]  kthread+0x116/0x130
[25338.625283]  ? kthread_flush_work_fn+0x10/0x10
[25338.629731]  ret_from_fork+0x1f/0x40
[25338.633395] virtio_blk: probe of virtio418 failed with error -16

The log :
"genirq: Flags mismatch irq 0. 00000080 (virtio418) vs. 00015a00 (timer)"
was printed because of the irq 0 is used by timer exclusive,and when
vp_find_vqs call vp_find_vqs_msix and returns false twice (for
whatever reason), then it will call vp_find_vqs_intx as a fallback.
Because vp_dev->pci_dev->irq is zero, we request irq 0 with
flag IRQF_SHARED, and get a backtrace like above.

According to PCI spec about "Interrupt Pin" Register (Offset 3Dh):
"The Interrupt Pin register is a read-only register that identifies the
 legacy interrupt Message(s) the Function uses. Valid values are 01h, 02h,
 03h, and 04h that map to legacy interrupt Messages for INTA,
 INTB, INTC, and INTD respectively. A value of 00h indicates that the
 Function uses no legacy interrupt Message(s)."

So if vp_dev->pci_dev->pin is zero, we should not request legacy
interrupt.

Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20220930000915.548-1-angus.chen@jaguarmicro.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/virtio/virtio_pci_common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 924554b7010d..9f2f215a69b6 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -405,6 +405,9 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, desc);
 	if (!err)
 		return 0;
+	/* Is there an interrupt pin? If not give up. */
+	if (!(to_vp_device(vdev)->pci_dev->pin))
+		return err;
 	/* Finally fall back to regular interrupts. */
 	return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx);
 }
-- 
2.35.1