linux-kernel - Re: [Syzkaller & bisect] There is "__perf_event_overflow" WARNING in v6.1-rc5 kernel in guest

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Date:   Thu, 17 Nov 2022 09:37:03 +0800
From:   Pengfei Xu <pengfei.xu@...el.com>
To:     Peter Zijlstra <peterz@...radead.org>
CC:     <peter.zijlstra@...el.com>, <linux-kernel@...r.kernel.org>,
        <heng.su@...el.com>
Subject: Re: [Syzkaller & bisect] There is "__perf_event_overflow" WARNING in
 v6.1-rc5 kernel in guest

Hi Peter,

On 2022-11-16 at 15:40:24 +0100, Peter Zijlstra wrote:
> On Wed, Nov 16, 2022 at 11:39:53AM +0800, Pengfei Xu wrote:
> > Hi Peter and perf expert,
> > 
> > Greeting!
> > 
> > Platform: TGL-H
> > 
> > There is "__perf_event_overflow" WARNING issue in v6.1-rc5 kernel in
> > guest in double check test.
> > 
> > Found first bad commit is ca6c21327c6af02b7eec31ce4b9a740a18c6c13f
> > "perf: Fix missing SIGTRAPs"
> > 
> > And revert this commit on top of v6.1-rc5, this issue could not be reproduced.
> > 
> > Guest kconfig, reproduce code from syzkaller, and bisect info are in attached.
> > 
> > And more detailed info is in link:
> > https://github.com/xupengfe/syzkaller_logs/tree/main/221114_134736___perf_event_overflow
> > 
> > If it's helpful and in time, please add the Reported-by tag from me.
> 
> Does this help?
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=perf/urgent&id=bb88f9695460bec25aa30ba9072595025cf6c8af
Thanks for your link!
I installed the patch from above link on top of v6.1-rc5 kernel, the patch
is in attached.

And I still could reproduce this issue.
I use below loop to execute the binary, it's reproduced in the 485 times
execution.
"
for((i=0; ;i++)); do
  echo "$i times ./repro"
  ./repro
done
"
485 times ./repro
[   87.978410] ------------[ cut here ]------------
[   87.978430] WARNING: CPU: 0 PID: 970 at kernel/events/core.c:9329 __perf_event_overflow+0x22b/0x270
[   87.978464] Modules linked in:
[   87.978470] CPU: 0 PID: 970 Comm: repro Not tainted 6.1.0-rc5-kvmperfoverflow+ #10
[   87.978487] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   87.978498] RIP: 0010:__perf_event_overflow+0x22b/0x270
[   87.978516] Code: b6 45 d3 84 c0 0f 84 26 ff ff ff e8 4f 31 ec ff 8b 75 d4 44 89 ff e8 04 32 ec ff 44 3b 7d d4 0f 84 0c ff ff ff e8 35 31 ec ff <0f> 0b e9 00 6
[   87.978531] RSP: 0000:fffffe000000db58 EFLAGS: 00010046
[   87.978543] RAX: 0000000000000000 RBX: ffff888004ed5ce0 RCX: ffffffff8138b67c
[   87.978554] RDX: 0000000000000000 RSI: ffff88800b8e9fc0 RDI: 0000000000000002
[   87.978565] RBP: fffffe000000db88 R08: 0000001ffad06476 R09: 0000000000000000
[   87.978583] R10: 0000000000000000 R11: 0000000000000000 R12: fffffe000000def8
[   87.978594] R13: fffffe000000dc00 R14: 0000000000000000 R15: 0000000088db7a04
[   87.978607] FS:  00007f9988c8b740(0000) GS:ffff88807dc00000(0000) knlGS:ffff88807dc00000
[   87.978625] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   87.978639] CR2: 0000000020000200 CR3: 000000000a77c003 CR4: 0000000000770ef0
[   87.978655] PKRU: 55555554
[   87.978662] Call Trace:
[   87.978667]  <NMI>
[   87.978675]  perf_event_overflow+0x33/0x40
[   87.978705]  handle_pmi_common+0x2d8/0x560
[   87.978736]  ? write_comp_data+0x2f/0x90
[   87.978760]  ? write_comp_data+0x2f/0x90
[   87.978783]  intel_pmu_handle_irq+0x183/0x680
[   87.978805]  perf_event_nmi_handler+0x42/0x70
[   87.978842]  nmi_handle+0x63/0x160
[   87.978872]  default_do_nmi+0x77/0x190
[   87.978903]  exc_nmi+0x157/0x190
[   87.978932]  end_repeat_nmi+0x16/0x67
[   87.978963] RIP: 0010:asm_sysvec_irq_work+0x0/0x30
[   87.978993] Code: ca fc 6a ff e8 a1 05 00 00 48 89 c4 48 8d 6c 24 01 48 89 e7 e8 e1 56 ea ff e9 bc 06 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 90 <f3> 0f 1e fa 4
[   87.979010] RSP: 0000:fffffe0000002fd8 EFLAGS: 00000002
[   87.979024] RAX: 0000000000000003 RBX: 0000000000000000 RCX: 00007f9988db059d
[   87.979037] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000200
[   87.979049] RBP: 00007ffe528b2a70 R08: 0000000000000003 R09: 0000000000401a60
[   87.979062] R10: 00000000ffffffff R11: 0000000000000202 R12: 00000000004010e0
[   87.979075] R13: 00007ffe528b2b50 R14: 0000000000000000 R15: 0000000000000000
[   87.979093]  ? asm_sysvec_thermal+0x30/0x30
[   87.979123]  ? asm_sysvec_thermal+0x30/0x30
[   87.979153]  </NMI>
[   87.979158]  <ENTRY_TRAMPOLINE>
[   87.979165]  </ENTRY_TRAMPOLINE>
[   87.979171] ---[ end trace 0000000000000000 ]---

Before the loop execution, I tried several times manually, and sometimes, I
saw "Trace/breakpoint trap (core dumped)" after executed repro, but there is
no any dmesg info generated.

Anyway all the dmesg and patch is in attached. Hope it's helpful.

Thanks!
BR.

View attachment "0001-The-patch-from-https-git.kernel.org-pub-scm-linux-ke.patch" of type "text/plain" (1893 bytes)

View attachment "v6.1-rc5_patch_guest_perfoverflow_warning_dmesg.log" of type "text/plain" (36980 bytes)