From: Peter Zijlstra <peterz@infradead.org>
To: Marius Fleischer <fleischermarius@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller@googlegroups.com, harrisonmichaelgreen@gmail.com
Subject: Re: possible deadlock in __perf_event_task_sched_in
Date: Wed, 24 Apr 2024 11:43:05 +0200 [thread overview]
Message-ID: <20240424094305.GT40213@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <CAJg=8jw=5vKSE8ibuim0uFKQq=sA3sWULqM5auqKNJCq0=kqGg@mail.gmail.com>
On Mon, Apr 22, 2024 at 11:44:27AM -0700, Marius Fleischer wrote:
> Hi,
>
> We would like to report the following bug which has been found by our
> modified version of syzkaller.
>
> We found this report (https://lkml.org/lkml/2021/9/12/333) that seems
> to have a similar but different stack trace. We are unable to tell,
> though, whether it is the same cause. We’d be grateful for your
> advice.
This is just the printk thing sucks again. Some WARN/printk got tripped
in a non-suitable context.
> _printk+0xba/0xed kernel/printk/printk.c:2299
> ex_handler_msr.cold+0xb7/0x147 arch/x86/mm/extable.c:90
> fixup_exception+0x973/0xbb0 arch/x86/mm/extable.c:187
> __exc_general_protection arch/x86/kernel/traps.c:601 [inline]
> exc_general_protection+0xed/0x2f0 arch/x86/kernel/traps.c:562
> asm_exc_general_protection+0x22/0x30 arch/x86/include/asm/idtentry.h:562
> RIP: 0010:__wrmsr arch/x86/include/asm/msr.h:103 [inline]
> RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:154 [inline]
> RIP: 0010:wrmsrl arch/x86/include/asm/msr.h:271 [inline]
> RIP: 0010:__x86_pmu_enable_event
> arch/x86/events/intel/../perf_event.h:1120 [inline]
> RIP: 0010:intel_pmu_enable_event+0x2d9/0xff0 arch/x86/events/intel/core.c:2694
> Code: ea 03 49 81 cc 00 00 40 00 4d 21 f4 80 3c 02 00 0f 85 5b 0c 00
> 00 44 8b ab 70 01 00 00 4c 89 e2 44 89 e0 48 c1 ea 20 44 89 e9 <0f> 30
> 0f 1f 44 00 00 e8 1b 32 75 00 48 83 c4 20 5b 5d 41 5c 41 5d
> RSP: 0018:ffffc900115af348 EFLAGS: 00010002
> RAX: 0000000000530000 RBX: ffff888019dd6a50 RCX: 0000000000000188
> RDX: 0000000000000002 RSI: ffffffff81029464 RDI: ffff888019dd6bc0
> RBP: 0000000000000000 R08: 0000000000000001 R09: ffff888063e22ab7
> R10: 0000000000000000 R11: 0000000000000001 R12: 0000000200530000
> R13: 0000000000000188 R14: ffffffffffffffff R15: ffff888019dd6bb0
> x86_pmu_start+0x1cc/0x270 arch/x86/events/core.c:1520
> x86_pmu_enable+0x481/0xdf0 arch/x86/events/core.c:1337
> perf_pmu_enable kernel/events/core.c:1243 [inline]
> perf_pmu_enable kernel/events/core.c:1239 [inline]
Most likely your VM is wonky and perf tries to poke an MSR that either
doesn't exist or isn't emulated properly, who knows.
next prev parent reply other threads:[~2024-04-24 9:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-22 18:44 Marius Fleischer
2024-04-24 9:43 ` Peter Zijlstra [this message]
2024-04-29 16:38 ` Marius Fleischer
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