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From:   Vince Weaver <vincent.weaver@maine.edu>
Date:   Wed, 13 Dec 2023 09:54:09 -0500 (EST)
To:     xingwei lee <xrivendell7@gmail.com>
cc:     peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
        mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
        jolsa@kernel.org, namhyung@kernel.org, irogers@google.com,
        adrian.hunter@intel.com, linux-perf-users@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: possible deadlock in down_trylock/perf_event_open
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On Mon, 11 Dec 2023, xingwei lee wrote:

> Hello I found a bug in kernel/perf in the lastest upstream linux 6.7.rc5
> possible deadlock in down_trylock/perf_event_open
> 
> If you fix this issue, please add the following tag to the commit:
> Reported-by: xingwei Lee <xrivendell7@gmail.com>
> 

> 
> syzkaller login: root
> Linux syzkaller 6.7.0-rc5 #3 SMP PREEMPT_DYNAMIC Mon Dec 11 17:02:24
> HKT 2023 x86_64
> root@syzkaller:~# ./572
> [  113.795108][ T8266] ------------[ cut here ]------------
> [  113.795707][ T8266] WARNING: CPU: 1 PID: 8266 at
> kernel/events/core.c:1950 __do_sys_perf_event_open0


Just wanted to add that the perf_fuzzer will trigger this warning more or 
less immediately as well.

Vince