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Date: Thu, 30 Nov 2017 17:05:49 +0800
From: Fengguang Wu <fengguang.wu@intel.com>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>,
        LKML <linux-kernel@vger.kernel.org>, Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Ingo Molnar <mingo@kernel.org>,
        Aleksey Makarov <aleksey.makarov@linaro.org>,
        Nicolas Pitre <nicolas.pitre@linaro.org>,
        Nikitas Angelinas <nikitas.angelinas@gmail.com>, LKP <lkp@01.org>,
        kasan-dev <kasan-dev@googlegroups.com>
Subject: Re: [ 0.003333] BUG: KASAN: use-after-scope in
 console_unlock+0x605/0xcc0
Message-ID: <20171130090549.azhcfv3ugbtmts2g@wfg-t540p.sh.intel.com>
References: <20171130022655.2e5ehqmf3lyi4jy3@wfg-t540p.sh.intel.com>
 <20171130064712.GA488@jagdpanzerIV>
 <CACT4Y+amQZApke6MneeK0tax=MzDbj5bce6r4MuSf8PHpzeaoA@mail.gmail.com>
 <20171130082909.GA469@jagdpanzerIV>
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On Thu, Nov 30, 2017 at 05:29:09PM +0900, Sergey Senozhatsky wrote:
>On (11/30/17 09:16), Dmitry Vyukov wrote:
>[..]
>> > to be honest, this backtrace hardly makes any sense to me.
>> >
>> > vprintk_emit()
>> >  reserve_standard_io_resources()
>> >   __flush_tlb_all()
>> >    vprintk_emit()
>> >     __down_trylock_console_sem()
>> >      wake_up_klogd()
>> >       console_unlock()
>> >
>> > I need some help here.
>>
>>
>> You can try dirty patch from here:
>> https://groups.google.com/d/msg/kasan-dev/iDb5bhcMBT0/55QzwWaHAwAJ
>> It should make KASAN print the exact variable name and frame where it
>> was allocated.
>
>would be good if Fengguang can try this out. I can't reproduce the
>problem on my x86 box (linux-next and Linus's trees both work fine
>for me with KASAN + lockdep + TRACE_IRQ).

OK I'll try Dmitry's patch out.

Thanks,
Fengguang