Re: [LKP] [ 0.003333] BUG: KASAN: use-after-scope in console_unlock+0x605/0xcc0
On 11/30/2017 11:29 AM, 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.
.config has CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
It's known to cause use-after-scope problems, so printk/console code is likely
has nothing to do with the bug.
>
> 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).
I suspect you don't have gcc 7. That's is requirement for use-after-scope.
-ss