From: "Shi, Yang" <yang.shi@linaro.org>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>,
rostedt@goodmis.org, mingo@redhat.com
Cc: linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org
Subject: Re: [PATCH] trace, kasan: silence Kasan warning in check_stack
Date: Fri, 12 Feb 2016 10:50:36 -0800 [thread overview]
Message-ID: <56BE297C.2060402@linaro.org> (raw)
In-Reply-To: <56B9EC3C.4040405@virtuozzo.com>
Hi Steven,
Any comment for this patch?
Thanks,
Yang
On 2/9/2016 5:40 AM, Andrey Ryabinin wrote:
> On 02/08/2016 09:39 PM, Yang Shi wrote:
>> When enabling stack trace via "echo 1 > /proc/sys/kernel/stack_tracer_enabled",
>> the below KASAN warning is triggered:
>>
>> BUG: KASAN: stack-out-of-bounds in check_stack+0x344/0x848 at addr ffffffc0689ebab8
>> Read of size 8 by task ksoftirqd/4/29
>> page:ffffffbdc3a27ac0 count:0 mapcount:0 mapping: (null) index:0x0
>> flags: 0x0()
>> page dumped because: kasan: bad access detected
>> CPU: 4 PID: 29 Comm: ksoftirqd/4 Not tainted 4.5.0-rc1 #129
>> Hardware name: Freescale Layerscape 2085a RDB Board (DT)
>> Call trace:
>> [<ffffffc000091300>] dump_backtrace+0x0/0x3a0
>> [<ffffffc0000916c4>] show_stack+0x24/0x30
>> [<ffffffc0009bbd78>] dump_stack+0xd8/0x168
>> [<ffffffc000420bb0>] kasan_report_error+0x6a0/0x920
>> [<ffffffc000421688>] kasan_report+0x70/0xb8
>> [<ffffffc00041f7f0>] __asan_load8+0x60/0x78
>> [<ffffffc0002e05c4>] check_stack+0x344/0x848
>> [<ffffffc0002e0c8c>] stack_trace_call+0x1c4/0x370
>> [<ffffffc0002af558>] ftrace_ops_no_ops+0x2c0/0x590
>> [<ffffffc00009f25c>] ftrace_graph_call+0x0/0x14
>> [<ffffffc0000881bc>] fpsimd_thread_switch+0x24/0x1e8
>> [<ffffffc000089864>] __switch_to+0x34/0x218
>> [<ffffffc0011e089c>] __schedule+0x3ac/0x15b8
>> [<ffffffc0011e1f6c>] schedule+0x5c/0x178
>> [<ffffffc0001632a8>] smpboot_thread_fn+0x350/0x960
>> [<ffffffc00015b518>] kthread+0x1d8/0x2b0
>> [<ffffffc0000874d0>] ret_from_fork+0x10/0x40
>> Memory state around the buggy address:
>> ffffffc0689eb980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 f4 f4
>> ffffffc0689eba00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>>> ffffffc0689eba80: 00 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00
>> ^
>> ffffffc0689ebb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>> ffffffc0689ebb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>>
>> The stacker tracer traverses the whole kernel stack when saving the max stack
>> trace. It may touch the stack red zones to cause the warning. So, just disable
>> the instrumentation to silence the warning.
>>
>> Signed-off-by: Yang Shi <yang.shi@linaro.org>
>
> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
>
next prev parent reply other threads:[~2016-02-12 18:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-08 18:39 [PATCH] trace, kasan: silence Kasan warning in check_stack Yang Shi
2016-02-09 13:40 ` Andrey Ryabinin
2016-02-12 18:50 ` Shi, Yang [this message]
2016-02-12 19:35 ` Steven Rostedt
2016-02-12 19:46 ` Shi, Yang
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