From: Steven Rostedt <rostedt@goodmis.org>
To: Yang Shi <yang.shi@linaro.org>
Cc: aryabinin@virtuozzo.com, mingo@redhat.com,
linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org
Subject: Re: [v2 PATCH] trace, kasan: silence Kasan warning in check_stack
Date: Fri, 19 Feb 2016 12:38:10 -0500 [thread overview]
Message-ID: <20160219123810.4c5e152c@gandalf.local.home> (raw)
In-Reply-To: <1455309960-18930-1-git-send-email-yang.shi@linaro.org>
On Fri, 12 Feb 2016 12:46:00 -0800
Yang Shi <yang.shi@linaro.org> 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>
Applied, thanks!
-- Steve
prev parent reply other threads:[~2016-02-19 17:38 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-12 20:46 [v2 PATCH] trace, kasan: silence Kasan warning in check_stack Yang Shi
2016-02-19 17:38 ` Steven Rostedt [this message]
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