Re: [PATCH] sample-trace-array: Fix sleeping function called from invalid context

From: Divya Indi
Date: Mon Jun 08 2020 - 20:11:40 EST


Hi Steve,

Sure, I am looking into it and reviewing the patch.

Thanks,
Divya

On 6/8/20 7:37 AM, Steven Rostedt wrote:
> On Mon, 8 Jun 2020 07:54:37 +0000
> Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
>
>> BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935
>> in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/5
>> 1 lock held by swapper/5/0:
>> #0: ffff80001002bd90 (samples/ftrace/sample-trace-array.c:38){+.-.}-{0:0}, at: call_timer_fn+0x8/0x3e0
>> CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.7.0+ #8
>> Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
>> Call trace:
>> dump_backtrace+0x0/0x1a0
>> show_stack+0x20/0x30
>> dump_stack+0xe4/0x150
>> ___might_sleep+0x160/0x200
>> __might_sleep+0x58/0x90
>> __mutex_lock+0x64/0x948
>> mutex_lock_nested+0x3c/0x58
>> __ftrace_set_clr_event+0x44/0x88
>> trace_array_set_clr_event+0x24/0x38
>> mytimer_handler+0x34/0x40 [sample_trace_array]
>>
>> mutex_lock() will be called in interrupt context, using workqueueu to fix it.
>>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
>>
> Divya,
>
> Can you give a Reviewed-by for this?
>
> -- Steve