Re: [PATCH 1/3] clocksource/arm_arch_timer: mark arch_counter_get_* as notrace

From: Daniel Lezcano
Date: Tue Jun 04 2019 - 01:56:06 EST


Hi Anders,

thanks for your patch. As mentioned by Mark I already applied this fix
from Julien Thierry.

-- Daniel


On 03/06/2019 11:23, Marc Zyngier wrote:
> Hi Anders,
>
>
> On 03/06/2019 10:12, Anders Roxell wrote:
>> When CONFIG_FUNCTION_GRAPH_TRACER is enabled we end up in this circular
>> call trace since function arch_counter_get_cntvct() isn't marked with no
>> trace:
>>
>> [ 17.914934] Call trace:
>> [ 17.915211] ftrace_return_to_handler+0x194/0x288
>> [ 17.915551] return_to_handler+0x1c/0x38
>> [ 17.915855] trace_clock_local+0x38/0x88
>> [ 17.916159] function_graph_enter+0xf0/0x258
>> [ 17.916465] prepare_ftrace_return+0x60/0x90
>> [ 17.916772] ftrace_graph_caller+0x1c/0x24
>> [ 17.917093] arch_counter_get_cntvct+0x10/0x30
>> [ 17.917417] sched_clock+0x70/0x218
>> [ 17.917723] trace_clock_local+0x38/0x88
>> [ 17.918026] function_graph_enter+0xf0/0x258
>> [ 17.918332] prepare_ftrace_return+0x60/0x90
>> [ 17.918649] ftrace_graph_caller+0x1c/0x24
>> [ 17.918963] arch_counter_get_cntvct+0x10/0x30
>> [ 17.919286] sched_clock+0x70/0x218
>>
>> Rework so that function arch_counter_get_cntvct() is marked with notrace.
>>
>> Fixes: 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters")
>> Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
>
> This has already been queued by Daniel, I believe [1].
>
> [1] https://lore.kernel.org/lkml/1558689025-50679-1-git-send-email-julien.thierry@xxxxxxx/





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