Re: [PATCH] ftrace: Fix improper usage of __trace_stack() function.

From: Sebastian Andrzej Siewior
Date: Wed Aug 03 2022 - 03:50:26 EST


On 2022-07-23 12:19:43 [+0530], Anand Je Saipureddy wrote:
> In kernel/trace/trace_events_trigger.c --> stacktrace_trigger() -->
> __trace_stack() is not defined as per the function definition.
>
> With commit edbaaa13a660
> ("tracing: Merge irqflags + preemt counter, add RT bits")
> the irqflags(flags) and preemption counter(preempt_count()) are
> now should be evaluated early by tracing_gen_ctx().
>
> This patch replaces the irqflags and preemption counter
> with tracing_gen_ctx().
>
> Fixes: 5e8446e3820c ("tracing: Dump stacktrace trigger to the corresponding instance")
> Signed-off-by: Anand Je Saipureddy <s.anandje1@xxxxxxxxx>
> Reviewed-by: Corey Minyard <cminyard@xxxxxxxxxx>

Please use [PATCH RT v5.10] in the future.
Luis, could you please pick it up?

> ---
> kernel/trace/trace_events_trigger.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
> index 75fef9fcfd0f..3c6229f16e81 100644
> --- a/kernel/trace/trace_events_trigger.c
> +++ b/kernel/trace/trace_events_trigger.c
> @@ -1220,12 +1220,10 @@ stacktrace_trigger(struct event_trigger_data *data, void *rec,
> struct ring_buffer_event *event)
> {
> struct trace_event_file *file = data->private_data;
> - unsigned long flags;
>
> - if (file) {
> - local_save_flags(flags);
> - __trace_stack(file->tr, STACK_SKIP, preempt_count());
> - } else
> + if (file)
> + __trace_stack(file->tr, tracing_gen_ctx(), STACK_SKIP);
> + else
> trace_dump_stack(STACK_SKIP);
> }
>

Sebastian