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

From: Luis Claudio R. Goncalves
Date: Thu Aug 25 2022 - 09:41:50 EST


On Wed, Aug 03, 2022 at 09:50:17AM +0200, Sebastian Andrzej Siewior wrote:
> 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?

Added to the list.

And thank you for spotting this change, I missed that in my earlier sweep.

Luis

> > ---
> > 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
>
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