Re: [PATCH v1 6/8] tracing/ftrace: Add might_fault check to syscall probes

[Steven Rostedt]

On Thu,  3 Oct 2024 11:16:36 -0400
Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:

> diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
> index 0228d9ed94a3..e0d4850b0d77 100644
> --- a/include/trace/trace_events.h
> +++ b/include/trace/trace_events.h
> @@ -446,6 +446,7 @@ __DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
>  static notrace void							\
>  trace_event_raw_event_##call(void *__data, proto)			\
>  {									\
> +	might_fault();							\

I don't think we want "might_fault()" here, as this is called for every
tracepoint that is created by the TRACE_EVENT() macro. That means, there's
going to be plenty of locations this gets called at that do not allow faults.

-- Steve


>  	guard(preempt_notrace)();					\
>  	do_trace_event_raw_event_##call(__data, args);			\
>  }