Re: linux-next: manual merge of the rcu tree with the ftrace tree

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

On 2025-11-14 07:42:55 [-0500], Steven Rostedt wrote:
> > diff --cc kernel/trace/trace_syscalls.c
> > index e96d0063cbcf,3f699b198c56..000000000000
> > --- a/kernel/trace/trace_syscalls.c
> > +++ b/kernel/trace/trace_syscalls.c
> > @@@ -878,6 -322,8 +890,7 @@@ static void ftrace_syscall_enter(void *
> >   	 * buffer and per-cpu data require preemption to be disabled.
> >   	 */
> >   	might_fault();
> > + 	preempt_rt_guard();
> >  -	guard(preempt_notrace)();
> 
> My code made it so that preemption is not needed here but is moved later
> down for the logic that does the reading of user space data.
> 
> Note, it must have preemption disabled for all configs (including RT).
> Otherwise, the data it has can get corrupted.
> 
> Paul, can you change it so that you *do not* touch this file?

Where is preempt_rt_guard() from?

> Thanks,
> 
> -- Steve

Sebastian