Re: uprobe splat in PREEMP_RT

Sebastian Sewior
2025-04-02T12:24:50Z

On 2025-04-02 14:18:51 [+0200], Oleg Nesterov wrote:
> On 04/02, Sebastian Sewior wrote:

I need to tell mutt to replace my name in case it is misspelled.

> > The preempted ri_timer() could stall a read_seqcount_begin().
>
> Again, nobody use read_seqcount_begin(utask->ri_seqcount).
>
> free_ret_instance() uses raw_seqcount_try_begin(utask->ri_seqcount),
> which, since ri_seqcount is seqcount_t, is just smp_load_acquire().
> This can't stall.

Yes. This would work for here just to skip the check because of all
details that are hard to express. Therefore I suggested to use
raw_write_seqcount_begin() instead of write_seqcount_begin() in
20250402122158.j_8VoHQ-@linutronix.de. Would that work?

> Oleg.

Sebastian