Re: 3.14-rc2 XFS backtrace because irqs_disabled.

Oleg Nesterov
2014-02-15T14:27:06Z

On 02/15, Al Viro wrote:
>
> OK, _very_ preliminary patch follows. It's uglier than it has to

And I'm afraid it needs more uglifications...

> +void dismiss_siginfo(ksiginfo_t *info)
> +{
> + if (info->q)
> + __sigqueue_free(info->q);
> + info->q = NULL;
> +}

1. info->q can be already freed if SIGQUEUE_PREALLOC.

Once get_signal_to_deliver() or any other caller drops ->siglock
another thread can do sys_timer_delete()->sigqueue_free().

2. We need to move do_schedule_next_timer() from dequeue_signal()
here.

Otherwise ->q can be reused/overwritten by the next send_sigqueue()
right affter ->siglock is dropped.

Oleg.