On Wed, Feb 19, 2020 at 09:21:48AM -0800, Andy Lutomirski wrote:
> Unless there is a signal pending and the signal setup code is about to
> hit the same failed memory. I suppose we can just treat cases like
> this as "oh well, time to kill the whole system".
>
> But we should genuinely agree that we're okay with deferring this handling.
Good catch!
static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags)
{
...
/* deal with pending signal delivery */
if (cached_flags & _TIF_SIGPENDING)
do_signal(regs);
if (cached_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
rseq_handle_notify_resume(NULL, regs);
}
Err, can we make task_work run before we handle signals? Or there's a
reason it is run in this order?
Comment over task_work_add() says:
* This is like the signal handler which runs in kernel mode, but it doesn't
* try to wake up the @task.
which sounds to me like this should really run before the signal
handlers...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
