Messages in this thread Patch in this message | | | Date | Mon, 8 Oct 2012 20:59:51 +0200 | From | Oleg Nesterov <> | Subject | Re: [regression] boot failure on alpha, bisected |
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On 10/07, Al Viro wrote: > > On Sun, Oct 07, 2012 at 07:33:36PM +0200, Oleg Nesterov wrote: > > > > Um... There's a bunch of architectures that are in the same situation. > > > grep for do_notify_resume() and you'll see... > > > > And every do_notify_resume() should be changed anyway, do_signal() and > > tracehook_notify_resume() should be re-ordered. > > There's a bit more to it. > [...big snip...]
Thanks Al. I need to read your email carefully.
But what do you think we should do right now to fix this particular bug?
So far I am going to send the patch below. This was always wrong, even before task_works were added. key_replace_session_keyring() was might_sleep() too but it also did lock_irq/unlock_irq, so this was not noticed before.
Or do you think we should add local_irq_enable() into arch/alpha/kernel/signal.c:do_notify_resume() before tracehook_notify_resume and wait for other similar report?
Oleg. ---
diff --git a/kernel/task_work.c b/kernel/task_work.c index 65bd3c9..fd18bd7 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -51,6 +51,10 @@ void task_work_run(void) struct task_struct *task = current; struct callback_head *work, *head, *next; + if (WARN_ONCE(irqs_disabled(), + "do_notify_resume() with irqs disabled, fix this arch.")) + local_irq_enable(); + for (;;) { /* * work->func() can do task_work_add(), do not set
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