Re: Signal handling possibly wrong

[Steven Rostedt]

On Tue, 2005-08-09 at 16:03 -0400, Steven Rostedt wrote:

> Man pages and kernel are right.  I just tested this out on 2.6.13-rc3
> with the attached program and it seems to follow what is stated in the
> man pages. So the assumption of what the code did by looking at it
> proves to be the mistake. :-)
> 
> Conclusion:  sa_mask defers the signals. SA_NODEFER defers the sent
> signal.

I'm the one that's wrong here ;-)   OK the kernel _does_ have a bug.
Looking at the code, I now see it, and my last program didn't show it.
The code in question was (as Bodo showed earlier):

        if (ret && !(ka->sa.sa_flags & SA_NODEFER)) {
                spin_lock_irq(&current->sighand->siglock);
                sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
                sigaddset(&current->blocked,sig);
                recalc_sigpending();
                spin_unlock_irq(&current->sighand->siglock);
        }

Where, sa_mask is _ignored_ if NODEFER is set. (I now have woken up!).
The attached program shows that the sa_mask is indeed ignored when
SA_NODEFER is set.

Now the real question is... Is this a bug?

-- Steve

Attachment: signal2
Description: application/executable