Re: Signal handling possibly wrong

[Chris Wright]

* Steven Rostedt ([EMAIL PROTECTED]) wrote:
> 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?

That's not correct w.r.t. SUSv3.  sa_mask should be always used and
SA_NODEFER is just whether or not to add that signal in.

SA_NODEFER
    [XSI] If set and sig is caught, sig shall not be added to the thread's
    signal mask on entry to the signal handler unless it is included in
    sa_mask. Otherwise, sig shall always be added to the thread's signal
    mask on entry to the signal handler.

Brodo, is this what you mean?

thanks,
-chris
--

Subject: [PATCH] fix SA_NODEFER signals to honor sa_mask

When receiving SA_NODEFER signal, kernel was inapproriately not applying
the sa_mask.  As pointed out by Brodo Stroesser.

Signed-off-by: Chris Wright <[EMAIL PROTECTED]>
---

diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c
--- a/arch/i386/kernel/signal.c
+++ b/arch/i386/kernel/signal.c
@@ -577,13 +577,12 @@ handle_signal(unsigned long sig, siginfo
        else
                ret = setup_frame(sig, ka, oldset, regs);
 
-       if (ret && !(ka->sa.sa_flags & SA_NODEFER)) {
-               spin_lock_irq(&current->sighand->siglock);
-               sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+       spin_lock_irq(&current->sighand->siglock);
+       sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+       if (ret && !(ka->sa.sa_flags & SA_NODEFER))
                sigaddset(&current->blocked,sig);
-               recalc_sigpending();
-               spin_unlock_irq(&current->sighand->siglock);
-       }
+       recalc_sigpending();
+       spin_unlock_irq(&current->sighand->siglock);
 
        return ret;
 }
-
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