[PATCH] Fix i386 signal handling of NODEFER, should not affect sa_mask (was: Re: Signal handling possibly wrong)

[Steven Rostedt <rostedt@goodmis.org>]

On Tue, 2005-08-09 at 13:49 -0700, Chris Wright wrote:

> 
> 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 <chrisw@osdl.org>
> ---
> 
> 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;
>  }


Hmm, I think you want this patch. You still need to check the return of
setting up the frames.

-- Steve

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

--- linux-2.6.13-rc6-git1/arch/i386/kernel/signal.c.orig	2005-08-09 16:54:36.000000000 -0400
+++ linux-2.6.13-rc6-git1/arch/i386/kernel/signal.c	2005-08-09 16:55:24.000000000 -0400
@@ -577,10 +577,11 @@ handle_signal(unsigned long sig, siginfo
 	else
 		ret = setup_frame(sig, ka, oldset, regs);
 
-	if (ret && !(ka->sa.sa_flags & SA_NODEFER)) {
+	if (ret) {
 		spin_lock_irq(&current->sighand->siglock);
 		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
-		sigaddset(&current->blocked,sig);
+		if (!(ka->sa.sa_flags & SA_NODEFER))
+			sigaddset(&current->blocked,sig);
 		recalc_sigpending();
 		spin_unlock_irq(&current->sighand->siglock);
 	}