Re: 2.4.19-pre4-ac4 kills my gdm

[Corey Minyard <minyard@acm.org>]

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  Patrick R. McManus wrote:

>Alan,
>
>mea culpa on this one - my problem appears to be with the only other
>patch I was running - I believed I was also running it on ac3, but it
>now appears that I was thinking of another box.
>
>The other patch was corey minyard's "allow signal handler to not call
>handler" patch that I was interested in seeing its impact on a
>userspace project of mine. It kills gdm (at least with ac4.. maybe
>others?)
>
>thanks,
>-Pat
>
Yet, it does seem to kill gdm. xdm and kdm seem to work fine.

Ok, I see the problem. I've fixed it, booted and tried gdm, and it works 
fine. The SA_ONESHOT was checked in the wrong place, the handler is set 
in the frame_setup routines, so I have to check and set the handler due 
to the SA_ONESHOT flag after this. The patch is attached.

-Corey



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--- ./arch/i386/kernel/signal.c.nocallhndlr	Wed Mar 27 10:56:29 2002
+++ ./arch/i386/kernel/signal.c	Thu Apr  4 13:10:30 2002
@@ -558,22 +558,25 @@
 		}
 	}
 
-	/* Set up the stack frame */
-	if (ka->sa.sa_flags & SA_SIGINFO)
-		setup_rt_frame(sig, ka, info, oldset, regs);
-	else
-		setup_frame(sig, ka, oldset, regs);
+	/* Set up the stack frame if we are calling the handler. */
+	if (! (ka->sa.sa_flags & SA_NOCALLHNDLR)) {
+		if (ka->sa.sa_flags & SA_SIGINFO)
+			setup_rt_frame(sig, ka, info, oldset, regs);
+		else
+			setup_frame(sig, ka, oldset, regs);
+
+		if (!(ka->sa.sa_flags & SA_NODEFER)) {
+			spin_lock_irq(&current->sigmask_lock);
+			sigorsets(&current->blocked,&current->blocked,
+				  &ka->sa.sa_mask);
+			sigaddset(&current->blocked,sig);
+			recalc_sigpending(current);
+			spin_unlock_irq(&current->sigmask_lock);
+		}
+	}
 
 	if (ka->sa.sa_flags & SA_ONESHOT)
 		ka->sa.sa_handler = SIG_DFL;
-
-	if (!(ka->sa.sa_flags & SA_NODEFER)) {
-		spin_lock_irq(&current->sigmask_lock);
-		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
-		sigaddset(&current->blocked,sig);
-		recalc_sigpending(current);
-		spin_unlock_irq(&current->sigmask_lock);
-	}
 }
 
 /*
--- ./include/asm-i386/signal.h.nocallhndlr	Wed Mar 27 10:56:12 2002
+++ ./include/asm-i386/signal.h	Thu Apr  4 13:02:07 2002
@@ -91,6 +91,7 @@
 #define SA_RESTART	0x10000000
 #define SA_NODEFER	0x40000000
 #define SA_RESETHAND	0x80000000
+#define SA_NOCALLHNDLR	0x00800000 /* Don't really call the handler. */
 
 #define SA_NOMASK	SA_NODEFER
 #define SA_ONESHOT	SA_RESETHAND