Determine whether we're currently on the alternative signal stack

dynamically, by comparing the stack pointer against the altstack
base and size, so that you get the correct answer if you longjmp
out of the signal handler, as tested by regress/sys/kern/stackjmp/.
Also, fix alt stack handling on vax, where it was completely broken.

Testing and corrections by miod@, krw@, tobiasu@, pirofti@

2 files changed, 4 insertions, 3 deletions

diff --git a/sys/arch/powerpc/include/cpu.h b/sys/arch/powerpc/include/cpu.h
index fe996e04a5e..e8f521b988a 100644
--- a/sys/arch/powerpc/include/cpu.h
+++ b/sys/arch/powerpc/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.46 2010/09/28 20:27:55 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.47 2012/12/02 07:03:31 guenther Exp $	*/
 /*	$NetBSD: cpu.h,v 1.1 1996/09/30 16:34:21 ws Exp $	*/
 
 /*
@@ -150,6 +150,7 @@ extern struct cpu_info cpu_info[PPC_MAXPROCS];
  * This is used during profiling to integrate system time.
  */
 #define	PROC_PC(p)		(trapframe(p)->srr0)
+#define	PROC_STACK(p)		(trapframe(p)->fixreg[1])
 
 void	delay(unsigned);
 #define	DELAY(n)		delay(n)
diff --git a/sys/arch/powerpc/include/signal.h b/sys/arch/powerpc/include/signal.h
index 95340ba7602..7258c5a90df 100644
--- a/sys/arch/powerpc/include/signal.h
+++ b/sys/arch/powerpc/include/signal.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: signal.h,v 1.7 2006/01/08 14:20:17 millert Exp $	*/
+/*	$OpenBSD: signal.h,v 1.8 2012/12/02 07:03:31 guenther Exp $	*/
 /*	$NetBSD: signal.h,v 1.1 1996/09/30 16:34:34 ws Exp $	*/
 
 /*
@@ -64,7 +64,7 @@ struct trapframe {
 };
 
 struct sigcontext {
-	int sc_onstack;			/* saved onstack flag */
+	int __sc_unused;
 	int sc_mask;			/* saved signal mask */
 	struct trapframe sc_frame;	/* saved registers */
 };