[patch 4/13] s390: alternate signal stack handling bug.

[patch 4/13] s390: alternate signal stack handling bug.

[Martin Schwidefsky]

From: Laurent Meyer <meyerlau@fr.ibm.com>

[patch 4/13] s390: alternate signal stack handling bug.

If a signal handler has been established with the SA_ONSTACK option
but no alternate stack is provided with sigaltstack(), the kernel
still tries to install the alternate stack. Also when setting an
alternate stack with sigalstack() and the SS_DISABLE flag, the
kernel tries to install the alternate stack on signal delivery.
Use the correct conditions sas_ss_flags() to check if the alternate
stack has to be used.

Signed-off-by: Laurent Meyer <meyerlau@fr.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 arch/s390/kernel/compat_signal.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

diff -urpN linux-2.6/arch/s390/kernel/compat_signal.c linux-2.6-patched/arch/s390/kernel/compat_signal.c
--- linux-2.6/arch/s390/kernel/compat_signal.c	2006-03-20 06:53:29.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/compat_signal.c	2006-04-24 16:47:21.000000000 +0200
@@ -430,7 +430,7 @@ get_sigframe(struct k_sigaction *ka, str
 
 	/* This is the X/Open sanctioned signal stack switching.  */
 	if (ka->sa.sa_flags & SA_ONSTACK) {
-		if (! on_sig_stack(sp))
+		if (! sas_ss_flags(sp))
 			sp = current->sas_ss_sp + current->sas_ss_size;
 	}