[PATCH] s390: kernel stack corruption
When an asynchronous interruption occurs during the execution of the
'critical section' within the generic interruption handling code (entry.S),
a faulty check for a userspace PSW may result in a corrupted kernel stack
pointer which subsequently triggers a stack overflow check.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 58fc7fb..9b30f4c 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -108,7 +108,7 @@
bl BASED(0f)
l %r14,BASED(.Lcleanup_critical)
basr %r14,%r14
- tm 0(%r12),0x01 # retest problem state after cleanup
+ tm 1(%r12),0x01 # retest problem state after cleanup
bnz BASED(1f)
0: l %r14,__LC_ASYNC_STACK # are we already on the async stack ?
slr %r14,%r15
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index d0c9ffa..7b9b4a2 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -101,7 +101,7 @@
clc \psworg+8(8),BASED(.Lcritical_start)
jl 0f
brasl %r14,cleanup_critical
- tm 0(%r12),0x01 # retest problem state after cleanup
+ tm 1(%r12),0x01 # retest problem state after cleanup
jnz 1f
0: lg %r14,__LC_ASYNC_STACK # are we already on the async. stack ?
slgr %r14,%r15