2006-09-07 12:01:36

by Martin Schwidefsky

[permalink] [raw]
Subject: [patch] s390: Kernel stack overflow handling.

From: Heiko Carstens <[email protected]>

[S390] Kernel stack overflow handling.

Substract the size of the initial stack frame from the correct
register. Otherwise we will end up in a program check loop.
Fix the offset into the save area as well.

Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
---

arch/s390/kernel/entry64.S | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff -urpN linux-2.6/arch/s390/kernel/entry64.S linux-2.6-patched/arch/s390/kernel/entry64.S
--- linux-2.6/arch/s390/kernel/entry64.S 2006-09-07 12:39:04.000000000 +0200
+++ linux-2.6-patched/arch/s390/kernel/entry64.S 2006-09-07 12:39:25.000000000 +0200
@@ -827,7 +827,7 @@ restart_go:
*/
stack_overflow:
lg %r15,__LC_PANIC_STACK # change to panic stack
- aghi %r1,-SP_SIZE
+ aghi %r15,-SP_SIZE
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
stmg %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
la %r1,__LC_SAVE_AREA
@@ -835,7 +835,7 @@ stack_overflow:
je 0f
chi %r12,__LC_PGM_OLD_PSW
je 0f
- la %r1,__LC_SAVE_AREA+16
+ la %r1,__LC_SAVE_AREA+32
0: mvc SP_R12(32,%r15),0(%r1) # move %r12-%r15 to stack
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # clear back chain
la %r2,SP_PTREGS(%r15) # load pt_regs