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authorChristian Borntraeger <cborntra@de.ibm.com>2006-10-11 15:31:52 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2006-10-11 15:31:52 +0200
commit75e9de18f079a51fa987ef0703112d5bc125fdb7 (patch)
treee9bdf9972851d7de6a8b5392bd4666f6fa96046d /arch/s390
parent12975aef62836e9f3e179afaaded8045f8a25ac4 (diff)
downloadlinux-next-75e9de18f079a51fa987ef0703112d5bc125fdb7.tar.gz
[S390] stacktrace bug.
The latest kernel 2.6.19-rc1 triggers a bug in the s390 specific stack trace code when compiled with gcc 3.4. This patch fixes the latest lock dependency validator code (2.6.19-rc1) on s390 gcc 3.4. The variable sp was fixed to r15 (which is the stack pointer in the s390 abi) and assigned new values to r15. Therefore, gcc 3.4 assigns a new value to r15 and does not restore it on exit (r15 is supposed to be call save) - the kernel stack is broken. Avoid trouble by not assigning any new value to sp (r15). Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/stacktrace.c17
1 files changed, 8 insertions, 9 deletions
diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index d9428a0fc8fb..0d14a4789bf2 100644
--- a/arch/s390/kernel/stacktrace.c
+++ b/arch/s390/kernel/stacktrace.c
@@ -62,27 +62,26 @@ static inline unsigned long save_context_stack(struct stack_trace *trace,
void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
{
register unsigned long sp asm ("15");
- unsigned long orig_sp;
+ unsigned long orig_sp, new_sp;
- sp &= PSW_ADDR_INSN;
- orig_sp = sp;
+ orig_sp = sp & PSW_ADDR_INSN;
- sp = save_context_stack(trace, &trace->skip, sp,
+ new_sp = save_context_stack(trace, &trace->skip, orig_sp,
S390_lowcore.panic_stack - PAGE_SIZE,
S390_lowcore.panic_stack);
- if ((sp != orig_sp) && !trace->all_contexts)
+ if ((new_sp != orig_sp) && !trace->all_contexts)
return;
- sp = save_context_stack(trace, &trace->skip, sp,
+ new_sp = save_context_stack(trace, &trace->skip, new_sp,
S390_lowcore.async_stack - ASYNC_SIZE,
S390_lowcore.async_stack);
- if ((sp != orig_sp) && !trace->all_contexts)
+ if ((new_sp != orig_sp) && !trace->all_contexts)
return;
if (task)
- save_context_stack(trace, &trace->skip, sp,
+ save_context_stack(trace, &trace->skip, new_sp,
(unsigned long) task_stack_page(task),
(unsigned long) task_stack_page(task) + THREAD_SIZE);
else
- save_context_stack(trace, &trace->skip, sp,
+ save_context_stack(trace, &trace->skip, new_sp,
S390_lowcore.thread_info,
S390_lowcore.thread_info + THREAD_SIZE);
return;