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authorChristian Borntraeger <cborntra@de.ibm.com>2006-10-11 09:31:52 -0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2006-10-11 09:31:52 -0400
commit75e9de18f079a51fa987ef0703112d5bc125fdb7 (patch)
treee9bdf9972851d7de6a8b5392bd4666f6fa96046d /arch/s390/kernel/stacktrace.c
parent12975aef62836e9f3e179afaaded8045f8a25ac4 (diff)
[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/kernel/stacktrace.c')
-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,
62void save_stack_trace(struct stack_trace *trace, struct task_struct *task) 62void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
63{ 63{
64 register unsigned long sp asm ("15"); 64 register unsigned long sp asm ("15");
65 unsigned long orig_sp; 65 unsigned long orig_sp, new_sp;
66 66
67 sp &= PSW_ADDR_INSN; 67 orig_sp = sp & PSW_ADDR_INSN;
68 orig_sp = sp;
69 68
70 sp = save_context_stack(trace, &trace->skip, sp, 69 new_sp = save_context_stack(trace, &trace->skip, orig_sp,
71 S390_lowcore.panic_stack - PAGE_SIZE, 70 S390_lowcore.panic_stack - PAGE_SIZE,
72 S390_lowcore.panic_stack); 71 S390_lowcore.panic_stack);
73 if ((sp != orig_sp) && !trace->all_contexts) 72 if ((new_sp != orig_sp) && !trace->all_contexts)
74 return; 73 return;
75 sp = save_context_stack(trace, &trace->skip, sp, 74 new_sp = save_context_stack(trace, &trace->skip, new_sp,
76 S390_lowcore.async_stack - ASYNC_SIZE, 75 S390_lowcore.async_stack - ASYNC_SIZE,
77 S390_lowcore.async_stack); 76 S390_lowcore.async_stack);
78 if ((sp != orig_sp) && !trace->all_contexts) 77 if ((new_sp != orig_sp) && !trace->all_contexts)
79 return; 78 return;
80 if (task) 79 if (task)
81 save_context_stack(trace, &trace->skip, sp, 80 save_context_stack(trace, &trace->skip, new_sp,
82 (unsigned long) task_stack_page(task), 81 (unsigned long) task_stack_page(task),
83 (unsigned long) task_stack_page(task) + THREAD_SIZE); 82 (unsigned long) task_stack_page(task) + THREAD_SIZE);
84 else 83 else
85 save_context_stack(trace, &trace->skip, sp, 84 save_context_stack(trace, &trace->skip, new_sp,
86 S390_lowcore.thread_info, 85 S390_lowcore.thread_info,
87 S390_lowcore.thread_info + THREAD_SIZE); 86 S390_lowcore.thread_info + THREAD_SIZE);
88 return; 87 return;