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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2014-04-02 21:26:40 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-02 22:46:50 +0400 |
| commit | 1aabc5990d205cdb0789a1c26143c53601e9bb07 (patch) | |
| tree | 01e0db2ac388f630d964b2b33365af9d77307fb5 | |
| parent | b33ce442993865180292df2a314ee5251ba38b50 (diff) | |
| download | linux-1aabc5990d205cdb0789a1c26143c53601e9bb07.tar.xz | |
x86: Fix dumpstack_64 to keep state of "used" variable in loop
Commit 2223f6f6eeaa "x86: Clean up dumpstack_64.c code" moved the used
variable to a local within the loop, but the in_exception_stack()
depended on being non-volatile with the ability to change it.
By always re-initializing the "used" variable to zero, it would cause
the in_exception_stack() to return the same thing each time, and
cause the dump_stack loop to go into an infinite loop.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/x86/kernel/dumpstack_64.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 346b1df2412e..74c262a9b9f1 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -115,19 +115,18 @@ enum stack_type { }; static enum stack_type -analyze_stack(int cpu, struct task_struct *task, - unsigned long *stack, unsigned long **stack_end, char **id) +analyze_stack(int cpu, struct task_struct *task, unsigned long *stack, + unsigned long **stack_end, unsigned *used, char **id) { unsigned long *irq_stack; unsigned long addr; - unsigned used = 0; addr = ((unsigned long)stack & (~(THREAD_SIZE - 1))); if ((unsigned long)task_stack_page(task) == addr) return STACK_IS_NORMAL; *stack_end = in_exception_stack(cpu, (unsigned long)stack, - &used, id); + used, id); if (*stack_end) return STACK_IS_EXCEPTION; @@ -158,6 +157,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, struct thread_info *tinfo; unsigned long *irq_stack; unsigned long dummy; + unsigned used = 0; int graph = 0; int done = 0; @@ -186,7 +186,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, enum stack_type stype; char *id; - stype = analyze_stack(cpu, task, stack, &stack_end, &id); + stype = analyze_stack(cpu, task, stack, &stack_end, &used, &id); /* Default finish unless specified to continue */ done = 1; |