Right now, the xtensa stacktrace code reads the _current_ kernel stack
pointer if nothing is supplied. With debugging facilities like sysrq
this means that the backtrace of the sysrq-handler is printed instead
of a trace of the given task's stack.
When no stack pointer is specified in show_trace() and show_stack(),
use the stack pointer that comes with the handed in task descriptor to
make stack traces more useful.
Signed-off-by: Johannes Weiner <[email protected]>
---
arch/xtensa/kernel/traps.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -372,11 +372,10 @@ void show_trace(struct task_struct *task
unsigned long a0, a1, pc;
unsigned long sp_start, sp_end;
- a1 = (unsigned long)sp;
-
- if (a1 == 0)
- __asm__ __volatile__ ("mov %0, a1\n" : "=a"(a1));
-
+ if (sp)
+ a1 = (unsigned long)sp;
+ else
+ a1 = task->thread.sp;
sp_start = a1 & ~(THREAD_SIZE-1);
sp_end = sp_start + THREAD_SIZE;
@@ -418,9 +417,8 @@ void show_stack(struct task_struct *task
int i = 0;
unsigned long *stack;
- if (sp == 0)
- __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
-
+ if (!sp)
+ sp = (unsigned long *)task->thread.sp;
stack = sp;
printk("\nStack: ");
--