[SPARC64]: Fix show_stack() when stack argument is NULL.

It didn't handle that case at all, and now dump_stack()
can be implemented directly as show_stack(current, NULL)

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 7 deletions

diff --git a/arch/sparc64/kernel/traps.c b/arch/sparc64/kernel/traps.c
index 6ef2d299fb10..6ef42b8e53d8 100644
--- a/arch/sparc64/kernel/traps.c
+++ b/arch/sparc64/kernel/traps.c
@@ -2134,12 +2134,20 @@ static void user_instruction_dump (unsigned int __user *pc)
 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
 {
         unsigned long pc, fp, thread_base, ksp;
-        void *tp = task_stack_page(tsk);
+        struct thread_info *tp;
         struct reg_window *rw;
         int count = 0;
 
         ksp = (unsigned long) _ksp;
-
+        if (!tsk)
+                tsk = current;
+        tp = task_thread_info(tsk);
+        if (ksp == 0UL) {
+                if (tsk == current)
+                        asm("mov %%fp, %0" : "=r" (ksp));
+                else
+                        ksp = tp->ksp;
+        }
         if (tp == current_thread_info())
                 flushw_all();
 
@@ -2168,11 +2176,7 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp)
 
 void dump_stack(void)
 {
-        unsigned long *ksp;
-
-        __asm__ __volatile__("mov       %%fp, %0"
-                             : "=r" (ksp));
-        show_stack(current, ksp);
+        show_stack(current, NULL);
 }
 
 EXPORT_SYMBOL(dump_stack);