[ARM] 5382/1: unwind: Reorganise the stacktrace support

This patch changes the walk_stacktrace and its callers for easier
integration of stack unwinding. The arch/arm/kernel/stacktrace.h file is
also moved to arch/arm/include/asm/stacktrace.h.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 10 insertions, 11 deletions

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index d3ea6fa89521..af377c73d90b 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -34,6 +34,7 @@
 #include <asm/processor.h>
 #include <asm/system.h>
 #include <asm/thread_notify.h>
+#include <asm/stacktrace.h>
 #include <asm/mach/time.h>
 
 static const char *processor_modes[] = {
@@ -372,23 +373,21 @@ EXPORT_SYMBOL(kernel_thread);
 
 unsigned long get_wchan(struct task_struct *p)
 {
-        unsigned long fp, lr;
-        unsigned long stack_start, stack_end;
+        struct stackframe frame;
         int count = 0;
         if (!p || p == current || p->state == TASK_RUNNING)
                 return 0;
 
-        stack_start = (unsigned long)end_of_stack(p);
-        stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
-
-        fp = thread_saved_fp(p);
+        frame.fp = thread_saved_fp(p);
+        frame.sp = thread_saved_sp(p);
+        frame.lr = 0;                   /* recovered from the stack */
+        frame.pc = thread_saved_pc(p);
         do {
-                if (fp < stack_start || fp > stack_end)
+                int ret = unwind_frame(&frame);
+                if (ret < 0)
                         return 0;
-                lr = ((unsigned long *)fp)[-1];
-                if (!in_sched_functions(lr))
-                        return lr;
-                fp = *(unsigned long *) (fp - 12);
+                if (!in_sched_functions(frame.pc))
+                        return frame.pc;
         } while (count ++ < 16);
         return 0;
 }