[ARM] 5381/1: unwind: Reorganise the traps.c code

This patch moves code around in the arch/arm/kernel/traps.c file for
easier integration of the stack unwinding support.

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

2 files changed, 20 insertions, 15 deletions

diff --git a/arch/arm/include/asm/traps.h b/arch/arm/include/asm/traps.h
index aa399aec568e..491960bf4260 100644
--- a/arch/arm/include/asm/traps.h
+++ b/arch/arm/include/asm/traps.h
@@ -25,5 +25,6 @@ static inline int in_exception_text(unsigned long ptr)
 }
 
 extern void __init early_trap_init(void);
+extern void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame);
 
 #endif
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 79abc4ddc0cf..f68ca0fb0ed7 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -152,11 +152,25 @@ static void dump_instr(struct pt_regs *regs)
 
 static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 {
-        unsigned int fp;
+        unsigned int fp, mode;
         int ok = 1;
 
         printk("Backtrace: ");
-        fp = regs->ARM_fp;
+
+        if (!tsk)
+                tsk = current;
+
+        if (regs) {
+                fp = regs->ARM_fp;
+                mode = processor_mode(regs);
+        } else if (tsk != current) {
+                fp = thread_saved_fp(tsk);
+                mode = 0x10;
+        } else {
+                asm("mov %0, fp" : "=r" (fp) : : "cc");
+                mode = 0x10;
+        }
+
         if (!fp) {
                 printk("no frame pointer");
                 ok = 0;
@@ -168,29 +182,19 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
         printk("\n");
 
         if (ok)
-                c_backtrace(fp, processor_mode(regs));
+                c_backtrace(fp, mode);
 }
 
 void dump_stack(void)
 {
-        __backtrace();
+        dump_backtrace(NULL, NULL);
 }
 
 EXPORT_SYMBOL(dump_stack);
 
 void show_stack(struct task_struct *tsk, unsigned long *sp)
 {
-        unsigned long fp;
-
-        if (!tsk)
-                tsk = current;
-
-        if (tsk != current)
-                fp = thread_saved_fp(tsk);
-        else
-                asm("mov %0, fp" : "=r" (fp) : : "cc");
-
-        c_backtrace(fp, 0x10);
+        dump_backtrace(NULL, tsk);
         barrier();
 }