2 files changed, 41 insertions, 0 deletions

diff --git a/arch/parisc/include/asm/ftrace.h b/arch/parisc/include/asm/ftrace.h
index 2fa05dd6aeee..72c0fafaa039 100644
--- a/arch/parisc/include/asm/ftrace.h
+++ b/arch/parisc/include/asm/ftrace.h
@@ -20,6 +20,20 @@ struct ftrace_ret_stack {
  * Defined in entry.S
  */
 extern void return_to_handler(void);
+
+
+extern unsigned long return_address(unsigned int);
+
+#define HAVE_ARCH_CALLER_ADDR
+
+#define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
+#define CALLER_ADDR1 return_address(1)
+#define CALLER_ADDR2 return_address(2)
+#define CALLER_ADDR3 return_address(3)
+#define CALLER_ADDR4 return_address(4)
+#define CALLER_ADDR5 return_address(5)
+#define CALLER_ADDR6 return_address(6)
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_PARISC_FTRACE_H */
diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c
index a36799e85693..f03f6fb0ec83 100644
--- a/arch/parisc/kernel/unwind.c
+++ b/arch/parisc/kernel/unwind.c
@@ -417,3 +417,30 @@ int unwind_to_user(struct unwind_frame_info *info)
 
         return ret;
 }
+
+unsigned long return_address(unsigned int level)
+{
+        struct unwind_frame_info info;
+        struct pt_regs r;
+        unsigned long sp;
+
+        /* initialize unwind info */
+        asm volatile ("copy %%r30, %0" : "=r"(sp));
+        memset(&r, 0, sizeof(struct pt_regs));
+        r.iaoq[0] = (unsigned long) current_text_addr();
+        r.gr[2] = (unsigned long) __builtin_return_address(0);
+        r.gr[30] = sp;
+        unwind_frame_init(&info, current, &r);
+
+        /* unwind stack */
+        ++level;
+        do {
+                if (unwind_once(&info) < 0 || info.ip == 0)
+                        return 0;
+                if (!__kernel_text_address(info.ip)) {
+                        return 0;
+                }
+        } while (info.ip && level--);
+
+        return info.ip;
+}