2 files changed, 15 insertions, 5 deletions

diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 254883d0c7e0..02de29830ffe 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -140,6 +140,19 @@ extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
 extern unsigned long perf_misc_flags(struct pt_regs *regs);
 #define perf_misc_flags(regs)   perf_misc_flags(regs)
 
+#include <asm/stacktrace.h>
+
+/*
+ * We abuse bit 3 from flags to pass exact information, see perf_misc_flags
+ * and the comment with PERF_EFLAGS_EXACT.
+ */
+#define perf_arch_fetch_caller_regs(regs, __ip)         {       \
+        (regs)->ip = (__ip);                                    \
+        (regs)->bp = caller_frame_pointer();                    \
+        (regs)->cs = __KERNEL_CS;                               \
+        regs->flags = 0;                                        \
+}
+
 #else
 static inline void init_hw_perf_events(void)            { }
 static inline void perf_events_lapic_init(void) { }
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index a957463d3c7a..2b16a2ad23dc 100644
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -78,17 +78,14 @@ struct stack_frame_ia32 {
     u32 return_address;
 };
 
-static inline unsigned long rewind_frame_pointer(int n)
+static inline unsigned long caller_frame_pointer(void)
 {
         struct stack_frame *frame;
 
         get_bp(frame);
 
 #ifdef CONFIG_FRAME_POINTER
-        while (n--) {
-                if (probe_kernel_address(&frame->next_frame, frame))
-                        break;
-        }
+        frame = frame->next_frame;
 #endif
 
         return (unsigned long)frame;