1 files changed, 41 insertions, 1 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 80acbf3d5de1..70cffd052c04 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -452,6 +452,7 @@ enum perf_callchain_context {
 #include <linux/fs.h>
 #include <linux/pid_namespace.h>
 #include <linux/workqueue.h>
+#include <linux/ftrace.h>
 #include <asm/atomic.h>
 
 #define PERF_MAX_STACK_DEPTH            255
@@ -847,6 +848,44 @@ perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
                 __perf_sw_event(event_id, nr, nmi, regs, addr);
 }
 
+extern void
+perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip);
+
+/*
+ * Take a snapshot of the regs. Skip ip and frame pointer to
+ * the nth caller. We only need a few of the regs:
+ * - ip for PERF_SAMPLE_IP
+ * - cs for user_mode() tests
+ * - bp for callchains
+ * - eflags, for future purposes, just in case
+ */
+static inline void perf_fetch_caller_regs(struct pt_regs *regs, int skip)
+{
+        unsigned long ip;
+
+        memset(regs, 0, sizeof(*regs));
+
+        switch (skip) {
+        case 1 :
+                ip = CALLER_ADDR0;
+                break;
+        case 2 :
+                ip = CALLER_ADDR1;
+                break;
+        case 3 :
+                ip = CALLER_ADDR2;
+                break;
+        case 4:
+                ip = CALLER_ADDR3;
+                break;
+        /* No need to support further for now */
+        default:
+                ip = 0;
+        }
+
+        return perf_arch_fetch_caller_regs(regs, ip, skip);
+}
+
 extern void __perf_event_mmap(struct vm_area_struct *vma);
 
 static inline void perf_event_mmap(struct vm_area_struct *vma)
@@ -880,7 +919,8 @@ static inline bool perf_paranoid_kernel(void)
 }
 
 extern void perf_event_init(void);
-extern void perf_tp_event(int event_id, u64 addr, u64 count, void *record, int entry_size);
+extern void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
+                          int entry_size, struct pt_regs *regs);
 extern void perf_bp_event(struct perf_event *event, void *data);
 
 #ifndef perf_misc_flags