[PATCH] Add oprofile_add_ext_sample

On ppc64 we look at a profiling register to work out the sample address and
if it was in userspace or kernel.

The backtrace interface oprofile_add_sample does not allow this.  Create
oprofile_add_ext_sample and make oprofile_add_sample use it too.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: John Levon <levon@movementarian.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/oprofile/cpu_buffer.c

@@ -217,11 +217,10 @@ static void oprofile_end_trace(struct oprofile_cpu_buffer * cpu_buf)
 	cpu_buf->tracing = 0;
 }
 
-void oprofile_add_sample(struct pt_regs * const regs, unsigned long event)
+void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
+				unsigned long event, int is_kernel)
 {
 	struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[smp_processor_id()];
-	unsigned long pc = profile_pc(regs);
-	int is_kernel = !user_mode(regs);
 
 	if (!backtrace_depth) {
 		log_sample(cpu_buf, pc, is_kernel, event);
@@ -238,6 +237,14 @@ void oprofile_add_sample(struct pt_regs * const regs, unsigned long event)
 	oprofile_end_trace(cpu_buf);
 }
 
+void oprofile_add_sample(struct pt_regs * const regs, unsigned long event)
+{
+	int is_kernel = !user_mode(regs);
+	unsigned long pc = profile_pc(regs);
+
+	oprofile_add_ext_sample(pc, regs, event, is_kernel);
+}
+
 void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event)
 {
 	struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[smp_processor_id()];

include/linux/oprofile.h

@@ -61,6 +61,16 @@ void oprofile_arch_exit(void);
  */
 void oprofile_add_sample(struct pt_regs * const regs, unsigned long event);
 
+/**
+ * Add an extended sample.  Use this when the PC is not from the regs, and
+ * we cannot determine if we're in kernel mode from the regs.
+ *
+ * This function does perform a backtrace.
+ *
+ */
+void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
+				unsigned long event, int is_kernel);
+
 /* Use this instead when the PC value is not from the regs. Doesn't
  * backtrace. */
 void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event);