[PATCH 14/19] oprofile/x86: convert x86_backtrace() to the new unwinder

[Josh Poimboeuf]

Convert oprofile's x86_backtrace() to the new unwinder.  dump_trace()
has been deprecated.

Cc: Robert Richter <rric@xxxxxxxxxx>
Cc: oprofile-list@xxxxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 arch/x86/oprofile/backtrace.c | 42 +++++++++++++++++++-----------------------
 1 file changed, 19 insertions(+), 23 deletions(-)

diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index c594768..6cda1f4 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -16,27 +16,7 @@
 
 #include <asm/ptrace.h>
 #include <asm/stacktrace.h>
-
-static int backtrace_stack(void *data, char *name)
-{
-	/* Yes, we want all stacks */
-	return 0;
-}
-
-static int backtrace_address(void *data, unsigned long addr, int reliable)
-{
-	unsigned int *depth = data;
-
-	if ((*depth)--)
-		oprofile_add_trace(addr);
-	return 0;
-}
-
-static struct stacktrace_ops backtrace_ops = {
-	.stack		= backtrace_stack,
-	.address	= backtrace_address,
-	.walk_stack	= print_context_stack,
-};
+#include <asm/unwind.h>
 
 #ifdef CONFIG_COMPAT
 static struct stack_frame_ia32 *
@@ -113,8 +93,24 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
 	struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
 
 	if (!user_mode(regs)) {
-		if (depth)
-			dump_trace(NULL, regs, NULL, 0, &backtrace_ops, &depth);
+		struct unwind_state state;
+		unsigned long addr;
+
+		if (!depth)
+			return;
+
+		oprofile_add_trace(regs->ip);
+
+		if (!--depth)
+			return;
+
+		for (unwind_start(&state, NULL, regs, NULL);
+		     !unwind_done(&state); unwind_next_frame(&state)) {
+			addr = unwind_get_return_address(&state);
+			oprofile_add_trace(addr);
+			if (!--depth)
+				break;
+		}
 		return;
 	}
 
-- 
2.7.4