[PATCH v2 33/44] oprofile/x86: convert x86_backtrace() to use the new unwinder

[Josh Poimboeuf]

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

Cc: Robert Richter <r...@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
---
 arch/x86/oprofile/backtrace.c | 39 +++++++++++++++++----------------------
 1 file changed, 17 insertions(+), 22 deletions(-)

diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index 7539148..f28ac1a 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, const 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 *
@@ -113,14 +93,29 @@ x86_backtrace(struct pt_regs * const regs, unsigned int 
depth)
        struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
 
        if (!user_mode(regs)) {
+               struct unwind_state state;
+               unsigned long addr;
+
                if (!depth)
                        return;
 
                oprofile_add_trace(regs->ip);
+
                if (!--depth)
                        return;
 
-               dump_trace(NULL, regs, NULL, 0, &backtrace_ops, &depth);
+               for (unwind_start(&state, NULL, regs, NULL);
+                    !unwind_done(&state); unwind_next_frame(&state)) {
+                       addr = unwind_get_return_address(&state);
+                       if (!addr)
+                               break;
+
+                       oprofile_add_trace(addr);
+
+                       if (!--depth)
+                               break;
+               }
+
                return;
        }
 
-- 
2.7.4