[PATCH v3 36/51] perf/x86: convert perf_callchain_kernel() to use the new unwinder

[Josh Poimboeuf]

Convert perf_callchain_kernel() to use the new unwinder.  dump_trace()
has been deprecated.

Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
---
 arch/x86/events/core.c | 33 ++++++++++-----------------------
 1 file changed, 10 insertions(+), 23 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index dd3a1dc..b409e7c 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -37,6 +37,7 @@
 #include <asm/timer.h>
 #include <asm/desc.h>
 #include <asm/ldt.h>
+#include <asm/unwind.h>
 
 #include "perf_event.h"
 
@@ -2267,31 +2268,12 @@ void arch_perf_update_userpage(struct perf_event *event,
        cyc2ns_read_end(data);
 }
 
-/*
- * callchain support
- */
-
-static int backtrace_stack(void *data, const char *name)
-{
-       return 0;
-}
-
-static int backtrace_address(void *data, unsigned long addr, int reliable)
-{
-       struct perf_callchain_entry_ctx *entry = data;
-
-       return perf_callchain_store(entry, addr);
-}
-
-static const struct stacktrace_ops backtrace_ops = {
-       .stack                  = backtrace_stack,
-       .address                = backtrace_address,
-       .walk_stack             = print_context_stack_bp,
-};
-
 void
 perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs 
*regs)
 {
+       struct unwind_state state;
+       unsigned long addr;
+
        if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
                /* TODO: We don't support guest os callchain now */
                return;
@@ -2300,7 +2282,12 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx 
*entry, struct pt_regs *re
        if (perf_callchain_store(entry, regs->ip))
                return;
 
-       dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry);
+       for (unwind_start(&state, NULL, regs, NULL); !unwind_done(&state);
+            unwind_next_frame(&state)) {
+               addr = unwind_get_return_address(&state);
+               if (!addr || perf_callchain_store(entry, addr))
+                       return;
+       }
 }
 
 static inline int
-- 
2.7.4