From dc4552bf7176573ccf79af04ab8648b015738f4a Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Tue, 7 Aug 2012 23:32:05 -0300
Subject: perf tools: Add dump_stack function

To help in debugging the tools, provides functionality roughly similar
to the function with the same name in the kernel.

Copied from glibc backtrace function man page.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-6nw2sak21bqy8h1m2syyo816@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/util.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

(limited to 'tools/perf/util/util.c')

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index d03599fbe78b..1b8775c3707d 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -1,6 +1,9 @@
 #include "../perf.h"
 #include "util.h"
 #include <sys/mman.h>
+#include <execinfo.h>
+#include <stdio.h>
+#include <stdlib.h>
 
 /*
  * XXX We need to find a better place for these things...
@@ -158,3 +161,19 @@ size_t hex_width(u64 v)
 
 	return n;
 }
+
+/* Obtain a backtrace and print it to stdout. */
+void dump_stack(void)
+{
+	void *array[16];
+	size_t size = backtrace(array, ARRAY_SIZE(array));
+	char **strings = backtrace_symbols(array, size);
+	size_t i;
+
+	printf("Obtained %zd stack frames.\n", size);
+
+	for (i = 0; i < size; i++)
+		printf("%s\n", strings[i]);
+
+	free(strings);
+}
-- 
cgit v1.2.3


From c9f08bee50c71b06685ccff8110e56a7c05662b7 Mon Sep 17 00:00:00 2001
From: Irina Tirdea <irina.tirdea@intel.com>
Date: Sat, 8 Sep 2012 03:43:23 +0300
Subject: perf tools: add NO_BACKTRACE for application self-debugging

perf has support for self-debugging by defining dump_stack function.
This function uses backtrace and backtrace_symbols functions defined as
GNU extensions.

In Android, bionic does not offer support for these functions and
compilation will fail with the following error:

target  C: libperf <= tools/perf/util/util.c
tools/perf/util/util.c:4:22: fatal error: execinfo.h: No such file or directory
compilation terminated.

Add a compile-time option (NO_BACKTRACE) to enable or disable
self-debugging functionality in perf. This can also help in debugging
since it offers the possibility to turn on/off printing the backtrace.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1347065004-15306-12-git-send-email-irina.tirdea@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/util.c | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'tools/perf/util/util.c')

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 1b8775c3707d..2055cf38041c 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -1,7 +1,9 @@
 #include "../perf.h"
 #include "util.h"
 #include <sys/mman.h>
+#ifndef NO_BACKTRACE
 #include <execinfo.h>
+#endif
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -163,6 +165,7 @@ size_t hex_width(u64 v)
 }
 
 /* Obtain a backtrace and print it to stdout. */
+#ifndef NO_BACKTRACE
 void dump_stack(void)
 {
 	void *array[16];
@@ -177,3 +180,6 @@ void dump_stack(void)
 
 	free(strings);
 }
+#else
+void dump_stack(void) {}
+#endif
-- 
cgit v1.2.3