[PATCH -tip 5/7] perf bts trace: print file path of the executed elf

[Akihiro Nagai <akihiro.nagai.hw@hitachi.com>]

Provide the function to print file path to the executed elf.
Users can enable it with option '-e' or '--elfpath'.
For example,
    'perf bts -ae trace'
This command prints address and file path of elf.
And, output is:

address            elf_filepath
0xffffffff8146fe0e /lib/modules/2.6.37-rc2-tip+/build/vmlinux => 0x00007fd4038e3b20 /lib64/ld-2.12.90.so
0xffffffff8146fe0e /lib/modules/2.6.37-rc2-tip+/build/vmlinux => 0x00007fd4038e3b20 /lib64/ld-2.12.90.so
0x00007fd4038e3b23 /lib64/ld-2.12.90.so             => 0x00007fd4038e7910 /lib64/ld-2.12.90.so
0xffffffff8146fe0e /lib/modules/2.6.37-rc2-tip+/build/vmlinux => 0x00007fd4038e7910 /lib64/ld-2.12.90.so
0xffffffff8146fe0e /lib/modules/2.6.37-rc2-tip+/build/vmlinux => 0x00007fd4038e7936 /lib64/ld-2.12.90.so
0xffffffff8146fe0e /lib/modules/2.6.37-rc2-tip+/build/vmlinux => 0x00007fd4038e793d /lib64/ld-2.12.90.so
0x00007fd4038e7981 /lib64/ld-2.12.90.so             => 0x00007fd4038e79a3 /lib64/ld-2.12.90.so
0x00007fd4038e79a7 /lib64/ld-2.12.90.so             => 0x00007fd4038e7988 /lib64/ld-2.12.90.so
...

Signed-off-by: Akihiro Nagai <akihiro.nagai.hw@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: linux-kernel@vger.kernel.org
---

 tools/perf/Documentation/perf-bts.txt |    3 +++
 tools/perf/builtin-bts.c              |   31 +++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/tools/perf/Documentation/perf-bts.txt b/tools/perf/Documentation/perf-bts.txt
index 56ddaa4..acabffc 100644
--- a/tools/perf/Documentation/perf-bts.txt
+++ b/tools/perf/Documentation/perf-bts.txt
@@ -38,6 +38,9 @@ OPTIONS
 -p::
 --pid::
 	Print pid.
+-e::
+--elfpath::
+	Print file path of executed elf.
 
 SEE ALSO
 --------
diff --git a/tools/perf/builtin-bts.c b/tools/perf/builtin-bts.c
index 11e491b..3b2a21e 100644
--- a/tools/perf/builtin-bts.c
+++ b/tools/perf/builtin-bts.c
@@ -20,6 +20,7 @@ struct exec_info {
 	u64		addr;		/* recorded address by bts */
 	pid_t		pid;		/* tracee process pid */
 	const char	*comm;		/* command name */
+	const char	*elfpath;	/* file path to elf */
 };
 
 #define EI_PID_UNSET	-1
@@ -28,6 +29,7 @@ struct exec_info {
 #define EI_FLAG_PRINT_ADDR		(1 << 0)
 #define EI_FLAG_PRINT_PID		(1 << 1)
 #define EI_FLAG_PRINT_COMM		(1 << 2)
+#define EI_FLAG_PRINT_ELFPATH		(1 << 3)
 
 /* it's used when no print item specified */
 #define EI_FLAG_PRINT_DEFAULT		EI_FLAG_PRINT_ADDR
@@ -77,6 +79,9 @@ static const struct option bts_options[] = {
 	OPT_CALLBACK_DEFAULT_NOOPT('c', "comm", NULL, NULL,
 				   "print command name", set_print_flags,
 				   (void *)EI_FLAG_PRINT_COMM),
+	OPT_CALLBACK_DEFAULT_NOOPT('e', "elfpath", NULL, NULL,
+				   "print file path to elf", set_print_flags,
+				   (void *)EI_FLAG_PRINT_ELFPATH),
 	OPT_END()
 };
 
@@ -91,6 +96,7 @@ static void fill_exec_info(struct exec_info *ei, struct perf_session *session,
 						event_t *event, u64 addr)
 {
 	struct thread *thread;
+	struct addr_location al;
 
 	ei->addr = addr;
 	ei->pid = event->ip.pid;
@@ -99,12 +105,25 @@ static void fill_exec_info(struct exec_info *ei, struct perf_session *session,
 	if (!thread)
 		return;
 	ei->comm = thread->comm;
+
+	/* get file path to elf */
+	memset(&al, 0, sizeof(al));
+	thread__find_addr_map(thread, session, PERF_RECORD_MISC_USER,
+			      MAP__FUNCTION, event->ip.pid, addr, &al);
+	if (!al.map)
+		thread__find_addr_map(thread, session, PERF_RECORD_MISC_KERNEL,
+				      MAP__FUNCTION, event->ip.pid, addr, &al);
+	if (!al.map)
+		return;
+	map__load(al.map, NULL);
+	ei->elfpath = al.map->dso->long_name;
 }
 
 static void __print_exec_info(struct exec_info *ei)
 {
 	char pid[16];
 	const char *comm;
+	const char *elfpath;
 
 	if (print_flags & EI_FLAG_PRINT_PID) {
 		if (ei->pid == EI_PID_UNSET)
@@ -119,6 +138,10 @@ static void __print_exec_info(struct exec_info *ei)
 	}
 	if (print_flags & EI_FLAG_PRINT_ADDR)
 		printf(FMT_ADDR " ", ei->addr);
+	if (print_flags & EI_FLAG_PRINT_ELFPATH) {
+		elfpath = ei->elfpath ? : EI_UNKNOWN_TEXT;
+		printf("%-32s ", elfpath);
+	}
 }
 
 static void print_exec_info(struct exec_info *ei_from, struct exec_info *ei_to)
@@ -137,6 +160,8 @@ static void print_exec_info_header(void)
 		printf("%-12s ", "command");
 	if (print_flags & EI_FLAG_PRINT_ADDR)
 		printf("%-" FMT_ADDR_WIDTH "s ", "address");
+	if (print_flags & EI_FLAG_PRINT_ELFPATH)
+		printf("%-32s ", "elf_filepath");
 	printf("\n");
 }
 
@@ -163,6 +188,7 @@ static int process_sample_event(event_t *event, struct perf_session *session)
 static struct perf_event_ops event_ops = {
 	.sample			= process_sample_event,
 	.comm			= event__process_comm,
+	.mmap			= event__process_mmap,
 	.ordered_samples	= false,
 };
 
@@ -180,6 +206,11 @@ static int __cmd_trace(void)
 	if (is_flags_unset(print_flags))
 		print_flags = EI_FLAG_PRINT_DEFAULT;
 
+	/* setup kernel maps to resolve vmlinux file path */
+	perf_session__create_kernel_maps(session);
+	if (symbol__init() < 0)
+		fprintf(stderr, "failed to initialize symbol.\n");
+
 	setup_pager();
 	print_exec_info_header();
 	perf_session__process_events(session, &event_ops);