perf script: Add option resolving vmlinux path

Add the option get the path of [kernel.kallsyms].
Specify '--show-kernel-path' option to use this function.
This patch enables other applications to use this output easily.

Without --show-kernel-path  option

ffffffff81467612 irq_return ([kernel.kallsyms])
ffffffff81467612 irq_return ([kernel.kallsyms])
    7f24fc02a6b3 _start (/lib64/ld-2.14.so)
[snip]

With --show-kernel-path option

ffffffff81467612 irq_return (/lib/modules/3.2.0+/build/vmlinux)
ffffffff81467612 irq_return (/lib/modules/3.2.0+/build/vmlinux)
    7f24fc02a6b3 _start (/lib64/ld-2.14.so)
[snip]

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120130044320.2384.73322.stgit@linux3
Signed-off-by: Akihiro Nagai <akihiro.nagai.hw@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 1107960..dea6d1c 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -216,9 +216,12 @@
 {
 	const char *dsoname;
 
-	if (map && map->dso && map->dso->name)
-		dsoname = map->dso->name;
-	else
+	if (map && map->dso && (map->dso->name || map->dso->long_name)) {
+		if (symbol_conf.show_kernel_path && map->dso->long_name)
+			dsoname = map->dso->long_name;
+		else if (map->dso->name)
+			dsoname = map->dso->name;
+	} else
 		dsoname = "[unknown]";
 
 	return fprintf(fp, "%s", dsoname);