perf probe: Check build-id of vmlinux

Check build-id of vmlinux by using functions in symbol.c.
This also exposes map__load() for getting vmlinux path,
and removes vmlinux path list in builtin-probe.c,
because symbol.c already has that. Checking build-id
prevents users to open old or different debuginfo from
current running kernel.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091215153232.17436.45539.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 8b3dd46..c4d55a0 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -104,12 +104,16 @@
 
 #define DSO__DELETED "(deleted)"
 
-static int map__load(struct map *self, struct perf_session *session,
-		     symbol_filter_t filter)
+int map__load(struct map *self, struct perf_session *session,
+	      symbol_filter_t filter)
 {
 	const char *name = self->dso->long_name;
-	int nr = dso__load(self->dso, self, session, filter);
+	int nr;
 
+	if (dso__loaded(self->dso, self->type))
+		return 0;
+
+	nr = dso__load(self->dso, self, session, filter);
 	if (nr < 0) {
 		if (self->dso->has_build_id) {
 			char sbuild_id[BUILD_ID_SIZE * 2 + 1];
@@ -147,7 +151,7 @@
 struct symbol *map__find_symbol(struct map *self, struct perf_session *session,
 				u64 addr, symbol_filter_t filter)
 {
-	if (!dso__loaded(self->dso, self->type) && map__load(self, session, filter) < 0)
+	if (map__load(self, session, filter) < 0)
 		return NULL;
 
 	return dso__find_symbol(self->dso, self->type, addr);
@@ -157,7 +161,7 @@
 					struct perf_session *session,
 					symbol_filter_t filter)
 {
-	if (!dso__loaded(self->dso, self->type) && map__load(self, session, filter) < 0)
+	if (map__load(self, session, filter) < 0)
 		return NULL;
 
 	if (!dso__sorted_by_name(self->dso, self->type))