perf probe: Add filters support for available functions

Add filters support for available function list.

Default filter is "!_*" for filtering out local-purpose symbols.

e.g.:
 # perf probe --filter="add*" -F
add_disk
add_disk_randomness
add_input_randomness
add_interrupt_randomness
add_memory
add_page_to_unevictable_list
add_page_wait_queue
...

Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Chase Douglas <chase.douglas@canonical.com>
Cc: Franck Bui-Huu <fbuihuu@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20110120141545.25915.85930.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 077e051..9d237e3 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1951,21 +1951,23 @@
 
 	return ret;
 }
+/* TODO: don't use a global variable for filter ... */
+static struct strfilter *available_func_filter;
 
 /*
- * If a symbol corresponds to a function with global binding return 0.
- * For all others return 1.
+ * If a symbol corresponds to a function with global binding and
+ * matches filter return 0. For all others return 1.
  */
-static int filter_non_global_functions(struct map *map __unused,
-					struct symbol *sym)
+static int filter_available_functions(struct map *map __unused,
+				      struct symbol *sym)
 {
-	if (sym->binding != STB_GLOBAL)
-		return 1;
-
-	return 0;
+	if (sym->binding == STB_GLOBAL &&
+	    strfilter__compare(available_func_filter, sym->name))
+		return 0;
+	return 1;
 }
 
-int show_available_funcs(const char *module)
+int show_available_funcs(const char *module, struct strfilter *_filter)
 {
 	struct map *map;
 	int ret;
@@ -1981,7 +1983,8 @@
 		pr_err("Failed to find %s map.\n", (module) ? : "kernel");
 		return -EINVAL;
 	}
-	if (map__load(map, filter_non_global_functions)) {
+	available_func_filter = _filter;
+	if (map__load(map, filter_available_functions)) {
 		pr_err("Failed to load map.\n");
 		return -EINVAL;
 	}
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 4e80b2b..3434fc9 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -128,7 +128,7 @@
 extern int show_available_vars(struct perf_probe_event *pevs, int npevs,
 			       int max_probe_points, const char *module,
 			       struct strfilter *filter, bool externs);
-extern int show_available_funcs(const char *module);
+extern int show_available_funcs(const char *module, struct strfilter *filter);
 
 
 /* Maximum index number of event-name postfix */