perf probe: Add --funcs to show available functions in symtab

Add --funcs to show available functions in symtab.

Originally this feature came from Srikar's uprobes patches
( http://lkml.org/lkml/2010/8/27/244 )

e.g.
...
__ablkcipher_walk_complete
__absent_pages_in_range
__account_scheduler_latency
__add_pages
__alloc_pages_nodemask
__alloc_percpu
__alloc_reserved_percpu
__alloc_skb
__alloc_workqueue_key
__any_online_cpu
__ata_ehi_push_desc
...

This also supports symbols in module, e.g.

...
cleanup_module
cpuid_maxphyaddr
emulate_clts
emulate_instruction
emulate_int_real
emulate_invlpg
emulator_get_dr
emulator_set_dr
emulator_task_switch
emulator_write_emulated
emulator_write_phys
fx_init
...

Original-patch-from: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
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: <20110113124611.22426.10835.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ committer note: Add missing elf.h for STB_GLOBAL that broke a RHEL4 build ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 67 insertions, 2 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 6e29d9c9dcc..859d377a3df 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -31,6 +31,7 @@
 #include <string.h>
 #include <stdarg.h>
 #include <limits.h>
+#include <elf.h>
 
 #undef _GNU_SOURCE
 #include "util.h"
@@ -111,7 +112,25 @@ static struct symbol *__find_kernel_function_by_name(const char *name,
 						     NULL);
 }
 
-const char *kernel_get_module_path(const char *module)
+static struct map *kernel_get_module_map(const char *module)
+{
+	struct rb_node *nd;
+	struct map_groups *grp = &machine.kmaps;
+
+	if (!module)
+		module = "kernel";
+
+	for (nd = rb_first(&grp->maps[MAP__FUNCTION]); nd; nd = rb_next(nd)) {
+		struct map *pos = rb_entry(nd, struct map, rb_node);
+		if (strncmp(pos->dso->short_name + 1, module,
+			    pos->dso->short_name_len - 2) == 0) {
+			return pos;
+		}
+	}
+	return NULL;
+}
+
+static struct dso *kernel_get_module_dso(const char *module)
 {
 	struct dso *dso;
 	struct map *map;
@@ -141,7 +160,13 @@ const char *kernel_get_module_path(const char *module)
 		}
 	}
 found:
-	return dso->long_name;
+	return dso;
+}
+
+const char *kernel_get_module_path(const char *module)
+{
+	struct dso *dso = kernel_get_module_dso(module);
+	return (dso) ? dso->long_name : NULL;
 }
 
 #ifdef DWARF_SUPPORT
@@ -1913,3 +1938,42 @@ int del_perf_probe_events(struct strlist *dellist)
 	return ret;
 }
 
+/*
+ * If a symbol corresponds to a function with global binding return 0.
+ * For all others return 1.
+ */
+static int filter_non_global_functions(struct map *map __unused,
+					struct symbol *sym)
+{
+	if (sym->binding != STB_GLOBAL)
+		return 1;
+
+	return 0;
+}
+
+int show_available_funcs(const char *module)
+{
+	struct map *map;
+	int ret;
+
+	setup_pager();
+
+	ret = init_vmlinux();
+	if (ret < 0)
+		return ret;
+
+	map = kernel_get_module_map(module);
+	if (!map) {
+		pr_err("Failed to find %s map.\n", (module) ? : "kernel");
+		return -EINVAL;
+	}
+	if (map__load(map, filter_non_global_functions)) {
+		pr_err("Failed to load map.\n");
+		return -EINVAL;
+	}
+	if (!dso__sorted_by_name(map->dso, map->type))
+		dso__sort_by_name(map->dso, map->type);
+
+	dso__fprintf_symbols_by_name(map->dso, map->type, stdout);
+	return 0;
+}
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 5accbedfea3..1fb4f18337d 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -127,6 +127,7 @@ extern int show_line_range(struct line_range *lr, const char *module);
 extern int show_available_vars(struct perf_probe_event *pevs, int npevs,
 			       int max_probe_points, const char *module,
 			       bool externs);
+extern int show_available_funcs(const char *module);
 
 
 /* Maximum index number of event-name postfix */