[tip:perf/core] perf probe: Add --funcs to show available functions in symtab

tip-bot for Masami Hiramatsu
2011-01-26T07:23:32Z

Commit-ID: e80711ca8512c8586da0c3e18e2f1caf73c88731
Gitweb: http://git.kernel.org/tip/e80711ca8512c8586da0c3e18e2f1caf73c88731
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Thu, 13 Jan 2011 21:46:11 +0900
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 24 Jan 2011 10:57:55 -0200

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>
---
tools/perf/Documentation/perf-probe.txt | 4 ++
tools/perf/builtin-probe.c | 29 +++++++++++++-
tools/perf/util/probe-event.c | 68 ++++++++++++++++++++++++++++++-
tools/perf/util/probe-event.h | 1 +
4 files changed, 99 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index 86b797a..fcc51fe 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -73,6 +73,10 @@ OPTIONS
(Only for --vars) Show external defined variables in addition to local
variables.

+-F::
+--funcs::
+ Show available functions in given module or kernel.
+
-f::
--force::
Forcibly add events with existing name.
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index add163c..6cf708a 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -52,6 +52,7 @@ static struct {
bool show_lines;
bool show_vars;
bool show_ext_vars;
+ bool show_funcs;
bool mod_events;
int nevents;
struct perf_probe_event events[MAX_PROBES];
@@ -221,6 +222,8 @@ static const struct option options[] = {
OPT__DRY_RUN(&probe_event_dry_run),
OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
"Set how many probe points can be found for a probe."),
+ OPT_BOOLEAN('F', "funcs", &params.show_funcs,
+ "Show potential probe-able functions."),
OPT_END()
};

@@ -246,7 +249,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
params.max_probe_points = MAX_PROBES;

if ((!params.nevents && !params.dellist && !params.list_events &&
- !params.show_lines))
+ !params.show_lines && !params.show_funcs))
usage_with_options(probe_usage, options);

/*
@@ -267,12 +270,36 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
pr_err(" Error: Don't use --list with --vars.\n");
usage_with_options(probe_usage, options);
}
+ if (params.show_funcs) {
+ pr_err(" Error: Don't use --list with --funcs.\n");
+ usage_with_options(probe_usage, options);
+ }
ret = show_perf_probe_events();
if (ret < 0)
pr_err(" Error: Failed to show event list. (%d)\n",
ret);
return ret;
}
+ if (params.show_funcs) {
+ if (params.nevents != 0 || params.dellist) {
+ pr_err(" Error: Don't use --funcs with"
+ " --add/--del.\n");
+ usage_with_options(probe_usage, options);
+ }
+ if (params.show_lines) {
+ pr_err(" Error: Don't use --funcs with --line.\n");
+ usage_with_options(probe_usage, options);
+ }
+ if (params.show_vars) {
+ pr_err(" Error: Don't use --funcs with --vars.\n");
+ usage_with_options(probe_usage, options);
+ }
+ ret = show_available_funcs(params.target_module);
+ if (ret < 0)
+ pr_err(" Error: Failed to show functions."
+ " (%d)\n", ret);
+ return ret;
+ }

#ifdef DWARF_SUPPORT
if (params.show_lines) {
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 6e29d9c..859d377 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 5accbed..1fb4f18 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 */