path: root/tools/perf/builtin-probe.c
diff options
authorMasami Hiramatsu <>2013-12-26 05:41:53 +0000
committerArnaldo Carvalho de Melo <>2013-12-26 11:22:01 -0300
commitfb7345bbf7fad9bf72ef63a19c707970b9685812 (patch)
tree7e5dc7bb5ac68addf38718ee26ed1e91a36a60c6 /tools/perf/builtin-probe.c
parent8a613d40e389b723fd5889ac8d4033ed4030be31 (diff)
perf probe: Support basic dwarf-based operations on uprobe events
Support basic dwarf(debuginfo) based operations for uprobe events. With this change, perf probe can analyze debuginfo of user application binary to set up new uprobe event. This allows perf-probe --add(with local variables, line numbers) and --line works with -x option. (Actually, --vars has already accepted -x option) For example, the following command shows the probe-able lines of a given user space function. Something that so far was only available in the 'perf probe' tool for kernel space functions: # ./perf probe -x perf --line map__load <map__load@/home/fedora/ksrc/linux-2.6/tools/perf/util/map.c:0> 0 int map__load(struct map *map, symbol_filter_t filter) 1 { 2 const char *name = map->dso->long_name; int nr; 5 if (dso__loaded(map->dso, map->type)) 6 return 0; 8 nr = dso__load(map->dso, map, filter); 9 if (nr < 0) { 10 if (map->dso->has_build_id) { And this shows the available variables at the given line of the function. # ./perf probe -x perf --vars map__load:8 Available variables at map__load:8 @<map__load+96> char* name struct map* map symbol_filter_t filter @<map__find_symbol+112> char* name symbol_filter_t filter @<map__find_symbol_by_name+136> char* name symbol_filter_t filter @<map_groups__find_symbol_by_name+176> char* name struct map* map symbol_filter_t filter And lastly, we can now define probe(s) with all available variables on the given line: # ./perf probe -x perf --add 'map__load:8 $vars' Added new events: probe_perf:map__load (on map__load:8 with $vars) probe_perf:map__load_1 (on map__load:8 with $vars) probe_perf:map__load_2 (on map__load:8 with $vars) probe_perf:map__load_3 (on map__load:8 with $vars) You can now use it in all perf tools, such as: perf record -e probe_perf:map__load_3 -aR sleep 1 Changes from previous version: - Add examples in the patch description. - Use .text section start address and dwarf symbol address for calculating the offset of given symbol, instead of searching the symbol in symtab again. With this change, we can safely handle multiple local function instances (e.g. scnprintf in perf). Signed-off-by: Masami Hiramatsu <> Cc: David Ahern <> Cc: David A. Long <> Cc: Ingo Molnar <> Cc: Namhyung Kim <> Cc: Oleg Nesterov <> Cc: Srikar Dronamraju <> Cc: Steven Rostedt <> Cc: Cc: Link: Signed-off-by: Arnaldo Carvalho de Melo <>
Diffstat (limited to 'tools/perf/builtin-probe.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 1792a3f1f4ce..43ff33d0007b 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -424,7 +424,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
- if (params.show_lines && !params.uprobes) {
+ if (params.show_lines) {
if (params.mod_events) {
pr_err(" Error: Don't use --line with"
" --add/--del.\n");