[tip:perf/core] perf probe: Show trace event definition

From: tip-bot for Masami Hiramatsu
Date: Mon Sep 05 2016 - 09:24:58 EST


Commit-ID: 1c20b1d15473a91e2fccecbcd2809d80ff4b4924
Gitweb: http://git.kernel.org/tip/1c20b1d15473a91e2fccecbcd2809d80ff4b4924
Author: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
AuthorDate: Fri, 26 Aug 2016 01:24:27 +0900
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 1 Sep 2016 09:44:13 -0300

perf probe: Show trace event definition

Add --definition/-D option for showing the trace-event definition in
stdout. This can be useful in debugging or combined with a shell script.

e.g.
----
# perf probe --definition 'do_sys_open $params'
p:probe/do_sys_open _text+2261728 dfd=%di:s32 filename=%si:u64 flags=%dx:s32 mode=%cx:u16
----

Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/147214226712.23638.2240534040014013658.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-probe.txt | 7 +++++
tools/perf/builtin-probe.c | 26 ++++++++++++++-----
tools/perf/util/probe-event.c | 46 +++++++++++++++++++++++++++++++++
tools/perf/util/probe-event.h | 1 +
4 files changed, 73 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index f37d123..56db4d4 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -21,6 +21,8 @@ or
'perf probe' [options] --vars='PROBEPOINT'
or
'perf probe' [options] --funcs
+or
+'perf probe' [options] --definition='PROBE' [...]

DESCRIPTION
-----------
@@ -96,6 +98,11 @@ OPTIONS
can also list functions in a user space executable / shared library.
This also can accept a FILTER rule argument.

+-D::
+--definition=::
+ Show trace-event definition converted from given probe-event instead
+ of write it into tracing/[k,u]probe_events.
+
--filter=FILTER::
(Only for --vars and --funcs) Set filter. FILTER is a combination of glob
pattern, see FILTER PATTERN for detail.
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index ee5b421..7a3d8c4 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -326,6 +326,11 @@ static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
if (ret < 0)
goto out_cleanup;

+ if (params.command == 'D') { /* it shows definition */
+ ret = show_probe_trace_events(pevs, npevs);
+ goto out_cleanup;
+ }
+
ret = apply_perf_probe_events(pevs, npevs);
if (ret < 0)
goto out_cleanup;
@@ -454,6 +459,14 @@ out:
return ret;
}

+#ifdef HAVE_DWARF_SUPPORT
+#define PROBEDEF_STR \
+ "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
+#else
+#define PROBEDEF_STR "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
+#endif
+
+
static int
__cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
{
@@ -479,13 +492,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
opt_set_filter_with_command, DEFAULT_LIST_FILTER),
OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
opt_set_filter_with_command),
- OPT_CALLBACK('a', "add", NULL,
-#ifdef HAVE_DWARF_SUPPORT
- "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
- " [[NAME=]ARG ...]",
-#else
- "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
-#endif
+ OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
"probe point definition, where\n"
"\t\tGROUP:\tGroup name (optional)\n"
"\t\tEVENT:\tEvent name\n"
@@ -503,6 +510,9 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
#endif
opt_add_probe_event),
+ OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
+ "Show trace event definition of given traceevent for k/uprobe_events.",
+ opt_add_probe_event),
OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
" with existing name"),
OPT_CALLBACK('L', "line", NULL,
@@ -548,6 +558,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)

set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
+ set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
#ifdef HAVE_DWARF_SUPPORT
set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
@@ -644,6 +655,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
}
break;
case 'a':
+ case 'D':
/* Ensure the last given target is used */
if (params.target && !params.target_used) {
pr_err(" Error: -x/-m must follow the probe definitions.\n");
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0bed2ee..4a49cb8 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -3207,6 +3207,52 @@ int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs)
return 0;
}

+static int show_probe_trace_event(struct probe_trace_event *tev)
+{
+ char *buf = synthesize_probe_trace_command(tev);
+
+ if (!buf) {
+ pr_debug("Failed to synthesize probe trace event.\n");
+ return -EINVAL;
+ }
+
+ /* Showing definition always go stdout */
+ printf("%s\n", buf);
+ free(buf);
+
+ return 0;
+}
+
+int show_probe_trace_events(struct perf_probe_event *pevs, int npevs)
+{
+ struct strlist *namelist = strlist__new(NULL, NULL);
+ struct probe_trace_event *tev;
+ struct perf_probe_event *pev;
+ int i, j, ret = 0;
+
+ if (!namelist)
+ return -ENOMEM;
+
+ for (j = 0; j < npevs && !ret; j++) {
+ pev = &pevs[j];
+ for (i = 0; i < pev->ntevs && !ret; i++) {
+ tev = &pev->tevs[i];
+ /* Skip if the symbol is out of .text or blacklisted */
+ if (!tev->point.symbol && !pev->uprobes)
+ continue;
+
+ /* Set new name for tev (and update namelist) */
+ ret = probe_trace_event__set_name(tev, pev,
+ namelist, true);
+ if (!ret)
+ ret = show_probe_trace_event(tev);
+ }
+ }
+ strlist__delete(namelist);
+
+ return ret;
+}
+
int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs)
{
int i, ret = 0;
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index f4f45db..6209408 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -147,6 +147,7 @@ int line_range__init(struct line_range *lr);
int add_perf_probe_events(struct perf_probe_event *pevs, int npevs);
int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs);
int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs);
+int show_probe_trace_events(struct perf_probe_event *pevs, int npevs);
void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs);
int del_perf_probe_events(struct strfilter *filter);