perf probe: Support multiple probes on different binaries

Support multiple probes on different binaries with just
one command.

In the result, this example sets up the probes on icmp_rcv in
kernel, on main and set_target in perf, and on pcspkr_event
in pcspker.ko driver.
  -----
  # perf probe -a icmp_rcv -x ./perf -a main -a set_target \
   -m /lib/modules/4.0.0-rc5+/kernel/drivers/input/misc/pcspkr.ko \
   -a pcspkr_event
  Added new event:
    probe:icmp_rcv       (on icmp_rcv)

  You can now use it in all perf tools, such as:

          perf record -e probe:icmp_rcv -aR sleep 1

  Added new event:
    probe_perf:main      (on main in /home/mhiramat/ksrc/linux-3/tools/perf/perf)

  You can now use it in all perf tools, such as:

          perf record -e probe_perf:main -aR sleep 1

  Added new event:
    probe_perf:set_target (on set_target in /home/mhiramat/ksrc/linux-3/tools/perf/perf)

  You can now use it in all perf tools, such as:

          perf record -e probe_perf:set_target -aR sleep 1

  Added new event:
    probe:pcspkr_event   (on pcspkr_event in pcspkr)

  You can now use it in all perf tools, such as:

          perf record -e probe:pcspkr_event -aR sleep 1
  -----
Reported-by: Arnaldo Carvalho de Melo <acme@infradead.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150401102539.17137.46454.stgit@localhost.localdomainSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-probe.c

@@ -78,6 +78,11 @@ static int parse_probe_event(const char *str)
 	}
 
 	pev->uprobes = params.uprobes;
+	if (params.target) {
+		pev->target = strdup(params.target);
+		if (!pev->target)
+			return -ENOMEM;
+	}
 
 	/* Parse a perf-probe command into event */
 	ret = parse_perf_probe_command(str, pev);
@@ -178,7 +183,7 @@ static int opt_set_target(const struct option *opt, const char *str,
 	int ret = -ENOENT;
 	char *tmp;
 
-	if  (str && !params.target) {
+	if  (str) {
 		if (!strcmp(opt->long_name, "exec"))
 			params.uprobes = true;
 #ifdef HAVE_DWARF_SUPPORT
@@ -200,6 +205,7 @@ static int opt_set_target(const struct option *opt, const char *str,
 			if (!tmp)
 				return -ENOMEM;
 		}
+		free(params.target);
 		params.target = tmp;
 		ret = 0;
 	}
@@ -487,7 +493,6 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (params.nevents) {
 		ret = add_perf_probe_events(params.events, params.nevents,
 					    params.max_probe_points,
-					    params.target,
 					    params.force_add);
 		if (ret < 0) {
 			pr_err_with_code("  Error: Failed to add events.", ret);

tools/perf/util/probe-event.c

@@ -1906,6 +1906,7 @@ void clear_perf_probe_event(struct perf_probe_event *pev)
 
 	free(pev->event);
 	free(pev->group);
+	free(pev->target);
 	clear_perf_probe_point(&pev->point);
 
 	for (i = 0; i < pev->nargs; i++) {
@@ -2654,7 +2655,7 @@ struct __event_package {
 };
 
 int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
-			  int max_tevs, const char *target, bool force_add)
+			  int max_tevs, bool force_add)
 {
 	int i, j, ret;
 	struct __event_package *pkgs;
@@ -2678,7 +2679,7 @@ int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
 		ret  = convert_to_probe_trace_events(pkgs[i].pev,
 						     &pkgs[i].tevs,
 						     max_tevs,
-						     target);
+						     pkgs[i].pev->target);
 		if (ret < 0)
 			goto end;
 		pkgs[i].ntevs = ret;

tools/perf/util/probe-event.h

@@ -73,7 +73,8 @@ struct perf_probe_event {
 	char			*group;	/* Group name */
 	struct perf_probe_point	point;	/* Probe point */
 	int			nargs;	/* Number of arguments */
-	bool			uprobes;
+	bool			uprobes;	/* Uprobe event flag */
+	char			*target;	/* Target binary */
 	struct perf_probe_arg	*args;	/* Arguments */
 };
 
@@ -124,8 +125,7 @@ extern int line_range__init(struct line_range *lr);
 extern const char *kernel_get_module_path(const char *module);
 
 extern int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
-				 int max_probe_points, const char *module,
-				 bool force_add);
+				 int max_probe_points, bool force_add);
 extern int del_perf_probe_events(struct strlist *dellist);
 extern int show_perf_probe_events(void);
 extern int show_line_range(struct line_range *lr, const char *module,