perf probe: Reject second attempt of adding same-name event

Reject second attempt of adding same-name event. This patch
also provides --force option which allows user to add additional
probe events on the same-name event.

e.g.
(the first attempt : success)
 ./perf probe schedule
 Added new event:
   probe:schedule                           (on schedule+0)

(the second attempt : failure)
 ./perf probe schedule:11
 Error: event "schedule" already exists. (Use -f to force duplicates.)
   Fatal: Can't add new event.

(the second attempt with -f : successfully added)
 ./perf probe -f schedule:11
 Added new event:
   probe:schedule_1                         (on schedule+45)

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091215153225.17436.15166.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 1 deletions

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index adc0a55acd95..8b4fdaeefa29 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -61,6 +61,7 @@ static struct {
 	char *release;
 	bool need_dwarf;
 	bool list_events;
+	bool force_add;
 	int nr_probe;
 	struct probe_point probes[MAX_PROBES];
 	struct strlist *dellist;
@@ -192,6 +193,8 @@ static const struct option options[] = {
 #endif
 		"\t\t\tkprobe-tracer argument format.)\n",
 		opt_add_probe_event),
+	OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events"
+		    " with existing name"),
 	OPT_END()
 };
 
@@ -294,7 +297,8 @@ end_dwarf:
 	}
 
 	/* Settng up probe points */
-	add_trace_kprobe_events(session.probes, session.nr_probe);
+	add_trace_kprobe_events(session.probes, session.nr_probe,
+				session.force_add);
 	return 0;
 }