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authorMasami Hiramatsu <mhiramat@kernel.org>2019-09-19 12:41:10 +0900
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-09-20 15:22:00 -0300
commit1a375ae7659ab740d4c885ea98c1659b8a6e2071 (patch)
treec5d7ae0684b4aaa2c74e98d56c5011b4958880cb /tools/perf
parent0216234c2eed1367a318daeb9f4a97d8217412a0 (diff)
downloadlinux-1a375ae7659ab740d4c885ea98c1659b8a6e2071.tar.gz
perf probe: Skip same probe address for a given line
Fix to skip making a same probe address on given line.

Since a DWARF line info contains several entries for one line with
different column, perf probe will make a different probe on same address
if user specifies a probe point by "function:line" or "file:line".

e.g.
 $ perf probe -D kernel_read:8
 p:probe/kernel_read_L8 kernel_read+39
 p:probe/kernel_read_L8_1 kernel_read+39

This skips such duplicated probe addresses.

Committer testing:

  # uname -a
  Linux quaco 5.3.0+ #2 SMP Thu Sep 19 16:13:22 -03 2019 x86_64 x86_64 x86_64 GNU/Linux
  #

Before:

  # perf probe -D kernel_read:8
  p:probe/kernel_read _text+3115191
  p:probe/kernel_read_1 _text+3115191
  #

After:

  # perf probe -D kernel_read:8
  p:probe/kernel_read _text+3115191
  #

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lore.kernel.org/lkml/156886447061.10772.4261569305869149178.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/util/probe-finder.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 505905fc21c5..cd9f95e5044e 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1245,6 +1245,17 @@ static int expand_probe_args(Dwarf_Die *sc_die, struct probe_finder *pf,
 	return n;
 }
 
+static bool trace_event_finder_overlap(struct trace_event_finder *tf)
+{
+	int i;
+
+	for (i = 0; i < tf->ntevs; i++) {
+		if (tf->pf.addr == tf->tevs[i].point.address)
+			return true;
+	}
+	return false;
+}
+
 /* Add a found probe point into trace event list */
 static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
 {
@@ -1255,6 +1266,14 @@ static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf)
 	struct perf_probe_arg *args = NULL;
 	int ret, i;
 
+	/*
+	 * For some reason (e.g. different column assigned to same address)
+	 * This callback can be called with the address which already passed.
+	 * Ignore it first.
+	 */
+	if (trace_event_finder_overlap(tf))
+		return 0;
+
 	/* Check number of tevs */
 	if (tf->ntevs == tf->max_tevs) {
 		pr_warning("Too many( > %d) probe point found.\n",