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Subject[PATCH] perf/probe: Skip same probe address
Date
Fix to skip making a same probe address on given line.

Since 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 address.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
tools/perf/util/probe-finder.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 025fc4491993..02ca95deaf2c 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1244,6 +1244,17 @@ 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)
{
@@ -1254,6 +1265,14 @@ 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",
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