The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     1a375ae7659ab740d4c885ea98c1659b8a6e2071
Gitweb:        
https://git.kernel.org/tip/1a375ae7659ab740d4c885ea98c1659b8a6e2071
Author:        Masami Hiramatsu <[email protected]>
AuthorDate:    Thu, 19 Sep 2019 12:41:10 +09:00
Committer:     Arnaldo Carvalho de Melo <[email protected]>
CommitterDate: Fri, 20 Sep 2019 15:22:00 -03:00

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 <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: 
http://lore.kernel.org/lkml/156886447061.10772.4261569305869149178.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
 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 505905f..cd9f95e 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",

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