From: Jiri Olsa <[email protected]>

The 'perf stat' fallback for EACCES error sets the exclude_kernel
perf_event_attr and tries perf_event_open() again with it. In addition,
it also changes the name of the event to reflect that change by adding
the 'u' modifier.

But it does not take into account the '/' separator, so the event name
can end up mangled, like: (note the '/:' characters)

  $ perf stat -e cpu/cpu-cycles/ kill
  ...
             386,832      cpu/cpu-cycles/:u

Adding the code to check on the '/' separator and set the following
correct event name:

  $ perf stat -e cpu/cpu-cycles/ kill
  ...
             388,548      cpu/cpu-cycles/u

Signed-off-by: Jiri Olsa <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/evsel.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3e87486c28fe..7eb1e9850abf 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2754,8 +2754,14 @@ bool perf_evsel__fallback(struct perf_evsel *evsel, int 
err,
                   (paranoid = perf_event_paranoid()) > 1) {
                const char *name = perf_evsel__name(evsel);
                char *new_name;
+               const char *sep = ":";
 
-               if (asprintf(&new_name, "%s%su", name, strchr(name, ':') ? "" : 
":") < 0)
+               /* Is there already the separator in the name. */
+               if (strchr(name, '/') ||
+                   strchr(name, ':'))
+                       sep = "";
+
+               if (asprintf(&new_name, "%s%su", name, sep) < 0)
                        return false;
 
                if (evsel->name)
-- 
2.14.3

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