[tip:perf/urgent] perf pmu: Fix pmu events parsing rule

From: tip-bot for Jiri Olsa
Date: Thu Apr 26 2018 - 01:54:32 EST


Commit-ID: 9a4a931ce847f4aaa12edf11b2e050e18bf45910
Gitweb: https://git.kernel.org/tip/9a4a931ce847f4aaa12edf11b2e050e18bf45910
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Mon, 23 Apr 2018 11:08:18 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 23 Apr 2018 11:17:27 -0300

perf pmu: Fix pmu events parsing rule

Currently all the event parsing fails end up in the event_pmu rule, and
display misleading help like:

$ perf stat -e inst kill
event syntax error: 'inst'
\___ Cannot find PMU `inst'. Missing kernel support?
...

The reason is that the event_pmu is too strong and match also single
string. Changing it to force the '/' separators to be part of the rule,
and getting the proper error now:

$ perf stat -e inst kill
event syntax error: 'inst'
\___ parser error
Run 'perf list' for a list of valid events
...

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Reported-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180423090823.32309-5-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/parse-events.y | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 7afeb80cc39e..d14464c42714 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -224,15 +224,15 @@ event_def: event_pmu |
event_bpf_file

event_pmu:
-PE_NAME opt_event_config
+PE_NAME '/' event_config '/'
{
struct list_head *list, *orig_terms, *terms;

- if (parse_events_copy_term_list($2, &orig_terms))
+ if (parse_events_copy_term_list($3, &orig_terms))
YYABORT;

ALLOC_LIST(list);
- if (parse_events_add_pmu(_parse_state, list, $1, $2, false)) {
+ if (parse_events_add_pmu(_parse_state, list, $1, $3, false)) {
struct perf_pmu *pmu = NULL;
int ok = 0;
char *pattern;
@@ -262,7 +262,7 @@ PE_NAME opt_event_config
if (!ok)
YYABORT;
}
- parse_events_terms__delete($2);
+ parse_events_terms__delete($3);
parse_events_terms__delete(orig_terms);
$$ = list;
}