[PATCH 4.14 036/246] perf tools: Fix pmu events parsing rule

From: Greg Kroah-Hartman
Date: Wed Aug 01 2018 - 13:57:54 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jiri Olsa <jolsa@xxxxxxxxxx>

[ Upstream commit ceac7b79df7bd67ef9aaf464b0179a2686aff4ee ]

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
...

Suggested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
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/20180605121416.31645-1-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/perf/util/parse-events.y | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -72,6 +72,7 @@ static void inc_group_count(struct list_
%type <num> value_sym
%type <head> event_config
%type <head> opt_event_config
+%type <head> opt_pmu_config
%type <term> event_term
%type <head> event_pmu
%type <head> event_legacy_symbol
@@ -223,7 +224,7 @@ event_def: event_pmu |
event_bpf_file

event_pmu:
-PE_NAME opt_event_config
+PE_NAME opt_pmu_config
{
struct list_head *list, *orig_terms, *terms;

@@ -485,6 +486,17 @@ opt_event_config:
{
$$ = NULL;
}
+
+opt_pmu_config:
+'/' event_config '/'
+{
+ $$ = $2;
+}
+|
+'/' '/'
+{
+ $$ = NULL;
+}

start_terms: event_config
{