perf tools: Add basic event modifier sanity check

Updating event parser to allow any non zero string containing [ukhpGH]
characters for event modifier.

The modifier sanity is checked later in parse-event object logic.  The
check validates modifier to contain only one instance of any modifier
(apart from 'p') present.

v2:
  - added length check suggested Namhyung Kim

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20121113143258.GA2481@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index c0b785b508496f545648b280ea4e318a425b7920..020323af33640470934b95a8777bccfb412bdac2 100644 (file)
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -722,6 +722,27 @@ static int get_event_modifier(struct event_modifier *mod, char *str,
        return 0;
 }
 
+/*
+ * Basic modifier sanity check to validate it contains only one
+ * instance of any modifier (apart from 'p') present.
+ */
+static int check_modifier(char *str)
+{
+       char *p = str;
+
+       /* The sizeof includes 0 byte as well. */
+       if (strlen(str) > (sizeof("ukhGHppp") - 1))
+               return -1;
+
+       while (*p) {
+               if (*p != 'p' && strchr(p + 1, *p))
+                       return -1;
+               p++;
+       }
+
+       return 0;
+}
+
 int parse_events__modifier_event(struct list_head *list, char *str, bool add)
 {
        struct perf_evsel *evsel;
@@ -730,6 +751,9 @@ int parse_events__modifier_event(struct list_head *list, char *str, bool add)
        if (str == NULL)
                return 0;
 
+       if (check_modifier(str))
+               return -EINVAL;
+
        if (!add && get_event_modifier(&mod, str, NULL))
                return -EINVAL;
 

diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 66959fab6634366032ac2f1d5fbbda5e234464dc..e9d1134c2c68e97cdee78c889fd70156b5351497 100644 (file)
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -82,7 +82,7 @@ num_hex               0x[a-fA-F0-9]+
 num_raw_hex    [a-fA-F0-9]+
 name           [a-zA-Z_*?][a-zA-Z0-9_*?]*
 name_minus     [a-zA-Z_*?][a-zA-Z0-9\-_*?]*
-modifier_event [ukhpGH]{1,8}
+modifier_event [ukhpGH]+
 modifier_bp    [rwx]{1,3}
 
 %%