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Subject[PATCHv2 5/5] perf tool: Add basic event modifier sanity check
On Tue, Nov 13, 2012 at 11:22:24AM +0900, Namhyung Kim wrote:
> Hi Jiri,
>
> On Mon, 12 Nov 2012 18:34:04 +0100, Jiri Olsa wrote:
> > 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.
> [snip]
> > +/*
> > + * 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;
> > +
> > + while (*p) {
> > + if (*p != 'p' && strchr(p + 1, *p))
> > + return -1;
> > + p++;
> > + }
>
> How about adding a length check too? i.e. something like:
>
> if ((p - str) > strlen("ukhGHppp"))
> return -1;

ok, v2 attached

thanks,
jirka


---
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>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/parse-events.c | 24 ++++++++++++++++++++++++
tools/perf/util/parse-events.l | 2 +-
2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index c0b785b..020323a 100644
--- 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 66959fa..e9d1134 100644
--- 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}

%%
--
1.7.11.7


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