lkml.org 
[lkml]   [2014]   [Jan]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/2] perf stat: fix NULL pointer reference bug with event unit
Date
This patch fixes a problem with the handling of the newly
introduced optional event unit. The following cmdline
caused a segfault:
$ perf stat -e cpu/event-0x3c/ ls

This patch fixes the problem with the default setting
for alias->unit which was eventually causing the segfault.

Signed-off-by: Stephane Eranian <eranian@google.com>
---
tools/perf/util/parse-events.c | 2 +-
tools/perf/util/pmu.c | 24 ++++++++++++++++++++----
tools/perf/util/pmu.h | 2 +-
3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index a7f1b6a..d248fca 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -635,7 +635,7 @@ int parse_events_add_pmu(struct list_head *list, int *idx,
struct perf_event_attr attr;
struct perf_pmu *pmu;
struct perf_evsel *evsel;
- char *unit;
+ const char *unit;
double scale;

pmu = perf_pmu__find(name);
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index d9cab4d..b752ecb 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -105,7 +105,7 @@ static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, char *dir, char *
char scale[128];
int fd, ret = -1;
char path[PATH_MAX];
- char *lc;
+ const char *lc;

snprintf(path, PATH_MAX, "%s/%s.scale", dir, name);

@@ -609,7 +609,7 @@ static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,


static int check_unit_scale(struct perf_pmu_alias *alias,
- char **unit, double *scale)
+ const char **unit, double *scale)
{
/*
* Only one term in event definition can
@@ -634,14 +634,18 @@ static int check_unit_scale(struct perf_pmu_alias *alias,
* defined for the alias
*/
int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
- char **unit, double *scale)
+ const char **unit, double *scale)
{
struct parse_events_term *term, *h;
struct perf_pmu_alias *alias;
int ret;

+ /*
+ * Mark unit and scale as not set
+ * (different from default values, see below)
+ */
*unit = NULL;
- *scale = 0;
+ *scale = 0.0;

list_for_each_entry_safe(term, h, head_terms, list) {
alias = pmu_find_alias(pmu, term);
@@ -658,6 +662,18 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
list_del(&term->list);
free(term);
}
+
+ /*
+ * if no unit or scale foundin aliases, then
+ * set defaults as for evsel
+ * unit cannot left to NULL
+ */
+ if (*unit == NULL)
+ *unit = "";
+
+ if (*scale == 0.0)
+ *scale = 1.0;
+
return 0;
}

diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 9183380..8b64125 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -29,7 +29,7 @@ int perf_pmu__config_terms(struct list_head *formats,
struct perf_event_attr *attr,
struct list_head *head_terms);
int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
- char **unit, double *scale);
+ const char **unit, double *scale);
struct list_head *perf_pmu__alias(struct perf_pmu *pmu,
struct list_head *head_terms);
int perf_pmu_wrap(void);
--
1.7.9.5


\
 
 \ /
  Last update: 2014-01-18 00:41    [W:0.076 / U:0.296 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site