perf stat: fix NULL pointer reference bug with event unit
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>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389972846-6566-2-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 @@
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 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 @@
* 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 @@
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;
}