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perf stat: fix NULL pointer reference bug with event unit

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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>
This commit is contained in:
Stephane Eranian 2014-01-17 16:34:05 +01:00 committed by Arnaldo Carvalho de Melo
parent 3a46817f67
commit 8a398897ff
3 changed files with 22 additions and 6 deletions
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2
tools/perf/util/parse-events.c
View File

@ -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);

24
tools/perf/util/pmu.c
View File

@ -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;
}

2
tools/perf/util/pmu.h
View File

@ -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);