From 8a398897ff21f73cb8b15a19514660f032926882 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Fri, 17 Jan 2014 16:34:05 +0100 Subject: [PATCH] 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 Cc: David Ahern Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1389972846-6566-2-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo --- 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..8b64125a 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); -- 2.7.4