From: Elena Reshetova elena.reshetova@intel.com

The refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter.

This allows to avoid accidental refcounter overflows that might lead to use-after-free situations.

Signed-off-by: Elena Reshetova elena.reshetova@intel.com Signed-off-by: David Windsor dwindsor@gmail.com Signed-off-by: Hans Liljestrand ishkamiel@gmail.com Signed-off-by: Kees Kook keescook@chromium.org Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Andrew Morton akpm@linux-foundation.org Cc: David Windsor dwindsor@gmail.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Hans Liljestrand ishkamiel@gmail.com Cc: Jiri Olsa jolsa@kernel.org Cc: Kees Kook keescook@chromium.org Cc: Mark Rutland mark.rutland@arm.com Cc: Matija Glavinic Pecotic matija.glavinic-pecotic.ext@nokia.com Cc: Peter Zijlstra peterz@infradead.org Cc: alsa-devel@alsa-project.org Link: http://lkml.kernel.org/r/1487691303-31858-3-git-send-email-elena.reshetova@i... [ fixed mixed conversion to refcount in tests/cpumap.c ] Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com

Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com --- tools/perf/tests/cpumap.c | 2 +- tools/perf/util/cpumap.c | 16 ++++++++-------- tools/perf/util/cpumap.h | 4 ++-- 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/tools/perf/tests/cpumap.c b/tools/perf/tests/cpumap.c index f168a85992d0..4478773cdb97 100644 --- a/tools/perf/tests/cpumap.c +++ b/tools/perf/tests/cpumap.c @@ -66,7 +66,7 @@ static int process_event_cpus(struct perf_tool *tool __maybe_unused, TEST_ASSERT_VAL("wrong nr", map->nr == 2); TEST_ASSERT_VAL("wrong cpu", map->map[0] == 1); TEST_ASSERT_VAL("wrong cpu", map->map[1] == 256); - TEST_ASSERT_VAL("wrong refcnt", atomic_read(&map->refcnt) == 1); + TEST_ASSERT_VAL("wrong refcnt", refcount_read(&map->refcnt) == 1); cpu_map__put(map); return 0; } diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c index 8c7504939113..39ad2caccf56 100644 --- a/tools/perf/util/cpumap.c +++ b/tools/perf/util/cpumap.c @@ -29,7 +29,7 @@ static struct cpu_map *cpu_map__default_new(void) cpus->map[i] = i;

cpus->nr = nr_cpus; - atomic_set(&cpus->refcnt, 1); + refcount_set(&cpus->refcnt, 1); }

return cpus; @@ -43,7 +43,7 @@ static struct cpu_map *cpu_map__trim_new(int nr_cpus, int *tmp_cpus) if (cpus != NULL) { cpus->nr = nr_cpus; memcpy(cpus->map, tmp_cpus, payload_size); - atomic_set(&cpus->refcnt, 1); + refcount_set(&cpus->refcnt, 1); }

return cpus; @@ -252,7 +252,7 @@ struct cpu_map *cpu_map__dummy_new(void) if (cpus != NULL) { cpus->nr = 1; cpus->map[0] = -1; - atomic_set(&cpus->refcnt, 1); + refcount_set(&cpus->refcnt, 1); }

return cpus; @@ -269,7 +269,7 @@ struct cpu_map *cpu_map__empty_new(int nr) for (i = 0; i < nr; i++) cpus->map[i] = -1;

- atomic_set(&cpus->refcnt, 1); + refcount_set(&cpus->refcnt, 1); }

return cpus; @@ -278,7 +278,7 @@ struct cpu_map *cpu_map__empty_new(int nr) static void cpu_map__delete(struct cpu_map *map) { if (map) { - WARN_ONCE(atomic_read(&map->refcnt) != 0, + WARN_ONCE(refcount_read(&map->refcnt) != 0, "cpu_map refcnt unbalanced\n"); free(map); } @@ -287,13 +287,13 @@ static void cpu_map__delete(struct cpu_map *map) struct cpu_map *cpu_map__get(struct cpu_map *map) { if (map) - atomic_inc(&map->refcnt); + refcount_inc(&map->refcnt); return map; }

void cpu_map__put(struct cpu_map *map) { - if (map && atomic_dec_and_test(&map->refcnt)) + if (map && refcount_dec_and_test(&map->refcnt)) cpu_map__delete(map); }

@@ -357,7 +357,7 @@ int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res, /* ensure we process id in increasing order */ qsort(c->map, c->nr, sizeof(int), cmp_ids);

- atomic_set(&c->refcnt, 1); + refcount_set(&c->refcnt, 1); *res = c; return 0; } diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h index 1a0549af8f5c..e84491636c1b 100644 --- a/tools/perf/util/cpumap.h +++ b/tools/perf/util/cpumap.h @@ -3,13 +3,13 @@

#include <stdio.h> #include <stdbool.h> -#include <linux/atomic.h> +#include <linux/refcount.h>

#include "perf.h" #include "util/debug.h"

struct cpu_map { - atomic_t refcnt; + refcount_t refcnt; int nr; int map[]; };