Em Tue, Feb 21, 2017 at 05:34:56PM +0200, Elena Reshetova escreveu:
> 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.
The following patch was needed for this one to build:
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.h b/tools/perf/util/cpumap.h
index e84491636c1b..ab1aeed8cd5d 100644
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -3,10 +3,10 @@
#include <stdio.h>
#include <stdbool.h>
-#include <linux/refcount.h>
#include "perf.h"
#include "util/debug.h"
+#include <linux/refcount.h>
struct cpu_map {
refcount_t refcnt;
> Signed-off-by: Elena Reshetova <elena.reshet...@intel.com>
> Signed-off-by: Hans Liljestrand <ishkam...@gmail.com>
> Signed-off-by: Kees Cook <keesc...@chromium.org>
> Signed-off-by: David Windsor <dwind...@gmail.com>
> ---
> tools/perf/util/cpumap.c | 16 ++++++++--------
> tools/perf/util/cpumap.h | 4 ++--
> 2 files changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> index 2c0b522..0e21e28 100644
> --- a/tools/perf/util/cpumap.c
> +++ b/tools/perf/util/cpumap.c
> @@ -28,7 +28,7 @@ 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;
> @@ -42,7 +42,7 @@ 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;
> @@ -251,7 +251,7 @@ 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;
> @@ -268,7 +268,7 @@ 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;
> @@ -277,7 +277,7 @@ 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);
> }
> @@ -286,13 +286,13 @@ 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);
> }
>
> @@ -356,7 +356,7 @@ 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 06bd689..4f12a01 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[];
> };
> --
> 2.7.4
