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Subject[PATCH 5/9] tools: convert map.refcnt from atomic_t to refcount_t
Date
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: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
---
tools/perf/util/map.c | 6 +++---
tools/perf/util/map.h | 6 +++---
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 0a943e7..f0e2428 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -141,7 +141,7 @@ void map__init(struct map *map, enum map_type type,
RB_CLEAR_NODE(&map->rb_node);
map->groups = NULL;
map->erange_warned = false;
- atomic_set(&map->refcnt, 1);
+ refcount_set(&map->refcnt, 1);
}

struct map *map__new(struct machine *machine, u64 start, u64 len,
@@ -255,7 +255,7 @@ void map__delete(struct map *map)

void map__put(struct map *map)
{
- if (map && atomic_dec_and_test(&map->refcnt))
+ if (map && refcount_dec_and_test(&map->refcnt))
map__delete(map);
}

@@ -354,7 +354,7 @@ struct map *map__clone(struct map *from)
struct map *map = memdup(from, sizeof(*map));

if (map != NULL) {
- atomic_set(&map->refcnt, 1);
+ refcount_set(&map->refcnt, 1);
RB_CLEAR_NODE(&map->rb_node);
dso__get(map->dso);
map->groups = NULL;
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index abdacf8..9545ff3 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -1,7 +1,7 @@
#ifndef __PERF_MAP_H
#define __PERF_MAP_H

-#include <linux/atomic.h>
+#include <linux/refcount.h>
#include <linux/compiler.h>
#include <linux/list.h>
#include <linux/rbtree.h>
@@ -51,7 +51,7 @@ struct map {

struct dso *dso;
struct map_groups *groups;
- atomic_t refcnt;
+ refcount_t refcnt;
};

struct kmap {
@@ -150,7 +150,7 @@ struct map *map__clone(struct map *map);
static inline struct map *map__get(struct map *map)
{
if (map)
- atomic_inc(&map->refcnt);
+ refcount_inc(&map->refcnt);
return map;
}

--
2.7.4
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