perf map: Convert map.refcnt from atomic_t to refcount_t

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/1487691303-31858-6-git-send-email-elena.reshetova@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Elena Reshetova 2017-02-21 17:34:59 +02:00 committed by Arnaldo Carvalho de Melo
parent 7100810a75
commit e3a42cdd3e
2 changed files with 6 additions and 6 deletions

View File

@ -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;

View File

@ -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;
}