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authorElena Reshetova <elena.reshetova@intel.com>2017-10-20 10:23:37 +0300
committerDavid S. Miller <davem@davemloft.net>2017-10-22 04:22:38 +0300
commitff61b5e3f041c2f1aa8d7c700af3007889973889 (patch)
tree947c9d8b2625fee0155126d11c93d7f6267f8a88 /include/linux/mlx4
parentc6d4e63e065e796d2f2734c1e4e13f85f1c1c5e4 (diff)
downloadlinux-ff61b5e3f041c2f1aa8d7c700af3007889973889.tar.xz
drivers, net, mlx4: convert mlx4_cq.refcount from atomic_t to refcount_t
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable mlx4_cq.refcount is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/mlx4')
-rw-r--r--include/linux/mlx4/device.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index b0a57e043fa3..daac2e3a1a58 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -40,7 +40,7 @@
#include <linux/cpu_rmap.h>
#include <linux/crash_dump.h>
-#include <linux/atomic.h>
+#include <linux/refcount.h>
#include <linux/timecounter.h>
@@ -751,7 +751,7 @@ struct mlx4_cq {
int cqn;
unsigned vector;
- atomic_t refcount;
+ refcount_t refcount;
struct completion free;
struct {
struct list_head list;