summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorElena Reshetova <elena.reshetova@intel.com>2017-10-20 10:23:38 +0300
committerDavid S. Miller <davem@davemloft.net>2017-10-22 02:22:38 +0100
commit0068895ff845c38e9e2b65c002c53c623379e436 (patch)
tree7ca05c32618d53d389617dc93d90a36bcefc329b
parentff61b5e3f041c2f1aa8d7c700af3007889973889 (diff)
downloadop-kernel-dev-0068895ff845c38e9e2b65c002c53c623379e436.zip
op-kernel-dev-0068895ff845c38e9e2b65c002c53c623379e436.tar.gz
drivers, net, mlx4: convert mlx4_qp.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_qp.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>
-rw-r--r--drivers/net/ethernet/mellanox/mlx4/qp.c8
-rw-r--r--include/linux/mlx4/device.h2
2 files changed, 5 insertions, 5 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/qp.c b/drivers/net/ethernet/mellanox/mlx4/qp.c
index 2033209..769598f 100644
--- a/drivers/net/ethernet/mellanox/mlx4/qp.c
+++ b/drivers/net/ethernet/mellanox/mlx4/qp.c
@@ -55,7 +55,7 @@ void mlx4_qp_event(struct mlx4_dev *dev, u32 qpn, int event_type)
qp = __mlx4_qp_lookup(dev, qpn);
if (qp)
- atomic_inc(&qp->refcount);
+ refcount_inc(&qp->refcount);
spin_unlock(&qp_table->lock);
@@ -66,7 +66,7 @@ void mlx4_qp_event(struct mlx4_dev *dev, u32 qpn, int event_type)
qp->event(qp, event_type);
- if (atomic_dec_and_test(&qp->refcount))
+ if (refcount_dec_and_test(&qp->refcount))
complete(&qp->free);
}
@@ -420,7 +420,7 @@ int mlx4_qp_alloc(struct mlx4_dev *dev, int qpn, struct mlx4_qp *qp)
if (err)
goto err_icm;
- atomic_set(&qp->refcount, 1);
+ refcount_set(&qp->refcount, 1);
init_completion(&qp->free);
return 0;
@@ -520,7 +520,7 @@ EXPORT_SYMBOL_GPL(mlx4_qp_remove);
void mlx4_qp_free(struct mlx4_dev *dev, struct mlx4_qp *qp)
{
- if (atomic_dec_and_test(&qp->refcount))
+ if (refcount_dec_and_test(&qp->refcount))
complete(&qp->free);
wait_for_completion(&qp->free);
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index daac2e3..b8e19c4 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -768,7 +768,7 @@ struct mlx4_qp {
int qpn;
- atomic_t refcount;
+ refcount_t refcount;
struct completion free;
u8 usage;
};
OpenPOWER on IntegriCloud