diff options
author | Elena Reshetova <elena.reshetova@intel.com> | 2017-10-20 10:23:39 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-10-22 04:22:38 +0300 |
commit | 17ac99b2b8d08ed40f4525491d6eff330329a6d2 (patch) | |
tree | 1610c1f3c19209b8eaaaccfe4b7ecc40543e4db4 | |
parent | 0068895ff845c38e9e2b65c002c53c623379e436 (diff) | |
download | linux-17ac99b2b8d08ed40f4525491d6eff330329a6d2.tar.xz |
drivers, net, mlx4: convert mlx4_srq.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_srq.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/srq.c | 8 | ||||
-rw-r--r-- | include/linux/mlx4/device.h | 2 |
2 files changed, 5 insertions, 5 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/srq.c b/drivers/net/ethernet/mellanox/mlx4/srq.c index bedf52126824..cbe4d9746ddf 100644 --- a/drivers/net/ethernet/mellanox/mlx4/srq.c +++ b/drivers/net/ethernet/mellanox/mlx4/srq.c @@ -49,7 +49,7 @@ void mlx4_srq_event(struct mlx4_dev *dev, u32 srqn, int event_type) srq = radix_tree_lookup(&srq_table->tree, srqn & (dev->caps.num_srqs - 1)); rcu_read_unlock(); if (srq) - atomic_inc(&srq->refcount); + refcount_inc(&srq->refcount); else { mlx4_warn(dev, "Async event for bogus SRQ %08x\n", srqn); return; @@ -57,7 +57,7 @@ void mlx4_srq_event(struct mlx4_dev *dev, u32 srqn, int event_type) srq->event(srq, event_type); - if (atomic_dec_and_test(&srq->refcount)) + if (refcount_dec_and_test(&srq->refcount)) complete(&srq->free); } @@ -203,7 +203,7 @@ int mlx4_srq_alloc(struct mlx4_dev *dev, u32 pdn, u32 cqn, u16 xrcd, if (err) goto err_radix; - atomic_set(&srq->refcount, 1); + refcount_set(&srq->refcount, 1); init_completion(&srq->free); return 0; @@ -232,7 +232,7 @@ void mlx4_srq_free(struct mlx4_dev *dev, struct mlx4_srq *srq) radix_tree_delete(&srq_table->tree, srq->srqn); spin_unlock_irq(&srq_table->lock); - if (atomic_dec_and_test(&srq->refcount)) + if (refcount_dec_and_test(&srq->refcount)) complete(&srq->free); wait_for_completion(&srq->free); diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h index b8e19c4d6caa..a9b5fed8f7c6 100644 --- a/include/linux/mlx4/device.h +++ b/include/linux/mlx4/device.h @@ -781,7 +781,7 @@ struct mlx4_srq { int max_gs; int wqe_shift; - atomic_t refcount; + refcount_t refcount; struct completion free; }; |