From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eli Cohen Subject: [PATCH] IB core: Fix locking on device numbers allocation Date: Tue, 23 Mar 2010 21:13:17 +0200 Message-ID: <20100323191317.GA14496@mtldesk030.lab.mtl.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Roland Dreier Cc: Linux RDMA list List-Id: linux-rdma@vger.kernel.org When the driver needs to dynamically allocate char device numbers in systems with more than IB_UVERBS_MAX_DEVICES, it releases map lock, allocates a new range and a new device number from that range, and only then re-acquires the lock. This must be protected for the same reasoning that the map_lock spinlock is used. Without protecting we could also end up calling alloc_chrdev_region() a nubmer of times and cause a leakage. Fix this by replacing map_lock with a mutex and apply on the all the allocation code. Signed-off-by: Eli Cohen --- drivers/infiniband/core/uverbs_main.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index d805cf3..9589c71 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -72,7 +72,7 @@ DEFINE_IDR(ib_uverbs_cq_idr); DEFINE_IDR(ib_uverbs_qp_idr); DEFINE_IDR(ib_uverbs_srq_idr); -static DEFINE_SPINLOCK(map_lock); +static DEFINE_MUTEX(map_lock); static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES); static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file, @@ -738,15 +738,15 @@ static void ib_uverbs_add_one(struct ib_device *device) kref_init(&uverbs_dev->ref); init_completion(&uverbs_dev->comp); - spin_lock(&map_lock); + mutex_lock(&map_lock); devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES); if (devnum >= IB_UVERBS_MAX_DEVICES) { - spin_unlock(&map_lock); devnum = find_overflow_devnum(); - if (devnum < 0) + if (devnum < 0) { + mutex_unlock(&map_lock); goto err; + } - spin_lock(&map_lock); uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES; base = devnum + overflow_maj; set_bit(devnum, overflow_map); @@ -755,7 +755,7 @@ static void ib_uverbs_add_one(struct ib_device *device) base = devnum + IB_UVERBS_BASE_DEV; set_bit(devnum, dev_map); } - spin_unlock(&map_lock); + mutex_unlock(&map_lock); uverbs_dev->ib_dev = device; uverbs_dev->num_comp_vectors = device->num_comp_vectors; -- 1.7.0.3 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html