diff options
| author | Nikhil Rao <nikhil.rao@intel.com> | 2020-06-22 13:38:34 -0700 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2020-06-24 11:17:46 +0530 |
| commit | 66983bc18fad17d10766650b3685045f6f092d73 (patch) | |
| tree | d37c1f3ae350218ad08902cef5f72e5b06b92c6e /drivers/dma | |
| parent | 2f57b8d57673af2c2caf8c2c7bef01be940a5c2c (diff) | |
dmaengine: idxd: fix cdev locking for open and release
add the wq lock in cdev open and release call. This fixes
race conditions observed in the open and close routines.
Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159285824892.64944.2905413694915141834.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/idxd/cdev.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index ff49847e37a8..cb376cf6a2d2 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -74,6 +74,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) struct idxd_device *idxd; struct idxd_wq *wq; struct device *dev; + int rc = 0; wq = inode_wq(inode); idxd = wq->idxd; @@ -81,17 +82,27 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) dev_dbg(dev, "%s called: %d\n", __func__, idxd_wq_refcount(wq)); - if (idxd_wq_refcount(wq) > 0 && wq_dedicated(wq)) - return -EBUSY; - ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; + mutex_lock(&wq->wq_lock); + + if (idxd_wq_refcount(wq) > 0 && wq_dedicated(wq)) { + rc = -EBUSY; + goto failed; + } + ctx->wq = wq; filp->private_data = ctx; idxd_wq_get(wq); + mutex_unlock(&wq->wq_lock); return 0; + + failed: + mutex_unlock(&wq->wq_lock); + kfree(ctx); + return rc; } static int idxd_cdev_release(struct inode *node, struct file *filep) @@ -105,7 +116,9 @@ static int idxd_cdev_release(struct inode *node, struct file *filep) filep->private_data = NULL; kfree(ctx); + mutex_lock(&wq->wq_lock); idxd_wq_put(wq); + mutex_unlock(&wq->wq_lock); return 0; } |