diff options
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-core.c | 56 | ||||
| -rw-r--r-- | include/media/videobuf2-core.h | 2 |
2 files changed, 21 insertions, 37 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index c359006074a8..eb86913349fc 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -882,7 +882,9 @@ static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) * We already have buffers allocated, so first check if they * are not in use and can be freed. */ + mutex_lock(&q->mmap_lock); if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) { + mutex_unlock(&q->mmap_lock); dprintk(1, "memory in use, cannot free\n"); return -EBUSY; } @@ -894,6 +896,7 @@ static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) */ __vb2_queue_cancel(q); ret = __vb2_queue_free(q, q->num_buffers); + mutex_unlock(&q->mmap_lock); if (ret) return ret; @@ -955,6 +958,7 @@ static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) */ } + mutex_lock(&q->mmap_lock); q->num_buffers = allocated_buffers; if (ret < 0) { @@ -963,8 +967,10 @@ static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) * from q->num_buffers. */ __vb2_queue_free(q, allocated_buffers); + mutex_unlock(&q->mmap_lock); return ret; } + mutex_unlock(&q->mmap_lock); /* * Return the number of successfully allocated buffers @@ -1061,6 +1067,7 @@ static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create */ } + mutex_lock(&q->mmap_lock); q->num_buffers += allocated_buffers; if (ret < 0) { @@ -1069,8 +1076,10 @@ static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create * from q->num_buffers. */ __vb2_queue_free(q, allocated_buffers); + mutex_unlock(&q->mmap_lock); return -ENOMEM; } + mutex_unlock(&q->mmap_lock); /* * Return the number of successfully allocated buffers @@ -1582,7 +1591,6 @@ static void __enqueue_in_driver(struct vb2_buffer *vb) static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b) { struct vb2_queue *q = vb->vb2_queue; - struct rw_semaphore *mmap_sem; int ret; ret = __verify_length(vb, b); @@ -1619,26 +1627,7 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b) ret = __qbuf_mmap(vb, b); break; case V4L2_MEMORY_USERPTR: - /* - * In case of user pointer buffers vb2 allocators need to get - * direct access to userspace pages. This requires getting - * the mmap semaphore for read access in the current process - * structure. The same semaphore is taken before calling mmap - * operation, while both qbuf/prepare_buf and mmap are called - * by the driver or v4l2 core with the driver's lock held. - * To avoid an AB-BA deadlock (mmap_sem then driver's lock in - * mmap and driver's lock then mmap_sem in qbuf/prepare_buf), - * the videobuf2 core releases the driver's lock, takes - * mmap_sem and then takes the driver's lock again. - */ - mmap_sem = ¤t->mm->mmap_sem; - call_void_qop(q, wait_prepare, q); - down_read(mmap_sem); - call_void_qop(q, wait_finish, q); - ret = __qbuf_userptr(vb, b); - - up_read(mmap_sem); break; case V4L2_MEMORY_DMABUF: ret = __qbuf_dmabuf(vb, b); @@ -2485,7 +2474,9 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) return -EINVAL; } + mutex_lock(&q->mmap_lock); ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma); + mutex_unlock(&q->mmap_lock); if (ret) return ret; @@ -2504,6 +2495,7 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q, unsigned long off = pgoff << PAGE_SHIFT; struct vb2_buffer *vb; unsigned int buffer, plane; + void *vaddr; int ret; if (q->memory != V4L2_MEMORY_MMAP) { @@ -2520,7 +2512,8 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q, vb = q->bufs[buffer]; - return (unsigned long)vb2_plane_vaddr(vb, plane); + vaddr = vb2_plane_vaddr(vb, plane); + return vaddr ? (unsigned long)vaddr : -EINVAL; } EXPORT_SYMBOL_GPL(vb2_get_unmapped_area); #endif @@ -2660,6 +2653,7 @@ int vb2_queue_init(struct vb2_queue *q) INIT_LIST_HEAD(&q->queued_list); INIT_LIST_HEAD(&q->done_list); spin_lock_init(&q->done_lock); + mutex_init(&q->mmap_lock); init_waitqueue_head(&q->done_wq); if (q->buf_struct_size == 0) @@ -2681,7 +2675,9 @@ void vb2_queue_release(struct vb2_queue *q) { __vb2_cleanup_fileio(q); __vb2_queue_cancel(q); + mutex_lock(&q->mmap_lock); __vb2_queue_free(q, q->num_buffers); + mutex_unlock(&q->mmap_lock); } EXPORT_SYMBOL_GPL(vb2_queue_release); @@ -3346,15 +3342,8 @@ EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf); int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) { struct video_device *vdev = video_devdata(file); - struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; - int err; - if (lock && mutex_lock_interruptible(lock)) - return -ERESTARTSYS; - err = vb2_mmap(vdev->queue, vma); - if (lock) - mutex_unlock(lock); - return err; + return vb2_mmap(vdev->queue, vma); } EXPORT_SYMBOL_GPL(vb2_fop_mmap); @@ -3473,15 +3462,8 @@ unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct video_device *vdev = video_devdata(file); - struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; - int ret; - if (lock && mutex_lock_interruptible(lock)) - return -ERESTARTSYS; - ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags); - if (lock) - mutex_unlock(lock); - return ret; + return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags); } EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area); #endif diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index fc910a622451..5a10d8d695b4 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -366,6 +366,7 @@ struct v4l2_fh; * cannot be started unless at least this number of buffers * have been queued into the driver. * + * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped * @memory: current memory type used * @bufs: videobuf buffer structures * @num_buffers: number of allocated/used buffers @@ -399,6 +400,7 @@ struct vb2_queue { u32 min_buffers_needed; /* private: internal use only */ + struct mutex mmap_lock; enum v4l2_memory memory; struct vb2_buffer *bufs[VIDEO_MAX_FRAME]; unsigned int num_buffers; |