Commit 098e5edc authored by Hans Verkuil's avatar Hans Verkuil Committed by Linus Torvalds
Browse files

media: videobuf2-core: take mmap_lock in vb2_get_unmapped_area() 



While vb2_mmap took the mmap_lock mutex, vb2_get_unmapped_area didn't.
Add this.

Also take this opportunity to move the 'q->memory != VB2_MEMORY_MMAP'
check and vb2_fileio_is_active() check into __find_plane_by_offset() so
both vb2_mmap and vb2_get_unmapped_area do the same checks.

Since q->memory is checked while mmap_lock is held, also take that lock
in reqbufs and create_bufs when it is set, and set it back to
MEMORY_UNKNOWN on error.

Fixes: f035eb4e ("[media] videobuf2: fix lockdep warning")
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: default avatarTomasz Figa <tfiga@chromium.org>
Reviewed-by: default avatarRicardo Ribalda <ribalda@chromium.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8ed710da

drivers/media/common/videobuf2/videobuf2-core.c

+73 −29
Original line number Diff line number Diff line
@@ -813,7 +813,13 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 
	num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);

	num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);

	memset(q->alloc_devs, 0, sizeof(q->alloc_devs));

	/*

	 * Set this now to ensure that drivers see the correct q->memory value

	 * in the queue_setup op.

	 */

	mutex_lock(&q->mmap_lock);

	q->memory = memory;

	mutex_unlock(&q->mmap_lock);

	set_queue_coherency(q, non_coherent_mem);



	/*
@@ -823,22 +829,27 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 
	ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,

		       plane_sizes, q->alloc_devs);

	if (ret)

		return ret;

		goto error;



	/* Check that driver has set sane values */

	if (WARN_ON(!num_planes))

		return -EINVAL;

	if (WARN_ON(!num_planes)) {

		ret = -EINVAL;

		goto error;

	}



	for (i = 0; i < num_planes; i++)

		if (WARN_ON(!plane_sizes[i]))

			return -EINVAL;

		if (WARN_ON(!plane_sizes[i])) {

			ret = -EINVAL;

			goto error;

		}



	/* Finally, allocate buffers and video memory */

	allocated_buffers =

		__vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes);

	if (allocated_buffers == 0) {

		dprintk(q, 1, "memory allocation failed\n");

		return -ENOMEM;

		ret = -ENOMEM;

		goto error;

	}



	/*
@@ -879,7 +890,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 
	if (ret < 0) {

		/*

		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'

		 * from q->num_buffers.

		 * from q->num_buffers and it will reset q->memory to

		 * VB2_MEMORY_UNKNOWN.

		 */

		__vb2_queue_free(q, allocated_buffers);

		mutex_unlock(&q->mmap_lock);
@@ -895,6 +907,12 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 
	q->waiting_for_buffers = !q->is_output;



	return 0;



error:

	mutex_lock(&q->mmap_lock);

	q->memory = VB2_MEMORY_UNKNOWN;

	mutex_unlock(&q->mmap_lock);

	return ret;

}

EXPORT_SYMBOL_GPL(vb2_core_reqbufs);
@@ -906,6 +924,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 
	unsigned int num_planes = 0, num_buffers, allocated_buffers;

	unsigned plane_sizes[VB2_MAX_PLANES] = { };

	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;

	bool no_previous_buffers = !q->num_buffers;

	int ret;



	if (q->num_buffers == VB2_MAX_FRAME) {
@@ -913,13 +932,19 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 
		return -ENOBUFS;

	}



	if (!q->num_buffers) {

	if (no_previous_buffers) {

		if (q->waiting_in_dqbuf && *count) {

			dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");

			return -EBUSY;

		}

		memset(q->alloc_devs, 0, sizeof(q->alloc_devs));

		/*

		 * Set this now to ensure that drivers see the correct q->memory

		 * value in the queue_setup op.

		 */

		mutex_lock(&q->mmap_lock);

		q->memory = memory;

		mutex_unlock(&q->mmap_lock);

		q->waiting_for_buffers = !q->is_output;

		set_queue_coherency(q, non_coherent_mem);

	} else {
@@ -945,14 +970,15 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 
	ret = call_qop(q, queue_setup, q, &num_buffers,

		       &num_planes, plane_sizes, q->alloc_devs);

	if (ret)

		return ret;

		goto error;



	/* Finally, allocate buffers and video memory */

	allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,

				num_planes, plane_sizes);

	if (allocated_buffers == 0) {

		dprintk(q, 1, "memory allocation failed\n");

		return -ENOMEM;

		ret = -ENOMEM;

		goto error;

	}



	/*
@@ -983,7 +1009,8 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 
	if (ret < 0) {

		/*

		 * Note: __vb2_queue_free() will subtract 'allocated_buffers'

		 * from q->num_buffers.

		 * from q->num_buffers and it will reset q->memory to

		 * VB2_MEMORY_UNKNOWN.

		 */

		__vb2_queue_free(q, allocated_buffers);

		mutex_unlock(&q->mmap_lock);
@@ -998,6 +1025,14 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 
	*count = allocated_buffers;



	return 0;



error:

	if (no_previous_buffers) {

		mutex_lock(&q->mmap_lock);

		q->memory = VB2_MEMORY_UNKNOWN;

		mutex_unlock(&q->mmap_lock);

	}

	return ret;

}

EXPORT_SYMBOL_GPL(vb2_core_create_bufs);
@@ -2164,6 +2199,22 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, 
	struct vb2_buffer *vb;

	unsigned int buffer, plane;



	/*

	 * Sanity checks to ensure the lock is held, MEMORY_MMAP is

	 * used and fileio isn't active.

	 */

	lockdep_assert_held(&q->mmap_lock);



	if (q->memory != VB2_MEMORY_MMAP) {

		dprintk(q, 1, "queue is not currently set up for mmap\n");

		return -EINVAL;

	}



	if (vb2_fileio_is_active(q)) {

		dprintk(q, 1, "file io in progress\n");

		return -EBUSY;

	}



	/*

	 * Go over all buffers and their planes, comparing the given offset

	 * with an offset assigned to each plane. If a match is found,
@@ -2265,11 +2316,6 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) 
	int ret;

	unsigned long length;



	if (q->memory != VB2_MEMORY_MMAP) {

		dprintk(q, 1, "queue is not currently set up for mmap\n");

		return -EINVAL;

	}



	/*

	 * Check memory area access mode.

	 */
@@ -2291,14 +2337,9 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) 


	mutex_lock(&q->mmap_lock);



	if (vb2_fileio_is_active(q)) {

		dprintk(q, 1, "mmap: file io in progress\n");

		ret = -EBUSY;

		goto unlock;

	}



	/*

	 * Find the plane corresponding to the offset passed by userspace.

	 * Find the plane corresponding to the offset passed by userspace. This

	 * will return an error if not MEMORY_MMAP or file I/O is in progress.

	 */

	ret = __find_plane_by_offset(q, off, &buffer, &plane);

	if (ret)
@@ -2351,22 +2392,25 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q, 
	void *vaddr;

	int ret;



	if (q->memory != VB2_MEMORY_MMAP) {

		dprintk(q, 1, "queue is not currently set up for mmap\n");

		return -EINVAL;

	}

	mutex_lock(&q->mmap_lock);



	/*

	 * Find the plane corresponding to the offset passed by userspace.

	 * Find the plane corresponding to the offset passed by userspace. This

	 * will return an error if not MEMORY_MMAP or file I/O is in progress.

	 */

	ret = __find_plane_by_offset(q, off, &buffer, &plane);

	if (ret)

		return ret;

		goto unlock;



	vb = q->bufs[buffer];



	vaddr = vb2_plane_vaddr(vb, plane);

	mutex_unlock(&q->mmap_lock);

	return vaddr ? (unsigned long)vaddr : -EINVAL;



unlock:

	mutex_unlock(&q->mmap_lock);

	return ret;

}

EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);

#endif