On 07/11/2024 00:41, Tomasz Figa wrote:
> On Wed, Nov 6, 2024 at 9:18 PM Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> wrote:
>>
>> Copy the relevant data from userspace to the vb->planes unconditionally
>> as it's possible some of the fields may have changed after the buffer
>> has been validated.
>>
>> Keep the dma_buf_put(planes[plane].dbuf) calls in the first
>> `if (!reacquired)` case, in order to be close to the plane validation code
>> where the buffers were got in the first place.
>>
>> Cc: stable@xxxxxxxxxxxxxxx
>> Fixes: 95af7c00f35b ("media: videobuf2-core: release all planes first in __prepare_dmabuf()")
>> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
>> ---
>> .../media/common/videobuf2/videobuf2-core.c | 28 ++++++++++---------
>> 1 file changed, 15 insertions(+), 13 deletions(-)
>>
>
> Thanks for the fix.
>
> Acked-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
>
> (We probably need some tests to verify this behavior... It seems like
> the way v4l2-compliance is implemented [1] would only trigger the
> !reacquired case on most drivers.)
>
> [1] https://git.linuxtv.org/v4l-utils.git/tree/utils/v4l2-compliance/v4l2-test-buffers.cpp#n2071
> (just queuing all imported buffers in order and re-queuing them
> exactly as they are dequeued [2])
> [2] https://git.linuxtv.org/v4l-utils.git/tree/utils/v4l2-compliance/v4l2-test-buffers.cpp#n1299
I'll see if I can improve that test.
Regards,
Hans
>
> Best regards,
> Tomasz
>
>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>> index f07dc53a9d06..c0cc441b5164 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>> @@ -1482,18 +1482,23 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
>> }
>> vb->planes[plane].dbuf_mapped = 1;
>> }
>> + } else {
>> + for (plane = 0; plane < vb->num_planes; ++plane)
>> + dma_buf_put(planes[plane].dbuf);
>> + }
>>
>> - /*
>> - * Now that everything is in order, copy relevant information
>> - * provided by userspace.
>> - */
>> - for (plane = 0; plane < vb->num_planes; ++plane) {
>> - vb->planes[plane].bytesused = planes[plane].bytesused;
>> - vb->planes[plane].length = planes[plane].length;
>> - vb->planes[plane].m.fd = planes[plane].m.fd;
>> - vb->planes[plane].data_offset = planes[plane].data_offset;
>> - }
>> + /*
>> + * Now that everything is in order, copy relevant information
>> + * provided by userspace.
>> + */
>> + for (plane = 0; plane < vb->num_planes; ++plane) {
>> + vb->planes[plane].bytesused = planes[plane].bytesused;
>> + vb->planes[plane].length = planes[plane].length;
>> + vb->planes[plane].m.fd = planes[plane].m.fd;
>> + vb->planes[plane].data_offset = planes[plane].data_offset;
>> + }
>>
>> + if (reacquired) {
>> /*
>> * Call driver-specific initialization on the newly acquired buffer,
>> * if provided.
>> @@ -1503,9 +1508,6 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
>> dprintk(q, 1, "buffer initialization failed\n");
>> goto err_put_vb2_buf;
>> }
>> - } else {
>> - for (plane = 0; plane < vb->num_planes; ++plane)
>> - dma_buf_put(planes[plane].dbuf);
>> }
>>
>> ret = call_vb_qop(vb, buf_prepare, vb);
>> --
>> 2.47.0.199.ga7371fff76-goog
>>
