Re: [PATCH v5 02/10] media: videobuf2: Access vb2_queue bufs array through helper functions
From: Hans Verkuil
Date: Thu Aug 31 2023 - 06:22:22 EST
On 31/08/2023 09:54, Benjamin Gaignard wrote:
>
> Le 30/08/2023 à 18:36, Hans Verkuil a écrit :
>> On 30/08/2023 18:24, Benjamin Gaignard wrote:
>>> Le 30/08/2023 à 15:23, Hans Verkuil a écrit :
>>>> On 24/08/2023 11:21, Benjamin Gaignard wrote:
>>>>> The first step before changing how vb2 buffers are stored into queue
>>>>> is to avoid direct access to bufs arrays.
>>>>>
>>>>> This patch adds 2 helpers functions to add and remove vb2 buffers
>>>>> from a queue. With these 2 and vb2_get_buffer(), bufs field of
>>>>> struct vb2_queue becomes like a private member of the structure.
>>>>>
>>>>> After each call to vb2_get_buffer() we need to be sure that we get
>>>>> a valid pointer so check the return value of all of them.
>>>>>
>>>>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
>>>>>
>>>>> # Conflicts:
>>>>> # drivers/media/common/videobuf2/videobuf2-core.c
>>>>> ---
>>>>> .../media/common/videobuf2/videobuf2-core.c | 203 ++++++++++++++----
>>>>> .../media/common/videobuf2/videobuf2-v4l2.c | 28 ++-
>>>>> drivers/media/platform/amphion/vpu_dbg.c | 22 +-
>>>>> .../platform/mediatek/jpeg/mtk_jpeg_core.c | 6 +-
>>>>> .../vcodec/decoder/vdec/vdec_vp9_req_lat_if.c | 2 +-
>>>>> drivers/media/platform/st/sti/hva/hva-v4l2.c | 4 +
>>>>> drivers/media/test-drivers/visl/visl-dec.c | 28 ++-
>>>>> .../staging/media/atomisp/pci/atomisp_ioctl.c | 2 +-
>>>>> 8 files changed, 230 insertions(+), 65 deletions(-)
>>>>>
>>>>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>>>>> index e06905533ef4..8aa13591b782 100644
>>>>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>>>>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>>>>> @@ -403,6 +403,37 @@ static void init_buffer_cache_hints(struct vb2_queue *q, struct vb2_buffer *vb)
>>>>> vb->skip_cache_sync_on_finish = 1;
>>>>> }
>>>>> +/**
>>>>> + * vb2_queue_add_buffer() - add a buffer to a queue
>>>>> + * @q: pointer to &struct vb2_queue with videobuf2 queue.
>>>>> + * @vb: pointer to &struct vb2_buffer to be added to the queue.
>>>>> + * @index: index where add vb2_buffer in the queue
>>>>> + */
>>>>> +static bool vb2_queue_add_buffer(struct vb2_queue *q, struct vb2_buffer *vb, int index)
>>>>> +{
>>>>> + if (index < VB2_MAX_FRAME && !q->bufs[index]) {
>>>>> + q->bufs[index] = vb;
>>>>> + vb->index = index;
>>>>> + vb->vb2_queue = q;
>>>>> + return true;
>>>>> + }
>>>>> +
>>>>> + return false;
>>>>> +}
>>>>> +
>>>>> +/**
>>>>> + * vb2_queue_remove_buffer() - remove a buffer from a queue
>>>>> + * @q: pointer to &struct vb2_queue with videobuf2 queue.
>>>>> + * @vb: pointer to &struct vb2_buffer to be removed from the queue.
>>>>> + */
>>>>> +static void vb2_queue_remove_buffer(struct vb2_queue *q, struct vb2_buffer *vb)
>>>>> +{
>>>>> + if (vb->index < VB2_MAX_FRAME) {
>>>>> + q->bufs[vb->index] = NULL;
>>>>> + vb->vb2_queue = NULL;
>>>>> + }
>>>>> +}
>>>>> +
>>>>> /*
>>>>> * __vb2_queue_alloc() - allocate vb2 buffer structures and (for MMAP type)
>>>>> * video buffer memory for all buffers/planes on the queue and initializes the
>>>>> @@ -431,9 +462,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>>>> }
>>>>> vb->state = VB2_BUF_STATE_DEQUEUED;
>>>>> - vb->vb2_queue = q;
>>>>> vb->num_planes = num_planes;
>>>>> - vb->index = q->num_buffers + buffer;
>>>>> vb->type = q->type;
>>>>> vb->memory = memory;
>>>>> init_buffer_cache_hints(q, vb);
>>>>> @@ -443,7 +472,11 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>>>> }
>>>>> call_void_bufop(q, init_buffer, vb);
>>>>> - q->bufs[vb->index] = vb;
>>>>> + if (!vb2_queue_add_buffer(q, vb, q->num_buffers + buffer)) {
>>>>> + dprintk(q, 1, "failed adding buffer %d to queue\n", buffer);
>>>>> + kfree(vb);
>>>>> + break;
>>>>> + }
>>>>> /* Allocate video buffer memory for the MMAP type */
>>>>> if (memory == VB2_MEMORY_MMAP) {
>>>>> @@ -451,7 +484,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>>>> if (ret) {
>>>>> dprintk(q, 1, "failed allocating memory for buffer %d\n",
>>>>> buffer);
>>>>> - q->bufs[vb->index] = NULL;
>>>>> + vb2_queue_remove_buffer(q, vb);
>>>>> kfree(vb);
>>>>> break;
>>>>> }
>>>>> @@ -466,7 +499,7 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>>>> dprintk(q, 1, "buffer %d %p initialization failed\n",
>>>>> buffer, vb);
>>>>> __vb2_buf_mem_free(vb);
>>>>> - q->bufs[vb->index] = NULL;
>>>>> + vb2_queue_remove_buffer(q, vb);
>>>>> kfree(vb);
>>>>> break;
>>>>> }
>>>>> @@ -489,7 +522,7 @@ static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
>>>>> for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
>>>>> ++buffer) {
>>>>> - vb = q->bufs[buffer];
>>>>> + vb = vb2_get_buffer(q, buffer);
>>>>> if (!vb)
>>>>> continue;
>>>>> @@ -517,7 +550,7 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
>>>>> /* Call driver-provided cleanup function for each buffer, if provided */
>>>>> for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
>>>>> ++buffer) {
>>>>> - struct vb2_buffer *vb = q->bufs[buffer];
>>>>> + struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
>>>>> if (vb && vb->planes[0].mem_priv)
>>>>> call_void_vb_qop(vb, buf_cleanup, vb);
>>>>> @@ -557,15 +590,20 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
>>>>> q->cnt_unprepare_streaming = 0;
>>>>> }
>>>>> for (buffer = 0; buffer < q->num_buffers; ++buffer) {
>>>>> - struct vb2_buffer *vb = q->bufs[buffer];
>>>>> - bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
>>>>> - vb->cnt_mem_prepare != vb->cnt_mem_finish ||
>>>>> - vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
>>>>> - vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
>>>>> - vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
>>>>> - vb->cnt_buf_queue != vb->cnt_buf_done ||
>>>>> - vb->cnt_buf_prepare != vb->cnt_buf_finish ||
>>>>> - vb->cnt_buf_init != vb->cnt_buf_cleanup;
>>>>> + struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
>>>>> + bool unbalanced;
>>>>> +
>>>>> + if (!vb)
>>>>> + continue;
>>>>> +
>>>>> + unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put ||
>>>>> + vb->cnt_mem_prepare != vb->cnt_mem_finish ||
>>>>> + vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr ||
>>>>> + vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf ||
>>>>> + vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf ||
>>>>> + vb->cnt_buf_queue != vb->cnt_buf_done ||
>>>>> + vb->cnt_buf_prepare != vb->cnt_buf_finish ||
>>>>> + vb->cnt_buf_init != vb->cnt_buf_cleanup;
>>>>> if (unbalanced || debug) {
>>>> I think we should drop the '|| debug' part. It is already annoying today to see these
>>>> messages when the debug parameter is > 0, and now the number of buffers is still
>>>> fairly small. But if we allow a lot more buffers, then this will really spam the
>>>> kernel log.
>>>>
>>>> I think this should be dropped, and we only report unbalanced buffers.
>>>>
>>>> And another optimization is to only report the unbalanced counters. Right now
>>>> it reports all counters, but it is again too much spamming of the kernel log.
>>>>
>>>> I think this change can be done as a separate patch before this patch.
>>>> That way it can be picked up separately from the other changes in this series.
>>>>
>>>>> pr_info(" counters for queue %p, buffer %d:%s\n",
>>>>> @@ -597,8 +635,13 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
>>>>> /* Free vb2 buffers */
>>>>> for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
>>>>> ++buffer) {
>>>>> - kfree(q->bufs[buffer]);
>>>>> - q->bufs[buffer] = NULL;
>>>>> + struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
>>>>> +
>>>>> + if (!vb)
>>>>> + continue;
>>>>> +
>>>>> + vb2_queue_remove_buffer(q, vb);
>>>>> + kfree(vb);
>>>>> }
>>>>> q->num_buffers -= buffers;
>>>>> @@ -634,7 +677,12 @@ static bool __buffers_in_use(struct vb2_queue *q)
>>>>> {
>>>>> unsigned int buffer;
>>>>> for (buffer = 0; buffer < q->num_buffers; ++buffer) {
>>>>> - if (vb2_buffer_in_use(q, q->bufs[buffer]))
>>>>> + struct vb2_buffer *vb = vb2_get_buffer(q, buffer);
>>>>> +
>>>>> + if (!vb)
>>>>> + continue;
>>>>> +
>>>>> + if (vb2_buffer_in_use(q, vb))
>>>>> return true;
>>>>> }
>>>>> return false;
>>>>> @@ -642,7 +690,10 @@ static bool __buffers_in_use(struct vb2_queue *q)
>>>>> void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb)
>>>>> {
>>>>> - call_void_bufop(q, fill_user_buffer, q->bufs[index], pb);
>>>>> + struct vb2_buffer *vb = vb2_get_buffer(q, index);
>>>>> +
>>>>> + if (vb)
>>>>> + call_void_bufop(q, fill_user_buffer, vb, pb);
>>>> I think that rather than passing the index (that then has to be verified)
>>>> it is better to pass the vb2_buffer pointer directly and leave it up to
>>>> the caller to do the index verification.
>>>>
>>>> Another option is to drop this function altogether and let the called
>>>> call the fill_user_buffer function. Either works for me.
>>>>
>>>>> }
>>>>> EXPORT_SYMBOL_GPL(vb2_core_querybuf);
>>>>> @@ -1553,7 +1604,13 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
>>>> Here too it is better to pass the vb2_buffer pointer instead of an index.
>>>>
>>>> This function assumes that the index is valid, so the called actually does the
>>>> validation. Passing the vb pointer instead of the index makes more sense
>>>> in this new situation.
>>>>
>>>> This is also true for two other core functions: vb2_core_qbuf and vb2_core_expbuf.
>>>>
>>>>> struct vb2_buffer *vb;
>>>>> int ret;
>>>>> - vb = q->bufs[index];
>>>>> + vb = vb2_get_buffer(q, index);
>>>>> +
>>>>> + if (!vb) {
>>>>> + dprintk(q, 1, "can't find the requested buffer\n");
>>>>> + return -EINVAL;
>>>>> + }
>>>> Changing that avoids having to add this check, so it simplifies the code.
>>>>
>>>> I think that this change can be done in a separate patch before this one.
>>>>
>>>> It makes sense to apply that regardless of the remainder of this series.
>>>>
>>>>> +
>>>>> if (vb->state != VB2_BUF_STATE_DEQUEUED) {
>>>>> dprintk(q, 1, "invalid buffer state %s\n",
>>>>> vb2_state_name(vb->state));
>>>>> @@ -1624,7 +1681,11 @@ static int vb2_start_streaming(struct vb2_queue *q)
>>>>> * correctly return them to vb2.
>>>>> */
>>>>> for (i = 0; i < q->num_buffers; ++i) {
>>>>> - vb = q->bufs[i];
>>>>> + vb = vb2_get_buffer(q, i);
>>>>> +
>>>>> + if (!vb)
>>>>> + continue;
>>>>> +
>>>>> if (vb->state == VB2_BUF_STATE_ACTIVE)
>>>>> vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED);
>>>>> }
>>>>> @@ -1652,7 +1713,12 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
>>>>> return -EIO;
>>>>> }
>>>>> - vb = q->bufs[index];
>>>>> + vb = vb2_get_buffer(q, index);
>>>>> +
>>>>> + if (!vb) {
>>>>> + dprintk(q, 1, "can't find the requested buffer\n");
>>>>> + return -EINVAL;
>>>>> + }
>>>>> if (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
>>>>> q->requires_requests) {
>>>>> @@ -2028,12 +2094,18 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
>>>>> * to vb2 in stop_streaming().
>>>>> */
>>>>> if (WARN_ON(atomic_read(&q->owned_by_drv_count))) {
>>>>> - for (i = 0; i < q->num_buffers; ++i)
>>>>> - if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) {
>>>>> + for (i = 0; i < q->num_buffers; ++i) {
>>>>> + struct vb2_buffer *vb = vb2_get_buffer(q, i);
>>>>> +
>>>>> + if (!vb)
>>>>> + continue;
>>>>> +
>>>>> + if (vb->state == VB2_BUF_STATE_ACTIVE) {
>>>>> pr_warn("driver bug: stop_streaming operation is leaving buf %p in active state\n",
>>>>> - q->bufs[i]);
>>>>> - vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR);
>>>>> + vb);
>>>>> + vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
>>>>> }
>>>>> + }
>>>>> /* Must be zero now */
>>>>> WARN_ON(atomic_read(&q->owned_by_drv_count));
>>>>> }
>>>>> @@ -2067,9 +2139,14 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
>>>>> * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
>>>>> */
>>>>> for (i = 0; i < q->num_buffers; ++i) {
>>>>> - struct vb2_buffer *vb = q->bufs[i];
>>>>> - struct media_request *req = vb->req_obj.req;
>>>>> + struct vb2_buffer *vb;
>>>>> + struct media_request *req;
>>>>> +
>>>>> + vb = vb2_get_buffer(q, i);
>>>>> + if (!vb)
>>>>> + continue;
>>>>> + req = vb->req_obj.req;
>>>>> /*
>>>>> * If a request is associated with this buffer, then
>>>>> * call buf_request_cancel() to give the driver to complete()
>>>>> @@ -2219,7 +2296,10 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
>>>>> buffer = (off >> (PLANE_INDEX_SHIFT + PAGE_SHIFT)) & MAX_BUFFERS;
>>>>> plane = (off >> PAGE_SHIFT) & PLANE_INDEX_MASK;
>>>>> - vb = q->bufs[buffer];
>>>>> + vb = vb2_get_buffer(q, buffer);
>>>>> + if (!vb)
>>>>> + return -EINVAL;
>>>>> +
>>>>> if (vb->planes[plane].m.offset == off) {
>>>>> *_buffer = buffer;
>>>>> *_plane = plane;
>>>>> @@ -2262,7 +2342,12 @@ int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
>>>>> return -EINVAL;
>>>>> }
>>>>> - vb = q->bufs[index];
>>>>> + vb = vb2_get_buffer(q, index);
>>>>> +
>>>>> + if (!vb) {
>>>>> + dprintk(q, 1, "can't find the requested buffer\n");
>>>>> + return -EINVAL;
>>>>> + }
>>>>> if (plane >= vb->num_planes) {
>>>>> dprintk(q, 1, "buffer plane out of range\n");
>>>>> @@ -2339,7 +2424,13 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
>>>>> if (ret)
>>>>> goto unlock;
>>>>> - vb = q->bufs[buffer];
>>>>> + vb = vb2_get_buffer(q, buffer);
>>>>> +
>>>>> + if (!vb) {
>>>>> + dprintk(q, 1, "can't find the requested buffer\n");
>>>>> + ret = -EINVAL;
>>>>> + goto unlock;
>>>>> + }
>>>>> /*
>>>>> * MMAP requires page_aligned buffers.
>>>>> @@ -2396,7 +2487,12 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
>>>>> if (ret)
>>>>> goto unlock;
>>>>> - vb = q->bufs[buffer];
>>>>> + vb = vb2_get_buffer(q, buffer);
>>>>> + if (!vb) {
>>>>> + dprintk(q, 1, "can't find the requested buffer\n");
>>>>> + ret = -EINVAL;
>>>>> + goto unlock;
>>>>> + }
>>>>> vaddr = vb2_plane_vaddr(vb, plane);
>>>>> mutex_unlock(&q->mmap_lock);
>>>>> @@ -2625,6 +2721,7 @@ struct vb2_fileio_data {
>>>>> static int __vb2_init_fileio(struct vb2_queue *q, int read)
>>>>> {
>>>>> struct vb2_fileio_data *fileio;
>>>>> + struct vb2_buffer *vb;
>>>>> int i, ret;
>>>>> unsigned int count = 0;
>>>>> @@ -2679,7 +2776,13 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
>>>>> * Check if plane_count is correct
>>>>> * (multiplane buffers are not supported).
>>>>> */
>>>>> - if (q->bufs[0]->num_planes != 1) {
>>>>> + vb = vb2_get_buffer(q, 0);
>>>>> + if (!vb) {
>>>>> + ret = -EBUSY;
>>>>> + goto err_reqbufs;
>>>>> + }
>>>> This cannot happen. These fileio helper functions implement the read() support
>>>> and all the buffer allocation happens here. Userspace can never add or delete
>>>> buffers later, so there will never be holes. It is safe to assume that
>>>> vb2_get_buffer(q, i) will always return a valid vb pointer for i in the range
>>>> of 0 - q->num_buffers-1.
>>>>
>>>> Perhaps add a comment to that effect, but otherwise you can drop the checks.
>>>>
>>>>> +
>>>>> + if (vb->num_planes != 1) {
>>>>> ret = -EBUSY;
>>>>> goto err_reqbufs;
>>>>> }
>>>>> @@ -2688,12 +2791,17 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
>>>>> * Get kernel address of each buffer.
>>>>> */
>>>>> for (i = 0; i < q->num_buffers; i++) {
>>>>> - fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
>>>>> + vb = vb2_get_buffer(q, i);
>>>>> +
>>>>> + if (!vb)
>>>>> + continue;
>>>>> +
>>>>> + fileio->bufs[i].vaddr = vb2_plane_vaddr(vb, 0);
>>>>> if (fileio->bufs[i].vaddr == NULL) {
>>>>> ret = -EINVAL;
>>>>> goto err_reqbufs;
>>>>> }
>>>>> - fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
>>>>> + fileio->bufs[i].size = vb2_plane_size(vb, 0);
>>>>> }
>>>>> /*
>>>>> @@ -2821,15 +2929,18 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
>>>>> fileio->cur_index = index;
>>>>> buf = &fileio->bufs[index];
>>>>> - b = q->bufs[index];
>>>>> + b = vb2_get_buffer(q, index);
>>>>> +
>>>>> + if (!b)
>>>>> + return -EINVAL;
>>>>> /*
>>>>> * Get number of bytes filled by the driver
>>>>> */
>>>>> buf->pos = 0;
>>>>> buf->queued = 0;
>>>>> - buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
>>>>> - : vb2_plane_size(q->bufs[index], 0);
>>>>> + buf->size = read ? vb2_get_plane_payload(b, 0)
>>>>> + : vb2_plane_size(b, 0);
>>>>> /* Compensate for data_offset on read in the multiplanar case. */
>>>>> if (is_multiplanar && read &&
>>>>> b->planes[0].data_offset < buf->size) {
>>>>> @@ -2872,8 +2983,12 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
>>>>> * Queue next buffer if required.
>>>>> */
>>>>> if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
>>>>> - struct vb2_buffer *b = q->bufs[index];
>>>>> + struct vb2_buffer *b = vb2_get_buffer(q, index);
>>>>> + if (!b) {
>>>>> + dprintk(q, 1, "can't find the requested buffer\n");
>>>>> + return -EINVAL;
>>>>> + }
>>>>> /*
>>>>> * Check if this is the last buffer to read.
>>>>> */
>>>>> @@ -2899,7 +3014,7 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
>>>>> */
>>>>> buf->pos = 0;
>>>>> buf->queued = 1;
>>>>> - buf->size = vb2_plane_size(q->bufs[index], 0);
>>>>> + buf->size = vb2_plane_size(b, 0);
>>>>> fileio->q_count += 1;
>>>>> /*
>>>>> * If we are queuing up buffers for the first time, then
>>>>> @@ -2970,7 +3085,9 @@ static int vb2_thread(void *data)
>>>>> * Call vb2_dqbuf to get buffer back.
>>>>> */
>>>>> if (prequeue) {
>>>>> - vb = q->bufs[index++];
>>>>> + vb = vb2_get_buffer(q, index++);
>>>>> + if (!vb)
>>>>> + continue;
>>>>> prequeue--;
>>>>> } else {
>>>>> call_void_qop(q, wait_finish, q);
>>>>> @@ -2979,7 +3096,7 @@ static int vb2_thread(void *data)
>>>>> call_void_qop(q, wait_prepare, q);
>>>>> dprintk(q, 5, "file io: vb2_dqbuf result: %d\n", ret);
>>>>> if (!ret)
>>>>> - vb = q->bufs[index];
>>>>> + vb = vb2_get_buffer(q, index);
>>>>> }
>>>>> if (ret || threadio->stop)
>>>>> break;
>>>>> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>>>> index c7a54d82a55e..724135d41f7f 100644
>>>>> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>>>> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
>>>>> @@ -383,8 +383,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
>>>>> return -EINVAL;
>>>>> }
>>>>> - if (q->bufs[b->index] == NULL) {
>>>>> - /* Should never happen */
>>>>> + if (!vb2_get_buffer(q, b->index)) {
>>>>> dprintk(q, 1, "%s: buffer is NULL\n", opname);
>>>> How about:
>>>>
>>>> dprintk(q, 1, "%s: buffer %u was deleted\n", opname, b->index);
>>>>
>>>> although perhaps that change is more appropriate in patch 09/10?
>>>>
>>>> Regardless, once it is possible to delete buffers, then this message should be
>>>> adjusted accordingly.
>>>>
>>>>> return -EINVAL;
>>>>> }
>>>>> @@ -394,7 +393,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
>>>>> return -EINVAL;
>>>>> }
>>>>> - vb = q->bufs[b->index];
>>>>> + vb = vb2_get_buffer(q, b->index);
>>>> This can be moved up to the 'if (!vb2_get_buffer(q, b->index)) {' check above.
>>>> That avoids calling vb2_get_buffer twice.
>>>>
>>>>> vbuf = to_vb2_v4l2_buffer(vb);
>>>>> ret = __verify_planes_array(vb, b);
>>>>> if (ret)
>>>>> @@ -628,11 +627,18 @@ static const struct vb2_buf_ops v4l2_buf_ops = {
>>>>> struct vb2_buffer *vb2_find_buffer(struct vb2_queue *q, u64 timestamp)
>>>>> {
>>>>> unsigned int i;
>>>>> + struct vb2_buffer *vb2;
>>>>> - for (i = 0; i < q->num_buffers; i++)
>>>>> - if (q->bufs[i]->copied_timestamp &&
>>>>> - q->bufs[i]->timestamp == timestamp)
>>>>> - return vb2_get_buffer(q, i);
>>>> Perhaps add a comment here that this loop doesn't scale if there
>>>> is a really large number of buffers and something more efficient
>>>> will have to be found in that case.
>>>>
>>>>> + for (i = 0; i < q->num_buffers; i++) {
>>>>> + vb2 = vb2_get_buffer(q, i);
>>>>> +
>>>>> + if (!vb2)
>>>>> + continue;
>>>>> +
>>>>> + if (vb2->copied_timestamp &&
>>>>> + vb2->timestamp == timestamp)
>>>>> + return vb2;
>>>>> + }
>>>>> return NULL;
>>>>> }
>>>>> EXPORT_SYMBOL_GPL(vb2_find_buffer);
>>>>> @@ -664,7 +670,13 @@ int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
>>>>> dprintk(q, 1, "buffer index out of range\n");
>>>>> return -EINVAL;
>>>>> }
>>>>> - vb = q->bufs[b->index];
>>>>> + vb = vb2_get_buffer(q, b->index);
>>>>> +
>>>>> + if (!vb) {
>>>>> + dprintk(q, 1, "can't find the requested buffer\n");
>>>>> + return -EINVAL;
>>>>> + }
>>>>> +
>>>>> ret = __verify_planes_array(vb, b);
>>>>> if (!ret)
>>>>> vb2_core_querybuf(q, b->index, b);
>>>>> diff --git a/drivers/media/platform/amphion/vpu_dbg.c b/drivers/media/platform/amphion/vpu_dbg.c
>>>>> index 982c2c777484..a462d6fe4ea9 100644
>>>>> --- a/drivers/media/platform/amphion/vpu_dbg.c
>>>>> +++ b/drivers/media/platform/amphion/vpu_dbg.c
>>>>> @@ -140,11 +140,18 @@ static int vpu_dbg_instance(struct seq_file *s, void *data)
>>>>> vq = v4l2_m2m_get_src_vq(inst->fh.m2m_ctx);
>>>>> for (i = 0; i < vq->num_buffers; i++) {
>>>>> - struct vb2_buffer *vb = vq->bufs[i];
>>>>> - struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>>>>> + struct vb2_buffer *vb;
>>>>> + struct vb2_v4l2_buffer *vbuf;
>>>>> +
>>>>> + vb = vb2_get_buffer(vq, i);
>>>>> + if (!vb)
>>>>> + continue;
>>>>> if (vb->state == VB2_BUF_STATE_DEQUEUED)
>>>>> continue;
>>>>> +
>>>>> + vbuf = to_vb2_v4l2_buffer(vb);
>>>>> +
>>>>> num = scnprintf(str, sizeof(str),
>>>>> "output [%2d] state = %10s, %8s\n",
>>>>> i, vb2_stat_name[vb->state],
>>>>> @@ -155,11 +162,18 @@ static int vpu_dbg_instance(struct seq_file *s, void *data)
>>>>> vq = v4l2_m2m_get_dst_vq(inst->fh.m2m_ctx);
>>>>> for (i = 0; i < vq->num_buffers; i++) {
>>>>> - struct vb2_buffer *vb = vq->bufs[i];
>>>>> - struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>>>>> + struct vb2_buffer *vb;
>>>>> + struct vb2_v4l2_buffer *vbuf;
>>>>> +
>>>>> + vb = vb2_get_buffer(vq, i);
>>>>> + if (!vb)
>>>>> + continue;
>>>>> if (vb->state == VB2_BUF_STATE_DEQUEUED)
>>>>> continue;
>>>>> +
>>>>> + vbuf = to_vb2_v4l2_buffer(vb);
>>>>> +
>>>>> num = scnprintf(str, sizeof(str),
>>>>> "capture[%2d] state = %10s, %8s\n",
>>>>> i, vb2_stat_name[vb->state],
>>>> This can be a separate patch, right? It doesn't depend on any core changes.
>>>>
>>>> And this can also be applied before this patch.
>>> Hans, I would like to clarify this comment (and the following Ditto).
>>> Are you against use vb2_get_buffer() outside core ?
>>> or testing vb2_get_buffer() result ?
>>> The goal of this patch was to remove all access like vq->bufs[i] and to make
>>> sure that vb buffer are always valid.
>> Sorry for the confusion. I meant that AFAICS each of these driver changes can be
>> done in the separate patch and that those separate patches can be applied before
>> this patch. I.e., they are independent.
>>
>> I always prefer specific driver changes to be done as separate patches rather
>> than one patch modifying a lot of drivers in one go. That is not always possible,
>> of course, but in this case I think it is fine, unless I missed something.
>
> All changes in the drivers use vb2_get_buffer() which is introduced in this patch
> so I can't do them before.
> If you want I can make a patch per driver but after this patch.
??? vb2_get_buffer() has been defined in include/media/videobuf2-core.h for a long
time (2019 to be precise).
Regards,
Hans
>
> Regards,
> Benjamin
>
>>
>> Regards,
>>
>> Hans
>>
>>> Regards,
>>> Benjamin
>>>
>>>>> diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
>>>>> index 621038aab116..62910a1b8a98 100644
>>>>> --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
>>>>> +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
>>>>> @@ -603,7 +603,11 @@ static int mtk_jpeg_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
>>>>> return -EINVAL;
>>>>> }
>>>>> - vb = vq->bufs[buf->index];
>>>>> + vb = vb2_get_buffer(vq, buf->index);
>>>>> + if (!vb) {
>>>>> + dev_err(ctx->jpeg->dev, "buffer not found\n");
>>>>> + return -EINVAL;
>>>>> + }
>>>>> jpeg_src_buf = mtk_jpeg_vb2_to_srcbuf(vb);
>>>>> jpeg_src_buf->bs_size = buf->m.planes[0].bytesused;
>>>>>
>>>> Ditto.
>>>>
>>>>> diff --git a/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c b/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c
>>>>> index e393e3e668f8..3d2ae0e1b5b6 100644
>>>>> --- a/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c
>>>>> +++ b/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_vp9_req_lat_if.c
>>>>> @@ -1696,7 +1696,7 @@ static int vdec_vp9_slice_setup_core_buffer(struct vdec_vp9_slice_instance *inst
>>>>> /* update internal buffer's width/height */
>>>>> for (i = 0; i < vq->num_buffers; i++) {
>>>>> - if (vb == vq->bufs[i]) {
>>>>> + if (vb == vb2_get_buffer(vq, i)) {
>>>>> instance->dpb[i].width = w;
>>>>> instance->dpb[i].height = h;
>>>>> break;
>>>> Ditto.
>>>>
>>>>> diff --git a/drivers/media/platform/st/sti/hva/hva-v4l2.c b/drivers/media/platform/st/sti/hva/hva-v4l2.c
>>>>> index 3a848ca32a0e..326be09bdb55 100644
>>>>> --- a/drivers/media/platform/st/sti/hva/hva-v4l2.c
>>>>> +++ b/drivers/media/platform/st/sti/hva/hva-v4l2.c
>>>>> @@ -577,6 +577,10 @@ static int hva_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
>>>>> }
>>>>> vb2_buf = vb2_get_buffer(vq, buf->index);
>>>>> + if (!vb2_buf) {
>>>>> + dev_dbg(dev, "%s buffer index %d not found\n", ctx->name, buf->index);
>>>>> + return -EINVAL;
>>>>> + }
>>>>> stream = to_hva_stream(to_vb2_v4l2_buffer(vb2_buf));
>>>>> stream->bytesused = buf->bytesused;
>>>>> }
>>>> Ditto.
>>>>
>>>>> diff --git a/drivers/media/test-drivers/visl/visl-dec.c b/drivers/media/test-drivers/visl/visl-dec.c
>>>>> index 318d675e5668..ba20ea998d19 100644
>>>>> --- a/drivers/media/test-drivers/visl/visl-dec.c
>>>>> +++ b/drivers/media/test-drivers/visl/visl-dec.c
>>>>> @@ -290,13 +290,20 @@ static void visl_tpg_fill(struct visl_ctx *ctx, struct visl_run *run)
>>>>> for (i = 0; i < out_q->num_buffers; i++) {
>>>>> char entry[] = "index: %u, state: %s, request_fd: %d, ";
>>>>> u32 old_len = len;
>>>>> - char *q_status = visl_get_vb2_state(out_q->bufs[i]->state);
>>>>> + struct vb2_buffer *vb2;
>>>>> + char *q_status;
>>>>> +
>>>>> + vb2 = vb2_get_buffer(out_q, i);
>>>>> + if (!vb2)
>>>>> + continue;
>>>>> +
>>>>> + q_status = visl_get_vb2_state(vb2->state);
>>>>> len += scnprintf(&buf[len], TPG_STR_BUF_SZ - len,
>>>>> entry, i, q_status,
>>>>> - to_vb2_v4l2_buffer(out_q->bufs[i])->request_fd);
>>>>> + to_vb2_v4l2_buffer(vb2)->request_fd);
>>>>> - len += visl_fill_bytesused(to_vb2_v4l2_buffer(out_q->bufs[i]),
>>>>> + len += visl_fill_bytesused(to_vb2_v4l2_buffer(vb2),
>>>>> &buf[len],
>>>>> TPG_STR_BUF_SZ - len);
>>>>> @@ -342,13 +349,20 @@ static void visl_tpg_fill(struct visl_ctx *ctx, struct visl_run *run)
>>>>> len = 0;
>>>>> for (i = 0; i < cap_q->num_buffers; i++) {
>>>>> u32 old_len = len;
>>>>> - char *q_status = visl_get_vb2_state(cap_q->bufs[i]->state);
>>>>> + struct vb2_buffer *vb2;
>>>>> + char *q_status;
>>>>> +
>>>>> + vb2 = vb2_get_buffer(cap_q, i);
>>>>> + if (!vb2)
>>>>> + continue;
>>>>> +
>>>>> + q_status = visl_get_vb2_state(vb2->state);
>>>>> len += scnprintf(&buf[len], TPG_STR_BUF_SZ - len,
>>>>> "index: %u, status: %s, timestamp: %llu, is_held: %d",
>>>>> - cap_q->bufs[i]->index, q_status,
>>>>> - cap_q->bufs[i]->timestamp,
>>>>> - to_vb2_v4l2_buffer(cap_q->bufs[i])->is_held);
>>>>> + vb2->index, q_status,
>>>>> + vb2->timestamp,
>>>>> + to_vb2_v4l2_buffer(vb2)->is_held);
>>>>> tpg_gen_text(&ctx->tpg, basep, line++ * line_height, 16, &buf[old_len]);
>>>>> frame_dprintk(ctx->dev, run->dst->sequence, "%s", &buf[old_len]);
>>>> Ditto.
>>>>
>>>>> diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
>>>>> index d2174156573a..4b65c69fa60d 100644
>>>>> --- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
>>>>> +++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
>>>>> @@ -1061,7 +1061,7 @@ static int atomisp_dqbuf_wrapper(struct file *file, void *fh, struct v4l2_buffer
>>>>> if (ret)
>>>>> return ret;
>>>>> - vb = pipe->vb_queue.bufs[buf->index];
>>>>> + vb = vb2_get_buffer(&pipe->vb_queue, buf->index);
>>>>> frame = vb_to_frame(vb);
>>>>> buf->reserved = asd->frame_status[buf->index];
>>>> Ditto.
>>>>
>>>> Background: I think it is really useful to merge a lot of the groundwork early
>>>> on, where possible. It simplifies the remainder of the patch series.
>>>>
>>>> Regards,
>>>>
>>>> Hans
>>>>