Commit fac710e4 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab

[media] vb2: fix nasty vb2_thread regression

The vb2_thread implementation was made generic and was moved from
videobuf2-v4l2.c to videobuf2-core.c in commit af3bac1a. Unfortunately
that clearly was never tested since it broke read() causing NULL address
references.

The root cause was confused handling of vb2_buffer vs v4l2_buffer (the pb
pointer in various core functions).

The v4l2_buffer no longer exists after moving the code into the core and
it is no longer needed. However, the vb2_thread code passed a pointer to
a vb2_buffer to the core functions were a v4l2_buffer pointer was expected
and vb2_thread expected that the vb2_buffer fields would be filled in
correctly.

This is obviously wrong since v4l2_buffer != vb2_buffer. Note that the
pb pointer is a void pointer, so no type-checking took place.

This patch fixes this problem:

1) allow pb to be NULL for vb2_core_(d)qbuf. The vb2_thread code will use
   a NULL pointer here since they don't care about v4l2_buffer anyway.
2) let vb2_core_dqbuf pass back the index of the received buffer. This is
   all vb2_thread needs: this index is the index into the q->bufs array
   and vb2_thread just gets the vb2_buffer from there.
3) the fileio->b pointer (that originally contained a v4l2_buffer) is
   removed altogether since it is no longer needed.

Tested with vivid and the cobalt driver.

Cc: stable@vger.kernel.org # Kernel >= 4.3
Signed-off-by: 's avatarHans Verkuil <hans.verkuil@cisco.com>
Reported-by: 's avatarMatthias Schwarzott <zzam@gentoo.org>
Signed-off-by: 's avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent e8beb023
......@@ -1063,8 +1063,11 @@ EXPORT_SYMBOL_GPL(vb2_discard_done);
*/
static int __qbuf_mmap(struct vb2_buffer *vb, const void *pb)
{
int ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
vb, pb, vb->planes);
int ret = 0;
if (pb)
ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
vb, pb, vb->planes);
return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
}
......@@ -1077,14 +1080,16 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb)
struct vb2_queue *q = vb->vb2_queue;
void *mem_priv;
unsigned int plane;
int ret;
int ret = 0;
enum dma_data_direction dma_dir =
q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
bool reacquired = vb->planes[0].mem_priv == NULL;
memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
/* Copy relevant information provided by the userspace */
ret = call_bufop(vb->vb2_queue, fill_vb2_buffer, vb, pb, planes);
if (pb)
ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
vb, pb, planes);
if (ret)
return ret;
......@@ -1192,14 +1197,16 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const void *pb)
struct vb2_queue *q = vb->vb2_queue;
void *mem_priv;
unsigned int plane;
int ret;
int ret = 0;
enum dma_data_direction dma_dir =
q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
bool reacquired = vb->planes[0].mem_priv == NULL;
memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
/* Copy relevant information provided by the userspace */
ret = call_bufop(vb->vb2_queue, fill_vb2_buffer, vb, pb, planes);
if (pb)
ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
vb, pb, planes);
if (ret)
return ret;
......@@ -1520,7 +1527,8 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
q->waiting_for_buffers = false;
vb->state = VB2_BUF_STATE_QUEUED;
call_void_bufop(q, copy_timestamp, vb, pb);
if (pb)
call_void_bufop(q, copy_timestamp, vb, pb);
trace_vb2_qbuf(q, vb);
......@@ -1532,7 +1540,8 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
__enqueue_in_driver(vb);
/* Fill buffer information for the userspace */
call_void_bufop(q, fill_user_buffer, vb, pb);
if (pb)
call_void_bufop(q, fill_user_buffer, vb, pb);
/*
* If streamon has been called, and we haven't yet called
......@@ -1731,7 +1740,8 @@ static void __vb2_dqbuf(struct vb2_buffer *vb)
* The return values from this function are intended to be directly returned
* from vidioc_dqbuf handler in driver.
*/
int vb2_core_dqbuf(struct vb2_queue *q, void *pb, bool nonblocking)
int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
bool nonblocking)
{
struct vb2_buffer *vb = NULL;
int ret;
......@@ -1754,8 +1764,12 @@ int vb2_core_dqbuf(struct vb2_queue *q, void *pb, bool nonblocking)
call_void_vb_qop(vb, buf_finish, vb);
if (pindex)
*pindex = vb->index;
/* Fill buffer information for the userspace */
call_void_bufop(q, fill_user_buffer, vb, pb);
if (pb)
call_void_bufop(q, fill_user_buffer, vb, pb);
/* Remove from videobuf queue */
list_del(&vb->queued_entry);
......@@ -1828,7 +1842,7 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
* that's done in dqbuf, but that's not going to happen when we
* cancel the whole queue. Note: this code belongs here, not in
* __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
* call to __fill_v4l2_buffer() after buf_finish(). That order can't
* call to __fill_user_buffer() after buf_finish(). That order can't
* be changed, so we can't move the buf_finish() to __vb2_dqbuf().
*/
for (i = 0; i < q->num_buffers; ++i) {
......@@ -2357,7 +2371,6 @@ struct vb2_fileio_data {
unsigned int count;
unsigned int type;
unsigned int memory;
struct vb2_buffer *b;
struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
unsigned int cur_index;
unsigned int initial_index;
......@@ -2410,12 +2423,6 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
if (fileio == NULL)
return -ENOMEM;
fileio->b = kzalloc(q->buf_struct_size, GFP_KERNEL);
if (fileio->b == NULL) {
kfree(fileio);
return -ENOMEM;
}
fileio->read_once = q->fileio_read_once;
fileio->write_immediately = q->fileio_write_immediately;
......@@ -2460,13 +2467,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
* Queue all buffers.
*/
for (i = 0; i < q->num_buffers; i++) {
struct vb2_buffer *b = fileio->b;
memset(b, 0, q->buf_struct_size);
b->type = q->type;
b->memory = q->memory;
b->index = i;
ret = vb2_core_qbuf(q, i, b);
ret = vb2_core_qbuf(q, i, NULL);
if (ret)
goto err_reqbufs;
fileio->bufs[i].queued = 1;
......@@ -2511,7 +2512,6 @@ static int __vb2_cleanup_fileio(struct vb2_queue *q)
q->fileio = NULL;
fileio->count = 0;
vb2_core_reqbufs(q, fileio->memory, &fileio->count);
kfree(fileio->b);
kfree(fileio);
dprintk(3, "file io emulator closed\n");
}
......@@ -2539,7 +2539,8 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
* else is able to provide this information with the write() operation.
*/
bool copy_timestamp = !read && q->copy_timestamp;
int ret, index;
unsigned index;
int ret;
dprintk(3, "mode %s, offset %ld, count %zd, %sblocking\n",
read ? "read" : "write", (long)*ppos, count,
......@@ -2564,22 +2565,20 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
*/
index = fileio->cur_index;
if (index >= q->num_buffers) {
struct vb2_buffer *b = fileio->b;
struct vb2_buffer *b;
/*
* Call vb2_dqbuf to get buffer back.
*/
memset(b, 0, q->buf_struct_size);
b->type = q->type;
b->memory = q->memory;
ret = vb2_core_dqbuf(q, b, nonblock);
ret = vb2_core_dqbuf(q, &index, NULL, nonblock);
dprintk(5, "vb2_dqbuf result: %d\n", ret);
if (ret)
return ret;
fileio->dq_count += 1;
fileio->cur_index = index = b->index;
fileio->cur_index = index;
buf = &fileio->bufs[index];
b = q->bufs[index];
/*
* Get number of bytes filled by the driver
......@@ -2630,7 +2629,7 @@ 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 = fileio->b;
struct vb2_buffer *b = q->bufs[index];
/*
* Check if this is the last buffer to read.
......@@ -2643,15 +2642,11 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
/*
* Call vb2_qbuf and give buffer to the driver.
*/
memset(b, 0, q->buf_struct_size);
b->type = q->type;
b->memory = q->memory;
b->index = index;
b->planes[0].bytesused = buf->pos;
if (copy_timestamp)
b->timestamp = ktime_get_ns();
ret = vb2_core_qbuf(q, index, b);
ret = vb2_core_qbuf(q, index, NULL);
dprintk(5, "vb2_dbuf result: %d\n", ret);
if (ret)
return ret;
......@@ -2713,10 +2708,9 @@ static int vb2_thread(void *data)
{
struct vb2_queue *q = data;
struct vb2_threadio_data *threadio = q->threadio;
struct vb2_fileio_data *fileio = q->fileio;
bool copy_timestamp = false;
int prequeue = 0;
int index = 0;
unsigned prequeue = 0;
unsigned index = 0;
int ret = 0;
if (q->is_output) {
......@@ -2728,37 +2722,34 @@ static int vb2_thread(void *data)
for (;;) {
struct vb2_buffer *vb;
struct vb2_buffer *b = fileio->b;
/*
* Call vb2_dqbuf to get buffer back.
*/
memset(b, 0, q->buf_struct_size);
b->type = q->type;
b->memory = q->memory;
if (prequeue) {
b->index = index++;
vb = q->bufs[index++];
prequeue--;
} else {
call_void_qop(q, wait_finish, q);
if (!threadio->stop)
ret = vb2_core_dqbuf(q, b, 0);
ret = vb2_core_dqbuf(q, &index, NULL, 0);
call_void_qop(q, wait_prepare, q);
dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
if (!ret)
vb = q->bufs[index];
}
if (ret || threadio->stop)
break;
try_to_freeze();
vb = q->bufs[b->index];
if (b->state == VB2_BUF_STATE_DONE)
if (vb->state == VB2_BUF_STATE_DONE)
if (threadio->fnc(vb, threadio->priv))
break;
call_void_qop(q, wait_finish, q);
if (copy_timestamp)
b->timestamp = ktime_get_ns();;
vb->timestamp = ktime_get_ns();;
if (!threadio->stop)
ret = vb2_core_qbuf(q, b->index, b);
ret = vb2_core_qbuf(q, vb->index, NULL);
call_void_qop(q, wait_prepare, q);
if (ret || threadio->stop)
break;
......
......@@ -625,7 +625,7 @@ static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b,
return -EINVAL;
}
ret = vb2_core_dqbuf(q, b, nonblocking);
ret = vb2_core_dqbuf(q, NULL, b, nonblocking);
return ret;
}
......
......@@ -533,7 +533,8 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
const unsigned int requested_sizes[]);
int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
int vb2_core_dqbuf(struct vb2_queue *q, void *pb, bool nonblocking);
int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
bool nonblocking);
int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
......
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