[v7,02/28] v4l2: handle restricted memory flags in queue setup
Commit Message
From: Jeffrey Kardatzke <jkardatzke@google.com>
Validates the restricted memory flags when setting up a queue and
ensures the queue has the proper capability.
Signed-off-by: Jeffrey Kardatzke <jkardatzke@google.com>
Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
[Yunfei: Change reviewer's comments]
---
.../media/common/videobuf2/videobuf2-core.c | 29 +++++++++++++++++++
.../media/common/videobuf2/videobuf2-v4l2.c | 4 ++-
2 files changed, 32 insertions(+), 1 deletion(-)
Comments
On 20/07/2024 09:15, Yunfei Dong wrote:
> From: Jeffrey Kardatzke <jkardatzke@google.com>
>
> Validates the restricted memory flags when setting up a queue and
> ensures the queue has the proper capability.
>
> Signed-off-by: Jeffrey Kardatzke <jkardatzke@google.com>
> Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> [Yunfei: Change reviewer's comments]
> ---
> .../media/common/videobuf2/videobuf2-core.c | 29 +++++++++++++++++++
> .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++-
> 2 files changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index 0217392fcc0d..44080121f37e 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -830,6 +830,23 @@ static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
> return true;
> }
>
> +static bool verify_restricted_mem_flags(struct vb2_queue *q, bool restricted_mem)
> +{
> + if (restricted_mem != q->restricted_mem) {
> + dprintk(q, 1, "restricted memory model mismatch\n");
> + return false;
> + }
> +
> + return true;
> +}
> +
> +static inline int restricted_mem_mismatch(bool restricted_mem, struct vb2_queue *q,
> + enum vb2_memory memory)
> +{
> + return restricted_mem && (!q->allow_restricted_mem || memory != VB2_MEMORY_DMABUF) ?
> + -1 : 0;
Returning -1 is odd, just return a bool here.
> +}
> +
> static int vb2_core_allocated_buffers_storage(struct vb2_queue *q)
> {
> if (!q->bufs)
> @@ -863,6 +880,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int q_num_bufs = vb2_get_num_buffers(q);
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> + bool restricted_mem = flags & V4L2_MEMORY_FLAG_RESTRICTED;
> unsigned int i, first_index;
> int ret = 0;
>
> @@ -906,6 +924,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> return 0;
> }
>
> + if (restricted_mem_mismatch(restricted_mem, q, memory))
> + return -EINVAL;
> +
> /*
> * Make sure the requested values and current defaults are sane.
> */
> @@ -923,6 +944,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> if (ret)
> return ret;
> set_queue_coherency(q, non_coherent_mem);
> + q->restricted_mem = restricted_mem;
>
> /*
> * Ask the driver how many buffers and planes per buffer it requires.
> @@ -1031,6 +1053,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> unsigned int q_num_bufs = vb2_get_num_buffers(q);
> + bool restricted_mem = flags & V4L2_MEMORY_FLAG_RESTRICTED;
> bool no_previous_buffers = !q_num_bufs;
> int ret = 0;
>
> @@ -1039,6 +1062,9 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> return -ENOBUFS;
> }
>
> + if (restricted_mem_mismatch(restricted_mem, q, memory))
> + return -EINVAL;
> +
> if (no_previous_buffers) {
> if (q->waiting_in_dqbuf && *count) {
> dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
> @@ -1057,6 +1083,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> return ret;
> q->waiting_for_buffers = !q->is_output;
> set_queue_coherency(q, non_coherent_mem);
> + q->restricted_mem = restricted_mem;
> } else {
> if (q->memory != memory) {
> dprintk(q, 1, "memory model mismatch\n");
> @@ -1064,6 +1091,8 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> }
> if (!verify_coherency_flags(q, non_coherent_mem))
> return -EINVAL;
> + if (!verify_restricted_mem_flags(q, restricted_mem))
> + return -EINVAL;
> }
>
> num_buffers = min(*count, q->max_num_buffers - q_num_bufs);
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 293f3d5f1c4e..9ee24e537e0c 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -682,7 +682,7 @@ static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory,
> *flags = 0;
> } else {
> /* Clear all unknown flags. */
> - *flags &= V4L2_MEMORY_FLAG_NON_COHERENT;
> + *flags &= V4L2_MEMORY_FLAG_NON_COHERENT | V4L2_MEMORY_FLAG_RESTRICTED;
> }
>
> *caps |= V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;
> @@ -698,6 +698,8 @@ static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory,
> *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
> if (q->supports_requests)
> *caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
> + if (q->allow_restricted_mem && q->io_modes & VB2_DMABUF)
I think this io_modes test can be dropped.
But it might be useful to add a WARN_ON in vb2_core_queue_init where
this is checked. The WARN_ONs in that function really protect against
driver bugs, making sure the driver doesn't pass incompatible combinations.
Regards,
Hans
> + *caps |= V4L2_BUF_CAP_SUPPORTS_RESTRICTED_MEM;
> if (max_num_bufs) {
> *max_num_bufs = q->max_num_buffers;
> *caps |= V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS;
On 20/07/2024 09:15, Yunfei Dong wrote:
> From: Jeffrey Kardatzke <jkardatzke@google.com>
>
> Validates the restricted memory flags when setting up a queue and
> ensures the queue has the proper capability.
>
> Signed-off-by: Jeffrey Kardatzke <jkardatzke@google.com>
> Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> [Yunfei: Change reviewer's comments]
> ---
> .../media/common/videobuf2/videobuf2-core.c | 29 +++++++++++++++++++
> .../media/common/videobuf2/videobuf2-v4l2.c | 4 ++-
> 2 files changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index 0217392fcc0d..44080121f37e 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -830,6 +830,23 @@ static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
> return true;
> }
>
> +static bool verify_restricted_mem_flags(struct vb2_queue *q, bool restricted_mem)
> +{
> + if (restricted_mem != q->restricted_mem) {
> + dprintk(q, 1, "restricted memory model mismatch\n");
> + return false;
> + }
> +
> + return true;
> +}
> +
> +static inline int restricted_mem_mismatch(bool restricted_mem, struct vb2_queue *q,
> + enum vb2_memory memory)
> +{
> + return restricted_mem && (!q->allow_restricted_mem || memory != VB2_MEMORY_DMABUF) ?
> + -1 : 0;
> +}
> +
> static int vb2_core_allocated_buffers_storage(struct vb2_queue *q)
> {
> if (!q->bufs)
> @@ -863,6 +880,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned int q_num_bufs = vb2_get_num_buffers(q);
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> + bool restricted_mem = flags & V4L2_MEMORY_FLAG_RESTRICTED;
> unsigned int i, first_index;
> int ret = 0;
>
> @@ -906,6 +924,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> return 0;
> }
>
> + if (restricted_mem_mismatch(restricted_mem, q, memory))
> + return -EINVAL;
> +
> /*
> * Make sure the requested values and current defaults are sane.
> */
> @@ -923,6 +944,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> if (ret)
> return ret;
> set_queue_coherency(q, non_coherent_mem);
> + q->restricted_mem = restricted_mem;
>
> /*
> * Ask the driver how many buffers and planes per buffer it requires.
> @@ -1031,6 +1053,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> unsigned plane_sizes[VB2_MAX_PLANES] = { };
> bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> unsigned int q_num_bufs = vb2_get_num_buffers(q);
> + bool restricted_mem = flags & V4L2_MEMORY_FLAG_RESTRICTED;
> bool no_previous_buffers = !q_num_bufs;
> int ret = 0;
>
> @@ -1039,6 +1062,9 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> return -ENOBUFS;
> }
>
> + if (restricted_mem_mismatch(restricted_mem, q, memory))
> + return -EINVAL;
> +
> if (no_previous_buffers) {
> if (q->waiting_in_dqbuf && *count) {
> dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
> @@ -1057,6 +1083,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> return ret;
> q->waiting_for_buffers = !q->is_output;
> set_queue_coherency(q, non_coherent_mem);
> + q->restricted_mem = restricted_mem;
> } else {
> if (q->memory != memory) {
> dprintk(q, 1, "memory model mismatch\n");
> @@ -1064,6 +1091,8 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
> }
> if (!verify_coherency_flags(q, non_coherent_mem))
> return -EINVAL;
> + if (!verify_restricted_mem_flags(q, restricted_mem))
> + return -EINVAL;
> }
>
> num_buffers = min(*count, q->max_num_buffers - q_num_bufs);
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 293f3d5f1c4e..9ee24e537e0c 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -682,7 +682,7 @@ static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory,
> *flags = 0;
Hmm, unless I am mistaken, this clears all flags. So if memory is DMABUF, then
the V4L2_MEMORY_FLAG_RESTRICTED is just overwritten with 0. And that's what will
be passed to vb2_core_reqbufs.
So how can this work? I'm not sure how you can have tested this.
In any case, this function should change and do this instead:
/* Clear all unknown flags. */
*flags &= V4L2_MEMORY_FLAG_NON_COHERENT | V4L2_MEMORY_FLAG_RESTRICTED;
if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP)
*flags &= ~V4L2_MEMORY_FLAG_NON_COHERENT;
I considered whether V4L2_MEMORY_FLAG_RESTRICTED should be cleared if memory
wasn't DMABUF, but I don't think that is right: you want to see an error
returned if you try such a combination.
> } else {
> /* Clear all unknown flags. */
> - *flags &= V4L2_MEMORY_FLAG_NON_COHERENT;
> + *flags &= V4L2_MEMORY_FLAG_NON_COHERENT | V4L2_MEMORY_FLAG_RESTRICTED;
> }
>
> *caps |= V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;
> @@ -698,6 +698,8 @@ static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory,
> *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
> if (q->supports_requests)
> *caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
> + if (q->allow_restricted_mem && q->io_modes & VB2_DMABUF)
> + *caps |= V4L2_BUF_CAP_SUPPORTS_RESTRICTED_MEM;
> if (max_num_bufs) {
> *max_num_bufs = q->max_num_buffers;
> *caps |= V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS;
What appears to be missing in this patch is what happens if you pass unrestricted
memory to a queue that is configured for restricted memory: there does not appear
to be a check for that. Or is that allowed? If so, that should be documented.
And what happens if you pass a dmabuf for restricted memory to a queue that expects
unrestricted memory? You want to get a nice error code for that (EACCES/EPERM, I
never quite know which is the right one for that). That would apply to VIDIOC_QBUF
and VIDIOC_PREPARE_BUF. This assumes you can easily query a dmabuf fd to see whether
it is in restricted memory or not. I'm not sure if that is the case today.
I also think that it would be useful to add a V4L2_BUF_FLAG_RESTRICTED_MEM flag
that vb2 will return to userspace if the queue is configured for restricted memory.
That will indicate to the application that the buffer indeed represents a buffer
in restricted memory.
Regards,
Hans
@@ -830,6 +830,23 @@ static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
return true;
}
+static bool verify_restricted_mem_flags(struct vb2_queue *q, bool restricted_mem)
+{
+ if (restricted_mem != q->restricted_mem) {
+ dprintk(q, 1, "restricted memory model mismatch\n");
+ return false;
+ }
+
+ return true;
+}
+
+static inline int restricted_mem_mismatch(bool restricted_mem, struct vb2_queue *q,
+ enum vb2_memory memory)
+{
+ return restricted_mem && (!q->allow_restricted_mem || memory != VB2_MEMORY_DMABUF) ?
+ -1 : 0;
+}
+
static int vb2_core_allocated_buffers_storage(struct vb2_queue *q)
{
if (!q->bufs)
@@ -863,6 +880,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int q_num_bufs = vb2_get_num_buffers(q);
unsigned plane_sizes[VB2_MAX_PLANES] = { };
bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
+ bool restricted_mem = flags & V4L2_MEMORY_FLAG_RESTRICTED;
unsigned int i, first_index;
int ret = 0;
@@ -906,6 +924,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
return 0;
}
+ if (restricted_mem_mismatch(restricted_mem, q, memory))
+ return -EINVAL;
+
/*
* Make sure the requested values and current defaults are sane.
*/
@@ -923,6 +944,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
if (ret)
return ret;
set_queue_coherency(q, non_coherent_mem);
+ q->restricted_mem = restricted_mem;
/*
* Ask the driver how many buffers and planes per buffer it requires.
@@ -1031,6 +1053,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned plane_sizes[VB2_MAX_PLANES] = { };
bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
unsigned int q_num_bufs = vb2_get_num_buffers(q);
+ bool restricted_mem = flags & V4L2_MEMORY_FLAG_RESTRICTED;
bool no_previous_buffers = !q_num_bufs;
int ret = 0;
@@ -1039,6 +1062,9 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
return -ENOBUFS;
}
+ if (restricted_mem_mismatch(restricted_mem, q, memory))
+ return -EINVAL;
+
if (no_previous_buffers) {
if (q->waiting_in_dqbuf && *count) {
dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
@@ -1057,6 +1083,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
return ret;
q->waiting_for_buffers = !q->is_output;
set_queue_coherency(q, non_coherent_mem);
+ q->restricted_mem = restricted_mem;
} else {
if (q->memory != memory) {
dprintk(q, 1, "memory model mismatch\n");
@@ -1064,6 +1091,8 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
}
if (!verify_coherency_flags(q, non_coherent_mem))
return -EINVAL;
+ if (!verify_restricted_mem_flags(q, restricted_mem))
+ return -EINVAL;
}
num_buffers = min(*count, q->max_num_buffers - q_num_bufs);
@@ -682,7 +682,7 @@ static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory,
*flags = 0;
} else {
/* Clear all unknown flags. */
- *flags &= V4L2_MEMORY_FLAG_NON_COHERENT;
+ *flags &= V4L2_MEMORY_FLAG_NON_COHERENT | V4L2_MEMORY_FLAG_RESTRICTED;
}
*caps |= V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;
@@ -698,6 +698,8 @@ static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory,
*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
if (q->supports_requests)
*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
+ if (q->allow_restricted_mem && q->io_modes & VB2_DMABUF)
+ *caps |= V4L2_BUF_CAP_SUPPORTS_RESTRICTED_MEM;
if (max_num_bufs) {
*max_num_bufs = q->max_num_buffers;
*caps |= V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS;