Remove VB2_MAX_FRAME buffer limit since Xarray allows to store
more than that.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
---
drivers/media/common/videobuf2/videobuf2-core.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index f1ff7af34a9f..86e1e926fa45 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -455,9 +455,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
struct vb2_buffer *vb;
int ret;
- /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
+ /* Ensure that q->num_buffers + num_buffers is UINT_MAX */
num_buffers = min_t(unsigned int, num_buffers,
- VB2_MAX_FRAME - q->num_buffers);
+ UINT_MAX - q->num_buffers);
for (buffer = 0; buffer < num_buffers; ++buffer) {
/* Allocate vb2 buffer structures */
@@ -858,9 +858,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
/*
* Make sure the requested values and current defaults are sane.
*/
- WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
+ WARN_ON(q->min_buffers_needed > UINT_MAX);
num_buffers = max_t(unsigned int, *count, q->min_buffers_needed);
- num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
+ num_buffers = min_t(unsigned int, num_buffers, UINT_MAX);
memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
/*
* Set this now to ensure that drivers see the correct q->memory value
@@ -976,11 +976,6 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
bool no_previous_buffers = !q->num_buffers;
int ret;
- if (q->num_buffers == VB2_MAX_FRAME) {
- dprintk(q, 1, "maximum number of buffers already allocated\n");
- return -ENOBUFS;
- }
-
if (no_previous_buffers) {
if (q->waiting_in_dqbuf && *count) {
dprintk(q, 1, "another dup()ped fd is waiting for a buffer\n");
@@ -1005,7 +1000,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
return -EINVAL;
}
- num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
+ num_buffers = min(*count, UINT_MAX - q->num_buffers);
if (requested_planes && requested_sizes) {
num_planes = requested_planes;
--
2.39.2On Thu, Jun 22, 2023 at 03:13:41PM +0200, Benjamin Gaignard wrote:
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index f1ff7af34a9f..86e1e926fa45 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -455,9 +455,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> struct vb2_buffer *vb;
> int ret;
>
> - /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
> + /* Ensure that q->num_buffers + num_buffers is UINT_MAX */
> num_buffers = min_t(unsigned int, num_buffers,
> - VB2_MAX_FRAME - q->num_buffers);
> + UINT_MAX - q->num_buffers);
>
> for (buffer = 0; buffer < num_buffers; ++buffer) {
> /* Allocate vb2 buffer structures */
Ah... Here's one of the integer overflow bugs I was talking about. The
__vb2_queue_alloc() function returns an int so if num_buffers goes over
INT_MAX we are hosed.
regards,
dan carpenter
Le 22/06/2023 à 16:11, Dan Carpenter a écrit :
> On Thu, Jun 22, 2023 at 03:13:41PM +0200, Benjamin Gaignard wrote:
>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>> index f1ff7af34a9f..86e1e926fa45 100644
>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>> @@ -455,9 +455,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>> struct vb2_buffer *vb;
>> int ret;
>>
>> - /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
>> + /* Ensure that q->num_buffers + num_buffers is UINT_MAX */
>> num_buffers = min_t(unsigned int, num_buffers,
>> - VB2_MAX_FRAME - q->num_buffers);
>> + UINT_MAX - q->num_buffers);
>>
>> for (buffer = 0; buffer < num_buffers; ++buffer) {
>> /* Allocate vb2 buffer structures */
> Ah... Here's one of the integer overflow bugs I was talking about. The
> __vb2_queue_alloc() function returns an int so if num_buffers goes over
> INT_MAX we are hosed.
I will limit it to:
#define VB2_QUEUE_MAX_BUFFERS (INT_MAX & PAGE_MASK) /* The mask prevents 85% of integer overflows */
as you have suggest it.
That will be in version 4.
Thanks,
Benjamin
>
> regards,
> dan carpenter
>
On 22/06/2023 16:13, Benjamin Gaignard wrote:
>
> Le 22/06/2023 à 16:11, Dan Carpenter a écrit :
>> On Thu, Jun 22, 2023 at 03:13:41PM +0200, Benjamin Gaignard wrote:
>>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>>> index f1ff7af34a9f..86e1e926fa45 100644
>>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>>> @@ -455,9 +455,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>> struct vb2_buffer *vb;
>>> int ret;
>>> - /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
>>> + /* Ensure that q->num_buffers + num_buffers is UINT_MAX */
>>> num_buffers = min_t(unsigned int, num_buffers,
>>> - VB2_MAX_FRAME - q->num_buffers);
>>> + UINT_MAX - q->num_buffers);
>>> for (buffer = 0; buffer < num_buffers; ++buffer) {
>>> /* Allocate vb2 buffer structures */
>> Ah... Here's one of the integer overflow bugs I was talking about. The
>> __vb2_queue_alloc() function returns an int so if num_buffers goes over
>> INT_MAX we are hosed.
>
> I will limit it to:
> #define VB2_QUEUE_MAX_BUFFERS (INT_MAX & PAGE_MASK) /* The mask prevents 85% of integer overflows */
> as you have suggest it.
IMHO INT_MAX is way overkill. How about (1U << 20)? I would like some sort of
sanity check here. 1048576 buffers of 640x480 and 4 bytes per pixel is 1.2 TB.
Since a TB of memory is doable these days, I think this is a reasonable
value for MAX_BUFFERS without allowing just anything.
An alternative is to make this a kernel config.
Regards,
Hans
>
> That will be in version 4.
>
> Thanks,
> Benjamin
>
>>
>> regards,
>> dan carpenter
>>
Le 23/06/2023 à 09:02, Hans Verkuil a écrit :
> On 22/06/2023 16:13, Benjamin Gaignard wrote:
>> Le 22/06/2023 à 16:11, Dan Carpenter a écrit :
>>> On Thu, Jun 22, 2023 at 03:13:41PM +0200, Benjamin Gaignard wrote:
>>>> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
>>>> index f1ff7af34a9f..86e1e926fa45 100644
>>>> --- a/drivers/media/common/videobuf2/videobuf2-core.c
>>>> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
>>>> @@ -455,9 +455,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
>>>> struct vb2_buffer *vb;
>>>> int ret;
>>>> - /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
>>>> + /* Ensure that q->num_buffers + num_buffers is UINT_MAX */
>>>> num_buffers = min_t(unsigned int, num_buffers,
>>>> - VB2_MAX_FRAME - q->num_buffers);
>>>> + UINT_MAX - q->num_buffers);
>>>> for (buffer = 0; buffer < num_buffers; ++buffer) {
>>>> /* Allocate vb2 buffer structures */
>>> Ah... Here's one of the integer overflow bugs I was talking about. The
>>> __vb2_queue_alloc() function returns an int so if num_buffers goes over
>>> INT_MAX we are hosed.
>> I will limit it to:
>> #define VB2_QUEUE_MAX_BUFFERS (INT_MAX & PAGE_MASK) /* The mask prevents 85% of integer overflows */
>> as you have suggest it.
> IMHO INT_MAX is way overkill. How about (1U << 20)? I would like some sort of
> sanity check here. 1048576 buffers of 640x480 and 4 bytes per pixel is 1.2 TB.
I will go for (1U << 20) in next version.
Regards,
Benjamin
>
> Since a TB of memory is doable these days, I think this is a reasonable
> value for MAX_BUFFERS without allowing just anything.
>
> An alternative is to make this a kernel config.
>
> Regards,
>
> Hans
>
>> That will be in version 4.
>>
>> Thanks,
>> Benjamin
>>
>>> regards,
>>> dan carpenter
>>>
On Thu, Jun 22, 2023 at 03:13:41PM +0200, Benjamin Gaignard wrote:
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index f1ff7af34a9f..86e1e926fa45 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -455,9 +455,9 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
> struct vb2_buffer *vb;
> int ret;
>
> - /* Ensure that q->num_buffers+num_buffers is below VB2_MAX_FRAME */
> + /* Ensure that q->num_buffers + num_buffers is UINT_MAX */
> num_buffers = min_t(unsigned int, num_buffers,
> - VB2_MAX_FRAME - q->num_buffers);
> + UINT_MAX - q->num_buffers);
The UINT_MAX limit adds a level of danger. It would be safer to do what
the vfs layer does for MAX_RW_COUNT and use "INT_MAX - PAGE_SIZE". That
way you can take size + sizeof() and it's only very rarely going to turn
negative. Or at least just INT_MAX. I would keep the VB2_MAX_FRAME and
define it as:
#define VB2_MAX_FRAME (INT_MAX & PAGE_MASK) /* The mask prevents 85% of integer overflows */
>
> for (buffer = 0; buffer < num_buffers; ++buffer) {
> /* Allocate vb2 buffer structures */
> @@ -858,9 +858,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
> /*
> * Make sure the requested values and current defaults are sane.
> */
> - WARN_ON(q->min_buffers_needed > VB2_MAX_FRAME);
> + WARN_ON(q->min_buffers_needed > UINT_MAX);
This will trigger a static checker warning because the condition is
impossible.
regards,
dan carpenter
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