On Mon, 2016-03-14 at 08:21 +0100, Hans Verkuil wrote:
> On 03/14/2016 08:12 AM, tiffany lin wrote:
> > Hi Hans,
> >
> > After change to use "v4l-utils.git master branch", "V4l2-compliance
> > -d /dev/video1" fail on "fail: v4l2-test-buffers.cpp(555):
> > check_0(crbufs.reserved, sizeof(crbufs.reserved))".
> >
> > Check the source code and found
> >
> > memset(&crbufs, 0xff, sizeof(crbufs)); -> crbufs to 0xff
> > node->g_fmt(crbufs.format, i);
> > crbufs.count = 0;
> > crbufs.memory = m;
> > fail_on_test(doioctl(node, VIDIOC_CREATE_BUFS, &crbufs));
> > fail_on_test(check_0(crbufs.reserved, sizeof(crbufs.reserved)));
> > fail_on_test(crbufs.index != q.g_buffers());
> >
> > crbufs is initialized to fill with 0xff and after VIDIOC_CREATE_BUFS,
> > crbufs.reserved field should be 0x0. But v4l2_m2m_create_bufs and
> > vb2_create_bufs do not process reserved filed.
> > Do we really need to check reserved filed filled with 0x0? Or we need to
> > change vb2_create_bufs to fix this issue?
>
> The reserved field is zeroed in v4l_create_bufs() in v4l2-ioctl.c, so even before
> vb2_create_bufs et al is called.
>
> The fact that it is no longer zeroed afterwards suggests that someone is messing
> with the reserved field.
>
> You'll have to do a bit more digging, I'm afraid.
>
Hi Hans,
Thanks for your information.
I found the root cause is in "put_v4l2_create32".
It do not copy reserved field from kernel space to user space.
After modification,"test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: OK"
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index f38c076..109f687 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -280,7 +280,8 @@ static int put_v4l2_format32(struct v4l2_format *kp,
struct v4l2_format32 __user
static int put_v4l2_create32(struct v4l2_create_buffers *kp, struct
v4l2_create_buffers32 __user *up)
{
if (!access_ok(VERIFY_WRITE, up, sizeof(struct
v4l2_create_buffers32)) ||
- copy_to_user(up, kp, offsetof(struct v4l2_create_buffers32,
format)))
+ copy_to_user(up, kp, offsetof(struct v4l2_create_buffers32,
format)) ||
+ copy_to_user(up->reserved, kp->reserved,
sizeof(kp->reserved)))
return -EFAULT;
return __put_v4l2_format32(&kp->format, &up->format);
}
best regards,
Tiffany
> Regards,
>
> Hans
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