[media] v4l: Support extending the v4l2_pix_format structure

The v4l2_pix_format structure has no reserved field. It is embedded in
the v4l2_framebuffer structure which has no reserved fields either, and
in the v4l2_format structure which has reserved fields that were not
previously required to be zeroed out by applications.

To allow extending v4l2_pix_format, inline it in the v4l2_framebuffer
structure, and use the priv field as a magic value to indicate that the
application has set all v4l2_pix_format extended fields and zeroed all
reserved fields following the v4l2_pix_format field in the v4l2_format
structure.

The availability of this API extension is reported to userspace through
the new V4L2_CAP_EXT_PIX_FORMAT capability flag. Just checking that the
priv field is still set to the magic value at [GS]_FMT return wouldn't
be enough, as older kernels don't zero the priv field on return.

To simplify the internal API towards drivers zero the extended fields
and set the priv field to the magic value for applications not aware of
the extensions.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 14 insertions, 5 deletions

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index 7e2411c36419..cca6c2f76b3a 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -540,7 +540,16 @@ struct v4l2_framebuffer32 {
 	__u32			capability;
 	__u32			flags;
 	compat_caddr_t 		base;
-	struct v4l2_pix_format	fmt;
+	struct {
+		__u32		width;
+		__u32		height;
+		__u32		pixelformat;
+		__u32		field;
+		__u32		bytesperline;
+		__u32		sizeimage;
+		__u32		colorspace;
+		__u32		priv;
+	} fmt;
 };
 
 static int get_v4l2_framebuffer32(struct v4l2_framebuffer *kp, struct v4l2_framebuffer32 __user *up)
@@ -550,10 +559,10 @@ static int get_v4l2_framebuffer32(struct v4l2_framebuffer *kp, struct v4l2_frame
 	if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_framebuffer32)) ||
 		get_user(tmp, &up->base) ||
 		get_user(kp->capability, &up->capability) ||
-		get_user(kp->flags, &up->flags))
+		get_user(kp->flags, &up->flags) ||
+		copy_from_user(&kp->fmt, &up->fmt, sizeof(up->fmt)))
 			return -EFAULT;
 	kp->base = compat_ptr(tmp);
-	get_v4l2_pix_format(&kp->fmt, &up->fmt);
 	return 0;
 }
 
@@ -564,9 +573,9 @@ static int put_v4l2_framebuffer32(struct v4l2_framebuffer *kp, struct v4l2_frame
 	if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_framebuffer32)) ||
 		put_user(tmp, &up->base) ||
 		put_user(kp->capability, &up->capability) ||
-		put_user(kp->flags, &up->flags))
+		put_user(kp->flags, &up->flags) ||
+		copy_to_user(&up->fmt, &kp->fmt, sizeof(up->fmt)))
 			return -EFAULT;
-	put_v4l2_pix_format(&kp->fmt, &up->fmt);
 	return 0;
 }