Improve v4l2-compat-ioctl32 handler getting rid of smatch warnings

index d03a44d89649..51c7c5ab15ef 100644
@@ -443,8 +443,8 @@ static int put_v4l2_plane32(struct v4l2_plane __user *up,
 			return -EFAULT;
 		break;
 	case V4L2_MEMORY_USERPTR:
-		if (get_user(p, &up->m.userptr) ||
-		    put_user((compat_ulong_t)ptr_to_compat((__force void *)p),
+		if (get_user(p, &up->m.userptr)||
+		    put_user((compat_ulong_t)ptr_to_compat((void __user *)p),
 			     &up32->m.userptr))
 			return -EFAULT;
 		break;

@@ -587,7 +587,7 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *kp,
 	u32 length;
 	enum v4l2_memory memory;
 	struct v4l2_plane32 __user *uplane32;
-	struct v4l2_plane __user *uplane;
+	struct v4l2_plane *uplane;
 	compat_caddr_t p;
 	int ret;
 

@@ -617,15 +617,22 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *kp,
 
 		if (num_planes == 0)
 			return 0;
-
-		if (get_user(uplane, ((__force struct v4l2_plane __user **)&kp->m.planes)))
+		/* We need to define uplane without __user, even though
+		 * it does point to data in userspace here. The reason is
+		 * that v4l2-ioctl.c copies it from userspace to kernelspace,
+		 * so its definition in videodev2.h doesn't have a
+		 * __user markup. Defining uplane with __user causes
+		 * smatch warnings, so instead declare it without __user
+		 * and cast it as a userspace pointer to put_v4l2_plane32().
+		 */
+		if (get_user(uplane, &kp->m.planes))
 			return -EFAULT;
 		if (get_user(p, &up->m.planes))
 			return -EFAULT;
 		uplane32 = compat_ptr(p);
 
 		while (num_planes--) {
-			ret = put_v4l2_plane32(uplane, uplane32, memory);
+			ret = put_v4l2_plane32((void __user *)uplane, uplane32, memory);
 			if (ret)
 				return ret;
 			++uplane;

@@ -675,7 +682,7 @@ static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *kp,
 
 	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
 	    get_user(tmp, &up->base) ||
-	    put_user((__force void *)compat_ptr(tmp), &kp->base) ||
+	    put_user((void __force *)compat_ptr(tmp), &kp->base) ||
 	    assign_in_user(&kp->capability, &up->capability) ||
 	    assign_in_user(&kp->flags, &up->flags) ||
 	    copy_in_user(&kp->fmt, &up->fmt, sizeof(kp->fmt)))

@@ -690,7 +697,7 @@ static int put_v4l2_framebuffer32(struct v4l2_framebuffer __user *kp,
 
 	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
 	    get_user(base, &kp->base) ||
-	    put_user(ptr_to_compat(base), &up->base) ||
+	    put_user(ptr_to_compat((void __user *)base), &up->base) ||
 	    assign_in_user(&up->capability, &kp->capability) ||
 	    assign_in_user(&up->flags, &kp->flags) ||
 	    copy_in_user(&up->fmt, &kp->fmt, sizeof(kp->fmt)))

@@ -857,11 +864,19 @@ static int put_v4l2_ext_controls32(struct file *file,
 				   struct v4l2_ext_controls32 __user *up)
 {
 	struct v4l2_ext_control32 __user *ucontrols;
-	struct v4l2_ext_control __user *kcontrols;
+	struct v4l2_ext_control *kcontrols;
 	u32 count;
 	u32 n;
 	compat_caddr_t p;
 
+	/*
+	 * We need to define kcontrols without __user, even though it does
+	 * point to data in userspace here. The reason is that v4l2-ioctl.c
+	 * copies it from userspace to kernelspace, so its definition in
+	 * videodev2.h doesn't have a __user markup. Defining kcontrols
+	 * with __user causes smatch warnings, so instead declare it
+	 * without __user and cast it as a userspace pointer where needed.
+	 */
 	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
 	    assign_in_user(&up->which, &kp->which) ||
 	    get_user(count, &kp->count) ||

@@ -883,10 +898,12 @@ static int put_v4l2_ext_controls32(struct file *file,
 		unsigned int size = sizeof(*ucontrols);
 		u32 id;
 
-		if (get_user(id, &kcontrols->id) ||
+		if (get_user(id, (unsigned int __user *)&kcontrols->id) ||
 		    put_user(id, &ucontrols->id) ||
-		    assign_in_user(&ucontrols->size, &kcontrols->size) ||
-		    copy_in_user(&ucontrols->reserved2, &kcontrols->reserved2,
+		    assign_in_user(&ucontrols->size,
+				   (unsigned int __user *)&kcontrols->size) ||
+		    copy_in_user(&ucontrols->reserved2,
+				 (void __user *)&kcontrols->reserved2,
 				 sizeof(ucontrols->reserved2)))
 			return -EFAULT;
 

@@ -898,7 +915,8 @@ static int put_v4l2_ext_controls32(struct file *file,
 		if (ctrl_is_pointer(file, id))
 			size -= sizeof(ucontrols->value64);
 
-		if (copy_in_user(ucontrols, kcontrols, size))
+		if (copy_in_user(ucontrols,
+			         (void __user *)kcontrols, size))
 			return -EFAULT;
 
 		ucontrols++;

@@ -952,9 +970,10 @@ static int get_v4l2_edid32(struct v4l2_edid __user *kp,
 	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
 	    assign_in_user(&kp->pad, &up->pad) ||
 	    assign_in_user(&kp->start_block, &up->start_block) ||
-	    assign_in_user(&kp->blocks, &up->blocks) ||
+	    assign_in_user(&kp->blocks,
+			   (u32 __user *)&up->blocks) ||
 	    get_user(tmp, &up->edid) ||
-	    put_user(compat_ptr(tmp), &kp->edid) ||
+	    put_user((void __force *)compat_ptr(tmp), &kp->edid) ||
 	    copy_in_user(kp->reserved, up->reserved, sizeof(kp->reserved)))
 		return -EFAULT;
 	return 0;

@@ -970,7 +989,7 @@ static int put_v4l2_edid32(struct v4l2_edid __user *kp,
 	    assign_in_user(&up->start_block, &kp->start_block) ||
 	    assign_in_user(&up->blocks, &kp->blocks) ||
 	    get_user(edid, &kp->edid) ||
-	    put_user(ptr_to_compat(edid), &up->edid) ||
+	    put_user(ptr_to_compat((void __user *)edid), &up->edid) ||
 	    copy_in_user(up->reserved, kp->reserved, sizeof(up->reserved)))
 		return -EFAULT;
 	return 0;

index 51c7c5ab15ef..680b64c1d69a 100644
@@ -56,8 +56,8 @@ struct v4l2_window32 {
 	__u8                    global_alpha;
 };
 
-static int get_v4l2_window32(struct v4l2_window __user *kp,
-			     struct v4l2_window32 __user *up,
+static int get_v4l2_window32(struct v4l2_window __user *p64,
+			     struct v4l2_window32 __user *p32,
 			     void __user *aux_buf, u32 aux_space)
 {
 	struct v4l2_clip32 __user *uclips;

@@ -65,26 +65,26 @@ static int get_v4l2_window32(struct v4l2_window __user *kp,
 	compat_caddr_t p;
 	u32 clipcount;
 
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    copy_in_user(&kp->w, &up->w, sizeof(up->w)) ||
-	    assign_in_user(&kp->field, &up->field) ||
-	    assign_in_user(&kp->chromakey, &up->chromakey) ||
-	    assign_in_user(&kp->global_alpha, &up->global_alpha) ||
-	    get_user(clipcount, &up->clipcount) ||
-	    put_user(clipcount, &kp->clipcount))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    copy_in_user(&p64->w, &p32->w, sizeof(p32->w)) ||
+	    assign_in_user(&p64->field, &p32->field) ||
+	    assign_in_user(&p64->chromakey, &p32->chromakey) ||
+	    assign_in_user(&p64->global_alpha, &p32->global_alpha) ||
+	    get_user(clipcount, &p32->clipcount) ||
+	    put_user(clipcount, &p64->clipcount))
 		return -EFAULT;
 	if (clipcount > 2048)
 		return -EINVAL;
 	if (!clipcount)
-		return put_user(NULL, &kp->clips);
+		return put_user(NULL, &p64->clips);
 
-	if (get_user(p, &up->clips))
+	if (get_user(p, &p32->clips))
 		return -EFAULT;
 	uclips = compat_ptr(p);
 	if (aux_space < clipcount * sizeof(*kclips))
 		return -EFAULT;
 	kclips = aux_buf;
-	if (put_user(kclips, &kp->clips))
+	if (put_user(kclips, &p64->clips))
 		return -EFAULT;
 
 	while (clipcount--) {

@@ -98,27 +98,27 @@ static int get_v4l2_window32(struct v4l2_window __user *kp,
 	return 0;
 }
 
-static int put_v4l2_window32(struct v4l2_window __user *kp,
-			     struct v4l2_window32 __user *up)
+static int put_v4l2_window32(struct v4l2_window __user *p64,
+			     struct v4l2_window32 __user *p32)
 {
 	struct v4l2_clip __user *kclips;
 	struct v4l2_clip32 __user *uclips;
 	compat_caddr_t p;
 	u32 clipcount;
 
-	if (copy_in_user(&up->w, &kp->w, sizeof(kp->w)) ||
-	    assign_in_user(&up->field, &kp->field) ||
-	    assign_in_user(&up->chromakey, &kp->chromakey) ||
-	    assign_in_user(&up->global_alpha, &kp->global_alpha) ||
-	    get_user(clipcount, &kp->clipcount) ||
-	    put_user(clipcount, &up->clipcount))
+	if (copy_in_user(&p32->w, &p64->w, sizeof(p64->w)) ||
+	    assign_in_user(&p32->field, &p64->field) ||
+	    assign_in_user(&p32->chromakey, &p64->chromakey) ||
+	    assign_in_user(&p32->global_alpha, &p64->global_alpha) ||
+	    get_user(clipcount, &p64->clipcount) ||
+	    put_user(clipcount, &p32->clipcount))
 		return -EFAULT;
 	if (!clipcount)
 		return 0;
 
-	if (get_user(kclips, &kp->clips))
+	if (get_user(kclips, &p64->clips))
 		return -EFAULT;
-	if (get_user(p, &up->clips))
+	if (get_user(p, &p32->clips))
 		return -EFAULT;
 	uclips = compat_ptr(p);
 	while (clipcount--) {

@@ -161,11 +161,11 @@ struct v4l2_create_buffers32 {
 	__u32			reserved[8];
 };
 
-static int __bufsize_v4l2_format(struct v4l2_format32 __user *up, u32 *size)
+static int __bufsize_v4l2_format(struct v4l2_format32 __user *p32, u32 *size)
 {
 	u32 type;
 
-	if (get_user(type, &up->type))
+	if (get_user(type, &p32->type))
 		return -EFAULT;
 
 	switch (type) {

@@ -173,7 +173,7 @@ static int __bufsize_v4l2_format(struct v4l2_format32 __user *up, u32 *size)
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY: {
 		u32 clipcount;
 
-		if (get_user(clipcount, &up->fmt.win.clipcount))
+		if (get_user(clipcount, &p32->fmt.win.clipcount))
 			return -EFAULT;
 		if (clipcount > 2048)
 			return -EINVAL;

@@ -186,141 +186,141 @@ static int __bufsize_v4l2_format(struct v4l2_format32 __user *up, u32 *size)
 	}
 }
 
-static int bufsize_v4l2_format(struct v4l2_format32 __user *up, u32 *size)
+static int bufsize_v4l2_format(struct v4l2_format32 __user *p32, u32 *size)
 {
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)))
 		return -EFAULT;
-	return __bufsize_v4l2_format(up, size);
+	return __bufsize_v4l2_format(p32, size);
 }
 
-static int __get_v4l2_format32(struct v4l2_format __user *kp,
-			       struct v4l2_format32 __user *up,
+static int __get_v4l2_format32(struct v4l2_format __user *p64,
+			       struct v4l2_format32 __user *p32,
 			       void __user *aux_buf, u32 aux_space)
 {
 	u32 type;
 
-	if (get_user(type, &up->type) || put_user(type, &kp->type))
+	if (get_user(type, &p32->type) || put_user(type, &p64->type))
 		return -EFAULT;
 
 	switch (type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
-		return copy_in_user(&kp->fmt.pix, &up->fmt.pix,
-				    sizeof(kp->fmt.pix)) ? -EFAULT : 0;
+		return copy_in_user(&p64->fmt.pix, &p32->fmt.pix,
+				    sizeof(p64->fmt.pix)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
-		return copy_in_user(&kp->fmt.pix_mp, &up->fmt.pix_mp,
-				    sizeof(kp->fmt.pix_mp)) ? -EFAULT : 0;
+		return copy_in_user(&p64->fmt.pix_mp, &p32->fmt.pix_mp,
+				    sizeof(p64->fmt.pix_mp)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_VIDEO_OVERLAY:
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
-		return get_v4l2_window32(&kp->fmt.win, &up->fmt.win,
+		return get_v4l2_window32(&p64->fmt.win, &p32->fmt.win,
 					 aux_buf, aux_space);
 	case V4L2_BUF_TYPE_VBI_CAPTURE:
 	case V4L2_BUF_TYPE_VBI_OUTPUT:
-		return copy_in_user(&kp->fmt.vbi, &up->fmt.vbi,
-				    sizeof(kp->fmt.vbi)) ? -EFAULT : 0;
+		return copy_in_user(&p64->fmt.vbi, &p32->fmt.vbi,
+				    sizeof(p64->fmt.vbi)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
 	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
-		return copy_in_user(&kp->fmt.sliced, &up->fmt.sliced,
-				    sizeof(kp->fmt.sliced)) ? -EFAULT : 0;
+		return copy_in_user(&p64->fmt.sliced, &p32->fmt.sliced,
+				    sizeof(p64->fmt.sliced)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_SDR_CAPTURE:
 	case V4L2_BUF_TYPE_SDR_OUTPUT:
-		return copy_in_user(&kp->fmt.sdr, &up->fmt.sdr,
-				    sizeof(kp->fmt.sdr)) ? -EFAULT : 0;
+		return copy_in_user(&p64->fmt.sdr, &p32->fmt.sdr,
+				    sizeof(p64->fmt.sdr)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_META_CAPTURE:
-		return copy_in_user(&kp->fmt.meta, &up->fmt.meta,
-				    sizeof(kp->fmt.meta)) ? -EFAULT : 0;
+		return copy_in_user(&p64->fmt.meta, &p32->fmt.meta,
+				    sizeof(p64->fmt.meta)) ? -EFAULT : 0;
 	default:
 		return -EINVAL;
 	}
 }
 
-static int get_v4l2_format32(struct v4l2_format __user *kp,
-			     struct v4l2_format32 __user *up,
+static int get_v4l2_format32(struct v4l2_format __user *p64,
+			     struct v4l2_format32 __user *p32,
 			     void __user *aux_buf, u32 aux_space)
 {
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)))
 		return -EFAULT;
-	return __get_v4l2_format32(kp, up, aux_buf, aux_space);
+	return __get_v4l2_format32(p64, p32, aux_buf, aux_space);
 }
 
-static int bufsize_v4l2_create(struct v4l2_create_buffers32 __user *up,
+static int bufsize_v4l2_create(struct v4l2_create_buffers32 __user *p32,
 			       u32 *size)
 {
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)))
 		return -EFAULT;
-	return __bufsize_v4l2_format(&up->format, size);
+	return __bufsize_v4l2_format(&p32->format, size);
 }
 
-static int get_v4l2_create32(struct v4l2_create_buffers __user *kp,
-			     struct v4l2_create_buffers32 __user *up,
+static int get_v4l2_create32(struct v4l2_create_buffers __user *p64,
+			     struct v4l2_create_buffers32 __user *p32,
 			     void __user *aux_buf, u32 aux_space)
 {
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    copy_in_user(kp, up,
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    copy_in_user(p64, p32,
 			 offsetof(struct v4l2_create_buffers32, format)))
 		return -EFAULT;
-	return __get_v4l2_format32(&kp->format, &up->format,
+	return __get_v4l2_format32(&p64->format, &p32->format,
 				   aux_buf, aux_space);
 }
 
-static int __put_v4l2_format32(struct v4l2_format __user *kp,
-			       struct v4l2_format32 __user *up)
+static int __put_v4l2_format32(struct v4l2_format __user *p64,
+			       struct v4l2_format32 __user *p32)
 {
 	u32 type;
 
-	if (get_user(type, &kp->type))
+	if (get_user(type, &p64->type))
 		return -EFAULT;
 
 	switch (type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
-		return copy_in_user(&up->fmt.pix, &kp->fmt.pix,
-				    sizeof(kp->fmt.pix)) ? -EFAULT : 0;
+		return copy_in_user(&p32->fmt.pix, &p64->fmt.pix,
+				    sizeof(p64->fmt.pix)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
-		return copy_in_user(&up->fmt.pix_mp, &kp->fmt.pix_mp,
-				    sizeof(kp->fmt.pix_mp)) ? -EFAULT : 0;
+		return copy_in_user(&p32->fmt.pix_mp, &p64->fmt.pix_mp,
+				    sizeof(p64->fmt.pix_mp)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_VIDEO_OVERLAY:
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
-		return put_v4l2_window32(&kp->fmt.win, &up->fmt.win);
+		return put_v4l2_window32(&p64->fmt.win, &p32->fmt.win);
 	case V4L2_BUF_TYPE_VBI_CAPTURE:
 	case V4L2_BUF_TYPE_VBI_OUTPUT:
-		return copy_in_user(&up->fmt.vbi, &kp->fmt.vbi,
-				    sizeof(kp->fmt.vbi)) ? -EFAULT : 0;
+		return copy_in_user(&p32->fmt.vbi, &p64->fmt.vbi,
+				    sizeof(p64->fmt.vbi)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
 	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
-		return copy_in_user(&up->fmt.sliced, &kp->fmt.sliced,
-				    sizeof(kp->fmt.sliced)) ? -EFAULT : 0;
+		return copy_in_user(&p32->fmt.sliced, &p64->fmt.sliced,
+				    sizeof(p64->fmt.sliced)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_SDR_CAPTURE:
 	case V4L2_BUF_TYPE_SDR_OUTPUT:
-		return copy_in_user(&up->fmt.sdr, &kp->fmt.sdr,
-				    sizeof(kp->fmt.sdr)) ? -EFAULT : 0;
+		return copy_in_user(&p32->fmt.sdr, &p64->fmt.sdr,
+				    sizeof(p64->fmt.sdr)) ? -EFAULT : 0;
 	case V4L2_BUF_TYPE_META_CAPTURE:
-		return copy_in_user(&up->fmt.meta, &kp->fmt.meta,
-				    sizeof(kp->fmt.meta)) ? -EFAULT : 0;
+		return copy_in_user(&p32->fmt.meta, &p64->fmt.meta,
+				    sizeof(p64->fmt.meta)) ? -EFAULT : 0;
 	default:
 		return -EINVAL;
 	}
 }
 
-static int put_v4l2_format32(struct v4l2_format __user *kp,
-			     struct v4l2_format32 __user *up)
+static int put_v4l2_format32(struct v4l2_format __user *p64,
+			     struct v4l2_format32 __user *p32)
 {
-	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
+	if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)))
 		return -EFAULT;
-	return __put_v4l2_format32(kp, up);
+	return __put_v4l2_format32(p64, p32);
 }
 
-static int put_v4l2_create32(struct v4l2_create_buffers __user *kp,
-			     struct v4l2_create_buffers32 __user *up)
+static int put_v4l2_create32(struct v4l2_create_buffers __user *p64,
+			     struct v4l2_create_buffers32 __user *p32)
 {
-	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
-	    copy_in_user(up, kp,
+	if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) ||
+	    copy_in_user(p32, p64,
 			 offsetof(struct v4l2_create_buffers32, format)) ||
-	    copy_in_user(up->reserved, kp->reserved, sizeof(kp->reserved)))
+	    copy_in_user(p32->reserved, p64->reserved, sizeof(p64->reserved)))
 		return -EFAULT;
-	return __put_v4l2_format32(&kp->format, &up->format);
+	return __put_v4l2_format32(&p64->format, &p32->format);
 }
 
 struct v4l2_standard32 {

@@ -332,27 +332,27 @@ struct v4l2_standard32 {
 	__u32		     reserved[4];
 };
 
-static int get_v4l2_standard32(struct v4l2_standard __user *kp,
-			       struct v4l2_standard32 __user *up)
+static int get_v4l2_standard32(struct v4l2_standard __user *p64,
+			       struct v4l2_standard32 __user *p32)
 {
 	/* other fields are not set by the user, nor used by the driver */
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    assign_in_user(&kp->index, &up->index))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    assign_in_user(&p64->index, &p32->index))
 		return -EFAULT;
 	return 0;
 }
 
-static int put_v4l2_standard32(struct v4l2_standard __user *kp,
-			       struct v4l2_standard32 __user *up)
+static int put_v4l2_standard32(struct v4l2_standard __user *p64,
+			       struct v4l2_standard32 __user *p32)
 {
-	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
-	    assign_in_user(&up->index, &kp->index) ||
-	    assign_in_user(&up->id, &kp->id) ||
-	    copy_in_user(up->name, kp->name, sizeof(up->name)) ||
-	    copy_in_user(&up->frameperiod, &kp->frameperiod,
-			 sizeof(up->frameperiod)) ||
-	    assign_in_user(&up->framelines, &kp->framelines) ||
-	    copy_in_user(up->reserved, kp->reserved, sizeof(up->reserved)))
+	if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) ||
+	    assign_in_user(&p32->index, &p64->index) ||
+	    assign_in_user(&p32->id, &p64->id) ||
+	    copy_in_user(p32->name, p64->name, sizeof(p32->name)) ||
+	    copy_in_user(&p32->frameperiod, &p64->frameperiod,
+			 sizeof(p32->frameperiod)) ||
+	    assign_in_user(&p32->framelines, &p64->framelines) ||
+	    copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)))
 		return -EFAULT;
 	return 0;
 }

@@ -392,31 +392,31 @@ struct v4l2_buffer32 {
 	__u32			reserved;
 };
 
-static int get_v4l2_plane32(struct v4l2_plane __user *up,
-			    struct v4l2_plane32 __user *up32,
+static int get_v4l2_plane32(struct v4l2_plane __user *p64,
+			    struct v4l2_plane32 __user *p32,
 			    enum v4l2_memory memory)
 {
 	compat_ulong_t p;
 
-	if (copy_in_user(up, up32, 2 * sizeof(__u32)) ||
-	    copy_in_user(&up->data_offset, &up32->data_offset,
-			 sizeof(up->data_offset)))
+	if (copy_in_user(p64, p32, 2 * sizeof(__u32)) ||
+	    copy_in_user(&p64->data_offset, &p32->data_offset,
+			 sizeof(p64->data_offset)))
 		return -EFAULT;
 
 	switch (memory) {
 	case V4L2_MEMORY_MMAP:
 	case V4L2_MEMORY_OVERLAY:
-		if (copy_in_user(&up->m.mem_offset, &up32->m.mem_offset,
-				 sizeof(up32->m.mem_offset)))
+		if (copy_in_user(&p64->m.mem_offset, &p32->m.mem_offset,
+				 sizeof(p32->m.mem_offset)))
 			return -EFAULT;
 		break;
 	case V4L2_MEMORY_USERPTR:
-		if (get_user(p, &up32->m.userptr) ||
-		    put_user((unsigned long)compat_ptr(p), &up->m.userptr))
+		if (get_user(p, &p32->m.userptr) ||
+		    put_user((unsigned long)compat_ptr(p), &p64->m.userptr))
 			return -EFAULT;
 		break;
 	case V4L2_MEMORY_DMABUF:
-		if (copy_in_user(&up->m.fd, &up32->m.fd, sizeof(up32->m.fd)))
+		if (copy_in_user(&p64->m.fd, &p32->m.fd, sizeof(p32->m.fd)))
 			return -EFAULT;
 		break;
 	}

@@ -424,32 +424,32 @@ static int get_v4l2_plane32(struct v4l2_plane __user *up,
 	return 0;
 }
 
-static int put_v4l2_plane32(struct v4l2_plane __user *up,
-			    struct v4l2_plane32 __user *up32,
+static int put_v4l2_plane32(struct v4l2_plane __user *p64,
+			    struct v4l2_plane32 __user *p32,
 			    enum v4l2_memory memory)
 {
 	unsigned long p;
 
-	if (copy_in_user(up32, up, 2 * sizeof(__u32)) ||
-	    copy_in_user(&up32->data_offset, &up->data_offset,
-			 sizeof(up->data_offset)))
+	if (copy_in_user(p32, p64, 2 * sizeof(__u32)) ||
+	    copy_in_user(&p32->data_offset, &p64->data_offset,
+			 sizeof(p64->data_offset)))
 		return -EFAULT;
 
 	switch (memory) {
 	case V4L2_MEMORY_MMAP:
 	case V4L2_MEMORY_OVERLAY:
-		if (copy_in_user(&up32->m.mem_offset, &up->m.mem_offset,
-				 sizeof(up->m.mem_offset)))
+		if (copy_in_user(&p32->m.mem_offset, &p64->m.mem_offset,
+				 sizeof(p64->m.mem_offset)))
 			return -EFAULT;
 		break;
 	case V4L2_MEMORY_USERPTR:
-		if (get_user(p, &up->m.userptr)||
+		if (get_user(p, &p64->m.userptr)||
 		    put_user((compat_ulong_t)ptr_to_compat((void __user *)p),
-			     &up32->m.userptr))
+			     &p32->m.userptr))
 			return -EFAULT;
 		break;
 	case V4L2_MEMORY_DMABUF:
-		if (copy_in_user(&up32->m.fd, &up->m.fd, sizeof(up->m.fd)))
+		if (copy_in_user(&p32->m.fd, &p64->m.fd, sizeof(p64->m.fd)))
 			return -EFAULT;
 		break;
 	}

@@ -457,14 +457,14 @@ static int put_v4l2_plane32(struct v4l2_plane __user *up,
 	return 0;
 }
 
-static int bufsize_v4l2_buffer(struct v4l2_buffer32 __user *up, u32 *size)
+static int bufsize_v4l2_buffer(struct v4l2_buffer32 __user *p32, u32 *size)
 {
 	u32 type;
 	u32 length;
 
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    get_user(type, &up->type) ||
-	    get_user(length, &up->length))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    get_user(type, &p32->type) ||
+	    get_user(length, &p32->length))
 		return -EFAULT;
 
 	if (V4L2_TYPE_IS_MULTIPLANAR(type)) {

@@ -482,8 +482,8 @@ static int bufsize_v4l2_buffer(struct v4l2_buffer32 __user *up, u32 *size)
 	return 0;
 }
 
-static int get_v4l2_buffer32(struct v4l2_buffer __user *kp,
-			     struct v4l2_buffer32 __user *up,
+static int get_v4l2_buffer32(struct v4l2_buffer __user *p64,
+			     struct v4l2_buffer32 __user *p32,
 			     void __user *aux_buf, u32 aux_space)
 {
 	u32 type;

@@ -494,24 +494,24 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *kp,
 	compat_caddr_t p;
 	int ret;
 
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    assign_in_user(&kp->index, &up->index) ||
-	    get_user(type, &up->type) ||
-	    put_user(type, &kp->type) ||
-	    assign_in_user(&kp->flags, &up->flags) ||
-	    get_user(memory, &up->memory) ||
-	    put_user(memory, &kp->memory) ||
-	    get_user(length, &up->length) ||
-	    put_user(length, &kp->length))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    assign_in_user(&p64->index, &p32->index) ||
+	    get_user(type, &p32->type) ||
+	    put_user(type, &p64->type) ||
+	    assign_in_user(&p64->flags, &p32->flags) ||
+	    get_user(memory, &p32->memory) ||
+	    put_user(memory, &p64->memory) ||
+	    get_user(length, &p32->length) ||
+	    put_user(length, &p64->length))
 		return -EFAULT;
 
 	if (V4L2_TYPE_IS_OUTPUT(type))
-		if (assign_in_user(&kp->bytesused, &up->bytesused) ||
-		    assign_in_user(&kp->field, &up->field) ||
-		    assign_in_user(&kp->timestamp.tv_sec,
-				   &up->timestamp.tv_sec) ||
-		    assign_in_user(&kp->timestamp.tv_usec,
-				   &up->timestamp.tv_usec))
+		if (assign_in_user(&p64->bytesused, &p32->bytesused) ||
+		    assign_in_user(&p64->field, &p32->field) ||
+		    assign_in_user(&p64->timestamp.tv_sec,
+				   &p32->timestamp.tv_sec) ||
+		    assign_in_user(&p64->timestamp.tv_usec,
+				   &p32->timestamp.tv_usec))
 			return -EFAULT;
 
 	if (V4L2_TYPE_IS_MULTIPLANAR(type)) {

@@ -522,12 +522,12 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *kp,
 			 * num_planes == 0 is legal, e.g. when userspace doesn't
 			 * need planes array on DQBUF
 			 */
-			return put_user(NULL, &kp->m.planes);
+			return put_user(NULL, &p64->m.planes);
 		}
 		if (num_planes > VIDEO_MAX_PLANES)
 			return -EINVAL;
 
-		if (get_user(p, &up->m.planes))
+		if (get_user(p, &p32->m.planes))
 			return -EFAULT;
 
 		uplane32 = compat_ptr(p);

@@ -544,7 +544,7 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *kp,
 
 		uplane = aux_buf;
 		if (put_user((__force struct v4l2_plane *)uplane,
-			     &kp->m.planes))
+			     &p64->m.planes))
 			return -EFAULT;
 
 		while (num_planes--) {

@@ -558,20 +558,20 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *kp,
 		switch (memory) {
 		case V4L2_MEMORY_MMAP:
 		case V4L2_MEMORY_OVERLAY:
-			if (assign_in_user(&kp->m.offset, &up->m.offset))
+			if (assign_in_user(&p64->m.offset, &p32->m.offset))
 				return -EFAULT;
 			break;
 		case V4L2_MEMORY_USERPTR: {
 			compat_ulong_t userptr;
 
-			if (get_user(userptr, &up->m.userptr) ||
+			if (get_user(userptr, &p32->m.userptr) ||
 			    put_user((unsigned long)compat_ptr(userptr),
-				     &kp->m.userptr))
+				     &p64->m.userptr))
 				return -EFAULT;
 			break;
 		}
 		case V4L2_MEMORY_DMABUF:
-			if (assign_in_user(&kp->m.fd, &up->m.fd))
+			if (assign_in_user(&p64->m.fd, &p32->m.fd))
 				return -EFAULT;
 			break;
 		}

@@ -580,8 +580,8 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *kp,
 	return 0;
 }
 
-static int put_v4l2_buffer32(struct v4l2_buffer __user *kp,
-			     struct v4l2_buffer32 __user *up)
+static int put_v4l2_buffer32(struct v4l2_buffer __user *p64,
+			     struct v4l2_buffer32 __user *p32)
 {
 	u32 type;
 	u32 length;

@@ -591,25 +591,25 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *kp,
 	compat_caddr_t p;
 	int ret;
 
-	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
-	    assign_in_user(&up->index, &kp->index) ||
-	    get_user(type, &kp->type) ||
-	    put_user(type, &up->type) ||
-	    assign_in_user(&up->flags, &kp->flags) ||
-	    get_user(memory, &kp->memory) ||
-	    put_user(memory, &up->memory))
+	if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) ||
+	    assign_in_user(&p32->index, &p64->index) ||
+	    get_user(type, &p64->type) ||
+	    put_user(type, &p32->type) ||
+	    assign_in_user(&p32->flags, &p64->flags) ||
+	    get_user(memory, &p64->memory) ||
+	    put_user(memory, &p32->memory))
 		return -EFAULT;
 
-	if (assign_in_user(&up->bytesused, &kp->bytesused) ||
-	    assign_in_user(&up->field, &kp->field) ||
-	    assign_in_user(&up->timestamp.tv_sec, &kp->timestamp.tv_sec) ||
-	    assign_in_user(&up->timestamp.tv_usec, &kp->timestamp.tv_usec) ||
-	    copy_in_user(&up->timecode, &kp->timecode, sizeof(kp->timecode)) ||
-	    assign_in_user(&up->sequence, &kp->sequence) ||
-	    assign_in_user(&up->reserved2, &kp->reserved2) ||
-	    assign_in_user(&up->reserved, &kp->reserved) ||
-	    get_user(length, &kp->length) ||
-	    put_user(length, &up->length))
+	if (assign_in_user(&p32->bytesused, &p64->bytesused) ||
+	    assign_in_user(&p32->field, &p64->field) ||
+	    assign_in_user(&p32->timestamp.tv_sec, &p64->timestamp.tv_sec) ||
+	    assign_in_user(&p32->timestamp.tv_usec, &p64->timestamp.tv_usec) ||
+	    copy_in_user(&p32->timecode, &p64->timecode, sizeof(p64->timecode)) ||
+	    assign_in_user(&p32->sequence, &p64->sequence) ||
+	    assign_in_user(&p32->reserved2, &p64->reserved2) ||
+	    assign_in_user(&p32->reserved, &p64->reserved) ||
+	    get_user(length, &p64->length) ||
+	    put_user(length, &p32->length))
 		return -EFAULT;
 
 	if (V4L2_TYPE_IS_MULTIPLANAR(type)) {

@@ -625,9 +625,9 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *kp,
 		 * smatch warnings, so instead declare it without __user
 		 * and cast it as a userspace pointer to put_v4l2_plane32().
 		 */
-		if (get_user(uplane, &kp->m.planes))
+		if (get_user(uplane, &p64->m.planes))
 			return -EFAULT;
-		if (get_user(p, &up->m.planes))
+		if (get_user(p, &p32->m.planes))
 			return -EFAULT;
 		uplane32 = compat_ptr(p);
 

@@ -642,15 +642,15 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *kp,
 		switch (memory) {
 		case V4L2_MEMORY_MMAP:
 		case V4L2_MEMORY_OVERLAY:
-			if (assign_in_user(&up->m.offset, &kp->m.offset))
+			if (assign_in_user(&p32->m.offset, &p64->m.offset))
 				return -EFAULT;
 			break;
 		case V4L2_MEMORY_USERPTR:
-			if (assign_in_user(&up->m.userptr, &kp->m.userptr))
+			if (assign_in_user(&p32->m.userptr, &p64->m.userptr))
 				return -EFAULT;
 			break;
 		case V4L2_MEMORY_DMABUF:
-			if (assign_in_user(&up->m.fd, &kp->m.fd))
+			if (assign_in_user(&p32->m.fd, &p64->m.fd))
 				return -EFAULT;
 			break;
 		}

@@ -675,32 +675,32 @@ struct v4l2_framebuffer32 {
 	} fmt;
 };
 
-static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *kp,
-				  struct v4l2_framebuffer32 __user *up)
+static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64,
+				  struct v4l2_framebuffer32 __user *p32)
 {
 	compat_caddr_t tmp;
 
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    get_user(tmp, &up->base) ||
-	    put_user((void __force *)compat_ptr(tmp), &kp->base) ||
-	    assign_in_user(&kp->capability, &up->capability) ||
-	    assign_in_user(&kp->flags, &up->flags) ||
-	    copy_in_user(&kp->fmt, &up->fmt, sizeof(kp->fmt)))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    get_user(tmp, &p32->base) ||
+	    put_user((void __force *)compat_ptr(tmp), &p64->base) ||
+	    assign_in_user(&p64->capability, &p32->capability) ||
+	    assign_in_user(&p64->flags, &p32->flags) ||
+	    copy_in_user(&p64->fmt, &p32->fmt, sizeof(p64->fmt)))
 		return -EFAULT;
 	return 0;
 }
 
-static int put_v4l2_framebuffer32(struct v4l2_framebuffer __user *kp,
-				  struct v4l2_framebuffer32 __user *up)
+static int put_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64,
+				  struct v4l2_framebuffer32 __user *p32)
 {
 	void *base;
 
-	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
-	    get_user(base, &kp->base) ||
-	    put_user(ptr_to_compat((void __user *)base), &up->base) ||
-	    assign_in_user(&up->capability, &kp->capability) ||
-	    assign_in_user(&up->flags, &kp->flags) ||
-	    copy_in_user(&up->fmt, &kp->fmt, sizeof(kp->fmt)))
+	if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) ||
+	    get_user(base, &p64->base) ||
+	    put_user(ptr_to_compat((void __user *)base), &p32->base) ||
+	    assign_in_user(&p32->capability, &p64->capability) ||
+	    assign_in_user(&p32->flags, &p64->flags) ||
+	    copy_in_user(&p32->fmt, &p64->fmt, sizeof(p64->fmt)))
 		return -EFAULT;
 	return 0;
 }

@@ -721,18 +721,18 @@ struct v4l2_input32 {
  * The 64-bit v4l2_input struct has extra padding at the end of the struct.
  * Otherwise it is identical to the 32-bit version.
  */
-static inline int get_v4l2_input32(struct v4l2_input __user *kp,
-				   struct v4l2_input32 __user *up)
+static inline int get_v4l2_input32(struct v4l2_input __user *p64,
+				   struct v4l2_input32 __user *p32)
 {
-	if (copy_in_user(kp, up, sizeof(*up)))
+	if (copy_in_user(p64, p32, sizeof(*p32)))
 		return -EFAULT;
 	return 0;
 }
 
-static inline int put_v4l2_input32(struct v4l2_input __user *kp,
-				   struct v4l2_input32 __user *up)
+static inline int put_v4l2_input32(struct v4l2_input __user *p64,
+				   struct v4l2_input32 __user *p32)
 {
-	if (copy_in_user(up, kp, sizeof(*up)))
+	if (copy_in_user(p32, p64, sizeof(*p32)))
 		return -EFAULT;
 	return 0;
 }

@@ -786,13 +786,13 @@ static inline bool ctrl_is_pointer(struct file *file, u32 id)
 		(qec.flags & V4L2_CTRL_FLAG_HAS_PAYLOAD);
 }
 
-static int bufsize_v4l2_ext_controls(struct v4l2_ext_controls32 __user *up,
+static int bufsize_v4l2_ext_controls(struct v4l2_ext_controls32 __user *p32,
 				     u32 *size)
 {
 	u32 count;
 
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    get_user(count, &up->count))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    get_user(count, &p32->count))
 		return -EFAULT;
 	if (count > V4L2_CID_MAX_CTRLS)
 		return -EINVAL;

@@ -801,8 +801,8 @@ static int bufsize_v4l2_ext_controls(struct v4l2_ext_controls32 __user *up,
 }
 
 static int get_v4l2_ext_controls32(struct file *file,
-				   struct v4l2_ext_controls __user *kp,
-				   struct v4l2_ext_controls32 __user *up,
+				   struct v4l2_ext_controls __user *p64,
+				   struct v4l2_ext_controls32 __user *p32,
 				   void __user *aux_buf, u32 aux_space)
 {
 	struct v4l2_ext_control32 __user *ucontrols;

@@ -811,19 +811,19 @@ static int get_v4l2_ext_controls32(struct file *file,
 	u32 n;
 	compat_caddr_t p;
 
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    assign_in_user(&kp->which, &up->which) ||
-	    get_user(count, &up->count) ||
-	    put_user(count, &kp->count) ||
-	    assign_in_user(&kp->error_idx, &up->error_idx) ||
-	    copy_in_user(kp->reserved, up->reserved, sizeof(kp->reserved)))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    assign_in_user(&p64->which, &p32->which) ||
+	    get_user(count, &p32->count) ||
+	    put_user(count, &p64->count) ||
+	    assign_in_user(&p64->error_idx, &p32->error_idx) ||
+	    copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved)))
 		return -EFAULT;
 
 	if (count == 0)
-		return put_user(NULL, &kp->controls);
+		return put_user(NULL, &p64->controls);
 	if (count > V4L2_CID_MAX_CTRLS)
 		return -EINVAL;
-	if (get_user(p, &up->controls))
+	if (get_user(p, &p32->controls))
 		return -EFAULT;
 	ucontrols = compat_ptr(p);
 	if (!access_ok(VERIFY_READ, ucontrols, count * sizeof(*ucontrols)))

@@ -832,7 +832,7 @@ static int get_v4l2_ext_controls32(struct file *file,
 		return -EFAULT;
 	kcontrols = aux_buf;
 	if (put_user((__force struct v4l2_ext_control *)kcontrols,
-		     &kp->controls))
+		     &p64->controls))
 		return -EFAULT;
 
 	for (n = 0; n < count; n++) {

@@ -860,8 +860,8 @@ static int get_v4l2_ext_controls32(struct file *file,
 }
 
 static int put_v4l2_ext_controls32(struct file *file,
-				   struct v4l2_ext_controls __user *kp,
-				   struct v4l2_ext_controls32 __user *up)
+				   struct v4l2_ext_controls __user *p64,
+				   struct v4l2_ext_controls32 __user *p32)
 {
 	struct v4l2_ext_control32 __user *ucontrols;
 	struct v4l2_ext_control *kcontrols;

@@ -877,18 +877,18 @@ static int put_v4l2_ext_controls32(struct file *file,
 	 * with __user causes smatch warnings, so instead declare it
 	 * without __user and cast it as a userspace pointer where needed.
 	 */
-	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
-	    assign_in_user(&up->which, &kp->which) ||
-	    get_user(count, &kp->count) ||
-	    put_user(count, &up->count) ||
-	    assign_in_user(&up->error_idx, &kp->error_idx) ||
-	    copy_in_user(up->reserved, kp->reserved, sizeof(up->reserved)) ||
-	    get_user(kcontrols, &kp->controls))
+	if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) ||
+	    assign_in_user(&p32->which, &p64->which) ||
+	    get_user(count, &p64->count) ||
+	    put_user(count, &p32->count) ||
+	    assign_in_user(&p32->error_idx, &p64->error_idx) ||
+	    copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)) ||
+	    get_user(kcontrols, &p64->controls))
 		return -EFAULT;
 
 	if (!count || count > (U32_MAX/sizeof(*ucontrols)))
 		return 0;
-	if (get_user(p, &up->controls))
+	if (get_user(p, &p32->controls))
 		return -EFAULT;
 	ucontrols = compat_ptr(p);
 	if (!access_ok(VERIFY_WRITE, ucontrols, count * sizeof(*ucontrols)))

@@ -938,18 +938,18 @@ struct v4l2_event32 {
 	__u32				reserved[8];
 };
 
-static int put_v4l2_event32(struct v4l2_event __user *kp,
-			    struct v4l2_event32 __user *up)
+static int put_v4l2_event32(struct v4l2_event __user *p64,
+			    struct v4l2_event32 __user *p32)
 {
-	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
-	    assign_in_user(&up->type, &kp->type) ||
-	    copy_in_user(&up->u, &kp->u, sizeof(kp->u)) ||
-	    assign_in_user(&up->pending, &kp->pending) ||
-	    assign_in_user(&up->sequence, &kp->sequence) ||
-	    assign_in_user(&up->timestamp.tv_sec, &kp->timestamp.tv_sec) ||
-	    assign_in_user(&up->timestamp.tv_nsec, &kp->timestamp.tv_nsec) ||
-	    assign_in_user(&up->id, &kp->id) ||
-	    copy_in_user(up->reserved, kp->reserved, sizeof(up->reserved)))
+	if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) ||
+	    assign_in_user(&p32->type, &p64->type) ||
+	    copy_in_user(&p32->u, &p64->u, sizeof(p64->u)) ||
+	    assign_in_user(&p32->pending, &p64->pending) ||
+	    assign_in_user(&p32->sequence, &p64->sequence) ||
+	    assign_in_user(&p32->timestamp.tv_sec, &p64->timestamp.tv_sec) ||
+	    assign_in_user(&p32->timestamp.tv_nsec, &p64->timestamp.tv_nsec) ||
+	    assign_in_user(&p32->id, &p64->id) ||
+	    copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)))
 		return -EFAULT;
 	return 0;
 }

@@ -962,35 +962,35 @@ struct v4l2_edid32 {
 	compat_caddr_t edid;
 };
 
-static int get_v4l2_edid32(struct v4l2_edid __user *kp,
-			   struct v4l2_edid32 __user *up)
+static int get_v4l2_edid32(struct v4l2_edid __user *p64,
+			   struct v4l2_edid32 __user *p32)
 {
 	compat_uptr_t tmp;
 
-	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
-	    assign_in_user(&kp->pad, &up->pad) ||
-	    assign_in_user(&kp->start_block, &up->start_block) ||
-	    assign_in_user(&kp->blocks,
-			   (u32 __user *)&up->blocks) ||
-	    get_user(tmp, &up->edid) ||
-	    put_user((void __force *)compat_ptr(tmp), &kp->edid) ||
-	    copy_in_user(kp->reserved, up->reserved, sizeof(kp->reserved)))
+	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
+	    assign_in_user(&p64->pad, &p32->pad) ||
+	    assign_in_user(&p64->start_block, &p32->start_block) ||
+	    assign_in_user(&p64->blocks,
+			   (u32 __user *)&p32->blocks) ||
+	    get_user(tmp, &p32->edid) ||
+	    put_user((void __force *)compat_ptr(tmp), &p64->edid) ||
+	    copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved)))
 		return -EFAULT;
 	return 0;
 }
 
-static int put_v4l2_edid32(struct v4l2_edid __user *kp,
-			   struct v4l2_edid32 __user *up)
+static int put_v4l2_edid32(struct v4l2_edid __user *p64,
+			   struct v4l2_edid32 __user *p32)
 {
 	void *edid;
 
-	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
-	    assign_in_user(&up->pad, &kp->pad) ||
-	    assign_in_user(&up->start_block, &kp->start_block) ||
-	    assign_in_user(&up->blocks, &kp->blocks) ||
-	    get_user(edid, &kp->edid) ||
-	    put_user(ptr_to_compat((void __user *)edid), &up->edid) ||
-	    copy_in_user(up->reserved, kp->reserved, sizeof(up->reserved)))
+	if (!access_ok(VERIFY_WRITE, p32, sizeof(*p32)) ||
+	    assign_in_user(&p32->pad, &p64->pad) ||
+	    assign_in_user(&p32->start_block, &p64->start_block) ||
+	    assign_in_user(&p32->blocks, &p64->blocks) ||
+	    get_user(edid, &p64->edid) ||
+	    put_user(ptr_to_compat((void __user *)edid), &p32->edid) ||
+	    copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)))
 		return -EFAULT;
 	return 0;
 }

@@ -1024,20 +1024,20 @@ static int put_v4l2_edid32(struct v4l2_edid __user *kp,
 #define VIDIOC_S_OUTPUT32	_IOWR('V', 47, s32)
 
 static int alloc_userspace(unsigned int size, u32 aux_space,
-			   void __user **up_native)
+			   void __user **new_p64)
 {
-	*up_native = compat_alloc_user_space(size + aux_space);
-	if (!*up_native)
+	*new_p64 = compat_alloc_user_space(size + aux_space);
+	if (!*new_p64)
 		return -ENOMEM;
-	if (clear_user(*up_native, size))
+	if (clear_user(*new_p64, size))
 		return -EFAULT;
 	return 0;
 }
 
 static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	void __user *up = compat_ptr(arg);
-	void __user *up_native = NULL;
+	void __user *p32 = compat_ptr(arg);
+	void __user *new_p64 = NULL;
 	void __user *aux_buf;
 	u32 aux_space;
 	int compatible_arg = 1;

@@ -1078,50 +1078,50 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	case VIDIOC_STREAMOFF:
 	case VIDIOC_S_INPUT:
 	case VIDIOC_S_OUTPUT:
-		err = alloc_userspace(sizeof(unsigned int), 0, &up_native);
-		if (!err && assign_in_user((unsigned int __user *)up_native,
-					   (compat_uint_t __user *)up))
+		err = alloc_userspace(sizeof(unsigned int), 0, &new_p64);
+		if (!err && assign_in_user((unsigned int __user *)new_p64,
+					   (compat_uint_t __user *)p32))
 			err = -EFAULT;
 		compatible_arg = 0;
 		break;
 
 	case VIDIOC_G_INPUT:
 	case VIDIOC_G_OUTPUT:
-		err = alloc_userspace(sizeof(unsigned int), 0, &up_native);
+		err = alloc_userspace(sizeof(unsigned int), 0, &new_p64);
 		compatible_arg = 0;
 		break;
 
 	case VIDIOC_G_EDID:
 	case VIDIOC_S_EDID:
-		err = alloc_userspace(sizeof(struct v4l2_edid), 0, &up_native);
+		err = alloc_userspace(sizeof(struct v4l2_edid), 0, &new_p64);
 		if (!err)
-			err = get_v4l2_edid32(up_native, up);
+			err = get_v4l2_edid32(new_p64, p32);
 		compatible_arg = 0;
 		break;
 
 	case VIDIOC_G_FMT:
 	case VIDIOC_S_FMT:
 	case VIDIOC_TRY_FMT:
-		err = bufsize_v4l2_format(up, &aux_space);
+		err = bufsize_v4l2_format(p32, &aux_space);
 		if (!err)
 			err = alloc_userspace(sizeof(struct v4l2_format),
-					      aux_space, &up_native);
+					      aux_space, &new_p64);
 		if (!err) {
-			aux_buf = up_native + sizeof(struct v4l2_format);
-			err = get_v4l2_format32(up_native, up,
+			aux_buf = new_p64 + sizeof(struct v4l2_format);
+			err = get_v4l2_format32(new_p64, p32,
 						aux_buf, aux_space);
 		}
 		compatible_arg = 0;
 		break;
 
 	case VIDIOC_CREATE_BUFS:
-		err = bufsize_v4l2_create(up, &aux_space);
+		err = bufsize_v4l2_create(p32, &aux_space);
 		if (!err)
 			err = alloc_userspace(sizeof(struct v4l2_create_buffers),
-					      aux_space, &up_native);
+					      aux_space, &new_p64);
 		if (!err) {
-			aux_buf = up_native + sizeof(struct v4l2_create_buffers);
-			err = get_v4l2_create32(up_native, up,
+			aux_buf = new_p64 + sizeof(struct v4l2_create_buffers);
+			err = get_v4l2_create32(new_p64, p32,
 						aux_buf, aux_space);
 		}
 		compatible_arg = 0;

@@ -1131,13 +1131,13 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	case VIDIOC_QUERYBUF:
 	case VIDIOC_QBUF:
 	case VIDIOC_DQBUF:
-		err = bufsize_v4l2_buffer(up, &aux_space);
+		err = bufsize_v4l2_buffer(p32, &aux_space);
 		if (!err)
 			err = alloc_userspace(sizeof(struct v4l2_buffer),
-					      aux_space, &up_native);
+					      aux_space, &new_p64);
 		if (!err) {
-			aux_buf = up_native + sizeof(struct v4l2_buffer);
-			err = get_v4l2_buffer32(up_native, up,
+			aux_buf = new_p64 + sizeof(struct v4l2_buffer);
+			err = get_v4l2_buffer32(new_p64, p32,
 						aux_buf, aux_space);
 		}
 		compatible_arg = 0;

@@ -1145,49 +1145,49 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 
 	case VIDIOC_S_FBUF:
 		err = alloc_userspace(sizeof(struct v4l2_framebuffer), 0,
-				      &up_native);
+				      &new_p64);
 		if (!err)
-			err = get_v4l2_framebuffer32(up_native, up);
+			err = get_v4l2_framebuffer32(new_p64, p32);
 		compatible_arg = 0;
 		break;
 
 	case VIDIOC_G_FBUF:
 		err = alloc_userspace(sizeof(struct v4l2_framebuffer), 0,
-				      &up_native);
+				      &new_p64);
 		compatible_arg = 0;
 		break;
 
 	case VIDIOC_ENUMSTD:
 		err = alloc_userspace(sizeof(struct v4l2_standard), 0,
-				      &up_native);
+				      &new_p64);
 		if (!err)
-			err = get_v4l2_standard32(up_native, up);
+			err = get_v4l2_standard32(new_p64, p32);
 		compatible_arg = 0;
 		break;
 
 	case VIDIOC_ENUMINPUT:
-		err = alloc_userspace(sizeof(struct v4l2_input), 0, &up_native);
+		err = alloc_userspace(sizeof(struct v4l2_input), 0, &new_p64);
 		if (!err)
-			err = get_v4l2_input32(up_native, up);
+			err = get_v4l2_input32(new_p64, p32);
 		compatible_arg = 0;
 		break;
 
 	case VIDIOC_G_EXT_CTRLS:
 	case VIDIOC_S_EXT_CTRLS:
 	case VIDIOC_TRY_EXT_CTRLS:
-		err = bufsize_v4l2_ext_controls(up, &aux_space);
+		err = bufsize_v4l2_ext_controls(p32, &aux_space);
 		if (!err)
 			err = alloc_userspace(sizeof(struct v4l2_ext_controls),
-					      aux_space, &up_native);
+					      aux_space, &new_p64);
 		if (!err) {
-			aux_buf = up_native + sizeof(struct v4l2_ext_controls);
-			err = get_v4l2_ext_controls32(file, up_native, up,
+			aux_buf = new_p64 + sizeof(struct v4l2_ext_controls);
+			err = get_v4l2_ext_controls32(file, new_p64, p32,
 						      aux_buf, aux_space);
 		}
 		compatible_arg = 0;
 		break;
 	case VIDIOC_DQEVENT:
-		err = alloc_userspace(sizeof(struct v4l2_event), 0, &up_native);
+		err = alloc_userspace(sizeof(struct v4l2_event), 0, &new_p64);
 		compatible_arg = 0;
 		break;
 	}

@@ -1195,9 +1195,9 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 		return err;
 
 	if (compatible_arg)
-		err = native_ioctl(file, cmd, (unsigned long)up);
+		err = native_ioctl(file, cmd, (unsigned long)p32);
 	else
-		err = native_ioctl(file, cmd, (unsigned long)up_native);
+		err = native_ioctl(file, cmd, (unsigned long)new_p64);
 
 	if (err == -ENOTTY)
 		return err;

@@ -1211,11 +1211,11 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	case VIDIOC_G_EXT_CTRLS:
 	case VIDIOC_S_EXT_CTRLS:
 	case VIDIOC_TRY_EXT_CTRLS:
-		if (put_v4l2_ext_controls32(file, up_native, up))
+		if (put_v4l2_ext_controls32(file, new_p64, p32))
 			err = -EFAULT;
 		break;
 	case VIDIOC_S_EDID:
-		if (put_v4l2_edid32(up_native, up))
+		if (put_v4l2_edid32(new_p64, p32))
 			err = -EFAULT;
 		break;
 	}

@@ -1227,46 +1227,46 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	case VIDIOC_S_OUTPUT:
 	case VIDIOC_G_INPUT:
 	case VIDIOC_G_OUTPUT:
-		if (assign_in_user((compat_uint_t __user *)up,
-				   ((unsigned int __user *)up_native)))
+		if (assign_in_user((compat_uint_t __user *)p32,
+				   ((unsigned int __user *)new_p64)))
 			err = -EFAULT;
 		break;
 
 	case VIDIOC_G_FBUF:
-		err = put_v4l2_framebuffer32(up_native, up);
+		err = put_v4l2_framebuffer32(new_p64, p32);
 		break;
 
 	case VIDIOC_DQEVENT:
-		err = put_v4l2_event32(up_native, up);
+		err = put_v4l2_event32(new_p64, p32);
 		break;
 
 	case VIDIOC_G_EDID:
-		err = put_v4l2_edid32(up_native, up);
+		err = put_v4l2_edid32(new_p64, p32);
 		break;
 
 	case VIDIOC_G_FMT:
 	case VIDIOC_S_FMT:
 	case VIDIOC_TRY_FMT:
-		err = put_v4l2_format32(up_native, up);
+		err = put_v4l2_format32(new_p64, p32);
 		break;
 
 	case VIDIOC_CREATE_BUFS:
-		err = put_v4l2_create32(up_native, up);
+		err = put_v4l2_create32(new_p64, p32);
 		break;
 
 	case VIDIOC_PREPARE_BUF:
 	case VIDIOC_QUERYBUF:
 	case VIDIOC_QBUF:
 	case VIDIOC_DQBUF:
-		err = put_v4l2_buffer32(up_native, up);
+		err = put_v4l2_buffer32(new_p64, p32);
 		break;
 
 	case VIDIOC_ENUMSTD:
-		err = put_v4l2_standard32(up_native, up);
+		err = put_v4l2_standard32(new_p64, p32);
 		break;
 
 	case VIDIOC_ENUMINPUT:
-		err = put_v4l2_input32(up_native, up);
+		err = put_v4l2_input32(new_p64, p32);
 		break;
 	}
 	return err;

index 680b64c1d69a..d2f0268427c2 100644
@@ -30,6 +30,24 @@
 	get_user(__assign_tmp, from) || put_user(__assign_tmp, to);	\
 })
 
+#define get_user_cast(__x, __ptr)					\
+({									\
+	get_user(__x, (typeof(*__ptr) __user *)(__ptr));		\
+})
+
+#define put_user_force(__x, __ptr)					\
+({									\
+	put_user((typeof(*__x) __force *)(__x), __ptr);			\
+})
+
+#define assign_in_user_cast(to, from)					\
+({									\
+	typeof(*from) __assign_tmp;					\
+									\
+	get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\
+})
+
+
 static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	long ret = -ENOIOCTLCMD;

@@ -543,8 +561,7 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64,
 			return -EFAULT;
 
 		uplane = aux_buf;
-		if (put_user((__force struct v4l2_plane *)uplane,
-			     &p64->m.planes))
+		if (put_user_force(uplane, &p64->m.planes))
 			return -EFAULT;
 
 		while (num_planes--) {

@@ -682,7 +699,7 @@ static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64,
 
 	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
 	    get_user(tmp, &p32->base) ||
-	    put_user((void __force *)compat_ptr(tmp), &p64->base) ||
+	    put_user_force(compat_ptr(tmp), &p64->base) ||
 	    assign_in_user(&p64->capability, &p32->capability) ||
 	    assign_in_user(&p64->flags, &p32->flags) ||
 	    copy_in_user(&p64->fmt, &p32->fmt, sizeof(p64->fmt)))

@@ -831,8 +848,7 @@ static int get_v4l2_ext_controls32(struct file *file,
 	if (aux_space < count * sizeof(*kcontrols))
 		return -EFAULT;
 	kcontrols = aux_buf;
-	if (put_user((__force struct v4l2_ext_control *)kcontrols,
-		     &p64->controls))
+	if (put_user_force(kcontrols, &p64->controls))
 		return -EFAULT;
 
 	for (n = 0; n < count; n++) {

@@ -898,10 +914,9 @@ static int put_v4l2_ext_controls32(struct file *file,
 		unsigned int size = sizeof(*ucontrols);
 		u32 id;
 
-		if (get_user(id, (unsigned int __user *)&kcontrols->id) ||
+		if (get_user_cast(id, &kcontrols->id) ||
 		    put_user(id, &ucontrols->id) ||
-		    assign_in_user(&ucontrols->size,
-				   (unsigned int __user *)&kcontrols->size) ||
+		    assign_in_user_cast(&ucontrols->size, &kcontrols->size) ||
 		    copy_in_user(&ucontrols->reserved2,
 				 (void __user *)&kcontrols->reserved2,
 				 sizeof(ucontrols->reserved2)))

@@ -970,10 +985,9 @@ static int get_v4l2_edid32(struct v4l2_edid __user *p64,
 	if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) ||
 	    assign_in_user(&p64->pad, &p32->pad) ||
 	    assign_in_user(&p64->start_block, &p32->start_block) ||
-	    assign_in_user(&p64->blocks,
-			   (u32 __user *)&p32->blocks) ||
+	    assign_in_user_cast(&p64->blocks, &p32->blocks) ||
 	    get_user(tmp, &p32->edid) ||
-	    put_user((void __force *)compat_ptr(tmp), &p64->edid) ||
+	    put_user_force(compat_ptr(tmp), &p64->edid) ||
 	    copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved)))
 		return -EFAULT;
 	return 0;

index d2f0268427c2..777ed179af5f 100644
@@ -22,7 +22,18 @@
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-ioctl.h>
 
-/* Use the same argument order as copy_in_user */
+/**
+ * assign_in_user() - Copy from one __user var to another one
+ *
+ * @to: __user var where data will be stored
+ * @from: __user var were data will be retrieved.
+ *
+ * As this code very often needs to allocate userspace memory, it is easier
+ * to have a macro that will do both get_user() and put_user() at once.
+ *
+ * This function complements the macros defined at asm-generic/uaccess.h.
+ * It uses the same argument order as copy_in_user()
+ */
 #define assign_in_user(to, from)					\
 ({									\
 	typeof(*from) __assign_tmp;					\

@@ -30,16 +41,57 @@
 	get_user(__assign_tmp, from) || put_user(__assign_tmp, to);	\
 })
 
+/**
+ * get_user_cast() - Stores at a kernelspace local var the contents from a
+ *		pointer with userspace data that is not tagged with __user.
+ *
+ * @__x: var where data will be stored
+ * @ptr: var were data will be retrieved.
+ *
+ * Sometimes, we need to declare a pointer without __user, because it
+ * comes from a pointer struct field that will be retrieved from userspace
+ * by the 64-bit native ioctl handler. This function ensures that the
+ * @ptr will be casted to __user before calling get_user(), in order to
+ * avoid warnings with static code analyzers like smatch.
+ */
 #define get_user_cast(__x, __ptr)					\
 ({									\
 	get_user(__x, (typeof(*__ptr) __user *)(__ptr));		\
 })
 
+/**
+ * put_user_force() - Stores at the contents of a kernelspace local var
+ *		      into an userspace pointer, removing any __user cast.
+ *
+ * @__x: var where data will be stored
+ * @ptr: var were data will be retrieved.
+ *
+ * As the compat32 code now handles with 32-bits and 64-bits __user
+ * structs, sometimes we need to remove the __user atributes from some data,
+ * by passing __force macro. This function ensures that the
+ * @ptr will be casted with __force before calling put_user(), in order to
+ * avoid warnings with static code analyzers like smatch.
+ */
 #define put_user_force(__x, __ptr)					\
 ({									\
 	put_user((typeof(*__x) __force *)(__x), __ptr);			\
 })
 
+/**
+ * assign_in_user_cast() - Copy from one __user var to another one
+ *
+ * @to: __user var where data will be stored
+ * @from: var were data will be retrieved that needs to be cast to __user.
+ *
+ * As this code very often needs to allocate userspace memory, it is easier
+ * to have a macro that will do both get_user_cast() and put_user() at once.
+ *
+ * This function should be used instead of assign_in_user() when the @from
+ * variable was not declared as __user. See get_user_cast() for more details.
+ *
+ * This function complements the macros defined at asm-generic/uaccess.h.
+ * It uses the same argument order as copy_in_user()
+ */
 #define assign_in_user_cast(to, from)					\
 ({									\
 	typeof(*from) __assign_tmp;					\

@@ -47,7 +99,16 @@
 	get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\
 })
 
-
+/**
+ * native_ioctl - Ancillary function that calls the native 64 bits ioctl
+ * handler.
+ *
+ * @file: pointer to &struct file with the file handler
+ * @cmd: ioctl to be called
+ * @arg: arguments passed from/to the ioctl handler
+ *
+ * This function calls the native ioctl handler at v4l2-dev, e. g. v4l2_ioctl()
+ */
 static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	long ret = -ENOIOCTLCMD;

@@ -59,6 +120,21 @@ static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 }
 
 
+/*
+ * Per-ioctl data copy handlers.
+ *
+ * Those come in pairs, with a get_v4l2_foo() and a put_v4l2_foo() routine,
+ * where "v4l2_foo" is the name of the V4L2 struct.
+ *
+ * They basically get two __user pointers, one with a 32-bits struct that
+ * came from the userspace call and a 64-bits struct, also allocated as
+ * userspace, but filled internally by do_video_ioctl().
+ *
+ * For ioctls that have pointers inside it, the functions will also
+ * receive an ancillary buffer with extra space, used to pass extra
+ * data to the routine.
+ */
+
 struct v4l2_clip32 {
 	struct v4l2_rect        c;
 	compat_caddr_t		next;

@@ -1009,6 +1085,13 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64,
 	return 0;
 }
 
+/*
+ * List of ioctl's that require 32-bits/64-bits conversion
+ *
+ * The V4L2 ioctls that aren't listed there don't have pointer arguments
+ * and the struct size is identical for both 32 and 64 bits versions, so
+ * don't need translations.
+ */
 
 #define VIDIOC_G_FMT32		_IOWR('V',  4, struct v4l2_format32)
 #define VIDIOC_S_FMT32		_IOWR('V',  5, struct v4l2_format32)

@@ -1037,6 +1120,21 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64,
 #define VIDIOC_G_OUTPUT32	_IOR ('V', 46, s32)
 #define VIDIOC_S_OUTPUT32	_IOWR('V', 47, s32)
 
+/**
+ * alloc_userspace() - Allocates a 64-bits userspace pointer compatible
+ *	for calling the native 64-bits version of an ioctl.
+ *
+ * @size:	size of the structure itself to be allocated.
+ * @aux_space:	extra size needed to store "extra" data, e. g. space for
+ *		other __user data that comes pointed by fields inside the
+ *		structure.
+ * @new_p64:	pointer to a pointer to be filled with the allocated struct.
+ *
+ * Return:
+ *
+ * if it can't allocate memory, either -ENOMEM or -EFAULT will be returned.
+ * Zero otherwise.
+ */
 static int alloc_userspace(unsigned int size, u32 aux_space,
 			   void __user **new_p64)
 {

@@ -1048,6 +1146,23 @@ static int alloc_userspace(unsigned int size, u32 aux_space,
 	return 0;
 }
 
+/**
+ * do_video_ioctl() - Ancillary function with handles a compat32 ioctl call
+ *
+ * @file: pointer to &struct file with the file handler
+ * @cmd: ioctl to be called
+ * @arg: arguments passed from/to the ioctl handler
+ *
+ * This function is called when a 32 bits application calls a V4L2 ioctl
+ * and the Kernel is compiled with 64 bits.
+ *
+ * This function is called by v4l2_compat_ioctl32() when the function is
+ * not private to some specific driver.
+ *
+ * It converts a 32-bits struct into a 64 bits one, calls the native 64-bits
+ * ioctl handles and fills back the 32-bits struct with the results of the
+ * native call.
+ */
 static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	void __user *p32 = compat_ptr(arg);

@@ -1057,7 +1172,9 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	int compatible_arg = 1;
 	long err = 0;
 
-	/* First, convert the command. */
+	/*
+	 * 1. When struct size is different, converts the command.
+	 */
 	switch (cmd) {
 	case VIDIOC_G_FMT32: cmd = VIDIOC_G_FMT; break;
 	case VIDIOC_S_FMT32: cmd = VIDIOC_S_FMT; break;

@@ -1086,6 +1203,11 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	case VIDIOC_S_EDID32: cmd = VIDIOC_S_EDID; break;
 	}
 
+	/*
+	 * 2. Allocates a 64-bits userspace pointer to store the
+	 * values of the ioctl and copy data from the 32-bits __user
+	 * argument into it.
+	 */
 	switch (cmd) {
 	case VIDIOC_OVERLAY:
 	case VIDIOC_STREAMON:

@@ -1208,6 +1330,15 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	if (err)
 		return err;
 
+	/*
+	 * 3. Calls the native 64-bits ioctl handler.
+	 *
+	 * For the functions where a conversion was not needed,
+	 * compatible_arg is true, and it will call it with the arguments
+	 * provided by userspace and stored at @p32 var.
+	 *
+	 * Otherwise, it will pass the newly allocated @new_p64 argument.
+	 */
 	if (compatible_arg)
 		err = native_ioctl(file, cmd, (unsigned long)p32);
 	else

@@ -1217,9 +1348,14 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 		return err;
 
 	/*
-	 * Special case: even after an error we need to put the
-	 * results back for these ioctls since the error_idx will
-	 * contain information on which control failed.
+	 * 4. Special case: even after an error we need to put the
+	 * results back for some ioctls.
+	 *
+	 * In the case of EXT_CTRLS, the error_idx will contain information
+	 * on which control failed.
+	 *
+	 * In the case of S_EDID, the driver can return E2BIG and set
+	 * the blocks to maximum allowed value.
 	 */
 	switch (cmd) {
 	case VIDIOC_G_EXT_CTRLS:

@@ -1236,6 +1372,10 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	if (err)
 		return err;
 
+	/*
+	 * 5. Copy the data returned at the 64 bits userspace pointer to
+	 * the original 32 bits structure.
+	 */
 	switch (cmd) {
 	case VIDIOC_S_INPUT:
 	case VIDIOC_S_OUTPUT:

@@ -1286,6 +1426,20 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	return err;
 }
 
+/**
+ * v4l2_compat_ioctl32() - Handles a compat32 ioctl call
+ *
+ * @file: pointer to &struct file with the file handler
+ * @cmd: ioctl to be called
+ * @arg: arguments passed from/to the ioctl handler
+ *
+ * This function is meant to be used as .compat_ioctl fops at v4l2-dev.c
+ * in order to deal with 32-bit calls on a 64-bits Kernel.
+ *
+ * This function calls do_video_ioctl() for non-private V4L2 ioctls.
+ * If the function is a private one, it calls, instead,
+ * vdev->fops->compat_ioctl32.
+ */
 long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct video_device *vdev = video_devdata(file);

index 777ed179af5f..c460fbcbc035 100644
@@ -46,12 +46,12 @@
  *		pointer with userspace data that is not tagged with __user.
  *
  * @__x: var where data will be stored
- * @ptr: var were data will be retrieved.
+ * @__ptr: var were data will be retrieved.
  *
  * Sometimes, we need to declare a pointer without __user, because it
  * comes from a pointer struct field that will be retrieved from userspace
  * by the 64-bit native ioctl handler. This function ensures that the
- * @ptr will be casted to __user before calling get_user(), in order to
+ * @__ptr will be casted to __user before calling get_user(), in order to
  * avoid warnings with static code analyzers like smatch.
  */
 #define get_user_cast(__x, __ptr)					\

@@ -64,12 +64,12 @@
  *		      into an userspace pointer, removing any __user cast.
  *
  * @__x: var where data will be stored
- * @ptr: var were data will be retrieved.
+ * @__ptr: var were data will be retrieved.
  *
  * As the compat32 code now handles with 32-bits and 64-bits __user
  * structs, sometimes we need to remove the __user atributes from some data,
  * by passing __force macro. This function ensures that the
- * @ptr will be casted with __force before calling put_user(), in order to
+ * @__ptr will be casted with __force before calling put_user(), in order to
  * avoid warnings with static code analyzers like smatch.
  */
 #define put_user_force(__x, __ptr)					\

254 lines not on this page · raw message

index c460fbcbc035..9611c3aae8ca 100644
@@ -26,7 +26,7 @@
  * assign_in_user() - Copy from one __user var to another one
  *
  * @to: __user var where data will be stored
- * @from: __user var were data will be retrieved.
+ * @from: __user var where data will be retrieved.
  *
  * As this code very often needs to allocate userspace memory, it is easier
  * to have a macro that will do both get_user() and put_user() at once.

@@ -46,12 +46,12 @@
  *		pointer with userspace data that is not tagged with __user.
  *
  * @__x: var where data will be stored
- * @__ptr: var were data will be retrieved.
+ * @__ptr: var where data will be retrieved.
  *
- * Sometimes, we need to declare a pointer without __user, because it
+ * Sometimes we need to declare a pointer without __user because it
  * comes from a pointer struct field that will be retrieved from userspace
  * by the 64-bit native ioctl handler. This function ensures that the
- * @__ptr will be casted to __user before calling get_user(), in order to
+ * @__ptr will be cast to __user before calling get_user() in order to
  * avoid warnings with static code analyzers like smatch.
  */
 #define get_user_cast(__x, __ptr)					\

@@ -60,16 +60,15 @@
 })
 
 /**
- * put_user_force() - Stores at the contents of a kernelspace local var
+ * put_user_force() - Stores the contents of a kernelspace local var
  *		      into an userspace pointer, removing any __user cast.
  *
  * @__x: var where data will be stored
- * @__ptr: var were data will be retrieved.
+ * @__ptr: var where data will be retrieved.
  *
- * As the compat32 code now handles with 32-bits and 64-bits __user
- * structs, sometimes we need to remove the __user atributes from some data,
- * by passing __force macro. This function ensures that the
- * @__ptr will be casted with __force before calling put_user(), in order to
+ * Sometimes we need to remove the __user attribute from some data,
+ * by passing the __force macro. This function ensures that the
+ * @__ptr will be cast with __force before calling put_user(), in order to
  * avoid warnings with static code analyzers like smatch.
  */
 #define put_user_force(__x, __ptr)					\

@@ -81,7 +80,7 @@
  * assign_in_user_cast() - Copy from one __user var to another one
  *
  * @to: __user var where data will be stored
- * @from: var were data will be retrieved that needs to be cast to __user.
+ * @from: var where data will be retrieved that needs to be cast to __user.
  *
  * As this code very often needs to allocate userspace memory, it is easier
  * to have a macro that will do both get_user_cast() and put_user() at once.

@@ -1086,11 +1085,11 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64,
 }
 
 /*
- * List of ioctl's that require 32-bits/64-bits conversion
+ * List of ioctls that require 32-bits/64-bits conversion
  *
  * The V4L2 ioctls that aren't listed there don't have pointer arguments
  * and the struct size is identical for both 32 and 64 bits versions, so
- * don't need translations.
+ * they don't need translations.
  */
 
 #define VIDIOC_G_FMT32		_IOWR('V',  4, struct v4l2_format32)

@@ -1125,8 +1124,8 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64,
  *	for calling the native 64-bits version of an ioctl.
  *
  * @size:	size of the structure itself to be allocated.
- * @aux_space:	extra size needed to store "extra" data, e. g. space for
- *		other __user data that comes pointed by fields inside the
+ * @aux_space:	extra size needed to store "extra" data, e.g. space for
+ *		other __user data that is pointed to fields inside the
  *		structure.
  * @new_p64:	pointer to a pointer to be filled with the allocated struct.
  *

@@ -1160,7 +1159,7 @@ static int alloc_userspace(unsigned int size, u32 aux_space,
  * not private to some specific driver.
  *
  * It converts a 32-bits struct into a 64 bits one, calls the native 64-bits
- * ioctl handles and fills back the 32-bits struct with the results of the
+ * ioctl handler and fills back the 32-bits struct with the results of the
  * native call.
  */
 static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

@@ -1437,8 +1436,8 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
  * in order to deal with 32-bit calls on a 64-bits Kernel.
  *
  * This function calls do_video_ioctl() for non-private V4L2 ioctls.
- * If the function is a private one, it calls, instead,
- * vdev->fops->compat_ioctl32.
+ * If the function is a private one it calls vdev->fops->compat_ioctl32
+ * instead.
  */
 long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg)
 {

index d2f0268427c2..9611c3aae8ca 100644
@@ -22,7 +22,18 @@
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-ioctl.h>
 
-/* Use the same argument order as copy_in_user */
+/**
+ * assign_in_user() - Copy from one __user var to another one
+ *
+ * @to: __user var where data will be stored
+ * @from: __user var where data will be retrieved.
+ *
+ * As this code very often needs to allocate userspace memory, it is easier
+ * to have a macro that will do both get_user() and put_user() at once.
+ *
+ * This function complements the macros defined at asm-generic/uaccess.h.
+ * It uses the same argument order as copy_in_user()
+ */
 #define assign_in_user(to, from)					\
 ({									\
 	typeof(*from) __assign_tmp;					\

@@ -30,16 +41,56 @@
 	get_user(__assign_tmp, from) || put_user(__assign_tmp, to);	\
 })
 
+/**
+ * get_user_cast() - Stores at a kernelspace local var the contents from a
+ *		pointer with userspace data that is not tagged with __user.
+ *
+ * @__x: var where data will be stored
+ * @__ptr: var where data will be retrieved.
+ *
+ * Sometimes we need to declare a pointer without __user because it
+ * comes from a pointer struct field that will be retrieved from userspace
+ * by the 64-bit native ioctl handler. This function ensures that the
+ * @__ptr will be cast to __user before calling get_user() in order to
+ * avoid warnings with static code analyzers like smatch.
+ */
 #define get_user_cast(__x, __ptr)					\
 ({									\
 	get_user(__x, (typeof(*__ptr) __user *)(__ptr));		\
 })
 
+/**
+ * put_user_force() - Stores the contents of a kernelspace local var
+ *		      into an userspace pointer, removing any __user cast.
+ *
+ * @__x: var where data will be stored
+ * @__ptr: var where data will be retrieved.
+ *
+ * Sometimes we need to remove the __user attribute from some data,
+ * by passing the __force macro. This function ensures that the
+ * @__ptr will be cast with __force before calling put_user(), in order to
+ * avoid warnings with static code analyzers like smatch.
+ */
 #define put_user_force(__x, __ptr)					\
 ({									\
 	put_user((typeof(*__x) __force *)(__x), __ptr);			\
 })
 
+/**
+ * assign_in_user_cast() - Copy from one __user var to another one
+ *
+ * @to: __user var where data will be stored
+ * @from: var where data will be retrieved that needs to be cast to __user.
+ *
+ * As this code very often needs to allocate userspace memory, it is easier
+ * to have a macro that will do both get_user_cast() and put_user() at once.
+ *
+ * This function should be used instead of assign_in_user() when the @from
+ * variable was not declared as __user. See get_user_cast() for more details.
+ *
+ * This function complements the macros defined at asm-generic/uaccess.h.
+ * It uses the same argument order as copy_in_user()
+ */
 #define assign_in_user_cast(to, from)					\
 ({									\
 	typeof(*from) __assign_tmp;					\

@@ -47,7 +98,16 @@
 	get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\
 })
 
-
+/**
+ * native_ioctl - Ancillary function that calls the native 64 bits ioctl
+ * handler.
+ *
+ * @file: pointer to &struct file with the file handler
+ * @cmd: ioctl to be called
+ * @arg: arguments passed from/to the ioctl handler
+ *
+ * This function calls the native ioctl handler at v4l2-dev, e. g. v4l2_ioctl()
+ */
 static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	long ret = -ENOIOCTLCMD;

@@ -59,6 +119,21 @@ static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 }
 
 
+/*
+ * Per-ioctl data copy handlers.
+ *
+ * Those come in pairs, with a get_v4l2_foo() and a put_v4l2_foo() routine,
+ * where "v4l2_foo" is the name of the V4L2 struct.
+ *
+ * They basically get two __user pointers, one with a 32-bits struct that
+ * came from the userspace call and a 64-bits struct, also allocated as
+ * userspace, but filled internally by do_video_ioctl().
+ *
+ * For ioctls that have pointers inside it, the functions will also
+ * receive an ancillary buffer with extra space, used to pass extra
+ * data to the routine.
+ */
+
 struct v4l2_clip32 {
 	struct v4l2_rect        c;
 	compat_caddr_t		next;

@@ -1009,6 +1084,13 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64,
 	return 0;
 }
 
+/*
+ * List of ioctls that require 32-bits/64-bits conversion
+ *
+ * The V4L2 ioctls that aren't listed there don't have pointer arguments
+ * and the struct size is identical for both 32 and 64 bits versions, so
+ * they don't need translations.
+ */
 
 #define VIDIOC_G_FMT32		_IOWR('V',  4, struct v4l2_format32)
 #define VIDIOC_S_FMT32		_IOWR('V',  5, struct v4l2_format32)

@@ -1037,6 +1119,21 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64,
 #define VIDIOC_G_OUTPUT32	_IOR ('V', 46, s32)
 #define VIDIOC_S_OUTPUT32	_IOWR('V', 47, s32)
 
+/**
+ * alloc_userspace() - Allocates a 64-bits userspace pointer compatible
+ *	for calling the native 64-bits version of an ioctl.
+ *
+ * @size:	size of the structure itself to be allocated.
+ * @aux_space:	extra size needed to store "extra" data, e.g. space for
+ *		other __user data that is pointed to fields inside the
+ *		structure.
+ * @new_p64:	pointer to a pointer to be filled with the allocated struct.
+ *
+ * Return:
+ *
+ * if it can't allocate memory, either -ENOMEM or -EFAULT will be returned.
+ * Zero otherwise.
+ */
 static int alloc_userspace(unsigned int size, u32 aux_space,
 			   void __user **new_p64)
 {

@@ -1048,6 +1145,23 @@ static int alloc_userspace(unsigned int size, u32 aux_space,
 	return 0;
 }
 
+/**
+ * do_video_ioctl() - Ancillary function with handles a compat32 ioctl call
+ *
+ * @file: pointer to &struct file with the file handler
+ * @cmd: ioctl to be called
+ * @arg: arguments passed from/to the ioctl handler
+ *
+ * This function is called when a 32 bits application calls a V4L2 ioctl
+ * and the Kernel is compiled with 64 bits.
+ *
+ * This function is called by v4l2_compat_ioctl32() when the function is
+ * not private to some specific driver.
+ *
+ * It converts a 32-bits struct into a 64 bits one, calls the native 64-bits
+ * ioctl handler and fills back the 32-bits struct with the results of the
+ * native call.
+ */
 static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	void __user *p32 = compat_ptr(arg);

@@ -1057,7 +1171,9 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	int compatible_arg = 1;
 	long err = 0;
 
-	/* First, convert the command. */
+	/*
+	 * 1. When struct size is different, converts the command.
+	 */
 	switch (cmd) {
 	case VIDIOC_G_FMT32: cmd = VIDIOC_G_FMT; break;
 	case VIDIOC_S_FMT32: cmd = VIDIOC_S_FMT; break;

@@ -1086,6 +1202,11 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	case VIDIOC_S_EDID32: cmd = VIDIOC_S_EDID; break;
 	}
 
+	/*
+	 * 2. Allocates a 64-bits userspace pointer to store the
+	 * values of the ioctl and copy data from the 32-bits __user
+	 * argument into it.
+	 */
 	switch (cmd) {
 	case VIDIOC_OVERLAY:
 	case VIDIOC_STREAMON:

@@ -1208,6 +1329,15 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	if (err)
 		return err;
 
+	/*
+	 * 3. Calls the native 64-bits ioctl handler.
+	 *
+	 * For the functions where a conversion was not needed,
+	 * compatible_arg is true, and it will call it with the arguments
+	 * provided by userspace and stored at @p32 var.
+	 *
+	 * Otherwise, it will pass the newly allocated @new_p64 argument.
+	 */
 	if (compatible_arg)
 		err = native_ioctl(file, cmd, (unsigned long)p32);
 	else

@@ -1217,9 +1347,14 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 		return err;
 
 	/*
-	 * Special case: even after an error we need to put the
-	 * results back for these ioctls since the error_idx will
-	 * contain information on which control failed.
+	 * 4. Special case: even after an error we need to put the
+	 * results back for some ioctls.
+	 *
+	 * In the case of EXT_CTRLS, the error_idx will contain information
+	 * on which control failed.
+	 *
+	 * In the case of S_EDID, the driver can return E2BIG and set
+	 * the blocks to maximum allowed value.
 	 */
 	switch (cmd) {
 	case VIDIOC_G_EXT_CTRLS:

@@ -1236,6 +1371,10 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	if (err)
 		return err;
 
+	/*
+	 * 5. Copy the data returned at the 64 bits userspace pointer to
+	 * the original 32 bits structure.
+	 */
 	switch (cmd) {
 	case VIDIOC_S_INPUT:
 	case VIDIOC_S_OUTPUT:

@@ -1286,6 +1425,20 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 	return err;
 }
 
+/**
+ * v4l2_compat_ioctl32() - Handles a compat32 ioctl call
+ *
+ * @file: pointer to &struct file with the file handler
+ * @cmd: ioctl to be called
+ * @arg: arguments passed from/to the ioctl handler
+ *
+ * This function is meant to be used as .compat_ioctl fops at v4l2-dev.c
+ * in order to deal with 32-bit calls on a 64-bits Kernel.
+ *
+ * This function calls do_video_ioctl() for non-private V4L2 ioctls.
+ * If the function is a private one it calls vdev->fops->compat_ioctl32
+ * instead.
+ */
 long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct video_device *vdev = video_devdata(file);