The v4l2_event structure contains a 'struct timespec' member that is defined by the user space C library, creating an ABI incompatibility when that gets updated to a 64-bit time_t.
While passing a 32-bit time_t here would be sufficient for CLOCK_MONOTONIC timestamps, simply redefining the structure to use the kernel's __kernel_old_timespec would not work for any library that uses a copy of the linux/videodev2.h header file rather than including the copy from the latest kernel headers.
This means the kernel has to be changed to handle both versions of the structure layout on a 32-bit architecture. The easiest way to do this is during the copy from/to user space.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/media/v4l2-core/v4l2-event.c | 5 ++++- drivers/media/v4l2-core/v4l2-ioctl.c | 22 ++++++++++++++++++++ drivers/media/v4l2-core/v4l2-subdev.c | 20 +++++++++++++++++- include/uapi/linux/videodev2.h | 30 +++++++++++++++++++++++++++ 4 files changed, 75 insertions(+), 2 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-event.c b/drivers/media/v4l2-core/v4l2-event.c index 9d673d113d7a..290c6b213179 100644 --- a/drivers/media/v4l2-core/v4l2-event.c +++ b/drivers/media/v4l2-core/v4l2-event.c @@ -27,6 +27,7 @@ static unsigned sev_pos(const struct v4l2_subscribed_event *sev, unsigned idx) static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event) { struct v4l2_kevent *kev; + struct timespec64 ts; unsigned long flags;
spin_lock_irqsave(&fh->vdev->fh_lock, flags); @@ -44,7 +45,9 @@ static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
kev->event.pending = fh->navailable; *event = kev->event; - event->timestamp = ns_to_timespec(kev->ts); + ts = ns_to_timespec64(kev->ts); + event->timestamp.tv_sec = ts.tv_sec; + event->timestamp.tv_nsec = ts.tv_nsec; kev->sev->first = sev_pos(kev->sev, 1); kev->sev->in_use--;
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 50612b4749d3..b8aca0d174bd 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -3025,6 +3025,13 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size,
static unsigned int video_translate_cmd(unsigned int cmd) { + switch (cmd) { +#ifdef CONFIG_COMPAT_32BIT_TIME + case VIDIOC_DQEVENT_TIME32: + return VIDIOC_DQEVENT; +#endif + } + return cmd; }
@@ -3074,6 +3081,21 @@ static int video_put_user(void __user *arg, void *parg, unsigned int cmd) return 0;
switch (cmd) { +#ifdef CONFIG_COMPAT_32BIT_TIME + case VIDIOC_DQEVENT_TIME32: { + struct v4l2_event_time32 ev32; + struct v4l2_event *ev = parg; + + memcpy(&ev32, ev, offsetof(struct v4l2_event, timestamp)); + ev32.timestamp.tv_sec = ev->timestamp.tv_sec; + ev32.timestamp.tv_nsec = ev->timestamp.tv_nsec; + memcpy(&ev32.id, &ev->id, sizeof(*ev) - offsetof(struct v4l2_event, id)); + + if (copy_to_user(arg, &ev32, sizeof(ev32))) + return -EFAULT; + break; + } +#endif default: /* Copy results into user buffer */ if (copy_to_user(arg, parg, _IOC_SIZE(cmd))) diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index 9e987c0f840e..77b77807aaca 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -331,8 +331,8 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) struct v4l2_fh *vfh = file->private_data; #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh); - int rval; #endif + int rval;
switch (cmd) { case VIDIOC_QUERYCTRL: @@ -392,6 +392,24 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
return v4l2_event_dequeue(vfh, arg, file->f_flags & O_NONBLOCK);
+ case VIDIOC_DQEVENT_TIME32: { + struct v4l2_event_time32 *ev32 = arg; + struct v4l2_event ev; + + if (!(sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS)) + return -ENOIOCTLCMD; + + rval = v4l2_event_dequeue(vfh, &ev, file->f_flags & O_NONBLOCK); + + memcpy(ev32, &ev, offsetof(struct v4l2_event, timestamp)); + ev32->timestamp.tv_sec = ev.timestamp.tv_sec; + ev32->timestamp.tv_nsec = ev.timestamp.tv_nsec; + memcpy(&ev32->id, &ev.id, + sizeof(ev) - offsetof(struct v4l2_event, id)); + + return rval; + } + case VIDIOC_SUBSCRIBE_EVENT: return v4l2_subdev_call(sd, core, subscribe_event, vfh, arg);
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 5de1e37995c0..e38afa71a327 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -2340,11 +2340,40 @@ struct v4l2_event { } u; __u32 pending; __u32 sequence; +#ifdef __KERNEL__ + struct __kernel_timespec timestamp; +#else struct timespec timestamp; +#endif __u32 id; __u32 reserved[8]; };
+#ifdef __KERNEL__ +/* + * The user space interpretation of the 'v4l2_event' differs + * based on the 'time_t' definition on 32-bit architectures, so + * the kernel has to handle both. + * This is the old version for 32-bit architectures. + */ +struct v4l2_event_time32 { + __u32 type; + union { + struct v4l2_event_vsync vsync; + struct v4l2_event_ctrl ctrl; + struct v4l2_event_frame_sync frame_sync; + struct v4l2_event_src_change src_change; + struct v4l2_event_motion_det motion_det; + __u8 data[64]; + } u; + __u32 pending; + __u32 sequence; + struct old_timespec32 timestamp; + __u32 id; + __u32 reserved[8]; +}; +#endif + #define V4L2_EVENT_SUB_FL_SEND_INITIAL (1 << 0) #define V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK (1 << 1)
@@ -2497,6 +2526,7 @@ struct v4l2_create_buffers { #define VIDIOC_S_DV_TIMINGS _IOWR('V', 87, struct v4l2_dv_timings) #define VIDIOC_G_DV_TIMINGS _IOWR('V', 88, struct v4l2_dv_timings) #define VIDIOC_DQEVENT _IOR('V', 89, struct v4l2_event) +#define VIDIOC_DQEVENT_TIME32 _IOR('V', 89, struct v4l2_event_time32) #define VIDIOC_SUBSCRIBE_EVENT _IOW('V', 90, struct v4l2_event_subscription) #define VIDIOC_UNSUBSCRIBE_EVENT _IOW('V', 91, struct v4l2_event_subscription) #define VIDIOC_CREATE_BUFS _IOWR('V', 92, struct v4l2_create_buffers)