I'm in the process of finishing up the last bits on y2038-unsafe code in the kernel, this series is for v4l2, which has no problem with overflow, but has multiple ioctls that break with user space built against a new 32-bit libc.
I posted similar patches as part of a series back in 2015, the new version was rewritten from scratch and I double-checked with the old version to make sure I did not miss anything I had already taken care of before.
Hans Verkuil worked on a different patch set in 2017, but this also did not get to the point of being merged.
My new version contains compat-ioctl support, which the old one did not and should be complete, but given its size likely contains bugs. I did randconfig build tests, but no runtime test, so careful review as well as testing would be much appreciated.
With this version, the newly added code takes care of the existing ABI, while the existing code got moved to the 64-bit time_t interface and is used internally. This means that testing with existing binaries should exercise most of the modifications and if that works and doesn't get shot down in review, we can probably live without testing the new ABI explicitly.
I'm not entirely happy with the compat-ioctl implementation that adds quite a bit of code duplication, but I hope this is acceptable anyway, as a better implementation would likely require a larger refactoring of the compat-ioctl file, while my approach simply adds support for the additional data structure variants.
This is a minor update compared to version 3 of this series, with bugfixes for small mistakes that I found or that were reported by automated build bots. I updated the tree at [2] to this version now.
Arnd
[1] https://lwn.net/Articles/657754/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=y...
Arnd Bergmann (8): media: documentation: fix video_event description media: v4l2: abstract timeval handling in v4l2_buffer media: v4l2-core: compat: ignore native command codes media: v4l2-core: split out data copy from video_usercopy media: v4l2-core: fix VIDIOC_DQEVENT for time64 ABI media: v4l2-core: fix v4l2_buffer handling for time64 ABI media: v4l2-core: fix compat VIDIOC_DQEVENT for time64 ABI media: v4l2-core: fix compat v4l2_buffer handling for time64 ABI
.../media/uapi/dvb/video-get-event.rst | 2 +- Documentation/media/uapi/dvb/video_types.rst | 2 +- .../media/common/videobuf2/videobuf2-v4l2.c | 4 +- drivers/media/pci/meye/meye.c | 4 +- drivers/media/usb/cpia2/cpia2_v4l.c | 4 +- drivers/media/usb/stkwebcam/stk-webcam.c | 2 +- drivers/media/usb/usbvision/usbvision-video.c | 4 +- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 470 +++++++++++++++--- drivers/media/v4l2-core/v4l2-event.c | 5 +- drivers/media/v4l2-core/v4l2-ioctl.c | 188 +++++-- drivers/media/v4l2-core/v4l2-subdev.c | 20 +- drivers/media/v4l2-core/videobuf-core.c | 4 +- include/linux/videodev2.h | 17 +- include/trace/events/v4l2.h | 2 +- include/uapi/linux/videodev2.h | 77 +++ 15 files changed, 669 insertions(+), 136 deletions(-)
The type for the timestamp in video_event was changed to 'long' a long time ago, change the documentation to match.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- Documentation/media/uapi/dvb/video-get-event.rst | 2 +- Documentation/media/uapi/dvb/video_types.rst | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/Documentation/media/uapi/dvb/video-get-event.rst b/Documentation/media/uapi/dvb/video-get-event.rst index def6c40db601..7f03fbe3d3b0 100644 --- a/Documentation/media/uapi/dvb/video-get-event.rst +++ b/Documentation/media/uapi/dvb/video-get-event.rst @@ -81,7 +81,7 @@ for this ioctl call. #define VIDEO_EVENT_FRAME_RATE_CHANGED 2 #define VIDEO_EVENT_DECODER_STOPPED 3 #define VIDEO_EVENT_VSYNC 4 - __kernel_time_t timestamp; + long timestamp; union { video_size_t size; unsigned int frame_rate; /* in frames per 1000sec */ diff --git a/Documentation/media/uapi/dvb/video_types.rst b/Documentation/media/uapi/dvb/video_types.rst index 479942ce6fb8..2697400ccf62 100644 --- a/Documentation/media/uapi/dvb/video_types.rst +++ b/Documentation/media/uapi/dvb/video_types.rst @@ -170,7 +170,7 @@ VIDEO_GET_EVENT call. #define VIDEO_EVENT_FRAME_RATE_CHANGED 2 #define VIDEO_EVENT_DECODER_STOPPED 3 #define VIDEO_EVENT_VSYNC 4 - __kernel_time_t timestamp; + long timestamp; union { video_size_t size; unsigned int frame_rate; /* in frames per 1000sec */
As a preparation for adding 64-bit time_t support in the uapi, change the drivers to no longer care about the format of the timestamp field in struct v4l2_buffer.
The v4l2_timeval_to_ns() function is no longer needed in the kernel after this, but there may be userspace code relying on it because it is part of the uapi header.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/media/common/videobuf2/videobuf2-v4l2.c | 4 ++-- drivers/media/pci/meye/meye.c | 4 ++-- drivers/media/usb/cpia2/cpia2_v4l.c | 4 ++-- drivers/media/usb/stkwebcam/stk-webcam.c | 2 +- drivers/media/usb/usbvision/usbvision-video.c | 4 ++-- drivers/media/v4l2-core/videobuf-core.c | 4 ++-- include/linux/videodev2.h | 17 ++++++++++++++++- include/trace/events/v4l2.h | 2 +- include/uapi/linux/videodev2.h | 2 ++ 9 files changed, 30 insertions(+), 13 deletions(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 5a9ba3846f0a..9ec710878db6 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -143,7 +143,7 @@ static void __copy_timestamp(struct vb2_buffer *vb, const void *pb) * and the timecode field and flag if needed. */ if (q->copy_timestamp) - vb->timestamp = v4l2_timeval_to_ns(&b->timestamp); + vb->timestamp = v4l2_buffer_get_timestamp(b); vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE; if (b->flags & V4L2_BUF_FLAG_TIMECODE) vbuf->timecode = b->timecode; @@ -476,7 +476,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
b->flags = vbuf->flags; b->field = vbuf->field; - b->timestamp = ns_to_timeval(vb->timestamp); + v4l2_buffer_set_timestamp(b, vb->timestamp); b->timecode = vbuf->timecode; b->sequence = vbuf->sequence; b->reserved2 = 0; diff --git a/drivers/media/pci/meye/meye.c b/drivers/media/pci/meye/meye.c index 0e61c81356ef..3a4c29bc0ba5 100644 --- a/drivers/media/pci/meye/meye.c +++ b/drivers/media/pci/meye/meye.c @@ -1266,7 +1266,7 @@ static int vidioc_querybuf(struct file *file, void *fh, struct v4l2_buffer *buf) buf->flags |= V4L2_BUF_FLAG_DONE;
buf->field = V4L2_FIELD_NONE; - buf->timestamp = ns_to_timeval(meye.grab_buffer[index].ts); + v4l2_buffer_set_timestamp(buf, meye.grab_buffer[index].ts); buf->sequence = meye.grab_buffer[index].sequence; buf->memory = V4L2_MEMORY_MMAP; buf->m.offset = index * gbufsize; @@ -1332,7 +1332,7 @@ static int vidioc_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf) buf->bytesused = meye.grab_buffer[reqnr].size; buf->flags = V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; buf->field = V4L2_FIELD_NONE; - buf->timestamp = ns_to_timeval(meye.grab_buffer[reqnr].ts); + v4l2_buffer_set_timestamp(buf, meye.grab_buffer[reqnr].ts); buf->sequence = meye.grab_buffer[reqnr].sequence; buf->memory = V4L2_MEMORY_MMAP; buf->m.offset = reqnr * gbufsize; diff --git a/drivers/media/usb/cpia2/cpia2_v4l.c b/drivers/media/usb/cpia2/cpia2_v4l.c index 626264a56517..9d3d05125d7b 100644 --- a/drivers/media/usb/cpia2/cpia2_v4l.c +++ b/drivers/media/usb/cpia2/cpia2_v4l.c @@ -800,7 +800,7 @@ static int cpia2_querybuf(struct file *file, void *fh, struct v4l2_buffer *buf) break; case FRAME_READY: buf->bytesused = cam->buffers[buf->index].length; - buf->timestamp = ns_to_timeval(cam->buffers[buf->index].ts); + v4l2_buffer_set_timestamp(buf, cam->buffers[buf->index].ts); buf->sequence = cam->buffers[buf->index].seq; buf->flags = V4L2_BUF_FLAG_DONE; break; @@ -907,7 +907,7 @@ static int cpia2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf) buf->flags = V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; buf->field = V4L2_FIELD_NONE; - buf->timestamp = ns_to_timeval(cam->buffers[buf->index].ts); + v4l2_buffer_set_timestamp(buf, cam->buffers[buf->index].ts); buf->sequence = cam->buffers[buf->index].seq; buf->m.offset = cam->buffers[buf->index].data - cam->frame_buffer; buf->length = cam->frame_size; diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c index 21f90a887485..b22501f76b78 100644 --- a/drivers/media/usb/stkwebcam/stk-webcam.c +++ b/drivers/media/usb/stkwebcam/stk-webcam.c @@ -1125,7 +1125,7 @@ static int stk_vidioc_dqbuf(struct file *filp, sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_QUEUED; sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_DONE; sbuf->v4lbuf.sequence = ++dev->sequence; - sbuf->v4lbuf.timestamp = ns_to_timeval(ktime_get_ns()); + v4l2_buffer_set_timestamp(&sbuf->v4lbuf, ktime_get_ns());
*buf = sbuf->v4lbuf; return 0; diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c index cdc66adda755..15a423c5deb7 100644 --- a/drivers/media/usb/usbvision/usbvision-video.c +++ b/drivers/media/usb/usbvision/usbvision-video.c @@ -687,7 +687,7 @@ static int vidioc_querybuf(struct file *file, vb->length = usbvision->curwidth * usbvision->curheight * usbvision->palette.bytes_per_pixel; - vb->timestamp = ns_to_timeval(usbvision->frame[vb->index].ts); + v4l2_buffer_set_timestamp(vb, usbvision->frame[vb->index].ts); vb->sequence = usbvision->frame[vb->index].sequence; return 0; } @@ -756,7 +756,7 @@ static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *vb) V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; vb->index = f->index; vb->sequence = f->sequence; - vb->timestamp = ns_to_timeval(f->ts); + v4l2_buffer_set_timestamp(vb, f->ts); vb->field = V4L2_FIELD_NONE; vb->bytesused = f->scanlength;
diff --git a/drivers/media/v4l2-core/videobuf-core.c b/drivers/media/v4l2-core/videobuf-core.c index 939fc11cf080..ab650371c151 100644 --- a/drivers/media/v4l2-core/videobuf-core.c +++ b/drivers/media/v4l2-core/videobuf-core.c @@ -364,7 +364,7 @@ static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b, }
b->field = vb->field; - b->timestamp = ns_to_timeval(vb->ts); + v4l2_buffer_set_timestamp(b, vb->ts); b->bytesused = vb->size; b->sequence = vb->field_count >> 1; } @@ -578,7 +578,7 @@ int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b) || q->type == V4L2_BUF_TYPE_SDR_OUTPUT) { buf->size = b->bytesused; buf->field = b->field; - buf->ts = v4l2_timeval_to_ns(&b->timestamp); + buf->ts = v4l2_buffer_get_timestamp(b); } break; case V4L2_MEMORY_USERPTR: diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index 16c0ed6c50a7..4086036e37d5 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -56,7 +56,22 @@ #ifndef __LINUX_VIDEODEV2_H #define __LINUX_VIDEODEV2_H
-#include <linux/time.h> /* need struct timeval */ +#include <linux/time.h> #include <uapi/linux/videodev2.h>
+static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf) +{ + return buf->timestamp.tv_sec * NSEC_PER_SEC + + (u32)buf->timestamp.tv_usec * NSEC_PER_USEC; +} + +static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf, + u64 timestamp) +{ + struct timespec64 ts = ns_to_timespec64(timestamp); + + buf->timestamp.tv_sec = ts.tv_sec; + buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC; +} + #endif /* __LINUX_VIDEODEV2_H */ diff --git a/include/trace/events/v4l2.h b/include/trace/events/v4l2.h index 83860de120e3..248bc09bfc99 100644 --- a/include/trace/events/v4l2.h +++ b/include/trace/events/v4l2.h @@ -130,7 +130,7 @@ DECLARE_EVENT_CLASS(v4l2_event_class, __entry->bytesused = buf->bytesused; __entry->flags = buf->flags; __entry->field = buf->field; - __entry->timestamp = timeval_to_ns(&buf->timestamp); + __entry->timestamp = v4l2_buffer_get_timestamp(buf); __entry->timecode_type = buf->timecode.type; __entry->timecode_flags = buf->timecode.flags; __entry->timecode_frames = buf->timecode.frames; diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 530638dffd93..74d3d522f3db 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1010,6 +1010,7 @@ struct v4l2_buffer { }; };
+#ifndef __KERNEL__ /** * v4l2_timeval_to_ns - Convert timeval to nanoseconds * @ts: pointer to the timeval variable to be converted @@ -1021,6 +1022,7 @@ static inline __u64 v4l2_timeval_to_ns(const struct timeval *tv) { return (__u64)tv->tv_sec * 1000000000ULL + tv->tv_usec * 1000; } +#endif
/* Flags for 'flags' field */ /* Buffer is mapped (flag) */
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
As a preparation for adding 64-bit time_t support in the uapi, change the drivers to no longer care about the format of the timestamp field in struct v4l2_buffer.
The v4l2_timeval_to_ns() function is no longer needed in the kernel after this, but there may be userspace code relying on it because it is part of the uapi header.
There is indeed userspace code that relies on this.
Signed-off-by: Arnd Bergmann arnd@arndb.de
drivers/media/common/videobuf2/videobuf2-v4l2.c | 4 ++-- drivers/media/pci/meye/meye.c | 4 ++-- drivers/media/usb/cpia2/cpia2_v4l.c | 4 ++-- drivers/media/usb/stkwebcam/stk-webcam.c | 2 +- drivers/media/usb/usbvision/usbvision-video.c | 4 ++-- drivers/media/v4l2-core/videobuf-core.c | 4 ++-- include/linux/videodev2.h | 17 ++++++++++++++++- include/trace/events/v4l2.h | 2 +- include/uapi/linux/videodev2.h | 2 ++ 9 files changed, 30 insertions(+), 13 deletions(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 5a9ba3846f0a..9ec710878db6 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -143,7 +143,7 @@ static void __copy_timestamp(struct vb2_buffer *vb, const void *pb) * and the timecode field and flag if needed. */ if (q->copy_timestamp)
vb->timestamp = v4l2_timeval_to_ns(&b->timestamp);
vb->timestamp = v4l2_buffer_get_timestamp(b);@@ -476,7 +476,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb) b->flags = vbuf->flags; b->field = vbuf->field;
- b->timestamp = ns_to_timeval(vb->timestamp);
- v4l2_buffer_set_timestamp(b, vb->timestamp); b->timecode = vbuf->timecode; b->sequence = vbuf->sequence; b->reserved2 = 0;
diff --git a/drivers/media/pci/meye/meye.c b/drivers/media/pci/meye/meye.c index 0e61c81356ef..3a4c29bc0ba5 100644 --- a/drivers/media/pci/meye/meye.c +++ b/drivers/media/pci/meye/meye.c @@ -1266,7 +1266,7 @@ static int vidioc_querybuf(struct file *file, void *fh, struct v4l2_buffer *buf) buf->flags |= V4L2_BUF_FLAG_DONE; buf->field = V4L2_FIELD_NONE;
- buf->timestamp = ns_to_timeval(meye.grab_buffer[index].ts);
- v4l2_buffer_set_timestamp(buf, meye.grab_buffer[index].ts); buf->sequence = meye.grab_buffer[index].sequence; buf->memory = V4L2_MEMORY_MMAP; buf->m.offset = index * gbufsize;
@@ -1332,7 +1332,7 @@ static int vidioc_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf) buf->bytesused = meye.grab_buffer[reqnr].size; buf->flags = V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; buf->field = V4L2_FIELD_NONE;
- buf->timestamp = ns_to_timeval(meye.grab_buffer[reqnr].ts);
- v4l2_buffer_set_timestamp(buf, meye.grab_buffer[reqnr].ts); buf->sequence = meye.grab_buffer[reqnr].sequence; buf->memory = V4L2_MEMORY_MMAP; buf->m.offset = reqnr * gbufsize;
diff --git a/drivers/media/usb/cpia2/cpia2_v4l.c b/drivers/media/usb/cpia2/cpia2_v4l.c index 626264a56517..9d3d05125d7b 100644 --- a/drivers/media/usb/cpia2/cpia2_v4l.c +++ b/drivers/media/usb/cpia2/cpia2_v4l.c @@ -800,7 +800,7 @@ static int cpia2_querybuf(struct file *file, void *fh, struct v4l2_buffer *buf) break; case FRAME_READY: buf->bytesused = cam->buffers[buf->index].length;
buf->timestamp = ns_to_timeval(cam->buffers[buf->index].ts);
v4l2_buffer_set_timestamp(buf, cam->buffers[buf->index].ts);@@ -907,7 +907,7 @@ static int cpia2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf) buf->flags = V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; buf->field = V4L2_FIELD_NONE;
- buf->timestamp = ns_to_timeval(cam->buffers[buf->index].ts);
- v4l2_buffer_set_timestamp(buf, cam->buffers[buf->index].ts); buf->sequence = cam->buffers[buf->index].seq; buf->m.offset = cam->buffers[buf->index].data - cam->frame_buffer; buf->length = cam->frame_size;
diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c index 21f90a887485..b22501f76b78 100644 --- a/drivers/media/usb/stkwebcam/stk-webcam.c +++ b/drivers/media/usb/stkwebcam/stk-webcam.c @@ -1125,7 +1125,7 @@ static int stk_vidioc_dqbuf(struct file *filp, sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_QUEUED; sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_DONE; sbuf->v4lbuf.sequence = ++dev->sequence;
- sbuf->v4lbuf.timestamp = ns_to_timeval(ktime_get_ns());
- v4l2_buffer_set_timestamp(&sbuf->v4lbuf, ktime_get_ns());
*buf = sbuf->v4lbuf; return 0; diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c index cdc66adda755..15a423c5deb7 100644 --- a/drivers/media/usb/usbvision/usbvision-video.c +++ b/drivers/media/usb/usbvision/usbvision-video.c @@ -687,7 +687,7 @@ static int vidioc_querybuf(struct file *file, vb->length = usbvision->curwidth * usbvision->curheight * usbvision->palette.bytes_per_pixel;
- vb->timestamp = ns_to_timeval(usbvision->frame[vb->index].ts);
- v4l2_buffer_set_timestamp(vb, usbvision->frame[vb->index].ts); vb->sequence = usbvision->frame[vb->index].sequence; return 0;
} @@ -756,7 +756,7 @@ static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *vb) V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; vb->index = f->index; vb->sequence = f->sequence;
- vb->timestamp = ns_to_timeval(f->ts);
- v4l2_buffer_set_timestamp(vb, f->ts); vb->field = V4L2_FIELD_NONE; vb->bytesused = f->scanlength;
diff --git a/drivers/media/v4l2-core/videobuf-core.c b/drivers/media/v4l2-core/videobuf-core.c index 939fc11cf080..ab650371c151 100644 --- a/drivers/media/v4l2-core/videobuf-core.c +++ b/drivers/media/v4l2-core/videobuf-core.c @@ -364,7 +364,7 @@ static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b, } b->field = vb->field;
- b->timestamp = ns_to_timeval(vb->ts);
- v4l2_buffer_set_timestamp(b, vb->ts); b->bytesused = vb->size; b->sequence = vb->field_count >> 1;
} @@ -578,7 +578,7 @@ int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b) || q->type == V4L2_BUF_TYPE_SDR_OUTPUT) { buf->size = b->bytesused; buf->field = b->field;
buf->ts = v4l2_timeval_to_ns(&b->timestamp);
buf->ts = v4l2_buffer_get_timestamp(b);diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index 16c0ed6c50a7..4086036e37d5 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -56,7 +56,22 @@ #ifndef __LINUX_VIDEODEV2_H #define __LINUX_VIDEODEV2_H -#include <linux/time.h> /* need struct timeval */ +#include <linux/time.h> #include <uapi/linux/videodev2.h> +static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf) +{
- return buf->timestamp.tv_sec * NSEC_PER_SEC +
(u32)buf->timestamp.tv_usec * NSEC_PER_USEC;
Why the (u32) cast?
+}
+static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf,
u64 timestamp)+{
- struct timespec64 ts = ns_to_timespec64(timestamp);
- buf->timestamp.tv_sec = ts.tv_sec;
- buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
+}
This does not belong in the public header. This is kernel specific, so media/v4l2-common.h would be a good place.
Regards,
Hans
#endif /* __LINUX_VIDEODEV2_H */ diff --git a/include/trace/events/v4l2.h b/include/trace/events/v4l2.h index 83860de120e3..248bc09bfc99 100644 --- a/include/trace/events/v4l2.h +++ b/include/trace/events/v4l2.h @@ -130,7 +130,7 @@ DECLARE_EVENT_CLASS(v4l2_event_class, __entry->bytesused = buf->bytesused; __entry->flags = buf->flags; __entry->field = buf->field;
__entry->timestamp = timeval_to_ns(&buf->timestamp);
__entry->timestamp = v4l2_buffer_get_timestamp(buf);diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 530638dffd93..74d3d522f3db 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1010,6 +1010,7 @@ struct v4l2_buffer { }; }; +#ifndef __KERNEL__ /**
- v4l2_timeval_to_ns - Convert timeval to nanoseconds
- @ts: pointer to the timeval variable to be converted
@@ -1021,6 +1022,7 @@ static inline __u64 v4l2_timeval_to_ns(const struct timeval *tv) { return (__u64)tv->tv_sec * 1000000000ULL + tv->tv_usec * 1000; } +#endif /* Flags for 'flags' field */ /* Buffer is mapped (flag) */
On Mon, Nov 25, 2019 at 4:52 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
As a preparation for adding 64-bit time_t support in the uapi, change the drivers to no longer care about the format of the timestamp field in struct v4l2_buffer.
The v4l2_timeval_to_ns() function is no longer needed in the kernel after this, but there may be userspace code relying on it because it is part of the uapi header.
There is indeed userspace code that relies on this.
Ok, good to know. I rephrased the changelog text as
The v4l2_timeval_to_ns() function is no longer needed in the kernel after this, but there is userspace code relying on it to be part of the uapi header.
+static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf) +{
return buf->timestamp.tv_sec * NSEC_PER_SEC +(u32)buf->timestamp.tv_usec * NSEC_PER_USEC;Why the (u32) cast?
Simple question, long answer:
on 32-bit architectures, the tv_usec member may be 32-bit wide plus padding in user space when interpreted as a regular 'struct timeval', but the kernel implementation now sees it as a 64-bit member, with half of it being possibly uninitialized user space data.
The 32-bit cast avoids that uninitialized data and ensures user space passing garbage in the upper half gets ignored, as it has to be on 32-bit user space.
On 64-bit native user space, the tv_usec field is always 64 bit wide, so this is a change in behavior for denormalized timeval data with tv_usec > U32_MAX, but the current behavior does not appear worth preserving either.
The correct way would probably be to return an error for tv_usec >USEC_PER_SEC, but as the code never did that, this would risk a regression for user space that relies on passing invalid timestamps without getting an error.
+static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf,
u64 timestamp)+{
struct timespec64 ts = ns_to_timespec64(timestamp);buf->timestamp.tv_sec = ts.tv_sec;buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;+}
This does not belong in the public header. This is kernel specific,
Note: this is not the uapi header but the in-kernel one.
so media/v4l2-common.h would be a good place.
Ok, sounds good. I wasn't sure where to put it, and ended up with include/linux/videodev2.h as the best replacement for include/uapi/linux/videodev2.h, changed it to include/media/v4l2-common.h now.
Arnd
On 11/26/19 12:34 PM, Arnd Bergmann wrote:
On Mon, Nov 25, 2019 at 4:52 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
As a preparation for adding 64-bit time_t support in the uapi, change the drivers to no longer care about the format of the timestamp field in struct v4l2_buffer.
The v4l2_timeval_to_ns() function is no longer needed in the kernel after this, but there may be userspace code relying on it because it is part of the uapi header.
There is indeed userspace code that relies on this.
Ok, good to know. I rephrased the changelog text as
The v4l2_timeval_to_ns() function is no longer needed in the kernel after this, but there is userspace code relying on it to be part of the uapi header.
+static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf) +{
return buf->timestamp.tv_sec * NSEC_PER_SEC +(u32)buf->timestamp.tv_usec * NSEC_PER_USEC;Why the (u32) cast?
Simple question, long answer:
on 32-bit architectures, the tv_usec member may be 32-bit wide plus padding in user space when interpreted as a regular 'struct timeval', but the kernel implementation now sees it as a 64-bit member, with half of it being possibly uninitialized user space data.
The 32-bit cast avoids that uninitialized data and ensures user space passing garbage in the upper half gets ignored, as it has to be on 32-bit user space.
But that's only valid for little endian 32 bit systems, right? Is this only an issue for x86 platforms?
On 64-bit native user space, the tv_usec field is always 64 bit wide, so this is a change in behavior for denormalized timeval data with tv_usec > U32_MAX, but the current behavior does not appear worth preserving either.
The correct way would probably be to return an error for tv_usec >USEC_PER_SEC, but as the code never did that, this would risk a regression for user space that relies on passing invalid timestamps without getting an error.
This long answer needs to be added to a comment to that function. Because otherwise someone will come along later and remove that seemingly unnecessary cast.
It's OK if it is a long comment, it's a non-trivial reason.
+static inline void v4l2_buffer_set_timestamp(struct v4l2_buffer *buf,
u64 timestamp)+{
struct timespec64 ts = ns_to_timespec64(timestamp);buf->timestamp.tv_sec = ts.tv_sec;buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;+}
This does not belong in the public header. This is kernel specific,
Note: this is not the uapi header but the in-kernel one.
Ah, I missed that.
so media/v4l2-common.h would be a good place.
Ok, sounds good. I wasn't sure where to put it, and ended up with include/linux/videodev2.h as the best replacement for include/uapi/linux/videodev2.h, changed it to include/media/v4l2-common.h now.
Never use include/linux/videodev2.h. It's just a wrapper around the uapi header and should not contain any 'real' code.
It's also why I missed that you modified that header since we never touch it.
Regards,
Hans
Arnd
On Tue, Nov 26, 2019 at 12:43 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/26/19 12:34 PM, Arnd Bergmann wrote:
On Mon, Nov 25, 2019 at 4:52 PM Hans Verkuil hverkuil@xs4all.nl wrote:
+static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf) +{
return buf->timestamp.tv_sec * NSEC_PER_SEC +(u32)buf->timestamp.tv_usec * NSEC_PER_USEC;Why the (u32) cast?
Simple question, long answer:
on 32-bit architectures, the tv_usec member may be 32-bit wide plus padding in user space when interpreted as a regular 'struct timeval', but the kernel implementation now sees it as a 64-bit member, with half of it being possibly uninitialized user space data.
The 32-bit cast avoids that uninitialized data and ensures user space passing garbage in the upper half gets ignored, as it has to be on 32-bit user space.
But that's only valid for little endian 32 bit systems, right? Is this only an issue for x86 platforms?
Uninitialized data is an issue on all 32-bit architectures. The layout of the new timeval is such that the low 32 bits of tv_sec are in the same place on both 32-bit and 64-bit architectures of the same endianess, but if an application initializes the fields individually without a memset before it, it may still pass invalid data.
On 64-bit native user space, the tv_usec field is always 64 bit wide, so this is a change in behavior for denormalized timeval data with tv_usec > U32_MAX, but the current behavior does not appear worth preserving either.
The correct way would probably be to return an error for tv_usec >USEC_PER_SEC, but as the code never did that, this would risk a regression for user space that relies on passing invalid timestamps without getting an error.
This long answer needs to be added to a comment to that function. Because otherwise someone will come along later and remove that seemingly unnecessary cast.
It's OK if it is a long comment, it's a non-trivial reason.
Added this comment now:
/* * When the timestamp comes from 32-bit user space, there may be * uninitialized data in tv_usec, so cast it to u32. * Otherwise allow invalid input for backwards compatibility. */
Let me know if you prefer a more elaborate version.
so media/v4l2-common.h would be a good place.
Ok, sounds good. I wasn't sure where to put it, and ended up with include/linux/videodev2.h as the best replacement for include/uapi/linux/videodev2.h, changed it to include/media/v4l2-common.h now.
Never use include/linux/videodev2.h. It's just a wrapper around the uapi header and should not contain any 'real' code.
It's also why I missed that you modified that header since we never touch it.
Ok, got it. I now tried to remove this file completely, hoping that the include <linux/time.h> is no longer needed after my series, but it seems we still need it.
Arnd
The do_video_ioctl() compat handler converts the compat command codes into the native ones before processing further, but this causes problems for 32-bit user applications that pass a command code that matches a 64-bit native number, which will then be handled the same way.
Specifically, this breaks VIDIOC_DQEVENT_TIME from user space applications with 64-bit time_t, as the structure layout is the same as the native 64-bit layout on many architectures (x86 being the notable exception).
Change the handler to use the converted command code only for passing into the native ioctl handler, not for deciding on the conversion, in order to make the compat behavior match the native behavior.
Actual support for the 64-bit time_t version of VIDIOC_DQEVENT_TIME and other commands still needs to be added in a separate patch.
Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 148 +++++++++--------- 1 file changed, 75 insertions(+), 73 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index e1eaf1135c7f..7ad6db8dd9f6 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -1183,36 +1183,38 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar u32 aux_space; int compatible_arg = 1; long err = 0; + unsigned int ncmd;
/* * 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; - case VIDIOC_QUERYBUF32: cmd = VIDIOC_QUERYBUF; break; - case VIDIOC_G_FBUF32: cmd = VIDIOC_G_FBUF; break; - case VIDIOC_S_FBUF32: cmd = VIDIOC_S_FBUF; break; - case VIDIOC_QBUF32: cmd = VIDIOC_QBUF; break; - case VIDIOC_DQBUF32: cmd = VIDIOC_DQBUF; break; - case VIDIOC_ENUMSTD32: cmd = VIDIOC_ENUMSTD; break; - case VIDIOC_ENUMINPUT32: cmd = VIDIOC_ENUMINPUT; break; - case VIDIOC_TRY_FMT32: cmd = VIDIOC_TRY_FMT; break; - case VIDIOC_G_EXT_CTRLS32: cmd = VIDIOC_G_EXT_CTRLS; break; - case VIDIOC_S_EXT_CTRLS32: cmd = VIDIOC_S_EXT_CTRLS; break; - case VIDIOC_TRY_EXT_CTRLS32: cmd = VIDIOC_TRY_EXT_CTRLS; break; - case VIDIOC_DQEVENT32: cmd = VIDIOC_DQEVENT; break; - case VIDIOC_OVERLAY32: cmd = VIDIOC_OVERLAY; break; - case VIDIOC_STREAMON32: cmd = VIDIOC_STREAMON; break; - case VIDIOC_STREAMOFF32: cmd = VIDIOC_STREAMOFF; break; - case VIDIOC_G_INPUT32: cmd = VIDIOC_G_INPUT; break; - case VIDIOC_S_INPUT32: cmd = VIDIOC_S_INPUT; break; - case VIDIOC_G_OUTPUT32: cmd = VIDIOC_G_OUTPUT; break; - case VIDIOC_S_OUTPUT32: cmd = VIDIOC_S_OUTPUT; break; - case VIDIOC_CREATE_BUFS32: cmd = VIDIOC_CREATE_BUFS; break; - case VIDIOC_PREPARE_BUF32: cmd = VIDIOC_PREPARE_BUF; break; - case VIDIOC_G_EDID32: cmd = VIDIOC_G_EDID; break; - case VIDIOC_S_EDID32: cmd = VIDIOC_S_EDID; break; + case VIDIOC_G_FMT32: ncmd = VIDIOC_G_FMT; break; + case VIDIOC_S_FMT32: ncmd = VIDIOC_S_FMT; break; + case VIDIOC_QUERYBUF32: ncmd = VIDIOC_QUERYBUF; break; + case VIDIOC_G_FBUF32: ncmd = VIDIOC_G_FBUF; break; + case VIDIOC_S_FBUF32: ncmd = VIDIOC_S_FBUF; break; + case VIDIOC_QBUF32: ncmd = VIDIOC_QBUF; break; + case VIDIOC_DQBUF32: ncmd = VIDIOC_DQBUF; break; + case VIDIOC_ENUMSTD32: ncmd = VIDIOC_ENUMSTD; break; + case VIDIOC_ENUMINPUT32: ncmd = VIDIOC_ENUMINPUT; break; + case VIDIOC_TRY_FMT32: ncmd = VIDIOC_TRY_FMT; break; + case VIDIOC_G_EXT_CTRLS32: ncmd = VIDIOC_G_EXT_CTRLS; break; + case VIDIOC_S_EXT_CTRLS32: ncmd = VIDIOC_S_EXT_CTRLS; break; + case VIDIOC_TRY_EXT_CTRLS32: ncmd = VIDIOC_TRY_EXT_CTRLS; break; + case VIDIOC_DQEVENT32: ncmd = VIDIOC_DQEVENT; break; + case VIDIOC_OVERLAY32: ncmd = VIDIOC_OVERLAY; break; + case VIDIOC_STREAMON32: ncmd = VIDIOC_STREAMON; break; + case VIDIOC_STREAMOFF32: ncmd = VIDIOC_STREAMOFF; break; + case VIDIOC_G_INPUT32: ncmd = VIDIOC_G_INPUT; break; + case VIDIOC_S_INPUT32: ncmd = VIDIOC_S_INPUT; break; + case VIDIOC_G_OUTPUT32: ncmd = VIDIOC_G_OUTPUT; break; + case VIDIOC_S_OUTPUT32: ncmd = VIDIOC_S_OUTPUT; break; + case VIDIOC_CREATE_BUFS32: ncmd = VIDIOC_CREATE_BUFS; break; + case VIDIOC_PREPARE_BUF32: ncmd = VIDIOC_PREPARE_BUF; break; + case VIDIOC_G_EDID32: ncmd = VIDIOC_G_EDID; break; + case VIDIOC_S_EDID32: ncmd = VIDIOC_S_EDID; break; + default: ncmd = cmd; break; }
/* @@ -1221,11 +1223,11 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar * argument into it. */ switch (cmd) { - case VIDIOC_OVERLAY: - case VIDIOC_STREAMON: - case VIDIOC_STREAMOFF: - case VIDIOC_S_INPUT: - case VIDIOC_S_OUTPUT: + case VIDIOC_OVERLAY32: + case VIDIOC_STREAMON32: + case VIDIOC_STREAMOFF32: + case VIDIOC_S_INPUT32: + case VIDIOC_S_OUTPUT32: err = alloc_userspace(sizeof(unsigned int), 0, &new_p64); if (!err && assign_in_user((unsigned int __user *)new_p64, (compat_uint_t __user *)p32)) @@ -1233,23 +1235,23 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar compatible_arg = 0; break;
- case VIDIOC_G_INPUT: - case VIDIOC_G_OUTPUT: + case VIDIOC_G_INPUT32: + case VIDIOC_G_OUTPUT32: err = alloc_userspace(sizeof(unsigned int), 0, &new_p64); compatible_arg = 0; break;
- case VIDIOC_G_EDID: - case VIDIOC_S_EDID: + case VIDIOC_G_EDID32: + case VIDIOC_S_EDID32: err = alloc_userspace(sizeof(struct v4l2_edid), 0, &new_p64); if (!err) err = get_v4l2_edid32(new_p64, p32); compatible_arg = 0; break;
- case VIDIOC_G_FMT: - case VIDIOC_S_FMT: - case VIDIOC_TRY_FMT: + case VIDIOC_G_FMT32: + case VIDIOC_S_FMT32: + case VIDIOC_TRY_FMT32: err = bufsize_v4l2_format(p32, &aux_space); if (!err) err = alloc_userspace(sizeof(struct v4l2_format), @@ -1262,7 +1264,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar compatible_arg = 0; break;
- case VIDIOC_CREATE_BUFS: + case VIDIOC_CREATE_BUFS32: err = bufsize_v4l2_create(p32, &aux_space); if (!err) err = alloc_userspace(sizeof(struct v4l2_create_buffers), @@ -1275,10 +1277,10 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar compatible_arg = 0; break;
- case VIDIOC_PREPARE_BUF: - case VIDIOC_QUERYBUF: - case VIDIOC_QBUF: - case VIDIOC_DQBUF: + case VIDIOC_PREPARE_BUF32: + case VIDIOC_QUERYBUF32: + case VIDIOC_QBUF32: + case VIDIOC_DQBUF32: err = bufsize_v4l2_buffer(p32, &aux_space); if (!err) err = alloc_userspace(sizeof(struct v4l2_buffer), @@ -1291,7 +1293,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar compatible_arg = 0; break;
- case VIDIOC_S_FBUF: + case VIDIOC_S_FBUF32: err = alloc_userspace(sizeof(struct v4l2_framebuffer), 0, &new_p64); if (!err) @@ -1299,13 +1301,13 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar compatible_arg = 0; break;
- case VIDIOC_G_FBUF: + case VIDIOC_G_FBUF32: err = alloc_userspace(sizeof(struct v4l2_framebuffer), 0, &new_p64); compatible_arg = 0; break;
- case VIDIOC_ENUMSTD: + case VIDIOC_ENUMSTD32: err = alloc_userspace(sizeof(struct v4l2_standard), 0, &new_p64); if (!err) @@ -1313,16 +1315,16 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar compatible_arg = 0; break;
- case VIDIOC_ENUMINPUT: + case VIDIOC_ENUMINPUT32: err = alloc_userspace(sizeof(struct v4l2_input), 0, &new_p64); if (!err) 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: + case VIDIOC_G_EXT_CTRLS32: + case VIDIOC_S_EXT_CTRLS32: + case VIDIOC_TRY_EXT_CTRLS32: err = bufsize_v4l2_ext_controls(p32, &aux_space); if (!err) err = alloc_userspace(sizeof(struct v4l2_ext_controls), @@ -1334,7 +1336,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar } compatible_arg = 0; break; - case VIDIOC_DQEVENT: + case VIDIOC_DQEVENT32: err = alloc_userspace(sizeof(struct v4l2_event), 0, &new_p64); compatible_arg = 0; break; @@ -1352,9 +1354,9 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar * Otherwise, it will pass the newly allocated @new_p64 argument. */ if (compatible_arg) - err = native_ioctl(file, cmd, (unsigned long)p32); + err = native_ioctl(file, ncmd, (unsigned long)p32); else - err = native_ioctl(file, cmd, (unsigned long)new_p64); + err = native_ioctl(file, ncmd, (unsigned long)new_p64);
if (err == -ENOTTY) return err; @@ -1370,13 +1372,13 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar * the blocks to maximum allowed value. */ switch (cmd) { - case VIDIOC_G_EXT_CTRLS: - case VIDIOC_S_EXT_CTRLS: - case VIDIOC_TRY_EXT_CTRLS: + case VIDIOC_G_EXT_CTRLS32: + case VIDIOC_S_EXT_CTRLS32: + case VIDIOC_TRY_EXT_CTRLS32: if (put_v4l2_ext_controls32(file, new_p64, p32)) err = -EFAULT; break; - case VIDIOC_S_EDID: + case VIDIOC_S_EDID32: if (put_v4l2_edid32(new_p64, p32)) err = -EFAULT; break; @@ -1389,49 +1391,49 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar * the original 32 bits structure. */ switch (cmd) { - case VIDIOC_S_INPUT: - case VIDIOC_S_OUTPUT: - case VIDIOC_G_INPUT: - case VIDIOC_G_OUTPUT: + case VIDIOC_S_INPUT32: + case VIDIOC_S_OUTPUT32: + case VIDIOC_G_INPUT32: + case VIDIOC_G_OUTPUT32: if (assign_in_user((compat_uint_t __user *)p32, ((unsigned int __user *)new_p64))) err = -EFAULT; break;
- case VIDIOC_G_FBUF: + case VIDIOC_G_FBUF32: err = put_v4l2_framebuffer32(new_p64, p32); break;
- case VIDIOC_DQEVENT: + case VIDIOC_DQEVENT32: err = put_v4l2_event32(new_p64, p32); break;
- case VIDIOC_G_EDID: + case VIDIOC_G_EDID32: err = put_v4l2_edid32(new_p64, p32); break;
- case VIDIOC_G_FMT: - case VIDIOC_S_FMT: - case VIDIOC_TRY_FMT: + case VIDIOC_G_FMT32: + case VIDIOC_S_FMT32: + case VIDIOC_TRY_FMT32: err = put_v4l2_format32(new_p64, p32); break;
- case VIDIOC_CREATE_BUFS: + case VIDIOC_CREATE_BUFS32: err = put_v4l2_create32(new_p64, p32); break;
- case VIDIOC_PREPARE_BUF: - case VIDIOC_QUERYBUF: - case VIDIOC_QBUF: - case VIDIOC_DQBUF: + case VIDIOC_PREPARE_BUF32: + case VIDIOC_QUERYBUF32: + case VIDIOC_QBUF32: + case VIDIOC_DQBUF32: err = put_v4l2_buffer32(new_p64, p32); break;
- case VIDIOC_ENUMSTD: + case VIDIOC_ENUMSTD32: err = put_v4l2_standard32(new_p64, p32); break;
- case VIDIOC_ENUMINPUT: + case VIDIOC_ENUMINPUT32: err = put_v4l2_input32(new_p64, p32); break; }
The copy-in/out portions of video_usercopy() are about to get more complex, so turn then into separate functions as a cleanup first.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/media/v4l2-core/v4l2-ioctl.c | 107 +++++++++++++++++---------- 1 file changed, 68 insertions(+), 39 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 51b912743f0f..693f9eb8e01b 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -3008,8 +3008,69 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size, return ret; }
+static unsigned int video_translate_cmd(unsigned int cmd) +{ + return cmd; +} + +static int video_get_user(void __user *arg, void *parg, unsigned int cmd, + bool *always_copy) +{ + unsigned int n = _IOC_SIZE(cmd); + + if (!(_IOC_DIR(cmd) & _IOC_WRITE)) { + /* read-only ioctl */ + memset(parg, 0, n); + return 0; + } + + switch (cmd) { + default: + /* + * In some cases, only a few fields are used as input, + * i.e. when the app sets "index" and then the driver + * fills in the rest of the structure for the thing + * with that index. We only need to copy up the first + * non-input field. + */ + if (v4l2_is_known_ioctl(cmd)) { + u32 flags = v4l2_ioctls[_IOC_NR(cmd)].flags; + + if (flags & INFO_FL_CLEAR_MASK) + n = (flags & INFO_FL_CLEAR_MASK) >> 16; + *always_copy = flags & INFO_FL_ALWAYS_COPY; + } + + if (copy_from_user(parg, (void __user *)arg, n)) + return -EFAULT; + + /* zero out anything we don't copy from userspace */ + if (n < _IOC_SIZE(cmd)) + memset((u8 *)parg + n, 0, _IOC_SIZE(cmd) - n); + break; + } + + return 0; +} + +static int video_put_user(void __user *arg, void *parg, unsigned int cmd) +{ + if (!(_IOC_DIR(cmd) & _IOC_READ)) + return 0; + + switch (cmd) { + default: + /* Copy results into user buffer */ + if (copy_to_user(arg, parg, _IOC_SIZE(cmd))) + return -EFAULT; + break; + } + + return 0; +} + long -video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, +video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg, v4l2_kioctl func) { char sbuf[128]; @@ -3021,6 +3082,7 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, size_t array_size = 0; void __user *user_ptr = NULL; void **kernel_ptr = NULL; + unsigned int cmd = video_translate_cmd(orig_cmd); const size_t ioc_size = _IOC_SIZE(cmd);
/* Copy arguments into temp kernel buffer */ @@ -3035,37 +3097,12 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, parg = mbuf; }
- err = -EFAULT; - if (_IOC_DIR(cmd) & _IOC_WRITE) { - unsigned int n = ioc_size; - - /* - * In some cases, only a few fields are used as input, - * i.e. when the app sets "index" and then the driver - * fills in the rest of the structure for the thing - * with that index. We only need to copy up the first - * non-input field. - */ - if (v4l2_is_known_ioctl(cmd)) { - u32 flags = v4l2_ioctls[_IOC_NR(cmd)].flags; - - if (flags & INFO_FL_CLEAR_MASK) - n = (flags & INFO_FL_CLEAR_MASK) >> 16; - always_copy = flags & INFO_FL_ALWAYS_COPY; - } - - if (copy_from_user(parg, (void __user *)arg, n)) - goto out; - - /* zero out anything we don't copy from userspace */ - if (n < ioc_size) - memset((u8 *)parg + n, 0, ioc_size - n); - } else { - /* read-only ioctl */ - memset(parg, 0, ioc_size); - } }
+ err = video_get_user((void __user *)arg, parg, orig_cmd, &always_copy); + if (err) + goto out; + err = check_array_args(cmd, parg, &array_size, &user_ptr, &kernel_ptr); if (err < 0) goto out; @@ -3116,15 +3153,7 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, goto out;
out_array_args: - /* Copy results into user buffer */ - switch (_IOC_DIR(cmd)) { - case _IOC_READ: - case (_IOC_WRITE | _IOC_READ): - if (copy_to_user((void __user *)arg, parg, ioc_size)) - err = -EFAULT; - break; - } - + err = video_put_user((void __user *)arg, parg, orig_cmd); out: kvfree(mbuf); return err;
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 | 24 ++++++++++++++++++++- drivers/media/v4l2-core/v4l2-subdev.c | 20 +++++++++++++++++- include/uapi/linux/videodev2.h | 30 +++++++++++++++++++++++++++ 4 files changed, 76 insertions(+), 3 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 693f9eb8e01b..1de939d11628 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -821,7 +821,7 @@ static void v4l_print_event(const void *arg, bool write_only) const struct v4l2_event *p = arg; const struct v4l2_event_ctrl *c;
- pr_cont("type=0x%x, pending=%u, sequence=%u, id=%u, timestamp=%lu.%9.9lu\n", + pr_cont("type=0x%x, pending=%u, sequence=%u, id=%u, timestamp=%llu.%9.9llu\n", p->type, p->pending, p->sequence, p->id, p->timestamp.tv_sec, p->timestamp.tv_nsec); switch (p->type) { @@ -3010,6 +3010,13 @@ 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; }
@@ -3059,6 +3066,21 @@ 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 f725cd9b66b9..45454a628e45 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 74d3d522f3db..1d2553d4ed5b 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -2329,11 +2329,40 @@ 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)
@@ -2486,6 +2515,7 @@ 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)
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
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 | 24 ++++++++++++++++++++- drivers/media/v4l2-core/v4l2-subdev.c | 20 +++++++++++++++++- include/uapi/linux/videodev2.h | 30 +++++++++++++++++++++++++++ 4 files changed, 76 insertions(+), 3 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 693f9eb8e01b..1de939d11628 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -821,7 +821,7 @@ static void v4l_print_event(const void *arg, bool write_only) const struct v4l2_event *p = arg; const struct v4l2_event_ctrl *c;
- pr_cont("type=0x%x, pending=%u, sequence=%u, id=%u, timestamp=%lu.%9.9lu\n",
- pr_cont("type=0x%x, pending=%u, sequence=%u, id=%u, timestamp=%llu.%9.9llu\n", p->type, p->pending, p->sequence, p->id, p->timestamp.tv_sec, p->timestamp.tv_nsec); switch (p->type) {
@@ -3010,6 +3010,13 @@ 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;
} @@ -3059,6 +3066,21 @@ 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));
This looks dangerous: due to 64-bit alignment requirements the v4l2_event struct may end with a 4-byte hole at the end of the struct, which you do not want to copy to ev32.
I think it is safer to just copy id and reserved separately:
ev32.id = ev->id; memcpy(ev32.reserved, ev->reserved, sizeof(ev->reserved));
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 f725cd9b66b9..45454a628e45 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));
Ditto.
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 74d3d522f3db..1d2553d4ed5b 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -2329,11 +2329,40 @@ 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) @@ -2486,6 +2515,7 @@ 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)
Shouldn't this be under #ifdef __KERNEL__?
And should this be in the public header at all? media/v4l2-ioctl.h might be a better place.
Regards,
Hans
#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)
On Mon, Nov 25, 2019 at 3:40 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
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));This looks dangerous: due to 64-bit alignment requirements the v4l2_event struct may end with a 4-byte hole at the end of the struct, which you do not want to copy to ev32.
I think it is safer to just copy id and reserved separately:
ev32.id = ev->id; memcpy(ev32.reserved, ev->reserved, sizeof(ev->reserved));
Actually I think it's that's also bad: The padding in *ev must already be cleared here (otherwise there is a leak of stack data in the kernel already), so *not* copying the padding requires at least adding a memset upfront.
I would do the per-member copy like I did for v4l2_buffer in my other reply:
struct v4l2_event *ev = parg; struct v4l2_event_time32 ev32 = { .type = ev->type, .pending = ev->pending, .sequence = ev->sequence, .timestamp.tv_sec = ev->timestamp.tv_sec, .timestamp.tv_nsec = ev->timestamp.tv_nsec, .id = ev->id, };
memcpy(ev32.u, ev->u, sizeof(ev->u)); memcpy(ev32.reserved, ev->reserved, sizeof(ev->reserved));
if (copy_to_user(arg, &ev32, sizeof(ev32))) return -EFAULT;
Unfortunately this is a little uglier because it still requires the two memcpy() for the arrays, but I think it's good enough.
Any other ideas? Let me know if I should do a memset() plus individual member copy instead.
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));Ditto.
Using the corresponding code here as well.
#define V4L2_EVENT_SUB_FL_SEND_INITIAL (1 << 0) #define V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK (1 << 1)
@@ -2486,6 +2515,7 @@ 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)
Shouldn't this be under #ifdef __KERNEL__?
And should this be in the public header at all? media/v4l2-ioctl.h might be a better place.
Done.
Arnd
On 11/26/19 3:43 PM, Arnd Bergmann wrote:
On Mon, Nov 25, 2019 at 3:40 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
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));This looks dangerous: due to 64-bit alignment requirements the v4l2_event struct may end with a 4-byte hole at the end of the struct, which you do not want to copy to ev32.
I think it is safer to just copy id and reserved separately:
ev32.id = ev->id; memcpy(ev32.reserved, ev->reserved, sizeof(ev->reserved));Actually I think it's that's also bad: The padding in *ev must already be cleared here (otherwise there is a leak of stack data in the kernel already), so *not* copying the padding requires at least adding a memset upfront.
I would do the per-member copy like I did for v4l2_buffer in my other reply:
struct v4l2_event *ev = parg; struct v4l2_event_time32 ev32 = { .type = ev->type, .pending = ev->pending, .sequence = ev->sequence, .timestamp.tv_sec = ev->timestamp.tv_sec, .timestamp.tv_nsec = ev->timestamp.tv_nsec, .id = ev->id, }; memcpy(ev32.u, ev->u, sizeof(ev->u)); memcpy(ev32.reserved, ev->reserved, sizeof(ev->reserved)); if (copy_to_user(arg, &ev32, sizeof(ev32))) return -EFAULT;Unfortunately this is a little uglier because it still requires the two memcpy() for the arrays, but I think it's good enough.
I agree.
Hmm, can't you do .u = ev->u ? Or is that not allowed by this syntax?
Any other ideas? Let me know if I should do a memset() plus individual member copy instead.
I think we have to, unless you have a better solution. This is leaking information from the holes in the struct.
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));Ditto.
Using the corresponding code here as well.
#define V4L2_EVENT_SUB_FL_SEND_INITIAL (1 << 0) #define V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK (1 << 1)
@@ -2486,6 +2515,7 @@ 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)
Shouldn't this be under #ifdef __KERNEL__?
And should this be in the public header at all? media/v4l2-ioctl.h might be a better place.
Done.
Arnd
Regards,
Hans
On Tue, Nov 26, 2019 at 4:10 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/26/19 3:43 PM, Arnd Bergmann wrote:
On Mon, Nov 25, 2019 at 3:40 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
struct v4l2_event *ev = parg; struct v4l2_event_time32 ev32 = { .type = ev->type, .pending = ev->pending, .sequence = ev->sequence, .timestamp.tv_sec = ev->timestamp.tv_sec, .timestamp.tv_nsec = ev->timestamp.tv_nsec, .id = ev->id, }; memcpy(ev32.u, ev->u, sizeof(ev->u)); memcpy(ev32.reserved, ev->reserved, sizeof(ev->reserved)); if (copy_to_user(arg, &ev32, sizeof(ev32))) return -EFAULT;Unfortunately this is a little uglier because it still requires the two memcpy() for the arrays, but I think it's good enough.
I agree.
Hmm, can't you do .u = ev->u ? Or is that not allowed by this syntax?
No, that doesn't work here since the two unions are considered different types despite being defined identically. It would work by giving the union a name, but that name would also become visible to user space without adding more hacks.
Arnd
The v4l2_buffer structure contains a 'struct timeval' member that is defined by the user space C library, creating an ABI incompatibility when that gets updated to a 64-bit time_t.
As in v4l2_event, handle this with a special case in video_put_user() and video_get_user() to replace the memcpy there.
Since the structure also contains a pointer, there are now two native versions (on 32-bit systems) as well as two compat versions (on 64-bit systems), which unfortunately complicates the compat handler quite a bit.
Duplicating the existing handlers for the new types is a safe conversion for now, but unfortunately this may turn into a maintenance burden later. A larger-scale rework of the compat code might be a better alternative, but is out of scope of the y2038 work.
Sparc64 needs a special case because of their special suseconds_t definition.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/media/v4l2-core/v4l2-ioctl.c | 57 ++++++++++++++++++++++++++-- include/uapi/linux/videodev2.h | 45 ++++++++++++++++++++++ 2 files changed, 98 insertions(+), 4 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 1de939d11628..4ae1bcaec3fa 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -474,10 +474,10 @@ static void v4l_print_buffer(const void *arg, bool write_only) const struct v4l2_plane *plane; int i;
- pr_cont("%02ld:%02d:%02d.%08ld index=%d, type=%s, request_fd=%d, flags=0x%08x, field=%s, sequence=%d, memory=%s", - p->timestamp.tv_sec / 3600, - (int)(p->timestamp.tv_sec / 60) % 60, - (int)(p->timestamp.tv_sec % 60), + pr_cont("%02d:%02d:%02d.%09ld index=%d, type=%s, request_fd=%d, flags=0x%08x, field=%s, sequence=%d, memory=%s", + (int)p->timestamp.tv_sec / 3600, + ((int)p->timestamp.tv_sec / 60) % 60, + ((int)p->timestamp.tv_sec % 60), (long)p->timestamp.tv_usec, p->index, prt_names(p->type, v4l2_type_names), p->request_fd, @@ -3014,6 +3014,14 @@ static unsigned int video_translate_cmd(unsigned int cmd) #ifdef CONFIG_COMPAT_32BIT_TIME case VIDIOC_DQEVENT_TIME32: return VIDIOC_DQEVENT; + case VIDIOC_QUERYBUF_TIME32: + return VIDIOC_QUERYBUF; + case VIDIOC_QBUF_TIME32: + return VIDIOC_QBUF; + case VIDIOC_DQBUF_TIME32: + return VIDIOC_DQBUF; + case VIDIOC_PREPARE_BUF_TIME32: + return VIDIOC_PREPARE_BUF; #endif }
@@ -3032,6 +3040,30 @@ static int video_get_user(void __user *arg, void *parg, unsigned int cmd, }
switch (cmd) { +#ifdef COMPAT_32BIT_TIME + case VIDIOC_QUERYBUF_TIME32: + case VIDIOC_QBUF_TIME32: + case VIDIOC_DQBUF_TIME32: + case VIDIOC_PREPARE_BUF_TIME32: { + struct v4l2_buffer_time32 vb32; + struct v4l2_buffer *vb = parg; + + if (copy_from_user(&vb32, arg, sizeof(vb32))) + return -EFAULT; + + memcpy(vb, &vb32, offsetof(struct v4l2_buffer, timestamp)); + vb->timestamp.tv_sec = vb32.timestamp.tv_sec; + vb->timestamp.tv_usec = vb32.timestamp.tv_usec; + memcpy(&vb->timecode, &vb32.timecode, + sizeof(*vb) - offsetof(struct v4l2_buffer, timecode)); + + if (cmd == VIDIOC_QUERYBUF_TIME32) + memset(&vb->length, 0, sizeof(*vb) - + offsetof(struct v4l2_buffer, length)); + + break; + } +#endif default: /* * In some cases, only a few fields are used as input, @@ -3080,6 +3112,23 @@ static int video_put_user(void __user *arg, void *parg, unsigned int cmd) return -EFAULT; break; } + case VIDIOC_QUERYBUF_TIME32: + case VIDIOC_QBUF_TIME32: + case VIDIOC_DQBUF_TIME32: + case VIDIOC_PREPARE_BUF_TIME32: { + struct v4l2_buffer_time32 vb32; + struct v4l2_buffer *vb = parg; + + memcpy(&vb32, vb, offsetof(struct v4l2_buffer, timestamp)); + vb32.timestamp.tv_sec = vb->timestamp.tv_sec; + vb32.timestamp.tv_usec = vb->timestamp.tv_usec; + memcpy(&vb32.timecode, &vb->timecode, + sizeof(*vb) - offsetof(struct v4l2_buffer, timecode)); + + if (copy_to_user(arg, &vb32, sizeof(vb32))) + return -EFAULT; + break; + } #endif default: /* Copy results into user buffer */ diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 1d2553d4ed5b..f05c54d63f96 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -990,7 +990,47 @@ struct v4l2_buffer { __u32 bytesused; __u32 flags; __u32 field; +#ifdef __KERNEL__ + /* match glibc timeval64 format */ + struct { + long long tv_sec; +# if defined(__sparc__) && defined(__arch64__) + int tv_usec; + int __pad; +# else + long long tv_usec; +# endif + } timestamp; +#else struct timeval timestamp; +#endif + struct v4l2_timecode timecode; + __u32 sequence; + + /* memory location */ + __u32 memory; + union { + __u32 offset; + unsigned long userptr; + struct v4l2_plane *planes; + __s32 fd; + } m; + __u32 length; + __u32 reserved2; + union { + __s32 request_fd; + __u32 reserved; + }; +}; + +#ifdef __KERNEL__ +struct v4l2_buffer_time32 { + __u32 index; + __u32 type; + __u32 bytesused; + __u32 flags; + __u32 field; + struct old_timeval32 timestamp; struct v4l2_timecode timecode; __u32 sequence;
@@ -1009,6 +1049,7 @@ struct v4l2_buffer { __u32 reserved; }; }; +#endif
#ifndef __KERNEL__ /** @@ -2446,12 +2487,15 @@ struct v4l2_create_buffers { #define VIDIOC_S_FMT _IOWR('V', 5, struct v4l2_format) #define VIDIOC_REQBUFS _IOWR('V', 8, struct v4l2_requestbuffers) #define VIDIOC_QUERYBUF _IOWR('V', 9, struct v4l2_buffer) +#define VIDIOC_QUERYBUF_TIME32 _IOWR('V', 9, struct v4l2_buffer_time32) #define VIDIOC_G_FBUF _IOR('V', 10, struct v4l2_framebuffer) #define VIDIOC_S_FBUF _IOW('V', 11, struct v4l2_framebuffer) #define VIDIOC_OVERLAY _IOW('V', 14, int) #define VIDIOC_QBUF _IOWR('V', 15, struct v4l2_buffer) +#define VIDIOC_QBUF_TIME32 _IOWR('V', 15, struct v4l2_buffer_time32) #define VIDIOC_EXPBUF _IOWR('V', 16, struct v4l2_exportbuffer) #define VIDIOC_DQBUF _IOWR('V', 17, struct v4l2_buffer) +#define VIDIOC_DQBUF_TIME32 _IOWR('V', 17, struct v4l2_buffer_time32) #define VIDIOC_STREAMON _IOW('V', 18, int) #define VIDIOC_STREAMOFF _IOW('V', 19, int) #define VIDIOC_G_PARM _IOWR('V', 21, struct v4l2_streamparm) @@ -2520,6 +2564,7 @@ struct v4l2_create_buffers { #define VIDIOC_UNSUBSCRIBE_EVENT _IOW('V', 91, struct v4l2_event_subscription) #define VIDIOC_CREATE_BUFS _IOWR('V', 92, struct v4l2_create_buffers) #define VIDIOC_PREPARE_BUF _IOWR('V', 93, struct v4l2_buffer) +#define VIDIOC_PREPARE_BUF_TIME32 _IOWR('V', 93, struct v4l2_buffer_time32) #define VIDIOC_G_SELECTION _IOWR('V', 94, struct v4l2_selection) #define VIDIOC_S_SELECTION _IOWR('V', 95, struct v4l2_selection) #define VIDIOC_DECODER_CMD _IOWR('V', 96, struct v4l2_decoder_cmd)
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
The v4l2_buffer structure contains a 'struct timeval' member that is defined by the user space C library, creating an ABI incompatibility when that gets updated to a 64-bit time_t.
As in v4l2_event, handle this with a special case in video_put_user() and video_get_user() to replace the memcpy there.
Since the structure also contains a pointer, there are now two native versions (on 32-bit systems) as well as two compat versions (on 64-bit systems), which unfortunately complicates the compat handler quite a bit.
Duplicating the existing handlers for the new types is a safe conversion for now, but unfortunately this may turn into a maintenance burden later. A larger-scale rework of the compat code might be a better alternative, but is out of scope of the y2038 work.
Sparc64 needs a special case because of their special suseconds_t definition.
Signed-off-by: Arnd Bergmann arnd@arndb.de
drivers/media/v4l2-core/v4l2-ioctl.c | 57 ++++++++++++++++++++++++++-- include/uapi/linux/videodev2.h | 45 ++++++++++++++++++++++ 2 files changed, 98 insertions(+), 4 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 1de939d11628..4ae1bcaec3fa 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -474,10 +474,10 @@ static void v4l_print_buffer(const void *arg, bool write_only) const struct v4l2_plane *plane; int i;
- pr_cont("%02ld:%02d:%02d.%08ld index=%d, type=%s, request_fd=%d, flags=0x%08x, field=%s, sequence=%d, memory=%s",
p->timestamp.tv_sec / 3600,(int)(p->timestamp.tv_sec / 60) % 60,(int)(p->timestamp.tv_sec % 60),
- pr_cont("%02d:%02d:%02d.%09ld index=%d, type=%s, request_fd=%d, flags=0x%08x, field=%s, sequence=%d, memory=%s",
(int)p->timestamp.tv_sec / 3600,((int)p->timestamp.tv_sec / 60) % 60,((int)p->timestamp.tv_sec % 60), (long)p->timestamp.tv_usec, p->index, prt_names(p->type, v4l2_type_names), p->request_fd,@@ -3014,6 +3014,14 @@ static unsigned int video_translate_cmd(unsigned int cmd) #ifdef CONFIG_COMPAT_32BIT_TIME case VIDIOC_DQEVENT_TIME32: return VIDIOC_DQEVENT;
- case VIDIOC_QUERYBUF_TIME32:
return VIDIOC_QUERYBUF;- case VIDIOC_QBUF_TIME32:
return VIDIOC_QBUF;- case VIDIOC_DQBUF_TIME32:
return VIDIOC_DQBUF;- case VIDIOC_PREPARE_BUF_TIME32:
return VIDIOC_PREPARE_BUF;#endif } @@ -3032,6 +3040,30 @@ static int video_get_user(void __user *arg, void *parg, unsigned int cmd, } switch (cmd) { +#ifdef COMPAT_32BIT_TIME
- case VIDIOC_QUERYBUF_TIME32:
- case VIDIOC_QBUF_TIME32:
- case VIDIOC_DQBUF_TIME32:
- case VIDIOC_PREPARE_BUF_TIME32: {
struct v4l2_buffer_time32 vb32;struct v4l2_buffer *vb = parg;if (copy_from_user(&vb32, arg, sizeof(vb32)))return -EFAULT;memcpy(vb, &vb32, offsetof(struct v4l2_buffer, timestamp));vb->timestamp.tv_sec = vb32.timestamp.tv_sec;vb->timestamp.tv_usec = vb32.timestamp.tv_usec;memcpy(&vb->timecode, &vb32.timecode,sizeof(*vb) - offsetof(struct v4l2_buffer, timecode));
I have similar concerns as with dqevent about whether this memcpy is the right approach. Unless you can prove with a utility like pahole that this memcpy is safe.
if (cmd == VIDIOC_QUERYBUF_TIME32)memset(&vb->length, 0, sizeof(*vb) -offsetof(struct v4l2_buffer, length));break;- }
+#endif default: /* * In some cases, only a few fields are used as input, @@ -3080,6 +3112,23 @@ static int video_put_user(void __user *arg, void *parg, unsigned int cmd) return -EFAULT; break; }
- case VIDIOC_QUERYBUF_TIME32:
- case VIDIOC_QBUF_TIME32:
- case VIDIOC_DQBUF_TIME32:
- case VIDIOC_PREPARE_BUF_TIME32: {
struct v4l2_buffer_time32 vb32;struct v4l2_buffer *vb = parg;memcpy(&vb32, vb, offsetof(struct v4l2_buffer, timestamp));vb32.timestamp.tv_sec = vb->timestamp.tv_sec;vb32.timestamp.tv_usec = vb->timestamp.tv_usec;memcpy(&vb32.timecode, &vb->timecode,sizeof(*vb) - offsetof(struct v4l2_buffer, timecode));
Ditto.
if (copy_to_user(arg, &vb32, sizeof(vb32)))return -EFAULT;break;- }
#endif default: /* Copy results into user buffer */ diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 1d2553d4ed5b..f05c54d63f96 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -990,7 +990,47 @@ struct v4l2_buffer { __u32 bytesused; __u32 flags; __u32 field; +#ifdef __KERNEL__
- /* match glibc timeval64 format */
- struct {
long long tv_sec;+# if defined(__sparc__) && defined(__arch64__)
int tv_usec;int __pad;+# else
long long tv_usec;+# endif
- } timestamp;
Ewww!
Are there more places where this is needed? If so, then I very much prefer that a __kernel_timeval struct is defined somewhere, with appropriate comments.
+#else struct timeval timestamp; +#endif
- struct v4l2_timecode timecode;
- __u32 sequence;
- /* memory location */
- __u32 memory;
- union {
__u32 offset;unsigned long userptr;struct v4l2_plane *planes;__s32 fd;- } m;
- __u32 length;
- __u32 reserved2;
- union {
__s32 request_fd;__u32 reserved;- };
+};
+#ifdef __KERNEL__ +struct v4l2_buffer_time32 {
- __u32 index;
- __u32 type;
- __u32 bytesused;
- __u32 flags;
- __u32 field;
- struct old_timeval32 timestamp; struct v4l2_timecode timecode; __u32 sequence;
@@ -1009,6 +1049,7 @@ struct v4l2_buffer { __u32 reserved; }; }; +#endif
Can this be moved to v4l2-ioctls.h?
#ifndef __KERNEL__ /** @@ -2446,12 +2487,15 @@ struct v4l2_create_buffers { #define VIDIOC_S_FMT _IOWR('V', 5, struct v4l2_format) #define VIDIOC_REQBUFS _IOWR('V', 8, struct v4l2_requestbuffers) #define VIDIOC_QUERYBUF _IOWR('V', 9, struct v4l2_buffer) +#define VIDIOC_QUERYBUF_TIME32 _IOWR('V', 9, struct v4l2_buffer_time32)
And all these should be moved there as well.
#define VIDIOC_G_FBUF _IOR('V', 10, struct v4l2_framebuffer) #define VIDIOC_S_FBUF _IOW('V', 11, struct v4l2_framebuffer) #define VIDIOC_OVERLAY _IOW('V', 14, int) #define VIDIOC_QBUF _IOWR('V', 15, struct v4l2_buffer) +#define VIDIOC_QBUF_TIME32 _IOWR('V', 15, struct v4l2_buffer_time32) #define VIDIOC_EXPBUF _IOWR('V', 16, struct v4l2_exportbuffer) #define VIDIOC_DQBUF _IOWR('V', 17, struct v4l2_buffer) +#define VIDIOC_DQBUF_TIME32 _IOWR('V', 17, struct v4l2_buffer_time32) #define VIDIOC_STREAMON _IOW('V', 18, int) #define VIDIOC_STREAMOFF _IOW('V', 19, int) #define VIDIOC_G_PARM _IOWR('V', 21, struct v4l2_streamparm) @@ -2520,6 +2564,7 @@ struct v4l2_create_buffers { #define VIDIOC_UNSUBSCRIBE_EVENT _IOW('V', 91, struct v4l2_event_subscription) #define VIDIOC_CREATE_BUFS _IOWR('V', 92, struct v4l2_create_buffers) #define VIDIOC_PREPARE_BUF _IOWR('V', 93, struct v4l2_buffer) +#define VIDIOC_PREPARE_BUF_TIME32 _IOWR('V', 93, struct v4l2_buffer_time32) #define VIDIOC_G_SELECTION _IOWR('V', 94, struct v4l2_selection) #define VIDIOC_S_SELECTION _IOWR('V', 95, struct v4l2_selection) #define VIDIOC_DECODER_CMD _IOWR('V', 96, struct v4l2_decoder_cmd)
Regards,
Hans
On Mon, Nov 25, 2019 at 3:57 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
switch (cmd) {+#ifdef COMPAT_32BIT_TIME
case VIDIOC_QUERYBUF_TIME32:case VIDIOC_QBUF_TIME32:case VIDIOC_DQBUF_TIME32:case VIDIOC_PREPARE_BUF_TIME32: {struct v4l2_buffer_time32 vb32;struct v4l2_buffer *vb = parg;if (copy_from_user(&vb32, arg, sizeof(vb32)))return -EFAULT;memcpy(vb, &vb32, offsetof(struct v4l2_buffer, timestamp));vb->timestamp.tv_sec = vb32.timestamp.tv_sec;vb->timestamp.tv_usec = vb32.timestamp.tv_usec;memcpy(&vb->timecode, &vb32.timecode,sizeof(*vb) - offsetof(struct v4l2_buffer, timecode));I have similar concerns as with dqevent about whether this memcpy is the right approach. Unless you can prove with a utility like pahole that this memcpy is safe.
This is the video_get_user() function, so the input data comes from user space and gets copied into the kernel, which has to check each field for validity already, so I think this is safe regardless of the padding (which exists before the 64-bit timestamp on 32-bit architectures). The fields match because the definition of all members other than the timeval is the same.
On the other hand, I agree it's not obvious from the code why this is correct. I've changed my copy to this version below now, do you like that better?
struct v4l2_buffer_time32 vb32; struct v4l2_buffer *vb = parg;
if (copy_from_user(&vb32, arg, sizeof(vb32))) return -EFAULT;
*vb = (struct v4l2_buffer) { .index = vb32.index, .type = vb32.type, .bytesused = vb32.bytesused, .flags = vb32.flags, .field = vb32.field, .timestamp.tv_sec = vb32.timestamp.tv_sec, .timestamp.tv_usec = vb32.timestamp.tv_usec, .timecode = vb32.timecode, .memory = vb32.memory, .m.userptr = vb32.usercopy, .length = vb32.length, .request_fd = vb32.request_fd, };
if (cmd == VIDIOC_QUERYBUF_TIME32) memset(&vb->length, 0, sizeof(*vb) - offsetof(struct v4l2_buffer, length));
This way, all padding is zeroed out, and it's obvious to human readers that each field gets set in the correct location.
memcpy(&vb32, vb, offsetof(struct v4l2_buffer, timestamp));vb32.timestamp.tv_sec = vb->timestamp.tv_sec;vb32.timestamp.tv_usec = vb->timestamp.tv_usec;memcpy(&vb32.timecode, &vb->timecode,sizeof(*vb) - offsetof(struct v4l2_buffer, timecode));Ditto.
This is my new version:
struct v4l2_buffer *vb = parg; struct v4l2_buffer_time32 vb32 = { .index = vb->index, .type = vb->type, .bytesused = vb->bytesused, .flags = vb->flags, .field = vb->field, .timestamp.tv_sec = vb->timestamp.tv_sec, .timestamp.tv_usec = vb->timestamp.tv_usec, .timecode = vb->timecode, .memory = vb->memory, .m.userptr = vb->usercopy, .length = vb->length, .request_fd = vb->request_fd, };
if (copy_to_user(arg, &vb32, sizeof(vb32))) return -EFAULT;
__u32 field;+#ifdef __KERNEL__
/* match glibc timeval64 format */struct {long long tv_sec;+# if defined(__sparc__) && defined(__arch64__)
int tv_usec;int __pad;+# else
long long tv_usec;+# endif
} timestamp;Ewww!
Are there more places where this is needed? If so, then I very much prefer that a __kernel_timeval struct is defined somewhere, with appropriate comments.
I was trying hard to avoid adding a modern version of timeval, because all new code should be encouraged to use __kernel_timespec instead.
There are not many users of timeval in the uapi, and this is the last one after the others all got invididual treatment.
Usually what I would do is to have a kernel-internal type based on timespec or u64, and then define three uapi types: old native (based on __kernel_old_timeval), old compat (using old_timeval32) and the new type with 64-bit time_t.
The problem with v4l2_buffer is that it includes another compat-incompatible field (m.userptr) and that it's passed between kernel functions, so then I'd probably need five variants of it in total, and it would slow down the common case (64-bit native) because it would require an extra copy.
I can try a few more things here, but I don't expect to find anything much better than this.
+#ifdef __KERNEL__ +struct v4l2_buffer_time32 {
__u32 index;__u32 type;__u32 bytesused;__u32 flags;__u32 field;struct old_timeval32 timestamp; struct v4l2_timecode timecode; __u32 sequence;@@ -1009,6 +1049,7 @@ struct v4l2_buffer { __u32 reserved; }; }; +#endif
Can this be moved to v4l2-ioctls.h?
done.
#ifndef __KERNEL__ /** @@ -2446,12 +2487,15 @@ struct v4l2_create_buffers { #define VIDIOC_S_FMT _IOWR('V', 5, struct v4l2_format) #define VIDIOC_REQBUFS _IOWR('V', 8, struct v4l2_requestbuffers) #define VIDIOC_QUERYBUF _IOWR('V', 9, struct v4l2_buffer) +#define VIDIOC_QUERYBUF_TIME32 _IOWR('V', 9, struct v4l2_buffer_time32)
And all these should be moved there as well.
done.
Arnd
On 11/26/19 2:50 PM, Arnd Bergmann wrote:
On Mon, Nov 25, 2019 at 3:57 PM Hans Verkuil hverkuil@xs4all.nl wrote:
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
switch (cmd) {+#ifdef COMPAT_32BIT_TIME
case VIDIOC_QUERYBUF_TIME32:case VIDIOC_QBUF_TIME32:case VIDIOC_DQBUF_TIME32:case VIDIOC_PREPARE_BUF_TIME32: {struct v4l2_buffer_time32 vb32;struct v4l2_buffer *vb = parg;if (copy_from_user(&vb32, arg, sizeof(vb32)))return -EFAULT;memcpy(vb, &vb32, offsetof(struct v4l2_buffer, timestamp));vb->timestamp.tv_sec = vb32.timestamp.tv_sec;vb->timestamp.tv_usec = vb32.timestamp.tv_usec;memcpy(&vb->timecode, &vb32.timecode,sizeof(*vb) - offsetof(struct v4l2_buffer, timecode));I have similar concerns as with dqevent about whether this memcpy is the right approach. Unless you can prove with a utility like pahole that this memcpy is safe.
This is the video_get_user() function, so the input data comes from user space and gets copied into the kernel, which has to check each field for validity already, so I think this is safe regardless of the padding (which exists before the 64-bit timestamp on 32-bit architectures). The fields match because the definition of all members other than the timeval is the same.
On the other hand, I agree it's not obvious from the code why this is correct. I've changed my copy to this version below now, do you like that better?
struct v4l2_buffer_time32 vb32; struct v4l2_buffer *vb = parg; if (copy_from_user(&vb32, arg, sizeof(vb32))) return -EFAULT; *vb = (struct v4l2_buffer) { .index = vb32.index, .type = vb32.type, .bytesused = vb32.bytesused, .flags = vb32.flags, .field = vb32.field, .timestamp.tv_sec = vb32.timestamp.tv_sec, .timestamp.tv_usec = vb32.timestamp.tv_usec, .timecode = vb32.timecode, .memory = vb32.memory, .m.userptr = vb32.usercopy, .length = vb32.length, .request_fd = vb32.request_fd, }; if (cmd == VIDIOC_QUERYBUF_TIME32) memset(&vb->length, 0, sizeof(*vb) - offsetof(struct v4l2_buffer, length));This way, all padding is zeroed out, and it's obvious to human readers that each field gets set in the correct location.
memcpy(&vb32, vb, offsetof(struct v4l2_buffer, timestamp));vb32.timestamp.tv_sec = vb->timestamp.tv_sec;vb32.timestamp.tv_usec = vb->timestamp.tv_usec;memcpy(&vb32.timecode, &vb->timecode,sizeof(*vb) - offsetof(struct v4l2_buffer, timecode));Ditto.
This is my new version:
struct v4l2_buffer *vb = parg; struct v4l2_buffer_time32 vb32 = { .index = vb->index, .type = vb->type, .bytesused = vb->bytesused, .flags = vb->flags, .field = vb->field, .timestamp.tv_sec = vb->timestamp.tv_sec, .timestamp.tv_usec = vb->timestamp.tv_usec, .timecode = vb->timecode, .memory = vb->memory, .m.userptr = vb->usercopy, .length = vb->length, .request_fd = vb->request_fd, };
That looks clean.
if (copy_to_user(arg, &vb32, sizeof(vb32))) return -EFAULT;__u32 field;+#ifdef __KERNEL__
/* match glibc timeval64 format */struct {long long tv_sec;+# if defined(__sparc__) && defined(__arch64__)
int tv_usec;int __pad;+# else
long long tv_usec;+# endif
} timestamp;Ewww!
Are there more places where this is needed? If so, then I very much prefer that a __kernel_timeval struct is defined somewhere, with appropriate comments.
I was trying hard to avoid adding a modern version of timeval, because all new code should be encouraged to use __kernel_timespec instead.
There are not many users of timeval in the uapi, and this is the last one after the others all got invididual treatment.
Usually what I would do is to have a kernel-internal type based on timespec or u64, and then define three uapi types: old native (based on __kernel_old_timeval), old compat (using old_timeval32) and the new type with 64-bit time_t.
The problem with v4l2_buffer is that it includes another compat-incompatible field (m.userptr) and that it's passed between kernel functions, so then I'd probably need five variants of it in total, and it would slow down the common case (64-bit native) because it would require an extra copy.
I can try a few more things here, but I don't expect to find anything much better than this.
How about something like this in videodev2.h:
Split off the ugly kernel timeval definition in a separate struct:
#ifdef __KERNEL__ /* match glibc timeval64 format */ struct __kernel_v4l2_timeval { long long tv_sec; # if defined(__sparc__) && defined(__arch64__) int tv_usec; int __pad; # else long long tv_usec; # endif }; #endif
Then use that in the struct v4l2_buffer definition:
struct v4l2_buffer { ... #ifdef __KERNEL__ struct __kernel_v4l2_timeval timestamp; #else struct timeval timestamp; #endif
That keeps struct v4l2_buffer fairly clean. And it also makes it possible to have a bit more extensive documentation for the struct __kernel_v4l2_timeval without polluting the actual struct v4l2_buffer definition.
The videodev2.h header is something users of the API look at a lot and having this really ugly kernel timestamp in there is not acceptably IMHO. But splitting it off should work.
+#ifdef __KERNEL__ +struct v4l2_buffer_time32 {
__u32 index;__u32 type;__u32 bytesused;__u32 flags;__u32 field;struct old_timeval32 timestamp; struct v4l2_timecode timecode; __u32 sequence;@@ -1009,6 +1049,7 @@ struct v4l2_buffer { __u32 reserved; }; }; +#endif
Can this be moved to v4l2-ioctls.h?
done.
#ifndef __KERNEL__ /** @@ -2446,12 +2487,15 @@ struct v4l2_create_buffers { #define VIDIOC_S_FMT _IOWR('V', 5, struct v4l2_format) #define VIDIOC_REQBUFS _IOWR('V', 8, struct v4l2_requestbuffers) #define VIDIOC_QUERYBUF _IOWR('V', 9, struct v4l2_buffer) +#define VIDIOC_QUERYBUF_TIME32 _IOWR('V', 9, struct v4l2_buffer_time32)
And all these should be moved there as well.
done.
Arnd
Regards,
Hans
On Tue, Nov 26, 2019 at 3:15 PM Hans Verkuil hverkuil@xs4all.nl wrote:
Then use that in the struct v4l2_buffer definition:
struct v4l2_buffer { ... #ifdef __KERNEL__ struct __kernel_v4l2_timeval timestamp; #else struct timeval timestamp; #endif
That keeps struct v4l2_buffer fairly clean. And it also makes it possible to have a bit more extensive documentation for the struct __kernel_v4l2_timeval without polluting the actual struct v4l2_buffer definition.
Yes, good idea. I've added this version now:
#ifdef __KERNEL__ /* * This corresponds to the user space version of timeval * for 64-bit time_t. sparc64 is different from everyone * else, using the microseconds in the wrong half of the * second 64-bit word. */ struct __kernel_v4l2_timeval { long long tv_sec; #if defined(__sparc__) && defined(__arch64__) int tv_usec; int __pad; #else long long tv_usec; #endif }; #endif
I briefly considered using #else #define __kernel_v4l2_timeval timeval to avoid the second #ifdef, but went back to your version again for clarify.
The videodev2.h header is something users of the API look at a lot and having this really ugly kernel timestamp in there is not acceptably IMHO. But splitting it off should work.
Do you also mean moving it into a separate header file, or just outside of struct v4l2_buffer? Since it's hidden in #ifdef __KERNEL__, it could be moved to media/ioctl.h or elsewhere.
Arnd
On 11/26/19 4:17 PM, Arnd Bergmann wrote:
On Tue, Nov 26, 2019 at 3:15 PM Hans Verkuil hverkuil@xs4all.nl wrote:
Then use that in the struct v4l2_buffer definition:
struct v4l2_buffer { ... #ifdef __KERNEL__ struct __kernel_v4l2_timeval timestamp; #else struct timeval timestamp; #endif
That keeps struct v4l2_buffer fairly clean. And it also makes it possible to have a bit more extensive documentation for the struct __kernel_v4l2_timeval without polluting the actual struct v4l2_buffer definition.
Yes, good idea. I've added this version now:
#ifdef __KERNEL__ /*
- This corresponds to the user space version of timeval
- for 64-bit time_t. sparc64 is different from everyone
- else, using the microseconds in the wrong half of the
- second 64-bit word.
*/ struct __kernel_v4l2_timeval { long long tv_sec; #if defined(__sparc__) && defined(__arch64__) int tv_usec; int __pad; #else long long tv_usec; #endif }; #endif
I briefly considered using #else #define __kernel_v4l2_timeval timeval to avoid the second #ifdef, but went back to your version again for clarify.
The videodev2.h header is something users of the API look at a lot and having this really ugly kernel timestamp in there is not acceptably IMHO. But splitting it off should work.
Do you also mean moving it into a separate header file, or just outside of struct v4l2_buffer? Since it's hidden in #ifdef __KERNEL__, it could be moved to media/ioctl.h or elsewhere.
I've thought about that, but that risks having to change drivers since they would now have to include another header to get the right timeval definition. In the end I don't think it is worth the effort.
I think it is best to define __kernel_v4l2_timeval just before the struct v4l2_requestbuffers definition rather than before the struct v4l2_buffer. That way it doesn't interfere with the userspace structs for the buffer API.
Regards,
Hans
Arnd
The native code supports the variant of struct v4l2_event for 64-bit time_t, so add the compat version as well.
Here, a new incompatibility arises: while almost all 32-bit architectures now use the same layout as 64-bit architectures and the commands can simply be passed through, on x86 the internal alignment of v4l2_event is different because of the 64-bit member in v4l2_event_ctrl.
To handle all architectures, this now requires defining four different versions of the structure to cover all possible combinations. The compat handling for VIDIOC_DQEVENT32 and VIDIOC_DQEVENT32_TIME32 is now inside of an #ifdef so it does not get used on architectures other than x86.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 57 ++++++++++++++++++- 1 file changed, 56 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 7ad6db8dd9f6..46cd84879c1f 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -1028,6 +1028,15 @@ static int put_v4l2_ext_controls32(struct file *file, return 0; }
+#ifdef CONFIG_X86_64 +/* + * x86 is the only compat architecture with different struct alignment + * between 32-bit and 64-bit tasks. + * + * On all other architectures, v4l2_event32 and v4l2_event32_time32 are + * the same as v4l2_event and v4l2_event_time32, so we can use the native + * handlers, converting v4l2_event to v4l2_event_time32 if necessary. + */ struct v4l2_event32 { __u32 type; union { @@ -1036,7 +1045,20 @@ struct v4l2_event32 { } u; __u32 pending; __u32 sequence; - struct compat_timespec timestamp; + struct __kernel_timespec timestamp; + __u32 id; + __u32 reserved[8]; +}; + +struct v4l2_event32_time32 { + __u32 type; + union { + compat_s64 value64; + __u8 data[64]; + } u; + __u32 pending; + __u32 sequence; + struct old_timespec32 timestamp; __u32 id; __u32 reserved[8]; }; @@ -1057,6 +1079,23 @@ static int put_v4l2_event32(struct v4l2_event __user *p64, return 0; }
+static int put_v4l2_event32_time32(struct v4l2_event_time32 __user *p64, + struct v4l2_event32_time32 __user *p32) +{ + if (!access_ok(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; +} +#endif + struct v4l2_edid32 { __u32 pad; __u32 start_block; @@ -1121,6 +1160,7 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64, #define VIDIOC_S_EXT_CTRLS32 _IOWR('V', 72, struct v4l2_ext_controls32) #define VIDIOC_TRY_EXT_CTRLS32 _IOWR('V', 73, struct v4l2_ext_controls32) #define VIDIOC_DQEVENT32 _IOR ('V', 89, struct v4l2_event32) +#define VIDIOC_DQEVENT32_TIME32 _IOR ('V', 89, struct v4l2_event32_time32) #define VIDIOC_CREATE_BUFS32 _IOWR('V', 92, struct v4l2_create_buffers32) #define VIDIOC_PREPARE_BUF32 _IOWR('V', 93, struct v4l2_buffer32)
@@ -1202,7 +1242,10 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar case VIDIOC_G_EXT_CTRLS32: ncmd = VIDIOC_G_EXT_CTRLS; break; case VIDIOC_S_EXT_CTRLS32: ncmd = VIDIOC_S_EXT_CTRLS; break; case VIDIOC_TRY_EXT_CTRLS32: ncmd = VIDIOC_TRY_EXT_CTRLS; break; +#ifdef CONFIG_X86_64 case VIDIOC_DQEVENT32: ncmd = VIDIOC_DQEVENT; break; + case VIDIOC_DQEVENT32_TIME32: ncmd = VIDIOC_DQEVENT_TIME32; break; +#endif case VIDIOC_OVERLAY32: ncmd = VIDIOC_OVERLAY; break; case VIDIOC_STREAMON32: ncmd = VIDIOC_STREAMON; break; case VIDIOC_STREAMOFF32: ncmd = VIDIOC_STREAMOFF; break; @@ -1336,10 +1379,16 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar } compatible_arg = 0; break; +#ifdef CONFIG_X86_64 case VIDIOC_DQEVENT32: err = alloc_userspace(sizeof(struct v4l2_event), 0, &new_p64); compatible_arg = 0; break; + case VIDIOC_DQEVENT32_TIME32: + err = alloc_userspace(sizeof(struct v4l2_event_time32), 0, &new_p64); + compatible_arg = 0; + break; +#endif } if (err) return err; @@ -1404,10 +1453,16 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar err = put_v4l2_framebuffer32(new_p64, p32); break;
+#ifdef CONFIG_X86_64 case VIDIOC_DQEVENT32: err = put_v4l2_event32(new_p64, p32); break;
+ case VIDIOC_DQEVENT32_TIME32: + err = put_v4l2_event32_time32(new_p64, p32); + break; +#endif + case VIDIOC_G_EDID32: err = put_v4l2_edid32(new_p64, p32); break;
Add support for the four new variants of ioctl commands for 64-bit time_t in v4l2_buffer.
The existing v4l2_buffer32 structure for the traditional format gets changed to match the new v4l2_buffer format, and the old layout is now called v4l2_buffer32_time32. Neither of these matches the native 64-bit architecture format of v4l2_buffer, so both require special handling in compat code.
Duplicating the existing handlers for the new types is a safe conversion for now, but unfortunately this may turn into a maintenance burden later. A larger-scale rework of the compat code might be a better alternative, but is out of scope of the y2038 work.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 265 +++++++++++++++++- 1 file changed, 264 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 46cd84879c1f..3bbf47d950e0 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -474,7 +474,33 @@ struct v4l2_buffer32 { __u32 bytesused; __u32 flags; __u32 field; /* enum v4l2_field */ - struct compat_timeval timestamp; + struct { + long long tv_sec; + long long tv_usec; + } timestamp; + struct v4l2_timecode timecode; + __u32 sequence; + + /* memory location */ + __u32 memory; /* enum v4l2_memory */ + union { + __u32 offset; + compat_long_t userptr; + compat_caddr_t planes; + __s32 fd; + } m; + __u32 length; + __u32 reserved2; + __s32 request_fd; +}; + +struct v4l2_buffer32_time32 { + __u32 index; + __u32 type; /* enum v4l2_buf_type */ + __u32 bytesused; + __u32 flags; + __u32 field; /* enum v4l2_field */ + struct old_timeval32 timestamp; struct v4l2_timecode timecode; __u32 sequence;
@@ -581,6 +607,31 @@ static int bufsize_v4l2_buffer(struct v4l2_buffer32 __user *p32, u32 *size) return 0; }
+static int bufsize_v4l2_buffer_time32(struct v4l2_buffer32_time32 __user *p32, u32 *size) +{ + u32 type; + u32 length; + + if (!access_ok(p32, sizeof(*p32)) || + get_user(type, &p32->type) || + get_user(length, &p32->length)) + return -EFAULT; + + if (V4L2_TYPE_IS_MULTIPLANAR(type)) { + if (length > VIDEO_MAX_PLANES) + return -EINVAL; + + /* + * We don't really care if userspace decides to kill itself + * by passing a very big length value + */ + *size = length * sizeof(struct v4l2_plane); + } else { + *size = 0; + } + return 0; +} + static int get_v4l2_buffer32(struct v4l2_buffer __user *p64, struct v4l2_buffer32 __user *p32, void __user *aux_buf, u32 aux_space) @@ -681,6 +732,106 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64, return 0; }
+static int get_v4l2_buffer32_time32(struct v4l2_buffer_time32 __user *p64, + struct v4l2_buffer32_time32 __user *p32, + void __user *aux_buf, u32 aux_space) +{ + u32 type; + u32 length; + s32 request_fd; + enum v4l2_memory memory; + struct v4l2_plane32 __user *uplane32; + struct v4l2_plane __user *uplane; + compat_caddr_t p; + int ret; + + if (!access_ok(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) || + get_user(request_fd, &p32->request_fd) || + put_user(request_fd, &p64->request_fd)) + return -EFAULT; + + if (V4L2_TYPE_IS_OUTPUT(type)) + 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)) { + u32 num_planes = length; + + if (num_planes == 0) { + /* + * num_planes == 0 is legal, e.g. when userspace doesn't + * need planes array on DQBUF + */ + return put_user(NULL, &p64->m.planes); + } + if (num_planes > VIDEO_MAX_PLANES) + return -EINVAL; + + if (get_user(p, &p32->m.planes)) + return -EFAULT; + + uplane32 = compat_ptr(p); + if (!access_ok(uplane32, + num_planes * sizeof(*uplane32))) + return -EFAULT; + + /* + * We don't really care if userspace decides to kill itself + * by passing a very big num_planes value + */ + if (aux_space < num_planes * sizeof(*uplane)) + return -EFAULT; + + uplane = aux_buf; + if (put_user_force(uplane, &p64->m.planes)) + return -EFAULT; + + while (num_planes--) { + ret = get_v4l2_plane32(uplane, uplane32, memory); + if (ret) + return ret; + uplane++; + uplane32++; + } + } else { + switch (memory) { + case V4L2_MEMORY_MMAP: + case V4L2_MEMORY_OVERLAY: + 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, &p32->m.userptr) || + put_user((unsigned long)compat_ptr(userptr), + &p64->m.userptr)) + return -EFAULT; + break; + } + case V4L2_MEMORY_DMABUF: + if (assign_in_user(&p64->m.fd, &p32->m.fd)) + return -EFAULT; + break; + } + } + + return 0; +} + static int put_v4l2_buffer32(struct v4l2_buffer __user *p64, struct v4l2_buffer32 __user *p32) { @@ -761,6 +912,87 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *p64, return 0; }
+ +static int put_v4l2_buffer32_time32(struct v4l2_buffer_time32 __user *p64, + struct v4l2_buffer32_time32 __user *p32) +{ + u32 type; + u32 length; + enum v4l2_memory memory; + struct v4l2_plane32 __user *uplane32; + struct v4l2_plane *uplane; + compat_caddr_t p; + int ret; + + if (!access_ok(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(&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->request_fd, &p64->request_fd) || + get_user(length, &p64->length) || + put_user(length, &p32->length)) + return -EFAULT; + + if (V4L2_TYPE_IS_MULTIPLANAR(type)) { + u32 num_planes = length; + + if (num_planes == 0) + return 0; + /* 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, &p64->m.planes)) + return -EFAULT; + if (get_user(p, &p32->m.planes)) + return -EFAULT; + uplane32 = compat_ptr(p); + + while (num_planes--) { + ret = put_v4l2_plane32((void __user *)uplane, + uplane32, memory); + if (ret) + return ret; + ++uplane; + ++uplane32; + } + } else { + switch (memory) { + case V4L2_MEMORY_MMAP: + case V4L2_MEMORY_OVERLAY: + if (assign_in_user(&p32->m.offset, &p64->m.offset)) + return -EFAULT; + break; + case V4L2_MEMORY_USERPTR: + if (assign_in_user(&p32->m.userptr, &p64->m.userptr)) + return -EFAULT; + break; + case V4L2_MEMORY_DMABUF: + if (assign_in_user(&p32->m.fd, &p64->m.fd)) + return -EFAULT; + break; + } + } + + return 0; +} + struct v4l2_framebuffer32 { __u32 capability; __u32 flags; @@ -1147,10 +1379,13 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64, #define VIDIOC_G_FMT32 _IOWR('V', 4, struct v4l2_format32) #define VIDIOC_S_FMT32 _IOWR('V', 5, struct v4l2_format32) #define VIDIOC_QUERYBUF32 _IOWR('V', 9, struct v4l2_buffer32) +#define VIDIOC_QUERYBUF32_TIME32 _IOWR('V', 9, struct v4l2_buffer32_time32) #define VIDIOC_G_FBUF32 _IOR ('V', 10, struct v4l2_framebuffer32) #define VIDIOC_S_FBUF32 _IOW ('V', 11, struct v4l2_framebuffer32) #define VIDIOC_QBUF32 _IOWR('V', 15, struct v4l2_buffer32) +#define VIDIOC_QBUF32_TIME32 _IOWR('V', 15, struct v4l2_buffer32_time32) #define VIDIOC_DQBUF32 _IOWR('V', 17, struct v4l2_buffer32) +#define VIDIOC_DQBUF32_TIME32 _IOWR('V', 17, struct v4l2_buffer32_time32) #define VIDIOC_ENUMSTD32 _IOWR('V', 25, struct v4l2_standard32) #define VIDIOC_ENUMINPUT32 _IOWR('V', 26, struct v4l2_input32) #define VIDIOC_G_EDID32 _IOWR('V', 40, struct v4l2_edid32) @@ -1163,6 +1398,7 @@ static int put_v4l2_edid32(struct v4l2_edid __user *p64, #define VIDIOC_DQEVENT32_TIME32 _IOR ('V', 89, struct v4l2_event32_time32) #define VIDIOC_CREATE_BUFS32 _IOWR('V', 92, struct v4l2_create_buffers32) #define VIDIOC_PREPARE_BUF32 _IOWR('V', 93, struct v4l2_buffer32) +#define VIDIOC_PREPARE_BUF32_TIME32 _IOWR('V', 93, struct v4l2_buffer32_time32)
#define VIDIOC_OVERLAY32 _IOW ('V', 14, s32) #define VIDIOC_STREAMON32 _IOW ('V', 18, s32) @@ -1232,10 +1468,13 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar case VIDIOC_G_FMT32: ncmd = VIDIOC_G_FMT; break; case VIDIOC_S_FMT32: ncmd = VIDIOC_S_FMT; break; case VIDIOC_QUERYBUF32: ncmd = VIDIOC_QUERYBUF; break; + case VIDIOC_QUERYBUF32_TIME32: ncmd = VIDIOC_QUERYBUF_TIME32; break; case VIDIOC_G_FBUF32: ncmd = VIDIOC_G_FBUF; break; case VIDIOC_S_FBUF32: ncmd = VIDIOC_S_FBUF; break; case VIDIOC_QBUF32: ncmd = VIDIOC_QBUF; break; + case VIDIOC_QBUF32_TIME32: ncmd = VIDIOC_QBUF_TIME32; break; case VIDIOC_DQBUF32: ncmd = VIDIOC_DQBUF; break; + case VIDIOC_DQBUF32_TIME32: ncmd = VIDIOC_DQBUF_TIME32; break; case VIDIOC_ENUMSTD32: ncmd = VIDIOC_ENUMSTD; break; case VIDIOC_ENUMINPUT32: ncmd = VIDIOC_ENUMINPUT; break; case VIDIOC_TRY_FMT32: ncmd = VIDIOC_TRY_FMT; break; @@ -1255,6 +1494,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar case VIDIOC_S_OUTPUT32: ncmd = VIDIOC_S_OUTPUT; break; case VIDIOC_CREATE_BUFS32: ncmd = VIDIOC_CREATE_BUFS; break; case VIDIOC_PREPARE_BUF32: ncmd = VIDIOC_PREPARE_BUF; break; + case VIDIOC_PREPARE_BUF32_TIME32: ncmd = VIDIOC_PREPARE_BUF_TIME32; break; case VIDIOC_G_EDID32: ncmd = VIDIOC_G_EDID; break; case VIDIOC_S_EDID32: ncmd = VIDIOC_S_EDID; break; default: ncmd = cmd; break; @@ -1336,6 +1576,22 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar compatible_arg = 0; break;
+ case VIDIOC_PREPARE_BUF32_TIME32: + case VIDIOC_QUERYBUF32_TIME32: + case VIDIOC_QBUF32_TIME32: + case VIDIOC_DQBUF32_TIME32: + err = bufsize_v4l2_buffer_time32(p32, &aux_space); + if (!err) + err = alloc_userspace(sizeof(struct v4l2_buffer), + aux_space, &new_p64); + if (!err) { + aux_buf = new_p64 + sizeof(struct v4l2_buffer); + err = get_v4l2_buffer32_time32(new_p64, p32, + aux_buf, aux_space); + } + compatible_arg = 0; + break; + case VIDIOC_S_FBUF32: err = alloc_userspace(sizeof(struct v4l2_framebuffer), 0, &new_p64); @@ -1484,6 +1740,13 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar err = put_v4l2_buffer32(new_p64, p32); break;
+ case VIDIOC_PREPARE_BUF32_TIME32: + case VIDIOC_QUERYBUF32_TIME32: + case VIDIOC_QBUF32_TIME32: + case VIDIOC_DQBUF32_TIME32: + err = put_v4l2_buffer32_time32(new_p64, p32); + break; + case VIDIOC_ENUMSTD32: err = put_v4l2_standard32(new_p64, p32); break;
Hi Arnd,
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
I'm in the process of finishing up the last bits on y2038-unsafe code in the kernel, this series is for v4l2, which has no problem with overflow, but has multiple ioctls that break with user space built against a new 32-bit libc.
Thank you for working on this. Much appreciated!
I've reviewed this v4 series and found a few issues (mostly things that ended up in videodev2.h that shouldn't be there).
Once a v5 is posted I'll try to test this more.
Is there an easy(-ish) way to test this with a time64 ABI? Do you have such an environment set up for testing?
I posted similar patches as part of a series back in 2015, the new version was rewritten from scratch and I double-checked with the old version to make sure I did not miss anything I had already taken care of before.
Hans Verkuil worked on a different patch set in 2017, but this also did not get to the point of being merged.
My new version contains compat-ioctl support, which the old one did not and should be complete, but given its size likely contains bugs. I did randconfig build tests, but no runtime test, so careful review as well as testing would be much appreciated.
With this version, the newly added code takes care of the existing ABI, while the existing code got moved to the 64-bit time_t interface and is used internally. This means that testing with existing binaries should exercise most of the modifications and if that works and doesn't get shot down in review, we can probably live without testing the new ABI explicitly.
I'm not entirely happy with the compat-ioctl implementation that adds quite a bit of code duplication, but I hope this is acceptable anyway, as a better implementation would likely require a larger refactoring of the compat-ioctl file, while my approach simply adds support for the additional data structure variants.
A cleanup is indeed much more work. This y2038 code is awful, but that's really because the original structs are aligned in the worst possible way.
Regards,
Hans
This is a minor update compared to version 3 of this series, with bugfixes for small mistakes that I found or that were reported by automated build bots. I updated the tree at [2] to this version now.
Arnd[1] https://lwn.net/Articles/657754/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=y...
Arnd Bergmann (8): media: documentation: fix video_event description media: v4l2: abstract timeval handling in v4l2_buffer media: v4l2-core: compat: ignore native command codes media: v4l2-core: split out data copy from video_usercopy media: v4l2-core: fix VIDIOC_DQEVENT for time64 ABI media: v4l2-core: fix v4l2_buffer handling for time64 ABI media: v4l2-core: fix compat VIDIOC_DQEVENT for time64 ABI media: v4l2-core: fix compat v4l2_buffer handling for time64 ABI
.../media/uapi/dvb/video-get-event.rst | 2 +- Documentation/media/uapi/dvb/video_types.rst | 2 +- .../media/common/videobuf2/videobuf2-v4l2.c | 4 +- drivers/media/pci/meye/meye.c | 4 +- drivers/media/usb/cpia2/cpia2_v4l.c | 4 +- drivers/media/usb/stkwebcam/stk-webcam.c | 2 +- drivers/media/usb/usbvision/usbvision-video.c | 4 +- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 470 +++++++++++++++--- drivers/media/v4l2-core/v4l2-event.c | 5 +- drivers/media/v4l2-core/v4l2-ioctl.c | 188 +++++-- drivers/media/v4l2-core/v4l2-subdev.c | 20 +- drivers/media/v4l2-core/videobuf-core.c | 4 +- include/linux/videodev2.h | 17 +- include/trace/events/v4l2.h | 2 +- include/uapi/linux/videodev2.h | 77 +++ 15 files changed, 669 insertions(+), 136 deletions(-)
On Mon, Nov 25, 2019 at 5:02 PM Hans Verkuil hverkuil@xs4all.nl wrote:
Hi Arnd,
On 11/11/19 9:38 PM, Arnd Bergmann wrote:
I'm in the process of finishing up the last bits on y2038-unsafe code in the kernel, this series is for v4l2, which has no problem with overflow, but has multiple ioctls that break with user space built against a new 32-bit libc.
Thank you for working on this. Much appreciated!
I've reviewed this v4 series and found a few issues (mostly things that ended up in videodev2.h that shouldn't be there).
Once a v5 is posted I'll try to test this more.
Ok, great!
Is there an easy(-ish) way to test this with a time64 ABI? Do you have such an environment set up for testing?
If you can build your user space with musl, you can test using a recent snapshot from http://git.musl-libc.org/cgit/musl/.
I'm not entirely happy with the compat-ioctl implementation that adds quite a bit of code duplication, but I hope this is acceptable anyway, as a better implementation would likely require a larger refactoring of the compat-ioctl file, while my approach simply adds support for the additional data structure variants.
A cleanup is indeed much more work. This y2038 code is awful, but that's really because the original structs are aligned in the worst possible way.
Ok.
Arnd
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Arnd Bergmann -
Hans Verkuil