lkml.org 
[lkml]   [2019]   [Dec]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v5 6/8] media: v4l2-core: fix v4l2_buffer handling for time64 ABI
From
Date
On 11/26/19 5:18 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 | 73 ++++++++++++++++++++++++++--
> include/media/v4l2-ioctl.h | 30 ++++++++++++
> include/uapi/linux/videodev2.h | 23 +++++++++
> 3 files changed, 122 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 96aafb659783..4d611a847462 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,
> @@ -3029,6 +3029,14 @@ 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
> }
>
> @@ -3047,6 +3055,39 @@ static int video_get_user(void __user *arg, void *parg, unsigned int cmd,
> }
>
> switch (cmd) {
> +#ifdef COMPAT_32BIT_TIME

COMPAT_32BIT_TIME -> CONFIG_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;
> +
> + *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,

You forgot to copy sequence.

> + .memory = vb32.memory,
> + .m.userptr = vb32.m.usercopy,

usercopy -> userptr

> + .length = vb32.length,
> + .request_fd = vb32.request_fd,
> + };
> +
> + if (cmd == VIDIOC_QUERYBUF_TIME32)
> + memset(&vb->length, 0, sizeof(*vb) -
> + offsetof(struct v4l2_buffer, length));

It's from the field AFTER vb->length that this needs to be zeroed. It's best to
use the CLEAR_AFTER_FIELD macro here.

> +
> + break;
> + }
> +#endif
> default:
> /*
> * In some cases, only a few fields are used as input,
> @@ -3100,6 +3141,30 @@ 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 *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,

You forgot to copy sequence.

> + .memory = vb->memory,
> + .m.userptr = vb->m.userptr,
> + .length = vb->length,
> + .request_fd = vb->request_fd,
> + };
> +
> + if (copy_to_user(arg, &vb32, sizeof(vb32)))
> + return -EFAULT;
> + break;
> + }
> #endif
> default:
> /* Copy results into user buffer */
> diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
> index 05c1ec93a911..86878fba332b 100644
> --- a/include/media/v4l2-ioctl.h
> +++ b/include/media/v4l2-ioctl.h
> @@ -749,4 +749,34 @@ struct v4l2_event_time32 {
>
> #define VIDIOC_DQEVENT_TIME32 _IOR('V', 89, struct v4l2_event_time32)
>
> +struct v4l2_buffer_time32 {
> + __u32 index;
> + __u32 type;
> + __u32 bytesused;
> + __u32 flags;
> + __u32 field;
> + struct old_timeval32 timestamp;
> + 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;
> + };
> +};
> +#define VIDIOC_QUERYBUF_TIME32 _IOWR('V', 9, struct v4l2_buffer_time32)
> +#define VIDIOC_QBUF_TIME32 _IOWR('V', 15, struct v4l2_buffer_time32)
> +#define VIDIOC_DQBUF_TIME32 _IOWR('V', 17, struct v4l2_buffer_time32)
> +#define VIDIOC_PREPARE_BUF_TIME32 _IOWR('V', 93, struct v4l2_buffer_time32)
> +
> #endif /* _V4L2_IOCTL_H */
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index caf156d45842..5f9357dcb060 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -912,6 +912,25 @@ struct v4l2_jpegcompression {
> /*
> * M E M O R Y - M A P P I N G B U F F E R S
> */
> +
> +#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
> +
> struct v4l2_requestbuffers {
> __u32 count;
> __u32 type; /* enum v4l2_buf_type */
> @@ -997,7 +1016,11 @@ struct v4l2_buffer {
> __u32 bytesused;
> __u32 flags;
> __u32 field;
> +#ifdef __KERNEL__
> + struct __kernel_v4l2_timeval timestamp;
> +#else
> struct timeval timestamp;
> +#endif
> struct v4l2_timecode timecode;
> __u32 sequence;
>
>

With these changes this patch series passed both the 64 and 32 bit compliance
tests (in fact, all the issues mentioned above were found with these compliance
tests).

I am unable to test with musl since v4l2-ctl and v4l2-compliance are C++ programs,
and there doesn't appear to be an easy way to compile a C++ program with musl.

If you happen to have a test environment where you can compile C++ with musl,
then let me know and I can give instructions on how to run the compliance tests.

If you can't test that, then I can merge this regardless, and hope for the best
once the Y2038 fixes end up in glibc. But ideally I'd like to have this tested.

Regards,

Hans

\
 
 \ /
  Last update: 2019-12-12 16:44    [W:0.100 / U:0.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site