media: v4l2-core: fix v4l2_buffer handling for time64 ABI

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>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Arnd Bergmann 2019-12-16 15:15:04 +01:00 committed by Mauro Carvalho Chehab
parent 1a6c0b36dd
commit 577c89b0ce
3 changed files with 123 additions and 4 deletions

View File

@ -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 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,
.sequence = vb32.sequence,
.memory = vb32.memory,
.m.userptr = vb32.m.userptr,
.length = vb32.length,
.request_fd = vb32.request_fd,
};
if (cmd == VIDIOC_QUERYBUF_TIME32)
vb->request_fd = 0;
break;
}
#endif
default:
/*
* In some cases, only a few fields are used as input,
@ -3100,6 +3141,31 @@ 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,
.sequence = vb->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 */

View File

@ -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 */

View File

@ -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;