[PATCH v4 6/8] media: v4l2-core: fix v4l2_buffer handling for time64 ABI
From: Arnd Bergmann
Date: Mon Nov 11 2019 - 15:38:58 EST
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@xxxxxxxx>
---
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)
--
2.20.0