Below the conversion from uiomovei() to uiomove() for bktr. The patch also replaces two occurrences of uio->uio_iov->iov_len with uio->uio_resid. I don't see a reason why bktr should inspect iov_len directly.
Index: dev/pci/bktr/bktr_core.c =================================================================== RCS file: /cvs/src/sys/dev/pci/bktr/bktr_core.c,v retrieving revision 1.36 diff -u -p -u -r1.36 bktr_core.c --- dev/pci/bktr/bktr_core.c 14 Mar 2015 03:38:49 -0000 1.36 +++ dev/pci/bktr/bktr_core.c 24 Jan 2016 11:25:49 -0000 @@ -993,7 +993,7 @@ int video_read(bktr_ptr_t bktr, int unit, dev_t dev, struct uio *uio) { int status; - int count; + size_t count; if (bktr->bigbuf == 0) /* no frame buffer allocated (ioctl failed) */ @@ -1008,7 +1008,7 @@ video_read(bktr_ptr_t bktr, int unit, de count = bktr->rows * bktr->cols * pixfmt_table[ bktr->pixfmt ].public.Bpp; - if ((int) uio->uio_iov->iov_len < count) + if (uio->uio_resid < count) return( EINVAL ); bktr->flags &= ~(METEOR_CAP_MASK | METEOR_WANT_MASK); @@ -1027,7 +1027,7 @@ video_read(bktr_ptr_t bktr, int unit, de status = tsleep(BKTR_SLEEP, BKTRPRI, "captur", 0); if (!status) /* successful capture */ - status = uiomovei((caddr_t)bktr->bigbuf, count, uio); + status = uiomove((caddr_t)bktr->bigbuf, count, uio); else printf ("%s: read: tsleep error %d\n", bktr_name(bktr), status); @@ -1047,7 +1047,7 @@ video_read(bktr_ptr_t bktr, int unit, de int vbi_read(bktr_ptr_t bktr, struct uio *uio, int ioflag) { - int readsize, readsize2; + size_t readsize, readsize2; int status; @@ -1067,22 +1067,20 @@ vbi_read(bktr_ptr_t bktr, struct uio *ui /* We cannot read more bytes than there are in * the circular buffer */ - readsize = (int)uio->uio_iov->iov_len; - - if (readsize > bktr->vbisize) readsize = bktr->vbisize; + readsize = ulmin(uio->uio_resid, bktr->vbisize); /* Check if we can read this number of bytes without having * to wrap around the circular buffer */ - if((bktr->vbistart + readsize) >= VBI_BUFFER_SIZE) { + if (readsize >= VBI_BUFFER_SIZE - bktr->vbistart) { /* We need to wrap around */ readsize2 = VBI_BUFFER_SIZE - bktr->vbistart; - status = uiomovei((caddr_t)bktr->vbibuffer + bktr->vbistart, readsize2, uio); + status = uiomove((caddr_t)bktr->vbibuffer + bktr->vbistart, readsize2, uio); if (status == 0) - status = uiomovei((caddr_t)bktr->vbibuffer, (readsize - readsize2), uio); + status = uiomove((caddr_t)bktr->vbibuffer, (readsize - readsize2), uio); } else { /* We do not need to wrap around */ - status = uiomovei((caddr_t)bktr->vbibuffer + bktr->vbistart, readsize, uio); + status = uiomove((caddr_t)bktr->vbibuffer + bktr->vbistart, readsize, uio); } /* Update the number of bytes left to read */ cheers, natano