diff options
| -rw-r--r-- | drivers/media/video/ivtv/ivtv-yuv.c | 52 |
1 files changed, 40 insertions, 12 deletions
diff --git a/drivers/media/video/ivtv/ivtv-yuv.c b/drivers/media/video/ivtv/ivtv-yuv.c index c0875378acc2..dcbab6ad4c26 100644 --- a/drivers/media/video/ivtv/ivtv-yuv.c +++ b/drivers/media/video/ivtv/ivtv-yuv.c @@ -77,23 +77,51 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma, /* Get user pages for DMA Xfer */ down_read(¤t->mm->mmap_sem); y_pages = get_user_pages(current, current->mm, y_dma.uaddr, y_dma.page_count, 0, 1, &dma->map[0], NULL); - uv_pages = get_user_pages(current, current->mm, uv_dma.uaddr, uv_dma.page_count, 0, 1, &dma->map[y_pages], NULL); + uv_pages = 0; /* silence gcc. value is set and consumed only if: */ + if (y_pages == y_dma.page_count) { + uv_pages = get_user_pages(current, current->mm, + uv_dma.uaddr, uv_dma.page_count, 0, 1, + &dma->map[y_pages], NULL); + } up_read(¤t->mm->mmap_sem); - dma->page_count = y_dma.page_count + uv_dma.page_count; - - if (y_pages + uv_pages != dma->page_count) { - IVTV_DEBUG_WARN - ("failed to map user pages, returned %d instead of %d\n", - y_pages + uv_pages, dma->page_count); - - for (i = 0; i < dma->page_count; i++) { - put_page(dma->map[i]); + if (y_pages != y_dma.page_count || uv_pages != uv_dma.page_count) { + int rc = -EFAULT; + + if (y_pages == y_dma.page_count) { + IVTV_DEBUG_WARN + ("failed to map uv user pages, returned %d " + "expecting %d\n", uv_pages, uv_dma.page_count); + + if (uv_pages >= 0) { + for (i = 0; i < uv_pages; i++) + put_page(dma->map[y_pages + i]); + rc = -EFAULT; + } else { + rc = uv_pages; + } + } else { + IVTV_DEBUG_WARN + ("failed to map y user pages, returned %d " + "expecting %d\n", y_pages, y_dma.page_count); } - dma->page_count = 0; - return -EINVAL; + if (y_pages >= 0) { + for (i = 0; i < y_pages; i++) + put_page(dma->map[i]); + /* + * Inherit the -EFAULT from rc's + * initialization, but allow it to be + * overriden by uv_pages above if it was an + * actual errno. + */ + } else { + rc = y_pages; + } + return rc; } + dma->page_count = y_pages + uv_pages; + /* Fill & map SG List */ if (ivtv_udma_fill_sg_list (dma, &uv_dma, ivtv_udma_fill_sg_list (dma, &y_dma, 0)) < 0) { IVTV_DEBUG_WARN("could not allocate bounce buffers for highmem userspace buffers\n"); |