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path: root/drivers/media/video/ivtv/ivtv-yuv.c
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Diffstat (limited to 'drivers/media/video/ivtv/ivtv-yuv.c')
-rw-r--r--drivers/media/video/ivtv/ivtv-yuv.c52
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(&current->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(&current->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");