On 11/3/19 10:18 PM, John Hubbard wrote:

1. Change v4l2 from get_user_pages(FOLL_LONGTERM), to

pin_longterm_pages(), which sets both FOLL_LONGTERM and FOLL_PIN.

2. Because all FOLL_PIN-acquired pages must be released via

put_user_page(), also convert the put_page() call over to put_user_pages_dirty_lock().

Reviewed-by: Ira Weiny ira.weiny@intel.com Cc: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: John Hubbard jhubbard@nvidia.com

Acked-by: Hans Verkuil hverkuil-cisco@xs4all.nl

Looks good, thanks!

Hans

---

drivers/media/v4l2-core/videobuf-dma-sg.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c index 28262190c3ab..9b9c5b37bf59 100644 --- a/drivers/media/v4l2-core/videobuf-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf-dma-sg.c @@ -183,12 +183,12 @@ static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma, dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n", data, size, dma->nr_pages);

• err = get_user_pages(data & PAGE_MASK, dma->nr_pages,

• 	     flags | FOLL_LONGTERM, dma->pages, NULL);
  

• err = pin_longterm_pages(data & PAGE_MASK, dma->nr_pages,

• 		 flags, dma->pages, NULL);
  
  

  if (err != dma->nr_pages) { dma->nr_pages = (err >= 0) ? err : 0;

• dprintk(1, "get_user_pages: err=%d [%d]\n", err,
  

• dprintk(1, "pin_longterm_pages: err=%d [%d]\n", err,
  dma->nr_pages);
  

  return err < 0 ? err : -EINVAL; }

@@ -349,11 +349,8 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma) BUG_ON(dma->sglen);

if (dma->pages) {

• for (i = 0; i < dma->nr_pages; i++) {
  

• 	if (dma->direction == DMA_FROM_DEVICE)
  

• 		set_page_dirty_lock(dma->pages[i]);
  

• 	put_page(dma->pages[i]);
  

• }
  

• put_user_pages_dirty_lock(dma->pages, dma->nr_pages,
  

• 			  dma->direction == DMA_FROM_DEVICE);
  

  kfree(dma->pages); dma->pages = NULL; }