The media model assumes that buffers are all preallocated, so that when a media pipeline is running we never miss a deadline because the buffers aren't allocated or available.
This means we cannot fix the v4l follow_pfn usage through mmu_notifier, without breaking how this all works. The only real fix is to deprecate userptr support for VM_IO | VM_PFNMAP mappings and tell everyone to cut over to dma-buf memory sharing for zerocopy.
userptr for normal memory will keep working as-is.
Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Jason Gunthorpe jgg@ziepe.ca Cc: Kees Cook keescook@chromium.org Cc: Dan Williams dan.j.williams@intel.com Cc: Andrew Morton akpm@linux-foundation.org Cc: John Hubbard jhubbard@nvidia.com Cc: Jérôme Glisse jglisse@redhat.com Cc: Jan Kara jack@suse.cz Cc: Dan Williams dan.j.williams@intel.com Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: Pawel Osciak pawel@osciak.com Cc: Marek Szyprowski m.szyprowski@samsung.com Cc: Kyungmin Park kyungmin.park@samsung.com Cc: Tomasz Figa tfiga@chromium.org Cc: Laurent Dufour ldufour@linux.ibm.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Daniel Jordan daniel.m.jordan@oracle.com Cc: Michel Lespinasse walken@google.com --- drivers/media/common/videobuf2/frame_vector.c | 2 +- drivers/media/v4l2-core/videobuf-dma-contig.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c index b95f4f371681..d56eb6258f09 100644 --- a/drivers/media/common/videobuf2/frame_vector.c +++ b/drivers/media/common/videobuf2/frame_vector.c @@ -71,7 +71,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, unsigned long *nums = frame_vector_pfns(vec);
while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { - err = follow_pfn(vma, start, &nums[ret]); + err = unsafe_follow_pfn(vma, start, &nums[ret]); if (err) { if (ret == 0) ret = err; diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c b/drivers/media/v4l2-core/videobuf-dma-contig.c index 52312ce2ba05..821c4a76ab96 100644 --- a/drivers/media/v4l2-core/videobuf-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c @@ -183,7 +183,7 @@ static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, user_address = untagged_baddr;
while (pages_done < (mem->size >> PAGE_SHIFT)) { - ret = follow_pfn(vma, user_address, &this_pfn); + ret = unsafe_follow_pfn(vma, user_address, &this_pfn); if (ret) break;