From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Konovalov Subject: [PATCH v18 06/15] mm: untag user pointers in get_vaddr_frames Date: Mon, 24 Jun 2019 16:32:51 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Catalin Marinas , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Luc Van Oostenryck , Dave Martin , Khalid Aziz , enh List-Id: linux-rdma@vger.kernel.org This patch is a part of a series that extends kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. get_vaddr_frames uses provided user pointers for vma lookups, which can only by done with untagged pointers. Instead of locating and changing all callers of this function, perform untagging in it. Reviewed-by: Khalid Aziz Reviewed-by: Vincenzo Frascino Acked-by: Catalin Marinas Reviewed-by: Kees Cook Signed-off-by: Andrey Konovalov --- mm/frame_vector.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/frame_vector.c b/mm/frame_vector.c index c64dca6e27c2..c431ca81dad5 100644 --- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -46,6 +46,8 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, if (WARN_ON_ONCE(nr_frames > vec->nr_allocated)) nr_frames = vec->nr_allocated; + start = untagged_addr(start); + down_read(&mm->mmap_sem); locked = 1; vma = find_vma_intersection(mm, start, start + 1); -- 2.22.0.410.gd8fdbe21b5-goog