From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 398EBC4332F for ; Wed, 23 Nov 2022 13:34:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238841AbiKWNe3 (ORCPT ); Wed, 23 Nov 2022 08:34:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238921AbiKWNcZ (ORCPT ); Wed, 23 Nov 2022 08:32:25 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78F0628706; Wed, 23 Nov 2022 05:18:40 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1BA6261CAC; Wed, 23 Nov 2022 13:18:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74BDEC433C1; Wed, 23 Nov 2022 13:18:32 +0000 (UTC) Message-ID: Date: Wed, 23 Nov 2022 14:18:31 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.1 Subject: Re: [PATCH mm-unstable v1 15/20] media: pci/ivtv: remove FOLL_FORCE usage Content-Language: en-US To: David Hildenbrand , linux-kernel@vger.kernel.org Cc: x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Linus Torvalds , Andrew Morton , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Shuah Khan , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann , Christoph Hellwig , Alex Williamson , Andy Walls , Mauro Carvalho Chehab References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-16-david@redhat.com> From: Hans Verkuil In-Reply-To: <20221116102659.70287-16-david@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/11/2022 11:26, David Hildenbrand wrote: > FOLL_FORCE is really only for ptrace access. R/O pinning a page is > supposed to fail if the VMA misses proper access permissions (no VM_READ). > > Let's just remove FOLL_FORCE usage here; there would have to be a pretty > good reason to allow arbitrary drivers to R/O pin pages in a PROT_NONE > VMA. Most probably, FOLL_FORCE usage is just some legacy leftover. I'm pretty sure about that as well, so: Acked-by: Hans Verkuil Regards, Hans > > Cc: Andy Walls > Cc: Mauro Carvalho Chehab > Signed-off-by: David Hildenbrand > --- > drivers/media/pci/ivtv/ivtv-udma.c | 2 +- > drivers/media/pci/ivtv/ivtv-yuv.c | 5 ++--- > 2 files changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/pci/ivtv/ivtv-udma.c b/drivers/media/pci/ivtv/ivtv-udma.c > index 210be8290f24..99b9f55ca829 100644 > --- a/drivers/media/pci/ivtv/ivtv-udma.c > +++ b/drivers/media/pci/ivtv/ivtv-udma.c > @@ -115,7 +115,7 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr, > > /* Pin user pages for DMA Xfer */ > err = pin_user_pages_unlocked(user_dma.uaddr, user_dma.page_count, > - dma->map, FOLL_FORCE); > + dma->map, 0); > > if (user_dma.page_count != err) { > IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n", > diff --git a/drivers/media/pci/ivtv/ivtv-yuv.c b/drivers/media/pci/ivtv/ivtv-yuv.c > index 4ba10c34a16a..582146f8d70d 100644 > --- a/drivers/media/pci/ivtv/ivtv-yuv.c > +++ b/drivers/media/pci/ivtv/ivtv-yuv.c > @@ -63,12 +63,11 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma, > > /* Pin user pages for DMA Xfer */ > y_pages = pin_user_pages_unlocked(y_dma.uaddr, > - y_dma.page_count, &dma->map[0], FOLL_FORCE); > + y_dma.page_count, &dma->map[0], 0); > uv_pages = 0; /* silence gcc. value is set and consumed only if: */ > if (y_pages == y_dma.page_count) { > uv_pages = pin_user_pages_unlocked(uv_dma.uaddr, > - uv_dma.page_count, &dma->map[y_pages], > - FOLL_FORCE); > + uv_dma.page_count, &dma->map[y_pages], 0); > } > > if (y_pages != y_dma.page_count || uv_pages != uv_dma.page_count) {