From patchwork Wed Oct 7 16:44:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11821149 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1902316C1 for ; Wed, 7 Oct 2020 16:45:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5D6B206FC for ; Wed, 7 Oct 2020 16:45:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="PbdDP59N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728746AbgJGQpM (ORCPT ); Wed, 7 Oct 2020 12:45:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728737AbgJGQpL (ORCPT ); Wed, 7 Oct 2020 12:45:11 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 563DEC0613AC for ; Wed, 7 Oct 2020 09:44:52 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id p15so3042410wmi.4 for ; Wed, 07 Oct 2020 09:44:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=dvMOl5qn3xQqngcKVpyNX+ax+2goWhkEVg7LeNCEKtI=; b=PbdDP59NrSDZxmLOWczSE2cRJJsMLzvw4mEtmBjBj9fgeRsN0fZSKVabWIN7hFcZtv xzAe3LJduGn0vaaDjiW4G/C3Uf4XUZO2JllwyTJ9Wsq0tezSYJkYYoiFOthcqAJ5SpO/ 3t8nzxUBbNP7hSXTX+L3BgEGTBUq+RyoYYKLk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=dvMOl5qn3xQqngcKVpyNX+ax+2goWhkEVg7LeNCEKtI=; b=IlcqWCz99TQDCz+sV9jPMdty/RRft0Vy7hQphheDMIQIGD9p+rNfuUJsVRzSFj9P4T ES6LFP37GER/tF6kqUzkKKtuuvCLzu0MLf5ttRnKPRSxyc2jELDzES0nCUBNeyc2wdOB nM9O1WEPfqYww+vgH88R0w+vwFYL+BYXrcTVtZokEQ/Hhm11tKw2Mm1sg3G06swVkBVp xeJv4vU+1uRptckarJt9omRsFkvK7YX5YnsmnWYp3ezERsb+5+nZ6/ATiSM3OkI9MhqS bX//Qs4MtQ1aFpYLGGPwhcOKG5pZB/0c/r3HYR1CaLT4J2BNUyfOEj6xVyijpRDsvj5E UH5A== X-Gm-Message-State: AOAM533DG7S4NLUiULGLYlMoRs8dGY+95SzLTfutsk+fVvnaWCKakbhL igKZgFwqOd0qwJp050DZlrCrOQ== X-Google-Smtp-Source: ABdhPJzw6PlCUbNqoLiPN5u1sFMl1viobOv7pIsUUzeqLWeTM2j6wE9ncJp2ranbphS6F7r51TbDeQ== X-Received: by 2002:a1c:1905:: with SMTP id 5mr4404786wmz.32.1602089090410; Wed, 07 Oct 2020 09:44:50 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id z191sm3332280wme.40.2020.10.07.09.44.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Oct 2020 09:44:49 -0700 (PDT) From: Daniel Vetter To: DRI Development , LKML Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, linux-s390@vger.kernel.org, Daniel Vetter , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , Pawel Osciak , Marek Szyprowski , Kyungmin Park , Tomasz Figa , Laurent Dufour , Vlastimil Babka , Daniel Jordan , Michel Lespinasse Subject: [PATCH 12/13] media/videbuf1|2: Mark follow_pfn usage as unsafe Date: Wed, 7 Oct 2020 18:44:25 +0200 Message-Id: <20201007164426.1812530-13-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201007164426.1812530-1-daniel.vetter@ffwll.ch> References: <20201007164426.1812530-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org 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 Cc: Jason Gunthorpe Cc: Kees Cook Cc: Dan Williams Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams 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 Cc: Marek Szyprowski Cc: Kyungmin Park Cc: Tomasz Figa Cc: Laurent Dufour Cc: Vlastimil Babka Cc: Daniel Jordan Cc: Michel Lespinasse --- 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;