From patchwork Fri Oct 23 12:21:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11852975 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 AAA3C16BC for ; Fri, 23 Oct 2020 12:23:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 809962463C for ; Fri, 23 Oct 2020 12:23:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="braem6Gm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S463683AbgJWMXJ (ORCPT ); Fri, 23 Oct 2020 08:23:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S463677AbgJWMXI (ORCPT ); Fri, 23 Oct 2020 08:23:08 -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 84E61C0613CE for ; Fri, 23 Oct 2020 05:23:08 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id 13so1240745wmf.0 for ; Fri, 23 Oct 2020 05:23:08 -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=fFEiUvLl06c3j38++d5NzLL6L7leWWZ4E8u91rYq/3A=; b=braem6GmR1a0W1U9n+P0ZjCixCoaNwItneKf4XXmwiM+nUddiP16QJccIkWq1nfeRZ 9G1sNxdp8zuH24WxTyNX0vImxMRYFV400Sbo4uC5sqzrP2mUvG1zzNo4wpm+ElGlMrv0 BVEObXOiwYJO5XRjv1iDH7j7YCFz5rnvbq8qg= 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=fFEiUvLl06c3j38++d5NzLL6L7leWWZ4E8u91rYq/3A=; b=n9JAdU9QeVB3FlxEI92/8HithpEaO6NJHKH9PDeMYHzLCpKOXfnzX9lIjDJ3f9y23w 4rq+bK5xL1T3gMu1TLQmeckZ2a5L8kNaBmQyqdR2jMjATdmChBdGBgqGqA0HOnEfgWR+ 3gvmGrkre+yh8krC3d9iH22mfX+EW0mCiT6rubtMjZCX+4YrG7dXTUx1ONVCqFl+mlo6 wXs3NNwc0Hfbq5MRPXp6sLj36xA7nKodlGI8A2Pu32iqdQDka3eK/dQVBxZAyKXqDcqS ai/WYgG/NuWiZa129CpUWkyI7KR96Lkw6uSj/whipUmzKPlp1/goxAYS70k6suGTbe6s wIWA== X-Gm-Message-State: AOAM530JMdOhI+6AsNAI9V1HcG9aIkE4Pq2J6o4Ah4eKKvXYsNr4kUHo mgi9g1YC1sStS7Po4gKaSW8CxA== X-Google-Smtp-Source: ABdhPJx8R5/3dC+619rMxj0G4kaFtGbCPSV2VZg+ru6CCCIKgtbWbWS3poGnwIzyRcabuPIieQR+6w== X-Received: by 2002:a1c:2042:: with SMTP id g63mr1996821wmg.174.1603455787244; Fri, 23 Oct 2020 05:23:07 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id y4sm3056484wrp.74.2020.10.23.05.23.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Oct 2020 05:23:06 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , Daniel Vetter , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, Pawel Osciak , Marek Szyprowski , Kyungmin Park , Tomasz Figa , Laurent Dufour , Vlastimil Babka , Daniel Jordan , Michel Lespinasse Subject: [PATCH 38/65] media/videbuf1|2: Mark follow_pfn usage as unsafe Date: Fri, 23 Oct 2020 14:21:49 +0200 Message-Id: <20201023122216.2373294-38-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201023122216.2373294-1-daniel.vetter@ffwll.ch> References: <20201021163242.1458885-1-daniel.vetter@ffwll.ch> <20201023122216.2373294-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@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, this only affects the zerocopy userptr usage enabled in 50ac952d2263 ("[media] videobuf2-dma-sg: Support io userptr operations on io memory"). 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 Signed-off-by: Daniel Vetter --- v3: - Reference the commit that enabled the zerocopy userptr use case to make it abundandtly clear that this patch only affects that, and not normal memory userptr. The old commit message already explained that normal memory userptr is unaffected, but I guess that was not clear enough. --- 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 6590987c14bd..e630494da65c 100644 --- a/drivers/media/common/videobuf2/frame_vector.c +++ b/drivers/media/common/videobuf2/frame_vector.c @@ -69,7 +69,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, break; 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;