From patchwork Mon Oct 26 10:58:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11856523 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 930BF92C for ; Mon, 26 Oct 2020 10:59:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B84D22277 for ; Mon, 26 Oct 2020 10:59:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="BE6oxOGm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1772805AbgJZK6m (ORCPT ); Mon, 26 Oct 2020 06:58:42 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:37640 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1772800AbgJZK6l (ORCPT ); Mon, 26 Oct 2020 06:58:41 -0400 Received: by mail-wr1-f67.google.com with SMTP id h7so11903160wre.4 for ; Mon, 26 Oct 2020 03:58:39 -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=BE6oxOGm6LpmFehTBcLW4JPuAVn0ztXRRhPFdKmp1PBfZHMfOH6ZZMUim7N+RidGFG 0CE8UiBULFscc13H0ar8GrDLO4yJ1P0bnnkFlnldicZz6vS1PSOwsA2+DLJdMtAv2h85 Tg25hld8e9Oy330GCD/SQEbTeh0mowIk6eEfA= 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=hBOv7xslmLckzH3jmy+YbDePV1UvDG5Tgi+aJoag/ACzLMBRKPBjxPirkO9kVMfpAl BUhD4wZoxiiwMqWMvosoTCfz1JlSbXDZFEWR25BODh55hyqtUgUxmITdQ5ioGOPrBZgb lxRwgIL7hPjUkEuphgzO4hwMllC2KL04zq6sLj/KYLiHgXCANi956h1Kf54HqfRCObsd GVk9U2JODh2yYJfLhzhB3ry3up3l3Zf3LKshk1Slr/ukJ7XyHjzUzftiaOEVy4oe4xzu sNrzp5tDDXN8eEn27a/+YofOx9pSW9xNHHvZSZohDoroxlAXHMEvPCMmNYvyAGTOFnwq lcPQ== X-Gm-Message-State: AOAM532Xk7EVlHFdwRutMx7EhsSKEGUaMCExKHebqQr0PkbZZ4Ql7I5e QuESV8lmBz2KigFKoTwnvYFCCg== X-Google-Smtp-Source: ABdhPJyJPBqr4xzE4feUIHJFFKeriugShRo0uGRtLd+TVzcLzKKWgkZaYccYEU5/Oo10Zk0lMDMkEw== X-Received: by 2002:a05:6000:12c9:: with SMTP id l9mr16792055wrx.309.1603709918272; Mon, 26 Oct 2020 03:58:38 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id w83sm21165156wmg.48.2020.10.26.03.58.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2020 03:58:37 -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 v4 09/15] media/videbuf1|2: Mark follow_pfn usage as unsafe Date: Mon, 26 Oct 2020 11:58:12 +0100 Message-Id: <20201026105818.2585306-10-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201026105818.2585306-1-daniel.vetter@ffwll.ch> References: <20201026105818.2585306-1-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, 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 Acked-by: Tomasz Figa --- 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;