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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0079BC2BA83 for ; Fri, 14 Feb 2020 11:59:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE681222C4 for ; Fri, 14 Feb 2020 11:59:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="U30YN/B2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728582AbgBNL75 (ORCPT ); Fri, 14 Feb 2020 06:59:57 -0500 Received: from mail-io1-f68.google.com ([209.85.166.68]:40718 "EHLO mail-io1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728123AbgBNL75 (ORCPT ); Fri, 14 Feb 2020 06:59:57 -0500 Received: by mail-io1-f68.google.com with SMTP id x1so10235730iop.7 for ; Fri, 14 Feb 2020 03:59:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1uraVtsrzVMHzePG2yR6DCPEUMyavhEyjVs6nxEu24o=; b=U30YN/B2MumWYRiXps0fXkEWwSbju05SSBqJ4/raPl8BGRwatykH4NN5BhmTGAAcSP t0MWzBlOIlELWnQbS7pogaTu9V3noHu3hw2QYvs8WYZ93cF4NLKnuYa/kfrmCHch/ADb lbs1t4fy6PqAkeECeCkNqgUuytFbP1GcOSaDU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=1uraVtsrzVMHzePG2yR6DCPEUMyavhEyjVs6nxEu24o=; b=sRasOtKUq7On6OGgUjbnUYjPNHkObM5kbnYw3zYKsjX2ne7uiljEudF0AqETwbpMJG 6D3MjzPl4udKLji+wHvSoMVMLgf3d1rD3ROisxyQiAv4/PR02MRXXu0VqwTrgSWz5i85 xT5O32uPBmtfo3y1qMrnni9gBtcURgK537gxKxGd7XXYlCeBx5LiqFmktSVN/jWERDKO sOVWm9FcGozTuTEuUbBx/lI5j/1JCjOIlnunEiZFwdXktl/DQxjGVfhgg5N6Ov8e+Rnx j6CHsi/W7Yh552eAigewElMu+sPUcnHyD6ldKsqKbPZRlc3XRhbD1+bpyVk8qLOA2RsN Wr6A== X-Gm-Message-State: APjAAAXCwR7znYmp2iaXPAN1NamgqHZyg1mm8gFt3EQeSBNdk2nnvgUc Kv+ztoYKxFkPOYLSSWvsCwHwL96Mvb7Hf+NXbF+DjQ== X-Google-Smtp-Source: APXvYqxMO1/xuTDVrtKd0ZSFbiILKTJtYtsmXOvsUOD0CpbVMimQ6kn9e/yNKOWoZ4c8M8RRzOmpBWPZFwTqt9iA31E= X-Received: by 2002:a6b:3845:: with SMTP id f66mr2068307ioa.102.1581681596283; Fri, 14 Feb 2020 03:59:56 -0800 (PST) MIME-Version: 1.0 References: <20200210035351.227499-1-hsinyi@chromium.org> In-Reply-To: From: Hsin-Yi Wang Date: Fri, 14 Feb 2020 19:59:30 +0800 Message-ID: Subject: Re: [PATCH] media: mtk-vpu: avoid unaligned access to DTCM buffer. To: Hans Verkuil Cc: "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , Minghsiu Tsai , Houlong Wei , Andrew-CT Chen , Tiffany Lin , Mauro Carvalho Chehab , Matthias Brugger , Enric Balletbo i Serra , linux-media@vger.kernel.org, linux-mediatek@lists.infradead.org, lkml Content-Type: text/plain; charset="UTF-8" Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Fri, Feb 14, 2020 at 6:52 PM Hans Verkuil wrote: > > Hi Hsin-Yi Wang, > > On 2/10/20 4:53 AM, Hsin-Yi Wang wrote: > > struct vpu_run *run in vpu_init_ipi_handler() is an ioremapped DTCM (Data > > Tightly Coupled Memory) buffer shared with AP. It's not able to do > > unaligned access. Otherwise kernel would crash due to unable to handle > > kernel paging request. > > > > struct vpu_run { > > u32 signaled; > > char fw_ver[VPU_FW_VER_LEN]; > > unsigned int dec_capability; > > unsigned int enc_capability; > > wait_queue_head_t wq; > > }; > > > > fw_ver starts at 4 byte boundary. If system enables > > CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, strscpy() will do > > read_word_at_a_time(), which tries to read 8-byte: *(unsigned long *)addr > > > > Copy the string by memcpy_fromio() for this buffer to avoid unaligned > > access. > > > > Fixes: 85709cbf1524 ("media: replace strncpy() by strscpy()") > > Signed-off-by: Hsin-Yi Wang > > This patch results in the following sparse warnings: > > sparse: WARNINGS > SPARSE:mtk-vpu/mtk_vpu.c mtk-vpu/mtk_vpu.c:834:52: warning: incorrect type in argument 3 (incompatible argument 1 (different address spaces)) > SPARSE:mtk-vpu/mtk_vpu.c mtk-vpu/mtk_vpu.c:609:29: warning: dereference of noderef expression > SPARSE:mtk-vpu/mtk_vpu.c mtk-vpu/mtk_vpu.c:613:35: warning: dereference of noderef expression > SPARSE:mtk-vpu/mtk_vpu.c mtk-vpu/mtk_vpu.c:614:35: warning: dereference of noderef expression > > Can you take a look? > > Regards, > > Hans > Thanks, I'll send a v2 to fix this