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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 2E238C433E2 for ; Thu, 28 May 2020 08:29:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F700208DB for ; Thu, 28 May 2020 08:29:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="ERqBDMdA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726914AbgE1I3a (ORCPT ); Thu, 28 May 2020 04:29:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726878AbgE1I3a (ORCPT ); Thu, 28 May 2020 04:29:30 -0400 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92591C05BD1E for ; Thu, 28 May 2020 01:29:28 -0700 (PDT) Received: by mail-wm1-x341.google.com with SMTP id k26so2228550wmi.4 for ; Thu, 28 May 2020 01:29:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=3a+6oUJ3RVAXmDVoeSWKckQbnvzhZe/iIrVHhbckTSA=; b=ERqBDMdAnQDYPD9KzJ57eRE4d+vU/o813ShwTbfBLtbCPVIBgTaGUk/HN4PKVgHz5s ssiiZRJ60nWDc+hDFscU9QlTDVUzDb9MRNK98C0hJwkIiyOSSelVGtknQyCpx4ES2ly1 yNdD/WL4E0sqjH6i2/6NDVraxFVCuAVJXsZxo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=3a+6oUJ3RVAXmDVoeSWKckQbnvzhZe/iIrVHhbckTSA=; b=NMCiyAJ0+9zrWBwt2d4oEMkHbm/dKO7Hp0i9H5fmHZwD61L5oRd91nlg5MbbC4JXPL M9pTEFmviBBWyoaxWHjjnR+UbNcgPrcIyIkrOV10aqnXrWCQkNi9CSxgThTmxgxSOY29 NBe8+4XzDwPfFcuhma08fND8NXLJd9AyTNlvzKD4y6zL6waF+JC3Qx6+5iH6CduRzPad lUlTGl3mF86lqRhcIHwnEJV6f4dRrRWxTVfZ7XDqdSNm5u/f6jaNyrkJgdFBBes1sm9b XKVBYox2mrnycA73gQzTzE5VV+nyRmEtGWsHkSGGlmDruy/fTSzf8qZ58KNjClvR24nv 6z8g== X-Gm-Message-State: AOAM531xYn+noQLfnDIl970tjR2sD8i5ImHuxXMTB7ixF1aQZx7pcxcJ 6kZGI/FUInL1Hv0cx3N01dd5dA== X-Google-Smtp-Source: ABdhPJw4yVmexsCHhZYQAMfsaB18NxRGTxyj/lu3EJI0gih192r5q6aVr+bET/fdfmcmLb2vss9cyA== X-Received: by 2002:a05:600c:2201:: with SMTP id z1mr2224541wml.70.1590654567303; Thu, 28 May 2020 01:29:27 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id y4sm5288810wro.91.2020.05.28.01.29.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 May 2020 01:29:26 -0700 (PDT) Date: Thu, 28 May 2020 10:29:24 +0200 From: Daniel Vetter To: DRI Development Cc: Daniel Vetter , Daniel Vetter , Rob Clark , Sean Paul , linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org Subject: Re: [PATCH] drm/msm: Don't call dma_buf_vunmap without _vmap Message-ID: <20200528082924.GT206103@phenom.ffwll.local> References: <20200511093554.211493-2-daniel.vetter@ffwll.ch> <20200514201117.465146-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200514201117.465146-1-daniel.vetter@ffwll.ch> X-Operating-System: Linux phenom 5.6.0-1-amd64 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Thu, May 14, 2020 at 10:11:17PM +0200, Daniel Vetter wrote: > I honestly don't exactly understand what's going on here, but the > current code is wrong for sure: It calls dma_buf_vunmap without ever > calling dma_buf_vmap. > > What I'm not sure about is whether the WARN_ON is correct: > - msm imports dma-buf using drm_prime_sg_to_page_addr_arrays. Which is > a pretty neat layering violation of how you shouldn't peek behind > the curtain of the dma-buf exporter, but par for course. Note that > all the nice new helpers don't (and we should probably have a bit a > warning about this in the kerneldoc). > > - but then in the get_vaddr() in msm_gem.c, we seems to happily wrap a > vmap() around any object with ->pages set (so including imported > dma-buf). > > - I'm not seeing any guarantees that userspace can't use an imported > dma-buf for e.g. MSM_SUBMIT_CMD_BUF in a5xx_submit_in_rb, so no > guarantees that an imported dma-buf won't end up with a ->vaddr set. > > But even if that WARN_ON is wrong, cleaning up a vmap() done by msm by > calling dma_buf_vunmap is the wrong thing to do. > > v2: Rob said in review that we do indeed have a gap in get_vaddr() that > needs to be plugged. But the users I've found aren't legit users on > imported dma-buf, so we can just reject that. > > Signed-off-by: Daniel Vetter > Cc: Rob Clark > Cc: Sean Paul > Cc: linux-arm-msm@vger.kernel.org > Cc: freedreno@lists.freedesktop.org Ping for some review/ack so I can start landing thist stuff please? Thanks, Daniel > --- > drivers/gpu/drm/msm/msm_gem.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c > index 5a6a79fbc9d6..e70abd1cde43 100644 > --- a/drivers/gpu/drm/msm/msm_gem.c > +++ b/drivers/gpu/drm/msm/msm_gem.c > @@ -554,6 +554,9 @@ static void *get_vaddr(struct drm_gem_object *obj, unsigned madv) > struct msm_gem_object *msm_obj = to_msm_bo(obj); > int ret = 0; > > + if (obj->import_attach) > + return ERR_PTR(-ENODEV); > + > mutex_lock(&msm_obj->lock); > > if (WARN_ON(msm_obj->madv > madv)) { > @@ -907,8 +910,7 @@ static void free_object(struct msm_gem_object *msm_obj) > put_iova(obj); > > if (obj->import_attach) { > - if (msm_obj->vaddr) > - dma_buf_vunmap(obj->import_attach->dmabuf, msm_obj->vaddr); > + WARN_ON(msm_obj->vaddr); > > /* Don't drop the pages for imported dmabuf, as they are not > * ours, just free the array we allocated: > -- > 2.26.2 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch 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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 8A6FFC433E0 for ; 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Thu, 28 May 2020 01:29:27 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id y4sm5288810wro.91.2020.05.28.01.29.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 May 2020 01:29:26 -0700 (PDT) Date: Thu, 28 May 2020 10:29:24 +0200 From: Daniel Vetter To: DRI Development Subject: Re: [PATCH] drm/msm: Don't call dma_buf_vunmap without _vmap Message-ID: <20200528082924.GT206103@phenom.ffwll.local> References: <20200511093554.211493-2-daniel.vetter@ffwll.ch> <20200514201117.465146-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200514201117.465146-1-daniel.vetter@ffwll.ch> X-Operating-System: Linux phenom 5.6.0-1-amd64 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sean Paul , Daniel Vetter , linux-arm-msm@vger.kernel.org, Daniel Vetter , freedreno@lists.freedesktop.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, May 14, 2020 at 10:11:17PM +0200, Daniel Vetter wrote: > I honestly don't exactly understand what's going on here, but the > current code is wrong for sure: It calls dma_buf_vunmap without ever > calling dma_buf_vmap. > > What I'm not sure about is whether the WARN_ON is correct: > - msm imports dma-buf using drm_prime_sg_to_page_addr_arrays. Which is > a pretty neat layering violation of how you shouldn't peek behind > the curtain of the dma-buf exporter, but par for course. Note that > all the nice new helpers don't (and we should probably have a bit a > warning about this in the kerneldoc). > > - but then in the get_vaddr() in msm_gem.c, we seems to happily wrap a > vmap() around any object with ->pages set (so including imported > dma-buf). > > - I'm not seeing any guarantees that userspace can't use an imported > dma-buf for e.g. MSM_SUBMIT_CMD_BUF in a5xx_submit_in_rb, so no > guarantees that an imported dma-buf won't end up with a ->vaddr set. > > But even if that WARN_ON is wrong, cleaning up a vmap() done by msm by > calling dma_buf_vunmap is the wrong thing to do. > > v2: Rob said in review that we do indeed have a gap in get_vaddr() that > needs to be plugged. But the users I've found aren't legit users on > imported dma-buf, so we can just reject that. > > Signed-off-by: Daniel Vetter > Cc: Rob Clark > Cc: Sean Paul > Cc: linux-arm-msm@vger.kernel.org > Cc: freedreno@lists.freedesktop.org Ping for some review/ack so I can start landing thist stuff please? Thanks, Daniel > --- > drivers/gpu/drm/msm/msm_gem.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c > index 5a6a79fbc9d6..e70abd1cde43 100644 > --- a/drivers/gpu/drm/msm/msm_gem.c > +++ b/drivers/gpu/drm/msm/msm_gem.c > @@ -554,6 +554,9 @@ static void *get_vaddr(struct drm_gem_object *obj, unsigned madv) > struct msm_gem_object *msm_obj = to_msm_bo(obj); > int ret = 0; > > + if (obj->import_attach) > + return ERR_PTR(-ENODEV); > + > mutex_lock(&msm_obj->lock); > > if (WARN_ON(msm_obj->madv > madv)) { > @@ -907,8 +910,7 @@ static void free_object(struct msm_gem_object *msm_obj) > put_iova(obj); > > if (obj->import_attach) { > - if (msm_obj->vaddr) > - dma_buf_vunmap(obj->import_attach->dmabuf, msm_obj->vaddr); > + WARN_ON(msm_obj->vaddr); > > /* Don't drop the pages for imported dmabuf, as they are not > * ours, just free the array we allocated: > -- > 2.26.2 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel