Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967525AbaFTMP3 (ORCPT ); Fri, 20 Jun 2014 08:15:29 -0400 Received: from mail-vc0-f174.google.com ([209.85.220.174]:63296 "EHLO mail-vc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966858AbaFTMP1 (ORCPT ); Fri, 20 Jun 2014 08:15:27 -0400 MIME-Version: 1.0 In-Reply-To: <20140620025938.2e80efa0@i7> References: <1396603322-13585-1-git-send-email-djkurtz@chromium.org> <20140620025938.2e80efa0@i7> From: Daniel Kurtz Date: Fri, 20 Jun 2014 20:15:06 +0800 X-Google-Sender-Auth: XU7bQ92_zMfX7HLVA1lyBLteLrM Message-ID: Subject: Re: [PATCH 1/2] drm/exynos/fbdev: don't set fix.smem/mmio_{start,len} To: Siarhei Siamashka Cc: Inki Dae , dri-devel , Kukjin Kim , Seung-Woo Kim , "linux-kernel@vger.kernel.org" , Kyungmin Park , linux-samsung-soc , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 20, 2014 at 7:59 AM, Siarhei Siamashka wrote: > > On Fri, 4 Apr 2014 17:22:01 +0800 > Daniel Kurtz wrote: > > > Kernel access to the eyxnos fbdev framebuffer is via its gem object's > > kernel mapping (kvaddr, stored in info->screen_base). > > > > User space access is provided by mmap(), read() and write() of /dev/fb/fb0. > > These functions also only use screen_base/screen_size(). > > > > Therefore, it is not necessary to set fix->smem_{start,len} or > > fix->mmio_{start,len} fields. > > > > This avoids leaking kernel, physical and dma mapped addresses to user > > space via the ioctls FBIOGET_VSCREENINFO and FBIOGET_FSCREENINFO. > > > > Signed-off-by: Daniel Kurtz > > --- > > drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 7 ------- > > 1 file changed, 7 deletions(-) > > > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c > > index 5fa342e..2dcc589 100644 > > --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c > > +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c > > @@ -123,14 +123,7 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper, > > > > dev->mode_config.fb_base = (resource_size_t)buffer->dma_addr; > > fbi->screen_base = buffer->kvaddr + offset; > > - if (is_drm_iommu_supported(dev)) > > - fbi->fix.smem_start = (unsigned long) > > - (page_to_phys(sg_page(buffer->sgt->sgl)) + offset); > > - else > > - fbi->fix.smem_start = (unsigned long)buffer->dma_addr; > > - > > fbi->screen_size = size; > > - fbi->fix.smem_len = size; > > Can we keep proper initialization of 'smem_len'? Some userland > applications use it for calculating the size for mmap: > > http://cgit.freedesktop.org/xorg/xserver/tree/hw/xfree86/fbdevhw/fbdevhw.c?id=xorg-server-1.15.99.903#n571 > > > > > return 0; > > } > > Basically, this patch breaks the xf86-video-fbdev ddx and some users > are already unhappy. I'm so sorry this patch broke things for some users. Can you upload a patch to correct it? I'll happily review it. -djk > > > -- > Best regards, > Siarhei Siamashka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/