From: Archit Taneja <architt@codeaurora.org>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: "Terje Bergström" <tbergstrom@nvidia.com>,
"Stephen Warren" <swarren@wwwdotorg.org>,
linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 12/25] drm/tegra: Use new drm_fb_helper functions
Date: Tue, 14 Jul 2015 14:41:58 +0530 [thread overview]
Message-ID: <55A4D25E.1050204@codeaurora.org> (raw)
In-Reply-To: <20150714085009.GD12465@ulmo.nvidia.com>
On 07/14/2015 02:20 PM, Thierry Reding wrote:
> On Mon, Jul 13, 2015 at 12:08:08PM +0530, Archit Taneja wrote:
> [...]
>> diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
> [...]
>> @@ -224,11 +224,11 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
>> if (IS_ERR(bo))
>> return PTR_ERR(bo);
>>
>> - info = framebuffer_alloc(0, drm->dev);
>> - if (!info) {
>> + info = drm_fb_helper_alloc_fbi(helper);
>> + if (IS_ERR(info)) {
>> dev_err(drm->dev, "failed to allocate framebuffer info\n");
>> - drm_gem_object_unreference_unlocked(&bo->gem);
>> - return -ENOMEM;
>> + err = PTR_ERR(info);
>> + goto gem_unref;
>> }
>>
>> fbdev->fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
>> @@ -236,7 +236,6 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
>> err = PTR_ERR(fbdev->fb);
>> dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
>> err);
>> - drm_gem_object_unreference_unlocked(&bo->gem);
>> goto release;
>> }
>>
>> @@ -248,12 +247,6 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
>> info->flags = FBINFO_FLAG_DEFAULT;
>> info->fbops = &tegra_fb_ops;
>>
>> - err = fb_alloc_cmap(&info->cmap, 256, 0);
>> - if (err < 0) {
>> - dev_err(drm->dev, "failed to allocate color map: %d\n", err);
>> - goto destroy;
>> - }
>> -
>> drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);
>> drm_fb_helper_fill_var(info, helper, fb->width, fb->height);
>>
>> @@ -282,7 +275,9 @@ destroy:
>> drm_framebuffer_unregister_private(fb);
>> tegra_fb_destroy(fb);
>> release:
>> - framebuffer_release(info);
>> + drm_fb_helper_release_fbi(helper);
>> +gem_unref:
>> + drm_gem_object_unreference_unlocked(&bo->gem);
>
> You can't do this. tegra_fb_alloc() takes ownership of the buffer, so
> unless you compensate for that (by taking an explicit reference to the
> buffer in tegra_fb_alloc()) you'd be dereferencing twice and likely end
> up with use-after-free errors later on.
>
> I'd prefer to keep the error clean up as it is.
Okay. I missed out on the fact that tegra_fb_destroy in the clean up
code calls drm_gem_object_unreference_unlocked. I'll keep it as is.
Archit
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
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next prev parent reply other threads:[~2015-07-14 9:12 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-13 6:37 [PATCH 00/25] drm: fb emulation: Step 1: Create new drm_fb_helper wrapper funcs Archit Taneja
2015-07-13 6:37 ` [PATCH 01/25] drm/fb_helper: Add drm_fb_helper functions to manage fb_info creation Archit Taneja
2015-07-13 6:37 ` [PATCH 02/25] drm/fb_helper: Create a wrapper for unlink_framebuffer Archit Taneja
2015-07-13 7:30 ` Daniel Vetter
2015-07-13 6:37 ` [PATCH 03/25] drm/fb_helper: Create wrappers for fb_sys_read/write funcs Archit Taneja
2015-07-13 7:31 ` Daniel Vetter
2015-07-13 9:59 ` Archit Taneja
2015-07-13 7:39 ` Daniel Vetter
2015-07-13 6:38 ` [PATCH 04/25] drm/fb_helper: Create wrappers for blit, copyarea and fillrect funcs Archit Taneja
2015-07-13 7:40 ` Daniel Vetter
2015-07-13 6:38 ` [PATCH 05/25] drm/fb_helper: Create a wrapper for fb_set_suspend Archit Taneja
2015-07-13 6:38 ` [PATCH 06/25] drm/fb_helper: Create a wrapper for remove_conflicting_framebuffers Archit Taneja
2015-07-13 6:38 ` [PATCH 07/25] drm/cirrus: Use new drm_fb_helper functions Archit Taneja
2015-07-13 6:38 ` [PATCH 08/25] drm/rockchip: " Archit Taneja
2015-07-13 6:38 ` [PATCH 09/25] drm/armada: " Archit Taneja
2015-07-13 6:38 ` [PATCH 10/25] drm/ast: " Archit Taneja
2015-07-13 6:38 ` [PATCH 11/25] drm/omap: " Archit Taneja
2015-07-13 6:38 ` [PATCH 12/25] drm/tegra: " Archit Taneja
2015-07-14 8:50 ` Thierry Reding
2015-07-14 9:11 ` Archit Taneja [this message]
2015-07-13 6:38 ` [PATCH 13/25] drm/msm: " Archit Taneja
2015-07-13 6:38 ` [PATCH 14/25] drm/exynos: " Archit Taneja
2015-08-11 9:04 ` Inki Dae
2015-08-11 9:11 ` Inki Dae
2015-07-13 6:38 ` [PATCH 15/25] drm/gma500: " Archit Taneja
2015-07-13 6:38 ` [PATCH 16/25] drm/mgag200: " Archit Taneja
2015-07-13 6:38 ` [PATCH 17/25] drm/radeon: " Archit Taneja
2015-07-13 6:38 ` [PATCH 18/25] drm/qxl: " Archit Taneja
2015-07-13 6:38 ` [PATCH 19/25] drm/i915: " Archit Taneja
2015-07-13 6:38 ` [PATCH 20/25] drm/nouveau: " Archit Taneja
2015-07-13 6:38 ` [PATCH 21/25] drm/udl: " Archit Taneja
2015-07-13 6:38 ` [PATCH 22/25] drm/boschs: " Archit Taneja
2015-07-13 6:38 ` [PATCH 23/25] drm/amdgpu: " Archit Taneja
2015-07-13 6:38 ` [PATCH 24/25] drm/virtio: " Archit Taneja
2015-07-13 6:38 ` [PATCH 25/25] drm/fb_cma_helper: " Archit Taneja
2015-07-13 8:07 ` [PATCH 00/25] drm: fb emulation: Step 1: Create new drm_fb_helper wrapper funcs Daniel Vetter
2015-07-13 10:29 ` Archit Taneja
2015-07-13 14:11 ` Daniel Vetter
2015-07-13 15:25 ` Alex Deucher
2015-07-22 6:59 ` [PATCH v2 " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 01/25] drm/fb_helper: Add drm_fb_helper functions to manage fb_info creation Archit Taneja
2015-07-22 6:59 ` [PATCH v2 02/25] drm/fb_helper: Create a wrapper for unlink_framebuffer Archit Taneja
2015-07-22 6:59 ` [PATCH v2 03/25] drm/fb_helper: Create wrappers for fb_sys_read/write funcs Archit Taneja
2015-07-22 6:59 ` [PATCH v2 04/25] drm/fb_helper: Create wrappers for blit, copyarea and fillrect funcs Archit Taneja
2015-07-22 6:59 ` [PATCH v2 05/25] drm/fb_helper: Create a wrapper for fb_set_suspend Archit Taneja
2015-07-22 6:59 ` [PATCH v2 06/25] drm/fb_helper: Create a wrapper for remove_conflicting_framebuffers Archit Taneja
2015-07-22 6:59 ` [PATCH v2 07/25] drm/cirrus: Use new drm_fb_helper functions Archit Taneja
2015-07-22 6:59 ` [PATCH v2 08/25] drm/rockchip: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 09/25] drm/armada: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 10/25] drm/ast: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 11/25] drm/omap: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 12/25] drm/tegra: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 13/25] drm/msm: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 14/25] drm/exynos: " Archit Taneja
2015-08-11 12:27 ` Inki Dae
2015-07-22 6:59 ` [PATCH v2 15/25] drm/gma500: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 16/25] drm/mgag200: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 17/25] drm/radeon: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 18/25] drm/qxl: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 19/25] drm/i915: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 20/25] drm/nouveau: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 21/25] drm/udl: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 22/25] drm/bochs: " Archit Taneja
2015-07-22 6:59 ` [PATCH v2 23/25] drm/amdgpu: " Archit Taneja
2015-07-22 7:00 ` [PATCH v2 24/25] drm/virtio: " Archit Taneja
2015-07-22 7:00 ` [PATCH v2 25/25] drm/fb_cma_helper: " Archit Taneja
2015-07-22 7:41 ` [PATCH v2 00/25] drm: fb emulation: Step 1: Create new drm_fb_helper wrapper funcs Daniel Vetter
2015-07-22 8:34 ` Archit Taneja
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