From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH] drm/prime: drop reference on imported dma-buf Date: Wed, 5 Sep 2012 11:02:20 +0200 Message-ID: <20120905090220.GA5357@phenom.ffwll.local> References: <1343084868-13427-1-git-send-email-rob.clark@linaro.org> <20120724080522.GA5506@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wg0-f43.google.com (mail-wg0-f43.google.com [74.125.82.43]) by gabe.freedesktop.org (Postfix) with ESMTP id B6BB59F07C for ; Wed, 5 Sep 2012 02:01:54 -0700 (PDT) Received: by wgbdr1 with SMTP id dr1so253620wgb.12 for ; Wed, 05 Sep 2012 02:01:53 -0700 (PDT) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Rob Clark Cc: dri-devel@lists.freedesktop.org, patches@linaro.org List-Id: dri-devel@lists.freedesktop.org On Tue, Sep 04, 2012 at 05:32:21PM -0500, Rob Clark wrote: > Dave, I just noticed that I still have this patch locally, but don't > see it in drm-next.. so just checking that it didn't get forgotten My locking fixes blew up :( -Daniel > > BR, > -R > > On Tue, Jul 24, 2012 at 3:05 AM, Daniel Vetter wrote: > > On Tue, Jul 24, 2012 at 1:07 AM, Rob Clark wrote: > >> From: Rob Clark > >> > >> The GEM handle takes the reference. If a driver is actually importing a > >> foreign dmabuf, rather than just re-importing it's own dmabuf, it needs > >> to do a get_dma_buf(). > >> > >> Signed-off-by: Rob Clark > > [Maybe mention that this is on top of my locking fixes.] > > > > We've discussed this a bit on irc and concluded that every function taking > > care of their own references to the dma buf works best in avoiding > > potential use-after-free issues when evil userspaces sneaks in a > > close(dma_buf_fd). > > > > Reviewed-by: Daniel Vetter > >> --- > >> drivers/gpu/drm/drm_prime.c | 7 +++++++ > >> drivers/gpu/drm/exynos/exynos_drm_dmabuf.c | 4 ++++ > >> drivers/gpu/drm/i915/i915_gem_dmabuf.c | 4 ++++ > >> drivers/gpu/drm/nouveau/nouveau_prime.c | 5 +++++ > >> drivers/gpu/drm/radeon/radeon_prime.c | 4 ++++ > >> drivers/gpu/drm/udl/udl_gem.c | 4 ++++ > >> 6 files changed, 28 insertions(+) > >> > >> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c > >> index 4f80374..088e018 100644 > >> --- a/drivers/gpu/drm/drm_prime.c > >> +++ b/drivers/gpu/drm/drm_prime.c > >> @@ -185,6 +185,13 @@ int drm_gem_prime_fd_to_handle(struct drm_device *dev, > >> mutex_unlock(&file_priv->prime.lock); > >> drm_gem_object_unreference_unlocked(obj); > >> > >> + /* > >> + * Drop the ref we obtained w/ dma_buf_get() for the benefit of > >> + * drivers simply re-importing their own dma-buf.. if drivers > >> + * import a foreign dma-buf, they should get_dma_buf(). > >> + */ > >> + dma_buf_put(dma_buf); > >> + > >> return 0; > >> > >> fail: > >> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c > >> index f270790..f8ac75b 100644 > >> --- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c > >> +++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c > >> @@ -190,6 +190,9 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev, > >> } > >> } > >> > >> + /* since we are attaching, we need to hold a ref */ > >> + get_dma_buf(dma_buf); > >> + > >> attach = dma_buf_attach(dma_buf, drm_dev->dev); > >> if (IS_ERR(attach)) > >> return ERR_PTR(-EINVAL); > >> @@ -250,6 +253,7 @@ err_unmap_attach: > >> dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL); > >> err_buf_detach: > >> dma_buf_detach(dma_buf, attach); > >> + dma_buf_put(dma_buf); > >> return ERR_PTR(ret); > >> } > >> > >> diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c > >> index cf6bdec..9d2b2eb 100644 > >> --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c > >> +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c > >> @@ -189,6 +189,9 @@ struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev, > >> } > >> } > >> > >> + /* since we are attaching, we need to hold a ref */ > >> + get_dma_buf(dma_buf); > >> + > >> /* need to attach */ > >> attach = dma_buf_attach(dma_buf, dev->dev); > >> if (IS_ERR(attach)) > >> @@ -224,5 +227,6 @@ fail_unmap: > >> dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); > >> fail_detach: > >> dma_buf_detach(dma_buf, attach); > >> + dma_buf_put(dma_buf); > >> return ERR_PTR(ret); > >> } > >> diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c b/drivers/gpu/drm/nouveau/nouveau_prime.c > >> index 4c82801..fc30886 100644 > >> --- a/drivers/gpu/drm/nouveau/nouveau_prime.c > >> +++ b/drivers/gpu/drm/nouveau/nouveau_prime.c > >> @@ -200,6 +200,10 @@ struct drm_gem_object *nouveau_gem_prime_import(struct drm_device *dev, > >> } > >> } > >> } > >> + > >> + /* since we are attaching, we need to hold a ref */ > >> + get_dma_buf(dma_buf); > >> + > >> /* need to attach */ > >> attach = dma_buf_attach(dma_buf, dev->dev); > >> if (IS_ERR(attach)) > >> @@ -223,6 +227,7 @@ fail_unmap: > >> dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); > >> fail_detach: > >> dma_buf_detach(dma_buf, attach); > >> + dma_buf_put(dma_buf); > >> return ERR_PTR(ret); > >> } > >> > >> diff --git a/drivers/gpu/drm/radeon/radeon_prime.c b/drivers/gpu/drm/radeon/radeon_prime.c > >> index 28f79ac..073a8d3 100644 > >> --- a/drivers/gpu/drm/radeon/radeon_prime.c > >> +++ b/drivers/gpu/drm/radeon/radeon_prime.c > >> @@ -195,6 +195,9 @@ struct drm_gem_object *radeon_gem_prime_import(struct drm_device *dev, > >> } > >> } > >> > >> + /* since we are attaching, we need to hold a ref */ > >> + get_dma_buf(dma_buf); > >> + > >> /* need to attach */ > >> attach = dma_buf_attach(dma_buf, dev->dev); > >> if (IS_ERR(attach)) > >> @@ -218,5 +221,6 @@ fail_unmap: > >> dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); > >> fail_detach: > >> dma_buf_detach(dma_buf, attach); > >> + dma_buf_put(dma_buf); > >> return ERR_PTR(ret); > >> } > >> diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c > >> index 7bd65bd..47f25d5 100644 > >> --- a/drivers/gpu/drm/udl/udl_gem.c > >> +++ b/drivers/gpu/drm/udl/udl_gem.c > >> @@ -305,6 +305,9 @@ struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev, > >> struct udl_gem_object *uobj; > >> int ret; > >> > >> + /* since we are attaching, we need to hold a ref */ > >> + get_dma_buf(dma_buf); > >> + > >> /* need to attach */ > >> attach = dma_buf_attach(dma_buf, dev->dev); > >> if (IS_ERR(attach)) > >> @@ -329,5 +332,6 @@ fail_unmap: > >> dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); > >> fail_detach: > >> dma_buf_detach(dma_buf, attach); > >> + dma_buf_put(dma_buf); > >> return ERR_PTR(ret); > >> } > >> -- > >> 1.7.9.5 > >> > >> _______________________________________________ > >> dri-devel mailing list > >> dri-devel@lists.freedesktop.org > >> http://lists.freedesktop.org/mailman/listinfo/dri-devel > > > > > > > > -- > > Daniel Vetter > > daniel.vetter@ffwll.ch - +41 (0) 79 364 57 48 - http://blog.ffwll.ch > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/dri-devel > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Mail: daniel@ffwll.ch Mobile: +41 (0)79 365 57 48