From patchwork Wed Mar 4 22:00:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Luba X-Patchwork-Id: 213551 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 1B3A7C3F2D1 for ; Wed, 4 Mar 2020 22:01:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E916520716 for ; Wed, 4 Mar 2020 22:01:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388410AbgCDWBB (ORCPT ); Wed, 4 Mar 2020 17:01:01 -0500 Received: from foss.arm.com ([217.140.110.172]:40268 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388407AbgCDWBB (ORCPT ); Wed, 4 Mar 2020 17:01:01 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 56EA41FB; Wed, 4 Mar 2020 14:01:00 -0800 (PST) Received: from e123648.arm.com (unknown [10.37.12.115]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 20A3E3F6CF; Wed, 4 Mar 2020 14:00:54 -0800 (PST) From: Lukasz Luba To: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org Cc: inki.dae@samsung.com, jy0922.shim@samsung.com, sw0312.kim@samsung.com, kyungmin.park@samsung.com, airlied@linux.ie, daniel@ffwll.ch, kgene@kernel.org, krzk@kernel.org, b.zolnierkie@samsung.com, a.hajda@samsung.com, Dietmar.Eggemann@arm.com, lukasz.luba@arm.com Subject: [PATCH] drm/exynos: Fix memory leak and release IOMMU mapping structures Date: Wed, 4 Mar 2020 22:00:22 +0000 Message-Id: <20200304220022.8003-1-lukasz.luba@arm.com> X-Mailer: git-send-email 2.17.1 Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org There is a memory leak which left some objects not freed. The reference counter of mapping: 'mapping->kref' was 2 when calling arm_iommu_detach_device(), so the release_iommu_mapping() won't be called. Since the old mapping structure is not going to be used any more (because it is detached and new one attached), call arm_iommu_release_mapping() to trigger cleanup. Found using kmemleak detector, the output: unreferenced object 0xc2137640 (size 64): comm "swapper/0", pid 1, jiffies 4294937900 (age 3127.400s) hex dump (first 32 bytes): 50 a3 14 c2 80 a2 14 c2 01 00 00 00 20 00 00 00 P........... ... 00 10 00 00 00 80 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<3acd268d>] arch_setup_dma_ops+0x4c/0x104 [<9f7d2cce>] of_dma_configure+0x19c/0x3a4 [] really_probe+0xb0/0x47c [<4f510e4f>] driver_probe_device+0x78/0x1c4 [<7481a0cf>] device_driver_attach+0x58/0x60 [<0ff8f5c1>] __driver_attach+0xb8/0x158 [<86006144>] bus_for_each_dev+0x74/0xb4 [<10159dca>] bus_add_driver+0x1c0/0x200 [<8a265265>] driver_register+0x74/0x108 [] exynos_drm_init+0xb0/0x134 [] do_one_initcall+0x90/0x458 [<6da35917>] kernel_init_freeable+0x188/0x200 [] kernel_init+0x8/0x110 [<1f3cddf9>] ret_from_fork+0x14/0x20 [<8cd12507>] 0x0 unreferenced object 0xc214a280 (size 128): comm "swapper/0", pid 1, jiffies 4294937900 (age 3127.400s) hex dump (first 32 bytes): 00 a0 ec ed 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<3acd268d>] arch_setup_dma_ops+0x4c/0x104 [<9f7d2cce>] of_dma_configure+0x19c/0x3a4 [] really_probe+0xb0/0x47c [<4f510e4f>] driver_probe_device+0x78/0x1c4 [<7481a0cf>] device_driver_attach+0x58/0x60 [<0ff8f5c1>] __driver_attach+0xb8/0x158 [<86006144>] bus_for_each_dev+0x74/0xb4 [<10159dca>] bus_add_driver+0x1c0/0x200 [<8a265265>] driver_register+0x74/0x108 [] exynos_drm_init+0xb0/0x134 [] do_one_initcall+0x90/0x458 [<6da35917>] kernel_init_freeable+0x188/0x200 [] kernel_init+0x8/0x110 [<1f3cddf9>] ret_from_fork+0x14/0x20 [<8cd12507>] 0x0 unreferenced object 0xedeca000 (size 4096): comm "swapper/0", pid 1, jiffies 4294937900 (age 3127.400s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<3acd268d>] arch_setup_dma_ops+0x4c/0x104 [<9f7d2cce>] of_dma_configure+0x19c/0x3a4 [] really_probe+0xb0/0x47c [<4f510e4f>] driver_probe_device+0x78/0x1c4 [<7481a0cf>] device_driver_attach+0x58/0x60 [<0ff8f5c1>] __driver_attach+0xb8/0x158 [<86006144>] bus_for_each_dev+0x74/0xb4 [<10159dca>] bus_add_driver+0x1c0/0x200 [<8a265265>] driver_register+0x74/0x108 [] exynos_drm_init+0xb0/0x134 [] do_one_initcall+0x90/0x458 [<6da35917>] kernel_init_freeable+0x188/0x200 [] kernel_init+0x8/0x110 [<1f3cddf9>] ret_from_fork+0x14/0x20 [<8cd12507>] 0x0 unreferenced object 0xc214a300 (size 128): comm "swapper/0", pid 1, jiffies 4294937900 (age 3127.400s) hex dump (first 32 bytes): 00 a3 14 c2 00 a3 14 c2 00 40 18 c2 00 80 18 c2 .........@...... 02 00 02 00 ad 4e ad de ff ff ff ff ff ff ff ff .....N.......... backtrace: [<08cbd8bc>] iommu_domain_alloc+0x24/0x50 [] arm_iommu_create_mapping+0xe4/0x134 [<3acd268d>] arch_setup_dma_ops+0x4c/0x104 [<9f7d2cce>] of_dma_configure+0x19c/0x3a4 [] really_probe+0xb0/0x47c [<4f510e4f>] driver_probe_device+0x78/0x1c4 [<7481a0cf>] device_driver_attach+0x58/0x60 [<0ff8f5c1>] __driver_attach+0xb8/0x158 [<86006144>] bus_for_each_dev+0x74/0xb4 [<10159dca>] bus_add_driver+0x1c0/0x200 [<8a265265>] driver_register+0x74/0x108 [] exynos_drm_init+0xb0/0x134 [] do_one_initcall+0x90/0x458 [<6da35917>] kernel_init_freeable+0x188/0x200 [] kernel_init+0x8/0x110 [<1f3cddf9>] ret_from_fork+0x14/0x20 Signed-off-by: Lukasz Luba --- Hi all, I have discovered this issue on OdroidXU4 while running some stress tests for upcoming Energy Model. To reproduce it, kernel must be compiled with DEBUG_KMEMLEAK. When the boot has finished, type: # echo scan > /sys/kernel/debug/kmemleak # cat /sys/kernel/debug/kmemleak You should expect similar output to the one from the commit message. I don't know if it should go via stable tree as well. I can resend with CC stable, if there is a need. Regards, Lukasz Luba drivers/gpu/drm/exynos/exynos_drm_dma.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_dma.c b/drivers/gpu/drm/exynos/exynos_drm_dma.c index 9ebc02768847..45f209ec107f 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dma.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c @@ -74,8 +74,13 @@ static int drm_iommu_attach_device(struct drm_device *drm_dev, return ret; if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) { - if (to_dma_iommu_mapping(subdrv_dev)) + struct dma_iommu_mapping *mapping = + to_dma_iommu_mapping(subdrv_dev); + + if (mapping) { arm_iommu_detach_device(subdrv_dev); + arm_iommu_release_mapping(mapping); + } ret = arm_iommu_attach_device(subdrv_dev, priv->mapping); } else if (IS_ENABLED(CONFIG_IOMMU_DMA)) {