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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59808C433EF for ; Tue, 22 Feb 2022 07:40:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229541AbiBVHlK (ORCPT ); Tue, 22 Feb 2022 02:41:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229452AbiBVHlK (ORCPT ); Tue, 22 Feb 2022 02:41:10 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD89D127D78 for ; Mon, 21 Feb 2022 23:40:44 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id BBBA3CE12FE for ; Tue, 22 Feb 2022 07:40:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C636C340E8; Tue, 22 Feb 2022 07:40:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645515641; bh=F72nzu5AzJZV8tlqf9nIForjQFMgox8nj7lTK2/X2oE=; h=Subject:To:From:Date:From; b=AUJOAWHGuFliMqUUTY6V/23M2GGANknlumH+8zUBLbMorwggsi4VX3VcGLA9j5kEY a2DKbaRVDFAjEMTqAXlqwAk+IzZZyjYLmXHgyEHohr/ifWp87f8x3RU7Aq8MSA+LIN krTH53mZMZOfSh3KSHvLKYELtGpRikbo3oumk088= Subject: patch "driver core: Free DMA range map when device is released" added to driver-core-linus To: marten.lindahl@axis.com, gregkh@linuxfoundation.org, robh@kernel.org, stable@vger.kernel.org From: Date: Tue, 22 Feb 2022 08:40:38 +0100 Message-ID: <164551563877162@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled driver core: Free DMA range map when device is released to my driver-core git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git in the driver-core-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From d8f7a5484f2188e9af2d9e4e587587d724501b12 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?M=C3=A5rten=20Lindahl?= Date: Wed, 16 Feb 2022 10:41:28 +0100 Subject: driver core: Free DMA range map when device is released MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When unbinding/binding a driver with DMA mapped memory, the DMA map is not freed before the driver is reloaded. This leads to a memory leak when the DMA map is overwritten when reprobing the driver. This can be reproduced with a platform driver having a dma-range: dummy { ... #address-cells = <0x2>; #size-cells = <0x2>; ranges; dma-ranges = <...>; ... }; and then unbinding/binding it: ~# echo soc:dummy >/sys/bus/platform/drivers//unbind DMA map object 0xffffff800b0ae540 still being held by &pdev->dev ~# echo soc:dummy >/sys/bus/platform/drivers//bind ~# echo scan > /sys/kernel/debug/kmemleak ~# cat /sys/kernel/debug/kmemleak unreferenced object 0xffffff800b0ae540 (size 64): comm "sh", pid 833, jiffies 4295174550 (age 2535.352s) hex dump (first 32 bytes): 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 80 00 00 00 00 00 00 00 80 00 00 00 00 ................ backtrace: [] create_object.isra.0+0x108/0x344 [] kmemleak_alloc+0x8c/0xd0 [] __kmalloc+0x440/0x6f0 [] of_dma_get_range+0x124/0x220 [] of_dma_configure_id+0x40/0x2d0 [] platform_dma_configure+0x5c/0xa4 [] really_probe+0x8c/0x514 [] __driver_probe_device+0x9c/0x19c [] device_driver_attach+0x54/0xbc [] bind_store+0xc4/0x120 [] drv_attr_store+0x30/0x44 [] sysfs_kf_write+0x50/0x60 [] kernfs_fop_write_iter+0x124/0x1b4 [] new_sync_write+0xdc/0x160 [] vfs_write+0x23c/0x2a0 [] ksys_write+0x64/0xec To prevent this we should free the dma_range_map when the device is released. Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset") Cc: stable Suggested-by: Rob Herring Reviewed-by: Rob Herring Signed-off-by: Mårten Lindahl Link: https://lore.kernel.org/r/20220216094128.4025861-1-marten.lindahl@axis.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 9eaaff2f556c..f47cab21430f 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -629,6 +629,9 @@ static int really_probe(struct device *dev, struct device_driver *drv) drv->remove(dev); devres_release_all(dev); + arch_teardown_dma_ops(dev); + kfree(dev->dma_range_map); + dev->dma_range_map = NULL; driver_sysfs_remove(dev); dev->driver = NULL; dev_set_drvdata(dev, NULL); @@ -1209,6 +1212,8 @@ static void __device_release_driver(struct device *dev, struct device *parent) devres_release_all(dev); arch_teardown_dma_ops(dev); + kfree(dev->dma_range_map); + dev->dma_range_map = NULL; dev->driver = NULL; dev_set_drvdata(dev, NULL); if (dev->pm_domain && dev->pm_domain->dismiss) -- 2.35.1