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 X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 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 13CEDC432C0 for ; Tue, 26 Nov 2019 04:45:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D69C1204FD for ; Tue, 26 Nov 2019 04:45:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574743553; bh=P7JZP8kJ96uw813GsugjfM/jpsA5+dfDymDZrXgKasM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=0ZGBQ8JlekrumVJqjCgbSpJTR7AQNY5ND5Ovvo4edhM3lJplqmZZnRbarBmrtduCv xDCzIuHujDsDxWI57MwFPIYNghiZ1JV+5YuEx4s+5Sv9BxlgQmXvi+QwYQdYP2Lj66 YxNSJrIH5iZ3AL3TXpt9X/bCEVBWZiX70DnHjz58= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729189AbfKZEpx (ORCPT ); Mon, 25 Nov 2019 23:45:53 -0500 Received: from inca-roads.misterjones.org ([213.251.177.50]:60457 "EHLO inca-roads.misterjones.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729172AbfKZEpw (ORCPT ); Mon, 25 Nov 2019 23:45:52 -0500 Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why) by cheepnis.misterjones.org with esmtpsa (TLSv1.2:AES256-GCM-SHA384:256) (Exim 4.80) (envelope-from ) id 1iZSjN-0003Ml-3g; Tue, 26 Nov 2019 05:45:41 +0100 Date: Tue, 26 Nov 2019 04:45:33 +0000 From: Marc Zyngier To: "Andrew Jeffery" Cc: "Roy van Doormaal" , "Brendan Higgins" , "Benjamin Herrenschmidt" , "Joel Stanley" , "Thomas Gleixner" , "Jason Cooper" , linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org Subject: Re: [PATCH] irqchip/aspeed-i2c-ic: Fix irq domain name memory leak Message-ID: <20191126044533.20d84e37@why> In-Reply-To: References: <20191125202937.23133-1-roy.van.doormaal@prodrive-technologies.com> Organization: Approximate X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: andrew@aj.id.au, roy.van.doormaal@prodrive-technologies.com, brendanhiggins@google.com, benh@kernel.crashing.org, joel@jms.id.au, tglx@linutronix.de, jason@lakedaemon.net, linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on cheepnis.misterjones.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 26 Nov 2019 10:08:36 +1030 "Andrew Jeffery" wrote: > On Tue, 26 Nov 2019, at 06:59, Roy van Doormaal wrote: > > The aspeed irqchip driver overwrites the default irq domain name, > > but doesn't free the existing domain name. > > This patch frees the irq domain name before overwriting it. > > > > kmemleak trace: > > > > unreferenced object 0xb8004c40 (size 64): > > comm "swapper", pid 0, jiffies 4294937303 (age 747.660s) > > hex dump (first 32 bytes): > > 3a 61 68 62 3a 61 70 62 3a 62 75 73 40 31 65 37 :ahb:apb:bus@1e7 > > 38 61 30 30 30 3a 69 6e 74 65 72 72 75 70 74 2d 8a000:interrupt- > > backtrace: > > [<086b59b8>] kmemleak_alloc+0xa8/0xc0 > > [] __kmalloc_track_caller+0x118/0x1a0 > > [] kvasprintf+0x5c/0xc0 > > [<49275eec>] kasprintf+0x30/0x50 > > [<5713064b>] __irq_domain_add+0x184/0x25c > > [<53c594d0>] aspeed_i2c_ic_of_init+0x9c/0x128 > > [] of_irq_init+0x1ec/0x314 > > [] irqchip_init+0x1c/0x24 > > [<7ef974b3>] init_IRQ+0x30/0x90 > > [<87a1438f>] start_kernel+0x28c/0x458 > > [< (null)>] (null) > > [] 0xffffffff > > > > Signed-off-by: Roy van Doormaal > > --- > > drivers/irqchip/irq-aspeed-i2c-ic.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/irqchip/irq-aspeed-i2c-ic.c > > b/drivers/irqchip/irq-aspeed-i2c-ic.c > > index 8d591c179f81..8081b8483a79 100644 > > --- a/drivers/irqchip/irq-aspeed-i2c-ic.c > > +++ b/drivers/irqchip/irq-aspeed-i2c-ic.c > > @@ -92,6 +92,8 @@ static int __init aspeed_i2c_ic_of_init(struct > > device_node *node, > > goto err_iounmap; > > } > > > > + if (i2c_ic->irq_domain->flags & IRQ_DOMAIN_NAME_ALLOCATED) > > + kfree(i2c_ic->irq_domain->name); > > i2c_ic->irq_domain->name = "aspeed-i2c-domain"; > > Given that the name is no-longer allocated I think you need to clear the > IRQ_DOMAIN_NAME_ALLOCATED bit from flags to avoid attempting to > free the const string in irq_domain_remove(): > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/kernel/irq/irqdomain.c?h=v5.4#n263 > > Or do a kstrdup(). Or even better, drop the whole domain name assignment, which is pretty pointless and makes debugging pointlessly difficult (see how the name is used to build the irq debugfs). Thanks, M. -- Jazz is not dead. It just smells funny...