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=-8.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 96FB7C433E0 for ; Thu, 16 Jul 2020 10:39:31 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5E42A2074B for ; Thu, 16 Jul 2020 10:39:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="XmldyL4k" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E42A2074B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=70rTRJydTBfYX5UB+h2DA/9PIUN3IVbgXaTS7zBN9xk=; b=XmldyL4kz8j3CXIWslmi9M+/k qj9DLuCRHWvrjdyfxC0x1BhRhRqBlLqC5H4Ep1IGz9E+xIEDfZCGk5NrMHEVoGVw2FfkBGCuPULF2 fgvEPXmw6HLZA3eMeRfKI6elkzqlxJ1sd/JRgJj0Iim3IhWN3PLOQeN0oKeL2pkiNGDvT96Sos5Fb G6MKHfDIt1mu0GY4XzssgGTpzRG7lkuTJrnFUALS/lfsNOyX8g30Y+t1GriDCE1z5ySvqHiVjjRPp Yr8v1Wbsacw4zWA8dLamd86oknkBfpF2pRVTzwafNWnHsFvVcxqF+8X6FSye5GqDpkyR40BDsRWu1 J2jnGIJZw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jw1HC-0006oS-FP; Thu, 16 Jul 2020 10:38:06 +0000 Received: from lhrrgout.huawei.com ([185.176.76.210] helo=huawei.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jw1H9-0006nW-2e for linux-arm-kernel@lists.infradead.org; Thu, 16 Jul 2020 10:38:03 +0000 Received: from lhreml724-chm.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id E3D58E3A008D52B700C1; Thu, 16 Jul 2020 11:37:58 +0100 (IST) Received: from [127.0.0.1] (10.210.168.254) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1913.5; Thu, 16 Jul 2020 11:37:57 +0100 Subject: Re: [PATCH] drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling To: Will Deacon , Robin Murphy References: <1594891165-8228-1-git-send-email-liuqi115@huawei.com> <20200716094144.GC6771@willie-the-truck> <20200716103058.GE7036@willie-the-truck> From: John Garry Message-ID: <66a8eb37-b91a-d228-4ea4-8601e5518b31@huawei.com> Date: Thu, 16 Jul 2020 11:36:10 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <20200716103058.GE7036@willie-the-truck> Content-Language: en-US X-Originating-IP: [10.210.168.254] X-ClientProxiedBy: lhreml714-chm.china.huawei.com (10.201.108.65) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200716_063803_233084_E78F238C X-CRM114-Status: GOOD ( 16.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, linux-kernel@vger.kernel.org, linuxarm@huawei.com, zhangshaokun@hisilicon.com, wang.wanghaifeng@huawei.com, Qi Liu , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 16/07/2020 11:30, Will Deacon wrote: > On Thu, Jul 16, 2020 at 11:26:25AM +0100, Robin Murphy wrote: >> On 2020-07-16 10:41, Will Deacon wrote: >>> On Thu, Jul 16, 2020 at 05:19:25PM +0800, Qi Liu wrote: >>>> Kernel panic will also happen when users try to unbind PMU drivers with >>>> device. This unbind issue could be solved by another patch latter. >>>> >>>> drivers/perf/arm_smmuv3_pmu.c | 1 + >>>> drivers/perf/fsl_imx8_ddr_perf.c | 1 + >>>> drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c | 1 + >>>> drivers/perf/hisilicon/hisi_uncore_hha_pmu.c | 1 + >>>> drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c | 1 + >>>> 5 files changed, 5 insertions(+) >>>> >>>> diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c >>>> index 48e28ef..90caba56 100644 >>>> --- a/drivers/perf/arm_smmuv3_pmu.c >>>> +++ b/drivers/perf/arm_smmuv3_pmu.c >>>> @@ -742,6 +742,7 @@ static int smmu_pmu_probe(struct platform_device *pdev) >>>> platform_set_drvdata(pdev, smmu_pmu); >>>> >>>> smmu_pmu->pmu = (struct pmu) { >>>> + .module = THIS_MODULE, >>> I thought platform_driver_register() did this automatically? >> For the platform device itself, yes, but this is for the PMU device - perf >> needs to take a reference to the module, otherwise the platform device can >> still be pulled out from under its feet. > Urgh, gross. > >> I can't remember if we ever discussed making perf_pmu_register() do the same >> trick as platform_device_register() and friends, but obviously it's a >> possibility. > Yeah, but I suppose this patch is the right thing to do for now. I'll queue > it as a fix. > Please also note what Qi Liu wrote about being able to unbind the driver and cause the same issue. I don't know if you can about that issue also. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel