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,INCLUDES_PATCH,MAILING_LIST_MULTI,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 93E8CC433E1 for ; Thu, 16 Jul 2020 10:32:19 +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 443BE2065D for ; Thu, 16 Jul 2020 10:32:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="fFls4DsN"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="LQRv2fEJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 443BE2065D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=z8Uc2jvsin99zKumzLE2rfEcaY1W/ubw6MHoeLjxhuI=; b=fFls4DsNNkm8C7kaxCr0lpqAM shD+SBow38jrFaqYgpgdXSTLbmqorFmdVFASnQFeHTlYoskdEy252qqJMx86XhvrLOVipOJMv9vFY TS4GPlDZ1RQBnzgNn859T7PZCyZvi0ktDN8hGYdSCRs8Qsyc40gsasPxlWIp1Q8wQnOJUgDKrdyRj KXyZ1lMZ4MveUNDWviNFGak1bcQgN7WVn05QerTlcMyTVYhx4mX6bXoYvL+HmOAhtHYJY4qom6sWY z7BBQJ9zhvdHOFQ1SmNviPV4yCAUkmDz6DqhzS+g9L4EZyqslDaCyRBiYe1qJN3q1q1vkT1os0MSN YlGi1d3Vw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jw1AQ-0005y4-7j; Thu, 16 Jul 2020 10:31:06 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jw1AO-0005xV-5Q for linux-arm-kernel@lists.infradead.org; Thu, 16 Jul 2020 10:31:04 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C82AD2065D; Thu, 16 Jul 2020 10:31:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594895463; bh=I4dTQBrnodALq8P0qz+UQRJ3T5gEQmUi6IPIDUy1meg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LQRv2fEJmtV5M30Lx6P6L4E4+ujyB+W6Fz5SJmIfLSeDES1/5LXrpnhZMqfZLSFf6 VPTI+clOYCJGtXMFgi9J56Mb/qwXD3h5qWbwOCvxJx0WgpvLzOuAz2tBERfUAcjHJ1 JYLwHHbIO5FDxFwOC64JE/PjLsyaG9VOKyK9Su2k= Date: Thu, 16 Jul 2020 11:30:59 +0100 From: Will Deacon To: Robin Murphy Subject: Re: [PATCH] drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling Message-ID: <20200716103058.GE7036@willie-the-truck> References: <1594891165-8228-1-git-send-email-liuqi115@huawei.com> <20200716094144.GC6771@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200716_063104_274031_21E784BD X-CRM114-Status: GOOD ( 19.21 ) 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, john.garry@huawei.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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel