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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 03869C00140 for ; Mon, 15 Aug 2022 11:28:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=kA/cpYCyL7rp7ONjtR7hsWWJIyU7qDtb71R+65sejxw=; b=OPLwSkJa273RxX 3dA0WplrUSaFfq7KKKbzne/MXOhs6ip/0wpvKDwQjzCMzLCDsZjv/sJW8VUEAiz2l2otmfFPtIDye 5jC3mFrmuV7UV8DKSH1sPu6/qs2YXYUcoY36aWne026WInxpwbsN6dCyUD5pe1/Ct6U1yicQMuhwC v5DbgquWtUsYSErftPGiwKlu6d90RHIETqRb7kFsH9BBtni6Q3yL7A+2F7f8bx/G5cgQYosdTLB5i 8ic6Lno75ifMxx4sZuY7p8c8nxgi6JqKJx0e84PVWzgZaPD4K63++/U7eKXgtxAuj5D7621vwLUKW KJLv2aul5fHFbkh3WWgw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oNYEw-00FMPY-RW; Mon, 15 Aug 2022 11:26:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oNYDh-00FLYc-JG for linux-arm-kernel@lists.infradead.org; Mon, 15 Aug 2022 11:25:29 +0000 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 8EEBE113E; Mon, 15 Aug 2022 04:25:14 -0700 (PDT) Received: from FVFF77S0Q05N (unknown [10.57.45.65]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C80B73F67D; Mon, 15 Aug 2022 04:25:10 -0700 (PDT) Date: Mon, 15 Aug 2022 12:25:05 +0100 From: Mark Rutland To: Yicong Yang Cc: will@kernel.org, Frank.li@nxp.com, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, zhangshaokun@hisilicon.com, agross@kernel.org, bjorn.andersson@linaro.org, konrad.dybcio@somainline.org, khuong@os.amperecomputing.com, john.garry@huawei.com, jonathan.cameron@huawei.com, yangyicong@hisilicon.com, gregkh@linuxfoundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH] drivers/perf: Change WARN_ON() to dev_err() on irq_set_affinity() failure Message-ID: References: <20220815092815.11597-1-yangyicong@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220815092815.11597-1-yangyicong@huawei.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220815_042522_202321_C3818FAA X-CRM114-Status: GOOD ( 27.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Mon, Aug 15, 2022 at 05:28:15PM +0800, Yicong Yang wrote: > From: Yicong Yang > > The WARN_ON() on irq_set_affinity() failure is misused according to the [1] > and may crash people's box unintentionally. This may also be redundant since > in the failure case we may also trigger the WARN and dump the stack in the > perf core[2] for a second time. In what way do you think are these misused? I can't immediately see what you think applies from [1]. In perf we rely upon interrupt affinity to enforce serialization in a few places, so if we fail to set the interrupt affinity there are a number of things which could go wrong (e.g. memory corruption, and all the fun that could result from that). We use WARN_ON() to catch that early. I can't immediately see how [2] is relevant, since that's in the context of an IPI handler, and this patch affects the affinity of the PMU HW IRQ handler. Thanks, Mark. > > So change the WARN_ON() to dev_err() to just print the failure message. > > [1] https://github.com/torvalds/linux/blob/master/include/asm-generic/bug.h#L74 > [2] https://github.com/torvalds/linux/blob/master/kernel/events/core.c#L313 > > Suggested-by: Greg KH > [https://lore.kernel.org/lkml/YuOi3i0XHV++z1YI@kroah.com/] > Signed-off-by: Yicong Yang > --- > drivers/perf/arm-ccn.c | 5 +++-- > drivers/perf/arm_dmc620_pmu.c | 3 ++- > drivers/perf/arm_smmuv3_pmu.c | 6 ++++-- > drivers/perf/fsl_imx8_ddr_perf.c | 3 ++- > drivers/perf/hisilicon/hisi_pcie_pmu.c | 6 ++++-- > drivers/perf/hisilicon/hisi_uncore_pmu.c | 6 ++++-- > drivers/perf/qcom_l2_pmu.c | 8 ++++++-- > drivers/perf/xgene_pmu.c | 6 ++++-- > 8 files changed, 29 insertions(+), 14 deletions(-) > > diff --git a/drivers/perf/arm-ccn.c b/drivers/perf/arm-ccn.c > index 728d13d8e98a..83abd909ba49 100644 > --- a/drivers/perf/arm-ccn.c > +++ b/drivers/perf/arm-ccn.c > @@ -1210,8 +1210,9 @@ static int arm_ccn_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) > return 0; > perf_pmu_migrate_context(&dt->pmu, cpu, target); > dt->cpu = target; > - if (ccn->irq) > - WARN_ON(irq_set_affinity(ccn->irq, cpumask_of(dt->cpu))); > + if (ccn->irq && irq_set_affinity(ccn->irq, cpumask_of(dt->cpu))) > + dev_err(ccn->dev, "Failed to set interrupt affinity\n"); > + > return 0; > } > > diff --git a/drivers/perf/arm_dmc620_pmu.c b/drivers/perf/arm_dmc620_pmu.c > index 280a6ae3e27c..b59d3d9eb779 100644 > --- a/drivers/perf/arm_dmc620_pmu.c > +++ b/drivers/perf/arm_dmc620_pmu.c > @@ -621,7 +621,8 @@ static int dmc620_pmu_cpu_teardown(unsigned int cpu, > perf_pmu_migrate_context(&dmc620_pmu->pmu, irq->cpu, target); > mutex_unlock(&dmc620_pmu_irqs_lock); > > - WARN_ON(irq_set_affinity(irq->irq_num, cpumask_of(target))); > + if (irq_set_affinity(irq->irq_num, cpumask_of(target))) > + dev_err(dmc620_pmu->pmu.dev, "Failed to set interrupt affinity\n"); > irq->cpu = target; > > return 0; > diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c > index 00d4c45a8017..05e1b3e274d7 100644 > --- a/drivers/perf/arm_smmuv3_pmu.c > +++ b/drivers/perf/arm_smmuv3_pmu.c > @@ -646,7 +646,8 @@ static int smmu_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) > > perf_pmu_migrate_context(&smmu_pmu->pmu, cpu, target); > smmu_pmu->on_cpu = target; > - WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(target))); > + if (irq_set_affinity(smmu_pmu->irq, cpumask_of(target))) > + dev_err(smmu_pmu->dev, "Failed to set interrupt affinity\n"); > > return 0; > } > @@ -892,7 +893,8 @@ static int smmu_pmu_probe(struct platform_device *pdev) > > /* Pick one CPU to be the preferred one to use */ > smmu_pmu->on_cpu = raw_smp_processor_id(); > - WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu))); > + if (irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu))) > + dev_err(dev, "Failed to set interrupt affinity\n"); > > err = cpuhp_state_add_instance_nocalls(cpuhp_state_num, > &smmu_pmu->node); > diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c > index 8e058e08fe81..c44192e2d9db 100644 > --- a/drivers/perf/fsl_imx8_ddr_perf.c > +++ b/drivers/perf/fsl_imx8_ddr_perf.c > @@ -671,7 +671,8 @@ static int ddr_perf_offline_cpu(unsigned int cpu, struct hlist_node *node) > perf_pmu_migrate_context(&pmu->pmu, cpu, target); > pmu->cpu = target; > > - WARN_ON(irq_set_affinity(pmu->irq, cpumask_of(pmu->cpu))); > + if (irq_set_affinity(pmu->irq, cpumask_of(pmu->cpu))) > + dev_err(pmu->dev, "Failed to set interrupt affinity\n"); > > return 0; > } > diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c > index 21771708597d..90aed9e51396 100644 > --- a/drivers/perf/hisilicon/hisi_pcie_pmu.c > +++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c > @@ -655,7 +655,8 @@ static int hisi_pcie_pmu_online_cpu(unsigned int cpu, struct hlist_node *node) > > if (pcie_pmu->on_cpu == -1) { > pcie_pmu->on_cpu = cpu; > - WARN_ON(irq_set_affinity(pcie_pmu->irq, cpumask_of(cpu))); > + if (irq_set_affinity(pcie_pmu->irq, cpumask_of(cpu))) > + pci_err(pcie_pmu->pdev, "Failed to set interrupt affinity\n"); > } > > return 0; > @@ -681,7 +682,8 @@ static int hisi_pcie_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) > perf_pmu_migrate_context(&pcie_pmu->pmu, cpu, target); > /* Use this CPU for event counting */ > pcie_pmu->on_cpu = target; > - WARN_ON(irq_set_affinity(pcie_pmu->irq, cpumask_of(target))); > + if (irq_set_affinity(pcie_pmu->irq, cpumask_of(target))) > + pci_err(pcie_pmu->pdev, "Failed to set interrupt affinity\n"); > > return 0; > } > diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c > index fbc8a93d5eac..74397b5ec889 100644 > --- a/drivers/perf/hisilicon/hisi_uncore_pmu.c > +++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c > @@ -492,7 +492,8 @@ int hisi_uncore_pmu_online_cpu(unsigned int cpu, struct hlist_node *node) > hisi_pmu->on_cpu = cpu; > > /* Overflow interrupt also should use the same CPU */ > - WARN_ON(irq_set_affinity(hisi_pmu->irq, cpumask_of(cpu))); > + if (irq_set_affinity(hisi_pmu->irq, cpumask_of(cpu))) > + dev_err(hisi_pmu->dev, "Failed to set interrupt affinity\n"); > > return 0; > } > @@ -525,7 +526,8 @@ int hisi_uncore_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) > perf_pmu_migrate_context(&hisi_pmu->pmu, cpu, target); > /* Use this CPU for event counting */ > hisi_pmu->on_cpu = target; > - WARN_ON(irq_set_affinity(hisi_pmu->irq, cpumask_of(target))); > + if (irq_set_affinity(hisi_pmu->irq, cpumask_of(target))) > + dev_err(hisi_pmu->dev, "Failed to set interrupt affinity\n"); > > return 0; > } > diff --git a/drivers/perf/qcom_l2_pmu.c b/drivers/perf/qcom_l2_pmu.c > index 30234c261b05..c6fe01c7e637 100644 > --- a/drivers/perf/qcom_l2_pmu.c > +++ b/drivers/perf/qcom_l2_pmu.c > @@ -793,7 +793,9 @@ static int l2cache_pmu_online_cpu(unsigned int cpu, struct hlist_node *node) > cpumask_set_cpu(cpu, &l2cache_pmu->cpumask); > cluster_pmu_reset(); > > - WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(cpu))); > + if (irq_set_affinity(cluster->irq, cpumask_of(cpu))) > + dev_err(&l2cache_pmu->pdev->dev, > + "Failed to set interrupt affinity\n"); > enable_irq(cluster->irq); > > return 0; > @@ -831,7 +833,9 @@ static int l2cache_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) > perf_pmu_migrate_context(&l2cache_pmu->pmu, cpu, target); > cluster->on_cpu = target; > cpumask_set_cpu(target, &l2cache_pmu->cpumask); > - WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(target))); > + if (irq_set_affinity(cluster->irq, cpumask_of(target))) > + dev_err(&l2cache_pmu->pdev->dev, > + "Failed to set interrupt affinity\n"); > > return 0; > } > diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c > index 0c32dffc7ede..f31e678fdb69 100644 > --- a/drivers/perf/xgene_pmu.c > +++ b/drivers/perf/xgene_pmu.c > @@ -1790,7 +1790,8 @@ static int xgene_pmu_online_cpu(unsigned int cpu, struct hlist_node *node) > cpumask_set_cpu(cpu, &xgene_pmu->cpu); > > /* Overflow interrupt also should use the same CPU */ > - WARN_ON(irq_set_affinity(xgene_pmu->irq, &xgene_pmu->cpu)); > + if (irq_set_affinity(xgene_pmu->irq, &xgene_pmu->cpu)) > + dev_err(xgene_pmu->dev, "Failed to set interrupt affinity\n"); > > return 0; > } > @@ -1823,7 +1824,8 @@ static int xgene_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node) > > cpumask_set_cpu(target, &xgene_pmu->cpu); > /* Overflow interrupt also should use the same CPU */ > - WARN_ON(irq_set_affinity(xgene_pmu->irq, &xgene_pmu->cpu)); > + if (irq_set_affinity(xgene_pmu->irq, &xgene_pmu->cpu)) > + dev_err(xgene_pmu->dev, "Failed to set interrupt affinity\n"); > > return 0; > } > -- > 2.24.0 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel