From patchwork Fri Aug 18 08:40:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junhao He X-Patchwork-Id: 13357475 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 26792C05052 for ; Fri, 18 Aug 2023 08:45:04 +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:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=6EpAfoU1ZNQ2YciAbkmoSl7SHq52SaQe7BObtj32Ix4=; b=f82NBGceXBTnaf AljP0FwaWLGl6h+4ui/6N3bu8nLlkw3GQC6O1qT3bG0gTlxY+Qs3cDN/EDwjhpRgBjOuJ5oonNV6l 7ijOg0WjdhD2hoLyuye3jwzJ44VkLCVGuf/Z0GTVr4m+VQpUJiU8eBEkrSqh9Ed8Yj64GoiadCU/Y 5BP0hN/5bWSKCWENKl5aOCmCsTNmTdCdiW/gs3Fj9NqI1rIpJKk5DeDziL2RXV8VYFshtqSsnQ6fO kIonK0LZ1uWlhDPo4Pr+Q2YqwnJpKsPchr81pgTkNAVg91nRQ6eDHRINsNQbvUlaK5rqNVqnDq4QH rbXC3rNPV59f2oDO3Uew==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qWv5r-00817z-2r; Fri, 18 Aug 2023 08:44:32 +0000 Received: from szxga08-in.huawei.com ([45.249.212.255]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qWv5K-0080to-0A for linux-arm-kernel@lists.infradead.org; Fri, 18 Aug 2023 08:44:01 +0000 Received: from dggpeml500002.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4RRwNb25k4z1GF5y; Fri, 18 Aug 2023 16:42:23 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpeml500002.china.huawei.com (7.185.36.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Fri, 18 Aug 2023 16:43:45 +0800 From: Junhao He To: , , , CC: , , , , , , , Subject: [PATCH V3] coresight: trbe: Fix TRBE potential sleep in atomic context Date: Fri, 18 Aug 2023 16:40:52 +0800 Message-ID: <20230818084052.10116-1-hejunhao3@huawei.com> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500002.china.huawei.com (7.185.36.158) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230818_014358_594134_3C98405F X-CRM114-Status: GOOD ( 12.98 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org smp_call_function_single() will allocate an IPI interrupt vector to the target processor and send a function call request to the interrupt vector. After the target processor receives the IPI interrupt, it will execute arm_trbe_remove_coresight_cpu() call request in the interrupt handler. According to the device_unregister() stack information, if other process is useing the device, the down_write() may sleep, and trigger deadlocks or unexpected errors. arm_trbe_remove_coresight_cpu coresight_unregister device_unregister device_del kobject_del __kobject_del sysfs_remove_dir kernfs_remove down_write ---------> it may sleep Add a helper arm_trbe_disable_cpu() to disable TRBE precpu irq and reset per TRBE. Simply call arm_trbe_remove_coresight_cpu() directly without useing the smp_call_function_single(), which is the same as registering the TRBE coresight device. Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver") Signed-off-by: Junhao He Link: https://lore.kernel.org/r/20230814093813.19152-2-hejunhao3@huawei.com [ Remove duplicate cpumask checks during removal ] Signed-off-by: Suzuki K Poulose [ v3 - Remove the operation of assigning NULL to cpudata->drvdata ] --- drivers/hwtracing/coresight/coresight-trbe.c | 32 +++++++++++--------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 8e4eb37e66e8..e20c1c6acc73 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -1225,6 +1225,16 @@ static void arm_trbe_enable_cpu(void *info) enable_percpu_irq(drvdata->irq, IRQ_TYPE_NONE); } +static void arm_trbe_disable_cpu(void *info) +{ + struct trbe_drvdata *drvdata = info; + struct trbe_cpudata *cpudata = this_cpu_ptr(drvdata->cpudata); + + disable_percpu_irq(drvdata->irq); + trbe_reset_local(cpudata); +} + + static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cpu) { struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu); @@ -1329,18 +1339,12 @@ static void arm_trbe_probe_cpu(void *info) cpumask_clear_cpu(cpu, &drvdata->supported_cpus); } -static void arm_trbe_remove_coresight_cpu(void *info) +static void arm_trbe_remove_coresight_cpu(struct trbe_drvdata *drvdata, int cpu) { - int cpu = smp_processor_id(); - struct trbe_drvdata *drvdata = info; - struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu); struct coresight_device *trbe_csdev = coresight_get_percpu_sink(cpu); - disable_percpu_irq(drvdata->irq); - trbe_reset_local(cpudata); if (trbe_csdev) { coresight_unregister(trbe_csdev); - cpudata->drvdata = NULL; coresight_set_percpu_sink(cpu, NULL); } } @@ -1369,8 +1373,10 @@ static int arm_trbe_remove_coresight(struct trbe_drvdata *drvdata) { int cpu; - for_each_cpu(cpu, &drvdata->supported_cpus) - smp_call_function_single(cpu, arm_trbe_remove_coresight_cpu, drvdata, 1); + for_each_cpu(cpu, &drvdata->supported_cpus) { + smp_call_function_single(cpu, arm_trbe_disable_cpu, drvdata, 1); + arm_trbe_remove_coresight_cpu(drvdata, cpu); + } free_percpu(drvdata->cpudata); return 0; } @@ -1409,12 +1415,8 @@ static int arm_trbe_cpu_teardown(unsigned int cpu, struct hlist_node *node) { struct trbe_drvdata *drvdata = hlist_entry_safe(node, struct trbe_drvdata, hotplug_node); - if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) { - struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu); - - disable_percpu_irq(drvdata->irq); - trbe_reset_local(cpudata); - } + if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) + arm_trbe_disable_cpu(drvdata); return 0; }