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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3764C433EF for ; Tue, 16 Nov 2021 01:00:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD62D61B44 for ; Tue, 16 Nov 2021 01:00:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346465AbhKPBDN (ORCPT ); Mon, 15 Nov 2021 20:03:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:44644 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245596AbhKOTUu (ORCPT ); Mon, 15 Nov 2021 14:20:50 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 22E8E6326D; Mon, 15 Nov 2021 18:37:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637001473; bh=/eAyvJcOIIskG6EktApnuPDSLl0zARuaaGExkp6GUy0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NYTfeuUxd8hqwIq024i19hBlaI8GQzsj/GgOppRkyQ+w++VavhIGNL6+3+fMGoDTI eUt4dFCZ1Wipp4tbEmFj0EZHzMFx/UXlKmB5wVQGBh/iLU4vWj7VyabS+m+qZk/Pqe HdSglafzh+I3bXdhf+/DIT3NpkVoDt86/eVkYorY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bransilav Rankov , Anshuman Khandual , Mathieu Poirier , Mike Leach , Leo Yan , Suzuki K Poulose Subject: [PATCH 5.15 162/917] coresight: trbe: Defer the probe on offline CPUs Date: Mon, 15 Nov 2021 17:54:17 +0100 Message-Id: <20211115165434.262028387@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165428.722074685@linuxfoundation.org> References: <20211115165428.722074685@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Suzuki K Poulose commit a08025b3fe56185290a1ea476581f03ca733f967 upstream. If a CPU is offline during the driver init, we could end up causing a kernel crash trying to register the coresight device for the TRBE instance. The trbe_cpudata for the TRBE instance is initialized only when it is probed. Otherwise, we could end up dereferencing a NULL cpudata->drvdata. e.g: [ 0.149999] coresight ete0: CPU0: ete v1.1 initialized [ 0.149999] coresight-etm4x ete_1: ETM arch init failed [ 0.149999] coresight-etm4x: probe of ete_1 failed with error -22 [ 0.150085] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050 [ 0.150085] Mem abort info: [ 0.150085] ESR = 0x96000005 [ 0.150085] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.150085] SET = 0, FnV = 0 [ 0.150085] EA = 0, S1PTW = 0 [ 0.150085] Data abort info: [ 0.150085] ISV = 0, ISS = 0x00000005 [ 0.150085] CM = 0, WnR = 0 [ 0.150085] [0000000000000050] user address but active_mm is swapper [ 0.150085] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 0.150085] Modules linked in: [ 0.150085] Hardware name: FVP Base RevC (DT) [ 0.150085] pstate: 00800009 (nzcv daif -PAN +UAO -TCO BTYPE=--) [ 0.150155] pc : arm_trbe_register_coresight_cpu+0x74/0x144 [ 0.150155] lr : arm_trbe_register_coresight_cpu+0x48/0x144 ... [ 0.150237] Call trace: [ 0.150237] arm_trbe_register_coresight_cpu+0x74/0x144 [ 0.150237] arm_trbe_device_probe+0x1c0/0x2d8 [ 0.150259] platform_drv_probe+0x94/0xbc [ 0.150259] really_probe+0x1bc/0x4a8 [ 0.150266] driver_probe_device+0x7c/0xb8 [ 0.150266] device_driver_attach+0x6c/0xac [ 0.150266] __driver_attach+0xc4/0x148 [ 0.150266] bus_for_each_dev+0x7c/0xc8 [ 0.150266] driver_attach+0x24/0x30 [ 0.150266] bus_add_driver+0x100/0x1e0 [ 0.150266] driver_register+0x78/0x110 [ 0.150266] __platform_driver_register+0x44/0x50 [ 0.150266] arm_trbe_init+0x28/0x84 [ 0.150266] do_one_initcall+0x94/0x2bc [ 0.150266] do_initcall_level+0xa4/0x158 [ 0.150266] do_initcalls+0x54/0x94 [ 0.150319] do_basic_setup+0x24/0x30 [ 0.150319] kernel_init_freeable+0xe8/0x14c [ 0.150319] kernel_init+0x14/0x18c [ 0.150319] ret_from_fork+0x10/0x30 [ 0.150319] Code: f94012c8 b0004ce2 9134a442 52819801 (f9402917) [ 0.150319] ---[ end trace d23e0cfe5098535e ]--- [ 0.150346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Fix this by skipping the step, if we are unable to probe the CPU. Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver") Reported-by: Bransilav Rankov Cc: Anshuman Khandual Cc: Mathieu Poirier Cc: Mike Leach Cc: Leo Yan Cc: stable Tested-by: Branislav Rankov Signed-off-by: Suzuki K Poulose Reviewed-by: Anshuman Khandual Link: https://lore.kernel.org/r/20211014142238.2221248-1-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-trbe.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -869,6 +869,10 @@ static void arm_trbe_register_coresight_ if (WARN_ON(trbe_csdev)) return; + /* If the TRBE was not probed on the CPU, we shouldn't be here */ + if (WARN_ON(!cpudata->drvdata)) + return; + dev = &cpudata->drvdata->pdev->dev; desc.name = devm_kasprintf(dev, GFP_KERNEL, "trbe%d", cpu); if (!desc.name) @@ -950,7 +954,9 @@ static int arm_trbe_probe_coresight(stru return -ENOMEM; for_each_cpu(cpu, &drvdata->supported_cpus) { - smp_call_function_single(cpu, arm_trbe_probe_cpu, drvdata, 1); + /* If we fail to probe the CPU, let us defer it to hotplug callbacks */ + if (smp_call_function_single(cpu, arm_trbe_probe_cpu, drvdata, 1)) + continue; if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) arm_trbe_register_coresight_cpu(drvdata, cpu); if (cpumask_test_cpu(cpu, &drvdata->supported_cpus))