From patchwork Thu Mar 23 15:22:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vaidyanathan Srinivasan X-Patchwork-Id: 9641497 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 118836020B for ; Thu, 23 Mar 2017 15:24:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 03D56272F9 for ; Thu, 23 Mar 2017 15:24:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id ECB942766D; Thu, 23 Mar 2017 15:24:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A34E0272F9 for ; Thu, 23 Mar 2017 15:24:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935261AbdCWPYN (ORCPT ); Thu, 23 Mar 2017 11:24:13 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57586 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S935288AbdCWPYH (ORCPT ); Thu, 23 Mar 2017 11:24:07 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v2NFNo3V069129 for ; Thu, 23 Mar 2017 11:24:06 -0400 Received: from e23smtp09.au.ibm.com (e23smtp09.au.ibm.com [202.81.31.142]) by mx0b-001b2d01.pphosted.com with ESMTP id 29c0uhfg5g-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 23 Mar 2017 11:24:05 -0400 Received: from localhost by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 24 Mar 2017 01:24:02 +1000 Received: from d23relay09.au.ibm.com (202.81.31.228) by e23smtp09.au.ibm.com (202.81.31.206) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Fri, 24 Mar 2017 01:23:59 +1000 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v2NFNpxm26804336; Fri, 24 Mar 2017 02:23:59 +1100 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v2NFNOUB015176; Fri, 24 Mar 2017 02:23:24 +1100 Received: from drishya.in.ibm.com ([9.85.69.216]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id v2NFNHXi014978; Fri, 24 Mar 2017 02:23:22 +1100 From: Vaidyanathan Srinivasan To: Michael Neuling , Michael Ellerman , "Rafael J . Wysocki" , Daniel Lezcano Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: [PATCH v2 2/2] cpuidle: Validate cpu_dev in cpuidle_add_sysfs Date: Thu, 23 Mar 2017 20:52:47 +0530 X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170323152247.14733-1-svaidy@linux.vnet.ibm.com> References: <20170323152247.14733-1-svaidy@linux.vnet.ibm.com> X-TM-AS-MML: disable x-cbid: 17032315-0052-0000-0000-000002279E3A X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17032315-0053-0000-0000-0000080048B3 Message-Id: <20170323152247.14733-3-svaidy@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-03-23_13:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1702020001 definitions=main-1703230137 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If a given cpu is not in cpu_present and cpu hotplug is disabled, arch can skip setting up the cpu_dev. Arch cpuidle driver should pass correct cpu mask for registration, but failing to do so by the driver causes error to propagate and crash like this: [ 30.076045] Unable to handle kernel paging request for data at address 0x00000048 [ 30.076100] Faulting instruction address: 0xc0000000007b2f30 cpu 0x4d: Vector: 300 (Data Access) at [c000003feb18b670] pc: c0000000007b2f30: kobject_get+0x20/0x70 lr: c0000000007b3c94: kobject_add_internal+0x54/0x3f0 sp: c000003feb18b8f0 msr: 9000000000009033 dar: 48 dsisr: 40000000 current = 0xc000003fd2ed8300 paca = 0xc00000000fbab500 softe: 0 irq_happened: 0x01 pid = 1, comm = swapper/0 Linux version 4.11.0-rc2-svaidy+ (sv@sagarika) (gcc version 6.2.0 20161005 (Ubuntu 6.2.0-5ubuntu12) ) #10 SMP Sun Mar 19 00:08:09 IST 2017 enter ? for help [c000003feb18b960] c0000000007b3c94 kobject_add_internal+0x54/0x3f0 [c000003feb18b9f0] c0000000007b43a4 kobject_init_and_add+0x64/0xa0 [c000003feb18ba70] c000000000e284f4 cpuidle_add_sysfs+0xb4/0x130 [c000003feb18baf0] c000000000e26038 cpuidle_register_device+0x118/0x1c0 [c000003feb18bb30] c000000000e26c48 cpuidle_register+0x78/0x120 [c000003feb18bbc0] c00000000168fd9c powernv_processor_idle_init+0x110/0x1c4 [c000003feb18bc40] c00000000000cff8 do_one_initcall+0x68/0x1d0 [c000003feb18bd00] c0000000016242f4 kernel_init_freeable+0x280/0x360 [c000003feb18bdc0] c00000000000d864 kernel_init+0x24/0x160 [c000003feb18be30] c00000000000b4e8 ret_from_kernel_thread+0x5c/0x74 Validating cpu_dev fixes the crash and reports correct error message like: [ 30.163506] Failed to register cpuidle device for cpu136 [ 30.173329] Registration of powernv driver failed. Signed-off-by: Vaidyanathan Srinivasan --- drivers/cpuidle/sysfs.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c index c5adc8c..f2c3bce 100644 --- a/drivers/cpuidle/sysfs.c +++ b/drivers/cpuidle/sysfs.c @@ -615,6 +615,18 @@ int cpuidle_add_sysfs(struct cpuidle_device *dev) struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu); int error; + /* + * Return error if cpu_device is not setup for this cpu. This + * could happen if arch did not setup cpu_device since this + * cpu is not in cpu_present mask and the driver did not send + * correct cpu mask at registration. Without this check we + * would end up passing bogus value for &cpu_dev->kobj in + * kobject_init_and_add(). + */ + + if (!cpu_dev) + return -ENODEV; + kdev = kzalloc(sizeof(*kdev), GFP_KERNEL); if (!kdev) return -ENOMEM;