Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756242AbdCWPkZ (ORCPT ); Thu, 23 Mar 2017 11:40:25 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57718 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S935420AbdCWPkX (ORCPT ); Thu, 23 Mar 2017 11:40:23 -0400 Date: Thu, 23 Mar 2017 21:10:01 +0530 From: Vaidyanathan Srinivasan To: "Rafael J. Wysocki" Cc: Michael Neuling , Michael Ellerman , "Rafael J . Wysocki" , Daniel Lezcano , linuxppc-dev , Linux Kernel Mailing List , Linux PM Subject: Re: [PATCH v2 2/2] cpuidle: Validate cpu_dev in cpuidle_add_sysfs Reply-To: svaidy@linux.vnet.ibm.com References: <20170323152247.14733-1-svaidy@linux.vnet.ibm.com> <20170323152247.14733-3-svaidy@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.0 (2017-02-23) X-TM-AS-MML: disable x-cbid: 17032315-7323-0000-0000-000000E067F4 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17032315-7324-0000-0000-000002856C6C Message-Id: <20170323154001.GA9058@drishya.in.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-1703230139 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2376 Lines: 51 * Rafael J. Wysocki [2017-03-23 16:27:31]: > On Thu, Mar 23, 2017 at 4:22 PM, Vaidyanathan Srinivasan > wrote: > > 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 > > The previous version is in linux-next already and I'm going to push it > for merging shortly. Thanks Rafael. The previous version is good for merge. --Vaidy