From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35464 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751933AbdLUJzo (ORCPT ); Thu, 21 Dec 2017 04:55:44 -0500 Subject: Patch "cpuidle: Validate cpu_dev in cpuidle_add_sysfs()" has been added to the 3.18-stable tree To: svaidy@linux.vnet.ibm.com, alexander.levin@verizon.com, gregkh@linuxfoundation.org, rafael.j.wysocki@intel.com Cc: , From: Date: Thu, 21 Dec 2017 10:55:31 +0100 Message-ID: <1513850131119143@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled cpuidle: Validate cpu_dev in cpuidle_add_sysfs() to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cpuidle-validate-cpu_dev-in-cpuidle_add_sysfs.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Thu Dec 21 10:55:04 CET 2017 From: Vaidyanathan Srinivasan Date: Sun, 19 Mar 2017 00:51:59 +0530 Subject: cpuidle: Validate cpu_dev in cpuidle_add_sysfs() From: Vaidyanathan Srinivasan [ Upstream commit ad0a45fd9c14feebd000b6e84189d0edff265170 ] 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 [ rjw: Comment massage ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/cpuidle/sysfs.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/cpuidle/sysfs.c +++ b/drivers/cpuidle/sysfs.c @@ -613,6 +613,18 @@ int cpuidle_add_sysfs(struct cpuidle_dev struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu); int error; + /* + * Return if cpu_device is not setup for this CPU. + * + * This could happen if the arch did not set up cpu_device + * since this CPU is not in cpu_present mask and the + * driver did not send a correct CPU mask during 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; Patches currently in stable-queue which might be from svaidy@linux.vnet.ibm.com are queue-3.18/cpuidle-validate-cpu_dev-in-cpuidle_add_sysfs.patch queue-3.18/cpuidle-powernv-pass-correct-drv-cpumask-for-registration.patch