On Tuesday, January 15, 2013 05:23:24 PM Konrad Rzeszutek Wilk wrote: > If cpuidle is disabled, that means the: > > per_cpu(acpi_cpuidle_device, pr->id) > > is set to NULL as the acpi_processor_power_init ends up failing at > > retval = cpuidle_register_driver(&acpi_idle_driver) > > (in acpi_processor_power_init) and never sets the per_cpu idle > device. So when acpi_processor_hotplug on CPU online notification tries > to reference said device it crashes: > > cpu 3 spinlock event irq 62 > BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 > IP: [<ffffffff81381013>] acpi_processor_setup_cpuidle_cx+0x3f/0x105 > PGD a259b067 PUD ab38b067 PMD 0 > Oops: 0002 [#1] SMP > odules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi libcrc32c crc32c nouveau mxm_wmi wmi radeon ttm sg sr_mod sd_mod cdrom ata_generic ata_piix libata crc32c_intel scsi_mod atl1c i915 fbcon tileblit font bitblit softcursor drm_kms_helper video xen_blkfront xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea xenfs xen_privcmd mperf > CPU 1 > Pid: 3047, comm: bash Not tainted 3.8.0-rc3upstream-00250-g165c029 #1 MSI MS-7680/H61M-P23 (MS-7680) > RIP: e030:[<ffffffff81381013>] [<ffffffff81381013>] acpi_processor_setup_cpuidle_cx+0x3f/0x105 > RSP: e02b:ffff88001742dca8 EFLAGS: 00010202 > RAX: 0000000000010be9 RBX: ffff8800a0a61800 RCX: ffff880105380000 > RDX: 0000000000000003 RSI: 0000000000000200 RDI: ffff8800a0a61800 > RBP: ffff88001742dce8 R08: ffffffff81812360 R09: 0000000000000200 > R10: aaaaaaaaaaaaaaaa R11: 0000000000000001 R12: ffff8800a0a61800 > R13: 00000000ffffff01 R14: 0000000000000000 R15: ffffffff81a907a0 > FS: 00007fd6942f7700(0000) GS:ffff880105280000(0000) knlGS:0000000000000000 > CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000004 CR3: 00000000a6773000 CR4: 0000000000042660 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process bash (pid: 3047, threadinfo ffff88001742c000, task ffff880017944000) > Stack: > 0000000000000150 ffff880100f59e00 ffff88001742dcd8 ffff8800a0a61800 > 0000000000000000 00000000ffffff01 0000000000000000 ffffffff81a907a0 > ffff88001742dd18 ffffffff813815b1 ffff88001742dd08 ffffffff810ae336 > Call Trace: > [<ffffffff813815b1>] acpi_processor_hotplug+0x7c/0x9f > [<ffffffff810ae336>] ? schedule_delayed_work_on+0x16/0x20 > [<ffffffff8137ee8f>] acpi_cpu_soft_notify+0x90/0xca > [<ffffffff8166023d>] notifier_call_chain+0x4d/0x70 > [<ffffffff810bc369>] __raw_notifier_call_chain+0x9/0x10 > [<ffffffff81094a4b>] __cpu_notify+0x1b/0x30 > [<ffffffff81652cf7>] _cpu_up+0x103/0x14b > [<ffffffff81652e18>] cpu_up+0xd9/0xec > [<ffffffff8164a254>] store_online+0x94/0xd0 > [<ffffffff814122fb>] dev_attr_store+0x1b/0x20 > [<ffffffff81216404>] sysfs_write_file+0xf4/0x170 > > This patch fixes it. This appears to be -stable material too. Which -stable kernels should it be applied to? Rafael > Cc: Rafael J. Wysocki <rjw@xxxxxxx> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> > --- > drivers/acpi/processor_idle.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c > index f1a5da4..fea6f8d 100644 > --- a/drivers/acpi/processor_idle.c > +++ b/drivers/acpi/processor_idle.c > @@ -958,6 +958,9 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr) > return -EINVAL; > } > > + if (!dev) > + return -EINVAL; > + > dev->cpu = pr->id; > > if (max_cstate == 0) > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
