releases/3.4.28/acpi-cpuidle-fix-null-pointer-issues-when-cpuidle-is-disabled.patch

   1 From b88a634a903d9670aa5f2f785aa890628ce0dece Mon Sep 17 00:00:00 2001
   2 From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
   3 Date: Wed, 16 Jan 2013 23:40:07 +0100
   4 Subject: ACPI / cpuidle: Fix NULL pointer issues when cpuidle is disabled
   5
   6 From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
   7
   8 commit b88a634a903d9670aa5f2f785aa890628ce0dece upstream.
   9
  10 If cpuidle is disabled, that means that:
  11
  12         per_cpu(acpi_cpuidle_device, pr->id)
  13
  14 is set to NULL as the acpi_processor_power_init ends up failing at
  15
  16          retval = cpuidle_register_driver(&acpi_idle_driver)
  17
  18 (in acpi_processor_power_init) and never sets the per_cpu idle
  19 device.  So when acpi_processor_hotplug on CPU online notification
  20 tries to reference said device it crashes:
  21
  22 cpu 3 spinlock event irq 62
  23 BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
  24 IP: [<ffffffff81381013>] acpi_processor_setup_cpuidle_cx+0x3f/0x105
  25 PGD a259b067 PUD ab38b067 PMD 0
  26 Oops: 0002 [#1] SMP
  27 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
  28 CPU 1
  29 Pid: 3047, comm: bash Not tainted 3.8.0-rc3upstream-00250-g165c029 #1 MSI MS-7680/H61M-P23 (MS-7680)
  30 RIP: e030:[<ffffffff81381013>]  [<ffffffff81381013>] acpi_processor_setup_cpuidle_cx+0x3f/0x105
  31 RSP: e02b:ffff88001742dca8  EFLAGS: 00010202
  32 RAX: 0000000000010be9 RBX: ffff8800a0a61800 RCX: ffff880105380000
  33 RDX: 0000000000000003 RSI: 0000000000000200 RDI: ffff8800a0a61800
  34 RBP: ffff88001742dce8 R08: ffffffff81812360 R09: 0000000000000200
  35 R10: aaaaaaaaaaaaaaaa R11: 0000000000000001 R12: ffff8800a0a61800
  36 R13: 00000000ffffff01 R14: 0000000000000000 R15: ffffffff81a907a0
  37 FS:  00007fd6942f7700(0000) GS:ffff880105280000(0000) knlGS:0000000000000000
  38 CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
  39 CR2: 0000000000000004 CR3: 00000000a6773000 CR4: 0000000000042660
  40 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  41 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  42 Process bash (pid: 3047, threadinfo ffff88001742c000, task ffff880017944000)
  43 Stack:
  44  0000000000000150 ffff880100f59e00 ffff88001742dcd8 ffff8800a0a61800
  45  0000000000000000 00000000ffffff01 0000000000000000 ffffffff81a907a0
  46  ffff88001742dd18 ffffffff813815b1 ffff88001742dd08 ffffffff810ae336
  47 Call Trace:
  48  [<ffffffff813815b1>] acpi_processor_hotplug+0x7c/0x9f
  49  [<ffffffff810ae336>] ? schedule_delayed_work_on+0x16/0x20
  50  [<ffffffff8137ee8f>] acpi_cpu_soft_notify+0x90/0xca
  51  [<ffffffff8166023d>] notifier_call_chain+0x4d/0x70
  52  [<ffffffff810bc369>] __raw_notifier_call_chain+0x9/0x10
  53  [<ffffffff81094a4b>] __cpu_notify+0x1b/0x30
  54  [<ffffffff81652cf7>] _cpu_up+0x103/0x14b
  55  [<ffffffff81652e18>] cpu_up+0xd9/0xec
  56  [<ffffffff8164a254>] store_online+0x94/0xd0
  57  [<ffffffff814122fb>] dev_attr_store+0x1b/0x20
  58  [<ffffffff81216404>] sysfs_write_file+0xf4/0x170
  59
  60 This patch fixes it.
  61
  62 Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
  63 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  64 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  65
  66 ---
  67  drivers/acpi/processor_idle.c |    3 +++
  68  1 file changed, 3 insertions(+)
  69
  70 --- a/drivers/acpi/processor_idle.c
  71 +++ b/drivers/acpi/processor_idle.c
  72 @@ -1018,6 +1018,9 @@ static int acpi_processor_setup_cpuidle_
  73                 return -EINVAL;
  74         }
  75
  76 +       if (!dev)
  77 +               return -EINVAL;
  78 +
  79         dev->cpu = pr->id;
  80
  81         if (max_cstate == 0)