• Zhimin Gu's avatar
    x86, hibernate: Fix nosave_regions setup for hibernation · cc55f753
    Zhimin Gu authored
    On 32bit systems, nosave_regions(non RAM areas) located between
    max_low_pfn and max_pfn are not excluded from hibernation snapshot
    currently, which may result in a machine check exception when
    trying to access these unsafe regions during hibernation:
    
    [  612.800453] Disabling lock debugging due to kernel taint
    [  612.805786] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 6: fe00000000801136
    [  612.814344] mce: [Hardware Error]: RIP !INEXACT! 60:<00000000d90be566> {swsusp_save+0x436/0x560}
    [  612.823167] mce: [Hardware Error]: TSC 1f5939fe276 ADDR dd000000 MISC 30e0000086
    [  612.830677] mce: [Hardware Error]: PROCESSOR 0:306c3 TIME 1529487426 SOCKET 0 APIC 0 microcode 24
    [  612.839581] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
    [  612.846394] mce: [Hardware Error]: Machine check: Processor context corrupt
    [  612.853380] Kernel panic - not syncing: Fatal machine check
    [  612.858978] Kernel Offset: 0x18000000 from 0xc1000000 (relocation range: 0xc0000000-0xf7ffdfff)
    
    This is because on 32bit systems, pages above max_low_pfn are regarded
    as high memeory, and accessing unsafe pages might cause expected MCE.
    On the problematic 32bit system, there are reserved memory above low
    memory, which triggered the MCE:
    
    e820 memory mapping:
    [    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009d7ff] usable
    [    0.000000] BIOS-e820: [mem 0x000000000009d800-0x000000000009ffff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
    [    0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000d160cfff] usable
    [    0.000000] BIOS-e820: [mem 0x00000000d160d000-0x00000000d1613fff] ACPI NVS
    [    0.000000] BIOS-e820: [mem 0x00000000d1614000-0x00000000d1a44fff] usable
    [    0.000000] BIOS-e820: [mem 0x00000000d1a45000-0x00000000d1ecffff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000d1ed0000-0x00000000d7eeafff] usable
    [    0.000000] BIOS-e820: [mem 0x00000000d7eeb000-0x00000000d7ffffff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000d8000000-0x00000000d875ffff] usable
    [    0.000000] BIOS-e820: [mem 0x00000000d8760000-0x00000000d87fffff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000d8800000-0x00000000d8fadfff] usable
    [    0.000000] BIOS-e820: [mem 0x00000000d8fae000-0x00000000d8ffffff] ACPI data
    [    0.000000] BIOS-e820: [mem 0x00000000d9000000-0x00000000da71bfff] usable
    [    0.000000] BIOS-e820: [mem 0x00000000da71c000-0x00000000da7fffff] ACPI NVS
    [    0.000000] BIOS-e820: [mem 0x00000000da800000-0x00000000dbb8bfff] usable
    [    0.000000] BIOS-e820: [mem 0x00000000dbb8c000-0x00000000dbffffff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000dd000000-0x00000000df1fffff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000f8000000-0x00000000fbffffff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed03fff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
    [    0.000000] BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
    [    0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000041edfffff] usable
    
    Fix this problem by changing pfn limit from max_low_pfn to max_pfn.
    This fix does not impact 64bit system because on 64bit max_low_pfn
    is the same as max_pfn.
    Signed-off-by: default avatarZhimin Gu <kookoo.gu@intel.com>
    Acked-by: default avatarPavel Machek <pavel@ucw.cz>
    Signed-off-by: default avatarChen Yu <yu.c.chen@intel.com>
    Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Cc: All applicable <stable@vger.kernel.org>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    cc55f753
setup.c 32.4 KB