Messages in this thread | | | Date | Tue, 29 Oct 2019 10:59:20 +0800 | From | Baoquan He <> | Subject | Re: [PATCH v3 0/5] Adjust the padding size for KASLR |
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Hi Masa,
On 08/30/19 at 05:47pm, Masayoshi Mizuma wrote: > From: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Any plan about this patchset?
Thanks Baoquan
> > The system sometimes crashes while memory hot-adding on KASLR > enabled system. The crash happens because the regions pointed by > kaslr_regions[].base are overwritten by the hot-added memory. > > It happens because of the padding size for kaslr_regions[].base isn't > enough for the system whose physical memory layout has huge space for > memory hotplug. kaslr_regions[].base points "actual installed > memory size + padding" or higher address. So, if the "actual + padding" > is lower address than the maximum memory address, which means the memory > address reachable by memory hot-add, kaslr_regions[].base is destroyed by > the overwritten. > > address > ^ > |------- maximum memory address (Hotplug) > | ^ > |------- kaslr_regions[0].base | Hotadd-able region > | ^ | > | | padding | > | V V > |------- actual memory address (Installed on boot) > | > > Fix it by getting the maximum memory address from SRAT and store > the value in boot_param, then set the padding size while KASLR > initializing if the default padding size isn't enough. > > Masayoshi Mizuma (5): > x86/boot: Wrap up the SRAT traversing code into subtable_parse() > x86/boot: Add max_addr field in struct boot_params > x86/boot: Get the max address from SRAT > x86/mm/KASLR: Cleanup calculation for direct mapping size > x86/mm/KASLR: Adjust the padding size for the direct mapping. > > Documentation/x86/zero-page.rst | 4 ++ > arch/x86/boot/compressed/acpi.c | 33 +++++++++--- > arch/x86/include/uapi/asm/bootparam.h | 2 +- > arch/x86/mm/kaslr.c | 77 +++++++++++++++++++++------ > 4 files changed, 93 insertions(+), 23 deletions(-) > > -- > 2.18.1 >
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