Messages in this thread | | | Date | Tue, 29 Oct 2019 11:58:07 -0400 | From | Masayoshi Mizuma <> | Subject | Re: [PATCH v3 0/5] Adjust the padding size for KASLR |
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Hi Baoquan,
On Tue, Oct 29, 2019 at 10:59:20AM +0800, Baoquan He wrote: > 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?
Thank you for pinging me and so sorry for the delay. I'll post the v4 in this week.
Thanks, Masa
> > 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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