From: Masayoshi Mizuma <msys.mizuma@gmail.com>
To: Borislav Petkov <bp@alien8.de>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Baoquan He <bhe@redhat.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>,
Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH v5 0/4] Adjust the padding size for KASLR
Date: Fri, 15 Nov 2019 09:49:13 -0500 [thread overview]
Message-ID: <20191115144917.28469-1-msys.mizuma@gmail.com> (raw)
From: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
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 (4):
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: Adjust the padding size for the direct mapping.
Documentation/x86/zero-page.rst | 4 ++
arch/x86/boot/compressed/acpi.c | 42 ++++++++++++++++----
arch/x86/include/uapi/asm/bootparam.h | 2 +-
arch/x86/mm/kaslr.c | 57 ++++++++++++++++++++-------
4 files changed, 82 insertions(+), 23 deletions(-)
--
2.20.1
next reply other threads:[~2019-11-15 14:50 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-15 14:49 Masayoshi Mizuma [this message]
2019-11-15 14:49 ` [PATCH v5 1/4] x86/boot: Wrap up the SRAT traversing code into subtable_parse() Masayoshi Mizuma
2019-12-12 20:18 ` Borislav Petkov
2019-11-15 14:49 ` [PATCH v5 2/4] x86/boot: Add max_addr field in struct boot_params Masayoshi Mizuma
2019-11-15 14:49 ` [PATCH v5 3/4] x86/boot: Get the max address from SRAT Masayoshi Mizuma
2019-11-15 14:49 ` [PATCH v5 4/4] x86/mm/KASLR: Adjust the padding size for the direct mapping Masayoshi Mizuma
2019-11-17 0:42 ` Baoquan He
2019-12-12 20:19 ` Borislav Petkov
2019-12-13 13:28 ` Baoquan He
2019-12-13 14:15 ` Borislav Petkov
2019-12-13 14:54 ` Baoquan He
2019-12-13 16:38 ` Borislav Petkov
2019-12-13 23:29 ` Baoquan He
2019-12-14 7:13 ` Borislav Petkov
2019-12-14 10:07 ` Baoquan He
2019-12-14 3:33 ` Baoquan He
2019-12-14 7:15 ` Borislav Petkov
2019-12-12 20:17 ` [PATCH v5 0/4] Adjust the padding size for KASLR Borislav Petkov
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