[PATCH v6 0/3] Add a kernel parameter to change the padding size for KASLR

From: Masayoshi Mizuma
Date: Tue Oct 02 2018 - 21:40:02 EST


This patch series are adding an kernel parameter to change
the padding size used for KASLR. It is useful for memory hotplug
capable system. User can adjust the padding size to use it.

It is better if the padding size is calculated automatically,
however, ACPI SRAT is not available at the KASLR initialization
time. So, I add a message for user to tell the suitable padding
size. User can set it on next reboot.

This patch series don't change the current default padding size.

Change log from v5:
- Fix build error if CONFIG_RANDOMIZE_MEMORY is not defined.

Change log from v4:
- Fix the padding size check (2nd patch)
- Add explanation for the parameter in the document. (3rd patch)

Change log from v3:
- Add a warning message if the padding size for KASLR is not enough.
And it says the suitable padding size to user.

Change log from v2:
- Simplify the description. As Baoquan said, this is similar SGI UV issue,
but a little different. Remove SGI UV description.

Masayoshi Mizuma (3):
x86/mm: Add a kernel parameter to change the padding used for the
physical memory mapping
ACPI/NUMA: Add warning message if the padding size for KASLR is not
enough
Documentation/kernel-parameters.txt: Document
rand_mem_physical_padding=

.../admin-guide/kernel-parameters.txt | 19 ++++++++++++++++
arch/x86/include/asm/setup.h | 9 ++++++++
arch/x86/mm/kaslr.c | 22 ++++++++++++++++++-
drivers/acpi/numa.c | 16 ++++++++++++++
4 files changed, 65 insertions(+), 1 deletion(-)

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2.18.0