kernel_optimize_test/Documentation/x86
Kirill A. Shutemov d52888aa27 x86/mm: Move LDT remap out of KASLR region on 5-level paging
On 5-level paging the LDT remap area is placed in the middle of the KASLR
randomization region and it can overlap with the direct mapping, the
vmalloc or the vmap area.

The LDT mapping is per mm, so it cannot be moved into the P4D page table
next to the CPU_ENTRY_AREA without complicating PGD table allocation for
5-level paging.

The 4 PGD slot gap just before the direct mapping is reserved for
hypervisors, so it cannot be used.

Move the direct mapping one slot deeper and use the resulting gap for the
LDT remap area. The resulting layout is the same for 4 and 5 level paging.

[ tglx: Massaged changelog ]

Fixes: f55f0501cb ("x86/pti: Put the LDT in its own PGD if PTI is on")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: dave.hansen@linux.intel.com
Cc: peterz@infradead.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: bhe@redhat.com
Cc: willy@infradead.org
Cc: linux-mm@kvack.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181026122856.66224-2-kirill.shutemov@linux.intel.com
2018-11-06 21:35:11 +01:00
..
i386
x86_64 x86/mm: Move LDT remap out of KASLR region on 5-level paging 2018-11-06 21:35:11 +01:00
amd-memory-encryption.txt
boot.txt x86/boot: Add ACPI RSDP address to setup_header 2018-10-10 10:44:22 +02:00
earlyprintk.txt x86/doc: Fix Documentation/x86/earlyprintk.txt 2018-09-10 15:09:30 +02:00
entry_64.txt
exception-tables.txt
intel_mpx.txt
intel_rdt_ui.txt x86/intel_rdt: Use perf infrastructure for measurements 2018-09-28 22:48:27 +02:00
kernel-stacks
microcode.txt
mtrr.txt
orc-unwinder.txt
pat.txt mm: remove references to vm_insert_pfn() 2018-10-26 16:25:20 -07:00
protection-keys.txt
pti.txt
tlb.txt
topology.txt
usb-legacy-support.txt
zero-page.txt Documentation/x86: Fix typo in zero-page.txt 2018-11-05 07:05:45 +01:00