kernel-fxtec-pro1x/Documentation/x86
Kirill A. Shutemov 4074ca7d8a x86/mm: Move LDT remap out of KASLR region on 5-level paging
commit d52888aa2753e3063a9d3a0c9f72f94aa9809c15 upstream

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-27 16:13:08 +01:00
..
i386
x86_64 x86/mm: Move LDT remap out of KASLR region on 5-level paging 2018-11-27 16:13:08 +01:00
00-INDEX
amd-memory-encryption.txt
boot.txt
earlyprintk.txt
entry_64.txt
exception-tables.txt
intel_mpx.txt
intel_rdt_ui.txt
kernel-stacks
microcode.txt
mtrr.txt
orc-unwinder.txt
pat.txt
protection-keys.txt
pti.txt
tlb.txt
topology.txt
usb-legacy-support.txt
zero-page.txt