On Fri, Nov 23, 2018 at 03:05:44PM +0300, Kirill A. Shutemov wrote:
On Mon, Nov 19, 2018 at 12:23:54PM +0000, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
From 2ae991254da9fd19f6c2fe2ceeb9bdfe37b744e2 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Date: Fri, 26 Oct 2018 15:28:54 +0300 Subject: [PATCH 1/2] 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: f55f0501cbf6 ("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...
Queued for 4.14, thank you.
-- Thanks, Sasha