[tip:x86/mm] x86/mm: Allow userspace have mappings above 47-bit

From: tip-bot for Kirill A. Shutemov
Date: Fri Jul 21 2017 - 05:46:24 EST


Commit-ID: ee00f4a32a76ef631394f31d5b6028d50462b357
Gitweb: http://git.kernel.org/tip/ee00f4a32a76ef631394f31d5b6028d50462b357
Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
AuthorDate: Mon, 17 Jul 2017 01:59:53 +0300
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 21 Jul 2017 10:05:19 +0200

x86/mm: Allow userspace have mappings above 47-bit

All bits and pieces are now in place and we can allow userspace to have VMAs
above 47 bits.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/20170716225954.74185-8-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/processor.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 58fd40a3..ed26e14 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -850,9 +850,9 @@ static inline void spin_lock_prefetch(const void *x)
* particular problem by preventing anything from being mapped
* at the maximum canonical address.
*/
-#define TASK_SIZE_MAX ((1UL << 47) - PAGE_SIZE)
+#define TASK_SIZE_MAX ((1UL << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)

-#define DEFAULT_MAP_WINDOW TASK_SIZE_MAX
+#define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE)

/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.