x86/mm: Fix the 56-bit addresses memory map in Documentation/x86/x86_64/mm.txt

This fixes a PT typo, and the following 56-bit address-space
addresses:

  * the hole extends from 0100000000000000 to feffffffffffffff
  * the KASAN shadow memory area stops at fffffbffffffffff (see kasan.h)
Signed-off-by: Stephen Kitt <steve@sk2.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: alex.popov@linux.com
Cc: bhe@redhat.com
Cc: corbet@lwn.net
Cc: kirill.shutemov@linux.intel.com
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20190415150853.10354-1-steve@sk2.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

Documentation/x86/x86_64/mm.txt

@@ -72,7 +72,7 @@ Complete virtual memory map with 5-level page tables
 Notes:
 
  - With 56-bit addresses, user-space memory gets expanded by a factor of 512x,
-   from 0.125 PB to 64 PB. All kernel mappings shift down to the -64 PT starting
+   from 0.125 PB to 64 PB. All kernel mappings shift down to the -64 PB starting
    offset and many of the regions expand to support the much larger physical
    memory supported.
 
@@ -83,7 +83,7 @@ Notes:
  0000000000000000 |    0       | 00ffffffffffffff |   64 PB | user-space virtual memory, different per mm
 __________________|____________|__________________|_________|___________________________________________________________
                   |            |                  |         |
- 0000800000000000 |  +64    PB | ffff7fffffffffff | ~16K PB | ... huge, still almost 64 bits wide hole of non-canonical
+ 0100000000000000 |  +64    PB | feffffffffffffff | ~16K PB | ... huge, still almost 64 bits wide hole of non-canonical
                   |            |                  |         |     virtual memory addresses up to the -64 PB
                   |            |                  |         |     starting offset of kernel mappings.
 __________________|____________|__________________|_________|___________________________________________________________
@@ -99,7 +99,7 @@ ____________________________________________________________|___________________
  ffd2000000000000 |  -11.5  PB | ffd3ffffffffffff |  0.5 PB | ... unused hole
  ffd4000000000000 |  -11    PB | ffd5ffffffffffff |  0.5 PB | virtual memory map (vmemmap_base)
  ffd6000000000000 |  -10.5  PB | ffdeffffffffffff | 2.25 PB | ... unused hole
- ffdf000000000000 |   -8.25 PB | fffffdffffffffff |   ~8 PB | KASAN shadow memory
+ ffdf000000000000 |   -8.25 PB | fffffbffffffffff |   ~8 PB | KASAN shadow memory
 __________________|____________|__________________|_________|____________________________________________________________
                                                             |
                                                             | Identical layout to the 47-bit one from here on: