leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

x86: define PTE_MASK in a universally useful way

Browse Source 
Define PTE_MASK so that it contains a meaningful value for all x86
pagetable configurations.  Previously it was defined as a "long" which
means that it was too short to cover a 32-bit PAE pte entry.

It is now defined as a pteval_t, which is an integer type long enough
to contain a full pte (or pmd, pud, pgd).

This fixes an Xorg crash on 32-bit x86 with PAE due to corruption of the
NX bit in mprotect due to the incorrect type/value of PTE_MASK reported
by Hugh Dickins:

  "Yes, thanks Jeremy: I've checked that each stage builds and runs X on
   my boxes here, x86_32 and x86_32+PAE and x86_64.  (So even 1/8 is
   enough to fix the PAT pte_modify issue, though 2/8 then fixes
   compiler warnings.)"

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Tested-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jeremy Fitzhardinge 2008-05-20 08:26:17 +01:00 committed by Linus Torvalds
parent 8033c6e973
commit 2bd3a99c9d
1 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
include/asm-x86/page.h
View File

@ -10,8 +10,13 @@
#ifdef __KERNEL__
#define PHYSICAL_PAGE_MASK (PAGE_MASK & __PHYSICAL_MASK)
#define PTE_MASK (_AT(long, PHYSICAL_PAGE_MASK))
/* Cast PAGE_MASK to a signed type so that it is sign-extended if
virtual addresses are 32-bits but physical addresses are larger
(ie, 32-bit PAE). */
#define PHYSICAL_PAGE_MASK (((signed long)PAGE_MASK) & __PHYSICAL_MASK)
/* PTE_MASK extracts the PFN from a (pte|pmd|pud|pgd)val_t */
#define PTE_MASK ((pteval_t)PHYSICAL_PAGE_MASK)
#define PMD_PAGE_SIZE (_AC(1, UL) << PMD_SHIFT)
#define PMD_PAGE_MASK (~(PMD_PAGE_SIZE-1))
@ -24,8 +29,8 @@
/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)
#define __PHYSICAL_MASK _AT(phys_addr_t, (_AC(1,ULL) << __PHYSICAL_MASK_SHIFT) - 1)
#define __VIRTUAL_MASK ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - 1)
#define __PHYSICAL_MASK ((((phys_addr_t)1) << __PHYSICAL_MASK_SHIFT) - 1)
#define __VIRTUAL_MASK ((1UL << __VIRTUAL_MASK_SHIFT) - 1)
#ifndef __ASSEMBLY__
#include <linux/types.h>