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| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-05-20 07:26:17 (GMT) |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-05-20 14:51:20 (GMT) |
| commit | 2bd3a99c9d1851182f73d0a024dc5bdb0a470e8c (patch) | |
| tree | b6fae90c97de3abf7f68d47f98eee65f6b4bc174 /include | |
| parent | 8033c6e9736c29cce5f0d0abbca9a44dffb20c39 (diff) | |
| download | linux-2bd3a99c9d1851182f73d0a024dc5bdb0a470e8c.tar.xz | |
x86: define PTE_MASK in a universally useful way
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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-x86/page.h | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/include/asm-x86/page.h b/include/asm-x86/page.h index b381f4a..76b35e6 100644 --- a/include/asm-x86/page.h +++ b/include/asm-x86/page.h @@ -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> |