Messages in this thread Patch in this message | | | Date | Mon, 19 May 2008 19:33:45 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [Bug 10732] REGRESSION: 2.6.26-rc2-git4: X server failed start onX61s laptop |
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On Mon, 19 May 2008, Linus Torvalds wrote: > > IOE, PTE_MASK should be a "pteval_t". And it should have absolutely > *nothing* to do with PAGE_MASK. EVER. > > IOW, maybe something like this?
.. and in addition to that, perhaps something like this too?
Making the actual _PAGE_XYZ bits be of the proper type makes using bitops and negation on them automatically DTRT, so that we don't need those insane casts in pte_mkclean() and friends.
Again, totally untested, but we really should just get the types right, instead of getting them wrogn and then messing around with various silly and incorrect work-arounds for the fact that we got them wrong.
And while it's untested - if this cleanup is buggy (or even generates different code), then we're doing something really wrong somewhere.
Linus
--- include/asm-x86/pgtable.h | 49 +++++++++++++++++++++++---------------------- 1 files changed, 25 insertions(+), 24 deletions(-)
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h index 55c3a0e..b38b540 100644 --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -21,27 +21,28 @@ #define _PAGE_BIT_NX 63 /* No execute: only valid after cpuid check */ /* - * Note: we use _AC(1, L) instead of _AC(1, UL) so that we get a - * sign-extended value on 32-bit with all 1's in the upper word, - * which preserves the upper pte values on 64-bit ptes: + * Note: we use _AT(pteval_t,1) so that we get the right type + * even when we're using PAE and everything is 64-bit with a + " 32-bit word-size. That's important for various bit masks. */ -#define _PAGE_PRESENT (_AC(1, L)<<_PAGE_BIT_PRESENT) -#define _PAGE_RW (_AC(1, L)<<_PAGE_BIT_RW) -#define _PAGE_USER (_AC(1, L)<<_PAGE_BIT_USER) -#define _PAGE_PWT (_AC(1, L)<<_PAGE_BIT_PWT) -#define _PAGE_PCD (_AC(1, L)<<_PAGE_BIT_PCD) -#define _PAGE_ACCESSED (_AC(1, L)<<_PAGE_BIT_ACCESSED) -#define _PAGE_DIRTY (_AC(1, L)<<_PAGE_BIT_DIRTY) -#define _PAGE_PSE (_AC(1, L)<<_PAGE_BIT_PSE) /* 2MB page */ -#define _PAGE_GLOBAL (_AC(1, L)<<_PAGE_BIT_GLOBAL) /* Global TLB entry */ -#define _PAGE_UNUSED1 (_AC(1, L)<<_PAGE_BIT_UNUSED1) -#define _PAGE_UNUSED2 (_AC(1, L)<<_PAGE_BIT_UNUSED2) -#define _PAGE_UNUSED3 (_AC(1, L)<<_PAGE_BIT_UNUSED3) -#define _PAGE_PAT (_AC(1, L)<<_PAGE_BIT_PAT) -#define _PAGE_PAT_LARGE (_AC(1, L)<<_PAGE_BIT_PAT_LARGE) +#define _PAGE_BIT(x) (_AT(pteval_t,1) << (x)) +#define _PAGE_PRESENT _PAGE_BIT(_PAGE_BIT_PRESENT) +#define _PAGE_RW _PAGE_BIT(_PAGE_BIT_RW) +#define _PAGE_USER _PAGE_BIT(_PAGE_BIT_USER) +#define _PAGE_PWT _PAGE_BIT(_PAGE_BIT_PWT) +#define _PAGE_PCD _PAGE_BIT(_PAGE_BIT_PCD) +#define _PAGE_ACCESSED _PAGE_BIT(_PAGE_BIT_ACCESSED) +#define _PAGE_DIRTY _PAGE_BIT(_PAGE_BIT_DIRTY) +#define _PAGE_PSE _PAGE_BIT(_PAGE_BIT_PSE) /* 2MB page */ +#define _PAGE_GLOBAL _PAGE_BIT(_PAGE_BIT_GLOBAL) /* Global TLB entry */ +#define _PAGE_UNUSED1 _PAGE_BIT(_PAGE_BIT_UNUSED1) +#define _PAGE_UNUSED2 _PAGE_BIT(_PAGE_BIT_UNUSED2) +#define _PAGE_UNUSED3 _PAGE_BIT(_PAGE_BIT_UNUSED3) +#define _PAGE_PAT _PAGE_BIT(_PAGE_BIT_PAT) +#define _PAGE_PAT_LARGE _PAGE_BIT(_PAGE_BIT_PAT_LARGE) #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) -#define _PAGE_NX (_AC(1, ULL) << _PAGE_BIT_NX) +#define _PAGE_NX _PAGE_BIT(_PAGE_BIT_NX) #else #define _PAGE_NX 0 #endif @@ -209,22 +210,22 @@ static inline int pmd_large(pmd_t pte) static inline pte_t pte_mkclean(pte_t pte) { - return __pte(pte_val(pte) & ~(pteval_t)_PAGE_DIRTY); + return __pte(pte_val(pte) & ~_PAGE_DIRTY); } static inline pte_t pte_mkold(pte_t pte) { - return __pte(pte_val(pte) & ~(pteval_t)_PAGE_ACCESSED); + return __pte(pte_val(pte) & ~_PAGE_ACCESSED); } static inline pte_t pte_wrprotect(pte_t pte) { - return __pte(pte_val(pte) & ~(pteval_t)_PAGE_RW); + return __pte(pte_val(pte) & ~_PAGE_RW); } static inline pte_t pte_mkexec(pte_t pte) { - return __pte(pte_val(pte) & ~(pteval_t)_PAGE_NX); + return __pte(pte_val(pte) & ~_PAGE_NX); } static inline pte_t pte_mkdirty(pte_t pte) @@ -249,7 +250,7 @@ static inline pte_t pte_mkhuge(pte_t pte) static inline pte_t pte_clrhuge(pte_t pte) { - return __pte(pte_val(pte) & ~(pteval_t)_PAGE_PSE); + return __pte(pte_val(pte) & ~_PAGE_PSE); } static inline pte_t pte_mkglobal(pte_t pte) @@ -259,7 +260,7 @@ static inline pte_t pte_mkglobal(pte_t pte) static inline pte_t pte_clrglobal(pte_t pte) { - return __pte(pte_val(pte) & ~(pteval_t)_PAGE_GLOBAL); + return __pte(pte_val(pte) & ~_PAGE_GLOBAL); } static inline pte_t pte_mkspecial(pte_t pte)
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