From: Hugh Dickins Date: Tue, 20 May 2008 12:59:47 +0000 (+0100) Subject: x86: strengthen 64-bit p?d_bad() X-Git-Tag: v2.6.26-rc4~103 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a8375bd81cf99cb81be37127eaf08316ecb87619;p=linux-2.6 x86: strengthen 64-bit p?d_bad() The x86_64 pgd_bad(), pud_bad(), pmd_bad() inlines have differed from their x86_32 counterparts in a couple of ways: they've been unnecessarily weak (e.g. letting 0 or 1 count as good), and were typed as unsigned long. Strengthen them and return int. The PAE pmd_bad was too weak before, allowing any junk in the upper half; but got strengthened by the patch correcting its ~PAGE_MASK to ~PTE_MASK. The PAE pud_bad already said ~PTE_MASK; and since it folds into pgd_bad, and we don't set the protection bits at that level, it'll do as is. Signed-off-by: Hugh Dickins Signed-off-by: Linus Torvalds --- diff --git a/include/asm-x86/pgtable_64.h b/include/asm-x86/pgtable_64.h index efe83dcbd4..1cc50d22d7 100644 --- a/include/asm-x86/pgtable_64.h +++ b/include/asm-x86/pgtable_64.h @@ -151,19 +151,19 @@ static inline void native_pgd_clear(pgd_t *pgd) #ifndef __ASSEMBLY__ -static inline unsigned long pgd_bad(pgd_t pgd) +static inline int pgd_bad(pgd_t pgd) { - return pgd_val(pgd) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER); + return (pgd_val(pgd) & ~(PTE_MASK | _PAGE_USER)) != _KERNPG_TABLE; } -static inline unsigned long pud_bad(pud_t pud) +static inline int pud_bad(pud_t pud) { - return pud_val(pud) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER); + return (pud_val(pud) & ~(PTE_MASK | _PAGE_USER)) != _KERNPG_TABLE; } -static inline unsigned long pmd_bad(pmd_t pmd) +static inline int pmd_bad(pmd_t pmd) { - return pmd_val(pmd) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER); + return (pmd_val(pmd) & ~(PTE_MASK | _PAGE_USER)) != _KERNPG_TABLE; } #define pte_none(x) (!pte_val((x)))