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| author | Cyrill Gorcunov <gorcunov@gmail.com> | 2013-09-11 14:22:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-11 15:58:06 -0700 |
| commit | fa0f281cf9de8e6877e6536f18a3fc77368df64d (patch) | |
| tree | f542d0f6b19d56f4bfddca7d971bac6c00fca63b /arch/x86 | |
| parent | 5a53748568f79641eaf40e41081a2f4987f005c2 (diff) | |
| download | linux-fa0f281cf9de8e6877e6536f18a3fc77368df64d.tar.bz2 | |
mm: make sure _PAGE_SWP_SOFT_DIRTY bit is not set on present pte
_PAGE_SOFT_DIRTY bit should never be set on present pte so add VM_BUG_ON
to catch any potential future abuse.
Also add a comment on _PAGE_SWP_SOFT_DIRTY definition explaining scope of
its usage.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 34 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 3 |
2 files changed, 22 insertions, 15 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 8d16befdec88..3d1999458709 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -315,21 +315,6 @@ static inline pmd_t pmd_mksoft_dirty(pmd_t pmd) return pmd_set_flags(pmd, _PAGE_SOFT_DIRTY); } -static inline pte_t pte_swp_mksoft_dirty(pte_t pte) -{ - return pte_set_flags(pte, _PAGE_SWP_SOFT_DIRTY); -} - -static inline int pte_swp_soft_dirty(pte_t pte) -{ - return pte_flags(pte) & _PAGE_SWP_SOFT_DIRTY; -} - -static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) -{ - return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY); -} - static inline pte_t pte_file_clear_soft_dirty(pte_t pte) { return pte_clear_flags(pte, _PAGE_SOFT_DIRTY); @@ -446,6 +431,7 @@ pte_t *populate_extra_pte(unsigned long vaddr); #ifndef __ASSEMBLY__ #include <linux/mm_types.h> +#include <linux/mmdebug.h> #include <linux/log2.h> static inline int pte_none(pte_t pte) @@ -864,6 +850,24 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, { } +static inline pte_t pte_swp_mksoft_dirty(pte_t pte) +{ + VM_BUG_ON(pte_present(pte)); + return pte_set_flags(pte, _PAGE_SWP_SOFT_DIRTY); +} + +static inline int pte_swp_soft_dirty(pte_t pte) +{ + VM_BUG_ON(pte_present(pte)); + return pte_flags(pte) & _PAGE_SWP_SOFT_DIRTY; +} + +static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) +{ + VM_BUG_ON(pte_present(pte)); + return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY); +} + #include <asm-generic/pgtable.h> #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index f4843e031131..0ecac257fb26 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -75,6 +75,9 @@ * with swap entry format. On x86 bits 6 and 7 are *not* involved * into swap entry computation, but bit 6 is used for nonlinear * file mapping, so we borrow bit 7 for soft dirty tracking. + * + * Please note that this bit must be treated as swap dirty page + * mark if and only if the PTE has present bit clear! */ #ifdef CONFIG_MEM_SOFT_DIRTY #define _PAGE_SWP_SOFT_DIRTY _PAGE_PSE |