diff options
| -rw-r--r-- | include/linux/mm.h | 1 | ||||
| -rw-r--r-- | mm/page_alloc.c | 9 | ||||
| -rw-r--r-- | mm/page_ext.c | 3 | ||||
| -rw-r--r-- | mm/page_poison.c | 73 |
4 files changed, 15 insertions, 71 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index d9fe27c8a57e..3c10d4638646 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2306,7 +2306,6 @@ extern void copy_user_huge_page(struct page *dst, struct page *src, #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */ extern struct page_ext_operations debug_guardpage_ops; -extern struct page_ext_operations page_poisoning_ops; #ifdef CONFIG_DEBUG_PAGEALLOC extern unsigned int _debug_guardpage_minorder; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a4cfa64634b4..170c1486e5c9 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1397,24 +1397,21 @@ static inline int check_new_page(struct page *page) return 0; } -static inline bool free_pages_prezeroed(bool poisoned) +static inline bool free_pages_prezeroed(void) { return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) && - page_poisoning_enabled() && poisoned; + page_poisoning_enabled(); } static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, int alloc_flags) { int i; - bool poisoned = true; for (i = 0; i < (1 << order); i++) { struct page *p = page + i; if (unlikely(check_new_page(p))) return 1; - if (poisoned) - poisoned &= page_is_poisoned(p); } set_page_private(page, 0); @@ -1425,7 +1422,7 @@ static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, kernel_map_pages(page, 1 << order, 1); kernel_poison_pages(page, 1 << order, 1); - if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO)) + if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO)) for (i = 0; i < (1 << order); i++) clear_highpage(page + i); diff --git a/mm/page_ext.c b/mm/page_ext.c index 2d864e64f7fe..916accfec86a 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -54,9 +54,6 @@ static struct page_ext_operations *page_ext_ops[] = { &debug_guardpage_ops, -#ifdef CONFIG_PAGE_POISONING - &page_poisoning_ops, -#endif #ifdef CONFIG_PAGE_OWNER &page_owner_ops, #endif diff --git a/mm/page_poison.c b/mm/page_poison.c index 09192467efc9..eb3c4f1aade3 100644 --- a/mm/page_poison.c +++ b/mm/page_poison.c @@ -6,7 +6,6 @@ #include <linux/poison.h> #include <linux/ratelimit.h> -static bool __page_poisoning_enabled __read_mostly; static bool want_page_poisoning __read_mostly; static int early_page_poison_param(char *buf) @@ -25,70 +24,22 @@ early_param("page_poison", early_page_poison_param); bool page_poisoning_enabled(void) { - return __page_poisoning_enabled; -} - -static bool need_page_poisoning(void) -{ - return want_page_poisoning; -} - -static void init_page_poisoning(void) -{ /* - * page poisoning is debug page alloc for some arches. If either - * of those options are enabled, enable poisoning + * Assumes that debug_pagealloc_enabled is set before + * free_all_bootmem. + * Page poisoning is debug page alloc for some arches. If + * either of those options are enabled, enable poisoning. */ - if (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC)) { - if (!want_page_poisoning && !debug_pagealloc_enabled()) - return; - } else { - if (!want_page_poisoning) - return; - } - - __page_poisoning_enabled = true; -} - -struct page_ext_operations page_poisoning_ops = { - .need = need_page_poisoning, - .init = init_page_poisoning, -}; - -static inline void set_page_poison(struct page *page) -{ - struct page_ext *page_ext; - - page_ext = lookup_page_ext(page); - __set_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); -} - -static inline void clear_page_poison(struct page *page) -{ - struct page_ext *page_ext; - - page_ext = lookup_page_ext(page); - __clear_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); -} - -bool page_is_poisoned(struct page *page) -{ - struct page_ext *page_ext; - - page_ext = lookup_page_ext(page); - if (!page_ext) - return false; - - return test_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); + return (want_page_poisoning || + (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && + debug_pagealloc_enabled())); } static void poison_page(struct page *page) { void *addr = kmap_atomic(page); - set_page_poison(page); memset(addr, PAGE_POISON, PAGE_SIZE); - mark_addr_rdonly(addr); kunmap_atomic(addr); } @@ -145,13 +96,13 @@ static void unpoison_page(struct page *page) { void *addr; - if (!page_is_poisoned(page)) - return; - addr = kmap_atomic(page); + /* + * Page poisoning when enabled poisons each and every page + * that is freed to buddy. Thus no extra check is done to + * see if a page was posioned. + */ check_poison_mem(page, addr, PAGE_SIZE); - mark_addr_rdwrite(addr); - clear_page_poison(page); kunmap_atomic(addr); } |