diff options
Diffstat (limited to 'mm/page_poison.c')
-rw-r--r-- | mm/page_poison.c | 77 |
1 files changed, 12 insertions, 65 deletions
diff --git a/mm/page_poison.c b/mm/page_poison.c index 2e647c65916b..be19e989ccff 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) @@ -19,74 +18,21 @@ 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); - if (unlikely(!page_ext)) - return; - - __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); - if (unlikely(!page_ext)) - return; - - __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 (unlikely(!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); kunmap_atomic(addr); } @@ -140,12 +86,13 @@ 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(addr, PAGE_SIZE); - clear_page_poison(page); kunmap_atomic(addr); } |