diff options
Diffstat (limited to 'mm/debug-pagealloc.c')
-rw-r--r-- | mm/debug-pagealloc.c | 137 |
1 files changed, 0 insertions, 137 deletions
diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c deleted file mode 100644 index 5bf5906ce..000000000 --- a/mm/debug-pagealloc.c +++ /dev/null @@ -1,137 +0,0 @@ -#include <linux/kernel.h> -#include <linux/string.h> -#include <linux/mm.h> -#include <linux/highmem.h> -#include <linux/page_ext.h> -#include <linux/poison.h> -#include <linux/ratelimit.h> - -static bool page_poisoning_enabled __read_mostly; - -static bool need_page_poisoning(void) -{ - if (!debug_pagealloc_enabled()) - return false; - - return true; -} - -static void init_page_poisoning(void) -{ - if (!debug_pagealloc_enabled()) - 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); -} - -static inline bool page_poison(struct page *page) -{ - struct page_ext *page_ext; - - page_ext = lookup_page_ext(page); - return test_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); -} - -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); -} - -static void poison_pages(struct page *page, int n) -{ - int i; - - for (i = 0; i < n; i++) - poison_page(page + i); -} - -static bool single_bit_flip(unsigned char a, unsigned char b) -{ - unsigned char error = a ^ b; - - return error && !(error & (error - 1)); -} - -static void check_poison_mem(unsigned char *mem, size_t bytes) -{ - static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 10); - unsigned char *start; - unsigned char *end; - - start = memchr_inv(mem, PAGE_POISON, bytes); - if (!start) - return; - - for (end = mem + bytes - 1; end > start; end--) { - if (*end != PAGE_POISON) - break; - } - - if (!__ratelimit(&ratelimit)) - return; - else if (start == end && single_bit_flip(*start, PAGE_POISON)) - printk(KERN_ERR "pagealloc: single bit error\n"); - else - printk(KERN_ERR "pagealloc: memory corruption\n"); - - print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, start, - end - start + 1, 1); - dump_stack(); -} - -static void unpoison_page(struct page *page) -{ - void *addr; - - if (!page_poison(page)) - return; - - addr = kmap_atomic(page); - check_poison_mem(addr, PAGE_SIZE); - clear_page_poison(page); - kunmap_atomic(addr); -} - -static void unpoison_pages(struct page *page, int n) -{ - int i; - - for (i = 0; i < n; i++) - unpoison_page(page + i); -} - -void __kernel_map_pages(struct page *page, int numpages, int enable) -{ - if (!page_poisoning_enabled) - return; - - if (enable) - unpoison_pages(page, numpages); - else - poison_pages(page, numpages); -} |