diff options
Diffstat (limited to 'mm/debug-pagealloc.c')
| -rw-r--r-- | mm/debug-pagealloc.c | 59 |
1 files changed, 16 insertions, 43 deletions
diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index a1e3324de2b..789ff70c8a4 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -1,7 +1,10 @@ #include <linux/kernel.h> +#include <linux/string.h> #include <linux/mm.h> +#include <linux/highmem.h> #include <linux/page-debug-flags.h> #include <linux/poison.h> +#include <linux/ratelimit.h> static inline void set_page_poison(struct page *page) { @@ -18,28 +21,13 @@ static inline bool page_poison(struct page *page) return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags); } -static void poison_highpage(struct page *page) -{ - /* - * Page poisoning for highmem pages is not implemented. - * - * This can be called from interrupt contexts. - * So we need to create a new kmap_atomic slot for this - * application and it will need interrupt protection. - */ -} - static void poison_page(struct page *page) { - void *addr; + void *addr = kmap_atomic(page); - if (PageHighMem(page)) { - poison_highpage(page); - return; - } set_page_poison(page); - addr = page_address(page); memset(addr, PAGE_POISON, PAGE_SIZE); + kunmap_atomic(addr); } static void poison_pages(struct page *page, int n) @@ -59,14 +47,12 @@ static bool single_bit_flip(unsigned char a, unsigned char b) 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; - for (start = mem; start < mem + bytes; start++) { - if (*start != PAGE_POISON) - break; - } - if (start == mem + bytes) + start = memchr_inv(mem, PAGE_POISON, bytes); + if (!start) return; for (end = mem + bytes - 1; end > start; end--) { @@ -74,7 +60,7 @@ static void check_poison_mem(unsigned char *mem, size_t bytes) break; } - if (!printk_ratelimit()) + if (!__ratelimit(&ratelimit)) return; else if (start == end && single_bit_flip(*start, PAGE_POISON)) printk(KERN_ERR "pagealloc: single bit error\n"); @@ -86,27 +72,17 @@ static void check_poison_mem(unsigned char *mem, size_t bytes) dump_stack(); } -static void unpoison_highpage(struct page *page) -{ - /* - * See comment in poison_highpage(). - * Highmem pages should not be poisoned for now - */ - BUG_ON(page_poison(page)); -} - static void unpoison_page(struct page *page) { - if (PageHighMem(page)) { - unpoison_highpage(page); + void *addr; + + if (!page_poison(page)) return; - } - if (page_poison(page)) { - void *addr = page_address(page); - check_poison_mem(addr, PAGE_SIZE); - clear_page_poison(page); - } + 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) @@ -119,9 +95,6 @@ static void unpoison_pages(struct page *page, int n) void kernel_map_pages(struct page *page, int numpages, int enable) { - if (!debug_pagealloc_enabled) - return; - if (enable) unpoison_pages(page, numpages); else |