diff options
| -rw-r--r-- | mm/page_alloc.c | 52 |
1 files changed, 24 insertions, 28 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b90a74d..bd33025 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -231,9 +231,9 @@ static void bad_page(struct page *page) printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n" KERN_EMERG "Backtrace:\n"); dump_stack(); - set_page_count(page, 0); - reset_page_mapcount(page); - page->mapping = NULL; + + /* Leave bad fields for debug, except PageBuddy could make trouble */ + __ClearPageBuddy(page); add_taint(TAINT_BAD_PAGE); } @@ -290,25 +290,31 @@ void prep_compound_gigantic_page(struct page *page, unsigned long order) } #endif -static void destroy_compound_page(struct page *page, unsigned long order) +static int destroy_compound_page(struct page *page, unsigned long order) { int i; int nr_pages = 1 << order; + int bad = 0; - if (unlikely(compound_order(page) != order)) + if (unlikely(compound_order(page) != order) || + unlikely(!PageHead(page))) { bad_page(page); + bad++; + } - if (unlikely(!PageHead(page))) - bad_page(page); __ClearPageHead(page); + for (i = 1; i < nr_pages; i++) { struct page *p = page + i; - if (unlikely(!PageTail(p) | - (p->first_page != page))) + if (unlikely(!PageTail(p) | (p->first_page != page))) { bad_page(page); + bad++; + } __ClearPageTail(p); } + + return bad; } static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) @@ -428,7 +434,8 @@ static inline void __free_one_page(struct page *page, int migratetype = get_pageblock_migratetype(page); if (unlikely(PageCompound(page))) - destroy_compound_page(page, order); + if (unlikely(destroy_compound_page(page, order))) + return; page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); @@ -465,15 +472,10 @@ static inline int free_pages_check(struct page *page) if (unlikely(page_mapcount(page) | (page->mapping != NULL) | (page_count(page) != 0) | - (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) + (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) { bad_page(page); - /* - * For now, we report if PG_reserved was found set, but do not - * clear it, and do not free the page. But we shall soon need - * to do more, for when the ZERO_PAGE count wraps negative. - */ - if (PageReserved(page)) return 1; + } if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; return 0; @@ -521,11 +523,11 @@ static void __free_pages_ok(struct page *page, unsigned int order) { unsigned long flags; int i; - int reserved = 0; + int bad = 0; for (i = 0 ; i < (1 << order) ; ++i) - reserved += free_pages_check(page + i); - if (reserved) + bad += free_pages_check(page + i); + if (bad) return; if (!PageHighMem(page)) { @@ -610,17 +612,11 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) if (unlikely(page_mapcount(page) | (page->mapping != NULL) | (page_count(page) != 0) | - (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) + (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) { bad_page(page); - - /* - * For now, we report if PG_reserved was found set, but do not - * clear it, and do not allocate the page: as a safety net. - */ - if (PageReserved(page)) return 1; + } - page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; set_page_private(page, 0); set_page_refcounted(page); |
