diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 3ec44e27aa9d..e34a27727b9a 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -46,11 +46,6 @@ * guarantees that this bit is cleared for a page when it first is entered into * the page cache. * - * PG_highmem pages are not permanently mapped into the kernel virtual address - * space, they need to be kmapped separately for doing IO on the pages. The - * struct page (these bits with information) are always mapped into kernel - * address space... - * * PG_hwpoison indicates that a page got corrupted in hardware and contains * data with incorrect ECC bits that triggered a machine check. Accessing is * not safe since it may cause another machine check. Don't touch! @@ -161,9 +156,18 @@ static __always_inline int PageCompound(struct page *page) return test_bit(PG_head, &page->flags) || PageTail(page); } +#define PAGE_POISON_PATTERN -1l +static inline int PagePoisoned(const struct page *page) +{ + return page->flags == PAGE_POISON_PATTERN; +} + /* * Page flags policies wrt compound pages * + * PF_POISONED_CHECK + * check if this struct page poisoned/uninitialized + * * PF_ANY: * the page flag is relevant for small, head and tail pages. * @@ -181,17 +185,20 @@ static __always_inline int PageCompound(struct page *page) * PF_NO_COMPOUND: * the page flag is not relevant for compound pages. */ -#define PF_ANY(page, enforce) page -#define PF_HEAD(page, enforce) compound_head(page) +#define PF_POISONED_CHECK(page) ({ \ + VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ + page; }) +#define PF_ANY(page, enforce) PF_POISONED_CHECK(page) +#define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page)) #define PF_ONLY_HEAD(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(PageTail(page), page); \ - page;}) + PF_POISONED_CHECK(page); }) #define PF_NO_TAIL(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ - compound_head(page);}) + PF_POISONED_CHECK(compound_head(page)); }) #define PF_NO_COMPOUND(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ - page;}) + PF_POISONED_CHECK(page); }) /* * Macros to create function definitions for page flags |