diff options
| -rw-r--r-- | include/linux/highmem.h | 22 | ||||
| -rw-r--r-- | mm/page_alloc.c | 12 |
2 files changed, 32 insertions, 2 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 7fb31da45..41a50714f 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -7,6 +7,7 @@ #include <linux/mm.h> #include <linux/uaccess.h> #include <linux/hardirq.h> +#include <linux/string.h> #include <asm/cacheflush.h> @@ -189,6 +190,27 @@ static inline void clear_highpage(struct page *page) kunmap_atomic(kaddr); } +static inline void sanitize_highpage(struct page *page) +{ + void *kaddr; + unsigned long flags; + + local_irq_save(flags); + kaddr = kmap_atomic(page); + clear_page(kaddr); + kunmap_atomic(kaddr); + local_irq_restore(flags); +} + +static inline void sanitize_highpage_verify(struct page *page) +{ + void *kaddr; + + kaddr = kmap_atomic(page); + BUG_ON(memchr_inv(kaddr, 0, PAGE_SIZE)); + kunmap_atomic(kaddr); +} + static inline void zero_user_segments(struct page *page, unsigned start1, unsigned end1, unsigned start2, unsigned end2) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 884c13be9..1139bde1d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -872,6 +872,8 @@ static bool free_pages_prepare(struct page *page, unsigned int order) int i; int bad = 0; + unsigned long index = 1UL << order; + trace_mm_page_free(page, order); kmemcheck_free_shadow(page, order); kasan_free_pages(page, order); @@ -888,6 +890,10 @@ static bool free_pages_prepare(struct page *page, unsigned int order) debug_check_no_obj_freed(page_address(page), PAGE_SIZE << order); } + + for (; index; --index) + sanitize_highpage(page + index - 1); + arch_free_page(page, order); kernel_map_pages(page, 1 << order, 0); @@ -1096,6 +1102,8 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) { int i; + unsigned long index = 1UL << order; + for (i = 0; i < (1 << order); i++) { struct page *p = page + i; if (unlikely(check_new_page(p))) @@ -1109,8 +1117,8 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) kernel_map_pages(page, 1 << order, 1); kasan_alloc_pages(page, order); - if (gfp_flags & __GFP_ZERO) - prep_zero_page(page, order, gfp_flags); + for (; index; --index) + sanitize_highpage_verify(page + index - 1); if (order && (gfp_flags & __GFP_COMP)) prep_compound_page(page, order); |