diff options
Diffstat (limited to 'mm/sparse-vmemmap.c')
| -rw-r--r-- | mm/sparse-vmemmap.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index db6df27c852a..e881f5db7091 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -245,6 +245,26 @@ static void vmemmap_remap_pte(pte_t *pte, unsigned long addr, set_pte_at(&init_mm, addr, pte, entry); } +/* + * How many struct page structs need to be reset. When we reuse the head + * struct page, the special metadata (e.g. page->flags or page->mapping) + * cannot copy to the tail struct page structs. The invalid value will be + * checked in the free_tail_pages_check(). In order to avoid the message + * of "corrupted mapping in tail page". We need to reset at least 3 (one + * head struct page struct and two tail struct page structs) struct page + * structs. + */ +#define NR_RESET_STRUCT_PAGE 3 + +static inline void reset_struct_pages(struct page *start) +{ + int i; + struct page *from = start + NR_RESET_STRUCT_PAGE; + + for (i = 0; i < NR_RESET_STRUCT_PAGE; i++) + memcpy(start + i, from, sizeof(*from)); +} + static void vmemmap_restore_pte(pte_t *pte, unsigned long addr, struct vmemmap_remap_walk *walk) { @@ -258,6 +278,7 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr, list_del(&page->lru); to = page_to_virt(page); copy_page(to, (void *)walk->reuse_addr); + reset_struct_pages(to); set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot)); } |