diff options
| -rw-r--r-- | arch/x86/mm/pageattr.c | 19 | ||||
| -rw-r--r-- | include/linux/mm.h | 6 | ||||
| -rw-r--r-- | kernel/power/snapshot.c | 42 |
3 files changed, 53 insertions, 14 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index e2a74ea11a53..464d8fc21ce6 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -899,7 +899,24 @@ void kernel_map_pages(struct page *page, int numpages, int enable) */ cpa_fill_pool(); } -#endif + +#ifdef CONFIG_HIBERNATION + +bool kernel_page_present(struct page *page) +{ + unsigned int level; + pte_t *pte; + + if (PageHighMem(page)) + return false; + + pte = lookup_address((unsigned long)page_address(page), &level); + return (pte_val(*pte) & _PAGE_PRESENT); +} + +#endif /* CONFIG_HIBERNATION */ + +#endif /* CONFIG_DEBUG_PAGEALLOC */ /* * The testcases use internal knowledge of the implementation that shouldn't diff --git a/include/linux/mm.h b/include/linux/mm.h index 26c7124b841a..3b3e1341163f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1171,12 +1171,18 @@ static inline void enable_debug_pagealloc(void) { debug_pagealloc_enabled = 1; } +#ifdef CONFIG_HIBERNATION +extern bool kernel_page_present(struct page *page); +#endif /* CONFIG_HIBERNATION */ #else static inline void kernel_map_pages(struct page *page, int numpages, int enable) {} static inline void enable_debug_pagealloc(void) { } +#ifdef CONFIG_HIBERNATION +static inline bool kernel_page_present(struct page *page) { return true; } +#endif /* CONFIG_HIBERNATION */ #endif extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk); diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 95250d7c8d91..72a020cabb4c 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -875,8 +875,8 @@ static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; } #endif /* CONFIG_HIGHMEM */ /** - * saveable - Determine whether a non-highmem page should be included in - * the suspend image. + * saveable_page - Determine whether a non-highmem page should be included + * in the suspend image. * * We should save the page if it isn't Nosave, and is not in the range * of pages statically defined as 'unsaveable', and it isn't a part of @@ -897,7 +897,8 @@ static struct page *saveable_page(unsigned long pfn) if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page)) return NULL; - if (PageReserved(page) && pfn_is_nosave(pfn)) + if (PageReserved(page) + && (!kernel_page_present(page) || pfn_is_nosave(pfn))) return NULL; return page; @@ -938,6 +939,25 @@ static inline void do_copy_page(long *dst, long *src) *dst++ = *src++; } + +/** + * safe_copy_page - check if the page we are going to copy is marked as + * present in the kernel page tables (this always is the case if + * CONFIG_DEBUG_PAGEALLOC is not set and in that case + * kernel_page_present() always returns 'true'). + */ +static void safe_copy_page(void *dst, struct page *s_page) +{ + if (kernel_page_present(s_page)) { + do_copy_page(dst, page_address(s_page)); + } else { + kernel_map_pages(s_page, 1, 1); + do_copy_page(dst, page_address(s_page)); + kernel_map_pages(s_page, 1, 0); + } +} + + #ifdef CONFIG_HIGHMEM static inline struct page * page_is_saveable(struct zone *zone, unsigned long pfn) @@ -946,8 +966,7 @@ page_is_saveable(struct zone *zone, unsigned long pfn) saveable_highmem_page(pfn) : saveable_page(pfn); } -static inline void -copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) +static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) { struct page *s_page, *d_page; void *src, *dst; @@ -961,29 +980,26 @@ copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) kunmap_atomic(src, KM_USER0); kunmap_atomic(dst, KM_USER1); } else { - src = page_address(s_page); if (PageHighMem(d_page)) { /* Page pointed to by src may contain some kernel * data modified by kmap_atomic() */ - do_copy_page(buffer, src); + safe_copy_page(buffer, s_page); dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0); memcpy(dst, buffer, PAGE_SIZE); kunmap_atomic(dst, KM_USER0); } else { - dst = page_address(d_page); - do_copy_page(dst, src); + safe_copy_page(page_address(d_page), s_page); } } } #else #define page_is_saveable(zone, pfn) saveable_page(pfn) -static inline void -copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) +static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn) { - do_copy_page(page_address(pfn_to_page(dst_pfn)), - page_address(pfn_to_page(src_pfn))); + safe_copy_page(page_address(pfn_to_page(dst_pfn)), + pfn_to_page(src_pfn)); } #endif /* CONFIG_HIGHMEM */ |