diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/gup.c | 4 | ||||
| -rw-r--r-- | mm/internal.h | 20 | ||||
| -rw-r--r-- | mm/page_poison.c | 4 |
3 files changed, 27 insertions, 1 deletions
@@ -1535,6 +1535,10 @@ struct page *get_dump_page(unsigned long addr) FOLL_FORCE | FOLL_DUMP | FOLL_GET); if (locked) mmap_read_unlock(mm); + + if (ret == 1 && is_page_poisoned(page)) + return NULL; + return (ret == 1) ? page : NULL; } #endif /* CONFIG_ELF_CORE */ diff --git a/mm/internal.h b/mm/internal.h index 1432feec62df..cb3c5e0a7799 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -97,6 +97,26 @@ static inline void set_page_refcounted(struct page *page) set_page_count(page, 1); } +/* + * When kernel touch the user page, the user page may be have been marked + * poison but still mapped in user space, if without this page, the kernel + * can guarantee the data integrity and operation success, the kernel is + * better to check the posion status and avoid touching it, be good not to + * panic, coredump for process fatal signal is a sample case matching this + * scenario. Or if kernel can't guarantee the data integrity, it's better + * not to call this function, let kernel touch the poison page and get to + * panic. + */ +static inline bool is_page_poisoned(struct page *page) +{ + if (PageHWPoison(page)) + return true; + else if (PageHuge(page) && PageHWPoison(compound_head(page))) + return true; + + return false; +} + extern unsigned long highest_memmap_pfn; /* diff --git a/mm/page_poison.c b/mm/page_poison.c index 65cdf844c8ad..655dc5895604 100644 --- a/mm/page_poison.c +++ b/mm/page_poison.c @@ -77,12 +77,14 @@ static void unpoison_page(struct page *page) void *addr; addr = kmap_atomic(page); + kasan_disable_current(); /* * Page poisoning when enabled poisons each and every page * that is freed to buddy. Thus no extra check is done to * see if a page was poisoned. */ - check_poison_mem(addr, PAGE_SIZE); + check_poison_mem(kasan_reset_tag(addr), PAGE_SIZE); + kasan_enable_current(); kunmap_atomic(addr); } |