diff options
Diffstat (limited to 'include/linux/poison.h')
| -rw-r--r-- | include/linux/poison.h | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/include/linux/poison.h b/include/linux/poison.h index 7fc194aef8c2..34066ffd893d 100644 --- a/include/linux/poison.h +++ b/include/linux/poison.h @@ -2,13 +2,25 @@ #define _LINUX_POISON_H /********** include/linux/list.h **********/ + +/* + * Architectures might want to move the poison pointer offset + * into some well-recognized area such as 0xdead000000000000, + * that is also not mappable by user-space exploits: + */ +#ifdef CONFIG_ILLEGAL_POINTER_VALUE +# define POISON_POINTER_DELTA _AC(CONFIG_ILLEGAL_POINTER_VALUE, UL) +#else +# define POISON_POINTER_DELTA 0 +#endif + /* * These are non-NULL pointers that will result in page faults * under normal circumstances, used to verify that nobody uses * non-initialized list entries. */ -#define LIST_POISON1 ((void *) 0x00100100) -#define LIST_POISON2 ((void *) 0x00200200) +#define LIST_POISON1 ((void *) 0x00100100 + POISON_POINTER_DELTA) +#define LIST_POISON2 ((void *) 0x00200200 + POISON_POINTER_DELTA) /********** include/linux/timer.h **********/ /* @@ -36,6 +48,15 @@ #define POISON_FREE 0x6b /* for use-after-free poisoning */ #define POISON_END 0xa5 /* end-byte of poisoning */ +/********** mm/hugetlb.c **********/ +/* + * Private mappings of hugetlb pages use this poisoned value for + * page->mapping. The core VM should not be doing anything with this mapping + * but futex requires the existence of some page->mapping value even though it + * is unused if PAGE_MAPPING_ANON is set. + */ +#define HUGETLB_POISON ((void *)(0x00300300 + POISON_POINTER_DELTA + PAGE_MAPPING_ANON)) + /********** arch/$ARCH/mm/init.c **********/ #define POISON_FREE_INITMEM 0xcc |