1 #ifndef _LINUX_KAISER_H
2 #define _LINUX_KAISER_H
3
4 #ifdef CONFIG_PAGE_TABLE_ISOLATION
5 #include <asm/kaiser.h>
6
kaiser_map_thread_stack(void * stack)7 static inline int kaiser_map_thread_stack(void *stack)
8 {
9 /*
10 * Map that page of kernel stack on which we enter from user context.
11 */
12 return kaiser_add_mapping((unsigned long)stack +
13 THREAD_SIZE - PAGE_SIZE, PAGE_SIZE, __PAGE_KERNEL);
14 }
15
kaiser_unmap_thread_stack(void * stack)16 static inline void kaiser_unmap_thread_stack(void *stack)
17 {
18 /*
19 * Note: may be called even when kaiser_map_thread_stack() failed.
20 */
21 kaiser_remove_mapping((unsigned long)stack +
22 THREAD_SIZE - PAGE_SIZE, PAGE_SIZE);
23 }
24 #else
25
26 /*
27 * These stubs are used whenever CONFIG_PAGE_TABLE_ISOLATION is off, which
28 * includes architectures that support KAISER, but have it disabled.
29 */
30
kaiser_init(void)31 static inline void kaiser_init(void)
32 {
33 }
kaiser_add_mapping(unsigned long addr,unsigned long size,u64 flags)34 static inline int kaiser_add_mapping(unsigned long addr,
35 unsigned long size, u64 flags)
36 {
37 return 0;
38 }
kaiser_remove_mapping(unsigned long start,unsigned long size)39 static inline void kaiser_remove_mapping(unsigned long start,
40 unsigned long size)
41 {
42 }
kaiser_map_thread_stack(void * stack)43 static inline int kaiser_map_thread_stack(void *stack)
44 {
45 return 0;
46 }
kaiser_unmap_thread_stack(void * stack)47 static inline void kaiser_unmap_thread_stack(void *stack)
48 {
49 }
50
51 #endif /* !CONFIG_PAGE_TABLE_ISOLATION */
52 #endif /* _LINUX_KAISER_H */
53