include/linux/kaiser.h

   1 #ifndef _LINUX_KAISER_H
   2 #define _LINUX_KAISER_H
   3
   4 #ifdef CONFIG_PAGE_TABLE_ISOLATION
   5 #include <asm/kaiser.h>
   6
   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
  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
  31 static inline void kaiser_init(void)
  32 {
  33 }
  34 static inline int kaiser_add_mapping(unsigned long addr,
  35                                      unsigned long size, u64 flags)
  36 {
  37         return 0;
  38 }
  39 static inline void kaiser_remove_mapping(unsigned long start,
  40                                          unsigned long size)
  41 {
  42 }
  43 static inline int kaiser_map_thread_stack(void *stack)
  44 {
  45         return 0;
  46 }
  47 static inline void kaiser_unmap_thread_stack(void *stack)
  48 {
  49 }
  50
  51 #endif /* !CONFIG_PAGE_TABLE_ISOLATION */
  52 #endif /* _LINUX_KAISER_H */