arch/powerpc/include/asm/kup.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_POWERPC_KUP_H_
   3 #define _ASM_POWERPC_KUP_H_
   4
   5 #define KUAP_READ       1
   6 #define KUAP_WRITE      2
   7 #define KUAP_READ_WRITE (KUAP_READ | KUAP_WRITE)
   8
   9 #ifdef CONFIG_PPC_BOOK3S_64
  10 #include <asm/book3s/64/kup.h>
  11 #endif
  12
  13 #ifdef CONFIG_PPC_8xx
  14 #include <asm/nohash/32/kup-8xx.h>
  15 #endif
  16
  17 #ifdef CONFIG_PPC_BOOK3S_32
  18 #include <asm/book3s/32/kup.h>
  19 #endif
  20
  21 #ifdef __ASSEMBLY__
  22 #ifndef CONFIG_PPC_KUAP
  23 .macro kuap_check_amr   gpr1, gpr2
  24 .endm
  25
  26 #endif
  27
  28 #else /* !__ASSEMBLY__ */
  29
  30 extern bool disable_kuep;
  31 extern bool disable_kuap;
  32
  33 #include <linux/pgtable.h>
  34
  35 #ifdef CONFIG_PPC_KUEP
  36 void setup_kuep(bool disabled);
  37 #else
  38 static inline void setup_kuep(bool disabled) { }
  39 #endif /* CONFIG_PPC_KUEP */
  40
  41 #ifndef CONFIG_PPC_BOOK3S_32
  42 static inline void kuep_lock(void) { }
  43 static inline void kuep_unlock(void) { }
  44 #endif
  45
  46 #ifdef CONFIG_PPC_KUAP
  47 void setup_kuap(bool disabled);
  48 #else
  49 static inline void setup_kuap(bool disabled) { }
  50
  51 static inline bool
  52 bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
  53 {
  54         return false;
  55 }
  56
  57 static inline void kuap_assert_locked(void) { }
  58 static inline void kuap_save_and_lock(struct pt_regs *regs) { }
  59 static inline void kuap_user_restore(struct pt_regs *regs) { }
  60 static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
  61
  62 static inline unsigned long kuap_get_and_assert_locked(void)
  63 {
  64         return 0;
  65 }
  66
  67 /*
  68  * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
  69  * the L1D cache after user accesses. Only include the empty stubs for other
  70  * platforms.
  71  */
  72 #ifndef CONFIG_PPC_BOOK3S_64
  73 static inline void allow_user_access(void __user *to, const void __user *from,
  74                                      unsigned long size, unsigned long dir) { }
  75 static inline void prevent_user_access(unsigned long dir) { }
  76 static inline unsigned long prevent_user_access_return(void) { return 0UL; }
  77 static inline void restore_user_access(unsigned long flags) { }
  78 #endif /* CONFIG_PPC_BOOK3S_64 */
  79 #endif /* CONFIG_PPC_KUAP */
  80
  81 static __always_inline void setup_kup(void)
  82 {
  83         setup_kuep(disable_kuep);
  84         setup_kuap(disable_kuap);
  85 }
  86
  87 static __always_inline void allow_read_from_user(const void __user *from, unsigned long size)
  88 {
  89         barrier_nospec();
  90         allow_user_access(NULL, from, size, KUAP_READ);
  91 }
  92
  93 static __always_inline void allow_write_to_user(void __user *to, unsigned long size)
  94 {
  95         allow_user_access(to, NULL, size, KUAP_WRITE);
  96 }
  97
  98 static __always_inline void allow_read_write_user(void __user *to, const void __user *from,
  99                                                   unsigned long size)
 100 {
 101         barrier_nospec();
 102         allow_user_access(to, from, size, KUAP_READ_WRITE);
 103 }
 104
 105 static __always_inline void prevent_read_from_user(const void __user *from, unsigned long size)
 106 {
 107         prevent_user_access(KUAP_READ);
 108 }
 109
 110 static __always_inline void prevent_write_to_user(void __user *to, unsigned long size)
 111 {
 112         prevent_user_access(KUAP_WRITE);
 113 }
 114
 115 static __always_inline void prevent_read_write_user(void __user *to, const void __user *from,
 116                                                     unsigned long size)
 117 {
 118         prevent_user_access(KUAP_READ_WRITE);
 119 }
 120
 121 static __always_inline void prevent_current_access_user(void)
 122 {
 123         prevent_user_access(KUAP_READ_WRITE);
 124 }
 125
 126 static __always_inline void prevent_current_read_from_user(void)
 127 {
 128         prevent_user_access(KUAP_READ);
 129 }
 130
 131 static __always_inline void prevent_current_write_to_user(void)
 132 {
 133         prevent_user_access(KUAP_WRITE);
 134 }
 135
 136 #endif /* !__ASSEMBLY__ */
 137
 138 #endif /* _ASM_POWERPC_KUAP_H_ */