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  * For prevent_user_access() only.
  10  * Use the current saved situation instead of the to/from/size params.
  11  * Used on book3s/32
  12  */
  13 #define KUAP_CURRENT_READ       4
  14 #define KUAP_CURRENT_WRITE      8
  15 #define KUAP_CURRENT            (KUAP_CURRENT_READ | KUAP_CURRENT_WRITE)
  16
  17 #ifdef CONFIG_PPC_BOOK3S_64
  18 #include <asm/book3s/64/kup.h>
  19 #endif
  20
  21 #ifdef CONFIG_PPC_8xx
  22 #include <asm/nohash/32/kup-8xx.h>
  23 #endif
  24
  25 #ifdef CONFIG_PPC_BOOK3S_32
  26 #include <asm/book3s/32/kup.h>
  27 #endif
  28
  29 #ifdef __ASSEMBLY__
  30 #ifndef CONFIG_PPC_KUAP
  31 .macro kuap_save_and_lock       sp, thread, gpr1, gpr2, gpr3
  32 .endm
  33
  34 .macro kuap_restore     sp, current, gpr1, gpr2, gpr3
  35 .endm
  36
  37 .macro kuap_check       current, gpr
  38 .endm
  39
  40 .macro kuap_check_amr   gpr1, gpr2
  41 .endm
  42
  43 #endif
  44
  45 #else /* !__ASSEMBLY__ */
  46
  47 extern bool disable_kuep;
  48 extern bool disable_kuap;
  49
  50 #include <linux/pgtable.h>
  51
  52 #ifdef CONFIG_PPC_KUEP
  53 void setup_kuep(bool disabled);
  54 #else
  55 static inline void setup_kuep(bool disabled) { }
  56 #endif /* CONFIG_PPC_KUEP */
  57
  58 #ifdef CONFIG_PPC_KUAP
  59 void setup_kuap(bool disabled);
  60 #else
  61 static inline void setup_kuap(bool disabled) { }
  62
  63 static inline bool
  64 bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
  65 {
  66         return false;
  67 }
  68
  69 static inline void kuap_check_amr(void) { }
  70
  71 /*
  72  * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
  73  * the L1D cache after user accesses. Only include the empty stubs for other
  74  * platforms.
  75  */
  76 #ifndef CONFIG_PPC_BOOK3S_64
  77 static inline void allow_user_access(void __user *to, const void __user *from,
  78                                      unsigned long size, unsigned long dir) { }
  79 static inline void prevent_user_access(void __user *to, const void __user *from,
  80                                        unsigned long size, unsigned long dir) { }
  81 static inline unsigned long prevent_user_access_return(void) { return 0UL; }
  82 static inline void restore_user_access(unsigned long flags) { }
  83 #endif /* CONFIG_PPC_BOOK3S_64 */
  84 #endif /* CONFIG_PPC_KUAP */
  85
  86 static __always_inline void setup_kup(void)
  87 {
  88         setup_kuep(disable_kuep);
  89         setup_kuap(disable_kuap);
  90 }
  91
  92 static inline void allow_read_from_user(const void __user *from, unsigned long size)
  93 {
  94         allow_user_access(NULL, from, size, KUAP_READ);
  95 }
  96
  97 static inline void allow_write_to_user(void __user *to, unsigned long size)
  98 {
  99         allow_user_access(to, NULL, size, KUAP_WRITE);
 100 }
 101
 102 static inline void allow_read_write_user(void __user *to, const void __user *from,
 103                                          unsigned long size)
 104 {
 105         allow_user_access(to, from, size, KUAP_READ_WRITE);
 106 }
 107
 108 static inline void prevent_read_from_user(const void __user *from, unsigned long size)
 109 {
 110         prevent_user_access(NULL, from, size, KUAP_READ);
 111 }
 112
 113 static inline void prevent_write_to_user(void __user *to, unsigned long size)
 114 {
 115         prevent_user_access(to, NULL, size, KUAP_WRITE);
 116 }
 117
 118 static inline void prevent_read_write_user(void __user *to, const void __user *from,
 119                                            unsigned long size)
 120 {
 121         prevent_user_access(to, from, size, KUAP_READ_WRITE);
 122 }
 123
 124 static inline void prevent_current_access_user(void)
 125 {
 126         prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT);
 127 }
 128
 129 static inline void prevent_current_read_from_user(void)
 130 {
 131         prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_READ);
 132 }
 133
 134 static inline void prevent_current_write_to_user(void)
 135 {
 136         prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE);
 137 }
 138
 139 #endif /* !__ASSEMBLY__ */
 140
 141 #endif /* _ASM_POWERPC_KUAP_H_ */