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_PPC64
  18 #include <asm/book3s/64/kup-radix.h>
  19 #endif
  20 #ifdef CONFIG_PPC_8xx
  21 #include <asm/nohash/32/kup-8xx.h>
  22 #endif
  23 #ifdef CONFIG_PPC_BOOK3S_32
  24 #include <asm/book3s/32/kup.h>
  25 #endif
  26
  27 #ifdef __ASSEMBLY__
  28 #ifndef CONFIG_PPC_KUAP
  29 .macro kuap_save_and_lock       sp, thread, gpr1, gpr2, gpr3
  30 .endm
  31
  32 .macro kuap_restore     sp, current, gpr1, gpr2, gpr3
  33 .endm
  34
  35 .macro kuap_check       current, gpr
  36 .endm
  37
  38 #endif
  39
  40 #else /* !__ASSEMBLY__ */
  41
  42 #include <linux/pgtable.h>
  43
  44 void setup_kup(void);
  45
  46 #ifdef CONFIG_PPC_KUEP
  47 void setup_kuep(bool disabled);
  48 #else
  49 static inline void setup_kuep(bool disabled) { }
  50 #endif /* CONFIG_PPC_KUEP */
  51
  52 #ifdef CONFIG_PPC_KUAP
  53 void setup_kuap(bool disabled);
  54 #else
  55 static inline void setup_kuap(bool disabled) { }
  56
  57 static inline bool
  58 bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
  59 {
  60         return false;
  61 }
  62
  63 /*
  64  * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
  65  * the L1D cache after user accesses. Only include the empty stubs for other
  66  * platforms.
  67  */
  68 #ifndef CONFIG_PPC64
  69 static inline void allow_user_access(void __user *to, const void __user *from,
  70                                      unsigned long size, unsigned long dir) { }
  71 static inline void prevent_user_access(void __user *to, const void __user *from,
  72                                        unsigned long size, unsigned long dir) { }
  73 static inline unsigned long prevent_user_access_return(void) { return 0UL; }
  74 static inline void restore_user_access(unsigned long flags) { }
  75 #endif /* CONFIG_PPC64 */
  76 #endif /* CONFIG_PPC_KUAP */
  77
  78 static inline void allow_read_from_user(const void __user *from, unsigned long size)
  79 {
  80         allow_user_access(NULL, from, size, KUAP_READ);
  81 }
  82
  83 static inline void allow_write_to_user(void __user *to, unsigned long size)
  84 {
  85         allow_user_access(to, NULL, size, KUAP_WRITE);
  86 }
  87
  88 static inline void allow_read_write_user(void __user *to, const void __user *from,
  89                                          unsigned long size)
  90 {
  91         allow_user_access(to, from, size, KUAP_READ_WRITE);
  92 }
  93
  94 static inline void prevent_read_from_user(const void __user *from, unsigned long size)
  95 {
  96         prevent_user_access(NULL, from, size, KUAP_READ);
  97 }
  98
  99 static inline void prevent_write_to_user(void __user *to, unsigned long size)
 100 {
 101         prevent_user_access(to, NULL, size, KUAP_WRITE);
 102 }
 103
 104 static inline void prevent_read_write_user(void __user *to, const void __user *from,
 105                                            unsigned long size)
 106 {
 107         prevent_user_access(to, from, size, KUAP_READ_WRITE);
 108 }
 109
 110 static inline void prevent_current_access_user(void)
 111 {
 112         prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT);
 113 }
 114
 115 static inline void prevent_current_read_from_user(void)
 116 {
 117         prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_READ);
 118 }
 119
 120 static inline void prevent_current_write_to_user(void)
 121 {
 122         prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE);
 123 }
 124
 125 #endif /* !__ASSEMBLY__ */
 126
 127 #endif /* _ASM_POWERPC_KUAP_H_ */