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_check_amr gpr1, gpr2 32 .endm 33 34 #endif 35 36 #else /* !__ASSEMBLY__ */ 37 38 extern bool disable_kuep; 39 extern bool disable_kuap; 40 41 #include <linux/pgtable.h> 42 43 #ifdef CONFIG_PPC_KUEP 44 void setup_kuep(bool disabled); 45 #else 46 static inline void setup_kuep(bool disabled) { } 47 #endif /* CONFIG_PPC_KUEP */ 48 49 #if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32) 50 void kuep_lock(void); 51 void kuep_unlock(void); 52 #else 53 static inline void kuep_lock(void) { } 54 static inline void kuep_unlock(void) { } 55 #endif 56 57 #ifdef CONFIG_PPC_KUAP 58 void setup_kuap(bool disabled); 59 #else 60 static inline void setup_kuap(bool disabled) { } 61 62 static inline bool 63 bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) 64 { 65 return false; 66 } 67 68 static inline void kuap_assert_locked(void) { } 69 static inline void kuap_save_and_lock(struct pt_regs *regs) { } 70 static inline void kuap_user_restore(struct pt_regs *regs) { } 71 static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { } 72 73 static inline unsigned long kuap_get_and_assert_locked(void) 74 { 75 return 0; 76 } 77 78 /* 79 * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush 80 * the L1D cache after user accesses. Only include the empty stubs for other 81 * platforms. 82 */ 83 #ifndef CONFIG_PPC_BOOK3S_64 84 static inline void allow_user_access(void __user *to, const void __user *from, 85 unsigned long size, unsigned long dir) { } 86 static inline void prevent_user_access(void __user *to, const void __user *from, 87 unsigned long size, unsigned long dir) { } 88 static inline unsigned long prevent_user_access_return(void) { return 0UL; } 89 static inline void restore_user_access(unsigned long flags) { } 90 #endif /* CONFIG_PPC_BOOK3S_64 */ 91 #endif /* CONFIG_PPC_KUAP */ 92 93 static __always_inline void setup_kup(void) 94 { 95 setup_kuep(disable_kuep); 96 setup_kuap(disable_kuap); 97 } 98 99 static inline void allow_read_from_user(const void __user *from, unsigned long size) 100 { 101 barrier_nospec(); 102 allow_user_access(NULL, from, size, KUAP_READ); 103 } 104 105 static inline void allow_write_to_user(void __user *to, unsigned long size) 106 { 107 allow_user_access(to, NULL, size, KUAP_WRITE); 108 } 109 110 static inline void allow_read_write_user(void __user *to, const void __user *from, 111 unsigned long size) 112 { 113 barrier_nospec(); 114 allow_user_access(to, from, size, KUAP_READ_WRITE); 115 } 116 117 static inline void prevent_read_from_user(const void __user *from, unsigned long size) 118 { 119 prevent_user_access(NULL, from, size, KUAP_READ); 120 } 121 122 static inline void prevent_write_to_user(void __user *to, unsigned long size) 123 { 124 prevent_user_access(to, NULL, size, KUAP_WRITE); 125 } 126 127 static inline void prevent_read_write_user(void __user *to, const void __user *from, 128 unsigned long size) 129 { 130 prevent_user_access(to, from, size, KUAP_READ_WRITE); 131 } 132 133 static inline void prevent_current_access_user(void) 134 { 135 prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT); 136 } 137 138 static inline void prevent_current_read_from_user(void) 139 { 140 prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_READ); 141 } 142 143 static inline void prevent_current_write_to_user(void) 144 { 145 prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE); 146 } 147 148 #endif /* !__ASSEMBLY__ */ 149 150 #endif /* _ASM_POWERPC_KUAP_H_ */ 151