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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_POWERPC_BOOK3S_32_KUP_H #define _ASM_POWERPC_BOOK3S_32_KUP_H #include <asm/bug.h> #include <asm/book3s/32/mmu-hash.h> #include <asm/mmu.h> #include <asm/synch.h> #ifndef __ASSEMBLY__ #include <linux/jump_label.h> extern struct static_key_false disable_kuap_key; static __always_inline bool kuep_is_disabled(void) { return !IS_ENABLED(CONFIG_PPC_KUEP); } #ifdef CONFIG_PPC_KUAP #include <linux/sched.h> #define KUAP_NONE (~0UL) #define KUAP_ALL (~1UL) static __always_inline bool kuap_is_disabled(void) { return static_branch_unlikely(&disable_kuap_key); } static inline void kuap_lock_one(unsigned long addr) { mtsr(mfsr(addr) | SR_KS, addr); isync(); /* Context sync required after mtsr() */ } static inline void kuap_unlock_one(unsigned long addr) { mtsr(mfsr(addr) & ~SR_KS, addr); isync(); /* Context sync required after mtsr() */ } static inline void kuap_lock_all(void) { update_user_segments(mfsr(0) | SR_KS); isync(); /* Context sync required after mtsr() */ } static inline void kuap_unlock_all(void) { update_user_segments(mfsr(0) & ~SR_KS); isync(); /* Context sync required after mtsr() */ } void kuap_lock_all_ool(void); void kuap_unlock_all_ool(void); static inline void kuap_lock_addr(unsigned long addr, bool ool) { if (likely(addr != KUAP_ALL)) kuap_lock_one(addr); else if (!ool) kuap_lock_all(); else kuap_lock_all_ool(); } static inline void kuap_unlock(unsigned long addr, bool ool) { if (likely(addr != KUAP_ALL)) kuap_unlock_one(addr); else if (!ool) kuap_unlock_all(); else kuap_unlock_all_ool(); } static inline void __kuap_lock(void) { } static inline void __kuap_save_and_lock(struct pt_regs *regs) { unsigned long kuap = current->thread.kuap; regs->kuap = kuap; if (unlikely(kuap == KUAP_NONE)) return; current->thread.kuap = KUAP_NONE; kuap_lock_addr(kuap, false); } static inline void kuap_user_restore(struct pt_regs *regs) { } static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap) { if (unlikely(kuap != KUAP_NONE)) { current->thread.kuap = KUAP_NONE; kuap_lock_addr(kuap, false); } if (likely(regs->kuap == KUAP_NONE)) return; current->thread.kuap = regs->kuap; kuap_unlock(regs->kuap, false); } static inline unsigned long __kuap_get_and_assert_locked(void) { unsigned long kuap = current->thread.kuap; WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != KUAP_NONE); return kuap; } static __always_inline void __allow_user_access(void __user *to, const void __user *from, u32 size, unsigned long dir) { BUILD_BUG_ON(!__builtin_constant_p(dir)); if (!(dir & KUAP_WRITE)) return; current->thread.kuap = (__force u32)to; kuap_unlock_one((__force u32)to); } static __always_inline void __prevent_user_access(unsigned long dir) { u32 kuap = current->thread.kuap; BUILD_BUG_ON(!__builtin_constant_p(dir)); if (!(dir & KUAP_WRITE)) return; current->thread.kuap = KUAP_NONE; kuap_lock_addr(kuap, true); } static inline unsigned long __prevent_user_access_return(void) { unsigned long flags = current->thread.kuap; if (flags != KUAP_NONE) { current->thread.kuap = KUAP_NONE; kuap_lock_addr(flags, true); } return flags; } static inline void __restore_user_access(unsigned long flags) { if (flags != KUAP_NONE) { current->thread.kuap = flags; kuap_unlock(flags, true); } } static inline bool __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) { unsigned long kuap = regs->kuap; if (!is_write || kuap == KUAP_ALL) return false; if (kuap == KUAP_NONE) return true; /* If faulting address doesn't match unlocked segment, unlock all */ if ((kuap ^ address) & 0xf0000000) regs->kuap = KUAP_ALL; return false; } #endif /* CONFIG_PPC_KUAP */ #endif /* __ASSEMBLY__ */ #endif /* _ASM_POWERPC_BOOK3S_32_KUP_H */ |