1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* thread_info.h: common low-level thread information accessors 3 * 4 * Copyright (C) 2002 David Howells (dhowells@redhat.com) 5 * - Incorporating suggestions made by Linus Torvalds 6 */ 7 8 #ifndef _LINUX_THREAD_INFO_H 9 #define _LINUX_THREAD_INFO_H 10 11 #include <linux/types.h> 12 #include <linux/limits.h> 13 #include <linux/bug.h> 14 #include <linux/restart_block.h> 15 #include <linux/errno.h> 16 17 #ifdef CONFIG_THREAD_INFO_IN_TASK 18 /* 19 * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the 20 * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels, 21 * including <asm/current.h> can cause a circular dependency on some platforms. 22 */ 23 #include <asm/current.h> 24 #define current_thread_info() ((struct thread_info *)current) 25 #endif 26 27 #include <linux/bitops.h> 28 29 /* 30 * For per-arch arch_within_stack_frames() implementations, defined in 31 * asm/thread_info.h. 32 */ 33 enum { 34 BAD_STACK = -1, 35 NOT_STACK = 0, 36 GOOD_FRAME, 37 GOOD_STACK, 38 }; 39 40 #ifdef CONFIG_GENERIC_ENTRY 41 enum syscall_work_bit { 42 SYSCALL_WORK_BIT_SECCOMP, 43 SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT, 44 SYSCALL_WORK_BIT_SYSCALL_TRACE, 45 SYSCALL_WORK_BIT_SYSCALL_EMU, 46 SYSCALL_WORK_BIT_SYSCALL_AUDIT, 47 SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH, 48 SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP, 49 }; 50 51 #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP) 52 #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT) 53 #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE) 54 #define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU) 55 #define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT) 56 #define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH) 57 #define SYSCALL_WORK_SYSCALL_EXIT_TRAP BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP) 58 #endif 59 60 #include <asm/thread_info.h> 61 62 #ifdef __KERNEL__ 63 64 #ifndef arch_set_restart_data 65 #define arch_set_restart_data(restart) do { } while (0) 66 #endif 67 68 static inline long set_restart_fn(struct restart_block *restart, 69 long (*fn)(struct restart_block *)) 70 { 71 restart->fn = fn; 72 arch_set_restart_data(restart); 73 return -ERESTART_RESTARTBLOCK; 74 } 75 76 #ifndef THREAD_ALIGN 77 #define THREAD_ALIGN THREAD_SIZE 78 #endif 79 80 #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO) 81 82 /* 83 * flag set/clear/test wrappers 84 * - pass TIF_xxxx constants to these functions 85 */ 86 87 static inline void set_ti_thread_flag(struct thread_info *ti, int flag) 88 { 89 set_bit(flag, (unsigned long *)&ti->flags); 90 } 91 92 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag) 93 { 94 clear_bit(flag, (unsigned long *)&ti->flags); 95 } 96 97 static inline void update_ti_thread_flag(struct thread_info *ti, int flag, 98 bool value) 99 { 100 if (value) 101 set_ti_thread_flag(ti, flag); 102 else 103 clear_ti_thread_flag(ti, flag); 104 } 105 106 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag) 107 { 108 return test_and_set_bit(flag, (unsigned long *)&ti->flags); 109 } 110 111 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag) 112 { 113 return test_and_clear_bit(flag, (unsigned long *)&ti->flags); 114 } 115 116 static inline int test_ti_thread_flag(struct thread_info *ti, int flag) 117 { 118 return test_bit(flag, (unsigned long *)&ti->flags); 119 } 120 121 /* 122 * This may be used in noinstr code, and needs to be __always_inline to prevent 123 * inadvertent instrumentation. 124 */ 125 static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti) 126 { 127 return READ_ONCE(ti->flags); 128 } 129 130 #define set_thread_flag(flag) \ 131 set_ti_thread_flag(current_thread_info(), flag) 132 #define clear_thread_flag(flag) \ 133 clear_ti_thread_flag(current_thread_info(), flag) 134 #define update_thread_flag(flag, value) \ 135 update_ti_thread_flag(current_thread_info(), flag, value) 136 #define test_and_set_thread_flag(flag) \ 137 test_and_set_ti_thread_flag(current_thread_info(), flag) 138 #define test_and_clear_thread_flag(flag) \ 139 test_and_clear_ti_thread_flag(current_thread_info(), flag) 140 #define test_thread_flag(flag) \ 141 test_ti_thread_flag(current_thread_info(), flag) 142 #define read_thread_flags() \ 143 read_ti_thread_flags(current_thread_info()) 144 145 #define read_task_thread_flags(t) \ 146 read_ti_thread_flags(task_thread_info(t)) 147 148 #ifdef CONFIG_GENERIC_ENTRY 149 #define set_syscall_work(fl) \ 150 set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 151 #define test_syscall_work(fl) \ 152 test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 153 #define clear_syscall_work(fl) \ 154 clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 155 156 #define set_task_syscall_work(t, fl) \ 157 set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 158 #define test_task_syscall_work(t, fl) \ 159 test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 160 #define clear_task_syscall_work(t, fl) \ 161 clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 162 163 #else /* CONFIG_GENERIC_ENTRY */ 164 165 #define set_syscall_work(fl) \ 166 set_ti_thread_flag(current_thread_info(), TIF_##fl) 167 #define test_syscall_work(fl) \ 168 test_ti_thread_flag(current_thread_info(), TIF_##fl) 169 #define clear_syscall_work(fl) \ 170 clear_ti_thread_flag(current_thread_info(), TIF_##fl) 171 172 #define set_task_syscall_work(t, fl) \ 173 set_ti_thread_flag(task_thread_info(t), TIF_##fl) 174 #define test_task_syscall_work(t, fl) \ 175 test_ti_thread_flag(task_thread_info(t), TIF_##fl) 176 #define clear_task_syscall_work(t, fl) \ 177 clear_ti_thread_flag(task_thread_info(t), TIF_##fl) 178 #endif /* !CONFIG_GENERIC_ENTRY */ 179 180 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) 181 182 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES 183 static inline int arch_within_stack_frames(const void * const stack, 184 const void * const stackend, 185 const void *obj, unsigned long len) 186 { 187 return 0; 188 } 189 #endif 190 191 #ifdef CONFIG_HARDENED_USERCOPY 192 extern void __check_object_size(const void *ptr, unsigned long n, 193 bool to_user); 194 195 static __always_inline void check_object_size(const void *ptr, unsigned long n, 196 bool to_user) 197 { 198 if (!__builtin_constant_p(n)) 199 __check_object_size(ptr, n, to_user); 200 } 201 #else 202 static inline void check_object_size(const void *ptr, unsigned long n, 203 bool to_user) 204 { } 205 #endif /* CONFIG_HARDENED_USERCOPY */ 206 207 extern void __compiletime_error("copy source size is too small") 208 __bad_copy_from(void); 209 extern void __compiletime_error("copy destination size is too small") 210 __bad_copy_to(void); 211 212 static inline void copy_overflow(int size, unsigned long count) 213 { 214 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); 215 } 216 217 static __always_inline __must_check bool 218 check_copy_size(const void *addr, size_t bytes, bool is_source) 219 { 220 int sz = __builtin_object_size(addr, 0); 221 if (unlikely(sz >= 0 && sz < bytes)) { 222 if (!__builtin_constant_p(bytes)) 223 copy_overflow(sz, bytes); 224 else if (is_source) 225 __bad_copy_from(); 226 else 227 __bad_copy_to(); 228 return false; 229 } 230 if (WARN_ON_ONCE(bytes > INT_MAX)) 231 return false; 232 check_object_size(addr, bytes, is_source); 233 return true; 234 } 235 236 #ifndef arch_setup_new_exec 237 static inline void arch_setup_new_exec(void) { } 238 #endif 239 240 #endif /* __KERNEL__ */ 241 242 #endif /* _LINUX_THREAD_INFO_H */ 243