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 #ifndef TIF_NEED_RESCHED_LAZY 63 #ifdef CONFIG_ARCH_HAS_PREEMPT_LAZY 64 #error Inconsistent PREEMPT_LAZY 65 #endif 66 #define TIF_NEED_RESCHED_LAZY TIF_NEED_RESCHED 67 #define _TIF_NEED_RESCHED_LAZY _TIF_NEED_RESCHED 68 #endif 69 70 #ifdef __KERNEL__ 71 72 #ifndef arch_set_restart_data 73 #define arch_set_restart_data(restart) do { } while (0) 74 #endif 75 76 static inline long set_restart_fn(struct restart_block *restart, 77 long (*fn)(struct restart_block *)) 78 { 79 restart->fn = fn; 80 arch_set_restart_data(restart); 81 return -ERESTART_RESTARTBLOCK; 82 } 83 84 #ifndef THREAD_ALIGN 85 #define THREAD_ALIGN THREAD_SIZE 86 #endif 87 88 #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO) 89 90 /* 91 * flag set/clear/test wrappers 92 * - pass TIF_xxxx constants to these functions 93 */ 94 95 static inline void set_ti_thread_flag(struct thread_info *ti, int flag) 96 { 97 set_bit(flag, (unsigned long *)&ti->flags); 98 } 99 100 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag) 101 { 102 clear_bit(flag, (unsigned long *)&ti->flags); 103 } 104 105 static inline void update_ti_thread_flag(struct thread_info *ti, int flag, 106 bool value) 107 { 108 if (value) 109 set_ti_thread_flag(ti, flag); 110 else 111 clear_ti_thread_flag(ti, flag); 112 } 113 114 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag) 115 { 116 return test_and_set_bit(flag, (unsigned long *)&ti->flags); 117 } 118 119 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag) 120 { 121 return test_and_clear_bit(flag, (unsigned long *)&ti->flags); 122 } 123 124 static inline int test_ti_thread_flag(struct thread_info *ti, int flag) 125 { 126 return test_bit(flag, (unsigned long *)&ti->flags); 127 } 128 129 /* 130 * This may be used in noinstr code, and needs to be __always_inline to prevent 131 * inadvertent instrumentation. 132 */ 133 static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti) 134 { 135 return READ_ONCE(ti->flags); 136 } 137 138 #define set_thread_flag(flag) \ 139 set_ti_thread_flag(current_thread_info(), flag) 140 #define clear_thread_flag(flag) \ 141 clear_ti_thread_flag(current_thread_info(), flag) 142 #define update_thread_flag(flag, value) \ 143 update_ti_thread_flag(current_thread_info(), flag, value) 144 #define test_and_set_thread_flag(flag) \ 145 test_and_set_ti_thread_flag(current_thread_info(), flag) 146 #define test_and_clear_thread_flag(flag) \ 147 test_and_clear_ti_thread_flag(current_thread_info(), flag) 148 #define test_thread_flag(flag) \ 149 test_ti_thread_flag(current_thread_info(), flag) 150 #define read_thread_flags() \ 151 read_ti_thread_flags(current_thread_info()) 152 153 #define read_task_thread_flags(t) \ 154 read_ti_thread_flags(task_thread_info(t)) 155 156 #ifdef CONFIG_GENERIC_ENTRY 157 #define set_syscall_work(fl) \ 158 set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 159 #define test_syscall_work(fl) \ 160 test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 161 #define clear_syscall_work(fl) \ 162 clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 163 164 #define set_task_syscall_work(t, fl) \ 165 set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 166 #define test_task_syscall_work(t, fl) \ 167 test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 168 #define clear_task_syscall_work(t, fl) \ 169 clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 170 171 #else /* CONFIG_GENERIC_ENTRY */ 172 173 #define set_syscall_work(fl) \ 174 set_ti_thread_flag(current_thread_info(), TIF_##fl) 175 #define test_syscall_work(fl) \ 176 test_ti_thread_flag(current_thread_info(), TIF_##fl) 177 #define clear_syscall_work(fl) \ 178 clear_ti_thread_flag(current_thread_info(), TIF_##fl) 179 180 #define set_task_syscall_work(t, fl) \ 181 set_ti_thread_flag(task_thread_info(t), TIF_##fl) 182 #define test_task_syscall_work(t, fl) \ 183 test_ti_thread_flag(task_thread_info(t), TIF_##fl) 184 #define clear_task_syscall_work(t, fl) \ 185 clear_ti_thread_flag(task_thread_info(t), TIF_##fl) 186 #endif /* !CONFIG_GENERIC_ENTRY */ 187 188 #ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H 189 190 static __always_inline bool tif_test_bit(int bit) 191 { 192 return arch_test_bit(bit, 193 (unsigned long *)(¤t_thread_info()->flags)); 194 } 195 196 #else 197 198 static __always_inline bool tif_test_bit(int bit) 199 { 200 return test_bit(bit, 201 (unsigned long *)(¤t_thread_info()->flags)); 202 } 203 204 #endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */ 205 206 static __always_inline bool tif_need_resched(void) 207 { 208 return tif_test_bit(TIF_NEED_RESCHED); 209 } 210 211 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES 212 static inline int arch_within_stack_frames(const void * const stack, 213 const void * const stackend, 214 const void *obj, unsigned long len) 215 { 216 return 0; 217 } 218 #endif 219 220 #ifdef CONFIG_HARDENED_USERCOPY 221 extern void __check_object_size(const void *ptr, unsigned long n, 222 bool to_user); 223 224 static __always_inline void check_object_size(const void *ptr, unsigned long n, 225 bool to_user) 226 { 227 if (!__builtin_constant_p(n)) 228 __check_object_size(ptr, n, to_user); 229 } 230 #else 231 static inline void check_object_size(const void *ptr, unsigned long n, 232 bool to_user) 233 { } 234 #endif /* CONFIG_HARDENED_USERCOPY */ 235 236 extern void __compiletime_error("copy source size is too small") 237 __bad_copy_from(void); 238 extern void __compiletime_error("copy destination size is too small") 239 __bad_copy_to(void); 240 241 void __copy_overflow(int size, unsigned long count); 242 243 static inline void copy_overflow(int size, unsigned long count) 244 { 245 if (IS_ENABLED(CONFIG_BUG)) 246 __copy_overflow(size, count); 247 } 248 249 static __always_inline __must_check bool 250 check_copy_size(const void *addr, size_t bytes, bool is_source) 251 { 252 int sz = __builtin_object_size(addr, 0); 253 if (unlikely(sz >= 0 && sz < bytes)) { 254 if (!__builtin_constant_p(bytes)) 255 copy_overflow(sz, bytes); 256 else if (is_source) 257 __bad_copy_from(); 258 else 259 __bad_copy_to(); 260 return false; 261 } 262 if (WARN_ON_ONCE(bytes > INT_MAX)) 263 return false; 264 check_object_size(addr, bytes, is_source); 265 return true; 266 } 267 268 #ifndef arch_setup_new_exec 269 static inline void arch_setup_new_exec(void) { } 270 #endif 271 272 void arch_task_cache_init(void); /* for CONFIG_SH */ 273 void arch_release_task_struct(struct task_struct *tsk); 274 int arch_dup_task_struct(struct task_struct *dst, 275 struct task_struct *src); 276 277 #endif /* __KERNEL__ */ 278 279 #endif /* _LINUX_THREAD_INFO_H */ 280