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