1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* thread_info.h: common low-level thread information accessors 3 * 4 * Copyright (C) 2002 David Howells ([email protected]) 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 enum syscall_work_bit { 39 SYSCALL_WORK_BIT_SECCOMP, 40 SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT, 41 SYSCALL_WORK_BIT_SYSCALL_TRACE, 42 }; 43 44 #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP) 45 #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT) 46 #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE) 47 48 #include <asm/thread_info.h> 49 50 #ifdef __KERNEL__ 51 52 #ifndef THREAD_ALIGN 53 #define THREAD_ALIGN THREAD_SIZE 54 #endif 55 56 #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO) 57 58 /* 59 * flag set/clear/test wrappers 60 * - pass TIF_xxxx constants to these functions 61 */ 62 63 static inline void set_ti_thread_flag(struct thread_info *ti, int flag) 64 { 65 set_bit(flag, (unsigned long *)&ti->flags); 66 } 67 68 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag) 69 { 70 clear_bit(flag, (unsigned long *)&ti->flags); 71 } 72 73 static inline void update_ti_thread_flag(struct thread_info *ti, int flag, 74 bool value) 75 { 76 if (value) 77 set_ti_thread_flag(ti, flag); 78 else 79 clear_ti_thread_flag(ti, flag); 80 } 81 82 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag) 83 { 84 return test_and_set_bit(flag, (unsigned long *)&ti->flags); 85 } 86 87 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag) 88 { 89 return test_and_clear_bit(flag, (unsigned long *)&ti->flags); 90 } 91 92 static inline int test_ti_thread_flag(struct thread_info *ti, int flag) 93 { 94 return test_bit(flag, (unsigned long *)&ti->flags); 95 } 96 97 #define set_thread_flag(flag) \ 98 set_ti_thread_flag(current_thread_info(), flag) 99 #define clear_thread_flag(flag) \ 100 clear_ti_thread_flag(current_thread_info(), flag) 101 #define update_thread_flag(flag, value) \ 102 update_ti_thread_flag(current_thread_info(), flag, value) 103 #define test_and_set_thread_flag(flag) \ 104 test_and_set_ti_thread_flag(current_thread_info(), flag) 105 #define test_and_clear_thread_flag(flag) \ 106 test_and_clear_ti_thread_flag(current_thread_info(), flag) 107 #define test_thread_flag(flag) \ 108 test_ti_thread_flag(current_thread_info(), flag) 109 110 #ifdef CONFIG_GENERIC_ENTRY 111 #define set_syscall_work(fl) \ 112 set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 113 #define test_syscall_work(fl) \ 114 test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 115 #define clear_syscall_work(fl) \ 116 clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 117 118 #define set_task_syscall_work(t, fl) \ 119 set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 120 #define test_task_syscall_work(t, fl) \ 121 test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 122 #define clear_task_syscall_work(t, fl) \ 123 clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 124 125 #else /* CONFIG_GENERIC_ENTRY */ 126 127 #define set_syscall_work(fl) \ 128 set_ti_thread_flag(current_thread_info(), SYSCALL_WORK_##fl) 129 #define test_syscall_work(fl) \ 130 test_ti_thread_flag(current_thread_info(), SYSCALL_WORK_##fl) 131 #define clear_syscall_work(fl) \ 132 clear_ti_thread_flag(current_thread_info(), SYSCALL_WORK_##fl) 133 134 #define set_task_syscall_work(t, fl) \ 135 set_ti_thread_flag(task_thread_info(t), TIF_##fl) 136 #define test_task_syscall_work(t, fl) \ 137 test_ti_thread_flag(task_thread_info(t), TIF_##fl) 138 #define clear_task_syscall_work(t, fl) \ 139 clear_ti_thread_flag(task_thread_info(t), TIF_##fl) 140 #endif /* !CONFIG_GENERIC_ENTRY */ 141 142 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) 143 144 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES 145 static inline int arch_within_stack_frames(const void * const stack, 146 const void * const stackend, 147 const void *obj, unsigned long len) 148 { 149 return 0; 150 } 151 #endif 152 153 #ifdef CONFIG_HARDENED_USERCOPY 154 extern void __check_object_size(const void *ptr, unsigned long n, 155 bool to_user); 156 157 static __always_inline void check_object_size(const void *ptr, unsigned long n, 158 bool to_user) 159 { 160 if (!__builtin_constant_p(n)) 161 __check_object_size(ptr, n, to_user); 162 } 163 #else 164 static inline void check_object_size(const void *ptr, unsigned long n, 165 bool to_user) 166 { } 167 #endif /* CONFIG_HARDENED_USERCOPY */ 168 169 extern void __compiletime_error("copy source size is too small") 170 __bad_copy_from(void); 171 extern void __compiletime_error("copy destination size is too small") 172 __bad_copy_to(void); 173 174 static inline void copy_overflow(int size, unsigned long count) 175 { 176 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); 177 } 178 179 static __always_inline __must_check bool 180 check_copy_size(const void *addr, size_t bytes, bool is_source) 181 { 182 int sz = __compiletime_object_size(addr); 183 if (unlikely(sz >= 0 && sz < bytes)) { 184 if (!__builtin_constant_p(bytes)) 185 copy_overflow(sz, bytes); 186 else if (is_source) 187 __bad_copy_from(); 188 else 189 __bad_copy_to(); 190 return false; 191 } 192 if (WARN_ON_ONCE(bytes > INT_MAX)) 193 return false; 194 check_object_size(addr, bytes, is_source); 195 return true; 196 } 197 198 #ifndef arch_setup_new_exec 199 static inline void arch_setup_new_exec(void) { } 200 #endif 201 202 #endif /* __KERNEL__ */ 203 204 #endif /* _LINUX_THREAD_INFO_H */ 205