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