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