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