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