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 #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 }; 46 47 #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP) 48 #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT) 49 #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE) 50 #define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU) 51 #define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT) 52 #endif 53 54 #include <asm/thread_info.h> 55 56 #ifdef __KERNEL__ 57 58 #ifndef THREAD_ALIGN 59 #define THREAD_ALIGN THREAD_SIZE 60 #endif 61 62 #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO) 63 64 /* 65 * flag set/clear/test wrappers 66 * - pass TIF_xxxx constants to these functions 67 */ 68 69 static inline void set_ti_thread_flag(struct thread_info *ti, int flag) 70 { 71 set_bit(flag, (unsigned long *)&ti->flags); 72 } 73 74 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag) 75 { 76 clear_bit(flag, (unsigned long *)&ti->flags); 77 } 78 79 static inline void update_ti_thread_flag(struct thread_info *ti, int flag, 80 bool value) 81 { 82 if (value) 83 set_ti_thread_flag(ti, flag); 84 else 85 clear_ti_thread_flag(ti, flag); 86 } 87 88 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag) 89 { 90 return test_and_set_bit(flag, (unsigned long *)&ti->flags); 91 } 92 93 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag) 94 { 95 return test_and_clear_bit(flag, (unsigned long *)&ti->flags); 96 } 97 98 static inline int test_ti_thread_flag(struct thread_info *ti, int flag) 99 { 100 return test_bit(flag, (unsigned long *)&ti->flags); 101 } 102 103 #define set_thread_flag(flag) \ 104 set_ti_thread_flag(current_thread_info(), flag) 105 #define clear_thread_flag(flag) \ 106 clear_ti_thread_flag(current_thread_info(), flag) 107 #define update_thread_flag(flag, value) \ 108 update_ti_thread_flag(current_thread_info(), flag, value) 109 #define test_and_set_thread_flag(flag) \ 110 test_and_set_ti_thread_flag(current_thread_info(), flag) 111 #define test_and_clear_thread_flag(flag) \ 112 test_and_clear_ti_thread_flag(current_thread_info(), flag) 113 #define test_thread_flag(flag) \ 114 test_ti_thread_flag(current_thread_info(), flag) 115 116 #ifdef CONFIG_GENERIC_ENTRY 117 #define set_syscall_work(fl) \ 118 set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 119 #define test_syscall_work(fl) \ 120 test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 121 #define clear_syscall_work(fl) \ 122 clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 123 124 #define set_task_syscall_work(t, fl) \ 125 set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 126 #define test_task_syscall_work(t, fl) \ 127 test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 128 #define clear_task_syscall_work(t, fl) \ 129 clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 130 131 #else /* CONFIG_GENERIC_ENTRY */ 132 133 #define set_syscall_work(fl) \ 134 set_ti_thread_flag(current_thread_info(), TIF_##fl) 135 #define test_syscall_work(fl) \ 136 test_ti_thread_flag(current_thread_info(), TIF_##fl) 137 #define clear_syscall_work(fl) \ 138 clear_ti_thread_flag(current_thread_info(), TIF_##fl) 139 140 #define set_task_syscall_work(t, fl) \ 141 set_ti_thread_flag(task_thread_info(t), TIF_##fl) 142 #define test_task_syscall_work(t, fl) \ 143 test_ti_thread_flag(task_thread_info(t), TIF_##fl) 144 #define clear_task_syscall_work(t, fl) \ 145 clear_ti_thread_flag(task_thread_info(t), TIF_##fl) 146 #endif /* !CONFIG_GENERIC_ENTRY */ 147 148 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) 149 150 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES 151 static inline int arch_within_stack_frames(const void * const stack, 152 const void * const stackend, 153 const void *obj, unsigned long len) 154 { 155 return 0; 156 } 157 #endif 158 159 #ifdef CONFIG_HARDENED_USERCOPY 160 extern void __check_object_size(const void *ptr, unsigned long n, 161 bool to_user); 162 163 static __always_inline void check_object_size(const void *ptr, unsigned long n, 164 bool to_user) 165 { 166 if (!__builtin_constant_p(n)) 167 __check_object_size(ptr, n, to_user); 168 } 169 #else 170 static inline void check_object_size(const void *ptr, unsigned long n, 171 bool to_user) 172 { } 173 #endif /* CONFIG_HARDENED_USERCOPY */ 174 175 extern void __compiletime_error("copy source size is too small") 176 __bad_copy_from(void); 177 extern void __compiletime_error("copy destination size is too small") 178 __bad_copy_to(void); 179 180 static inline void copy_overflow(int size, unsigned long count) 181 { 182 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); 183 } 184 185 static __always_inline __must_check bool 186 check_copy_size(const void *addr, size_t bytes, bool is_source) 187 { 188 int sz = __compiletime_object_size(addr); 189 if (unlikely(sz >= 0 && sz < bytes)) { 190 if (!__builtin_constant_p(bytes)) 191 copy_overflow(sz, bytes); 192 else if (is_source) 193 __bad_copy_from(); 194 else 195 __bad_copy_to(); 196 return false; 197 } 198 if (WARN_ON_ONCE(bytes > INT_MAX)) 199 return false; 200 check_object_size(addr, bytes, is_source); 201 return true; 202 } 203 204 #ifndef arch_setup_new_exec 205 static inline void arch_setup_new_exec(void) { } 206 #endif 207 208 #endif /* __KERNEL__ */ 209 210 #endif /* _LINUX_THREAD_INFO_H */ 211