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 SYSCALL_WORK_BIT_SYSCALL_TRACE, 42 SYSCALL_WORK_BIT_SYSCALL_EMU, 43 SYSCALL_WORK_BIT_SYSCALL_AUDIT, 44 }; 45 46 #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP) 47 #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT) 48 #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE) 49 #define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU) 50 #define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT) 51 52 #include <asm/thread_info.h> 53 54 #ifdef __KERNEL__ 55 56 #ifndef THREAD_ALIGN 57 #define THREAD_ALIGN THREAD_SIZE 58 #endif 59 60 #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO) 61 62 /* 63 * flag set/clear/test wrappers 64 * - pass TIF_xxxx constants to these functions 65 */ 66 67 static inline void set_ti_thread_flag(struct thread_info *ti, int flag) 68 { 69 set_bit(flag, (unsigned long *)&ti->flags); 70 } 71 72 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag) 73 { 74 clear_bit(flag, (unsigned long *)&ti->flags); 75 } 76 77 static inline void update_ti_thread_flag(struct thread_info *ti, int flag, 78 bool value) 79 { 80 if (value) 81 set_ti_thread_flag(ti, flag); 82 else 83 clear_ti_thread_flag(ti, flag); 84 } 85 86 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag) 87 { 88 return test_and_set_bit(flag, (unsigned long *)&ti->flags); 89 } 90 91 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag) 92 { 93 return test_and_clear_bit(flag, (unsigned long *)&ti->flags); 94 } 95 96 static inline int test_ti_thread_flag(struct thread_info *ti, int flag) 97 { 98 return test_bit(flag, (unsigned long *)&ti->flags); 99 } 100 101 #define set_thread_flag(flag) \ 102 set_ti_thread_flag(current_thread_info(), flag) 103 #define clear_thread_flag(flag) \ 104 clear_ti_thread_flag(current_thread_info(), flag) 105 #define update_thread_flag(flag, value) \ 106 update_ti_thread_flag(current_thread_info(), flag, value) 107 #define test_and_set_thread_flag(flag) \ 108 test_and_set_ti_thread_flag(current_thread_info(), flag) 109 #define test_and_clear_thread_flag(flag) \ 110 test_and_clear_ti_thread_flag(current_thread_info(), flag) 111 #define test_thread_flag(flag) \ 112 test_ti_thread_flag(current_thread_info(), flag) 113 114 #ifdef CONFIG_GENERIC_ENTRY 115 #define set_syscall_work(fl) \ 116 set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 117 #define test_syscall_work(fl) \ 118 test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 119 #define clear_syscall_work(fl) \ 120 clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work) 121 122 #define set_task_syscall_work(t, fl) \ 123 set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 124 #define test_task_syscall_work(t, fl) \ 125 test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 126 #define clear_task_syscall_work(t, fl) \ 127 clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work) 128 129 #else /* CONFIG_GENERIC_ENTRY */ 130 131 #define set_syscall_work(fl) \ 132 set_ti_thread_flag(current_thread_info(), SYSCALL_WORK_##fl) 133 #define test_syscall_work(fl) \ 134 test_ti_thread_flag(current_thread_info(), SYSCALL_WORK_##fl) 135 #define clear_syscall_work(fl) \ 136 clear_ti_thread_flag(current_thread_info(), SYSCALL_WORK_##fl) 137 138 #define set_task_syscall_work(t, fl) \ 139 set_ti_thread_flag(task_thread_info(t), TIF_##fl) 140 #define test_task_syscall_work(t, fl) \ 141 test_ti_thread_flag(task_thread_info(t), TIF_##fl) 142 #define clear_task_syscall_work(t, fl) \ 143 clear_ti_thread_flag(task_thread_info(t), TIF_##fl) 144 #endif /* !CONFIG_GENERIC_ENTRY */ 145 146 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) 147 148 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES 149 static inline int arch_within_stack_frames(const void * const stack, 150 const void * const stackend, 151 const void *obj, unsigned long len) 152 { 153 return 0; 154 } 155 #endif 156 157 #ifdef CONFIG_HARDENED_USERCOPY 158 extern void __check_object_size(const void *ptr, unsigned long n, 159 bool to_user); 160 161 static __always_inline void check_object_size(const void *ptr, unsigned long n, 162 bool to_user) 163 { 164 if (!__builtin_constant_p(n)) 165 __check_object_size(ptr, n, to_user); 166 } 167 #else 168 static inline void check_object_size(const void *ptr, unsigned long n, 169 bool to_user) 170 { } 171 #endif /* CONFIG_HARDENED_USERCOPY */ 172 173 extern void __compiletime_error("copy source size is too small") 174 __bad_copy_from(void); 175 extern void __compiletime_error("copy destination size is too small") 176 __bad_copy_to(void); 177 178 static inline void copy_overflow(int size, unsigned long count) 179 { 180 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); 181 } 182 183 static __always_inline __must_check bool 184 check_copy_size(const void *addr, size_t bytes, bool is_source) 185 { 186 int sz = __compiletime_object_size(addr); 187 if (unlikely(sz >= 0 && sz < bytes)) { 188 if (!__builtin_constant_p(bytes)) 189 copy_overflow(sz, bytes); 190 else if (is_source) 191 __bad_copy_from(); 192 else 193 __bad_copy_to(); 194 return false; 195 } 196 if (WARN_ON_ONCE(bytes > INT_MAX)) 197 return false; 198 check_object_size(addr, bytes, is_source); 199 return true; 200 } 201 202 #ifndef arch_setup_new_exec 203 static inline void arch_setup_new_exec(void) { } 204 #endif 205 206 #endif /* __KERNEL__ */ 207 208 #endif /* _LINUX_THREAD_INFO_H */ 209