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