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 #include <asm/thread_info.h> 39 40 #ifdef __KERNEL__ 41 42 #ifndef THREAD_ALIGN 43 #define THREAD_ALIGN THREAD_SIZE 44 #endif 45 46 #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO) 47 48 /* 49 * flag set/clear/test wrappers 50 * - pass TIF_xxxx constants to these functions 51 */ 52 53 static inline void set_ti_thread_flag(struct thread_info *ti, int flag) 54 { 55 set_bit(flag, (unsigned long *)&ti->flags); 56 } 57 58 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag) 59 { 60 clear_bit(flag, (unsigned long *)&ti->flags); 61 } 62 63 static inline void update_ti_thread_flag(struct thread_info *ti, int flag, 64 bool value) 65 { 66 if (value) 67 set_ti_thread_flag(ti, flag); 68 else 69 clear_ti_thread_flag(ti, flag); 70 } 71 72 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag) 73 { 74 return test_and_set_bit(flag, (unsigned long *)&ti->flags); 75 } 76 77 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag) 78 { 79 return test_and_clear_bit(flag, (unsigned long *)&ti->flags); 80 } 81 82 static inline int test_ti_thread_flag(struct thread_info *ti, int flag) 83 { 84 return test_bit(flag, (unsigned long *)&ti->flags); 85 } 86 87 #define set_thread_flag(flag) \ 88 set_ti_thread_flag(current_thread_info(), flag) 89 #define clear_thread_flag(flag) \ 90 clear_ti_thread_flag(current_thread_info(), flag) 91 #define update_thread_flag(flag, value) \ 92 update_ti_thread_flag(current_thread_info(), flag, value) 93 #define test_and_set_thread_flag(flag) \ 94 test_and_set_ti_thread_flag(current_thread_info(), flag) 95 #define test_and_clear_thread_flag(flag) \ 96 test_and_clear_ti_thread_flag(current_thread_info(), flag) 97 #define test_thread_flag(flag) \ 98 test_ti_thread_flag(current_thread_info(), flag) 99 100 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) 101 102 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES 103 static inline int arch_within_stack_frames(const void * const stack, 104 const void * const stackend, 105 const void *obj, unsigned long len) 106 { 107 return 0; 108 } 109 #endif 110 111 #ifdef CONFIG_HARDENED_USERCOPY 112 extern void __check_object_size(const void *ptr, unsigned long n, 113 bool to_user); 114 115 static __always_inline void check_object_size(const void *ptr, unsigned long n, 116 bool to_user) 117 { 118 if (!__builtin_constant_p(n)) 119 __check_object_size(ptr, n, to_user); 120 } 121 #else 122 static inline void check_object_size(const void *ptr, unsigned long n, 123 bool to_user) 124 { } 125 #endif /* CONFIG_HARDENED_USERCOPY */ 126 127 extern void __compiletime_error("copy source size is too small") 128 __bad_copy_from(void); 129 extern void __compiletime_error("copy destination size is too small") 130 __bad_copy_to(void); 131 132 static inline void copy_overflow(int size, unsigned long count) 133 { 134 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); 135 } 136 137 static __always_inline bool 138 check_copy_size(const void *addr, size_t bytes, bool is_source) 139 { 140 int sz = __compiletime_object_size(addr); 141 if (unlikely(sz >= 0 && sz < bytes)) { 142 if (!__builtin_constant_p(bytes)) 143 copy_overflow(sz, bytes); 144 else if (is_source) 145 __bad_copy_from(); 146 else 147 __bad_copy_to(); 148 return false; 149 } 150 check_object_size(addr, bytes, is_source); 151 return true; 152 } 153 154 #ifndef arch_setup_new_exec 155 static inline void arch_setup_new_exec(void) { } 156 #endif 157 158 #endif /* __KERNEL__ */ 159 160 #endif /* _LINUX_THREAD_INFO_H */ 161