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