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