1 /* thread_info.h: common low-level thread information accessors 2 * 3 * Copyright (C) 2002 David Howells (dhowells@redhat.com) 4 * - Incorporating suggestions made by Linus Torvalds 5 */ 6 7 #ifndef _LINUX_THREAD_INFO_H 8 #define _LINUX_THREAD_INFO_H 9 10 #include <linux/types.h> 11 #include <linux/bug.h> 12 #include <linux/restart_block.h> 13 14 #ifdef CONFIG_THREAD_INFO_IN_TASK 15 /* 16 * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the 17 * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels, 18 * including <asm/current.h> can cause a circular dependency on some platforms. 19 */ 20 #include <asm/current.h> 21 #define current_thread_info() ((struct thread_info *)current) 22 #endif 23 24 #include <linux/bitops.h> 25 26 /* 27 * For per-arch arch_within_stack_frames() implementations, defined in 28 * asm/thread_info.h. 29 */ 30 enum { 31 BAD_STACK = -1, 32 NOT_STACK = 0, 33 GOOD_FRAME, 34 GOOD_STACK, 35 }; 36 37 #include <asm/thread_info.h> 38 39 #ifdef __KERNEL__ 40 41 #ifdef CONFIG_DEBUG_STACK_USAGE 42 # define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \ 43 __GFP_ZERO) 44 #else 45 # define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK) 46 #endif 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 int test_and_set_ti_thread_flag(struct thread_info *ti, int flag) 64 { 65 return test_and_set_bit(flag, (unsigned long *)&ti->flags); 66 } 67 68 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag) 69 { 70 return test_and_clear_bit(flag, (unsigned long *)&ti->flags); 71 } 72 73 static inline int test_ti_thread_flag(struct thread_info *ti, int flag) 74 { 75 return test_bit(flag, (unsigned long *)&ti->flags); 76 } 77 78 #define set_thread_flag(flag) \ 79 set_ti_thread_flag(current_thread_info(), flag) 80 #define clear_thread_flag(flag) \ 81 clear_ti_thread_flag(current_thread_info(), flag) 82 #define test_and_set_thread_flag(flag) \ 83 test_and_set_ti_thread_flag(current_thread_info(), flag) 84 #define test_and_clear_thread_flag(flag) \ 85 test_and_clear_ti_thread_flag(current_thread_info(), flag) 86 #define test_thread_flag(flag) \ 87 test_ti_thread_flag(current_thread_info(), flag) 88 89 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) 90 91 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES 92 static inline int arch_within_stack_frames(const void * const stack, 93 const void * const stackend, 94 const void *obj, unsigned long len) 95 { 96 return 0; 97 } 98 #endif 99 100 #ifdef CONFIG_HARDENED_USERCOPY 101 extern void __check_object_size(const void *ptr, unsigned long n, 102 bool to_user); 103 104 static __always_inline void check_object_size(const void *ptr, unsigned long n, 105 bool to_user) 106 { 107 if (!__builtin_constant_p(n)) 108 __check_object_size(ptr, n, to_user); 109 } 110 #else 111 static inline void check_object_size(const void *ptr, unsigned long n, 112 bool to_user) 113 { } 114 #endif /* CONFIG_HARDENED_USERCOPY */ 115 116 extern void __compiletime_error("copy source size is too small") 117 __bad_copy_from(void); 118 extern void __compiletime_error("copy destination size is too small") 119 __bad_copy_to(void); 120 121 static inline void copy_overflow(int size, unsigned long count) 122 { 123 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); 124 } 125 126 static __always_inline bool 127 check_copy_size(const void *addr, size_t bytes, bool is_source) 128 { 129 int sz = __compiletime_object_size(addr); 130 if (unlikely(sz >= 0 && sz < bytes)) { 131 if (!__builtin_constant_p(bytes)) 132 copy_overflow(sz, bytes); 133 else if (is_source) 134 __bad_copy_from(); 135 else 136 __bad_copy_to(); 137 return false; 138 } 139 check_object_size(addr, bytes, is_source); 140 return true; 141 } 142 143 #ifndef arch_setup_new_exec 144 static inline void arch_setup_new_exec(void) { } 145 #endif 146 147 #endif /* __KERNEL__ */ 148 149 #endif /* _LINUX_THREAD_INFO_H */ 150