xref: /linux/include/linux/thread_info.h (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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 #ifndef arch_setup_new_exec
117 static inline void arch_setup_new_exec(void) { }
118 #endif
119 
120 #endif	/* __KERNEL__ */
121 
122 #endif /* _LINUX_THREAD_INFO_H */
123