xref: /linux/include/linux/thread_info.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 
13 struct timespec;
14 struct compat_timespec;
15 
16 /*
17  * System call restart block.
18  */
19 struct restart_block {
20 	long (*fn)(struct restart_block *);
21 	union {
22 		/* For futex_wait and futex_wait_requeue_pi */
23 		struct {
24 			u32 __user *uaddr;
25 			u32 val;
26 			u32 flags;
27 			u32 bitset;
28 			u64 time;
29 			u32 __user *uaddr2;
30 		} futex;
31 		/* For nanosleep */
32 		struct {
33 			clockid_t clockid;
34 			struct timespec __user *rmtp;
35 #ifdef CONFIG_COMPAT
36 			struct compat_timespec __user *compat_rmtp;
37 #endif
38 			u64 expires;
39 		} nanosleep;
40 		/* For poll */
41 		struct {
42 			struct pollfd __user *ufds;
43 			int nfds;
44 			int has_timeout;
45 			unsigned long tv_sec;
46 			unsigned long tv_nsec;
47 		} poll;
48 	};
49 };
50 
51 extern long do_no_restart_syscall(struct restart_block *parm);
52 
53 #include <linux/bitops.h>
54 #include <asm/thread_info.h>
55 
56 #ifdef __KERNEL__
57 
58 #ifdef CONFIG_DEBUG_STACK_USAGE
59 # define THREADINFO_GFP		(GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
60 #else
61 # define THREADINFO_GFP		(GFP_KERNEL | __GFP_NOTRACK)
62 #endif
63 
64 /*
65  * flag set/clear/test wrappers
66  * - pass TIF_xxxx constants to these functions
67  */
68 
69 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
70 {
71 	set_bit(flag, (unsigned long *)&ti->flags);
72 }
73 
74 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
75 {
76 	clear_bit(flag, (unsigned long *)&ti->flags);
77 }
78 
79 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
80 {
81 	return test_and_set_bit(flag, (unsigned long *)&ti->flags);
82 }
83 
84 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
85 {
86 	return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
87 }
88 
89 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
90 {
91 	return test_bit(flag, (unsigned long *)&ti->flags);
92 }
93 
94 #define set_thread_flag(flag) \
95 	set_ti_thread_flag(current_thread_info(), flag)
96 #define clear_thread_flag(flag) \
97 	clear_ti_thread_flag(current_thread_info(), flag)
98 #define test_and_set_thread_flag(flag) \
99 	test_and_set_ti_thread_flag(current_thread_info(), flag)
100 #define test_and_clear_thread_flag(flag) \
101 	test_and_clear_ti_thread_flag(current_thread_info(), flag)
102 #define test_thread_flag(flag) \
103 	test_ti_thread_flag(current_thread_info(), flag)
104 
105 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
106 
107 #if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
108 /*
109  * An arch can define its own version of set_restore_sigmask() to get the
110  * job done however works, with or without TIF_RESTORE_SIGMASK.
111  */
112 #define HAVE_SET_RESTORE_SIGMASK	1
113 
114 /**
115  * set_restore_sigmask() - make sure saved_sigmask processing gets done
116  *
117  * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
118  * will run before returning to user mode, to process the flag.  For
119  * all callers, TIF_SIGPENDING is already set or it's no harm to set
120  * it.  TIF_RESTORE_SIGMASK need not be in the set of bits that the
121  * arch code will notice on return to user mode, in case those bits
122  * are scarce.  We set TIF_SIGPENDING here to ensure that the arch
123  * signal code always gets run when TIF_RESTORE_SIGMASK is set.
124  */
125 static inline void set_restore_sigmask(void)
126 {
127 	set_thread_flag(TIF_RESTORE_SIGMASK);
128 	WARN_ON(!test_thread_flag(TIF_SIGPENDING));
129 }
130 static inline void clear_restore_sigmask(void)
131 {
132 	clear_thread_flag(TIF_RESTORE_SIGMASK);
133 }
134 static inline bool test_restore_sigmask(void)
135 {
136 	return test_thread_flag(TIF_RESTORE_SIGMASK);
137 }
138 static inline bool test_and_clear_restore_sigmask(void)
139 {
140 	return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
141 }
142 #endif	/* TIF_RESTORE_SIGMASK && !HAVE_SET_RESTORE_SIGMASK */
143 
144 #ifndef HAVE_SET_RESTORE_SIGMASK
145 #error "no set_restore_sigmask() provided and default one won't work"
146 #endif
147 
148 #endif	/* __KERNEL__ */
149 
150 #endif /* _LINUX_THREAD_INFO_H */
151