xref: /linux/include/linux/thread_info.h (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
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_ACCOUNT | __GFP_NOTRACK | \
60 				 __GFP_ZERO)
61 #else
62 # define THREADINFO_GFP		(GFP_KERNEL_ACCOUNT | __GFP_NOTRACK)
63 #endif
64 
65 /*
66  * flag set/clear/test wrappers
67  * - pass TIF_xxxx constants to these functions
68  */
69 
70 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
71 {
72 	set_bit(flag, (unsigned long *)&ti->flags);
73 }
74 
75 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
76 {
77 	clear_bit(flag, (unsigned long *)&ti->flags);
78 }
79 
80 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
81 {
82 	return test_and_set_bit(flag, (unsigned long *)&ti->flags);
83 }
84 
85 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
86 {
87 	return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
88 }
89 
90 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
91 {
92 	return test_bit(flag, (unsigned long *)&ti->flags);
93 }
94 
95 #define set_thread_flag(flag) \
96 	set_ti_thread_flag(current_thread_info(), flag)
97 #define clear_thread_flag(flag) \
98 	clear_ti_thread_flag(current_thread_info(), flag)
99 #define test_and_set_thread_flag(flag) \
100 	test_and_set_ti_thread_flag(current_thread_info(), flag)
101 #define test_and_clear_thread_flag(flag) \
102 	test_and_clear_ti_thread_flag(current_thread_info(), flag)
103 #define test_thread_flag(flag) \
104 	test_ti_thread_flag(current_thread_info(), flag)
105 
106 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
107 
108 #if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
109 /*
110  * An arch can define its own version of set_restore_sigmask() to get the
111  * job done however works, with or without TIF_RESTORE_SIGMASK.
112  */
113 #define HAVE_SET_RESTORE_SIGMASK	1
114 
115 /**
116  * set_restore_sigmask() - make sure saved_sigmask processing gets done
117  *
118  * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
119  * will run before returning to user mode, to process the flag.  For
120  * all callers, TIF_SIGPENDING is already set or it's no harm to set
121  * it.  TIF_RESTORE_SIGMASK need not be in the set of bits that the
122  * arch code will notice on return to user mode, in case those bits
123  * are scarce.  We set TIF_SIGPENDING here to ensure that the arch
124  * signal code always gets run when TIF_RESTORE_SIGMASK is set.
125  */
126 static inline void set_restore_sigmask(void)
127 {
128 	set_thread_flag(TIF_RESTORE_SIGMASK);
129 	WARN_ON(!test_thread_flag(TIF_SIGPENDING));
130 }
131 static inline void clear_restore_sigmask(void)
132 {
133 	clear_thread_flag(TIF_RESTORE_SIGMASK);
134 }
135 static inline bool test_restore_sigmask(void)
136 {
137 	return test_thread_flag(TIF_RESTORE_SIGMASK);
138 }
139 static inline bool test_and_clear_restore_sigmask(void)
140 {
141 	return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
142 }
143 #endif	/* TIF_RESTORE_SIGMASK && !HAVE_SET_RESTORE_SIGMASK */
144 
145 #ifndef HAVE_SET_RESTORE_SIGMASK
146 #error "no set_restore_sigmask() provided and default one won't work"
147 #endif
148 
149 #endif	/* __KERNEL__ */
150 
151 #endif /* _LINUX_THREAD_INFO_H */
152