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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 #define THREADINFO_GFP_ACCOUNTED (THREADINFO_GFP | __GFP_KMEMCG)
65 
66 /*
67  * flag set/clear/test wrappers
68  * - pass TIF_xxxx constants to these functions
69  */
70 
set_ti_thread_flag(struct thread_info * ti,int flag)71 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
72 {
73 	set_bit(flag, (unsigned long *)&ti->flags);
74 }
75 
clear_ti_thread_flag(struct thread_info * ti,int flag)76 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
77 {
78 	clear_bit(flag, (unsigned long *)&ti->flags);
79 }
80 
test_and_set_ti_thread_flag(struct thread_info * ti,int flag)81 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
82 {
83 	return test_and_set_bit(flag, (unsigned long *)&ti->flags);
84 }
85 
test_and_clear_ti_thread_flag(struct thread_info * ti,int flag)86 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
87 {
88 	return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
89 }
90 
test_ti_thread_flag(struct thread_info * ti,int flag)91 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
92 {
93 	return test_bit(flag, (unsigned long *)&ti->flags);
94 }
95 
96 #define set_thread_flag(flag) \
97 	set_ti_thread_flag(current_thread_info(), flag)
98 #define clear_thread_flag(flag) \
99 	clear_ti_thread_flag(current_thread_info(), flag)
100 #define test_and_set_thread_flag(flag) \
101 	test_and_set_ti_thread_flag(current_thread_info(), flag)
102 #define test_and_clear_thread_flag(flag) \
103 	test_and_clear_ti_thread_flag(current_thread_info(), flag)
104 #define test_thread_flag(flag) \
105 	test_ti_thread_flag(current_thread_info(), flag)
106 
107 #define set_need_resched()	set_thread_flag(TIF_NEED_RESCHED)
108 #define clear_need_resched()	clear_thread_flag(TIF_NEED_RESCHED)
109 
110 #if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
111 /*
112  * An arch can define its own version of set_restore_sigmask() to get the
113  * job done however works, with or without TIF_RESTORE_SIGMASK.
114  */
115 #define HAVE_SET_RESTORE_SIGMASK	1
116 
117 /**
118  * set_restore_sigmask() - make sure saved_sigmask processing gets done
119  *
120  * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
121  * will run before returning to user mode, to process the flag.  For
122  * all callers, TIF_SIGPENDING is already set or it's no harm to set
123  * it.  TIF_RESTORE_SIGMASK need not be in the set of bits that the
124  * arch code will notice on return to user mode, in case those bits
125  * are scarce.  We set TIF_SIGPENDING here to ensure that the arch
126  * signal code always gets run when TIF_RESTORE_SIGMASK is set.
127  */
set_restore_sigmask(void)128 static inline void set_restore_sigmask(void)
129 {
130 	set_thread_flag(TIF_RESTORE_SIGMASK);
131 	WARN_ON(!test_thread_flag(TIF_SIGPENDING));
132 }
clear_restore_sigmask(void)133 static inline void clear_restore_sigmask(void)
134 {
135 	clear_thread_flag(TIF_RESTORE_SIGMASK);
136 }
test_restore_sigmask(void)137 static inline bool test_restore_sigmask(void)
138 {
139 	return test_thread_flag(TIF_RESTORE_SIGMASK);
140 }
test_and_clear_restore_sigmask(void)141 static inline bool test_and_clear_restore_sigmask(void)
142 {
143 	return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
144 }
145 #endif	/* TIF_RESTORE_SIGMASK && !HAVE_SET_RESTORE_SIGMASK */
146 
147 #ifndef HAVE_SET_RESTORE_SIGMASK
148 #error "no set_restore_sigmask() provided and default one won't work"
149 #endif
150 
151 #endif	/* __KERNEL__ */
152 
153 #endif /* _LINUX_THREAD_INFO_H */
154