include/linux/thread_info.h

   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 */