include/linux/signal.h

   1 #ifndef _LINUX_SIGNAL_H
   2 #define _LINUX_SIGNAL_H
   3
   4 #include <asm/signal.h>
   5 #include <asm/siginfo.h>
   6
   7 #ifdef __KERNEL__
   8 #include <linux/list.h>
   9
  10 /* for sysctl */
  11 extern int print_fatal_signals;
  12 /*
  13  * Real Time signals may be queued.
  14  */
  15
  16 struct sigqueue {
  17         struct list_head list;
  18         int flags;
  19         siginfo_t info;
  20         struct user_struct *user;
  21 };
  22
  23 /* flags values. */
  24 #define SIGQUEUE_PREALLOC       1
  25
  26 struct sigpending {
  27         struct list_head list;
  28         sigset_t signal;
  29 };
  30
  31 /*
  32  * Define some primitives to manipulate sigset_t.
  33  */
  34
  35 #ifndef __HAVE_ARCH_SIG_BITOPS
  36 #include <linux/bitops.h>
  37
  38 /* We don't use <linux/bitops.h> for these because there is no need to
  39    be atomic.  */
  40 static inline void sigaddset(sigset_t *set, int _sig)
  41 {
  42         unsigned long sig = _sig - 1;
  43         if (_NSIG_WORDS == 1)
  44                 set->sig[0] |= 1UL << sig;
  45         else
  46                 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
  47 }
  48
  49 static inline void sigdelset(sigset_t *set, int _sig)
  50 {
  51         unsigned long sig = _sig - 1;
  52         if (_NSIG_WORDS == 1)
  53                 set->sig[0] &= ~(1UL << sig);
  54         else
  55                 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
  56 }
  57
  58 static inline int sigismember(sigset_t *set, int _sig)
  59 {
  60         unsigned long sig = _sig - 1;
  61         if (_NSIG_WORDS == 1)
  62                 return 1 & (set->sig[0] >> sig);
  63         else
  64                 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
  65 }
  66
  67 static inline int sigfindinword(unsigned long word)
  68 {
  69         return ffz(~word);
  70 }
  71
  72 #endif /* __HAVE_ARCH_SIG_BITOPS */
  73
  74 static inline int sigisemptyset(sigset_t *set)
  75 {
  76         extern void _NSIG_WORDS_is_unsupported_size(void);
  77         switch (_NSIG_WORDS) {
  78         case 4:
  79                 return (set->sig[3] | set->sig[2] |
  80                         set->sig[1] | set->sig[0]) == 0;
  81         case 2:
  82                 return (set->sig[1] | set->sig[0]) == 0;
  83         case 1:
  84                 return set->sig[0] == 0;
  85         default:
  86                 _NSIG_WORDS_is_unsupported_size();
  87                 return 0;
  88         }
  89 }
  90
  91 #define sigmask(sig)    (1UL << ((sig) - 1))
  92
  93 #ifndef __HAVE_ARCH_SIG_SETOPS
  94 #include <linux/string.h>
  95
  96 #define _SIG_SET_BINOP(name, op)                                        \
  97 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
  98 {                                                                       \
  99         extern void _NSIG_WORDS_is_unsupported_size(void);              \
 100         unsigned long a0, a1, a2, a3, b0, b1, b2, b3;                   \
 101                                                                         \
 102         switch (_NSIG_WORDS) {                                          \
 103             case 4:                                                     \
 104                 a3 = a->sig[3]; a2 = a->sig[2];                         \
 105                 b3 = b->sig[3]; b2 = b->sig[2];                         \
 106                 r->sig[3] = op(a3, b3);                                 \
 107                 r->sig[2] = op(a2, b2);                                 \
 108             case 2:                                                     \
 109                 a1 = a->sig[1]; b1 = b->sig[1];                         \
 110                 r->sig[1] = op(a1, b1);                                 \
 111             case 1:                                                     \
 112                 a0 = a->sig[0]; b0 = b->sig[0];                         \
 113                 r->sig[0] = op(a0, b0);                                 \
 114                 break;                                                  \
 115             default:                                                    \
 116                 _NSIG_WORDS_is_unsupported_size();                      \
 117         }                                                               \
 118 }
 119
 120 #define _sig_or(x,y)    ((x) | (y))
 121 _SIG_SET_BINOP(sigorsets, _sig_or)
 122
 123 #define _sig_and(x,y)   ((x) & (y))
 124 _SIG_SET_BINOP(sigandsets, _sig_and)
 125
 126 #define _sig_nand(x,y)  ((x) & ~(y))
 127 _SIG_SET_BINOP(signandsets, _sig_nand)
 128
 129 #undef _SIG_SET_BINOP
 130 #undef _sig_or
 131 #undef _sig_and
 132 #undef _sig_nand
 133
 134 #define _SIG_SET_OP(name, op)                                           \
 135 static inline void name(sigset_t *set)                                  \
 136 {                                                                       \
 137         extern void _NSIG_WORDS_is_unsupported_size(void);              \
 138                                                                         \
 139         switch (_NSIG_WORDS) {                                          \
 140             case 4: set->sig[3] = op(set->sig[3]);                      \
 141                     set->sig[2] = op(set->sig[2]);                      \
 142             case 2: set->sig[1] = op(set->sig[1]);                      \
 143             case 1: set->sig[0] = op(set->sig[0]);                      \
 144                     break;                                              \
 145             default:                                                    \
 146                 _NSIG_WORDS_is_unsupported_size();                      \
 147         }                                                               \
 148 }
 149
 150 #define _sig_not(x)     (~(x))
 151 _SIG_SET_OP(signotset, _sig_not)
 152
 153 #undef _SIG_SET_OP
 154 #undef _sig_not
 155
 156 static inline void sigemptyset(sigset_t *set)
 157 {
 158         switch (_NSIG_WORDS) {
 159         default:
 160                 memset(set, 0, sizeof(sigset_t));
 161                 break;
 162         case 2: set->sig[1] = 0;
 163         case 1: set->sig[0] = 0;
 164                 break;
 165         }
 166 }
 167
 168 static inline void sigfillset(sigset_t *set)
 169 {
 170         switch (_NSIG_WORDS) {
 171         default:
 172                 memset(set, -1, sizeof(sigset_t));
 173                 break;
 174         case 2: set->sig[1] = -1;
 175         case 1: set->sig[0] = -1;
 176                 break;
 177         }
 178 }
 179
 180 /* Some extensions for manipulating the low 32 signals in particular.  */
 181
 182 static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
 183 {
 184         set->sig[0] |= mask;
 185 }
 186
 187 static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
 188 {
 189         set->sig[0] &= ~mask;
 190 }
 191
 192 static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
 193 {
 194         return (set->sig[0] & mask) != 0;
 195 }
 196
 197 static inline void siginitset(sigset_t *set, unsigned long mask)
 198 {
 199         set->sig[0] = mask;
 200         switch (_NSIG_WORDS) {
 201         default:
 202                 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
 203                 break;
 204         case 2: set->sig[1] = 0;
 205         case 1: ;
 206         }
 207 }
 208
 209 static inline void siginitsetinv(sigset_t *set, unsigned long mask)
 210 {
 211         set->sig[0] = ~mask;
 212         switch (_NSIG_WORDS) {
 213         default:
 214                 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
 215                 break;
 216         case 2: set->sig[1] = -1;
 217         case 1: ;
 218         }
 219 }
 220
 221 #endif /* __HAVE_ARCH_SIG_SETOPS */
 222
 223 static inline void init_sigpending(struct sigpending *sig)
 224 {
 225         sigemptyset(&sig->signal);
 226         INIT_LIST_HEAD(&sig->list);
 227 }
 228
 229 extern void flush_sigqueue(struct sigpending *queue);
 230
 231 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
 232 static inline int valid_signal(unsigned long sig)
 233 {
 234         return sig <= _NSIG ? 1 : 0;
 235 }
 236
 237 extern int next_signal(struct sigpending *pending, sigset_t *mask);
 238 extern int do_send_sig_info(int sig, struct siginfo *info,
 239                                 struct task_struct *p, bool group);
 240 extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
 241 extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
 242 extern long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig,
 243                                  siginfo_t *info);
 244 extern long do_sigpending(void __user *, unsigned long);
 245 extern int sigprocmask(int, sigset_t *, sigset_t *);
 246 extern void set_current_blocked(const sigset_t *);
 247 extern int show_unhandled_signals;
 248
 249 struct pt_regs;
 250 extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
 251 extern void exit_signals(struct task_struct *tsk);
 252
 253 extern struct kmem_cache *sighand_cachep;
 254
 255 int unhandled_signal(struct task_struct *tsk, int sig);
 256
 257 /*
 258  * In POSIX a signal is sent either to a specific thread (Linux task)
 259  * or to the process as a whole (Linux thread group).  How the signal
 260  * is sent determines whether it's to one thread or the whole group,
 261  * which determines which signal mask(s) are involved in blocking it
 262  * from being delivered until later.  When the signal is delivered,
 263  * either it's caught or ignored by a user handler or it has a default
 264  * effect that applies to the whole thread group (POSIX process).
 265  *
 266  * The possible effects an unblocked signal set to SIG_DFL can have are:
 267  *   ignore     - Nothing Happens
 268  *   terminate  - kill the process, i.e. all threads in the group,
 269  *                similar to exit_group.  The group leader (only) reports
 270  *                WIFSIGNALED status to its parent.
 271  *   coredump   - write a core dump file describing all threads using
 272  *                the same mm and then kill all those threads
 273  *   stop       - stop all the threads in the group, i.e. TASK_STOPPED state
 274  *
 275  * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
 276  * Other signals when not blocked and set to SIG_DFL behaves as follows.
 277  * The job control signals also have other special effects.
 278  *
 279  *      +--------------------+------------------+
 280  *      |  POSIX signal      |  default action  |
 281  *      +--------------------+------------------+
 282  *      |  SIGHUP            |  terminate       |
 283  *      |  SIGINT            |  terminate       |
 284  *      |  SIGQUIT           |  coredump        |
 285  *      |  SIGILL            |  coredump        |
 286  *      |  SIGTRAP           |  coredump        |
 287  *      |  SIGABRT/SIGIOT    |  coredump        |
 288  *      |  SIGBUS            |  coredump        |
 289  *      |  SIGFPE            |  coredump        |
 290  *      |  SIGKILL           |  terminate(+)    |
 291  *      |  SIGUSR1           |  terminate       |
 292  *      |  SIGSEGV           |  coredump        |
 293  *      |  SIGUSR2           |  terminate       |
 294  *      |  SIGPIPE           |  terminate       |
 295  *      |  SIGALRM           |  terminate       |
 296  *      |  SIGTERM           |  terminate       |
 297  *      |  SIGCHLD           |  ignore          |
 298  *      |  SIGCONT           |  ignore(*)       |
 299  *      |  SIGSTOP           |  stop(*)(+)      |
 300  *      |  SIGTSTP           |  stop(*)         |
 301  *      |  SIGTTIN           |  stop(*)         |
 302  *      |  SIGTTOU           |  stop(*)         |
 303  *      |  SIGURG            |  ignore          |
 304  *      |  SIGXCPU           |  coredump        |
 305  *      |  SIGXFSZ           |  coredump        |
 306  *      |  SIGVTALRM         |  terminate       |
 307  *      |  SIGPROF           |  terminate       |
 308  *      |  SIGPOLL/SIGIO     |  terminate       |
 309  *      |  SIGSYS/SIGUNUSED  |  coredump        |
 310  *      |  SIGSTKFLT         |  terminate       |
 311  *      |  SIGWINCH          |  ignore          |
 312  *      |  SIGPWR            |  terminate       |
 313  *      |  SIGRTMIN-SIGRTMAX |  terminate       |
 314  *      +--------------------+------------------+
 315  *      |  non-POSIX signal  |  default action  |
 316  *      +--------------------+------------------+
 317  *      |  SIGEMT            |  coredump        |
 318  *      +--------------------+------------------+
 319  *
 320  * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
 321  * (*) Special job control effects:
 322  * When SIGCONT is sent, it resumes the process (all threads in the group)
 323  * from TASK_STOPPED state and also clears any pending/queued stop signals
 324  * (any of those marked with "stop(*)").  This happens regardless of blocking,
 325  * catching, or ignoring SIGCONT.  When any stop signal is sent, it clears
 326  * any pending/queued SIGCONT signals; this happens regardless of blocking,
 327  * catching, or ignored the stop signal, though (except for SIGSTOP) the
 328  * default action of stopping the process may happen later or never.
 329  */
 330
 331 #ifdef SIGEMT
 332 #define SIGEMT_MASK     rt_sigmask(SIGEMT)
 333 #else
 334 #define SIGEMT_MASK     0
 335 #endif
 336
 337 #if SIGRTMIN > BITS_PER_LONG
 338 #define rt_sigmask(sig) (1ULL << ((sig)-1))
 339 #else
 340 #define rt_sigmask(sig) sigmask(sig)
 341 #endif
 342 #define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
 343
 344 #define SIG_KERNEL_ONLY_MASK (\
 345         rt_sigmask(SIGKILL)   |  rt_sigmask(SIGSTOP))
 346
 347 #define SIG_KERNEL_STOP_MASK (\
 348         rt_sigmask(SIGSTOP)   |  rt_sigmask(SIGTSTP)   | \
 349         rt_sigmask(SIGTTIN)   |  rt_sigmask(SIGTTOU)   )
 350
 351 #define SIG_KERNEL_COREDUMP_MASK (\
 352         rt_sigmask(SIGQUIT)   |  rt_sigmask(SIGILL)    | \
 353         rt_sigmask(SIGTRAP)   |  rt_sigmask(SIGABRT)   | \
 354         rt_sigmask(SIGFPE)    |  rt_sigmask(SIGSEGV)   | \
 355         rt_sigmask(SIGBUS)    |  rt_sigmask(SIGSYS)    | \
 356         rt_sigmask(SIGXCPU)   |  rt_sigmask(SIGXFSZ)   | \
 357         SIGEMT_MASK                                    )
 358
 359 #define SIG_KERNEL_IGNORE_MASK (\
 360         rt_sigmask(SIGCONT)   |  rt_sigmask(SIGCHLD)   | \
 361         rt_sigmask(SIGWINCH)  |  rt_sigmask(SIGURG)    )
 362
 363 #define sig_kernel_only(sig) \
 364         (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
 365 #define sig_kernel_coredump(sig) \
 366         (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
 367 #define sig_kernel_ignore(sig) \
 368         (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
 369 #define sig_kernel_stop(sig) \
 370         (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
 371
 372 #define sig_user_defined(t, signr) \
 373         (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) &&  \
 374          ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
 375
 376 #define sig_fatal(t, signr) \
 377         (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
 378          (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
 379
 380 void signals_init(void);
 381
 382 #endif /* __KERNEL__ */
 383
 384 #endif /* _LINUX_SIGNAL_H */