include/linux/signal.h

   1 #ifndef _LINUX_SIGNAL_H
   2 #define _LINUX_SIGNAL_H
   3
   4 #include <linux/list.h>
   5 #include <uapi/linux/signal.h>
   6
   7 struct task_struct;
   8
   9 /* for sysctl */
  10 extern int print_fatal_signals;
  11 /*
  12  * Real Time signals may be queued.
  13  */
  14
  15 struct sigqueue {
  16         struct list_head list;
  17         int flags;
  18         siginfo_t info;
  19         struct user_struct *user;
  20 };
  21
  22 /* flags values. */
  23 #define SIGQUEUE_PREALLOC       1
  24
  25 struct sigpending {
  26         struct list_head list;
  27         sigset_t signal;
  28 };
  29
  30 /*
  31  * Define some primitives to manipulate sigset_t.
  32  */
  33
  34 #ifndef __HAVE_ARCH_SIG_BITOPS
  35 #include <linux/bitops.h>
  36
  37 /* We don't use <linux/bitops.h> for these because there is no need to
  38    be atomic.  */
  39 static inline void sigaddset(sigset_t *set, int _sig)
  40 {
  41         unsigned long sig = _sig - 1;
  42         if (_NSIG_WORDS == 1)
  43                 set->sig[0] |= 1UL << sig;
  44         else
  45                 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
  46 }
  47
  48 static inline void sigdelset(sigset_t *set, int _sig)
  49 {
  50         unsigned long sig = _sig - 1;
  51         if (_NSIG_WORDS == 1)
  52                 set->sig[0] &= ~(1UL << sig);
  53         else
  54                 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
  55 }
  56
  57 static inline int sigismember(sigset_t *set, int _sig)
  58 {
  59         unsigned long sig = _sig - 1;
  60         if (_NSIG_WORDS == 1)
  61                 return 1 & (set->sig[0] >> sig);
  62         else
  63                 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
  64 }
  65
  66 static inline int sigfindinword(unsigned long word)
  67 {
  68         return ffz(~word);
  69 }
  70
  71 #endif /* __HAVE_ARCH_SIG_BITOPS */
  72
  73 static inline int sigisemptyset(sigset_t *set)
  74 {
  75         extern void _NSIG_WORDS_is_unsupported_size(void);
  76         switch (_NSIG_WORDS) {
  77         case 4:
  78                 return (set->sig[3] | set->sig[2] |
  79                         set->sig[1] | set->sig[0]) == 0;
  80         case 2:
  81                 return (set->sig[1] | set->sig[0]) == 0;
  82         case 1:
  83                 return set->sig[0] == 0;
  84         default:
  85                 _NSIG_WORDS_is_unsupported_size();
  86                 return 0;
  87         }
  88 }
  89
  90 #define sigmask(sig)    (1UL << ((sig) - 1))
  91
  92 #ifndef __HAVE_ARCH_SIG_SETOPS
  93 #include <linux/string.h>
  94
  95 #define _SIG_SET_BINOP(name, op)                                        \
  96 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
  97 {                                                                       \
  98         extern void _NSIG_WORDS_is_unsupported_size(void);              \
  99         unsigned long a0, a1, a2, a3, b0, b1, b2, b3;                   \
 100                                                                         \
 101         switch (_NSIG_WORDS) {                                          \
 102             case 4:                                                     \
 103                 a3 = a->sig[3]; a2 = a->sig[2];                         \
 104                 b3 = b->sig[3]; b2 = b->sig[2];                         \
 105                 r->sig[3] = op(a3, b3);                                 \
 106                 r->sig[2] = op(a2, b2);                                 \
 107             case 2:                                                     \
 108                 a1 = a->sig[1]; b1 = b->sig[1];                         \
 109                 r->sig[1] = op(a1, b1);                                 \
 110             case 1:                                                     \
 111                 a0 = a->sig[0]; b0 = b->sig[0];                         \
 112                 r->sig[0] = op(a0, b0);                                 \
 113                 break;                                                  \
 114             default:                                                    \
 115                 _NSIG_WORDS_is_unsupported_size();                      \
 116         }                                                               \
 117 }
 118
 119 #define _sig_or(x,y)    ((x) | (y))
 120 _SIG_SET_BINOP(sigorsets, _sig_or)
 121
 122 #define _sig_and(x,y)   ((x) & (y))
 123 _SIG_SET_BINOP(sigandsets, _sig_and)
 124
 125 #define _sig_andn(x,y)  ((x) & ~(y))
 126 _SIG_SET_BINOP(sigandnsets, _sig_andn)
 127
 128 #undef _SIG_SET_BINOP
 129 #undef _sig_or
 130 #undef _sig_and
 131 #undef _sig_andn
 132
 133 #define _SIG_SET_OP(name, op)                                           \
 134 static inline void name(sigset_t *set)                                  \
 135 {                                                                       \
 136         extern void _NSIG_WORDS_is_unsupported_size(void);              \
 137                                                                         \
 138         switch (_NSIG_WORDS) {                                          \
 139             case 4: set->sig[3] = op(set->sig[3]);                      \
 140                     set->sig[2] = op(set->sig[2]);                      \
 141             case 2: set->sig[1] = op(set->sig[1]);                      \
 142             case 1: set->sig[0] = op(set->sig[0]);                      \
 143                     break;                                              \
 144             default:                                                    \
 145                 _NSIG_WORDS_is_unsupported_size();                      \
 146         }                                                               \
 147 }
 148
 149 #define _sig_not(x)     (~(x))
 150 _SIG_SET_OP(signotset, _sig_not)
 151
 152 #undef _SIG_SET_OP
 153 #undef _sig_not
 154
 155 static inline void sigemptyset(sigset_t *set)
 156 {
 157         switch (_NSIG_WORDS) {
 158         default:
 159                 memset(set, 0, sizeof(sigset_t));
 160                 break;
 161         case 2: set->sig[1] = 0;
 162         case 1: set->sig[0] = 0;
 163                 break;
 164         }
 165 }
 166
 167 static inline void sigfillset(sigset_t *set)
 168 {
 169         switch (_NSIG_WORDS) {
 170         default:
 171                 memset(set, -1, sizeof(sigset_t));
 172                 break;
 173         case 2: set->sig[1] = -1;
 174         case 1: set->sig[0] = -1;
 175                 break;
 176         }
 177 }
 178
 179 /* Some extensions for manipulating the low 32 signals in particular.  */
 180
 181 static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
 182 {
 183         set->sig[0] |= mask;
 184 }
 185
 186 static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
 187 {
 188         set->sig[0] &= ~mask;
 189 }
 190
 191 static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
 192 {
 193         return (set->sig[0] & mask) != 0;
 194 }
 195
 196 static inline void siginitset(sigset_t *set, unsigned long mask)
 197 {
 198         set->sig[0] = mask;
 199         switch (_NSIG_WORDS) {
 200         default:
 201                 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
 202                 break;
 203         case 2: set->sig[1] = 0;
 204         case 1: ;
 205         }
 206 }
 207
 208 static inline void siginitsetinv(sigset_t *set, unsigned long mask)
 209 {
 210         set->sig[0] = ~mask;
 211         switch (_NSIG_WORDS) {
 212         default:
 213                 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
 214                 break;
 215         case 2: set->sig[1] = -1;
 216         case 1: ;
 217         }
 218 }
 219
 220 #endif /* __HAVE_ARCH_SIG_SETOPS */
 221
 222 static inline void init_sigpending(struct sigpending *sig)
 223 {
 224         sigemptyset(&sig->signal);
 225         INIT_LIST_HEAD(&sig->list);
 226 }
 227
 228 extern void flush_sigqueue(struct sigpending *queue);
 229
 230 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
 231 static inline int valid_signal(unsigned long sig)
 232 {
 233         return sig <= _NSIG ? 1 : 0;
 234 }
 235
 236 struct timespec;
 237 struct pt_regs;
 238
 239 extern int next_signal(struct sigpending *pending, sigset_t *mask);
 240 extern int do_send_sig_info(int sig, struct siginfo *info,
 241                                 struct task_struct *p, bool group);
 242 extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
 243 extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
 244 extern int do_sigtimedwait(const sigset_t *, siginfo_t *,
 245                                 const struct timespec *);
 246 extern int sigprocmask(int, sigset_t *, sigset_t *);
 247 extern void set_current_blocked(sigset_t *);
 248 extern void __set_current_blocked(const sigset_t *);
 249 extern int show_unhandled_signals;
 250 extern int sigsuspend(sigset_t *);
 251
 252 struct sigaction {
 253 #ifndef __ARCH_HAS_IRIX_SIGACTION
 254         __sighandler_t  sa_handler;
 255         unsigned long   sa_flags;
 256 #else
 257         unsigned int    sa_flags;
 258         __sighandler_t  sa_handler;
 259 #endif
 260 #ifdef __ARCH_HAS_SA_RESTORER
 261         __sigrestore_t sa_restorer;
 262 #endif
 263         sigset_t        sa_mask;        /* mask last for extensibility */
 264 };
 265
 266 struct k_sigaction {
 267         struct sigaction sa;
 268 #ifdef __ARCH_HAS_KA_RESTORER
 269         __sigrestore_t ka_restorer;
 270 #endif
 271 };
 272
 273 #ifdef CONFIG_OLD_SIGACTION
 274 struct old_sigaction {
 275         __sighandler_t sa_handler;
 276         old_sigset_t sa_mask;
 277         unsigned long sa_flags;
 278         __sigrestore_t sa_restorer;
 279 };
 280 #endif
 281
 282 struct ksignal {
 283         struct k_sigaction ka;
 284         siginfo_t info;
 285         int sig;
 286 };
 287
 288 extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
 289 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
 290 extern void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs *regs, int stepping);
 291 extern void exit_signals(struct task_struct *tsk);
 292
 293 /*
 294  * Eventually that'll replace get_signal_to_deliver(); macro for now,
 295  * to avoid nastiness with include order.
 296  */
 297 #define get_signal(ksig)                                        \
 298 ({                                                              \
 299         struct ksignal *p = (ksig);                             \
 300         p->sig = get_signal_to_deliver(&p->info, &p->ka,        \
 301                                         signal_pt_regs(), NULL);\
 302         p->sig > 0;                                             \
 303 })
 304
 305 extern struct kmem_cache *sighand_cachep;
 306
 307 int unhandled_signal(struct task_struct *tsk, int sig);
 308
 309 /*
 310  * In POSIX a signal is sent either to a specific thread (Linux task)
 311  * or to the process as a whole (Linux thread group).  How the signal
 312  * is sent determines whether it's to one thread or the whole group,
 313  * which determines which signal mask(s) are involved in blocking it
 314  * from being delivered until later.  When the signal is delivered,
 315  * either it's caught or ignored by a user handler or it has a default
 316  * effect that applies to the whole thread group (POSIX process).
 317  *
 318  * The possible effects an unblocked signal set to SIG_DFL can have are:
 319  *   ignore     - Nothing Happens
 320  *   terminate  - kill the process, i.e. all threads in the group,
 321  *                similar to exit_group.  The group leader (only) reports
 322  *                WIFSIGNALED status to its parent.
 323  *   coredump   - write a core dump file describing all threads using
 324  *                the same mm and then kill all those threads
 325  *   stop       - stop all the threads in the group, i.e. TASK_STOPPED state
 326  *
 327  * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
 328  * Other signals when not blocked and set to SIG_DFL behaves as follows.
 329  * The job control signals also have other special effects.
 330  *
 331  *      +--------------------+------------------+
 332  *      |  POSIX signal      |  default action  |
 333  *      +--------------------+------------------+
 334  *      |  SIGHUP            |  terminate       |
 335  *      |  SIGINT            |  terminate       |
 336  *      |  SIGQUIT           |  coredump        |
 337  *      |  SIGILL            |  coredump        |
 338  *      |  SIGTRAP           |  coredump        |
 339  *      |  SIGABRT/SIGIOT    |  coredump        |
 340  *      |  SIGBUS            |  coredump        |
 341  *      |  SIGFPE            |  coredump        |
 342  *      |  SIGKILL           |  terminate(+)    |
 343  *      |  SIGUSR1           |  terminate       |
 344  *      |  SIGSEGV           |  coredump        |
 345  *      |  SIGUSR2           |  terminate       |
 346  *      |  SIGPIPE           |  terminate       |
 347  *      |  SIGALRM           |  terminate       |
 348  *      |  SIGTERM           |  terminate       |
 349  *      |  SIGCHLD           |  ignore          |
 350  *      |  SIGCONT           |  ignore(*)       |
 351  *      |  SIGSTOP           |  stop(*)(+)      |
 352  *      |  SIGTSTP           |  stop(*)         |
 353  *      |  SIGTTIN           |  stop(*)         |
 354  *      |  SIGTTOU           |  stop(*)         |
 355  *      |  SIGURG            |  ignore          |
 356  *      |  SIGXCPU           |  coredump        |
 357  *      |  SIGXFSZ           |  coredump        |
 358  *      |  SIGVTALRM         |  terminate       |
 359  *      |  SIGPROF           |  terminate       |
 360  *      |  SIGPOLL/SIGIO     |  terminate       |
 361  *      |  SIGSYS/SIGUNUSED  |  coredump        |
 362  *      |  SIGSTKFLT         |  terminate       |
 363  *      |  SIGWINCH          |  ignore          |
 364  *      |  SIGPWR            |  terminate       |
 365  *      |  SIGRTMIN-SIGRTMAX |  terminate       |
 366  *      +--------------------+------------------+
 367  *      |  non-POSIX signal  |  default action  |
 368  *      +--------------------+------------------+
 369  *      |  SIGEMT            |  coredump        |
 370  *      +--------------------+------------------+
 371  *
 372  * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
 373  * (*) Special job control effects:
 374  * When SIGCONT is sent, it resumes the process (all threads in the group)
 375  * from TASK_STOPPED state and also clears any pending/queued stop signals
 376  * (any of those marked with "stop(*)").  This happens regardless of blocking,
 377  * catching, or ignoring SIGCONT.  When any stop signal is sent, it clears
 378  * any pending/queued SIGCONT signals; this happens regardless of blocking,
 379  * catching, or ignored the stop signal, though (except for SIGSTOP) the
 380  * default action of stopping the process may happen later or never.
 381  */
 382
 383 #ifdef SIGEMT
 384 #define SIGEMT_MASK     rt_sigmask(SIGEMT)
 385 #else
 386 #define SIGEMT_MASK     0
 387 #endif
 388
 389 #if SIGRTMIN > BITS_PER_LONG
 390 #define rt_sigmask(sig) (1ULL << ((sig)-1))
 391 #else
 392 #define rt_sigmask(sig) sigmask(sig)
 393 #endif
 394 #define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
 395
 396 #define SIG_KERNEL_ONLY_MASK (\
 397         rt_sigmask(SIGKILL)   |  rt_sigmask(SIGSTOP))
 398
 399 #define SIG_KERNEL_STOP_MASK (\
 400         rt_sigmask(SIGSTOP)   |  rt_sigmask(SIGTSTP)   | \
 401         rt_sigmask(SIGTTIN)   |  rt_sigmask(SIGTTOU)   )
 402
 403 #define SIG_KERNEL_COREDUMP_MASK (\
 404         rt_sigmask(SIGQUIT)   |  rt_sigmask(SIGILL)    | \
 405         rt_sigmask(SIGTRAP)   |  rt_sigmask(SIGABRT)   | \
 406         rt_sigmask(SIGFPE)    |  rt_sigmask(SIGSEGV)   | \
 407         rt_sigmask(SIGBUS)    |  rt_sigmask(SIGSYS)    | \
 408         rt_sigmask(SIGXCPU)   |  rt_sigmask(SIGXFSZ)   | \
 409         SIGEMT_MASK                                    )
 410
 411 #define SIG_KERNEL_IGNORE_MASK (\
 412         rt_sigmask(SIGCONT)   |  rt_sigmask(SIGCHLD)   | \
 413         rt_sigmask(SIGWINCH)  |  rt_sigmask(SIGURG)    )
 414
 415 #define sig_kernel_only(sig) \
 416         (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
 417 #define sig_kernel_coredump(sig) \
 418         (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
 419 #define sig_kernel_ignore(sig) \
 420         (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
 421 #define sig_kernel_stop(sig) \
 422         (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
 423
 424 #define sig_user_defined(t, signr) \
 425         (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) &&  \
 426          ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
 427
 428 #define sig_fatal(t, signr) \
 429         (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
 430          (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
 431
 432 void signals_init(void);
 433
 434 int restore_altstack(const stack_t __user *);
 435 int __save_altstack(stack_t __user *, unsigned long);
 436
 437 #ifdef CONFIG_PROC_FS
 438 struct seq_file;
 439 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
 440 #endif
 441
 442 #endif /* _LINUX_SIGNAL_H */