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