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