linux/include/linux/signal.h History
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   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
  14struct 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
  24struct 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.  */
  38static 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
  47static 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
  56static 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
  65static inline int sigfindinword(unsigned long word)
  66{
  67        return ffz(~word);
  68}
  69
  70#endif /* __HAVE_ARCH_SIG_BITOPS */
  71
  72static 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)                                        \
  95static 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)                                           \
 133static 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
 154static 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
 166static 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
 180static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
 181{
 182        set->sig[0] |= mask;
 183}
 184
 185static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
 186{
 187        set->sig[0] &= ~mask;
 188}
 189
 190static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
 191{
 192        return (set->sig[0] & mask) != 0;
 193}
 194
 195static 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
 207static 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
 221static inline void init_sigpending(struct sigpending *sig)
 222{
 223        sigemptyset(&sig->signal);
 224        INIT_LIST_HEAD(&sig->list);
 225}
 226
 227extern void flush_sigqueue(struct sigpending *queue);
 228
 229/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
 230static inline int valid_signal(unsigned long sig)
 231{
 232        return sig <= _NSIG ? 1 : 0;
 233}
 234
 235extern int next_signal(struct sigpending *pending, sigset_t *mask);
 236extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
 237extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
 238extern long do_sigpending(void __user *, unsigned long);
 239extern int sigprocmask(int, sigset_t *, sigset_t *);
 240extern int show_unhandled_signals;
 241
 242struct pt_regs;
 243extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
 244extern void exit_signals(struct task_struct *tsk);
 245
 246extern struct kmem_cache *sighand_cachep;
 247
 248int 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
 375void signals_init(void);
 376
 377#endif /* __KERNEL__ */
 378
 379#endif /* _LINUX_SIGNAL_H */
 380
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