linux/include/linux/signal.h
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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
  10struct task_struct;
  11
  12/* for sysctl */
  13extern int print_fatal_signals;
  14/*
  15 * Real Time signals may be queued.
  16 */
  17
  18struct 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
  28struct 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.  */
  42static 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
  51static 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
  60static 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
  69static inline int sigfindinword(unsigned long word)
  70{
  71        return ffz(~word);
  72}
  73
  74#endif /* __HAVE_ARCH_SIG_BITOPS */
  75
  76static 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)                                        \
  99static 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)                                           \
 137static 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
 158static 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
 170static 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
 184static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
 185{
 186        set->sig[0] |= mask;
 187}
 188
 189static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
 190{
 191        set->sig[0] &= ~mask;
 192}
 193
 194static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
 195{
 196        return (set->sig[0] & mask) != 0;
 197}
 198
 199static 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
 211static 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
 225static inline void init_sigpending(struct sigpending *sig)
 226{
 227        sigemptyset(&sig->signal);
 228        INIT_LIST_HEAD(&sig->list);
 229}
 230
 231extern void flush_sigqueue(struct sigpending *queue);
 232
 233/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
 234static inline int valid_signal(unsigned long sig)
 235{
 236        return sig <= _NSIG ? 1 : 0;
 237}
 238
 239struct timespec;
 240struct pt_regs;
 241
 242extern int next_signal(struct sigpending *pending, sigset_t *mask);
 243extern int do_send_sig_info(int sig, struct siginfo *info,
 244                                struct task_struct *p, bool group);
 245extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
 246extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
 247extern long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig,
 248                                 siginfo_t *info);
 249extern long do_sigpending(void __user *, unsigned long);
 250extern int do_sigtimedwait(const sigset_t *, siginfo_t *,
 251                                const struct timespec *);
 252extern int sigprocmask(int, sigset_t *, sigset_t *);
 253extern void set_current_blocked(sigset_t *);
 254extern void __set_current_blocked(const sigset_t *);
 255extern int show_unhandled_signals;
 256extern int sigsuspend(sigset_t *);
 257
 258extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
 259extern void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs *regs, int stepping);
 260extern void exit_signals(struct task_struct *tsk);
 261
 262extern struct kmem_cache *sighand_cachep;
 263
 264int unhandled_signal(struct task_struct *tsk, int sig);
 265
 266/*
 267 * In POSIX a signal is sent either to a specific thread (Linux task)
 268 * or to the process as a whole (Linux thread group).  How the signal
 269 * is sent determines whether it's to one thread or the whole group,
 270 * which determines which signal mask(s) are involved in blocking it
 271 * from being delivered until later.  When the signal is delivered,
 272 * either it's caught or ignored by a user handler or it has a default
 273 * effect that applies to the whole thread group (POSIX process).
 274 *
 275 * The possible effects an unblocked signal set to SIG_DFL can have are:
 276 *   ignore     - Nothing Happens
 277 *   terminate  - kill the process, i.e. all threads in the group,
 278 *                similar to exit_group.  The group leader (only) reports
 279 *                WIFSIGNALED status to its parent.
 280 *   coredump   - write a core dump file describing all threads using
 281 *                the same mm and then kill all those threads
 282 *   stop       - stop all the threads in the group, i.e. TASK_STOPPED state
 283 *
 284 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
 285 * Other signals when not blocked and set to SIG_DFL behaves as follows.
 286 * The job control signals also have other special effects.
 287 *
 288 *      +--------------------+------------------+
 289 *      |  POSIX signal      |  default action  |
 290 *      +--------------------+------------------+
 291 *      |  SIGHUP            |  terminate       |
 292 *      |  SIGINT            |  terminate       |
 293 *      |  SIGQUIT           |  coredump        |
 294 *      |  SIGILL            |  coredump        |
 295 *      |  SIGTRAP           |  coredump        |
 296 *      |  SIGABRT/SIGIOT    |  coredump        |
 297 *      |  SIGBUS            |  coredump        |
 298 *      |  SIGFPE            |  coredump        |
 299 *      |  SIGKILL           |  terminate(+)    |
 300 *      |  SIGUSR1           |  terminate       |
 301 *      |  SIGSEGV           |  coredump        |
 302 *      |  SIGUSR2           |  terminate       |
 303 *      |  SIGPIPE           |  terminate       |
 304 *      |  SIGALRM           |  terminate       |
 305 *      |  SIGTERM           |  terminate       |
 306 *      |  SIGCHLD           |  ignore          |
 307 *      |  SIGCONT           |  ignore(*)       |
 308 *      |  SIGSTOP           |  stop(*)(+)      |
 309 *      |  SIGTSTP           |  stop(*)         |
 310 *      |  SIGTTIN           |  stop(*)         |
 311 *      |  SIGTTOU           |  stop(*)         |
 312 *      |  SIGURG            |  ignore          |
 313 *      |  SIGXCPU           |  coredump        |
 314 *      |  SIGXFSZ           |  coredump        |
 315 *      |  SIGVTALRM         |  terminate       |
 316 *      |  SIGPROF           |  terminate       |
 317 *      |  SIGPOLL/SIGIO     |  terminate       |
 318 *      |  SIGSYS/SIGUNUSED  |  coredump        |
 319 *      |  SIGSTKFLT         |  terminate       |
 320 *      |  SIGWINCH          |  ignore          |
 321 *      |  SIGPWR            |  terminate       |
 322 *      |  SIGRTMIN-SIGRTMAX |  terminate       |
 323 *      +--------------------+------------------+
 324 *      |  non-POSIX signal  |  default action  |
 325 *      +--------------------+------------------+
 326 *      |  SIGEMT            |  coredump        |
 327 *      +--------------------+------------------+
 328 *
 329 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
 330 * (*) Special job control effects:
 331 * When SIGCONT is sent, it resumes the process (all threads in the group)
 332 * from TASK_STOPPED state and also clears any pending/queued stop signals
 333 * (any of those marked with "stop(*)").  This happens regardless of blocking,
 334 * catching, or ignoring SIGCONT.  When any stop signal is sent, it clears
 335 * any pending/queued SIGCONT signals; this happens regardless of blocking,
 336 * catching, or ignored the stop signal, though (except for SIGSTOP) the
 337 * default action of stopping the process may happen later or never.
 338 */
 339
 340#ifdef SIGEMT
 341#define SIGEMT_MASK     rt_sigmask(SIGEMT)
 342#else
 343#define SIGEMT_MASK     0
 344#endif
 345
 346#if SIGRTMIN > BITS_PER_LONG
 347#define rt_sigmask(sig) (1ULL << ((sig)-1))
 348#else
 349#define rt_sigmask(sig) sigmask(sig)
 350#endif
 351#define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
 352
 353#define SIG_KERNEL_ONLY_MASK (\
 354        rt_sigmask(SIGKILL)   |  rt_sigmask(SIGSTOP))
 355
 356#define SIG_KERNEL_STOP_MASK (\
 357        rt_sigmask(SIGSTOP)   |  rt_sigmask(SIGTSTP)   | \
 358        rt_sigmask(SIGTTIN)   |  rt_sigmask(SIGTTOU)   )
 359
 360#define SIG_KERNEL_COREDUMP_MASK (\
 361        rt_sigmask(SIGQUIT)   |  rt_sigmask(SIGILL)    | \
 362        rt_sigmask(SIGTRAP)   |  rt_sigmask(SIGABRT)   | \
 363        rt_sigmask(SIGFPE)    |  rt_sigmask(SIGSEGV)   | \
 364        rt_sigmask(SIGBUS)    |  rt_sigmask(SIGSYS)    | \
 365        rt_sigmask(SIGXCPU)   |  rt_sigmask(SIGXFSZ)   | \
 366        SIGEMT_MASK                                    )
 367
 368#define SIG_KERNEL_IGNORE_MASK (\
 369        rt_sigmask(SIGCONT)   |  rt_sigmask(SIGCHLD)   | \
 370        rt_sigmask(SIGWINCH)  |  rt_sigmask(SIGURG)    )
 371
 372#define sig_kernel_only(sig) \
 373        (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
 374#define sig_kernel_coredump(sig) \
 375        (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
 376#define sig_kernel_ignore(sig) \
 377        (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
 378#define sig_kernel_stop(sig) \
 379        (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
 380
 381#define sig_user_defined(t, signr) \
 382        (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) &&  \
 383         ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
 384
 385#define sig_fatal(t, signr) \
 386        (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
 387         (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
 388
 389void signals_init(void);
 390
 391#endif /* __KERNEL__ */
 392
 393#endif /* _LINUX_SIGNAL_H */
 394
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