linux/include/linux/signal.h
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   1#ifndef _LINUX_SIGNAL_H
   2#define _LINUX_SIGNAL_H
   3
   4#include <linux/list.h>
   5#include <uapi/linux/signal.h>
   6
   7struct task_struct;
   8
   9/* for sysctl */
  10extern int print_fatal_signals;
  11/*
  12 * Real Time signals may be queued.
  13 */
  14
  15struct 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
  25struct 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.  */
  39static 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
  48static 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
  57static 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
  66static inline int sigfindinword(unsigned long word)
  67{
  68        return ffz(~word);
  69}
  70
  71#endif /* __HAVE_ARCH_SIG_BITOPS */
  72
  73static 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)                                        \
  96static 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)                                           \
 134static 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
 155static 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
 167static 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
 181static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
 182{
 183        set->sig[0] |= mask;
 184}
 185
 186static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
 187{
 188        set->sig[0] &= ~mask;
 189}
 190
 191static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
 192{
 193        return (set->sig[0] & mask) != 0;
 194}
 195
 196static 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
 208static 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
 222static inline void init_sigpending(struct sigpending *sig)
 223{
 224        sigemptyset(&sig->signal);
 225        INIT_LIST_HEAD(&sig->list);
 226}
 227
 228extern void flush_sigqueue(struct sigpending *queue);
 229
 230/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
 231static inline int valid_signal(unsigned long sig)
 232{
 233        return sig <= _NSIG ? 1 : 0;
 234}
 235
 236struct timespec;
 237struct pt_regs;
 238
 239extern int next_signal(struct sigpending *pending, sigset_t *mask);
 240extern int do_send_sig_info(int sig, struct siginfo *info,
 241                                struct task_struct *p, bool group);
 242extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p);
 243extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
 244extern long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig,
 245                                 siginfo_t *info);
 246extern long do_sigpending(void __user *, unsigned long);
 247extern int do_sigtimedwait(const sigset_t *, siginfo_t *,
 248                                const struct timespec *);
 249extern int sigprocmask(int, sigset_t *, sigset_t *);
 250extern void set_current_blocked(sigset_t *);
 251extern void __set_current_blocked(const sigset_t *);
 252extern int show_unhandled_signals;
 253extern int sigsuspend(sigset_t *);
 254
 255extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
 256extern void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka, struct pt_regs *regs, int stepping);
 257extern void exit_signals(struct task_struct *tsk);
 258
 259extern struct kmem_cache *sighand_cachep;
 260
 261int unhandled_signal(struct task_struct *tsk, int sig);
 262
 263/*
 264 * In POSIX a signal is sent either to a specific thread (Linux task)
 265 * or to the process as a whole (Linux thread group).  How the signal
 266 * is sent determines whether it's to one thread or the whole group,
 267 * which determines which signal mask(s) are involved in blocking it
 268 * from being delivered until later.  When the signal is delivered,
 269 * either it's caught or ignored by a user handler or it has a default
 270 * effect that applies to the whole thread group (POSIX process).
 271 *
 272 * The possible effects an unblocked signal set to SIG_DFL can have are:
 273 *   ignore     - Nothing Happens
 274 *   terminate  - kill the process, i.e. all threads in the group,
 275 *                similar to exit_group.  The group leader (only) reports
 276 *                WIFSIGNALED status to its parent.
 277 *   coredump   - write a core dump file describing all threads using
 278 *                the same mm and then kill all those threads
 279 *   stop       - stop all the threads in the group, i.e. TASK_STOPPED state
 280 *
 281 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
 282 * Other signals when not blocked and set to SIG_DFL behaves as follows.
 283 * The job control signals also have other special effects.
 284 *
 285 *      +--------------------+------------------+
 286 *      |  POSIX signal      |  default action  |
 287 *      +--------------------+------------------+
 288 *      |  SIGHUP            |  terminate       |
 289 *      |  SIGINT            |  terminate       |
 290 *      |  SIGQUIT           |  coredump        |
 291 *      |  SIGILL            |  coredump        |
 292 *      |  SIGTRAP           |  coredump        |
 293 *      |  SIGABRT/SIGIOT    |  coredump        |
 294 *      |  SIGBUS            |  coredump        |
 295 *      |  SIGFPE            |  coredump        |
 296 *      |  SIGKILL           |  terminate(+)    |
 297 *      |  SIGUSR1           |  terminate       |
 298 *      |  SIGSEGV           |  coredump        |
 299 *      |  SIGUSR2           |  terminate       |
 300 *      |  SIGPIPE           |  terminate       |
 301 *      |  SIGALRM           |  terminate       |
 302 *      |  SIGTERM           |  terminate       |
 303 *      |  SIGCHLD           |  ignore          |
 304 *      |  SIGCONT           |  ignore(*)       |
 305 *      |  SIGSTOP           |  stop(*)(+)      |
 306 *      |  SIGTSTP           |  stop(*)         |
 307 *      |  SIGTTIN           |  stop(*)         |
 308 *      |  SIGTTOU           |  stop(*)         |
 309 *      |  SIGURG            |  ignore          |
 310 *      |  SIGXCPU           |  coredump        |
 311 *      |  SIGXFSZ           |  coredump        |
 312 *      |  SIGVTALRM         |  terminate       |
 313 *      |  SIGPROF           |  terminate       |
 314 *      |  SIGPOLL/SIGIO     |  terminate       |
 315 *      |  SIGSYS/SIGUNUSED  |  coredump        |
 316 *      |  SIGSTKFLT         |  terminate       |
 317 *      |  SIGWINCH          |  ignore          |
 318 *      |  SIGPWR            |  terminate       |
 319 *      |  SIGRTMIN-SIGRTMAX |  terminate       |
 320 *      +--------------------+------------------+
 321 *      |  non-POSIX signal  |  default action  |
 322 *      +--------------------+------------------+
 323 *      |  SIGEMT            |  coredump        |
 324 *      +--------------------+------------------+
 325 *
 326 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
 327 * (*) Special job control effects:
 328 * When SIGCONT is sent, it resumes the process (all threads in the group)
 329 * from TASK_STOPPED state and also clears any pending/queued stop signals
 330 * (any of those marked with "stop(*)").  This happens regardless of blocking,
 331 * catching, or ignoring SIGCONT.  When any stop signal is sent, it clears
 332 * any pending/queued SIGCONT signals; this happens regardless of blocking,
 333 * catching, or ignored the stop signal, though (except for SIGSTOP) the
 334 * default action of stopping the process may happen later or never.
 335 */
 336
 337#ifdef SIGEMT
 338#define SIGEMT_MASK     rt_sigmask(SIGEMT)
 339#else
 340#define SIGEMT_MASK     0
 341#endif
 342
 343#if SIGRTMIN > BITS_PER_LONG
 344#define rt_sigmask(sig) (1ULL << ((sig)-1))
 345#else
 346#define rt_sigmask(sig) sigmask(sig)
 347#endif
 348#define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
 349
 350#define SIG_KERNEL_ONLY_MASK (\
 351        rt_sigmask(SIGKILL)   |  rt_sigmask(SIGSTOP))
 352
 353#define SIG_KERNEL_STOP_MASK (\
 354        rt_sigmask(SIGSTOP)   |  rt_sigmask(SIGTSTP)   | \
 355        rt_sigmask(SIGTTIN)   |  rt_sigmask(SIGTTOU)   )
 356
 357#define SIG_KERNEL_COREDUMP_MASK (\
 358        rt_sigmask(SIGQUIT)   |  rt_sigmask(SIGILL)    | \
 359        rt_sigmask(SIGTRAP)   |  rt_sigmask(SIGABRT)   | \
 360        rt_sigmask(SIGFPE)    |  rt_sigmask(SIGSEGV)   | \
 361        rt_sigmask(SIGBUS)    |  rt_sigmask(SIGSYS)    | \
 362        rt_sigmask(SIGXCPU)   |  rt_sigmask(SIGXFSZ)   | \
 363        SIGEMT_MASK                                    )
 364
 365#define SIG_KERNEL_IGNORE_MASK (\
 366        rt_sigmask(SIGCONT)   |  rt_sigmask(SIGCHLD)   | \
 367        rt_sigmask(SIGWINCH)  |  rt_sigmask(SIGURG)    )
 368
 369#define sig_kernel_only(sig) \
 370        (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
 371#define sig_kernel_coredump(sig) \
 372        (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
 373#define sig_kernel_ignore(sig) \
 374        (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
 375#define sig_kernel_stop(sig) \
 376        (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
 377
 378#define sig_user_defined(t, signr) \
 379        (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) &&  \
 380         ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
 381
 382#define sig_fatal(t, signr) \
 383        (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
 384         (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
 385
 386void signals_init(void);
 387
 388int restore_altstack(const stack_t __user *);
 389int __save_altstack(stack_t __user *, unsigned long);
 390
 391#endif /* _LINUX_SIGNAL_H */
 392
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