1 /* Copyright (C) 1991-2003, 2004, 2007, 2009 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <http://www.gnu.org/licenses/>.  */
17 
18 /*
19  *	ISO C99 Standard: 7.14 Signal handling <signal.h>
20  */
21 
22 #ifndef	_SIGNAL_H
23 
24 #if !defined __need_sig_atomic_t && !defined __need_sigset_t
25 # define _SIGNAL_H
26 #endif
27 
28 #include <features.h>
29 
30 __BEGIN_DECLS
31 
32 #include <bits/sigset.h>		/* __sigset_t, __sig_atomic_t.  */
33 
34 /* An integral type that can be modified atomically, without the
35    possibility of a signal arriving in the middle of the operation.  */
36 #if defined __need_sig_atomic_t || defined _SIGNAL_H
37 # ifndef __sig_atomic_t_defined
38 #  define __sig_atomic_t_defined
39 __BEGIN_NAMESPACE_STD
40 typedef __sig_atomic_t sig_atomic_t;
41 __END_NAMESPACE_STD
42 # endif
43 # undef __need_sig_atomic_t
44 #endif
45 
46 #if defined __need_sigset_t || (defined _SIGNAL_H && defined __USE_POSIX)
47 # ifndef __sigset_t_defined
48 #  define __sigset_t_defined
49 typedef __sigset_t sigset_t;
50 # endif
51 # undef __need_sigset_t
52 #endif
53 
54 #ifdef _SIGNAL_H
55 
56 #include <bits/types.h>
57 #include <bits/signum.h>
58 
59 /* Fake signal functions.  */
60 #define SIG_ERR    ((__sighandler_t) -1) /* Error return.  */
61 #define SIG_DFL    ((__sighandler_t) 0)  /* Default action.  */
62 #define SIG_IGN    ((__sighandler_t) 1)  /* Ignore signal.  */
63 #ifdef __USE_UNIX98
64 # define SIG_HOLD  ((__sighandler_t) 2)  /* Add signal to hold mask.  */
65 #endif
66 /* Biggest signal number + 1 (including real-time signals).  */
67 #ifndef _NSIG /* if arch has not defined it in bits/signum.h... */
68 # define _NSIG 65
69 #endif
70 #ifdef __USE_MISC
71 # define NSIG _NSIG
72 #endif
73 /* Real-time signal range */
74 #define SIGRTMIN   (__libc_current_sigrtmin())
75 #define SIGRTMAX   (__libc_current_sigrtmax())
76 /* These are the hard limits of the kernel.  These values should not be
77    used directly at user level.  */
78 #ifndef __SIGRTMIN /* if arch has not defined it in bits/signum.h... */
79 # define __SIGRTMIN 32
80 #endif
81 #define __SIGRTMAX (_NSIG - 1)
82 
83 
84 #if defined __USE_XOPEN || defined __USE_XOPEN2K
85 # ifndef __pid_t_defined
86 typedef __pid_t pid_t;
87 #  define __pid_t_defined
88 # endif
89 #endif
90 #ifdef __USE_XOPEN
91 # ifndef __uid_t_defined
92 typedef __uid_t uid_t;
93 #  define __uid_t_defined
94 # endif
95 #endif	/* Unix98 */
96 
97 #if defined __USE_POSIX199309 && defined __UCLIBC_HAS_REALTIME__
98 /* We need `struct timespec' later on.  */
99 # define __need_timespec
100 # include <time.h>
101 #endif
102 
103 #if defined __USE_POSIX199309 || defined __USE_XOPEN_EXTENDED
104 /* Get the `siginfo_t' type plus the needed symbols.  */
105 # include <bits/siginfo.h>
106 #endif
107 
108 
109 /* Type of a signal handler.  */
110 typedef void (*__sighandler_t) (int);
111 
112 #if defined __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__
113 /* The X/Open definition of `signal' specifies the SVID semantic.  Use
114    the additional function `sysv_signal' when X/Open compatibility is
115    requested.  */
116 extern __sighandler_t __sysv_signal (int __sig, __sighandler_t __handler)
117      __THROW;
118 # ifdef __USE_GNU
119 extern __sighandler_t sysv_signal (int __sig, __sighandler_t __handler)
120      __THROW;
121 # endif
122 #endif /* __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__ */
123 
124 /* Set the handler for the signal SIG to HANDLER, returning the old
125    handler, or SIG_ERR on error.
126    By default `signal' has the BSD semantic.  */
127 __BEGIN_NAMESPACE_STD
128 #if defined __USE_BSD || !defined __UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL__
129 extern __sighandler_t signal (int __sig, __sighandler_t __handler)
130      __THROW;
131 libc_hidden_proto(signal)
132 #else
133 /* Make sure the used `signal' implementation is the SVID version. */
134 # ifdef __REDIRECT_NTH
135 extern __sighandler_t __REDIRECT_NTH (signal,
136 				      (int __sig, __sighandler_t __handler),
137 				      __sysv_signal);
138 # else
139 #  define signal __sysv_signal
140 # endif
141 #endif
142 __END_NAMESPACE_STD
143 
144 #if defined __USE_XOPEN && defined __UCLIBC_SUSV3_LEGACY__
145 /* The X/Open definition of `signal' conflicts with the BSD version.
146    So they defined another function `bsd_signal'.  */
147 extern __sighandler_t bsd_signal (int __sig, __sighandler_t __handler)
148      __THROW;
149 #endif
150 
151 /* Send signal SIG to process number PID.  If PID is zero,
152    send SIG to all processes in the current process's process group.
153    If PID is < -1, send SIG to all processes in process group - PID.  */
154 #ifdef __USE_POSIX
155 extern int kill (__pid_t __pid, int __sig) __THROW;
156 libc_hidden_proto(kill)
157 #endif
158 
159 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
160 /* Send SIG to all processes in process group PGRP.
161    If PGRP is zero, send SIG to all processes in
162    the current process's process group.  */
163 extern int killpg (__pid_t __pgrp, int __sig) __THROW;
164 #endif
165 
166 __BEGIN_NAMESPACE_STD
167 /* Raise signal SIG, i.e., send SIG to yourself.  */
168 extern int raise (int __sig) __THROW;
169 libc_hidden_proto(raise)
170 __END_NAMESPACE_STD
171 
172 #if 0 /*def __USE_SVID*/
173 /* SVID names for the same things.  */
174 extern __sighandler_t ssignal (int __sig, __sighandler_t __handler)
175      __THROW;
176 extern int gsignal (int __sig) __THROW;
177 #endif /* Use SVID.  */
178 
179 /* glibc guards the next two wrong with __USE_XOPEN2K */
180 #if defined __USE_MISC || defined __USE_XOPEN2K8
181 /* Print a message describing the meaning of the given signal number.  */
182 extern void psignal (int __sig, const char *__s);
183 #endif /* Use misc or POSIX 2008.  */
184 
185 #if 0 /*def __USE_XOPEN2K8*/
186 /* Print a message describing the meaning of the given signal information.  */
187 extern void psiginfo (const siginfo_t *__pinfo, const char *__s);
188 #endif /* POSIX 2008.  */
189 
190 #ifdef __UCLIBC_SUSV4_LEGACY__
191 /* The `sigpause' function has two different interfaces.  The original
192    BSD definition defines the argument as a mask of the signal, while
193    the more modern interface in X/Open defines it as the signal
194    number.  We go with the X/Open version.
195 
196    This function is a cancellation point and therefore not marked with
197    __THROW.  */
198 
199 # ifdef __USE_XOPEN_EXTENDED
200 /* Remove a signal from the signal mask and suspend the process.  */
201 extern int sigpause(int __sig);
202 # endif
203 #endif /* __UCLIBC_SUSV4_LEGACY__ */
204 
205 #if 0 /*def __USE_BSD*/
206 /* None of the following functions should be used anymore.  They are here
207    only for compatibility.  A single word (`int') is not guaranteed to be
208    enough to hold a complete signal mask and therefore these functions
209    simply do not work in many situations.  Use `sigprocmask' instead.  */
210 
211 /* Compute mask for signal SIG.  */
212 # define sigmask(sig)	__sigmask(sig)
213 
214 /* Block signals in MASK, returning the old mask.  */
215 extern int sigblock (int __mask) __THROW __attribute_deprecated__;
216 
217 /* Set the mask of blocked signals to MASK, returning the old mask.  */
218 extern int sigsetmask (int __mask) __THROW __attribute_deprecated__;
219 
220 /* Return currently selected signal mask.  */
221 extern int siggetmask (void) __THROW __attribute_deprecated__;
222 #endif /* Use BSD.  */
223 
224 
225 #ifdef __USE_GNU
226 typedef __sighandler_t sighandler_t;
227 #endif
228 
229 /* 4.4 BSD uses the name `sig_t' for this.  */
230 #ifdef __USE_BSD
231 typedef __sighandler_t sig_t;
232 #endif
233 
234 #ifdef __USE_POSIX
235 
236 /* Clear all signals from SET.  */
237 extern int sigemptyset (sigset_t *__set) __THROW __nonnull ((1));
238 
239 /* Set all signals in SET.  */
240 extern int sigfillset (sigset_t *__set) __THROW __nonnull ((1));
241 
242 /* Add SIGNO to SET.  */
243 extern int sigaddset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
244 libc_hidden_proto(sigaddset)
245 
246 /* Remove SIGNO from SET.  */
247 extern int sigdelset (sigset_t *__set, int __signo) __THROW __nonnull ((1));
248 libc_hidden_proto(sigdelset)
249 
250 /* Return 1 if SIGNO is in SET, 0 if not.  */
251 extern int sigismember (const sigset_t *__set, int __signo)
252      __THROW __nonnull ((1));
253 
254 # ifdef __USE_GNU
255 /* Return non-empty value is SET is not empty.  */
256 extern int sigisemptyset (const sigset_t *__set) __THROW __nonnull ((1));
257 
258 /* Build new signal set by combining the two inputs set using logical AND.  */
259 extern int sigandset (sigset_t *__set, const sigset_t *__left,
260 		      const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
261 
262 /* Build new signal set by combining the two inputs set using logical OR.  */
263 extern int sigorset (sigset_t *__set, const sigset_t *__left,
264 		     const sigset_t *__right) __THROW __nonnull ((1, 2, 3));
265 # endif /* GNU */
266 
267 /* Get the system-specific definitions of `struct sigaction'
268    and the `SA_*' and `SIG_*'. constants.  */
269 # include <bits/sigaction.h>
270 
271 /* Get and/or change the set of blocked signals.  */
272 extern int sigprocmask (int __how, const sigset_t *__restrict __set,
273 			sigset_t *__restrict __oset) __THROW;
274 libc_hidden_proto(sigprocmask)
275 
276 /* Change the set of blocked signals to SET,
277    wait until a signal arrives, and restore the set of blocked signals.
278 
279    This function is a cancellation point and therefore not marked with
280    __THROW.  */
281 extern int sigsuspend (const sigset_t *__set) __nonnull ((1));
282 #ifdef _LIBC
283 extern __typeof(sigsuspend) __sigsuspend_nocancel attribute_hidden;
284 libc_hidden_proto(sigsuspend)
285 #endif
286 
287 /* Get and/or set the action for signal SIG.  */
288 extern int sigaction (int __sig, const struct sigaction *__restrict __act,
289 		      struct sigaction *__restrict __oact) __THROW;
290 #ifdef _LIBC
291 # if 0 /* this is in headers */
292 /* In uclibc, userspace struct sigaction is identical to
293  * "new" struct kernel_sigaction (one from the Linux 2.1.68 kernel).
294  * See sigaction.h
295  */
296 struct old_kernel_sigaction;
297 extern int __syscall_sigaction(int, const struct old_kernel_sigaction *,
298 	struct old_kernel_sigaction *) attribute_hidden;
299 # else /* this is how the function is built */
300 extern __typeof(sigaction) __syscall_sigaction attribute_hidden;
301 # endif
302 # define __need_size_t
303 # include <stddef.h>
304 /* candidate for attribute_hidden, if NPTL would behave */
305 extern int __syscall_rt_sigaction(int, const struct sigaction *,
306 	struct sigaction *, size_t)
307 # ifndef __UCLIBC_HAS_THREADS_NATIVE__
308 		attribute_hidden
309 # endif
310 	;
311 extern __typeof(sigaction) __libc_sigaction;
312 libc_hidden_proto(sigaction)
313 
314 # ifdef __mips__
315 #  define _KERNEL_NSIG_WORDS (_NSIG / _MIPS_SZLONG)
316 typedef struct {
317 	unsigned long sig[_KERNEL_NSIG_WORDS];
318 } kernel_sigset_t;
319 #  define __SYSCALL_SIGSET_T_SIZE (sizeof(kernel_sigset_t))
320 # else
321 #  define __SYSCALL_SIGSET_T_SIZE (_NSIG / 8)
322 # endif
323 #endif
324 
325 /* Put in SET all signals that are blocked and waiting to be delivered.  */
326 extern int sigpending (sigset_t *__set) __THROW __nonnull ((1));
327 
328 
329 /* Select any of pending signals from SET or wait for any to arrive.
330 
331    This function is a cancellation point and therefore not marked with
332    __THROW.  */
333 extern int sigwait (const sigset_t *__restrict __set, int *__restrict __sig)
334      __nonnull ((1, 2));
335 
336 # if defined __USE_POSIX199309 && defined __UCLIBC_HAS_REALTIME__
337 /* Select any of pending signals from SET and place information in INFO.
338 
339    This function is a cancellation point and therefore not marked with
340    __THROW.  */
341 extern int sigwaitinfo (const sigset_t *__restrict __set,
342 			siginfo_t *__restrict __info) __nonnull ((1));
343 #ifdef _LIBC
344 extern __typeof(sigwaitinfo) __sigwaitinfo attribute_hidden;
345 #endif
346 
347 /* Select any of pending signals from SET and place information in INFO.
348    Wait the time specified by TIMEOUT if no signal is pending.
349 
350    This function is a cancellation point and therefore not marked with
351    __THROW.  */
352 extern int sigtimedwait (const sigset_t *__restrict __set,
353 			 siginfo_t *__restrict __info,
354 			 const struct timespec *__restrict __timeout)
355      __nonnull ((1));
356 #ifdef _LIBC
357 extern __typeof(sigtimedwait) __sigtimedwait_nocancel attribute_hidden;
358 libc_hidden_proto(sigtimedwait)
359 #endif
360 
361 /* Send signal SIG to the process PID.  Associate data in VAL with the
362    signal.  */
363 extern int sigqueue (__pid_t __pid, int __sig, const union sigval __val)
364      __THROW;
365 # endif	/* Use POSIX 199306.  */
366 
367 #endif /* Use POSIX.  */
368 
369 #ifdef __USE_BSD
370 
371 # ifdef __UCLIBC_HAS_SYS_SIGLIST__
372 /* Names of the signals.  This variable exists only for compatibility.
373    Use `strsignal' instead (see <string.h>).  */
374 #  define _sys_siglist sys_siglist
375 extern const char *const sys_siglist[_NSIG];
376 # endif
377 
378 #ifndef __UCLIBC_STRICT_HEADERS__
379 /* Structure passed to `sigvec'.  */
380 struct sigvec
381   {
382     __sighandler_t sv_handler;	/* Signal handler.  */
383     int sv_mask;		/* Mask of signals to be blocked.  */
384 
385     int sv_flags;		/* Flags (see below).  */
386 # define sv_onstack	sv_flags /* 4.2 BSD compatibility.  */
387   };
388 
389 /* Bits in `sv_flags'.  */
390 # define SV_ONSTACK	(1 << 0)/* Take the signal on the signal stack.  */
391 # define SV_INTERRUPT	(1 << 1)/* Do not restart system calls.  */
392 # define SV_RESETHAND	(1 << 2)/* Reset handler to SIG_DFL on receipt.  */
393 #endif
394 
395 /* Get machine-dependent `struct sigcontext' and signal subcodes.  */
396 # include <bits/sigcontext.h>
397 
398 #endif /*  use BSD.  */
399 
400 
401 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
402 # define __need_size_t
403 # include <stddef.h>
404 
405 # ifdef __UCLIBC_SUSV4_LEGACY__
406 /* If INTERRUPT is nonzero, make signal SIG interrupt system calls
407    (causing them to fail with EINTR); if INTERRUPT is zero, make system
408    calls be restarted after signal SIG.  */
409 extern int siginterrupt (int __sig, int __interrupt) __THROW;
410 # endif
411 
412 # include <bits/sigstack.h>
413 # ifdef __USE_XOPEN
414 /* This will define `ucontext_t' and `mcontext_t'.  */
415 /* SuSv4 obsoleted include/ucontext.h */
416 #  include <sys/ucontext.h>
417 # endif
418 
419 # if 0
420 /* Run signals handlers on the stack specified by SS (if not NULL).
421    If OSS is not NULL, it is filled in with the old signal stack status.
422    This interface is obsolete and on many platform not implemented.  */
423 extern int sigstack (struct sigstack *__ss, struct sigstack *__oss)
424      __THROW __attribute_deprecated__;
425 # endif
426 
427 /* Alternate signal handler stack interface.
428    This interface should always be preferred over `sigstack'.  */
429 extern int sigaltstack (const struct sigaltstack *__restrict __ss,
430 			struct sigaltstack *__restrict __oss) __THROW;
431 
432 #endif /* use BSD or X/Open Unix.  */
433 
434 #if defined __USE_XOPEN_EXTENDED && defined __UCLIBC_HAS_OBSOLETE_BSD_SIGNAL__
435 /* Simplified interface for signal management.  */
436 
437 /* Add SIG to the calling process' signal mask.  */
438 extern int sighold (int __sig) __THROW;
439 
440 /* Remove SIG from the calling process' signal mask.  */
441 extern int sigrelse (int __sig) __THROW;
442 
443 /* Set the disposition of SIG to SIG_IGN.  */
444 extern int sigignore (int __sig) __THROW;
445 
446 /* Set the disposition of SIG.  */
447 extern __sighandler_t sigset (int __sig, __sighandler_t __disp) __THROW;
448 #endif
449 
450 #if defined __UCLIBC_HAS_THREADS__ && (defined __USE_POSIX199506 || defined __USE_UNIX98)
451 /* Some of the functions for handling signals in threaded programs must
452    be defined here.  */
453 # include <bits/pthreadtypes.h>
454 # include <bits/sigthread.h>
455 #endif
456 
457 /* The following functions are used internally in the C library and in
458    other code which need deep insights.  */
459 
460 /* Return number of available real-time signal with highest priority.  */
461 extern int __libc_current_sigrtmin (void) __THROW;
462 /* Return number of available real-time signal with lowest priority.  */
463 extern int __libc_current_sigrtmax (void) __THROW;
464 
465 #ifdef _LIBC
466 extern sigset_t _sigintr attribute_hidden;
467 # include <string.h>
468 #endif
469 #endif /* signal.h  */
470 
471 __END_DECLS
472 
473 #endif /* not signal.h */
474