1 #ifndef _LINUX_SIGNAL_H 2 #define _LINUX_SIGNAL_H 3 4 #include <linux/list.h> 5 #include <linux/bug.h> 6 #include <uapi/linux/signal.h> 7 8 struct task_struct; 9 10 /* for sysctl */ 11 extern int print_fatal_signals; 12 /* 13 * Real Time signals may be queued. 14 */ 15 16 struct sigqueue { 17 struct list_head list; 18 int flags; 19 siginfo_t info; 20 struct user_struct *user; 21 }; 22 23 /* flags values. */ 24 #define SIGQUEUE_PREALLOC 1 25 26 struct sigpending { 27 struct list_head list; 28 sigset_t signal; 29 }; 30 31 #ifndef HAVE_ARCH_COPY_SIGINFO 32 33 #include <linux/string.h> 34 35 static inline void copy_siginfo(struct siginfo *to, struct siginfo *from) 36 { 37 if (from->si_code < 0) 38 memcpy(to, from, sizeof(*to)); 39 else 40 /* _sigchld is currently the largest know union member */ 41 memcpy(to, from, __ARCH_SI_PREAMBLE_SIZE + sizeof(from->_sifields._sigchld)); 42 } 43 44 #endif 45 46 /* 47 * Define some primitives to manipulate sigset_t. 48 */ 49 50 #ifndef __HAVE_ARCH_SIG_BITOPS 51 #include <linux/bitops.h> 52 53 /* We don't use <linux/bitops.h> for these because there is no need to 54 be atomic. */ 55 static inline void sigaddset(sigset_t *set, int _sig) 56 { 57 unsigned long sig = _sig - 1; 58 if (_NSIG_WORDS == 1) 59 set->sig[0] |= 1UL << sig; 60 else 61 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW); 62 } 63 64 static inline void sigdelset(sigset_t *set, int _sig) 65 { 66 unsigned long sig = _sig - 1; 67 if (_NSIG_WORDS == 1) 68 set->sig[0] &= ~(1UL << sig); 69 else 70 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW)); 71 } 72 73 static inline int sigismember(sigset_t *set, int _sig) 74 { 75 unsigned long sig = _sig - 1; 76 if (_NSIG_WORDS == 1) 77 return 1 & (set->sig[0] >> sig); 78 else 79 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW)); 80 } 81 82 #endif /* __HAVE_ARCH_SIG_BITOPS */ 83 84 static inline int sigisemptyset(sigset_t *set) 85 { 86 switch (_NSIG_WORDS) { 87 case 4: 88 return (set->sig[3] | set->sig[2] | 89 set->sig[1] | set->sig[0]) == 0; 90 case 2: 91 return (set->sig[1] | set->sig[0]) == 0; 92 case 1: 93 return set->sig[0] == 0; 94 default: 95 BUILD_BUG(); 96 return 0; 97 } 98 } 99 100 static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2) 101 { 102 switch (_NSIG_WORDS) { 103 case 4: 104 return (set1->sig[3] == set2->sig[3]) && 105 (set1->sig[2] == set2->sig[2]) && 106 (set1->sig[1] == set2->sig[1]) && 107 (set1->sig[0] == set2->sig[0]); 108 case 2: 109 return (set1->sig[1] == set2->sig[1]) && 110 (set1->sig[0] == set2->sig[0]); 111 case 1: 112 return set1->sig[0] == set2->sig[0]; 113 } 114 return 0; 115 } 116 117 #define sigmask(sig) (1UL << ((sig) - 1)) 118 119 #ifndef __HAVE_ARCH_SIG_SETOPS 120 #include <linux/string.h> 121 122 #define _SIG_SET_BINOP(name, op) \ 123 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \ 124 { \ 125 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \ 126 \ 127 switch (_NSIG_WORDS) { \ 128 case 4: \ 129 a3 = a->sig[3]; a2 = a->sig[2]; \ 130 b3 = b->sig[3]; b2 = b->sig[2]; \ 131 r->sig[3] = op(a3, b3); \ 132 r->sig[2] = op(a2, b2); \ 133 case 2: \ 134 a1 = a->sig[1]; b1 = b->sig[1]; \ 135 r->sig[1] = op(a1, b1); \ 136 case 1: \ 137 a0 = a->sig[0]; b0 = b->sig[0]; \ 138 r->sig[0] = op(a0, b0); \ 139 break; \ 140 default: \ 141 BUILD_BUG(); \ 142 } \ 143 } 144 145 #define _sig_or(x,y) ((x) | (y)) 146 _SIG_SET_BINOP(sigorsets, _sig_or) 147 148 #define _sig_and(x,y) ((x) & (y)) 149 _SIG_SET_BINOP(sigandsets, _sig_and) 150 151 #define _sig_andn(x,y) ((x) & ~(y)) 152 _SIG_SET_BINOP(sigandnsets, _sig_andn) 153 154 #undef _SIG_SET_BINOP 155 #undef _sig_or 156 #undef _sig_and 157 #undef _sig_andn 158 159 #define _SIG_SET_OP(name, op) \ 160 static inline void name(sigset_t *set) \ 161 { \ 162 switch (_NSIG_WORDS) { \ 163 case 4: set->sig[3] = op(set->sig[3]); \ 164 set->sig[2] = op(set->sig[2]); \ 165 case 2: set->sig[1] = op(set->sig[1]); \ 166 case 1: set->sig[0] = op(set->sig[0]); \ 167 break; \ 168 default: \ 169 BUILD_BUG(); \ 170 } \ 171 } 172 173 #define _sig_not(x) (~(x)) 174 _SIG_SET_OP(signotset, _sig_not) 175 176 #undef _SIG_SET_OP 177 #undef _sig_not 178 179 static inline void sigemptyset(sigset_t *set) 180 { 181 switch (_NSIG_WORDS) { 182 default: 183 memset(set, 0, sizeof(sigset_t)); 184 break; 185 case 2: set->sig[1] = 0; 186 case 1: set->sig[0] = 0; 187 break; 188 } 189 } 190 191 static inline void sigfillset(sigset_t *set) 192 { 193 switch (_NSIG_WORDS) { 194 default: 195 memset(set, -1, sizeof(sigset_t)); 196 break; 197 case 2: set->sig[1] = -1; 198 case 1: set->sig[0] = -1; 199 break; 200 } 201 } 202 203 /* Some extensions for manipulating the low 32 signals in particular. */ 204 205 static inline void sigaddsetmask(sigset_t *set, unsigned long mask) 206 { 207 set->sig[0] |= mask; 208 } 209 210 static inline void sigdelsetmask(sigset_t *set, unsigned long mask) 211 { 212 set->sig[0] &= ~mask; 213 } 214 215 static inline int sigtestsetmask(sigset_t *set, unsigned long mask) 216 { 217 return (set->sig[0] & mask) != 0; 218 } 219 220 static inline void siginitset(sigset_t *set, unsigned long mask) 221 { 222 set->sig[0] = mask; 223 switch (_NSIG_WORDS) { 224 default: 225 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1)); 226 break; 227 case 2: set->sig[1] = 0; 228 case 1: ; 229 } 230 } 231 232 static inline void siginitsetinv(sigset_t *set, unsigned long mask) 233 { 234 set->sig[0] = ~mask; 235 switch (_NSIG_WORDS) { 236 default: 237 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1)); 238 break; 239 case 2: set->sig[1] = -1; 240 case 1: ; 241 } 242 } 243 244 #endif /* __HAVE_ARCH_SIG_SETOPS */ 245 246 static inline void init_sigpending(struct sigpending *sig) 247 { 248 sigemptyset(&sig->signal); 249 INIT_LIST_HEAD(&sig->list); 250 } 251 252 extern void flush_sigqueue(struct sigpending *queue); 253 254 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */ 255 static inline int valid_signal(unsigned long sig) 256 { 257 return sig <= _NSIG ? 1 : 0; 258 } 259 260 struct timespec; 261 struct pt_regs; 262 263 extern int next_signal(struct sigpending *pending, sigset_t *mask); 264 extern int do_send_sig_info(int sig, struct siginfo *info, 265 struct task_struct *p, bool group); 266 extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p); 267 extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *); 268 extern int do_sigtimedwait(const sigset_t *, siginfo_t *, 269 const struct timespec *); 270 extern int sigprocmask(int, sigset_t *, sigset_t *); 271 extern void set_current_blocked(sigset_t *); 272 extern void __set_current_blocked(const sigset_t *); 273 extern int show_unhandled_signals; 274 275 struct sigaction { 276 #ifndef __ARCH_HAS_IRIX_SIGACTION 277 __sighandler_t sa_handler; 278 unsigned long sa_flags; 279 #else 280 unsigned int sa_flags; 281 __sighandler_t sa_handler; 282 #endif 283 #ifdef __ARCH_HAS_SA_RESTORER 284 __sigrestore_t sa_restorer; 285 #endif 286 sigset_t sa_mask; /* mask last for extensibility */ 287 }; 288 289 struct k_sigaction { 290 struct sigaction sa; 291 #ifdef __ARCH_HAS_KA_RESTORER 292 __sigrestore_t ka_restorer; 293 #endif 294 }; 295 296 #ifdef CONFIG_OLD_SIGACTION 297 struct old_sigaction { 298 __sighandler_t sa_handler; 299 old_sigset_t sa_mask; 300 unsigned long sa_flags; 301 __sigrestore_t sa_restorer; 302 }; 303 #endif 304 305 struct ksignal { 306 struct k_sigaction ka; 307 siginfo_t info; 308 int sig; 309 }; 310 311 extern int get_signal(struct ksignal *ksig); 312 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping); 313 extern void exit_signals(struct task_struct *tsk); 314 extern void kernel_sigaction(int, __sighandler_t); 315 316 static inline void allow_signal(int sig) 317 { 318 /* 319 * Kernel threads handle their own signals. Let the signal code 320 * know it'll be handled, so that they don't get converted to 321 * SIGKILL or just silently dropped. 322 */ 323 kernel_sigaction(sig, (__force __sighandler_t)2); 324 } 325 326 static inline void disallow_signal(int sig) 327 { 328 kernel_sigaction(sig, SIG_IGN); 329 } 330 331 extern struct kmem_cache *sighand_cachep; 332 333 int unhandled_signal(struct task_struct *tsk, int sig); 334 335 /* 336 * In POSIX a signal is sent either to a specific thread (Linux task) 337 * or to the process as a whole (Linux thread group). How the signal 338 * is sent determines whether it's to one thread or the whole group, 339 * which determines which signal mask(s) are involved in blocking it 340 * from being delivered until later. When the signal is delivered, 341 * either it's caught or ignored by a user handler or it has a default 342 * effect that applies to the whole thread group (POSIX process). 343 * 344 * The possible effects an unblocked signal set to SIG_DFL can have are: 345 * ignore - Nothing Happens 346 * terminate - kill the process, i.e. all threads in the group, 347 * similar to exit_group. The group leader (only) reports 348 * WIFSIGNALED status to its parent. 349 * coredump - write a core dump file describing all threads using 350 * the same mm and then kill all those threads 351 * stop - stop all the threads in the group, i.e. TASK_STOPPED state 352 * 353 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored. 354 * Other signals when not blocked and set to SIG_DFL behaves as follows. 355 * The job control signals also have other special effects. 356 * 357 * +--------------------+------------------+ 358 * | POSIX signal | default action | 359 * +--------------------+------------------+ 360 * | SIGHUP | terminate | 361 * | SIGINT | terminate | 362 * | SIGQUIT | coredump | 363 * | SIGILL | coredump | 364 * | SIGTRAP | coredump | 365 * | SIGABRT/SIGIOT | coredump | 366 * | SIGBUS | coredump | 367 * | SIGFPE | coredump | 368 * | SIGKILL | terminate(+) | 369 * | SIGUSR1 | terminate | 370 * | SIGSEGV | coredump | 371 * | SIGUSR2 | terminate | 372 * | SIGPIPE | terminate | 373 * | SIGALRM | terminate | 374 * | SIGTERM | terminate | 375 * | SIGCHLD | ignore | 376 * | SIGCONT | ignore(*) | 377 * | SIGSTOP | stop(*)(+) | 378 * | SIGTSTP | stop(*) | 379 * | SIGTTIN | stop(*) | 380 * | SIGTTOU | stop(*) | 381 * | SIGURG | ignore | 382 * | SIGXCPU | coredump | 383 * | SIGXFSZ | coredump | 384 * | SIGVTALRM | terminate | 385 * | SIGPROF | terminate | 386 * | SIGPOLL/SIGIO | terminate | 387 * | SIGSYS/SIGUNUSED | coredump | 388 * | SIGSTKFLT | terminate | 389 * | SIGWINCH | ignore | 390 * | SIGPWR | terminate | 391 * | SIGRTMIN-SIGRTMAX | terminate | 392 * +--------------------+------------------+ 393 * | non-POSIX signal | default action | 394 * +--------------------+------------------+ 395 * | SIGEMT | coredump | 396 * +--------------------+------------------+ 397 * 398 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default". 399 * (*) Special job control effects: 400 * When SIGCONT is sent, it resumes the process (all threads in the group) 401 * from TASK_STOPPED state and also clears any pending/queued stop signals 402 * (any of those marked with "stop(*)"). This happens regardless of blocking, 403 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears 404 * any pending/queued SIGCONT signals; this happens regardless of blocking, 405 * catching, or ignored the stop signal, though (except for SIGSTOP) the 406 * default action of stopping the process may happen later or never. 407 */ 408 409 #ifdef SIGEMT 410 #define SIGEMT_MASK rt_sigmask(SIGEMT) 411 #else 412 #define SIGEMT_MASK 0 413 #endif 414 415 #if SIGRTMIN > BITS_PER_LONG 416 #define rt_sigmask(sig) (1ULL << ((sig)-1)) 417 #else 418 #define rt_sigmask(sig) sigmask(sig) 419 #endif 420 421 #define siginmask(sig, mask) \ 422 ((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask))) 423 424 #define SIG_KERNEL_ONLY_MASK (\ 425 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP)) 426 427 #define SIG_KERNEL_STOP_MASK (\ 428 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \ 429 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) ) 430 431 #define SIG_KERNEL_COREDUMP_MASK (\ 432 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \ 433 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \ 434 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \ 435 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \ 436 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \ 437 SIGEMT_MASK ) 438 439 #define SIG_KERNEL_IGNORE_MASK (\ 440 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \ 441 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) ) 442 443 #define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK) 444 #define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK) 445 #define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK) 446 #define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK) 447 448 #define sig_user_defined(t, signr) \ 449 (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \ 450 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN)) 451 452 #define sig_fatal(t, signr) \ 453 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \ 454 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL) 455 456 void signals_init(void); 457 458 int restore_altstack(const stack_t __user *); 459 int __save_altstack(stack_t __user *, unsigned long); 460 461 #define save_altstack_ex(uss, sp) do { \ 462 stack_t __user *__uss = uss; \ 463 struct task_struct *t = current; \ 464 put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \ 465 put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \ 466 put_user_ex(t->sas_ss_size, &__uss->ss_size); \ 467 if (t->sas_ss_flags & SS_AUTODISARM) \ 468 sas_ss_reset(t); \ 469 } while (0); 470 471 #ifdef CONFIG_PROC_FS 472 struct seq_file; 473 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *); 474 #endif 475 476 #endif /* _LINUX_SIGNAL_H */ 477