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