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