1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SIGNAL_H 3 #define _LINUX_SIGNAL_H 4 5 #include <linux/bug.h> 6 #include <linux/signal_types.h> 7 #include <linux/string.h> 8 9 struct task_struct; 10 11 /* for sysctl */ 12 extern int print_fatal_signals; 13 14 static inline void copy_siginfo(struct siginfo *to, struct siginfo *from) 15 { 16 if (from->si_code < 0) 17 memcpy(to, from, sizeof(*to)); 18 else 19 /* _sigchld is currently the largest know union member */ 20 memcpy(to, from, __ARCH_SI_PREAMBLE_SIZE + sizeof(from->_sifields._sigchld)); 21 } 22 23 int copy_siginfo_to_user(struct siginfo __user *to, const struct siginfo *from); 24 25 enum siginfo_layout { 26 SIL_KILL, 27 SIL_TIMER, 28 SIL_POLL, 29 SIL_FAULT, 30 SIL_CHLD, 31 SIL_RT, 32 #ifdef __ARCH_SIGSYS 33 SIL_SYS, 34 #endif 35 }; 36 37 enum siginfo_layout siginfo_layout(int sig, int si_code); 38 39 /* 40 * Define some primitives to manipulate sigset_t. 41 */ 42 43 #ifndef __HAVE_ARCH_SIG_BITOPS 44 #include <linux/bitops.h> 45 46 /* We don't use <linux/bitops.h> for these because there is no need to 47 be atomic. */ 48 static inline void sigaddset(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 57 static inline void sigdelset(sigset_t *set, int _sig) 58 { 59 unsigned long sig = _sig - 1; 60 if (_NSIG_WORDS == 1) 61 set->sig[0] &= ~(1UL << sig); 62 else 63 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW)); 64 } 65 66 static inline int sigismember(sigset_t *set, int _sig) 67 { 68 unsigned long sig = _sig - 1; 69 if (_NSIG_WORDS == 1) 70 return 1 & (set->sig[0] >> sig); 71 else 72 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW)); 73 } 74 75 #endif /* __HAVE_ARCH_SIG_BITOPS */ 76 77 static inline int sigisemptyset(sigset_t *set) 78 { 79 switch (_NSIG_WORDS) { 80 case 4: 81 return (set->sig[3] | set->sig[2] | 82 set->sig[1] | set->sig[0]) == 0; 83 case 2: 84 return (set->sig[1] | set->sig[0]) == 0; 85 case 1: 86 return set->sig[0] == 0; 87 default: 88 BUILD_BUG(); 89 return 0; 90 } 91 } 92 93 static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2) 94 { 95 switch (_NSIG_WORDS) { 96 case 4: 97 return (set1->sig[3] == set2->sig[3]) && 98 (set1->sig[2] == set2->sig[2]) && 99 (set1->sig[1] == set2->sig[1]) && 100 (set1->sig[0] == set2->sig[0]); 101 case 2: 102 return (set1->sig[1] == set2->sig[1]) && 103 (set1->sig[0] == set2->sig[0]); 104 case 1: 105 return set1->sig[0] == set2->sig[0]; 106 } 107 return 0; 108 } 109 110 #define sigmask(sig) (1UL << ((sig) - 1)) 111 112 #ifndef __HAVE_ARCH_SIG_SETOPS 113 #include <linux/string.h> 114 115 #define _SIG_SET_BINOP(name, op) \ 116 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \ 117 { \ 118 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \ 119 \ 120 switch (_NSIG_WORDS) { \ 121 case 4: \ 122 a3 = a->sig[3]; a2 = a->sig[2]; \ 123 b3 = b->sig[3]; b2 = b->sig[2]; \ 124 r->sig[3] = op(a3, b3); \ 125 r->sig[2] = op(a2, b2); \ 126 case 2: \ 127 a1 = a->sig[1]; b1 = b->sig[1]; \ 128 r->sig[1] = op(a1, b1); \ 129 case 1: \ 130 a0 = a->sig[0]; b0 = b->sig[0]; \ 131 r->sig[0] = op(a0, b0); \ 132 break; \ 133 default: \ 134 BUILD_BUG(); \ 135 } \ 136 } 137 138 #define _sig_or(x,y) ((x) | (y)) 139 _SIG_SET_BINOP(sigorsets, _sig_or) 140 141 #define _sig_and(x,y) ((x) & (y)) 142 _SIG_SET_BINOP(sigandsets, _sig_and) 143 144 #define _sig_andn(x,y) ((x) & ~(y)) 145 _SIG_SET_BINOP(sigandnsets, _sig_andn) 146 147 #undef _SIG_SET_BINOP 148 #undef _sig_or 149 #undef _sig_and 150 #undef _sig_andn 151 152 #define _SIG_SET_OP(name, op) \ 153 static inline void name(sigset_t *set) \ 154 { \ 155 switch (_NSIG_WORDS) { \ 156 case 4: set->sig[3] = op(set->sig[3]); \ 157 set->sig[2] = op(set->sig[2]); \ 158 case 2: set->sig[1] = op(set->sig[1]); \ 159 case 1: set->sig[0] = op(set->sig[0]); \ 160 break; \ 161 default: \ 162 BUILD_BUG(); \ 163 } \ 164 } 165 166 #define _sig_not(x) (~(x)) 167 _SIG_SET_OP(signotset, _sig_not) 168 169 #undef _SIG_SET_OP 170 #undef _sig_not 171 172 static inline void sigemptyset(sigset_t *set) 173 { 174 switch (_NSIG_WORDS) { 175 default: 176 memset(set, 0, sizeof(sigset_t)); 177 break; 178 case 2: set->sig[1] = 0; 179 case 1: set->sig[0] = 0; 180 break; 181 } 182 } 183 184 static inline void sigfillset(sigset_t *set) 185 { 186 switch (_NSIG_WORDS) { 187 default: 188 memset(set, -1, sizeof(sigset_t)); 189 break; 190 case 2: set->sig[1] = -1; 191 case 1: set->sig[0] = -1; 192 break; 193 } 194 } 195 196 /* Some extensions for manipulating the low 32 signals in particular. */ 197 198 static inline void sigaddsetmask(sigset_t *set, unsigned long mask) 199 { 200 set->sig[0] |= mask; 201 } 202 203 static inline void sigdelsetmask(sigset_t *set, unsigned long mask) 204 { 205 set->sig[0] &= ~mask; 206 } 207 208 static inline int sigtestsetmask(sigset_t *set, unsigned long mask) 209 { 210 return (set->sig[0] & mask) != 0; 211 } 212 213 static inline void siginitset(sigset_t *set, unsigned long mask) 214 { 215 set->sig[0] = mask; 216 switch (_NSIG_WORDS) { 217 default: 218 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1)); 219 break; 220 case 2: set->sig[1] = 0; 221 case 1: ; 222 } 223 } 224 225 static inline void siginitsetinv(sigset_t *set, unsigned long mask) 226 { 227 set->sig[0] = ~mask; 228 switch (_NSIG_WORDS) { 229 default: 230 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1)); 231 break; 232 case 2: set->sig[1] = -1; 233 case 1: ; 234 } 235 } 236 237 #endif /* __HAVE_ARCH_SIG_SETOPS */ 238 239 static inline void init_sigpending(struct sigpending *sig) 240 { 241 sigemptyset(&sig->signal); 242 INIT_LIST_HEAD(&sig->list); 243 } 244 245 extern void flush_sigqueue(struct sigpending *queue); 246 247 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */ 248 static inline int valid_signal(unsigned long sig) 249 { 250 return sig <= _NSIG ? 1 : 0; 251 } 252 253 struct timespec; 254 struct pt_regs; 255 256 extern int next_signal(struct sigpending *pending, sigset_t *mask); 257 extern int do_send_sig_info(int sig, struct siginfo *info, 258 struct task_struct *p, bool group); 259 extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p); 260 extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *); 261 extern int sigprocmask(int, sigset_t *, sigset_t *); 262 extern void set_current_blocked(sigset_t *); 263 extern void __set_current_blocked(const sigset_t *); 264 extern int show_unhandled_signals; 265 266 extern int get_signal(struct ksignal *ksig); 267 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping); 268 extern void exit_signals(struct task_struct *tsk); 269 extern void kernel_sigaction(int, __sighandler_t); 270 271 static inline void allow_signal(int sig) 272 { 273 /* 274 * Kernel threads handle their own signals. Let the signal code 275 * know it'll be handled, so that they don't get converted to 276 * SIGKILL or just silently dropped. 277 */ 278 kernel_sigaction(sig, (__force __sighandler_t)2); 279 } 280 281 static inline void disallow_signal(int sig) 282 { 283 kernel_sigaction(sig, SIG_IGN); 284 } 285 286 extern struct kmem_cache *sighand_cachep; 287 288 int unhandled_signal(struct task_struct *tsk, int sig); 289 290 /* 291 * In POSIX a signal is sent either to a specific thread (Linux task) 292 * or to the process as a whole (Linux thread group). How the signal 293 * is sent determines whether it's to one thread or the whole group, 294 * which determines which signal mask(s) are involved in blocking it 295 * from being delivered until later. When the signal is delivered, 296 * either it's caught or ignored by a user handler or it has a default 297 * effect that applies to the whole thread group (POSIX process). 298 * 299 * The possible effects an unblocked signal set to SIG_DFL can have are: 300 * ignore - Nothing Happens 301 * terminate - kill the process, i.e. all threads in the group, 302 * similar to exit_group. The group leader (only) reports 303 * WIFSIGNALED status to its parent. 304 * coredump - write a core dump file describing all threads using 305 * the same mm and then kill all those threads 306 * stop - stop all the threads in the group, i.e. TASK_STOPPED state 307 * 308 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored. 309 * Other signals when not blocked and set to SIG_DFL behaves as follows. 310 * The job control signals also have other special effects. 311 * 312 * +--------------------+------------------+ 313 * | POSIX signal | default action | 314 * +--------------------+------------------+ 315 * | SIGHUP | terminate | 316 * | SIGINT | terminate | 317 * | SIGQUIT | coredump | 318 * | SIGILL | coredump | 319 * | SIGTRAP | coredump | 320 * | SIGABRT/SIGIOT | coredump | 321 * | SIGBUS | coredump | 322 * | SIGFPE | coredump | 323 * | SIGKILL | terminate(+) | 324 * | SIGUSR1 | terminate | 325 * | SIGSEGV | coredump | 326 * | SIGUSR2 | terminate | 327 * | SIGPIPE | terminate | 328 * | SIGALRM | terminate | 329 * | SIGTERM | terminate | 330 * | SIGCHLD | ignore | 331 * | SIGCONT | ignore(*) | 332 * | SIGSTOP | stop(*)(+) | 333 * | SIGTSTP | stop(*) | 334 * | SIGTTIN | stop(*) | 335 * | SIGTTOU | stop(*) | 336 * | SIGURG | ignore | 337 * | SIGXCPU | coredump | 338 * | SIGXFSZ | coredump | 339 * | SIGVTALRM | terminate | 340 * | SIGPROF | terminate | 341 * | SIGPOLL/SIGIO | terminate | 342 * | SIGSYS/SIGUNUSED | coredump | 343 * | SIGSTKFLT | terminate | 344 * | SIGWINCH | ignore | 345 * | SIGPWR | terminate | 346 * | SIGRTMIN-SIGRTMAX | terminate | 347 * +--------------------+------------------+ 348 * | non-POSIX signal | default action | 349 * +--------------------+------------------+ 350 * | SIGEMT | coredump | 351 * +--------------------+------------------+ 352 * 353 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default". 354 * (*) Special job control effects: 355 * When SIGCONT is sent, it resumes the process (all threads in the group) 356 * from TASK_STOPPED state and also clears any pending/queued stop signals 357 * (any of those marked with "stop(*)"). This happens regardless of blocking, 358 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears 359 * any pending/queued SIGCONT signals; this happens regardless of blocking, 360 * catching, or ignored the stop signal, though (except for SIGSTOP) the 361 * default action of stopping the process may happen later or never. 362 */ 363 364 #ifdef SIGEMT 365 #define SIGEMT_MASK rt_sigmask(SIGEMT) 366 #else 367 #define SIGEMT_MASK 0 368 #endif 369 370 #if SIGRTMIN > BITS_PER_LONG 371 #define rt_sigmask(sig) (1ULL << ((sig)-1)) 372 #else 373 #define rt_sigmask(sig) sigmask(sig) 374 #endif 375 376 #define siginmask(sig, mask) \ 377 ((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask))) 378 379 #define SIG_KERNEL_ONLY_MASK (\ 380 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP)) 381 382 #define SIG_KERNEL_STOP_MASK (\ 383 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \ 384 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) ) 385 386 #define SIG_KERNEL_COREDUMP_MASK (\ 387 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \ 388 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \ 389 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \ 390 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \ 391 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \ 392 SIGEMT_MASK ) 393 394 #define SIG_KERNEL_IGNORE_MASK (\ 395 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \ 396 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) ) 397 398 #define SIG_SPECIFIC_SICODES_MASK (\ 399 rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \ 400 rt_sigmask(SIGSEGV) | rt_sigmask(SIGBUS) | \ 401 rt_sigmask(SIGTRAP) | rt_sigmask(SIGCHLD) | \ 402 rt_sigmask(SIGPOLL) | rt_sigmask(SIGSYS) | \ 403 SIGEMT_MASK ) 404 405 #define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK) 406 #define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK) 407 #define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK) 408 #define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK) 409 #define sig_specific_sicodes(sig) siginmask(sig, SIG_SPECIFIC_SICODES_MASK) 410 411 #define sig_fatal(t, signr) \ 412 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \ 413 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL) 414 415 void signals_init(void); 416 417 int restore_altstack(const stack_t __user *); 418 int __save_altstack(stack_t __user *, unsigned long); 419 420 #define save_altstack_ex(uss, sp) do { \ 421 stack_t __user *__uss = uss; \ 422 struct task_struct *t = current; \ 423 put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \ 424 put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \ 425 put_user_ex(t->sas_ss_size, &__uss->ss_size); \ 426 if (t->sas_ss_flags & SS_AUTODISARM) \ 427 sas_ss_reset(t); \ 428 } while (0); 429 430 #ifdef CONFIG_PROC_FS 431 struct seq_file; 432 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *); 433 #endif 434 435 #endif /* _LINUX_SIGNAL_H */ 436