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