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