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(kernel_siginfo_t *to, 15 const kernel_siginfo_t *from) 16 { 17 memcpy(to, from, sizeof(*to)); 18 } 19 20 static inline void clear_siginfo(kernel_siginfo_t *info) 21 { 22 memset(info, 0, sizeof(*info)); 23 } 24 25 #define SI_EXPANSION_SIZE (sizeof(struct siginfo) - sizeof(struct kernel_siginfo)) 26 27 int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from); 28 int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from); 29 30 enum siginfo_layout { 31 SIL_KILL, 32 SIL_TIMER, 33 SIL_POLL, 34 SIL_FAULT, 35 SIL_FAULT_MCEERR, 36 SIL_FAULT_BNDERR, 37 SIL_FAULT_PKUERR, 38 SIL_CHLD, 39 SIL_RT, 40 SIL_SYS, 41 }; 42 43 enum siginfo_layout siginfo_layout(unsigned sig, int si_code); 44 45 /* 46 * Define some primitives to manipulate sigset_t. 47 */ 48 49 #ifndef __HAVE_ARCH_SIG_BITOPS 50 #include <linux/bitops.h> 51 52 /* We don't use <linux/bitops.h> for these because there is no need to 53 be atomic. */ 54 static inline void sigaddset(sigset_t *set, int _sig) 55 { 56 unsigned long sig = _sig - 1; 57 if (_NSIG_WORDS == 1) 58 set->sig[0] |= 1UL << sig; 59 else 60 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW); 61 } 62 63 static inline void sigdelset(sigset_t *set, int _sig) 64 { 65 unsigned long sig = _sig - 1; 66 if (_NSIG_WORDS == 1) 67 set->sig[0] &= ~(1UL << sig); 68 else 69 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW)); 70 } 71 72 static inline int sigismember(sigset_t *set, int _sig) 73 { 74 unsigned long sig = _sig - 1; 75 if (_NSIG_WORDS == 1) 76 return 1 & (set->sig[0] >> sig); 77 else 78 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW)); 79 } 80 81 #endif /* __HAVE_ARCH_SIG_BITOPS */ 82 83 static inline int sigisemptyset(sigset_t *set) 84 { 85 switch (_NSIG_WORDS) { 86 case 4: 87 return (set->sig[3] | set->sig[2] | 88 set->sig[1] | set->sig[0]) == 0; 89 case 2: 90 return (set->sig[1] | set->sig[0]) == 0; 91 case 1: 92 return set->sig[0] == 0; 93 default: 94 BUILD_BUG(); 95 return 0; 96 } 97 } 98 99 static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2) 100 { 101 switch (_NSIG_WORDS) { 102 case 4: 103 return (set1->sig[3] == set2->sig[3]) && 104 (set1->sig[2] == set2->sig[2]) && 105 (set1->sig[1] == set2->sig[1]) && 106 (set1->sig[0] == set2->sig[0]); 107 case 2: 108 return (set1->sig[1] == set2->sig[1]) && 109 (set1->sig[0] == set2->sig[0]); 110 case 1: 111 return set1->sig[0] == set2->sig[0]; 112 } 113 return 0; 114 } 115 116 #define sigmask(sig) (1UL << ((sig) - 1)) 117 118 #ifndef __HAVE_ARCH_SIG_SETOPS 119 #include <linux/string.h> 120 121 #define _SIG_SET_BINOP(name, op) \ 122 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \ 123 { \ 124 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \ 125 \ 126 switch (_NSIG_WORDS) { \ 127 case 4: \ 128 a3 = a->sig[3]; a2 = a->sig[2]; \ 129 b3 = b->sig[3]; b2 = b->sig[2]; \ 130 r->sig[3] = op(a3, b3); \ 131 r->sig[2] = op(a2, b2); \ 132 /* fall through */ \ 133 case 2: \ 134 a1 = a->sig[1]; b1 = b->sig[1]; \ 135 r->sig[1] = op(a1, b1); \ 136 /* fall through */ \ 137 case 1: \ 138 a0 = a->sig[0]; b0 = b->sig[0]; \ 139 r->sig[0] = op(a0, b0); \ 140 break; \ 141 default: \ 142 BUILD_BUG(); \ 143 } \ 144 } 145 146 #define _sig_or(x,y) ((x) | (y)) 147 _SIG_SET_BINOP(sigorsets, _sig_or) 148 149 #define _sig_and(x,y) ((x) & (y)) 150 _SIG_SET_BINOP(sigandsets, _sig_and) 151 152 #define _sig_andn(x,y) ((x) & ~(y)) 153 _SIG_SET_BINOP(sigandnsets, _sig_andn) 154 155 #undef _SIG_SET_BINOP 156 #undef _sig_or 157 #undef _sig_and 158 #undef _sig_andn 159 160 #define _SIG_SET_OP(name, op) \ 161 static inline void name(sigset_t *set) \ 162 { \ 163 switch (_NSIG_WORDS) { \ 164 case 4: set->sig[3] = op(set->sig[3]); \ 165 set->sig[2] = op(set->sig[2]); \ 166 /* fall through */ \ 167 case 2: set->sig[1] = op(set->sig[1]); \ 168 /* fall through */ \ 169 case 1: set->sig[0] = op(set->sig[0]); \ 170 break; \ 171 default: \ 172 BUILD_BUG(); \ 173 } \ 174 } 175 176 #define _sig_not(x) (~(x)) 177 _SIG_SET_OP(signotset, _sig_not) 178 179 #undef _SIG_SET_OP 180 #undef _sig_not 181 182 static inline void sigemptyset(sigset_t *set) 183 { 184 switch (_NSIG_WORDS) { 185 default: 186 memset(set, 0, sizeof(sigset_t)); 187 break; 188 case 2: set->sig[1] = 0; 189 /* fall through */ 190 case 1: set->sig[0] = 0; 191 break; 192 } 193 } 194 195 static inline void sigfillset(sigset_t *set) 196 { 197 switch (_NSIG_WORDS) { 198 default: 199 memset(set, -1, sizeof(sigset_t)); 200 break; 201 case 2: set->sig[1] = -1; 202 /* fall through */ 203 case 1: set->sig[0] = -1; 204 break; 205 } 206 } 207 208 /* Some extensions for manipulating the low 32 signals in particular. */ 209 210 static inline void sigaddsetmask(sigset_t *set, unsigned long mask) 211 { 212 set->sig[0] |= mask; 213 } 214 215 static inline void sigdelsetmask(sigset_t *set, unsigned long mask) 216 { 217 set->sig[0] &= ~mask; 218 } 219 220 static inline int sigtestsetmask(sigset_t *set, unsigned long mask) 221 { 222 return (set->sig[0] & mask) != 0; 223 } 224 225 static inline void siginitset(sigset_t *set, unsigned long mask) 226 { 227 set->sig[0] = mask; 228 switch (_NSIG_WORDS) { 229 default: 230 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1)); 231 break; 232 case 2: set->sig[1] = 0; 233 case 1: ; 234 } 235 } 236 237 static inline void siginitsetinv(sigset_t *set, unsigned long mask) 238 { 239 set->sig[0] = ~mask; 240 switch (_NSIG_WORDS) { 241 default: 242 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1)); 243 break; 244 case 2: set->sig[1] = -1; 245 case 1: ; 246 } 247 } 248 249 #endif /* __HAVE_ARCH_SIG_SETOPS */ 250 251 static inline void init_sigpending(struct sigpending *sig) 252 { 253 sigemptyset(&sig->signal); 254 INIT_LIST_HEAD(&sig->list); 255 } 256 257 extern void flush_sigqueue(struct sigpending *queue); 258 259 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */ 260 static inline int valid_signal(unsigned long sig) 261 { 262 return sig <= _NSIG ? 1 : 0; 263 } 264 265 struct timespec; 266 struct pt_regs; 267 enum pid_type; 268 269 extern int next_signal(struct sigpending *pending, sigset_t *mask); 270 extern int do_send_sig_info(int sig, struct kernel_siginfo *info, 271 struct task_struct *p, enum pid_type type); 272 extern int group_send_sig_info(int sig, struct kernel_siginfo *info, 273 struct task_struct *p, enum pid_type type); 274 extern int __group_send_sig_info(int, struct kernel_siginfo *, struct task_struct *); 275 extern int sigprocmask(int, sigset_t *, sigset_t *); 276 extern int set_user_sigmask(const sigset_t __user *usigmask, sigset_t *set, 277 sigset_t *oldset, size_t sigsetsize); 278 extern void restore_user_sigmask(const void __user *usigmask, 279 sigset_t *sigsaved); 280 extern void set_current_blocked(sigset_t *); 281 extern void __set_current_blocked(const sigset_t *); 282 extern int show_unhandled_signals; 283 284 extern bool get_signal(struct ksignal *ksig); 285 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping); 286 extern void exit_signals(struct task_struct *tsk); 287 extern void kernel_sigaction(int, __sighandler_t); 288 289 static inline void allow_signal(int sig) 290 { 291 /* 292 * Kernel threads handle their own signals. Let the signal code 293 * know it'll be handled, so that they don't get converted to 294 * SIGKILL or just silently dropped. 295 */ 296 kernel_sigaction(sig, (__force __sighandler_t)2); 297 } 298 299 static inline void disallow_signal(int sig) 300 { 301 kernel_sigaction(sig, SIG_IGN); 302 } 303 304 extern struct kmem_cache *sighand_cachep; 305 306 extern bool unhandled_signal(struct task_struct *tsk, int sig); 307 308 /* 309 * In POSIX a signal is sent either to a specific thread (Linux task) 310 * or to the process as a whole (Linux thread group). How the signal 311 * is sent determines whether it's to one thread or the whole group, 312 * which determines which signal mask(s) are involved in blocking it 313 * from being delivered until later. When the signal is delivered, 314 * either it's caught or ignored by a user handler or it has a default 315 * effect that applies to the whole thread group (POSIX process). 316 * 317 * The possible effects an unblocked signal set to SIG_DFL can have are: 318 * ignore - Nothing Happens 319 * terminate - kill the process, i.e. all threads in the group, 320 * similar to exit_group. The group leader (only) reports 321 * WIFSIGNALED status to its parent. 322 * coredump - write a core dump file describing all threads using 323 * the same mm and then kill all those threads 324 * stop - stop all the threads in the group, i.e. TASK_STOPPED state 325 * 326 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored. 327 * Other signals when not blocked and set to SIG_DFL behaves as follows. 328 * The job control signals also have other special effects. 329 * 330 * +--------------------+------------------+ 331 * | POSIX signal | default action | 332 * +--------------------+------------------+ 333 * | SIGHUP | terminate | 334 * | SIGINT | terminate | 335 * | SIGQUIT | coredump | 336 * | SIGILL | coredump | 337 * | SIGTRAP | coredump | 338 * | SIGABRT/SIGIOT | coredump | 339 * | SIGBUS | coredump | 340 * | SIGFPE | coredump | 341 * | SIGKILL | terminate(+) | 342 * | SIGUSR1 | terminate | 343 * | SIGSEGV | coredump | 344 * | SIGUSR2 | terminate | 345 * | SIGPIPE | terminate | 346 * | SIGALRM | terminate | 347 * | SIGTERM | terminate | 348 * | SIGCHLD | ignore | 349 * | SIGCONT | ignore(*) | 350 * | SIGSTOP | stop(*)(+) | 351 * | SIGTSTP | stop(*) | 352 * | SIGTTIN | stop(*) | 353 * | SIGTTOU | stop(*) | 354 * | SIGURG | ignore | 355 * | SIGXCPU | coredump | 356 * | SIGXFSZ | coredump | 357 * | SIGVTALRM | terminate | 358 * | SIGPROF | terminate | 359 * | SIGPOLL/SIGIO | terminate | 360 * | SIGSYS/SIGUNUSED | coredump | 361 * | SIGSTKFLT | terminate | 362 * | SIGWINCH | ignore | 363 * | SIGPWR | terminate | 364 * | SIGRTMIN-SIGRTMAX | terminate | 365 * +--------------------+------------------+ 366 * | non-POSIX signal | default action | 367 * +--------------------+------------------+ 368 * | SIGEMT | coredump | 369 * +--------------------+------------------+ 370 * 371 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default". 372 * (*) Special job control effects: 373 * When SIGCONT is sent, it resumes the process (all threads in the group) 374 * from TASK_STOPPED state and also clears any pending/queued stop signals 375 * (any of those marked with "stop(*)"). This happens regardless of blocking, 376 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears 377 * any pending/queued SIGCONT signals; this happens regardless of blocking, 378 * catching, or ignored the stop signal, though (except for SIGSTOP) the 379 * default action of stopping the process may happen later or never. 380 */ 381 382 #ifdef SIGEMT 383 #define SIGEMT_MASK rt_sigmask(SIGEMT) 384 #else 385 #define SIGEMT_MASK 0 386 #endif 387 388 #if SIGRTMIN > BITS_PER_LONG 389 #define rt_sigmask(sig) (1ULL << ((sig)-1)) 390 #else 391 #define rt_sigmask(sig) sigmask(sig) 392 #endif 393 394 #define siginmask(sig, mask) \ 395 ((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask))) 396 397 #define SIG_KERNEL_ONLY_MASK (\ 398 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP)) 399 400 #define SIG_KERNEL_STOP_MASK (\ 401 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \ 402 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) ) 403 404 #define SIG_KERNEL_COREDUMP_MASK (\ 405 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \ 406 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \ 407 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \ 408 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \ 409 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \ 410 SIGEMT_MASK ) 411 412 #define SIG_KERNEL_IGNORE_MASK (\ 413 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \ 414 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) ) 415 416 #define SIG_SPECIFIC_SICODES_MASK (\ 417 rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \ 418 rt_sigmask(SIGSEGV) | rt_sigmask(SIGBUS) | \ 419 rt_sigmask(SIGTRAP) | rt_sigmask(SIGCHLD) | \ 420 rt_sigmask(SIGPOLL) | rt_sigmask(SIGSYS) | \ 421 SIGEMT_MASK ) 422 423 #define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK) 424 #define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK) 425 #define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK) 426 #define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK) 427 #define sig_specific_sicodes(sig) siginmask(sig, SIG_SPECIFIC_SICODES_MASK) 428 429 #define sig_fatal(t, signr) \ 430 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \ 431 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL) 432 433 void signals_init(void); 434 435 int restore_altstack(const stack_t __user *); 436 int __save_altstack(stack_t __user *, unsigned long); 437 438 #define save_altstack_ex(uss, sp) do { \ 439 stack_t __user *__uss = uss; \ 440 struct task_struct *t = current; \ 441 put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \ 442 put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \ 443 put_user_ex(t->sas_ss_size, &__uss->ss_size); \ 444 if (t->sas_ss_flags & SS_AUTODISARM) \ 445 sas_ss_reset(t); \ 446 } while (0); 447 448 #ifdef CONFIG_PROC_FS 449 struct seq_file; 450 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *); 451 #endif 452 453 #endif /* _LINUX_SIGNAL_H */ 454