1#ifndef _LINUX_SIGNAL_H 2#define _LINUX_SIGNAL_H 3 4#include <linux/list.h> 5#include <linux/bug.h> 6#include <uapi/linux/signal.h> 7 8struct task_struct; 9 10/* for sysctl */ 11extern int print_fatal_signals; 12/* 13 * Real Time signals may be queued. 14 */ 15 16struct sigqueue { 17 struct list_head list; 18 int flags; 19 siginfo_t info; 20 struct user_struct *user; 21}; 22 23/* flags values. */ 24#define SIGQUEUE_PREALLOC 1 25 26struct sigpending { 27 struct list_head list; 28 sigset_t signal; 29}; 30 31/* 32 * Define some primitives to manipulate sigset_t. 33 */ 34 35#ifndef __HAVE_ARCH_SIG_BITOPS 36#include <linux/bitops.h> 37 38/* We don't use <linux/bitops.h> for these because there is no need to 39 be atomic. */ 40static inline void sigaddset(sigset_t *set, int _sig) 41{ 42 unsigned long sig = _sig - 1; 43 if (_NSIG_WORDS == 1) 44 set->sig[0] |= 1UL << sig; 45 else 46 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW); 47} 48 49static inline void sigdelset(sigset_t *set, int _sig) 50{ 51 unsigned long sig = _sig - 1; 52 if (_NSIG_WORDS == 1) 53 set->sig[0] &= ~(1UL << sig); 54 else 55 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW)); 56} 57 58static inline int sigismember(sigset_t *set, int _sig) 59{ 60 unsigned long sig = _sig - 1; 61 if (_NSIG_WORDS == 1) 62 return 1 & (set->sig[0] >> sig); 63 else 64 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW)); 65} 66 67#endif /* __HAVE_ARCH_SIG_BITOPS */ 68 69static inline int sigisemptyset(sigset_t *set) 70{ 71 switch (_NSIG_WORDS) { 72 case 4: 73 return (set->sig[3] | set->sig[2] | 74 set->sig[1] | set->sig[0]) == 0; 75 case 2: 76 return (set->sig[1] | set->sig[0]) == 0; 77 case 1: 78 return set->sig[0] == 0; 79 default: 80 BUILD_BUG(); 81 return 0; 82 } 83} 84 85#define sigmask(sig) (1UL << ((sig) - 1)) 86 87#ifndef __HAVE_ARCH_SIG_SETOPS 88#include <linux/string.h> 89 90#define _SIG_SET_BINOP(name, op) \ 91static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \ 92{ \ 93 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \ 94 \ 95 switch (_NSIG_WORDS) { \ 96 case 4: \ 97 a3 = a->sig[3]; a2 = a->sig[2]; \ 98 b3 = b->sig[3]; b2 = b->sig[2]; \ 99 r->sig[3] = op(a3, b3); \ 100 r->sig[2] = op(a2, b2); \ 101 case 2: \ 102 a1 = a->sig[1]; b1 = b->sig[1]; \ 103 r->sig[1] = op(a1, b1); \ 104 case 1: \ 105 a0 = a->sig[0]; b0 = b->sig[0]; \ 106 r->sig[0] = op(a0, b0); \ 107 break; \ 108 default: \ 109 BUILD_BUG(); \ 110 } \ 111} 112 113#define _sig_or(x,y) ((x) | (y)) 114_SIG_SET_BINOP(sigorsets, _sig_or) 115 116#define _sig_and(x,y) ((x) & (y)) 117_SIG_SET_BINOP(sigandsets, _sig_and) 118 119#define _sig_andn(x,y) ((x) & ~(y)) 120_SIG_SET_BINOP(sigandnsets, _sig_andn) 121 122#undef _SIG_SET_BINOP 123#undef _sig_or 124#undef _sig_and 125#undef _sig_andn 126 127#define _SIG_SET_OP(name, op) \ 128static inline void name(sigset_t *set) \ 129{ \ 130 switch (_NSIG_WORDS) { \ 131 case 4: set->sig[3] = op(set->sig[3]); \ 132 set->sig[2] = op(set->sig[2]); \ 133 case 2: set->sig[1] = op(set->sig[1]); \ 134 case 1: set->sig[0] = op(set->sig[0]); \ 135 break; \ 136 default: \ 137 BUILD_BUG(); \ 138 } \ 139} 140 141#define _sig_not(x) (~(x)) 142_SIG_SET_OP(signotset, _sig_not) 143 144#undef _SIG_SET_OP 145#undef _sig_not 146 147static inline void sigemptyset(sigset_t *set) 148{ 149 switch (_NSIG_WORDS) { 150 default: 151 memset(set, 0, sizeof(sigset_t)); 152 break; 153 case 2: set->sig[1] = 0; 154 case 1: set->sig[0] = 0; 155 break; 156 } 157} 158 159static inline void sigfillset(sigset_t *set) 160{ 161 switch (_NSIG_WORDS) { 162 default: 163 memset(set, -1, sizeof(sigset_t)); 164 break; 165 case 2: set->sig[1] = -1; 166 case 1: set->sig[0] = -1; 167 break; 168 } 169} 170 171/* Some extensions for manipulating the low 32 signals in particular. */ 172 173static inline void sigaddsetmask(sigset_t *set, unsigned long mask) 174{ 175 set->sig[0] |= mask; 176} 177 178static inline void sigdelsetmask(sigset_t *set, unsigned long mask) 179{ 180 set->sig[0] &= ~mask; 181} 182 183static inline int sigtestsetmask(sigset_t *set, unsigned long mask) 184{ 185 return (set->sig[0] & mask) != 0; 186} 187 188static inline void siginitset(sigset_t *set, unsigned long mask) 189{ 190 set->sig[0] = mask; 191 switch (_NSIG_WORDS) { 192 default: 193 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1)); 194 break; 195 case 2: set->sig[1] = 0; 196 case 1: ; 197 } 198} 199 200static inline void siginitsetinv(sigset_t *set, unsigned long mask) 201{ 202 set->sig[0] = ~mask; 203 switch (_NSIG_WORDS) { 204 default: 205 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1)); 206 break; 207 case 2: set->sig[1] = -1; 208 case 1: ; 209 } 210} 211 212#endif /* __HAVE_ARCH_SIG_SETOPS */ 213 214static inline void init_sigpending(struct sigpending *sig) 215{ 216 sigemptyset(&sig->signal); 217 INIT_LIST_HEAD(&sig->list); 218} 219 220extern void flush_sigqueue(struct sigpending *queue); 221 222/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */ 223static inline int valid_signal(unsigned long sig) 224{ 225 return sig <= _NSIG ? 1 : 0; 226} 227 228struct timespec; 229struct pt_regs; 230 231extern int next_signal(struct sigpending *pending, sigset_t *mask); 232extern int do_send_sig_info(int sig, struct siginfo *info, 233 struct task_struct *p, bool group); 234extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p); 235extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *); 236extern int do_sigtimedwait(const sigset_t *, siginfo_t *, 237 const struct timespec *); 238extern int sigprocmask(int, sigset_t *, sigset_t *); 239extern void set_current_blocked(sigset_t *); 240extern void __set_current_blocked(const sigset_t *); 241extern int show_unhandled_signals; 242extern int sigsuspend(sigset_t *); 243 244struct sigaction { 245#ifndef __ARCH_HAS_IRIX_SIGACTION 246 __sighandler_t sa_handler; 247 unsigned long sa_flags; 248#else 249 unsigned int sa_flags; 250 __sighandler_t sa_handler; 251#endif 252#ifdef __ARCH_HAS_SA_RESTORER 253 __sigrestore_t sa_restorer; 254#endif 255 sigset_t sa_mask; /* mask last for extensibility */ 256}; 257 258struct k_sigaction { 259 struct sigaction sa; 260#ifdef __ARCH_HAS_KA_RESTORER 261 __sigrestore_t ka_restorer; 262#endif 263}; 264 265#ifdef CONFIG_OLD_SIGACTION 266struct old_sigaction { 267 __sighandler_t sa_handler; 268 old_sigset_t sa_mask; 269 unsigned long sa_flags; 270 __sigrestore_t sa_restorer; 271}; 272#endif 273 274struct ksignal { 275 struct k_sigaction ka; 276 siginfo_t info; 277 int sig; 278}; 279 280extern int get_signal(struct ksignal *ksig); 281extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping); 282extern void exit_signals(struct task_struct *tsk); 283extern void kernel_sigaction(int, __sighandler_t); 284 285static inline void allow_signal(int sig) 286{ 287 /* 288 * Kernel threads handle their own signals. Let the signal code 289 * know it'll be handled, so that they don't get converted to 290 * SIGKILL or just silently dropped. 291 */ 292 kernel_sigaction(sig, (__force __sighandler_t)2); 293} 294 295static inline void disallow_signal(int sig) 296{ 297 kernel_sigaction(sig, SIG_IGN); 298} 299 300extern struct kmem_cache *sighand_cachep; 301 302int unhandled_signal(struct task_struct *tsk, int sig); 303 304/* 305 * In POSIX a signal is sent either to a specific thread (Linux task) 306 * or to the process as a whole (Linux thread group). How the signal 307 * is sent determines whether it's to one thread or the whole group, 308 * which determines which signal mask(s) are involved in blocking it 309 * from being delivered until later. When the signal is delivered, 310 * either it's caught or ignored by a user handler or it has a default 311 * effect that applies to the whole thread group (POSIX process). 312 * 313 * The possible effects an unblocked signal set to SIG_DFL can have are: 314 * ignore - Nothing Happens 315 * terminate - kill the process, i.e. all threads in the group, 316 * similar to exit_group. The group leader (only) reports 317 * WIFSIGNALED status to its parent. 318 * coredump - write a core dump file describing all threads using 319 * the same mm and then kill all those threads 320 * stop - stop all the threads in the group, i.e. TASK_STOPPED state 321 * 322 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored. 323 * Other signals when not blocked and set to SIG_DFL behaves as follows. 324 * The job control signals also have other special effects. 325 * 326 * +--------------------+------------------+ 327 * | POSIX signal | default action | 328 * +--------------------+------------------+ 329 * | SIGHUP | terminate | 330 * | SIGINT | terminate | 331 * | SIGQUIT | coredump | 332 * | SIGILL | coredump | 333 * | SIGTRAP | coredump | 334 * | SIGABRT/SIGIOT | coredump | 335 * | SIGBUS | coredump | 336 * | SIGFPE | coredump | 337 * | SIGKILL | terminate(+) | 338 * | SIGUSR1 | terminate | 339 * | SIGSEGV | coredump | 340 * | SIGUSR2 | terminate | 341 * | SIGPIPE | terminate | 342 * | SIGALRM | terminate | 343 * | SIGTERM | terminate | 344 * | SIGCHLD | ignore | 345 * | SIGCONT | ignore(*) | 346 * | SIGSTOP | stop(*)(+) | 347 * | SIGTSTP | stop(*) | 348 * | SIGTTIN | stop(*) | 349 * | SIGTTOU | stop(*) | 350 * | SIGURG | ignore | 351 * | SIGXCPU | coredump | 352 * | SIGXFSZ | coredump | 353 * | SIGVTALRM | terminate | 354 * | SIGPROF | terminate | 355 * | SIGPOLL/SIGIO | terminate | 356 * | SIGSYS/SIGUNUSED | coredump | 357 * | SIGSTKFLT | terminate | 358 * | SIGWINCH | ignore | 359 * | SIGPWR | terminate | 360 * | SIGRTMIN-SIGRTMAX | terminate | 361 * +--------------------+------------------+ 362 * | non-POSIX signal | default action | 363 * +--------------------+------------------+ 364 * | SIGEMT | coredump | 365 * +--------------------+------------------+ 366 * 367 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default". 368 * (*) Special job control effects: 369 * When SIGCONT is sent, it resumes the process (all threads in the group) 370 * from TASK_STOPPED state and also clears any pending/queued stop signals 371 * (any of those marked with "stop(*)"). This happens regardless of blocking, 372 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears 373 * any pending/queued SIGCONT signals; this happens regardless of blocking, 374 * catching, or ignored the stop signal, though (except for SIGSTOP) the 375 * default action of stopping the process may happen later or never. 376 */ 377 378#ifdef SIGEMT 379#define SIGEMT_MASK rt_sigmask(SIGEMT) 380#else 381#define SIGEMT_MASK 0 382#endif 383 384#if SIGRTMIN > BITS_PER_LONG 385#define rt_sigmask(sig) (1ULL << ((sig)-1)) 386#else 387#define rt_sigmask(sig) sigmask(sig) 388#endif 389#define siginmask(sig, mask) (rt_sigmask(sig) & (mask)) 390 391#define SIG_KERNEL_ONLY_MASK (\ 392 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP)) 393 394#define SIG_KERNEL_STOP_MASK (\ 395 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \ 396 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) ) 397 398#define SIG_KERNEL_COREDUMP_MASK (\ 399 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \ 400 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \ 401 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \ 402 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \ 403 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \ 404 SIGEMT_MASK ) 405 406#define SIG_KERNEL_IGNORE_MASK (\ 407 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \ 408 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) ) 409 410#define sig_kernel_only(sig) \ 411 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK)) 412#define sig_kernel_coredump(sig) \ 413 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK)) 414#define sig_kernel_ignore(sig) \ 415 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK)) 416#define sig_kernel_stop(sig) \ 417 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK)) 418 419#define sig_user_defined(t, signr) \ 420 (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \ 421 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN)) 422 423#define sig_fatal(t, signr) \ 424 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \ 425 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL) 426 427void signals_init(void); 428 429int restore_altstack(const stack_t __user *); 430int __save_altstack(stack_t __user *, unsigned long); 431 432#define save_altstack_ex(uss, sp) do { \ 433 stack_t __user *__uss = uss; \ 434 struct task_struct *t = current; \ 435 put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \ 436 put_user_ex(sas_ss_flags(sp), &__uss->ss_flags); \ 437 put_user_ex(t->sas_ss_size, &__uss->ss_size); \ 438} while (0); 439 440#ifdef CONFIG_PROC_FS 441struct seq_file; 442extern void render_sigset_t(struct seq_file *, const char *, sigset_t *); 443#endif 444 445#endif /* _LINUX_SIGNAL_H */ 446