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