Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/signal.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | * |
| 6 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson |
| 7 | * |
| 8 | * 2003-06-02 Jim Houston - Concurrent Computer Corp. |
| 9 | * Changes to use preallocated sigqueue structures |
| 10 | * to allow signals to be sent reliably. |
| 11 | */ |
| 12 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/slab.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/smp_lock.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/fs.h> |
| 19 | #include <linux/tty.h> |
| 20 | #include <linux/binfmts.h> |
| 21 | #include <linux/security.h> |
| 22 | #include <linux/syscalls.h> |
| 23 | #include <linux/ptrace.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 24 | #include <linux/signal.h> |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 25 | #include <linux/capability.h> |
Nigel Cunningham | 7dfb710 | 2006-12-06 20:34:23 -0800 | [diff] [blame] | 26 | #include <linux/freezer.h> |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 27 | #include <linux/pid_namespace.h> |
| 28 | #include <linux/nsproxy.h> |
| 29 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <asm/param.h> |
| 31 | #include <asm/uaccess.h> |
| 32 | #include <asm/unistd.h> |
| 33 | #include <asm/siginfo.h> |
Al Viro | e139606 | 2006-05-25 10:19:47 -0400 | [diff] [blame] | 34 | #include "audit.h" /* audit_signal_info() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
| 36 | /* |
| 37 | * SLAB caches for signal bits. |
| 38 | */ |
| 39 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 40 | static struct kmem_cache *sigqueue_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
| 42 | /* |
| 43 | * In POSIX a signal is sent either to a specific thread (Linux task) |
| 44 | * or to the process as a whole (Linux thread group). How the signal |
| 45 | * is sent determines whether it's to one thread or the whole group, |
| 46 | * which determines which signal mask(s) are involved in blocking it |
| 47 | * from being delivered until later. When the signal is delivered, |
| 48 | * either it's caught or ignored by a user handler or it has a default |
| 49 | * effect that applies to the whole thread group (POSIX process). |
| 50 | * |
| 51 | * The possible effects an unblocked signal set to SIG_DFL can have are: |
| 52 | * ignore - Nothing Happens |
| 53 | * terminate - kill the process, i.e. all threads in the group, |
| 54 | * similar to exit_group. The group leader (only) reports |
| 55 | * WIFSIGNALED status to its parent. |
| 56 | * coredump - write a core dump file describing all threads using |
| 57 | * the same mm and then kill all those threads |
| 58 | * stop - stop all the threads in the group, i.e. TASK_STOPPED state |
| 59 | * |
| 60 | * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored. |
| 61 | * Other signals when not blocked and set to SIG_DFL behaves as follows. |
| 62 | * The job control signals also have other special effects. |
| 63 | * |
| 64 | * +--------------------+------------------+ |
| 65 | * | POSIX signal | default action | |
| 66 | * +--------------------+------------------+ |
| 67 | * | SIGHUP | terminate | |
| 68 | * | SIGINT | terminate | |
| 69 | * | SIGQUIT | coredump | |
| 70 | * | SIGILL | coredump | |
| 71 | * | SIGTRAP | coredump | |
| 72 | * | SIGABRT/SIGIOT | coredump | |
| 73 | * | SIGBUS | coredump | |
| 74 | * | SIGFPE | coredump | |
| 75 | * | SIGKILL | terminate(+) | |
| 76 | * | SIGUSR1 | terminate | |
| 77 | * | SIGSEGV | coredump | |
| 78 | * | SIGUSR2 | terminate | |
| 79 | * | SIGPIPE | terminate | |
| 80 | * | SIGALRM | terminate | |
| 81 | * | SIGTERM | terminate | |
| 82 | * | SIGCHLD | ignore | |
| 83 | * | SIGCONT | ignore(*) | |
| 84 | * | SIGSTOP | stop(*)(+) | |
| 85 | * | SIGTSTP | stop(*) | |
| 86 | * | SIGTTIN | stop(*) | |
| 87 | * | SIGTTOU | stop(*) | |
| 88 | * | SIGURG | ignore | |
| 89 | * | SIGXCPU | coredump | |
| 90 | * | SIGXFSZ | coredump | |
| 91 | * | SIGVTALRM | terminate | |
| 92 | * | SIGPROF | terminate | |
| 93 | * | SIGPOLL/SIGIO | terminate | |
| 94 | * | SIGSYS/SIGUNUSED | coredump | |
| 95 | * | SIGSTKFLT | terminate | |
| 96 | * | SIGWINCH | ignore | |
| 97 | * | SIGPWR | terminate | |
| 98 | * | SIGRTMIN-SIGRTMAX | terminate | |
| 99 | * +--------------------+------------------+ |
| 100 | * | non-POSIX signal | default action | |
| 101 | * +--------------------+------------------+ |
| 102 | * | SIGEMT | coredump | |
| 103 | * +--------------------+------------------+ |
| 104 | * |
| 105 | * (+) For SIGKILL and SIGSTOP the action is "always", not just "default". |
| 106 | * (*) Special job control effects: |
| 107 | * When SIGCONT is sent, it resumes the process (all threads in the group) |
| 108 | * from TASK_STOPPED state and also clears any pending/queued stop signals |
| 109 | * (any of those marked with "stop(*)"). This happens regardless of blocking, |
| 110 | * catching, or ignoring SIGCONT. When any stop signal is sent, it clears |
| 111 | * any pending/queued SIGCONT signals; this happens regardless of blocking, |
| 112 | * catching, or ignored the stop signal, though (except for SIGSTOP) the |
| 113 | * default action of stopping the process may happen later or never. |
| 114 | */ |
| 115 | |
| 116 | #ifdef SIGEMT |
| 117 | #define M_SIGEMT M(SIGEMT) |
| 118 | #else |
| 119 | #define M_SIGEMT 0 |
| 120 | #endif |
| 121 | |
| 122 | #if SIGRTMIN > BITS_PER_LONG |
| 123 | #define M(sig) (1ULL << ((sig)-1)) |
| 124 | #else |
| 125 | #define M(sig) (1UL << ((sig)-1)) |
| 126 | #endif |
| 127 | #define T(sig, mask) (M(sig) & (mask)) |
| 128 | |
| 129 | #define SIG_KERNEL_ONLY_MASK (\ |
| 130 | M(SIGKILL) | M(SIGSTOP) ) |
| 131 | |
| 132 | #define SIG_KERNEL_STOP_MASK (\ |
| 133 | M(SIGSTOP) | M(SIGTSTP) | M(SIGTTIN) | M(SIGTTOU) ) |
| 134 | |
| 135 | #define SIG_KERNEL_COREDUMP_MASK (\ |
| 136 | M(SIGQUIT) | M(SIGILL) | M(SIGTRAP) | M(SIGABRT) | \ |
| 137 | M(SIGFPE) | M(SIGSEGV) | M(SIGBUS) | M(SIGSYS) | \ |
| 138 | M(SIGXCPU) | M(SIGXFSZ) | M_SIGEMT ) |
| 139 | |
| 140 | #define SIG_KERNEL_IGNORE_MASK (\ |
| 141 | M(SIGCONT) | M(SIGCHLD) | M(SIGWINCH) | M(SIGURG) ) |
| 142 | |
| 143 | #define sig_kernel_only(sig) \ |
| 144 | (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_ONLY_MASK)) |
| 145 | #define sig_kernel_coredump(sig) \ |
| 146 | (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_COREDUMP_MASK)) |
| 147 | #define sig_kernel_ignore(sig) \ |
| 148 | (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_IGNORE_MASK)) |
| 149 | #define sig_kernel_stop(sig) \ |
| 150 | (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_STOP_MASK)) |
| 151 | |
Oleg Nesterov | 6108ccd3 | 2006-03-28 16:11:22 -0800 | [diff] [blame] | 152 | #define sig_needs_tasklist(sig) ((sig) == SIGCONT) |
Oleg Nesterov | a9e88e8 | 2006-03-28 16:11:14 -0800 | [diff] [blame] | 153 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | #define sig_user_defined(t, signr) \ |
| 155 | (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \ |
| 156 | ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN)) |
| 157 | |
| 158 | #define sig_fatal(t, signr) \ |
| 159 | (!T(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \ |
| 160 | (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL) |
| 161 | |
| 162 | static int sig_ignored(struct task_struct *t, int sig) |
| 163 | { |
| 164 | void __user * handler; |
| 165 | |
| 166 | /* |
| 167 | * Tracers always want to know about signals.. |
| 168 | */ |
| 169 | if (t->ptrace & PT_PTRACED) |
| 170 | return 0; |
| 171 | |
| 172 | /* |
| 173 | * Blocked signals are never ignored, since the |
| 174 | * signal handler may change by the time it is |
| 175 | * unblocked. |
| 176 | */ |
| 177 | if (sigismember(&t->blocked, sig)) |
| 178 | return 0; |
| 179 | |
| 180 | /* Is it explicitly or implicitly ignored? */ |
| 181 | handler = t->sighand->action[sig-1].sa.sa_handler; |
| 182 | return handler == SIG_IGN || |
| 183 | (handler == SIG_DFL && sig_kernel_ignore(sig)); |
| 184 | } |
| 185 | |
| 186 | /* |
| 187 | * Re-calculate pending state from the set of locally pending |
| 188 | * signals, globally pending signals, and blocked signals. |
| 189 | */ |
| 190 | static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) |
| 191 | { |
| 192 | unsigned long ready; |
| 193 | long i; |
| 194 | |
| 195 | switch (_NSIG_WORDS) { |
| 196 | default: |
| 197 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) |
| 198 | ready |= signal->sig[i] &~ blocked->sig[i]; |
| 199 | break; |
| 200 | |
| 201 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; |
| 202 | ready |= signal->sig[2] &~ blocked->sig[2]; |
| 203 | ready |= signal->sig[1] &~ blocked->sig[1]; |
| 204 | ready |= signal->sig[0] &~ blocked->sig[0]; |
| 205 | break; |
| 206 | |
| 207 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; |
| 208 | ready |= signal->sig[0] &~ blocked->sig[0]; |
| 209 | break; |
| 210 | |
| 211 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; |
| 212 | } |
| 213 | return ready != 0; |
| 214 | } |
| 215 | |
| 216 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) |
| 217 | |
| 218 | fastcall void recalc_sigpending_tsk(struct task_struct *t) |
| 219 | { |
| 220 | if (t->signal->group_stop_count > 0 || |
Christoph Lameter | 3e1d1d2 | 2005-06-24 23:13:50 -0700 | [diff] [blame] | 221 | (freezing(t)) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | PENDING(&t->pending, &t->blocked) || |
| 223 | PENDING(&t->signal->shared_pending, &t->blocked)) |
| 224 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
| 225 | else |
| 226 | clear_tsk_thread_flag(t, TIF_SIGPENDING); |
| 227 | } |
| 228 | |
| 229 | void recalc_sigpending(void) |
| 230 | { |
| 231 | recalc_sigpending_tsk(current); |
| 232 | } |
| 233 | |
| 234 | /* Given the mask, find the first available signal that should be serviced. */ |
| 235 | |
| 236 | static int |
| 237 | next_signal(struct sigpending *pending, sigset_t *mask) |
| 238 | { |
| 239 | unsigned long i, *s, *m, x; |
| 240 | int sig = 0; |
| 241 | |
| 242 | s = pending->signal.sig; |
| 243 | m = mask->sig; |
| 244 | switch (_NSIG_WORDS) { |
| 245 | default: |
| 246 | for (i = 0; i < _NSIG_WORDS; ++i, ++s, ++m) |
| 247 | if ((x = *s &~ *m) != 0) { |
| 248 | sig = ffz(~x) + i*_NSIG_BPW + 1; |
| 249 | break; |
| 250 | } |
| 251 | break; |
| 252 | |
| 253 | case 2: if ((x = s[0] &~ m[0]) != 0) |
| 254 | sig = 1; |
| 255 | else if ((x = s[1] &~ m[1]) != 0) |
| 256 | sig = _NSIG_BPW + 1; |
| 257 | else |
| 258 | break; |
| 259 | sig += ffz(~x); |
| 260 | break; |
| 261 | |
| 262 | case 1: if ((x = *s &~ *m) != 0) |
| 263 | sig = ffz(~x) + 1; |
| 264 | break; |
| 265 | } |
| 266 | |
| 267 | return sig; |
| 268 | } |
| 269 | |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 270 | static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | int override_rlimit) |
| 272 | { |
| 273 | struct sigqueue *q = NULL; |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 274 | struct user_struct *user; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 276 | /* |
| 277 | * In order to avoid problems with "switch_user()", we want to make |
| 278 | * sure that the compiler doesn't re-load "t->user" |
| 279 | */ |
| 280 | user = t->user; |
| 281 | barrier(); |
| 282 | atomic_inc(&user->sigpending); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | if (override_rlimit || |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 284 | atomic_read(&user->sigpending) <= |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) |
| 286 | q = kmem_cache_alloc(sigqueue_cachep, flags); |
| 287 | if (unlikely(q == NULL)) { |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 288 | atomic_dec(&user->sigpending); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | } else { |
| 290 | INIT_LIST_HEAD(&q->list); |
| 291 | q->flags = 0; |
Linus Torvalds | 10b1fbd | 2006-11-04 13:03:00 -0800 | [diff] [blame] | 292 | q->user = get_uid(user); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | } |
| 294 | return(q); |
| 295 | } |
| 296 | |
Andrew Morton | 514a01b | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 297 | static void __sigqueue_free(struct sigqueue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | { |
| 299 | if (q->flags & SIGQUEUE_PREALLOC) |
| 300 | return; |
| 301 | atomic_dec(&q->user->sigpending); |
| 302 | free_uid(q->user); |
| 303 | kmem_cache_free(sigqueue_cachep, q); |
| 304 | } |
| 305 | |
Oleg Nesterov | 6a14c5c | 2006-03-28 16:11:18 -0800 | [diff] [blame] | 306 | void flush_sigqueue(struct sigpending *queue) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | { |
| 308 | struct sigqueue *q; |
| 309 | |
| 310 | sigemptyset(&queue->signal); |
| 311 | while (!list_empty(&queue->list)) { |
| 312 | q = list_entry(queue->list.next, struct sigqueue , list); |
| 313 | list_del_init(&q->list); |
| 314 | __sigqueue_free(q); |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | /* |
| 319 | * Flush all pending signals for a task. |
| 320 | */ |
Oleg Nesterov | c81addc | 2006-03-28 16:11:17 -0800 | [diff] [blame] | 321 | void flush_signals(struct task_struct *t) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | { |
| 323 | unsigned long flags; |
| 324 | |
| 325 | spin_lock_irqsave(&t->sighand->siglock, flags); |
| 326 | clear_tsk_thread_flag(t,TIF_SIGPENDING); |
| 327 | flush_sigqueue(&t->pending); |
| 328 | flush_sigqueue(&t->signal->shared_pending); |
| 329 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
| 330 | } |
| 331 | |
| 332 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | * Flush all handlers for a task. |
| 334 | */ |
| 335 | |
| 336 | void |
| 337 | flush_signal_handlers(struct task_struct *t, int force_default) |
| 338 | { |
| 339 | int i; |
| 340 | struct k_sigaction *ka = &t->sighand->action[0]; |
| 341 | for (i = _NSIG ; i != 0 ; i--) { |
| 342 | if (force_default || ka->sa.sa_handler != SIG_IGN) |
| 343 | ka->sa.sa_handler = SIG_DFL; |
| 344 | ka->sa.sa_flags = 0; |
| 345 | sigemptyset(&ka->sa.sa_mask); |
| 346 | ka++; |
| 347 | } |
| 348 | } |
| 349 | |
| 350 | |
| 351 | /* Notify the system that a driver wants to block all signals for this |
| 352 | * process, and wants to be notified if any signals at all were to be |
| 353 | * sent/acted upon. If the notifier routine returns non-zero, then the |
| 354 | * signal will be acted upon after all. If the notifier routine returns 0, |
| 355 | * then then signal will be blocked. Only one block per process is |
| 356 | * allowed. priv is a pointer to private data that the notifier routine |
| 357 | * can use to determine if the signal should be blocked or not. */ |
| 358 | |
| 359 | void |
| 360 | block_all_signals(int (*notifier)(void *priv), void *priv, sigset_t *mask) |
| 361 | { |
| 362 | unsigned long flags; |
| 363 | |
| 364 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
| 365 | current->notifier_mask = mask; |
| 366 | current->notifier_data = priv; |
| 367 | current->notifier = notifier; |
| 368 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| 369 | } |
| 370 | |
| 371 | /* Notify the system that blocking has ended. */ |
| 372 | |
| 373 | void |
| 374 | unblock_all_signals(void) |
| 375 | { |
| 376 | unsigned long flags; |
| 377 | |
| 378 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
| 379 | current->notifier = NULL; |
| 380 | current->notifier_data = NULL; |
| 381 | recalc_sigpending(); |
| 382 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| 383 | } |
| 384 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 385 | static int collect_signal(int sig, struct sigpending *list, siginfo_t *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | { |
| 387 | struct sigqueue *q, *first = NULL; |
| 388 | int still_pending = 0; |
| 389 | |
| 390 | if (unlikely(!sigismember(&list->signal, sig))) |
| 391 | return 0; |
| 392 | |
| 393 | /* |
| 394 | * Collect the siginfo appropriate to this signal. Check if |
| 395 | * there is another siginfo for the same signal. |
| 396 | */ |
| 397 | list_for_each_entry(q, &list->list, list) { |
| 398 | if (q->info.si_signo == sig) { |
| 399 | if (first) { |
| 400 | still_pending = 1; |
| 401 | break; |
| 402 | } |
| 403 | first = q; |
| 404 | } |
| 405 | } |
| 406 | if (first) { |
| 407 | list_del_init(&first->list); |
| 408 | copy_siginfo(info, &first->info); |
| 409 | __sigqueue_free(first); |
| 410 | if (!still_pending) |
| 411 | sigdelset(&list->signal, sig); |
| 412 | } else { |
| 413 | |
| 414 | /* Ok, it wasn't in the queue. This must be |
| 415 | a fast-pathed signal or we must have been |
| 416 | out of queue space. So zero out the info. |
| 417 | */ |
| 418 | sigdelset(&list->signal, sig); |
| 419 | info->si_signo = sig; |
| 420 | info->si_errno = 0; |
| 421 | info->si_code = 0; |
| 422 | info->si_pid = 0; |
| 423 | info->si_uid = 0; |
| 424 | } |
| 425 | return 1; |
| 426 | } |
| 427 | |
| 428 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, |
| 429 | siginfo_t *info) |
| 430 | { |
Roland McGrath | 27d91e0 | 2006-09-29 02:00:31 -0700 | [diff] [blame] | 431 | int sig = next_signal(pending, mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | if (sig) { |
| 434 | if (current->notifier) { |
| 435 | if (sigismember(current->notifier_mask, sig)) { |
| 436 | if (!(current->notifier)(current->notifier_data)) { |
| 437 | clear_thread_flag(TIF_SIGPENDING); |
| 438 | return 0; |
| 439 | } |
| 440 | } |
| 441 | } |
| 442 | |
| 443 | if (!collect_signal(sig, pending, info)) |
| 444 | sig = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | |
| 447 | return sig; |
| 448 | } |
| 449 | |
| 450 | /* |
| 451 | * Dequeue a signal and return the element to the caller, which is |
| 452 | * expected to free it. |
| 453 | * |
| 454 | * All callers have to hold the siglock. |
| 455 | */ |
| 456 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) |
| 457 | { |
| 458 | int signr = __dequeue_signal(&tsk->pending, mask, info); |
Thomas Gleixner | 8bfd9a7 | 2007-02-16 01:28:12 -0800 | [diff] [blame] | 459 | if (!signr) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | signr = __dequeue_signal(&tsk->signal->shared_pending, |
| 461 | mask, info); |
Thomas Gleixner | 8bfd9a7 | 2007-02-16 01:28:12 -0800 | [diff] [blame] | 462 | /* |
| 463 | * itimer signal ? |
| 464 | * |
| 465 | * itimers are process shared and we restart periodic |
| 466 | * itimers in the signal delivery path to prevent DoS |
| 467 | * attacks in the high resolution timer case. This is |
| 468 | * compliant with the old way of self restarting |
| 469 | * itimers, as the SIGALRM is a legacy signal and only |
| 470 | * queued once. Changing the restart behaviour to |
| 471 | * restart the timer in the signal dequeue path is |
| 472 | * reducing the timer noise on heavy loaded !highres |
| 473 | * systems too. |
| 474 | */ |
| 475 | if (unlikely(signr == SIGALRM)) { |
| 476 | struct hrtimer *tmr = &tsk->signal->real_timer; |
| 477 | |
| 478 | if (!hrtimer_is_queued(tmr) && |
| 479 | tsk->signal->it_real_incr.tv64 != 0) { |
| 480 | hrtimer_forward(tmr, tmr->base->get_time(), |
| 481 | tsk->signal->it_real_incr); |
| 482 | hrtimer_restart(tmr); |
| 483 | } |
| 484 | } |
| 485 | } |
Roland McGrath | 27d91e0 | 2006-09-29 02:00:31 -0700 | [diff] [blame] | 486 | recalc_sigpending_tsk(tsk); |
Thomas Gleixner | 8bfd9a7 | 2007-02-16 01:28:12 -0800 | [diff] [blame] | 487 | if (signr && unlikely(sig_kernel_stop(signr))) { |
| 488 | /* |
| 489 | * Set a marker that we have dequeued a stop signal. Our |
| 490 | * caller might release the siglock and then the pending |
| 491 | * stop signal it is about to process is no longer in the |
| 492 | * pending bitmasks, but must still be cleared by a SIGCONT |
| 493 | * (and overruled by a SIGKILL). So those cases clear this |
| 494 | * shared flag after we've set it. Note that this flag may |
| 495 | * remain set after the signal we return is ignored or |
| 496 | * handled. That doesn't matter because its only purpose |
| 497 | * is to alert stop-signal processing code when another |
| 498 | * processor has come along and cleared the flag. |
| 499 | */ |
| 500 | if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) |
| 501 | tsk->signal->flags |= SIGNAL_STOP_DEQUEUED; |
| 502 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | if ( signr && |
| 504 | ((info->si_code & __SI_MASK) == __SI_TIMER) && |
| 505 | info->si_sys_private){ |
| 506 | /* |
| 507 | * Release the siglock to ensure proper locking order |
| 508 | * of timer locks outside of siglocks. Note, we leave |
| 509 | * irqs disabled here, since the posix-timers code is |
| 510 | * about to disable them again anyway. |
| 511 | */ |
| 512 | spin_unlock(&tsk->sighand->siglock); |
| 513 | do_schedule_next_timer(info); |
| 514 | spin_lock(&tsk->sighand->siglock); |
| 515 | } |
| 516 | return signr; |
| 517 | } |
| 518 | |
| 519 | /* |
| 520 | * Tell a process that it has a new active signal.. |
| 521 | * |
| 522 | * NOTE! we rely on the previous spin_lock to |
| 523 | * lock interrupts for us! We can only be called with |
| 524 | * "siglock" held, and the local interrupt must |
| 525 | * have been disabled when that got acquired! |
| 526 | * |
| 527 | * No need to set need_resched since signal event passing |
| 528 | * goes through ->blocked |
| 529 | */ |
| 530 | void signal_wake_up(struct task_struct *t, int resume) |
| 531 | { |
| 532 | unsigned int mask; |
| 533 | |
| 534 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
| 535 | |
| 536 | /* |
| 537 | * For SIGKILL, we want to wake it up in the stopped/traced case. |
| 538 | * We don't check t->state here because there is a race with it |
| 539 | * executing another processor and just now entering stopped state. |
| 540 | * By using wake_up_state, we ensure the process will wake up and |
| 541 | * handle its death signal. |
| 542 | */ |
| 543 | mask = TASK_INTERRUPTIBLE; |
| 544 | if (resume) |
| 545 | mask |= TASK_STOPPED | TASK_TRACED; |
| 546 | if (!wake_up_state(t, mask)) |
| 547 | kick_process(t); |
| 548 | } |
| 549 | |
| 550 | /* |
| 551 | * Remove signals in mask from the pending set and queue. |
| 552 | * Returns 1 if any signals were found. |
| 553 | * |
| 554 | * All callers must be holding the siglock. |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 555 | * |
| 556 | * This version takes a sigset mask and looks at all signals, |
| 557 | * not just those in the first mask word. |
| 558 | */ |
| 559 | static int rm_from_queue_full(sigset_t *mask, struct sigpending *s) |
| 560 | { |
| 561 | struct sigqueue *q, *n; |
| 562 | sigset_t m; |
| 563 | |
| 564 | sigandsets(&m, mask, &s->signal); |
| 565 | if (sigisemptyset(&m)) |
| 566 | return 0; |
| 567 | |
| 568 | signandsets(&s->signal, &s->signal, mask); |
| 569 | list_for_each_entry_safe(q, n, &s->list, list) { |
| 570 | if (sigismember(mask, q->info.si_signo)) { |
| 571 | list_del_init(&q->list); |
| 572 | __sigqueue_free(q); |
| 573 | } |
| 574 | } |
| 575 | return 1; |
| 576 | } |
| 577 | /* |
| 578 | * Remove signals in mask from the pending set and queue. |
| 579 | * Returns 1 if any signals were found. |
| 580 | * |
| 581 | * All callers must be holding the siglock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | */ |
| 583 | static int rm_from_queue(unsigned long mask, struct sigpending *s) |
| 584 | { |
| 585 | struct sigqueue *q, *n; |
| 586 | |
| 587 | if (!sigtestsetmask(&s->signal, mask)) |
| 588 | return 0; |
| 589 | |
| 590 | sigdelsetmask(&s->signal, mask); |
| 591 | list_for_each_entry_safe(q, n, &s->list, list) { |
| 592 | if (q->info.si_signo < SIGRTMIN && |
| 593 | (mask & sigmask(q->info.si_signo))) { |
| 594 | list_del_init(&q->list); |
| 595 | __sigqueue_free(q); |
| 596 | } |
| 597 | } |
| 598 | return 1; |
| 599 | } |
| 600 | |
| 601 | /* |
| 602 | * Bad permissions for sending the signal |
| 603 | */ |
| 604 | static int check_kill_permission(int sig, struct siginfo *info, |
| 605 | struct task_struct *t) |
| 606 | { |
| 607 | int error = -EINVAL; |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 608 | if (!valid_signal(sig)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | return error; |
| 610 | error = -EPERM; |
Oleg Nesterov | 621d312 | 2005-10-30 15:03:45 -0800 | [diff] [blame] | 611 | if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | && ((sig != SIGCONT) || |
Cedric Le Goater | 937949d | 2006-12-08 02:37:54 -0800 | [diff] [blame] | 613 | (process_session(current) != process_session(t))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | && (current->euid ^ t->suid) && (current->euid ^ t->uid) |
| 615 | && (current->uid ^ t->suid) && (current->uid ^ t->uid) |
| 616 | && !capable(CAP_KILL)) |
| 617 | return error; |
Steve Grubb | c2f0c7c | 2005-05-06 12:38:39 +0100 | [diff] [blame] | 618 | |
David Quigley | 8f95dc5 | 2006-06-30 01:55:47 -0700 | [diff] [blame] | 619 | error = security_task_kill(t, info, sig, 0); |
Steve Grubb | c2f0c7c | 2005-05-06 12:38:39 +0100 | [diff] [blame] | 620 | if (!error) |
| 621 | audit_signal_info(sig, t); /* Let audit system see the signal */ |
| 622 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | } |
| 624 | |
| 625 | /* forward decl */ |
Oleg Nesterov | a1d5e21 | 2006-03-28 16:11:29 -0800 | [diff] [blame] | 626 | static void do_notify_parent_cldstop(struct task_struct *tsk, int why); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | |
| 628 | /* |
| 629 | * Handle magic process-wide effects of stop/continue signals. |
| 630 | * Unlike the signal actions, these happen immediately at signal-generation |
| 631 | * time regardless of blocking, ignoring, or handling. This does the |
| 632 | * actual continuing for SIGCONT, but not the actual stopping for stop |
| 633 | * signals. The process stop is done as a signal action for SIG_DFL. |
| 634 | */ |
| 635 | static void handle_stop_signal(int sig, struct task_struct *p) |
| 636 | { |
| 637 | struct task_struct *t; |
| 638 | |
Bhavesh P. Davda | dd12f48 | 2005-08-17 12:26:33 -0600 | [diff] [blame] | 639 | if (p->signal->flags & SIGNAL_GROUP_EXIT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | /* |
| 641 | * The process is in the middle of dying already. |
| 642 | */ |
| 643 | return; |
| 644 | |
| 645 | if (sig_kernel_stop(sig)) { |
| 646 | /* |
| 647 | * This is a stop signal. Remove SIGCONT from all queues. |
| 648 | */ |
| 649 | rm_from_queue(sigmask(SIGCONT), &p->signal->shared_pending); |
| 650 | t = p; |
| 651 | do { |
| 652 | rm_from_queue(sigmask(SIGCONT), &t->pending); |
| 653 | t = next_thread(t); |
| 654 | } while (t != p); |
| 655 | } else if (sig == SIGCONT) { |
| 656 | /* |
| 657 | * Remove all stop signals from all queues, |
| 658 | * and wake all threads. |
| 659 | */ |
| 660 | if (unlikely(p->signal->group_stop_count > 0)) { |
| 661 | /* |
| 662 | * There was a group stop in progress. We'll |
| 663 | * pretend it finished before we got here. We are |
| 664 | * obliged to report it to the parent: if the |
| 665 | * SIGSTOP happened "after" this SIGCONT, then it |
| 666 | * would have cleared this pending SIGCONT. If it |
| 667 | * happened "before" this SIGCONT, then the parent |
| 668 | * got the SIGCHLD about the stop finishing before |
| 669 | * the continue happened. We do the notification |
| 670 | * now, and it's as if the stop had finished and |
| 671 | * the SIGCHLD was pending on entry to this kill. |
| 672 | */ |
| 673 | p->signal->group_stop_count = 0; |
| 674 | p->signal->flags = SIGNAL_STOP_CONTINUED; |
| 675 | spin_unlock(&p->sighand->siglock); |
Oleg Nesterov | a1d5e21 | 2006-03-28 16:11:29 -0800 | [diff] [blame] | 676 | do_notify_parent_cldstop(p, CLD_STOPPED); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | spin_lock(&p->sighand->siglock); |
| 678 | } |
| 679 | rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending); |
| 680 | t = p; |
| 681 | do { |
| 682 | unsigned int state; |
| 683 | rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); |
| 684 | |
| 685 | /* |
| 686 | * If there is a handler for SIGCONT, we must make |
| 687 | * sure that no thread returns to user mode before |
| 688 | * we post the signal, in case it was the only |
| 689 | * thread eligible to run the signal handler--then |
| 690 | * it must not do anything between resuming and |
| 691 | * running the handler. With the TIF_SIGPENDING |
| 692 | * flag set, the thread will pause and acquire the |
| 693 | * siglock that we hold now and until we've queued |
| 694 | * the pending signal. |
| 695 | * |
| 696 | * Wake up the stopped thread _after_ setting |
| 697 | * TIF_SIGPENDING |
| 698 | */ |
| 699 | state = TASK_STOPPED; |
| 700 | if (sig_user_defined(t, SIGCONT) && !sigismember(&t->blocked, SIGCONT)) { |
| 701 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
| 702 | state |= TASK_INTERRUPTIBLE; |
| 703 | } |
| 704 | wake_up_state(t, state); |
| 705 | |
| 706 | t = next_thread(t); |
| 707 | } while (t != p); |
| 708 | |
| 709 | if (p->signal->flags & SIGNAL_STOP_STOPPED) { |
| 710 | /* |
| 711 | * We were in fact stopped, and are now continued. |
| 712 | * Notify the parent with CLD_CONTINUED. |
| 713 | */ |
| 714 | p->signal->flags = SIGNAL_STOP_CONTINUED; |
| 715 | p->signal->group_exit_code = 0; |
| 716 | spin_unlock(&p->sighand->siglock); |
Oleg Nesterov | a1d5e21 | 2006-03-28 16:11:29 -0800 | [diff] [blame] | 717 | do_notify_parent_cldstop(p, CLD_CONTINUED); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | spin_lock(&p->sighand->siglock); |
| 719 | } else { |
| 720 | /* |
| 721 | * We are not stopped, but there could be a stop |
| 722 | * signal in the middle of being processed after |
| 723 | * being removed from the queue. Clear that too. |
| 724 | */ |
| 725 | p->signal->flags = 0; |
| 726 | } |
| 727 | } else if (sig == SIGKILL) { |
| 728 | /* |
| 729 | * Make sure that any pending stop signal already dequeued |
| 730 | * is undone by the wakeup for SIGKILL. |
| 731 | */ |
| 732 | p->signal->flags = 0; |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | static int send_signal(int sig, struct siginfo *info, struct task_struct *t, |
| 737 | struct sigpending *signals) |
| 738 | { |
| 739 | struct sigqueue * q = NULL; |
| 740 | int ret = 0; |
| 741 | |
| 742 | /* |
| 743 | * fast-pathed signals for kernel-internal things like SIGSTOP |
| 744 | * or SIGKILL. |
| 745 | */ |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 746 | if (info == SEND_SIG_FORCED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | goto out_set; |
| 748 | |
| 749 | /* Real-time signals must be queued if sent by sigqueue, or |
| 750 | some other real-time mechanism. It is implementation |
| 751 | defined whether kill() does so. We attempt to do so, on |
| 752 | the principle of least surprise, but since kill is not |
| 753 | allowed to fail with EAGAIN when low on memory we just |
| 754 | make sure at least one signal gets delivered and don't |
| 755 | pass on the info struct. */ |
| 756 | |
| 757 | q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN && |
Oleg Nesterov | 621d312 | 2005-10-30 15:03:45 -0800 | [diff] [blame] | 758 | (is_si_special(info) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | info->si_code >= 0))); |
| 760 | if (q) { |
| 761 | list_add_tail(&q->list, &signals->list); |
| 762 | switch ((unsigned long) info) { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 763 | case (unsigned long) SEND_SIG_NOINFO: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | q->info.si_signo = sig; |
| 765 | q->info.si_errno = 0; |
| 766 | q->info.si_code = SI_USER; |
| 767 | q->info.si_pid = current->pid; |
| 768 | q->info.si_uid = current->uid; |
| 769 | break; |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 770 | case (unsigned long) SEND_SIG_PRIV: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | q->info.si_signo = sig; |
| 772 | q->info.si_errno = 0; |
| 773 | q->info.si_code = SI_KERNEL; |
| 774 | q->info.si_pid = 0; |
| 775 | q->info.si_uid = 0; |
| 776 | break; |
| 777 | default: |
| 778 | copy_siginfo(&q->info, info); |
| 779 | break; |
| 780 | } |
Oleg Nesterov | 621d312 | 2005-10-30 15:03:45 -0800 | [diff] [blame] | 781 | } else if (!is_si_special(info)) { |
| 782 | if (sig >= SIGRTMIN && info->si_code != SI_USER) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | /* |
| 784 | * Queue overflow, abort. We may abort if the signal was rt |
| 785 | * and sent by user using something other than kill(). |
| 786 | */ |
| 787 | return -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | } |
| 789 | |
| 790 | out_set: |
| 791 | sigaddset(&signals->signal, sig); |
| 792 | return ret; |
| 793 | } |
| 794 | |
| 795 | #define LEGACY_QUEUE(sigptr, sig) \ |
| 796 | (((sig) < SIGRTMIN) && sigismember(&(sigptr)->signal, (sig))) |
| 797 | |
| 798 | |
| 799 | static int |
| 800 | specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) |
| 801 | { |
| 802 | int ret = 0; |
| 803 | |
Eric Sesterhenn | fda8bd78 | 2006-04-02 13:44:47 +0200 | [diff] [blame] | 804 | BUG_ON(!irqs_disabled()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | assert_spin_locked(&t->sighand->siglock); |
| 806 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | /* Short-circuit ignored signals. */ |
| 808 | if (sig_ignored(t, sig)) |
| 809 | goto out; |
| 810 | |
| 811 | /* Support queueing exactly one non-rt signal, so that we |
| 812 | can get more detailed information about the cause of |
| 813 | the signal. */ |
| 814 | if (LEGACY_QUEUE(&t->pending, sig)) |
| 815 | goto out; |
| 816 | |
| 817 | ret = send_signal(sig, info, t, &t->pending); |
| 818 | if (!ret && !sigismember(&t->blocked, sig)) |
| 819 | signal_wake_up(t, sig == SIGKILL); |
| 820 | out: |
| 821 | return ret; |
| 822 | } |
| 823 | |
| 824 | /* |
| 825 | * Force a signal that the process can't ignore: if necessary |
| 826 | * we unblock the signal and change any SIG_IGN to SIG_DFL. |
Linus Torvalds | ae74c3b | 2006-08-02 20:17:49 -0700 | [diff] [blame] | 827 | * |
| 828 | * Note: If we unblock the signal, we always reset it to SIG_DFL, |
| 829 | * since we do not want to have a signal handler that was blocked |
| 830 | * be invoked when user space had explicitly blocked it. |
| 831 | * |
| 832 | * We don't want to have recursive SIGSEGV's etc, for example. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | int |
| 835 | force_sig_info(int sig, struct siginfo *info, struct task_struct *t) |
| 836 | { |
| 837 | unsigned long int flags; |
Linus Torvalds | ae74c3b | 2006-08-02 20:17:49 -0700 | [diff] [blame] | 838 | int ret, blocked, ignored; |
| 839 | struct k_sigaction *action; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | |
| 841 | spin_lock_irqsave(&t->sighand->siglock, flags); |
Linus Torvalds | ae74c3b | 2006-08-02 20:17:49 -0700 | [diff] [blame] | 842 | action = &t->sighand->action[sig-1]; |
| 843 | ignored = action->sa.sa_handler == SIG_IGN; |
| 844 | blocked = sigismember(&t->blocked, sig); |
| 845 | if (blocked || ignored) { |
| 846 | action->sa.sa_handler = SIG_DFL; |
| 847 | if (blocked) { |
| 848 | sigdelset(&t->blocked, sig); |
| 849 | recalc_sigpending_tsk(t); |
| 850 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | } |
| 852 | ret = specific_send_sig_info(sig, info, t); |
| 853 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
| 854 | |
| 855 | return ret; |
| 856 | } |
| 857 | |
| 858 | void |
| 859 | force_sig_specific(int sig, struct task_struct *t) |
| 860 | { |
Paul E. McKenney | b0423a0 | 2005-10-30 15:03:46 -0800 | [diff] [blame] | 861 | force_sig_info(sig, SEND_SIG_FORCED, t); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | } |
| 863 | |
| 864 | /* |
| 865 | * Test if P wants to take SIG. After we've checked all threads with this, |
| 866 | * it's equivalent to finding no threads not blocking SIG. Any threads not |
| 867 | * blocking SIG were ruled out because they are not running and already |
| 868 | * have pending signals. Such threads will dequeue from the shared queue |
| 869 | * as soon as they're available, so putting the signal on the shared queue |
| 870 | * will be equivalent to sending it to one such thread. |
| 871 | */ |
Linus Torvalds | 188a1eaf | 2005-09-23 13:22:21 -0700 | [diff] [blame] | 872 | static inline int wants_signal(int sig, struct task_struct *p) |
| 873 | { |
| 874 | if (sigismember(&p->blocked, sig)) |
| 875 | return 0; |
| 876 | if (p->flags & PF_EXITING) |
| 877 | return 0; |
| 878 | if (sig == SIGKILL) |
| 879 | return 1; |
| 880 | if (p->state & (TASK_STOPPED | TASK_TRACED)) |
| 881 | return 0; |
| 882 | return task_curr(p) || !signal_pending(p); |
| 883 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | |
| 885 | static void |
| 886 | __group_complete_signal(int sig, struct task_struct *p) |
| 887 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | struct task_struct *t; |
| 889 | |
| 890 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | * Now find a thread we can wake up to take the signal off the queue. |
| 892 | * |
| 893 | * If the main thread wants the signal, it gets first crack. |
| 894 | * Probably the least surprising to the average bear. |
| 895 | */ |
Linus Torvalds | 188a1eaf | 2005-09-23 13:22:21 -0700 | [diff] [blame] | 896 | if (wants_signal(sig, p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | t = p; |
| 898 | else if (thread_group_empty(p)) |
| 899 | /* |
| 900 | * There is just one thread and it does not need to be woken. |
| 901 | * It will dequeue unblocked signals before it runs again. |
| 902 | */ |
| 903 | return; |
| 904 | else { |
| 905 | /* |
| 906 | * Otherwise try to find a suitable thread. |
| 907 | */ |
| 908 | t = p->signal->curr_target; |
| 909 | if (t == NULL) |
| 910 | /* restart balancing at this thread */ |
| 911 | t = p->signal->curr_target = p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 912 | |
Linus Torvalds | 188a1eaf | 2005-09-23 13:22:21 -0700 | [diff] [blame] | 913 | while (!wants_signal(sig, t)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 914 | t = next_thread(t); |
| 915 | if (t == p->signal->curr_target) |
| 916 | /* |
| 917 | * No thread needs to be woken. |
| 918 | * Any eligible threads will see |
| 919 | * the signal in the queue soon. |
| 920 | */ |
| 921 | return; |
| 922 | } |
| 923 | p->signal->curr_target = t; |
| 924 | } |
| 925 | |
| 926 | /* |
| 927 | * Found a killable thread. If the signal will be fatal, |
| 928 | * then start taking the whole group down immediately. |
| 929 | */ |
| 930 | if (sig_fatal(p, sig) && !(p->signal->flags & SIGNAL_GROUP_EXIT) && |
| 931 | !sigismember(&t->real_blocked, sig) && |
| 932 | (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) { |
| 933 | /* |
| 934 | * This signal will be fatal to the whole group. |
| 935 | */ |
| 936 | if (!sig_kernel_coredump(sig)) { |
| 937 | /* |
| 938 | * Start a group exit and wake everybody up. |
| 939 | * This way we don't have other threads |
| 940 | * running and doing things after a slower |
| 941 | * thread has the fatal signal pending. |
| 942 | */ |
| 943 | p->signal->flags = SIGNAL_GROUP_EXIT; |
| 944 | p->signal->group_exit_code = sig; |
| 945 | p->signal->group_stop_count = 0; |
| 946 | t = p; |
| 947 | do { |
| 948 | sigaddset(&t->pending.signal, SIGKILL); |
| 949 | signal_wake_up(t, 1); |
| 950 | t = next_thread(t); |
| 951 | } while (t != p); |
| 952 | return; |
| 953 | } |
| 954 | |
| 955 | /* |
| 956 | * There will be a core dump. We make all threads other |
| 957 | * than the chosen one go into a group stop so that nothing |
| 958 | * happens until it gets scheduled, takes the signal off |
| 959 | * the shared queue, and does the core dump. This is a |
| 960 | * little more complicated than strictly necessary, but it |
| 961 | * keeps the signal state that winds up in the core dump |
| 962 | * unchanged from the death state, e.g. which thread had |
| 963 | * the core-dump signal unblocked. |
| 964 | */ |
| 965 | rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); |
| 966 | rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending); |
| 967 | p->signal->group_stop_count = 0; |
| 968 | p->signal->group_exit_task = t; |
| 969 | t = p; |
| 970 | do { |
| 971 | p->signal->group_stop_count++; |
| 972 | signal_wake_up(t, 0); |
| 973 | t = next_thread(t); |
| 974 | } while (t != p); |
| 975 | wake_up_process(p->signal->group_exit_task); |
| 976 | return; |
| 977 | } |
| 978 | |
| 979 | /* |
| 980 | * The signal is already in the shared-pending queue. |
| 981 | * Tell the chosen thread to wake up and dequeue it. |
| 982 | */ |
| 983 | signal_wake_up(t, sig == SIGKILL); |
| 984 | return; |
| 985 | } |
| 986 | |
| 987 | int |
| 988 | __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
| 989 | { |
| 990 | int ret = 0; |
| 991 | |
| 992 | assert_spin_locked(&p->sighand->siglock); |
| 993 | handle_stop_signal(sig, p); |
| 994 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 995 | /* Short-circuit ignored signals. */ |
| 996 | if (sig_ignored(p, sig)) |
| 997 | return ret; |
| 998 | |
| 999 | if (LEGACY_QUEUE(&p->signal->shared_pending, sig)) |
| 1000 | /* This is a non-RT signal and we already have one queued. */ |
| 1001 | return ret; |
| 1002 | |
| 1003 | /* |
| 1004 | * Put this signal on the shared-pending queue, or fail with EAGAIN. |
| 1005 | * We always use the shared queue for process-wide signals, |
| 1006 | * to avoid several races. |
| 1007 | */ |
| 1008 | ret = send_signal(sig, info, p, &p->signal->shared_pending); |
| 1009 | if (unlikely(ret)) |
| 1010 | return ret; |
| 1011 | |
| 1012 | __group_complete_signal(sig, p); |
| 1013 | return 0; |
| 1014 | } |
| 1015 | |
| 1016 | /* |
| 1017 | * Nuke all other threads in the group. |
| 1018 | */ |
| 1019 | void zap_other_threads(struct task_struct *p) |
| 1020 | { |
| 1021 | struct task_struct *t; |
| 1022 | |
| 1023 | p->signal->flags = SIGNAL_GROUP_EXIT; |
| 1024 | p->signal->group_stop_count = 0; |
| 1025 | |
| 1026 | if (thread_group_empty(p)) |
| 1027 | return; |
| 1028 | |
| 1029 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
| 1030 | /* |
| 1031 | * Don't bother with already dead threads |
| 1032 | */ |
| 1033 | if (t->exit_state) |
| 1034 | continue; |
| 1035 | |
| 1036 | /* |
| 1037 | * We don't want to notify the parent, since we are |
| 1038 | * killed as part of a thread group due to another |
| 1039 | * thread doing an execve() or similar. So set the |
| 1040 | * exit signal to -1 to allow immediate reaping of |
| 1041 | * the process. But don't detach the thread group |
| 1042 | * leader. |
| 1043 | */ |
| 1044 | if (t != p->group_leader) |
| 1045 | t->exit_signal = -1; |
| 1046 | |
Andrea Arcangeli | 30e0fca6 | 2005-10-30 15:02:38 -0800 | [diff] [blame] | 1047 | /* SIGKILL will be handled before any pending SIGSTOP */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1048 | sigaddset(&t->pending.signal, SIGKILL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1049 | signal_wake_up(t, 1); |
| 1050 | } |
| 1051 | } |
| 1052 | |
| 1053 | /* |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1054 | * Must be called under rcu_read_lock() or with tasklist_lock read-held. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1055 | */ |
Oleg Nesterov | f63ee72 | 2006-03-28 16:11:13 -0800 | [diff] [blame] | 1056 | struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags) |
| 1057 | { |
| 1058 | struct sighand_struct *sighand; |
| 1059 | |
| 1060 | for (;;) { |
| 1061 | sighand = rcu_dereference(tsk->sighand); |
| 1062 | if (unlikely(sighand == NULL)) |
| 1063 | break; |
| 1064 | |
| 1065 | spin_lock_irqsave(&sighand->siglock, *flags); |
| 1066 | if (likely(sighand == tsk->sighand)) |
| 1067 | break; |
| 1068 | spin_unlock_irqrestore(&sighand->siglock, *flags); |
| 1069 | } |
| 1070 | |
| 1071 | return sighand; |
| 1072 | } |
| 1073 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
| 1075 | { |
| 1076 | unsigned long flags; |
| 1077 | int ret; |
| 1078 | |
| 1079 | ret = check_kill_permission(sig, info, p); |
Oleg Nesterov | f63ee72 | 2006-03-28 16:11:13 -0800 | [diff] [blame] | 1080 | |
| 1081 | if (!ret && sig) { |
| 1082 | ret = -ESRCH; |
| 1083 | if (lock_task_sighand(p, &flags)) { |
| 1084 | ret = __group_send_sig_info(sig, info, p); |
| 1085 | unlock_task_sighand(p, &flags); |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1086 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1087 | } |
| 1088 | |
| 1089 | return ret; |
| 1090 | } |
| 1091 | |
| 1092 | /* |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1093 | * kill_pgrp_info() sends a signal to a process group: this is what the tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1094 | * control characters do (^C, ^Z etc) |
| 1095 | */ |
| 1096 | |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1097 | int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1098 | { |
| 1099 | struct task_struct *p = NULL; |
| 1100 | int retval, success; |
| 1101 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1102 | success = 0; |
| 1103 | retval = -ESRCH; |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1104 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1105 | int err = group_send_sig_info(sig, info, p); |
| 1106 | success |= !err; |
| 1107 | retval = err; |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1108 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1109 | return success ? 0 : retval; |
| 1110 | } |
| 1111 | |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1112 | int kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) |
| 1113 | { |
| 1114 | int retval; |
| 1115 | |
| 1116 | read_lock(&tasklist_lock); |
| 1117 | retval = __kill_pgrp_info(sig, info, pgrp); |
| 1118 | read_unlock(&tasklist_lock); |
| 1119 | |
| 1120 | return retval; |
| 1121 | } |
| 1122 | |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1123 | int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1124 | { |
| 1125 | int error; |
| 1126 | struct task_struct *p; |
| 1127 | |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1128 | rcu_read_lock(); |
Oleg Nesterov | 0c12b51 | 2007-02-10 01:44:56 -0800 | [diff] [blame] | 1129 | if (unlikely(sig_needs_tasklist(sig))) |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1130 | read_lock(&tasklist_lock); |
Oleg Nesterov | 0c12b51 | 2007-02-10 01:44:56 -0800 | [diff] [blame] | 1131 | |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1132 | p = pid_task(pid, PIDTYPE_PID); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | error = -ESRCH; |
| 1134 | if (p) |
| 1135 | error = group_send_sig_info(sig, info, p); |
Oleg Nesterov | 0c12b51 | 2007-02-10 01:44:56 -0800 | [diff] [blame] | 1136 | |
| 1137 | if (unlikely(sig_needs_tasklist(sig))) |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1138 | read_unlock(&tasklist_lock); |
| 1139 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | return error; |
| 1141 | } |
| 1142 | |
Matthew Wilcox | c3de4b3 | 2007-02-09 08:11:47 -0700 | [diff] [blame] | 1143 | int |
| 1144 | kill_proc_info(int sig, struct siginfo *info, pid_t pid) |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1145 | { |
| 1146 | int error; |
| 1147 | rcu_read_lock(); |
| 1148 | error = kill_pid_info(sig, info, find_pid(pid)); |
| 1149 | rcu_read_unlock(); |
| 1150 | return error; |
| 1151 | } |
| 1152 | |
Eric W. Biederman | 2425c08 | 2006-10-02 02:17:28 -0700 | [diff] [blame] | 1153 | /* like kill_pid_info(), but doesn't use uid/euid of "current" */ |
| 1154 | int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, |
David Quigley | 8f95dc5 | 2006-06-30 01:55:47 -0700 | [diff] [blame] | 1155 | uid_t uid, uid_t euid, u32 secid) |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1156 | { |
| 1157 | int ret = -EINVAL; |
| 1158 | struct task_struct *p; |
| 1159 | |
| 1160 | if (!valid_signal(sig)) |
| 1161 | return ret; |
| 1162 | |
| 1163 | read_lock(&tasklist_lock); |
Eric W. Biederman | 2425c08 | 2006-10-02 02:17:28 -0700 | [diff] [blame] | 1164 | p = pid_task(pid, PIDTYPE_PID); |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1165 | if (!p) { |
| 1166 | ret = -ESRCH; |
| 1167 | goto out_unlock; |
| 1168 | } |
Oleg Nesterov | 0811af2 | 2006-01-08 01:03:09 -0800 | [diff] [blame] | 1169 | if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1170 | && (euid != p->suid) && (euid != p->uid) |
| 1171 | && (uid != p->suid) && (uid != p->uid)) { |
| 1172 | ret = -EPERM; |
| 1173 | goto out_unlock; |
| 1174 | } |
David Quigley | 8f95dc5 | 2006-06-30 01:55:47 -0700 | [diff] [blame] | 1175 | ret = security_task_kill(p, info, sig, secid); |
| 1176 | if (ret) |
| 1177 | goto out_unlock; |
Harald Welte | 4611383 | 2005-10-10 19:44:29 +0200 | [diff] [blame] | 1178 | if (sig && p->sighand) { |
| 1179 | unsigned long flags; |
| 1180 | spin_lock_irqsave(&p->sighand->siglock, flags); |
| 1181 | ret = __group_send_sig_info(sig, info, p); |
| 1182 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
| 1183 | } |
| 1184 | out_unlock: |
| 1185 | read_unlock(&tasklist_lock); |
| 1186 | return ret; |
| 1187 | } |
Eric W. Biederman | 2425c08 | 2006-10-02 02:17:28 -0700 | [diff] [blame] | 1188 | EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | |
| 1190 | /* |
| 1191 | * kill_something_info() interprets pid in interesting ways just like kill(2). |
| 1192 | * |
| 1193 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have |
| 1194 | * is probably wrong. Should make it like BSD or SYSV. |
| 1195 | */ |
| 1196 | |
| 1197 | static int kill_something_info(int sig, struct siginfo *info, int pid) |
| 1198 | { |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1199 | int ret; |
| 1200 | rcu_read_lock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | if (!pid) { |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1202 | ret = kill_pgrp_info(sig, info, task_pgrp(current)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1203 | } else if (pid == -1) { |
| 1204 | int retval = 0, count = 0; |
| 1205 | struct task_struct * p; |
| 1206 | |
| 1207 | read_lock(&tasklist_lock); |
| 1208 | for_each_process(p) { |
| 1209 | if (p->pid > 1 && p->tgid != current->tgid) { |
| 1210 | int err = group_send_sig_info(sig, info, p); |
| 1211 | ++count; |
| 1212 | if (err != -EPERM) |
| 1213 | retval = err; |
| 1214 | } |
| 1215 | } |
| 1216 | read_unlock(&tasklist_lock); |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1217 | ret = count ? retval : -ESRCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1218 | } else if (pid < 0) { |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1219 | ret = kill_pgrp_info(sig, info, find_pid(-pid)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1220 | } else { |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1221 | ret = kill_pid_info(sig, info, find_pid(pid)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1222 | } |
Eric W. Biederman | 8d42db18 | 2007-02-12 00:52:55 -0800 | [diff] [blame] | 1223 | rcu_read_unlock(); |
| 1224 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1225 | } |
| 1226 | |
| 1227 | /* |
| 1228 | * These are for backward compatibility with the rest of the kernel source. |
| 1229 | */ |
| 1230 | |
| 1231 | /* |
| 1232 | * These two are the most common entry points. They send a signal |
| 1233 | * just to the specific thread. |
| 1234 | */ |
| 1235 | int |
| 1236 | send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
| 1237 | { |
| 1238 | int ret; |
| 1239 | unsigned long flags; |
| 1240 | |
| 1241 | /* |
| 1242 | * Make sure legacy kernel users don't send in bad values |
| 1243 | * (normal paths check this in check_kill_permission). |
| 1244 | */ |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 1245 | if (!valid_signal(sig)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1246 | return -EINVAL; |
| 1247 | |
| 1248 | /* |
| 1249 | * We need the tasklist lock even for the specific |
| 1250 | * thread case (when we don't need to follow the group |
| 1251 | * lists) in order to avoid races with "p->sighand" |
| 1252 | * going away or changing from under us. |
| 1253 | */ |
| 1254 | read_lock(&tasklist_lock); |
| 1255 | spin_lock_irqsave(&p->sighand->siglock, flags); |
| 1256 | ret = specific_send_sig_info(sig, info, p); |
| 1257 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
| 1258 | read_unlock(&tasklist_lock); |
| 1259 | return ret; |
| 1260 | } |
| 1261 | |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1262 | #define __si_special(priv) \ |
| 1263 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) |
| 1264 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1265 | int |
| 1266 | send_sig(int sig, struct task_struct *p, int priv) |
| 1267 | { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1268 | return send_sig_info(sig, __si_special(priv), p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | } |
| 1270 | |
| 1271 | /* |
| 1272 | * This is the entry point for "process-wide" signals. |
| 1273 | * They will go to an appropriate thread in the thread group. |
| 1274 | */ |
| 1275 | int |
| 1276 | send_group_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
| 1277 | { |
| 1278 | int ret; |
| 1279 | read_lock(&tasklist_lock); |
| 1280 | ret = group_send_sig_info(sig, info, p); |
| 1281 | read_unlock(&tasklist_lock); |
| 1282 | return ret; |
| 1283 | } |
| 1284 | |
| 1285 | void |
| 1286 | force_sig(int sig, struct task_struct *p) |
| 1287 | { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1288 | force_sig_info(sig, SEND_SIG_PRIV, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1289 | } |
| 1290 | |
| 1291 | /* |
| 1292 | * When things go south during signal handling, we |
| 1293 | * will force a SIGSEGV. And if the signal that caused |
| 1294 | * the problem was already a SIGSEGV, we'll want to |
| 1295 | * make sure we don't even try to deliver the signal.. |
| 1296 | */ |
| 1297 | int |
| 1298 | force_sigsegv(int sig, struct task_struct *p) |
| 1299 | { |
| 1300 | if (sig == SIGSEGV) { |
| 1301 | unsigned long flags; |
| 1302 | spin_lock_irqsave(&p->sighand->siglock, flags); |
| 1303 | p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; |
| 1304 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
| 1305 | } |
| 1306 | force_sig(SIGSEGV, p); |
| 1307 | return 0; |
| 1308 | } |
| 1309 | |
Eric W. Biederman | c4b92fc | 2006-10-02 02:17:10 -0700 | [diff] [blame] | 1310 | int kill_pgrp(struct pid *pid, int sig, int priv) |
| 1311 | { |
| 1312 | return kill_pgrp_info(sig, __si_special(priv), pid); |
| 1313 | } |
| 1314 | EXPORT_SYMBOL(kill_pgrp); |
| 1315 | |
| 1316 | int kill_pid(struct pid *pid, int sig, int priv) |
| 1317 | { |
| 1318 | return kill_pid_info(sig, __si_special(priv), pid); |
| 1319 | } |
| 1320 | EXPORT_SYMBOL(kill_pid); |
| 1321 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1322 | int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1323 | kill_proc(pid_t pid, int sig, int priv) |
| 1324 | { |
Oleg Nesterov | b67a1b9 | 2005-10-30 15:03:44 -0800 | [diff] [blame] | 1325 | return kill_proc_info(sig, __si_special(priv), pid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1326 | } |
| 1327 | |
| 1328 | /* |
| 1329 | * These functions support sending signals using preallocated sigqueue |
| 1330 | * structures. This is needed "because realtime applications cannot |
| 1331 | * afford to lose notifications of asynchronous events, like timer |
| 1332 | * expirations or I/O completions". In the case of Posix Timers |
| 1333 | * we allocate the sigqueue structure from the timer_create. If this |
| 1334 | * allocation fails we are able to report the failure to the application |
| 1335 | * with an EAGAIN error. |
| 1336 | */ |
| 1337 | |
| 1338 | struct sigqueue *sigqueue_alloc(void) |
| 1339 | { |
| 1340 | struct sigqueue *q; |
| 1341 | |
| 1342 | if ((q = __sigqueue_alloc(current, GFP_KERNEL, 0))) |
| 1343 | q->flags |= SIGQUEUE_PREALLOC; |
| 1344 | return(q); |
| 1345 | } |
| 1346 | |
| 1347 | void sigqueue_free(struct sigqueue *q) |
| 1348 | { |
| 1349 | unsigned long flags; |
| 1350 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
| 1351 | /* |
| 1352 | * If the signal is still pending remove it from the |
| 1353 | * pending queue. |
| 1354 | */ |
| 1355 | if (unlikely(!list_empty(&q->list))) { |
Oleg Nesterov | 19a4fcb5 | 2005-10-30 15:02:17 -0800 | [diff] [blame] | 1356 | spinlock_t *lock = ¤t->sighand->siglock; |
| 1357 | read_lock(&tasklist_lock); |
| 1358 | spin_lock_irqsave(lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1359 | if (!list_empty(&q->list)) |
| 1360 | list_del_init(&q->list); |
Oleg Nesterov | 19a4fcb5 | 2005-10-30 15:02:17 -0800 | [diff] [blame] | 1361 | spin_unlock_irqrestore(lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1362 | read_unlock(&tasklist_lock); |
| 1363 | } |
| 1364 | q->flags &= ~SIGQUEUE_PREALLOC; |
| 1365 | __sigqueue_free(q); |
| 1366 | } |
| 1367 | |
Oleg Nesterov | 5476790 | 2006-03-28 16:11:30 -0800 | [diff] [blame] | 1368 | int send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1369 | { |
| 1370 | unsigned long flags; |
| 1371 | int ret = 0; |
| 1372 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1374 | |
| 1375 | /* |
| 1376 | * The rcu based delayed sighand destroy makes it possible to |
| 1377 | * run this without tasklist lock held. The task struct itself |
| 1378 | * cannot go away as create_timer did get_task_struct(). |
| 1379 | * |
| 1380 | * We return -1, when the task is marked exiting, so |
| 1381 | * posix_timer_event can redirect it to the group leader |
| 1382 | */ |
| 1383 | rcu_read_lock(); |
Oleg Nesterov | e752dd6 | 2005-09-06 15:17:42 -0700 | [diff] [blame] | 1384 | |
Oleg Nesterov | 5476790 | 2006-03-28 16:11:30 -0800 | [diff] [blame] | 1385 | if (!likely(lock_task_sighand(p, &flags))) { |
Oleg Nesterov | e752dd6 | 2005-09-06 15:17:42 -0700 | [diff] [blame] | 1386 | ret = -1; |
| 1387 | goto out_err; |
| 1388 | } |
| 1389 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1390 | if (unlikely(!list_empty(&q->list))) { |
| 1391 | /* |
| 1392 | * If an SI_TIMER entry is already queue just increment |
| 1393 | * the overrun count. |
| 1394 | */ |
Oleg Nesterov | 5476790 | 2006-03-28 16:11:30 -0800 | [diff] [blame] | 1395 | BUG_ON(q->info.si_code != SI_TIMER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | q->info.si_overrun++; |
| 1397 | goto out; |
Oleg Nesterov | e752dd6 | 2005-09-06 15:17:42 -0700 | [diff] [blame] | 1398 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1399 | /* Short-circuit ignored signals. */ |
| 1400 | if (sig_ignored(p, sig)) { |
| 1401 | ret = 1; |
| 1402 | goto out; |
| 1403 | } |
| 1404 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1405 | list_add_tail(&q->list, &p->pending.list); |
| 1406 | sigaddset(&p->pending.signal, sig); |
| 1407 | if (!sigismember(&p->blocked, sig)) |
| 1408 | signal_wake_up(p, sig == SIGKILL); |
| 1409 | |
| 1410 | out: |
Oleg Nesterov | 5476790 | 2006-03-28 16:11:30 -0800 | [diff] [blame] | 1411 | unlock_task_sighand(p, &flags); |
Oleg Nesterov | e752dd6 | 2005-09-06 15:17:42 -0700 | [diff] [blame] | 1412 | out_err: |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1413 | rcu_read_unlock(); |
Oleg Nesterov | e752dd6 | 2005-09-06 15:17:42 -0700 | [diff] [blame] | 1414 | |
| 1415 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1416 | } |
| 1417 | |
| 1418 | int |
| 1419 | send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) |
| 1420 | { |
| 1421 | unsigned long flags; |
| 1422 | int ret = 0; |
| 1423 | |
| 1424 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1425 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1426 | read_lock(&tasklist_lock); |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1427 | /* Since it_lock is held, p->sighand cannot be NULL. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | spin_lock_irqsave(&p->sighand->siglock, flags); |
| 1429 | handle_stop_signal(sig, p); |
| 1430 | |
| 1431 | /* Short-circuit ignored signals. */ |
| 1432 | if (sig_ignored(p, sig)) { |
| 1433 | ret = 1; |
| 1434 | goto out; |
| 1435 | } |
| 1436 | |
| 1437 | if (unlikely(!list_empty(&q->list))) { |
| 1438 | /* |
| 1439 | * If an SI_TIMER entry is already queue just increment |
| 1440 | * the overrun count. Other uses should not try to |
| 1441 | * send the signal multiple times. |
| 1442 | */ |
Eric Sesterhenn | fda8bd78 | 2006-04-02 13:44:47 +0200 | [diff] [blame] | 1443 | BUG_ON(q->info.si_code != SI_TIMER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1444 | q->info.si_overrun++; |
| 1445 | goto out; |
| 1446 | } |
| 1447 | |
| 1448 | /* |
| 1449 | * Put this signal on the shared-pending queue. |
| 1450 | * We always use the shared queue for process-wide signals, |
| 1451 | * to avoid several races. |
| 1452 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1453 | list_add_tail(&q->list, &p->signal->shared_pending.list); |
| 1454 | sigaddset(&p->signal->shared_pending.signal, sig); |
| 1455 | |
| 1456 | __group_complete_signal(sig, p); |
| 1457 | out: |
| 1458 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
| 1459 | read_unlock(&tasklist_lock); |
Ingo Molnar | e56d090 | 2006-01-08 01:01:37 -0800 | [diff] [blame] | 1460 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | } |
| 1462 | |
| 1463 | /* |
| 1464 | * Wake up any threads in the parent blocked in wait* syscalls. |
| 1465 | */ |
| 1466 | static inline void __wake_up_parent(struct task_struct *p, |
| 1467 | struct task_struct *parent) |
| 1468 | { |
| 1469 | wake_up_interruptible_sync(&parent->signal->wait_chldexit); |
| 1470 | } |
| 1471 | |
| 1472 | /* |
| 1473 | * Let a parent know about the death of a child. |
| 1474 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. |
| 1475 | */ |
| 1476 | |
| 1477 | void do_notify_parent(struct task_struct *tsk, int sig) |
| 1478 | { |
| 1479 | struct siginfo info; |
| 1480 | unsigned long flags; |
| 1481 | struct sighand_struct *psig; |
| 1482 | |
| 1483 | BUG_ON(sig == -1); |
| 1484 | |
| 1485 | /* do_notify_parent_cldstop should have been called instead. */ |
| 1486 | BUG_ON(tsk->state & (TASK_STOPPED|TASK_TRACED)); |
| 1487 | |
| 1488 | BUG_ON(!tsk->ptrace && |
| 1489 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); |
| 1490 | |
| 1491 | info.si_signo = sig; |
| 1492 | info.si_errno = 0; |
| 1493 | info.si_pid = tsk->pid; |
| 1494 | info.si_uid = tsk->uid; |
| 1495 | |
| 1496 | /* FIXME: find out whether or not this is supposed to be c*time. */ |
| 1497 | info.si_utime = cputime_to_jiffies(cputime_add(tsk->utime, |
| 1498 | tsk->signal->utime)); |
| 1499 | info.si_stime = cputime_to_jiffies(cputime_add(tsk->stime, |
| 1500 | tsk->signal->stime)); |
| 1501 | |
| 1502 | info.si_status = tsk->exit_code & 0x7f; |
| 1503 | if (tsk->exit_code & 0x80) |
| 1504 | info.si_code = CLD_DUMPED; |
| 1505 | else if (tsk->exit_code & 0x7f) |
| 1506 | info.si_code = CLD_KILLED; |
| 1507 | else { |
| 1508 | info.si_code = CLD_EXITED; |
| 1509 | info.si_status = tsk->exit_code >> 8; |
| 1510 | } |
| 1511 | |
| 1512 | psig = tsk->parent->sighand; |
| 1513 | spin_lock_irqsave(&psig->siglock, flags); |
Oleg Nesterov | 7ed0175 | 2005-11-10 17:22:18 +0300 | [diff] [blame] | 1514 | if (!tsk->ptrace && sig == SIGCHLD && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1515 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || |
| 1516 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { |
| 1517 | /* |
| 1518 | * We are exiting and our parent doesn't care. POSIX.1 |
| 1519 | * defines special semantics for setting SIGCHLD to SIG_IGN |
| 1520 | * or setting the SA_NOCLDWAIT flag: we should be reaped |
| 1521 | * automatically and not left for our parent's wait4 call. |
| 1522 | * Rather than having the parent do it as a magic kind of |
| 1523 | * signal handler, we just set this to tell do_exit that we |
| 1524 | * can be cleaned up without becoming a zombie. Note that |
| 1525 | * we still call __wake_up_parent in this case, because a |
| 1526 | * blocked sys_wait4 might now return -ECHILD. |
| 1527 | * |
| 1528 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT |
| 1529 | * is implementation-defined: we do (if you don't want |
| 1530 | * it, just use SIG_IGN instead). |
| 1531 | */ |
| 1532 | tsk->exit_signal = -1; |
| 1533 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) |
| 1534 | sig = 0; |
| 1535 | } |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 1536 | if (valid_signal(sig) && sig > 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1537 | __group_send_sig_info(sig, &info, tsk->parent); |
| 1538 | __wake_up_parent(tsk, tsk->parent); |
| 1539 | spin_unlock_irqrestore(&psig->siglock, flags); |
| 1540 | } |
| 1541 | |
Oleg Nesterov | a1d5e21 | 2006-03-28 16:11:29 -0800 | [diff] [blame] | 1542 | static void do_notify_parent_cldstop(struct task_struct *tsk, int why) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1543 | { |
| 1544 | struct siginfo info; |
| 1545 | unsigned long flags; |
Oleg Nesterov | bc505a4 | 2005-09-06 15:17:32 -0700 | [diff] [blame] | 1546 | struct task_struct *parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1547 | struct sighand_struct *sighand; |
| 1548 | |
Oleg Nesterov | a1d5e21 | 2006-03-28 16:11:29 -0800 | [diff] [blame] | 1549 | if (tsk->ptrace & PT_PTRACED) |
Oleg Nesterov | bc505a4 | 2005-09-06 15:17:32 -0700 | [diff] [blame] | 1550 | parent = tsk->parent; |
| 1551 | else { |
| 1552 | tsk = tsk->group_leader; |
| 1553 | parent = tsk->real_parent; |
| 1554 | } |
| 1555 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1556 | info.si_signo = SIGCHLD; |
| 1557 | info.si_errno = 0; |
| 1558 | info.si_pid = tsk->pid; |
| 1559 | info.si_uid = tsk->uid; |
| 1560 | |
| 1561 | /* FIXME: find out whether or not this is supposed to be c*time. */ |
| 1562 | info.si_utime = cputime_to_jiffies(tsk->utime); |
| 1563 | info.si_stime = cputime_to_jiffies(tsk->stime); |
| 1564 | |
| 1565 | info.si_code = why; |
| 1566 | switch (why) { |
| 1567 | case CLD_CONTINUED: |
| 1568 | info.si_status = SIGCONT; |
| 1569 | break; |
| 1570 | case CLD_STOPPED: |
| 1571 | info.si_status = tsk->signal->group_exit_code & 0x7f; |
| 1572 | break; |
| 1573 | case CLD_TRAPPED: |
| 1574 | info.si_status = tsk->exit_code & 0x7f; |
| 1575 | break; |
| 1576 | default: |
| 1577 | BUG(); |
| 1578 | } |
| 1579 | |
| 1580 | sighand = parent->sighand; |
| 1581 | spin_lock_irqsave(&sighand->siglock, flags); |
| 1582 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && |
| 1583 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) |
| 1584 | __group_send_sig_info(SIGCHLD, &info, parent); |
| 1585 | /* |
| 1586 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. |
| 1587 | */ |
| 1588 | __wake_up_parent(tsk, parent); |
| 1589 | spin_unlock_irqrestore(&sighand->siglock, flags); |
| 1590 | } |
| 1591 | |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1592 | static inline int may_ptrace_stop(void) |
| 1593 | { |
| 1594 | if (!likely(current->ptrace & PT_PTRACED)) |
| 1595 | return 0; |
| 1596 | |
| 1597 | if (unlikely(current->parent == current->real_parent && |
| 1598 | (current->ptrace & PT_ATTACHED))) |
| 1599 | return 0; |
| 1600 | |
| 1601 | if (unlikely(current->signal == current->parent->signal) && |
| 1602 | unlikely(current->signal->flags & SIGNAL_GROUP_EXIT)) |
| 1603 | return 0; |
| 1604 | |
| 1605 | /* |
| 1606 | * Are we in the middle of do_coredump? |
| 1607 | * If so and our tracer is also part of the coredump stopping |
| 1608 | * is a deadlock situation, and pointless because our tracer |
| 1609 | * is dead so don't allow us to stop. |
| 1610 | * If SIGKILL was already sent before the caller unlocked |
| 1611 | * ->siglock we must see ->core_waiters != 0. Otherwise it |
| 1612 | * is safe to enter schedule(). |
| 1613 | */ |
| 1614 | if (unlikely(current->mm->core_waiters) && |
| 1615 | unlikely(current->mm == current->parent->mm)) |
| 1616 | return 0; |
| 1617 | |
| 1618 | return 1; |
| 1619 | } |
| 1620 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | /* |
| 1622 | * This must be called with current->sighand->siglock held. |
| 1623 | * |
| 1624 | * This should be the path for all ptrace stops. |
| 1625 | * We always set current->last_siginfo while stopped here. |
| 1626 | * That makes it a way to test a stopped process for |
| 1627 | * being ptrace-stopped vs being job-control-stopped. |
| 1628 | * |
| 1629 | * If we actually decide not to stop at all because the tracer is gone, |
| 1630 | * we leave nostop_code in current->exit_code. |
| 1631 | */ |
| 1632 | static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info) |
| 1633 | { |
| 1634 | /* |
| 1635 | * If there is a group stop in progress, |
| 1636 | * we must participate in the bookkeeping. |
| 1637 | */ |
| 1638 | if (current->signal->group_stop_count > 0) |
| 1639 | --current->signal->group_stop_count; |
| 1640 | |
| 1641 | current->last_siginfo = info; |
| 1642 | current->exit_code = exit_code; |
| 1643 | |
| 1644 | /* Let the debugger run. */ |
| 1645 | set_current_state(TASK_TRACED); |
| 1646 | spin_unlock_irq(¤t->sighand->siglock); |
Pavel Machek | 85b6bce | 2006-03-31 02:30:06 -0800 | [diff] [blame] | 1647 | try_to_freeze(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1648 | read_lock(&tasklist_lock); |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1649 | if (may_ptrace_stop()) { |
Oleg Nesterov | a1d5e21 | 2006-03-28 16:11:29 -0800 | [diff] [blame] | 1650 | do_notify_parent_cldstop(current, CLD_TRAPPED); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1651 | read_unlock(&tasklist_lock); |
| 1652 | schedule(); |
| 1653 | } else { |
| 1654 | /* |
| 1655 | * By the time we got the lock, our tracer went away. |
| 1656 | * Don't stop here. |
| 1657 | */ |
| 1658 | read_unlock(&tasklist_lock); |
| 1659 | set_current_state(TASK_RUNNING); |
| 1660 | current->exit_code = nostop_code; |
| 1661 | } |
| 1662 | |
| 1663 | /* |
| 1664 | * We are back. Now reacquire the siglock before touching |
| 1665 | * last_siginfo, so that we are sure to have synchronized with |
| 1666 | * any signal-sending on another CPU that wants to examine it. |
| 1667 | */ |
| 1668 | spin_lock_irq(¤t->sighand->siglock); |
| 1669 | current->last_siginfo = NULL; |
| 1670 | |
| 1671 | /* |
| 1672 | * Queued signals ignored us while we were stopped for tracing. |
| 1673 | * So check for any that we should take before resuming user mode. |
| 1674 | */ |
| 1675 | recalc_sigpending(); |
| 1676 | } |
| 1677 | |
| 1678 | void ptrace_notify(int exit_code) |
| 1679 | { |
| 1680 | siginfo_t info; |
| 1681 | |
| 1682 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); |
| 1683 | |
| 1684 | memset(&info, 0, sizeof info); |
| 1685 | info.si_signo = SIGTRAP; |
| 1686 | info.si_code = exit_code; |
| 1687 | info.si_pid = current->pid; |
| 1688 | info.si_uid = current->uid; |
| 1689 | |
| 1690 | /* Let the debugger run. */ |
| 1691 | spin_lock_irq(¤t->sighand->siglock); |
| 1692 | ptrace_stop(exit_code, 0, &info); |
| 1693 | spin_unlock_irq(¤t->sighand->siglock); |
| 1694 | } |
| 1695 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1696 | static void |
| 1697 | finish_stop(int stop_count) |
| 1698 | { |
| 1699 | /* |
| 1700 | * If there are no other threads in the group, or if there is |
| 1701 | * a group stop in progress and we are the last to stop, |
| 1702 | * report to the parent. When ptraced, every thread reports itself. |
| 1703 | */ |
Oleg Nesterov | a1d5e21 | 2006-03-28 16:11:29 -0800 | [diff] [blame] | 1704 | if (stop_count == 0 || (current->ptrace & PT_PTRACED)) { |
| 1705 | read_lock(&tasklist_lock); |
| 1706 | do_notify_parent_cldstop(current, CLD_STOPPED); |
| 1707 | read_unlock(&tasklist_lock); |
| 1708 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1709 | |
Rafael J. Wysocki | 3df494a | 2006-12-13 00:34:28 -0800 | [diff] [blame] | 1710 | do { |
| 1711 | schedule(); |
| 1712 | } while (try_to_freeze()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1713 | /* |
| 1714 | * Now we don't run again until continued. |
| 1715 | */ |
| 1716 | current->exit_code = 0; |
| 1717 | } |
| 1718 | |
| 1719 | /* |
| 1720 | * This performs the stopping for SIGSTOP and other stop signals. |
| 1721 | * We have to stop all threads in the thread group. |
| 1722 | * Returns nonzero if we've actually stopped and released the siglock. |
| 1723 | * Returns zero if we didn't stop and still hold the siglock. |
| 1724 | */ |
Oleg Nesterov | a122b34 | 2006-03-28 16:11:22 -0800 | [diff] [blame] | 1725 | static int do_signal_stop(int signr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1726 | { |
| 1727 | struct signal_struct *sig = current->signal; |
Oleg Nesterov | dac27f4 | 2006-03-28 16:11:28 -0800 | [diff] [blame] | 1728 | int stop_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1729 | |
| 1730 | if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED)) |
| 1731 | return 0; |
| 1732 | |
| 1733 | if (sig->group_stop_count > 0) { |
| 1734 | /* |
| 1735 | * There is a group stop in progress. We don't need to |
| 1736 | * start another one. |
| 1737 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1738 | stop_count = --sig->group_stop_count; |
Oleg Nesterov | dac27f4 | 2006-03-28 16:11:28 -0800 | [diff] [blame] | 1739 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1740 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1741 | * There is no group stop already in progress. |
Oleg Nesterov | a122b34 | 2006-03-28 16:11:22 -0800 | [diff] [blame] | 1742 | * We must initiate one now. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1743 | */ |
| 1744 | struct task_struct *t; |
| 1745 | |
Oleg Nesterov | a122b34 | 2006-03-28 16:11:22 -0800 | [diff] [blame] | 1746 | sig->group_exit_code = signr; |
| 1747 | |
| 1748 | stop_count = 0; |
| 1749 | for (t = next_thread(current); t != current; t = next_thread(t)) |
| 1750 | /* |
| 1751 | * Setting state to TASK_STOPPED for a group |
| 1752 | * stop is always done with the siglock held, |
| 1753 | * so this check has no races. |
| 1754 | */ |
| 1755 | if (!t->exit_state && |
| 1756 | !(t->state & (TASK_STOPPED|TASK_TRACED))) { |
| 1757 | stop_count++; |
| 1758 | signal_wake_up(t, 0); |
| 1759 | } |
| 1760 | sig->group_stop_count = stop_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1761 | } |
| 1762 | |
Oleg Nesterov | dac27f4 | 2006-03-28 16:11:28 -0800 | [diff] [blame] | 1763 | if (stop_count == 0) |
| 1764 | sig->flags = SIGNAL_STOP_STOPPED; |
| 1765 | current->exit_code = sig->group_exit_code; |
| 1766 | __set_current_state(TASK_STOPPED); |
| 1767 | |
| 1768 | spin_unlock_irq(¤t->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1769 | finish_stop(stop_count); |
| 1770 | return 1; |
| 1771 | } |
| 1772 | |
| 1773 | /* |
| 1774 | * Do appropriate magic when group_stop_count > 0. |
| 1775 | * We return nonzero if we stopped, after releasing the siglock. |
| 1776 | * We return zero if we still hold the siglock and should look |
| 1777 | * for another signal without checking group_stop_count again. |
| 1778 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1779 | static int handle_group_stop(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1780 | { |
| 1781 | int stop_count; |
| 1782 | |
| 1783 | if (current->signal->group_exit_task == current) { |
| 1784 | /* |
| 1785 | * Group stop is so we can do a core dump, |
| 1786 | * We are the initiating thread, so get on with it. |
| 1787 | */ |
| 1788 | current->signal->group_exit_task = NULL; |
| 1789 | return 0; |
| 1790 | } |
| 1791 | |
| 1792 | if (current->signal->flags & SIGNAL_GROUP_EXIT) |
| 1793 | /* |
| 1794 | * Group stop is so another thread can do a core dump, |
| 1795 | * or else we are racing against a death signal. |
| 1796 | * Just punt the stop so we can get the next signal. |
| 1797 | */ |
| 1798 | return 0; |
| 1799 | |
| 1800 | /* |
| 1801 | * There is a group stop in progress. We stop |
| 1802 | * without any associated signal being in our queue. |
| 1803 | */ |
| 1804 | stop_count = --current->signal->group_stop_count; |
| 1805 | if (stop_count == 0) |
| 1806 | current->signal->flags = SIGNAL_STOP_STOPPED; |
| 1807 | current->exit_code = current->signal->group_exit_code; |
| 1808 | set_current_state(TASK_STOPPED); |
| 1809 | spin_unlock_irq(¤t->sighand->siglock); |
| 1810 | finish_stop(stop_count); |
| 1811 | return 1; |
| 1812 | } |
| 1813 | |
| 1814 | int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, |
| 1815 | struct pt_regs *regs, void *cookie) |
| 1816 | { |
| 1817 | sigset_t *mask = ¤t->blocked; |
| 1818 | int signr = 0; |
| 1819 | |
Rafael J. Wysocki | fc558a7 | 2006-03-23 03:00:05 -0800 | [diff] [blame] | 1820 | try_to_freeze(); |
| 1821 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1822 | relock: |
| 1823 | spin_lock_irq(¤t->sighand->siglock); |
| 1824 | for (;;) { |
| 1825 | struct k_sigaction *ka; |
| 1826 | |
| 1827 | if (unlikely(current->signal->group_stop_count > 0) && |
| 1828 | handle_group_stop()) |
| 1829 | goto relock; |
| 1830 | |
| 1831 | signr = dequeue_signal(current, mask, info); |
| 1832 | |
| 1833 | if (!signr) |
| 1834 | break; /* will return 0 */ |
| 1835 | |
| 1836 | if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) { |
| 1837 | ptrace_signal_deliver(regs, cookie); |
| 1838 | |
| 1839 | /* Let the debugger run. */ |
| 1840 | ptrace_stop(signr, signr, info); |
| 1841 | |
Roland McGrath | e57a505 | 2006-04-12 16:30:20 -0700 | [diff] [blame] | 1842 | /* We're back. Did the debugger cancel the sig? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1843 | signr = current->exit_code; |
Roland McGrath | e57a505 | 2006-04-12 16:30:20 -0700 | [diff] [blame] | 1844 | if (signr == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1845 | continue; |
| 1846 | |
| 1847 | current->exit_code = 0; |
| 1848 | |
| 1849 | /* Update the siginfo structure if the signal has |
| 1850 | changed. If the debugger wanted something |
| 1851 | specific in the siginfo structure then it should |
| 1852 | have updated *info via PTRACE_SETSIGINFO. */ |
| 1853 | if (signr != info->si_signo) { |
| 1854 | info->si_signo = signr; |
| 1855 | info->si_errno = 0; |
| 1856 | info->si_code = SI_USER; |
| 1857 | info->si_pid = current->parent->pid; |
| 1858 | info->si_uid = current->parent->uid; |
| 1859 | } |
| 1860 | |
| 1861 | /* If the (new) signal is now blocked, requeue it. */ |
| 1862 | if (sigismember(¤t->blocked, signr)) { |
| 1863 | specific_send_sig_info(signr, info, current); |
| 1864 | continue; |
| 1865 | } |
| 1866 | } |
| 1867 | |
| 1868 | ka = ¤t->sighand->action[signr-1]; |
| 1869 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ |
| 1870 | continue; |
| 1871 | if (ka->sa.sa_handler != SIG_DFL) { |
| 1872 | /* Run the handler. */ |
| 1873 | *return_ka = *ka; |
| 1874 | |
| 1875 | if (ka->sa.sa_flags & SA_ONESHOT) |
| 1876 | ka->sa.sa_handler = SIG_DFL; |
| 1877 | |
| 1878 | break; /* will return non-zero "signr" value */ |
| 1879 | } |
| 1880 | |
| 1881 | /* |
| 1882 | * Now we are doing the default action for this signal. |
| 1883 | */ |
| 1884 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ |
| 1885 | continue; |
| 1886 | |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 1887 | /* |
| 1888 | * Init of a pid space gets no signals it doesn't want from |
| 1889 | * within that pid space. It can of course get signals from |
| 1890 | * its parent pid space. |
| 1891 | */ |
| 1892 | if (current == child_reaper(current)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1893 | continue; |
| 1894 | |
| 1895 | if (sig_kernel_stop(signr)) { |
| 1896 | /* |
| 1897 | * The default action is to stop all threads in |
| 1898 | * the thread group. The job control signals |
| 1899 | * do nothing in an orphaned pgrp, but SIGSTOP |
| 1900 | * always works. Note that siglock needs to be |
| 1901 | * dropped during the call to is_orphaned_pgrp() |
| 1902 | * because of lock ordering with tasklist_lock. |
| 1903 | * This allows an intervening SIGCONT to be posted. |
| 1904 | * We need to check for that and bail out if necessary. |
| 1905 | */ |
| 1906 | if (signr != SIGSTOP) { |
| 1907 | spin_unlock_irq(¤t->sighand->siglock); |
| 1908 | |
| 1909 | /* signals can be posted during this window */ |
| 1910 | |
Eric W. Biederman | 3e7cd6c | 2007-02-12 00:52:58 -0800 | [diff] [blame] | 1911 | if (is_current_pgrp_orphaned()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1912 | goto relock; |
| 1913 | |
| 1914 | spin_lock_irq(¤t->sighand->siglock); |
| 1915 | } |
| 1916 | |
| 1917 | if (likely(do_signal_stop(signr))) { |
| 1918 | /* It released the siglock. */ |
| 1919 | goto relock; |
| 1920 | } |
| 1921 | |
| 1922 | /* |
| 1923 | * We didn't actually stop, due to a race |
| 1924 | * with SIGCONT or something like that. |
| 1925 | */ |
| 1926 | continue; |
| 1927 | } |
| 1928 | |
| 1929 | spin_unlock_irq(¤t->sighand->siglock); |
| 1930 | |
| 1931 | /* |
| 1932 | * Anything else is fatal, maybe with a core dump. |
| 1933 | */ |
| 1934 | current->flags |= PF_SIGNALED; |
| 1935 | if (sig_kernel_coredump(signr)) { |
| 1936 | /* |
| 1937 | * If it was able to dump core, this kills all |
| 1938 | * other threads in the group and synchronizes with |
| 1939 | * their demise. If we lost the race with another |
| 1940 | * thread getting here, it set group_exit_code |
| 1941 | * first and our do_group_exit call below will use |
| 1942 | * that value and ignore the one we pass it. |
| 1943 | */ |
| 1944 | do_coredump((long)signr, signr, regs); |
| 1945 | } |
| 1946 | |
| 1947 | /* |
| 1948 | * Death signals, no core dump. |
| 1949 | */ |
| 1950 | do_group_exit(signr); |
| 1951 | /* NOTREACHED */ |
| 1952 | } |
| 1953 | spin_unlock_irq(¤t->sighand->siglock); |
| 1954 | return signr; |
| 1955 | } |
| 1956 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1957 | EXPORT_SYMBOL(recalc_sigpending); |
| 1958 | EXPORT_SYMBOL_GPL(dequeue_signal); |
| 1959 | EXPORT_SYMBOL(flush_signals); |
| 1960 | EXPORT_SYMBOL(force_sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1961 | EXPORT_SYMBOL(kill_proc); |
| 1962 | EXPORT_SYMBOL(ptrace_notify); |
| 1963 | EXPORT_SYMBOL(send_sig); |
| 1964 | EXPORT_SYMBOL(send_sig_info); |
| 1965 | EXPORT_SYMBOL(sigprocmask); |
| 1966 | EXPORT_SYMBOL(block_all_signals); |
| 1967 | EXPORT_SYMBOL(unblock_all_signals); |
| 1968 | |
| 1969 | |
| 1970 | /* |
| 1971 | * System call entry points. |
| 1972 | */ |
| 1973 | |
| 1974 | asmlinkage long sys_restart_syscall(void) |
| 1975 | { |
| 1976 | struct restart_block *restart = ¤t_thread_info()->restart_block; |
| 1977 | return restart->fn(restart); |
| 1978 | } |
| 1979 | |
| 1980 | long do_no_restart_syscall(struct restart_block *param) |
| 1981 | { |
| 1982 | return -EINTR; |
| 1983 | } |
| 1984 | |
| 1985 | /* |
| 1986 | * We don't need to get the kernel lock - this is all local to this |
| 1987 | * particular thread.. (and that's good, because this is _heavily_ |
| 1988 | * used by various programs) |
| 1989 | */ |
| 1990 | |
| 1991 | /* |
| 1992 | * This is also useful for kernel threads that want to temporarily |
| 1993 | * (or permanently) block certain signals. |
| 1994 | * |
| 1995 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel |
| 1996 | * interface happily blocks "unblockable" signals like SIGKILL |
| 1997 | * and friends. |
| 1998 | */ |
| 1999 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) |
| 2000 | { |
| 2001 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2002 | |
| 2003 | spin_lock_irq(¤t->sighand->siglock); |
Oleg Nesterov | a26fd33 | 2006-03-23 03:00:49 -0800 | [diff] [blame] | 2004 | if (oldset) |
| 2005 | *oldset = current->blocked; |
| 2006 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2007 | error = 0; |
| 2008 | switch (how) { |
| 2009 | case SIG_BLOCK: |
| 2010 | sigorsets(¤t->blocked, ¤t->blocked, set); |
| 2011 | break; |
| 2012 | case SIG_UNBLOCK: |
| 2013 | signandsets(¤t->blocked, ¤t->blocked, set); |
| 2014 | break; |
| 2015 | case SIG_SETMASK: |
| 2016 | current->blocked = *set; |
| 2017 | break; |
| 2018 | default: |
| 2019 | error = -EINVAL; |
| 2020 | } |
| 2021 | recalc_sigpending(); |
| 2022 | spin_unlock_irq(¤t->sighand->siglock); |
Oleg Nesterov | a26fd33 | 2006-03-23 03:00:49 -0800 | [diff] [blame] | 2023 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2024 | return error; |
| 2025 | } |
| 2026 | |
| 2027 | asmlinkage long |
| 2028 | sys_rt_sigprocmask(int how, sigset_t __user *set, sigset_t __user *oset, size_t sigsetsize) |
| 2029 | { |
| 2030 | int error = -EINVAL; |
| 2031 | sigset_t old_set, new_set; |
| 2032 | |
| 2033 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 2034 | if (sigsetsize != sizeof(sigset_t)) |
| 2035 | goto out; |
| 2036 | |
| 2037 | if (set) { |
| 2038 | error = -EFAULT; |
| 2039 | if (copy_from_user(&new_set, set, sizeof(*set))) |
| 2040 | goto out; |
| 2041 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
| 2042 | |
| 2043 | error = sigprocmask(how, &new_set, &old_set); |
| 2044 | if (error) |
| 2045 | goto out; |
| 2046 | if (oset) |
| 2047 | goto set_old; |
| 2048 | } else if (oset) { |
| 2049 | spin_lock_irq(¤t->sighand->siglock); |
| 2050 | old_set = current->blocked; |
| 2051 | spin_unlock_irq(¤t->sighand->siglock); |
| 2052 | |
| 2053 | set_old: |
| 2054 | error = -EFAULT; |
| 2055 | if (copy_to_user(oset, &old_set, sizeof(*oset))) |
| 2056 | goto out; |
| 2057 | } |
| 2058 | error = 0; |
| 2059 | out: |
| 2060 | return error; |
| 2061 | } |
| 2062 | |
| 2063 | long do_sigpending(void __user *set, unsigned long sigsetsize) |
| 2064 | { |
| 2065 | long error = -EINVAL; |
| 2066 | sigset_t pending; |
| 2067 | |
| 2068 | if (sigsetsize > sizeof(sigset_t)) |
| 2069 | goto out; |
| 2070 | |
| 2071 | spin_lock_irq(¤t->sighand->siglock); |
| 2072 | sigorsets(&pending, ¤t->pending.signal, |
| 2073 | ¤t->signal->shared_pending.signal); |
| 2074 | spin_unlock_irq(¤t->sighand->siglock); |
| 2075 | |
| 2076 | /* Outside the lock because only this thread touches it. */ |
| 2077 | sigandsets(&pending, ¤t->blocked, &pending); |
| 2078 | |
| 2079 | error = -EFAULT; |
| 2080 | if (!copy_to_user(set, &pending, sigsetsize)) |
| 2081 | error = 0; |
| 2082 | |
| 2083 | out: |
| 2084 | return error; |
| 2085 | } |
| 2086 | |
| 2087 | asmlinkage long |
| 2088 | sys_rt_sigpending(sigset_t __user *set, size_t sigsetsize) |
| 2089 | { |
| 2090 | return do_sigpending(set, sigsetsize); |
| 2091 | } |
| 2092 | |
| 2093 | #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER |
| 2094 | |
| 2095 | int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) |
| 2096 | { |
| 2097 | int err; |
| 2098 | |
| 2099 | if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) |
| 2100 | return -EFAULT; |
| 2101 | if (from->si_code < 0) |
| 2102 | return __copy_to_user(to, from, sizeof(siginfo_t)) |
| 2103 | ? -EFAULT : 0; |
| 2104 | /* |
| 2105 | * If you change siginfo_t structure, please be sure |
| 2106 | * this code is fixed accordingly. |
| 2107 | * It should never copy any pad contained in the structure |
| 2108 | * to avoid security leaks, but must copy the generic |
| 2109 | * 3 ints plus the relevant union member. |
| 2110 | */ |
| 2111 | err = __put_user(from->si_signo, &to->si_signo); |
| 2112 | err |= __put_user(from->si_errno, &to->si_errno); |
| 2113 | err |= __put_user((short)from->si_code, &to->si_code); |
| 2114 | switch (from->si_code & __SI_MASK) { |
| 2115 | case __SI_KILL: |
| 2116 | err |= __put_user(from->si_pid, &to->si_pid); |
| 2117 | err |= __put_user(from->si_uid, &to->si_uid); |
| 2118 | break; |
| 2119 | case __SI_TIMER: |
| 2120 | err |= __put_user(from->si_tid, &to->si_tid); |
| 2121 | err |= __put_user(from->si_overrun, &to->si_overrun); |
| 2122 | err |= __put_user(from->si_ptr, &to->si_ptr); |
| 2123 | break; |
| 2124 | case __SI_POLL: |
| 2125 | err |= __put_user(from->si_band, &to->si_band); |
| 2126 | err |= __put_user(from->si_fd, &to->si_fd); |
| 2127 | break; |
| 2128 | case __SI_FAULT: |
| 2129 | err |= __put_user(from->si_addr, &to->si_addr); |
| 2130 | #ifdef __ARCH_SI_TRAPNO |
| 2131 | err |= __put_user(from->si_trapno, &to->si_trapno); |
| 2132 | #endif |
| 2133 | break; |
| 2134 | case __SI_CHLD: |
| 2135 | err |= __put_user(from->si_pid, &to->si_pid); |
| 2136 | err |= __put_user(from->si_uid, &to->si_uid); |
| 2137 | err |= __put_user(from->si_status, &to->si_status); |
| 2138 | err |= __put_user(from->si_utime, &to->si_utime); |
| 2139 | err |= __put_user(from->si_stime, &to->si_stime); |
| 2140 | break; |
| 2141 | case __SI_RT: /* This is not generated by the kernel as of now. */ |
| 2142 | case __SI_MESGQ: /* But this is */ |
| 2143 | err |= __put_user(from->si_pid, &to->si_pid); |
| 2144 | err |= __put_user(from->si_uid, &to->si_uid); |
| 2145 | err |= __put_user(from->si_ptr, &to->si_ptr); |
| 2146 | break; |
| 2147 | default: /* this is just in case for now ... */ |
| 2148 | err |= __put_user(from->si_pid, &to->si_pid); |
| 2149 | err |= __put_user(from->si_uid, &to->si_uid); |
| 2150 | break; |
| 2151 | } |
| 2152 | return err; |
| 2153 | } |
| 2154 | |
| 2155 | #endif |
| 2156 | |
| 2157 | asmlinkage long |
| 2158 | sys_rt_sigtimedwait(const sigset_t __user *uthese, |
| 2159 | siginfo_t __user *uinfo, |
| 2160 | const struct timespec __user *uts, |
| 2161 | size_t sigsetsize) |
| 2162 | { |
| 2163 | int ret, sig; |
| 2164 | sigset_t these; |
| 2165 | struct timespec ts; |
| 2166 | siginfo_t info; |
| 2167 | long timeout = 0; |
| 2168 | |
| 2169 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 2170 | if (sigsetsize != sizeof(sigset_t)) |
| 2171 | return -EINVAL; |
| 2172 | |
| 2173 | if (copy_from_user(&these, uthese, sizeof(these))) |
| 2174 | return -EFAULT; |
| 2175 | |
| 2176 | /* |
| 2177 | * Invert the set of allowed signals to get those we |
| 2178 | * want to block. |
| 2179 | */ |
| 2180 | sigdelsetmask(&these, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
| 2181 | signotset(&these); |
| 2182 | |
| 2183 | if (uts) { |
| 2184 | if (copy_from_user(&ts, uts, sizeof(ts))) |
| 2185 | return -EFAULT; |
| 2186 | if (ts.tv_nsec >= 1000000000L || ts.tv_nsec < 0 |
| 2187 | || ts.tv_sec < 0) |
| 2188 | return -EINVAL; |
| 2189 | } |
| 2190 | |
| 2191 | spin_lock_irq(¤t->sighand->siglock); |
| 2192 | sig = dequeue_signal(current, &these, &info); |
| 2193 | if (!sig) { |
| 2194 | timeout = MAX_SCHEDULE_TIMEOUT; |
| 2195 | if (uts) |
| 2196 | timeout = (timespec_to_jiffies(&ts) |
| 2197 | + (ts.tv_sec || ts.tv_nsec)); |
| 2198 | |
| 2199 | if (timeout) { |
| 2200 | /* None ready -- temporarily unblock those we're |
| 2201 | * interested while we are sleeping in so that we'll |
| 2202 | * be awakened when they arrive. */ |
| 2203 | current->real_blocked = current->blocked; |
| 2204 | sigandsets(¤t->blocked, ¤t->blocked, &these); |
| 2205 | recalc_sigpending(); |
| 2206 | spin_unlock_irq(¤t->sighand->siglock); |
| 2207 | |
Nishanth Aravamudan | 75bcc8c | 2005-09-10 00:27:24 -0700 | [diff] [blame] | 2208 | timeout = schedule_timeout_interruptible(timeout); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2209 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2210 | spin_lock_irq(¤t->sighand->siglock); |
| 2211 | sig = dequeue_signal(current, &these, &info); |
| 2212 | current->blocked = current->real_blocked; |
| 2213 | siginitset(¤t->real_blocked, 0); |
| 2214 | recalc_sigpending(); |
| 2215 | } |
| 2216 | } |
| 2217 | spin_unlock_irq(¤t->sighand->siglock); |
| 2218 | |
| 2219 | if (sig) { |
| 2220 | ret = sig; |
| 2221 | if (uinfo) { |
| 2222 | if (copy_siginfo_to_user(uinfo, &info)) |
| 2223 | ret = -EFAULT; |
| 2224 | } |
| 2225 | } else { |
| 2226 | ret = -EAGAIN; |
| 2227 | if (timeout) |
| 2228 | ret = -EINTR; |
| 2229 | } |
| 2230 | |
| 2231 | return ret; |
| 2232 | } |
| 2233 | |
| 2234 | asmlinkage long |
| 2235 | sys_kill(int pid, int sig) |
| 2236 | { |
| 2237 | struct siginfo info; |
| 2238 | |
| 2239 | info.si_signo = sig; |
| 2240 | info.si_errno = 0; |
| 2241 | info.si_code = SI_USER; |
| 2242 | info.si_pid = current->tgid; |
| 2243 | info.si_uid = current->uid; |
| 2244 | |
| 2245 | return kill_something_info(sig, &info, pid); |
| 2246 | } |
| 2247 | |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2248 | static int do_tkill(int tgid, int pid, int sig) |
| 2249 | { |
| 2250 | int error; |
| 2251 | struct siginfo info; |
| 2252 | struct task_struct *p; |
| 2253 | |
| 2254 | error = -ESRCH; |
| 2255 | info.si_signo = sig; |
| 2256 | info.si_errno = 0; |
| 2257 | info.si_code = SI_TKILL; |
| 2258 | info.si_pid = current->tgid; |
| 2259 | info.si_uid = current->uid; |
| 2260 | |
| 2261 | read_lock(&tasklist_lock); |
| 2262 | p = find_task_by_pid(pid); |
| 2263 | if (p && (tgid <= 0 || p->tgid == tgid)) { |
| 2264 | error = check_kill_permission(sig, &info, p); |
| 2265 | /* |
| 2266 | * The null signal is a permissions and process existence |
| 2267 | * probe. No signal is actually delivered. |
| 2268 | */ |
| 2269 | if (!error && sig && p->sighand) { |
| 2270 | spin_lock_irq(&p->sighand->siglock); |
| 2271 | handle_stop_signal(sig, p); |
| 2272 | error = specific_send_sig_info(sig, &info, p); |
| 2273 | spin_unlock_irq(&p->sighand->siglock); |
| 2274 | } |
| 2275 | } |
| 2276 | read_unlock(&tasklist_lock); |
| 2277 | |
| 2278 | return error; |
| 2279 | } |
| 2280 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2281 | /** |
| 2282 | * sys_tgkill - send signal to one specific thread |
| 2283 | * @tgid: the thread group ID of the thread |
| 2284 | * @pid: the PID of the thread |
| 2285 | * @sig: signal to be sent |
| 2286 | * |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 2287 | * This syscall also checks the @tgid and returns -ESRCH even if the PID |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2288 | * exists but it's not belonging to the target process anymore. This |
| 2289 | * method solves the problem of threads exiting and PIDs getting reused. |
| 2290 | */ |
| 2291 | asmlinkage long sys_tgkill(int tgid, int pid, int sig) |
| 2292 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2293 | /* This is only valid for single tasks */ |
| 2294 | if (pid <= 0 || tgid <= 0) |
| 2295 | return -EINVAL; |
| 2296 | |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2297 | return do_tkill(tgid, pid, sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2298 | } |
| 2299 | |
| 2300 | /* |
| 2301 | * Send a signal to only one task, even if it's a CLONE_THREAD task. |
| 2302 | */ |
| 2303 | asmlinkage long |
| 2304 | sys_tkill(int pid, int sig) |
| 2305 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2306 | /* This is only valid for single tasks */ |
| 2307 | if (pid <= 0) |
| 2308 | return -EINVAL; |
| 2309 | |
Vadim Lobanov | 6dd69f1 | 2005-10-30 15:02:18 -0800 | [diff] [blame] | 2310 | return do_tkill(0, pid, sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2311 | } |
| 2312 | |
| 2313 | asmlinkage long |
| 2314 | sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo) |
| 2315 | { |
| 2316 | siginfo_t info; |
| 2317 | |
| 2318 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) |
| 2319 | return -EFAULT; |
| 2320 | |
| 2321 | /* Not even root can pretend to send signals from the kernel. |
| 2322 | Nor can they impersonate a kill(), which adds source info. */ |
| 2323 | if (info.si_code >= 0) |
| 2324 | return -EPERM; |
| 2325 | info.si_signo = sig; |
| 2326 | |
| 2327 | /* POSIX.1b doesn't mention process groups. */ |
| 2328 | return kill_proc_info(sig, &info, pid); |
| 2329 | } |
| 2330 | |
Oleg Nesterov | 88531f7 | 2006-03-28 16:11:24 -0800 | [diff] [blame] | 2331 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2332 | { |
| 2333 | struct k_sigaction *k; |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 2334 | sigset_t mask; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2335 | |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 2336 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2337 | return -EINVAL; |
| 2338 | |
| 2339 | k = ¤t->sighand->action[sig-1]; |
| 2340 | |
| 2341 | spin_lock_irq(¤t->sighand->siglock); |
| 2342 | if (signal_pending(current)) { |
| 2343 | /* |
| 2344 | * If there might be a fatal signal pending on multiple |
| 2345 | * threads, make sure we take it before changing the action. |
| 2346 | */ |
| 2347 | spin_unlock_irq(¤t->sighand->siglock); |
| 2348 | return -ERESTARTNOINTR; |
| 2349 | } |
| 2350 | |
| 2351 | if (oact) |
| 2352 | *oact = *k; |
| 2353 | |
| 2354 | if (act) { |
Oleg Nesterov | 9ac95f2 | 2006-02-09 22:41:50 +0300 | [diff] [blame] | 2355 | sigdelsetmask(&act->sa.sa_mask, |
| 2356 | sigmask(SIGKILL) | sigmask(SIGSTOP)); |
Oleg Nesterov | 88531f7 | 2006-03-28 16:11:24 -0800 | [diff] [blame] | 2357 | *k = *act; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2358 | /* |
| 2359 | * POSIX 3.3.1.3: |
| 2360 | * "Setting a signal action to SIG_IGN for a signal that is |
| 2361 | * pending shall cause the pending signal to be discarded, |
| 2362 | * whether or not it is blocked." |
| 2363 | * |
| 2364 | * "Setting a signal action to SIG_DFL for a signal that is |
| 2365 | * pending and whose default action is to ignore the signal |
| 2366 | * (for example, SIGCHLD), shall cause the pending signal to |
| 2367 | * be discarded, whether or not it is blocked" |
| 2368 | */ |
| 2369 | if (act->sa.sa_handler == SIG_IGN || |
Oleg Nesterov | 88531f7 | 2006-03-28 16:11:24 -0800 | [diff] [blame] | 2370 | (act->sa.sa_handler == SIG_DFL && sig_kernel_ignore(sig))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2371 | struct task_struct *t = current; |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 2372 | sigemptyset(&mask); |
| 2373 | sigaddset(&mask, sig); |
| 2374 | rm_from_queue_full(&mask, &t->signal->shared_pending); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2375 | do { |
George Anzinger | 71fabd5 | 2006-01-08 01:02:48 -0800 | [diff] [blame] | 2376 | rm_from_queue_full(&mask, &t->pending); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2377 | recalc_sigpending_tsk(t); |
| 2378 | t = next_thread(t); |
| 2379 | } while (t != current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2380 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2381 | } |
| 2382 | |
| 2383 | spin_unlock_irq(¤t->sighand->siglock); |
| 2384 | return 0; |
| 2385 | } |
| 2386 | |
| 2387 | int |
| 2388 | do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp) |
| 2389 | { |
| 2390 | stack_t oss; |
| 2391 | int error; |
| 2392 | |
| 2393 | if (uoss) { |
| 2394 | oss.ss_sp = (void __user *) current->sas_ss_sp; |
| 2395 | oss.ss_size = current->sas_ss_size; |
| 2396 | oss.ss_flags = sas_ss_flags(sp); |
| 2397 | } |
| 2398 | |
| 2399 | if (uss) { |
| 2400 | void __user *ss_sp; |
| 2401 | size_t ss_size; |
| 2402 | int ss_flags; |
| 2403 | |
| 2404 | error = -EFAULT; |
| 2405 | if (!access_ok(VERIFY_READ, uss, sizeof(*uss)) |
| 2406 | || __get_user(ss_sp, &uss->ss_sp) |
| 2407 | || __get_user(ss_flags, &uss->ss_flags) |
| 2408 | || __get_user(ss_size, &uss->ss_size)) |
| 2409 | goto out; |
| 2410 | |
| 2411 | error = -EPERM; |
| 2412 | if (on_sig_stack(sp)) |
| 2413 | goto out; |
| 2414 | |
| 2415 | error = -EINVAL; |
| 2416 | /* |
| 2417 | * |
| 2418 | * Note - this code used to test ss_flags incorrectly |
| 2419 | * old code may have been written using ss_flags==0 |
| 2420 | * to mean ss_flags==SS_ONSTACK (as this was the only |
| 2421 | * way that worked) - this fix preserves that older |
| 2422 | * mechanism |
| 2423 | */ |
| 2424 | if (ss_flags != SS_DISABLE && ss_flags != SS_ONSTACK && ss_flags != 0) |
| 2425 | goto out; |
| 2426 | |
| 2427 | if (ss_flags == SS_DISABLE) { |
| 2428 | ss_size = 0; |
| 2429 | ss_sp = NULL; |
| 2430 | } else { |
| 2431 | error = -ENOMEM; |
| 2432 | if (ss_size < MINSIGSTKSZ) |
| 2433 | goto out; |
| 2434 | } |
| 2435 | |
| 2436 | current->sas_ss_sp = (unsigned long) ss_sp; |
| 2437 | current->sas_ss_size = ss_size; |
| 2438 | } |
| 2439 | |
| 2440 | if (uoss) { |
| 2441 | error = -EFAULT; |
| 2442 | if (copy_to_user(uoss, &oss, sizeof(oss))) |
| 2443 | goto out; |
| 2444 | } |
| 2445 | |
| 2446 | error = 0; |
| 2447 | out: |
| 2448 | return error; |
| 2449 | } |
| 2450 | |
| 2451 | #ifdef __ARCH_WANT_SYS_SIGPENDING |
| 2452 | |
| 2453 | asmlinkage long |
| 2454 | sys_sigpending(old_sigset_t __user *set) |
| 2455 | { |
| 2456 | return do_sigpending(set, sizeof(*set)); |
| 2457 | } |
| 2458 | |
| 2459 | #endif |
| 2460 | |
| 2461 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK |
| 2462 | /* Some platforms have their own version with special arguments others |
| 2463 | support only sys_rt_sigprocmask. */ |
| 2464 | |
| 2465 | asmlinkage long |
| 2466 | sys_sigprocmask(int how, old_sigset_t __user *set, old_sigset_t __user *oset) |
| 2467 | { |
| 2468 | int error; |
| 2469 | old_sigset_t old_set, new_set; |
| 2470 | |
| 2471 | if (set) { |
| 2472 | error = -EFAULT; |
| 2473 | if (copy_from_user(&new_set, set, sizeof(*set))) |
| 2474 | goto out; |
| 2475 | new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); |
| 2476 | |
| 2477 | spin_lock_irq(¤t->sighand->siglock); |
| 2478 | old_set = current->blocked.sig[0]; |
| 2479 | |
| 2480 | error = 0; |
| 2481 | switch (how) { |
| 2482 | default: |
| 2483 | error = -EINVAL; |
| 2484 | break; |
| 2485 | case SIG_BLOCK: |
| 2486 | sigaddsetmask(¤t->blocked, new_set); |
| 2487 | break; |
| 2488 | case SIG_UNBLOCK: |
| 2489 | sigdelsetmask(¤t->blocked, new_set); |
| 2490 | break; |
| 2491 | case SIG_SETMASK: |
| 2492 | current->blocked.sig[0] = new_set; |
| 2493 | break; |
| 2494 | } |
| 2495 | |
| 2496 | recalc_sigpending(); |
| 2497 | spin_unlock_irq(¤t->sighand->siglock); |
| 2498 | if (error) |
| 2499 | goto out; |
| 2500 | if (oset) |
| 2501 | goto set_old; |
| 2502 | } else if (oset) { |
| 2503 | old_set = current->blocked.sig[0]; |
| 2504 | set_old: |
| 2505 | error = -EFAULT; |
| 2506 | if (copy_to_user(oset, &old_set, sizeof(*oset))) |
| 2507 | goto out; |
| 2508 | } |
| 2509 | error = 0; |
| 2510 | out: |
| 2511 | return error; |
| 2512 | } |
| 2513 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ |
| 2514 | |
| 2515 | #ifdef __ARCH_WANT_SYS_RT_SIGACTION |
| 2516 | asmlinkage long |
| 2517 | sys_rt_sigaction(int sig, |
| 2518 | const struct sigaction __user *act, |
| 2519 | struct sigaction __user *oact, |
| 2520 | size_t sigsetsize) |
| 2521 | { |
| 2522 | struct k_sigaction new_sa, old_sa; |
| 2523 | int ret = -EINVAL; |
| 2524 | |
| 2525 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 2526 | if (sigsetsize != sizeof(sigset_t)) |
| 2527 | goto out; |
| 2528 | |
| 2529 | if (act) { |
| 2530 | if (copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) |
| 2531 | return -EFAULT; |
| 2532 | } |
| 2533 | |
| 2534 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); |
| 2535 | |
| 2536 | if (!ret && oact) { |
| 2537 | if (copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) |
| 2538 | return -EFAULT; |
| 2539 | } |
| 2540 | out: |
| 2541 | return ret; |
| 2542 | } |
| 2543 | #endif /* __ARCH_WANT_SYS_RT_SIGACTION */ |
| 2544 | |
| 2545 | #ifdef __ARCH_WANT_SYS_SGETMASK |
| 2546 | |
| 2547 | /* |
| 2548 | * For backwards compatibility. Functionality superseded by sigprocmask. |
| 2549 | */ |
| 2550 | asmlinkage long |
| 2551 | sys_sgetmask(void) |
| 2552 | { |
| 2553 | /* SMP safe */ |
| 2554 | return current->blocked.sig[0]; |
| 2555 | } |
| 2556 | |
| 2557 | asmlinkage long |
| 2558 | sys_ssetmask(int newmask) |
| 2559 | { |
| 2560 | int old; |
| 2561 | |
| 2562 | spin_lock_irq(¤t->sighand->siglock); |
| 2563 | old = current->blocked.sig[0]; |
| 2564 | |
| 2565 | siginitset(¤t->blocked, newmask & ~(sigmask(SIGKILL)| |
| 2566 | sigmask(SIGSTOP))); |
| 2567 | recalc_sigpending(); |
| 2568 | spin_unlock_irq(¤t->sighand->siglock); |
| 2569 | |
| 2570 | return old; |
| 2571 | } |
| 2572 | #endif /* __ARCH_WANT_SGETMASK */ |
| 2573 | |
| 2574 | #ifdef __ARCH_WANT_SYS_SIGNAL |
| 2575 | /* |
| 2576 | * For backwards compatibility. Functionality superseded by sigaction. |
| 2577 | */ |
| 2578 | asmlinkage unsigned long |
| 2579 | sys_signal(int sig, __sighandler_t handler) |
| 2580 | { |
| 2581 | struct k_sigaction new_sa, old_sa; |
| 2582 | int ret; |
| 2583 | |
| 2584 | new_sa.sa.sa_handler = handler; |
| 2585 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; |
Oleg Nesterov | c70d3d70 | 2006-02-09 22:41:41 +0300 | [diff] [blame] | 2586 | sigemptyset(&new_sa.sa.sa_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2587 | |
| 2588 | ret = do_sigaction(sig, &new_sa, &old_sa); |
| 2589 | |
| 2590 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; |
| 2591 | } |
| 2592 | #endif /* __ARCH_WANT_SYS_SIGNAL */ |
| 2593 | |
| 2594 | #ifdef __ARCH_WANT_SYS_PAUSE |
| 2595 | |
| 2596 | asmlinkage long |
| 2597 | sys_pause(void) |
| 2598 | { |
| 2599 | current->state = TASK_INTERRUPTIBLE; |
| 2600 | schedule(); |
| 2601 | return -ERESTARTNOHAND; |
| 2602 | } |
| 2603 | |
| 2604 | #endif |
| 2605 | |
David Woodhouse | 150256d | 2006-01-18 17:43:57 -0800 | [diff] [blame] | 2606 | #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND |
| 2607 | asmlinkage long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize) |
| 2608 | { |
| 2609 | sigset_t newset; |
| 2610 | |
| 2611 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
| 2612 | if (sigsetsize != sizeof(sigset_t)) |
| 2613 | return -EINVAL; |
| 2614 | |
| 2615 | if (copy_from_user(&newset, unewset, sizeof(newset))) |
| 2616 | return -EFAULT; |
| 2617 | sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
| 2618 | |
| 2619 | spin_lock_irq(¤t->sighand->siglock); |
| 2620 | current->saved_sigmask = current->blocked; |
| 2621 | current->blocked = newset; |
| 2622 | recalc_sigpending(); |
| 2623 | spin_unlock_irq(¤t->sighand->siglock); |
| 2624 | |
| 2625 | current->state = TASK_INTERRUPTIBLE; |
| 2626 | schedule(); |
| 2627 | set_thread_flag(TIF_RESTORE_SIGMASK); |
| 2628 | return -ERESTARTNOHAND; |
| 2629 | } |
| 2630 | #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */ |
| 2631 | |
David Howells | f269fdd | 2006-09-27 01:50:23 -0700 | [diff] [blame] | 2632 | __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma) |
| 2633 | { |
| 2634 | return NULL; |
| 2635 | } |
| 2636 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2637 | void __init signals_init(void) |
| 2638 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame^] | 2639 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2640 | } |