| 1 | /* |
| 2 | * Copyright (c) 1982, 1986, 1989, 1991, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * (c) UNIX System Laboratories, Inc. |
| 5 | * All or some portions of this file are derived from material licensed |
| 6 | * to the University of California by American Telephone and Telegraph |
| 7 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 8 | * the permission of UNIX System Laboratories, Inc. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * 3. All advertising materials mentioning features or use of this software |
| 19 | * must display the following acknowledgement: |
| 20 | * This product includes software developed by the University of |
| 21 | * California, Berkeley and its contributors. |
| 22 | * 4. Neither the name of the University nor the names of its contributors |
| 23 | * may be used to endorse or promote products derived from this software |
| 24 | * without specific prior written permission. |
| 25 | * |
| 26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 36 | * SUCH DAMAGE. |
| 37 | * |
| 38 | * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 |
| 39 | * $FreeBSD: src/sys/kern/kern_sig.c,v 1.72.2.17 2003/05/16 16:34:34 obrien Exp $ |
| 40 | */ |
| 41 | |
| 42 | #include "opt_ktrace.h" |
| 43 | |
| 44 | #include <sys/param.h> |
| 45 | #include <sys/systm.h> |
| 46 | #include <sys/kernel.h> |
| 47 | #include <sys/sysproto.h> |
| 48 | #include <sys/signalvar.h> |
| 49 | #include <sys/resourcevar.h> |
| 50 | #include <sys/vnode.h> |
| 51 | #include <sys/event.h> |
| 52 | #include <sys/proc.h> |
| 53 | #include <sys/nlookup.h> |
| 54 | #include <sys/pioctl.h> |
| 55 | #include <sys/systm.h> |
| 56 | #include <sys/acct.h> |
| 57 | #include <sys/fcntl.h> |
| 58 | #include <sys/lock.h> |
| 59 | #include <sys/wait.h> |
| 60 | #include <sys/ktrace.h> |
| 61 | #include <sys/syslog.h> |
| 62 | #include <sys/stat.h> |
| 63 | #include <sys/sysent.h> |
| 64 | #include <sys/sysctl.h> |
| 65 | #include <sys/malloc.h> |
| 66 | #include <sys/interrupt.h> |
| 67 | #include <sys/unistd.h> |
| 68 | #include <sys/kern_syscall.h> |
| 69 | #include <sys/vkernel.h> |
| 70 | |
| 71 | #include <sys/signal2.h> |
| 72 | #include <sys/thread2.h> |
| 73 | |
| 74 | #include <machine/cpu.h> |
| 75 | #include <machine/smp.h> |
| 76 | |
| 77 | static int coredump(struct lwp *, int); |
| 78 | static char *expand_name(const char *, uid_t, pid_t); |
| 79 | static int dokillpg(int sig, int pgid, int all); |
| 80 | static int sig_ffs(sigset_t *set); |
| 81 | static int sigprop(int sig); |
| 82 | static void lwp_signotify(struct lwp *lp); |
| 83 | #ifdef SMP |
| 84 | static void signotify_remote(void *arg); |
| 85 | #endif |
| 86 | static int kern_sigtimedwait(sigset_t set, siginfo_t *info, |
| 87 | struct timespec *timeout); |
| 88 | |
| 89 | static int filt_sigattach(struct knote *kn); |
| 90 | static void filt_sigdetach(struct knote *kn); |
| 91 | static int filt_signal(struct knote *kn, long hint); |
| 92 | |
| 93 | struct filterops sig_filtops = |
| 94 | { 0, filt_sigattach, filt_sigdetach, filt_signal }; |
| 95 | |
| 96 | static int kern_logsigexit = 1; |
| 97 | SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, |
| 98 | &kern_logsigexit, 0, |
| 99 | "Log processes quitting on abnormal signals to syslog(3)"); |
| 100 | |
| 101 | /* |
| 102 | * Can process p, with pcred pc, send the signal sig to process q? |
| 103 | */ |
| 104 | #define CANSIGNAL(q, sig) \ |
| 105 | (!p_trespass(curproc->p_ucred, (q)->p_ucred) || \ |
| 106 | ((sig) == SIGCONT && (q)->p_session == curproc->p_session)) |
| 107 | |
| 108 | /* |
| 109 | * Policy -- Can real uid ruid with ucred uc send a signal to process q? |
| 110 | */ |
| 111 | #define CANSIGIO(ruid, uc, q) \ |
| 112 | ((uc)->cr_uid == 0 || \ |
| 113 | (ruid) == (q)->p_ucred->cr_ruid || \ |
| 114 | (uc)->cr_uid == (q)->p_ucred->cr_ruid || \ |
| 115 | (ruid) == (q)->p_ucred->cr_uid || \ |
| 116 | (uc)->cr_uid == (q)->p_ucred->cr_uid) |
| 117 | |
| 118 | int sugid_coredump; |
| 119 | SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, |
| 120 | &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); |
| 121 | |
| 122 | static int do_coredump = 1; |
| 123 | SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, |
| 124 | &do_coredump, 0, "Enable/Disable coredumps"); |
| 125 | |
| 126 | /* |
| 127 | * Signal properties and actions. |
| 128 | * The array below categorizes the signals and their default actions |
| 129 | * according to the following properties: |
| 130 | */ |
| 131 | #define SA_KILL 0x01 /* terminates process by default */ |
| 132 | #define SA_CORE 0x02 /* ditto and coredumps */ |
| 133 | #define SA_STOP 0x04 /* suspend process */ |
| 134 | #define SA_TTYSTOP 0x08 /* ditto, from tty */ |
| 135 | #define SA_IGNORE 0x10 /* ignore by default */ |
| 136 | #define SA_CONT 0x20 /* continue if suspended */ |
| 137 | #define SA_CANTMASK 0x40 /* non-maskable, catchable */ |
| 138 | #define SA_CKPT 0x80 /* checkpoint process */ |
| 139 | |
| 140 | |
| 141 | static int sigproptbl[NSIG] = { |
| 142 | SA_KILL, /* SIGHUP */ |
| 143 | SA_KILL, /* SIGINT */ |
| 144 | SA_KILL|SA_CORE, /* SIGQUIT */ |
| 145 | SA_KILL|SA_CORE, /* SIGILL */ |
| 146 | SA_KILL|SA_CORE, /* SIGTRAP */ |
| 147 | SA_KILL|SA_CORE, /* SIGABRT */ |
| 148 | SA_KILL|SA_CORE, /* SIGEMT */ |
| 149 | SA_KILL|SA_CORE, /* SIGFPE */ |
| 150 | SA_KILL, /* SIGKILL */ |
| 151 | SA_KILL|SA_CORE, /* SIGBUS */ |
| 152 | SA_KILL|SA_CORE, /* SIGSEGV */ |
| 153 | SA_KILL|SA_CORE, /* SIGSYS */ |
| 154 | SA_KILL, /* SIGPIPE */ |
| 155 | SA_KILL, /* SIGALRM */ |
| 156 | SA_KILL, /* SIGTERM */ |
| 157 | SA_IGNORE, /* SIGURG */ |
| 158 | SA_STOP, /* SIGSTOP */ |
| 159 | SA_STOP|SA_TTYSTOP, /* SIGTSTP */ |
| 160 | SA_IGNORE|SA_CONT, /* SIGCONT */ |
| 161 | SA_IGNORE, /* SIGCHLD */ |
| 162 | SA_STOP|SA_TTYSTOP, /* SIGTTIN */ |
| 163 | SA_STOP|SA_TTYSTOP, /* SIGTTOU */ |
| 164 | SA_IGNORE, /* SIGIO */ |
| 165 | SA_KILL, /* SIGXCPU */ |
| 166 | SA_KILL, /* SIGXFSZ */ |
| 167 | SA_KILL, /* SIGVTALRM */ |
| 168 | SA_KILL, /* SIGPROF */ |
| 169 | SA_IGNORE, /* SIGWINCH */ |
| 170 | SA_IGNORE, /* SIGINFO */ |
| 171 | SA_KILL, /* SIGUSR1 */ |
| 172 | SA_KILL, /* SIGUSR2 */ |
| 173 | SA_IGNORE, /* SIGTHR */ |
| 174 | SA_CKPT, /* SIGCKPT */ |
| 175 | SA_KILL|SA_CKPT, /* SIGCKPTEXIT */ |
| 176 | SA_IGNORE, |
| 177 | SA_IGNORE, |
| 178 | SA_IGNORE, |
| 179 | SA_IGNORE, |
| 180 | SA_IGNORE, |
| 181 | SA_IGNORE, |
| 182 | SA_IGNORE, |
| 183 | SA_IGNORE, |
| 184 | SA_IGNORE, |
| 185 | SA_IGNORE, |
| 186 | SA_IGNORE, |
| 187 | SA_IGNORE, |
| 188 | SA_IGNORE, |
| 189 | SA_IGNORE, |
| 190 | SA_IGNORE, |
| 191 | SA_IGNORE, |
| 192 | SA_IGNORE, |
| 193 | SA_IGNORE, |
| 194 | SA_IGNORE, |
| 195 | SA_IGNORE, |
| 196 | SA_IGNORE, |
| 197 | SA_IGNORE, |
| 198 | SA_IGNORE, |
| 199 | SA_IGNORE, |
| 200 | SA_IGNORE, |
| 201 | SA_IGNORE, |
| 202 | SA_IGNORE, |
| 203 | SA_IGNORE, |
| 204 | SA_IGNORE, |
| 205 | SA_IGNORE, |
| 206 | |
| 207 | }; |
| 208 | |
| 209 | static __inline int |
| 210 | sigprop(int sig) |
| 211 | { |
| 212 | |
| 213 | if (sig > 0 && sig < NSIG) |
| 214 | return (sigproptbl[_SIG_IDX(sig)]); |
| 215 | return (0); |
| 216 | } |
| 217 | |
| 218 | static __inline int |
| 219 | sig_ffs(sigset_t *set) |
| 220 | { |
| 221 | int i; |
| 222 | |
| 223 | for (i = 0; i < _SIG_WORDS; i++) |
| 224 | if (set->__bits[i]) |
| 225 | return (ffs(set->__bits[i]) + (i * 32)); |
| 226 | return (0); |
| 227 | } |
| 228 | |
| 229 | /* |
| 230 | * No requirements. |
| 231 | */ |
| 232 | int |
| 233 | kern_sigaction(int sig, struct sigaction *act, struct sigaction *oact) |
| 234 | { |
| 235 | struct thread *td = curthread; |
| 236 | struct proc *p = td->td_proc; |
| 237 | struct lwp *lp; |
| 238 | struct sigacts *ps = p->p_sigacts; |
| 239 | |
| 240 | if (sig <= 0 || sig > _SIG_MAXSIG) |
| 241 | return (EINVAL); |
| 242 | |
| 243 | lwkt_gettoken(&p->p_token); |
| 244 | |
| 245 | if (oact) { |
| 246 | oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; |
| 247 | oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; |
| 248 | oact->sa_flags = 0; |
| 249 | if (SIGISMEMBER(ps->ps_sigonstack, sig)) |
| 250 | oact->sa_flags |= SA_ONSTACK; |
| 251 | if (!SIGISMEMBER(ps->ps_sigintr, sig)) |
| 252 | oact->sa_flags |= SA_RESTART; |
| 253 | if (SIGISMEMBER(ps->ps_sigreset, sig)) |
| 254 | oact->sa_flags |= SA_RESETHAND; |
| 255 | if (SIGISMEMBER(ps->ps_signodefer, sig)) |
| 256 | oact->sa_flags |= SA_NODEFER; |
| 257 | if (SIGISMEMBER(ps->ps_siginfo, sig)) |
| 258 | oact->sa_flags |= SA_SIGINFO; |
| 259 | if (SIGISMEMBER(ps->ps_sigmailbox, sig)) |
| 260 | oact->sa_flags |= SA_MAILBOX; |
| 261 | if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDSTOP) |
| 262 | oact->sa_flags |= SA_NOCLDSTOP; |
| 263 | if (sig == SIGCHLD && p->p_sigacts->ps_flag & PS_NOCLDWAIT) |
| 264 | oact->sa_flags |= SA_NOCLDWAIT; |
| 265 | } |
| 266 | if (act) { |
| 267 | /* |
| 268 | * Check for invalid requests. KILL and STOP cannot be |
| 269 | * caught. |
| 270 | */ |
| 271 | if (sig == SIGKILL || sig == SIGSTOP) { |
| 272 | if (act->sa_handler != SIG_DFL) { |
| 273 | lwkt_reltoken(&p->p_token); |
| 274 | return (EINVAL); |
| 275 | } |
| 276 | #if 0 |
| 277 | /* (not needed, SIG_DFL forces action to occur) */ |
| 278 | if (act->sa_flags & SA_MAILBOX) { |
| 279 | lwkt_reltoken(&p->p_token); |
| 280 | return (EINVAL); |
| 281 | } |
| 282 | #endif |
| 283 | } |
| 284 | |
| 285 | /* |
| 286 | * Change setting atomically. |
| 287 | */ |
| 288 | crit_enter(); |
| 289 | |
| 290 | ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; |
| 291 | SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); |
| 292 | if (act->sa_flags & SA_SIGINFO) { |
| 293 | ps->ps_sigact[_SIG_IDX(sig)] = |
| 294 | (__sighandler_t *)act->sa_sigaction; |
| 295 | SIGADDSET(ps->ps_siginfo, sig); |
| 296 | } else { |
| 297 | ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; |
| 298 | SIGDELSET(ps->ps_siginfo, sig); |
| 299 | } |
| 300 | if (!(act->sa_flags & SA_RESTART)) |
| 301 | SIGADDSET(ps->ps_sigintr, sig); |
| 302 | else |
| 303 | SIGDELSET(ps->ps_sigintr, sig); |
| 304 | if (act->sa_flags & SA_ONSTACK) |
| 305 | SIGADDSET(ps->ps_sigonstack, sig); |
| 306 | else |
| 307 | SIGDELSET(ps->ps_sigonstack, sig); |
| 308 | if (act->sa_flags & SA_RESETHAND) |
| 309 | SIGADDSET(ps->ps_sigreset, sig); |
| 310 | else |
| 311 | SIGDELSET(ps->ps_sigreset, sig); |
| 312 | if (act->sa_flags & SA_NODEFER) |
| 313 | SIGADDSET(ps->ps_signodefer, sig); |
| 314 | else |
| 315 | SIGDELSET(ps->ps_signodefer, sig); |
| 316 | if (act->sa_flags & SA_MAILBOX) |
| 317 | SIGADDSET(ps->ps_sigmailbox, sig); |
| 318 | else |
| 319 | SIGDELSET(ps->ps_sigmailbox, sig); |
| 320 | if (sig == SIGCHLD) { |
| 321 | if (act->sa_flags & SA_NOCLDSTOP) |
| 322 | p->p_sigacts->ps_flag |= PS_NOCLDSTOP; |
| 323 | else |
| 324 | p->p_sigacts->ps_flag &= ~PS_NOCLDSTOP; |
| 325 | if (act->sa_flags & SA_NOCLDWAIT) { |
| 326 | /* |
| 327 | * Paranoia: since SA_NOCLDWAIT is implemented |
| 328 | * by reparenting the dying child to PID 1 (and |
| 329 | * trust it to reap the zombie), PID 1 itself |
| 330 | * is forbidden to set SA_NOCLDWAIT. |
| 331 | */ |
| 332 | if (p->p_pid == 1) |
| 333 | p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; |
| 334 | else |
| 335 | p->p_sigacts->ps_flag |= PS_NOCLDWAIT; |
| 336 | } else { |
| 337 | p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; |
| 338 | } |
| 339 | } |
| 340 | /* |
| 341 | * Set bit in p_sigignore for signals that are set to SIG_IGN, |
| 342 | * and for signals set to SIG_DFL where the default is to |
| 343 | * ignore. However, don't put SIGCONT in p_sigignore, as we |
| 344 | * have to restart the process. |
| 345 | */ |
| 346 | if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || |
| 347 | (sigprop(sig) & SA_IGNORE && |
| 348 | ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { |
| 349 | /* never to be seen again */ |
| 350 | SIGDELSET(p->p_siglist, sig); |
| 351 | /* |
| 352 | * Remove the signal also from the thread lists. |
| 353 | */ |
| 354 | FOREACH_LWP_IN_PROC(lp, p) { |
| 355 | SIGDELSET(lp->lwp_siglist, sig); |
| 356 | } |
| 357 | if (sig != SIGCONT) { |
| 358 | /* easier in ksignal */ |
| 359 | SIGADDSET(p->p_sigignore, sig); |
| 360 | } |
| 361 | SIGDELSET(p->p_sigcatch, sig); |
| 362 | } else { |
| 363 | SIGDELSET(p->p_sigignore, sig); |
| 364 | if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) |
| 365 | SIGDELSET(p->p_sigcatch, sig); |
| 366 | else |
| 367 | SIGADDSET(p->p_sigcatch, sig); |
| 368 | } |
| 369 | |
| 370 | crit_exit(); |
| 371 | } |
| 372 | lwkt_reltoken(&p->p_token); |
| 373 | return (0); |
| 374 | } |
| 375 | |
| 376 | int |
| 377 | sys_sigaction(struct sigaction_args *uap) |
| 378 | { |
| 379 | struct sigaction act, oact; |
| 380 | struct sigaction *actp, *oactp; |
| 381 | int error; |
| 382 | |
| 383 | actp = (uap->act != NULL) ? &act : NULL; |
| 384 | oactp = (uap->oact != NULL) ? &oact : NULL; |
| 385 | if (actp) { |
| 386 | error = copyin(uap->act, actp, sizeof(act)); |
| 387 | if (error) |
| 388 | return (error); |
| 389 | } |
| 390 | error = kern_sigaction(uap->sig, actp, oactp); |
| 391 | if (oactp && !error) { |
| 392 | error = copyout(oactp, uap->oact, sizeof(oact)); |
| 393 | } |
| 394 | return (error); |
| 395 | } |
| 396 | |
| 397 | /* |
| 398 | * Initialize signal state for process 0; |
| 399 | * set to ignore signals that are ignored by default. |
| 400 | */ |
| 401 | void |
| 402 | siginit(struct proc *p) |
| 403 | { |
| 404 | int i; |
| 405 | |
| 406 | for (i = 1; i <= NSIG; i++) |
| 407 | if (sigprop(i) & SA_IGNORE && i != SIGCONT) |
| 408 | SIGADDSET(p->p_sigignore, i); |
| 409 | } |
| 410 | |
| 411 | /* |
| 412 | * Reset signals for an exec of the specified process. |
| 413 | */ |
| 414 | void |
| 415 | execsigs(struct proc *p) |
| 416 | { |
| 417 | struct sigacts *ps = p->p_sigacts; |
| 418 | struct lwp *lp; |
| 419 | int sig; |
| 420 | |
| 421 | lp = ONLY_LWP_IN_PROC(p); |
| 422 | |
| 423 | /* |
| 424 | * Reset caught signals. Held signals remain held |
| 425 | * through p_sigmask (unless they were caught, |
| 426 | * and are now ignored by default). |
| 427 | */ |
| 428 | while (SIGNOTEMPTY(p->p_sigcatch)) { |
| 429 | sig = sig_ffs(&p->p_sigcatch); |
| 430 | SIGDELSET(p->p_sigcatch, sig); |
| 431 | if (sigprop(sig) & SA_IGNORE) { |
| 432 | if (sig != SIGCONT) |
| 433 | SIGADDSET(p->p_sigignore, sig); |
| 434 | SIGDELSET(p->p_siglist, sig); |
| 435 | SIGDELSET(lp->lwp_siglist, sig); |
| 436 | } |
| 437 | ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; |
| 438 | } |
| 439 | |
| 440 | /* |
| 441 | * Reset stack state to the user stack. |
| 442 | * Clear set of signals caught on the signal stack. |
| 443 | */ |
| 444 | lp->lwp_sigstk.ss_flags = SS_DISABLE; |
| 445 | lp->lwp_sigstk.ss_size = 0; |
| 446 | lp->lwp_sigstk.ss_sp = 0; |
| 447 | lp->lwp_flag &= ~LWP_ALTSTACK; |
| 448 | /* |
| 449 | * Reset no zombies if child dies flag as Solaris does. |
| 450 | */ |
| 451 | p->p_sigacts->ps_flag &= ~PS_NOCLDWAIT; |
| 452 | } |
| 453 | |
| 454 | /* |
| 455 | * kern_sigprocmask() - MP SAFE ONLY IF p == curproc |
| 456 | * |
| 457 | * Manipulate signal mask. This routine is MP SAFE *ONLY* if |
| 458 | * p == curproc. |
| 459 | */ |
| 460 | int |
| 461 | kern_sigprocmask(int how, sigset_t *set, sigset_t *oset) |
| 462 | { |
| 463 | struct thread *td = curthread; |
| 464 | struct lwp *lp = td->td_lwp; |
| 465 | struct proc *p = td->td_proc; |
| 466 | int error; |
| 467 | |
| 468 | lwkt_gettoken(&p->p_token); |
| 469 | |
| 470 | if (oset != NULL) |
| 471 | *oset = lp->lwp_sigmask; |
| 472 | |
| 473 | error = 0; |
| 474 | if (set != NULL) { |
| 475 | switch (how) { |
| 476 | case SIG_BLOCK: |
| 477 | SIG_CANTMASK(*set); |
| 478 | SIGSETOR(lp->lwp_sigmask, *set); |
| 479 | break; |
| 480 | case SIG_UNBLOCK: |
| 481 | SIGSETNAND(lp->lwp_sigmask, *set); |
| 482 | break; |
| 483 | case SIG_SETMASK: |
| 484 | SIG_CANTMASK(*set); |
| 485 | lp->lwp_sigmask = *set; |
| 486 | break; |
| 487 | default: |
| 488 | error = EINVAL; |
| 489 | break; |
| 490 | } |
| 491 | } |
| 492 | |
| 493 | lwkt_reltoken(&p->p_token); |
| 494 | |
| 495 | return (error); |
| 496 | } |
| 497 | |
| 498 | /* |
| 499 | * sigprocmask() |
| 500 | * |
| 501 | * MPSAFE |
| 502 | */ |
| 503 | int |
| 504 | sys_sigprocmask(struct sigprocmask_args *uap) |
| 505 | { |
| 506 | sigset_t set, oset; |
| 507 | sigset_t *setp, *osetp; |
| 508 | int error; |
| 509 | |
| 510 | setp = (uap->set != NULL) ? &set : NULL; |
| 511 | osetp = (uap->oset != NULL) ? &oset : NULL; |
| 512 | if (setp) { |
| 513 | error = copyin(uap->set, setp, sizeof(set)); |
| 514 | if (error) |
| 515 | return (error); |
| 516 | } |
| 517 | error = kern_sigprocmask(uap->how, setp, osetp); |
| 518 | if (osetp && !error) { |
| 519 | error = copyout(osetp, uap->oset, sizeof(oset)); |
| 520 | } |
| 521 | return (error); |
| 522 | } |
| 523 | |
| 524 | /* |
| 525 | * MPSAFE |
| 526 | */ |
| 527 | int |
| 528 | kern_sigpending(struct __sigset *set) |
| 529 | { |
| 530 | struct lwp *lp = curthread->td_lwp; |
| 531 | |
| 532 | *set = lwp_sigpend(lp); |
| 533 | |
| 534 | return (0); |
| 535 | } |
| 536 | |
| 537 | /* |
| 538 | * MPSAFE |
| 539 | */ |
| 540 | int |
| 541 | sys_sigpending(struct sigpending_args *uap) |
| 542 | { |
| 543 | sigset_t set; |
| 544 | int error; |
| 545 | |
| 546 | error = kern_sigpending(&set); |
| 547 | |
| 548 | if (error == 0) |
| 549 | error = copyout(&set, uap->set, sizeof(set)); |
| 550 | return (error); |
| 551 | } |
| 552 | |
| 553 | /* |
| 554 | * Suspend process until signal, providing mask to be set |
| 555 | * in the meantime. |
| 556 | * |
| 557 | * MPSAFE |
| 558 | */ |
| 559 | int |
| 560 | kern_sigsuspend(struct __sigset *set) |
| 561 | { |
| 562 | struct thread *td = curthread; |
| 563 | struct lwp *lp = td->td_lwp; |
| 564 | struct proc *p = td->td_proc; |
| 565 | struct sigacts *ps = p->p_sigacts; |
| 566 | |
| 567 | /* |
| 568 | * When returning from sigsuspend, we want |
| 569 | * the old mask to be restored after the |
| 570 | * signal handler has finished. Thus, we |
| 571 | * save it here and mark the sigacts structure |
| 572 | * to indicate this. |
| 573 | */ |
| 574 | lp->lwp_oldsigmask = lp->lwp_sigmask; |
| 575 | lp->lwp_flag |= LWP_OLDMASK; |
| 576 | |
| 577 | SIG_CANTMASK(*set); |
| 578 | lp->lwp_sigmask = *set; |
| 579 | while (tsleep(ps, PCATCH, "pause", 0) == 0) |
| 580 | /* void */; |
| 581 | /* always return EINTR rather than ERESTART... */ |
| 582 | return (EINTR); |
| 583 | } |
| 584 | |
| 585 | /* |
| 586 | * Note nonstandard calling convention: libc stub passes mask, not |
| 587 | * pointer, to save a copyin. |
| 588 | * |
| 589 | * MPSAFE |
| 590 | */ |
| 591 | int |
| 592 | sys_sigsuspend(struct sigsuspend_args *uap) |
| 593 | { |
| 594 | sigset_t mask; |
| 595 | int error; |
| 596 | |
| 597 | error = copyin(uap->sigmask, &mask, sizeof(mask)); |
| 598 | if (error) |
| 599 | return (error); |
| 600 | |
| 601 | error = kern_sigsuspend(&mask); |
| 602 | |
| 603 | return (error); |
| 604 | } |
| 605 | |
| 606 | /* |
| 607 | * MPSAFE |
| 608 | */ |
| 609 | int |
| 610 | kern_sigaltstack(struct sigaltstack *ss, struct sigaltstack *oss) |
| 611 | { |
| 612 | struct thread *td = curthread; |
| 613 | struct lwp *lp = td->td_lwp; |
| 614 | struct proc *p = td->td_proc; |
| 615 | |
| 616 | if ((lp->lwp_flag & LWP_ALTSTACK) == 0) |
| 617 | lp->lwp_sigstk.ss_flags |= SS_DISABLE; |
| 618 | |
| 619 | if (oss) |
| 620 | *oss = lp->lwp_sigstk; |
| 621 | |
| 622 | if (ss) { |
| 623 | if (ss->ss_flags & SS_DISABLE) { |
| 624 | if (lp->lwp_sigstk.ss_flags & SS_ONSTACK) |
| 625 | return (EINVAL); |
| 626 | lp->lwp_flag &= ~LWP_ALTSTACK; |
| 627 | lp->lwp_sigstk.ss_flags = ss->ss_flags; |
| 628 | } else { |
| 629 | if (ss->ss_size < p->p_sysent->sv_minsigstksz) |
| 630 | return (ENOMEM); |
| 631 | lp->lwp_flag |= LWP_ALTSTACK; |
| 632 | lp->lwp_sigstk = *ss; |
| 633 | } |
| 634 | } |
| 635 | |
| 636 | return (0); |
| 637 | } |
| 638 | |
| 639 | /* |
| 640 | * MPSAFE |
| 641 | */ |
| 642 | int |
| 643 | sys_sigaltstack(struct sigaltstack_args *uap) |
| 644 | { |
| 645 | stack_t ss, oss; |
| 646 | int error; |
| 647 | |
| 648 | if (uap->ss) { |
| 649 | error = copyin(uap->ss, &ss, sizeof(ss)); |
| 650 | if (error) |
| 651 | return (error); |
| 652 | } |
| 653 | |
| 654 | error = kern_sigaltstack(uap->ss ? &ss : NULL, |
| 655 | uap->oss ? &oss : NULL); |
| 656 | |
| 657 | if (error == 0 && uap->oss) |
| 658 | error = copyout(&oss, uap->oss, sizeof(*uap->oss)); |
| 659 | return (error); |
| 660 | } |
| 661 | |
| 662 | /* |
| 663 | * Common code for kill process group/broadcast kill. |
| 664 | * cp is calling process. |
| 665 | */ |
| 666 | struct killpg_info { |
| 667 | int nfound; |
| 668 | int sig; |
| 669 | }; |
| 670 | |
| 671 | static int killpg_all_callback(struct proc *p, void *data); |
| 672 | |
| 673 | static int |
| 674 | dokillpg(int sig, int pgid, int all) |
| 675 | { |
| 676 | struct killpg_info info; |
| 677 | struct proc *cp = curproc; |
| 678 | struct proc *p; |
| 679 | struct pgrp *pgrp; |
| 680 | |
| 681 | info.nfound = 0; |
| 682 | info.sig = sig; |
| 683 | |
| 684 | if (all) { |
| 685 | /* |
| 686 | * broadcast |
| 687 | */ |
| 688 | allproc_scan(killpg_all_callback, &info); |
| 689 | } else { |
| 690 | if (pgid == 0) { |
| 691 | /* |
| 692 | * zero pgid means send to my process group. |
| 693 | */ |
| 694 | pgrp = cp->p_pgrp; |
| 695 | pgref(pgrp); |
| 696 | } else { |
| 697 | pgrp = pgfind(pgid); |
| 698 | if (pgrp == NULL) |
| 699 | return (ESRCH); |
| 700 | } |
| 701 | |
| 702 | /* |
| 703 | * Must interlock all signals against fork |
| 704 | */ |
| 705 | lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE); |
| 706 | LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { |
| 707 | if (p->p_pid <= 1 || |
| 708 | p->p_stat == SZOMB || |
| 709 | (p->p_flag & P_SYSTEM) || |
| 710 | !CANSIGNAL(p, sig)) { |
| 711 | continue; |
| 712 | } |
| 713 | ++info.nfound; |
| 714 | if (sig) |
| 715 | ksignal(p, sig); |
| 716 | } |
| 717 | lockmgr(&pgrp->pg_lock, LK_RELEASE); |
| 718 | pgrel(pgrp); |
| 719 | } |
| 720 | return (info.nfound ? 0 : ESRCH); |
| 721 | } |
| 722 | |
| 723 | static int |
| 724 | killpg_all_callback(struct proc *p, void *data) |
| 725 | { |
| 726 | struct killpg_info *info = data; |
| 727 | |
| 728 | if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) || |
| 729 | p == curproc || !CANSIGNAL(p, info->sig)) { |
| 730 | return (0); |
| 731 | } |
| 732 | ++info->nfound; |
| 733 | if (info->sig) |
| 734 | ksignal(p, info->sig); |
| 735 | return(0); |
| 736 | } |
| 737 | |
| 738 | /* |
| 739 | * Send a general signal to a process or LWPs within that process. Note |
| 740 | * that new signals cannot be sent if a process is exiting. |
| 741 | * |
| 742 | * No requirements. |
| 743 | */ |
| 744 | int |
| 745 | kern_kill(int sig, pid_t pid, lwpid_t tid) |
| 746 | { |
| 747 | int t; |
| 748 | |
| 749 | if ((u_int)sig > _SIG_MAXSIG) |
| 750 | return (EINVAL); |
| 751 | |
| 752 | lwkt_gettoken(&proc_token); |
| 753 | |
| 754 | if (pid > 0) { |
| 755 | struct proc *p; |
| 756 | struct lwp *lp = NULL; |
| 757 | |
| 758 | /* kill single process */ |
| 759 | if ((p = pfind(pid)) == NULL) { |
| 760 | lwkt_reltoken(&proc_token); |
| 761 | return (ESRCH); |
| 762 | } |
| 763 | lwkt_gettoken(&p->p_token); |
| 764 | if (!CANSIGNAL(p, sig)) { |
| 765 | lwkt_reltoken(&p->p_token); |
| 766 | PRELE(p); |
| 767 | lwkt_reltoken(&proc_token); |
| 768 | return (EPERM); |
| 769 | } |
| 770 | |
| 771 | /* |
| 772 | * NOP if the process is exiting. Note that lwpsignal() is |
| 773 | * called directly with P_WEXIT set to kill individual LWPs |
| 774 | * during exit, which is allowed. |
| 775 | */ |
| 776 | if (p->p_flag & P_WEXIT) { |
| 777 | lwkt_reltoken(&p->p_token); |
| 778 | PRELE(p); |
| 779 | lwkt_reltoken(&proc_token); |
| 780 | return (0); |
| 781 | } |
| 782 | if (tid != -1) { |
| 783 | lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, tid); |
| 784 | if (lp == NULL) { |
| 785 | lwkt_reltoken(&p->p_token); |
| 786 | PRELE(p); |
| 787 | lwkt_reltoken(&proc_token); |
| 788 | return (ESRCH); |
| 789 | } |
| 790 | } |
| 791 | if (sig) |
| 792 | lwpsignal(p, lp, sig); |
| 793 | lwkt_reltoken(&p->p_token); |
| 794 | PRELE(p); |
| 795 | lwkt_reltoken(&proc_token); |
| 796 | return (0); |
| 797 | } |
| 798 | |
| 799 | /* |
| 800 | * If we come here, pid is a special broadcast pid. |
| 801 | * This doesn't mix with a tid. |
| 802 | */ |
| 803 | if (tid != -1) { |
| 804 | lwkt_reltoken(&proc_token); |
| 805 | return (EINVAL); |
| 806 | } |
| 807 | switch (pid) { |
| 808 | case -1: /* broadcast signal */ |
| 809 | t = (dokillpg(sig, 0, 1)); |
| 810 | break; |
| 811 | case 0: /* signal own process group */ |
| 812 | t = (dokillpg(sig, 0, 0)); |
| 813 | break; |
| 814 | default: /* negative explicit process group */ |
| 815 | t = (dokillpg(sig, -pid, 0)); |
| 816 | break; |
| 817 | } |
| 818 | lwkt_reltoken(&proc_token); |
| 819 | return t; |
| 820 | } |
| 821 | |
| 822 | int |
| 823 | sys_kill(struct kill_args *uap) |
| 824 | { |
| 825 | int error; |
| 826 | |
| 827 | error = kern_kill(uap->signum, uap->pid, -1); |
| 828 | return (error); |
| 829 | } |
| 830 | |
| 831 | int |
| 832 | sys_lwp_kill(struct lwp_kill_args *uap) |
| 833 | { |
| 834 | int error; |
| 835 | pid_t pid = uap->pid; |
| 836 | |
| 837 | /* |
| 838 | * A tid is mandatory for lwp_kill(), otherwise |
| 839 | * you could simply use kill(). |
| 840 | */ |
| 841 | if (uap->tid == -1) |
| 842 | return (EINVAL); |
| 843 | |
| 844 | /* |
| 845 | * To save on a getpid() function call for intra-process |
| 846 | * signals, pid == -1 means current process. |
| 847 | */ |
| 848 | if (pid == -1) |
| 849 | pid = curproc->p_pid; |
| 850 | |
| 851 | error = kern_kill(uap->signum, pid, uap->tid); |
| 852 | return (error); |
| 853 | } |
| 854 | |
| 855 | /* |
| 856 | * Send a signal to a process group. |
| 857 | */ |
| 858 | void |
| 859 | gsignal(int pgid, int sig) |
| 860 | { |
| 861 | struct pgrp *pgrp; |
| 862 | |
| 863 | if (pgid && (pgrp = pgfind(pgid))) |
| 864 | pgsignal(pgrp, sig, 0); |
| 865 | } |
| 866 | |
| 867 | /* |
| 868 | * Send a signal to a process group. If checktty is 1, |
| 869 | * limit to members which have a controlling terminal. |
| 870 | * |
| 871 | * pg_lock interlocks against a fork that might be in progress, to |
| 872 | * ensure that the new child process picks up the signal. |
| 873 | */ |
| 874 | void |
| 875 | pgsignal(struct pgrp *pgrp, int sig, int checkctty) |
| 876 | { |
| 877 | struct proc *p; |
| 878 | |
| 879 | /* |
| 880 | * Must interlock all signals against fork |
| 881 | */ |
| 882 | if (pgrp) { |
| 883 | pgref(pgrp); |
| 884 | lockmgr(&pgrp->pg_lock, LK_EXCLUSIVE); |
| 885 | LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { |
| 886 | if (checkctty == 0 || p->p_flag & P_CONTROLT) |
| 887 | ksignal(p, sig); |
| 888 | } |
| 889 | lockmgr(&pgrp->pg_lock, LK_RELEASE); |
| 890 | pgrel(pgrp); |
| 891 | } |
| 892 | } |
| 893 | |
| 894 | /* |
| 895 | * Send a signal caused by a trap to the current lwp. If it will be caught |
| 896 | * immediately, deliver it with correct code. Otherwise, post it normally. |
| 897 | * |
| 898 | * These signals may ONLY be delivered to the specified lwp and may never |
| 899 | * be delivered to the process generically. |
| 900 | */ |
| 901 | void |
| 902 | trapsignal(struct lwp *lp, int sig, u_long code) |
| 903 | { |
| 904 | struct proc *p = lp->lwp_proc; |
| 905 | struct sigacts *ps = p->p_sigacts; |
| 906 | |
| 907 | /* |
| 908 | * If we are a virtual kernel running an emulated user process |
| 909 | * context, switch back to the virtual kernel context before |
| 910 | * trying to post the signal. |
| 911 | */ |
| 912 | if (lp->lwp_vkernel && lp->lwp_vkernel->ve) { |
| 913 | struct trapframe *tf = lp->lwp_md.md_regs; |
| 914 | tf->tf_trapno = 0; |
| 915 | vkernel_trap(lp, tf); |
| 916 | } |
| 917 | |
| 918 | |
| 919 | if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && |
| 920 | !SIGISMEMBER(lp->lwp_sigmask, sig)) { |
| 921 | lp->lwp_ru.ru_nsignals++; |
| 922 | #ifdef KTRACE |
| 923 | if (KTRPOINT(lp->lwp_thread, KTR_PSIG)) |
| 924 | ktrpsig(lp, sig, ps->ps_sigact[_SIG_IDX(sig)], |
| 925 | &lp->lwp_sigmask, code); |
| 926 | #endif |
| 927 | (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, |
| 928 | &lp->lwp_sigmask, code); |
| 929 | SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); |
| 930 | if (!SIGISMEMBER(ps->ps_signodefer, sig)) |
| 931 | SIGADDSET(lp->lwp_sigmask, sig); |
| 932 | if (SIGISMEMBER(ps->ps_sigreset, sig)) { |
| 933 | /* |
| 934 | * See kern_sigaction() for origin of this code. |
| 935 | */ |
| 936 | SIGDELSET(p->p_sigcatch, sig); |
| 937 | if (sig != SIGCONT && |
| 938 | sigprop(sig) & SA_IGNORE) |
| 939 | SIGADDSET(p->p_sigignore, sig); |
| 940 | ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; |
| 941 | } |
| 942 | } else { |
| 943 | lp->lwp_code = code; /* XXX for core dump/debugger */ |
| 944 | lp->lwp_sig = sig; /* XXX to verify code */ |
| 945 | lwpsignal(p, lp, sig); |
| 946 | } |
| 947 | } |
| 948 | |
| 949 | /* |
| 950 | * Find a suitable lwp to deliver the signal to. Returns NULL if all |
| 951 | * lwps hold the signal blocked. |
| 952 | * |
| 953 | * Caller must hold p->p_token. |
| 954 | */ |
| 955 | static struct lwp * |
| 956 | find_lwp_for_signal(struct proc *p, int sig) |
| 957 | { |
| 958 | struct lwp *lp; |
| 959 | struct lwp *run, *sleep, *stop; |
| 960 | |
| 961 | /* |
| 962 | * If the running/preempted thread belongs to the proc to which |
| 963 | * the signal is being delivered and this thread does not block |
| 964 | * the signal, then we can avoid a context switch by delivering |
| 965 | * the signal to this thread, because it will return to userland |
| 966 | * soon anyways. |
| 967 | */ |
| 968 | lp = lwkt_preempted_proc(); |
| 969 | if (lp != NULL && lp->lwp_proc == p && |
| 970 | !SIGISMEMBER(lp->lwp_sigmask, sig)) { |
| 971 | return (lp); |
| 972 | } |
| 973 | |
| 974 | run = sleep = stop = NULL; |
| 975 | FOREACH_LWP_IN_PROC(lp, p) { |
| 976 | /* |
| 977 | * If the signal is being blocked by the lwp, then this |
| 978 | * lwp is not eligible for receiving the signal. |
| 979 | */ |
| 980 | if (SIGISMEMBER(lp->lwp_sigmask, sig)) |
| 981 | continue; |
| 982 | |
| 983 | switch (lp->lwp_stat) { |
| 984 | case LSRUN: |
| 985 | run = lp; |
| 986 | break; |
| 987 | |
| 988 | case LSSTOP: |
| 989 | stop = lp; |
| 990 | break; |
| 991 | |
| 992 | case LSSLEEP: |
| 993 | if (lp->lwp_flag & LWP_SINTR) |
| 994 | sleep = lp; |
| 995 | break; |
| 996 | } |
| 997 | } |
| 998 | |
| 999 | if (run != NULL) |
| 1000 | return (run); |
| 1001 | else if (sleep != NULL) |
| 1002 | return (sleep); |
| 1003 | else |
| 1004 | return (stop); |
| 1005 | } |
| 1006 | |
| 1007 | /* |
| 1008 | * Send the signal to the process. If the signal has an action, the action |
| 1009 | * is usually performed by the target process rather than the caller; we add |
| 1010 | * the signal to the set of pending signals for the process. |
| 1011 | * |
| 1012 | * Exceptions: |
| 1013 | * o When a stop signal is sent to a sleeping process that takes the |
| 1014 | * default action, the process is stopped without awakening it. |
| 1015 | * o SIGCONT restarts stopped processes (or puts them back to sleep) |
| 1016 | * regardless of the signal action (eg, blocked or ignored). |
| 1017 | * |
| 1018 | * Other ignored signals are discarded immediately. |
| 1019 | * |
| 1020 | * If the caller wishes to call this function from a hard code section the |
| 1021 | * caller must already hold p->p_token (see kern_clock.c). |
| 1022 | * |
| 1023 | * No requirements. |
| 1024 | */ |
| 1025 | void |
| 1026 | ksignal(struct proc *p, int sig) |
| 1027 | { |
| 1028 | lwpsignal(p, NULL, sig); |
| 1029 | } |
| 1030 | |
| 1031 | /* |
| 1032 | * The core for ksignal. lp may be NULL, then a suitable thread |
| 1033 | * will be chosen. If not, lp MUST be a member of p. |
| 1034 | * |
| 1035 | * If the caller wishes to call this function from a hard code section the |
| 1036 | * caller must already hold p->p_token. |
| 1037 | * |
| 1038 | * No requirements. |
| 1039 | */ |
| 1040 | void |
| 1041 | lwpsignal(struct proc *p, struct lwp *lp, int sig) |
| 1042 | { |
| 1043 | int prop; |
| 1044 | sig_t action; |
| 1045 | |
| 1046 | if (sig > _SIG_MAXSIG || sig <= 0) { |
| 1047 | kprintf("lwpsignal: signal %d\n", sig); |
| 1048 | panic("lwpsignal signal number"); |
| 1049 | } |
| 1050 | |
| 1051 | KKASSERT(lp == NULL || lp->lwp_proc == p); |
| 1052 | |
| 1053 | PHOLD(p); |
| 1054 | lwkt_gettoken(&p->p_token); |
| 1055 | |
| 1056 | prop = sigprop(sig); |
| 1057 | |
| 1058 | /* |
| 1059 | * If proc is traced, always give parent a chance; |
| 1060 | * if signal event is tracked by procfs, give *that* |
| 1061 | * a chance, as well. |
| 1062 | */ |
| 1063 | if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { |
| 1064 | action = SIG_DFL; |
| 1065 | } else { |
| 1066 | /* |
| 1067 | * Do not try to deliver signals to an exiting lwp. Note |
| 1068 | * that we must still deliver the signal if P_WEXIT is set |
| 1069 | * in the process flags. |
| 1070 | */ |
| 1071 | if (lp && (lp->lwp_flag & LWP_WEXIT)) { |
| 1072 | lwkt_reltoken(&p->p_token); |
| 1073 | PRELE(p); |
| 1074 | return; |
| 1075 | } |
| 1076 | |
| 1077 | /* |
| 1078 | * If the signal is being ignored, then we forget about |
| 1079 | * it immediately. NOTE: We don't set SIGCONT in p_sigignore, |
| 1080 | * and if it is set to SIG_IGN, action will be SIG_DFL here. |
| 1081 | */ |
| 1082 | if (SIGISMEMBER(p->p_sigignore, sig)) { |
| 1083 | /* |
| 1084 | * Even if a signal is set SIG_IGN, it may still be |
| 1085 | * lurking in a kqueue. |
| 1086 | */ |
| 1087 | KNOTE(&p->p_klist, NOTE_SIGNAL | sig); |
| 1088 | lwkt_reltoken(&p->p_token); |
| 1089 | PRELE(p); |
| 1090 | return; |
| 1091 | } |
| 1092 | if (SIGISMEMBER(p->p_sigcatch, sig)) |
| 1093 | action = SIG_CATCH; |
| 1094 | else |
| 1095 | action = SIG_DFL; |
| 1096 | } |
| 1097 | |
| 1098 | /* |
| 1099 | * If continuing, clear any pending STOP signals. |
| 1100 | */ |
| 1101 | if (prop & SA_CONT) |
| 1102 | SIG_STOPSIGMASK(p->p_siglist); |
| 1103 | |
| 1104 | if (prop & SA_STOP) { |
| 1105 | /* |
| 1106 | * If sending a tty stop signal to a member of an orphaned |
| 1107 | * process group, discard the signal here if the action |
| 1108 | * is default; don't stop the process below if sleeping, |
| 1109 | * and don't clear any pending SIGCONT. |
| 1110 | */ |
| 1111 | if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && |
| 1112 | action == SIG_DFL) { |
| 1113 | lwkt_reltoken(&p->p_token); |
| 1114 | PRELE(p); |
| 1115 | return; |
| 1116 | } |
| 1117 | SIG_CONTSIGMASK(p->p_siglist); |
| 1118 | p->p_flag &= ~P_CONTINUED; |
| 1119 | } |
| 1120 | |
| 1121 | crit_enter(); |
| 1122 | |
| 1123 | if (p->p_stat == SSTOP) { |
| 1124 | /* |
| 1125 | * Nobody can handle this signal, add it to the lwp or |
| 1126 | * process pending list |
| 1127 | */ |
| 1128 | if (lp) |
| 1129 | SIGADDSET(lp->lwp_siglist, sig); |
| 1130 | else |
| 1131 | SIGADDSET(p->p_siglist, sig); |
| 1132 | |
| 1133 | /* |
| 1134 | * If the process is stopped and is being traced, then no |
| 1135 | * further action is necessary. |
| 1136 | */ |
| 1137 | if (p->p_flag & P_TRACED) |
| 1138 | goto out; |
| 1139 | |
| 1140 | /* |
| 1141 | * If the process is stopped and receives a KILL signal, |
| 1142 | * make the process runnable. |
| 1143 | */ |
| 1144 | if (sig == SIGKILL) { |
| 1145 | proc_unstop(p); |
| 1146 | goto active_process; |
| 1147 | } |
| 1148 | |
| 1149 | /* |
| 1150 | * If the process is stopped and receives a CONT signal, |
| 1151 | * then try to make the process runnable again. |
| 1152 | */ |
| 1153 | if (prop & SA_CONT) { |
| 1154 | /* |
| 1155 | * If SIGCONT is default (or ignored), we continue the |
| 1156 | * process but don't leave the signal in p_siglist, as |
| 1157 | * it has no further action. If SIGCONT is held, we |
| 1158 | * continue the process and leave the signal in |
| 1159 | * p_siglist. If the process catches SIGCONT, let it |
| 1160 | * handle the signal itself. |
| 1161 | */ |
| 1162 | /* XXX what if the signal is being held blocked? */ |
| 1163 | p->p_flag |= P_CONTINUED; |
| 1164 | wakeup(p->p_pptr); |
| 1165 | if (action == SIG_DFL) |
| 1166 | SIGDELSET(p->p_siglist, sig); |
| 1167 | proc_unstop(p); |
| 1168 | if (action == SIG_CATCH) |
| 1169 | goto active_process; |
| 1170 | goto out; |
| 1171 | } |
| 1172 | |
| 1173 | /* |
| 1174 | * If the process is stopped and receives another STOP |
| 1175 | * signal, we do not need to stop it again. If we did |
| 1176 | * the shell could get confused. |
| 1177 | * |
| 1178 | * However, if the current/preempted lwp is part of the |
| 1179 | * process receiving the signal, we need to keep it, |
| 1180 | * so that this lwp can stop in issignal() later, as |
| 1181 | * we don't want to wait until it reaches userret! |
| 1182 | */ |
| 1183 | if (prop & SA_STOP) { |
| 1184 | if (lwkt_preempted_proc() == NULL || |
| 1185 | lwkt_preempted_proc()->lwp_proc != p) |
| 1186 | SIGDELSET(p->p_siglist, sig); |
| 1187 | } |
| 1188 | |
| 1189 | /* |
| 1190 | * Otherwise the process is stopped and it received some |
| 1191 | * signal, which does not change its stopped state. |
| 1192 | * |
| 1193 | * We have to select one thread to set LWP_BREAKTSLEEP, |
| 1194 | * so that the current signal will break the sleep |
| 1195 | * as soon as a SA_CONT signal will unstop the process. |
| 1196 | */ |
| 1197 | if (lp == NULL) |
| 1198 | lp = find_lwp_for_signal(p, sig); |
| 1199 | if (lp != NULL && |
| 1200 | (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP)) |
| 1201 | lp->lwp_flag |= LWP_BREAKTSLEEP; |
| 1202 | goto out; |
| 1203 | |
| 1204 | /* NOTREACHED */ |
| 1205 | } |
| 1206 | /* else not stopped */ |
| 1207 | active_process: |
| 1208 | |
| 1209 | /* |
| 1210 | * Never deliver a lwp-specific signal to a random lwp. |
| 1211 | */ |
| 1212 | if (lp == NULL) { |
| 1213 | lp = find_lwp_for_signal(p, sig); |
| 1214 | if (lp && SIGISMEMBER(lp->lwp_sigmask, sig)) |
| 1215 | lp = NULL; |
| 1216 | } |
| 1217 | |
| 1218 | /* |
| 1219 | * Deliver to the process generically if (1) the signal is being |
| 1220 | * sent to any thread or (2) we could not find a thread to deliver |
| 1221 | * it to. |
| 1222 | */ |
| 1223 | if (lp == NULL) { |
| 1224 | SIGADDSET(p->p_siglist, sig); |
| 1225 | goto out; |
| 1226 | } |
| 1227 | |
| 1228 | /* |
| 1229 | * Deliver to a specific LWP whether it masks it or not. It will |
| 1230 | * not be dispatched if masked but we must still deliver it. |
| 1231 | */ |
| 1232 | if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && |
| 1233 | (p->p_flag & P_TRACED) == 0) { |
| 1234 | p->p_nice = NZERO; |
| 1235 | } |
| 1236 | |
| 1237 | /* |
| 1238 | * If the process receives a STOP signal which indeed needs to |
| 1239 | * stop the process, do so. If the process chose to catch the |
| 1240 | * signal, it will be treated like any other signal. |
| 1241 | */ |
| 1242 | if ((prop & SA_STOP) && action == SIG_DFL) { |
| 1243 | /* |
| 1244 | * If a child holding parent blocked, stopping |
| 1245 | * could cause deadlock. Take no action at this |
| 1246 | * time. |
| 1247 | */ |
| 1248 | if (p->p_flag & P_PPWAIT) { |
| 1249 | SIGADDSET(p->p_siglist, sig); |
| 1250 | goto out; |
| 1251 | } |
| 1252 | |
| 1253 | /* |
| 1254 | * Do not actually try to manipulate the process, but simply |
| 1255 | * stop it. Lwps will stop as soon as they safely can. |
| 1256 | */ |
| 1257 | p->p_xstat = sig; |
| 1258 | proc_stop(p); |
| 1259 | goto out; |
| 1260 | } |
| 1261 | |
| 1262 | /* |
| 1263 | * If it is a CONT signal with default action, just ignore it. |
| 1264 | */ |
| 1265 | if ((prop & SA_CONT) && action == SIG_DFL) |
| 1266 | goto out; |
| 1267 | |
| 1268 | /* |
| 1269 | * Mark signal pending at this specific thread. |
| 1270 | */ |
| 1271 | SIGADDSET(lp->lwp_siglist, sig); |
| 1272 | |
| 1273 | lwp_signotify(lp); |
| 1274 | |
| 1275 | out: |
| 1276 | lwkt_reltoken(&p->p_token); |
| 1277 | PRELE(p); |
| 1278 | crit_exit(); |
| 1279 | } |
| 1280 | |
| 1281 | /* |
| 1282 | * p->p_token must be held |
| 1283 | */ |
| 1284 | static void |
| 1285 | lwp_signotify(struct lwp *lp) |
| 1286 | { |
| 1287 | ASSERT_LWKT_TOKEN_HELD(&lp->lwp_proc->p_token); |
| 1288 | crit_enter(); |
| 1289 | |
| 1290 | if (lp->lwp_stat == LSSLEEP || lp->lwp_stat == LSSTOP) { |
| 1291 | /* |
| 1292 | * Thread is in tsleep. |
| 1293 | */ |
| 1294 | |
| 1295 | /* |
| 1296 | * If the thread is sleeping uninterruptibly |
| 1297 | * we can't interrupt the sleep... the signal will |
| 1298 | * be noticed when the lwp returns through |
| 1299 | * trap() or syscall(). |
| 1300 | * |
| 1301 | * Otherwise the signal can interrupt the sleep. |
| 1302 | * |
| 1303 | * If the process is traced, the lwp will handle the |
| 1304 | * tracing in issignal() when it returns to userland. |
| 1305 | */ |
| 1306 | if (lp->lwp_flag & LWP_SINTR) { |
| 1307 | /* |
| 1308 | * Make runnable and break out of any tsleep as well. |
| 1309 | */ |
| 1310 | lp->lwp_flag |= LWP_BREAKTSLEEP; |
| 1311 | setrunnable(lp); |
| 1312 | } |
| 1313 | } else { |
| 1314 | /* |
| 1315 | * Otherwise the thread is running |
| 1316 | * |
| 1317 | * LSRUN does nothing with the signal, other than kicking |
| 1318 | * ourselves if we are running. |
| 1319 | * SZOMB and SIDL mean that it will either never be noticed, |
| 1320 | * or noticed very soon. |
| 1321 | * |
| 1322 | * Note that lwp_thread may be NULL or may not be completely |
| 1323 | * initialized if the process is in the SIDL or SZOMB state. |
| 1324 | * |
| 1325 | * For SMP we may have to forward the request to another cpu. |
| 1326 | * YYY the MP lock prevents the target process from moving |
| 1327 | * to another cpu, see kern/kern_switch.c |
| 1328 | * |
| 1329 | * If the target thread is waiting on its message port, |
| 1330 | * wakeup the target thread so it can check (or ignore) |
| 1331 | * the new signal. YYY needs cleanup. |
| 1332 | */ |
| 1333 | if (lp == lwkt_preempted_proc()) { |
| 1334 | signotify(); |
| 1335 | } else if (lp->lwp_stat == LSRUN) { |
| 1336 | struct thread *td = lp->lwp_thread; |
| 1337 | struct proc *p __debugvar = lp->lwp_proc; |
| 1338 | |
| 1339 | KASSERT(td != NULL, |
| 1340 | ("pid %d/%d NULL lwp_thread stat %d flags %08x/%08x", |
| 1341 | p->p_pid, lp->lwp_tid, lp->lwp_stat, |
| 1342 | p->p_flag, lp->lwp_flag)); |
| 1343 | |
| 1344 | /* |
| 1345 | * To prevent a MP race with TDF_SINTR we must |
| 1346 | * schedule the thread on the correct cpu. |
| 1347 | */ |
| 1348 | #ifdef SMP |
| 1349 | if (td->td_gd != mycpu) { |
| 1350 | LWPHOLD(lp); |
| 1351 | lwkt_send_ipiq(td->td_gd, signotify_remote, lp); |
| 1352 | } else |
| 1353 | #endif |
| 1354 | if (td->td_flags & TDF_SINTR) |
| 1355 | lwkt_schedule(td); |
| 1356 | } |
| 1357 | } |
| 1358 | crit_exit(); |
| 1359 | } |
| 1360 | |
| 1361 | #ifdef SMP |
| 1362 | |
| 1363 | /* |
| 1364 | * This function is called via an IPI. We will be in a critical section but |
| 1365 | * the MP lock will NOT be held. The passed lp will be held. |
| 1366 | * |
| 1367 | * We must essentially repeat the code at the end of lwp_signotify(), |
| 1368 | * in particular rechecking all races. If we are still not on the |
| 1369 | * correct cpu we leave the lwp ref intact and continue the chase. |
| 1370 | * |
| 1371 | * XXX this may still not be entirely correct, since we are checking |
| 1372 | * lwp_stat asynchronously. |
| 1373 | */ |
| 1374 | static void |
| 1375 | signotify_remote(void *arg) |
| 1376 | { |
| 1377 | struct lwp *lp = arg; |
| 1378 | thread_t td; |
| 1379 | |
| 1380 | if (lp == lwkt_preempted_proc()) { |
| 1381 | signotify(); |
| 1382 | } else if (lp->lwp_stat == LSRUN) { |
| 1383 | /* |
| 1384 | * To prevent a MP race with TDF_SINTR we must |
| 1385 | * schedule the thread on the correct cpu. |
| 1386 | */ |
| 1387 | td = lp->lwp_thread; |
| 1388 | if (td->td_gd != mycpu) { |
| 1389 | lwkt_send_ipiq(td->td_gd, signotify_remote, lp); |
| 1390 | return; |
| 1391 | /* NOT REACHED */ |
| 1392 | } |
| 1393 | if (td->td_flags & TDF_SINTR) |
| 1394 | lwkt_schedule(td); |
| 1395 | } |
| 1396 | LWPRELE(lp); |
| 1397 | } |
| 1398 | |
| 1399 | #endif |
| 1400 | |
| 1401 | /* |
| 1402 | * Caller must hold p->p_token |
| 1403 | */ |
| 1404 | void |
| 1405 | proc_stop(struct proc *p) |
| 1406 | { |
| 1407 | struct lwp *lp; |
| 1408 | |
| 1409 | ASSERT_LWKT_TOKEN_HELD(&p->p_token); |
| 1410 | crit_enter(); |
| 1411 | |
| 1412 | /* If somebody raced us, be happy with it */ |
| 1413 | if (p->p_stat == SSTOP || p->p_stat == SZOMB) { |
| 1414 | crit_exit(); |
| 1415 | return; |
| 1416 | } |
| 1417 | p->p_stat = SSTOP; |
| 1418 | |
| 1419 | FOREACH_LWP_IN_PROC(lp, p) { |
| 1420 | switch (lp->lwp_stat) { |
| 1421 | case LSSTOP: |
| 1422 | /* |
| 1423 | * Do nothing, we are already counted in |
| 1424 | * p_nstopped. |
| 1425 | */ |
| 1426 | break; |
| 1427 | |
| 1428 | case LSSLEEP: |
| 1429 | /* |
| 1430 | * We're sleeping, but we will stop before |
| 1431 | * returning to userspace, so count us |
| 1432 | * as stopped as well. We set LWP_WSTOP |
| 1433 | * to signal the lwp that it should not |
| 1434 | * increase p_nstopped when reaching tstop(). |
| 1435 | */ |
| 1436 | if ((lp->lwp_flag & LWP_WSTOP) == 0) { |
| 1437 | lp->lwp_flag |= LWP_WSTOP; |
| 1438 | ++p->p_nstopped; |
| 1439 | } |
| 1440 | break; |
| 1441 | |
| 1442 | case LSRUN: |
| 1443 | /* |
| 1444 | * We might notify ourself, but that's not |
| 1445 | * a problem. |
| 1446 | */ |
| 1447 | lwp_signotify(lp); |
| 1448 | break; |
| 1449 | } |
| 1450 | } |
| 1451 | |
| 1452 | if (p->p_nstopped == p->p_nthreads) { |
| 1453 | p->p_flag &= ~P_WAITED; |
| 1454 | wakeup(p->p_pptr); |
| 1455 | if ((p->p_pptr->p_sigacts->ps_flag & PS_NOCLDSTOP) == 0) |
| 1456 | ksignal(p->p_pptr, SIGCHLD); |
| 1457 | } |
| 1458 | crit_exit(); |
| 1459 | } |
| 1460 | |
| 1461 | /* |
| 1462 | * Caller must hold proc_token |
| 1463 | */ |
| 1464 | void |
| 1465 | proc_unstop(struct proc *p) |
| 1466 | { |
| 1467 | struct lwp *lp; |
| 1468 | |
| 1469 | ASSERT_LWKT_TOKEN_HELD(&p->p_token); |
| 1470 | crit_enter(); |
| 1471 | |
| 1472 | if (p->p_stat != SSTOP) { |
| 1473 | crit_exit(); |
| 1474 | return; |
| 1475 | } |
| 1476 | |
| 1477 | p->p_stat = SACTIVE; |
| 1478 | |
| 1479 | FOREACH_LWP_IN_PROC(lp, p) { |
| 1480 | switch (lp->lwp_stat) { |
| 1481 | case LSRUN: |
| 1482 | /* |
| 1483 | * Uh? Not stopped? Well, I guess that's okay. |
| 1484 | */ |
| 1485 | if (bootverbose) |
| 1486 | kprintf("proc_unstop: lwp %d/%d not sleeping\n", |
| 1487 | p->p_pid, lp->lwp_tid); |
| 1488 | break; |
| 1489 | |
| 1490 | case LSSLEEP: |
| 1491 | /* |
| 1492 | * Still sleeping. Don't bother waking it up. |
| 1493 | * However, if this thread was counted as |
| 1494 | * stopped, undo this. |
| 1495 | * |
| 1496 | * Nevertheless we call setrunnable() so that it |
| 1497 | * will wake up in case a signal or timeout arrived |
| 1498 | * in the meantime. |
| 1499 | */ |
| 1500 | if (lp->lwp_flag & LWP_WSTOP) { |
| 1501 | lp->lwp_flag &= ~LWP_WSTOP; |
| 1502 | --p->p_nstopped; |
| 1503 | } else { |
| 1504 | if (bootverbose) |
| 1505 | kprintf("proc_unstop: lwp %d/%d sleeping, not stopped\n", |
| 1506 | p->p_pid, lp->lwp_tid); |
| 1507 | } |
| 1508 | /* FALLTHROUGH */ |
| 1509 | |
| 1510 | case LSSTOP: |
| 1511 | setrunnable(lp); |
| 1512 | break; |
| 1513 | |
| 1514 | } |
| 1515 | } |
| 1516 | crit_exit(); |
| 1517 | } |
| 1518 | |
| 1519 | /* |
| 1520 | * No requirements. |
| 1521 | */ |
| 1522 | static int |
| 1523 | kern_sigtimedwait(sigset_t waitset, siginfo_t *info, struct timespec *timeout) |
| 1524 | { |
| 1525 | sigset_t savedmask, set; |
| 1526 | struct proc *p = curproc; |
| 1527 | struct lwp *lp = curthread->td_lwp; |
| 1528 | int error, sig, hz, timevalid = 0; |
| 1529 | struct timespec rts, ets, ts; |
| 1530 | struct timeval tv; |
| 1531 | |
| 1532 | error = 0; |
| 1533 | sig = 0; |
| 1534 | ets.tv_sec = 0; /* silence compiler warning */ |
| 1535 | ets.tv_nsec = 0; /* silence compiler warning */ |
| 1536 | SIG_CANTMASK(waitset); |
| 1537 | savedmask = lp->lwp_sigmask; |
| 1538 | |
| 1539 | if (timeout) { |
| 1540 | if (timeout->tv_sec >= 0 && timeout->tv_nsec >= 0 && |
| 1541 | timeout->tv_nsec < 1000000000) { |
| 1542 | timevalid = 1; |
| 1543 | getnanouptime(&rts); |
| 1544 | ets = rts; |
| 1545 | timespecadd(&ets, timeout); |
| 1546 | } |
| 1547 | } |
| 1548 | |
| 1549 | for (;;) { |
| 1550 | set = lwp_sigpend(lp); |
| 1551 | SIGSETAND(set, waitset); |
| 1552 | if ((sig = sig_ffs(&set)) != 0) { |
| 1553 | SIGFILLSET(lp->lwp_sigmask); |
| 1554 | SIGDELSET(lp->lwp_sigmask, sig); |
| 1555 | SIG_CANTMASK(lp->lwp_sigmask); |
| 1556 | sig = issignal(lp, 1); |
| 1557 | /* |
| 1558 | * It may be a STOP signal, in the case, issignal |
| 1559 | * returns 0, because we may stop there, and new |
| 1560 | * signal can come in, we should restart if we got |
| 1561 | * nothing. |
| 1562 | */ |
| 1563 | if (sig == 0) |
| 1564 | continue; |
| 1565 | else |
| 1566 | break; |
| 1567 | } |
| 1568 | |
| 1569 | /* |
| 1570 | * Previous checking got nothing, and we retried but still |
| 1571 | * got nothing, we should return the error status. |
| 1572 | */ |
| 1573 | if (error) |
| 1574 | break; |
| 1575 | |
| 1576 | /* |
| 1577 | * POSIX says this must be checked after looking for pending |
| 1578 | * signals. |
| 1579 | */ |
| 1580 | if (timeout) { |
| 1581 | if (timevalid == 0) { |
| 1582 | error = EINVAL; |
| 1583 | break; |
| 1584 | } |
| 1585 | getnanouptime(&rts); |
| 1586 | if (timespeccmp(&rts, &ets, >=)) { |
| 1587 | error = EAGAIN; |
| 1588 | break; |
| 1589 | } |
| 1590 | ts = ets; |
| 1591 | timespecsub(&ts, &rts); |
| 1592 | TIMESPEC_TO_TIMEVAL(&tv, &ts); |
| 1593 | hz = tvtohz_high(&tv); |
| 1594 | } else { |
| 1595 | hz = 0; |
| 1596 | } |
| 1597 | |
| 1598 | lp->lwp_sigmask = savedmask; |
| 1599 | SIGSETNAND(lp->lwp_sigmask, waitset); |
| 1600 | /* |
| 1601 | * We won't ever be woken up. Instead, our sleep will |
| 1602 | * be broken in lwpsignal(). |
| 1603 | */ |
| 1604 | error = tsleep(&p->p_sigacts, PCATCH, "sigwt", hz); |
| 1605 | if (timeout) { |
| 1606 | if (error == ERESTART) { |
| 1607 | /* can not restart a timeout wait. */ |
| 1608 | error = EINTR; |
| 1609 | } else if (error == EAGAIN) { |
| 1610 | /* will calculate timeout by ourself. */ |
| 1611 | error = 0; |
| 1612 | } |
| 1613 | } |
| 1614 | /* Retry ... */ |
| 1615 | } |
| 1616 | |
| 1617 | lp->lwp_sigmask = savedmask; |
| 1618 | if (sig) { |
| 1619 | error = 0; |
| 1620 | bzero(info, sizeof(*info)); |
| 1621 | info->si_signo = sig; |
| 1622 | lwp_delsig(lp, sig); /* take the signal! */ |
| 1623 | |
| 1624 | if (sig == SIGKILL) { |
| 1625 | sigexit(lp, sig); |
| 1626 | /* NOT REACHED */ |
| 1627 | } |
| 1628 | } |
| 1629 | |
| 1630 | return (error); |
| 1631 | } |
| 1632 | |
| 1633 | /* |
| 1634 | * MPALMOSTSAFE |
| 1635 | */ |
| 1636 | int |
| 1637 | sys_sigtimedwait(struct sigtimedwait_args *uap) |
| 1638 | { |
| 1639 | struct timespec ts; |
| 1640 | struct timespec *timeout; |
| 1641 | sigset_t set; |
| 1642 | siginfo_t info; |
| 1643 | int error; |
| 1644 | |
| 1645 | if (uap->timeout) { |
| 1646 | error = copyin(uap->timeout, &ts, sizeof(ts)); |
| 1647 | if (error) |
| 1648 | return (error); |
| 1649 | timeout = &ts; |
| 1650 | } else { |
| 1651 | timeout = NULL; |
| 1652 | } |
| 1653 | error = copyin(uap->set, &set, sizeof(set)); |
| 1654 | if (error) |
| 1655 | return (error); |
| 1656 | error = kern_sigtimedwait(set, &info, timeout); |
| 1657 | if (error) |
| 1658 | return (error); |
| 1659 | if (uap->info) |
| 1660 | error = copyout(&info, uap->info, sizeof(info)); |
| 1661 | /* Repost if we got an error. */ |
| 1662 | /* |
| 1663 | * XXX lwp |
| 1664 | * |
| 1665 | * This could transform a thread-specific signal to another |
| 1666 | * thread / process pending signal. |
| 1667 | */ |
| 1668 | if (error) { |
| 1669 | ksignal(curproc, info.si_signo); |
| 1670 | } else { |
| 1671 | uap->sysmsg_result = info.si_signo; |
| 1672 | } |
| 1673 | return (error); |
| 1674 | } |
| 1675 | |
| 1676 | /* |
| 1677 | * MPALMOSTSAFE |
| 1678 | */ |
| 1679 | int |
| 1680 | sys_sigwaitinfo(struct sigwaitinfo_args *uap) |
| 1681 | { |
| 1682 | siginfo_t info; |
| 1683 | sigset_t set; |
| 1684 | int error; |
| 1685 | |
| 1686 | error = copyin(uap->set, &set, sizeof(set)); |
| 1687 | if (error) |
| 1688 | return (error); |
| 1689 | error = kern_sigtimedwait(set, &info, NULL); |
| 1690 | if (error) |
| 1691 | return (error); |
| 1692 | if (uap->info) |
| 1693 | error = copyout(&info, uap->info, sizeof(info)); |
| 1694 | /* Repost if we got an error. */ |
| 1695 | /* |
| 1696 | * XXX lwp |
| 1697 | * |
| 1698 | * This could transform a thread-specific signal to another |
| 1699 | * thread / process pending signal. |
| 1700 | */ |
| 1701 | if (error) { |
| 1702 | ksignal(curproc, info.si_signo); |
| 1703 | } else { |
| 1704 | uap->sysmsg_result = info.si_signo; |
| 1705 | } |
| 1706 | return (error); |
| 1707 | } |
| 1708 | |
| 1709 | /* |
| 1710 | * If the current process has received a signal that would interrupt a |
| 1711 | * system call, return EINTR or ERESTART as appropriate. |
| 1712 | */ |
| 1713 | int |
| 1714 | iscaught(struct lwp *lp) |
| 1715 | { |
| 1716 | struct proc *p = lp->lwp_proc; |
| 1717 | int sig; |
| 1718 | |
| 1719 | if (p) { |
| 1720 | if ((sig = CURSIG(lp)) != 0) { |
| 1721 | if (SIGISMEMBER(p->p_sigacts->ps_sigintr, sig)) |
| 1722 | return (EINTR); |
| 1723 | return (ERESTART); |
| 1724 | } |
| 1725 | } |
| 1726 | return(EWOULDBLOCK); |
| 1727 | } |
| 1728 | |
| 1729 | /* |
| 1730 | * If the current process has received a signal (should be caught or cause |
| 1731 | * termination, should interrupt current syscall), return the signal number. |
| 1732 | * Stop signals with default action are processed immediately, then cleared; |
| 1733 | * they aren't returned. This is checked after each entry to the system for |
| 1734 | * a syscall or trap (though this can usually be done without calling issignal |
| 1735 | * by checking the pending signal masks in the CURSIG macro). |
| 1736 | * |
| 1737 | * This routine is called via CURSIG/__cursig. We will acquire and release |
| 1738 | * p->p_token but if the caller needs to interlock the test the caller must |
| 1739 | * also hold p->p_token. |
| 1740 | * |
| 1741 | * while (sig = CURSIG(curproc)) |
| 1742 | * postsig(sig); |
| 1743 | * |
| 1744 | * MPSAFE |
| 1745 | */ |
| 1746 | int |
| 1747 | issignal(struct lwp *lp, int maytrace) |
| 1748 | { |
| 1749 | struct proc *p = lp->lwp_proc; |
| 1750 | sigset_t mask; |
| 1751 | int sig, prop; |
| 1752 | |
| 1753 | lwkt_gettoken(&p->p_token); |
| 1754 | |
| 1755 | for (;;) { |
| 1756 | int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); |
| 1757 | |
| 1758 | /* |
| 1759 | * If this process is supposed to stop, stop this thread. |
| 1760 | */ |
| 1761 | if (p->p_stat == SSTOP) |
| 1762 | tstop(); |
| 1763 | |
| 1764 | mask = lwp_sigpend(lp); |
| 1765 | SIGSETNAND(mask, lp->lwp_sigmask); |
| 1766 | if (p->p_flag & P_PPWAIT) |
| 1767 | SIG_STOPSIGMASK(mask); |
| 1768 | if (SIGISEMPTY(mask)) { /* no signal to send */ |
| 1769 | lwkt_reltoken(&p->p_token); |
| 1770 | return (0); |
| 1771 | } |
| 1772 | sig = sig_ffs(&mask); |
| 1773 | |
| 1774 | STOPEVENT(p, S_SIG, sig); |
| 1775 | |
| 1776 | /* |
| 1777 | * We should see pending but ignored signals |
| 1778 | * only if P_TRACED was on when they were posted. |
| 1779 | */ |
| 1780 | if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { |
| 1781 | lwp_delsig(lp, sig); |
| 1782 | continue; |
| 1783 | } |
| 1784 | if (maytrace && (p->p_flag & P_TRACED) && (p->p_flag & P_PPWAIT) == 0) { |
| 1785 | /* |
| 1786 | * If traced, always stop, and stay stopped until |
| 1787 | * released by the parent. |
| 1788 | * |
| 1789 | * NOTE: SSTOP may get cleared during the loop, |
| 1790 | * but we do not re-notify the parent if we have |
| 1791 | * to loop several times waiting for the parent |
| 1792 | * to let us continue. |
| 1793 | * |
| 1794 | * XXX not sure if this is still true |
| 1795 | */ |
| 1796 | p->p_xstat = sig; |
| 1797 | proc_stop(p); |
| 1798 | do { |
| 1799 | tstop(); |
| 1800 | } while (!trace_req(p) && (p->p_flag & P_TRACED)); |
| 1801 | |
| 1802 | /* |
| 1803 | * If parent wants us to take the signal, |
| 1804 | * then it will leave it in p->p_xstat; |
| 1805 | * otherwise we just look for signals again. |
| 1806 | */ |
| 1807 | lwp_delsig(lp, sig); /* clear old signal */ |
| 1808 | sig = p->p_xstat; |
| 1809 | if (sig == 0) |
| 1810 | continue; |
| 1811 | |
| 1812 | /* |
| 1813 | * Put the new signal into p_siglist. If the |
| 1814 | * signal is being masked, look for other signals. |
| 1815 | * |
| 1816 | * XXX lwp might need a call to ksignal() |
| 1817 | */ |
| 1818 | SIGADDSET(p->p_siglist, sig); |
| 1819 | if (SIGISMEMBER(lp->lwp_sigmask, sig)) |
| 1820 | continue; |
| 1821 | |
| 1822 | /* |
| 1823 | * If the traced bit got turned off, go back up |
| 1824 | * to the top to rescan signals. This ensures |
| 1825 | * that p_sig* and ps_sigact are consistent. |
| 1826 | */ |
| 1827 | if ((p->p_flag & P_TRACED) == 0) |
| 1828 | continue; |
| 1829 | } |
| 1830 | |
| 1831 | prop = sigprop(sig); |
| 1832 | |
| 1833 | /* |
| 1834 | * Decide whether the signal should be returned. |
| 1835 | * Return the signal's number, or fall through |
| 1836 | * to clear it from the pending mask. |
| 1837 | */ |
| 1838 | switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { |
| 1839 | case (intptr_t)SIG_DFL: |
| 1840 | /* |
| 1841 | * Don't take default actions on system processes. |
| 1842 | */ |
| 1843 | if (p->p_pid <= 1) { |
| 1844 | #ifdef DIAGNOSTIC |
| 1845 | /* |
| 1846 | * Are you sure you want to ignore SIGSEGV |
| 1847 | * in init? XXX |
| 1848 | */ |
| 1849 | kprintf("Process (pid %lu) got signal %d\n", |
| 1850 | (u_long)p->p_pid, sig); |
| 1851 | #endif |
| 1852 | break; /* == ignore */ |
| 1853 | } |
| 1854 | |
| 1855 | /* |
| 1856 | * Handle the in-kernel checkpoint action |
| 1857 | */ |
| 1858 | if (prop & SA_CKPT) { |
| 1859 | checkpoint_signal_handler(lp); |
| 1860 | break; |
| 1861 | } |
| 1862 | |
| 1863 | /* |
| 1864 | * If there is a pending stop signal to process |
| 1865 | * with default action, stop here, |
| 1866 | * then clear the signal. However, |
| 1867 | * if process is member of an orphaned |
| 1868 | * process group, ignore tty stop signals. |
| 1869 | */ |
| 1870 | if (prop & SA_STOP) { |
| 1871 | if (p->p_flag & P_TRACED || |
| 1872 | (p->p_pgrp->pg_jobc == 0 && |
| 1873 | prop & SA_TTYSTOP)) |
| 1874 | break; /* == ignore */ |
| 1875 | p->p_xstat = sig; |
| 1876 | proc_stop(p); |
| 1877 | tstop(); |
| 1878 | break; |
| 1879 | } else if (prop & SA_IGNORE) { |
| 1880 | /* |
| 1881 | * Except for SIGCONT, shouldn't get here. |
| 1882 | * Default action is to ignore; drop it. |
| 1883 | */ |
| 1884 | break; /* == ignore */ |
| 1885 | } else { |
| 1886 | lwkt_reltoken(&p->p_token); |
| 1887 | return (sig); |
| 1888 | } |
| 1889 | |
| 1890 | /*NOTREACHED*/ |
| 1891 | |
| 1892 | case (intptr_t)SIG_IGN: |
| 1893 | /* |
| 1894 | * Masking above should prevent us ever trying |
| 1895 | * to take action on an ignored signal other |
| 1896 | * than SIGCONT, unless process is traced. |
| 1897 | */ |
| 1898 | if ((prop & SA_CONT) == 0 && |
| 1899 | (p->p_flag & P_TRACED) == 0) |
| 1900 | kprintf("issignal\n"); |
| 1901 | break; /* == ignore */ |
| 1902 | |
| 1903 | default: |
| 1904 | /* |
| 1905 | * This signal has an action, let |
| 1906 | * postsig() process it. |
| 1907 | */ |
| 1908 | lwkt_reltoken(&p->p_token); |
| 1909 | return (sig); |
| 1910 | } |
| 1911 | lwp_delsig(lp, sig); /* take the signal! */ |
| 1912 | } |
| 1913 | /* NOTREACHED */ |
| 1914 | } |
| 1915 | |
| 1916 | /* |
| 1917 | * Take the action for the specified signal |
| 1918 | * from the current set of pending signals. |
| 1919 | * |
| 1920 | * Caller must hold p->p_token |
| 1921 | */ |
| 1922 | void |
| 1923 | postsig(int sig) |
| 1924 | { |
| 1925 | struct lwp *lp = curthread->td_lwp; |
| 1926 | struct proc *p = lp->lwp_proc; |
| 1927 | struct sigacts *ps = p->p_sigacts; |
| 1928 | sig_t action; |
| 1929 | sigset_t returnmask; |
| 1930 | int code; |
| 1931 | |
| 1932 | KASSERT(sig != 0, ("postsig")); |
| 1933 | |
| 1934 | KNOTE(&p->p_klist, NOTE_SIGNAL | sig); |
| 1935 | |
| 1936 | /* |
| 1937 | * If we are a virtual kernel running an emulated user process |
| 1938 | * context, switch back to the virtual kernel context before |
| 1939 | * trying to post the signal. |
| 1940 | */ |
| 1941 | if (lp->lwp_vkernel && lp->lwp_vkernel->ve) { |
| 1942 | struct trapframe *tf = lp->lwp_md.md_regs; |
| 1943 | tf->tf_trapno = 0; |
| 1944 | vkernel_trap(lp, tf); |
| 1945 | } |
| 1946 | |
| 1947 | lwp_delsig(lp, sig); |
| 1948 | action = ps->ps_sigact[_SIG_IDX(sig)]; |
| 1949 | #ifdef KTRACE |
| 1950 | if (KTRPOINT(lp->lwp_thread, KTR_PSIG)) |
| 1951 | ktrpsig(lp, sig, action, lp->lwp_flag & LWP_OLDMASK ? |
| 1952 | &lp->lwp_oldsigmask : &lp->lwp_sigmask, 0); |
| 1953 | #endif |
| 1954 | STOPEVENT(p, S_SIG, sig); |
| 1955 | |
| 1956 | if (action == SIG_DFL) { |
| 1957 | /* |
| 1958 | * Default action, where the default is to kill |
| 1959 | * the process. (Other cases were ignored above.) |
| 1960 | */ |
| 1961 | sigexit(lp, sig); |
| 1962 | /* NOTREACHED */ |
| 1963 | } else { |
| 1964 | /* |
| 1965 | * If we get here, the signal must be caught. |
| 1966 | */ |
| 1967 | KASSERT(action != SIG_IGN && !SIGISMEMBER(lp->lwp_sigmask, sig), |
| 1968 | ("postsig action")); |
| 1969 | |
| 1970 | crit_enter(); |
| 1971 | |
| 1972 | /* |
| 1973 | * Reset the signal handler if asked to |
| 1974 | */ |
| 1975 | if (SIGISMEMBER(ps->ps_sigreset, sig)) { |
| 1976 | /* |
| 1977 | * See kern_sigaction() for origin of this code. |
| 1978 | */ |
| 1979 | SIGDELSET(p->p_sigcatch, sig); |
| 1980 | if (sig != SIGCONT && |
| 1981 | sigprop(sig) & SA_IGNORE) |
| 1982 | SIGADDSET(p->p_sigignore, sig); |
| 1983 | ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; |
| 1984 | } |
| 1985 | |
| 1986 | /* |
| 1987 | * Handle the mailbox case. Copyout to the appropriate |
| 1988 | * location but do not generate a signal frame. The system |
| 1989 | * call simply returns EINTR and the user is responsible for |
| 1990 | * polling the mailbox. |
| 1991 | */ |
| 1992 | if (SIGISMEMBER(ps->ps_sigmailbox, sig)) { |
| 1993 | int sig_copy = sig; |
| 1994 | copyout(&sig_copy, (void *)action, sizeof(int)); |
| 1995 | curproc->p_flag |= P_MAILBOX; |
| 1996 | crit_exit(); |
| 1997 | goto done; |
| 1998 | } |
| 1999 | |
| 2000 | /* |
| 2001 | * Set the signal mask and calculate the mask to restore |
| 2002 | * when the signal function returns. |
| 2003 | * |
| 2004 | * Special case: user has done a sigsuspend. Here the |
| 2005 | * current mask is not of interest, but rather the |
| 2006 | * mask from before the sigsuspend is what we want |
| 2007 | * restored after the signal processing is completed. |
| 2008 | */ |
| 2009 | if (lp->lwp_flag & LWP_OLDMASK) { |
| 2010 | returnmask = lp->lwp_oldsigmask; |
| 2011 | lp->lwp_flag &= ~LWP_OLDMASK; |
| 2012 | } else { |
| 2013 | returnmask = lp->lwp_sigmask; |
| 2014 | } |
| 2015 | |
| 2016 | SIGSETOR(lp->lwp_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); |
| 2017 | if (!SIGISMEMBER(ps->ps_signodefer, sig)) |
| 2018 | SIGADDSET(lp->lwp_sigmask, sig); |
| 2019 | |
| 2020 | crit_exit(); |
| 2021 | lp->lwp_ru.ru_nsignals++; |
| 2022 | if (lp->lwp_sig != sig) { |
| 2023 | code = 0; |
| 2024 | } else { |
| 2025 | code = lp->lwp_code; |
| 2026 | lp->lwp_code = 0; |
| 2027 | lp->lwp_sig = 0; |
| 2028 | } |
| 2029 | (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); |
| 2030 | } |
| 2031 | done: |
| 2032 | ; |
| 2033 | } |
| 2034 | |
| 2035 | /* |
| 2036 | * Kill the current process for stated reason. |
| 2037 | */ |
| 2038 | void |
| 2039 | killproc(struct proc *p, char *why) |
| 2040 | { |
| 2041 | log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", |
| 2042 | p->p_pid, p->p_comm, |
| 2043 | p->p_ucred ? p->p_ucred->cr_uid : -1, why); |
| 2044 | ksignal(p, SIGKILL); |
| 2045 | } |
| 2046 | |
| 2047 | /* |
| 2048 | * Force the current process to exit with the specified signal, dumping core |
| 2049 | * if appropriate. We bypass the normal tests for masked and caught signals, |
| 2050 | * allowing unrecoverable failures to terminate the process without changing |
| 2051 | * signal state. Mark the accounting record with the signal termination. |
| 2052 | * If dumping core, save the signal number for the debugger. Calls exit and |
| 2053 | * does not return. |
| 2054 | * |
| 2055 | * This routine does not return. |
| 2056 | */ |
| 2057 | void |
| 2058 | sigexit(struct lwp *lp, int sig) |
| 2059 | { |
| 2060 | struct proc *p = lp->lwp_proc; |
| 2061 | |
| 2062 | lwkt_gettoken(&p->p_token); |
| 2063 | p->p_acflag |= AXSIG; |
| 2064 | if (sigprop(sig) & SA_CORE) { |
| 2065 | lp->lwp_sig = sig; |
| 2066 | /* |
| 2067 | * Log signals which would cause core dumps |
| 2068 | * (Log as LOG_INFO to appease those who don't want |
| 2069 | * these messages.) |
| 2070 | * XXX : Todo, as well as euid, write out ruid too |
| 2071 | */ |
| 2072 | if (coredump(lp, sig) == 0) |
| 2073 | sig |= WCOREFLAG; |
| 2074 | if (kern_logsigexit) |
| 2075 | log(LOG_INFO, |
| 2076 | "pid %d (%s), uid %d: exited on signal %d%s\n", |
| 2077 | p->p_pid, p->p_comm, |
| 2078 | p->p_ucred ? p->p_ucred->cr_uid : -1, |
| 2079 | sig &~ WCOREFLAG, |
| 2080 | sig & WCOREFLAG ? " (core dumped)" : ""); |
| 2081 | } |
| 2082 | lwkt_reltoken(&p->p_token); |
| 2083 | exit1(W_EXITCODE(0, sig)); |
| 2084 | /* NOTREACHED */ |
| 2085 | } |
| 2086 | |
| 2087 | static char corefilename[MAXPATHLEN+1] = {"%N.core"}; |
| 2088 | SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, |
| 2089 | sizeof(corefilename), "process corefile name format string"); |
| 2090 | |
| 2091 | /* |
| 2092 | * expand_name(name, uid, pid) |
| 2093 | * Expand the name described in corefilename, using name, uid, and pid. |
| 2094 | * corefilename is a kprintf-like string, with three format specifiers: |
| 2095 | * %N name of process ("name") |
| 2096 | * %P process id (pid) |
| 2097 | * %U user id (uid) |
| 2098 | * For example, "%N.core" is the default; they can be disabled completely |
| 2099 | * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". |
| 2100 | * This is controlled by the sysctl variable kern.corefile (see above). |
| 2101 | */ |
| 2102 | |
| 2103 | static char * |
| 2104 | expand_name(const char *name, uid_t uid, pid_t pid) |
| 2105 | { |
| 2106 | char *temp; |
| 2107 | char buf[11]; /* Buffer for pid/uid -- max 4B */ |
| 2108 | int i, n; |
| 2109 | char *format = corefilename; |
| 2110 | size_t namelen; |
| 2111 | |
| 2112 | temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); |
| 2113 | if (temp == NULL) |
| 2114 | return NULL; |
| 2115 | namelen = strlen(name); |
| 2116 | for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { |
| 2117 | int l; |
| 2118 | switch (format[i]) { |
| 2119 | case '%': /* Format character */ |
| 2120 | i++; |
| 2121 | switch (format[i]) { |
| 2122 | case '%': |
| 2123 | temp[n++] = '%'; |
| 2124 | break; |
| 2125 | case 'N': /* process name */ |
| 2126 | if ((n + namelen) > MAXPATHLEN) { |
| 2127 | log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", |
| 2128 | pid, name, uid, temp, name); |
| 2129 | kfree(temp, M_TEMP); |
| 2130 | return NULL; |
| 2131 | } |
| 2132 | memcpy(temp+n, name, namelen); |
| 2133 | n += namelen; |
| 2134 | break; |
| 2135 | case 'P': /* process id */ |
| 2136 | l = ksprintf(buf, "%u", pid); |
| 2137 | if ((n + l) > MAXPATHLEN) { |
| 2138 | log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", |
| 2139 | pid, name, uid, temp, name); |
| 2140 | kfree(temp, M_TEMP); |
| 2141 | return NULL; |
| 2142 | } |
| 2143 | memcpy(temp+n, buf, l); |
| 2144 | n += l; |
| 2145 | break; |
| 2146 | case 'U': /* user id */ |
| 2147 | l = ksprintf(buf, "%u", uid); |
| 2148 | if ((n + l) > MAXPATHLEN) { |
| 2149 | log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", |
| 2150 | pid, name, uid, temp, name); |
| 2151 | kfree(temp, M_TEMP); |
| 2152 | return NULL; |
| 2153 | } |
| 2154 | memcpy(temp+n, buf, l); |
| 2155 | n += l; |
| 2156 | break; |
| 2157 | default: |
| 2158 | log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); |
| 2159 | } |
| 2160 | break; |
| 2161 | default: |
| 2162 | temp[n++] = format[i]; |
| 2163 | } |
| 2164 | } |
| 2165 | temp[n] = '\0'; |
| 2166 | return temp; |
| 2167 | } |
| 2168 | |
| 2169 | /* |
| 2170 | * Dump a process' core. The main routine does some |
| 2171 | * policy checking, and creates the name of the coredump; |
| 2172 | * then it passes on a vnode and a size limit to the process-specific |
| 2173 | * coredump routine if there is one; if there _is not_ one, it returns |
| 2174 | * ENOSYS; otherwise it returns the error from the process-specific routine. |
| 2175 | * |
| 2176 | * The parameter `lp' is the lwp which triggered the coredump. |
| 2177 | */ |
| 2178 | |
| 2179 | static int |
| 2180 | coredump(struct lwp *lp, int sig) |
| 2181 | { |
| 2182 | struct proc *p = lp->lwp_proc; |
| 2183 | struct vnode *vp; |
| 2184 | struct ucred *cred = p->p_ucred; |
| 2185 | struct flock lf; |
| 2186 | struct nlookupdata nd; |
| 2187 | struct vattr vattr; |
| 2188 | int error, error1; |
| 2189 | char *name; /* name of corefile */ |
| 2190 | off_t limit; |
| 2191 | |
| 2192 | STOPEVENT(p, S_CORE, 0); |
| 2193 | |
| 2194 | if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) |
| 2195 | return (EFAULT); |
| 2196 | |
| 2197 | /* |
| 2198 | * Note that the bulk of limit checking is done after |
| 2199 | * the corefile is created. The exception is if the limit |
| 2200 | * for corefiles is 0, in which case we don't bother |
| 2201 | * creating the corefile at all. This layout means that |
| 2202 | * a corefile is truncated instead of not being created, |
| 2203 | * if it is larger than the limit. |
| 2204 | */ |
| 2205 | limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; |
| 2206 | if (limit == 0) |
| 2207 | return EFBIG; |
| 2208 | |
| 2209 | name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); |
| 2210 | if (name == NULL) |
| 2211 | return (EINVAL); |
| 2212 | error = nlookup_init(&nd, name, UIO_SYSSPACE, NLC_LOCKVP); |
| 2213 | if (error == 0) |
| 2214 | error = vn_open(&nd, NULL, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); |
| 2215 | kfree(name, M_TEMP); |
| 2216 | if (error) { |
| 2217 | nlookup_done(&nd); |
| 2218 | return (error); |
| 2219 | } |
| 2220 | vp = nd.nl_open_vp; |
| 2221 | nd.nl_open_vp = NULL; |
| 2222 | nlookup_done(&nd); |
| 2223 | |
| 2224 | vn_unlock(vp); |
| 2225 | lf.l_whence = SEEK_SET; |
| 2226 | lf.l_start = 0; |
| 2227 | lf.l_len = 0; |
| 2228 | lf.l_type = F_WRLCK; |
| 2229 | error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, 0); |
| 2230 | if (error) |
| 2231 | goto out2; |
| 2232 | |
| 2233 | /* Don't dump to non-regular files or files with links. */ |
| 2234 | if (vp->v_type != VREG || |
| 2235 | VOP_GETATTR(vp, &vattr) || vattr.va_nlink != 1) { |
| 2236 | error = EFAULT; |
| 2237 | goto out1; |
| 2238 | } |
| 2239 | |
| 2240 | /* Don't dump to files current user does not own */ |
| 2241 | if (vattr.va_uid != p->p_ucred->cr_uid) { |
| 2242 | error = EFAULT; |
| 2243 | goto out1; |
| 2244 | } |
| 2245 | |
| 2246 | VATTR_NULL(&vattr); |
| 2247 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 2248 | vattr.va_size = 0; |
| 2249 | VOP_SETATTR(vp, &vattr, cred); |
| 2250 | p->p_acflag |= ACORE; |
| 2251 | vn_unlock(vp); |
| 2252 | |
| 2253 | error = p->p_sysent->sv_coredump ? |
| 2254 | p->p_sysent->sv_coredump(lp, sig, vp, limit) : ENOSYS; |
| 2255 | |
| 2256 | out1: |
| 2257 | lf.l_type = F_UNLCK; |
| 2258 | VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, 0); |
| 2259 | out2: |
| 2260 | error1 = vn_close(vp, FWRITE); |
| 2261 | if (error == 0) |
| 2262 | error = error1; |
| 2263 | return (error); |
| 2264 | } |
| 2265 | |
| 2266 | /* |
| 2267 | * Nonexistent system call-- signal process (may want to handle it). |
| 2268 | * Flag error in case process won't see signal immediately (blocked or ignored). |
| 2269 | * |
| 2270 | * MPALMOSTSAFE |
| 2271 | */ |
| 2272 | /* ARGSUSED */ |
| 2273 | int |
| 2274 | sys_nosys(struct nosys_args *args) |
| 2275 | { |
| 2276 | lwpsignal(curproc, curthread->td_lwp, SIGSYS); |
| 2277 | return (EINVAL); |
| 2278 | } |
| 2279 | |
| 2280 | /* |
| 2281 | * Send a SIGIO or SIGURG signal to a process or process group using |
| 2282 | * stored credentials rather than those of the current process. |
| 2283 | */ |
| 2284 | void |
| 2285 | pgsigio(struct sigio *sigio, int sig, int checkctty) |
| 2286 | { |
| 2287 | if (sigio == NULL) |
| 2288 | return; |
| 2289 | |
| 2290 | if (sigio->sio_pgid > 0) { |
| 2291 | if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, |
| 2292 | sigio->sio_proc)) |
| 2293 | ksignal(sigio->sio_proc, sig); |
| 2294 | } else if (sigio->sio_pgid < 0) { |
| 2295 | struct proc *p; |
| 2296 | struct pgrp *pg = sigio->sio_pgrp; |
| 2297 | |
| 2298 | /* |
| 2299 | * Must interlock all signals against fork |
| 2300 | */ |
| 2301 | pgref(pg); |
| 2302 | lockmgr(&pg->pg_lock, LK_EXCLUSIVE); |
| 2303 | LIST_FOREACH(p, &pg->pg_members, p_pglist) { |
| 2304 | if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && |
| 2305 | (checkctty == 0 || (p->p_flag & P_CONTROLT))) |
| 2306 | ksignal(p, sig); |
| 2307 | } |
| 2308 | lockmgr(&pg->pg_lock, LK_RELEASE); |
| 2309 | pgrel(pg); |
| 2310 | } |
| 2311 | } |
| 2312 | |
| 2313 | static int |
| 2314 | filt_sigattach(struct knote *kn) |
| 2315 | { |
| 2316 | struct proc *p = curproc; |
| 2317 | |
| 2318 | kn->kn_ptr.p_proc = p; |
| 2319 | kn->kn_flags |= EV_CLEAR; /* automatically set */ |
| 2320 | |
| 2321 | /* XXX lock the proc here while adding to the list? */ |
| 2322 | knote_insert(&p->p_klist, kn); |
| 2323 | |
| 2324 | return (0); |
| 2325 | } |
| 2326 | |
| 2327 | static void |
| 2328 | filt_sigdetach(struct knote *kn) |
| 2329 | { |
| 2330 | struct proc *p = kn->kn_ptr.p_proc; |
| 2331 | |
| 2332 | knote_remove(&p->p_klist, kn); |
| 2333 | } |
| 2334 | |
| 2335 | /* |
| 2336 | * signal knotes are shared with proc knotes, so we apply a mask to |
| 2337 | * the hint in order to differentiate them from process hints. This |
| 2338 | * could be avoided by using a signal-specific knote list, but probably |
| 2339 | * isn't worth the trouble. |
| 2340 | */ |
| 2341 | static int |
| 2342 | filt_signal(struct knote *kn, long hint) |
| 2343 | { |
| 2344 | if (hint & NOTE_SIGNAL) { |
| 2345 | hint &= ~NOTE_SIGNAL; |
| 2346 | |
| 2347 | if (kn->kn_id == hint) |
| 2348 | kn->kn_data++; |
| 2349 | } |
| 2350 | return (kn->kn_data != 0); |
| 2351 | } |