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 * $Id: kern_sig.c,v 1.60 1999/08/16 18:13:38 billf Exp $ 40 */ 41 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #define SIGPROP /* include signal properties table */ 46 #include <sys/param.h> 47 #include <sys/kernel.h> 48 #include <sys/sysproto.h> 49 #include <sys/signalvar.h> 50 #include <sys/resourcevar.h> 51 #include <sys/namei.h> 52 #include <sys/vnode.h> 53 #include <sys/proc.h> 54 #include <sys/pioctl.h> 55 #include <sys/systm.h> 56 #include <sys/acct.h> 57 #include <sys/fcntl.h> 58 #include <sys/wait.h> 59 #include <sys/ktrace.h> 60 #include <sys/syslog.h> 61 #include <sys/stat.h> 62 #include <sys/sysent.h> 63 #include <sys/sysctl.h> 64 #include <sys/malloc.h> 65 66 #include <machine/cpu.h> 67 #ifdef SMP 68 #include <machine/smp.h> 69 #endif 70 71 static int killpg1 __P((struct proc *cp, int signum, int pgid, int all)); 72 static void setsigvec __P((struct proc *p, int signum, struct sigaction *sa)); 73 static void stop __P((struct proc *)); 74 75 static int kern_logsigexit = 1; 76 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 77 &kern_logsigexit, 0, 78 "Log processes quitting on abnormal signals to syslog(3)"); 79 80 /* 81 * Can process p, with pcred pc, send the signal signum to process q? 82 */ 83 #define CANSIGNAL(p, pc, q, signum) \ 84 (PRISON_CHECK(p, q) && ((pc)->pc_ucred->cr_uid == 0 || \ 85 (pc)->p_ruid == (q)->p_cred->p_ruid || \ 86 (pc)->pc_ucred->cr_uid == (q)->p_cred->p_ruid || \ 87 (pc)->p_ruid == (q)->p_ucred->cr_uid || \ 88 (pc)->pc_ucred->cr_uid == (q)->p_ucred->cr_uid || \ 89 ((signum) == SIGCONT && (q)->p_session == (p)->p_session))) 90 91 /* 92 * Policy -- Can real uid ruid with ucred uc send a signal to process q? 93 */ 94 #define CANSIGIO(ruid, uc, q) \ 95 ((uc)->cr_uid == 0 || \ 96 (ruid) == (q)->p_cred->p_ruid || \ 97 (uc)->cr_uid == (q)->p_cred->p_ruid || \ 98 (ruid) == (q)->p_ucred->cr_uid || \ 99 (uc)->cr_uid == (q)->p_ucred->cr_uid) 100 101 int sugid_coredump; 102 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 103 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 104 105 #ifndef _SYS_SYSPROTO_H_ 106 struct sigaction_args { 107 int signum; 108 struct sigaction *nsa; 109 struct sigaction *osa; 110 }; 111 #endif 112 /* ARGSUSED */ 113 int 114 sigaction(p, uap) 115 struct proc *p; 116 register struct sigaction_args *uap; 117 { 118 struct sigaction vec; 119 register struct sigaction *sa; 120 register struct sigacts *ps = p->p_sigacts; 121 register int signum; 122 int bit, error; 123 124 signum = uap->signum; 125 if (signum <= 0 || signum >= NSIG) 126 return (EINVAL); 127 sa = &vec; 128 if (uap->osa) { 129 bit = sigmask(signum); 130 if ((ps->ps_siginfo & bit) != 0) 131 sa->sa_sigaction = 132 (__siginfohandler_t *)ps->ps_sigact[signum]; 133 else 134 sa->sa_handler = ps->ps_sigact[signum]; 135 sa->sa_mask = ps->ps_catchmask[signum]; 136 sa->sa_flags = 0; 137 if ((ps->ps_sigonstack & bit) != 0) 138 sa->sa_flags |= SA_ONSTACK; 139 if ((ps->ps_sigintr & bit) == 0) 140 sa->sa_flags |= SA_RESTART; 141 if ((ps->ps_sigreset & bit) != 0) 142 sa->sa_flags |= SA_RESETHAND; 143 if ((ps->ps_signodefer & bit) != 0) 144 sa->sa_flags |= SA_NODEFER; 145 if ((ps->ps_siginfo & bit) != 0) 146 sa->sa_flags |= SA_SIGINFO; 147 if (signum == SIGCHLD && p->p_procsig->ps_flag & P_NOCLDSTOP) 148 sa->sa_flags |= SA_NOCLDSTOP; 149 if (signum == SIGCHLD && p->p_procsig->ps_flag & P_NOCLDWAIT) 150 sa->sa_flags |= SA_NOCLDWAIT; 151 if ((error = copyout((caddr_t)sa, (caddr_t)uap->osa, 152 sizeof (vec)))) 153 return (error); 154 } 155 if (uap->nsa) { 156 if ((error = copyin((caddr_t)uap->nsa, (caddr_t)sa, 157 sizeof (vec)))) 158 return (error); 159 if ((signum == SIGKILL || signum == SIGSTOP) && 160 sa->sa_handler != SIG_DFL) 161 return (EINVAL); 162 setsigvec(p, signum, sa); 163 } 164 return (0); 165 } 166 167 static void 168 setsigvec(p, signum, sa) 169 register struct proc *p; 170 int signum; 171 register struct sigaction *sa; 172 { 173 register struct sigacts *ps = p->p_sigacts; 174 register int bit; 175 176 bit = sigmask(signum); 177 /* 178 * Change setting atomically. 179 */ 180 (void) splhigh(); 181 ps->ps_catchmask[signum] = sa->sa_mask &~ sigcantmask; 182 if (sa->sa_flags & SA_SIGINFO) { 183 ps->ps_sigact[signum] = sa->sa_handler; 184 ps->ps_siginfo |= bit; 185 } else { 186 ps->ps_sigact[signum] = (__sighandler_t *)sa->sa_sigaction; 187 ps->ps_siginfo &= ~bit; 188 } 189 if ((sa->sa_flags & SA_RESTART) == 0) 190 ps->ps_sigintr |= bit; 191 else 192 ps->ps_sigintr &= ~bit; 193 if (sa->sa_flags & SA_ONSTACK) 194 ps->ps_sigonstack |= bit; 195 else 196 ps->ps_sigonstack &= ~bit; 197 if (sa->sa_flags & SA_RESETHAND) 198 ps->ps_sigreset |= bit; 199 else 200 ps->ps_sigreset &= ~bit; 201 if (sa->sa_flags & SA_NODEFER) 202 ps->ps_signodefer |= bit; 203 else 204 ps->ps_signodefer &= ~bit; 205 #ifdef COMPAT_SUNOS 206 if (sa->sa_flags & SA_USERTRAMP) 207 ps->ps_usertramp |= bit; 208 else 209 ps->ps_usertramp &= ~bit; 210 #endif 211 if (signum == SIGCHLD) { 212 if (sa->sa_flags & SA_NOCLDSTOP) 213 p->p_procsig->ps_flag |= P_NOCLDSTOP; 214 else 215 p->p_procsig->ps_flag &= ~P_NOCLDSTOP; 216 if (sa->sa_flags & SA_NOCLDWAIT) { 217 /* 218 * Paranoia: since SA_NOCLDWAIT is implemented by 219 * reparenting the dying child to PID 1 (and 220 * trust it to reap the zombie), PID 1 itself is 221 * forbidden to set SA_NOCLDWAIT. 222 */ 223 if (p->p_pid == 1) 224 p->p_procsig->ps_flag &= ~P_NOCLDWAIT; 225 else 226 p->p_procsig->ps_flag |= P_NOCLDWAIT; 227 } else 228 p->p_procsig->ps_flag &= ~P_NOCLDWAIT; 229 } 230 /* 231 * Set bit in p_sigignore for signals that are set to SIG_IGN, 232 * and for signals set to SIG_DFL where the default is to ignore. 233 * However, don't put SIGCONT in p_sigignore, 234 * as we have to restart the process. 235 */ 236 if (ps->ps_sigact[signum] == SIG_IGN || 237 (sigprop[signum] & SA_IGNORE && ps->ps_sigact[signum] == SIG_DFL)) { 238 p->p_siglist &= ~bit; /* never to be seen again */ 239 if (signum != SIGCONT) 240 p->p_sigignore |= bit; /* easier in psignal */ 241 p->p_sigcatch &= ~bit; 242 } else { 243 p->p_sigignore &= ~bit; 244 if (ps->ps_sigact[signum] == SIG_DFL) 245 p->p_sigcatch &= ~bit; 246 else 247 p->p_sigcatch |= bit; 248 } 249 (void) spl0(); 250 } 251 252 /* 253 * Initialize signal state for process 0; 254 * set to ignore signals that are ignored by default. 255 */ 256 void 257 siginit(p) 258 struct proc *p; 259 { 260 register int i; 261 262 for (i = 0; i < NSIG; i++) 263 if (sigprop[i] & SA_IGNORE && i != SIGCONT) 264 p->p_sigignore |= sigmask(i); 265 } 266 267 /* 268 * Reset signals for an exec of the specified process. 269 */ 270 void 271 execsigs(p) 272 register struct proc *p; 273 { 274 register struct sigacts *ps = p->p_sigacts; 275 register int nc, mask; 276 277 /* 278 * Reset caught signals. Held signals remain held 279 * through p_sigmask (unless they were caught, 280 * and are now ignored by default). 281 */ 282 while (p->p_sigcatch) { 283 nc = ffs((long)p->p_sigcatch); 284 mask = sigmask(nc); 285 p->p_sigcatch &= ~mask; 286 if (sigprop[nc] & SA_IGNORE) { 287 if (nc != SIGCONT) 288 p->p_sigignore |= mask; 289 p->p_siglist &= ~mask; 290 } 291 ps->ps_sigact[nc] = SIG_DFL; 292 } 293 /* 294 * Reset stack state to the user stack. 295 * Clear set of signals caught on the signal stack. 296 */ 297 ps->ps_sigstk.ss_flags = SS_DISABLE; 298 ps->ps_sigstk.ss_size = 0; 299 ps->ps_sigstk.ss_sp = 0; 300 ps->ps_flags = 0; 301 /* 302 * Reset no zombies if child dies flag as Solaris does. 303 */ 304 p->p_procsig->ps_flag &= ~P_NOCLDWAIT; 305 } 306 307 /* 308 * Manipulate signal mask. 309 * Note that we receive new mask, not pointer, 310 * and return old mask as return value; 311 * the library stub does the rest. 312 */ 313 #ifndef _SYS_SYSPROTO_H_ 314 struct sigprocmask_args { 315 int how; 316 sigset_t mask; 317 }; 318 #endif 319 int 320 sigprocmask(p, uap) 321 register struct proc *p; 322 struct sigprocmask_args *uap; 323 { 324 int error = 0; 325 326 p->p_retval[0] = p->p_sigmask; 327 (void) splhigh(); 328 329 switch (uap->how) { 330 case SIG_BLOCK: 331 p->p_sigmask |= uap->mask &~ sigcantmask; 332 break; 333 334 case SIG_UNBLOCK: 335 p->p_sigmask &= ~uap->mask; 336 break; 337 338 case SIG_SETMASK: 339 p->p_sigmask = uap->mask &~ sigcantmask; 340 break; 341 342 default: 343 error = EINVAL; 344 break; 345 } 346 (void) spl0(); 347 return (error); 348 } 349 350 #ifndef _SYS_SYSPROTO_H_ 351 struct sigpending_args { 352 int dummy; 353 }; 354 #endif 355 /* ARGSUSED */ 356 int 357 sigpending(p, uap) 358 struct proc *p; 359 struct sigpending_args *uap; 360 { 361 362 p->p_retval[0] = p->p_siglist; 363 return (0); 364 } 365 366 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 367 /* 368 * Generalized interface signal handler, 4.3-compatible. 369 */ 370 #ifndef _SYS_SYSPROTO_H_ 371 struct osigvec_args { 372 int signum; 373 struct sigvec *nsv; 374 struct sigvec *osv; 375 }; 376 #endif 377 /* ARGSUSED */ 378 int 379 osigvec(p, uap) 380 struct proc *p; 381 register struct osigvec_args *uap; 382 { 383 struct sigvec vec; 384 register struct sigacts *ps = p->p_sigacts; 385 register struct sigvec *sv; 386 register int signum; 387 int bit, error; 388 389 signum = uap->signum; 390 if (signum <= 0 || signum >= NSIG) 391 return (EINVAL); 392 sv = &vec; 393 if (uap->osv) { 394 *(sig_t *)&sv->sv_handler = ps->ps_sigact[signum]; 395 sv->sv_mask = ps->ps_catchmask[signum]; 396 bit = sigmask(signum); 397 sv->sv_flags = 0; 398 if ((ps->ps_sigonstack & bit) != 0) 399 sv->sv_flags |= SV_ONSTACK; 400 if ((ps->ps_sigintr & bit) != 0) 401 sv->sv_flags |= SV_INTERRUPT; 402 if ((ps->ps_sigreset & bit) != 0) 403 sv->sv_flags |= SV_RESETHAND; 404 if ((ps->ps_signodefer & bit) != 0) 405 sv->sv_flags |= SV_NODEFER; 406 if ((ps->ps_siginfo & bit) != 0) 407 sv->sv_flags |= SV_SIGINFO; 408 #ifndef COMPAT_SUNOS 409 if (signum == SIGCHLD && p->p_procsig->ps_flag & P_NOCLDSTOP) 410 sv->sv_flags |= SV_NOCLDSTOP; 411 #endif 412 if ((error = copyout((caddr_t)sv, (caddr_t)uap->osv, 413 sizeof (vec)))) 414 return (error); 415 } 416 if (uap->nsv) { 417 if ((error = copyin((caddr_t)uap->nsv, (caddr_t)sv, 418 sizeof (vec)))) 419 return (error); 420 if ((signum == SIGKILL || signum == SIGSTOP) && 421 sv->sv_handler != SIG_DFL) 422 return (EINVAL); 423 #ifdef COMPAT_SUNOS 424 sv->sv_flags |= SA_USERTRAMP; 425 #endif 426 sv->sv_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 427 setsigvec(p, signum, (struct sigaction *)sv); 428 } 429 return (0); 430 } 431 432 #ifndef _SYS_SYSPROTO_H_ 433 struct osigblock_args { 434 int mask; 435 }; 436 #endif 437 int 438 osigblock(p, uap) 439 register struct proc *p; 440 struct osigblock_args *uap; 441 { 442 443 (void) splhigh(); 444 p->p_retval[0] = p->p_sigmask; 445 p->p_sigmask |= uap->mask &~ sigcantmask; 446 (void) spl0(); 447 return (0); 448 } 449 450 #ifndef _SYS_SYSPROTO_H_ 451 struct osigsetmask_args { 452 int mask; 453 }; 454 #endif 455 int 456 osigsetmask(p, uap) 457 struct proc *p; 458 struct osigsetmask_args *uap; 459 { 460 461 (void) splhigh(); 462 p->p_retval[0] = p->p_sigmask; 463 p->p_sigmask = uap->mask &~ sigcantmask; 464 (void) spl0(); 465 return (0); 466 } 467 #endif /* COMPAT_43 || COMPAT_SUNOS */ 468 469 /* 470 * Suspend process until signal, providing mask to be set 471 * in the meantime. Note nonstandard calling convention: 472 * libc stub passes mask, not pointer, to save a copyin. 473 */ 474 #ifndef _SYS_SYSPROTO_H_ 475 struct sigsuspend_args { 476 sigset_t mask; 477 }; 478 #endif 479 /* ARGSUSED */ 480 int 481 sigsuspend(p, uap) 482 register struct proc *p; 483 struct sigsuspend_args *uap; 484 { 485 register struct sigacts *ps = p->p_sigacts; 486 487 /* 488 * When returning from sigpause, we want 489 * the old mask to be restored after the 490 * signal handler has finished. Thus, we 491 * save it here and mark the sigacts structure 492 * to indicate this. 493 */ 494 p->p_oldsigmask = p->p_sigmask; 495 p->p_sigmask = uap->mask &~ sigcantmask; 496 while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0) 497 /* void */; 498 /* always return EINTR rather than ERESTART... */ 499 return (EINTR); 500 } 501 502 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 503 #ifndef _SYS_SYSPROTO_H_ 504 struct osigstack_args { 505 struct sigstack *nss; 506 struct sigstack *oss; 507 }; 508 #endif 509 /* ARGSUSED */ 510 int 511 osigstack(p, uap) 512 struct proc *p; 513 register struct osigstack_args *uap; 514 { 515 struct sigstack ss; 516 struct sigacts *psp; 517 int error = 0; 518 519 psp = p->p_sigacts; 520 ss.ss_sp = psp->ps_sigstk.ss_sp; 521 ss.ss_onstack = psp->ps_sigstk.ss_flags & SS_ONSTACK; 522 if (uap->oss && (error = copyout((caddr_t)&ss, (caddr_t)uap->oss, 523 sizeof (struct sigstack)))) 524 return (error); 525 if (uap->nss && (error = copyin((caddr_t)uap->nss, (caddr_t)&ss, 526 sizeof (ss))) == 0) { 527 psp->ps_sigstk.ss_sp = ss.ss_sp; 528 psp->ps_sigstk.ss_size = 0; 529 psp->ps_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; 530 psp->ps_flags |= SAS_ALTSTACK; 531 } 532 return (error); 533 } 534 #endif /* COMPAT_43 || COMPAT_SUNOS */ 535 536 #ifndef _SYS_SYSPROTO_H_ 537 struct sigaltstack_args { 538 struct sigaltstack *nss; 539 struct sigaltstack *oss; 540 }; 541 #endif 542 /* ARGSUSED */ 543 int 544 sigaltstack(p, uap) 545 struct proc *p; 546 register struct sigaltstack_args *uap; 547 { 548 struct sigacts *psp; 549 struct sigaltstack ss; 550 int error; 551 552 psp = p->p_sigacts; 553 if ((psp->ps_flags & SAS_ALTSTACK) == 0) 554 psp->ps_sigstk.ss_flags |= SS_DISABLE; 555 if (uap->oss && (error = copyout((caddr_t)&psp->ps_sigstk, 556 (caddr_t)uap->oss, sizeof (struct sigaltstack)))) 557 return (error); 558 if (uap->nss == 0) 559 return (0); 560 if ((error = copyin((caddr_t)uap->nss, (caddr_t)&ss, sizeof (ss)))) 561 return (error); 562 if (ss.ss_flags & SS_DISABLE) { 563 if (psp->ps_sigstk.ss_flags & SS_ONSTACK) 564 return (EINVAL); 565 psp->ps_flags &= ~SAS_ALTSTACK; 566 psp->ps_sigstk.ss_flags = ss.ss_flags; 567 return (0); 568 } 569 if (ss.ss_size < MINSIGSTKSZ) 570 return (ENOMEM); 571 psp->ps_flags |= SAS_ALTSTACK; 572 psp->ps_sigstk= ss; 573 return (0); 574 } 575 576 /* 577 * Common code for kill process group/broadcast kill. 578 * cp is calling process. 579 */ 580 int 581 killpg1(cp, signum, pgid, all) 582 register struct proc *cp; 583 int signum, pgid, all; 584 { 585 register struct proc *p; 586 register struct pcred *pc = cp->p_cred; 587 struct pgrp *pgrp; 588 int nfound = 0; 589 590 if (all) 591 /* 592 * broadcast 593 */ 594 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 595 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 596 p == cp || !CANSIGNAL(cp, pc, p, signum)) 597 continue; 598 nfound++; 599 if (signum) 600 psignal(p, signum); 601 } 602 else { 603 if (pgid == 0) 604 /* 605 * zero pgid means send to my process group. 606 */ 607 pgrp = cp->p_pgrp; 608 else { 609 pgrp = pgfind(pgid); 610 if (pgrp == NULL) 611 return (ESRCH); 612 } 613 for (p = pgrp->pg_members.lh_first; p != 0; 614 p = p->p_pglist.le_next) { 615 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 616 p->p_stat == SZOMB || 617 !CANSIGNAL(cp, pc, p, signum)) 618 continue; 619 nfound++; 620 if (signum) 621 psignal(p, signum); 622 } 623 } 624 return (nfound ? 0 : ESRCH); 625 } 626 627 #ifndef _SYS_SYSPROTO_H_ 628 struct kill_args { 629 int pid; 630 int signum; 631 }; 632 #endif 633 /* ARGSUSED */ 634 int 635 kill(cp, uap) 636 register struct proc *cp; 637 register struct kill_args *uap; 638 { 639 register struct proc *p; 640 register struct pcred *pc = cp->p_cred; 641 642 if ((u_int)uap->signum >= NSIG) 643 return (EINVAL); 644 if (uap->pid > 0) { 645 /* kill single process */ 646 if ((p = pfind(uap->pid)) == NULL) 647 return (ESRCH); 648 if (!CANSIGNAL(cp, pc, p, uap->signum)) 649 return (EPERM); 650 if (uap->signum) 651 psignal(p, uap->signum); 652 return (0); 653 } 654 switch (uap->pid) { 655 case -1: /* broadcast signal */ 656 return (killpg1(cp, uap->signum, 0, 1)); 657 case 0: /* signal own process group */ 658 return (killpg1(cp, uap->signum, 0, 0)); 659 default: /* negative explicit process group */ 660 return (killpg1(cp, uap->signum, -uap->pid, 0)); 661 } 662 /* NOTREACHED */ 663 } 664 665 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 666 #ifndef _SYS_SYSPROTO_H_ 667 struct okillpg_args { 668 int pgid; 669 int signum; 670 }; 671 #endif 672 /* ARGSUSED */ 673 int 674 okillpg(p, uap) 675 struct proc *p; 676 register struct okillpg_args *uap; 677 { 678 679 if ((u_int)uap->signum >= NSIG) 680 return (EINVAL); 681 return (killpg1(p, uap->signum, uap->pgid, 0)); 682 } 683 #endif /* COMPAT_43 || COMPAT_SUNOS */ 684 685 /* 686 * Send a signal to a process group. 687 */ 688 void 689 gsignal(pgid, signum) 690 int pgid, signum; 691 { 692 struct pgrp *pgrp; 693 694 if (pgid && (pgrp = pgfind(pgid))) 695 pgsignal(pgrp, signum, 0); 696 } 697 698 /* 699 * Send a signal to a process group. If checktty is 1, 700 * limit to members which have a controlling terminal. 701 */ 702 void 703 pgsignal(pgrp, signum, checkctty) 704 struct pgrp *pgrp; 705 int signum, checkctty; 706 { 707 register struct proc *p; 708 709 if (pgrp) 710 for (p = pgrp->pg_members.lh_first; p != 0; 711 p = p->p_pglist.le_next) 712 if (checkctty == 0 || p->p_flag & P_CONTROLT) 713 psignal(p, signum); 714 } 715 716 /* 717 * Send a signal caused by a trap to the current process. 718 * If it will be caught immediately, deliver it with correct code. 719 * Otherwise, post it normally. 720 */ 721 void 722 trapsignal(p, signum, code) 723 struct proc *p; 724 register int signum; 725 u_long code; 726 { 727 register struct sigacts *ps = p->p_sigacts; 728 int mask; 729 730 mask = sigmask(signum); 731 if ((p->p_flag & P_TRACED) == 0 && (p->p_sigcatch & mask) != 0 && 732 (p->p_sigmask & mask) == 0) { 733 p->p_stats->p_ru.ru_nsignals++; 734 #ifdef KTRACE 735 if (KTRPOINT(p, KTR_PSIG)) 736 ktrpsig(p->p_tracep, signum, ps->ps_sigact[signum], 737 p->p_sigmask, code); 738 #endif 739 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[signum], signum, 740 p->p_sigmask, code); 741 p->p_sigmask |= ps->ps_catchmask[signum] | 742 (mask & ~ps->ps_signodefer); 743 if ((ps->ps_sigreset & mask) != 0) { 744 /* 745 * See setsigvec() for origin of this code. 746 */ 747 p->p_sigcatch &= ~mask; 748 if (signum != SIGCONT && sigprop[signum] & SA_IGNORE) 749 p->p_sigignore |= mask; 750 ps->ps_sigact[signum] = SIG_DFL; 751 } 752 } else { 753 p->p_code = code; /* XXX for core dump/debugger */ 754 p->p_sig = signum; /* XXX to verify code */ 755 psignal(p, signum); 756 } 757 } 758 759 /* 760 * Send the signal to the process. If the signal has an action, the action 761 * is usually performed by the target process rather than the caller; we add 762 * the signal to the set of pending signals for the process. 763 * 764 * Exceptions: 765 * o When a stop signal is sent to a sleeping process that takes the 766 * default action, the process is stopped without awakening it. 767 * o SIGCONT restarts stopped processes (or puts them back to sleep) 768 * regardless of the signal action (eg, blocked or ignored). 769 * 770 * Other ignored signals are discarded immediately. 771 */ 772 void 773 psignal(p, signum) 774 register struct proc *p; 775 register int signum; 776 { 777 register int s, prop; 778 register sig_t action; 779 int mask; 780 781 if ((u_int)signum >= NSIG || signum == 0) { 782 printf("psignal: signum %d\n", signum); 783 panic("psignal signal number"); 784 } 785 mask = sigmask(signum); 786 prop = sigprop[signum]; 787 788 /* 789 * If proc is traced, always give parent a chance; 790 * if signal event is tracked by procfs, give *that* 791 * a chance, as well. 792 */ 793 if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) 794 action = SIG_DFL; 795 else { 796 /* 797 * If the signal is being ignored, 798 * then we forget about it immediately. 799 * (Note: we don't set SIGCONT in p_sigignore, 800 * and if it is set to SIG_IGN, 801 * action will be SIG_DFL here.) 802 */ 803 if ((p->p_sigignore & mask) || (p->p_flag & P_WEXIT)) 804 return; 805 if (p->p_sigmask & mask) 806 action = SIG_HOLD; 807 else if (p->p_sigcatch & mask) 808 action = SIG_CATCH; 809 else 810 action = SIG_DFL; 811 } 812 813 if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) && 814 (p->p_flag & P_TRACED) == 0) 815 p->p_nice = NZERO; 816 817 if (prop & SA_CONT) 818 p->p_siglist &= ~stopsigmask; 819 820 if (prop & SA_STOP) { 821 /* 822 * If sending a tty stop signal to a member of an orphaned 823 * process group, discard the signal here if the action 824 * is default; don't stop the process below if sleeping, 825 * and don't clear any pending SIGCONT. 826 */ 827 if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0 && 828 action == SIG_DFL) 829 return; 830 p->p_siglist &= ~contsigmask; 831 } 832 p->p_siglist |= mask; 833 834 /* 835 * Defer further processing for signals which are held, 836 * except that stopped processes must be continued by SIGCONT. 837 */ 838 if (action == SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP)) 839 return; 840 s = splhigh(); 841 switch (p->p_stat) { 842 843 case SSLEEP: 844 /* 845 * If process is sleeping uninterruptibly 846 * we can't interrupt the sleep... the signal will 847 * be noticed when the process returns through 848 * trap() or syscall(). 849 */ 850 if ((p->p_flag & P_SINTR) == 0) 851 goto out; 852 /* 853 * Process is sleeping and traced... make it runnable 854 * so it can discover the signal in issignal() and stop 855 * for the parent. 856 */ 857 if (p->p_flag & P_TRACED) 858 goto run; 859 /* 860 * If SIGCONT is default (or ignored) and process is 861 * asleep, we are finished; the process should not 862 * be awakened. 863 */ 864 if ((prop & SA_CONT) && action == SIG_DFL) { 865 p->p_siglist &= ~mask; 866 goto out; 867 } 868 /* 869 * When a sleeping process receives a stop 870 * signal, process immediately if possible. 871 * All other (caught or default) signals 872 * cause the process to run. 873 */ 874 if (prop & SA_STOP) { 875 if (action != SIG_DFL) 876 goto runfast; 877 /* 878 * If a child holding parent blocked, 879 * stopping could cause deadlock. 880 */ 881 if (p->p_flag & P_PPWAIT) 882 goto out; 883 p->p_siglist &= ~mask; 884 p->p_xstat = signum; 885 if ((p->p_pptr->p_procsig->ps_flag & P_NOCLDSTOP) == 0) 886 psignal(p->p_pptr, SIGCHLD); 887 stop(p); 888 goto out; 889 } else 890 goto runfast; 891 /*NOTREACHED*/ 892 893 case SSTOP: 894 /* 895 * If traced process is already stopped, 896 * then no further action is necessary. 897 */ 898 if (p->p_flag & P_TRACED) 899 goto out; 900 901 /* 902 * Kill signal always sets processes running. 903 */ 904 if (signum == SIGKILL) 905 goto runfast; 906 907 if (prop & SA_CONT) { 908 /* 909 * If SIGCONT is default (or ignored), we continue the 910 * process but don't leave the signal in p_siglist, as 911 * it has no further action. If SIGCONT is held, we 912 * continue the process and leave the signal in 913 * p_siglist. If the process catches SIGCONT, let it 914 * handle the signal itself. If it isn't waiting on 915 * an event, then it goes back to run state. 916 * Otherwise, process goes back to sleep state. 917 */ 918 if (action == SIG_DFL) 919 p->p_siglist &= ~mask; 920 if (action == SIG_CATCH) 921 goto runfast; 922 if (p->p_wchan == 0) 923 goto run; 924 p->p_stat = SSLEEP; 925 goto out; 926 } 927 928 if (prop & SA_STOP) { 929 /* 930 * Already stopped, don't need to stop again. 931 * (If we did the shell could get confused.) 932 */ 933 p->p_siglist &= ~mask; /* take it away */ 934 goto out; 935 } 936 937 /* 938 * If process is sleeping interruptibly, then simulate a 939 * wakeup so that when it is continued, it will be made 940 * runnable and can look at the signal. But don't make 941 * the process runnable, leave it stopped. 942 */ 943 if (p->p_wchan && p->p_flag & P_SINTR) 944 unsleep(p); 945 goto out; 946 947 default: 948 /* 949 * SRUN, SIDL, SZOMB do nothing with the signal, 950 * other than kicking ourselves if we are running. 951 * It will either never be noticed, or noticed very soon. 952 */ 953 if (p == curproc) 954 signotify(p); 955 #ifdef SMP 956 else if (p->p_stat == SRUN) 957 forward_signal(p); 958 #endif 959 goto out; 960 } 961 /*NOTREACHED*/ 962 963 runfast: 964 /* 965 * Raise priority to at least PUSER. 966 */ 967 if (p->p_priority > PUSER) 968 p->p_priority = PUSER; 969 run: 970 setrunnable(p); 971 out: 972 splx(s); 973 } 974 975 /* 976 * If the current process has received a signal (should be caught or cause 977 * termination, should interrupt current syscall), return the signal number. 978 * Stop signals with default action are processed immediately, then cleared; 979 * they aren't returned. This is checked after each entry to the system for 980 * a syscall or trap (though this can usually be done without calling issignal 981 * by checking the pending signal masks in the CURSIG macro.) The normal call 982 * sequence is 983 * 984 * while (signum = CURSIG(curproc)) 985 * postsig(signum); 986 */ 987 int 988 issignal(p) 989 register struct proc *p; 990 { 991 register int signum, mask, prop; 992 993 for (;;) { 994 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 995 996 mask = p->p_siglist & ~p->p_sigmask; 997 if (p->p_flag & P_PPWAIT) 998 mask &= ~stopsigmask; 999 if (mask == 0) /* no signal to send */ 1000 return (0); 1001 signum = ffs((long)mask); 1002 mask = sigmask(signum); 1003 prop = sigprop[signum]; 1004 1005 STOPEVENT(p, S_SIG, signum); 1006 1007 /* 1008 * We should see pending but ignored signals 1009 * only if P_TRACED was on when they were posted. 1010 */ 1011 if ((mask & p->p_sigignore) && (traced == 0)) { 1012 p->p_siglist &= ~mask; 1013 continue; 1014 } 1015 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 1016 /* 1017 * If traced, always stop, and stay 1018 * stopped until released by the parent. 1019 */ 1020 p->p_xstat = signum; 1021 psignal(p->p_pptr, SIGCHLD); 1022 do { 1023 stop(p); 1024 mi_switch(); 1025 } while (!trace_req(p) 1026 && p->p_flag & P_TRACED); 1027 1028 /* 1029 * If the traced bit got turned off, go back up 1030 * to the top to rescan signals. This ensures 1031 * that p_sig* and ps_sigact are consistent. 1032 */ 1033 if ((p->p_flag & P_TRACED) == 0) 1034 continue; 1035 1036 /* 1037 * If parent wants us to take the signal, 1038 * then it will leave it in p->p_xstat; 1039 * otherwise we just look for signals again. 1040 */ 1041 p->p_siglist &= ~mask; /* clear the old signal */ 1042 signum = p->p_xstat; 1043 if (signum == 0) 1044 continue; 1045 1046 /* 1047 * Put the new signal into p_siglist. If the 1048 * signal is being masked, look for other signals. 1049 */ 1050 mask = sigmask(signum); 1051 p->p_siglist |= mask; 1052 if (p->p_sigmask & mask) 1053 continue; 1054 } 1055 1056 /* 1057 * Decide whether the signal should be returned. 1058 * Return the signal's number, or fall through 1059 * to clear it from the pending mask. 1060 */ 1061 switch ((int)(intptr_t)p->p_sigacts->ps_sigact[signum]) { 1062 1063 case (int)SIG_DFL: 1064 /* 1065 * Don't take default actions on system processes. 1066 */ 1067 if (p->p_pid <= 1) { 1068 #ifdef DIAGNOSTIC 1069 /* 1070 * Are you sure you want to ignore SIGSEGV 1071 * in init? XXX 1072 */ 1073 printf("Process (pid %lu) got signal %d\n", 1074 (u_long)p->p_pid, signum); 1075 #endif 1076 break; /* == ignore */ 1077 } 1078 /* 1079 * If there is a pending stop signal to process 1080 * with default action, stop here, 1081 * then clear the signal. However, 1082 * if process is member of an orphaned 1083 * process group, ignore tty stop signals. 1084 */ 1085 if (prop & SA_STOP) { 1086 if (p->p_flag & P_TRACED || 1087 (p->p_pgrp->pg_jobc == 0 && 1088 prop & SA_TTYSTOP)) 1089 break; /* == ignore */ 1090 p->p_xstat = signum; 1091 stop(p); 1092 if ((p->p_pptr->p_procsig->ps_flag & P_NOCLDSTOP) == 0) 1093 psignal(p->p_pptr, SIGCHLD); 1094 mi_switch(); 1095 break; 1096 } else if (prop & SA_IGNORE) { 1097 /* 1098 * Except for SIGCONT, shouldn't get here. 1099 * Default action is to ignore; drop it. 1100 */ 1101 break; /* == ignore */ 1102 } else 1103 return (signum); 1104 /*NOTREACHED*/ 1105 1106 case (int)SIG_IGN: 1107 /* 1108 * Masking above should prevent us ever trying 1109 * to take action on an ignored signal other 1110 * than SIGCONT, unless process is traced. 1111 */ 1112 if ((prop & SA_CONT) == 0 && 1113 (p->p_flag & P_TRACED) == 0) 1114 printf("issignal\n"); 1115 break; /* == ignore */ 1116 1117 default: 1118 /* 1119 * This signal has an action, let 1120 * postsig() process it. 1121 */ 1122 return (signum); 1123 } 1124 p->p_siglist &= ~mask; /* take the signal! */ 1125 } 1126 /* NOTREACHED */ 1127 } 1128 1129 /* 1130 * Put the argument process into the stopped state and notify the parent 1131 * via wakeup. Signals are handled elsewhere. The process must not be 1132 * on the run queue. 1133 */ 1134 void 1135 stop(p) 1136 register struct proc *p; 1137 { 1138 1139 p->p_stat = SSTOP; 1140 p->p_flag &= ~P_WAITED; 1141 wakeup((caddr_t)p->p_pptr); 1142 } 1143 1144 /* 1145 * Take the action for the specified signal 1146 * from the current set of pending signals. 1147 */ 1148 void 1149 postsig(signum) 1150 register int signum; 1151 { 1152 register struct proc *p = curproc; 1153 register struct sigacts *ps = p->p_sigacts; 1154 register sig_t action; 1155 int code, mask, returnmask; 1156 1157 KASSERT(signum != 0, ("postsig")); 1158 1159 mask = sigmask(signum); 1160 p->p_siglist &= ~mask; 1161 action = ps->ps_sigact[signum]; 1162 #ifdef KTRACE 1163 if (KTRPOINT(p, KTR_PSIG)) 1164 ktrpsig(p->p_tracep, 1165 signum, action, p->p_oldsigmask ? 1166 p->p_oldsigmask : p->p_sigmask, 0); 1167 #endif 1168 STOPEVENT(p, S_SIG, signum); 1169 1170 if (action == SIG_DFL) { 1171 /* 1172 * Default action, where the default is to kill 1173 * the process. (Other cases were ignored above.) 1174 */ 1175 sigexit(p, signum); 1176 /* NOTREACHED */ 1177 } else { 1178 /* 1179 * If we get here, the signal must be caught. 1180 */ 1181 KASSERT(action != SIG_IGN && (p->p_sigmask & mask) == 0, 1182 ("postsig action")); 1183 /* 1184 * Set the new mask value and also defer further 1185 * occurences of this signal. 1186 * 1187 * Special case: user has done a sigpause. Here the 1188 * current mask is not of interest, but rather the 1189 * mask from before the sigpause is what we want 1190 * restored after the signal processing is completed. 1191 */ 1192 (void) splhigh(); 1193 if (p->p_oldsigmask) { 1194 returnmask = p->p_oldsigmask; 1195 p->p_oldsigmask = 0; 1196 } else 1197 returnmask = p->p_sigmask; 1198 p->p_sigmask |= ps->ps_catchmask[signum] | 1199 (mask & ~ps->ps_signodefer); 1200 if ((ps->ps_sigreset & mask) != 0) { 1201 /* 1202 * See setsigvec() for origin of this code. 1203 */ 1204 p->p_sigcatch &= ~mask; 1205 if (signum != SIGCONT && sigprop[signum] & SA_IGNORE) 1206 p->p_sigignore |= mask; 1207 ps->ps_sigact[signum] = SIG_DFL; 1208 } 1209 (void) spl0(); 1210 p->p_stats->p_ru.ru_nsignals++; 1211 if (p->p_sig != signum) { 1212 code = 0; 1213 } else { 1214 code = p->p_code; 1215 p->p_code = 0; 1216 p->p_sig = 0; 1217 } 1218 (*p->p_sysent->sv_sendsig)(action, signum, returnmask, code); 1219 } 1220 } 1221 1222 /* 1223 * Kill the current process for stated reason. 1224 */ 1225 void 1226 killproc(p, why) 1227 struct proc *p; 1228 char *why; 1229 { 1230 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 1231 p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1, why); 1232 psignal(p, SIGKILL); 1233 } 1234 1235 /* 1236 * Force the current process to exit with the specified signal, dumping core 1237 * if appropriate. We bypass the normal tests for masked and caught signals, 1238 * allowing unrecoverable failures to terminate the process without changing 1239 * signal state. Mark the accounting record with the signal termination. 1240 * If dumping core, save the signal number for the debugger. Calls exit and 1241 * does not return. 1242 */ 1243 void 1244 sigexit(p, signum) 1245 register struct proc *p; 1246 int signum; 1247 { 1248 1249 p->p_acflag |= AXSIG; 1250 if (sigprop[signum] & SA_CORE) { 1251 p->p_sig = signum; 1252 /* 1253 * Log signals which would cause core dumps 1254 * (Log as LOG_INFO to appease those who don't want 1255 * these messages.) 1256 * XXX : Todo, as well as euid, write out ruid too 1257 */ 1258 if (p->p_sysent->sv_coredump != NULL && 1259 (*p->p_sysent->sv_coredump)(p) == 0) 1260 signum |= WCOREFLAG; 1261 if (kern_logsigexit) 1262 log(LOG_INFO, 1263 "pid %d (%s), uid %d: exited on signal %d%s\n", 1264 p->p_pid, p->p_comm, 1265 p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1, 1266 signum &~ WCOREFLAG, 1267 signum & WCOREFLAG ? " (core dumped)" : ""); 1268 } 1269 exit1(p, W_EXITCODE(0, signum)); 1270 /* NOTREACHED */ 1271 } 1272 1273 static char corefilename[MAXPATHLEN+1] = {"%N.core"}; 1274 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 1275 sizeof(corefilename), "process corefile name format string"); 1276 1277 /* 1278 * expand_name(name, uid, pid) 1279 * Expand the name described in corefilename, using name, uid, and pid. 1280 * corefilename is a printf-like string, with three format specifiers: 1281 * %N name of process ("name") 1282 * %P process id (pid) 1283 * %U user id (uid) 1284 * For example, "%N.core" is the default; they can be disabled completely 1285 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 1286 * This is controlled by the sysctl variable kern.corefile (see above). 1287 */ 1288 1289 char * 1290 expand_name(name, uid, pid) 1291 const char *name; uid_t uid; pid_t pid; { 1292 char *temp; 1293 char buf[11]; /* Buffer for pid/uid -- max 4B */ 1294 int i, n; 1295 char *format = corefilename; 1296 size_t namelen; 1297 1298 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 1299 if (temp == NULL) 1300 return NULL; 1301 namelen = strlen(name); 1302 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 1303 int l; 1304 switch (format[i]) { 1305 case '%': /* Format character */ 1306 i++; 1307 switch (format[i]) { 1308 case '%': 1309 temp[n++] = '%'; 1310 break; 1311 case 'N': /* process name */ 1312 if ((n + namelen) > MAXPATHLEN) { 1313 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1314 pid, name, uid, temp, name); 1315 free(temp, M_TEMP); 1316 return NULL; 1317 } 1318 memcpy(temp+n, name, namelen); 1319 n += namelen; 1320 break; 1321 case 'P': /* process id */ 1322 l = sprintf(buf, "%u", pid); 1323 if ((n + l) > MAXPATHLEN) { 1324 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1325 pid, name, uid, temp, name); 1326 free(temp, M_TEMP); 1327 return NULL; 1328 } 1329 memcpy(temp+n, buf, l); 1330 n += l; 1331 break; 1332 case 'U': /* user id */ 1333 l = sprintf(buf, "%u", uid); 1334 if ((n + l) > MAXPATHLEN) { 1335 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 1336 pid, name, uid, temp, name); 1337 free(temp, M_TEMP); 1338 return NULL; 1339 } 1340 memcpy(temp+n, buf, l); 1341 n += l; 1342 break; 1343 default: 1344 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 1345 } 1346 break; 1347 default: 1348 temp[n++] = format[i]; 1349 } 1350 } 1351 temp[n] = '\0'; 1352 return temp; 1353 } 1354 1355 /* 1356 * Nonexistent system call-- signal process (may want to handle it). 1357 * Flag error in case process won't see signal immediately (blocked or ignored). 1358 */ 1359 #ifndef _SYS_SYSPROTO_H_ 1360 struct nosys_args { 1361 int dummy; 1362 }; 1363 #endif 1364 /* ARGSUSED */ 1365 int 1366 nosys(p, args) 1367 struct proc *p; 1368 struct nosys_args *args; 1369 { 1370 1371 psignal(p, SIGSYS); 1372 return (EINVAL); 1373 } 1374 1375 /* 1376 * Send a signal to a SIGIO or SIGURG to a process or process group using 1377 * stored credentials rather than those of the current process. 1378 */ 1379 void 1380 pgsigio(sigio, signum, checkctty) 1381 struct sigio *sigio; 1382 int signum, checkctty; 1383 { 1384 if (sigio == NULL) 1385 return; 1386 1387 if (sigio->sio_pgid > 0) { 1388 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, 1389 sigio->sio_proc)) 1390 psignal(sigio->sio_proc, signum); 1391 } else if (sigio->sio_pgid < 0) { 1392 struct proc *p; 1393 1394 for (p = sigio->sio_pgrp->pg_members.lh_first; p != NULL; 1395 p = p->p_pglist.le_next) 1396 if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) && 1397 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 1398 psignal(p, signum); 1399 } 1400 } 1401