| 1 | /* $NetBSD: sys_sig.c,v 1.46 2016/08/04 06:43:43 christos Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Andrew Doran. |
| 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 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | /* |
| 33 | * Copyright (c) 1982, 1986, 1989, 1991, 1993 |
| 34 | * The Regents of the University of California. All rights reserved. |
| 35 | * (c) UNIX System Laboratories, Inc. |
| 36 | * All or some portions of this file are derived from material licensed |
| 37 | * to the University of California by American Telephone and Telegraph |
| 38 | * Co. or Unix System Laboratories, Inc. and are reproduced herein with |
| 39 | * the permission of UNIX System Laboratories, Inc. |
| 40 | * |
| 41 | * Redistribution and use in source and binary forms, with or without |
| 42 | * modification, are permitted provided that the following conditions |
| 43 | * are met: |
| 44 | * 1. Redistributions of source code must retain the above copyright |
| 45 | * notice, this list of conditions and the following disclaimer. |
| 46 | * 2. Redistributions in binary form must reproduce the above copyright |
| 47 | * notice, this list of conditions and the following disclaimer in the |
| 48 | * documentation and/or other materials provided with the distribution. |
| 49 | * 3. Neither the name of the University nor the names of its contributors |
| 50 | * may be used to endorse or promote products derived from this software |
| 51 | * without specific prior written permission. |
| 52 | * |
| 53 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 54 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 55 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 56 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 57 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 58 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 59 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 60 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 61 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 62 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 63 | * SUCH DAMAGE. |
| 64 | * |
| 65 | * @(#)kern_sig.c 8.14 (Berkeley) 5/14/95 |
| 66 | */ |
| 67 | |
| 68 | #include <sys/cdefs.h> |
| 69 | __KERNEL_RCSID(0, "$NetBSD: sys_sig.c,v 1.46 2016/08/04 06:43:43 christos Exp $" ); |
| 70 | |
| 71 | #include "opt_dtrace.h" |
| 72 | |
| 73 | #include <sys/param.h> |
| 74 | #include <sys/kernel.h> |
| 75 | #include <sys/signalvar.h> |
| 76 | #include <sys/proc.h> |
| 77 | #include <sys/pool.h> |
| 78 | #include <sys/syscallargs.h> |
| 79 | #include <sys/kauth.h> |
| 80 | #include <sys/wait.h> |
| 81 | #include <sys/kmem.h> |
| 82 | #include <sys/module.h> |
| 83 | #include <sys/sdt.h> |
| 84 | |
| 85 | SDT_PROVIDER_DECLARE(proc); |
| 86 | SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, |
| 87 | "int" , /* signal */ |
| 88 | "ksiginfo_t *" ); /* signal-info */ |
| 89 | |
| 90 | int |
| 91 | sys___sigaction_sigtramp(struct lwp *l, |
| 92 | const struct sys___sigaction_sigtramp_args *uap, register_t *retval) |
| 93 | { |
| 94 | /* { |
| 95 | syscallarg(int) signum; |
| 96 | syscallarg(const struct sigaction *) nsa; |
| 97 | syscallarg(struct sigaction *) osa; |
| 98 | syscallarg(void *) tramp; |
| 99 | syscallarg(int) vers; |
| 100 | } */ |
| 101 | struct sigaction nsa, osa; |
| 102 | int error; |
| 103 | |
| 104 | if (SCARG(uap, nsa)) { |
| 105 | error = copyin(SCARG(uap, nsa), &nsa, sizeof(nsa)); |
| 106 | if (error) |
| 107 | return (error); |
| 108 | } |
| 109 | error = sigaction1(l, SCARG(uap, signum), |
| 110 | SCARG(uap, nsa) ? &nsa : 0, SCARG(uap, osa) ? &osa : 0, |
| 111 | SCARG(uap, tramp), SCARG(uap, vers)); |
| 112 | if (error) |
| 113 | return (error); |
| 114 | if (SCARG(uap, osa)) { |
| 115 | error = copyout(&osa, SCARG(uap, osa), sizeof(osa)); |
| 116 | if (error) |
| 117 | return (error); |
| 118 | } |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | /* |
| 123 | * Manipulate signal mask. Note that we receive new mask, not pointer, and |
| 124 | * return old mask as return value; the library stub does the rest. |
| 125 | */ |
| 126 | int |
| 127 | sys___sigprocmask14(struct lwp *l, const struct sys___sigprocmask14_args *uap, |
| 128 | register_t *retval) |
| 129 | { |
| 130 | /* { |
| 131 | syscallarg(int) how; |
| 132 | syscallarg(const sigset_t *) set; |
| 133 | syscallarg(sigset_t *) oset; |
| 134 | } */ |
| 135 | struct proc *p = l->l_proc; |
| 136 | sigset_t nss, oss; |
| 137 | int error; |
| 138 | |
| 139 | if (SCARG(uap, set)) { |
| 140 | error = copyin(SCARG(uap, set), &nss, sizeof(nss)); |
| 141 | if (error) |
| 142 | return error; |
| 143 | } |
| 144 | mutex_enter(p->p_lock); |
| 145 | error = sigprocmask1(l, SCARG(uap, how), |
| 146 | SCARG(uap, set) ? &nss : 0, SCARG(uap, oset) ? &oss : 0); |
| 147 | mutex_exit(p->p_lock); |
| 148 | if (error) |
| 149 | return error; |
| 150 | if (SCARG(uap, oset)) { |
| 151 | error = copyout(&oss, SCARG(uap, oset), sizeof(oss)); |
| 152 | if (error) |
| 153 | return error; |
| 154 | } |
| 155 | return 0; |
| 156 | } |
| 157 | |
| 158 | int |
| 159 | sys___sigpending14(struct lwp *l, const struct sys___sigpending14_args *uap, |
| 160 | register_t *retval) |
| 161 | { |
| 162 | /* { |
| 163 | syscallarg(sigset_t *) set; |
| 164 | } */ |
| 165 | sigset_t ss; |
| 166 | |
| 167 | sigpending1(l, &ss); |
| 168 | return copyout(&ss, SCARG(uap, set), sizeof(ss)); |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * Suspend process until signal, providing mask to be set in the meantime. |
| 173 | * Note nonstandard calling convention: libc stub passes mask, not pointer, |
| 174 | * to save a copyin. |
| 175 | */ |
| 176 | int |
| 177 | sys___sigsuspend14(struct lwp *l, const struct sys___sigsuspend14_args *uap, |
| 178 | register_t *retval) |
| 179 | { |
| 180 | /* { |
| 181 | syscallarg(const sigset_t *) set; |
| 182 | } */ |
| 183 | sigset_t ss; |
| 184 | int error; |
| 185 | |
| 186 | if (SCARG(uap, set)) { |
| 187 | error = copyin(SCARG(uap, set), &ss, sizeof(ss)); |
| 188 | if (error) |
| 189 | return error; |
| 190 | } |
| 191 | return sigsuspend1(l, SCARG(uap, set) ? &ss : 0); |
| 192 | } |
| 193 | |
| 194 | int |
| 195 | sys___sigaltstack14(struct lwp *l, const struct sys___sigaltstack14_args *uap, |
| 196 | register_t *retval) |
| 197 | { |
| 198 | /* { |
| 199 | syscallarg(const struct sigaltstack *) nss; |
| 200 | syscallarg(struct sigaltstack *) oss; |
| 201 | } */ |
| 202 | struct sigaltstack nss, oss; |
| 203 | int error; |
| 204 | |
| 205 | if (SCARG(uap, nss)) { |
| 206 | error = copyin(SCARG(uap, nss), &nss, sizeof(nss)); |
| 207 | if (error) |
| 208 | return error; |
| 209 | } |
| 210 | error = sigaltstack1(l, |
| 211 | SCARG(uap, nss) ? &nss : 0, SCARG(uap, oss) ? &oss : 0); |
| 212 | if (error) |
| 213 | return error; |
| 214 | if (SCARG(uap, oss)) { |
| 215 | error = copyout(&oss, SCARG(uap, oss), sizeof(oss)); |
| 216 | if (error) |
| 217 | return error; |
| 218 | } |
| 219 | return 0; |
| 220 | } |
| 221 | |
| 222 | int |
| 223 | kill1(struct lwp *l, pid_t pid, ksiginfo_t *ksi, register_t *retval) |
| 224 | { |
| 225 | int error; |
| 226 | struct proc *p; |
| 227 | |
| 228 | if ((u_int)ksi->ksi_signo >= NSIG) |
| 229 | return EINVAL; |
| 230 | |
| 231 | if (pid != l->l_proc->p_pid) { |
| 232 | if (ksi->ksi_pid != l->l_proc->p_pid) |
| 233 | return EPERM; |
| 234 | |
| 235 | if (ksi->ksi_uid != kauth_cred_geteuid(l->l_cred)) |
| 236 | return EPERM; |
| 237 | |
| 238 | switch (ksi->ksi_code) { |
| 239 | case SI_USER: |
| 240 | case SI_QUEUE: |
| 241 | break; |
| 242 | default: |
| 243 | return EPERM; |
| 244 | } |
| 245 | } |
| 246 | |
| 247 | if (pid > 0) { |
| 248 | /* kill single process */ |
| 249 | mutex_enter(proc_lock); |
| 250 | p = proc_find_raw(pid); |
| 251 | if (p == NULL || (p->p_stat != SACTIVE && p->p_stat != SSTOP)) { |
| 252 | mutex_exit(proc_lock); |
| 253 | /* IEEE Std 1003.1-2001: return success for zombies */ |
| 254 | return p ? 0 : ESRCH; |
| 255 | } |
| 256 | mutex_enter(p->p_lock); |
| 257 | error = kauth_authorize_process(l->l_cred, |
| 258 | KAUTH_PROCESS_SIGNAL, p, KAUTH_ARG(ksi->ksi_signo), |
| 259 | NULL, NULL); |
| 260 | if (!error && ksi->ksi_signo) { |
| 261 | error = kpsignal2(p, ksi); |
| 262 | } |
| 263 | mutex_exit(p->p_lock); |
| 264 | mutex_exit(proc_lock); |
| 265 | return error; |
| 266 | } |
| 267 | |
| 268 | switch (pid) { |
| 269 | case -1: /* broadcast signal */ |
| 270 | return killpg1(l, ksi, 0, 1); |
| 271 | case 0: /* signal own process group */ |
| 272 | return killpg1(l, ksi, 0, 0); |
| 273 | default: /* negative explicit process group */ |
| 274 | return killpg1(l, ksi, -pid, 0); |
| 275 | } |
| 276 | /* NOTREACHED */ |
| 277 | } |
| 278 | |
| 279 | int |
| 280 | sys_sigqueueinfo(struct lwp *l, const struct sys_sigqueueinfo_args *uap, |
| 281 | register_t *retval) |
| 282 | { |
| 283 | /* { |
| 284 | syscallarg(pid_t int) pid; |
| 285 | syscallarg(const siginfo_t *) info; |
| 286 | } */ |
| 287 | ksiginfo_t ksi; |
| 288 | int error; |
| 289 | |
| 290 | KSI_INIT(&ksi); |
| 291 | |
| 292 | if ((error = copyin(&SCARG(uap, info)->_info, &ksi.ksi_info, |
| 293 | sizeof(ksi.ksi_info))) != 0) |
| 294 | return error; |
| 295 | |
| 296 | return kill1(l, SCARG(uap, pid), &ksi, retval); |
| 297 | } |
| 298 | |
| 299 | int |
| 300 | sys_kill(struct lwp *l, const struct sys_kill_args *uap, register_t *retval) |
| 301 | { |
| 302 | /* { |
| 303 | syscallarg(pid_t) pid; |
| 304 | syscallarg(int) signum; |
| 305 | } */ |
| 306 | ksiginfo_t ksi; |
| 307 | |
| 308 | KSI_INIT(&ksi); |
| 309 | |
| 310 | ksi.ksi_signo = SCARG(uap, signum); |
| 311 | ksi.ksi_code = SI_USER; |
| 312 | ksi.ksi_pid = l->l_proc->p_pid; |
| 313 | ksi.ksi_uid = kauth_cred_geteuid(l->l_cred); |
| 314 | |
| 315 | return kill1(l, SCARG(uap, pid), &ksi, retval); |
| 316 | } |
| 317 | |
| 318 | int |
| 319 | sys_getcontext(struct lwp *l, const struct sys_getcontext_args *uap, |
| 320 | register_t *retval) |
| 321 | { |
| 322 | /* { |
| 323 | syscallarg(struct __ucontext *) ucp; |
| 324 | } */ |
| 325 | struct proc *p = l->l_proc; |
| 326 | ucontext_t uc; |
| 327 | |
| 328 | memset(&uc, 0, sizeof(uc)); |
| 329 | |
| 330 | mutex_enter(p->p_lock); |
| 331 | getucontext(l, &uc); |
| 332 | mutex_exit(p->p_lock); |
| 333 | |
| 334 | return copyout(&uc, SCARG(uap, ucp), sizeof (*SCARG(uap, ucp))); |
| 335 | } |
| 336 | |
| 337 | int |
| 338 | sys_setcontext(struct lwp *l, const struct sys_setcontext_args *uap, |
| 339 | register_t *retval) |
| 340 | { |
| 341 | /* { |
| 342 | syscallarg(const ucontext_t *) ucp; |
| 343 | } */ |
| 344 | struct proc *p = l->l_proc; |
| 345 | ucontext_t uc; |
| 346 | int error; |
| 347 | |
| 348 | error = copyin(SCARG(uap, ucp), &uc, sizeof (uc)); |
| 349 | if (error) |
| 350 | return error; |
| 351 | if ((uc.uc_flags & _UC_CPU) == 0) |
| 352 | return EINVAL; |
| 353 | mutex_enter(p->p_lock); |
| 354 | error = setucontext(l, &uc); |
| 355 | mutex_exit(p->p_lock); |
| 356 | if (error) |
| 357 | return error; |
| 358 | |
| 359 | return EJUSTRETURN; |
| 360 | } |
| 361 | |
| 362 | /* |
| 363 | * sigtimedwait(2) system call, used also for implementation |
| 364 | * of sigwaitinfo() and sigwait(). |
| 365 | * |
| 366 | * This only handles single LWP in signal wait. libpthread provides |
| 367 | * its own sigtimedwait() wrapper to DTRT WRT individual threads. |
| 368 | */ |
| 369 | int |
| 370 | sys_____sigtimedwait50(struct lwp *l, |
| 371 | const struct sys_____sigtimedwait50_args *uap, register_t *retval) |
| 372 | { |
| 373 | |
| 374 | return sigtimedwait1(l, uap, retval, copyin, copyout, copyin, copyout); |
| 375 | } |
| 376 | |
| 377 | int |
| 378 | sigaction1(struct lwp *l, int signum, const struct sigaction *nsa, |
| 379 | struct sigaction *osa, const void *tramp, int vers) |
| 380 | { |
| 381 | struct proc *p; |
| 382 | struct sigacts *ps; |
| 383 | sigset_t tset; |
| 384 | int prop, error; |
| 385 | ksiginfoq_t kq; |
| 386 | static bool v0v1valid; |
| 387 | |
| 388 | if (signum <= 0 || signum >= NSIG) |
| 389 | return EINVAL; |
| 390 | |
| 391 | p = l->l_proc; |
| 392 | error = 0; |
| 393 | ksiginfo_queue_init(&kq); |
| 394 | |
| 395 | /* |
| 396 | * Trampoline ABI version 0 is reserved for the legacy kernel |
| 397 | * provided on-stack trampoline. Conversely, if we are using a |
| 398 | * non-0 ABI version, we must have a trampoline. Only validate the |
| 399 | * vers if a new sigaction was supplied and there was an actual |
| 400 | * handler specified (not SIG_IGN or SIG_DFL), which don't require |
| 401 | * a trampoline. Emulations use legacy kernel trampolines with |
| 402 | * version 0, alternatively check for that too. |
| 403 | * |
| 404 | * If version < 2, we try to autoload the compat module. Note |
| 405 | * that we interlock with the unload check in compat_modcmd() |
| 406 | * using kernconfig_lock. If the autoload fails, we don't try it |
| 407 | * again for this process. |
| 408 | */ |
| 409 | if (nsa != NULL && nsa->sa_handler != SIG_IGN |
| 410 | && nsa->sa_handler != SIG_DFL) { |
| 411 | if (__predict_false(vers < 2)) { |
| 412 | if (p->p_flag & PK_32) |
| 413 | v0v1valid = true; |
| 414 | else if ((p->p_lflag & PL_SIGCOMPAT) == 0) { |
| 415 | kernconfig_lock(); |
| 416 | if (sendsig_sigcontext_vec == NULL) { |
| 417 | (void)module_autoload("compat" , |
| 418 | MODULE_CLASS_ANY); |
| 419 | } |
| 420 | if (sendsig_sigcontext_vec != NULL) { |
| 421 | /* |
| 422 | * We need to remember if the |
| 423 | * sigcontext method may be useable, |
| 424 | * because libc may use it even |
| 425 | * if siginfo is available. |
| 426 | */ |
| 427 | v0v1valid = true; |
| 428 | } |
| 429 | mutex_enter(proc_lock); |
| 430 | /* |
| 431 | * Prevent unload of compat module while |
| 432 | * this process remains. |
| 433 | */ |
| 434 | p->p_lflag |= PL_SIGCOMPAT; |
| 435 | mutex_exit(proc_lock); |
| 436 | kernconfig_unlock(); |
| 437 | } |
| 438 | } |
| 439 | |
| 440 | switch (vers) { |
| 441 | case 0: |
| 442 | /* sigcontext, kernel supplied trampoline. */ |
| 443 | if (tramp != NULL || !v0v1valid) { |
| 444 | return EINVAL; |
| 445 | } |
| 446 | break; |
| 447 | case 1: |
| 448 | /* sigcontext, user supplied trampoline. */ |
| 449 | if (tramp == NULL || !v0v1valid) { |
| 450 | return EINVAL; |
| 451 | } |
| 452 | break; |
| 453 | case 2: |
| 454 | case 3: |
| 455 | /* siginfo, user supplied trampoline. */ |
| 456 | if (tramp == NULL) { |
| 457 | return EINVAL; |
| 458 | } |
| 459 | break; |
| 460 | default: |
| 461 | return EINVAL; |
| 462 | } |
| 463 | } |
| 464 | |
| 465 | mutex_enter(p->p_lock); |
| 466 | |
| 467 | ps = p->p_sigacts; |
| 468 | if (osa) |
| 469 | *osa = SIGACTION_PS(ps, signum); |
| 470 | if (!nsa) |
| 471 | goto out; |
| 472 | |
| 473 | prop = sigprop[signum]; |
| 474 | if ((nsa->sa_flags & ~SA_ALLBITS) || (prop & SA_CANTMASK)) { |
| 475 | error = EINVAL; |
| 476 | goto out; |
| 477 | } |
| 478 | |
| 479 | SIGACTION_PS(ps, signum) = *nsa; |
| 480 | ps->sa_sigdesc[signum].sd_tramp = tramp; |
| 481 | ps->sa_sigdesc[signum].sd_vers = vers; |
| 482 | sigminusset(&sigcantmask, &SIGACTION_PS(ps, signum).sa_mask); |
| 483 | |
| 484 | if ((prop & SA_NORESET) != 0) |
| 485 | SIGACTION_PS(ps, signum).sa_flags &= ~SA_RESETHAND; |
| 486 | |
| 487 | if (signum == SIGCHLD) { |
| 488 | if (nsa->sa_flags & SA_NOCLDSTOP) |
| 489 | p->p_sflag |= PS_NOCLDSTOP; |
| 490 | else |
| 491 | p->p_sflag &= ~PS_NOCLDSTOP; |
| 492 | if (nsa->sa_flags & SA_NOCLDWAIT) { |
| 493 | /* |
| 494 | * Paranoia: since SA_NOCLDWAIT is implemented by |
| 495 | * reparenting the dying child to PID 1 (and trust |
| 496 | * it to reap the zombie), PID 1 itself is forbidden |
| 497 | * to set SA_NOCLDWAIT. |
| 498 | */ |
| 499 | if (p->p_pid == 1) |
| 500 | p->p_flag &= ~PK_NOCLDWAIT; |
| 501 | else |
| 502 | p->p_flag |= PK_NOCLDWAIT; |
| 503 | } else |
| 504 | p->p_flag &= ~PK_NOCLDWAIT; |
| 505 | |
| 506 | if (nsa->sa_handler == SIG_IGN) { |
| 507 | /* |
| 508 | * Paranoia: same as above. |
| 509 | */ |
| 510 | if (p->p_pid == 1) |
| 511 | p->p_flag &= ~PK_CLDSIGIGN; |
| 512 | else |
| 513 | p->p_flag |= PK_CLDSIGIGN; |
| 514 | } else |
| 515 | p->p_flag &= ~PK_CLDSIGIGN; |
| 516 | } |
| 517 | |
| 518 | if ((nsa->sa_flags & SA_NODEFER) == 0) |
| 519 | sigaddset(&SIGACTION_PS(ps, signum).sa_mask, signum); |
| 520 | else |
| 521 | sigdelset(&SIGACTION_PS(ps, signum).sa_mask, signum); |
| 522 | |
| 523 | /* |
| 524 | * Set bit in p_sigctx.ps_sigignore for signals that are set to |
| 525 | * SIG_IGN, and for signals set to SIG_DFL where the default is to |
| 526 | * ignore. However, don't put SIGCONT in p_sigctx.ps_sigignore, as |
| 527 | * we have to restart the process. |
| 528 | */ |
| 529 | if (nsa->sa_handler == SIG_IGN || |
| 530 | (nsa->sa_handler == SIG_DFL && (prop & SA_IGNORE) != 0)) { |
| 531 | /* Never to be seen again. */ |
| 532 | sigemptyset(&tset); |
| 533 | sigaddset(&tset, signum); |
| 534 | sigclearall(p, &tset, &kq); |
| 535 | if (signum != SIGCONT) { |
| 536 | /* Easier in psignal */ |
| 537 | sigaddset(&p->p_sigctx.ps_sigignore, signum); |
| 538 | } |
| 539 | sigdelset(&p->p_sigctx.ps_sigcatch, signum); |
| 540 | } else { |
| 541 | sigdelset(&p->p_sigctx.ps_sigignore, signum); |
| 542 | if (nsa->sa_handler == SIG_DFL) |
| 543 | sigdelset(&p->p_sigctx.ps_sigcatch, signum); |
| 544 | else |
| 545 | sigaddset(&p->p_sigctx.ps_sigcatch, signum); |
| 546 | } |
| 547 | |
| 548 | /* |
| 549 | * Previously held signals may now have become visible. Ensure that |
| 550 | * we check for them before returning to userspace. |
| 551 | */ |
| 552 | if (sigispending(l, 0)) { |
| 553 | lwp_lock(l); |
| 554 | l->l_flag |= LW_PENDSIG; |
| 555 | lwp_unlock(l); |
| 556 | } |
| 557 | out: |
| 558 | mutex_exit(p->p_lock); |
| 559 | ksiginfo_queue_drain(&kq); |
| 560 | |
| 561 | return error; |
| 562 | } |
| 563 | |
| 564 | int |
| 565 | sigprocmask1(struct lwp *l, int how, const sigset_t *nss, sigset_t *oss) |
| 566 | { |
| 567 | sigset_t *mask = &l->l_sigmask; |
| 568 | bool more; |
| 569 | |
| 570 | KASSERT(mutex_owned(l->l_proc->p_lock)); |
| 571 | |
| 572 | if (oss) { |
| 573 | *oss = *mask; |
| 574 | } |
| 575 | |
| 576 | if (nss == NULL) { |
| 577 | return 0; |
| 578 | } |
| 579 | |
| 580 | switch (how) { |
| 581 | case SIG_BLOCK: |
| 582 | sigplusset(nss, mask); |
| 583 | more = false; |
| 584 | break; |
| 585 | case SIG_UNBLOCK: |
| 586 | sigminusset(nss, mask); |
| 587 | more = true; |
| 588 | break; |
| 589 | case SIG_SETMASK: |
| 590 | *mask = *nss; |
| 591 | more = true; |
| 592 | break; |
| 593 | default: |
| 594 | return EINVAL; |
| 595 | } |
| 596 | sigminusset(&sigcantmask, mask); |
| 597 | if (more && sigispending(l, 0)) { |
| 598 | /* |
| 599 | * Check for pending signals on return to user. |
| 600 | */ |
| 601 | lwp_lock(l); |
| 602 | l->l_flag |= LW_PENDSIG; |
| 603 | lwp_unlock(l); |
| 604 | } |
| 605 | return 0; |
| 606 | } |
| 607 | |
| 608 | void |
| 609 | sigpending1(struct lwp *l, sigset_t *ss) |
| 610 | { |
| 611 | struct proc *p = l->l_proc; |
| 612 | |
| 613 | mutex_enter(p->p_lock); |
| 614 | *ss = l->l_sigpend.sp_set; |
| 615 | sigplusset(&p->p_sigpend.sp_set, ss); |
| 616 | mutex_exit(p->p_lock); |
| 617 | } |
| 618 | |
| 619 | void |
| 620 | sigsuspendsetup(struct lwp *l, const sigset_t *ss) |
| 621 | { |
| 622 | struct proc *p = l->l_proc; |
| 623 | |
| 624 | /* |
| 625 | * When returning from sigsuspend/pselect/pollts, we want |
| 626 | * the old mask to be restored after the |
| 627 | * signal handler has finished. Thus, we |
| 628 | * save it here and mark the sigctx structure |
| 629 | * to indicate this. |
| 630 | */ |
| 631 | mutex_enter(p->p_lock); |
| 632 | l->l_sigrestore = 1; |
| 633 | l->l_sigoldmask = l->l_sigmask; |
| 634 | l->l_sigmask = *ss; |
| 635 | sigminusset(&sigcantmask, &l->l_sigmask); |
| 636 | |
| 637 | /* Check for pending signals when sleeping. */ |
| 638 | if (sigispending(l, 0)) { |
| 639 | lwp_lock(l); |
| 640 | l->l_flag |= LW_PENDSIG; |
| 641 | lwp_unlock(l); |
| 642 | } |
| 643 | mutex_exit(p->p_lock); |
| 644 | } |
| 645 | |
| 646 | void |
| 647 | sigsuspendteardown(struct lwp *l) |
| 648 | { |
| 649 | struct proc *p = l->l_proc; |
| 650 | |
| 651 | mutex_enter(p->p_lock); |
| 652 | /* Check for pending signals when sleeping. */ |
| 653 | if (l->l_sigrestore) { |
| 654 | if (sigispending(l, 0)) { |
| 655 | lwp_lock(l); |
| 656 | l->l_flag |= LW_PENDSIG; |
| 657 | lwp_unlock(l); |
| 658 | } else { |
| 659 | l->l_sigrestore = 0; |
| 660 | l->l_sigmask = l->l_sigoldmask; |
| 661 | } |
| 662 | } |
| 663 | mutex_exit(p->p_lock); |
| 664 | } |
| 665 | |
| 666 | int |
| 667 | sigsuspend1(struct lwp *l, const sigset_t *ss) |
| 668 | { |
| 669 | |
| 670 | if (ss) |
| 671 | sigsuspendsetup(l, ss); |
| 672 | |
| 673 | while (kpause("pause" , true, 0, NULL) == 0) |
| 674 | ; |
| 675 | |
| 676 | /* always return EINTR rather than ERESTART... */ |
| 677 | return EINTR; |
| 678 | } |
| 679 | |
| 680 | int |
| 681 | sigaltstack1(struct lwp *l, const struct sigaltstack *nss, |
| 682 | struct sigaltstack *oss) |
| 683 | { |
| 684 | struct proc *p = l->l_proc; |
| 685 | int error = 0; |
| 686 | |
| 687 | mutex_enter(p->p_lock); |
| 688 | |
| 689 | if (oss) |
| 690 | *oss = l->l_sigstk; |
| 691 | |
| 692 | if (nss) { |
| 693 | if (nss->ss_flags & ~SS_ALLBITS) |
| 694 | error = EINVAL; |
| 695 | else if (nss->ss_flags & SS_DISABLE) { |
| 696 | if (l->l_sigstk.ss_flags & SS_ONSTACK) |
| 697 | error = EINVAL; |
| 698 | } else if (nss->ss_size < MINSIGSTKSZ) |
| 699 | error = ENOMEM; |
| 700 | |
| 701 | if (!error) |
| 702 | l->l_sigstk = *nss; |
| 703 | } |
| 704 | |
| 705 | mutex_exit(p->p_lock); |
| 706 | |
| 707 | return error; |
| 708 | } |
| 709 | |
| 710 | int |
| 711 | sigtimedwait1(struct lwp *l, const struct sys_____sigtimedwait50_args *uap, |
| 712 | register_t *retval, copyin_t fetchss, copyout_t storeinf, copyin_t fetchts, |
| 713 | copyout_t storets) |
| 714 | { |
| 715 | /* { |
| 716 | syscallarg(const sigset_t *) set; |
| 717 | syscallarg(siginfo_t *) info; |
| 718 | syscallarg(struct timespec *) timeout; |
| 719 | } */ |
| 720 | struct proc *p = l->l_proc; |
| 721 | int error, signum, timo; |
| 722 | struct timespec ts, tsstart, tsnow; |
| 723 | ksiginfo_t ksi; |
| 724 | |
| 725 | /* |
| 726 | * Calculate timeout, if it was specified. |
| 727 | * |
| 728 | * NULL pointer means an infinite timeout. |
| 729 | * {.tv_sec = 0, .tv_nsec = 0} means do not block. |
| 730 | */ |
| 731 | if (SCARG(uap, timeout)) { |
| 732 | error = (*fetchts)(SCARG(uap, timeout), &ts, sizeof(ts)); |
| 733 | if (error) |
| 734 | return error; |
| 735 | |
| 736 | if ((error = itimespecfix(&ts)) != 0) |
| 737 | return error; |
| 738 | |
| 739 | timo = tstohz(&ts); |
| 740 | if (timo == 0) { |
| 741 | if (ts.tv_sec == 0 && ts.tv_nsec == 0) |
| 742 | timo = -1; /* do not block */ |
| 743 | else |
| 744 | timo = 1; /* the shortest possible timeout */ |
| 745 | } |
| 746 | |
| 747 | /* |
| 748 | * Remember current uptime, it would be used in |
| 749 | * ECANCELED/ERESTART case. |
| 750 | */ |
| 751 | getnanouptime(&tsstart); |
| 752 | } else { |
| 753 | memset(&tsstart, 0, sizeof(tsstart)); /* XXXgcc */ |
| 754 | timo = 0; /* infinite timeout */ |
| 755 | } |
| 756 | |
| 757 | error = (*fetchss)(SCARG(uap, set), &l->l_sigwaitset, |
| 758 | sizeof(l->l_sigwaitset)); |
| 759 | if (error) |
| 760 | return error; |
| 761 | |
| 762 | /* |
| 763 | * Silently ignore SA_CANTMASK signals. psignal1() would ignore |
| 764 | * SA_CANTMASK signals in waitset, we do this only for the below |
| 765 | * siglist check. |
| 766 | */ |
| 767 | sigminusset(&sigcantmask, &l->l_sigwaitset); |
| 768 | |
| 769 | mutex_enter(p->p_lock); |
| 770 | |
| 771 | /* Check for pending signals in the process, if no - then in LWP. */ |
| 772 | if ((signum = sigget(&p->p_sigpend, &ksi, 0, &l->l_sigwaitset)) == 0) |
| 773 | signum = sigget(&l->l_sigpend, &ksi, 0, &l->l_sigwaitset); |
| 774 | |
| 775 | if (signum != 0) { |
| 776 | /* If found a pending signal, just copy it out to the user. */ |
| 777 | mutex_exit(p->p_lock); |
| 778 | goto out; |
| 779 | } |
| 780 | |
| 781 | if (timo < 0) { |
| 782 | /* If not allowed to block, return an error */ |
| 783 | mutex_exit(p->p_lock); |
| 784 | return EAGAIN; |
| 785 | } |
| 786 | |
| 787 | /* |
| 788 | * Set up the sigwait list and wait for signal to arrive. |
| 789 | * We can either be woken up or time out. |
| 790 | */ |
| 791 | l->l_sigwaited = &ksi; |
| 792 | LIST_INSERT_HEAD(&p->p_sigwaiters, l, l_sigwaiter); |
| 793 | error = cv_timedwait_sig(&l->l_sigcv, p->p_lock, timo); |
| 794 | |
| 795 | /* |
| 796 | * Need to find out if we woke as a result of _lwp_wakeup() or a |
| 797 | * signal outside our wait set. |
| 798 | */ |
| 799 | if (l->l_sigwaited != NULL) { |
| 800 | if (error == EINTR) { |
| 801 | /* Wakeup via _lwp_wakeup(). */ |
| 802 | error = ECANCELED; |
| 803 | } else if (!error) { |
| 804 | /* Spurious wakeup - arrange for syscall restart. */ |
| 805 | error = ERESTART; |
| 806 | } |
| 807 | l->l_sigwaited = NULL; |
| 808 | LIST_REMOVE(l, l_sigwaiter); |
| 809 | } |
| 810 | mutex_exit(p->p_lock); |
| 811 | |
| 812 | /* |
| 813 | * If the sleep was interrupted (either by signal or wakeup), update |
| 814 | * the timeout and copyout new value back. It would be used when |
| 815 | * the syscall would be restarted or called again. |
| 816 | */ |
| 817 | if (timo && (error == ERESTART || error == ECANCELED)) { |
| 818 | getnanouptime(&tsnow); |
| 819 | |
| 820 | /* Compute how much time has passed since start. */ |
| 821 | timespecsub(&tsnow, &tsstart, &tsnow); |
| 822 | |
| 823 | /* Substract passed time from timeout. */ |
| 824 | timespecsub(&ts, &tsnow, &ts); |
| 825 | |
| 826 | if (ts.tv_sec < 0) |
| 827 | error = EAGAIN; |
| 828 | else { |
| 829 | /* Copy updated timeout to userland. */ |
| 830 | error = (*storets)(&ts, SCARG(uap, timeout), |
| 831 | sizeof(ts)); |
| 832 | } |
| 833 | } |
| 834 | out: |
| 835 | /* |
| 836 | * If a signal from the wait set arrived, copy it to userland. |
| 837 | * Copy only the used part of siginfo, the padding part is |
| 838 | * left unchanged (userland is not supposed to touch it anyway). |
| 839 | */ |
| 840 | if (error == 0 && SCARG(uap, info)) { |
| 841 | error = (*storeinf)(&ksi.ksi_info, SCARG(uap, info), |
| 842 | sizeof(ksi.ksi_info)); |
| 843 | } |
| 844 | if (error == 0) { |
| 845 | *retval = ksi.ksi_info._signo; |
| 846 | SDT_PROBE(proc, kernel, , signal__clear, *retval, |
| 847 | &ksi, 0, 0, 0); |
| 848 | } |
| 849 | return error; |
| 850 | } |
| 851 | |