1 /* $NetBSD: kern_exec.c,v 1.362 2013/09/10 21:30:21 matt Exp $ */ 2 3 /*- 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /*- 30 * Copyright (C) 1993, 1994, 1996 Christopher G. Demetriou 31 * Copyright (C) 1992 Wolfgang Solfrank. 32 * Copyright (C) 1992 TooLs GmbH. 33 * All rights reserved. 34 * 35 * Redistribution and use in source and binary forms, with or without 36 * modification, are permitted provided that the following conditions 37 * are met: 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 2. Redistributions in binary form must reproduce the above copyright 41 * notice, this list of conditions and the following disclaimer in the 42 * documentation and/or other materials provided with the distribution. 43 * 3. All advertising materials mentioning features or use of this software 44 * must display the following acknowledgement: 45 * This product includes software developed by TooLs GmbH. 46 * 4. The name of TooLs GmbH may not be used to endorse or promote products 47 * derived from this software without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 50 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 51 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 52 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 53 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 54 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 55 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 56 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 57 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 58 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 59 */ 60 61 #include <sys/cdefs.h> 62 __KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.362 2013/09/10 21:30:21 matt Exp $"); 63 64 #include "opt_exec.h" 65 #include "opt_execfmt.h" 66 #include "opt_ktrace.h" 67 #include "opt_modular.h" 68 #include "opt_syscall_debug.h" 69 #include "veriexec.h" 70 #include "opt_pax.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/filedesc.h> 75 #include <sys/kernel.h> 76 #include <sys/proc.h> 77 #include <sys/mount.h> 78 #include <sys/malloc.h> 79 #include <sys/kmem.h> 80 #include <sys/namei.h> 81 #include <sys/vnode.h> 82 #include <sys/file.h> 83 #include <sys/acct.h> 84 #include <sys/atomic.h> 85 #include <sys/exec.h> 86 #include <sys/ktrace.h> 87 #include <sys/uidinfo.h> 88 #include <sys/wait.h> 89 #include <sys/mman.h> 90 #include <sys/ras.h> 91 #include <sys/signalvar.h> 92 #include <sys/stat.h> 93 #include <sys/syscall.h> 94 #include <sys/kauth.h> 95 #include <sys/lwpctl.h> 96 #include <sys/pax.h> 97 #include <sys/cpu.h> 98 #include <sys/module.h> 99 #include <sys/syscallvar.h> 100 #include <sys/syscallargs.h> 101 #if NVERIEXEC > 0 102 #include <sys/verified_exec.h> 103 #endif /* NVERIEXEC > 0 */ 104 #include <sys/sdt.h> 105 #include <sys/spawn.h> 106 #include <sys/prot.h> 107 #include <sys/cprng.h> 108 109 #include <uvm/uvm_extern.h> 110 111 #include <machine/reg.h> 112 113 #include <compat/common/compat_util.h> 114 115 static int exec_sigcode_map(struct proc *, const struct emul *); 116 117 #ifdef DEBUG_EXEC 118 #define DPRINTF(a) printf a 119 #define COPYPRINTF(s, a, b) printf("%s, %d: copyout%s @%p %zu\n", __func__, \ 120 __LINE__, (s), (a), (b)) 121 #else 122 #define DPRINTF(a) 123 #define COPYPRINTF(s, a, b) 124 #endif /* DEBUG_EXEC */ 125 126 /* 127 * DTrace SDT provider definitions 128 */ 129 SDT_PROBE_DEFINE(proc,,,exec,exec, 130 "char *", NULL, 131 NULL, NULL, NULL, NULL, 132 NULL, NULL, NULL, NULL); 133 SDT_PROBE_DEFINE(proc,,,exec_success,exec-success, 134 "char *", NULL, 135 NULL, NULL, NULL, NULL, 136 NULL, NULL, NULL, NULL); 137 SDT_PROBE_DEFINE(proc,,,exec_failure,exec-failure, 138 "int", NULL, 139 NULL, NULL, NULL, NULL, 140 NULL, NULL, NULL, NULL); 141 142 /* 143 * Exec function switch: 144 * 145 * Note that each makecmds function is responsible for loading the 146 * exec package with the necessary functions for any exec-type-specific 147 * handling. 148 * 149 * Functions for specific exec types should be defined in their own 150 * header file. 151 */ 152 static const struct execsw **execsw = NULL; 153 static int nexecs; 154 155 u_int exec_maxhdrsz; /* must not be static - used by netbsd32 */ 156 157 /* list of dynamically loaded execsw entries */ 158 static LIST_HEAD(execlist_head, exec_entry) ex_head = 159 LIST_HEAD_INITIALIZER(ex_head); 160 struct exec_entry { 161 LIST_ENTRY(exec_entry) ex_list; 162 SLIST_ENTRY(exec_entry) ex_slist; 163 const struct execsw *ex_sw; 164 }; 165 166 #ifndef __HAVE_SYSCALL_INTERN 167 void syscall(void); 168 #endif 169 170 /* NetBSD emul struct */ 171 struct emul emul_netbsd = { 172 .e_name = "netbsd", 173 .e_path = NULL, 174 #ifndef __HAVE_MINIMAL_EMUL 175 .e_flags = EMUL_HAS_SYS___syscall, 176 .e_errno = NULL, 177 .e_nosys = SYS_syscall, 178 .e_nsysent = SYS_NSYSENT, 179 #endif 180 .e_sysent = sysent, 181 #ifdef SYSCALL_DEBUG 182 .e_syscallnames = syscallnames, 183 #else 184 .e_syscallnames = NULL, 185 #endif 186 .e_sendsig = sendsig, 187 .e_trapsignal = trapsignal, 188 .e_tracesig = NULL, 189 .e_sigcode = NULL, 190 .e_esigcode = NULL, 191 .e_sigobject = NULL, 192 .e_setregs = setregs, 193 .e_proc_exec = NULL, 194 .e_proc_fork = NULL, 195 .e_proc_exit = NULL, 196 .e_lwp_fork = NULL, 197 .e_lwp_exit = NULL, 198 #ifdef __HAVE_SYSCALL_INTERN 199 .e_syscall_intern = syscall_intern, 200 #else 201 .e_syscall = syscall, 202 #endif 203 .e_sysctlovly = NULL, 204 .e_fault = NULL, 205 .e_vm_default_addr = uvm_default_mapaddr, 206 .e_usertrap = NULL, 207 .e_ucsize = sizeof(ucontext_t), 208 .e_startlwp = startlwp 209 }; 210 211 /* 212 * Exec lock. Used to control access to execsw[] structures. 213 * This must not be static so that netbsd32 can access it, too. 214 */ 215 krwlock_t exec_lock; 216 217 static kmutex_t sigobject_lock; 218 219 /* 220 * Data used between a loadvm and execve part of an "exec" operation 221 */ 222 struct execve_data { 223 struct exec_package ed_pack; 224 struct pathbuf *ed_pathbuf; 225 struct vattr ed_attr; 226 struct ps_strings ed_arginfo; 227 char *ed_argp; 228 const char *ed_pathstring; 229 char *ed_resolvedpathbuf; 230 size_t ed_ps_strings_sz; 231 int ed_szsigcode; 232 long ed_argc; 233 long ed_envc; 234 }; 235 236 /* 237 * data passed from parent lwp to child during a posix_spawn() 238 */ 239 struct spawn_exec_data { 240 struct execve_data sed_exec; 241 struct posix_spawn_file_actions 242 *sed_actions; 243 struct posix_spawnattr *sed_attrs; 244 struct proc *sed_parent; 245 kcondvar_t sed_cv_child_ready; 246 kmutex_t sed_mtx_child; 247 int sed_error; 248 volatile uint32_t sed_refcnt; 249 }; 250 251 static void * 252 exec_pool_alloc(struct pool *pp, int flags) 253 { 254 255 return (void *)uvm_km_alloc(kernel_map, NCARGS, 0, 256 UVM_KMF_PAGEABLE | UVM_KMF_WAITVA); 257 } 258 259 static void 260 exec_pool_free(struct pool *pp, void *addr) 261 { 262 263 uvm_km_free(kernel_map, (vaddr_t)addr, NCARGS, UVM_KMF_PAGEABLE); 264 } 265 266 static struct pool exec_pool; 267 268 static struct pool_allocator exec_palloc = { 269 .pa_alloc = exec_pool_alloc, 270 .pa_free = exec_pool_free, 271 .pa_pagesz = NCARGS 272 }; 273 274 /* 275 * check exec: 276 * given an "executable" described in the exec package's namei info, 277 * see what we can do with it. 278 * 279 * ON ENTRY: 280 * exec package with appropriate namei info 281 * lwp pointer of exec'ing lwp 282 * NO SELF-LOCKED VNODES 283 * 284 * ON EXIT: 285 * error: nothing held, etc. exec header still allocated. 286 * ok: filled exec package, executable's vnode (unlocked). 287 * 288 * EXEC SWITCH ENTRY: 289 * Locked vnode to check, exec package, proc. 290 * 291 * EXEC SWITCH EXIT: 292 * ok: return 0, filled exec package, executable's vnode (unlocked). 293 * error: destructive: 294 * everything deallocated execept exec header. 295 * non-destructive: 296 * error code, executable's vnode (unlocked), 297 * exec header unmodified. 298 */ 299 int 300 /*ARGSUSED*/ 301 check_exec(struct lwp *l, struct exec_package *epp, struct pathbuf *pb) 302 { 303 int error, i; 304 struct vnode *vp; 305 struct nameidata nd; 306 size_t resid; 307 308 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb); 309 310 /* first get the vnode */ 311 if ((error = namei(&nd)) != 0) 312 return error; 313 epp->ep_vp = vp = nd.ni_vp; 314 /* this cannot overflow as both are size PATH_MAX */ 315 strcpy(epp->ep_resolvedname, nd.ni_pnbuf); 316 317 #ifdef DIAGNOSTIC 318 /* paranoia (take this out once namei stuff stabilizes) */ 319 memset(nd.ni_pnbuf, '~', PATH_MAX); 320 #endif 321 322 /* check access and type */ 323 if (vp->v_type != VREG) { 324 error = EACCES; 325 goto bad1; 326 } 327 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 328 goto bad1; 329 330 /* get attributes */ 331 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 332 goto bad1; 333 334 /* Check mount point */ 335 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 336 error = EACCES; 337 goto bad1; 338 } 339 if (vp->v_mount->mnt_flag & MNT_NOSUID) 340 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 341 342 /* try to open it */ 343 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 344 goto bad1; 345 346 /* unlock vp, since we need it unlocked from here on out. */ 347 VOP_UNLOCK(vp); 348 349 #if NVERIEXEC > 0 350 error = veriexec_verify(l, vp, epp->ep_resolvedname, 351 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 352 NULL); 353 if (error) 354 goto bad2; 355 #endif /* NVERIEXEC > 0 */ 356 357 #ifdef PAX_SEGVGUARD 358 error = pax_segvguard(l, vp, epp->ep_resolvedname, false); 359 if (error) 360 goto bad2; 361 #endif /* PAX_SEGVGUARD */ 362 363 /* now we have the file, get the exec header */ 364 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 365 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 366 if (error) 367 goto bad2; 368 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 369 370 /* 371 * Set up default address space limits. Can be overridden 372 * by individual exec packages. 373 * 374 * XXX probably should be all done in the exec packages. 375 */ 376 epp->ep_vm_minaddr = VM_MIN_ADDRESS; 377 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 378 /* 379 * set up the vmcmds for creation of the process 380 * address space 381 */ 382 error = ENOEXEC; 383 for (i = 0; i < nexecs; i++) { 384 int newerror; 385 386 epp->ep_esch = execsw[i]; 387 newerror = (*execsw[i]->es_makecmds)(l, epp); 388 389 if (!newerror) { 390 /* Seems ok: check that entry point is not too high */ 391 if (epp->ep_entry > epp->ep_vm_maxaddr) { 392 #ifdef DIAGNOSTIC 393 printf("%s: rejecting %p due to " 394 "too high entry address (> %p)\n", 395 __func__, (void *)epp->ep_entry, 396 (void *)epp->ep_vm_maxaddr); 397 #endif 398 error = ENOEXEC; 399 break; 400 } 401 /* Seems ok: check that entry point is not too low */ 402 if (epp->ep_entry < epp->ep_vm_minaddr) { 403 #ifdef DIAGNOSTIC 404 printf("%s: rejecting %p due to " 405 "too low entry address (< %p)\n", 406 __func__, (void *)epp->ep_entry, 407 (void *)epp->ep_vm_minaddr); 408 #endif 409 error = ENOEXEC; 410 break; 411 } 412 413 /* check limits */ 414 if ((epp->ep_tsize > MAXTSIZ) || 415 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 416 [RLIMIT_DATA].rlim_cur)) { 417 #ifdef DIAGNOSTIC 418 printf("%s: rejecting due to " 419 "limits (t=%llu > %llu || d=%llu > %llu)\n", 420 __func__, 421 (unsigned long long)epp->ep_tsize, 422 (unsigned long long)MAXTSIZ, 423 (unsigned long long)epp->ep_dsize, 424 (unsigned long long) 425 l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur); 426 #endif 427 error = ENOMEM; 428 break; 429 } 430 return 0; 431 } 432 433 if (epp->ep_emul_root != NULL) { 434 vrele(epp->ep_emul_root); 435 epp->ep_emul_root = NULL; 436 } 437 if (epp->ep_interp != NULL) { 438 vrele(epp->ep_interp); 439 epp->ep_interp = NULL; 440 } 441 442 /* make sure the first "interesting" error code is saved. */ 443 if (error == ENOEXEC) 444 error = newerror; 445 446 if (epp->ep_flags & EXEC_DESTR) 447 /* Error from "#!" code, tidied up by recursive call */ 448 return error; 449 } 450 451 /* not found, error */ 452 453 /* 454 * free any vmspace-creation commands, 455 * and release their references 456 */ 457 kill_vmcmds(&epp->ep_vmcmds); 458 459 bad2: 460 /* 461 * close and release the vnode, restore the old one, free the 462 * pathname buf, and punt. 463 */ 464 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 465 VOP_CLOSE(vp, FREAD, l->l_cred); 466 vput(vp); 467 return error; 468 469 bad1: 470 /* 471 * free the namei pathname buffer, and put the vnode 472 * (which we don't yet have open). 473 */ 474 vput(vp); /* was still locked */ 475 return error; 476 } 477 478 #ifdef __MACHINE_STACK_GROWS_UP 479 #define STACK_PTHREADSPACE NBPG 480 #else 481 #define STACK_PTHREADSPACE 0 482 #endif 483 484 static int 485 execve_fetch_element(char * const *array, size_t index, char **value) 486 { 487 return copyin(array + index, value, sizeof(*value)); 488 } 489 490 /* 491 * exec system call 492 */ 493 int 494 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 495 { 496 /* { 497 syscallarg(const char *) path; 498 syscallarg(char * const *) argp; 499 syscallarg(char * const *) envp; 500 } */ 501 502 return execve1(l, SCARG(uap, path), SCARG(uap, argp), 503 SCARG(uap, envp), execve_fetch_element); 504 } 505 506 int 507 sys_fexecve(struct lwp *l, const struct sys_fexecve_args *uap, 508 register_t *retval) 509 { 510 /* { 511 syscallarg(int) fd; 512 syscallarg(char * const *) argp; 513 syscallarg(char * const *) envp; 514 } */ 515 516 return ENOSYS; 517 } 518 519 /* 520 * Load modules to try and execute an image that we do not understand. 521 * If no execsw entries are present, we load those likely to be needed 522 * in order to run native images only. Otherwise, we autoload all 523 * possible modules that could let us run the binary. XXX lame 524 */ 525 static void 526 exec_autoload(void) 527 { 528 #ifdef MODULAR 529 static const char * const native[] = { 530 "exec_elf32", 531 "exec_elf64", 532 "exec_script", 533 NULL 534 }; 535 static const char * const compat[] = { 536 "exec_elf32", 537 "exec_elf64", 538 "exec_script", 539 "exec_aout", 540 "exec_coff", 541 "exec_ecoff", 542 "compat_aoutm68k", 543 "compat_freebsd", 544 "compat_ibcs2", 545 "compat_linux", 546 "compat_linux32", 547 "compat_netbsd32", 548 "compat_sunos", 549 "compat_sunos32", 550 "compat_svr4", 551 "compat_svr4_32", 552 "compat_ultrix", 553 NULL 554 }; 555 char const * const *list; 556 int i; 557 558 list = (nexecs == 0 ? native : compat); 559 for (i = 0; list[i] != NULL; i++) { 560 if (module_autoload(list[i], MODULE_CLASS_MISC) != 0) { 561 continue; 562 } 563 yield(); 564 } 565 #endif 566 } 567 568 static int 569 execve_loadvm(struct lwp *l, const char *path, char * const *args, 570 char * const *envs, execve_fetch_element_t fetch_element, 571 struct execve_data * restrict data) 572 { 573 int error; 574 struct proc *p; 575 char *dp, *sp; 576 size_t i, len; 577 struct exec_fakearg *tmpfap; 578 u_int modgen; 579 580 KASSERT(data != NULL); 581 582 p = l->l_proc; 583 modgen = 0; 584 585 SDT_PROBE(proc,,,exec, path, 0, 0, 0, 0); 586 587 /* 588 * Check if we have exceeded our number of processes limit. 589 * This is so that we handle the case where a root daemon 590 * forked, ran setuid to become the desired user and is trying 591 * to exec. The obvious place to do the reference counting check 592 * is setuid(), but we don't do the reference counting check there 593 * like other OS's do because then all the programs that use setuid() 594 * must be modified to check the return code of setuid() and exit(). 595 * It is dangerous to make setuid() fail, because it fails open and 596 * the program will continue to run as root. If we make it succeed 597 * and return an error code, again we are not enforcing the limit. 598 * The best place to enforce the limit is here, when the process tries 599 * to execute a new image, because eventually the process will need 600 * to call exec in order to do something useful. 601 */ 602 retry: 603 if (p->p_flag & PK_SUGID) { 604 if (kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT, 605 p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 606 &p->p_rlimit[RLIMIT_NPROC], 607 KAUTH_ARG(RLIMIT_NPROC)) != 0 && 608 chgproccnt(kauth_cred_getuid(l->l_cred), 0) > 609 p->p_rlimit[RLIMIT_NPROC].rlim_cur) 610 return EAGAIN; 611 } 612 613 /* 614 * Drain existing references and forbid new ones. The process 615 * should be left alone until we're done here. This is necessary 616 * to avoid race conditions - e.g. in ptrace() - that might allow 617 * a local user to illicitly obtain elevated privileges. 618 */ 619 rw_enter(&p->p_reflock, RW_WRITER); 620 621 /* 622 * Init the namei data to point the file user's program name. 623 * This is done here rather than in check_exec(), so that it's 624 * possible to override this settings if any of makecmd/probe 625 * functions call check_exec() recursively - for example, 626 * see exec_script_makecmds(). 627 */ 628 error = pathbuf_copyin(path, &data->ed_pathbuf); 629 if (error) { 630 DPRINTF(("%s: pathbuf_copyin path @%p %d\n", __func__, 631 path, error)); 632 goto clrflg; 633 } 634 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 635 636 data->ed_resolvedpathbuf = PNBUF_GET(); 637 #ifdef DIAGNOSTIC 638 strcpy(data->ed_resolvedpathbuf, "/wrong"); 639 #endif 640 641 /* 642 * initialize the fields of the exec package. 643 */ 644 data->ed_pack.ep_name = path; 645 data->ed_pack.ep_kname = data->ed_pathstring; 646 data->ed_pack.ep_resolvedname = data->ed_resolvedpathbuf; 647 data->ed_pack.ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 648 data->ed_pack.ep_hdrlen = exec_maxhdrsz; 649 data->ed_pack.ep_hdrvalid = 0; 650 data->ed_pack.ep_emul_arg = NULL; 651 data->ed_pack.ep_emul_arg_free = NULL; 652 data->ed_pack.ep_vmcmds.evs_cnt = 0; 653 data->ed_pack.ep_vmcmds.evs_used = 0; 654 data->ed_pack.ep_vap = &data->ed_attr; 655 data->ed_pack.ep_flags = 0; 656 data->ed_pack.ep_emul_root = NULL; 657 data->ed_pack.ep_interp = NULL; 658 data->ed_pack.ep_esch = NULL; 659 data->ed_pack.ep_pax_flags = 0; 660 memset(data->ed_pack.ep_machine_arch, 0, 661 sizeof(data->ed_pack.ep_machine_arch)); 662 663 rw_enter(&exec_lock, RW_READER); 664 665 /* see if we can run it. */ 666 if ((error = check_exec(l, &data->ed_pack, data->ed_pathbuf)) != 0) { 667 if (error != ENOENT) { 668 DPRINTF(("%s: check exec failed %d\n", 669 __func__, error)); 670 } 671 goto freehdr; 672 } 673 674 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 675 676 /* allocate an argument buffer */ 677 data->ed_argp = pool_get(&exec_pool, PR_WAITOK); 678 KASSERT(data->ed_argp != NULL); 679 dp = data->ed_argp; 680 data->ed_argc = 0; 681 682 /* copy the fake args list, if there's one, freeing it as we go */ 683 if (data->ed_pack.ep_flags & EXEC_HASARGL) { 684 tmpfap = data->ed_pack.ep_fa; 685 while (tmpfap->fa_arg != NULL) { 686 const char *cp; 687 688 cp = tmpfap->fa_arg; 689 while (*cp) 690 *dp++ = *cp++; 691 *dp++ = '\0'; 692 ktrexecarg(tmpfap->fa_arg, cp - tmpfap->fa_arg); 693 694 kmem_free(tmpfap->fa_arg, tmpfap->fa_len); 695 tmpfap++; data->ed_argc++; 696 } 697 kmem_free(data->ed_pack.ep_fa, data->ed_pack.ep_fa_len); 698 data->ed_pack.ep_flags &= ~EXEC_HASARGL; 699 } 700 701 /* Now get argv & environment */ 702 if (args == NULL) { 703 DPRINTF(("%s: null args\n", __func__)); 704 error = EINVAL; 705 goto bad; 706 } 707 /* 'i' will index the argp/envp element to be retrieved */ 708 i = 0; 709 if (data->ed_pack.ep_flags & EXEC_SKIPARG) 710 i++; 711 712 while (1) { 713 len = data->ed_argp + ARG_MAX - dp; 714 if ((error = (*fetch_element)(args, i, &sp)) != 0) { 715 DPRINTF(("%s: fetch_element args %d\n", 716 __func__, error)); 717 goto bad; 718 } 719 if (!sp) 720 break; 721 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 722 DPRINTF(("%s: copyinstr args %d\n", __func__, error)); 723 if (error == ENAMETOOLONG) 724 error = E2BIG; 725 goto bad; 726 } 727 ktrexecarg(dp, len - 1); 728 dp += len; 729 i++; 730 data->ed_argc++; 731 } 732 733 data->ed_envc = 0; 734 /* environment need not be there */ 735 if (envs != NULL) { 736 i = 0; 737 while (1) { 738 len = data->ed_argp + ARG_MAX - dp; 739 if ((error = (*fetch_element)(envs, i, &sp)) != 0) { 740 DPRINTF(("%s: fetch_element env %d\n", 741 __func__, error)); 742 goto bad; 743 } 744 if (!sp) 745 break; 746 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 747 DPRINTF(("%s: copyinstr env %d\n", 748 __func__, error)); 749 if (error == ENAMETOOLONG) 750 error = E2BIG; 751 goto bad; 752 } 753 754 ktrexecenv(dp, len - 1); 755 dp += len; 756 i++; 757 data->ed_envc++; 758 } 759 } 760 761 dp = (char *) ALIGN(dp); 762 763 data->ed_szsigcode = data->ed_pack.ep_esch->es_emul->e_esigcode - 764 data->ed_pack.ep_esch->es_emul->e_sigcode; 765 766 #ifdef __MACHINE_STACK_GROWS_UP 767 /* See big comment lower down */ 768 #define RTLD_GAP 32 769 #else 770 #define RTLD_GAP 0 771 #endif 772 773 /* Now check if args & environ fit into new stack */ 774 if (data->ed_pack.ep_flags & EXEC_32) { 775 data->ed_ps_strings_sz = sizeof(struct ps_strings32); 776 len = ((data->ed_argc + data->ed_envc + 2 + 777 data->ed_pack.ep_esch->es_arglen) * 778 sizeof(int) + sizeof(int) + dp + RTLD_GAP + 779 data->ed_szsigcode + data->ed_ps_strings_sz + STACK_PTHREADSPACE) 780 - data->ed_argp; 781 } else { 782 data->ed_ps_strings_sz = sizeof(struct ps_strings); 783 len = ((data->ed_argc + data->ed_envc + 2 + 784 data->ed_pack.ep_esch->es_arglen) * 785 sizeof(char *) + sizeof(int) + dp + RTLD_GAP + 786 data->ed_szsigcode + data->ed_ps_strings_sz + STACK_PTHREADSPACE) 787 - data->ed_argp; 788 } 789 790 #ifdef PAX_ASLR 791 if (pax_aslr_active(l)) 792 len += (cprng_fast32() % PAGE_SIZE); 793 #endif /* PAX_ASLR */ 794 795 /* make the stack "safely" aligned */ 796 len = STACK_LEN_ALIGN(len, STACK_ALIGNBYTES); 797 798 if (len > data->ed_pack.ep_ssize) { 799 /* in effect, compare to initial limit */ 800 DPRINTF(("%s: stack limit exceeded %zu\n", __func__, len)); 801 goto bad; 802 } 803 /* adjust "active stack depth" for process VSZ */ 804 data->ed_pack.ep_ssize = len; 805 806 return 0; 807 808 bad: 809 /* free the vmspace-creation commands, and release their references */ 810 kill_vmcmds(&data->ed_pack.ep_vmcmds); 811 /* kill any opened file descriptor, if necessary */ 812 if (data->ed_pack.ep_flags & EXEC_HASFD) { 813 data->ed_pack.ep_flags &= ~EXEC_HASFD; 814 fd_close(data->ed_pack.ep_fd); 815 } 816 /* close and put the exec'd file */ 817 vn_lock(data->ed_pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 818 VOP_CLOSE(data->ed_pack.ep_vp, FREAD, l->l_cred); 819 vput(data->ed_pack.ep_vp); 820 pool_put(&exec_pool, data->ed_argp); 821 822 freehdr: 823 kmem_free(data->ed_pack.ep_hdr, data->ed_pack.ep_hdrlen); 824 if (data->ed_pack.ep_emul_root != NULL) 825 vrele(data->ed_pack.ep_emul_root); 826 if (data->ed_pack.ep_interp != NULL) 827 vrele(data->ed_pack.ep_interp); 828 829 rw_exit(&exec_lock); 830 831 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 832 pathbuf_destroy(data->ed_pathbuf); 833 PNBUF_PUT(data->ed_resolvedpathbuf); 834 835 clrflg: 836 rw_exit(&p->p_reflock); 837 838 if (modgen != module_gen && error == ENOEXEC) { 839 modgen = module_gen; 840 exec_autoload(); 841 goto retry; 842 } 843 844 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0); 845 return error; 846 } 847 848 static void 849 execve_free_data(struct execve_data *data) 850 { 851 852 /* free the vmspace-creation commands, and release their references */ 853 kill_vmcmds(&data->ed_pack.ep_vmcmds); 854 /* kill any opened file descriptor, if necessary */ 855 if (data->ed_pack.ep_flags & EXEC_HASFD) { 856 data->ed_pack.ep_flags &= ~EXEC_HASFD; 857 fd_close(data->ed_pack.ep_fd); 858 } 859 860 /* close and put the exec'd file */ 861 vn_lock(data->ed_pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 862 VOP_CLOSE(data->ed_pack.ep_vp, FREAD, curlwp->l_cred); 863 vput(data->ed_pack.ep_vp); 864 pool_put(&exec_pool, data->ed_argp); 865 866 kmem_free(data->ed_pack.ep_hdr, data->ed_pack.ep_hdrlen); 867 if (data->ed_pack.ep_emul_root != NULL) 868 vrele(data->ed_pack.ep_emul_root); 869 if (data->ed_pack.ep_interp != NULL) 870 vrele(data->ed_pack.ep_interp); 871 872 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 873 pathbuf_destroy(data->ed_pathbuf); 874 PNBUF_PUT(data->ed_resolvedpathbuf); 875 } 876 877 static int 878 execve_runproc(struct lwp *l, struct execve_data * restrict data, 879 bool no_local_exec_lock, bool is_spawn) 880 { 881 int error = 0; 882 struct proc *p; 883 size_t i; 884 char *stack, *dp; 885 const char *commandname; 886 struct ps_strings32 arginfo32; 887 struct exec_vmcmd *base_vcp; 888 void *aip; 889 struct vmspace *vm; 890 ksiginfo_t ksi; 891 ksiginfoq_t kq; 892 893 /* 894 * In case of a posix_spawn operation, the child doing the exec 895 * might not hold the reader lock on exec_lock, but the parent 896 * will do this instead. 897 */ 898 KASSERT(no_local_exec_lock || rw_lock_held(&exec_lock)); 899 KASSERT(data != NULL); 900 if (data == NULL) 901 return (EINVAL); 902 903 p = l->l_proc; 904 if (no_local_exec_lock) 905 KASSERT(is_spawn); 906 907 base_vcp = NULL; 908 909 if (data->ed_pack.ep_flags & EXEC_32) 910 aip = &arginfo32; 911 else 912 aip = &data->ed_arginfo; 913 914 /* Get rid of other LWPs. */ 915 if (p->p_nlwps > 1) { 916 mutex_enter(p->p_lock); 917 exit_lwps(l); 918 mutex_exit(p->p_lock); 919 } 920 KDASSERT(p->p_nlwps == 1); 921 922 /* Destroy any lwpctl info. */ 923 if (p->p_lwpctl != NULL) 924 lwp_ctl_exit(); 925 926 /* Remove POSIX timers */ 927 timers_free(p, TIMERS_POSIX); 928 929 /* 930 * Do whatever is necessary to prepare the address space 931 * for remapping. Note that this might replace the current 932 * vmspace with another! 933 */ 934 if (is_spawn) 935 uvmspace_spawn(l, data->ed_pack.ep_vm_minaddr, 936 data->ed_pack.ep_vm_maxaddr); 937 else 938 uvmspace_exec(l, data->ed_pack.ep_vm_minaddr, 939 data->ed_pack.ep_vm_maxaddr); 940 941 /* record proc's vnode, for use by procfs and others */ 942 if (p->p_textvp) 943 vrele(p->p_textvp); 944 vref(data->ed_pack.ep_vp); 945 p->p_textvp = data->ed_pack.ep_vp; 946 947 /* Now map address space */ 948 vm = p->p_vmspace; 949 vm->vm_taddr = (void *)data->ed_pack.ep_taddr; 950 vm->vm_tsize = btoc(data->ed_pack.ep_tsize); 951 vm->vm_daddr = (void*)data->ed_pack.ep_daddr; 952 vm->vm_dsize = btoc(data->ed_pack.ep_dsize); 953 vm->vm_ssize = btoc(data->ed_pack.ep_ssize); 954 vm->vm_issize = 0; 955 vm->vm_maxsaddr = (void *)data->ed_pack.ep_maxsaddr; 956 vm->vm_minsaddr = (void *)data->ed_pack.ep_minsaddr; 957 958 #ifdef PAX_ASLR 959 pax_aslr_init(l, vm); 960 #endif /* PAX_ASLR */ 961 962 /* create the new process's VM space by running the vmcmds */ 963 #ifdef DIAGNOSTIC 964 if (data->ed_pack.ep_vmcmds.evs_used == 0) 965 panic("%s: no vmcmds", __func__); 966 #endif 967 968 #ifdef DEBUG_EXEC 969 { 970 size_t j; 971 struct exec_vmcmd *vp = &data->ed_pack.ep_vmcmds.evs_cmds[0]; 972 DPRINTF(("vmcmds %u\n", data->ed_pack.ep_vmcmds.evs_used)); 973 for (j = 0; j < data->ed_pack.ep_vmcmds.evs_used; j++) { 974 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#" 975 PRIxVADDR"/%#"PRIxVSIZE" fd@%#" 976 PRIxVSIZE" prot=0%o flags=%d\n", j, 977 vp[j].ev_proc == vmcmd_map_pagedvn ? 978 "pagedvn" : 979 vp[j].ev_proc == vmcmd_map_readvn ? 980 "readvn" : 981 vp[j].ev_proc == vmcmd_map_zero ? 982 "zero" : "*unknown*", 983 vp[j].ev_addr, vp[j].ev_len, 984 vp[j].ev_offset, vp[j].ev_prot, 985 vp[j].ev_flags)); 986 } 987 } 988 #endif /* DEBUG_EXEC */ 989 990 for (i = 0; i < data->ed_pack.ep_vmcmds.evs_used && !error; i++) { 991 struct exec_vmcmd *vcp; 992 993 vcp = &data->ed_pack.ep_vmcmds.evs_cmds[i]; 994 if (vcp->ev_flags & VMCMD_RELATIVE) { 995 #ifdef DIAGNOSTIC 996 if (base_vcp == NULL) 997 panic("%s: relative vmcmd with no base", 998 __func__); 999 if (vcp->ev_flags & VMCMD_BASE) 1000 panic("%s: illegal base & relative vmcmd", 1001 __func__); 1002 #endif 1003 vcp->ev_addr += base_vcp->ev_addr; 1004 } 1005 error = (*vcp->ev_proc)(l, vcp); 1006 #ifdef DEBUG_EXEC 1007 if (error) { 1008 size_t j; 1009 struct exec_vmcmd *vp = 1010 &data->ed_pack.ep_vmcmds.evs_cmds[0]; 1011 DPRINTF(("vmcmds %zu/%u, error %d\n", i, 1012 data->ed_pack.ep_vmcmds.evs_used, error)); 1013 for (j = 0; j < data->ed_pack.ep_vmcmds.evs_used; j++) { 1014 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#" 1015 PRIxVADDR"/%#"PRIxVSIZE" fd@%#" 1016 PRIxVSIZE" prot=0%o flags=%d\n", j, 1017 vp[j].ev_proc == vmcmd_map_pagedvn ? 1018 "pagedvn" : 1019 vp[j].ev_proc == vmcmd_map_readvn ? 1020 "readvn" : 1021 vp[j].ev_proc == vmcmd_map_zero ? 1022 "zero" : "*unknown*", 1023 vp[j].ev_addr, vp[j].ev_len, 1024 vp[j].ev_offset, vp[j].ev_prot, 1025 vp[j].ev_flags)); 1026 if (j == i) 1027 DPRINTF((" ^--- failed\n")); 1028 } 1029 } 1030 #endif /* DEBUG_EXEC */ 1031 if (vcp->ev_flags & VMCMD_BASE) 1032 base_vcp = vcp; 1033 } 1034 1035 /* free the vmspace-creation commands, and release their references */ 1036 kill_vmcmds(&data->ed_pack.ep_vmcmds); 1037 1038 vn_lock(data->ed_pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 1039 VOP_CLOSE(data->ed_pack.ep_vp, FREAD, l->l_cred); 1040 vput(data->ed_pack.ep_vp); 1041 1042 /* if an error happened, deallocate and punt */ 1043 if (error) { 1044 DPRINTF(("%s: vmcmd %zu failed: %d\n", __func__, i - 1, error)); 1045 goto exec_abort; 1046 } 1047 1048 /* remember information about the process */ 1049 data->ed_arginfo.ps_nargvstr = data->ed_argc; 1050 data->ed_arginfo.ps_nenvstr = data->ed_envc; 1051 1052 /* set command name & other accounting info */ 1053 commandname = strrchr(data->ed_pack.ep_resolvedname, '/'); 1054 if (commandname != NULL) { 1055 commandname++; 1056 } else { 1057 commandname = data->ed_pack.ep_resolvedname; 1058 } 1059 i = min(strlen(commandname), MAXCOMLEN); 1060 (void)memcpy(p->p_comm, commandname, i); 1061 p->p_comm[i] = '\0'; 1062 1063 dp = PNBUF_GET(); 1064 /* 1065 * If the path starts with /, we don't need to do any work. 1066 * This handles the majority of the cases. 1067 * In the future perhaps we could canonicalize it? 1068 */ 1069 if (data->ed_pathstring[0] == '/') 1070 (void)strlcpy(data->ed_pack.ep_path = dp, data->ed_pathstring, 1071 MAXPATHLEN); 1072 #ifdef notyet 1073 /* 1074 * Although this works most of the time [since the entry was just 1075 * entered in the cache] we don't use it because it theoretically 1076 * can fail and it is not the cleanest interface, because there 1077 * could be races. When the namei cache is re-written, this can 1078 * be changed to use the appropriate function. 1079 */ 1080 else if (!(error = vnode_to_path(dp, MAXPATHLEN, p->p_textvp, l, p))) 1081 data->ed_pack.ep_path = dp; 1082 #endif 1083 else { 1084 #ifdef notyet 1085 printf("Cannot get path for pid %d [%s] (error %d)\n", 1086 (int)p->p_pid, p->p_comm, error); 1087 #endif 1088 data->ed_pack.ep_path = NULL; 1089 PNBUF_PUT(dp); 1090 } 1091 1092 stack = (char *)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, 1093 STACK_PTHREADSPACE + data->ed_ps_strings_sz + data->ed_szsigcode), 1094 data->ed_pack.ep_ssize - (data->ed_ps_strings_sz + data->ed_szsigcode)); 1095 1096 #ifdef __MACHINE_STACK_GROWS_UP 1097 /* 1098 * The copyargs call always copies into lower addresses 1099 * first, moving towards higher addresses, starting with 1100 * the stack pointer that we give. When the stack grows 1101 * down, this puts argc/argv/envp very shallow on the 1102 * stack, right at the first user stack pointer. 1103 * When the stack grows up, the situation is reversed. 1104 * 1105 * Normally, this is no big deal. But the ld_elf.so _rtld() 1106 * function expects to be called with a single pointer to 1107 * a region that has a few words it can stash values into, 1108 * followed by argc/argv/envp. When the stack grows down, 1109 * it's easy to decrement the stack pointer a little bit to 1110 * allocate the space for these few words and pass the new 1111 * stack pointer to _rtld. When the stack grows up, however, 1112 * a few words before argc is part of the signal trampoline, XXX 1113 * so we have a problem. 1114 * 1115 * Instead of changing how _rtld works, we take the easy way 1116 * out and steal 32 bytes before we call copyargs. 1117 * This extra space was allowed for when 'pack.ep_ssize' was calculated. 1118 */ 1119 stack += RTLD_GAP; 1120 #endif /* __MACHINE_STACK_GROWS_UP */ 1121 1122 /* Now copy argc, args & environ to new stack */ 1123 error = (*data->ed_pack.ep_esch->es_copyargs)(l, &data->ed_pack, 1124 &data->ed_arginfo, &stack, data->ed_argp); 1125 1126 if (data->ed_pack.ep_path) { 1127 PNBUF_PUT(data->ed_pack.ep_path); 1128 data->ed_pack.ep_path = NULL; 1129 } 1130 if (error) { 1131 DPRINTF(("%s: copyargs failed %d\n", __func__, error)); 1132 goto exec_abort; 1133 } 1134 /* Move the stack back to original point */ 1135 stack = (char *)STACK_GROW(vm->vm_minsaddr, data->ed_pack.ep_ssize); 1136 1137 /* fill process ps_strings info */ 1138 p->p_psstrp = (vaddr_t)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, 1139 STACK_PTHREADSPACE), data->ed_ps_strings_sz); 1140 1141 if (data->ed_pack.ep_flags & EXEC_32) { 1142 arginfo32.ps_argvstr = (vaddr_t)data->ed_arginfo.ps_argvstr; 1143 arginfo32.ps_nargvstr = data->ed_arginfo.ps_nargvstr; 1144 arginfo32.ps_envstr = (vaddr_t)data->ed_arginfo.ps_envstr; 1145 arginfo32.ps_nenvstr = data->ed_arginfo.ps_nenvstr; 1146 } 1147 1148 /* copy out the process's ps_strings structure */ 1149 if ((error = copyout(aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)) 1150 != 0) { 1151 DPRINTF(("%s: ps_strings copyout %p->%p size %zu failed\n", 1152 __func__, aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)); 1153 goto exec_abort; 1154 } 1155 1156 cwdexec(p); 1157 fd_closeexec(); /* handle close on exec */ 1158 1159 if (__predict_false(ktrace_on)) 1160 fd_ktrexecfd(); 1161 1162 execsigs(p); /* reset catched signals */ 1163 1164 l->l_ctxlink = NULL; /* reset ucontext link */ 1165 1166 1167 p->p_acflag &= ~AFORK; 1168 mutex_enter(p->p_lock); 1169 p->p_flag |= PK_EXEC; 1170 mutex_exit(p->p_lock); 1171 1172 /* 1173 * Stop profiling. 1174 */ 1175 if ((p->p_stflag & PST_PROFIL) != 0) { 1176 mutex_spin_enter(&p->p_stmutex); 1177 stopprofclock(p); 1178 mutex_spin_exit(&p->p_stmutex); 1179 } 1180 1181 /* 1182 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 1183 * exited and exec()/exit() are the only places it will be cleared. 1184 */ 1185 if ((p->p_lflag & PL_PPWAIT) != 0) { 1186 #if 0 1187 lwp_t *lp; 1188 1189 mutex_enter(proc_lock); 1190 lp = p->p_vforklwp; 1191 p->p_vforklwp = NULL; 1192 1193 l->l_lwpctl = NULL; /* was on loan from blocked parent */ 1194 p->p_lflag &= ~PL_PPWAIT; 1195 1196 lp->l_pflag &= ~LP_VFORKWAIT; /* XXX */ 1197 cv_broadcast(&lp->l_waitcv); 1198 mutex_exit(proc_lock); 1199 #else 1200 mutex_enter(proc_lock); 1201 l->l_lwpctl = NULL; /* was on loan from blocked parent */ 1202 p->p_lflag &= ~PL_PPWAIT; 1203 cv_broadcast(&p->p_pptr->p_waitcv); 1204 mutex_exit(proc_lock); 1205 #endif 1206 } 1207 1208 /* 1209 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 1210 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 1211 * out additional references on the process for the moment. 1212 */ 1213 if ((p->p_slflag & PSL_TRACED) == 0 && 1214 1215 (((data->ed_attr.va_mode & S_ISUID) != 0 && 1216 kauth_cred_geteuid(l->l_cred) != data->ed_attr.va_uid) || 1217 1218 ((data->ed_attr.va_mode & S_ISGID) != 0 && 1219 kauth_cred_getegid(l->l_cred) != data->ed_attr.va_gid))) { 1220 /* 1221 * Mark the process as SUGID before we do 1222 * anything that might block. 1223 */ 1224 proc_crmod_enter(); 1225 proc_crmod_leave(NULL, NULL, true); 1226 1227 /* Make sure file descriptors 0..2 are in use. */ 1228 if ((error = fd_checkstd()) != 0) { 1229 DPRINTF(("%s: fdcheckstd failed %d\n", 1230 __func__, error)); 1231 goto exec_abort; 1232 } 1233 1234 /* 1235 * Copy the credential so other references don't see our 1236 * changes. 1237 */ 1238 l->l_cred = kauth_cred_copy(l->l_cred); 1239 #ifdef KTRACE 1240 /* 1241 * If the persistent trace flag isn't set, turn off. 1242 */ 1243 if (p->p_tracep) { 1244 mutex_enter(&ktrace_lock); 1245 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1246 ktrderef(p); 1247 mutex_exit(&ktrace_lock); 1248 } 1249 #endif 1250 if (data->ed_attr.va_mode & S_ISUID) 1251 kauth_cred_seteuid(l->l_cred, data->ed_attr.va_uid); 1252 if (data->ed_attr.va_mode & S_ISGID) 1253 kauth_cred_setegid(l->l_cred, data->ed_attr.va_gid); 1254 } else { 1255 if (kauth_cred_geteuid(l->l_cred) == 1256 kauth_cred_getuid(l->l_cred) && 1257 kauth_cred_getegid(l->l_cred) == 1258 kauth_cred_getgid(l->l_cred)) 1259 p->p_flag &= ~PK_SUGID; 1260 } 1261 1262 /* 1263 * Copy the credential so other references don't see our changes. 1264 * Test to see if this is necessary first, since in the common case 1265 * we won't need a private reference. 1266 */ 1267 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1268 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1269 l->l_cred = kauth_cred_copy(l->l_cred); 1270 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1271 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1272 } 1273 1274 /* Update the master credentials. */ 1275 if (l->l_cred != p->p_cred) { 1276 kauth_cred_t ocred; 1277 1278 kauth_cred_hold(l->l_cred); 1279 mutex_enter(p->p_lock); 1280 ocred = p->p_cred; 1281 p->p_cred = l->l_cred; 1282 mutex_exit(p->p_lock); 1283 kauth_cred_free(ocred); 1284 } 1285 1286 #if defined(__HAVE_RAS) 1287 /* 1288 * Remove all RASs from the address space. 1289 */ 1290 ras_purgeall(); 1291 #endif 1292 1293 doexechooks(p); 1294 1295 /* setup new registers and do misc. setup. */ 1296 (*data->ed_pack.ep_esch->es_emul->e_setregs)(l, &data->ed_pack, 1297 (vaddr_t)stack); 1298 if (data->ed_pack.ep_esch->es_setregs) 1299 (*data->ed_pack.ep_esch->es_setregs)(l, &data->ed_pack, 1300 (vaddr_t)stack); 1301 1302 /* Provide a consistent LWP private setting */ 1303 (void)lwp_setprivate(l, NULL); 1304 1305 /* Discard all PCU state; need to start fresh */ 1306 pcu_discard_all(l); 1307 1308 /* map the process's signal trampoline code */ 1309 if ((error = exec_sigcode_map(p, data->ed_pack.ep_esch->es_emul)) != 0) { 1310 DPRINTF(("%s: map sigcode failed %d\n", __func__, error)); 1311 goto exec_abort; 1312 } 1313 1314 pool_put(&exec_pool, data->ed_argp); 1315 1316 /* notify others that we exec'd */ 1317 KNOTE(&p->p_klist, NOTE_EXEC); 1318 1319 kmem_free(data->ed_pack.ep_hdr, data->ed_pack.ep_hdrlen); 1320 1321 SDT_PROBE(proc,,,exec_success, data->ed_pack.ep_name, 0, 0, 0, 0); 1322 1323 /* The emulation root will usually have been found when we looked 1324 * for the elf interpreter (or similar), if not look now. */ 1325 if (data->ed_pack.ep_esch->es_emul->e_path != NULL && 1326 data->ed_pack.ep_emul_root == NULL) 1327 emul_find_root(l, &data->ed_pack); 1328 1329 /* Any old emulation root got removed by fdcloseexec */ 1330 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1331 p->p_cwdi->cwdi_edir = data->ed_pack.ep_emul_root; 1332 rw_exit(&p->p_cwdi->cwdi_lock); 1333 data->ed_pack.ep_emul_root = NULL; 1334 if (data->ed_pack.ep_interp != NULL) 1335 vrele(data->ed_pack.ep_interp); 1336 1337 /* 1338 * Call emulation specific exec hook. This can setup per-process 1339 * p->p_emuldata or do any other per-process stuff an emulation needs. 1340 * 1341 * If we are executing process of different emulation than the 1342 * original forked process, call e_proc_exit() of the old emulation 1343 * first, then e_proc_exec() of new emulation. If the emulation is 1344 * same, the exec hook code should deallocate any old emulation 1345 * resources held previously by this process. 1346 */ 1347 if (p->p_emul && p->p_emul->e_proc_exit 1348 && p->p_emul != data->ed_pack.ep_esch->es_emul) 1349 (*p->p_emul->e_proc_exit)(p); 1350 1351 /* 1352 * This is now LWP 1. 1353 */ 1354 mutex_enter(p->p_lock); 1355 p->p_nlwpid = 1; 1356 l->l_lid = 1; 1357 mutex_exit(p->p_lock); 1358 1359 /* 1360 * Call exec hook. Emulation code may NOT store reference to anything 1361 * from &pack. 1362 */ 1363 if (data->ed_pack.ep_esch->es_emul->e_proc_exec) 1364 (*data->ed_pack.ep_esch->es_emul->e_proc_exec)(p, &data->ed_pack); 1365 1366 /* update p_emul, the old value is no longer needed */ 1367 p->p_emul = data->ed_pack.ep_esch->es_emul; 1368 1369 /* ...and the same for p_execsw */ 1370 p->p_execsw = data->ed_pack.ep_esch; 1371 1372 #ifdef __HAVE_SYSCALL_INTERN 1373 (*p->p_emul->e_syscall_intern)(p); 1374 #endif 1375 ktremul(); 1376 1377 /* Allow new references from the debugger/procfs. */ 1378 rw_exit(&p->p_reflock); 1379 if (!no_local_exec_lock) 1380 rw_exit(&exec_lock); 1381 1382 mutex_enter(proc_lock); 1383 1384 if ((p->p_slflag & (PSL_TRACED|PSL_SYSCALL)) == PSL_TRACED) { 1385 KSI_INIT_EMPTY(&ksi); 1386 ksi.ksi_signo = SIGTRAP; 1387 ksi.ksi_lid = l->l_lid; 1388 kpsignal(p, &ksi, NULL); 1389 } 1390 1391 if (p->p_sflag & PS_STOPEXEC) { 1392 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1393 p->p_pptr->p_nstopchild++; 1394 p->p_pptr->p_waited = 0; 1395 mutex_enter(p->p_lock); 1396 ksiginfo_queue_init(&kq); 1397 sigclearall(p, &contsigmask, &kq); 1398 lwp_lock(l); 1399 l->l_stat = LSSTOP; 1400 p->p_stat = SSTOP; 1401 p->p_nrlwps--; 1402 lwp_unlock(l); 1403 mutex_exit(p->p_lock); 1404 mutex_exit(proc_lock); 1405 lwp_lock(l); 1406 mi_switch(l); 1407 ksiginfo_queue_drain(&kq); 1408 KERNEL_LOCK(l->l_biglocks, l); 1409 } else { 1410 mutex_exit(proc_lock); 1411 } 1412 1413 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 1414 pathbuf_destroy(data->ed_pathbuf); 1415 PNBUF_PUT(data->ed_resolvedpathbuf); 1416 DPRINTF(("%s finished\n", __func__)); 1417 return (EJUSTRETURN); 1418 1419 exec_abort: 1420 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0); 1421 rw_exit(&p->p_reflock); 1422 if (!no_local_exec_lock) 1423 rw_exit(&exec_lock); 1424 1425 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 1426 pathbuf_destroy(data->ed_pathbuf); 1427 PNBUF_PUT(data->ed_resolvedpathbuf); 1428 1429 /* 1430 * the old process doesn't exist anymore. exit gracefully. 1431 * get rid of the (new) address space we have created, if any, get rid 1432 * of our namei data and vnode, and exit noting failure 1433 */ 1434 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1435 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1436 1437 exec_free_emul_arg(&data->ed_pack); 1438 pool_put(&exec_pool, data->ed_argp); 1439 kmem_free(data->ed_pack.ep_hdr, data->ed_pack.ep_hdrlen); 1440 if (data->ed_pack.ep_emul_root != NULL) 1441 vrele(data->ed_pack.ep_emul_root); 1442 if (data->ed_pack.ep_interp != NULL) 1443 vrele(data->ed_pack.ep_interp); 1444 1445 /* Acquire the sched-state mutex (exit1() will release it). */ 1446 if (!is_spawn) { 1447 mutex_enter(p->p_lock); 1448 exit1(l, W_EXITCODE(error, SIGABRT)); 1449 } 1450 1451 return error; 1452 } 1453 1454 int 1455 execve1(struct lwp *l, const char *path, char * const *args, 1456 char * const *envs, execve_fetch_element_t fetch_element) 1457 { 1458 struct execve_data data; 1459 int error; 1460 1461 error = execve_loadvm(l, path, args, envs, fetch_element, &data); 1462 if (error) 1463 return error; 1464 error = execve_runproc(l, &data, false, false); 1465 return error; 1466 } 1467 1468 int 1469 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1470 char **stackp, void *argp) 1471 { 1472 char **cpp, *dp, *sp; 1473 size_t len; 1474 void *nullp; 1475 long argc, envc; 1476 int error; 1477 1478 cpp = (char **)*stackp; 1479 nullp = NULL; 1480 argc = arginfo->ps_nargvstr; 1481 envc = arginfo->ps_nenvstr; 1482 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) { 1483 COPYPRINTF("", cpp - 1, sizeof(argc)); 1484 return error; 1485 } 1486 1487 dp = (char *) (cpp + argc + envc + 2 + pack->ep_esch->es_arglen); 1488 sp = argp; 1489 1490 /* XXX don't copy them out, remap them! */ 1491 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1492 1493 for (; --argc >= 0; sp += len, dp += len) { 1494 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1495 COPYPRINTF("", cpp - 1, sizeof(dp)); 1496 return error; 1497 } 1498 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1499 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1500 return error; 1501 } 1502 } 1503 1504 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1505 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1506 return error; 1507 } 1508 1509 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1510 1511 for (; --envc >= 0; sp += len, dp += len) { 1512 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1513 COPYPRINTF("", cpp - 1, sizeof(dp)); 1514 return error; 1515 } 1516 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1517 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1518 return error; 1519 } 1520 1521 } 1522 1523 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1524 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1525 return error; 1526 } 1527 1528 *stackp = (char *)cpp; 1529 return 0; 1530 } 1531 1532 1533 /* 1534 * Add execsw[] entries. 1535 */ 1536 int 1537 exec_add(struct execsw *esp, int count) 1538 { 1539 struct exec_entry *it; 1540 int i; 1541 1542 if (count == 0) { 1543 return 0; 1544 } 1545 1546 /* Check for duplicates. */ 1547 rw_enter(&exec_lock, RW_WRITER); 1548 for (i = 0; i < count; i++) { 1549 LIST_FOREACH(it, &ex_head, ex_list) { 1550 /* assume unique (makecmds, probe_func, emulation) */ 1551 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1552 it->ex_sw->u.elf_probe_func == 1553 esp[i].u.elf_probe_func && 1554 it->ex_sw->es_emul == esp[i].es_emul) { 1555 rw_exit(&exec_lock); 1556 return EEXIST; 1557 } 1558 } 1559 } 1560 1561 /* Allocate new entries. */ 1562 for (i = 0; i < count; i++) { 1563 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1564 it->ex_sw = &esp[i]; 1565 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1566 } 1567 1568 /* update execsw[] */ 1569 exec_init(0); 1570 rw_exit(&exec_lock); 1571 return 0; 1572 } 1573 1574 /* 1575 * Remove execsw[] entry. 1576 */ 1577 int 1578 exec_remove(struct execsw *esp, int count) 1579 { 1580 struct exec_entry *it, *next; 1581 int i; 1582 const struct proclist_desc *pd; 1583 proc_t *p; 1584 1585 if (count == 0) { 1586 return 0; 1587 } 1588 1589 /* Abort if any are busy. */ 1590 rw_enter(&exec_lock, RW_WRITER); 1591 for (i = 0; i < count; i++) { 1592 mutex_enter(proc_lock); 1593 for (pd = proclists; pd->pd_list != NULL; pd++) { 1594 PROCLIST_FOREACH(p, pd->pd_list) { 1595 if (p->p_execsw == &esp[i]) { 1596 mutex_exit(proc_lock); 1597 rw_exit(&exec_lock); 1598 return EBUSY; 1599 } 1600 } 1601 } 1602 mutex_exit(proc_lock); 1603 } 1604 1605 /* None are busy, so remove them all. */ 1606 for (i = 0; i < count; i++) { 1607 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1608 next = LIST_NEXT(it, ex_list); 1609 if (it->ex_sw == &esp[i]) { 1610 LIST_REMOVE(it, ex_list); 1611 kmem_free(it, sizeof(*it)); 1612 break; 1613 } 1614 } 1615 } 1616 1617 /* update execsw[] */ 1618 exec_init(0); 1619 rw_exit(&exec_lock); 1620 return 0; 1621 } 1622 1623 /* 1624 * Initialize exec structures. If init_boot is true, also does necessary 1625 * one-time initialization (it's called from main() that way). 1626 * Once system is multiuser, this should be called with exec_lock held, 1627 * i.e. via exec_{add|remove}(). 1628 */ 1629 int 1630 exec_init(int init_boot) 1631 { 1632 const struct execsw **sw; 1633 struct exec_entry *ex; 1634 SLIST_HEAD(,exec_entry) first; 1635 SLIST_HEAD(,exec_entry) any; 1636 SLIST_HEAD(,exec_entry) last; 1637 int i, sz; 1638 1639 if (init_boot) { 1640 /* do one-time initializations */ 1641 rw_init(&exec_lock); 1642 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1643 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1644 "execargs", &exec_palloc, IPL_NONE); 1645 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1646 } else { 1647 KASSERT(rw_write_held(&exec_lock)); 1648 } 1649 1650 /* Sort each entry onto the appropriate queue. */ 1651 SLIST_INIT(&first); 1652 SLIST_INIT(&any); 1653 SLIST_INIT(&last); 1654 sz = 0; 1655 LIST_FOREACH(ex, &ex_head, ex_list) { 1656 switch(ex->ex_sw->es_prio) { 1657 case EXECSW_PRIO_FIRST: 1658 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1659 break; 1660 case EXECSW_PRIO_ANY: 1661 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1662 break; 1663 case EXECSW_PRIO_LAST: 1664 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1665 break; 1666 default: 1667 panic("%s", __func__); 1668 break; 1669 } 1670 sz++; 1671 } 1672 1673 /* 1674 * Create new execsw[]. Ensure we do not try a zero-sized 1675 * allocation. 1676 */ 1677 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1678 i = 0; 1679 SLIST_FOREACH(ex, &first, ex_slist) { 1680 sw[i++] = ex->ex_sw; 1681 } 1682 SLIST_FOREACH(ex, &any, ex_slist) { 1683 sw[i++] = ex->ex_sw; 1684 } 1685 SLIST_FOREACH(ex, &last, ex_slist) { 1686 sw[i++] = ex->ex_sw; 1687 } 1688 1689 /* Replace old execsw[] and free used memory. */ 1690 if (execsw != NULL) { 1691 kmem_free(__UNCONST(execsw), 1692 nexecs * sizeof(struct execsw *) + 1); 1693 } 1694 execsw = sw; 1695 nexecs = sz; 1696 1697 /* Figure out the maximum size of an exec header. */ 1698 exec_maxhdrsz = sizeof(int); 1699 for (i = 0; i < nexecs; i++) { 1700 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1701 exec_maxhdrsz = execsw[i]->es_hdrsz; 1702 } 1703 1704 return 0; 1705 } 1706 1707 static int 1708 exec_sigcode_map(struct proc *p, const struct emul *e) 1709 { 1710 vaddr_t va; 1711 vsize_t sz; 1712 int error; 1713 struct uvm_object *uobj; 1714 1715 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1716 1717 if (e->e_sigobject == NULL || sz == 0) { 1718 return 0; 1719 } 1720 1721 /* 1722 * If we don't have a sigobject for this emulation, create one. 1723 * 1724 * sigobject is an anonymous memory object (just like SYSV shared 1725 * memory) that we keep a permanent reference to and that we map 1726 * in all processes that need this sigcode. The creation is simple, 1727 * we create an object, add a permanent reference to it, map it in 1728 * kernel space, copy out the sigcode to it and unmap it. 1729 * We map it with PROT_READ|PROT_EXEC into the process just 1730 * the way sys_mmap() would map it. 1731 */ 1732 1733 uobj = *e->e_sigobject; 1734 if (uobj == NULL) { 1735 mutex_enter(&sigobject_lock); 1736 if ((uobj = *e->e_sigobject) == NULL) { 1737 uobj = uao_create(sz, 0); 1738 (*uobj->pgops->pgo_reference)(uobj); 1739 va = vm_map_min(kernel_map); 1740 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1741 uobj, 0, 0, 1742 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1743 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1744 printf("kernel mapping failed %d\n", error); 1745 (*uobj->pgops->pgo_detach)(uobj); 1746 mutex_exit(&sigobject_lock); 1747 return (error); 1748 } 1749 memcpy((void *)va, e->e_sigcode, sz); 1750 #ifdef PMAP_NEED_PROCWR 1751 pmap_procwr(&proc0, va, sz); 1752 #endif 1753 uvm_unmap(kernel_map, va, va + round_page(sz)); 1754 *e->e_sigobject = uobj; 1755 } 1756 mutex_exit(&sigobject_lock); 1757 } 1758 1759 /* Just a hint to uvm_map where to put it. */ 1760 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1761 round_page(sz)); 1762 1763 #ifdef __alpha__ 1764 /* 1765 * Tru64 puts /sbin/loader at the end of user virtual memory, 1766 * which causes the above calculation to put the sigcode at 1767 * an invalid address. Put it just below the text instead. 1768 */ 1769 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1770 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1771 } 1772 #endif 1773 1774 (*uobj->pgops->pgo_reference)(uobj); 1775 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1776 uobj, 0, 0, 1777 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1778 UVM_ADV_RANDOM, 0)); 1779 if (error) { 1780 DPRINTF(("%s, %d: map %p " 1781 "uvm_map %#"PRIxVSIZE"@%#"PRIxVADDR" failed %d\n", 1782 __func__, __LINE__, &p->p_vmspace->vm_map, round_page(sz), 1783 va, error)); 1784 (*uobj->pgops->pgo_detach)(uobj); 1785 return (error); 1786 } 1787 p->p_sigctx.ps_sigcode = (void *)va; 1788 return (0); 1789 } 1790 1791 /* 1792 * Release a refcount on spawn_exec_data and destroy memory, if this 1793 * was the last one. 1794 */ 1795 static void 1796 spawn_exec_data_release(struct spawn_exec_data *data) 1797 { 1798 if (atomic_dec_32_nv(&data->sed_refcnt) != 0) 1799 return; 1800 1801 cv_destroy(&data->sed_cv_child_ready); 1802 mutex_destroy(&data->sed_mtx_child); 1803 1804 if (data->sed_actions) 1805 posix_spawn_fa_free(data->sed_actions, 1806 data->sed_actions->len); 1807 if (data->sed_attrs) 1808 kmem_free(data->sed_attrs, 1809 sizeof(*data->sed_attrs)); 1810 kmem_free(data, sizeof(*data)); 1811 } 1812 1813 /* 1814 * A child lwp of a posix_spawn operation starts here and ends up in 1815 * cpu_spawn_return, dealing with all filedescriptor and scheduler 1816 * manipulations in between. 1817 * The parent waits for the child, as it is not clear wether the child 1818 * will be able to aquire its own exec_lock. If it can, the parent can 1819 * be released early and continue running in parallel. If not (or if the 1820 * magic debug flag is passed in the scheduler attribute struct), the 1821 * child rides on the parent's exec lock untill it is ready to return to 1822 * to userland - and only then releases the parent. This method loses 1823 * concurrency, but improves error reporting. 1824 */ 1825 static void 1826 spawn_return(void *arg) 1827 { 1828 struct spawn_exec_data *spawn_data = arg; 1829 struct lwp *l = curlwp; 1830 int error, newfd; 1831 size_t i; 1832 const struct posix_spawn_file_actions_entry *fae; 1833 pid_t ppid; 1834 register_t retval; 1835 bool have_reflock; 1836 bool parent_is_waiting = true; 1837 1838 /* 1839 * Check if we can release parent early. 1840 * We either need to have no sed_attrs, or sed_attrs does not 1841 * have POSIX_SPAWN_RETURNERROR or one of the flags, that require 1842 * safe access to the parent proc (passed in sed_parent). 1843 * We then try to get the exec_lock, and only if that works, we can 1844 * release the parent here already. 1845 */ 1846 ppid = spawn_data->sed_parent->p_pid; 1847 if ((!spawn_data->sed_attrs 1848 || (spawn_data->sed_attrs->sa_flags 1849 & (POSIX_SPAWN_RETURNERROR|POSIX_SPAWN_SETPGROUP)) == 0) 1850 && rw_tryenter(&exec_lock, RW_READER)) { 1851 parent_is_waiting = false; 1852 mutex_enter(&spawn_data->sed_mtx_child); 1853 cv_signal(&spawn_data->sed_cv_child_ready); 1854 mutex_exit(&spawn_data->sed_mtx_child); 1855 } 1856 1857 /* don't allow debugger access yet */ 1858 rw_enter(&l->l_proc->p_reflock, RW_WRITER); 1859 have_reflock = true; 1860 1861 error = 0; 1862 /* handle posix_spawn_file_actions */ 1863 if (spawn_data->sed_actions != NULL) { 1864 for (i = 0; i < spawn_data->sed_actions->len; i++) { 1865 fae = &spawn_data->sed_actions->fae[i]; 1866 switch (fae->fae_action) { 1867 case FAE_OPEN: 1868 if (fd_getfile(fae->fae_fildes) != NULL) { 1869 error = fd_close(fae->fae_fildes); 1870 if (error) 1871 break; 1872 } 1873 error = fd_open(fae->fae_path, fae->fae_oflag, 1874 fae->fae_mode, &newfd); 1875 if (error) 1876 break; 1877 if (newfd != fae->fae_fildes) { 1878 error = dodup(l, newfd, 1879 fae->fae_fildes, 0, &retval); 1880 if (fd_getfile(newfd) != NULL) 1881 fd_close(newfd); 1882 } 1883 break; 1884 case FAE_DUP2: 1885 error = dodup(l, fae->fae_fildes, 1886 fae->fae_newfildes, 0, &retval); 1887 break; 1888 case FAE_CLOSE: 1889 if (fd_getfile(fae->fae_fildes) == NULL) { 1890 error = EBADF; 1891 break; 1892 } 1893 error = fd_close(fae->fae_fildes); 1894 break; 1895 } 1896 if (error) 1897 goto report_error; 1898 } 1899 } 1900 1901 /* handle posix_spawnattr */ 1902 if (spawn_data->sed_attrs != NULL) { 1903 int ostat; 1904 struct sigaction sigact; 1905 sigact._sa_u._sa_handler = SIG_DFL; 1906 sigact.sa_flags = 0; 1907 1908 /* 1909 * set state to SSTOP so that this proc can be found by pid. 1910 * see proc_enterprp, do_sched_setparam below 1911 */ 1912 ostat = l->l_proc->p_stat; 1913 l->l_proc->p_stat = SSTOP; 1914 1915 /* Set process group */ 1916 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETPGROUP) { 1917 pid_t mypid = l->l_proc->p_pid, 1918 pgrp = spawn_data->sed_attrs->sa_pgroup; 1919 1920 if (pgrp == 0) 1921 pgrp = mypid; 1922 1923 error = proc_enterpgrp(spawn_data->sed_parent, 1924 mypid, pgrp, false); 1925 if (error) 1926 goto report_error; 1927 } 1928 1929 /* Set scheduler policy */ 1930 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSCHEDULER) 1931 error = do_sched_setparam(l->l_proc->p_pid, 0, 1932 spawn_data->sed_attrs->sa_schedpolicy, 1933 &spawn_data->sed_attrs->sa_schedparam); 1934 else if (spawn_data->sed_attrs->sa_flags 1935 & POSIX_SPAWN_SETSCHEDPARAM) { 1936 error = do_sched_setparam(ppid, 0, 1937 SCHED_NONE, &spawn_data->sed_attrs->sa_schedparam); 1938 } 1939 if (error) 1940 goto report_error; 1941 1942 /* Reset user ID's */ 1943 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_RESETIDS) { 1944 error = do_setresuid(l, -1, 1945 kauth_cred_getgid(l->l_cred), -1, 1946 ID_E_EQ_R | ID_E_EQ_S); 1947 if (error) 1948 goto report_error; 1949 error = do_setresuid(l, -1, 1950 kauth_cred_getuid(l->l_cred), -1, 1951 ID_E_EQ_R | ID_E_EQ_S); 1952 if (error) 1953 goto report_error; 1954 } 1955 1956 /* Set signal masks/defaults */ 1957 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGMASK) { 1958 mutex_enter(l->l_proc->p_lock); 1959 error = sigprocmask1(l, SIG_SETMASK, 1960 &spawn_data->sed_attrs->sa_sigmask, NULL); 1961 mutex_exit(l->l_proc->p_lock); 1962 if (error) 1963 goto report_error; 1964 } 1965 1966 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGDEF) { 1967 for (i = 1; i <= NSIG; i++) { 1968 if (sigismember( 1969 &spawn_data->sed_attrs->sa_sigdefault, i)) 1970 sigaction1(l, i, &sigact, NULL, NULL, 1971 0); 1972 } 1973 } 1974 l->l_proc->p_stat = ostat; 1975 } 1976 1977 /* now do the real exec */ 1978 error = execve_runproc(l, &spawn_data->sed_exec, parent_is_waiting, 1979 true); 1980 have_reflock = false; 1981 if (error == EJUSTRETURN) 1982 error = 0; 1983 else if (error) 1984 goto report_error; 1985 1986 if (parent_is_waiting) { 1987 mutex_enter(&spawn_data->sed_mtx_child); 1988 cv_signal(&spawn_data->sed_cv_child_ready); 1989 mutex_exit(&spawn_data->sed_mtx_child); 1990 } 1991 1992 /* release our refcount on the data */ 1993 spawn_exec_data_release(spawn_data); 1994 1995 /* and finaly: leave to userland for the first time */ 1996 cpu_spawn_return(l); 1997 1998 /* NOTREACHED */ 1999 return; 2000 2001 report_error: 2002 if (have_reflock) { 2003 /* 2004 * We have not passed through execve_runproc(), 2005 * which would have released the p_reflock and also 2006 * taken ownership of the sed_exec part of spawn_data, 2007 * so release/free both here. 2008 */ 2009 rw_exit(&l->l_proc->p_reflock); 2010 execve_free_data(&spawn_data->sed_exec); 2011 } 2012 2013 if (parent_is_waiting) { 2014 /* pass error to parent */ 2015 mutex_enter(&spawn_data->sed_mtx_child); 2016 spawn_data->sed_error = error; 2017 cv_signal(&spawn_data->sed_cv_child_ready); 2018 mutex_exit(&spawn_data->sed_mtx_child); 2019 } else { 2020 rw_exit(&exec_lock); 2021 } 2022 2023 /* release our refcount on the data */ 2024 spawn_exec_data_release(spawn_data); 2025 2026 /* done, exit */ 2027 mutex_enter(l->l_proc->p_lock); 2028 /* 2029 * Posix explicitly asks for an exit code of 127 if we report 2030 * errors from the child process - so, unfortunately, there 2031 * is no way to report a more exact error code. 2032 * A NetBSD specific workaround is POSIX_SPAWN_RETURNERROR as 2033 * flag bit in the attrp argument to posix_spawn(2), see above. 2034 */ 2035 exit1(l, W_EXITCODE(127, 0)); 2036 } 2037 2038 void 2039 posix_spawn_fa_free(struct posix_spawn_file_actions *fa, size_t len) 2040 { 2041 2042 for (size_t i = 0; i < len; i++) { 2043 struct posix_spawn_file_actions_entry *fae = &fa->fae[i]; 2044 if (fae->fae_action != FAE_OPEN) 2045 continue; 2046 kmem_free(fae->fae_path, strlen(fae->fae_path) + 1); 2047 } 2048 if (fa->len > 0) 2049 kmem_free(fa->fae, sizeof(*fa->fae) * fa->len); 2050 kmem_free(fa, sizeof(*fa)); 2051 } 2052 2053 static int 2054 posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap, 2055 const struct posix_spawn_file_actions *ufa) 2056 { 2057 struct posix_spawn_file_actions *fa; 2058 struct posix_spawn_file_actions_entry *fae; 2059 char *pbuf = NULL; 2060 int error; 2061 size_t i = 0; 2062 2063 fa = kmem_alloc(sizeof(*fa), KM_SLEEP); 2064 error = copyin(ufa, fa, sizeof(*fa)); 2065 if (error) { 2066 fa->fae = NULL; 2067 fa->len = 0; 2068 goto out; 2069 } 2070 2071 if (fa->len == 0) { 2072 kmem_free(fa, sizeof(*fa)); 2073 return 0; 2074 } 2075 2076 fa->size = fa->len; 2077 size_t fal = fa->len * sizeof(*fae); 2078 fae = fa->fae; 2079 fa->fae = kmem_alloc(fal, KM_SLEEP); 2080 error = copyin(fae, fa->fae, fal); 2081 if (error) 2082 goto out; 2083 2084 pbuf = PNBUF_GET(); 2085 for (; i < fa->len; i++) { 2086 fae = &fa->fae[i]; 2087 if (fae->fae_action != FAE_OPEN) 2088 continue; 2089 error = copyinstr(fae->fae_path, pbuf, MAXPATHLEN, &fal); 2090 if (error) 2091 goto out; 2092 fae->fae_path = kmem_alloc(fal, KM_SLEEP); 2093 memcpy(fae->fae_path, pbuf, fal); 2094 } 2095 PNBUF_PUT(pbuf); 2096 2097 *fap = fa; 2098 return 0; 2099 out: 2100 if (pbuf) 2101 PNBUF_PUT(pbuf); 2102 posix_spawn_fa_free(fa, i); 2103 return error; 2104 } 2105 2106 int 2107 check_posix_spawn(struct lwp *l1) 2108 { 2109 int error, tnprocs, count; 2110 uid_t uid; 2111 struct proc *p1; 2112 2113 p1 = l1->l_proc; 2114 uid = kauth_cred_getuid(l1->l_cred); 2115 tnprocs = atomic_inc_uint_nv(&nprocs); 2116 2117 /* 2118 * Although process entries are dynamically created, we still keep 2119 * a global limit on the maximum number we will create. 2120 */ 2121 if (__predict_false(tnprocs >= maxproc)) 2122 error = -1; 2123 else 2124 error = kauth_authorize_process(l1->l_cred, 2125 KAUTH_PROCESS_FORK, p1, KAUTH_ARG(tnprocs), NULL, NULL); 2126 2127 if (error) { 2128 atomic_dec_uint(&nprocs); 2129 return EAGAIN; 2130 } 2131 2132 /* 2133 * Enforce limits. 2134 */ 2135 count = chgproccnt(uid, 1); 2136 if (kauth_authorize_process(l1->l_cred, KAUTH_PROCESS_RLIMIT, 2137 p1, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 2138 &p1->p_rlimit[RLIMIT_NPROC], KAUTH_ARG(RLIMIT_NPROC)) != 0 && 2139 __predict_false(count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) { 2140 (void)chgproccnt(uid, -1); 2141 atomic_dec_uint(&nprocs); 2142 return EAGAIN; 2143 } 2144 2145 return 0; 2146 } 2147 2148 int 2149 do_posix_spawn(struct lwp *l1, pid_t *pid_res, bool *child_ok, const char *path, 2150 struct posix_spawn_file_actions *fa, 2151 struct posix_spawnattr *sa, 2152 char *const *argv, char *const *envp, 2153 execve_fetch_element_t fetch) 2154 { 2155 2156 struct proc *p1, *p2; 2157 struct lwp *l2; 2158 int error; 2159 struct spawn_exec_data *spawn_data; 2160 vaddr_t uaddr; 2161 pid_t pid; 2162 bool have_exec_lock = false; 2163 2164 p1 = l1->l_proc; 2165 2166 /* Allocate and init spawn_data */ 2167 spawn_data = kmem_zalloc(sizeof(*spawn_data), KM_SLEEP); 2168 spawn_data->sed_refcnt = 1; /* only parent so far */ 2169 cv_init(&spawn_data->sed_cv_child_ready, "pspawn"); 2170 mutex_init(&spawn_data->sed_mtx_child, MUTEX_DEFAULT, IPL_NONE); 2171 mutex_enter(&spawn_data->sed_mtx_child); 2172 2173 /* 2174 * Do the first part of the exec now, collect state 2175 * in spawn_data. 2176 */ 2177 error = execve_loadvm(l1, path, argv, 2178 envp, fetch, &spawn_data->sed_exec); 2179 if (error == EJUSTRETURN) 2180 error = 0; 2181 else if (error) 2182 goto error_exit; 2183 2184 have_exec_lock = true; 2185 2186 /* 2187 * Allocate virtual address space for the U-area now, while it 2188 * is still easy to abort the fork operation if we're out of 2189 * kernel virtual address space. 2190 */ 2191 uaddr = uvm_uarea_alloc(); 2192 if (__predict_false(uaddr == 0)) { 2193 error = ENOMEM; 2194 goto error_exit; 2195 } 2196 2197 /* 2198 * Allocate new proc. Borrow proc0 vmspace for it, we will 2199 * replace it with its own before returning to userland 2200 * in the child. 2201 * This is a point of no return, we will have to go through 2202 * the child proc to properly clean it up past this point. 2203 */ 2204 p2 = proc_alloc(); 2205 pid = p2->p_pid; 2206 2207 /* 2208 * Make a proc table entry for the new process. 2209 * Start by zeroing the section of proc that is zero-initialized, 2210 * then copy the section that is copied directly from the parent. 2211 */ 2212 memset(&p2->p_startzero, 0, 2213 (unsigned) ((char *)&p2->p_endzero - (char *)&p2->p_startzero)); 2214 memcpy(&p2->p_startcopy, &p1->p_startcopy, 2215 (unsigned) ((char *)&p2->p_endcopy - (char *)&p2->p_startcopy)); 2216 p2->p_vmspace = proc0.p_vmspace; 2217 2218 CIRCLEQ_INIT(&p2->p_sigpend.sp_info); 2219 2220 LIST_INIT(&p2->p_lwps); 2221 LIST_INIT(&p2->p_sigwaiters); 2222 2223 /* 2224 * Duplicate sub-structures as needed. 2225 * Increase reference counts on shared objects. 2226 * Inherit flags we want to keep. The flags related to SIGCHLD 2227 * handling are important in order to keep a consistent behaviour 2228 * for the child after the fork. If we are a 32-bit process, the 2229 * child will be too. 2230 */ 2231 p2->p_flag = 2232 p1->p_flag & (PK_SUGID | PK_NOCLDWAIT | PK_CLDSIGIGN | PK_32); 2233 p2->p_emul = p1->p_emul; 2234 p2->p_execsw = p1->p_execsw; 2235 2236 mutex_init(&p2->p_stmutex, MUTEX_DEFAULT, IPL_HIGH); 2237 mutex_init(&p2->p_auxlock, MUTEX_DEFAULT, IPL_NONE); 2238 rw_init(&p2->p_reflock); 2239 cv_init(&p2->p_waitcv, "wait"); 2240 cv_init(&p2->p_lwpcv, "lwpwait"); 2241 2242 p2->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 2243 2244 kauth_proc_fork(p1, p2); 2245 2246 p2->p_raslist = NULL; 2247 p2->p_fd = fd_copy(); 2248 2249 /* XXX racy */ 2250 p2->p_mqueue_cnt = p1->p_mqueue_cnt; 2251 2252 p2->p_cwdi = cwdinit(); 2253 2254 /* 2255 * Note: p_limit (rlimit stuff) is copy-on-write, so normally 2256 * we just need increase pl_refcnt. 2257 */ 2258 if (!p1->p_limit->pl_writeable) { 2259 lim_addref(p1->p_limit); 2260 p2->p_limit = p1->p_limit; 2261 } else { 2262 p2->p_limit = lim_copy(p1->p_limit); 2263 } 2264 2265 p2->p_lflag = 0; 2266 p2->p_sflag = 0; 2267 p2->p_slflag = 0; 2268 p2->p_pptr = p1; 2269 p2->p_ppid = p1->p_pid; 2270 LIST_INIT(&p2->p_children); 2271 2272 p2->p_aio = NULL; 2273 2274 #ifdef KTRACE 2275 /* 2276 * Copy traceflag and tracefile if enabled. 2277 * If not inherited, these were zeroed above. 2278 */ 2279 if (p1->p_traceflag & KTRFAC_INHERIT) { 2280 mutex_enter(&ktrace_lock); 2281 p2->p_traceflag = p1->p_traceflag; 2282 if ((p2->p_tracep = p1->p_tracep) != NULL) 2283 ktradref(p2); 2284 mutex_exit(&ktrace_lock); 2285 } 2286 #endif 2287 2288 /* 2289 * Create signal actions for the child process. 2290 */ 2291 p2->p_sigacts = sigactsinit(p1, 0); 2292 mutex_enter(p1->p_lock); 2293 p2->p_sflag |= 2294 (p1->p_sflag & (PS_STOPFORK | PS_STOPEXEC | PS_NOCLDSTOP)); 2295 sched_proc_fork(p1, p2); 2296 mutex_exit(p1->p_lock); 2297 2298 p2->p_stflag = p1->p_stflag; 2299 2300 /* 2301 * p_stats. 2302 * Copy parts of p_stats, and zero out the rest. 2303 */ 2304 p2->p_stats = pstatscopy(p1->p_stats); 2305 2306 /* copy over machdep flags to the new proc */ 2307 cpu_proc_fork(p1, p2); 2308 2309 /* 2310 * Prepare remaining parts of spawn data 2311 */ 2312 spawn_data->sed_actions = fa; 2313 spawn_data->sed_attrs = sa; 2314 2315 spawn_data->sed_parent = p1; 2316 2317 /* create LWP */ 2318 lwp_create(l1, p2, uaddr, 0, NULL, 0, spawn_return, spawn_data, 2319 &l2, l1->l_class); 2320 l2->l_ctxlink = NULL; /* reset ucontext link */ 2321 2322 /* 2323 * Copy the credential so other references don't see our changes. 2324 * Test to see if this is necessary first, since in the common case 2325 * we won't need a private reference. 2326 */ 2327 if (kauth_cred_geteuid(l2->l_cred) != kauth_cred_getsvuid(l2->l_cred) || 2328 kauth_cred_getegid(l2->l_cred) != kauth_cred_getsvgid(l2->l_cred)) { 2329 l2->l_cred = kauth_cred_copy(l2->l_cred); 2330 kauth_cred_setsvuid(l2->l_cred, kauth_cred_geteuid(l2->l_cred)); 2331 kauth_cred_setsvgid(l2->l_cred, kauth_cred_getegid(l2->l_cred)); 2332 } 2333 2334 /* Update the master credentials. */ 2335 if (l2->l_cred != p2->p_cred) { 2336 kauth_cred_t ocred; 2337 2338 kauth_cred_hold(l2->l_cred); 2339 mutex_enter(p2->p_lock); 2340 ocred = p2->p_cred; 2341 p2->p_cred = l2->l_cred; 2342 mutex_exit(p2->p_lock); 2343 kauth_cred_free(ocred); 2344 } 2345 2346 *child_ok = true; 2347 spawn_data->sed_refcnt = 2; /* child gets it as well */ 2348 #if 0 2349 l2->l_nopreempt = 1; /* start it non-preemptable */ 2350 #endif 2351 2352 /* 2353 * It's now safe for the scheduler and other processes to see the 2354 * child process. 2355 */ 2356 mutex_enter(proc_lock); 2357 2358 if (p1->p_session->s_ttyvp != NULL && p1->p_lflag & PL_CONTROLT) 2359 p2->p_lflag |= PL_CONTROLT; 2360 2361 LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling); 2362 p2->p_exitsig = SIGCHLD; /* signal for parent on exit */ 2363 2364 LIST_INSERT_AFTER(p1, p2, p_pglist); 2365 LIST_INSERT_HEAD(&allproc, p2, p_list); 2366 2367 p2->p_trace_enabled = trace_is_enabled(p2); 2368 #ifdef __HAVE_SYSCALL_INTERN 2369 (*p2->p_emul->e_syscall_intern)(p2); 2370 #endif 2371 2372 /* 2373 * Make child runnable, set start time, and add to run queue except 2374 * if the parent requested the child to start in SSTOP state. 2375 */ 2376 mutex_enter(p2->p_lock); 2377 2378 getmicrotime(&p2->p_stats->p_start); 2379 2380 lwp_lock(l2); 2381 KASSERT(p2->p_nrlwps == 1); 2382 p2->p_nrlwps = 1; 2383 p2->p_stat = SACTIVE; 2384 l2->l_stat = LSRUN; 2385 sched_enqueue(l2, false); 2386 lwp_unlock(l2); 2387 2388 mutex_exit(p2->p_lock); 2389 mutex_exit(proc_lock); 2390 2391 cv_wait(&spawn_data->sed_cv_child_ready, &spawn_data->sed_mtx_child); 2392 error = spawn_data->sed_error; 2393 mutex_exit(&spawn_data->sed_mtx_child); 2394 spawn_exec_data_release(spawn_data); 2395 2396 rw_exit(&p1->p_reflock); 2397 rw_exit(&exec_lock); 2398 have_exec_lock = false; 2399 2400 *pid_res = pid; 2401 return error; 2402 2403 error_exit: 2404 if (have_exec_lock) { 2405 execve_free_data(&spawn_data->sed_exec); 2406 rw_exit(&p1->p_reflock); 2407 rw_exit(&exec_lock); 2408 } 2409 mutex_exit(&spawn_data->sed_mtx_child); 2410 spawn_exec_data_release(spawn_data); 2411 2412 return error; 2413 } 2414 2415 int 2416 sys_posix_spawn(struct lwp *l1, const struct sys_posix_spawn_args *uap, 2417 register_t *retval) 2418 { 2419 /* { 2420 syscallarg(pid_t *) pid; 2421 syscallarg(const char *) path; 2422 syscallarg(const struct posix_spawn_file_actions *) file_actions; 2423 syscallarg(const struct posix_spawnattr *) attrp; 2424 syscallarg(char *const *) argv; 2425 syscallarg(char *const *) envp; 2426 } */ 2427 2428 int error; 2429 struct posix_spawn_file_actions *fa = NULL; 2430 struct posix_spawnattr *sa = NULL; 2431 pid_t pid; 2432 bool child_ok = false; 2433 2434 error = check_posix_spawn(l1); 2435 if (error) { 2436 *retval = error; 2437 return 0; 2438 } 2439 2440 /* copy in file_actions struct */ 2441 if (SCARG(uap, file_actions) != NULL) { 2442 error = posix_spawn_fa_alloc(&fa, SCARG(uap, file_actions)); 2443 if (error) 2444 goto error_exit; 2445 } 2446 2447 /* copyin posix_spawnattr struct */ 2448 if (SCARG(uap, attrp) != NULL) { 2449 sa = kmem_alloc(sizeof(*sa), KM_SLEEP); 2450 error = copyin(SCARG(uap, attrp), sa, sizeof(*sa)); 2451 if (error) 2452 goto error_exit; 2453 } 2454 2455 /* 2456 * Do the spawn 2457 */ 2458 error = do_posix_spawn(l1, &pid, &child_ok, SCARG(uap, path), fa, sa, 2459 SCARG(uap, argv), SCARG(uap, envp), execve_fetch_element); 2460 if (error) 2461 goto error_exit; 2462 2463 if (error == 0 && SCARG(uap, pid) != NULL) 2464 error = copyout(&pid, SCARG(uap, pid), sizeof(pid)); 2465 2466 *retval = error; 2467 return 0; 2468 2469 error_exit: 2470 if (!child_ok) { 2471 (void)chgproccnt(kauth_cred_getuid(l1->l_cred), -1); 2472 atomic_dec_uint(&nprocs); 2473 2474 if (sa) 2475 kmem_free(sa, sizeof(*sa)); 2476 if (fa) 2477 posix_spawn_fa_free(fa, fa->len); 2478 } 2479 2480 *retval = error; 2481 return 0; 2482 } 2483 2484 void 2485 exec_free_emul_arg(struct exec_package *epp) 2486 { 2487 if (epp->ep_emul_arg_free != NULL) { 2488 KASSERT(epp->ep_emul_arg != NULL); 2489 (*epp->ep_emul_arg_free)(epp->ep_emul_arg); 2490 epp->ep_emul_arg_free = NULL; 2491 epp->ep_emul_arg = NULL; 2492 } else { 2493 KASSERT(epp->ep_emul_arg == NULL); 2494 } 2495 } 2496