1 /* $NetBSD: kern_exec.c,v 1.478 2019/07/05 17:14:48 maxv 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 1.478 2019/07/05 17:14:48 maxv 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/ptrace.h> 78 #include <sys/mount.h> 79 #include <sys/kmem.h> 80 #include <sys/namei.h> 81 #include <sys/vnode.h> 82 #include <sys/file.h> 83 #include <sys/filedesc.h> 84 #include <sys/acct.h> 85 #include <sys/atomic.h> 86 #include <sys/exec.h> 87 #include <sys/ktrace.h> 88 #include <sys/uidinfo.h> 89 #include <sys/wait.h> 90 #include <sys/mman.h> 91 #include <sys/ras.h> 92 #include <sys/signalvar.h> 93 #include <sys/stat.h> 94 #include <sys/syscall.h> 95 #include <sys/kauth.h> 96 #include <sys/lwpctl.h> 97 #include <sys/pax.h> 98 #include <sys/cpu.h> 99 #include <sys/module.h> 100 #include <sys/syscallvar.h> 101 #include <sys/syscallargs.h> 102 #if NVERIEXEC > 0 103 #include <sys/verified_exec.h> 104 #endif /* NVERIEXEC > 0 */ 105 #include <sys/sdt.h> 106 #include <sys/spawn.h> 107 #include <sys/prot.h> 108 #include <sys/cprng.h> 109 110 #include <uvm/uvm_extern.h> 111 112 #include <machine/reg.h> 113 114 #include <compat/common/compat_util.h> 115 116 #ifndef MD_TOPDOWN_INIT 117 #ifdef __USE_TOPDOWN_VM 118 #define MD_TOPDOWN_INIT(epp) (epp)->ep_flags |= EXEC_TOPDOWN_VM 119 #else 120 #define MD_TOPDOWN_INIT(epp) 121 #endif 122 #endif 123 124 struct execve_data; 125 126 extern int user_va0_disable; 127 128 static size_t calcargs(struct execve_data * restrict, const size_t); 129 static size_t calcstack(struct execve_data * restrict, const size_t); 130 static int copyoutargs(struct execve_data * restrict, struct lwp *, 131 char * const); 132 static int copyoutpsstrs(struct execve_data * restrict, struct proc *); 133 static int copyinargs(struct execve_data * restrict, char * const *, 134 char * const *, execve_fetch_element_t, char **); 135 static int copyinargstrs(struct execve_data * restrict, char * const *, 136 execve_fetch_element_t, char **, size_t *, void (*)(const void *, size_t)); 137 static int exec_sigcode_map(struct proc *, const struct emul *); 138 139 #if defined(DEBUG) && !defined(DEBUG_EXEC) 140 #define DEBUG_EXEC 141 #endif 142 #ifdef DEBUG_EXEC 143 #define DPRINTF(a) printf a 144 #define COPYPRINTF(s, a, b) printf("%s, %d: copyout%s @%p %zu\n", __func__, \ 145 __LINE__, (s), (a), (b)) 146 static void dump_vmcmds(const struct exec_package * const, size_t, int); 147 #define DUMPVMCMDS(p, x, e) do { dump_vmcmds((p), (x), (e)); } while (0) 148 #else 149 #define DPRINTF(a) 150 #define COPYPRINTF(s, a, b) 151 #define DUMPVMCMDS(p, x, e) do {} while (0) 152 #endif /* DEBUG_EXEC */ 153 154 /* 155 * DTrace SDT provider definitions 156 */ 157 SDT_PROVIDER_DECLARE(proc); 158 SDT_PROBE_DEFINE1(proc, kernel, , exec, "char *"); 159 SDT_PROBE_DEFINE1(proc, kernel, , exec__success, "char *"); 160 SDT_PROBE_DEFINE1(proc, kernel, , exec__failure, "int"); 161 162 /* 163 * Exec function switch: 164 * 165 * Note that each makecmds function is responsible for loading the 166 * exec package with the necessary functions for any exec-type-specific 167 * handling. 168 * 169 * Functions for specific exec types should be defined in their own 170 * header file. 171 */ 172 static const struct execsw **execsw = NULL; 173 static int nexecs; 174 175 u_int exec_maxhdrsz; /* must not be static - used by netbsd32 */ 176 177 /* list of dynamically loaded execsw entries */ 178 static LIST_HEAD(execlist_head, exec_entry) ex_head = 179 LIST_HEAD_INITIALIZER(ex_head); 180 struct exec_entry { 181 LIST_ENTRY(exec_entry) ex_list; 182 SLIST_ENTRY(exec_entry) ex_slist; 183 const struct execsw *ex_sw; 184 }; 185 186 #ifndef __HAVE_SYSCALL_INTERN 187 void syscall(void); 188 #endif 189 190 /* NetBSD autoloadable syscalls */ 191 #ifdef MODULAR 192 #include <kern/syscalls_autoload.c> 193 #endif 194 195 /* NetBSD emul struct */ 196 struct emul emul_netbsd = { 197 .e_name = "netbsd", 198 #ifdef EMUL_NATIVEROOT 199 .e_path = EMUL_NATIVEROOT, 200 #else 201 .e_path = NULL, 202 #endif 203 #ifndef __HAVE_MINIMAL_EMUL 204 .e_flags = EMUL_HAS_SYS___syscall, 205 .e_errno = NULL, 206 .e_nosys = SYS_syscall, 207 .e_nsysent = SYS_NSYSENT, 208 #endif 209 #ifdef MODULAR 210 .e_sc_autoload = netbsd_syscalls_autoload, 211 #endif 212 .e_sysent = sysent, 213 .e_nomodbits = sysent_nomodbits, 214 #ifdef SYSCALL_DEBUG 215 .e_syscallnames = syscallnames, 216 #else 217 .e_syscallnames = NULL, 218 #endif 219 .e_sendsig = sendsig, 220 .e_trapsignal = trapsignal, 221 .e_sigcode = NULL, 222 .e_esigcode = NULL, 223 .e_sigobject = NULL, 224 .e_setregs = setregs, 225 .e_proc_exec = NULL, 226 .e_proc_fork = NULL, 227 .e_proc_exit = NULL, 228 .e_lwp_fork = NULL, 229 .e_lwp_exit = NULL, 230 #ifdef __HAVE_SYSCALL_INTERN 231 .e_syscall_intern = syscall_intern, 232 #else 233 .e_syscall = syscall, 234 #endif 235 .e_sysctlovly = NULL, 236 .e_vm_default_addr = uvm_default_mapaddr, 237 .e_usertrap = NULL, 238 .e_ucsize = sizeof(ucontext_t), 239 .e_startlwp = startlwp 240 }; 241 242 /* 243 * Exec lock. Used to control access to execsw[] structures. 244 * This must not be static so that netbsd32 can access it, too. 245 */ 246 krwlock_t exec_lock; 247 248 static kmutex_t sigobject_lock; 249 250 /* 251 * Data used between a loadvm and execve part of an "exec" operation 252 */ 253 struct execve_data { 254 struct exec_package ed_pack; 255 struct pathbuf *ed_pathbuf; 256 struct vattr ed_attr; 257 struct ps_strings ed_arginfo; 258 char *ed_argp; 259 const char *ed_pathstring; 260 char *ed_resolvedpathbuf; 261 size_t ed_ps_strings_sz; 262 int ed_szsigcode; 263 size_t ed_argslen; 264 long ed_argc; 265 long ed_envc; 266 }; 267 268 /* 269 * data passed from parent lwp to child during a posix_spawn() 270 */ 271 struct spawn_exec_data { 272 struct execve_data sed_exec; 273 struct posix_spawn_file_actions 274 *sed_actions; 275 struct posix_spawnattr *sed_attrs; 276 struct proc *sed_parent; 277 kcondvar_t sed_cv_child_ready; 278 kmutex_t sed_mtx_child; 279 int sed_error; 280 volatile uint32_t sed_refcnt; 281 }; 282 283 static struct vm_map *exec_map; 284 static struct pool exec_pool; 285 286 static void * 287 exec_pool_alloc(struct pool *pp, int flags) 288 { 289 290 return (void *)uvm_km_alloc(exec_map, NCARGS, 0, 291 UVM_KMF_PAGEABLE | UVM_KMF_WAITVA); 292 } 293 294 static void 295 exec_pool_free(struct pool *pp, void *addr) 296 { 297 298 uvm_km_free(exec_map, (vaddr_t)addr, NCARGS, UVM_KMF_PAGEABLE); 299 } 300 301 static struct pool_allocator exec_palloc = { 302 .pa_alloc = exec_pool_alloc, 303 .pa_free = exec_pool_free, 304 .pa_pagesz = NCARGS 305 }; 306 307 /* 308 * check exec: 309 * given an "executable" described in the exec package's namei info, 310 * see what we can do with it. 311 * 312 * ON ENTRY: 313 * exec package with appropriate namei info 314 * lwp pointer of exec'ing lwp 315 * NO SELF-LOCKED VNODES 316 * 317 * ON EXIT: 318 * error: nothing held, etc. exec header still allocated. 319 * ok: filled exec package, executable's vnode (unlocked). 320 * 321 * EXEC SWITCH ENTRY: 322 * Locked vnode to check, exec package, proc. 323 * 324 * EXEC SWITCH EXIT: 325 * ok: return 0, filled exec package, executable's vnode (unlocked). 326 * error: destructive: 327 * everything deallocated execept exec header. 328 * non-destructive: 329 * error code, executable's vnode (unlocked), 330 * exec header unmodified. 331 */ 332 int 333 /*ARGSUSED*/ 334 check_exec(struct lwp *l, struct exec_package *epp, struct pathbuf *pb) 335 { 336 int error, i; 337 struct vnode *vp; 338 struct nameidata nd; 339 size_t resid; 340 341 #if 1 342 // grab the absolute pathbuf here before namei() trashes it. 343 pathbuf_copystring(pb, epp->ep_resolvedname, PATH_MAX); 344 #endif 345 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb); 346 347 /* first get the vnode */ 348 if ((error = namei(&nd)) != 0) 349 return error; 350 epp->ep_vp = vp = nd.ni_vp; 351 #if 0 352 /* 353 * XXX: can't use nd.ni_pnbuf, because although pb contains an 354 * absolute path, nd.ni_pnbuf does not if the path contains symlinks. 355 */ 356 /* normally this can't fail */ 357 error = copystr(nd.ni_pnbuf, epp->ep_resolvedname, PATH_MAX, NULL); 358 KASSERT(error == 0); 359 #endif 360 361 #ifdef DIAGNOSTIC 362 /* paranoia (take this out once namei stuff stabilizes) */ 363 memset(nd.ni_pnbuf, '~', PATH_MAX); 364 #endif 365 366 /* check access and type */ 367 if (vp->v_type != VREG) { 368 error = EACCES; 369 goto bad1; 370 } 371 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 372 goto bad1; 373 374 /* get attributes */ 375 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 376 goto bad1; 377 378 /* Check mount point */ 379 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 380 error = EACCES; 381 goto bad1; 382 } 383 if (vp->v_mount->mnt_flag & MNT_NOSUID) 384 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 385 386 /* try to open it */ 387 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 388 goto bad1; 389 390 /* unlock vp, since we need it unlocked from here on out. */ 391 VOP_UNLOCK(vp); 392 393 #if NVERIEXEC > 0 394 error = veriexec_verify(l, vp, epp->ep_resolvedname, 395 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 396 NULL); 397 if (error) 398 goto bad2; 399 #endif /* NVERIEXEC > 0 */ 400 401 #ifdef PAX_SEGVGUARD 402 error = pax_segvguard(l, vp, epp->ep_resolvedname, false); 403 if (error) 404 goto bad2; 405 #endif /* PAX_SEGVGUARD */ 406 407 /* now we have the file, get the exec header */ 408 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 409 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 410 if (error) 411 goto bad2; 412 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 413 414 /* 415 * Set up default address space limits. Can be overridden 416 * by individual exec packages. 417 */ 418 epp->ep_vm_minaddr = exec_vm_minaddr(VM_MIN_ADDRESS); 419 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 420 421 /* 422 * set up the vmcmds for creation of the process 423 * address space 424 */ 425 error = ENOEXEC; 426 for (i = 0; i < nexecs; i++) { 427 int newerror; 428 429 epp->ep_esch = execsw[i]; 430 newerror = (*execsw[i]->es_makecmds)(l, epp); 431 432 if (!newerror) { 433 /* Seems ok: check that entry point is not too high */ 434 if (epp->ep_entry >= epp->ep_vm_maxaddr) { 435 #ifdef DIAGNOSTIC 436 printf("%s: rejecting %p due to " 437 "too high entry address (>= %p)\n", 438 __func__, (void *)epp->ep_entry, 439 (void *)epp->ep_vm_maxaddr); 440 #endif 441 error = ENOEXEC; 442 break; 443 } 444 /* Seems ok: check that entry point is not too low */ 445 if (epp->ep_entry < epp->ep_vm_minaddr) { 446 #ifdef DIAGNOSTIC 447 printf("%s: rejecting %p due to " 448 "too low entry address (< %p)\n", 449 __func__, (void *)epp->ep_entry, 450 (void *)epp->ep_vm_minaddr); 451 #endif 452 error = ENOEXEC; 453 break; 454 } 455 456 /* check limits */ 457 if ((epp->ep_tsize > MAXTSIZ) || 458 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 459 [RLIMIT_DATA].rlim_cur)) { 460 #ifdef DIAGNOSTIC 461 printf("%s: rejecting due to " 462 "limits (t=%llu > %llu || d=%llu > %llu)\n", 463 __func__, 464 (unsigned long long)epp->ep_tsize, 465 (unsigned long long)MAXTSIZ, 466 (unsigned long long)epp->ep_dsize, 467 (unsigned long long) 468 l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur); 469 #endif 470 error = ENOMEM; 471 break; 472 } 473 return 0; 474 } 475 476 /* 477 * Reset all the fields that may have been modified by the 478 * loader. 479 */ 480 KASSERT(epp->ep_emul_arg == NULL); 481 if (epp->ep_emul_root != NULL) { 482 vrele(epp->ep_emul_root); 483 epp->ep_emul_root = NULL; 484 } 485 if (epp->ep_interp != NULL) { 486 vrele(epp->ep_interp); 487 epp->ep_interp = NULL; 488 } 489 epp->ep_pax_flags = 0; 490 491 /* make sure the first "interesting" error code is saved. */ 492 if (error == ENOEXEC) 493 error = newerror; 494 495 if (epp->ep_flags & EXEC_DESTR) 496 /* Error from "#!" code, tidied up by recursive call */ 497 return error; 498 } 499 500 /* not found, error */ 501 502 /* 503 * free any vmspace-creation commands, 504 * and release their references 505 */ 506 kill_vmcmds(&epp->ep_vmcmds); 507 508 bad2: 509 /* 510 * close and release the vnode, restore the old one, free the 511 * pathname buf, and punt. 512 */ 513 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 514 VOP_CLOSE(vp, FREAD, l->l_cred); 515 vput(vp); 516 return error; 517 518 bad1: 519 /* 520 * free the namei pathname buffer, and put the vnode 521 * (which we don't yet have open). 522 */ 523 vput(vp); /* was still locked */ 524 return error; 525 } 526 527 #ifdef __MACHINE_STACK_GROWS_UP 528 #define STACK_PTHREADSPACE NBPG 529 #else 530 #define STACK_PTHREADSPACE 0 531 #endif 532 533 static int 534 execve_fetch_element(char * const *array, size_t index, char **value) 535 { 536 return copyin(array + index, value, sizeof(*value)); 537 } 538 539 /* 540 * exec system call 541 */ 542 int 543 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 544 { 545 /* { 546 syscallarg(const char *) path; 547 syscallarg(char * const *) argp; 548 syscallarg(char * const *) envp; 549 } */ 550 551 return execve1(l, SCARG(uap, path), SCARG(uap, argp), 552 SCARG(uap, envp), execve_fetch_element); 553 } 554 555 int 556 sys_fexecve(struct lwp *l, const struct sys_fexecve_args *uap, 557 register_t *retval) 558 { 559 /* { 560 syscallarg(int) fd; 561 syscallarg(char * const *) argp; 562 syscallarg(char * const *) envp; 563 } */ 564 565 return ENOSYS; 566 } 567 568 /* 569 * Load modules to try and execute an image that we do not understand. 570 * If no execsw entries are present, we load those likely to be needed 571 * in order to run native images only. Otherwise, we autoload all 572 * possible modules that could let us run the binary. XXX lame 573 */ 574 static void 575 exec_autoload(void) 576 { 577 #ifdef MODULAR 578 static const char * const native[] = { 579 "exec_elf32", 580 "exec_elf64", 581 "exec_script", 582 NULL 583 }; 584 static const char * const compat[] = { 585 "exec_elf32", 586 "exec_elf64", 587 "exec_script", 588 "exec_aout", 589 "exec_coff", 590 "exec_ecoff", 591 "compat_aoutm68k", 592 "compat_netbsd32", 593 "compat_sunos", 594 "compat_sunos32", 595 "compat_ultrix", 596 NULL 597 }; 598 char const * const *list; 599 int i; 600 601 list = (nexecs == 0 ? native : compat); 602 for (i = 0; list[i] != NULL; i++) { 603 if (module_autoload(list[i], MODULE_CLASS_EXEC) != 0) { 604 continue; 605 } 606 yield(); 607 } 608 #endif 609 } 610 611 /* 612 * Copy the user or kernel supplied upath to the allocated pathbuffer pbp 613 * making it absolute in the process, by prepending the current working 614 * directory if it is not. If offs is supplied it will contain the offset 615 * where the original supplied copy of upath starts. 616 */ 617 int 618 exec_makepathbuf(struct lwp *l, const char *upath, enum uio_seg seg, 619 struct pathbuf **pbp, size_t *offs) 620 { 621 char *path, *bp; 622 size_t len, tlen; 623 int error; 624 struct cwdinfo *cwdi; 625 626 path = PNBUF_GET(); 627 if (seg == UIO_SYSSPACE) { 628 error = copystr(upath, path, MAXPATHLEN, &len); 629 } else { 630 error = copyinstr(upath, path, MAXPATHLEN, &len); 631 } 632 if (error) 633 goto err; 634 635 if (path[0] == '/') { 636 if (offs) 637 *offs = 0; 638 goto out; 639 } 640 641 len++; 642 if (len + 1 >= MAXPATHLEN) { 643 error = ENAMETOOLONG; 644 goto err; 645 } 646 bp = path + MAXPATHLEN - len; 647 memmove(bp, path, len); 648 *(--bp) = '/'; 649 650 cwdi = l->l_proc->p_cwdi; 651 rw_enter(&cwdi->cwdi_lock, RW_READER); 652 error = getcwd_common(cwdi->cwdi_cdir, NULL, &bp, path, MAXPATHLEN / 2, 653 GETCWD_CHECK_ACCESS, l); 654 rw_exit(&cwdi->cwdi_lock); 655 656 if (error) 657 goto err; 658 tlen = path + MAXPATHLEN - bp; 659 660 memmove(path, bp, tlen); 661 path[tlen - 1] = '\0'; 662 if (offs) 663 *offs = tlen - len; 664 out: 665 *pbp = pathbuf_assimilate(path); 666 return 0; 667 err: 668 PNBUF_PUT(path); 669 return error; 670 } 671 672 vaddr_t 673 exec_vm_minaddr(vaddr_t va_min) 674 { 675 /* 676 * Increase va_min if we don't want NULL to be mappable by the 677 * process. 678 */ 679 #define VM_MIN_GUARD PAGE_SIZE 680 if (user_va0_disable && (va_min < VM_MIN_GUARD)) 681 return VM_MIN_GUARD; 682 return va_min; 683 } 684 685 static int 686 execve_loadvm(struct lwp *l, const char *path, char * const *args, 687 char * const *envs, execve_fetch_element_t fetch_element, 688 struct execve_data * restrict data) 689 { 690 struct exec_package * const epp = &data->ed_pack; 691 int error; 692 struct proc *p; 693 char *dp; 694 u_int modgen; 695 size_t offs; 696 697 KASSERT(data != NULL); 698 699 p = l->l_proc; 700 modgen = 0; 701 702 SDT_PROBE(proc, kernel, , exec, path, 0, 0, 0, 0); 703 704 /* 705 * Check if we have exceeded our number of processes limit. 706 * This is so that we handle the case where a root daemon 707 * forked, ran setuid to become the desired user and is trying 708 * to exec. The obvious place to do the reference counting check 709 * is setuid(), but we don't do the reference counting check there 710 * like other OS's do because then all the programs that use setuid() 711 * must be modified to check the return code of setuid() and exit(). 712 * It is dangerous to make setuid() fail, because it fails open and 713 * the program will continue to run as root. If we make it succeed 714 * and return an error code, again we are not enforcing the limit. 715 * The best place to enforce the limit is here, when the process tries 716 * to execute a new image, because eventually the process will need 717 * to call exec in order to do something useful. 718 */ 719 retry: 720 if (p->p_flag & PK_SUGID) { 721 if (kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT, 722 p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 723 &p->p_rlimit[RLIMIT_NPROC], 724 KAUTH_ARG(RLIMIT_NPROC)) != 0 && 725 chgproccnt(kauth_cred_getuid(l->l_cred), 0) > 726 p->p_rlimit[RLIMIT_NPROC].rlim_cur) 727 return EAGAIN; 728 } 729 730 /* 731 * Drain existing references and forbid new ones. The process 732 * should be left alone until we're done here. This is necessary 733 * to avoid race conditions - e.g. in ptrace() - that might allow 734 * a local user to illicitly obtain elevated privileges. 735 */ 736 rw_enter(&p->p_reflock, RW_WRITER); 737 738 /* 739 * Init the namei data to point the file user's program name. 740 * This is done here rather than in check_exec(), so that it's 741 * possible to override this settings if any of makecmd/probe 742 * functions call check_exec() recursively - for example, 743 * see exec_script_makecmds(). 744 */ 745 if ((error = exec_makepathbuf(l, path, UIO_USERSPACE, 746 &data->ed_pathbuf, &offs)) != 0) 747 goto clrflg; 748 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 749 data->ed_resolvedpathbuf = PNBUF_GET(); 750 751 /* 752 * initialize the fields of the exec package. 753 */ 754 epp->ep_kname = data->ed_pathstring + offs; 755 epp->ep_resolvedname = data->ed_resolvedpathbuf; 756 epp->ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 757 epp->ep_hdrlen = exec_maxhdrsz; 758 epp->ep_hdrvalid = 0; 759 epp->ep_emul_arg = NULL; 760 epp->ep_emul_arg_free = NULL; 761 memset(&epp->ep_vmcmds, 0, sizeof(epp->ep_vmcmds)); 762 epp->ep_vap = &data->ed_attr; 763 epp->ep_flags = (p->p_flag & PK_32) ? EXEC_FROM32 : 0; 764 MD_TOPDOWN_INIT(epp); 765 epp->ep_emul_root = NULL; 766 epp->ep_interp = NULL; 767 epp->ep_esch = NULL; 768 epp->ep_pax_flags = 0; 769 memset(epp->ep_machine_arch, 0, sizeof(epp->ep_machine_arch)); 770 771 rw_enter(&exec_lock, RW_READER); 772 773 /* see if we can run it. */ 774 if ((error = check_exec(l, epp, data->ed_pathbuf)) != 0) { 775 if (error != ENOENT && error != EACCES && error != ENOEXEC) { 776 DPRINTF(("%s: check exec failed for %s, error %d\n", 777 __func__, epp->ep_kname, error)); 778 } 779 goto freehdr; 780 } 781 782 /* allocate an argument buffer */ 783 data->ed_argp = pool_get(&exec_pool, PR_WAITOK); 784 KASSERT(data->ed_argp != NULL); 785 dp = data->ed_argp; 786 787 if ((error = copyinargs(data, args, envs, fetch_element, &dp)) != 0) { 788 goto bad; 789 } 790 791 /* 792 * Calculate the new stack size. 793 */ 794 795 #ifdef __MACHINE_STACK_GROWS_UP 796 /* 797 * copyargs() fills argc/argv/envp from the lower address even on 798 * __MACHINE_STACK_GROWS_UP machines. Reserve a few words just below the SP 799 * so that _rtld() use it. 800 */ 801 #define RTLD_GAP 32 802 #else 803 #define RTLD_GAP 0 804 #endif 805 806 const size_t argenvstrlen = (char *)ALIGN(dp) - data->ed_argp; 807 808 data->ed_argslen = calcargs(data, argenvstrlen); 809 810 const size_t len = calcstack(data, pax_aslr_stack_gap(epp) + RTLD_GAP); 811 812 if (len > epp->ep_ssize) { 813 /* in effect, compare to initial limit */ 814 DPRINTF(("%s: stack limit exceeded %zu\n", __func__, len)); 815 error = ENOMEM; 816 goto bad; 817 } 818 /* adjust "active stack depth" for process VSZ */ 819 epp->ep_ssize = len; 820 821 return 0; 822 823 bad: 824 /* free the vmspace-creation commands, and release their references */ 825 kill_vmcmds(&epp->ep_vmcmds); 826 /* kill any opened file descriptor, if necessary */ 827 if (epp->ep_flags & EXEC_HASFD) { 828 epp->ep_flags &= ~EXEC_HASFD; 829 fd_close(epp->ep_fd); 830 } 831 /* close and put the exec'd file */ 832 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 833 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 834 vput(epp->ep_vp); 835 pool_put(&exec_pool, data->ed_argp); 836 837 freehdr: 838 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 839 if (epp->ep_emul_root != NULL) 840 vrele(epp->ep_emul_root); 841 if (epp->ep_interp != NULL) 842 vrele(epp->ep_interp); 843 844 rw_exit(&exec_lock); 845 846 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 847 pathbuf_destroy(data->ed_pathbuf); 848 PNBUF_PUT(data->ed_resolvedpathbuf); 849 850 clrflg: 851 rw_exit(&p->p_reflock); 852 853 if (modgen != module_gen && error == ENOEXEC) { 854 modgen = module_gen; 855 exec_autoload(); 856 goto retry; 857 } 858 859 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 860 return error; 861 } 862 863 static int 864 execve_dovmcmds(struct lwp *l, struct execve_data * restrict data) 865 { 866 struct exec_package * const epp = &data->ed_pack; 867 struct proc *p = l->l_proc; 868 struct exec_vmcmd *base_vcp; 869 int error = 0; 870 size_t i; 871 872 /* record proc's vnode, for use by procfs and others */ 873 if (p->p_textvp) 874 vrele(p->p_textvp); 875 vref(epp->ep_vp); 876 p->p_textvp = epp->ep_vp; 877 878 /* create the new process's VM space by running the vmcmds */ 879 KASSERTMSG(epp->ep_vmcmds.evs_used != 0, "%s: no vmcmds", __func__); 880 881 #ifdef TRACE_EXEC 882 DUMPVMCMDS(epp, 0, 0); 883 #endif 884 885 base_vcp = NULL; 886 887 for (i = 0; i < epp->ep_vmcmds.evs_used && !error; i++) { 888 struct exec_vmcmd *vcp; 889 890 vcp = &epp->ep_vmcmds.evs_cmds[i]; 891 if (vcp->ev_flags & VMCMD_RELATIVE) { 892 KASSERTMSG(base_vcp != NULL, 893 "%s: relative vmcmd with no base", __func__); 894 KASSERTMSG((vcp->ev_flags & VMCMD_BASE) == 0, 895 "%s: illegal base & relative vmcmd", __func__); 896 vcp->ev_addr += base_vcp->ev_addr; 897 } 898 error = (*vcp->ev_proc)(l, vcp); 899 if (error) 900 DUMPVMCMDS(epp, i, error); 901 if (vcp->ev_flags & VMCMD_BASE) 902 base_vcp = vcp; 903 } 904 905 /* free the vmspace-creation commands, and release their references */ 906 kill_vmcmds(&epp->ep_vmcmds); 907 908 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 909 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 910 vput(epp->ep_vp); 911 912 /* if an error happened, deallocate and punt */ 913 if (error != 0) { 914 DPRINTF(("%s: vmcmd %zu failed: %d\n", __func__, i - 1, error)); 915 } 916 return error; 917 } 918 919 static void 920 execve_free_data(struct execve_data *data) 921 { 922 struct exec_package * const epp = &data->ed_pack; 923 924 /* free the vmspace-creation commands, and release their references */ 925 kill_vmcmds(&epp->ep_vmcmds); 926 /* kill any opened file descriptor, if necessary */ 927 if (epp->ep_flags & EXEC_HASFD) { 928 epp->ep_flags &= ~EXEC_HASFD; 929 fd_close(epp->ep_fd); 930 } 931 932 /* close and put the exec'd file */ 933 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 934 VOP_CLOSE(epp->ep_vp, FREAD, curlwp->l_cred); 935 vput(epp->ep_vp); 936 pool_put(&exec_pool, data->ed_argp); 937 938 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 939 if (epp->ep_emul_root != NULL) 940 vrele(epp->ep_emul_root); 941 if (epp->ep_interp != NULL) 942 vrele(epp->ep_interp); 943 944 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 945 pathbuf_destroy(data->ed_pathbuf); 946 PNBUF_PUT(data->ed_resolvedpathbuf); 947 } 948 949 static void 950 pathexec(struct proc *p, const char *resolvedname) 951 { 952 KASSERT(resolvedname[0] == '/'); 953 954 /* set command name & other accounting info */ 955 strlcpy(p->p_comm, strrchr(resolvedname, '/') + 1, sizeof(p->p_comm)); 956 957 kmem_strfree(p->p_path); 958 p->p_path = kmem_strdupsize(resolvedname, NULL, KM_SLEEP); 959 } 960 961 /* XXX elsewhere */ 962 static int 963 credexec(struct lwp *l, struct vattr *attr) 964 { 965 struct proc *p = l->l_proc; 966 int error; 967 968 /* 969 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 970 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 971 * out additional references on the process for the moment. 972 */ 973 if ((p->p_slflag & PSL_TRACED) == 0 && 974 975 (((attr->va_mode & S_ISUID) != 0 && 976 kauth_cred_geteuid(l->l_cred) != attr->va_uid) || 977 978 ((attr->va_mode & S_ISGID) != 0 && 979 kauth_cred_getegid(l->l_cred) != attr->va_gid))) { 980 /* 981 * Mark the process as SUGID before we do 982 * anything that might block. 983 */ 984 proc_crmod_enter(); 985 proc_crmod_leave(NULL, NULL, true); 986 987 /* Make sure file descriptors 0..2 are in use. */ 988 if ((error = fd_checkstd()) != 0) { 989 DPRINTF(("%s: fdcheckstd failed %d\n", 990 __func__, error)); 991 return error; 992 } 993 994 /* 995 * Copy the credential so other references don't see our 996 * changes. 997 */ 998 l->l_cred = kauth_cred_copy(l->l_cred); 999 #ifdef KTRACE 1000 /* 1001 * If the persistent trace flag isn't set, turn off. 1002 */ 1003 if (p->p_tracep) { 1004 mutex_enter(&ktrace_lock); 1005 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1006 ktrderef(p); 1007 mutex_exit(&ktrace_lock); 1008 } 1009 #endif 1010 if (attr->va_mode & S_ISUID) 1011 kauth_cred_seteuid(l->l_cred, attr->va_uid); 1012 if (attr->va_mode & S_ISGID) 1013 kauth_cred_setegid(l->l_cred, attr->va_gid); 1014 } else { 1015 if (kauth_cred_geteuid(l->l_cred) == 1016 kauth_cred_getuid(l->l_cred) && 1017 kauth_cred_getegid(l->l_cred) == 1018 kauth_cred_getgid(l->l_cred)) 1019 p->p_flag &= ~PK_SUGID; 1020 } 1021 1022 /* 1023 * Copy the credential so other references don't see our changes. 1024 * Test to see if this is necessary first, since in the common case 1025 * we won't need a private reference. 1026 */ 1027 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1028 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1029 l->l_cred = kauth_cred_copy(l->l_cred); 1030 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1031 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1032 } 1033 1034 /* Update the master credentials. */ 1035 if (l->l_cred != p->p_cred) { 1036 kauth_cred_t ocred; 1037 1038 kauth_cred_hold(l->l_cred); 1039 mutex_enter(p->p_lock); 1040 ocred = p->p_cred; 1041 p->p_cred = l->l_cred; 1042 mutex_exit(p->p_lock); 1043 kauth_cred_free(ocred); 1044 } 1045 1046 return 0; 1047 } 1048 1049 static void 1050 emulexec(struct lwp *l, struct exec_package *epp) 1051 { 1052 struct proc *p = l->l_proc; 1053 1054 /* The emulation root will usually have been found when we looked 1055 * for the elf interpreter (or similar), if not look now. */ 1056 if (epp->ep_esch->es_emul->e_path != NULL && 1057 epp->ep_emul_root == NULL) 1058 emul_find_root(l, epp); 1059 1060 /* Any old emulation root got removed by fdcloseexec */ 1061 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1062 p->p_cwdi->cwdi_edir = epp->ep_emul_root; 1063 rw_exit(&p->p_cwdi->cwdi_lock); 1064 epp->ep_emul_root = NULL; 1065 if (epp->ep_interp != NULL) 1066 vrele(epp->ep_interp); 1067 1068 /* 1069 * Call emulation specific exec hook. This can setup per-process 1070 * p->p_emuldata or do any other per-process stuff an emulation needs. 1071 * 1072 * If we are executing process of different emulation than the 1073 * original forked process, call e_proc_exit() of the old emulation 1074 * first, then e_proc_exec() of new emulation. If the emulation is 1075 * same, the exec hook code should deallocate any old emulation 1076 * resources held previously by this process. 1077 */ 1078 if (p->p_emul && p->p_emul->e_proc_exit 1079 && p->p_emul != epp->ep_esch->es_emul) 1080 (*p->p_emul->e_proc_exit)(p); 1081 1082 /* 1083 * This is now LWP 1. 1084 */ 1085 /* XXX elsewhere */ 1086 mutex_enter(p->p_lock); 1087 p->p_nlwpid = 1; 1088 l->l_lid = 1; 1089 mutex_exit(p->p_lock); 1090 1091 /* 1092 * Call exec hook. Emulation code may NOT store reference to anything 1093 * from &pack. 1094 */ 1095 if (epp->ep_esch->es_emul->e_proc_exec) 1096 (*epp->ep_esch->es_emul->e_proc_exec)(p, epp); 1097 1098 /* update p_emul, the old value is no longer needed */ 1099 p->p_emul = epp->ep_esch->es_emul; 1100 1101 /* ...and the same for p_execsw */ 1102 p->p_execsw = epp->ep_esch; 1103 1104 #ifdef __HAVE_SYSCALL_INTERN 1105 (*p->p_emul->e_syscall_intern)(p); 1106 #endif 1107 ktremul(); 1108 } 1109 1110 static int 1111 execve_runproc(struct lwp *l, struct execve_data * restrict data, 1112 bool no_local_exec_lock, bool is_spawn) 1113 { 1114 struct exec_package * const epp = &data->ed_pack; 1115 int error = 0; 1116 struct proc *p; 1117 1118 /* 1119 * In case of a posix_spawn operation, the child doing the exec 1120 * might not hold the reader lock on exec_lock, but the parent 1121 * will do this instead. 1122 */ 1123 KASSERT(no_local_exec_lock || rw_lock_held(&exec_lock)); 1124 KASSERT(!no_local_exec_lock || is_spawn); 1125 KASSERT(data != NULL); 1126 1127 p = l->l_proc; 1128 1129 /* Get rid of other LWPs. */ 1130 if (p->p_nlwps > 1) { 1131 mutex_enter(p->p_lock); 1132 exit_lwps(l); 1133 mutex_exit(p->p_lock); 1134 } 1135 KDASSERT(p->p_nlwps == 1); 1136 1137 /* Destroy any lwpctl info. */ 1138 if (p->p_lwpctl != NULL) 1139 lwp_ctl_exit(); 1140 1141 /* Remove POSIX timers */ 1142 timers_free(p, TIMERS_POSIX); 1143 1144 /* Set the PaX flags. */ 1145 pax_set_flags(epp, p); 1146 1147 /* 1148 * Do whatever is necessary to prepare the address space 1149 * for remapping. Note that this might replace the current 1150 * vmspace with another! 1151 */ 1152 if (is_spawn) 1153 uvmspace_spawn(l, epp->ep_vm_minaddr, 1154 epp->ep_vm_maxaddr, 1155 epp->ep_flags & EXEC_TOPDOWN_VM); 1156 else 1157 uvmspace_exec(l, epp->ep_vm_minaddr, 1158 epp->ep_vm_maxaddr, 1159 epp->ep_flags & EXEC_TOPDOWN_VM); 1160 1161 struct vmspace *vm; 1162 vm = p->p_vmspace; 1163 vm->vm_taddr = (void *)epp->ep_taddr; 1164 vm->vm_tsize = btoc(epp->ep_tsize); 1165 vm->vm_daddr = (void*)epp->ep_daddr; 1166 vm->vm_dsize = btoc(epp->ep_dsize); 1167 vm->vm_ssize = btoc(epp->ep_ssize); 1168 vm->vm_issize = 0; 1169 vm->vm_maxsaddr = (void *)epp->ep_maxsaddr; 1170 vm->vm_minsaddr = (void *)epp->ep_minsaddr; 1171 1172 pax_aslr_init_vm(l, vm, epp); 1173 1174 /* Now map address space. */ 1175 error = execve_dovmcmds(l, data); 1176 if (error != 0) 1177 goto exec_abort; 1178 1179 pathexec(p, epp->ep_resolvedname); 1180 1181 char * const newstack = STACK_GROW(vm->vm_minsaddr, epp->ep_ssize); 1182 1183 error = copyoutargs(data, l, newstack); 1184 if (error != 0) 1185 goto exec_abort; 1186 1187 cwdexec(p); 1188 fd_closeexec(); /* handle close on exec */ 1189 1190 if (__predict_false(ktrace_on)) 1191 fd_ktrexecfd(); 1192 1193 execsigs(p); /* reset caught signals */ 1194 1195 mutex_enter(p->p_lock); 1196 l->l_ctxlink = NULL; /* reset ucontext link */ 1197 p->p_acflag &= ~AFORK; 1198 p->p_flag |= PK_EXEC; 1199 mutex_exit(p->p_lock); 1200 1201 /* 1202 * Stop profiling. 1203 */ 1204 if ((p->p_stflag & PST_PROFIL) != 0) { 1205 mutex_spin_enter(&p->p_stmutex); 1206 stopprofclock(p); 1207 mutex_spin_exit(&p->p_stmutex); 1208 } 1209 1210 /* 1211 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 1212 * exited and exec()/exit() are the only places it will be cleared. 1213 */ 1214 if ((p->p_lflag & PL_PPWAIT) != 0) { 1215 lwp_t *lp; 1216 1217 mutex_enter(proc_lock); 1218 lp = p->p_vforklwp; 1219 p->p_vforklwp = NULL; 1220 1221 l->l_lwpctl = NULL; /* was on loan from blocked parent */ 1222 p->p_lflag &= ~PL_PPWAIT; 1223 lp->l_vforkwaiting = false; 1224 1225 cv_broadcast(&lp->l_waitcv); 1226 mutex_exit(proc_lock); 1227 } 1228 1229 error = credexec(l, &data->ed_attr); 1230 if (error) 1231 goto exec_abort; 1232 1233 #if defined(__HAVE_RAS) 1234 /* 1235 * Remove all RASs from the address space. 1236 */ 1237 ras_purgeall(); 1238 #endif 1239 1240 doexechooks(p); 1241 1242 /* 1243 * Set initial SP at the top of the stack. 1244 * 1245 * Note that on machines where stack grows up (e.g. hppa), SP points to 1246 * the end of arg/env strings. Userland guesses the address of argc 1247 * via ps_strings::ps_argvstr. 1248 */ 1249 1250 /* Setup new registers and do misc. setup. */ 1251 (*epp->ep_esch->es_emul->e_setregs)(l, epp, (vaddr_t)newstack); 1252 if (epp->ep_esch->es_setregs) 1253 (*epp->ep_esch->es_setregs)(l, epp, (vaddr_t)newstack); 1254 1255 /* Provide a consistent LWP private setting */ 1256 (void)lwp_setprivate(l, NULL); 1257 1258 /* Discard all PCU state; need to start fresh */ 1259 pcu_discard_all(l); 1260 1261 /* map the process's signal trampoline code */ 1262 if ((error = exec_sigcode_map(p, epp->ep_esch->es_emul)) != 0) { 1263 DPRINTF(("%s: map sigcode failed %d\n", __func__, error)); 1264 goto exec_abort; 1265 } 1266 1267 pool_put(&exec_pool, data->ed_argp); 1268 1269 /* notify others that we exec'd */ 1270 KNOTE(&p->p_klist, NOTE_EXEC); 1271 1272 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1273 1274 SDT_PROBE(proc, kernel, , exec__success, epp->ep_kname, 0, 0, 0, 0); 1275 1276 emulexec(l, epp); 1277 1278 /* Allow new references from the debugger/procfs. */ 1279 rw_exit(&p->p_reflock); 1280 if (!no_local_exec_lock) 1281 rw_exit(&exec_lock); 1282 1283 mutex_enter(proc_lock); 1284 1285 /* posix_spawn(3) reports a single event with implied exec(3) */ 1286 if ((p->p_slflag & PSL_TRACED) && !is_spawn) { 1287 mutex_enter(p->p_lock); 1288 eventswitch(TRAP_EXEC); 1289 mutex_enter(proc_lock); 1290 } 1291 1292 if (p->p_sflag & PS_STOPEXEC) { 1293 ksiginfoq_t kq; 1294 1295 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1296 p->p_pptr->p_nstopchild++; 1297 p->p_waited = 0; 1298 mutex_enter(p->p_lock); 1299 ksiginfo_queue_init(&kq); 1300 sigclearall(p, &contsigmask, &kq); 1301 lwp_lock(l); 1302 l->l_stat = LSSTOP; 1303 p->p_stat = SSTOP; 1304 p->p_nrlwps--; 1305 lwp_unlock(l); 1306 mutex_exit(p->p_lock); 1307 mutex_exit(proc_lock); 1308 lwp_lock(l); 1309 mi_switch(l); 1310 ksiginfo_queue_drain(&kq); 1311 KERNEL_LOCK(l->l_biglocks, l); 1312 } else { 1313 mutex_exit(proc_lock); 1314 } 1315 1316 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 1317 pathbuf_destroy(data->ed_pathbuf); 1318 PNBUF_PUT(data->ed_resolvedpathbuf); 1319 #ifdef TRACE_EXEC 1320 DPRINTF(("%s finished\n", __func__)); 1321 #endif 1322 return EJUSTRETURN; 1323 1324 exec_abort: 1325 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 1326 rw_exit(&p->p_reflock); 1327 if (!no_local_exec_lock) 1328 rw_exit(&exec_lock); 1329 1330 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 1331 pathbuf_destroy(data->ed_pathbuf); 1332 PNBUF_PUT(data->ed_resolvedpathbuf); 1333 1334 /* 1335 * the old process doesn't exist anymore. exit gracefully. 1336 * get rid of the (new) address space we have created, if any, get rid 1337 * of our namei data and vnode, and exit noting failure 1338 */ 1339 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1340 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1341 1342 exec_free_emul_arg(epp); 1343 pool_put(&exec_pool, data->ed_argp); 1344 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1345 if (epp->ep_emul_root != NULL) 1346 vrele(epp->ep_emul_root); 1347 if (epp->ep_interp != NULL) 1348 vrele(epp->ep_interp); 1349 1350 /* Acquire the sched-state mutex (exit1() will release it). */ 1351 if (!is_spawn) { 1352 mutex_enter(p->p_lock); 1353 exit1(l, error, SIGABRT); 1354 } 1355 1356 return error; 1357 } 1358 1359 int 1360 execve1(struct lwp *l, const char *path, char * const *args, 1361 char * const *envs, execve_fetch_element_t fetch_element) 1362 { 1363 struct execve_data data; 1364 int error; 1365 1366 error = execve_loadvm(l, path, args, envs, fetch_element, &data); 1367 if (error) 1368 return error; 1369 error = execve_runproc(l, &data, false, false); 1370 return error; 1371 } 1372 1373 static size_t 1374 fromptrsz(const struct exec_package *epp) 1375 { 1376 return (epp->ep_flags & EXEC_FROM32) ? sizeof(int) : sizeof(char *); 1377 } 1378 1379 static size_t 1380 ptrsz(const struct exec_package *epp) 1381 { 1382 return (epp->ep_flags & EXEC_32) ? sizeof(int) : sizeof(char *); 1383 } 1384 1385 static size_t 1386 calcargs(struct execve_data * restrict data, const size_t argenvstrlen) 1387 { 1388 struct exec_package * const epp = &data->ed_pack; 1389 1390 const size_t nargenvptrs = 1391 1 + /* long argc */ 1392 data->ed_argc + /* char *argv[] */ 1393 1 + /* \0 */ 1394 data->ed_envc + /* char *env[] */ 1395 1; /* \0 */ 1396 1397 return (nargenvptrs * ptrsz(epp)) /* pointers */ 1398 + argenvstrlen /* strings */ 1399 + epp->ep_esch->es_arglen; /* auxinfo */ 1400 } 1401 1402 static size_t 1403 calcstack(struct execve_data * restrict data, const size_t gaplen) 1404 { 1405 struct exec_package * const epp = &data->ed_pack; 1406 1407 data->ed_szsigcode = epp->ep_esch->es_emul->e_esigcode - 1408 epp->ep_esch->es_emul->e_sigcode; 1409 1410 data->ed_ps_strings_sz = (epp->ep_flags & EXEC_32) ? 1411 sizeof(struct ps_strings32) : sizeof(struct ps_strings); 1412 1413 const size_t sigcode_psstr_sz = 1414 data->ed_szsigcode + /* sigcode */ 1415 data->ed_ps_strings_sz + /* ps_strings */ 1416 STACK_PTHREADSPACE; /* pthread space */ 1417 1418 const size_t stacklen = 1419 data->ed_argslen + 1420 gaplen + 1421 sigcode_psstr_sz; 1422 1423 /* make the stack "safely" aligned */ 1424 return STACK_LEN_ALIGN(stacklen, STACK_ALIGNBYTES); 1425 } 1426 1427 static int 1428 copyoutargs(struct execve_data * restrict data, struct lwp *l, 1429 char * const newstack) 1430 { 1431 struct exec_package * const epp = &data->ed_pack; 1432 struct proc *p = l->l_proc; 1433 int error; 1434 1435 memset(&data->ed_arginfo, 0, sizeof(data->ed_arginfo)); 1436 1437 /* remember information about the process */ 1438 data->ed_arginfo.ps_nargvstr = data->ed_argc; 1439 data->ed_arginfo.ps_nenvstr = data->ed_envc; 1440 1441 /* 1442 * Allocate the stack address passed to the newly execve()'ed process. 1443 * 1444 * The new stack address will be set to the SP (stack pointer) register 1445 * in setregs(). 1446 */ 1447 1448 char *newargs = STACK_ALLOC( 1449 STACK_SHRINK(newstack, data->ed_argslen), data->ed_argslen); 1450 1451 error = (*epp->ep_esch->es_copyargs)(l, epp, 1452 &data->ed_arginfo, &newargs, data->ed_argp); 1453 1454 if (error) { 1455 DPRINTF(("%s: copyargs failed %d\n", __func__, error)); 1456 return error; 1457 } 1458 1459 error = copyoutpsstrs(data, p); 1460 if (error != 0) 1461 return error; 1462 1463 return 0; 1464 } 1465 1466 static int 1467 copyoutpsstrs(struct execve_data * restrict data, struct proc *p) 1468 { 1469 struct exec_package * const epp = &data->ed_pack; 1470 struct ps_strings32 arginfo32; 1471 void *aip; 1472 int error; 1473 1474 /* fill process ps_strings info */ 1475 p->p_psstrp = (vaddr_t)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 1476 STACK_PTHREADSPACE), data->ed_ps_strings_sz); 1477 1478 if (epp->ep_flags & EXEC_32) { 1479 aip = &arginfo32; 1480 arginfo32.ps_argvstr = (vaddr_t)data->ed_arginfo.ps_argvstr; 1481 arginfo32.ps_nargvstr = data->ed_arginfo.ps_nargvstr; 1482 arginfo32.ps_envstr = (vaddr_t)data->ed_arginfo.ps_envstr; 1483 arginfo32.ps_nenvstr = data->ed_arginfo.ps_nenvstr; 1484 } else 1485 aip = &data->ed_arginfo; 1486 1487 /* copy out the process's ps_strings structure */ 1488 if ((error = copyout(aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)) 1489 != 0) { 1490 DPRINTF(("%s: ps_strings copyout %p->%p size %zu failed\n", 1491 __func__, aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)); 1492 return error; 1493 } 1494 1495 return 0; 1496 } 1497 1498 static int 1499 copyinargs(struct execve_data * restrict data, char * const *args, 1500 char * const *envs, execve_fetch_element_t fetch_element, char **dpp) 1501 { 1502 struct exec_package * const epp = &data->ed_pack; 1503 char *dp; 1504 size_t i; 1505 int error; 1506 1507 dp = *dpp; 1508 1509 data->ed_argc = 0; 1510 1511 /* copy the fake args list, if there's one, freeing it as we go */ 1512 if (epp->ep_flags & EXEC_HASARGL) { 1513 struct exec_fakearg *fa = epp->ep_fa; 1514 1515 while (fa->fa_arg != NULL) { 1516 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1517 size_t len; 1518 1519 len = strlcpy(dp, fa->fa_arg, maxlen); 1520 /* Count NUL into len. */ 1521 if (len < maxlen) 1522 len++; 1523 else { 1524 while (fa->fa_arg != NULL) { 1525 kmem_free(fa->fa_arg, fa->fa_len); 1526 fa++; 1527 } 1528 kmem_free(epp->ep_fa, epp->ep_fa_len); 1529 epp->ep_flags &= ~EXEC_HASARGL; 1530 return E2BIG; 1531 } 1532 ktrexecarg(fa->fa_arg, len - 1); 1533 dp += len; 1534 1535 kmem_free(fa->fa_arg, fa->fa_len); 1536 fa++; 1537 data->ed_argc++; 1538 } 1539 kmem_free(epp->ep_fa, epp->ep_fa_len); 1540 epp->ep_flags &= ~EXEC_HASARGL; 1541 } 1542 1543 /* 1544 * Read and count argument strings from user. 1545 */ 1546 1547 if (args == NULL) { 1548 DPRINTF(("%s: null args\n", __func__)); 1549 return EINVAL; 1550 } 1551 if (epp->ep_flags & EXEC_SKIPARG) 1552 args = (const void *)((const char *)args + fromptrsz(epp)); 1553 i = 0; 1554 error = copyinargstrs(data, args, fetch_element, &dp, &i, ktr_execarg); 1555 if (error != 0) { 1556 DPRINTF(("%s: copyin arg %d\n", __func__, error)); 1557 return error; 1558 } 1559 data->ed_argc += i; 1560 1561 /* 1562 * Read and count environment strings from user. 1563 */ 1564 1565 data->ed_envc = 0; 1566 /* environment need not be there */ 1567 if (envs == NULL) 1568 goto done; 1569 i = 0; 1570 error = copyinargstrs(data, envs, fetch_element, &dp, &i, ktr_execenv); 1571 if (error != 0) { 1572 DPRINTF(("%s: copyin env %d\n", __func__, error)); 1573 return error; 1574 } 1575 data->ed_envc += i; 1576 1577 done: 1578 *dpp = dp; 1579 1580 return 0; 1581 } 1582 1583 static int 1584 copyinargstrs(struct execve_data * restrict data, char * const *strs, 1585 execve_fetch_element_t fetch_element, char **dpp, size_t *ip, 1586 void (*ktr)(const void *, size_t)) 1587 { 1588 char *dp, *sp; 1589 size_t i; 1590 int error; 1591 1592 dp = *dpp; 1593 1594 i = 0; 1595 while (1) { 1596 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1597 size_t len; 1598 1599 if ((error = (*fetch_element)(strs, i, &sp)) != 0) { 1600 return error; 1601 } 1602 if (!sp) 1603 break; 1604 if ((error = copyinstr(sp, dp, maxlen, &len)) != 0) { 1605 if (error == ENAMETOOLONG) 1606 error = E2BIG; 1607 return error; 1608 } 1609 if (__predict_false(ktrace_on)) 1610 (*ktr)(dp, len - 1); 1611 dp += len; 1612 i++; 1613 } 1614 1615 *dpp = dp; 1616 *ip = i; 1617 1618 return 0; 1619 } 1620 1621 /* 1622 * Copy argv and env strings from kernel buffer (argp) to the new stack. 1623 * Those strings are located just after auxinfo. 1624 */ 1625 int 1626 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1627 char **stackp, void *argp) 1628 { 1629 char **cpp, *dp, *sp; 1630 size_t len; 1631 void *nullp; 1632 long argc, envc; 1633 int error; 1634 1635 cpp = (char **)*stackp; 1636 nullp = NULL; 1637 argc = arginfo->ps_nargvstr; 1638 envc = arginfo->ps_nenvstr; 1639 1640 /* argc on stack is long */ 1641 CTASSERT(sizeof(*cpp) == sizeof(argc)); 1642 1643 dp = (char *)(cpp + 1644 1 + /* long argc */ 1645 argc + /* char *argv[] */ 1646 1 + /* \0 */ 1647 envc + /* char *env[] */ 1648 1) + /* \0 */ 1649 pack->ep_esch->es_arglen; /* auxinfo */ 1650 sp = argp; 1651 1652 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) { 1653 COPYPRINTF("", cpp - 1, sizeof(argc)); 1654 return error; 1655 } 1656 1657 /* XXX don't copy them out, remap them! */ 1658 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1659 1660 for (; --argc >= 0; sp += len, dp += len) { 1661 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1662 COPYPRINTF("", cpp - 1, sizeof(dp)); 1663 return error; 1664 } 1665 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1666 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1667 return error; 1668 } 1669 } 1670 1671 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1672 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1673 return error; 1674 } 1675 1676 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1677 1678 for (; --envc >= 0; sp += len, dp += len) { 1679 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1680 COPYPRINTF("", cpp - 1, sizeof(dp)); 1681 return error; 1682 } 1683 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1684 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1685 return error; 1686 } 1687 1688 } 1689 1690 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1691 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1692 return error; 1693 } 1694 1695 *stackp = (char *)cpp; 1696 return 0; 1697 } 1698 1699 1700 /* 1701 * Add execsw[] entries. 1702 */ 1703 int 1704 exec_add(struct execsw *esp, int count) 1705 { 1706 struct exec_entry *it; 1707 int i; 1708 1709 if (count == 0) { 1710 return 0; 1711 } 1712 1713 /* Check for duplicates. */ 1714 rw_enter(&exec_lock, RW_WRITER); 1715 for (i = 0; i < count; i++) { 1716 LIST_FOREACH(it, &ex_head, ex_list) { 1717 /* assume unique (makecmds, probe_func, emulation) */ 1718 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1719 it->ex_sw->u.elf_probe_func == 1720 esp[i].u.elf_probe_func && 1721 it->ex_sw->es_emul == esp[i].es_emul) { 1722 rw_exit(&exec_lock); 1723 return EEXIST; 1724 } 1725 } 1726 } 1727 1728 /* Allocate new entries. */ 1729 for (i = 0; i < count; i++) { 1730 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1731 it->ex_sw = &esp[i]; 1732 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1733 } 1734 1735 /* update execsw[] */ 1736 exec_init(0); 1737 rw_exit(&exec_lock); 1738 return 0; 1739 } 1740 1741 /* 1742 * Remove execsw[] entry. 1743 */ 1744 int 1745 exec_remove(struct execsw *esp, int count) 1746 { 1747 struct exec_entry *it, *next; 1748 int i; 1749 const struct proclist_desc *pd; 1750 proc_t *p; 1751 1752 if (count == 0) { 1753 return 0; 1754 } 1755 1756 /* Abort if any are busy. */ 1757 rw_enter(&exec_lock, RW_WRITER); 1758 for (i = 0; i < count; i++) { 1759 mutex_enter(proc_lock); 1760 for (pd = proclists; pd->pd_list != NULL; pd++) { 1761 PROCLIST_FOREACH(p, pd->pd_list) { 1762 if (p->p_execsw == &esp[i]) { 1763 mutex_exit(proc_lock); 1764 rw_exit(&exec_lock); 1765 return EBUSY; 1766 } 1767 } 1768 } 1769 mutex_exit(proc_lock); 1770 } 1771 1772 /* None are busy, so remove them all. */ 1773 for (i = 0; i < count; i++) { 1774 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1775 next = LIST_NEXT(it, ex_list); 1776 if (it->ex_sw == &esp[i]) { 1777 LIST_REMOVE(it, ex_list); 1778 kmem_free(it, sizeof(*it)); 1779 break; 1780 } 1781 } 1782 } 1783 1784 /* update execsw[] */ 1785 exec_init(0); 1786 rw_exit(&exec_lock); 1787 return 0; 1788 } 1789 1790 /* 1791 * Initialize exec structures. If init_boot is true, also does necessary 1792 * one-time initialization (it's called from main() that way). 1793 * Once system is multiuser, this should be called with exec_lock held, 1794 * i.e. via exec_{add|remove}(). 1795 */ 1796 int 1797 exec_init(int init_boot) 1798 { 1799 const struct execsw **sw; 1800 struct exec_entry *ex; 1801 SLIST_HEAD(,exec_entry) first; 1802 SLIST_HEAD(,exec_entry) any; 1803 SLIST_HEAD(,exec_entry) last; 1804 int i, sz; 1805 1806 if (init_boot) { 1807 /* do one-time initializations */ 1808 vaddr_t vmin = 0, vmax; 1809 1810 rw_init(&exec_lock); 1811 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1812 exec_map = uvm_km_suballoc(kernel_map, &vmin, &vmax, 1813 maxexec*NCARGS, VM_MAP_PAGEABLE, false, NULL); 1814 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1815 "execargs", &exec_palloc, IPL_NONE); 1816 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1817 } else { 1818 KASSERT(rw_write_held(&exec_lock)); 1819 } 1820 1821 /* Sort each entry onto the appropriate queue. */ 1822 SLIST_INIT(&first); 1823 SLIST_INIT(&any); 1824 SLIST_INIT(&last); 1825 sz = 0; 1826 LIST_FOREACH(ex, &ex_head, ex_list) { 1827 switch(ex->ex_sw->es_prio) { 1828 case EXECSW_PRIO_FIRST: 1829 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1830 break; 1831 case EXECSW_PRIO_ANY: 1832 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1833 break; 1834 case EXECSW_PRIO_LAST: 1835 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1836 break; 1837 default: 1838 panic("%s", __func__); 1839 break; 1840 } 1841 sz++; 1842 } 1843 1844 /* 1845 * Create new execsw[]. Ensure we do not try a zero-sized 1846 * allocation. 1847 */ 1848 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1849 i = 0; 1850 SLIST_FOREACH(ex, &first, ex_slist) { 1851 sw[i++] = ex->ex_sw; 1852 } 1853 SLIST_FOREACH(ex, &any, ex_slist) { 1854 sw[i++] = ex->ex_sw; 1855 } 1856 SLIST_FOREACH(ex, &last, ex_slist) { 1857 sw[i++] = ex->ex_sw; 1858 } 1859 1860 /* Replace old execsw[] and free used memory. */ 1861 if (execsw != NULL) { 1862 kmem_free(__UNCONST(execsw), 1863 nexecs * sizeof(struct execsw *) + 1); 1864 } 1865 execsw = sw; 1866 nexecs = sz; 1867 1868 /* Figure out the maximum size of an exec header. */ 1869 exec_maxhdrsz = sizeof(int); 1870 for (i = 0; i < nexecs; i++) { 1871 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1872 exec_maxhdrsz = execsw[i]->es_hdrsz; 1873 } 1874 1875 return 0; 1876 } 1877 1878 static int 1879 exec_sigcode_map(struct proc *p, const struct emul *e) 1880 { 1881 vaddr_t va; 1882 vsize_t sz; 1883 int error; 1884 struct uvm_object *uobj; 1885 1886 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1887 1888 if (e->e_sigobject == NULL || sz == 0) { 1889 return 0; 1890 } 1891 1892 /* 1893 * If we don't have a sigobject for this emulation, create one. 1894 * 1895 * sigobject is an anonymous memory object (just like SYSV shared 1896 * memory) that we keep a permanent reference to and that we map 1897 * in all processes that need this sigcode. The creation is simple, 1898 * we create an object, add a permanent reference to it, map it in 1899 * kernel space, copy out the sigcode to it and unmap it. 1900 * We map it with PROT_READ|PROT_EXEC into the process just 1901 * the way sys_mmap() would map it. 1902 */ 1903 1904 uobj = *e->e_sigobject; 1905 if (uobj == NULL) { 1906 mutex_enter(&sigobject_lock); 1907 if ((uobj = *e->e_sigobject) == NULL) { 1908 uobj = uao_create(sz, 0); 1909 (*uobj->pgops->pgo_reference)(uobj); 1910 va = vm_map_min(kernel_map); 1911 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1912 uobj, 0, 0, 1913 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1914 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1915 printf("kernel mapping failed %d\n", error); 1916 (*uobj->pgops->pgo_detach)(uobj); 1917 mutex_exit(&sigobject_lock); 1918 return error; 1919 } 1920 memcpy((void *)va, e->e_sigcode, sz); 1921 #ifdef PMAP_NEED_PROCWR 1922 pmap_procwr(&proc0, va, sz); 1923 #endif 1924 uvm_unmap(kernel_map, va, va + round_page(sz)); 1925 *e->e_sigobject = uobj; 1926 } 1927 mutex_exit(&sigobject_lock); 1928 } 1929 1930 /* Just a hint to uvm_map where to put it. */ 1931 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1932 round_page(sz), p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN); 1933 1934 #ifdef __alpha__ 1935 /* 1936 * Tru64 puts /sbin/loader at the end of user virtual memory, 1937 * which causes the above calculation to put the sigcode at 1938 * an invalid address. Put it just below the text instead. 1939 */ 1940 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1941 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1942 } 1943 #endif 1944 1945 (*uobj->pgops->pgo_reference)(uobj); 1946 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1947 uobj, 0, 0, 1948 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1949 UVM_ADV_RANDOM, 0)); 1950 if (error) { 1951 DPRINTF(("%s, %d: map %p " 1952 "uvm_map %#"PRIxVSIZE"@%#"PRIxVADDR" failed %d\n", 1953 __func__, __LINE__, &p->p_vmspace->vm_map, round_page(sz), 1954 va, error)); 1955 (*uobj->pgops->pgo_detach)(uobj); 1956 return error; 1957 } 1958 p->p_sigctx.ps_sigcode = (void *)va; 1959 return 0; 1960 } 1961 1962 /* 1963 * Release a refcount on spawn_exec_data and destroy memory, if this 1964 * was the last one. 1965 */ 1966 static void 1967 spawn_exec_data_release(struct spawn_exec_data *data) 1968 { 1969 if (atomic_dec_32_nv(&data->sed_refcnt) != 0) 1970 return; 1971 1972 cv_destroy(&data->sed_cv_child_ready); 1973 mutex_destroy(&data->sed_mtx_child); 1974 1975 if (data->sed_actions) 1976 posix_spawn_fa_free(data->sed_actions, 1977 data->sed_actions->len); 1978 if (data->sed_attrs) 1979 kmem_free(data->sed_attrs, 1980 sizeof(*data->sed_attrs)); 1981 kmem_free(data, sizeof(*data)); 1982 } 1983 1984 /* 1985 * A child lwp of a posix_spawn operation starts here and ends up in 1986 * cpu_spawn_return, dealing with all filedescriptor and scheduler 1987 * manipulations in between. 1988 * The parent waits for the child, as it is not clear whether the child 1989 * will be able to acquire its own exec_lock. If it can, the parent can 1990 * be released early and continue running in parallel. If not (or if the 1991 * magic debug flag is passed in the scheduler attribute struct), the 1992 * child rides on the parent's exec lock until it is ready to return to 1993 * to userland - and only then releases the parent. This method loses 1994 * concurrency, but improves error reporting. 1995 */ 1996 static void 1997 spawn_return(void *arg) 1998 { 1999 struct spawn_exec_data *spawn_data = arg; 2000 struct lwp *l = curlwp; 2001 struct proc *p = l->l_proc; 2002 int error, newfd; 2003 int ostat; 2004 size_t i; 2005 const struct posix_spawn_file_actions_entry *fae; 2006 pid_t ppid; 2007 register_t retval; 2008 bool have_reflock; 2009 bool parent_is_waiting = true; 2010 2011 /* 2012 * Check if we can release parent early. 2013 * We either need to have no sed_attrs, or sed_attrs does not 2014 * have POSIX_SPAWN_RETURNERROR or one of the flags, that require 2015 * safe access to the parent proc (passed in sed_parent). 2016 * We then try to get the exec_lock, and only if that works, we can 2017 * release the parent here already. 2018 */ 2019 ppid = spawn_data->sed_parent->p_pid; 2020 if ((!spawn_data->sed_attrs 2021 || (spawn_data->sed_attrs->sa_flags 2022 & (POSIX_SPAWN_RETURNERROR|POSIX_SPAWN_SETPGROUP)) == 0) 2023 && rw_tryenter(&exec_lock, RW_READER)) { 2024 parent_is_waiting = false; 2025 mutex_enter(&spawn_data->sed_mtx_child); 2026 cv_signal(&spawn_data->sed_cv_child_ready); 2027 mutex_exit(&spawn_data->sed_mtx_child); 2028 } 2029 2030 /* don't allow debugger access yet */ 2031 rw_enter(&p->p_reflock, RW_WRITER); 2032 have_reflock = true; 2033 2034 error = 0; 2035 /* handle posix_spawn_file_actions */ 2036 if (spawn_data->sed_actions != NULL) { 2037 for (i = 0; i < spawn_data->sed_actions->len; i++) { 2038 fae = &spawn_data->sed_actions->fae[i]; 2039 switch (fae->fae_action) { 2040 case FAE_OPEN: 2041 if (fd_getfile(fae->fae_fildes) != NULL) { 2042 error = fd_close(fae->fae_fildes); 2043 if (error) 2044 break; 2045 } 2046 error = fd_open(fae->fae_path, fae->fae_oflag, 2047 fae->fae_mode, &newfd); 2048 if (error) 2049 break; 2050 if (newfd != fae->fae_fildes) { 2051 error = dodup(l, newfd, 2052 fae->fae_fildes, 0, &retval); 2053 if (fd_getfile(newfd) != NULL) 2054 fd_close(newfd); 2055 } 2056 break; 2057 case FAE_DUP2: 2058 error = dodup(l, fae->fae_fildes, 2059 fae->fae_newfildes, 0, &retval); 2060 break; 2061 case FAE_CLOSE: 2062 if (fd_getfile(fae->fae_fildes) == NULL) { 2063 error = EBADF; 2064 break; 2065 } 2066 error = fd_close(fae->fae_fildes); 2067 break; 2068 } 2069 if (error) 2070 goto report_error; 2071 } 2072 } 2073 2074 /* handle posix_spawnattr */ 2075 if (spawn_data->sed_attrs != NULL) { 2076 struct sigaction sigact; 2077 memset(&sigact, 0, sizeof(sigact)); 2078 sigact._sa_u._sa_handler = SIG_DFL; 2079 sigact.sa_flags = 0; 2080 2081 /* 2082 * set state to SSTOP so that this proc can be found by pid. 2083 * see proc_enterprp, do_sched_setparam below 2084 */ 2085 mutex_enter(proc_lock); 2086 /* 2087 * p_stat should be SACTIVE, so we need to adjust the 2088 * parent's p_nstopchild here. For safety, just make 2089 * we're on the good side of SDEAD before we adjust. 2090 */ 2091 ostat = p->p_stat; 2092 KASSERT(ostat < SSTOP); 2093 p->p_stat = SSTOP; 2094 p->p_waited = 0; 2095 p->p_pptr->p_nstopchild++; 2096 mutex_exit(proc_lock); 2097 2098 /* Set process group */ 2099 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETPGROUP) { 2100 pid_t mypid = p->p_pid, 2101 pgrp = spawn_data->sed_attrs->sa_pgroup; 2102 2103 if (pgrp == 0) 2104 pgrp = mypid; 2105 2106 error = proc_enterpgrp(spawn_data->sed_parent, 2107 mypid, pgrp, false); 2108 if (error) 2109 goto report_error_stopped; 2110 } 2111 2112 /* Set scheduler policy */ 2113 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSCHEDULER) 2114 error = do_sched_setparam(p->p_pid, 0, 2115 spawn_data->sed_attrs->sa_schedpolicy, 2116 &spawn_data->sed_attrs->sa_schedparam); 2117 else if (spawn_data->sed_attrs->sa_flags 2118 & POSIX_SPAWN_SETSCHEDPARAM) { 2119 error = do_sched_setparam(ppid, 0, 2120 SCHED_NONE, &spawn_data->sed_attrs->sa_schedparam); 2121 } 2122 if (error) 2123 goto report_error_stopped; 2124 2125 /* Reset user ID's */ 2126 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_RESETIDS) { 2127 error = do_setresuid(l, -1, 2128 kauth_cred_getgid(l->l_cred), -1, 2129 ID_E_EQ_R | ID_E_EQ_S); 2130 if (error) 2131 goto report_error_stopped; 2132 error = do_setresuid(l, -1, 2133 kauth_cred_getuid(l->l_cred), -1, 2134 ID_E_EQ_R | ID_E_EQ_S); 2135 if (error) 2136 goto report_error_stopped; 2137 } 2138 2139 /* Set signal masks/defaults */ 2140 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGMASK) { 2141 mutex_enter(p->p_lock); 2142 error = sigprocmask1(l, SIG_SETMASK, 2143 &spawn_data->sed_attrs->sa_sigmask, NULL); 2144 mutex_exit(p->p_lock); 2145 if (error) 2146 goto report_error_stopped; 2147 } 2148 2149 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGDEF) { 2150 /* 2151 * The following sigaction call is using a sigaction 2152 * version 0 trampoline which is in the compatibility 2153 * code only. This is not a problem because for SIG_DFL 2154 * and SIG_IGN, the trampolines are now ignored. If they 2155 * were not, this would be a problem because we are 2156 * holding the exec_lock, and the compat code needs 2157 * to do the same in order to replace the trampoline 2158 * code of the process. 2159 */ 2160 for (i = 1; i <= NSIG; i++) { 2161 if (sigismember( 2162 &spawn_data->sed_attrs->sa_sigdefault, i)) 2163 sigaction1(l, i, &sigact, NULL, NULL, 2164 0); 2165 } 2166 } 2167 mutex_enter(proc_lock); 2168 p->p_stat = ostat; 2169 p->p_pptr->p_nstopchild--; 2170 mutex_exit(proc_lock); 2171 } 2172 2173 /* now do the real exec */ 2174 error = execve_runproc(l, &spawn_data->sed_exec, parent_is_waiting, 2175 true); 2176 have_reflock = false; 2177 if (error == EJUSTRETURN) 2178 error = 0; 2179 else if (error) 2180 goto report_error; 2181 2182 if (parent_is_waiting) { 2183 mutex_enter(&spawn_data->sed_mtx_child); 2184 cv_signal(&spawn_data->sed_cv_child_ready); 2185 mutex_exit(&spawn_data->sed_mtx_child); 2186 } 2187 2188 /* release our refcount on the data */ 2189 spawn_exec_data_release(spawn_data); 2190 2191 if (p->p_slflag & PSL_TRACED) { 2192 /* Paranoid check */ 2193 mutex_enter(proc_lock); 2194 if (!(p->p_slflag & PSL_TRACED)) { 2195 mutex_exit(proc_lock); 2196 goto cpu_return; 2197 } 2198 2199 mutex_enter(p->p_lock); 2200 eventswitch(TRAP_CHLD); 2201 } 2202 2203 cpu_return: 2204 /* and finally: leave to userland for the first time */ 2205 cpu_spawn_return(l); 2206 2207 /* NOTREACHED */ 2208 return; 2209 2210 report_error_stopped: 2211 mutex_enter(proc_lock); 2212 p->p_stat = ostat; 2213 p->p_pptr->p_nstopchild--; 2214 mutex_exit(proc_lock); 2215 report_error: 2216 if (have_reflock) { 2217 /* 2218 * We have not passed through execve_runproc(), 2219 * which would have released the p_reflock and also 2220 * taken ownership of the sed_exec part of spawn_data, 2221 * so release/free both here. 2222 */ 2223 rw_exit(&p->p_reflock); 2224 execve_free_data(&spawn_data->sed_exec); 2225 } 2226 2227 if (parent_is_waiting) { 2228 /* pass error to parent */ 2229 mutex_enter(&spawn_data->sed_mtx_child); 2230 spawn_data->sed_error = error; 2231 cv_signal(&spawn_data->sed_cv_child_ready); 2232 mutex_exit(&spawn_data->sed_mtx_child); 2233 } else { 2234 rw_exit(&exec_lock); 2235 } 2236 2237 /* release our refcount on the data */ 2238 spawn_exec_data_release(spawn_data); 2239 2240 /* done, exit */ 2241 mutex_enter(p->p_lock); 2242 /* 2243 * Posix explicitly asks for an exit code of 127 if we report 2244 * errors from the child process - so, unfortunately, there 2245 * is no way to report a more exact error code. 2246 * A NetBSD specific workaround is POSIX_SPAWN_RETURNERROR as 2247 * flag bit in the attrp argument to posix_spawn(2), see above. 2248 */ 2249 exit1(l, 127, 0); 2250 } 2251 2252 void 2253 posix_spawn_fa_free(struct posix_spawn_file_actions *fa, size_t len) 2254 { 2255 2256 for (size_t i = 0; i < len; i++) { 2257 struct posix_spawn_file_actions_entry *fae = &fa->fae[i]; 2258 if (fae->fae_action != FAE_OPEN) 2259 continue; 2260 kmem_strfree(fae->fae_path); 2261 } 2262 if (fa->len > 0) 2263 kmem_free(fa->fae, sizeof(*fa->fae) * fa->len); 2264 kmem_free(fa, sizeof(*fa)); 2265 } 2266 2267 static int 2268 posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap, 2269 const struct posix_spawn_file_actions *ufa, rlim_t lim) 2270 { 2271 struct posix_spawn_file_actions *fa; 2272 struct posix_spawn_file_actions_entry *fae; 2273 char *pbuf = NULL; 2274 int error; 2275 size_t i = 0; 2276 2277 fa = kmem_alloc(sizeof(*fa), KM_SLEEP); 2278 error = copyin(ufa, fa, sizeof(*fa)); 2279 if (error || fa->len == 0) { 2280 kmem_free(fa, sizeof(*fa)); 2281 return error; /* 0 if not an error, and len == 0 */ 2282 } 2283 2284 if (fa->len > lim) { 2285 kmem_free(fa, sizeof(*fa)); 2286 return EINVAL; 2287 } 2288 2289 fa->size = fa->len; 2290 size_t fal = fa->len * sizeof(*fae); 2291 fae = fa->fae; 2292 fa->fae = kmem_alloc(fal, KM_SLEEP); 2293 error = copyin(fae, fa->fae, fal); 2294 if (error) 2295 goto out; 2296 2297 pbuf = PNBUF_GET(); 2298 for (; i < fa->len; i++) { 2299 fae = &fa->fae[i]; 2300 if (fae->fae_action != FAE_OPEN) 2301 continue; 2302 error = copyinstr(fae->fae_path, pbuf, MAXPATHLEN, &fal); 2303 if (error) 2304 goto out; 2305 fae->fae_path = kmem_alloc(fal, KM_SLEEP); 2306 memcpy(fae->fae_path, pbuf, fal); 2307 } 2308 PNBUF_PUT(pbuf); 2309 2310 *fap = fa; 2311 return 0; 2312 out: 2313 if (pbuf) 2314 PNBUF_PUT(pbuf); 2315 posix_spawn_fa_free(fa, i); 2316 return error; 2317 } 2318 2319 int 2320 check_posix_spawn(struct lwp *l1) 2321 { 2322 int error, tnprocs, count; 2323 uid_t uid; 2324 struct proc *p1; 2325 2326 p1 = l1->l_proc; 2327 uid = kauth_cred_getuid(l1->l_cred); 2328 tnprocs = atomic_inc_uint_nv(&nprocs); 2329 2330 /* 2331 * Although process entries are dynamically created, we still keep 2332 * a global limit on the maximum number we will create. 2333 */ 2334 if (__predict_false(tnprocs >= maxproc)) 2335 error = -1; 2336 else 2337 error = kauth_authorize_process(l1->l_cred, 2338 KAUTH_PROCESS_FORK, p1, KAUTH_ARG(tnprocs), NULL, NULL); 2339 2340 if (error) { 2341 atomic_dec_uint(&nprocs); 2342 return EAGAIN; 2343 } 2344 2345 /* 2346 * Enforce limits. 2347 */ 2348 count = chgproccnt(uid, 1); 2349 if (kauth_authorize_process(l1->l_cred, KAUTH_PROCESS_RLIMIT, 2350 p1, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 2351 &p1->p_rlimit[RLIMIT_NPROC], KAUTH_ARG(RLIMIT_NPROC)) != 0 && 2352 __predict_false(count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) { 2353 (void)chgproccnt(uid, -1); 2354 atomic_dec_uint(&nprocs); 2355 return EAGAIN; 2356 } 2357 2358 return 0; 2359 } 2360 2361 int 2362 do_posix_spawn(struct lwp *l1, pid_t *pid_res, bool *child_ok, const char *path, 2363 struct posix_spawn_file_actions *fa, 2364 struct posix_spawnattr *sa, 2365 char *const *argv, char *const *envp, 2366 execve_fetch_element_t fetch) 2367 { 2368 2369 struct proc *p1, *p2; 2370 struct lwp *l2; 2371 int error; 2372 struct spawn_exec_data *spawn_data; 2373 vaddr_t uaddr; 2374 pid_t pid; 2375 bool have_exec_lock = false; 2376 2377 p1 = l1->l_proc; 2378 2379 /* Allocate and init spawn_data */ 2380 spawn_data = kmem_zalloc(sizeof(*spawn_data), KM_SLEEP); 2381 spawn_data->sed_refcnt = 1; /* only parent so far */ 2382 cv_init(&spawn_data->sed_cv_child_ready, "pspawn"); 2383 mutex_init(&spawn_data->sed_mtx_child, MUTEX_DEFAULT, IPL_NONE); 2384 mutex_enter(&spawn_data->sed_mtx_child); 2385 2386 /* 2387 * Do the first part of the exec now, collect state 2388 * in spawn_data. 2389 */ 2390 error = execve_loadvm(l1, path, argv, 2391 envp, fetch, &spawn_data->sed_exec); 2392 if (error == EJUSTRETURN) 2393 error = 0; 2394 else if (error) 2395 goto error_exit; 2396 2397 have_exec_lock = true; 2398 2399 /* 2400 * Allocate virtual address space for the U-area now, while it 2401 * is still easy to abort the fork operation if we're out of 2402 * kernel virtual address space. 2403 */ 2404 uaddr = uvm_uarea_alloc(); 2405 if (__predict_false(uaddr == 0)) { 2406 error = ENOMEM; 2407 goto error_exit; 2408 } 2409 2410 /* 2411 * Allocate new proc. Borrow proc0 vmspace for it, we will 2412 * replace it with its own before returning to userland 2413 * in the child. 2414 * This is a point of no return, we will have to go through 2415 * the child proc to properly clean it up past this point. 2416 */ 2417 p2 = proc_alloc(); 2418 pid = p2->p_pid; 2419 2420 /* 2421 * Make a proc table entry for the new process. 2422 * Start by zeroing the section of proc that is zero-initialized, 2423 * then copy the section that is copied directly from the parent. 2424 */ 2425 memset(&p2->p_startzero, 0, 2426 (unsigned) ((char *)&p2->p_endzero - (char *)&p2->p_startzero)); 2427 memcpy(&p2->p_startcopy, &p1->p_startcopy, 2428 (unsigned) ((char *)&p2->p_endcopy - (char *)&p2->p_startcopy)); 2429 p2->p_vmspace = proc0.p_vmspace; 2430 2431 TAILQ_INIT(&p2->p_sigpend.sp_info); 2432 2433 LIST_INIT(&p2->p_lwps); 2434 LIST_INIT(&p2->p_sigwaiters); 2435 2436 /* 2437 * Duplicate sub-structures as needed. 2438 * Increase reference counts on shared objects. 2439 * Inherit flags we want to keep. The flags related to SIGCHLD 2440 * handling are important in order to keep a consistent behaviour 2441 * for the child after the fork. If we are a 32-bit process, the 2442 * child will be too. 2443 */ 2444 p2->p_flag = 2445 p1->p_flag & (PK_SUGID | PK_NOCLDWAIT | PK_CLDSIGIGN | PK_32); 2446 p2->p_emul = p1->p_emul; 2447 p2->p_execsw = p1->p_execsw; 2448 2449 mutex_init(&p2->p_stmutex, MUTEX_DEFAULT, IPL_HIGH); 2450 mutex_init(&p2->p_auxlock, MUTEX_DEFAULT, IPL_NONE); 2451 rw_init(&p2->p_reflock); 2452 cv_init(&p2->p_waitcv, "wait"); 2453 cv_init(&p2->p_lwpcv, "lwpwait"); 2454 2455 p2->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 2456 2457 kauth_proc_fork(p1, p2); 2458 2459 p2->p_raslist = NULL; 2460 p2->p_fd = fd_copy(); 2461 2462 /* XXX racy */ 2463 p2->p_mqueue_cnt = p1->p_mqueue_cnt; 2464 2465 p2->p_cwdi = cwdinit(); 2466 2467 /* 2468 * Note: p_limit (rlimit stuff) is copy-on-write, so normally 2469 * we just need increase pl_refcnt. 2470 */ 2471 if (!p1->p_limit->pl_writeable) { 2472 lim_addref(p1->p_limit); 2473 p2->p_limit = p1->p_limit; 2474 } else { 2475 p2->p_limit = lim_copy(p1->p_limit); 2476 } 2477 2478 p2->p_lflag = 0; 2479 l1->l_vforkwaiting = false; 2480 p2->p_sflag = 0; 2481 p2->p_slflag = 0; 2482 p2->p_pptr = p1; 2483 p2->p_ppid = p1->p_pid; 2484 LIST_INIT(&p2->p_children); 2485 2486 p2->p_aio = NULL; 2487 2488 #ifdef KTRACE 2489 /* 2490 * Copy traceflag and tracefile if enabled. 2491 * If not inherited, these were zeroed above. 2492 */ 2493 if (p1->p_traceflag & KTRFAC_INHERIT) { 2494 mutex_enter(&ktrace_lock); 2495 p2->p_traceflag = p1->p_traceflag; 2496 if ((p2->p_tracep = p1->p_tracep) != NULL) 2497 ktradref(p2); 2498 mutex_exit(&ktrace_lock); 2499 } 2500 #endif 2501 2502 /* 2503 * Create signal actions for the child process. 2504 */ 2505 p2->p_sigacts = sigactsinit(p1, 0); 2506 mutex_enter(p1->p_lock); 2507 p2->p_sflag |= 2508 (p1->p_sflag & (PS_STOPFORK | PS_STOPEXEC | PS_NOCLDSTOP)); 2509 sched_proc_fork(p1, p2); 2510 mutex_exit(p1->p_lock); 2511 2512 p2->p_stflag = p1->p_stflag; 2513 2514 /* 2515 * p_stats. 2516 * Copy parts of p_stats, and zero out the rest. 2517 */ 2518 p2->p_stats = pstatscopy(p1->p_stats); 2519 2520 /* copy over machdep flags to the new proc */ 2521 cpu_proc_fork(p1, p2); 2522 2523 /* 2524 * Prepare remaining parts of spawn data 2525 */ 2526 spawn_data->sed_actions = fa; 2527 spawn_data->sed_attrs = sa; 2528 2529 spawn_data->sed_parent = p1; 2530 2531 /* create LWP */ 2532 lwp_create(l1, p2, uaddr, 0, NULL, 0, spawn_return, spawn_data, 2533 &l2, l1->l_class, &l1->l_sigmask, &l1->l_sigstk); 2534 l2->l_ctxlink = NULL; /* reset ucontext link */ 2535 2536 /* 2537 * Copy the credential so other references don't see our changes. 2538 * Test to see if this is necessary first, since in the common case 2539 * we won't need a private reference. 2540 */ 2541 if (kauth_cred_geteuid(l2->l_cred) != kauth_cred_getsvuid(l2->l_cred) || 2542 kauth_cred_getegid(l2->l_cred) != kauth_cred_getsvgid(l2->l_cred)) { 2543 l2->l_cred = kauth_cred_copy(l2->l_cred); 2544 kauth_cred_setsvuid(l2->l_cred, kauth_cred_geteuid(l2->l_cred)); 2545 kauth_cred_setsvgid(l2->l_cred, kauth_cred_getegid(l2->l_cred)); 2546 } 2547 2548 /* Update the master credentials. */ 2549 if (l2->l_cred != p2->p_cred) { 2550 kauth_cred_t ocred; 2551 2552 kauth_cred_hold(l2->l_cred); 2553 mutex_enter(p2->p_lock); 2554 ocred = p2->p_cred; 2555 p2->p_cred = l2->l_cred; 2556 mutex_exit(p2->p_lock); 2557 kauth_cred_free(ocred); 2558 } 2559 2560 *child_ok = true; 2561 spawn_data->sed_refcnt = 2; /* child gets it as well */ 2562 #if 0 2563 l2->l_nopreempt = 1; /* start it non-preemptable */ 2564 #endif 2565 2566 /* 2567 * It's now safe for the scheduler and other processes to see the 2568 * child process. 2569 */ 2570 mutex_enter(proc_lock); 2571 2572 if (p1->p_session->s_ttyvp != NULL && p1->p_lflag & PL_CONTROLT) 2573 p2->p_lflag |= PL_CONTROLT; 2574 2575 LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling); 2576 p2->p_exitsig = SIGCHLD; /* signal for parent on exit */ 2577 2578 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) == 2579 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) { 2580 proc_changeparent(p2, p1->p_pptr); 2581 p1->p_pspid = p2->p_pid; 2582 p2->p_pspid = p1->p_pid; 2583 } 2584 2585 LIST_INSERT_AFTER(p1, p2, p_pglist); 2586 LIST_INSERT_HEAD(&allproc, p2, p_list); 2587 2588 p2->p_trace_enabled = trace_is_enabled(p2); 2589 #ifdef __HAVE_SYSCALL_INTERN 2590 (*p2->p_emul->e_syscall_intern)(p2); 2591 #endif 2592 2593 /* 2594 * Make child runnable, set start time, and add to run queue except 2595 * if the parent requested the child to start in SSTOP state. 2596 */ 2597 mutex_enter(p2->p_lock); 2598 2599 getmicrotime(&p2->p_stats->p_start); 2600 2601 lwp_lock(l2); 2602 KASSERT(p2->p_nrlwps == 1); 2603 p2->p_nrlwps = 1; 2604 p2->p_stat = SACTIVE; 2605 l2->l_stat = LSRUN; 2606 sched_enqueue(l2, false); 2607 lwp_unlock(l2); 2608 2609 mutex_exit(p2->p_lock); 2610 mutex_exit(proc_lock); 2611 2612 cv_wait(&spawn_data->sed_cv_child_ready, &spawn_data->sed_mtx_child); 2613 error = spawn_data->sed_error; 2614 mutex_exit(&spawn_data->sed_mtx_child); 2615 spawn_exec_data_release(spawn_data); 2616 2617 rw_exit(&p1->p_reflock); 2618 rw_exit(&exec_lock); 2619 have_exec_lock = false; 2620 2621 *pid_res = pid; 2622 2623 if (error) 2624 return error; 2625 2626 if (p1->p_slflag & PSL_TRACED) { 2627 /* Paranoid check */ 2628 mutex_enter(proc_lock); 2629 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) != 2630 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) { 2631 mutex_exit(proc_lock); 2632 return 0; 2633 } 2634 2635 mutex_enter(p1->p_lock); 2636 eventswitch(TRAP_CHLD); 2637 } 2638 return 0; 2639 2640 error_exit: 2641 if (have_exec_lock) { 2642 execve_free_data(&spawn_data->sed_exec); 2643 rw_exit(&p1->p_reflock); 2644 rw_exit(&exec_lock); 2645 } 2646 mutex_exit(&spawn_data->sed_mtx_child); 2647 spawn_exec_data_release(spawn_data); 2648 2649 return error; 2650 } 2651 2652 int 2653 sys_posix_spawn(struct lwp *l1, const struct sys_posix_spawn_args *uap, 2654 register_t *retval) 2655 { 2656 /* { 2657 syscallarg(pid_t *) pid; 2658 syscallarg(const char *) path; 2659 syscallarg(const struct posix_spawn_file_actions *) file_actions; 2660 syscallarg(const struct posix_spawnattr *) attrp; 2661 syscallarg(char *const *) argv; 2662 syscallarg(char *const *) envp; 2663 } */ 2664 2665 int error; 2666 struct posix_spawn_file_actions *fa = NULL; 2667 struct posix_spawnattr *sa = NULL; 2668 pid_t pid; 2669 bool child_ok = false; 2670 rlim_t max_fileactions; 2671 proc_t *p = l1->l_proc; 2672 2673 error = check_posix_spawn(l1); 2674 if (error) { 2675 *retval = error; 2676 return 0; 2677 } 2678 2679 /* copy in file_actions struct */ 2680 if (SCARG(uap, file_actions) != NULL) { 2681 max_fileactions = 2 * uimin(p->p_rlimit[RLIMIT_NOFILE].rlim_cur, 2682 maxfiles); 2683 error = posix_spawn_fa_alloc(&fa, SCARG(uap, file_actions), 2684 max_fileactions); 2685 if (error) 2686 goto error_exit; 2687 } 2688 2689 /* copyin posix_spawnattr struct */ 2690 if (SCARG(uap, attrp) != NULL) { 2691 sa = kmem_alloc(sizeof(*sa), KM_SLEEP); 2692 error = copyin(SCARG(uap, attrp), sa, sizeof(*sa)); 2693 if (error) 2694 goto error_exit; 2695 } 2696 2697 /* 2698 * Do the spawn 2699 */ 2700 error = do_posix_spawn(l1, &pid, &child_ok, SCARG(uap, path), fa, sa, 2701 SCARG(uap, argv), SCARG(uap, envp), execve_fetch_element); 2702 if (error) 2703 goto error_exit; 2704 2705 if (error == 0 && SCARG(uap, pid) != NULL) 2706 error = copyout(&pid, SCARG(uap, pid), sizeof(pid)); 2707 2708 *retval = error; 2709 return 0; 2710 2711 error_exit: 2712 if (!child_ok) { 2713 (void)chgproccnt(kauth_cred_getuid(l1->l_cred), -1); 2714 atomic_dec_uint(&nprocs); 2715 2716 if (sa) 2717 kmem_free(sa, sizeof(*sa)); 2718 if (fa) 2719 posix_spawn_fa_free(fa, fa->len); 2720 } 2721 2722 *retval = error; 2723 return 0; 2724 } 2725 2726 void 2727 exec_free_emul_arg(struct exec_package *epp) 2728 { 2729 if (epp->ep_emul_arg_free != NULL) { 2730 KASSERT(epp->ep_emul_arg != NULL); 2731 (*epp->ep_emul_arg_free)(epp->ep_emul_arg); 2732 epp->ep_emul_arg_free = NULL; 2733 epp->ep_emul_arg = NULL; 2734 } else { 2735 KASSERT(epp->ep_emul_arg == NULL); 2736 } 2737 } 2738 2739 #ifdef DEBUG_EXEC 2740 static void 2741 dump_vmcmds(const struct exec_package * const epp, size_t x, int error) 2742 { 2743 struct exec_vmcmd *vp = &epp->ep_vmcmds.evs_cmds[0]; 2744 size_t j; 2745 2746 if (error == 0) 2747 DPRINTF(("vmcmds %u\n", epp->ep_vmcmds.evs_used)); 2748 else 2749 DPRINTF(("vmcmds %zu/%u, error %d\n", x, 2750 epp->ep_vmcmds.evs_used, error)); 2751 2752 for (j = 0; j < epp->ep_vmcmds.evs_used; j++) { 2753 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#" 2754 PRIxVADDR"/%#"PRIxVSIZE" fd@%#" 2755 PRIxVSIZE" prot=0%o flags=%d\n", j, 2756 vp[j].ev_proc == vmcmd_map_pagedvn ? 2757 "pagedvn" : 2758 vp[j].ev_proc == vmcmd_map_readvn ? 2759 "readvn" : 2760 vp[j].ev_proc == vmcmd_map_zero ? 2761 "zero" : "*unknown*", 2762 vp[j].ev_addr, vp[j].ev_len, 2763 vp[j].ev_offset, vp[j].ev_prot, 2764 vp[j].ev_flags)); 2765 if (error != 0 && j == x) 2766 DPRINTF((" ^--- failed\n")); 2767 } 2768 } 2769 #endif 2770