1 /* $NetBSD: kern_exec.c,v 1.455 2018/01/09 20:55:43 maya 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 1.455 2018/01/09 20:55:43 maya 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/kmem.h> 79 #include <sys/namei.h> 80 #include <sys/vnode.h> 81 #include <sys/file.h> 82 #include <sys/filedesc.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 #ifndef MD_TOPDOWN_INIT 116 #ifdef __USE_TOPDOWN_VM 117 #define MD_TOPDOWN_INIT(epp) (epp)->ep_flags |= EXEC_TOPDOWN_VM 118 #else 119 #define MD_TOPDOWN_INIT(epp) 120 #endif 121 #endif 122 123 struct execve_data; 124 125 extern int user_va0_disable; 126 127 static size_t calcargs(struct execve_data * restrict, const size_t); 128 static size_t calcstack(struct execve_data * restrict, const size_t); 129 static int copyoutargs(struct execve_data * restrict, struct lwp *, 130 char * const); 131 static int copyoutpsstrs(struct execve_data * restrict, struct proc *); 132 static int copyinargs(struct execve_data * restrict, char * const *, 133 char * const *, execve_fetch_element_t, char **); 134 static int copyinargstrs(struct execve_data * restrict, char * const *, 135 execve_fetch_element_t, char **, size_t *, void (*)(const void *, size_t)); 136 static int exec_sigcode_map(struct proc *, const struct emul *); 137 138 #if defined(DEBUG) && !defined(DEBUG_EXEC) 139 #define DEBUG_EXEC 140 #endif 141 #ifdef DEBUG_EXEC 142 #define DPRINTF(a) printf a 143 #define COPYPRINTF(s, a, b) printf("%s, %d: copyout%s @%p %zu\n", __func__, \ 144 __LINE__, (s), (a), (b)) 145 static void dump_vmcmds(const struct exec_package * const, size_t, int); 146 #define DUMPVMCMDS(p, x, e) do { dump_vmcmds((p), (x), (e)); } while (0) 147 #else 148 #define DPRINTF(a) 149 #define COPYPRINTF(s, a, b) 150 #define DUMPVMCMDS(p, x, e) do {} while (0) 151 #endif /* DEBUG_EXEC */ 152 153 /* 154 * DTrace SDT provider definitions 155 */ 156 SDT_PROVIDER_DECLARE(proc); 157 SDT_PROBE_DEFINE1(proc, kernel, , exec, "char *"); 158 SDT_PROBE_DEFINE1(proc, kernel, , exec__success, "char *"); 159 SDT_PROBE_DEFINE1(proc, kernel, , exec__failure, "int"); 160 161 /* 162 * Exec function switch: 163 * 164 * Note that each makecmds function is responsible for loading the 165 * exec package with the necessary functions for any exec-type-specific 166 * handling. 167 * 168 * Functions for specific exec types should be defined in their own 169 * header file. 170 */ 171 static const struct execsw **execsw = NULL; 172 static int nexecs; 173 174 u_int exec_maxhdrsz; /* must not be static - used by netbsd32 */ 175 176 /* list of dynamically loaded execsw entries */ 177 static LIST_HEAD(execlist_head, exec_entry) ex_head = 178 LIST_HEAD_INITIALIZER(ex_head); 179 struct exec_entry { 180 LIST_ENTRY(exec_entry) ex_list; 181 SLIST_ENTRY(exec_entry) ex_slist; 182 const struct execsw *ex_sw; 183 }; 184 185 #ifndef __HAVE_SYSCALL_INTERN 186 void syscall(void); 187 #endif 188 189 /* NetBSD autoloadable syscalls */ 190 #ifdef MODULAR 191 #include <kern/syscalls_autoload.c> 192 #endif 193 194 /* NetBSD emul struct */ 195 struct emul emul_netbsd = { 196 .e_name = "netbsd", 197 #ifdef EMUL_NATIVEROOT 198 .e_path = EMUL_NATIVEROOT, 199 #else 200 .e_path = NULL, 201 #endif 202 #ifndef __HAVE_MINIMAL_EMUL 203 .e_flags = EMUL_HAS_SYS___syscall, 204 .e_errno = NULL, 205 .e_nosys = SYS_syscall, 206 .e_nsysent = SYS_NSYSENT, 207 #endif 208 #ifdef MODULAR 209 .e_sc_autoload = netbsd_syscalls_autoload, 210 #endif 211 .e_sysent = sysent, 212 #ifdef SYSCALL_DEBUG 213 .e_syscallnames = syscallnames, 214 #else 215 .e_syscallnames = NULL, 216 #endif 217 .e_sendsig = sendsig, 218 .e_trapsignal = trapsignal, 219 .e_tracesig = NULL, 220 .e_sigcode = NULL, 221 .e_esigcode = NULL, 222 .e_sigobject = NULL, 223 .e_setregs = setregs, 224 .e_proc_exec = NULL, 225 .e_proc_fork = NULL, 226 .e_proc_exit = NULL, 227 .e_lwp_fork = NULL, 228 .e_lwp_exit = NULL, 229 #ifdef __HAVE_SYSCALL_INTERN 230 .e_syscall_intern = syscall_intern, 231 #else 232 .e_syscall = syscall, 233 #endif 234 .e_sysctlovly = NULL, 235 .e_vm_default_addr = uvm_default_mapaddr, 236 .e_usertrap = NULL, 237 .e_ucsize = sizeof(ucontext_t), 238 .e_startlwp = startlwp 239 }; 240 241 /* 242 * Exec lock. Used to control access to execsw[] structures. 243 * This must not be static so that netbsd32 can access it, too. 244 */ 245 krwlock_t exec_lock; 246 247 static kmutex_t sigobject_lock; 248 249 /* 250 * Data used between a loadvm and execve part of an "exec" operation 251 */ 252 struct execve_data { 253 struct exec_package ed_pack; 254 struct pathbuf *ed_pathbuf; 255 struct vattr ed_attr; 256 struct ps_strings ed_arginfo; 257 char *ed_argp; 258 const char *ed_pathstring; 259 char *ed_resolvedpathbuf; 260 size_t ed_ps_strings_sz; 261 int ed_szsigcode; 262 size_t ed_argslen; 263 long ed_argc; 264 long ed_envc; 265 }; 266 267 /* 268 * data passed from parent lwp to child during a posix_spawn() 269 */ 270 struct spawn_exec_data { 271 struct execve_data sed_exec; 272 struct posix_spawn_file_actions 273 *sed_actions; 274 struct posix_spawnattr *sed_attrs; 275 struct proc *sed_parent; 276 kcondvar_t sed_cv_child_ready; 277 kmutex_t sed_mtx_child; 278 int sed_error; 279 volatile uint32_t sed_refcnt; 280 }; 281 282 static struct vm_map *exec_map; 283 static struct pool exec_pool; 284 285 static void * 286 exec_pool_alloc(struct pool *pp, int flags) 287 { 288 289 return (void *)uvm_km_alloc(exec_map, NCARGS, 0, 290 UVM_KMF_PAGEABLE | UVM_KMF_WAITVA); 291 } 292 293 static void 294 exec_pool_free(struct pool *pp, void *addr) 295 { 296 297 uvm_km_free(exec_map, (vaddr_t)addr, NCARGS, UVM_KMF_PAGEABLE); 298 } 299 300 static struct pool_allocator exec_palloc = { 301 .pa_alloc = exec_pool_alloc, 302 .pa_free = exec_pool_free, 303 .pa_pagesz = NCARGS 304 }; 305 306 /* 307 * check exec: 308 * given an "executable" described in the exec package's namei info, 309 * see what we can do with it. 310 * 311 * ON ENTRY: 312 * exec package with appropriate namei info 313 * lwp pointer of exec'ing lwp 314 * NO SELF-LOCKED VNODES 315 * 316 * ON EXIT: 317 * error: nothing held, etc. exec header still allocated. 318 * ok: filled exec package, executable's vnode (unlocked). 319 * 320 * EXEC SWITCH ENTRY: 321 * Locked vnode to check, exec package, proc. 322 * 323 * EXEC SWITCH EXIT: 324 * ok: return 0, filled exec package, executable's vnode (unlocked). 325 * error: destructive: 326 * everything deallocated execept exec header. 327 * non-destructive: 328 * error code, executable's vnode (unlocked), 329 * exec header unmodified. 330 */ 331 int 332 /*ARGSUSED*/ 333 check_exec(struct lwp *l, struct exec_package *epp, struct pathbuf *pb) 334 { 335 int error, i; 336 struct vnode *vp; 337 struct nameidata nd; 338 size_t resid; 339 340 #if 1 341 // grab the absolute pathbuf here before namei() trashes it. 342 pathbuf_copystring(pb, epp->ep_resolvedname, PATH_MAX); 343 #endif 344 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb); 345 346 /* first get the vnode */ 347 if ((error = namei(&nd)) != 0) 348 return error; 349 epp->ep_vp = vp = nd.ni_vp; 350 #if 0 351 /* 352 * XXX: can't use nd.ni_pnbuf, because although pb contains an 353 * absolute path, nd.ni_pnbuf does not if the path contains symlinks. 354 */ 355 /* normally this can't fail */ 356 error = copystr(nd.ni_pnbuf, epp->ep_resolvedname, PATH_MAX, NULL); 357 KASSERT(error == 0); 358 #endif 359 360 #ifdef DIAGNOSTIC 361 /* paranoia (take this out once namei stuff stabilizes) */ 362 memset(nd.ni_pnbuf, '~', PATH_MAX); 363 #endif 364 365 /* check access and type */ 366 if (vp->v_type != VREG) { 367 error = EACCES; 368 goto bad1; 369 } 370 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 371 goto bad1; 372 373 /* get attributes */ 374 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 375 goto bad1; 376 377 /* Check mount point */ 378 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 379 error = EACCES; 380 goto bad1; 381 } 382 if (vp->v_mount->mnt_flag & MNT_NOSUID) 383 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 384 385 /* try to open it */ 386 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 387 goto bad1; 388 389 /* unlock vp, since we need it unlocked from here on out. */ 390 VOP_UNLOCK(vp); 391 392 #if NVERIEXEC > 0 393 error = veriexec_verify(l, vp, epp->ep_resolvedname, 394 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 395 NULL); 396 if (error) 397 goto bad2; 398 #endif /* NVERIEXEC > 0 */ 399 400 #ifdef PAX_SEGVGUARD 401 error = pax_segvguard(l, vp, epp->ep_resolvedname, false); 402 if (error) 403 goto bad2; 404 #endif /* PAX_SEGVGUARD */ 405 406 /* now we have the file, get the exec header */ 407 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 408 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 409 if (error) 410 goto bad2; 411 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 412 413 /* 414 * Set up default address space limits. Can be overridden 415 * by individual exec packages. 416 */ 417 epp->ep_vm_minaddr = exec_vm_minaddr(VM_MIN_ADDRESS); 418 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 419 420 /* 421 * set up the vmcmds for creation of the process 422 * address space 423 */ 424 error = ENOEXEC; 425 for (i = 0; i < nexecs; i++) { 426 int newerror; 427 428 epp->ep_esch = execsw[i]; 429 newerror = (*execsw[i]->es_makecmds)(l, epp); 430 431 if (!newerror) { 432 /* Seems ok: check that entry point is not too high */ 433 if (epp->ep_entry > epp->ep_vm_maxaddr) { 434 #ifdef DIAGNOSTIC 435 printf("%s: rejecting %p due to " 436 "too high entry address (> %p)\n", 437 __func__, (void *)epp->ep_entry, 438 (void *)epp->ep_vm_maxaddr); 439 #endif 440 error = ENOEXEC; 441 break; 442 } 443 /* Seems ok: check that entry point is not too low */ 444 if (epp->ep_entry < epp->ep_vm_minaddr) { 445 #ifdef DIAGNOSTIC 446 printf("%s: rejecting %p due to " 447 "too low entry address (< %p)\n", 448 __func__, (void *)epp->ep_entry, 449 (void *)epp->ep_vm_minaddr); 450 #endif 451 error = ENOEXEC; 452 break; 453 } 454 455 /* check limits */ 456 if ((epp->ep_tsize > MAXTSIZ) || 457 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 458 [RLIMIT_DATA].rlim_cur)) { 459 #ifdef DIAGNOSTIC 460 printf("%s: rejecting due to " 461 "limits (t=%llu > %llu || d=%llu > %llu)\n", 462 __func__, 463 (unsigned long long)epp->ep_tsize, 464 (unsigned long long)MAXTSIZ, 465 (unsigned long long)epp->ep_dsize, 466 (unsigned long long) 467 l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur); 468 #endif 469 error = ENOMEM; 470 break; 471 } 472 return 0; 473 } 474 475 /* 476 * Reset all the fields that may have been modified by the 477 * loader. 478 */ 479 KASSERT(epp->ep_emul_arg == NULL); 480 if (epp->ep_emul_root != NULL) { 481 vrele(epp->ep_emul_root); 482 epp->ep_emul_root = NULL; 483 } 484 if (epp->ep_interp != NULL) { 485 vrele(epp->ep_interp); 486 epp->ep_interp = NULL; 487 } 488 epp->ep_pax_flags = 0; 489 490 /* make sure the first "interesting" error code is saved. */ 491 if (error == ENOEXEC) 492 error = newerror; 493 494 if (epp->ep_flags & EXEC_DESTR) 495 /* Error from "#!" code, tidied up by recursive call */ 496 return error; 497 } 498 499 /* not found, error */ 500 501 /* 502 * free any vmspace-creation commands, 503 * and release their references 504 */ 505 kill_vmcmds(&epp->ep_vmcmds); 506 507 bad2: 508 /* 509 * close and release the vnode, restore the old one, free the 510 * pathname buf, and punt. 511 */ 512 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 513 VOP_CLOSE(vp, FREAD, l->l_cred); 514 vput(vp); 515 return error; 516 517 bad1: 518 /* 519 * free the namei pathname buffer, and put the vnode 520 * (which we don't yet have open). 521 */ 522 vput(vp); /* was still locked */ 523 return error; 524 } 525 526 #ifdef __MACHINE_STACK_GROWS_UP 527 #define STACK_PTHREADSPACE NBPG 528 #else 529 #define STACK_PTHREADSPACE 0 530 #endif 531 532 static int 533 execve_fetch_element(char * const *array, size_t index, char **value) 534 { 535 return copyin(array + index, value, sizeof(*value)); 536 } 537 538 /* 539 * exec system call 540 */ 541 int 542 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 543 { 544 /* { 545 syscallarg(const char *) path; 546 syscallarg(char * const *) argp; 547 syscallarg(char * const *) envp; 548 } */ 549 550 return execve1(l, SCARG(uap, path), SCARG(uap, argp), 551 SCARG(uap, envp), execve_fetch_element); 552 } 553 554 int 555 sys_fexecve(struct lwp *l, const struct sys_fexecve_args *uap, 556 register_t *retval) 557 { 558 /* { 559 syscallarg(int) fd; 560 syscallarg(char * const *) argp; 561 syscallarg(char * const *) envp; 562 } */ 563 564 return ENOSYS; 565 } 566 567 /* 568 * Load modules to try and execute an image that we do not understand. 569 * If no execsw entries are present, we load those likely to be needed 570 * in order to run native images only. Otherwise, we autoload all 571 * possible modules that could let us run the binary. XXX lame 572 */ 573 static void 574 exec_autoload(void) 575 { 576 #ifdef MODULAR 577 static const char * const native[] = { 578 "exec_elf32", 579 "exec_elf64", 580 "exec_script", 581 NULL 582 }; 583 static const char * const compat[] = { 584 "exec_elf32", 585 "exec_elf64", 586 "exec_script", 587 "exec_aout", 588 "exec_coff", 589 "exec_ecoff", 590 "compat_aoutm68k", 591 "compat_netbsd32", 592 "compat_sunos", 593 "compat_sunos32", 594 "compat_ultrix", 595 NULL 596 }; 597 char const * const *list; 598 int i; 599 600 list = (nexecs == 0 ? native : compat); 601 for (i = 0; list[i] != NULL; i++) { 602 if (module_autoload(list[i], MODULE_CLASS_EXEC) != 0) { 603 continue; 604 } 605 yield(); 606 } 607 #endif 608 } 609 610 static int 611 makepathbuf(struct lwp *l, const char *upath, struct pathbuf **pbp, 612 size_t *offs) 613 { 614 char *path, *bp; 615 size_t len, tlen; 616 int error; 617 struct cwdinfo *cwdi; 618 619 path = PNBUF_GET(); 620 error = copyinstr(upath, path, MAXPATHLEN, &len); 621 if (error) { 622 PNBUF_PUT(path); 623 DPRINTF(("%s: copyin path @%p %d\n", __func__, upath, error)); 624 return error; 625 } 626 627 if (path[0] == '/') { 628 *offs = 0; 629 goto out; 630 } 631 632 len++; 633 if (len + 1 >= MAXPATHLEN) 634 goto out; 635 bp = path + MAXPATHLEN - len; 636 memmove(bp, path, len); 637 *(--bp) = '/'; 638 639 cwdi = l->l_proc->p_cwdi; 640 rw_enter(&cwdi->cwdi_lock, RW_READER); 641 error = getcwd_common(cwdi->cwdi_cdir, NULL, &bp, path, MAXPATHLEN / 2, 642 GETCWD_CHECK_ACCESS, l); 643 rw_exit(&cwdi->cwdi_lock); 644 645 if (error) { 646 DPRINTF(("%s: getcwd_common path %s %d\n", __func__, path, 647 error)); 648 goto out; 649 } 650 tlen = path + MAXPATHLEN - bp; 651 652 memmove(path, bp, tlen); 653 path[tlen] = '\0'; 654 *offs = tlen - len; 655 out: 656 *pbp = pathbuf_assimilate(path); 657 return 0; 658 } 659 660 vaddr_t 661 exec_vm_minaddr(vaddr_t va_min) 662 { 663 /* 664 * Increase va_min if we don't want NULL to be mappable by the 665 * process. 666 */ 667 #define VM_MIN_GUARD PAGE_SIZE 668 if (user_va0_disable && (va_min < VM_MIN_GUARD)) 669 return VM_MIN_GUARD; 670 return va_min; 671 } 672 673 static int 674 execve_loadvm(struct lwp *l, const char *path, char * const *args, 675 char * const *envs, execve_fetch_element_t fetch_element, 676 struct execve_data * restrict data) 677 { 678 struct exec_package * const epp = &data->ed_pack; 679 int error; 680 struct proc *p; 681 char *dp; 682 u_int modgen; 683 size_t offs = 0; // XXX: GCC 684 685 KASSERT(data != NULL); 686 687 p = l->l_proc; 688 modgen = 0; 689 690 SDT_PROBE(proc, kernel, , exec, path, 0, 0, 0, 0); 691 692 /* 693 * Check if we have exceeded our number of processes limit. 694 * This is so that we handle the case where a root daemon 695 * forked, ran setuid to become the desired user and is trying 696 * to exec. The obvious place to do the reference counting check 697 * is setuid(), but we don't do the reference counting check there 698 * like other OS's do because then all the programs that use setuid() 699 * must be modified to check the return code of setuid() and exit(). 700 * It is dangerous to make setuid() fail, because it fails open and 701 * the program will continue to run as root. If we make it succeed 702 * and return an error code, again we are not enforcing the limit. 703 * The best place to enforce the limit is here, when the process tries 704 * to execute a new image, because eventually the process will need 705 * to call exec in order to do something useful. 706 */ 707 retry: 708 if (p->p_flag & PK_SUGID) { 709 if (kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT, 710 p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 711 &p->p_rlimit[RLIMIT_NPROC], 712 KAUTH_ARG(RLIMIT_NPROC)) != 0 && 713 chgproccnt(kauth_cred_getuid(l->l_cred), 0) > 714 p->p_rlimit[RLIMIT_NPROC].rlim_cur) 715 return EAGAIN; 716 } 717 718 /* 719 * Drain existing references and forbid new ones. The process 720 * should be left alone until we're done here. This is necessary 721 * to avoid race conditions - e.g. in ptrace() - that might allow 722 * a local user to illicitly obtain elevated privileges. 723 */ 724 rw_enter(&p->p_reflock, RW_WRITER); 725 726 /* 727 * Init the namei data to point the file user's program name. 728 * This is done here rather than in check_exec(), so that it's 729 * possible to override this settings if any of makecmd/probe 730 * functions call check_exec() recursively - for example, 731 * see exec_script_makecmds(). 732 */ 733 if ((error = makepathbuf(l, path, &data->ed_pathbuf, &offs)) != 0) 734 goto clrflg; 735 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 736 data->ed_resolvedpathbuf = PNBUF_GET(); 737 738 /* 739 * initialize the fields of the exec package. 740 */ 741 epp->ep_kname = data->ed_pathstring + offs; 742 epp->ep_resolvedname = data->ed_resolvedpathbuf; 743 epp->ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 744 epp->ep_hdrlen = exec_maxhdrsz; 745 epp->ep_hdrvalid = 0; 746 epp->ep_emul_arg = NULL; 747 epp->ep_emul_arg_free = NULL; 748 memset(&epp->ep_vmcmds, 0, sizeof(epp->ep_vmcmds)); 749 epp->ep_vap = &data->ed_attr; 750 epp->ep_flags = (p->p_flag & PK_32) ? EXEC_FROM32 : 0; 751 MD_TOPDOWN_INIT(epp); 752 epp->ep_emul_root = NULL; 753 epp->ep_interp = NULL; 754 epp->ep_esch = NULL; 755 epp->ep_pax_flags = 0; 756 memset(epp->ep_machine_arch, 0, sizeof(epp->ep_machine_arch)); 757 758 rw_enter(&exec_lock, RW_READER); 759 760 /* see if we can run it. */ 761 if ((error = check_exec(l, epp, data->ed_pathbuf)) != 0) { 762 if (error != ENOENT && error != EACCES && error != ENOEXEC) { 763 DPRINTF(("%s: check exec failed for %s, error %d\n", 764 __func__, epp->ep_kname, error)); 765 } 766 goto freehdr; 767 } 768 769 /* allocate an argument buffer */ 770 data->ed_argp = pool_get(&exec_pool, PR_WAITOK); 771 KASSERT(data->ed_argp != NULL); 772 dp = data->ed_argp; 773 774 if ((error = copyinargs(data, args, envs, fetch_element, &dp)) != 0) { 775 goto bad; 776 } 777 778 /* 779 * Calculate the new stack size. 780 */ 781 782 #ifdef __MACHINE_STACK_GROWS_UP 783 /* 784 * copyargs() fills argc/argv/envp from the lower address even on 785 * __MACHINE_STACK_GROWS_UP machines. Reserve a few words just below the SP 786 * so that _rtld() use it. 787 */ 788 #define RTLD_GAP 32 789 #else 790 #define RTLD_GAP 0 791 #endif 792 793 const size_t argenvstrlen = (char *)ALIGN(dp) - data->ed_argp; 794 795 data->ed_argslen = calcargs(data, argenvstrlen); 796 797 const size_t len = calcstack(data, pax_aslr_stack_gap(epp) + RTLD_GAP); 798 799 if (len > epp->ep_ssize) { 800 /* in effect, compare to initial limit */ 801 DPRINTF(("%s: stack limit exceeded %zu\n", __func__, len)); 802 error = ENOMEM; 803 goto bad; 804 } 805 /* adjust "active stack depth" for process VSZ */ 806 epp->ep_ssize = len; 807 808 return 0; 809 810 bad: 811 /* free the vmspace-creation commands, and release their references */ 812 kill_vmcmds(&epp->ep_vmcmds); 813 /* kill any opened file descriptor, if necessary */ 814 if (epp->ep_flags & EXEC_HASFD) { 815 epp->ep_flags &= ~EXEC_HASFD; 816 fd_close(epp->ep_fd); 817 } 818 /* close and put the exec'd file */ 819 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 820 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 821 vput(epp->ep_vp); 822 pool_put(&exec_pool, data->ed_argp); 823 824 freehdr: 825 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 826 if (epp->ep_emul_root != NULL) 827 vrele(epp->ep_emul_root); 828 if (epp->ep_interp != NULL) 829 vrele(epp->ep_interp); 830 831 rw_exit(&exec_lock); 832 833 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 834 pathbuf_destroy(data->ed_pathbuf); 835 PNBUF_PUT(data->ed_resolvedpathbuf); 836 837 clrflg: 838 rw_exit(&p->p_reflock); 839 840 if (modgen != module_gen && error == ENOEXEC) { 841 modgen = module_gen; 842 exec_autoload(); 843 goto retry; 844 } 845 846 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 847 return error; 848 } 849 850 static int 851 execve_dovmcmds(struct lwp *l, struct execve_data * restrict data) 852 { 853 struct exec_package * const epp = &data->ed_pack; 854 struct proc *p = l->l_proc; 855 struct exec_vmcmd *base_vcp; 856 int error = 0; 857 size_t i; 858 859 /* record proc's vnode, for use by procfs and others */ 860 if (p->p_textvp) 861 vrele(p->p_textvp); 862 vref(epp->ep_vp); 863 p->p_textvp = epp->ep_vp; 864 865 /* create the new process's VM space by running the vmcmds */ 866 KASSERTMSG(epp->ep_vmcmds.evs_used != 0, "%s: no vmcmds", __func__); 867 868 #ifdef TRACE_EXEC 869 DUMPVMCMDS(epp, 0, 0); 870 #endif 871 872 base_vcp = NULL; 873 874 for (i = 0; i < epp->ep_vmcmds.evs_used && !error; i++) { 875 struct exec_vmcmd *vcp; 876 877 vcp = &epp->ep_vmcmds.evs_cmds[i]; 878 if (vcp->ev_flags & VMCMD_RELATIVE) { 879 KASSERTMSG(base_vcp != NULL, 880 "%s: relative vmcmd with no base", __func__); 881 KASSERTMSG((vcp->ev_flags & VMCMD_BASE) == 0, 882 "%s: illegal base & relative vmcmd", __func__); 883 vcp->ev_addr += base_vcp->ev_addr; 884 } 885 error = (*vcp->ev_proc)(l, vcp); 886 if (error) 887 DUMPVMCMDS(epp, i, error); 888 if (vcp->ev_flags & VMCMD_BASE) 889 base_vcp = vcp; 890 } 891 892 /* free the vmspace-creation commands, and release their references */ 893 kill_vmcmds(&epp->ep_vmcmds); 894 895 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 896 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 897 vput(epp->ep_vp); 898 899 /* if an error happened, deallocate and punt */ 900 if (error != 0) { 901 DPRINTF(("%s: vmcmd %zu failed: %d\n", __func__, i - 1, error)); 902 } 903 return error; 904 } 905 906 static void 907 execve_free_data(struct execve_data *data) 908 { 909 struct exec_package * const epp = &data->ed_pack; 910 911 /* free the vmspace-creation commands, and release their references */ 912 kill_vmcmds(&epp->ep_vmcmds); 913 /* kill any opened file descriptor, if necessary */ 914 if (epp->ep_flags & EXEC_HASFD) { 915 epp->ep_flags &= ~EXEC_HASFD; 916 fd_close(epp->ep_fd); 917 } 918 919 /* close and put the exec'd file */ 920 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 921 VOP_CLOSE(epp->ep_vp, FREAD, curlwp->l_cred); 922 vput(epp->ep_vp); 923 pool_put(&exec_pool, data->ed_argp); 924 925 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 926 if (epp->ep_emul_root != NULL) 927 vrele(epp->ep_emul_root); 928 if (epp->ep_interp != NULL) 929 vrele(epp->ep_interp); 930 931 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 932 pathbuf_destroy(data->ed_pathbuf); 933 PNBUF_PUT(data->ed_resolvedpathbuf); 934 } 935 936 static void 937 pathexec(struct proc *p, const char *resolvedname) 938 { 939 KASSERT(resolvedname[0] == '/'); 940 941 /* set command name & other accounting info */ 942 strlcpy(p->p_comm, strrchr(resolvedname, '/') + 1, sizeof(p->p_comm)); 943 944 kmem_strfree(p->p_path); 945 p->p_path = kmem_strdupsize(resolvedname, NULL, KM_SLEEP); 946 } 947 948 /* XXX elsewhere */ 949 static int 950 credexec(struct lwp *l, struct vattr *attr) 951 { 952 struct proc *p = l->l_proc; 953 int error; 954 955 /* 956 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 957 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 958 * out additional references on the process for the moment. 959 */ 960 if ((p->p_slflag & PSL_TRACED) == 0 && 961 962 (((attr->va_mode & S_ISUID) != 0 && 963 kauth_cred_geteuid(l->l_cred) != attr->va_uid) || 964 965 ((attr->va_mode & S_ISGID) != 0 && 966 kauth_cred_getegid(l->l_cred) != attr->va_gid))) { 967 /* 968 * Mark the process as SUGID before we do 969 * anything that might block. 970 */ 971 proc_crmod_enter(); 972 proc_crmod_leave(NULL, NULL, true); 973 974 /* Make sure file descriptors 0..2 are in use. */ 975 if ((error = fd_checkstd()) != 0) { 976 DPRINTF(("%s: fdcheckstd failed %d\n", 977 __func__, error)); 978 return error; 979 } 980 981 /* 982 * Copy the credential so other references don't see our 983 * changes. 984 */ 985 l->l_cred = kauth_cred_copy(l->l_cred); 986 #ifdef KTRACE 987 /* 988 * If the persistent trace flag isn't set, turn off. 989 */ 990 if (p->p_tracep) { 991 mutex_enter(&ktrace_lock); 992 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 993 ktrderef(p); 994 mutex_exit(&ktrace_lock); 995 } 996 #endif 997 if (attr->va_mode & S_ISUID) 998 kauth_cred_seteuid(l->l_cred, attr->va_uid); 999 if (attr->va_mode & S_ISGID) 1000 kauth_cred_setegid(l->l_cred, attr->va_gid); 1001 } else { 1002 if (kauth_cred_geteuid(l->l_cred) == 1003 kauth_cred_getuid(l->l_cred) && 1004 kauth_cred_getegid(l->l_cred) == 1005 kauth_cred_getgid(l->l_cred)) 1006 p->p_flag &= ~PK_SUGID; 1007 } 1008 1009 /* 1010 * Copy the credential so other references don't see our changes. 1011 * Test to see if this is necessary first, since in the common case 1012 * we won't need a private reference. 1013 */ 1014 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1015 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1016 l->l_cred = kauth_cred_copy(l->l_cred); 1017 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1018 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1019 } 1020 1021 /* Update the master credentials. */ 1022 if (l->l_cred != p->p_cred) { 1023 kauth_cred_t ocred; 1024 1025 kauth_cred_hold(l->l_cred); 1026 mutex_enter(p->p_lock); 1027 ocred = p->p_cred; 1028 p->p_cred = l->l_cred; 1029 mutex_exit(p->p_lock); 1030 kauth_cred_free(ocred); 1031 } 1032 1033 return 0; 1034 } 1035 1036 static void 1037 emulexec(struct lwp *l, struct exec_package *epp) 1038 { 1039 struct proc *p = l->l_proc; 1040 1041 /* The emulation root will usually have been found when we looked 1042 * for the elf interpreter (or similar), if not look now. */ 1043 if (epp->ep_esch->es_emul->e_path != NULL && 1044 epp->ep_emul_root == NULL) 1045 emul_find_root(l, epp); 1046 1047 /* Any old emulation root got removed by fdcloseexec */ 1048 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1049 p->p_cwdi->cwdi_edir = epp->ep_emul_root; 1050 rw_exit(&p->p_cwdi->cwdi_lock); 1051 epp->ep_emul_root = NULL; 1052 if (epp->ep_interp != NULL) 1053 vrele(epp->ep_interp); 1054 1055 /* 1056 * Call emulation specific exec hook. This can setup per-process 1057 * p->p_emuldata or do any other per-process stuff an emulation needs. 1058 * 1059 * If we are executing process of different emulation than the 1060 * original forked process, call e_proc_exit() of the old emulation 1061 * first, then e_proc_exec() of new emulation. If the emulation is 1062 * same, the exec hook code should deallocate any old emulation 1063 * resources held previously by this process. 1064 */ 1065 if (p->p_emul && p->p_emul->e_proc_exit 1066 && p->p_emul != epp->ep_esch->es_emul) 1067 (*p->p_emul->e_proc_exit)(p); 1068 1069 /* 1070 * This is now LWP 1. 1071 */ 1072 /* XXX elsewhere */ 1073 mutex_enter(p->p_lock); 1074 p->p_nlwpid = 1; 1075 l->l_lid = 1; 1076 mutex_exit(p->p_lock); 1077 1078 /* 1079 * Call exec hook. Emulation code may NOT store reference to anything 1080 * from &pack. 1081 */ 1082 if (epp->ep_esch->es_emul->e_proc_exec) 1083 (*epp->ep_esch->es_emul->e_proc_exec)(p, epp); 1084 1085 /* update p_emul, the old value is no longer needed */ 1086 p->p_emul = epp->ep_esch->es_emul; 1087 1088 /* ...and the same for p_execsw */ 1089 p->p_execsw = epp->ep_esch; 1090 1091 #ifdef __HAVE_SYSCALL_INTERN 1092 (*p->p_emul->e_syscall_intern)(p); 1093 #endif 1094 ktremul(); 1095 } 1096 1097 static int 1098 execve_runproc(struct lwp *l, struct execve_data * restrict data, 1099 bool no_local_exec_lock, bool is_spawn) 1100 { 1101 struct exec_package * const epp = &data->ed_pack; 1102 int error = 0; 1103 struct proc *p; 1104 1105 /* 1106 * In case of a posix_spawn operation, the child doing the exec 1107 * might not hold the reader lock on exec_lock, but the parent 1108 * will do this instead. 1109 */ 1110 KASSERT(no_local_exec_lock || rw_lock_held(&exec_lock)); 1111 KASSERT(!no_local_exec_lock || is_spawn); 1112 KASSERT(data != NULL); 1113 1114 p = l->l_proc; 1115 1116 /* Get rid of other LWPs. */ 1117 if (p->p_nlwps > 1) { 1118 mutex_enter(p->p_lock); 1119 exit_lwps(l); 1120 mutex_exit(p->p_lock); 1121 } 1122 KDASSERT(p->p_nlwps == 1); 1123 1124 /* Destroy any lwpctl info. */ 1125 if (p->p_lwpctl != NULL) 1126 lwp_ctl_exit(); 1127 1128 /* Remove POSIX timers */ 1129 timers_free(p, TIMERS_POSIX); 1130 1131 /* Set the PaX flags. */ 1132 pax_set_flags(epp, p); 1133 1134 /* 1135 * Do whatever is necessary to prepare the address space 1136 * for remapping. Note that this might replace the current 1137 * vmspace with another! 1138 */ 1139 if (is_spawn) 1140 uvmspace_spawn(l, epp->ep_vm_minaddr, 1141 epp->ep_vm_maxaddr, 1142 epp->ep_flags & EXEC_TOPDOWN_VM); 1143 else 1144 uvmspace_exec(l, epp->ep_vm_minaddr, 1145 epp->ep_vm_maxaddr, 1146 epp->ep_flags & EXEC_TOPDOWN_VM); 1147 1148 struct vmspace *vm; 1149 vm = p->p_vmspace; 1150 vm->vm_taddr = (void *)epp->ep_taddr; 1151 vm->vm_tsize = btoc(epp->ep_tsize); 1152 vm->vm_daddr = (void*)epp->ep_daddr; 1153 vm->vm_dsize = btoc(epp->ep_dsize); 1154 vm->vm_ssize = btoc(epp->ep_ssize); 1155 vm->vm_issize = 0; 1156 vm->vm_maxsaddr = (void *)epp->ep_maxsaddr; 1157 vm->vm_minsaddr = (void *)epp->ep_minsaddr; 1158 1159 pax_aslr_init_vm(l, vm, epp); 1160 1161 /* Now map address space. */ 1162 error = execve_dovmcmds(l, data); 1163 if (error != 0) 1164 goto exec_abort; 1165 1166 pathexec(p, epp->ep_resolvedname); 1167 1168 char * const newstack = STACK_GROW(vm->vm_minsaddr, epp->ep_ssize); 1169 1170 error = copyoutargs(data, l, newstack); 1171 if (error != 0) 1172 goto exec_abort; 1173 1174 cwdexec(p); 1175 fd_closeexec(); /* handle close on exec */ 1176 1177 if (__predict_false(ktrace_on)) 1178 fd_ktrexecfd(); 1179 1180 execsigs(p); /* reset caught signals */ 1181 1182 mutex_enter(p->p_lock); 1183 l->l_ctxlink = NULL; /* reset ucontext link */ 1184 p->p_acflag &= ~AFORK; 1185 p->p_flag |= PK_EXEC; 1186 mutex_exit(p->p_lock); 1187 1188 /* 1189 * Stop profiling. 1190 */ 1191 if ((p->p_stflag & PST_PROFIL) != 0) { 1192 mutex_spin_enter(&p->p_stmutex); 1193 stopprofclock(p); 1194 mutex_spin_exit(&p->p_stmutex); 1195 } 1196 1197 /* 1198 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 1199 * exited and exec()/exit() are the only places it will be cleared. 1200 */ 1201 if ((p->p_lflag & PL_PPWAIT) != 0) { 1202 mutex_enter(proc_lock); 1203 l->l_lwpctl = NULL; /* was on loan from blocked parent */ 1204 p->p_lflag &= ~PL_PPWAIT; 1205 cv_broadcast(&p->p_pptr->p_waitcv); 1206 mutex_exit(proc_lock); 1207 } 1208 1209 error = credexec(l, &data->ed_attr); 1210 if (error) 1211 goto exec_abort; 1212 1213 #if defined(__HAVE_RAS) 1214 /* 1215 * Remove all RASs from the address space. 1216 */ 1217 ras_purgeall(); 1218 #endif 1219 1220 doexechooks(p); 1221 1222 /* 1223 * Set initial SP at the top of the stack. 1224 * 1225 * Note that on machines where stack grows up (e.g. hppa), SP points to 1226 * the end of arg/env strings. Userland guesses the address of argc 1227 * via ps_strings::ps_argvstr. 1228 */ 1229 1230 /* Setup new registers and do misc. setup. */ 1231 (*epp->ep_esch->es_emul->e_setregs)(l, epp, (vaddr_t)newstack); 1232 if (epp->ep_esch->es_setregs) 1233 (*epp->ep_esch->es_setregs)(l, epp, (vaddr_t)newstack); 1234 1235 /* Provide a consistent LWP private setting */ 1236 (void)lwp_setprivate(l, NULL); 1237 1238 /* Discard all PCU state; need to start fresh */ 1239 pcu_discard_all(l); 1240 1241 /* map the process's signal trampoline code */ 1242 if ((error = exec_sigcode_map(p, epp->ep_esch->es_emul)) != 0) { 1243 DPRINTF(("%s: map sigcode failed %d\n", __func__, error)); 1244 goto exec_abort; 1245 } 1246 1247 pool_put(&exec_pool, data->ed_argp); 1248 1249 /* notify others that we exec'd */ 1250 KNOTE(&p->p_klist, NOTE_EXEC); 1251 1252 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1253 1254 SDT_PROBE(proc, kernel, , exec__success, epp->ep_kname, 0, 0, 0, 0); 1255 1256 emulexec(l, epp); 1257 1258 /* Allow new references from the debugger/procfs. */ 1259 rw_exit(&p->p_reflock); 1260 if (!no_local_exec_lock) 1261 rw_exit(&exec_lock); 1262 1263 mutex_enter(proc_lock); 1264 1265 if ((p->p_slflag & (PSL_TRACED|PSL_SYSCALL)) == PSL_TRACED) { 1266 ksiginfo_t ksi; 1267 1268 KSI_INIT_EMPTY(&ksi); 1269 ksi.ksi_signo = SIGTRAP; 1270 ksi.ksi_code = TRAP_EXEC; 1271 ksi.ksi_lid = l->l_lid; 1272 kpsignal(p, &ksi, NULL); 1273 } 1274 1275 if (p->p_sflag & PS_STOPEXEC) { 1276 ksiginfoq_t kq; 1277 1278 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1279 p->p_pptr->p_nstopchild++; 1280 p->p_waited = 0; 1281 mutex_enter(p->p_lock); 1282 ksiginfo_queue_init(&kq); 1283 sigclearall(p, &contsigmask, &kq); 1284 lwp_lock(l); 1285 l->l_stat = LSSTOP; 1286 p->p_stat = SSTOP; 1287 p->p_nrlwps--; 1288 lwp_unlock(l); 1289 mutex_exit(p->p_lock); 1290 mutex_exit(proc_lock); 1291 lwp_lock(l); 1292 mi_switch(l); 1293 ksiginfo_queue_drain(&kq); 1294 KERNEL_LOCK(l->l_biglocks, l); 1295 } else { 1296 mutex_exit(proc_lock); 1297 } 1298 1299 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 1300 pathbuf_destroy(data->ed_pathbuf); 1301 PNBUF_PUT(data->ed_resolvedpathbuf); 1302 #ifdef TRACE_EXEC 1303 DPRINTF(("%s finished\n", __func__)); 1304 #endif 1305 return EJUSTRETURN; 1306 1307 exec_abort: 1308 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 1309 rw_exit(&p->p_reflock); 1310 if (!no_local_exec_lock) 1311 rw_exit(&exec_lock); 1312 1313 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 1314 pathbuf_destroy(data->ed_pathbuf); 1315 PNBUF_PUT(data->ed_resolvedpathbuf); 1316 1317 /* 1318 * the old process doesn't exist anymore. exit gracefully. 1319 * get rid of the (new) address space we have created, if any, get rid 1320 * of our namei data and vnode, and exit noting failure 1321 */ 1322 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1323 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1324 1325 exec_free_emul_arg(epp); 1326 pool_put(&exec_pool, data->ed_argp); 1327 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1328 if (epp->ep_emul_root != NULL) 1329 vrele(epp->ep_emul_root); 1330 if (epp->ep_interp != NULL) 1331 vrele(epp->ep_interp); 1332 1333 /* Acquire the sched-state mutex (exit1() will release it). */ 1334 if (!is_spawn) { 1335 mutex_enter(p->p_lock); 1336 exit1(l, error, SIGABRT); 1337 } 1338 1339 return error; 1340 } 1341 1342 int 1343 execve1(struct lwp *l, const char *path, char * const *args, 1344 char * const *envs, execve_fetch_element_t fetch_element) 1345 { 1346 struct execve_data data; 1347 int error; 1348 1349 error = execve_loadvm(l, path, args, envs, fetch_element, &data); 1350 if (error) 1351 return error; 1352 error = execve_runproc(l, &data, false, false); 1353 return error; 1354 } 1355 1356 static size_t 1357 fromptrsz(const struct exec_package *epp) 1358 { 1359 return (epp->ep_flags & EXEC_FROM32) ? sizeof(int) : sizeof(char *); 1360 } 1361 1362 static size_t 1363 ptrsz(const struct exec_package *epp) 1364 { 1365 return (epp->ep_flags & EXEC_32) ? sizeof(int) : sizeof(char *); 1366 } 1367 1368 static size_t 1369 calcargs(struct execve_data * restrict data, const size_t argenvstrlen) 1370 { 1371 struct exec_package * const epp = &data->ed_pack; 1372 1373 const size_t nargenvptrs = 1374 1 + /* long argc */ 1375 data->ed_argc + /* char *argv[] */ 1376 1 + /* \0 */ 1377 data->ed_envc + /* char *env[] */ 1378 1; /* \0 */ 1379 1380 return (nargenvptrs * ptrsz(epp)) /* pointers */ 1381 + argenvstrlen /* strings */ 1382 + epp->ep_esch->es_arglen; /* auxinfo */ 1383 } 1384 1385 static size_t 1386 calcstack(struct execve_data * restrict data, const size_t gaplen) 1387 { 1388 struct exec_package * const epp = &data->ed_pack; 1389 1390 data->ed_szsigcode = epp->ep_esch->es_emul->e_esigcode - 1391 epp->ep_esch->es_emul->e_sigcode; 1392 1393 data->ed_ps_strings_sz = (epp->ep_flags & EXEC_32) ? 1394 sizeof(struct ps_strings32) : sizeof(struct ps_strings); 1395 1396 const size_t sigcode_psstr_sz = 1397 data->ed_szsigcode + /* sigcode */ 1398 data->ed_ps_strings_sz + /* ps_strings */ 1399 STACK_PTHREADSPACE; /* pthread space */ 1400 1401 const size_t stacklen = 1402 data->ed_argslen + 1403 gaplen + 1404 sigcode_psstr_sz; 1405 1406 /* make the stack "safely" aligned */ 1407 return STACK_LEN_ALIGN(stacklen, STACK_ALIGNBYTES); 1408 } 1409 1410 static int 1411 copyoutargs(struct execve_data * restrict data, struct lwp *l, 1412 char * const newstack) 1413 { 1414 struct exec_package * const epp = &data->ed_pack; 1415 struct proc *p = l->l_proc; 1416 int error; 1417 1418 /* remember information about the process */ 1419 data->ed_arginfo.ps_nargvstr = data->ed_argc; 1420 data->ed_arginfo.ps_nenvstr = data->ed_envc; 1421 1422 /* 1423 * Allocate the stack address passed to the newly execve()'ed process. 1424 * 1425 * The new stack address will be set to the SP (stack pointer) register 1426 * in setregs(). 1427 */ 1428 1429 char *newargs = STACK_ALLOC( 1430 STACK_SHRINK(newstack, data->ed_argslen), data->ed_argslen); 1431 1432 error = (*epp->ep_esch->es_copyargs)(l, epp, 1433 &data->ed_arginfo, &newargs, data->ed_argp); 1434 1435 if (error) { 1436 DPRINTF(("%s: copyargs failed %d\n", __func__, error)); 1437 return error; 1438 } 1439 1440 error = copyoutpsstrs(data, p); 1441 if (error != 0) 1442 return error; 1443 1444 return 0; 1445 } 1446 1447 static int 1448 copyoutpsstrs(struct execve_data * restrict data, struct proc *p) 1449 { 1450 struct exec_package * const epp = &data->ed_pack; 1451 struct ps_strings32 arginfo32; 1452 void *aip; 1453 int error; 1454 1455 /* fill process ps_strings info */ 1456 p->p_psstrp = (vaddr_t)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 1457 STACK_PTHREADSPACE), data->ed_ps_strings_sz); 1458 1459 if (epp->ep_flags & EXEC_32) { 1460 aip = &arginfo32; 1461 arginfo32.ps_argvstr = (vaddr_t)data->ed_arginfo.ps_argvstr; 1462 arginfo32.ps_nargvstr = data->ed_arginfo.ps_nargvstr; 1463 arginfo32.ps_envstr = (vaddr_t)data->ed_arginfo.ps_envstr; 1464 arginfo32.ps_nenvstr = data->ed_arginfo.ps_nenvstr; 1465 } else 1466 aip = &data->ed_arginfo; 1467 1468 /* copy out the process's ps_strings structure */ 1469 if ((error = copyout(aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)) 1470 != 0) { 1471 DPRINTF(("%s: ps_strings copyout %p->%p size %zu failed\n", 1472 __func__, aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)); 1473 return error; 1474 } 1475 1476 return 0; 1477 } 1478 1479 static int 1480 copyinargs(struct execve_data * restrict data, char * const *args, 1481 char * const *envs, execve_fetch_element_t fetch_element, char **dpp) 1482 { 1483 struct exec_package * const epp = &data->ed_pack; 1484 char *dp; 1485 size_t i; 1486 int error; 1487 1488 dp = *dpp; 1489 1490 data->ed_argc = 0; 1491 1492 /* copy the fake args list, if there's one, freeing it as we go */ 1493 if (epp->ep_flags & EXEC_HASARGL) { 1494 struct exec_fakearg *fa = epp->ep_fa; 1495 1496 while (fa->fa_arg != NULL) { 1497 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1498 size_t len; 1499 1500 len = strlcpy(dp, fa->fa_arg, maxlen); 1501 /* Count NUL into len. */ 1502 if (len < maxlen) 1503 len++; 1504 else { 1505 while (fa->fa_arg != NULL) { 1506 kmem_free(fa->fa_arg, fa->fa_len); 1507 fa++; 1508 } 1509 kmem_free(epp->ep_fa, epp->ep_fa_len); 1510 epp->ep_flags &= ~EXEC_HASARGL; 1511 return E2BIG; 1512 } 1513 ktrexecarg(fa->fa_arg, len - 1); 1514 dp += len; 1515 1516 kmem_free(fa->fa_arg, fa->fa_len); 1517 fa++; 1518 data->ed_argc++; 1519 } 1520 kmem_free(epp->ep_fa, epp->ep_fa_len); 1521 epp->ep_flags &= ~EXEC_HASARGL; 1522 } 1523 1524 /* 1525 * Read and count argument strings from user. 1526 */ 1527 1528 if (args == NULL) { 1529 DPRINTF(("%s: null args\n", __func__)); 1530 return EINVAL; 1531 } 1532 if (epp->ep_flags & EXEC_SKIPARG) 1533 args = (const void *)((const char *)args + fromptrsz(epp)); 1534 i = 0; 1535 error = copyinargstrs(data, args, fetch_element, &dp, &i, ktr_execarg); 1536 if (error != 0) { 1537 DPRINTF(("%s: copyin arg %d\n", __func__, error)); 1538 return error; 1539 } 1540 data->ed_argc += i; 1541 1542 /* 1543 * Read and count environment strings from user. 1544 */ 1545 1546 data->ed_envc = 0; 1547 /* environment need not be there */ 1548 if (envs == NULL) 1549 goto done; 1550 i = 0; 1551 error = copyinargstrs(data, envs, fetch_element, &dp, &i, ktr_execenv); 1552 if (error != 0) { 1553 DPRINTF(("%s: copyin env %d\n", __func__, error)); 1554 return error; 1555 } 1556 data->ed_envc += i; 1557 1558 done: 1559 *dpp = dp; 1560 1561 return 0; 1562 } 1563 1564 static int 1565 copyinargstrs(struct execve_data * restrict data, char * const *strs, 1566 execve_fetch_element_t fetch_element, char **dpp, size_t *ip, 1567 void (*ktr)(const void *, size_t)) 1568 { 1569 char *dp, *sp; 1570 size_t i; 1571 int error; 1572 1573 dp = *dpp; 1574 1575 i = 0; 1576 while (1) { 1577 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1578 size_t len; 1579 1580 if ((error = (*fetch_element)(strs, i, &sp)) != 0) { 1581 return error; 1582 } 1583 if (!sp) 1584 break; 1585 if ((error = copyinstr(sp, dp, maxlen, &len)) != 0) { 1586 if (error == ENAMETOOLONG) 1587 error = E2BIG; 1588 return error; 1589 } 1590 if (__predict_false(ktrace_on)) 1591 (*ktr)(dp, len - 1); 1592 dp += len; 1593 i++; 1594 } 1595 1596 *dpp = dp; 1597 *ip = i; 1598 1599 return 0; 1600 } 1601 1602 /* 1603 * Copy argv and env strings from kernel buffer (argp) to the new stack. 1604 * Those strings are located just after auxinfo. 1605 */ 1606 int 1607 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1608 char **stackp, void *argp) 1609 { 1610 char **cpp, *dp, *sp; 1611 size_t len; 1612 void *nullp; 1613 long argc, envc; 1614 int error; 1615 1616 cpp = (char **)*stackp; 1617 nullp = NULL; 1618 argc = arginfo->ps_nargvstr; 1619 envc = arginfo->ps_nenvstr; 1620 1621 /* argc on stack is long */ 1622 CTASSERT(sizeof(*cpp) == sizeof(argc)); 1623 1624 dp = (char *)(cpp + 1625 1 + /* long argc */ 1626 argc + /* char *argv[] */ 1627 1 + /* \0 */ 1628 envc + /* char *env[] */ 1629 1) + /* \0 */ 1630 pack->ep_esch->es_arglen; /* auxinfo */ 1631 sp = argp; 1632 1633 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) { 1634 COPYPRINTF("", cpp - 1, sizeof(argc)); 1635 return error; 1636 } 1637 1638 /* XXX don't copy them out, remap them! */ 1639 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1640 1641 for (; --argc >= 0; sp += len, dp += len) { 1642 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1643 COPYPRINTF("", cpp - 1, sizeof(dp)); 1644 return error; 1645 } 1646 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1647 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1648 return error; 1649 } 1650 } 1651 1652 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1653 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1654 return error; 1655 } 1656 1657 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1658 1659 for (; --envc >= 0; sp += len, dp += len) { 1660 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1661 COPYPRINTF("", cpp - 1, sizeof(dp)); 1662 return error; 1663 } 1664 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1665 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1666 return error; 1667 } 1668 1669 } 1670 1671 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1672 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1673 return error; 1674 } 1675 1676 *stackp = (char *)cpp; 1677 return 0; 1678 } 1679 1680 1681 /* 1682 * Add execsw[] entries. 1683 */ 1684 int 1685 exec_add(struct execsw *esp, int count) 1686 { 1687 struct exec_entry *it; 1688 int i; 1689 1690 if (count == 0) { 1691 return 0; 1692 } 1693 1694 /* Check for duplicates. */ 1695 rw_enter(&exec_lock, RW_WRITER); 1696 for (i = 0; i < count; i++) { 1697 LIST_FOREACH(it, &ex_head, ex_list) { 1698 /* assume unique (makecmds, probe_func, emulation) */ 1699 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1700 it->ex_sw->u.elf_probe_func == 1701 esp[i].u.elf_probe_func && 1702 it->ex_sw->es_emul == esp[i].es_emul) { 1703 rw_exit(&exec_lock); 1704 return EEXIST; 1705 } 1706 } 1707 } 1708 1709 /* Allocate new entries. */ 1710 for (i = 0; i < count; i++) { 1711 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1712 it->ex_sw = &esp[i]; 1713 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1714 } 1715 1716 /* update execsw[] */ 1717 exec_init(0); 1718 rw_exit(&exec_lock); 1719 return 0; 1720 } 1721 1722 /* 1723 * Remove execsw[] entry. 1724 */ 1725 int 1726 exec_remove(struct execsw *esp, int count) 1727 { 1728 struct exec_entry *it, *next; 1729 int i; 1730 const struct proclist_desc *pd; 1731 proc_t *p; 1732 1733 if (count == 0) { 1734 return 0; 1735 } 1736 1737 /* Abort if any are busy. */ 1738 rw_enter(&exec_lock, RW_WRITER); 1739 for (i = 0; i < count; i++) { 1740 mutex_enter(proc_lock); 1741 for (pd = proclists; pd->pd_list != NULL; pd++) { 1742 PROCLIST_FOREACH(p, pd->pd_list) { 1743 if (p->p_execsw == &esp[i]) { 1744 mutex_exit(proc_lock); 1745 rw_exit(&exec_lock); 1746 return EBUSY; 1747 } 1748 } 1749 } 1750 mutex_exit(proc_lock); 1751 } 1752 1753 /* None are busy, so remove them all. */ 1754 for (i = 0; i < count; i++) { 1755 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1756 next = LIST_NEXT(it, ex_list); 1757 if (it->ex_sw == &esp[i]) { 1758 LIST_REMOVE(it, ex_list); 1759 kmem_free(it, sizeof(*it)); 1760 break; 1761 } 1762 } 1763 } 1764 1765 /* update execsw[] */ 1766 exec_init(0); 1767 rw_exit(&exec_lock); 1768 return 0; 1769 } 1770 1771 /* 1772 * Initialize exec structures. If init_boot is true, also does necessary 1773 * one-time initialization (it's called from main() that way). 1774 * Once system is multiuser, this should be called with exec_lock held, 1775 * i.e. via exec_{add|remove}(). 1776 */ 1777 int 1778 exec_init(int init_boot) 1779 { 1780 const struct execsw **sw; 1781 struct exec_entry *ex; 1782 SLIST_HEAD(,exec_entry) first; 1783 SLIST_HEAD(,exec_entry) any; 1784 SLIST_HEAD(,exec_entry) last; 1785 int i, sz; 1786 1787 if (init_boot) { 1788 /* do one-time initializations */ 1789 vaddr_t vmin = 0, vmax; 1790 1791 rw_init(&exec_lock); 1792 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1793 exec_map = uvm_km_suballoc(kernel_map, &vmin, &vmax, 1794 maxexec*NCARGS, VM_MAP_PAGEABLE, false, NULL); 1795 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1796 "execargs", &exec_palloc, IPL_NONE); 1797 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1798 } else { 1799 KASSERT(rw_write_held(&exec_lock)); 1800 } 1801 1802 /* Sort each entry onto the appropriate queue. */ 1803 SLIST_INIT(&first); 1804 SLIST_INIT(&any); 1805 SLIST_INIT(&last); 1806 sz = 0; 1807 LIST_FOREACH(ex, &ex_head, ex_list) { 1808 switch(ex->ex_sw->es_prio) { 1809 case EXECSW_PRIO_FIRST: 1810 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1811 break; 1812 case EXECSW_PRIO_ANY: 1813 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1814 break; 1815 case EXECSW_PRIO_LAST: 1816 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1817 break; 1818 default: 1819 panic("%s", __func__); 1820 break; 1821 } 1822 sz++; 1823 } 1824 1825 /* 1826 * Create new execsw[]. Ensure we do not try a zero-sized 1827 * allocation. 1828 */ 1829 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1830 i = 0; 1831 SLIST_FOREACH(ex, &first, ex_slist) { 1832 sw[i++] = ex->ex_sw; 1833 } 1834 SLIST_FOREACH(ex, &any, ex_slist) { 1835 sw[i++] = ex->ex_sw; 1836 } 1837 SLIST_FOREACH(ex, &last, ex_slist) { 1838 sw[i++] = ex->ex_sw; 1839 } 1840 1841 /* Replace old execsw[] and free used memory. */ 1842 if (execsw != NULL) { 1843 kmem_free(__UNCONST(execsw), 1844 nexecs * sizeof(struct execsw *) + 1); 1845 } 1846 execsw = sw; 1847 nexecs = sz; 1848 1849 /* Figure out the maximum size of an exec header. */ 1850 exec_maxhdrsz = sizeof(int); 1851 for (i = 0; i < nexecs; i++) { 1852 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1853 exec_maxhdrsz = execsw[i]->es_hdrsz; 1854 } 1855 1856 return 0; 1857 } 1858 1859 static int 1860 exec_sigcode_map(struct proc *p, const struct emul *e) 1861 { 1862 vaddr_t va; 1863 vsize_t sz; 1864 int error; 1865 struct uvm_object *uobj; 1866 1867 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1868 1869 if (e->e_sigobject == NULL || sz == 0) { 1870 return 0; 1871 } 1872 1873 /* 1874 * If we don't have a sigobject for this emulation, create one. 1875 * 1876 * sigobject is an anonymous memory object (just like SYSV shared 1877 * memory) that we keep a permanent reference to and that we map 1878 * in all processes that need this sigcode. The creation is simple, 1879 * we create an object, add a permanent reference to it, map it in 1880 * kernel space, copy out the sigcode to it and unmap it. 1881 * We map it with PROT_READ|PROT_EXEC into the process just 1882 * the way sys_mmap() would map it. 1883 */ 1884 1885 uobj = *e->e_sigobject; 1886 if (uobj == NULL) { 1887 mutex_enter(&sigobject_lock); 1888 if ((uobj = *e->e_sigobject) == NULL) { 1889 uobj = uao_create(sz, 0); 1890 (*uobj->pgops->pgo_reference)(uobj); 1891 va = vm_map_min(kernel_map); 1892 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1893 uobj, 0, 0, 1894 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1895 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1896 printf("kernel mapping failed %d\n", error); 1897 (*uobj->pgops->pgo_detach)(uobj); 1898 mutex_exit(&sigobject_lock); 1899 return error; 1900 } 1901 memcpy((void *)va, e->e_sigcode, sz); 1902 #ifdef PMAP_NEED_PROCWR 1903 pmap_procwr(&proc0, va, sz); 1904 #endif 1905 uvm_unmap(kernel_map, va, va + round_page(sz)); 1906 *e->e_sigobject = uobj; 1907 } 1908 mutex_exit(&sigobject_lock); 1909 } 1910 1911 /* Just a hint to uvm_map where to put it. */ 1912 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1913 round_page(sz), p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN); 1914 1915 #ifdef __alpha__ 1916 /* 1917 * Tru64 puts /sbin/loader at the end of user virtual memory, 1918 * which causes the above calculation to put the sigcode at 1919 * an invalid address. Put it just below the text instead. 1920 */ 1921 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1922 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1923 } 1924 #endif 1925 1926 (*uobj->pgops->pgo_reference)(uobj); 1927 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1928 uobj, 0, 0, 1929 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1930 UVM_ADV_RANDOM, 0)); 1931 if (error) { 1932 DPRINTF(("%s, %d: map %p " 1933 "uvm_map %#"PRIxVSIZE"@%#"PRIxVADDR" failed %d\n", 1934 __func__, __LINE__, &p->p_vmspace->vm_map, round_page(sz), 1935 va, error)); 1936 (*uobj->pgops->pgo_detach)(uobj); 1937 return error; 1938 } 1939 p->p_sigctx.ps_sigcode = (void *)va; 1940 return 0; 1941 } 1942 1943 /* 1944 * Release a refcount on spawn_exec_data and destroy memory, if this 1945 * was the last one. 1946 */ 1947 static void 1948 spawn_exec_data_release(struct spawn_exec_data *data) 1949 { 1950 if (atomic_dec_32_nv(&data->sed_refcnt) != 0) 1951 return; 1952 1953 cv_destroy(&data->sed_cv_child_ready); 1954 mutex_destroy(&data->sed_mtx_child); 1955 1956 if (data->sed_actions) 1957 posix_spawn_fa_free(data->sed_actions, 1958 data->sed_actions->len); 1959 if (data->sed_attrs) 1960 kmem_free(data->sed_attrs, 1961 sizeof(*data->sed_attrs)); 1962 kmem_free(data, sizeof(*data)); 1963 } 1964 1965 /* 1966 * A child lwp of a posix_spawn operation starts here and ends up in 1967 * cpu_spawn_return, dealing with all filedescriptor and scheduler 1968 * manipulations in between. 1969 * The parent waits for the child, as it is not clear whether the child 1970 * will be able to acquire its own exec_lock. If it can, the parent can 1971 * be released early and continue running in parallel. If not (or if the 1972 * magic debug flag is passed in the scheduler attribute struct), the 1973 * child rides on the parent's exec lock until it is ready to return to 1974 * to userland - and only then releases the parent. This method loses 1975 * concurrency, but improves error reporting. 1976 */ 1977 static void 1978 spawn_return(void *arg) 1979 { 1980 struct spawn_exec_data *spawn_data = arg; 1981 struct lwp *l = curlwp; 1982 int error, newfd; 1983 int ostat; 1984 size_t i; 1985 const struct posix_spawn_file_actions_entry *fae; 1986 pid_t ppid; 1987 register_t retval; 1988 bool have_reflock; 1989 bool parent_is_waiting = true; 1990 1991 /* 1992 * Check if we can release parent early. 1993 * We either need to have no sed_attrs, or sed_attrs does not 1994 * have POSIX_SPAWN_RETURNERROR or one of the flags, that require 1995 * safe access to the parent proc (passed in sed_parent). 1996 * We then try to get the exec_lock, and only if that works, we can 1997 * release the parent here already. 1998 */ 1999 ppid = spawn_data->sed_parent->p_pid; 2000 if ((!spawn_data->sed_attrs 2001 || (spawn_data->sed_attrs->sa_flags 2002 & (POSIX_SPAWN_RETURNERROR|POSIX_SPAWN_SETPGROUP)) == 0) 2003 && rw_tryenter(&exec_lock, RW_READER)) { 2004 parent_is_waiting = false; 2005 mutex_enter(&spawn_data->sed_mtx_child); 2006 cv_signal(&spawn_data->sed_cv_child_ready); 2007 mutex_exit(&spawn_data->sed_mtx_child); 2008 } 2009 2010 /* don't allow debugger access yet */ 2011 rw_enter(&l->l_proc->p_reflock, RW_WRITER); 2012 have_reflock = true; 2013 2014 error = 0; 2015 /* handle posix_spawn_file_actions */ 2016 if (spawn_data->sed_actions != NULL) { 2017 for (i = 0; i < spawn_data->sed_actions->len; i++) { 2018 fae = &spawn_data->sed_actions->fae[i]; 2019 switch (fae->fae_action) { 2020 case FAE_OPEN: 2021 if (fd_getfile(fae->fae_fildes) != NULL) { 2022 error = fd_close(fae->fae_fildes); 2023 if (error) 2024 break; 2025 } 2026 error = fd_open(fae->fae_path, fae->fae_oflag, 2027 fae->fae_mode, &newfd); 2028 if (error) 2029 break; 2030 if (newfd != fae->fae_fildes) { 2031 error = dodup(l, newfd, 2032 fae->fae_fildes, 0, &retval); 2033 if (fd_getfile(newfd) != NULL) 2034 fd_close(newfd); 2035 } 2036 break; 2037 case FAE_DUP2: 2038 error = dodup(l, fae->fae_fildes, 2039 fae->fae_newfildes, 0, &retval); 2040 break; 2041 case FAE_CLOSE: 2042 if (fd_getfile(fae->fae_fildes) == NULL) { 2043 error = EBADF; 2044 break; 2045 } 2046 error = fd_close(fae->fae_fildes); 2047 break; 2048 } 2049 if (error) 2050 goto report_error; 2051 } 2052 } 2053 2054 /* handle posix_spawnattr */ 2055 if (spawn_data->sed_attrs != NULL) { 2056 struct sigaction sigact; 2057 sigact._sa_u._sa_handler = SIG_DFL; 2058 sigact.sa_flags = 0; 2059 2060 /* 2061 * set state to SSTOP so that this proc can be found by pid. 2062 * see proc_enterprp, do_sched_setparam below 2063 */ 2064 mutex_enter(proc_lock); 2065 /* 2066 * p_stat should be SACTIVE, so we need to adjust the 2067 * parent's p_nstopchild here. For safety, just make 2068 * we're on the good side of SDEAD before we adjust. 2069 */ 2070 ostat = l->l_proc->p_stat; 2071 KASSERT(ostat < SSTOP); 2072 l->l_proc->p_stat = SSTOP; 2073 l->l_proc->p_waited = 0; 2074 l->l_proc->p_pptr->p_nstopchild++; 2075 mutex_exit(proc_lock); 2076 2077 /* Set process group */ 2078 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETPGROUP) { 2079 pid_t mypid = l->l_proc->p_pid, 2080 pgrp = spawn_data->sed_attrs->sa_pgroup; 2081 2082 if (pgrp == 0) 2083 pgrp = mypid; 2084 2085 error = proc_enterpgrp(spawn_data->sed_parent, 2086 mypid, pgrp, false); 2087 if (error) 2088 goto report_error_stopped; 2089 } 2090 2091 /* Set scheduler policy */ 2092 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSCHEDULER) 2093 error = do_sched_setparam(l->l_proc->p_pid, 0, 2094 spawn_data->sed_attrs->sa_schedpolicy, 2095 &spawn_data->sed_attrs->sa_schedparam); 2096 else if (spawn_data->sed_attrs->sa_flags 2097 & POSIX_SPAWN_SETSCHEDPARAM) { 2098 error = do_sched_setparam(ppid, 0, 2099 SCHED_NONE, &spawn_data->sed_attrs->sa_schedparam); 2100 } 2101 if (error) 2102 goto report_error_stopped; 2103 2104 /* Reset user ID's */ 2105 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_RESETIDS) { 2106 error = do_setresuid(l, -1, 2107 kauth_cred_getgid(l->l_cred), -1, 2108 ID_E_EQ_R | ID_E_EQ_S); 2109 if (error) 2110 goto report_error_stopped; 2111 error = do_setresuid(l, -1, 2112 kauth_cred_getuid(l->l_cred), -1, 2113 ID_E_EQ_R | ID_E_EQ_S); 2114 if (error) 2115 goto report_error_stopped; 2116 } 2117 2118 /* Set signal masks/defaults */ 2119 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGMASK) { 2120 mutex_enter(l->l_proc->p_lock); 2121 error = sigprocmask1(l, SIG_SETMASK, 2122 &spawn_data->sed_attrs->sa_sigmask, NULL); 2123 mutex_exit(l->l_proc->p_lock); 2124 if (error) 2125 goto report_error_stopped; 2126 } 2127 2128 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGDEF) { 2129 /* 2130 * The following sigaction call is using a sigaction 2131 * version 0 trampoline which is in the compatibility 2132 * code only. This is not a problem because for SIG_DFL 2133 * and SIG_IGN, the trampolines are now ignored. If they 2134 * were not, this would be a problem because we are 2135 * holding the exec_lock, and the compat code needs 2136 * to do the same in order to replace the trampoline 2137 * code of the process. 2138 */ 2139 for (i = 1; i <= NSIG; i++) { 2140 if (sigismember( 2141 &spawn_data->sed_attrs->sa_sigdefault, i)) 2142 sigaction1(l, i, &sigact, NULL, NULL, 2143 0); 2144 } 2145 } 2146 mutex_enter(proc_lock); 2147 l->l_proc->p_stat = ostat; 2148 l->l_proc->p_pptr->p_nstopchild--; 2149 mutex_exit(proc_lock); 2150 } 2151 2152 /* now do the real exec */ 2153 error = execve_runproc(l, &spawn_data->sed_exec, parent_is_waiting, 2154 true); 2155 have_reflock = false; 2156 if (error == EJUSTRETURN) 2157 error = 0; 2158 else if (error) 2159 goto report_error; 2160 2161 if (parent_is_waiting) { 2162 mutex_enter(&spawn_data->sed_mtx_child); 2163 cv_signal(&spawn_data->sed_cv_child_ready); 2164 mutex_exit(&spawn_data->sed_mtx_child); 2165 } 2166 2167 /* release our refcount on the data */ 2168 spawn_exec_data_release(spawn_data); 2169 2170 /* and finally: leave to userland for the first time */ 2171 cpu_spawn_return(l); 2172 2173 /* NOTREACHED */ 2174 return; 2175 2176 report_error_stopped: 2177 mutex_enter(proc_lock); 2178 l->l_proc->p_stat = ostat; 2179 l->l_proc->p_pptr->p_nstopchild--; 2180 mutex_exit(proc_lock); 2181 report_error: 2182 if (have_reflock) { 2183 /* 2184 * We have not passed through execve_runproc(), 2185 * which would have released the p_reflock and also 2186 * taken ownership of the sed_exec part of spawn_data, 2187 * so release/free both here. 2188 */ 2189 rw_exit(&l->l_proc->p_reflock); 2190 execve_free_data(&spawn_data->sed_exec); 2191 } 2192 2193 if (parent_is_waiting) { 2194 /* pass error to parent */ 2195 mutex_enter(&spawn_data->sed_mtx_child); 2196 spawn_data->sed_error = error; 2197 cv_signal(&spawn_data->sed_cv_child_ready); 2198 mutex_exit(&spawn_data->sed_mtx_child); 2199 } else { 2200 rw_exit(&exec_lock); 2201 } 2202 2203 /* release our refcount on the data */ 2204 spawn_exec_data_release(spawn_data); 2205 2206 /* done, exit */ 2207 mutex_enter(l->l_proc->p_lock); 2208 /* 2209 * Posix explicitly asks for an exit code of 127 if we report 2210 * errors from the child process - so, unfortunately, there 2211 * is no way to report a more exact error code. 2212 * A NetBSD specific workaround is POSIX_SPAWN_RETURNERROR as 2213 * flag bit in the attrp argument to posix_spawn(2), see above. 2214 */ 2215 exit1(l, 127, 0); 2216 } 2217 2218 void 2219 posix_spawn_fa_free(struct posix_spawn_file_actions *fa, size_t len) 2220 { 2221 2222 for (size_t i = 0; i < len; i++) { 2223 struct posix_spawn_file_actions_entry *fae = &fa->fae[i]; 2224 if (fae->fae_action != FAE_OPEN) 2225 continue; 2226 kmem_strfree(fae->fae_path); 2227 } 2228 if (fa->len > 0) 2229 kmem_free(fa->fae, sizeof(*fa->fae) * fa->len); 2230 kmem_free(fa, sizeof(*fa)); 2231 } 2232 2233 static int 2234 posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap, 2235 const struct posix_spawn_file_actions *ufa, rlim_t lim) 2236 { 2237 struct posix_spawn_file_actions *fa; 2238 struct posix_spawn_file_actions_entry *fae; 2239 char *pbuf = NULL; 2240 int error; 2241 size_t i = 0; 2242 2243 fa = kmem_alloc(sizeof(*fa), KM_SLEEP); 2244 error = copyin(ufa, fa, sizeof(*fa)); 2245 if (error || fa->len == 0) { 2246 kmem_free(fa, sizeof(*fa)); 2247 return error; /* 0 if not an error, and len == 0 */ 2248 } 2249 2250 if (fa->len > lim) { 2251 kmem_free(fa, sizeof(*fa)); 2252 return EINVAL; 2253 } 2254 2255 fa->size = fa->len; 2256 size_t fal = fa->len * sizeof(*fae); 2257 fae = fa->fae; 2258 fa->fae = kmem_alloc(fal, KM_SLEEP); 2259 error = copyin(fae, fa->fae, fal); 2260 if (error) 2261 goto out; 2262 2263 pbuf = PNBUF_GET(); 2264 for (; i < fa->len; i++) { 2265 fae = &fa->fae[i]; 2266 if (fae->fae_action != FAE_OPEN) 2267 continue; 2268 error = copyinstr(fae->fae_path, pbuf, MAXPATHLEN, &fal); 2269 if (error) 2270 goto out; 2271 fae->fae_path = kmem_alloc(fal, KM_SLEEP); 2272 memcpy(fae->fae_path, pbuf, fal); 2273 } 2274 PNBUF_PUT(pbuf); 2275 2276 *fap = fa; 2277 return 0; 2278 out: 2279 if (pbuf) 2280 PNBUF_PUT(pbuf); 2281 posix_spawn_fa_free(fa, i); 2282 return error; 2283 } 2284 2285 int 2286 check_posix_spawn(struct lwp *l1) 2287 { 2288 int error, tnprocs, count; 2289 uid_t uid; 2290 struct proc *p1; 2291 2292 p1 = l1->l_proc; 2293 uid = kauth_cred_getuid(l1->l_cred); 2294 tnprocs = atomic_inc_uint_nv(&nprocs); 2295 2296 /* 2297 * Although process entries are dynamically created, we still keep 2298 * a global limit on the maximum number we will create. 2299 */ 2300 if (__predict_false(tnprocs >= maxproc)) 2301 error = -1; 2302 else 2303 error = kauth_authorize_process(l1->l_cred, 2304 KAUTH_PROCESS_FORK, p1, KAUTH_ARG(tnprocs), NULL, NULL); 2305 2306 if (error) { 2307 atomic_dec_uint(&nprocs); 2308 return EAGAIN; 2309 } 2310 2311 /* 2312 * Enforce limits. 2313 */ 2314 count = chgproccnt(uid, 1); 2315 if (kauth_authorize_process(l1->l_cred, KAUTH_PROCESS_RLIMIT, 2316 p1, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 2317 &p1->p_rlimit[RLIMIT_NPROC], KAUTH_ARG(RLIMIT_NPROC)) != 0 && 2318 __predict_false(count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) { 2319 (void)chgproccnt(uid, -1); 2320 atomic_dec_uint(&nprocs); 2321 return EAGAIN; 2322 } 2323 2324 return 0; 2325 } 2326 2327 int 2328 do_posix_spawn(struct lwp *l1, pid_t *pid_res, bool *child_ok, const char *path, 2329 struct posix_spawn_file_actions *fa, 2330 struct posix_spawnattr *sa, 2331 char *const *argv, char *const *envp, 2332 execve_fetch_element_t fetch) 2333 { 2334 2335 struct proc *p1, *p2; 2336 struct lwp *l2; 2337 int error; 2338 struct spawn_exec_data *spawn_data; 2339 vaddr_t uaddr; 2340 pid_t pid; 2341 bool have_exec_lock = false; 2342 2343 p1 = l1->l_proc; 2344 2345 /* Allocate and init spawn_data */ 2346 spawn_data = kmem_zalloc(sizeof(*spawn_data), KM_SLEEP); 2347 spawn_data->sed_refcnt = 1; /* only parent so far */ 2348 cv_init(&spawn_data->sed_cv_child_ready, "pspawn"); 2349 mutex_init(&spawn_data->sed_mtx_child, MUTEX_DEFAULT, IPL_NONE); 2350 mutex_enter(&spawn_data->sed_mtx_child); 2351 2352 /* 2353 * Do the first part of the exec now, collect state 2354 * in spawn_data. 2355 */ 2356 error = execve_loadvm(l1, path, argv, 2357 envp, fetch, &spawn_data->sed_exec); 2358 if (error == EJUSTRETURN) 2359 error = 0; 2360 else if (error) 2361 goto error_exit; 2362 2363 have_exec_lock = true; 2364 2365 /* 2366 * Allocate virtual address space for the U-area now, while it 2367 * is still easy to abort the fork operation if we're out of 2368 * kernel virtual address space. 2369 */ 2370 uaddr = uvm_uarea_alloc(); 2371 if (__predict_false(uaddr == 0)) { 2372 error = ENOMEM; 2373 goto error_exit; 2374 } 2375 2376 /* 2377 * Allocate new proc. Borrow proc0 vmspace for it, we will 2378 * replace it with its own before returning to userland 2379 * in the child. 2380 * This is a point of no return, we will have to go through 2381 * the child proc to properly clean it up past this point. 2382 */ 2383 p2 = proc_alloc(); 2384 pid = p2->p_pid; 2385 2386 /* 2387 * Make a proc table entry for the new process. 2388 * Start by zeroing the section of proc that is zero-initialized, 2389 * then copy the section that is copied directly from the parent. 2390 */ 2391 memset(&p2->p_startzero, 0, 2392 (unsigned) ((char *)&p2->p_endzero - (char *)&p2->p_startzero)); 2393 memcpy(&p2->p_startcopy, &p1->p_startcopy, 2394 (unsigned) ((char *)&p2->p_endcopy - (char *)&p2->p_startcopy)); 2395 p2->p_vmspace = proc0.p_vmspace; 2396 2397 TAILQ_INIT(&p2->p_sigpend.sp_info); 2398 2399 LIST_INIT(&p2->p_lwps); 2400 LIST_INIT(&p2->p_sigwaiters); 2401 2402 /* 2403 * Duplicate sub-structures as needed. 2404 * Increase reference counts on shared objects. 2405 * Inherit flags we want to keep. The flags related to SIGCHLD 2406 * handling are important in order to keep a consistent behaviour 2407 * for the child after the fork. If we are a 32-bit process, the 2408 * child will be too. 2409 */ 2410 p2->p_flag = 2411 p1->p_flag & (PK_SUGID | PK_NOCLDWAIT | PK_CLDSIGIGN | PK_32); 2412 p2->p_emul = p1->p_emul; 2413 p2->p_execsw = p1->p_execsw; 2414 2415 mutex_init(&p2->p_stmutex, MUTEX_DEFAULT, IPL_HIGH); 2416 mutex_init(&p2->p_auxlock, MUTEX_DEFAULT, IPL_NONE); 2417 rw_init(&p2->p_reflock); 2418 cv_init(&p2->p_waitcv, "wait"); 2419 cv_init(&p2->p_lwpcv, "lwpwait"); 2420 2421 p2->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 2422 2423 kauth_proc_fork(p1, p2); 2424 2425 p2->p_raslist = NULL; 2426 p2->p_fd = fd_copy(); 2427 2428 /* XXX racy */ 2429 p2->p_mqueue_cnt = p1->p_mqueue_cnt; 2430 2431 p2->p_cwdi = cwdinit(); 2432 2433 /* 2434 * Note: p_limit (rlimit stuff) is copy-on-write, so normally 2435 * we just need increase pl_refcnt. 2436 */ 2437 if (!p1->p_limit->pl_writeable) { 2438 lim_addref(p1->p_limit); 2439 p2->p_limit = p1->p_limit; 2440 } else { 2441 p2->p_limit = lim_copy(p1->p_limit); 2442 } 2443 2444 p2->p_lflag = 0; 2445 p2->p_sflag = 0; 2446 p2->p_slflag = 0; 2447 p2->p_pptr = p1; 2448 p2->p_ppid = p1->p_pid; 2449 LIST_INIT(&p2->p_children); 2450 2451 p2->p_aio = NULL; 2452 2453 #ifdef KTRACE 2454 /* 2455 * Copy traceflag and tracefile if enabled. 2456 * If not inherited, these were zeroed above. 2457 */ 2458 if (p1->p_traceflag & KTRFAC_INHERIT) { 2459 mutex_enter(&ktrace_lock); 2460 p2->p_traceflag = p1->p_traceflag; 2461 if ((p2->p_tracep = p1->p_tracep) != NULL) 2462 ktradref(p2); 2463 mutex_exit(&ktrace_lock); 2464 } 2465 #endif 2466 2467 /* 2468 * Create signal actions for the child process. 2469 */ 2470 p2->p_sigacts = sigactsinit(p1, 0); 2471 mutex_enter(p1->p_lock); 2472 p2->p_sflag |= 2473 (p1->p_sflag & (PS_STOPFORK | PS_STOPEXEC | PS_NOCLDSTOP)); 2474 sched_proc_fork(p1, p2); 2475 mutex_exit(p1->p_lock); 2476 2477 p2->p_stflag = p1->p_stflag; 2478 2479 /* 2480 * p_stats. 2481 * Copy parts of p_stats, and zero out the rest. 2482 */ 2483 p2->p_stats = pstatscopy(p1->p_stats); 2484 2485 /* copy over machdep flags to the new proc */ 2486 cpu_proc_fork(p1, p2); 2487 2488 /* 2489 * Prepare remaining parts of spawn data 2490 */ 2491 spawn_data->sed_actions = fa; 2492 spawn_data->sed_attrs = sa; 2493 2494 spawn_data->sed_parent = p1; 2495 2496 /* create LWP */ 2497 lwp_create(l1, p2, uaddr, 0, NULL, 0, spawn_return, spawn_data, 2498 &l2, l1->l_class, &l1->l_sigmask, &l1->l_sigstk); 2499 l2->l_ctxlink = NULL; /* reset ucontext link */ 2500 2501 /* 2502 * Copy the credential so other references don't see our changes. 2503 * Test to see if this is necessary first, since in the common case 2504 * we won't need a private reference. 2505 */ 2506 if (kauth_cred_geteuid(l2->l_cred) != kauth_cred_getsvuid(l2->l_cred) || 2507 kauth_cred_getegid(l2->l_cred) != kauth_cred_getsvgid(l2->l_cred)) { 2508 l2->l_cred = kauth_cred_copy(l2->l_cred); 2509 kauth_cred_setsvuid(l2->l_cred, kauth_cred_geteuid(l2->l_cred)); 2510 kauth_cred_setsvgid(l2->l_cred, kauth_cred_getegid(l2->l_cred)); 2511 } 2512 2513 /* Update the master credentials. */ 2514 if (l2->l_cred != p2->p_cred) { 2515 kauth_cred_t ocred; 2516 2517 kauth_cred_hold(l2->l_cred); 2518 mutex_enter(p2->p_lock); 2519 ocred = p2->p_cred; 2520 p2->p_cred = l2->l_cred; 2521 mutex_exit(p2->p_lock); 2522 kauth_cred_free(ocred); 2523 } 2524 2525 *child_ok = true; 2526 spawn_data->sed_refcnt = 2; /* child gets it as well */ 2527 #if 0 2528 l2->l_nopreempt = 1; /* start it non-preemptable */ 2529 #endif 2530 2531 /* 2532 * It's now safe for the scheduler and other processes to see the 2533 * child process. 2534 */ 2535 mutex_enter(proc_lock); 2536 2537 if (p1->p_session->s_ttyvp != NULL && p1->p_lflag & PL_CONTROLT) 2538 p2->p_lflag |= PL_CONTROLT; 2539 2540 LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling); 2541 p2->p_exitsig = SIGCHLD; /* signal for parent on exit */ 2542 2543 LIST_INSERT_AFTER(p1, p2, p_pglist); 2544 LIST_INSERT_HEAD(&allproc, p2, p_list); 2545 2546 p2->p_trace_enabled = trace_is_enabled(p2); 2547 #ifdef __HAVE_SYSCALL_INTERN 2548 (*p2->p_emul->e_syscall_intern)(p2); 2549 #endif 2550 2551 /* 2552 * Make child runnable, set start time, and add to run queue except 2553 * if the parent requested the child to start in SSTOP state. 2554 */ 2555 mutex_enter(p2->p_lock); 2556 2557 getmicrotime(&p2->p_stats->p_start); 2558 2559 lwp_lock(l2); 2560 KASSERT(p2->p_nrlwps == 1); 2561 p2->p_nrlwps = 1; 2562 p2->p_stat = SACTIVE; 2563 l2->l_stat = LSRUN; 2564 sched_enqueue(l2, false); 2565 lwp_unlock(l2); 2566 2567 mutex_exit(p2->p_lock); 2568 mutex_exit(proc_lock); 2569 2570 cv_wait(&spawn_data->sed_cv_child_ready, &spawn_data->sed_mtx_child); 2571 error = spawn_data->sed_error; 2572 mutex_exit(&spawn_data->sed_mtx_child); 2573 spawn_exec_data_release(spawn_data); 2574 2575 rw_exit(&p1->p_reflock); 2576 rw_exit(&exec_lock); 2577 have_exec_lock = false; 2578 2579 *pid_res = pid; 2580 return error; 2581 2582 error_exit: 2583 if (have_exec_lock) { 2584 execve_free_data(&spawn_data->sed_exec); 2585 rw_exit(&p1->p_reflock); 2586 rw_exit(&exec_lock); 2587 } 2588 mutex_exit(&spawn_data->sed_mtx_child); 2589 spawn_exec_data_release(spawn_data); 2590 2591 return error; 2592 } 2593 2594 int 2595 sys_posix_spawn(struct lwp *l1, const struct sys_posix_spawn_args *uap, 2596 register_t *retval) 2597 { 2598 /* { 2599 syscallarg(pid_t *) pid; 2600 syscallarg(const char *) path; 2601 syscallarg(const struct posix_spawn_file_actions *) file_actions; 2602 syscallarg(const struct posix_spawnattr *) attrp; 2603 syscallarg(char *const *) argv; 2604 syscallarg(char *const *) envp; 2605 } */ 2606 2607 int error; 2608 struct posix_spawn_file_actions *fa = NULL; 2609 struct posix_spawnattr *sa = NULL; 2610 pid_t pid; 2611 bool child_ok = false; 2612 rlim_t max_fileactions; 2613 proc_t *p = l1->l_proc; 2614 2615 error = check_posix_spawn(l1); 2616 if (error) { 2617 *retval = error; 2618 return 0; 2619 } 2620 2621 /* copy in file_actions struct */ 2622 if (SCARG(uap, file_actions) != NULL) { 2623 max_fileactions = 2 * min(p->p_rlimit[RLIMIT_NOFILE].rlim_cur, 2624 maxfiles); 2625 error = posix_spawn_fa_alloc(&fa, SCARG(uap, file_actions), 2626 max_fileactions); 2627 if (error) 2628 goto error_exit; 2629 } 2630 2631 /* copyin posix_spawnattr struct */ 2632 if (SCARG(uap, attrp) != NULL) { 2633 sa = kmem_alloc(sizeof(*sa), KM_SLEEP); 2634 error = copyin(SCARG(uap, attrp), sa, sizeof(*sa)); 2635 if (error) 2636 goto error_exit; 2637 } 2638 2639 /* 2640 * Do the spawn 2641 */ 2642 error = do_posix_spawn(l1, &pid, &child_ok, SCARG(uap, path), fa, sa, 2643 SCARG(uap, argv), SCARG(uap, envp), execve_fetch_element); 2644 if (error) 2645 goto error_exit; 2646 2647 if (error == 0 && SCARG(uap, pid) != NULL) 2648 error = copyout(&pid, SCARG(uap, pid), sizeof(pid)); 2649 2650 *retval = error; 2651 return 0; 2652 2653 error_exit: 2654 if (!child_ok) { 2655 (void)chgproccnt(kauth_cred_getuid(l1->l_cred), -1); 2656 atomic_dec_uint(&nprocs); 2657 2658 if (sa) 2659 kmem_free(sa, sizeof(*sa)); 2660 if (fa) 2661 posix_spawn_fa_free(fa, fa->len); 2662 } 2663 2664 *retval = error; 2665 return 0; 2666 } 2667 2668 void 2669 exec_free_emul_arg(struct exec_package *epp) 2670 { 2671 if (epp->ep_emul_arg_free != NULL) { 2672 KASSERT(epp->ep_emul_arg != NULL); 2673 (*epp->ep_emul_arg_free)(epp->ep_emul_arg); 2674 epp->ep_emul_arg_free = NULL; 2675 epp->ep_emul_arg = NULL; 2676 } else { 2677 KASSERT(epp->ep_emul_arg == NULL); 2678 } 2679 } 2680 2681 #ifdef DEBUG_EXEC 2682 static void 2683 dump_vmcmds(const struct exec_package * const epp, size_t x, int error) 2684 { 2685 struct exec_vmcmd *vp = &epp->ep_vmcmds.evs_cmds[0]; 2686 size_t j; 2687 2688 if (error == 0) 2689 DPRINTF(("vmcmds %u\n", epp->ep_vmcmds.evs_used)); 2690 else 2691 DPRINTF(("vmcmds %zu/%u, error %d\n", x, 2692 epp->ep_vmcmds.evs_used, error)); 2693 2694 for (j = 0; j < epp->ep_vmcmds.evs_used; j++) { 2695 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#" 2696 PRIxVADDR"/%#"PRIxVSIZE" fd@%#" 2697 PRIxVSIZE" prot=0%o flags=%d\n", j, 2698 vp[j].ev_proc == vmcmd_map_pagedvn ? 2699 "pagedvn" : 2700 vp[j].ev_proc == vmcmd_map_readvn ? 2701 "readvn" : 2702 vp[j].ev_proc == vmcmd_map_zero ? 2703 "zero" : "*unknown*", 2704 vp[j].ev_addr, vp[j].ev_len, 2705 vp[j].ev_offset, vp[j].ev_prot, 2706 vp[j].ev_flags)); 2707 if (error != 0 && j == x) 2708 DPRINTF((" ^--- failed\n")); 2709 } 2710 } 2711 #endif 2712