1 /* $NetBSD: kern_exec.c,v 1.483 2019/10/12 10:55:23 kamil 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 1.483 2019/10/12 10:55:23 kamil 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_resolvedname; 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 static void 308 exec_path_free(struct execve_data *data) 309 { 310 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 311 pathbuf_destroy(data->ed_pathbuf); 312 if (data->ed_resolvedname) 313 PNBUF_PUT(data->ed_resolvedname); 314 } 315 316 static void 317 exec_resolvename(struct lwp *l, struct exec_package *epp, struct vnode *vp, 318 char **rpath) 319 { 320 int error; 321 char *p; 322 323 KASSERT(rpath != NULL); 324 325 *rpath = PNBUF_GET(); 326 error = vnode_to_path(*rpath, MAXPATHLEN, vp, l, l->l_proc); 327 if (error) { 328 PNBUF_PUT(*rpath); 329 *rpath = NULL; 330 return; 331 } 332 epp->ep_resolvedname = *rpath; 333 if ((p = strrchr(*rpath, '/')) != NULL) 334 epp->ep_kname = p + 1; 335 } 336 337 338 /* 339 * check exec: 340 * given an "executable" described in the exec package's namei info, 341 * see what we can do with it. 342 * 343 * ON ENTRY: 344 * exec package with appropriate namei info 345 * lwp pointer of exec'ing lwp 346 * NO SELF-LOCKED VNODES 347 * 348 * ON EXIT: 349 * error: nothing held, etc. exec header still allocated. 350 * ok: filled exec package, executable's vnode (unlocked). 351 * 352 * EXEC SWITCH ENTRY: 353 * Locked vnode to check, exec package, proc. 354 * 355 * EXEC SWITCH EXIT: 356 * ok: return 0, filled exec package, executable's vnode (unlocked). 357 * error: destructive: 358 * everything deallocated execept exec header. 359 * non-destructive: 360 * error code, executable's vnode (unlocked), 361 * exec header unmodified. 362 */ 363 int 364 /*ARGSUSED*/ 365 check_exec(struct lwp *l, struct exec_package *epp, struct pathbuf *pb, 366 char **rpath) 367 { 368 int error, i; 369 struct vnode *vp; 370 size_t resid; 371 372 if (epp->ep_resolvedname) { 373 struct nameidata nd; 374 375 // grab the absolute pathbuf here before namei() trashes it. 376 pathbuf_copystring(pb, epp->ep_resolvedname, PATH_MAX); 377 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb); 378 379 /* first get the vnode */ 380 if ((error = namei(&nd)) != 0) 381 return error; 382 383 epp->ep_vp = vp = nd.ni_vp; 384 #ifdef DIAGNOSTIC 385 /* paranoia (take this out once namei stuff stabilizes) */ 386 memset(nd.ni_pnbuf, '~', PATH_MAX); 387 #endif 388 } else { 389 struct file *fp; 390 391 if ((error = fd_getvnode(epp->ep_xfd, &fp)) != 0) 392 return error; 393 epp->ep_vp = vp = fp->f_vnode; 394 vref(vp); 395 fd_putfile(epp->ep_xfd); 396 exec_resolvename(l, epp, vp, rpath); 397 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 398 } 399 400 /* check access and type */ 401 if (vp->v_type != VREG) { 402 error = EACCES; 403 goto bad1; 404 } 405 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 406 goto bad1; 407 408 /* get attributes */ 409 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 410 goto bad1; 411 412 /* Check mount point */ 413 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 414 error = EACCES; 415 goto bad1; 416 } 417 if (vp->v_mount->mnt_flag & MNT_NOSUID) 418 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 419 420 /* try to open it */ 421 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 422 goto bad1; 423 424 /* unlock vp, since we need it unlocked from here on out. */ 425 VOP_UNLOCK(vp); 426 427 #if NVERIEXEC > 0 428 error = veriexec_verify(l, vp, 429 epp->ep_resolvedname ? epp->ep_resolvedname : epp->ep_kname, 430 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 431 NULL); 432 if (error) 433 goto bad2; 434 #endif /* NVERIEXEC > 0 */ 435 436 #ifdef PAX_SEGVGUARD 437 error = pax_segvguard(l, vp, epp->ep_resolvedname, false); 438 if (error) 439 goto bad2; 440 #endif /* PAX_SEGVGUARD */ 441 442 /* now we have the file, get the exec header */ 443 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 444 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 445 if (error) 446 goto bad2; 447 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 448 449 /* 450 * Set up default address space limits. Can be overridden 451 * by individual exec packages. 452 */ 453 epp->ep_vm_minaddr = exec_vm_minaddr(VM_MIN_ADDRESS); 454 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 455 456 /* 457 * set up the vmcmds for creation of the process 458 * address space 459 */ 460 error = ENOEXEC; 461 for (i = 0; i < nexecs; i++) { 462 int newerror; 463 464 epp->ep_esch = execsw[i]; 465 newerror = (*execsw[i]->es_makecmds)(l, epp); 466 467 if (!newerror) { 468 /* Seems ok: check that entry point is not too high */ 469 if (epp->ep_entry >= epp->ep_vm_maxaddr) { 470 #ifdef DIAGNOSTIC 471 printf("%s: rejecting %p due to " 472 "too high entry address (>= %p)\n", 473 __func__, (void *)epp->ep_entry, 474 (void *)epp->ep_vm_maxaddr); 475 #endif 476 error = ENOEXEC; 477 break; 478 } 479 /* Seems ok: check that entry point is not too low */ 480 if (epp->ep_entry < epp->ep_vm_minaddr) { 481 #ifdef DIAGNOSTIC 482 printf("%s: rejecting %p due to " 483 "too low entry address (< %p)\n", 484 __func__, (void *)epp->ep_entry, 485 (void *)epp->ep_vm_minaddr); 486 #endif 487 error = ENOEXEC; 488 break; 489 } 490 491 /* check limits */ 492 if ((epp->ep_tsize > MAXTSIZ) || 493 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 494 [RLIMIT_DATA].rlim_cur)) { 495 #ifdef DIAGNOSTIC 496 printf("%s: rejecting due to " 497 "limits (t=%llu > %llu || d=%llu > %llu)\n", 498 __func__, 499 (unsigned long long)epp->ep_tsize, 500 (unsigned long long)MAXTSIZ, 501 (unsigned long long)epp->ep_dsize, 502 (unsigned long long) 503 l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur); 504 #endif 505 error = ENOMEM; 506 break; 507 } 508 return 0; 509 } 510 511 /* 512 * Reset all the fields that may have been modified by the 513 * loader. 514 */ 515 KASSERT(epp->ep_emul_arg == NULL); 516 if (epp->ep_emul_root != NULL) { 517 vrele(epp->ep_emul_root); 518 epp->ep_emul_root = NULL; 519 } 520 if (epp->ep_interp != NULL) { 521 vrele(epp->ep_interp); 522 epp->ep_interp = NULL; 523 } 524 epp->ep_pax_flags = 0; 525 526 /* make sure the first "interesting" error code is saved. */ 527 if (error == ENOEXEC) 528 error = newerror; 529 530 if (epp->ep_flags & EXEC_DESTR) 531 /* Error from "#!" code, tidied up by recursive call */ 532 return error; 533 } 534 535 /* not found, error */ 536 537 /* 538 * free any vmspace-creation commands, 539 * and release their references 540 */ 541 kill_vmcmds(&epp->ep_vmcmds); 542 543 bad2: 544 /* 545 * close and release the vnode, restore the old one, free the 546 * pathname buf, and punt. 547 */ 548 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 549 VOP_CLOSE(vp, FREAD, l->l_cred); 550 vput(vp); 551 return error; 552 553 bad1: 554 /* 555 * free the namei pathname buffer, and put the vnode 556 * (which we don't yet have open). 557 */ 558 vput(vp); /* was still locked */ 559 return error; 560 } 561 562 #ifdef __MACHINE_STACK_GROWS_UP 563 #define STACK_PTHREADSPACE NBPG 564 #else 565 #define STACK_PTHREADSPACE 0 566 #endif 567 568 static int 569 execve_fetch_element(char * const *array, size_t index, char **value) 570 { 571 return copyin(array + index, value, sizeof(*value)); 572 } 573 574 /* 575 * exec system call 576 */ 577 int 578 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 579 { 580 /* { 581 syscallarg(const char *) path; 582 syscallarg(char * const *) argp; 583 syscallarg(char * const *) envp; 584 } */ 585 586 return execve1(l, true, SCARG(uap, path), -1, SCARG(uap, argp), 587 SCARG(uap, envp), execve_fetch_element); 588 } 589 590 int 591 sys_fexecve(struct lwp *l, const struct sys_fexecve_args *uap, 592 register_t *retval) 593 { 594 /* { 595 syscallarg(int) fd; 596 syscallarg(char * const *) argp; 597 syscallarg(char * const *) envp; 598 } */ 599 600 return execve1(l, false, NULL, SCARG(uap, fd), SCARG(uap, argp), 601 SCARG(uap, envp), execve_fetch_element); 602 } 603 604 /* 605 * Load modules to try and execute an image that we do not understand. 606 * If no execsw entries are present, we load those likely to be needed 607 * in order to run native images only. Otherwise, we autoload all 608 * possible modules that could let us run the binary. XXX lame 609 */ 610 static void 611 exec_autoload(void) 612 { 613 #ifdef MODULAR 614 static const char * const native[] = { 615 "exec_elf32", 616 "exec_elf64", 617 "exec_script", 618 NULL 619 }; 620 static const char * const compat[] = { 621 "exec_elf32", 622 "exec_elf64", 623 "exec_script", 624 "exec_aout", 625 "exec_coff", 626 "exec_ecoff", 627 "compat_aoutm68k", 628 "compat_netbsd32", 629 "compat_sunos", 630 "compat_sunos32", 631 "compat_ultrix", 632 NULL 633 }; 634 char const * const *list; 635 int i; 636 637 list = (nexecs == 0 ? native : compat); 638 for (i = 0; list[i] != NULL; i++) { 639 if (module_autoload(list[i], MODULE_CLASS_EXEC) != 0) { 640 continue; 641 } 642 yield(); 643 } 644 #endif 645 } 646 647 /* 648 * Copy the user or kernel supplied upath to the allocated pathbuffer pbp 649 * making it absolute in the process, by prepending the current working 650 * directory if it is not. If offs is supplied it will contain the offset 651 * where the original supplied copy of upath starts. 652 */ 653 int 654 exec_makepathbuf(struct lwp *l, const char *upath, enum uio_seg seg, 655 struct pathbuf **pbp, size_t *offs) 656 { 657 char *path, *bp; 658 size_t len, tlen; 659 int error; 660 struct cwdinfo *cwdi; 661 662 path = PNBUF_GET(); 663 if (seg == UIO_SYSSPACE) { 664 error = copystr(upath, path, MAXPATHLEN, &len); 665 } else { 666 error = copyinstr(upath, path, MAXPATHLEN, &len); 667 } 668 if (error) 669 goto err; 670 671 if (path[0] == '/') { 672 if (offs) 673 *offs = 0; 674 goto out; 675 } 676 677 len++; 678 if (len + 1 >= MAXPATHLEN) { 679 error = ENAMETOOLONG; 680 goto err; 681 } 682 bp = path + MAXPATHLEN - len; 683 memmove(bp, path, len); 684 *(--bp) = '/'; 685 686 cwdi = l->l_proc->p_cwdi; 687 rw_enter(&cwdi->cwdi_lock, RW_READER); 688 error = getcwd_common(cwdi->cwdi_cdir, NULL, &bp, path, MAXPATHLEN / 2, 689 GETCWD_CHECK_ACCESS, l); 690 rw_exit(&cwdi->cwdi_lock); 691 692 if (error) 693 goto err; 694 tlen = path + MAXPATHLEN - bp; 695 696 memmove(path, bp, tlen); 697 path[tlen - 1] = '\0'; 698 if (offs) 699 *offs = tlen - len; 700 out: 701 *pbp = pathbuf_assimilate(path); 702 return 0; 703 err: 704 PNBUF_PUT(path); 705 return error; 706 } 707 708 vaddr_t 709 exec_vm_minaddr(vaddr_t va_min) 710 { 711 /* 712 * Increase va_min if we don't want NULL to be mappable by the 713 * process. 714 */ 715 #define VM_MIN_GUARD PAGE_SIZE 716 if (user_va0_disable && (va_min < VM_MIN_GUARD)) 717 return VM_MIN_GUARD; 718 return va_min; 719 } 720 721 static int 722 execve_loadvm(struct lwp *l, bool has_path, const char *path, int fd, 723 char * const *args, char * const *envs, 724 execve_fetch_element_t fetch_element, 725 struct execve_data * restrict data) 726 { 727 struct exec_package * const epp = &data->ed_pack; 728 int error; 729 struct proc *p; 730 char *dp; 731 u_int modgen; 732 733 KASSERT(data != NULL); 734 735 p = l->l_proc; 736 modgen = 0; 737 738 SDT_PROBE(proc, kernel, , exec, path, 0, 0, 0, 0); 739 740 /* 741 * Check if we have exceeded our number of processes limit. 742 * This is so that we handle the case where a root daemon 743 * forked, ran setuid to become the desired user and is trying 744 * to exec. The obvious place to do the reference counting check 745 * is setuid(), but we don't do the reference counting check there 746 * like other OS's do because then all the programs that use setuid() 747 * must be modified to check the return code of setuid() and exit(). 748 * It is dangerous to make setuid() fail, because it fails open and 749 * the program will continue to run as root. If we make it succeed 750 * and return an error code, again we are not enforcing the limit. 751 * The best place to enforce the limit is here, when the process tries 752 * to execute a new image, because eventually the process will need 753 * to call exec in order to do something useful. 754 */ 755 retry: 756 if (p->p_flag & PK_SUGID) { 757 if (kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT, 758 p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 759 &p->p_rlimit[RLIMIT_NPROC], 760 KAUTH_ARG(RLIMIT_NPROC)) != 0 && 761 chgproccnt(kauth_cred_getuid(l->l_cred), 0) > 762 p->p_rlimit[RLIMIT_NPROC].rlim_cur) 763 return EAGAIN; 764 } 765 766 /* 767 * Drain existing references and forbid new ones. The process 768 * should be left alone until we're done here. This is necessary 769 * to avoid race conditions - e.g. in ptrace() - that might allow 770 * a local user to illicitly obtain elevated privileges. 771 */ 772 rw_enter(&p->p_reflock, RW_WRITER); 773 774 if (has_path) { 775 size_t offs; 776 /* 777 * Init the namei data to point the file user's program name. 778 * This is done here rather than in check_exec(), so that it's 779 * possible to override this settings if any of makecmd/probe 780 * functions call check_exec() recursively - for example, 781 * see exec_script_makecmds(). 782 */ 783 if ((error = exec_makepathbuf(l, path, UIO_USERSPACE, 784 &data->ed_pathbuf, &offs)) != 0) 785 goto clrflg; 786 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 787 epp->ep_kname = data->ed_pathstring + offs; 788 data->ed_resolvedname = PNBUF_GET(); 789 epp->ep_resolvedname = data->ed_resolvedname; 790 epp->ep_xfd = -1; 791 } else { 792 data->ed_pathbuf = pathbuf_assimilate(strcpy(PNBUF_GET(), "/")); 793 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 794 epp->ep_kname = "*fexecve*"; 795 data->ed_resolvedname = NULL; 796 epp->ep_resolvedname = NULL; 797 epp->ep_xfd = fd; 798 } 799 800 801 /* 802 * initialize the fields of the exec package. 803 */ 804 epp->ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 805 epp->ep_hdrlen = exec_maxhdrsz; 806 epp->ep_hdrvalid = 0; 807 epp->ep_emul_arg = NULL; 808 epp->ep_emul_arg_free = NULL; 809 memset(&epp->ep_vmcmds, 0, sizeof(epp->ep_vmcmds)); 810 epp->ep_vap = &data->ed_attr; 811 epp->ep_flags = (p->p_flag & PK_32) ? EXEC_FROM32 : 0; 812 MD_TOPDOWN_INIT(epp); 813 epp->ep_emul_root = NULL; 814 epp->ep_interp = NULL; 815 epp->ep_esch = NULL; 816 epp->ep_pax_flags = 0; 817 memset(epp->ep_machine_arch, 0, sizeof(epp->ep_machine_arch)); 818 819 rw_enter(&exec_lock, RW_READER); 820 821 /* see if we can run it. */ 822 if ((error = check_exec(l, epp, data->ed_pathbuf, 823 &data->ed_resolvedname)) != 0) { 824 if (error != ENOENT && error != EACCES && error != ENOEXEC) { 825 DPRINTF(("%s: check exec failed for %s, error %d\n", 826 __func__, epp->ep_kname, error)); 827 } 828 goto freehdr; 829 } 830 831 /* allocate an argument buffer */ 832 data->ed_argp = pool_get(&exec_pool, PR_WAITOK); 833 KASSERT(data->ed_argp != NULL); 834 dp = data->ed_argp; 835 836 if ((error = copyinargs(data, args, envs, fetch_element, &dp)) != 0) { 837 goto bad; 838 } 839 840 /* 841 * Calculate the new stack size. 842 */ 843 844 #ifdef __MACHINE_STACK_GROWS_UP 845 /* 846 * copyargs() fills argc/argv/envp from the lower address even on 847 * __MACHINE_STACK_GROWS_UP machines. Reserve a few words just below the SP 848 * so that _rtld() use it. 849 */ 850 #define RTLD_GAP 32 851 #else 852 #define RTLD_GAP 0 853 #endif 854 855 const size_t argenvstrlen = (char *)ALIGN(dp) - data->ed_argp; 856 857 data->ed_argslen = calcargs(data, argenvstrlen); 858 859 const size_t len = calcstack(data, pax_aslr_stack_gap(epp) + RTLD_GAP); 860 861 if (len > epp->ep_ssize) { 862 /* in effect, compare to initial limit */ 863 DPRINTF(("%s: stack limit exceeded %zu\n", __func__, len)); 864 error = ENOMEM; 865 goto bad; 866 } 867 /* adjust "active stack depth" for process VSZ */ 868 epp->ep_ssize = len; 869 870 return 0; 871 872 bad: 873 /* free the vmspace-creation commands, and release their references */ 874 kill_vmcmds(&epp->ep_vmcmds); 875 /* kill any opened file descriptor, if necessary */ 876 if (epp->ep_flags & EXEC_HASFD) { 877 epp->ep_flags &= ~EXEC_HASFD; 878 fd_close(epp->ep_fd); 879 } 880 /* close and put the exec'd file */ 881 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 882 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 883 vput(epp->ep_vp); 884 pool_put(&exec_pool, data->ed_argp); 885 886 freehdr: 887 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 888 if (epp->ep_emul_root != NULL) 889 vrele(epp->ep_emul_root); 890 if (epp->ep_interp != NULL) 891 vrele(epp->ep_interp); 892 893 rw_exit(&exec_lock); 894 895 exec_path_free(data); 896 897 clrflg: 898 rw_exit(&p->p_reflock); 899 900 if (modgen != module_gen && error == ENOEXEC) { 901 modgen = module_gen; 902 exec_autoload(); 903 goto retry; 904 } 905 906 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 907 return error; 908 } 909 910 static int 911 execve_dovmcmds(struct lwp *l, struct execve_data * restrict data) 912 { 913 struct exec_package * const epp = &data->ed_pack; 914 struct proc *p = l->l_proc; 915 struct exec_vmcmd *base_vcp; 916 int error = 0; 917 size_t i; 918 919 /* record proc's vnode, for use by procfs and others */ 920 if (p->p_textvp) 921 vrele(p->p_textvp); 922 vref(epp->ep_vp); 923 p->p_textvp = epp->ep_vp; 924 925 /* create the new process's VM space by running the vmcmds */ 926 KASSERTMSG(epp->ep_vmcmds.evs_used != 0, "%s: no vmcmds", __func__); 927 928 #ifdef TRACE_EXEC 929 DUMPVMCMDS(epp, 0, 0); 930 #endif 931 932 base_vcp = NULL; 933 934 for (i = 0; i < epp->ep_vmcmds.evs_used && !error; i++) { 935 struct exec_vmcmd *vcp; 936 937 vcp = &epp->ep_vmcmds.evs_cmds[i]; 938 if (vcp->ev_flags & VMCMD_RELATIVE) { 939 KASSERTMSG(base_vcp != NULL, 940 "%s: relative vmcmd with no base", __func__); 941 KASSERTMSG((vcp->ev_flags & VMCMD_BASE) == 0, 942 "%s: illegal base & relative vmcmd", __func__); 943 vcp->ev_addr += base_vcp->ev_addr; 944 } 945 error = (*vcp->ev_proc)(l, vcp); 946 if (error) 947 DUMPVMCMDS(epp, i, error); 948 if (vcp->ev_flags & VMCMD_BASE) 949 base_vcp = vcp; 950 } 951 952 /* free the vmspace-creation commands, and release their references */ 953 kill_vmcmds(&epp->ep_vmcmds); 954 955 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 956 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 957 vput(epp->ep_vp); 958 959 /* if an error happened, deallocate and punt */ 960 if (error != 0) { 961 DPRINTF(("%s: vmcmd %zu failed: %d\n", __func__, i - 1, error)); 962 } 963 return error; 964 } 965 966 static void 967 execve_free_data(struct execve_data *data) 968 { 969 struct exec_package * const epp = &data->ed_pack; 970 971 /* free the vmspace-creation commands, and release their references */ 972 kill_vmcmds(&epp->ep_vmcmds); 973 /* kill any opened file descriptor, if necessary */ 974 if (epp->ep_flags & EXEC_HASFD) { 975 epp->ep_flags &= ~EXEC_HASFD; 976 fd_close(epp->ep_fd); 977 } 978 979 /* close and put the exec'd file */ 980 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 981 VOP_CLOSE(epp->ep_vp, FREAD, curlwp->l_cred); 982 vput(epp->ep_vp); 983 pool_put(&exec_pool, data->ed_argp); 984 985 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 986 if (epp->ep_emul_root != NULL) 987 vrele(epp->ep_emul_root); 988 if (epp->ep_interp != NULL) 989 vrele(epp->ep_interp); 990 991 exec_path_free(data); 992 } 993 994 static void 995 pathexec(struct proc *p, const char *resolvedname) 996 { 997 /* set command name & other accounting info */ 998 const char *cmdname; 999 1000 if (resolvedname == NULL) { 1001 cmdname = "*fexecve*"; 1002 resolvedname = "/"; 1003 } else { 1004 cmdname = strrchr(resolvedname, '/') + 1; 1005 } 1006 KASSERTMSG(resolvedname[0] == '/', "bad resolvedname `%s'", 1007 resolvedname); 1008 1009 strlcpy(p->p_comm, cmdname, sizeof(p->p_comm)); 1010 1011 kmem_strfree(p->p_path); 1012 p->p_path = kmem_strdupsize(resolvedname, NULL, KM_SLEEP); 1013 } 1014 1015 /* XXX elsewhere */ 1016 static int 1017 credexec(struct lwp *l, struct vattr *attr) 1018 { 1019 struct proc *p = l->l_proc; 1020 int error; 1021 1022 /* 1023 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 1024 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 1025 * out additional references on the process for the moment. 1026 */ 1027 if ((p->p_slflag & PSL_TRACED) == 0 && 1028 1029 (((attr->va_mode & S_ISUID) != 0 && 1030 kauth_cred_geteuid(l->l_cred) != attr->va_uid) || 1031 1032 ((attr->va_mode & S_ISGID) != 0 && 1033 kauth_cred_getegid(l->l_cred) != attr->va_gid))) { 1034 /* 1035 * Mark the process as SUGID before we do 1036 * anything that might block. 1037 */ 1038 proc_crmod_enter(); 1039 proc_crmod_leave(NULL, NULL, true); 1040 1041 /* Make sure file descriptors 0..2 are in use. */ 1042 if ((error = fd_checkstd()) != 0) { 1043 DPRINTF(("%s: fdcheckstd failed %d\n", 1044 __func__, error)); 1045 return error; 1046 } 1047 1048 /* 1049 * Copy the credential so other references don't see our 1050 * changes. 1051 */ 1052 l->l_cred = kauth_cred_copy(l->l_cred); 1053 #ifdef KTRACE 1054 /* 1055 * If the persistent trace flag isn't set, turn off. 1056 */ 1057 if (p->p_tracep) { 1058 mutex_enter(&ktrace_lock); 1059 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1060 ktrderef(p); 1061 mutex_exit(&ktrace_lock); 1062 } 1063 #endif 1064 if (attr->va_mode & S_ISUID) 1065 kauth_cred_seteuid(l->l_cred, attr->va_uid); 1066 if (attr->va_mode & S_ISGID) 1067 kauth_cred_setegid(l->l_cred, attr->va_gid); 1068 } else { 1069 if (kauth_cred_geteuid(l->l_cred) == 1070 kauth_cred_getuid(l->l_cred) && 1071 kauth_cred_getegid(l->l_cred) == 1072 kauth_cred_getgid(l->l_cred)) 1073 p->p_flag &= ~PK_SUGID; 1074 } 1075 1076 /* 1077 * Copy the credential so other references don't see our changes. 1078 * Test to see if this is necessary first, since in the common case 1079 * we won't need a private reference. 1080 */ 1081 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1082 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1083 l->l_cred = kauth_cred_copy(l->l_cred); 1084 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1085 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1086 } 1087 1088 /* Update the master credentials. */ 1089 if (l->l_cred != p->p_cred) { 1090 kauth_cred_t ocred; 1091 1092 kauth_cred_hold(l->l_cred); 1093 mutex_enter(p->p_lock); 1094 ocred = p->p_cred; 1095 p->p_cred = l->l_cred; 1096 mutex_exit(p->p_lock); 1097 kauth_cred_free(ocred); 1098 } 1099 1100 return 0; 1101 } 1102 1103 static void 1104 emulexec(struct lwp *l, struct exec_package *epp) 1105 { 1106 struct proc *p = l->l_proc; 1107 1108 /* The emulation root will usually have been found when we looked 1109 * for the elf interpreter (or similar), if not look now. */ 1110 if (epp->ep_esch->es_emul->e_path != NULL && 1111 epp->ep_emul_root == NULL) 1112 emul_find_root(l, epp); 1113 1114 /* Any old emulation root got removed by fdcloseexec */ 1115 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1116 p->p_cwdi->cwdi_edir = epp->ep_emul_root; 1117 rw_exit(&p->p_cwdi->cwdi_lock); 1118 epp->ep_emul_root = NULL; 1119 if (epp->ep_interp != NULL) 1120 vrele(epp->ep_interp); 1121 1122 /* 1123 * Call emulation specific exec hook. This can setup per-process 1124 * p->p_emuldata or do any other per-process stuff an emulation needs. 1125 * 1126 * If we are executing process of different emulation than the 1127 * original forked process, call e_proc_exit() of the old emulation 1128 * first, then e_proc_exec() of new emulation. If the emulation is 1129 * same, the exec hook code should deallocate any old emulation 1130 * resources held previously by this process. 1131 */ 1132 if (p->p_emul && p->p_emul->e_proc_exit 1133 && p->p_emul != epp->ep_esch->es_emul) 1134 (*p->p_emul->e_proc_exit)(p); 1135 1136 /* 1137 * This is now LWP 1. 1138 */ 1139 /* XXX elsewhere */ 1140 mutex_enter(p->p_lock); 1141 p->p_nlwpid = 1; 1142 l->l_lid = 1; 1143 mutex_exit(p->p_lock); 1144 1145 /* 1146 * Call exec hook. Emulation code may NOT store reference to anything 1147 * from &pack. 1148 */ 1149 if (epp->ep_esch->es_emul->e_proc_exec) 1150 (*epp->ep_esch->es_emul->e_proc_exec)(p, epp); 1151 1152 /* update p_emul, the old value is no longer needed */ 1153 p->p_emul = epp->ep_esch->es_emul; 1154 1155 /* ...and the same for p_execsw */ 1156 p->p_execsw = epp->ep_esch; 1157 1158 #ifdef __HAVE_SYSCALL_INTERN 1159 (*p->p_emul->e_syscall_intern)(p); 1160 #endif 1161 ktremul(); 1162 } 1163 1164 static int 1165 execve_runproc(struct lwp *l, struct execve_data * restrict data, 1166 bool no_local_exec_lock, bool is_spawn) 1167 { 1168 struct exec_package * const epp = &data->ed_pack; 1169 int error = 0; 1170 struct proc *p; 1171 1172 /* 1173 * In case of a posix_spawn operation, the child doing the exec 1174 * might not hold the reader lock on exec_lock, but the parent 1175 * will do this instead. 1176 */ 1177 KASSERT(no_local_exec_lock || rw_lock_held(&exec_lock)); 1178 KASSERT(!no_local_exec_lock || is_spawn); 1179 KASSERT(data != NULL); 1180 1181 p = l->l_proc; 1182 1183 /* Get rid of other LWPs. */ 1184 if (p->p_nlwps > 1) { 1185 mutex_enter(p->p_lock); 1186 exit_lwps(l); 1187 mutex_exit(p->p_lock); 1188 } 1189 KDASSERT(p->p_nlwps == 1); 1190 1191 /* Destroy any lwpctl info. */ 1192 if (p->p_lwpctl != NULL) 1193 lwp_ctl_exit(); 1194 1195 /* Remove POSIX timers */ 1196 timers_free(p, TIMERS_POSIX); 1197 1198 /* Set the PaX flags. */ 1199 pax_set_flags(epp, p); 1200 1201 /* 1202 * Do whatever is necessary to prepare the address space 1203 * for remapping. Note that this might replace the current 1204 * vmspace with another! 1205 */ 1206 if (is_spawn) 1207 uvmspace_spawn(l, epp->ep_vm_minaddr, 1208 epp->ep_vm_maxaddr, 1209 epp->ep_flags & EXEC_TOPDOWN_VM); 1210 else 1211 uvmspace_exec(l, epp->ep_vm_minaddr, 1212 epp->ep_vm_maxaddr, 1213 epp->ep_flags & EXEC_TOPDOWN_VM); 1214 1215 struct vmspace *vm; 1216 vm = p->p_vmspace; 1217 vm->vm_taddr = (void *)epp->ep_taddr; 1218 vm->vm_tsize = btoc(epp->ep_tsize); 1219 vm->vm_daddr = (void*)epp->ep_daddr; 1220 vm->vm_dsize = btoc(epp->ep_dsize); 1221 vm->vm_ssize = btoc(epp->ep_ssize); 1222 vm->vm_issize = 0; 1223 vm->vm_maxsaddr = (void *)epp->ep_maxsaddr; 1224 vm->vm_minsaddr = (void *)epp->ep_minsaddr; 1225 1226 pax_aslr_init_vm(l, vm, epp); 1227 1228 /* Now map address space. */ 1229 error = execve_dovmcmds(l, data); 1230 if (error != 0) 1231 goto exec_abort; 1232 1233 pathexec(p, epp->ep_resolvedname); 1234 1235 char * const newstack = STACK_GROW(vm->vm_minsaddr, epp->ep_ssize); 1236 1237 error = copyoutargs(data, l, newstack); 1238 if (error != 0) 1239 goto exec_abort; 1240 1241 cwdexec(p); 1242 fd_closeexec(); /* handle close on exec */ 1243 1244 if (__predict_false(ktrace_on)) 1245 fd_ktrexecfd(); 1246 1247 execsigs(p); /* reset caught signals */ 1248 1249 mutex_enter(p->p_lock); 1250 l->l_ctxlink = NULL; /* reset ucontext link */ 1251 p->p_acflag &= ~AFORK; 1252 p->p_flag |= PK_EXEC; 1253 mutex_exit(p->p_lock); 1254 1255 /* 1256 * Stop profiling. 1257 */ 1258 if ((p->p_stflag & PST_PROFIL) != 0) { 1259 mutex_spin_enter(&p->p_stmutex); 1260 stopprofclock(p); 1261 mutex_spin_exit(&p->p_stmutex); 1262 } 1263 1264 /* 1265 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 1266 * exited and exec()/exit() are the only places it will be cleared. 1267 */ 1268 if ((p->p_lflag & PL_PPWAIT) != 0) { 1269 lwp_t *lp; 1270 1271 mutex_enter(proc_lock); 1272 lp = p->p_vforklwp; 1273 p->p_vforklwp = NULL; 1274 1275 l->l_lwpctl = NULL; /* was on loan from blocked parent */ 1276 p->p_lflag &= ~PL_PPWAIT; 1277 lp->l_vforkwaiting = false; 1278 1279 cv_broadcast(&lp->l_waitcv); 1280 mutex_exit(proc_lock); 1281 } 1282 1283 error = credexec(l, &data->ed_attr); 1284 if (error) 1285 goto exec_abort; 1286 1287 #if defined(__HAVE_RAS) 1288 /* 1289 * Remove all RASs from the address space. 1290 */ 1291 ras_purgeall(); 1292 #endif 1293 1294 doexechooks(p); 1295 1296 /* 1297 * Set initial SP at the top of the stack. 1298 * 1299 * Note that on machines where stack grows up (e.g. hppa), SP points to 1300 * the end of arg/env strings. Userland guesses the address of argc 1301 * via ps_strings::ps_argvstr. 1302 */ 1303 1304 /* Setup new registers and do misc. setup. */ 1305 (*epp->ep_esch->es_emul->e_setregs)(l, epp, (vaddr_t)newstack); 1306 if (epp->ep_esch->es_setregs) 1307 (*epp->ep_esch->es_setregs)(l, epp, (vaddr_t)newstack); 1308 1309 /* Provide a consistent LWP private setting */ 1310 (void)lwp_setprivate(l, NULL); 1311 1312 /* Discard all PCU state; need to start fresh */ 1313 pcu_discard_all(l); 1314 1315 /* map the process's signal trampoline code */ 1316 if ((error = exec_sigcode_map(p, epp->ep_esch->es_emul)) != 0) { 1317 DPRINTF(("%s: map sigcode failed %d\n", __func__, error)); 1318 goto exec_abort; 1319 } 1320 1321 pool_put(&exec_pool, data->ed_argp); 1322 1323 /* notify others that we exec'd */ 1324 KNOTE(&p->p_klist, NOTE_EXEC); 1325 1326 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1327 1328 SDT_PROBE(proc, kernel, , exec__success, epp->ep_kname, 0, 0, 0, 0); 1329 1330 emulexec(l, epp); 1331 1332 /* Allow new references from the debugger/procfs. */ 1333 rw_exit(&p->p_reflock); 1334 if (!no_local_exec_lock) 1335 rw_exit(&exec_lock); 1336 1337 mutex_enter(proc_lock); 1338 1339 /* posix_spawn(3) reports a single event with implied exec(3) */ 1340 if ((p->p_slflag & PSL_TRACED) && !is_spawn) { 1341 mutex_enter(p->p_lock); 1342 eventswitch(TRAP_EXEC, 0, 0); 1343 mutex_enter(proc_lock); 1344 } 1345 1346 if (p->p_sflag & PS_STOPEXEC) { 1347 ksiginfoq_t kq; 1348 1349 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1350 p->p_pptr->p_nstopchild++; 1351 p->p_waited = 0; 1352 mutex_enter(p->p_lock); 1353 ksiginfo_queue_init(&kq); 1354 sigclearall(p, &contsigmask, &kq); 1355 lwp_lock(l); 1356 l->l_stat = LSSTOP; 1357 p->p_stat = SSTOP; 1358 p->p_nrlwps--; 1359 lwp_unlock(l); 1360 mutex_exit(p->p_lock); 1361 mutex_exit(proc_lock); 1362 lwp_lock(l); 1363 mi_switch(l); 1364 ksiginfo_queue_drain(&kq); 1365 KERNEL_LOCK(l->l_biglocks, l); 1366 } else { 1367 mutex_exit(proc_lock); 1368 } 1369 1370 exec_path_free(data); 1371 #ifdef TRACE_EXEC 1372 DPRINTF(("%s finished\n", __func__)); 1373 #endif 1374 return EJUSTRETURN; 1375 1376 exec_abort: 1377 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 1378 rw_exit(&p->p_reflock); 1379 if (!no_local_exec_lock) 1380 rw_exit(&exec_lock); 1381 1382 exec_path_free(data); 1383 1384 /* 1385 * the old process doesn't exist anymore. exit gracefully. 1386 * get rid of the (new) address space we have created, if any, get rid 1387 * of our namei data and vnode, and exit noting failure 1388 */ 1389 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1390 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1391 1392 exec_free_emul_arg(epp); 1393 pool_put(&exec_pool, data->ed_argp); 1394 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1395 if (epp->ep_emul_root != NULL) 1396 vrele(epp->ep_emul_root); 1397 if (epp->ep_interp != NULL) 1398 vrele(epp->ep_interp); 1399 1400 /* Acquire the sched-state mutex (exit1() will release it). */ 1401 if (!is_spawn) { 1402 mutex_enter(p->p_lock); 1403 exit1(l, error, SIGABRT); 1404 } 1405 1406 return error; 1407 } 1408 1409 int 1410 execve1(struct lwp *l, bool has_path, const char *path, int fd, 1411 char * const *args, char * const *envs, 1412 execve_fetch_element_t fetch_element) 1413 { 1414 struct execve_data data; 1415 int error; 1416 1417 error = execve_loadvm(l, has_path, path, fd, args, envs, fetch_element, 1418 &data); 1419 if (error) 1420 return error; 1421 error = execve_runproc(l, &data, false, false); 1422 return error; 1423 } 1424 1425 static size_t 1426 fromptrsz(const struct exec_package *epp) 1427 { 1428 return (epp->ep_flags & EXEC_FROM32) ? sizeof(int) : sizeof(char *); 1429 } 1430 1431 static size_t 1432 ptrsz(const struct exec_package *epp) 1433 { 1434 return (epp->ep_flags & EXEC_32) ? sizeof(int) : sizeof(char *); 1435 } 1436 1437 static size_t 1438 calcargs(struct execve_data * restrict data, const size_t argenvstrlen) 1439 { 1440 struct exec_package * const epp = &data->ed_pack; 1441 1442 const size_t nargenvptrs = 1443 1 + /* long argc */ 1444 data->ed_argc + /* char *argv[] */ 1445 1 + /* \0 */ 1446 data->ed_envc + /* char *env[] */ 1447 1; /* \0 */ 1448 1449 return (nargenvptrs * ptrsz(epp)) /* pointers */ 1450 + argenvstrlen /* strings */ 1451 + epp->ep_esch->es_arglen; /* auxinfo */ 1452 } 1453 1454 static size_t 1455 calcstack(struct execve_data * restrict data, const size_t gaplen) 1456 { 1457 struct exec_package * const epp = &data->ed_pack; 1458 1459 data->ed_szsigcode = epp->ep_esch->es_emul->e_esigcode - 1460 epp->ep_esch->es_emul->e_sigcode; 1461 1462 data->ed_ps_strings_sz = (epp->ep_flags & EXEC_32) ? 1463 sizeof(struct ps_strings32) : sizeof(struct ps_strings); 1464 1465 const size_t sigcode_psstr_sz = 1466 data->ed_szsigcode + /* sigcode */ 1467 data->ed_ps_strings_sz + /* ps_strings */ 1468 STACK_PTHREADSPACE; /* pthread space */ 1469 1470 const size_t stacklen = 1471 data->ed_argslen + 1472 gaplen + 1473 sigcode_psstr_sz; 1474 1475 /* make the stack "safely" aligned */ 1476 return STACK_LEN_ALIGN(stacklen, STACK_ALIGNBYTES); 1477 } 1478 1479 static int 1480 copyoutargs(struct execve_data * restrict data, struct lwp *l, 1481 char * const newstack) 1482 { 1483 struct exec_package * const epp = &data->ed_pack; 1484 struct proc *p = l->l_proc; 1485 int error; 1486 1487 memset(&data->ed_arginfo, 0, sizeof(data->ed_arginfo)); 1488 1489 /* remember information about the process */ 1490 data->ed_arginfo.ps_nargvstr = data->ed_argc; 1491 data->ed_arginfo.ps_nenvstr = data->ed_envc; 1492 1493 /* 1494 * Allocate the stack address passed to the newly execve()'ed process. 1495 * 1496 * The new stack address will be set to the SP (stack pointer) register 1497 * in setregs(). 1498 */ 1499 1500 char *newargs = STACK_ALLOC( 1501 STACK_SHRINK(newstack, data->ed_argslen), data->ed_argslen); 1502 1503 error = (*epp->ep_esch->es_copyargs)(l, epp, 1504 &data->ed_arginfo, &newargs, data->ed_argp); 1505 1506 if (error) { 1507 DPRINTF(("%s: copyargs failed %d\n", __func__, error)); 1508 return error; 1509 } 1510 1511 error = copyoutpsstrs(data, p); 1512 if (error != 0) 1513 return error; 1514 1515 return 0; 1516 } 1517 1518 static int 1519 copyoutpsstrs(struct execve_data * restrict data, struct proc *p) 1520 { 1521 struct exec_package * const epp = &data->ed_pack; 1522 struct ps_strings32 arginfo32; 1523 void *aip; 1524 int error; 1525 1526 /* fill process ps_strings info */ 1527 p->p_psstrp = (vaddr_t)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 1528 STACK_PTHREADSPACE), data->ed_ps_strings_sz); 1529 1530 if (epp->ep_flags & EXEC_32) { 1531 aip = &arginfo32; 1532 arginfo32.ps_argvstr = (vaddr_t)data->ed_arginfo.ps_argvstr; 1533 arginfo32.ps_nargvstr = data->ed_arginfo.ps_nargvstr; 1534 arginfo32.ps_envstr = (vaddr_t)data->ed_arginfo.ps_envstr; 1535 arginfo32.ps_nenvstr = data->ed_arginfo.ps_nenvstr; 1536 } else 1537 aip = &data->ed_arginfo; 1538 1539 /* copy out the process's ps_strings structure */ 1540 if ((error = copyout(aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)) 1541 != 0) { 1542 DPRINTF(("%s: ps_strings copyout %p->%p size %zu failed\n", 1543 __func__, aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)); 1544 return error; 1545 } 1546 1547 return 0; 1548 } 1549 1550 static int 1551 copyinargs(struct execve_data * restrict data, char * const *args, 1552 char * const *envs, execve_fetch_element_t fetch_element, char **dpp) 1553 { 1554 struct exec_package * const epp = &data->ed_pack; 1555 char *dp; 1556 size_t i; 1557 int error; 1558 1559 dp = *dpp; 1560 1561 data->ed_argc = 0; 1562 1563 /* copy the fake args list, if there's one, freeing it as we go */ 1564 if (epp->ep_flags & EXEC_HASARGL) { 1565 struct exec_fakearg *fa = epp->ep_fa; 1566 1567 while (fa->fa_arg != NULL) { 1568 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1569 size_t len; 1570 1571 len = strlcpy(dp, fa->fa_arg, maxlen); 1572 /* Count NUL into len. */ 1573 if (len < maxlen) 1574 len++; 1575 else { 1576 while (fa->fa_arg != NULL) { 1577 kmem_free(fa->fa_arg, fa->fa_len); 1578 fa++; 1579 } 1580 kmem_free(epp->ep_fa, epp->ep_fa_len); 1581 epp->ep_flags &= ~EXEC_HASARGL; 1582 return E2BIG; 1583 } 1584 ktrexecarg(fa->fa_arg, len - 1); 1585 dp += len; 1586 1587 kmem_free(fa->fa_arg, fa->fa_len); 1588 fa++; 1589 data->ed_argc++; 1590 } 1591 kmem_free(epp->ep_fa, epp->ep_fa_len); 1592 epp->ep_flags &= ~EXEC_HASARGL; 1593 } 1594 1595 /* 1596 * Read and count argument strings from user. 1597 */ 1598 1599 if (args == NULL) { 1600 DPRINTF(("%s: null args\n", __func__)); 1601 return EINVAL; 1602 } 1603 if (epp->ep_flags & EXEC_SKIPARG) 1604 args = (const void *)((const char *)args + fromptrsz(epp)); 1605 i = 0; 1606 error = copyinargstrs(data, args, fetch_element, &dp, &i, ktr_execarg); 1607 if (error != 0) { 1608 DPRINTF(("%s: copyin arg %d\n", __func__, error)); 1609 return error; 1610 } 1611 data->ed_argc += i; 1612 1613 /* 1614 * Read and count environment strings from user. 1615 */ 1616 1617 data->ed_envc = 0; 1618 /* environment need not be there */ 1619 if (envs == NULL) 1620 goto done; 1621 i = 0; 1622 error = copyinargstrs(data, envs, fetch_element, &dp, &i, ktr_execenv); 1623 if (error != 0) { 1624 DPRINTF(("%s: copyin env %d\n", __func__, error)); 1625 return error; 1626 } 1627 data->ed_envc += i; 1628 1629 done: 1630 *dpp = dp; 1631 1632 return 0; 1633 } 1634 1635 static int 1636 copyinargstrs(struct execve_data * restrict data, char * const *strs, 1637 execve_fetch_element_t fetch_element, char **dpp, size_t *ip, 1638 void (*ktr)(const void *, size_t)) 1639 { 1640 char *dp, *sp; 1641 size_t i; 1642 int error; 1643 1644 dp = *dpp; 1645 1646 i = 0; 1647 while (1) { 1648 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1649 size_t len; 1650 1651 if ((error = (*fetch_element)(strs, i, &sp)) != 0) { 1652 return error; 1653 } 1654 if (!sp) 1655 break; 1656 if ((error = copyinstr(sp, dp, maxlen, &len)) != 0) { 1657 if (error == ENAMETOOLONG) 1658 error = E2BIG; 1659 return error; 1660 } 1661 if (__predict_false(ktrace_on)) 1662 (*ktr)(dp, len - 1); 1663 dp += len; 1664 i++; 1665 } 1666 1667 *dpp = dp; 1668 *ip = i; 1669 1670 return 0; 1671 } 1672 1673 /* 1674 * Copy argv and env strings from kernel buffer (argp) to the new stack. 1675 * Those strings are located just after auxinfo. 1676 */ 1677 int 1678 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1679 char **stackp, void *argp) 1680 { 1681 char **cpp, *dp, *sp; 1682 size_t len; 1683 void *nullp; 1684 long argc, envc; 1685 int error; 1686 1687 cpp = (char **)*stackp; 1688 nullp = NULL; 1689 argc = arginfo->ps_nargvstr; 1690 envc = arginfo->ps_nenvstr; 1691 1692 /* argc on stack is long */ 1693 CTASSERT(sizeof(*cpp) == sizeof(argc)); 1694 1695 dp = (char *)(cpp + 1696 1 + /* long argc */ 1697 argc + /* char *argv[] */ 1698 1 + /* \0 */ 1699 envc + /* char *env[] */ 1700 1) + /* \0 */ 1701 pack->ep_esch->es_arglen; /* auxinfo */ 1702 sp = argp; 1703 1704 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) { 1705 COPYPRINTF("", cpp - 1, sizeof(argc)); 1706 return error; 1707 } 1708 1709 /* XXX don't copy them out, remap them! */ 1710 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1711 1712 for (; --argc >= 0; sp += len, dp += len) { 1713 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1714 COPYPRINTF("", cpp - 1, sizeof(dp)); 1715 return error; 1716 } 1717 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1718 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1719 return error; 1720 } 1721 } 1722 1723 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1724 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1725 return error; 1726 } 1727 1728 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1729 1730 for (; --envc >= 0; sp += len, dp += len) { 1731 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1732 COPYPRINTF("", cpp - 1, sizeof(dp)); 1733 return error; 1734 } 1735 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1736 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1737 return error; 1738 } 1739 1740 } 1741 1742 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1743 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1744 return error; 1745 } 1746 1747 *stackp = (char *)cpp; 1748 return 0; 1749 } 1750 1751 1752 /* 1753 * Add execsw[] entries. 1754 */ 1755 int 1756 exec_add(struct execsw *esp, int count) 1757 { 1758 struct exec_entry *it; 1759 int i; 1760 1761 if (count == 0) { 1762 return 0; 1763 } 1764 1765 /* Check for duplicates. */ 1766 rw_enter(&exec_lock, RW_WRITER); 1767 for (i = 0; i < count; i++) { 1768 LIST_FOREACH(it, &ex_head, ex_list) { 1769 /* assume unique (makecmds, probe_func, emulation) */ 1770 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1771 it->ex_sw->u.elf_probe_func == 1772 esp[i].u.elf_probe_func && 1773 it->ex_sw->es_emul == esp[i].es_emul) { 1774 rw_exit(&exec_lock); 1775 return EEXIST; 1776 } 1777 } 1778 } 1779 1780 /* Allocate new entries. */ 1781 for (i = 0; i < count; i++) { 1782 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1783 it->ex_sw = &esp[i]; 1784 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1785 } 1786 1787 /* update execsw[] */ 1788 exec_init(0); 1789 rw_exit(&exec_lock); 1790 return 0; 1791 } 1792 1793 /* 1794 * Remove execsw[] entry. 1795 */ 1796 int 1797 exec_remove(struct execsw *esp, int count) 1798 { 1799 struct exec_entry *it, *next; 1800 int i; 1801 const struct proclist_desc *pd; 1802 proc_t *p; 1803 1804 if (count == 0) { 1805 return 0; 1806 } 1807 1808 /* Abort if any are busy. */ 1809 rw_enter(&exec_lock, RW_WRITER); 1810 for (i = 0; i < count; i++) { 1811 mutex_enter(proc_lock); 1812 for (pd = proclists; pd->pd_list != NULL; pd++) { 1813 PROCLIST_FOREACH(p, pd->pd_list) { 1814 if (p->p_execsw == &esp[i]) { 1815 mutex_exit(proc_lock); 1816 rw_exit(&exec_lock); 1817 return EBUSY; 1818 } 1819 } 1820 } 1821 mutex_exit(proc_lock); 1822 } 1823 1824 /* None are busy, so remove them all. */ 1825 for (i = 0; i < count; i++) { 1826 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1827 next = LIST_NEXT(it, ex_list); 1828 if (it->ex_sw == &esp[i]) { 1829 LIST_REMOVE(it, ex_list); 1830 kmem_free(it, sizeof(*it)); 1831 break; 1832 } 1833 } 1834 } 1835 1836 /* update execsw[] */ 1837 exec_init(0); 1838 rw_exit(&exec_lock); 1839 return 0; 1840 } 1841 1842 /* 1843 * Initialize exec structures. If init_boot is true, also does necessary 1844 * one-time initialization (it's called from main() that way). 1845 * Once system is multiuser, this should be called with exec_lock held, 1846 * i.e. via exec_{add|remove}(). 1847 */ 1848 int 1849 exec_init(int init_boot) 1850 { 1851 const struct execsw **sw; 1852 struct exec_entry *ex; 1853 SLIST_HEAD(,exec_entry) first; 1854 SLIST_HEAD(,exec_entry) any; 1855 SLIST_HEAD(,exec_entry) last; 1856 int i, sz; 1857 1858 if (init_boot) { 1859 /* do one-time initializations */ 1860 vaddr_t vmin = 0, vmax; 1861 1862 rw_init(&exec_lock); 1863 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1864 exec_map = uvm_km_suballoc(kernel_map, &vmin, &vmax, 1865 maxexec*NCARGS, VM_MAP_PAGEABLE, false, NULL); 1866 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1867 "execargs", &exec_palloc, IPL_NONE); 1868 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1869 } else { 1870 KASSERT(rw_write_held(&exec_lock)); 1871 } 1872 1873 /* Sort each entry onto the appropriate queue. */ 1874 SLIST_INIT(&first); 1875 SLIST_INIT(&any); 1876 SLIST_INIT(&last); 1877 sz = 0; 1878 LIST_FOREACH(ex, &ex_head, ex_list) { 1879 switch(ex->ex_sw->es_prio) { 1880 case EXECSW_PRIO_FIRST: 1881 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1882 break; 1883 case EXECSW_PRIO_ANY: 1884 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1885 break; 1886 case EXECSW_PRIO_LAST: 1887 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1888 break; 1889 default: 1890 panic("%s", __func__); 1891 break; 1892 } 1893 sz++; 1894 } 1895 1896 /* 1897 * Create new execsw[]. Ensure we do not try a zero-sized 1898 * allocation. 1899 */ 1900 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1901 i = 0; 1902 SLIST_FOREACH(ex, &first, ex_slist) { 1903 sw[i++] = ex->ex_sw; 1904 } 1905 SLIST_FOREACH(ex, &any, ex_slist) { 1906 sw[i++] = ex->ex_sw; 1907 } 1908 SLIST_FOREACH(ex, &last, ex_slist) { 1909 sw[i++] = ex->ex_sw; 1910 } 1911 1912 /* Replace old execsw[] and free used memory. */ 1913 if (execsw != NULL) { 1914 kmem_free(__UNCONST(execsw), 1915 nexecs * sizeof(struct execsw *) + 1); 1916 } 1917 execsw = sw; 1918 nexecs = sz; 1919 1920 /* Figure out the maximum size of an exec header. */ 1921 exec_maxhdrsz = sizeof(int); 1922 for (i = 0; i < nexecs; i++) { 1923 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1924 exec_maxhdrsz = execsw[i]->es_hdrsz; 1925 } 1926 1927 return 0; 1928 } 1929 1930 static int 1931 exec_sigcode_map(struct proc *p, const struct emul *e) 1932 { 1933 vaddr_t va; 1934 vsize_t sz; 1935 int error; 1936 struct uvm_object *uobj; 1937 1938 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1939 1940 if (e->e_sigobject == NULL || sz == 0) { 1941 return 0; 1942 } 1943 1944 /* 1945 * If we don't have a sigobject for this emulation, create one. 1946 * 1947 * sigobject is an anonymous memory object (just like SYSV shared 1948 * memory) that we keep a permanent reference to and that we map 1949 * in all processes that need this sigcode. The creation is simple, 1950 * we create an object, add a permanent reference to it, map it in 1951 * kernel space, copy out the sigcode to it and unmap it. 1952 * We map it with PROT_READ|PROT_EXEC into the process just 1953 * the way sys_mmap() would map it. 1954 */ 1955 1956 uobj = *e->e_sigobject; 1957 if (uobj == NULL) { 1958 mutex_enter(&sigobject_lock); 1959 if ((uobj = *e->e_sigobject) == NULL) { 1960 uobj = uao_create(sz, 0); 1961 (*uobj->pgops->pgo_reference)(uobj); 1962 va = vm_map_min(kernel_map); 1963 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1964 uobj, 0, 0, 1965 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1966 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1967 printf("kernel mapping failed %d\n", error); 1968 (*uobj->pgops->pgo_detach)(uobj); 1969 mutex_exit(&sigobject_lock); 1970 return error; 1971 } 1972 memcpy((void *)va, e->e_sigcode, sz); 1973 #ifdef PMAP_NEED_PROCWR 1974 pmap_procwr(&proc0, va, sz); 1975 #endif 1976 uvm_unmap(kernel_map, va, va + round_page(sz)); 1977 *e->e_sigobject = uobj; 1978 } 1979 mutex_exit(&sigobject_lock); 1980 } 1981 1982 /* Just a hint to uvm_map where to put it. */ 1983 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1984 round_page(sz), p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN); 1985 1986 #ifdef __alpha__ 1987 /* 1988 * Tru64 puts /sbin/loader at the end of user virtual memory, 1989 * which causes the above calculation to put the sigcode at 1990 * an invalid address. Put it just below the text instead. 1991 */ 1992 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1993 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1994 } 1995 #endif 1996 1997 (*uobj->pgops->pgo_reference)(uobj); 1998 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1999 uobj, 0, 0, 2000 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 2001 UVM_ADV_RANDOM, 0)); 2002 if (error) { 2003 DPRINTF(("%s, %d: map %p " 2004 "uvm_map %#"PRIxVSIZE"@%#"PRIxVADDR" failed %d\n", 2005 __func__, __LINE__, &p->p_vmspace->vm_map, round_page(sz), 2006 va, error)); 2007 (*uobj->pgops->pgo_detach)(uobj); 2008 return error; 2009 } 2010 p->p_sigctx.ps_sigcode = (void *)va; 2011 return 0; 2012 } 2013 2014 /* 2015 * Release a refcount on spawn_exec_data and destroy memory, if this 2016 * was the last one. 2017 */ 2018 static void 2019 spawn_exec_data_release(struct spawn_exec_data *data) 2020 { 2021 if (atomic_dec_32_nv(&data->sed_refcnt) != 0) 2022 return; 2023 2024 cv_destroy(&data->sed_cv_child_ready); 2025 mutex_destroy(&data->sed_mtx_child); 2026 2027 if (data->sed_actions) 2028 posix_spawn_fa_free(data->sed_actions, 2029 data->sed_actions->len); 2030 if (data->sed_attrs) 2031 kmem_free(data->sed_attrs, 2032 sizeof(*data->sed_attrs)); 2033 kmem_free(data, sizeof(*data)); 2034 } 2035 2036 /* 2037 * A child lwp of a posix_spawn operation starts here and ends up in 2038 * cpu_spawn_return, dealing with all filedescriptor and scheduler 2039 * manipulations in between. 2040 * The parent waits for the child, as it is not clear whether the child 2041 * will be able to acquire its own exec_lock. If it can, the parent can 2042 * be released early and continue running in parallel. If not (or if the 2043 * magic debug flag is passed in the scheduler attribute struct), the 2044 * child rides on the parent's exec lock until it is ready to return to 2045 * to userland - and only then releases the parent. This method loses 2046 * concurrency, but improves error reporting. 2047 */ 2048 static void 2049 spawn_return(void *arg) 2050 { 2051 struct spawn_exec_data *spawn_data = arg; 2052 struct lwp *l = curlwp; 2053 struct proc *p = l->l_proc; 2054 int error, newfd; 2055 int ostat; 2056 size_t i; 2057 const struct posix_spawn_file_actions_entry *fae; 2058 pid_t ppid; 2059 register_t retval; 2060 bool have_reflock; 2061 bool parent_is_waiting = true; 2062 2063 /* 2064 * Check if we can release parent early. 2065 * We either need to have no sed_attrs, or sed_attrs does not 2066 * have POSIX_SPAWN_RETURNERROR or one of the flags, that require 2067 * safe access to the parent proc (passed in sed_parent). 2068 * We then try to get the exec_lock, and only if that works, we can 2069 * release the parent here already. 2070 */ 2071 ppid = spawn_data->sed_parent->p_pid; 2072 if ((!spawn_data->sed_attrs 2073 || (spawn_data->sed_attrs->sa_flags 2074 & (POSIX_SPAWN_RETURNERROR|POSIX_SPAWN_SETPGROUP)) == 0) 2075 && rw_tryenter(&exec_lock, RW_READER)) { 2076 parent_is_waiting = false; 2077 mutex_enter(&spawn_data->sed_mtx_child); 2078 cv_signal(&spawn_data->sed_cv_child_ready); 2079 mutex_exit(&spawn_data->sed_mtx_child); 2080 } 2081 2082 /* don't allow debugger access yet */ 2083 rw_enter(&p->p_reflock, RW_WRITER); 2084 have_reflock = true; 2085 2086 error = 0; 2087 /* handle posix_spawn_file_actions */ 2088 if (spawn_data->sed_actions != NULL) { 2089 for (i = 0; i < spawn_data->sed_actions->len; i++) { 2090 fae = &spawn_data->sed_actions->fae[i]; 2091 switch (fae->fae_action) { 2092 case FAE_OPEN: 2093 if (fd_getfile(fae->fae_fildes) != NULL) { 2094 error = fd_close(fae->fae_fildes); 2095 if (error) 2096 break; 2097 } 2098 error = fd_open(fae->fae_path, fae->fae_oflag, 2099 fae->fae_mode, &newfd); 2100 if (error) 2101 break; 2102 if (newfd != fae->fae_fildes) { 2103 error = dodup(l, newfd, 2104 fae->fae_fildes, 0, &retval); 2105 if (fd_getfile(newfd) != NULL) 2106 fd_close(newfd); 2107 } 2108 break; 2109 case FAE_DUP2: 2110 error = dodup(l, fae->fae_fildes, 2111 fae->fae_newfildes, 0, &retval); 2112 break; 2113 case FAE_CLOSE: 2114 if (fd_getfile(fae->fae_fildes) == NULL) { 2115 error = EBADF; 2116 break; 2117 } 2118 error = fd_close(fae->fae_fildes); 2119 break; 2120 } 2121 if (error) 2122 goto report_error; 2123 } 2124 } 2125 2126 /* handle posix_spawnattr */ 2127 if (spawn_data->sed_attrs != NULL) { 2128 struct sigaction sigact; 2129 memset(&sigact, 0, sizeof(sigact)); 2130 sigact._sa_u._sa_handler = SIG_DFL; 2131 sigact.sa_flags = 0; 2132 2133 /* 2134 * set state to SSTOP so that this proc can be found by pid. 2135 * see proc_enterprp, do_sched_setparam below 2136 */ 2137 mutex_enter(proc_lock); 2138 /* 2139 * p_stat should be SACTIVE, so we need to adjust the 2140 * parent's p_nstopchild here. For safety, just make 2141 * we're on the good side of SDEAD before we adjust. 2142 */ 2143 ostat = p->p_stat; 2144 KASSERT(ostat < SSTOP); 2145 p->p_stat = SSTOP; 2146 p->p_waited = 0; 2147 p->p_pptr->p_nstopchild++; 2148 mutex_exit(proc_lock); 2149 2150 /* Set process group */ 2151 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETPGROUP) { 2152 pid_t mypid = p->p_pid, 2153 pgrp = spawn_data->sed_attrs->sa_pgroup; 2154 2155 if (pgrp == 0) 2156 pgrp = mypid; 2157 2158 error = proc_enterpgrp(spawn_data->sed_parent, 2159 mypid, pgrp, false); 2160 if (error) 2161 goto report_error_stopped; 2162 } 2163 2164 /* Set scheduler policy */ 2165 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSCHEDULER) 2166 error = do_sched_setparam(p->p_pid, 0, 2167 spawn_data->sed_attrs->sa_schedpolicy, 2168 &spawn_data->sed_attrs->sa_schedparam); 2169 else if (spawn_data->sed_attrs->sa_flags 2170 & POSIX_SPAWN_SETSCHEDPARAM) { 2171 error = do_sched_setparam(ppid, 0, 2172 SCHED_NONE, &spawn_data->sed_attrs->sa_schedparam); 2173 } 2174 if (error) 2175 goto report_error_stopped; 2176 2177 /* Reset user ID's */ 2178 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_RESETIDS) { 2179 error = do_setresuid(l, -1, 2180 kauth_cred_getgid(l->l_cred), -1, 2181 ID_E_EQ_R | ID_E_EQ_S); 2182 if (error) 2183 goto report_error_stopped; 2184 error = do_setresuid(l, -1, 2185 kauth_cred_getuid(l->l_cred), -1, 2186 ID_E_EQ_R | ID_E_EQ_S); 2187 if (error) 2188 goto report_error_stopped; 2189 } 2190 2191 /* Set signal masks/defaults */ 2192 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGMASK) { 2193 mutex_enter(p->p_lock); 2194 error = sigprocmask1(l, SIG_SETMASK, 2195 &spawn_data->sed_attrs->sa_sigmask, NULL); 2196 mutex_exit(p->p_lock); 2197 if (error) 2198 goto report_error_stopped; 2199 } 2200 2201 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGDEF) { 2202 /* 2203 * The following sigaction call is using a sigaction 2204 * version 0 trampoline which is in the compatibility 2205 * code only. This is not a problem because for SIG_DFL 2206 * and SIG_IGN, the trampolines are now ignored. If they 2207 * were not, this would be a problem because we are 2208 * holding the exec_lock, and the compat code needs 2209 * to do the same in order to replace the trampoline 2210 * code of the process. 2211 */ 2212 for (i = 1; i <= NSIG; i++) { 2213 if (sigismember( 2214 &spawn_data->sed_attrs->sa_sigdefault, i)) 2215 sigaction1(l, i, &sigact, NULL, NULL, 2216 0); 2217 } 2218 } 2219 mutex_enter(proc_lock); 2220 p->p_stat = ostat; 2221 p->p_pptr->p_nstopchild--; 2222 mutex_exit(proc_lock); 2223 } 2224 2225 /* now do the real exec */ 2226 error = execve_runproc(l, &spawn_data->sed_exec, parent_is_waiting, 2227 true); 2228 have_reflock = false; 2229 if (error == EJUSTRETURN) 2230 error = 0; 2231 else if (error) 2232 goto report_error; 2233 2234 if (parent_is_waiting) { 2235 mutex_enter(&spawn_data->sed_mtx_child); 2236 cv_signal(&spawn_data->sed_cv_child_ready); 2237 mutex_exit(&spawn_data->sed_mtx_child); 2238 } 2239 2240 /* release our refcount on the data */ 2241 spawn_exec_data_release(spawn_data); 2242 2243 if (p->p_slflag & PSL_TRACED) { 2244 /* Paranoid check */ 2245 mutex_enter(proc_lock); 2246 if (!(p->p_slflag & PSL_TRACED)) { 2247 mutex_exit(proc_lock); 2248 goto cpu_return; 2249 } 2250 2251 mutex_enter(p->p_lock); 2252 eventswitch(TRAP_CHLD, PTRACE_POSIX_SPAWN, p->p_opptr->p_pid); 2253 } 2254 2255 cpu_return: 2256 /* and finally: leave to userland for the first time */ 2257 cpu_spawn_return(l); 2258 2259 /* NOTREACHED */ 2260 return; 2261 2262 report_error_stopped: 2263 mutex_enter(proc_lock); 2264 p->p_stat = ostat; 2265 p->p_pptr->p_nstopchild--; 2266 mutex_exit(proc_lock); 2267 report_error: 2268 if (have_reflock) { 2269 /* 2270 * We have not passed through execve_runproc(), 2271 * which would have released the p_reflock and also 2272 * taken ownership of the sed_exec part of spawn_data, 2273 * so release/free both here. 2274 */ 2275 rw_exit(&p->p_reflock); 2276 execve_free_data(&spawn_data->sed_exec); 2277 } 2278 2279 if (parent_is_waiting) { 2280 /* pass error to parent */ 2281 mutex_enter(&spawn_data->sed_mtx_child); 2282 spawn_data->sed_error = error; 2283 cv_signal(&spawn_data->sed_cv_child_ready); 2284 mutex_exit(&spawn_data->sed_mtx_child); 2285 } else { 2286 rw_exit(&exec_lock); 2287 } 2288 2289 /* release our refcount on the data */ 2290 spawn_exec_data_release(spawn_data); 2291 2292 /* done, exit */ 2293 mutex_enter(p->p_lock); 2294 /* 2295 * Posix explicitly asks for an exit code of 127 if we report 2296 * errors from the child process - so, unfortunately, there 2297 * is no way to report a more exact error code. 2298 * A NetBSD specific workaround is POSIX_SPAWN_RETURNERROR as 2299 * flag bit in the attrp argument to posix_spawn(2), see above. 2300 */ 2301 exit1(l, 127, 0); 2302 } 2303 2304 void 2305 posix_spawn_fa_free(struct posix_spawn_file_actions *fa, size_t len) 2306 { 2307 2308 for (size_t i = 0; i < len; i++) { 2309 struct posix_spawn_file_actions_entry *fae = &fa->fae[i]; 2310 if (fae->fae_action != FAE_OPEN) 2311 continue; 2312 kmem_strfree(fae->fae_path); 2313 } 2314 if (fa->len > 0) 2315 kmem_free(fa->fae, sizeof(*fa->fae) * fa->len); 2316 kmem_free(fa, sizeof(*fa)); 2317 } 2318 2319 static int 2320 posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap, 2321 const struct posix_spawn_file_actions *ufa, rlim_t lim) 2322 { 2323 struct posix_spawn_file_actions *fa; 2324 struct posix_spawn_file_actions_entry *fae; 2325 char *pbuf = NULL; 2326 int error; 2327 size_t i = 0; 2328 2329 fa = kmem_alloc(sizeof(*fa), KM_SLEEP); 2330 error = copyin(ufa, fa, sizeof(*fa)); 2331 if (error || fa->len == 0) { 2332 kmem_free(fa, sizeof(*fa)); 2333 return error; /* 0 if not an error, and len == 0 */ 2334 } 2335 2336 if (fa->len > lim) { 2337 kmem_free(fa, sizeof(*fa)); 2338 return EINVAL; 2339 } 2340 2341 fa->size = fa->len; 2342 size_t fal = fa->len * sizeof(*fae); 2343 fae = fa->fae; 2344 fa->fae = kmem_alloc(fal, KM_SLEEP); 2345 error = copyin(fae, fa->fae, fal); 2346 if (error) 2347 goto out; 2348 2349 pbuf = PNBUF_GET(); 2350 for (; i < fa->len; i++) { 2351 fae = &fa->fae[i]; 2352 if (fae->fae_action != FAE_OPEN) 2353 continue; 2354 error = copyinstr(fae->fae_path, pbuf, MAXPATHLEN, &fal); 2355 if (error) 2356 goto out; 2357 fae->fae_path = kmem_alloc(fal, KM_SLEEP); 2358 memcpy(fae->fae_path, pbuf, fal); 2359 } 2360 PNBUF_PUT(pbuf); 2361 2362 *fap = fa; 2363 return 0; 2364 out: 2365 if (pbuf) 2366 PNBUF_PUT(pbuf); 2367 posix_spawn_fa_free(fa, i); 2368 return error; 2369 } 2370 2371 int 2372 check_posix_spawn(struct lwp *l1) 2373 { 2374 int error, tnprocs, count; 2375 uid_t uid; 2376 struct proc *p1; 2377 2378 p1 = l1->l_proc; 2379 uid = kauth_cred_getuid(l1->l_cred); 2380 tnprocs = atomic_inc_uint_nv(&nprocs); 2381 2382 /* 2383 * Although process entries are dynamically created, we still keep 2384 * a global limit on the maximum number we will create. 2385 */ 2386 if (__predict_false(tnprocs >= maxproc)) 2387 error = -1; 2388 else 2389 error = kauth_authorize_process(l1->l_cred, 2390 KAUTH_PROCESS_FORK, p1, KAUTH_ARG(tnprocs), NULL, NULL); 2391 2392 if (error) { 2393 atomic_dec_uint(&nprocs); 2394 return EAGAIN; 2395 } 2396 2397 /* 2398 * Enforce limits. 2399 */ 2400 count = chgproccnt(uid, 1); 2401 if (kauth_authorize_process(l1->l_cred, KAUTH_PROCESS_RLIMIT, 2402 p1, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 2403 &p1->p_rlimit[RLIMIT_NPROC], KAUTH_ARG(RLIMIT_NPROC)) != 0 && 2404 __predict_false(count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) { 2405 (void)chgproccnt(uid, -1); 2406 atomic_dec_uint(&nprocs); 2407 return EAGAIN; 2408 } 2409 2410 return 0; 2411 } 2412 2413 int 2414 do_posix_spawn(struct lwp *l1, pid_t *pid_res, bool *child_ok, const char *path, 2415 struct posix_spawn_file_actions *fa, 2416 struct posix_spawnattr *sa, 2417 char *const *argv, char *const *envp, 2418 execve_fetch_element_t fetch) 2419 { 2420 2421 struct proc *p1, *p2; 2422 struct lwp *l2; 2423 int error; 2424 struct spawn_exec_data *spawn_data; 2425 vaddr_t uaddr; 2426 pid_t pid; 2427 bool have_exec_lock = false; 2428 2429 p1 = l1->l_proc; 2430 2431 /* Allocate and init spawn_data */ 2432 spawn_data = kmem_zalloc(sizeof(*spawn_data), KM_SLEEP); 2433 spawn_data->sed_refcnt = 1; /* only parent so far */ 2434 cv_init(&spawn_data->sed_cv_child_ready, "pspawn"); 2435 mutex_init(&spawn_data->sed_mtx_child, MUTEX_DEFAULT, IPL_NONE); 2436 mutex_enter(&spawn_data->sed_mtx_child); 2437 2438 /* 2439 * Do the first part of the exec now, collect state 2440 * in spawn_data. 2441 */ 2442 error = execve_loadvm(l1, true, path, -1, argv, 2443 envp, fetch, &spawn_data->sed_exec); 2444 if (error == EJUSTRETURN) 2445 error = 0; 2446 else if (error) 2447 goto error_exit; 2448 2449 have_exec_lock = true; 2450 2451 /* 2452 * Allocate virtual address space for the U-area now, while it 2453 * is still easy to abort the fork operation if we're out of 2454 * kernel virtual address space. 2455 */ 2456 uaddr = uvm_uarea_alloc(); 2457 if (__predict_false(uaddr == 0)) { 2458 error = ENOMEM; 2459 goto error_exit; 2460 } 2461 2462 /* 2463 * Allocate new proc. Borrow proc0 vmspace for it, we will 2464 * replace it with its own before returning to userland 2465 * in the child. 2466 * This is a point of no return, we will have to go through 2467 * the child proc to properly clean it up past this point. 2468 */ 2469 p2 = proc_alloc(); 2470 pid = p2->p_pid; 2471 2472 /* 2473 * Make a proc table entry for the new process. 2474 * Start by zeroing the section of proc that is zero-initialized, 2475 * then copy the section that is copied directly from the parent. 2476 */ 2477 memset(&p2->p_startzero, 0, 2478 (unsigned) ((char *)&p2->p_endzero - (char *)&p2->p_startzero)); 2479 memcpy(&p2->p_startcopy, &p1->p_startcopy, 2480 (unsigned) ((char *)&p2->p_endcopy - (char *)&p2->p_startcopy)); 2481 p2->p_vmspace = proc0.p_vmspace; 2482 2483 TAILQ_INIT(&p2->p_sigpend.sp_info); 2484 2485 LIST_INIT(&p2->p_lwps); 2486 LIST_INIT(&p2->p_sigwaiters); 2487 2488 /* 2489 * Duplicate sub-structures as needed. 2490 * Increase reference counts on shared objects. 2491 * Inherit flags we want to keep. The flags related to SIGCHLD 2492 * handling are important in order to keep a consistent behaviour 2493 * for the child after the fork. If we are a 32-bit process, the 2494 * child will be too. 2495 */ 2496 p2->p_flag = 2497 p1->p_flag & (PK_SUGID | PK_NOCLDWAIT | PK_CLDSIGIGN | PK_32); 2498 p2->p_emul = p1->p_emul; 2499 p2->p_execsw = p1->p_execsw; 2500 2501 mutex_init(&p2->p_stmutex, MUTEX_DEFAULT, IPL_HIGH); 2502 mutex_init(&p2->p_auxlock, MUTEX_DEFAULT, IPL_NONE); 2503 rw_init(&p2->p_reflock); 2504 cv_init(&p2->p_waitcv, "wait"); 2505 cv_init(&p2->p_lwpcv, "lwpwait"); 2506 2507 p2->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 2508 2509 kauth_proc_fork(p1, p2); 2510 2511 p2->p_raslist = NULL; 2512 p2->p_fd = fd_copy(); 2513 2514 /* XXX racy */ 2515 p2->p_mqueue_cnt = p1->p_mqueue_cnt; 2516 2517 p2->p_cwdi = cwdinit(); 2518 2519 /* 2520 * Note: p_limit (rlimit stuff) is copy-on-write, so normally 2521 * we just need increase pl_refcnt. 2522 */ 2523 if (!p1->p_limit->pl_writeable) { 2524 lim_addref(p1->p_limit); 2525 p2->p_limit = p1->p_limit; 2526 } else { 2527 p2->p_limit = lim_copy(p1->p_limit); 2528 } 2529 2530 p2->p_lflag = 0; 2531 l1->l_vforkwaiting = false; 2532 p2->p_sflag = 0; 2533 p2->p_slflag = 0; 2534 p2->p_pptr = p1; 2535 p2->p_ppid = p1->p_pid; 2536 LIST_INIT(&p2->p_children); 2537 2538 p2->p_aio = NULL; 2539 2540 #ifdef KTRACE 2541 /* 2542 * Copy traceflag and tracefile if enabled. 2543 * If not inherited, these were zeroed above. 2544 */ 2545 if (p1->p_traceflag & KTRFAC_INHERIT) { 2546 mutex_enter(&ktrace_lock); 2547 p2->p_traceflag = p1->p_traceflag; 2548 if ((p2->p_tracep = p1->p_tracep) != NULL) 2549 ktradref(p2); 2550 mutex_exit(&ktrace_lock); 2551 } 2552 #endif 2553 2554 /* 2555 * Create signal actions for the child process. 2556 */ 2557 p2->p_sigacts = sigactsinit(p1, 0); 2558 mutex_enter(p1->p_lock); 2559 p2->p_sflag |= 2560 (p1->p_sflag & (PS_STOPFORK | PS_STOPEXEC | PS_NOCLDSTOP)); 2561 sched_proc_fork(p1, p2); 2562 mutex_exit(p1->p_lock); 2563 2564 p2->p_stflag = p1->p_stflag; 2565 2566 /* 2567 * p_stats. 2568 * Copy parts of p_stats, and zero out the rest. 2569 */ 2570 p2->p_stats = pstatscopy(p1->p_stats); 2571 2572 /* copy over machdep flags to the new proc */ 2573 cpu_proc_fork(p1, p2); 2574 2575 /* 2576 * Prepare remaining parts of spawn data 2577 */ 2578 spawn_data->sed_actions = fa; 2579 spawn_data->sed_attrs = sa; 2580 2581 spawn_data->sed_parent = p1; 2582 2583 /* create LWP */ 2584 lwp_create(l1, p2, uaddr, 0, NULL, 0, spawn_return, spawn_data, 2585 &l2, l1->l_class, &l1->l_sigmask, &l1->l_sigstk); 2586 l2->l_ctxlink = NULL; /* reset ucontext link */ 2587 2588 /* 2589 * Copy the credential so other references don't see our changes. 2590 * Test to see if this is necessary first, since in the common case 2591 * we won't need a private reference. 2592 */ 2593 if (kauth_cred_geteuid(l2->l_cred) != kauth_cred_getsvuid(l2->l_cred) || 2594 kauth_cred_getegid(l2->l_cred) != kauth_cred_getsvgid(l2->l_cred)) { 2595 l2->l_cred = kauth_cred_copy(l2->l_cred); 2596 kauth_cred_setsvuid(l2->l_cred, kauth_cred_geteuid(l2->l_cred)); 2597 kauth_cred_setsvgid(l2->l_cred, kauth_cred_getegid(l2->l_cred)); 2598 } 2599 2600 /* Update the master credentials. */ 2601 if (l2->l_cred != p2->p_cred) { 2602 kauth_cred_t ocred; 2603 2604 kauth_cred_hold(l2->l_cred); 2605 mutex_enter(p2->p_lock); 2606 ocred = p2->p_cred; 2607 p2->p_cred = l2->l_cred; 2608 mutex_exit(p2->p_lock); 2609 kauth_cred_free(ocred); 2610 } 2611 2612 *child_ok = true; 2613 spawn_data->sed_refcnt = 2; /* child gets it as well */ 2614 #if 0 2615 l2->l_nopreempt = 1; /* start it non-preemptable */ 2616 #endif 2617 2618 /* 2619 * It's now safe for the scheduler and other processes to see the 2620 * child process. 2621 */ 2622 mutex_enter(proc_lock); 2623 2624 if (p1->p_session->s_ttyvp != NULL && p1->p_lflag & PL_CONTROLT) 2625 p2->p_lflag |= PL_CONTROLT; 2626 2627 LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling); 2628 p2->p_exitsig = SIGCHLD; /* signal for parent on exit */ 2629 2630 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) == 2631 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) { 2632 proc_changeparent(p2, p1->p_pptr); 2633 } 2634 2635 LIST_INSERT_AFTER(p1, p2, p_pglist); 2636 LIST_INSERT_HEAD(&allproc, p2, p_list); 2637 2638 p2->p_trace_enabled = trace_is_enabled(p2); 2639 #ifdef __HAVE_SYSCALL_INTERN 2640 (*p2->p_emul->e_syscall_intern)(p2); 2641 #endif 2642 2643 /* 2644 * Make child runnable, set start time, and add to run queue except 2645 * if the parent requested the child to start in SSTOP state. 2646 */ 2647 mutex_enter(p2->p_lock); 2648 2649 getmicrotime(&p2->p_stats->p_start); 2650 2651 lwp_lock(l2); 2652 KASSERT(p2->p_nrlwps == 1); 2653 p2->p_nrlwps = 1; 2654 p2->p_stat = SACTIVE; 2655 l2->l_stat = LSRUN; 2656 sched_enqueue(l2, false); 2657 lwp_unlock(l2); 2658 2659 mutex_exit(p2->p_lock); 2660 mutex_exit(proc_lock); 2661 2662 cv_wait(&spawn_data->sed_cv_child_ready, &spawn_data->sed_mtx_child); 2663 error = spawn_data->sed_error; 2664 mutex_exit(&spawn_data->sed_mtx_child); 2665 spawn_exec_data_release(spawn_data); 2666 2667 rw_exit(&p1->p_reflock); 2668 rw_exit(&exec_lock); 2669 have_exec_lock = false; 2670 2671 *pid_res = pid; 2672 2673 if (error) 2674 return error; 2675 2676 if (p1->p_slflag & PSL_TRACED) { 2677 /* Paranoid check */ 2678 mutex_enter(proc_lock); 2679 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) != 2680 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) { 2681 mutex_exit(proc_lock); 2682 return 0; 2683 } 2684 2685 mutex_enter(p1->p_lock); 2686 eventswitch(TRAP_CHLD, PTRACE_POSIX_SPAWN, pid); 2687 } 2688 return 0; 2689 2690 error_exit: 2691 if (have_exec_lock) { 2692 execve_free_data(&spawn_data->sed_exec); 2693 rw_exit(&p1->p_reflock); 2694 rw_exit(&exec_lock); 2695 } 2696 mutex_exit(&spawn_data->sed_mtx_child); 2697 spawn_exec_data_release(spawn_data); 2698 2699 return error; 2700 } 2701 2702 int 2703 sys_posix_spawn(struct lwp *l1, const struct sys_posix_spawn_args *uap, 2704 register_t *retval) 2705 { 2706 /* { 2707 syscallarg(pid_t *) pid; 2708 syscallarg(const char *) path; 2709 syscallarg(const struct posix_spawn_file_actions *) file_actions; 2710 syscallarg(const struct posix_spawnattr *) attrp; 2711 syscallarg(char *const *) argv; 2712 syscallarg(char *const *) envp; 2713 } */ 2714 2715 int error; 2716 struct posix_spawn_file_actions *fa = NULL; 2717 struct posix_spawnattr *sa = NULL; 2718 pid_t pid; 2719 bool child_ok = false; 2720 rlim_t max_fileactions; 2721 proc_t *p = l1->l_proc; 2722 2723 error = check_posix_spawn(l1); 2724 if (error) { 2725 *retval = error; 2726 return 0; 2727 } 2728 2729 /* copy in file_actions struct */ 2730 if (SCARG(uap, file_actions) != NULL) { 2731 max_fileactions = 2 * uimin(p->p_rlimit[RLIMIT_NOFILE].rlim_cur, 2732 maxfiles); 2733 error = posix_spawn_fa_alloc(&fa, SCARG(uap, file_actions), 2734 max_fileactions); 2735 if (error) 2736 goto error_exit; 2737 } 2738 2739 /* copyin posix_spawnattr struct */ 2740 if (SCARG(uap, attrp) != NULL) { 2741 sa = kmem_alloc(sizeof(*sa), KM_SLEEP); 2742 error = copyin(SCARG(uap, attrp), sa, sizeof(*sa)); 2743 if (error) 2744 goto error_exit; 2745 } 2746 2747 /* 2748 * Do the spawn 2749 */ 2750 error = do_posix_spawn(l1, &pid, &child_ok, SCARG(uap, path), fa, sa, 2751 SCARG(uap, argv), SCARG(uap, envp), execve_fetch_element); 2752 if (error) 2753 goto error_exit; 2754 2755 if (error == 0 && SCARG(uap, pid) != NULL) 2756 error = copyout(&pid, SCARG(uap, pid), sizeof(pid)); 2757 2758 *retval = error; 2759 return 0; 2760 2761 error_exit: 2762 if (!child_ok) { 2763 (void)chgproccnt(kauth_cred_getuid(l1->l_cred), -1); 2764 atomic_dec_uint(&nprocs); 2765 2766 if (sa) 2767 kmem_free(sa, sizeof(*sa)); 2768 if (fa) 2769 posix_spawn_fa_free(fa, fa->len); 2770 } 2771 2772 *retval = error; 2773 return 0; 2774 } 2775 2776 void 2777 exec_free_emul_arg(struct exec_package *epp) 2778 { 2779 if (epp->ep_emul_arg_free != NULL) { 2780 KASSERT(epp->ep_emul_arg != NULL); 2781 (*epp->ep_emul_arg_free)(epp->ep_emul_arg); 2782 epp->ep_emul_arg_free = NULL; 2783 epp->ep_emul_arg = NULL; 2784 } else { 2785 KASSERT(epp->ep_emul_arg == NULL); 2786 } 2787 } 2788 2789 #ifdef DEBUG_EXEC 2790 static void 2791 dump_vmcmds(const struct exec_package * const epp, size_t x, int error) 2792 { 2793 struct exec_vmcmd *vp = &epp->ep_vmcmds.evs_cmds[0]; 2794 size_t j; 2795 2796 if (error == 0) 2797 DPRINTF(("vmcmds %u\n", epp->ep_vmcmds.evs_used)); 2798 else 2799 DPRINTF(("vmcmds %zu/%u, error %d\n", x, 2800 epp->ep_vmcmds.evs_used, error)); 2801 2802 for (j = 0; j < epp->ep_vmcmds.evs_used; j++) { 2803 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#" 2804 PRIxVADDR"/%#"PRIxVSIZE" fd@%#" 2805 PRIxVSIZE" prot=0%o flags=%d\n", j, 2806 vp[j].ev_proc == vmcmd_map_pagedvn ? 2807 "pagedvn" : 2808 vp[j].ev_proc == vmcmd_map_readvn ? 2809 "readvn" : 2810 vp[j].ev_proc == vmcmd_map_zero ? 2811 "zero" : "*unknown*", 2812 vp[j].ev_addr, vp[j].ev_len, 2813 vp[j].ev_offset, vp[j].ev_prot, 2814 vp[j].ev_flags)); 2815 if (error != 0 && j == x) 2816 DPRINTF((" ^--- failed\n")); 2817 } 2818 } 2819 #endif 2820