1 /* $NetBSD: kern_exec.c,v 1.488 2020/01/12 22:03:22 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 2008, 2019 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /*- 33 * Copyright (C) 1993, 1994, 1996 Christopher G. Demetriou 34 * Copyright (C) 1992 Wolfgang Solfrank. 35 * Copyright (C) 1992 TooLs GmbH. 36 * All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by TooLs GmbH. 49 * 4. The name of TooLs GmbH may not be used to endorse or promote products 50 * derived from this software without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 53 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 54 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 55 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 56 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 57 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 58 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 59 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 60 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 61 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 62 */ 63 64 #include <sys/cdefs.h> 65 __KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.488 2020/01/12 22:03:22 ad Exp $"); 66 67 #include "opt_exec.h" 68 #include "opt_execfmt.h" 69 #include "opt_ktrace.h" 70 #include "opt_modular.h" 71 #include "opt_syscall_debug.h" 72 #include "veriexec.h" 73 #include "opt_pax.h" 74 75 #include <sys/param.h> 76 #include <sys/systm.h> 77 #include <sys/filedesc.h> 78 #include <sys/kernel.h> 79 #include <sys/proc.h> 80 #include <sys/ptrace.h> 81 #include <sys/mount.h> 82 #include <sys/kmem.h> 83 #include <sys/namei.h> 84 #include <sys/vnode.h> 85 #include <sys/file.h> 86 #include <sys/filedesc.h> 87 #include <sys/acct.h> 88 #include <sys/atomic.h> 89 #include <sys/exec.h> 90 #include <sys/ktrace.h> 91 #include <sys/uidinfo.h> 92 #include <sys/wait.h> 93 #include <sys/mman.h> 94 #include <sys/ras.h> 95 #include <sys/signalvar.h> 96 #include <sys/stat.h> 97 #include <sys/syscall.h> 98 #include <sys/kauth.h> 99 #include <sys/lwpctl.h> 100 #include <sys/pax.h> 101 #include <sys/cpu.h> 102 #include <sys/module.h> 103 #include <sys/syscallvar.h> 104 #include <sys/syscallargs.h> 105 #if NVERIEXEC > 0 106 #include <sys/verified_exec.h> 107 #endif /* NVERIEXEC > 0 */ 108 #include <sys/sdt.h> 109 #include <sys/spawn.h> 110 #include <sys/prot.h> 111 #include <sys/cprng.h> 112 113 #include <uvm/uvm_extern.h> 114 115 #include <machine/reg.h> 116 117 #include <compat/common/compat_util.h> 118 119 #ifndef MD_TOPDOWN_INIT 120 #ifdef __USE_TOPDOWN_VM 121 #define MD_TOPDOWN_INIT(epp) (epp)->ep_flags |= EXEC_TOPDOWN_VM 122 #else 123 #define MD_TOPDOWN_INIT(epp) 124 #endif 125 #endif 126 127 struct execve_data; 128 129 extern int user_va0_disable; 130 131 static size_t calcargs(struct execve_data * restrict, const size_t); 132 static size_t calcstack(struct execve_data * restrict, const size_t); 133 static int copyoutargs(struct execve_data * restrict, struct lwp *, 134 char * const); 135 static int copyoutpsstrs(struct execve_data * restrict, struct proc *); 136 static int copyinargs(struct execve_data * restrict, char * const *, 137 char * const *, execve_fetch_element_t, char **); 138 static int copyinargstrs(struct execve_data * restrict, char * const *, 139 execve_fetch_element_t, char **, size_t *, void (*)(const void *, size_t)); 140 static int exec_sigcode_map(struct proc *, const struct emul *); 141 142 #if defined(DEBUG) && !defined(DEBUG_EXEC) 143 #define DEBUG_EXEC 144 #endif 145 #ifdef DEBUG_EXEC 146 #define DPRINTF(a) printf a 147 #define COPYPRINTF(s, a, b) printf("%s, %d: copyout%s @%p %zu\n", __func__, \ 148 __LINE__, (s), (a), (b)) 149 static void dump_vmcmds(const struct exec_package * const, size_t, int); 150 #define DUMPVMCMDS(p, x, e) do { dump_vmcmds((p), (x), (e)); } while (0) 151 #else 152 #define DPRINTF(a) 153 #define COPYPRINTF(s, a, b) 154 #define DUMPVMCMDS(p, x, e) do {} while (0) 155 #endif /* DEBUG_EXEC */ 156 157 /* 158 * DTrace SDT provider definitions 159 */ 160 SDT_PROVIDER_DECLARE(proc); 161 SDT_PROBE_DEFINE1(proc, kernel, , exec, "char *"); 162 SDT_PROBE_DEFINE1(proc, kernel, , exec__success, "char *"); 163 SDT_PROBE_DEFINE1(proc, kernel, , exec__failure, "int"); 164 165 /* 166 * Exec function switch: 167 * 168 * Note that each makecmds function is responsible for loading the 169 * exec package with the necessary functions for any exec-type-specific 170 * handling. 171 * 172 * Functions for specific exec types should be defined in their own 173 * header file. 174 */ 175 static const struct execsw **execsw = NULL; 176 static int nexecs; 177 178 u_int exec_maxhdrsz; /* must not be static - used by netbsd32 */ 179 180 /* list of dynamically loaded execsw entries */ 181 static LIST_HEAD(execlist_head, exec_entry) ex_head = 182 LIST_HEAD_INITIALIZER(ex_head); 183 struct exec_entry { 184 LIST_ENTRY(exec_entry) ex_list; 185 SLIST_ENTRY(exec_entry) ex_slist; 186 const struct execsw *ex_sw; 187 }; 188 189 #ifndef __HAVE_SYSCALL_INTERN 190 void syscall(void); 191 #endif 192 193 /* NetBSD autoloadable syscalls */ 194 #ifdef MODULAR 195 #include <kern/syscalls_autoload.c> 196 #endif 197 198 /* NetBSD emul struct */ 199 struct emul emul_netbsd = { 200 .e_name = "netbsd", 201 #ifdef EMUL_NATIVEROOT 202 .e_path = EMUL_NATIVEROOT, 203 #else 204 .e_path = NULL, 205 #endif 206 #ifndef __HAVE_MINIMAL_EMUL 207 .e_flags = EMUL_HAS_SYS___syscall, 208 .e_errno = NULL, 209 .e_nosys = SYS_syscall, 210 .e_nsysent = SYS_NSYSENT, 211 #endif 212 #ifdef MODULAR 213 .e_sc_autoload = netbsd_syscalls_autoload, 214 #endif 215 .e_sysent = sysent, 216 .e_nomodbits = sysent_nomodbits, 217 #ifdef SYSCALL_DEBUG 218 .e_syscallnames = syscallnames, 219 #else 220 .e_syscallnames = NULL, 221 #endif 222 .e_sendsig = sendsig, 223 .e_trapsignal = trapsignal, 224 .e_sigcode = NULL, 225 .e_esigcode = NULL, 226 .e_sigobject = NULL, 227 .e_setregs = setregs, 228 .e_proc_exec = NULL, 229 .e_proc_fork = NULL, 230 .e_proc_exit = NULL, 231 .e_lwp_fork = NULL, 232 .e_lwp_exit = NULL, 233 #ifdef __HAVE_SYSCALL_INTERN 234 .e_syscall_intern = syscall_intern, 235 #else 236 .e_syscall = syscall, 237 #endif 238 .e_sysctlovly = NULL, 239 .e_vm_default_addr = uvm_default_mapaddr, 240 .e_usertrap = NULL, 241 .e_ucsize = sizeof(ucontext_t), 242 .e_startlwp = startlwp 243 }; 244 245 /* 246 * Exec lock. Used to control access to execsw[] structures. 247 * This must not be static so that netbsd32 can access it, too. 248 */ 249 krwlock_t exec_lock; 250 251 static kmutex_t sigobject_lock; 252 253 /* 254 * Data used between a loadvm and execve part of an "exec" operation 255 */ 256 struct execve_data { 257 struct exec_package ed_pack; 258 struct pathbuf *ed_pathbuf; 259 struct vattr ed_attr; 260 struct ps_strings ed_arginfo; 261 char *ed_argp; 262 const char *ed_pathstring; 263 char *ed_resolvedname; 264 size_t ed_ps_strings_sz; 265 int ed_szsigcode; 266 size_t ed_argslen; 267 long ed_argc; 268 long ed_envc; 269 }; 270 271 /* 272 * data passed from parent lwp to child during a posix_spawn() 273 */ 274 struct spawn_exec_data { 275 struct execve_data sed_exec; 276 struct posix_spawn_file_actions 277 *sed_actions; 278 struct posix_spawnattr *sed_attrs; 279 struct proc *sed_parent; 280 kcondvar_t sed_cv_child_ready; 281 kmutex_t sed_mtx_child; 282 int sed_error; 283 volatile uint32_t sed_refcnt; 284 }; 285 286 static struct vm_map *exec_map; 287 static struct pool exec_pool; 288 289 static void * 290 exec_pool_alloc(struct pool *pp, int flags) 291 { 292 293 return (void *)uvm_km_alloc(exec_map, NCARGS, 0, 294 UVM_KMF_PAGEABLE | UVM_KMF_WAITVA); 295 } 296 297 static void 298 exec_pool_free(struct pool *pp, void *addr) 299 { 300 301 uvm_km_free(exec_map, (vaddr_t)addr, NCARGS, UVM_KMF_PAGEABLE); 302 } 303 304 static struct pool_allocator exec_palloc = { 305 .pa_alloc = exec_pool_alloc, 306 .pa_free = exec_pool_free, 307 .pa_pagesz = NCARGS 308 }; 309 310 static void 311 exec_path_free(struct execve_data *data) 312 { 313 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring); 314 pathbuf_destroy(data->ed_pathbuf); 315 if (data->ed_resolvedname) 316 PNBUF_PUT(data->ed_resolvedname); 317 } 318 319 static void 320 exec_resolvename(struct lwp *l, struct exec_package *epp, struct vnode *vp, 321 char **rpath) 322 { 323 int error; 324 char *p; 325 326 KASSERT(rpath != NULL); 327 328 *rpath = PNBUF_GET(); 329 error = vnode_to_path(*rpath, MAXPATHLEN, vp, l, l->l_proc); 330 if (error) { 331 PNBUF_PUT(*rpath); 332 *rpath = NULL; 333 return; 334 } 335 epp->ep_resolvedname = *rpath; 336 if ((p = strrchr(*rpath, '/')) != NULL) 337 epp->ep_kname = p + 1; 338 } 339 340 341 /* 342 * check exec: 343 * given an "executable" described in the exec package's namei info, 344 * see what we can do with it. 345 * 346 * ON ENTRY: 347 * exec package with appropriate namei info 348 * lwp pointer of exec'ing lwp 349 * NO SELF-LOCKED VNODES 350 * 351 * ON EXIT: 352 * error: nothing held, etc. exec header still allocated. 353 * ok: filled exec package, executable's vnode (unlocked). 354 * 355 * EXEC SWITCH ENTRY: 356 * Locked vnode to check, exec package, proc. 357 * 358 * EXEC SWITCH EXIT: 359 * ok: return 0, filled exec package, executable's vnode (unlocked). 360 * error: destructive: 361 * everything deallocated execept exec header. 362 * non-destructive: 363 * error code, executable's vnode (unlocked), 364 * exec header unmodified. 365 */ 366 int 367 /*ARGSUSED*/ 368 check_exec(struct lwp *l, struct exec_package *epp, struct pathbuf *pb, 369 char **rpath) 370 { 371 int error, i; 372 struct vnode *vp; 373 size_t resid; 374 375 if (epp->ep_resolvedname) { 376 struct nameidata nd; 377 378 // grab the absolute pathbuf here before namei() trashes it. 379 pathbuf_copystring(pb, epp->ep_resolvedname, PATH_MAX); 380 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb); 381 382 /* first get the vnode */ 383 if ((error = namei(&nd)) != 0) 384 return error; 385 386 epp->ep_vp = vp = nd.ni_vp; 387 #ifdef DIAGNOSTIC 388 /* paranoia (take this out once namei stuff stabilizes) */ 389 memset(nd.ni_pnbuf, '~', PATH_MAX); 390 #endif 391 } else { 392 struct file *fp; 393 394 if ((error = fd_getvnode(epp->ep_xfd, &fp)) != 0) 395 return error; 396 epp->ep_vp = vp = fp->f_vnode; 397 vref(vp); 398 fd_putfile(epp->ep_xfd); 399 exec_resolvename(l, epp, vp, rpath); 400 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 401 } 402 403 /* check access and type */ 404 if (vp->v_type != VREG) { 405 error = EACCES; 406 goto bad1; 407 } 408 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 409 goto bad1; 410 411 /* get attributes */ 412 /* XXX VOP_GETATTR is the only thing that needs LK_EXCLUSIVE here */ 413 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 414 goto bad1; 415 416 /* Check mount point */ 417 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 418 error = EACCES; 419 goto bad1; 420 } 421 if (vp->v_mount->mnt_flag & MNT_NOSUID) 422 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 423 424 /* try to open it */ 425 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 426 goto bad1; 427 428 /* now we have the file, get the exec header */ 429 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 430 UIO_SYSSPACE, IO_NODELOCKED, l->l_cred, &resid, NULL); 431 if (error) 432 goto bad1; 433 434 /* unlock vp, since we need it unlocked from here on out. */ 435 VOP_UNLOCK(vp); 436 437 #if NVERIEXEC > 0 438 error = veriexec_verify(l, vp, 439 epp->ep_resolvedname ? epp->ep_resolvedname : epp->ep_kname, 440 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 441 NULL); 442 if (error) 443 goto bad2; 444 #endif /* NVERIEXEC > 0 */ 445 446 #ifdef PAX_SEGVGUARD 447 error = pax_segvguard(l, vp, epp->ep_resolvedname, false); 448 if (error) 449 goto bad2; 450 #endif /* PAX_SEGVGUARD */ 451 452 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 453 454 /* 455 * Set up default address space limits. Can be overridden 456 * by individual exec packages. 457 */ 458 epp->ep_vm_minaddr = exec_vm_minaddr(VM_MIN_ADDRESS); 459 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 460 461 /* 462 * set up the vmcmds for creation of the process 463 * address space 464 */ 465 error = ENOEXEC; 466 for (i = 0; i < nexecs; i++) { 467 int newerror; 468 469 epp->ep_esch = execsw[i]; 470 newerror = (*execsw[i]->es_makecmds)(l, epp); 471 472 if (!newerror) { 473 /* Seems ok: check that entry point is not too high */ 474 if (epp->ep_entry >= epp->ep_vm_maxaddr) { 475 #ifdef DIAGNOSTIC 476 printf("%s: rejecting %p due to " 477 "too high entry address (>= %p)\n", 478 __func__, (void *)epp->ep_entry, 479 (void *)epp->ep_vm_maxaddr); 480 #endif 481 error = ENOEXEC; 482 break; 483 } 484 /* Seems ok: check that entry point is not too low */ 485 if (epp->ep_entry < epp->ep_vm_minaddr) { 486 #ifdef DIAGNOSTIC 487 printf("%s: rejecting %p due to " 488 "too low entry address (< %p)\n", 489 __func__, (void *)epp->ep_entry, 490 (void *)epp->ep_vm_minaddr); 491 #endif 492 error = ENOEXEC; 493 break; 494 } 495 496 /* check limits */ 497 if ((epp->ep_tsize > MAXTSIZ) || 498 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 499 [RLIMIT_DATA].rlim_cur)) { 500 #ifdef DIAGNOSTIC 501 printf("%s: rejecting due to " 502 "limits (t=%llu > %llu || d=%llu > %llu)\n", 503 __func__, 504 (unsigned long long)epp->ep_tsize, 505 (unsigned long long)MAXTSIZ, 506 (unsigned long long)epp->ep_dsize, 507 (unsigned long long) 508 l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur); 509 #endif 510 error = ENOMEM; 511 break; 512 } 513 return 0; 514 } 515 516 /* 517 * Reset all the fields that may have been modified by the 518 * loader. 519 */ 520 KASSERT(epp->ep_emul_arg == NULL); 521 if (epp->ep_emul_root != NULL) { 522 vrele(epp->ep_emul_root); 523 epp->ep_emul_root = NULL; 524 } 525 if (epp->ep_interp != NULL) { 526 vrele(epp->ep_interp); 527 epp->ep_interp = NULL; 528 } 529 epp->ep_pax_flags = 0; 530 531 /* make sure the first "interesting" error code is saved. */ 532 if (error == ENOEXEC) 533 error = newerror; 534 535 if (epp->ep_flags & EXEC_DESTR) 536 /* Error from "#!" code, tidied up by recursive call */ 537 return error; 538 } 539 540 /* not found, error */ 541 542 /* 543 * free any vmspace-creation commands, 544 * and release their references 545 */ 546 kill_vmcmds(&epp->ep_vmcmds); 547 548 #if NVERIEXEC > 0 || defined(PAX_SEGVGUARD) 549 bad2: 550 #endif 551 /* 552 * close and release the vnode, restore the old one, free the 553 * pathname buf, and punt. 554 */ 555 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 556 VOP_CLOSE(vp, FREAD, l->l_cred); 557 vput(vp); 558 return error; 559 560 bad1: 561 /* 562 * free the namei pathname buffer, and put the vnode 563 * (which we don't yet have open). 564 */ 565 vput(vp); /* was still locked */ 566 return error; 567 } 568 569 #ifdef __MACHINE_STACK_GROWS_UP 570 #define STACK_PTHREADSPACE NBPG 571 #else 572 #define STACK_PTHREADSPACE 0 573 #endif 574 575 static int 576 execve_fetch_element(char * const *array, size_t index, char **value) 577 { 578 return copyin(array + index, value, sizeof(*value)); 579 } 580 581 /* 582 * exec system call 583 */ 584 int 585 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 586 { 587 /* { 588 syscallarg(const char *) path; 589 syscallarg(char * const *) argp; 590 syscallarg(char * const *) envp; 591 } */ 592 593 return execve1(l, true, SCARG(uap, path), -1, SCARG(uap, argp), 594 SCARG(uap, envp), execve_fetch_element); 595 } 596 597 int 598 sys_fexecve(struct lwp *l, const struct sys_fexecve_args *uap, 599 register_t *retval) 600 { 601 /* { 602 syscallarg(int) fd; 603 syscallarg(char * const *) argp; 604 syscallarg(char * const *) envp; 605 } */ 606 607 return execve1(l, false, NULL, SCARG(uap, fd), SCARG(uap, argp), 608 SCARG(uap, envp), execve_fetch_element); 609 } 610 611 /* 612 * Load modules to try and execute an image that we do not understand. 613 * If no execsw entries are present, we load those likely to be needed 614 * in order to run native images only. Otherwise, we autoload all 615 * possible modules that could let us run the binary. XXX lame 616 */ 617 static void 618 exec_autoload(void) 619 { 620 #ifdef MODULAR 621 static const char * const native[] = { 622 "exec_elf32", 623 "exec_elf64", 624 "exec_script", 625 NULL 626 }; 627 static const char * const compat[] = { 628 "exec_elf32", 629 "exec_elf64", 630 "exec_script", 631 "exec_aout", 632 "exec_coff", 633 "exec_ecoff", 634 "compat_aoutm68k", 635 "compat_netbsd32", 636 "compat_sunos", 637 "compat_sunos32", 638 "compat_ultrix", 639 NULL 640 }; 641 char const * const *list; 642 int i; 643 644 list = (nexecs == 0 ? native : compat); 645 for (i = 0; list[i] != NULL; i++) { 646 if (module_autoload(list[i], MODULE_CLASS_EXEC) != 0) { 647 continue; 648 } 649 yield(); 650 } 651 #endif 652 } 653 654 /* 655 * Copy the user or kernel supplied upath to the allocated pathbuffer pbp 656 * making it absolute in the process, by prepending the current working 657 * directory if it is not. If offs is supplied it will contain the offset 658 * where the original supplied copy of upath starts. 659 */ 660 int 661 exec_makepathbuf(struct lwp *l, const char *upath, enum uio_seg seg, 662 struct pathbuf **pbp, size_t *offs) 663 { 664 char *path, *bp; 665 size_t len, tlen; 666 int error; 667 struct cwdinfo *cwdi; 668 669 path = PNBUF_GET(); 670 if (seg == UIO_SYSSPACE) { 671 error = copystr(upath, path, MAXPATHLEN, &len); 672 } else { 673 error = copyinstr(upath, path, MAXPATHLEN, &len); 674 } 675 if (error) 676 goto err; 677 678 if (path[0] == '/') { 679 if (offs) 680 *offs = 0; 681 goto out; 682 } 683 684 len++; 685 if (len + 1 >= MAXPATHLEN) { 686 error = ENAMETOOLONG; 687 goto err; 688 } 689 bp = path + MAXPATHLEN - len; 690 memmove(bp, path, len); 691 *(--bp) = '/'; 692 693 cwdi = l->l_proc->p_cwdi; 694 rw_enter(&cwdi->cwdi_lock, RW_READER); 695 error = getcwd_common(cwdi->cwdi_cdir, NULL, &bp, path, MAXPATHLEN / 2, 696 GETCWD_CHECK_ACCESS, l); 697 rw_exit(&cwdi->cwdi_lock); 698 699 if (error) 700 goto err; 701 tlen = path + MAXPATHLEN - bp; 702 703 memmove(path, bp, tlen); 704 path[tlen - 1] = '\0'; 705 if (offs) 706 *offs = tlen - len; 707 out: 708 *pbp = pathbuf_assimilate(path); 709 return 0; 710 err: 711 PNBUF_PUT(path); 712 return error; 713 } 714 715 vaddr_t 716 exec_vm_minaddr(vaddr_t va_min) 717 { 718 /* 719 * Increase va_min if we don't want NULL to be mappable by the 720 * process. 721 */ 722 #define VM_MIN_GUARD PAGE_SIZE 723 if (user_va0_disable && (va_min < VM_MIN_GUARD)) 724 return VM_MIN_GUARD; 725 return va_min; 726 } 727 728 static int 729 execve_loadvm(struct lwp *l, bool has_path, const char *path, int fd, 730 char * const *args, char * const *envs, 731 execve_fetch_element_t fetch_element, 732 struct execve_data * restrict data) 733 { 734 struct exec_package * const epp = &data->ed_pack; 735 int error; 736 struct proc *p; 737 char *dp; 738 u_int modgen; 739 740 KASSERT(data != NULL); 741 742 p = l->l_proc; 743 modgen = 0; 744 745 SDT_PROBE(proc, kernel, , exec, path, 0, 0, 0, 0); 746 747 /* 748 * Check if we have exceeded our number of processes limit. 749 * This is so that we handle the case where a root daemon 750 * forked, ran setuid to become the desired user and is trying 751 * to exec. The obvious place to do the reference counting check 752 * is setuid(), but we don't do the reference counting check there 753 * like other OS's do because then all the programs that use setuid() 754 * must be modified to check the return code of setuid() and exit(). 755 * It is dangerous to make setuid() fail, because it fails open and 756 * the program will continue to run as root. If we make it succeed 757 * and return an error code, again we are not enforcing the limit. 758 * The best place to enforce the limit is here, when the process tries 759 * to execute a new image, because eventually the process will need 760 * to call exec in order to do something useful. 761 */ 762 retry: 763 if (p->p_flag & PK_SUGID) { 764 if (kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT, 765 p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 766 &p->p_rlimit[RLIMIT_NPROC], 767 KAUTH_ARG(RLIMIT_NPROC)) != 0 && 768 chgproccnt(kauth_cred_getuid(l->l_cred), 0) > 769 p->p_rlimit[RLIMIT_NPROC].rlim_cur) 770 return EAGAIN; 771 } 772 773 /* 774 * Drain existing references and forbid new ones. The process 775 * should be left alone until we're done here. This is necessary 776 * to avoid race conditions - e.g. in ptrace() - that might allow 777 * a local user to illicitly obtain elevated privileges. 778 */ 779 rw_enter(&p->p_reflock, RW_WRITER); 780 781 if (has_path) { 782 size_t offs; 783 /* 784 * Init the namei data to point the file user's program name. 785 * This is done here rather than in check_exec(), so that it's 786 * possible to override this settings if any of makecmd/probe 787 * functions call check_exec() recursively - for example, 788 * see exec_script_makecmds(). 789 */ 790 if ((error = exec_makepathbuf(l, path, UIO_USERSPACE, 791 &data->ed_pathbuf, &offs)) != 0) 792 goto clrflg; 793 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 794 epp->ep_kname = data->ed_pathstring + offs; 795 data->ed_resolvedname = PNBUF_GET(); 796 epp->ep_resolvedname = data->ed_resolvedname; 797 epp->ep_xfd = -1; 798 } else { 799 data->ed_pathbuf = pathbuf_assimilate(strcpy(PNBUF_GET(), "/")); 800 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 801 epp->ep_kname = "*fexecve*"; 802 data->ed_resolvedname = NULL; 803 epp->ep_resolvedname = NULL; 804 epp->ep_xfd = fd; 805 } 806 807 808 /* 809 * initialize the fields of the exec package. 810 */ 811 epp->ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 812 epp->ep_hdrlen = exec_maxhdrsz; 813 epp->ep_hdrvalid = 0; 814 epp->ep_emul_arg = NULL; 815 epp->ep_emul_arg_free = NULL; 816 memset(&epp->ep_vmcmds, 0, sizeof(epp->ep_vmcmds)); 817 epp->ep_vap = &data->ed_attr; 818 epp->ep_flags = (p->p_flag & PK_32) ? EXEC_FROM32 : 0; 819 MD_TOPDOWN_INIT(epp); 820 epp->ep_emul_root = NULL; 821 epp->ep_interp = NULL; 822 epp->ep_esch = NULL; 823 epp->ep_pax_flags = 0; 824 memset(epp->ep_machine_arch, 0, sizeof(epp->ep_machine_arch)); 825 826 rw_enter(&exec_lock, RW_READER); 827 828 /* see if we can run it. */ 829 if ((error = check_exec(l, epp, data->ed_pathbuf, 830 &data->ed_resolvedname)) != 0) { 831 if (error != ENOENT && error != EACCES && error != ENOEXEC) { 832 DPRINTF(("%s: check exec failed for %s, error %d\n", 833 __func__, epp->ep_kname, error)); 834 } 835 goto freehdr; 836 } 837 838 /* allocate an argument buffer */ 839 data->ed_argp = pool_get(&exec_pool, PR_WAITOK); 840 KASSERT(data->ed_argp != NULL); 841 dp = data->ed_argp; 842 843 if ((error = copyinargs(data, args, envs, fetch_element, &dp)) != 0) { 844 goto bad; 845 } 846 847 /* 848 * Calculate the new stack size. 849 */ 850 851 #ifdef __MACHINE_STACK_GROWS_UP 852 /* 853 * copyargs() fills argc/argv/envp from the lower address even on 854 * __MACHINE_STACK_GROWS_UP machines. Reserve a few words just below the SP 855 * so that _rtld() use it. 856 */ 857 #define RTLD_GAP 32 858 #else 859 #define RTLD_GAP 0 860 #endif 861 862 const size_t argenvstrlen = (char *)ALIGN(dp) - data->ed_argp; 863 864 data->ed_argslen = calcargs(data, argenvstrlen); 865 866 const size_t len = calcstack(data, pax_aslr_stack_gap(epp) + RTLD_GAP); 867 868 if (len > epp->ep_ssize) { 869 /* in effect, compare to initial limit */ 870 DPRINTF(("%s: stack limit exceeded %zu\n", __func__, len)); 871 error = ENOMEM; 872 goto bad; 873 } 874 /* adjust "active stack depth" for process VSZ */ 875 epp->ep_ssize = len; 876 877 return 0; 878 879 bad: 880 /* free the vmspace-creation commands, and release their references */ 881 kill_vmcmds(&epp->ep_vmcmds); 882 /* kill any opened file descriptor, if necessary */ 883 if (epp->ep_flags & EXEC_HASFD) { 884 epp->ep_flags &= ~EXEC_HASFD; 885 fd_close(epp->ep_fd); 886 } 887 /* close and put the exec'd file */ 888 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 889 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 890 vput(epp->ep_vp); 891 pool_put(&exec_pool, data->ed_argp); 892 893 freehdr: 894 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 895 if (epp->ep_emul_root != NULL) 896 vrele(epp->ep_emul_root); 897 if (epp->ep_interp != NULL) 898 vrele(epp->ep_interp); 899 900 rw_exit(&exec_lock); 901 902 exec_path_free(data); 903 904 clrflg: 905 rw_exit(&p->p_reflock); 906 907 if (modgen != module_gen && error == ENOEXEC) { 908 modgen = module_gen; 909 exec_autoload(); 910 goto retry; 911 } 912 913 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 914 return error; 915 } 916 917 static int 918 execve_dovmcmds(struct lwp *l, struct execve_data * restrict data) 919 { 920 struct exec_package * const epp = &data->ed_pack; 921 struct proc *p = l->l_proc; 922 struct exec_vmcmd *base_vcp; 923 int error = 0; 924 size_t i; 925 926 /* record proc's vnode, for use by procfs and others */ 927 if (p->p_textvp) 928 vrele(p->p_textvp); 929 vref(epp->ep_vp); 930 p->p_textvp = epp->ep_vp; 931 932 /* create the new process's VM space by running the vmcmds */ 933 KASSERTMSG(epp->ep_vmcmds.evs_used != 0, "%s: no vmcmds", __func__); 934 935 #ifdef TRACE_EXEC 936 DUMPVMCMDS(epp, 0, 0); 937 #endif 938 939 base_vcp = NULL; 940 941 for (i = 0; i < epp->ep_vmcmds.evs_used && !error; i++) { 942 struct exec_vmcmd *vcp; 943 944 vcp = &epp->ep_vmcmds.evs_cmds[i]; 945 if (vcp->ev_flags & VMCMD_RELATIVE) { 946 KASSERTMSG(base_vcp != NULL, 947 "%s: relative vmcmd with no base", __func__); 948 KASSERTMSG((vcp->ev_flags & VMCMD_BASE) == 0, 949 "%s: illegal base & relative vmcmd", __func__); 950 vcp->ev_addr += base_vcp->ev_addr; 951 } 952 error = (*vcp->ev_proc)(l, vcp); 953 if (error) 954 DUMPVMCMDS(epp, i, error); 955 if (vcp->ev_flags & VMCMD_BASE) 956 base_vcp = vcp; 957 } 958 959 /* free the vmspace-creation commands, and release their references */ 960 kill_vmcmds(&epp->ep_vmcmds); 961 962 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 963 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 964 vput(epp->ep_vp); 965 966 /* if an error happened, deallocate and punt */ 967 if (error != 0) { 968 DPRINTF(("%s: vmcmd %zu failed: %d\n", __func__, i - 1, error)); 969 } 970 return error; 971 } 972 973 static void 974 execve_free_data(struct execve_data *data) 975 { 976 struct exec_package * const epp = &data->ed_pack; 977 978 /* free the vmspace-creation commands, and release their references */ 979 kill_vmcmds(&epp->ep_vmcmds); 980 /* kill any opened file descriptor, if necessary */ 981 if (epp->ep_flags & EXEC_HASFD) { 982 epp->ep_flags &= ~EXEC_HASFD; 983 fd_close(epp->ep_fd); 984 } 985 986 /* close and put the exec'd file */ 987 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 988 VOP_CLOSE(epp->ep_vp, FREAD, curlwp->l_cred); 989 vput(epp->ep_vp); 990 pool_put(&exec_pool, data->ed_argp); 991 992 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 993 if (epp->ep_emul_root != NULL) 994 vrele(epp->ep_emul_root); 995 if (epp->ep_interp != NULL) 996 vrele(epp->ep_interp); 997 998 exec_path_free(data); 999 } 1000 1001 static void 1002 pathexec(struct proc *p, const char *resolvedname) 1003 { 1004 /* set command name & other accounting info */ 1005 const char *cmdname; 1006 1007 if (resolvedname == NULL) { 1008 cmdname = "*fexecve*"; 1009 resolvedname = "/"; 1010 } else { 1011 cmdname = strrchr(resolvedname, '/') + 1; 1012 } 1013 KASSERTMSG(resolvedname[0] == '/', "bad resolvedname `%s'", 1014 resolvedname); 1015 1016 strlcpy(p->p_comm, cmdname, sizeof(p->p_comm)); 1017 1018 kmem_strfree(p->p_path); 1019 p->p_path = kmem_strdupsize(resolvedname, NULL, KM_SLEEP); 1020 } 1021 1022 /* XXX elsewhere */ 1023 static int 1024 credexec(struct lwp *l, struct vattr *attr) 1025 { 1026 struct proc *p = l->l_proc; 1027 int error; 1028 1029 /* 1030 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 1031 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 1032 * out additional references on the process for the moment. 1033 */ 1034 if ((p->p_slflag & PSL_TRACED) == 0 && 1035 1036 (((attr->va_mode & S_ISUID) != 0 && 1037 kauth_cred_geteuid(l->l_cred) != attr->va_uid) || 1038 1039 ((attr->va_mode & S_ISGID) != 0 && 1040 kauth_cred_getegid(l->l_cred) != attr->va_gid))) { 1041 /* 1042 * Mark the process as SUGID before we do 1043 * anything that might block. 1044 */ 1045 proc_crmod_enter(); 1046 proc_crmod_leave(NULL, NULL, true); 1047 1048 /* Make sure file descriptors 0..2 are in use. */ 1049 if ((error = fd_checkstd()) != 0) { 1050 DPRINTF(("%s: fdcheckstd failed %d\n", 1051 __func__, error)); 1052 return error; 1053 } 1054 1055 /* 1056 * Copy the credential so other references don't see our 1057 * changes. 1058 */ 1059 l->l_cred = kauth_cred_copy(l->l_cred); 1060 #ifdef KTRACE 1061 /* 1062 * If the persistent trace flag isn't set, turn off. 1063 */ 1064 if (p->p_tracep) { 1065 mutex_enter(&ktrace_lock); 1066 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1067 ktrderef(p); 1068 mutex_exit(&ktrace_lock); 1069 } 1070 #endif 1071 if (attr->va_mode & S_ISUID) 1072 kauth_cred_seteuid(l->l_cred, attr->va_uid); 1073 if (attr->va_mode & S_ISGID) 1074 kauth_cred_setegid(l->l_cred, attr->va_gid); 1075 } else { 1076 if (kauth_cred_geteuid(l->l_cred) == 1077 kauth_cred_getuid(l->l_cred) && 1078 kauth_cred_getegid(l->l_cred) == 1079 kauth_cred_getgid(l->l_cred)) 1080 p->p_flag &= ~PK_SUGID; 1081 } 1082 1083 /* 1084 * Copy the credential so other references don't see our changes. 1085 * Test to see if this is necessary first, since in the common case 1086 * we won't need a private reference. 1087 */ 1088 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1089 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1090 l->l_cred = kauth_cred_copy(l->l_cred); 1091 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1092 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1093 } 1094 1095 /* Update the master credentials. */ 1096 if (l->l_cred != p->p_cred) { 1097 kauth_cred_t ocred; 1098 1099 kauth_cred_hold(l->l_cred); 1100 mutex_enter(p->p_lock); 1101 ocred = p->p_cred; 1102 p->p_cred = l->l_cred; 1103 mutex_exit(p->p_lock); 1104 kauth_cred_free(ocred); 1105 } 1106 1107 return 0; 1108 } 1109 1110 static void 1111 emulexec(struct lwp *l, struct exec_package *epp) 1112 { 1113 struct proc *p = l->l_proc; 1114 1115 /* The emulation root will usually have been found when we looked 1116 * for the elf interpreter (or similar), if not look now. */ 1117 if (epp->ep_esch->es_emul->e_path != NULL && 1118 epp->ep_emul_root == NULL) 1119 emul_find_root(l, epp); 1120 1121 /* Any old emulation root got removed by fdcloseexec */ 1122 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1123 p->p_cwdi->cwdi_edir = epp->ep_emul_root; 1124 rw_exit(&p->p_cwdi->cwdi_lock); 1125 epp->ep_emul_root = NULL; 1126 if (epp->ep_interp != NULL) 1127 vrele(epp->ep_interp); 1128 1129 /* 1130 * Call emulation specific exec hook. This can setup per-process 1131 * p->p_emuldata or do any other per-process stuff an emulation needs. 1132 * 1133 * If we are executing process of different emulation than the 1134 * original forked process, call e_proc_exit() of the old emulation 1135 * first, then e_proc_exec() of new emulation. If the emulation is 1136 * same, the exec hook code should deallocate any old emulation 1137 * resources held previously by this process. 1138 */ 1139 if (p->p_emul && p->p_emul->e_proc_exit 1140 && p->p_emul != epp->ep_esch->es_emul) 1141 (*p->p_emul->e_proc_exit)(p); 1142 1143 /* 1144 * This is now LWP 1. 1145 */ 1146 /* XXX elsewhere */ 1147 mutex_enter(p->p_lock); 1148 p->p_nlwpid = 1; 1149 l->l_lid = 1; 1150 mutex_exit(p->p_lock); 1151 1152 /* 1153 * Call exec hook. Emulation code may NOT store reference to anything 1154 * from &pack. 1155 */ 1156 if (epp->ep_esch->es_emul->e_proc_exec) 1157 (*epp->ep_esch->es_emul->e_proc_exec)(p, epp); 1158 1159 /* update p_emul, the old value is no longer needed */ 1160 p->p_emul = epp->ep_esch->es_emul; 1161 1162 /* ...and the same for p_execsw */ 1163 p->p_execsw = epp->ep_esch; 1164 1165 #ifdef __HAVE_SYSCALL_INTERN 1166 (*p->p_emul->e_syscall_intern)(p); 1167 #endif 1168 ktremul(); 1169 } 1170 1171 static int 1172 execve_runproc(struct lwp *l, struct execve_data * restrict data, 1173 bool no_local_exec_lock, bool is_spawn) 1174 { 1175 struct exec_package * const epp = &data->ed_pack; 1176 int error = 0; 1177 struct proc *p; 1178 struct vmspace *vm; 1179 1180 /* 1181 * In case of a posix_spawn operation, the child doing the exec 1182 * might not hold the reader lock on exec_lock, but the parent 1183 * will do this instead. 1184 */ 1185 KASSERT(no_local_exec_lock || rw_lock_held(&exec_lock)); 1186 KASSERT(!no_local_exec_lock || is_spawn); 1187 KASSERT(data != NULL); 1188 1189 p = l->l_proc; 1190 1191 /* Get rid of other LWPs. */ 1192 if (p->p_nlwps > 1) { 1193 mutex_enter(p->p_lock); 1194 exit_lwps(l); 1195 mutex_exit(p->p_lock); 1196 } 1197 KDASSERT(p->p_nlwps == 1); 1198 1199 /* Destroy any lwpctl info. */ 1200 if (p->p_lwpctl != NULL) 1201 lwp_ctl_exit(); 1202 1203 /* Remove POSIX timers */ 1204 timers_free(p, TIMERS_POSIX); 1205 1206 /* Set the PaX flags. */ 1207 pax_set_flags(epp, p); 1208 1209 /* 1210 * Do whatever is necessary to prepare the address space 1211 * for remapping. Note that this might replace the current 1212 * vmspace with another! 1213 * 1214 * vfork(): do not touch any user space data in the new child 1215 * until we have awoken the parent below, or it will defeat 1216 * lazy pmap switching (on x86). 1217 */ 1218 if (is_spawn) 1219 uvmspace_spawn(l, epp->ep_vm_minaddr, 1220 epp->ep_vm_maxaddr, 1221 epp->ep_flags & EXEC_TOPDOWN_VM); 1222 else 1223 uvmspace_exec(l, epp->ep_vm_minaddr, 1224 epp->ep_vm_maxaddr, 1225 epp->ep_flags & EXEC_TOPDOWN_VM); 1226 vm = p->p_vmspace; 1227 1228 vm->vm_taddr = (void *)epp->ep_taddr; 1229 vm->vm_tsize = btoc(epp->ep_tsize); 1230 vm->vm_daddr = (void*)epp->ep_daddr; 1231 vm->vm_dsize = btoc(epp->ep_dsize); 1232 vm->vm_ssize = btoc(epp->ep_ssize); 1233 vm->vm_issize = 0; 1234 vm->vm_maxsaddr = (void *)epp->ep_maxsaddr; 1235 vm->vm_minsaddr = (void *)epp->ep_minsaddr; 1236 1237 pax_aslr_init_vm(l, vm, epp); 1238 1239 cwdexec(p); 1240 fd_closeexec(); /* handle close on exec */ 1241 1242 if (__predict_false(ktrace_on)) 1243 fd_ktrexecfd(); 1244 1245 execsigs(p); /* reset caught signals */ 1246 1247 mutex_enter(p->p_lock); 1248 l->l_ctxlink = NULL; /* reset ucontext link */ 1249 p->p_acflag &= ~AFORK; 1250 p->p_flag |= PK_EXEC; 1251 mutex_exit(p->p_lock); 1252 1253 error = credexec(l, &data->ed_attr); 1254 if (error) 1255 goto exec_abort; 1256 1257 #if defined(__HAVE_RAS) 1258 /* 1259 * Remove all RASs from the address space. 1260 */ 1261 ras_purgeall(); 1262 #endif 1263 1264 /* 1265 * Stop profiling. 1266 */ 1267 if ((p->p_stflag & PST_PROFIL) != 0) { 1268 mutex_spin_enter(&p->p_stmutex); 1269 stopprofclock(p); 1270 mutex_spin_exit(&p->p_stmutex); 1271 } 1272 1273 /* 1274 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 1275 * exited and exec()/exit() are the only places it will be cleared. 1276 * 1277 * Once the parent has been awoken, curlwp may teleport to a new CPU 1278 * in sched_vforkexec(), and it's then OK to start messing with user 1279 * data. See comment above. 1280 */ 1281 if ((p->p_lflag & PL_PPWAIT) != 0) { 1282 bool samecpu; 1283 lwp_t *lp; 1284 1285 mutex_enter(proc_lock); 1286 lp = p->p_vforklwp; 1287 p->p_vforklwp = NULL; 1288 l->l_lwpctl = NULL; /* was on loan from blocked parent */ 1289 cv_broadcast(&lp->l_waitcv); 1290 1291 /* Clear flags after cv_broadcast() (scheduler needs them). */ 1292 p->p_lflag &= ~PL_PPWAIT; 1293 lp->l_vforkwaiting = false; 1294 1295 /* If parent is still on same CPU, teleport curlwp elsewhere. */ 1296 samecpu = (lp->l_cpu == curlwp->l_cpu); 1297 mutex_exit(proc_lock); 1298 1299 /* Give the parent its CPU back - find a new home. */ 1300 KASSERT(!is_spawn); 1301 sched_vforkexec(l, samecpu); 1302 } 1303 1304 /* Now map address space. */ 1305 error = execve_dovmcmds(l, data); 1306 if (error != 0) 1307 goto exec_abort; 1308 1309 pathexec(p, epp->ep_resolvedname); 1310 1311 char * const newstack = STACK_GROW(vm->vm_minsaddr, epp->ep_ssize); 1312 1313 error = copyoutargs(data, l, newstack); 1314 if (error != 0) 1315 goto exec_abort; 1316 1317 doexechooks(p); 1318 1319 /* 1320 * Set initial SP at the top of the stack. 1321 * 1322 * Note that on machines where stack grows up (e.g. hppa), SP points to 1323 * the end of arg/env strings. Userland guesses the address of argc 1324 * via ps_strings::ps_argvstr. 1325 */ 1326 1327 /* Setup new registers and do misc. setup. */ 1328 (*epp->ep_esch->es_emul->e_setregs)(l, epp, (vaddr_t)newstack); 1329 if (epp->ep_esch->es_setregs) 1330 (*epp->ep_esch->es_setregs)(l, epp, (vaddr_t)newstack); 1331 1332 /* Provide a consistent LWP private setting */ 1333 (void)lwp_setprivate(l, NULL); 1334 1335 /* Discard all PCU state; need to start fresh */ 1336 pcu_discard_all(l); 1337 1338 /* map the process's signal trampoline code */ 1339 if ((error = exec_sigcode_map(p, epp->ep_esch->es_emul)) != 0) { 1340 DPRINTF(("%s: map sigcode failed %d\n", __func__, error)); 1341 goto exec_abort; 1342 } 1343 1344 pool_put(&exec_pool, data->ed_argp); 1345 1346 /* notify others that we exec'd */ 1347 KNOTE(&p->p_klist, NOTE_EXEC); 1348 1349 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1350 1351 SDT_PROBE(proc, kernel, , exec__success, epp->ep_kname, 0, 0, 0, 0); 1352 1353 emulexec(l, epp); 1354 1355 /* Allow new references from the debugger/procfs. */ 1356 rw_exit(&p->p_reflock); 1357 if (!no_local_exec_lock) 1358 rw_exit(&exec_lock); 1359 1360 mutex_enter(proc_lock); 1361 1362 /* posix_spawn(3) reports a single event with implied exec(3) */ 1363 if ((p->p_slflag & PSL_TRACED) && !is_spawn) { 1364 mutex_enter(p->p_lock); 1365 eventswitch(TRAP_EXEC, 0, 0); 1366 mutex_enter(proc_lock); 1367 } 1368 1369 if (p->p_sflag & PS_STOPEXEC) { 1370 ksiginfoq_t kq; 1371 1372 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1373 p->p_pptr->p_nstopchild++; 1374 p->p_waited = 0; 1375 mutex_enter(p->p_lock); 1376 ksiginfo_queue_init(&kq); 1377 sigclearall(p, &contsigmask, &kq); 1378 lwp_lock(l); 1379 l->l_stat = LSSTOP; 1380 p->p_stat = SSTOP; 1381 p->p_nrlwps--; 1382 lwp_unlock(l); 1383 mutex_exit(p->p_lock); 1384 mutex_exit(proc_lock); 1385 lwp_lock(l); 1386 spc_lock(l->l_cpu); 1387 mi_switch(l); 1388 ksiginfo_queue_drain(&kq); 1389 } else { 1390 mutex_exit(proc_lock); 1391 } 1392 1393 exec_path_free(data); 1394 #ifdef TRACE_EXEC 1395 DPRINTF(("%s finished\n", __func__)); 1396 #endif 1397 return EJUSTRETURN; 1398 1399 exec_abort: 1400 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 1401 rw_exit(&p->p_reflock); 1402 if (!no_local_exec_lock) 1403 rw_exit(&exec_lock); 1404 1405 exec_path_free(data); 1406 1407 /* 1408 * the old process doesn't exist anymore. exit gracefully. 1409 * get rid of the (new) address space we have created, if any, get rid 1410 * of our namei data and vnode, and exit noting failure 1411 */ 1412 if (vm != NULL) { 1413 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1414 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1415 } 1416 1417 exec_free_emul_arg(epp); 1418 pool_put(&exec_pool, data->ed_argp); 1419 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1420 if (epp->ep_emul_root != NULL) 1421 vrele(epp->ep_emul_root); 1422 if (epp->ep_interp != NULL) 1423 vrele(epp->ep_interp); 1424 1425 /* Acquire the sched-state mutex (exit1() will release it). */ 1426 if (!is_spawn) { 1427 mutex_enter(p->p_lock); 1428 exit1(l, error, SIGABRT); 1429 } 1430 1431 return error; 1432 } 1433 1434 int 1435 execve1(struct lwp *l, bool has_path, const char *path, int fd, 1436 char * const *args, char * const *envs, 1437 execve_fetch_element_t fetch_element) 1438 { 1439 struct execve_data data; 1440 int error; 1441 1442 error = execve_loadvm(l, has_path, path, fd, args, envs, fetch_element, 1443 &data); 1444 if (error) 1445 return error; 1446 error = execve_runproc(l, &data, false, false); 1447 return error; 1448 } 1449 1450 static size_t 1451 fromptrsz(const struct exec_package *epp) 1452 { 1453 return (epp->ep_flags & EXEC_FROM32) ? sizeof(int) : sizeof(char *); 1454 } 1455 1456 static size_t 1457 ptrsz(const struct exec_package *epp) 1458 { 1459 return (epp->ep_flags & EXEC_32) ? sizeof(int) : sizeof(char *); 1460 } 1461 1462 static size_t 1463 calcargs(struct execve_data * restrict data, const size_t argenvstrlen) 1464 { 1465 struct exec_package * const epp = &data->ed_pack; 1466 1467 const size_t nargenvptrs = 1468 1 + /* long argc */ 1469 data->ed_argc + /* char *argv[] */ 1470 1 + /* \0 */ 1471 data->ed_envc + /* char *env[] */ 1472 1; /* \0 */ 1473 1474 return (nargenvptrs * ptrsz(epp)) /* pointers */ 1475 + argenvstrlen /* strings */ 1476 + epp->ep_esch->es_arglen; /* auxinfo */ 1477 } 1478 1479 static size_t 1480 calcstack(struct execve_data * restrict data, const size_t gaplen) 1481 { 1482 struct exec_package * const epp = &data->ed_pack; 1483 1484 data->ed_szsigcode = epp->ep_esch->es_emul->e_esigcode - 1485 epp->ep_esch->es_emul->e_sigcode; 1486 1487 data->ed_ps_strings_sz = (epp->ep_flags & EXEC_32) ? 1488 sizeof(struct ps_strings32) : sizeof(struct ps_strings); 1489 1490 const size_t sigcode_psstr_sz = 1491 data->ed_szsigcode + /* sigcode */ 1492 data->ed_ps_strings_sz + /* ps_strings */ 1493 STACK_PTHREADSPACE; /* pthread space */ 1494 1495 const size_t stacklen = 1496 data->ed_argslen + 1497 gaplen + 1498 sigcode_psstr_sz; 1499 1500 /* make the stack "safely" aligned */ 1501 return STACK_LEN_ALIGN(stacklen, STACK_ALIGNBYTES); 1502 } 1503 1504 static int 1505 copyoutargs(struct execve_data * restrict data, struct lwp *l, 1506 char * const newstack) 1507 { 1508 struct exec_package * const epp = &data->ed_pack; 1509 struct proc *p = l->l_proc; 1510 int error; 1511 1512 memset(&data->ed_arginfo, 0, sizeof(data->ed_arginfo)); 1513 1514 /* remember information about the process */ 1515 data->ed_arginfo.ps_nargvstr = data->ed_argc; 1516 data->ed_arginfo.ps_nenvstr = data->ed_envc; 1517 1518 /* 1519 * Allocate the stack address passed to the newly execve()'ed process. 1520 * 1521 * The new stack address will be set to the SP (stack pointer) register 1522 * in setregs(). 1523 */ 1524 1525 char *newargs = STACK_ALLOC( 1526 STACK_SHRINK(newstack, data->ed_argslen), data->ed_argslen); 1527 1528 error = (*epp->ep_esch->es_copyargs)(l, epp, 1529 &data->ed_arginfo, &newargs, data->ed_argp); 1530 1531 if (error) { 1532 DPRINTF(("%s: copyargs failed %d\n", __func__, error)); 1533 return error; 1534 } 1535 1536 error = copyoutpsstrs(data, p); 1537 if (error != 0) 1538 return error; 1539 1540 return 0; 1541 } 1542 1543 static int 1544 copyoutpsstrs(struct execve_data * restrict data, struct proc *p) 1545 { 1546 struct exec_package * const epp = &data->ed_pack; 1547 struct ps_strings32 arginfo32; 1548 void *aip; 1549 int error; 1550 1551 /* fill process ps_strings info */ 1552 p->p_psstrp = (vaddr_t)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 1553 STACK_PTHREADSPACE), data->ed_ps_strings_sz); 1554 1555 if (epp->ep_flags & EXEC_32) { 1556 aip = &arginfo32; 1557 arginfo32.ps_argvstr = (vaddr_t)data->ed_arginfo.ps_argvstr; 1558 arginfo32.ps_nargvstr = data->ed_arginfo.ps_nargvstr; 1559 arginfo32.ps_envstr = (vaddr_t)data->ed_arginfo.ps_envstr; 1560 arginfo32.ps_nenvstr = data->ed_arginfo.ps_nenvstr; 1561 } else 1562 aip = &data->ed_arginfo; 1563 1564 /* copy out the process's ps_strings structure */ 1565 if ((error = copyout(aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)) 1566 != 0) { 1567 DPRINTF(("%s: ps_strings copyout %p->%p size %zu failed\n", 1568 __func__, aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)); 1569 return error; 1570 } 1571 1572 return 0; 1573 } 1574 1575 static int 1576 copyinargs(struct execve_data * restrict data, char * const *args, 1577 char * const *envs, execve_fetch_element_t fetch_element, char **dpp) 1578 { 1579 struct exec_package * const epp = &data->ed_pack; 1580 char *dp; 1581 size_t i; 1582 int error; 1583 1584 dp = *dpp; 1585 1586 data->ed_argc = 0; 1587 1588 /* copy the fake args list, if there's one, freeing it as we go */ 1589 if (epp->ep_flags & EXEC_HASARGL) { 1590 struct exec_fakearg *fa = epp->ep_fa; 1591 1592 while (fa->fa_arg != NULL) { 1593 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1594 size_t len; 1595 1596 len = strlcpy(dp, fa->fa_arg, maxlen); 1597 /* Count NUL into len. */ 1598 if (len < maxlen) 1599 len++; 1600 else { 1601 while (fa->fa_arg != NULL) { 1602 kmem_free(fa->fa_arg, fa->fa_len); 1603 fa++; 1604 } 1605 kmem_free(epp->ep_fa, epp->ep_fa_len); 1606 epp->ep_flags &= ~EXEC_HASARGL; 1607 return E2BIG; 1608 } 1609 ktrexecarg(fa->fa_arg, len - 1); 1610 dp += len; 1611 1612 kmem_free(fa->fa_arg, fa->fa_len); 1613 fa++; 1614 data->ed_argc++; 1615 } 1616 kmem_free(epp->ep_fa, epp->ep_fa_len); 1617 epp->ep_flags &= ~EXEC_HASARGL; 1618 } 1619 1620 /* 1621 * Read and count argument strings from user. 1622 */ 1623 1624 if (args == NULL) { 1625 DPRINTF(("%s: null args\n", __func__)); 1626 return EINVAL; 1627 } 1628 if (epp->ep_flags & EXEC_SKIPARG) 1629 args = (const void *)((const char *)args + fromptrsz(epp)); 1630 i = 0; 1631 error = copyinargstrs(data, args, fetch_element, &dp, &i, ktr_execarg); 1632 if (error != 0) { 1633 DPRINTF(("%s: copyin arg %d\n", __func__, error)); 1634 return error; 1635 } 1636 data->ed_argc += i; 1637 1638 /* 1639 * Read and count environment strings from user. 1640 */ 1641 1642 data->ed_envc = 0; 1643 /* environment need not be there */ 1644 if (envs == NULL) 1645 goto done; 1646 i = 0; 1647 error = copyinargstrs(data, envs, fetch_element, &dp, &i, ktr_execenv); 1648 if (error != 0) { 1649 DPRINTF(("%s: copyin env %d\n", __func__, error)); 1650 return error; 1651 } 1652 data->ed_envc += i; 1653 1654 done: 1655 *dpp = dp; 1656 1657 return 0; 1658 } 1659 1660 static int 1661 copyinargstrs(struct execve_data * restrict data, char * const *strs, 1662 execve_fetch_element_t fetch_element, char **dpp, size_t *ip, 1663 void (*ktr)(const void *, size_t)) 1664 { 1665 char *dp, *sp; 1666 size_t i; 1667 int error; 1668 1669 dp = *dpp; 1670 1671 i = 0; 1672 while (1) { 1673 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1674 size_t len; 1675 1676 if ((error = (*fetch_element)(strs, i, &sp)) != 0) { 1677 return error; 1678 } 1679 if (!sp) 1680 break; 1681 if ((error = copyinstr(sp, dp, maxlen, &len)) != 0) { 1682 if (error == ENAMETOOLONG) 1683 error = E2BIG; 1684 return error; 1685 } 1686 if (__predict_false(ktrace_on)) 1687 (*ktr)(dp, len - 1); 1688 dp += len; 1689 i++; 1690 } 1691 1692 *dpp = dp; 1693 *ip = i; 1694 1695 return 0; 1696 } 1697 1698 /* 1699 * Copy argv and env strings from kernel buffer (argp) to the new stack. 1700 * Those strings are located just after auxinfo. 1701 */ 1702 int 1703 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1704 char **stackp, void *argp) 1705 { 1706 char **cpp, *dp, *sp; 1707 size_t len; 1708 void *nullp; 1709 long argc, envc; 1710 int error; 1711 1712 cpp = (char **)*stackp; 1713 nullp = NULL; 1714 argc = arginfo->ps_nargvstr; 1715 envc = arginfo->ps_nenvstr; 1716 1717 /* argc on stack is long */ 1718 CTASSERT(sizeof(*cpp) == sizeof(argc)); 1719 1720 dp = (char *)(cpp + 1721 1 + /* long argc */ 1722 argc + /* char *argv[] */ 1723 1 + /* \0 */ 1724 envc + /* char *env[] */ 1725 1) + /* \0 */ 1726 pack->ep_esch->es_arglen; /* auxinfo */ 1727 sp = argp; 1728 1729 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) { 1730 COPYPRINTF("", cpp - 1, sizeof(argc)); 1731 return error; 1732 } 1733 1734 /* XXX don't copy them out, remap them! */ 1735 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1736 1737 for (; --argc >= 0; sp += len, dp += len) { 1738 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1739 COPYPRINTF("", cpp - 1, sizeof(dp)); 1740 return error; 1741 } 1742 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1743 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1744 return error; 1745 } 1746 } 1747 1748 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1749 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1750 return error; 1751 } 1752 1753 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1754 1755 for (; --envc >= 0; sp += len, dp += len) { 1756 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1757 COPYPRINTF("", cpp - 1, sizeof(dp)); 1758 return error; 1759 } 1760 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1761 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1762 return error; 1763 } 1764 1765 } 1766 1767 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1768 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1769 return error; 1770 } 1771 1772 *stackp = (char *)cpp; 1773 return 0; 1774 } 1775 1776 1777 /* 1778 * Add execsw[] entries. 1779 */ 1780 int 1781 exec_add(struct execsw *esp, int count) 1782 { 1783 struct exec_entry *it; 1784 int i; 1785 1786 if (count == 0) { 1787 return 0; 1788 } 1789 1790 /* Check for duplicates. */ 1791 rw_enter(&exec_lock, RW_WRITER); 1792 for (i = 0; i < count; i++) { 1793 LIST_FOREACH(it, &ex_head, ex_list) { 1794 /* assume unique (makecmds, probe_func, emulation) */ 1795 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1796 it->ex_sw->u.elf_probe_func == 1797 esp[i].u.elf_probe_func && 1798 it->ex_sw->es_emul == esp[i].es_emul) { 1799 rw_exit(&exec_lock); 1800 return EEXIST; 1801 } 1802 } 1803 } 1804 1805 /* Allocate new entries. */ 1806 for (i = 0; i < count; i++) { 1807 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1808 it->ex_sw = &esp[i]; 1809 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1810 } 1811 1812 /* update execsw[] */ 1813 exec_init(0); 1814 rw_exit(&exec_lock); 1815 return 0; 1816 } 1817 1818 /* 1819 * Remove execsw[] entry. 1820 */ 1821 int 1822 exec_remove(struct execsw *esp, int count) 1823 { 1824 struct exec_entry *it, *next; 1825 int i; 1826 const struct proclist_desc *pd; 1827 proc_t *p; 1828 1829 if (count == 0) { 1830 return 0; 1831 } 1832 1833 /* Abort if any are busy. */ 1834 rw_enter(&exec_lock, RW_WRITER); 1835 for (i = 0; i < count; i++) { 1836 mutex_enter(proc_lock); 1837 for (pd = proclists; pd->pd_list != NULL; pd++) { 1838 PROCLIST_FOREACH(p, pd->pd_list) { 1839 if (p->p_execsw == &esp[i]) { 1840 mutex_exit(proc_lock); 1841 rw_exit(&exec_lock); 1842 return EBUSY; 1843 } 1844 } 1845 } 1846 mutex_exit(proc_lock); 1847 } 1848 1849 /* None are busy, so remove them all. */ 1850 for (i = 0; i < count; i++) { 1851 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1852 next = LIST_NEXT(it, ex_list); 1853 if (it->ex_sw == &esp[i]) { 1854 LIST_REMOVE(it, ex_list); 1855 kmem_free(it, sizeof(*it)); 1856 break; 1857 } 1858 } 1859 } 1860 1861 /* update execsw[] */ 1862 exec_init(0); 1863 rw_exit(&exec_lock); 1864 return 0; 1865 } 1866 1867 /* 1868 * Initialize exec structures. If init_boot is true, also does necessary 1869 * one-time initialization (it's called from main() that way). 1870 * Once system is multiuser, this should be called with exec_lock held, 1871 * i.e. via exec_{add|remove}(). 1872 */ 1873 int 1874 exec_init(int init_boot) 1875 { 1876 const struct execsw **sw; 1877 struct exec_entry *ex; 1878 SLIST_HEAD(,exec_entry) first; 1879 SLIST_HEAD(,exec_entry) any; 1880 SLIST_HEAD(,exec_entry) last; 1881 int i, sz; 1882 1883 if (init_boot) { 1884 /* do one-time initializations */ 1885 vaddr_t vmin = 0, vmax; 1886 1887 rw_init(&exec_lock); 1888 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1889 exec_map = uvm_km_suballoc(kernel_map, &vmin, &vmax, 1890 maxexec*NCARGS, VM_MAP_PAGEABLE, false, NULL); 1891 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1892 "execargs", &exec_palloc, IPL_NONE); 1893 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1894 } else { 1895 KASSERT(rw_write_held(&exec_lock)); 1896 } 1897 1898 /* Sort each entry onto the appropriate queue. */ 1899 SLIST_INIT(&first); 1900 SLIST_INIT(&any); 1901 SLIST_INIT(&last); 1902 sz = 0; 1903 LIST_FOREACH(ex, &ex_head, ex_list) { 1904 switch(ex->ex_sw->es_prio) { 1905 case EXECSW_PRIO_FIRST: 1906 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1907 break; 1908 case EXECSW_PRIO_ANY: 1909 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1910 break; 1911 case EXECSW_PRIO_LAST: 1912 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1913 break; 1914 default: 1915 panic("%s", __func__); 1916 break; 1917 } 1918 sz++; 1919 } 1920 1921 /* 1922 * Create new execsw[]. Ensure we do not try a zero-sized 1923 * allocation. 1924 */ 1925 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1926 i = 0; 1927 SLIST_FOREACH(ex, &first, ex_slist) { 1928 sw[i++] = ex->ex_sw; 1929 } 1930 SLIST_FOREACH(ex, &any, ex_slist) { 1931 sw[i++] = ex->ex_sw; 1932 } 1933 SLIST_FOREACH(ex, &last, ex_slist) { 1934 sw[i++] = ex->ex_sw; 1935 } 1936 1937 /* Replace old execsw[] and free used memory. */ 1938 if (execsw != NULL) { 1939 kmem_free(__UNCONST(execsw), 1940 nexecs * sizeof(struct execsw *) + 1); 1941 } 1942 execsw = sw; 1943 nexecs = sz; 1944 1945 /* Figure out the maximum size of an exec header. */ 1946 exec_maxhdrsz = sizeof(int); 1947 for (i = 0; i < nexecs; i++) { 1948 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1949 exec_maxhdrsz = execsw[i]->es_hdrsz; 1950 } 1951 1952 return 0; 1953 } 1954 1955 static int 1956 exec_sigcode_map(struct proc *p, const struct emul *e) 1957 { 1958 vaddr_t va; 1959 vsize_t sz; 1960 int error; 1961 struct uvm_object *uobj; 1962 1963 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1964 1965 if (e->e_sigobject == NULL || sz == 0) { 1966 return 0; 1967 } 1968 1969 /* 1970 * If we don't have a sigobject for this emulation, create one. 1971 * 1972 * sigobject is an anonymous memory object (just like SYSV shared 1973 * memory) that we keep a permanent reference to and that we map 1974 * in all processes that need this sigcode. The creation is simple, 1975 * we create an object, add a permanent reference to it, map it in 1976 * kernel space, copy out the sigcode to it and unmap it. 1977 * We map it with PROT_READ|PROT_EXEC into the process just 1978 * the way sys_mmap() would map it. 1979 */ 1980 1981 uobj = *e->e_sigobject; 1982 if (uobj == NULL) { 1983 mutex_enter(&sigobject_lock); 1984 if ((uobj = *e->e_sigobject) == NULL) { 1985 uobj = uao_create(sz, 0); 1986 (*uobj->pgops->pgo_reference)(uobj); 1987 va = vm_map_min(kernel_map); 1988 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1989 uobj, 0, 0, 1990 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1991 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1992 printf("kernel mapping failed %d\n", error); 1993 (*uobj->pgops->pgo_detach)(uobj); 1994 mutex_exit(&sigobject_lock); 1995 return error; 1996 } 1997 memcpy((void *)va, e->e_sigcode, sz); 1998 #ifdef PMAP_NEED_PROCWR 1999 pmap_procwr(&proc0, va, sz); 2000 #endif 2001 uvm_unmap(kernel_map, va, va + round_page(sz)); 2002 *e->e_sigobject = uobj; 2003 } 2004 mutex_exit(&sigobject_lock); 2005 } 2006 2007 /* Just a hint to uvm_map where to put it. */ 2008 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 2009 round_page(sz), p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN); 2010 2011 #ifdef __alpha__ 2012 /* 2013 * Tru64 puts /sbin/loader at the end of user virtual memory, 2014 * which causes the above calculation to put the sigcode at 2015 * an invalid address. Put it just below the text instead. 2016 */ 2017 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 2018 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 2019 } 2020 #endif 2021 2022 (*uobj->pgops->pgo_reference)(uobj); 2023 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 2024 uobj, 0, 0, 2025 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 2026 UVM_ADV_RANDOM, 0)); 2027 if (error) { 2028 DPRINTF(("%s, %d: map %p " 2029 "uvm_map %#"PRIxVSIZE"@%#"PRIxVADDR" failed %d\n", 2030 __func__, __LINE__, &p->p_vmspace->vm_map, round_page(sz), 2031 va, error)); 2032 (*uobj->pgops->pgo_detach)(uobj); 2033 return error; 2034 } 2035 p->p_sigctx.ps_sigcode = (void *)va; 2036 return 0; 2037 } 2038 2039 /* 2040 * Release a refcount on spawn_exec_data and destroy memory, if this 2041 * was the last one. 2042 */ 2043 static void 2044 spawn_exec_data_release(struct spawn_exec_data *data) 2045 { 2046 if (atomic_dec_32_nv(&data->sed_refcnt) != 0) 2047 return; 2048 2049 cv_destroy(&data->sed_cv_child_ready); 2050 mutex_destroy(&data->sed_mtx_child); 2051 2052 if (data->sed_actions) 2053 posix_spawn_fa_free(data->sed_actions, 2054 data->sed_actions->len); 2055 if (data->sed_attrs) 2056 kmem_free(data->sed_attrs, 2057 sizeof(*data->sed_attrs)); 2058 kmem_free(data, sizeof(*data)); 2059 } 2060 2061 /* 2062 * A child lwp of a posix_spawn operation starts here and ends up in 2063 * cpu_spawn_return, dealing with all filedescriptor and scheduler 2064 * manipulations in between. 2065 * The parent waits for the child, as it is not clear whether the child 2066 * will be able to acquire its own exec_lock. If it can, the parent can 2067 * be released early and continue running in parallel. If not (or if the 2068 * magic debug flag is passed in the scheduler attribute struct), the 2069 * child rides on the parent's exec lock until it is ready to return to 2070 * to userland - and only then releases the parent. This method loses 2071 * concurrency, but improves error reporting. 2072 */ 2073 static void 2074 spawn_return(void *arg) 2075 { 2076 struct spawn_exec_data *spawn_data = arg; 2077 struct lwp *l = curlwp; 2078 struct proc *p = l->l_proc; 2079 int error, newfd; 2080 int ostat; 2081 size_t i; 2082 const struct posix_spawn_file_actions_entry *fae; 2083 pid_t ppid; 2084 register_t retval; 2085 bool have_reflock; 2086 bool parent_is_waiting = true; 2087 2088 /* 2089 * Check if we can release parent early. 2090 * We either need to have no sed_attrs, or sed_attrs does not 2091 * have POSIX_SPAWN_RETURNERROR or one of the flags, that require 2092 * safe access to the parent proc (passed in sed_parent). 2093 * We then try to get the exec_lock, and only if that works, we can 2094 * release the parent here already. 2095 */ 2096 ppid = spawn_data->sed_parent->p_pid; 2097 if ((!spawn_data->sed_attrs 2098 || (spawn_data->sed_attrs->sa_flags 2099 & (POSIX_SPAWN_RETURNERROR|POSIX_SPAWN_SETPGROUP)) == 0) 2100 && rw_tryenter(&exec_lock, RW_READER)) { 2101 parent_is_waiting = false; 2102 mutex_enter(&spawn_data->sed_mtx_child); 2103 cv_signal(&spawn_data->sed_cv_child_ready); 2104 mutex_exit(&spawn_data->sed_mtx_child); 2105 } 2106 2107 /* don't allow debugger access yet */ 2108 rw_enter(&p->p_reflock, RW_WRITER); 2109 have_reflock = true; 2110 2111 error = 0; 2112 /* handle posix_spawn_file_actions */ 2113 if (spawn_data->sed_actions != NULL) { 2114 for (i = 0; i < spawn_data->sed_actions->len; i++) { 2115 fae = &spawn_data->sed_actions->fae[i]; 2116 switch (fae->fae_action) { 2117 case FAE_OPEN: 2118 if (fd_getfile(fae->fae_fildes) != NULL) { 2119 error = fd_close(fae->fae_fildes); 2120 if (error) 2121 break; 2122 } 2123 error = fd_open(fae->fae_path, fae->fae_oflag, 2124 fae->fae_mode, &newfd); 2125 if (error) 2126 break; 2127 if (newfd != fae->fae_fildes) { 2128 error = dodup(l, newfd, 2129 fae->fae_fildes, 0, &retval); 2130 if (fd_getfile(newfd) != NULL) 2131 fd_close(newfd); 2132 } 2133 break; 2134 case FAE_DUP2: 2135 error = dodup(l, fae->fae_fildes, 2136 fae->fae_newfildes, 0, &retval); 2137 break; 2138 case FAE_CLOSE: 2139 if (fd_getfile(fae->fae_fildes) == NULL) { 2140 error = EBADF; 2141 break; 2142 } 2143 error = fd_close(fae->fae_fildes); 2144 break; 2145 } 2146 if (error) 2147 goto report_error; 2148 } 2149 } 2150 2151 /* handle posix_spawnattr */ 2152 if (spawn_data->sed_attrs != NULL) { 2153 struct sigaction sigact; 2154 memset(&sigact, 0, sizeof(sigact)); 2155 sigact._sa_u._sa_handler = SIG_DFL; 2156 sigact.sa_flags = 0; 2157 2158 /* 2159 * set state to SSTOP so that this proc can be found by pid. 2160 * see proc_enterprp, do_sched_setparam below 2161 */ 2162 mutex_enter(proc_lock); 2163 /* 2164 * p_stat should be SACTIVE, so we need to adjust the 2165 * parent's p_nstopchild here. For safety, just make 2166 * we're on the good side of SDEAD before we adjust. 2167 */ 2168 ostat = p->p_stat; 2169 KASSERT(ostat < SSTOP); 2170 p->p_stat = SSTOP; 2171 p->p_waited = 0; 2172 p->p_pptr->p_nstopchild++; 2173 mutex_exit(proc_lock); 2174 2175 /* Set process group */ 2176 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETPGROUP) { 2177 pid_t mypid = p->p_pid, 2178 pgrp = spawn_data->sed_attrs->sa_pgroup; 2179 2180 if (pgrp == 0) 2181 pgrp = mypid; 2182 2183 error = proc_enterpgrp(spawn_data->sed_parent, 2184 mypid, pgrp, false); 2185 if (error) 2186 goto report_error_stopped; 2187 } 2188 2189 /* Set scheduler policy */ 2190 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSCHEDULER) 2191 error = do_sched_setparam(p->p_pid, 0, 2192 spawn_data->sed_attrs->sa_schedpolicy, 2193 &spawn_data->sed_attrs->sa_schedparam); 2194 else if (spawn_data->sed_attrs->sa_flags 2195 & POSIX_SPAWN_SETSCHEDPARAM) { 2196 error = do_sched_setparam(ppid, 0, 2197 SCHED_NONE, &spawn_data->sed_attrs->sa_schedparam); 2198 } 2199 if (error) 2200 goto report_error_stopped; 2201 2202 /* Reset user ID's */ 2203 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_RESETIDS) { 2204 error = do_setresuid(l, -1, 2205 kauth_cred_getgid(l->l_cred), -1, 2206 ID_E_EQ_R | ID_E_EQ_S); 2207 if (error) 2208 goto report_error_stopped; 2209 error = do_setresuid(l, -1, 2210 kauth_cred_getuid(l->l_cred), -1, 2211 ID_E_EQ_R | ID_E_EQ_S); 2212 if (error) 2213 goto report_error_stopped; 2214 } 2215 2216 /* Set signal masks/defaults */ 2217 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGMASK) { 2218 mutex_enter(p->p_lock); 2219 error = sigprocmask1(l, SIG_SETMASK, 2220 &spawn_data->sed_attrs->sa_sigmask, NULL); 2221 mutex_exit(p->p_lock); 2222 if (error) 2223 goto report_error_stopped; 2224 } 2225 2226 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGDEF) { 2227 /* 2228 * The following sigaction call is using a sigaction 2229 * version 0 trampoline which is in the compatibility 2230 * code only. This is not a problem because for SIG_DFL 2231 * and SIG_IGN, the trampolines are now ignored. If they 2232 * were not, this would be a problem because we are 2233 * holding the exec_lock, and the compat code needs 2234 * to do the same in order to replace the trampoline 2235 * code of the process. 2236 */ 2237 for (i = 1; i <= NSIG; i++) { 2238 if (sigismember( 2239 &spawn_data->sed_attrs->sa_sigdefault, i)) 2240 sigaction1(l, i, &sigact, NULL, NULL, 2241 0); 2242 } 2243 } 2244 mutex_enter(proc_lock); 2245 p->p_stat = ostat; 2246 p->p_pptr->p_nstopchild--; 2247 mutex_exit(proc_lock); 2248 } 2249 2250 /* now do the real exec */ 2251 error = execve_runproc(l, &spawn_data->sed_exec, parent_is_waiting, 2252 true); 2253 have_reflock = false; 2254 if (error == EJUSTRETURN) 2255 error = 0; 2256 else if (error) 2257 goto report_error; 2258 2259 if (parent_is_waiting) { 2260 mutex_enter(&spawn_data->sed_mtx_child); 2261 cv_signal(&spawn_data->sed_cv_child_ready); 2262 mutex_exit(&spawn_data->sed_mtx_child); 2263 } 2264 2265 /* release our refcount on the data */ 2266 spawn_exec_data_release(spawn_data); 2267 2268 if (p->p_slflag & PSL_TRACED) { 2269 /* Paranoid check */ 2270 mutex_enter(proc_lock); 2271 if (!(p->p_slflag & PSL_TRACED)) { 2272 mutex_exit(proc_lock); 2273 goto cpu_return; 2274 } 2275 2276 mutex_enter(p->p_lock); 2277 eventswitch(TRAP_CHLD, PTRACE_POSIX_SPAWN, p->p_opptr->p_pid); 2278 } 2279 2280 cpu_return: 2281 /* and finally: leave to userland for the first time */ 2282 cpu_spawn_return(l); 2283 2284 /* NOTREACHED */ 2285 return; 2286 2287 report_error_stopped: 2288 mutex_enter(proc_lock); 2289 p->p_stat = ostat; 2290 p->p_pptr->p_nstopchild--; 2291 mutex_exit(proc_lock); 2292 report_error: 2293 if (have_reflock) { 2294 /* 2295 * We have not passed through execve_runproc(), 2296 * which would have released the p_reflock and also 2297 * taken ownership of the sed_exec part of spawn_data, 2298 * so release/free both here. 2299 */ 2300 rw_exit(&p->p_reflock); 2301 execve_free_data(&spawn_data->sed_exec); 2302 } 2303 2304 if (parent_is_waiting) { 2305 /* pass error to parent */ 2306 mutex_enter(&spawn_data->sed_mtx_child); 2307 spawn_data->sed_error = error; 2308 cv_signal(&spawn_data->sed_cv_child_ready); 2309 mutex_exit(&spawn_data->sed_mtx_child); 2310 } else { 2311 rw_exit(&exec_lock); 2312 } 2313 2314 /* release our refcount on the data */ 2315 spawn_exec_data_release(spawn_data); 2316 2317 /* done, exit */ 2318 mutex_enter(p->p_lock); 2319 /* 2320 * Posix explicitly asks for an exit code of 127 if we report 2321 * errors from the child process - so, unfortunately, there 2322 * is no way to report a more exact error code. 2323 * A NetBSD specific workaround is POSIX_SPAWN_RETURNERROR as 2324 * flag bit in the attrp argument to posix_spawn(2), see above. 2325 */ 2326 exit1(l, 127, 0); 2327 } 2328 2329 void 2330 posix_spawn_fa_free(struct posix_spawn_file_actions *fa, size_t len) 2331 { 2332 2333 for (size_t i = 0; i < len; i++) { 2334 struct posix_spawn_file_actions_entry *fae = &fa->fae[i]; 2335 if (fae->fae_action != FAE_OPEN) 2336 continue; 2337 kmem_strfree(fae->fae_path); 2338 } 2339 if (fa->len > 0) 2340 kmem_free(fa->fae, sizeof(*fa->fae) * fa->len); 2341 kmem_free(fa, sizeof(*fa)); 2342 } 2343 2344 static int 2345 posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap, 2346 const struct posix_spawn_file_actions *ufa, rlim_t lim) 2347 { 2348 struct posix_spawn_file_actions *fa; 2349 struct posix_spawn_file_actions_entry *fae; 2350 char *pbuf = NULL; 2351 int error; 2352 size_t i = 0; 2353 2354 fa = kmem_alloc(sizeof(*fa), KM_SLEEP); 2355 error = copyin(ufa, fa, sizeof(*fa)); 2356 if (error || fa->len == 0) { 2357 kmem_free(fa, sizeof(*fa)); 2358 return error; /* 0 if not an error, and len == 0 */ 2359 } 2360 2361 if (fa->len > lim) { 2362 kmem_free(fa, sizeof(*fa)); 2363 return EINVAL; 2364 } 2365 2366 fa->size = fa->len; 2367 size_t fal = fa->len * sizeof(*fae); 2368 fae = fa->fae; 2369 fa->fae = kmem_alloc(fal, KM_SLEEP); 2370 error = copyin(fae, fa->fae, fal); 2371 if (error) 2372 goto out; 2373 2374 pbuf = PNBUF_GET(); 2375 for (; i < fa->len; i++) { 2376 fae = &fa->fae[i]; 2377 if (fae->fae_action != FAE_OPEN) 2378 continue; 2379 error = copyinstr(fae->fae_path, pbuf, MAXPATHLEN, &fal); 2380 if (error) 2381 goto out; 2382 fae->fae_path = kmem_alloc(fal, KM_SLEEP); 2383 memcpy(fae->fae_path, pbuf, fal); 2384 } 2385 PNBUF_PUT(pbuf); 2386 2387 *fap = fa; 2388 return 0; 2389 out: 2390 if (pbuf) 2391 PNBUF_PUT(pbuf); 2392 posix_spawn_fa_free(fa, i); 2393 return error; 2394 } 2395 2396 int 2397 check_posix_spawn(struct lwp *l1) 2398 { 2399 int error, tnprocs, count; 2400 uid_t uid; 2401 struct proc *p1; 2402 2403 p1 = l1->l_proc; 2404 uid = kauth_cred_getuid(l1->l_cred); 2405 tnprocs = atomic_inc_uint_nv(&nprocs); 2406 2407 /* 2408 * Although process entries are dynamically created, we still keep 2409 * a global limit on the maximum number we will create. 2410 */ 2411 if (__predict_false(tnprocs >= maxproc)) 2412 error = -1; 2413 else 2414 error = kauth_authorize_process(l1->l_cred, 2415 KAUTH_PROCESS_FORK, p1, KAUTH_ARG(tnprocs), NULL, NULL); 2416 2417 if (error) { 2418 atomic_dec_uint(&nprocs); 2419 return EAGAIN; 2420 } 2421 2422 /* 2423 * Enforce limits. 2424 */ 2425 count = chgproccnt(uid, 1); 2426 if (kauth_authorize_process(l1->l_cred, KAUTH_PROCESS_RLIMIT, 2427 p1, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 2428 &p1->p_rlimit[RLIMIT_NPROC], KAUTH_ARG(RLIMIT_NPROC)) != 0 && 2429 __predict_false(count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) { 2430 (void)chgproccnt(uid, -1); 2431 atomic_dec_uint(&nprocs); 2432 return EAGAIN; 2433 } 2434 2435 return 0; 2436 } 2437 2438 int 2439 do_posix_spawn(struct lwp *l1, pid_t *pid_res, bool *child_ok, const char *path, 2440 struct posix_spawn_file_actions *fa, 2441 struct posix_spawnattr *sa, 2442 char *const *argv, char *const *envp, 2443 execve_fetch_element_t fetch) 2444 { 2445 2446 struct proc *p1, *p2; 2447 struct lwp *l2; 2448 int error; 2449 struct spawn_exec_data *spawn_data; 2450 vaddr_t uaddr; 2451 pid_t pid; 2452 bool have_exec_lock = false; 2453 2454 p1 = l1->l_proc; 2455 2456 /* Allocate and init spawn_data */ 2457 spawn_data = kmem_zalloc(sizeof(*spawn_data), KM_SLEEP); 2458 spawn_data->sed_refcnt = 1; /* only parent so far */ 2459 cv_init(&spawn_data->sed_cv_child_ready, "pspawn"); 2460 mutex_init(&spawn_data->sed_mtx_child, MUTEX_DEFAULT, IPL_NONE); 2461 mutex_enter(&spawn_data->sed_mtx_child); 2462 2463 /* 2464 * Do the first part of the exec now, collect state 2465 * in spawn_data. 2466 */ 2467 error = execve_loadvm(l1, true, path, -1, argv, 2468 envp, fetch, &spawn_data->sed_exec); 2469 if (error == EJUSTRETURN) 2470 error = 0; 2471 else if (error) 2472 goto error_exit; 2473 2474 have_exec_lock = true; 2475 2476 /* 2477 * Allocate virtual address space for the U-area now, while it 2478 * is still easy to abort the fork operation if we're out of 2479 * kernel virtual address space. 2480 */ 2481 uaddr = uvm_uarea_alloc(); 2482 if (__predict_false(uaddr == 0)) { 2483 error = ENOMEM; 2484 goto error_exit; 2485 } 2486 2487 /* 2488 * Allocate new proc. Borrow proc0 vmspace for it, we will 2489 * replace it with its own before returning to userland 2490 * in the child. 2491 * This is a point of no return, we will have to go through 2492 * the child proc to properly clean it up past this point. 2493 */ 2494 p2 = proc_alloc(); 2495 pid = p2->p_pid; 2496 2497 /* 2498 * Make a proc table entry for the new process. 2499 * Start by zeroing the section of proc that is zero-initialized, 2500 * then copy the section that is copied directly from the parent. 2501 */ 2502 memset(&p2->p_startzero, 0, 2503 (unsigned) ((char *)&p2->p_endzero - (char *)&p2->p_startzero)); 2504 memcpy(&p2->p_startcopy, &p1->p_startcopy, 2505 (unsigned) ((char *)&p2->p_endcopy - (char *)&p2->p_startcopy)); 2506 p2->p_vmspace = proc0.p_vmspace; 2507 2508 TAILQ_INIT(&p2->p_sigpend.sp_info); 2509 2510 LIST_INIT(&p2->p_lwps); 2511 LIST_INIT(&p2->p_sigwaiters); 2512 2513 /* 2514 * Duplicate sub-structures as needed. 2515 * Increase reference counts on shared objects. 2516 * Inherit flags we want to keep. The flags related to SIGCHLD 2517 * handling are important in order to keep a consistent behaviour 2518 * for the child after the fork. If we are a 32-bit process, the 2519 * child will be too. 2520 */ 2521 p2->p_flag = 2522 p1->p_flag & (PK_SUGID | PK_NOCLDWAIT | PK_CLDSIGIGN | PK_32); 2523 p2->p_emul = p1->p_emul; 2524 p2->p_execsw = p1->p_execsw; 2525 2526 mutex_init(&p2->p_stmutex, MUTEX_DEFAULT, IPL_HIGH); 2527 mutex_init(&p2->p_auxlock, MUTEX_DEFAULT, IPL_NONE); 2528 rw_init(&p2->p_reflock); 2529 cv_init(&p2->p_waitcv, "wait"); 2530 cv_init(&p2->p_lwpcv, "lwpwait"); 2531 2532 p2->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 2533 2534 kauth_proc_fork(p1, p2); 2535 2536 p2->p_raslist = NULL; 2537 p2->p_fd = fd_copy(); 2538 2539 /* XXX racy */ 2540 p2->p_mqueue_cnt = p1->p_mqueue_cnt; 2541 2542 p2->p_cwdi = cwdinit(); 2543 2544 /* 2545 * Note: p_limit (rlimit stuff) is copy-on-write, so normally 2546 * we just need increase pl_refcnt. 2547 */ 2548 if (!p1->p_limit->pl_writeable) { 2549 lim_addref(p1->p_limit); 2550 p2->p_limit = p1->p_limit; 2551 } else { 2552 p2->p_limit = lim_copy(p1->p_limit); 2553 } 2554 2555 p2->p_lflag = 0; 2556 l1->l_vforkwaiting = false; 2557 p2->p_sflag = 0; 2558 p2->p_slflag = 0; 2559 p2->p_pptr = p1; 2560 p2->p_ppid = p1->p_pid; 2561 LIST_INIT(&p2->p_children); 2562 2563 p2->p_aio = NULL; 2564 2565 #ifdef KTRACE 2566 /* 2567 * Copy traceflag and tracefile if enabled. 2568 * If not inherited, these were zeroed above. 2569 */ 2570 if (p1->p_traceflag & KTRFAC_INHERIT) { 2571 mutex_enter(&ktrace_lock); 2572 p2->p_traceflag = p1->p_traceflag; 2573 if ((p2->p_tracep = p1->p_tracep) != NULL) 2574 ktradref(p2); 2575 mutex_exit(&ktrace_lock); 2576 } 2577 #endif 2578 2579 /* 2580 * Create signal actions for the child process. 2581 */ 2582 p2->p_sigacts = sigactsinit(p1, 0); 2583 mutex_enter(p1->p_lock); 2584 p2->p_sflag |= 2585 (p1->p_sflag & (PS_STOPFORK | PS_STOPEXEC | PS_NOCLDSTOP)); 2586 sched_proc_fork(p1, p2); 2587 mutex_exit(p1->p_lock); 2588 2589 p2->p_stflag = p1->p_stflag; 2590 2591 /* 2592 * p_stats. 2593 * Copy parts of p_stats, and zero out the rest. 2594 */ 2595 p2->p_stats = pstatscopy(p1->p_stats); 2596 2597 /* copy over machdep flags to the new proc */ 2598 cpu_proc_fork(p1, p2); 2599 2600 /* 2601 * Prepare remaining parts of spawn data 2602 */ 2603 spawn_data->sed_actions = fa; 2604 spawn_data->sed_attrs = sa; 2605 2606 spawn_data->sed_parent = p1; 2607 2608 /* create LWP */ 2609 lwp_create(l1, p2, uaddr, 0, NULL, 0, spawn_return, spawn_data, 2610 &l2, l1->l_class, &l1->l_sigmask, &l1->l_sigstk); 2611 l2->l_ctxlink = NULL; /* reset ucontext link */ 2612 2613 /* 2614 * Copy the credential so other references don't see our changes. 2615 * Test to see if this is necessary first, since in the common case 2616 * we won't need a private reference. 2617 */ 2618 if (kauth_cred_geteuid(l2->l_cred) != kauth_cred_getsvuid(l2->l_cred) || 2619 kauth_cred_getegid(l2->l_cred) != kauth_cred_getsvgid(l2->l_cred)) { 2620 l2->l_cred = kauth_cred_copy(l2->l_cred); 2621 kauth_cred_setsvuid(l2->l_cred, kauth_cred_geteuid(l2->l_cred)); 2622 kauth_cred_setsvgid(l2->l_cred, kauth_cred_getegid(l2->l_cred)); 2623 } 2624 2625 /* Update the master credentials. */ 2626 if (l2->l_cred != p2->p_cred) { 2627 kauth_cred_t ocred; 2628 2629 kauth_cred_hold(l2->l_cred); 2630 mutex_enter(p2->p_lock); 2631 ocred = p2->p_cred; 2632 p2->p_cred = l2->l_cred; 2633 mutex_exit(p2->p_lock); 2634 kauth_cred_free(ocred); 2635 } 2636 2637 *child_ok = true; 2638 spawn_data->sed_refcnt = 2; /* child gets it as well */ 2639 #if 0 2640 l2->l_nopreempt = 1; /* start it non-preemptable */ 2641 #endif 2642 2643 /* 2644 * It's now safe for the scheduler and other processes to see the 2645 * child process. 2646 */ 2647 mutex_enter(proc_lock); 2648 2649 if (p1->p_session->s_ttyvp != NULL && p1->p_lflag & PL_CONTROLT) 2650 p2->p_lflag |= PL_CONTROLT; 2651 2652 LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling); 2653 p2->p_exitsig = SIGCHLD; /* signal for parent on exit */ 2654 2655 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) == 2656 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) { 2657 proc_changeparent(p2, p1->p_pptr); 2658 } 2659 2660 LIST_INSERT_AFTER(p1, p2, p_pglist); 2661 LIST_INSERT_HEAD(&allproc, p2, p_list); 2662 2663 p2->p_trace_enabled = trace_is_enabled(p2); 2664 #ifdef __HAVE_SYSCALL_INTERN 2665 (*p2->p_emul->e_syscall_intern)(p2); 2666 #endif 2667 2668 /* 2669 * Make child runnable, set start time, and add to run queue except 2670 * if the parent requested the child to start in SSTOP state. 2671 */ 2672 mutex_enter(p2->p_lock); 2673 2674 getmicrotime(&p2->p_stats->p_start); 2675 2676 lwp_lock(l2); 2677 KASSERT(p2->p_nrlwps == 1); 2678 KASSERT(l2->l_stat == LSIDL); 2679 p2->p_nrlwps = 1; 2680 p2->p_stat = SACTIVE; 2681 setrunnable(l2); 2682 /* LWP now unlocked */ 2683 2684 mutex_exit(p2->p_lock); 2685 mutex_exit(proc_lock); 2686 2687 cv_wait(&spawn_data->sed_cv_child_ready, &spawn_data->sed_mtx_child); 2688 error = spawn_data->sed_error; 2689 mutex_exit(&spawn_data->sed_mtx_child); 2690 spawn_exec_data_release(spawn_data); 2691 2692 rw_exit(&p1->p_reflock); 2693 rw_exit(&exec_lock); 2694 have_exec_lock = false; 2695 2696 *pid_res = pid; 2697 2698 if (error) 2699 return error; 2700 2701 if (p1->p_slflag & PSL_TRACED) { 2702 /* Paranoid check */ 2703 mutex_enter(proc_lock); 2704 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) != 2705 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) { 2706 mutex_exit(proc_lock); 2707 return 0; 2708 } 2709 2710 mutex_enter(p1->p_lock); 2711 eventswitch(TRAP_CHLD, PTRACE_POSIX_SPAWN, pid); 2712 } 2713 return 0; 2714 2715 error_exit: 2716 if (have_exec_lock) { 2717 execve_free_data(&spawn_data->sed_exec); 2718 rw_exit(&p1->p_reflock); 2719 rw_exit(&exec_lock); 2720 } 2721 mutex_exit(&spawn_data->sed_mtx_child); 2722 spawn_exec_data_release(spawn_data); 2723 2724 return error; 2725 } 2726 2727 int 2728 sys_posix_spawn(struct lwp *l1, const struct sys_posix_spawn_args *uap, 2729 register_t *retval) 2730 { 2731 /* { 2732 syscallarg(pid_t *) pid; 2733 syscallarg(const char *) path; 2734 syscallarg(const struct posix_spawn_file_actions *) file_actions; 2735 syscallarg(const struct posix_spawnattr *) attrp; 2736 syscallarg(char *const *) argv; 2737 syscallarg(char *const *) envp; 2738 } */ 2739 2740 int error; 2741 struct posix_spawn_file_actions *fa = NULL; 2742 struct posix_spawnattr *sa = NULL; 2743 pid_t pid; 2744 bool child_ok = false; 2745 rlim_t max_fileactions; 2746 proc_t *p = l1->l_proc; 2747 2748 error = check_posix_spawn(l1); 2749 if (error) { 2750 *retval = error; 2751 return 0; 2752 } 2753 2754 /* copy in file_actions struct */ 2755 if (SCARG(uap, file_actions) != NULL) { 2756 max_fileactions = 2 * uimin(p->p_rlimit[RLIMIT_NOFILE].rlim_cur, 2757 maxfiles); 2758 error = posix_spawn_fa_alloc(&fa, SCARG(uap, file_actions), 2759 max_fileactions); 2760 if (error) 2761 goto error_exit; 2762 } 2763 2764 /* copyin posix_spawnattr struct */ 2765 if (SCARG(uap, attrp) != NULL) { 2766 sa = kmem_alloc(sizeof(*sa), KM_SLEEP); 2767 error = copyin(SCARG(uap, attrp), sa, sizeof(*sa)); 2768 if (error) 2769 goto error_exit; 2770 } 2771 2772 /* 2773 * Do the spawn 2774 */ 2775 error = do_posix_spawn(l1, &pid, &child_ok, SCARG(uap, path), fa, sa, 2776 SCARG(uap, argv), SCARG(uap, envp), execve_fetch_element); 2777 if (error) 2778 goto error_exit; 2779 2780 if (error == 0 && SCARG(uap, pid) != NULL) 2781 error = copyout(&pid, SCARG(uap, pid), sizeof(pid)); 2782 2783 *retval = error; 2784 return 0; 2785 2786 error_exit: 2787 if (!child_ok) { 2788 (void)chgproccnt(kauth_cred_getuid(l1->l_cred), -1); 2789 atomic_dec_uint(&nprocs); 2790 2791 if (sa) 2792 kmem_free(sa, sizeof(*sa)); 2793 if (fa) 2794 posix_spawn_fa_free(fa, fa->len); 2795 } 2796 2797 *retval = error; 2798 return 0; 2799 } 2800 2801 void 2802 exec_free_emul_arg(struct exec_package *epp) 2803 { 2804 if (epp->ep_emul_arg_free != NULL) { 2805 KASSERT(epp->ep_emul_arg != NULL); 2806 (*epp->ep_emul_arg_free)(epp->ep_emul_arg); 2807 epp->ep_emul_arg_free = NULL; 2808 epp->ep_emul_arg = NULL; 2809 } else { 2810 KASSERT(epp->ep_emul_arg == NULL); 2811 } 2812 } 2813 2814 #ifdef DEBUG_EXEC 2815 static void 2816 dump_vmcmds(const struct exec_package * const epp, size_t x, int error) 2817 { 2818 struct exec_vmcmd *vp = &epp->ep_vmcmds.evs_cmds[0]; 2819 size_t j; 2820 2821 if (error == 0) 2822 DPRINTF(("vmcmds %u\n", epp->ep_vmcmds.evs_used)); 2823 else 2824 DPRINTF(("vmcmds %zu/%u, error %d\n", x, 2825 epp->ep_vmcmds.evs_used, error)); 2826 2827 for (j = 0; j < epp->ep_vmcmds.evs_used; j++) { 2828 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#" 2829 PRIxVADDR"/%#"PRIxVSIZE" fd@%#" 2830 PRIxVSIZE" prot=0%o flags=%d\n", j, 2831 vp[j].ev_proc == vmcmd_map_pagedvn ? 2832 "pagedvn" : 2833 vp[j].ev_proc == vmcmd_map_readvn ? 2834 "readvn" : 2835 vp[j].ev_proc == vmcmd_map_zero ? 2836 "zero" : "*unknown*", 2837 vp[j].ev_addr, vp[j].ev_len, 2838 vp[j].ev_offset, vp[j].ev_prot, 2839 vp[j].ev_flags)); 2840 if (error != 0 && j == x) 2841 DPRINTF((" ^--- failed\n")); 2842 } 2843 } 2844 #endif 2845