1 /* $NetBSD: kern_exec.c,v 1.502 2020/10/06 13:38:00 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2008, 2019, 2020 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 1.502 2020/10/06 13:38:00 christos 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 __cacheline_aligned; 250 251 static kmutex_t sigobject_lock __cacheline_aligned; 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 int 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 DPRINTF(("%s: can't resolve name for %s, error %d\n", 332 __func__, epp->ep_kname, error)); 333 PNBUF_PUT(*rpath); 334 *rpath = NULL; 335 return error; 336 } 337 epp->ep_resolvedname = *rpath; 338 if ((p = strrchr(*rpath, '/')) != NULL) 339 epp->ep_kname = p + 1; 340 return 0; 341 } 342 343 344 /* 345 * check exec: 346 * given an "executable" described in the exec package's namei info, 347 * see what we can do with it. 348 * 349 * ON ENTRY: 350 * exec package with appropriate namei info 351 * lwp pointer of exec'ing lwp 352 * NO SELF-LOCKED VNODES 353 * 354 * ON EXIT: 355 * error: nothing held, etc. exec header still allocated. 356 * ok: filled exec package, executable's vnode (unlocked). 357 * 358 * EXEC SWITCH ENTRY: 359 * Locked vnode to check, exec package, proc. 360 * 361 * EXEC SWITCH EXIT: 362 * ok: return 0, filled exec package, executable's vnode (unlocked). 363 * error: destructive: 364 * everything deallocated execept exec header. 365 * non-destructive: 366 * error code, executable's vnode (unlocked), 367 * exec header unmodified. 368 */ 369 int 370 /*ARGSUSED*/ 371 check_exec(struct lwp *l, struct exec_package *epp, struct pathbuf *pb, 372 char **rpath) 373 { 374 int error, i; 375 struct vnode *vp; 376 size_t resid; 377 378 if (epp->ep_resolvedname) { 379 struct nameidata nd; 380 381 // grab the absolute pathbuf here before namei() trashes it. 382 pathbuf_copystring(pb, epp->ep_resolvedname, PATH_MAX); 383 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb); 384 385 /* first get the vnode */ 386 if ((error = namei(&nd)) != 0) 387 return error; 388 389 epp->ep_vp = vp = nd.ni_vp; 390 #ifdef DIAGNOSTIC 391 /* paranoia (take this out once namei stuff stabilizes) */ 392 memset(nd.ni_pnbuf, '~', PATH_MAX); 393 #endif 394 } else { 395 struct file *fp; 396 397 if ((error = fd_getvnode(epp->ep_xfd, &fp)) != 0) 398 return error; 399 epp->ep_vp = vp = fp->f_vnode; 400 vref(vp); 401 fd_putfile(epp->ep_xfd); 402 if ((error = exec_resolvename(l, epp, vp, rpath)) != 0) 403 return error; 404 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 405 } 406 407 /* check access and type */ 408 if (vp->v_type != VREG) { 409 error = EACCES; 410 goto bad1; 411 } 412 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 413 goto bad1; 414 415 /* get attributes */ 416 /* XXX VOP_GETATTR is the only thing that needs LK_EXCLUSIVE here */ 417 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 418 goto bad1; 419 420 /* Check mount point */ 421 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 422 error = EACCES; 423 goto bad1; 424 } 425 if (vp->v_mount->mnt_flag & MNT_NOSUID) 426 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 427 428 /* try to open it */ 429 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 430 goto bad1; 431 432 /* now we have the file, get the exec header */ 433 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 434 UIO_SYSSPACE, IO_NODELOCKED, l->l_cred, &resid, NULL); 435 if (error) 436 goto bad1; 437 438 /* unlock vp, since we need it unlocked from here on out. */ 439 VOP_UNLOCK(vp); 440 441 #if NVERIEXEC > 0 442 error = veriexec_verify(l, vp, 443 epp->ep_resolvedname ? epp->ep_resolvedname : epp->ep_kname, 444 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 445 NULL); 446 if (error) 447 goto bad2; 448 #endif /* NVERIEXEC > 0 */ 449 450 #ifdef PAX_SEGVGUARD 451 error = pax_segvguard(l, vp, epp->ep_resolvedname, false); 452 if (error) 453 goto bad2; 454 #endif /* PAX_SEGVGUARD */ 455 456 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 457 458 /* 459 * Set up default address space limits. Can be overridden 460 * by individual exec packages. 461 */ 462 epp->ep_vm_minaddr = exec_vm_minaddr(VM_MIN_ADDRESS); 463 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 464 465 /* 466 * set up the vmcmds for creation of the process 467 * address space 468 */ 469 error = ENOEXEC; 470 for (i = 0; i < nexecs; i++) { 471 int newerror; 472 473 epp->ep_esch = execsw[i]; 474 newerror = (*execsw[i]->es_makecmds)(l, epp); 475 476 if (!newerror) { 477 /* Seems ok: check that entry point is not too high */ 478 if (epp->ep_entry >= epp->ep_vm_maxaddr) { 479 #ifdef DIAGNOSTIC 480 printf("%s: rejecting %p due to " 481 "too high entry address (>= %p)\n", 482 __func__, (void *)epp->ep_entry, 483 (void *)epp->ep_vm_maxaddr); 484 #endif 485 error = ENOEXEC; 486 break; 487 } 488 /* Seems ok: check that entry point is not too low */ 489 if (epp->ep_entry < epp->ep_vm_minaddr) { 490 #ifdef DIAGNOSTIC 491 printf("%s: rejecting %p due to " 492 "too low entry address (< %p)\n", 493 __func__, (void *)epp->ep_entry, 494 (void *)epp->ep_vm_minaddr); 495 #endif 496 error = ENOEXEC; 497 break; 498 } 499 500 /* check limits */ 501 #ifdef MAXTSIZ 502 if (epp->ep_tsize > MAXTSIZ) { 503 #ifdef DIAGNOSTIC 504 #define LMSG "%s: rejecting due to %s limit (%ju > %ju)\n" 505 printf(LMSG, __func__, "text", 506 (uintmax_t)epp->ep_tsize, 507 (uintmax_t)MAXTSIZ); 508 #endif 509 error = ENOMEM; 510 break; 511 } 512 #endif 513 vsize_t dlimit = 514 (vsize_t)l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur; 515 if (epp->ep_dsize > dlimit) { 516 #ifdef DIAGNOSTIC 517 printf(LMSG, __func__, "data", 518 (uintmax_t)epp->ep_dsize, 519 (uintmax_t)dlimit); 520 #endif 521 error = ENOMEM; 522 break; 523 } 524 return 0; 525 } 526 527 /* 528 * Reset all the fields that may have been modified by the 529 * loader. 530 */ 531 KASSERT(epp->ep_emul_arg == NULL); 532 if (epp->ep_emul_root != NULL) { 533 vrele(epp->ep_emul_root); 534 epp->ep_emul_root = NULL; 535 } 536 if (epp->ep_interp != NULL) { 537 vrele(epp->ep_interp); 538 epp->ep_interp = NULL; 539 } 540 epp->ep_pax_flags = 0; 541 542 /* make sure the first "interesting" error code is saved. */ 543 if (error == ENOEXEC) 544 error = newerror; 545 546 if (epp->ep_flags & EXEC_DESTR) 547 /* Error from "#!" code, tidied up by recursive call */ 548 return error; 549 } 550 551 /* not found, error */ 552 553 /* 554 * free any vmspace-creation commands, 555 * and release their references 556 */ 557 kill_vmcmds(&epp->ep_vmcmds); 558 559 #if NVERIEXEC > 0 || defined(PAX_SEGVGUARD) 560 bad2: 561 #endif 562 /* 563 * close and release the vnode, restore the old one, free the 564 * pathname buf, and punt. 565 */ 566 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 567 VOP_CLOSE(vp, FREAD, l->l_cred); 568 vput(vp); 569 return error; 570 571 bad1: 572 /* 573 * free the namei pathname buffer, and put the vnode 574 * (which we don't yet have open). 575 */ 576 vput(vp); /* was still locked */ 577 return error; 578 } 579 580 #ifdef __MACHINE_STACK_GROWS_UP 581 #define STACK_PTHREADSPACE NBPG 582 #else 583 #define STACK_PTHREADSPACE 0 584 #endif 585 586 static int 587 execve_fetch_element(char * const *array, size_t index, char **value) 588 { 589 return copyin(array + index, value, sizeof(*value)); 590 } 591 592 /* 593 * exec system call 594 */ 595 int 596 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 597 { 598 /* { 599 syscallarg(const char *) path; 600 syscallarg(char * const *) argp; 601 syscallarg(char * const *) envp; 602 } */ 603 604 return execve1(l, true, SCARG(uap, path), -1, SCARG(uap, argp), 605 SCARG(uap, envp), execve_fetch_element); 606 } 607 608 int 609 sys_fexecve(struct lwp *l, const struct sys_fexecve_args *uap, 610 register_t *retval) 611 { 612 /* { 613 syscallarg(int) fd; 614 syscallarg(char * const *) argp; 615 syscallarg(char * const *) envp; 616 } */ 617 618 return execve1(l, false, NULL, SCARG(uap, fd), SCARG(uap, argp), 619 SCARG(uap, envp), execve_fetch_element); 620 } 621 622 /* 623 * Load modules to try and execute an image that we do not understand. 624 * If no execsw entries are present, we load those likely to be needed 625 * in order to run native images only. Otherwise, we autoload all 626 * possible modules that could let us run the binary. XXX lame 627 */ 628 static void 629 exec_autoload(void) 630 { 631 #ifdef MODULAR 632 static const char * const native[] = { 633 "exec_elf32", 634 "exec_elf64", 635 "exec_script", 636 NULL 637 }; 638 static const char * const compat[] = { 639 "exec_elf32", 640 "exec_elf64", 641 "exec_script", 642 "exec_aout", 643 "exec_coff", 644 "exec_ecoff", 645 "compat_aoutm68k", 646 "compat_netbsd32", 647 #if 0 648 "compat_linux", 649 "compat_linux32", 650 #endif 651 "compat_sunos", 652 "compat_sunos32", 653 "compat_ultrix", 654 NULL 655 }; 656 char const * const *list; 657 int i; 658 659 list = nexecs == 0 ? native : compat; 660 for (i = 0; list[i] != NULL; i++) { 661 if (module_autoload(list[i], MODULE_CLASS_EXEC) != 0) { 662 continue; 663 } 664 yield(); 665 } 666 #endif 667 } 668 669 /* 670 * Copy the user or kernel supplied upath to the allocated pathbuffer pbp 671 * making it absolute in the process, by prepending the current working 672 * directory if it is not. If offs is supplied it will contain the offset 673 * where the original supplied copy of upath starts. 674 */ 675 int 676 exec_makepathbuf(struct lwp *l, const char *upath, enum uio_seg seg, 677 struct pathbuf **pbp, size_t *offs) 678 { 679 char *path, *bp; 680 size_t len, tlen; 681 int error; 682 struct cwdinfo *cwdi; 683 684 path = PNBUF_GET(); 685 if (seg == UIO_SYSSPACE) { 686 error = copystr(upath, path, MAXPATHLEN, &len); 687 } else { 688 error = copyinstr(upath, path, MAXPATHLEN, &len); 689 } 690 if (error) 691 goto err; 692 693 if (path[0] == '/') { 694 if (offs) 695 *offs = 0; 696 goto out; 697 } 698 699 len++; 700 if (len + 1 >= MAXPATHLEN) { 701 error = ENAMETOOLONG; 702 goto err; 703 } 704 bp = path + MAXPATHLEN - len; 705 memmove(bp, path, len); 706 *(--bp) = '/'; 707 708 cwdi = l->l_proc->p_cwdi; 709 rw_enter(&cwdi->cwdi_lock, RW_READER); 710 error = getcwd_common(cwdi->cwdi_cdir, NULL, &bp, path, MAXPATHLEN / 2, 711 GETCWD_CHECK_ACCESS, l); 712 rw_exit(&cwdi->cwdi_lock); 713 714 if (error) 715 goto err; 716 tlen = path + MAXPATHLEN - bp; 717 718 memmove(path, bp, tlen); 719 path[tlen - 1] = '\0'; 720 if (offs) 721 *offs = tlen - len; 722 out: 723 *pbp = pathbuf_assimilate(path); 724 return 0; 725 err: 726 PNBUF_PUT(path); 727 return error; 728 } 729 730 vaddr_t 731 exec_vm_minaddr(vaddr_t va_min) 732 { 733 /* 734 * Increase va_min if we don't want NULL to be mappable by the 735 * process. 736 */ 737 #define VM_MIN_GUARD PAGE_SIZE 738 if (user_va0_disable && (va_min < VM_MIN_GUARD)) 739 return VM_MIN_GUARD; 740 return va_min; 741 } 742 743 static int 744 execve_loadvm(struct lwp *l, bool has_path, const char *path, int fd, 745 char * const *args, char * const *envs, 746 execve_fetch_element_t fetch_element, 747 struct execve_data * restrict data) 748 { 749 struct exec_package * const epp = &data->ed_pack; 750 int error; 751 struct proc *p; 752 char *dp; 753 u_int modgen; 754 755 KASSERT(data != NULL); 756 757 p = l->l_proc; 758 modgen = 0; 759 760 SDT_PROBE(proc, kernel, , exec, path, 0, 0, 0, 0); 761 762 /* 763 * Check if we have exceeded our number of processes limit. 764 * This is so that we handle the case where a root daemon 765 * forked, ran setuid to become the desired user and is trying 766 * to exec. The obvious place to do the reference counting check 767 * is setuid(), but we don't do the reference counting check there 768 * like other OS's do because then all the programs that use setuid() 769 * must be modified to check the return code of setuid() and exit(). 770 * It is dangerous to make setuid() fail, because it fails open and 771 * the program will continue to run as root. If we make it succeed 772 * and return an error code, again we are not enforcing the limit. 773 * The best place to enforce the limit is here, when the process tries 774 * to execute a new image, because eventually the process will need 775 * to call exec in order to do something useful. 776 */ 777 retry: 778 if (p->p_flag & PK_SUGID) { 779 if (kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT, 780 p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 781 &p->p_rlimit[RLIMIT_NPROC], 782 KAUTH_ARG(RLIMIT_NPROC)) != 0 && 783 chgproccnt(kauth_cred_getuid(l->l_cred), 0) > 784 p->p_rlimit[RLIMIT_NPROC].rlim_cur) 785 return EAGAIN; 786 } 787 788 /* 789 * Drain existing references and forbid new ones. The process 790 * should be left alone until we're done here. This is necessary 791 * to avoid race conditions - e.g. in ptrace() - that might allow 792 * a local user to illicitly obtain elevated privileges. 793 */ 794 rw_enter(&p->p_reflock, RW_WRITER); 795 796 if (has_path) { 797 size_t offs; 798 /* 799 * Init the namei data to point the file user's program name. 800 * This is done here rather than in check_exec(), so that it's 801 * possible to override this settings if any of makecmd/probe 802 * functions call check_exec() recursively - for example, 803 * see exec_script_makecmds(). 804 */ 805 if ((error = exec_makepathbuf(l, path, UIO_USERSPACE, 806 &data->ed_pathbuf, &offs)) != 0) 807 goto clrflg; 808 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 809 epp->ep_kname = data->ed_pathstring + offs; 810 data->ed_resolvedname = PNBUF_GET(); 811 epp->ep_resolvedname = data->ed_resolvedname; 812 epp->ep_xfd = -1; 813 } else { 814 data->ed_pathbuf = pathbuf_assimilate(strcpy(PNBUF_GET(), "/")); 815 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf); 816 epp->ep_kname = "*fexecve*"; 817 data->ed_resolvedname = NULL; 818 epp->ep_resolvedname = NULL; 819 epp->ep_xfd = fd; 820 } 821 822 823 /* 824 * initialize the fields of the exec package. 825 */ 826 epp->ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 827 epp->ep_hdrlen = exec_maxhdrsz; 828 epp->ep_hdrvalid = 0; 829 epp->ep_emul_arg = NULL; 830 epp->ep_emul_arg_free = NULL; 831 memset(&epp->ep_vmcmds, 0, sizeof(epp->ep_vmcmds)); 832 epp->ep_vap = &data->ed_attr; 833 epp->ep_flags = (p->p_flag & PK_32) ? EXEC_FROM32 : 0; 834 MD_TOPDOWN_INIT(epp); 835 epp->ep_emul_root = NULL; 836 epp->ep_interp = NULL; 837 epp->ep_esch = NULL; 838 epp->ep_pax_flags = 0; 839 memset(epp->ep_machine_arch, 0, sizeof(epp->ep_machine_arch)); 840 841 rw_enter(&exec_lock, RW_READER); 842 843 /* see if we can run it. */ 844 if ((error = check_exec(l, epp, data->ed_pathbuf, 845 &data->ed_resolvedname)) != 0) { 846 if (error != ENOENT && error != EACCES && error != ENOEXEC) { 847 DPRINTF(("%s: check exec failed for %s, error %d\n", 848 __func__, epp->ep_kname, error)); 849 } 850 goto freehdr; 851 } 852 853 /* allocate an argument buffer */ 854 data->ed_argp = pool_get(&exec_pool, PR_WAITOK); 855 KASSERT(data->ed_argp != NULL); 856 dp = data->ed_argp; 857 858 if ((error = copyinargs(data, args, envs, fetch_element, &dp)) != 0) { 859 goto bad; 860 } 861 862 /* 863 * Calculate the new stack size. 864 */ 865 866 #ifdef __MACHINE_STACK_GROWS_UP 867 /* 868 * copyargs() fills argc/argv/envp from the lower address even on 869 * __MACHINE_STACK_GROWS_UP machines. Reserve a few words just below the SP 870 * so that _rtld() use it. 871 */ 872 #define RTLD_GAP 32 873 #else 874 #define RTLD_GAP 0 875 #endif 876 877 const size_t argenvstrlen = (char *)ALIGN(dp) - data->ed_argp; 878 879 data->ed_argslen = calcargs(data, argenvstrlen); 880 881 const size_t len = calcstack(data, pax_aslr_stack_gap(epp) + RTLD_GAP); 882 883 if (len > epp->ep_ssize) { 884 /* in effect, compare to initial limit */ 885 DPRINTF(("%s: stack limit exceeded %zu\n", __func__, len)); 886 error = ENOMEM; 887 goto bad; 888 } 889 /* adjust "active stack depth" for process VSZ */ 890 epp->ep_ssize = len; 891 892 return 0; 893 894 bad: 895 /* free the vmspace-creation commands, and release their references */ 896 kill_vmcmds(&epp->ep_vmcmds); 897 /* kill any opened file descriptor, if necessary */ 898 if (epp->ep_flags & EXEC_HASFD) { 899 epp->ep_flags &= ~EXEC_HASFD; 900 fd_close(epp->ep_fd); 901 } 902 /* close and put the exec'd file */ 903 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 904 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 905 vput(epp->ep_vp); 906 pool_put(&exec_pool, data->ed_argp); 907 908 freehdr: 909 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 910 if (epp->ep_emul_root != NULL) 911 vrele(epp->ep_emul_root); 912 if (epp->ep_interp != NULL) 913 vrele(epp->ep_interp); 914 915 rw_exit(&exec_lock); 916 917 exec_path_free(data); 918 919 clrflg: 920 rw_exit(&p->p_reflock); 921 922 if (modgen != module_gen && error == ENOEXEC) { 923 modgen = module_gen; 924 exec_autoload(); 925 goto retry; 926 } 927 928 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 929 return error; 930 } 931 932 static int 933 execve_dovmcmds(struct lwp *l, struct execve_data * restrict data) 934 { 935 struct exec_package * const epp = &data->ed_pack; 936 struct proc *p = l->l_proc; 937 struct exec_vmcmd *base_vcp; 938 int error = 0; 939 size_t i; 940 941 /* record proc's vnode, for use by procfs and others */ 942 if (p->p_textvp) 943 vrele(p->p_textvp); 944 vref(epp->ep_vp); 945 p->p_textvp = epp->ep_vp; 946 947 /* create the new process's VM space by running the vmcmds */ 948 KASSERTMSG(epp->ep_vmcmds.evs_used != 0, "%s: no vmcmds", __func__); 949 950 #ifdef TRACE_EXEC 951 DUMPVMCMDS(epp, 0, 0); 952 #endif 953 954 base_vcp = NULL; 955 956 for (i = 0; i < epp->ep_vmcmds.evs_used && !error; i++) { 957 struct exec_vmcmd *vcp; 958 959 vcp = &epp->ep_vmcmds.evs_cmds[i]; 960 if (vcp->ev_flags & VMCMD_RELATIVE) { 961 KASSERTMSG(base_vcp != NULL, 962 "%s: relative vmcmd with no base", __func__); 963 KASSERTMSG((vcp->ev_flags & VMCMD_BASE) == 0, 964 "%s: illegal base & relative vmcmd", __func__); 965 vcp->ev_addr += base_vcp->ev_addr; 966 } 967 error = (*vcp->ev_proc)(l, vcp); 968 if (error) 969 DUMPVMCMDS(epp, i, error); 970 if (vcp->ev_flags & VMCMD_BASE) 971 base_vcp = vcp; 972 } 973 974 /* free the vmspace-creation commands, and release their references */ 975 kill_vmcmds(&epp->ep_vmcmds); 976 977 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 978 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred); 979 vput(epp->ep_vp); 980 981 /* if an error happened, deallocate and punt */ 982 if (error != 0) { 983 DPRINTF(("%s: vmcmd %zu failed: %d\n", __func__, i - 1, error)); 984 } 985 return error; 986 } 987 988 static void 989 execve_free_data(struct execve_data *data) 990 { 991 struct exec_package * const epp = &data->ed_pack; 992 993 /* free the vmspace-creation commands, and release their references */ 994 kill_vmcmds(&epp->ep_vmcmds); 995 /* kill any opened file descriptor, if necessary */ 996 if (epp->ep_flags & EXEC_HASFD) { 997 epp->ep_flags &= ~EXEC_HASFD; 998 fd_close(epp->ep_fd); 999 } 1000 1001 /* close and put the exec'd file */ 1002 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY); 1003 VOP_CLOSE(epp->ep_vp, FREAD, curlwp->l_cred); 1004 vput(epp->ep_vp); 1005 pool_put(&exec_pool, data->ed_argp); 1006 1007 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1008 if (epp->ep_emul_root != NULL) 1009 vrele(epp->ep_emul_root); 1010 if (epp->ep_interp != NULL) 1011 vrele(epp->ep_interp); 1012 1013 exec_path_free(data); 1014 } 1015 1016 static void 1017 pathexec(struct proc *p, const char *resolvedname) 1018 { 1019 /* set command name & other accounting info */ 1020 const char *cmdname; 1021 1022 if (resolvedname == NULL) { 1023 cmdname = "*fexecve*"; 1024 resolvedname = "/"; 1025 } else { 1026 cmdname = strrchr(resolvedname, '/') + 1; 1027 } 1028 KASSERTMSG(resolvedname[0] == '/', "bad resolvedname `%s'", 1029 resolvedname); 1030 1031 strlcpy(p->p_comm, cmdname, sizeof(p->p_comm)); 1032 1033 kmem_strfree(p->p_path); 1034 p->p_path = kmem_strdupsize(resolvedname, NULL, KM_SLEEP); 1035 } 1036 1037 /* XXX elsewhere */ 1038 static int 1039 credexec(struct lwp *l, struct vattr *attr) 1040 { 1041 struct proc *p = l->l_proc; 1042 int error; 1043 1044 /* 1045 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 1046 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 1047 * out additional references on the process for the moment. 1048 */ 1049 if ((p->p_slflag & PSL_TRACED) == 0 && 1050 1051 (((attr->va_mode & S_ISUID) != 0 && 1052 kauth_cred_geteuid(l->l_cred) != attr->va_uid) || 1053 1054 ((attr->va_mode & S_ISGID) != 0 && 1055 kauth_cred_getegid(l->l_cred) != attr->va_gid))) { 1056 /* 1057 * Mark the process as SUGID before we do 1058 * anything that might block. 1059 */ 1060 proc_crmod_enter(); 1061 proc_crmod_leave(NULL, NULL, true); 1062 1063 /* Make sure file descriptors 0..2 are in use. */ 1064 if ((error = fd_checkstd()) != 0) { 1065 DPRINTF(("%s: fdcheckstd failed %d\n", 1066 __func__, error)); 1067 return error; 1068 } 1069 1070 /* 1071 * Copy the credential so other references don't see our 1072 * changes. 1073 */ 1074 l->l_cred = kauth_cred_copy(l->l_cred); 1075 #ifdef KTRACE 1076 /* 1077 * If the persistent trace flag isn't set, turn off. 1078 */ 1079 if (p->p_tracep) { 1080 mutex_enter(&ktrace_lock); 1081 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1082 ktrderef(p); 1083 mutex_exit(&ktrace_lock); 1084 } 1085 #endif 1086 if (attr->va_mode & S_ISUID) 1087 kauth_cred_seteuid(l->l_cred, attr->va_uid); 1088 if (attr->va_mode & S_ISGID) 1089 kauth_cred_setegid(l->l_cred, attr->va_gid); 1090 } else { 1091 if (kauth_cred_geteuid(l->l_cred) == 1092 kauth_cred_getuid(l->l_cred) && 1093 kauth_cred_getegid(l->l_cred) == 1094 kauth_cred_getgid(l->l_cred)) 1095 p->p_flag &= ~PK_SUGID; 1096 } 1097 1098 /* 1099 * Copy the credential so other references don't see our changes. 1100 * Test to see if this is necessary first, since in the common case 1101 * we won't need a private reference. 1102 */ 1103 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1104 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1105 l->l_cred = kauth_cred_copy(l->l_cred); 1106 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1107 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1108 } 1109 1110 /* Update the master credentials. */ 1111 if (l->l_cred != p->p_cred) { 1112 kauth_cred_t ocred; 1113 1114 kauth_cred_hold(l->l_cred); 1115 mutex_enter(p->p_lock); 1116 ocred = p->p_cred; 1117 p->p_cred = l->l_cred; 1118 mutex_exit(p->p_lock); 1119 kauth_cred_free(ocred); 1120 } 1121 1122 return 0; 1123 } 1124 1125 static void 1126 emulexec(struct lwp *l, struct exec_package *epp) 1127 { 1128 struct proc *p = l->l_proc; 1129 1130 /* The emulation root will usually have been found when we looked 1131 * for the elf interpreter (or similar), if not look now. */ 1132 if (epp->ep_esch->es_emul->e_path != NULL && 1133 epp->ep_emul_root == NULL) 1134 emul_find_root(l, epp); 1135 1136 /* Any old emulation root got removed by fdcloseexec */ 1137 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1138 p->p_cwdi->cwdi_edir = epp->ep_emul_root; 1139 rw_exit(&p->p_cwdi->cwdi_lock); 1140 epp->ep_emul_root = NULL; 1141 if (epp->ep_interp != NULL) 1142 vrele(epp->ep_interp); 1143 1144 /* 1145 * Call emulation specific exec hook. This can setup per-process 1146 * p->p_emuldata or do any other per-process stuff an emulation needs. 1147 * 1148 * If we are executing process of different emulation than the 1149 * original forked process, call e_proc_exit() of the old emulation 1150 * first, then e_proc_exec() of new emulation. If the emulation is 1151 * same, the exec hook code should deallocate any old emulation 1152 * resources held previously by this process. 1153 */ 1154 if (p->p_emul && p->p_emul->e_proc_exit 1155 && p->p_emul != epp->ep_esch->es_emul) 1156 (*p->p_emul->e_proc_exit)(p); 1157 1158 /* 1159 * Call exec hook. Emulation code may NOT store reference to anything 1160 * from &pack. 1161 */ 1162 if (epp->ep_esch->es_emul->e_proc_exec) 1163 (*epp->ep_esch->es_emul->e_proc_exec)(p, epp); 1164 1165 /* update p_emul, the old value is no longer needed */ 1166 p->p_emul = epp->ep_esch->es_emul; 1167 1168 /* ...and the same for p_execsw */ 1169 p->p_execsw = epp->ep_esch; 1170 1171 #ifdef __HAVE_SYSCALL_INTERN 1172 (*p->p_emul->e_syscall_intern)(p); 1173 #endif 1174 ktremul(); 1175 } 1176 1177 static int 1178 execve_runproc(struct lwp *l, struct execve_data * restrict data, 1179 bool no_local_exec_lock, bool is_spawn) 1180 { 1181 struct exec_package * const epp = &data->ed_pack; 1182 int error = 0; 1183 struct proc *p; 1184 struct vmspace *vm; 1185 1186 /* 1187 * In case of a posix_spawn operation, the child doing the exec 1188 * might not hold the reader lock on exec_lock, but the parent 1189 * will do this instead. 1190 */ 1191 KASSERT(no_local_exec_lock || rw_lock_held(&exec_lock)); 1192 KASSERT(!no_local_exec_lock || is_spawn); 1193 KASSERT(data != NULL); 1194 1195 p = l->l_proc; 1196 1197 /* Get rid of other LWPs. */ 1198 if (p->p_nlwps > 1) { 1199 mutex_enter(p->p_lock); 1200 exit_lwps(l); 1201 mutex_exit(p->p_lock); 1202 } 1203 KDASSERT(p->p_nlwps == 1); 1204 1205 /* Destroy any lwpctl info. */ 1206 if (p->p_lwpctl != NULL) 1207 lwp_ctl_exit(); 1208 1209 /* Remove POSIX timers */ 1210 timers_free(p, TIMERS_POSIX); 1211 1212 /* Set the PaX flags. */ 1213 pax_set_flags(epp, p); 1214 1215 /* 1216 * Do whatever is necessary to prepare the address space 1217 * for remapping. Note that this might replace the current 1218 * vmspace with another! 1219 * 1220 * vfork(): do not touch any user space data in the new child 1221 * until we have awoken the parent below, or it will defeat 1222 * lazy pmap switching (on x86). 1223 */ 1224 if (is_spawn) 1225 uvmspace_spawn(l, epp->ep_vm_minaddr, 1226 epp->ep_vm_maxaddr, 1227 epp->ep_flags & EXEC_TOPDOWN_VM); 1228 else 1229 uvmspace_exec(l, epp->ep_vm_minaddr, 1230 epp->ep_vm_maxaddr, 1231 epp->ep_flags & EXEC_TOPDOWN_VM); 1232 vm = p->p_vmspace; 1233 1234 vm->vm_taddr = (void *)epp->ep_taddr; 1235 vm->vm_tsize = btoc(epp->ep_tsize); 1236 vm->vm_daddr = (void*)epp->ep_daddr; 1237 vm->vm_dsize = btoc(epp->ep_dsize); 1238 vm->vm_ssize = btoc(epp->ep_ssize); 1239 vm->vm_issize = 0; 1240 vm->vm_maxsaddr = (void *)epp->ep_maxsaddr; 1241 vm->vm_minsaddr = (void *)epp->ep_minsaddr; 1242 1243 pax_aslr_init_vm(l, vm, epp); 1244 1245 cwdexec(p); 1246 fd_closeexec(); /* handle close on exec */ 1247 1248 if (__predict_false(ktrace_on)) 1249 fd_ktrexecfd(); 1250 1251 execsigs(p); /* reset caught signals */ 1252 1253 mutex_enter(p->p_lock); 1254 l->l_ctxlink = NULL; /* reset ucontext link */ 1255 p->p_acflag &= ~AFORK; 1256 p->p_flag |= PK_EXEC; 1257 mutex_exit(p->p_lock); 1258 1259 error = credexec(l, &data->ed_attr); 1260 if (error) 1261 goto exec_abort; 1262 1263 #if defined(__HAVE_RAS) 1264 /* 1265 * Remove all RASs from the address space. 1266 */ 1267 ras_purgeall(); 1268 #endif 1269 1270 /* 1271 * Stop profiling. 1272 */ 1273 if ((p->p_stflag & PST_PROFIL) != 0) { 1274 mutex_spin_enter(&p->p_stmutex); 1275 stopprofclock(p); 1276 mutex_spin_exit(&p->p_stmutex); 1277 } 1278 1279 /* 1280 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 1281 * exited and exec()/exit() are the only places it will be cleared. 1282 * 1283 * Once the parent has been awoken, curlwp may teleport to a new CPU 1284 * in sched_vforkexec(), and it's then OK to start messing with user 1285 * data. See comment above. 1286 */ 1287 if ((p->p_lflag & PL_PPWAIT) != 0) { 1288 bool samecpu; 1289 lwp_t *lp; 1290 1291 mutex_enter(&proc_lock); 1292 lp = p->p_vforklwp; 1293 p->p_vforklwp = NULL; 1294 l->l_lwpctl = NULL; /* was on loan from blocked parent */ 1295 cv_broadcast(&lp->l_waitcv); 1296 1297 /* Clear flags after cv_broadcast() (scheduler needs them). */ 1298 p->p_lflag &= ~PL_PPWAIT; 1299 lp->l_vforkwaiting = false; 1300 1301 /* If parent is still on same CPU, teleport curlwp elsewhere. */ 1302 samecpu = (lp->l_cpu == curlwp->l_cpu); 1303 mutex_exit(&proc_lock); 1304 1305 /* Give the parent its CPU back - find a new home. */ 1306 KASSERT(!is_spawn); 1307 sched_vforkexec(l, samecpu); 1308 } 1309 1310 /* Now map address space. */ 1311 error = execve_dovmcmds(l, data); 1312 if (error != 0) 1313 goto exec_abort; 1314 1315 pathexec(p, epp->ep_resolvedname); 1316 1317 char * const newstack = STACK_GROW(vm->vm_minsaddr, epp->ep_ssize); 1318 1319 error = copyoutargs(data, l, newstack); 1320 if (error != 0) 1321 goto exec_abort; 1322 1323 doexechooks(p); 1324 1325 /* 1326 * Set initial SP at the top of the stack. 1327 * 1328 * Note that on machines where stack grows up (e.g. hppa), SP points to 1329 * the end of arg/env strings. Userland guesses the address of argc 1330 * via ps_strings::ps_argvstr. 1331 */ 1332 1333 /* Setup new registers and do misc. setup. */ 1334 (*epp->ep_esch->es_emul->e_setregs)(l, epp, (vaddr_t)newstack); 1335 if (epp->ep_esch->es_setregs) 1336 (*epp->ep_esch->es_setregs)(l, epp, (vaddr_t)newstack); 1337 1338 /* Provide a consistent LWP private setting */ 1339 (void)lwp_setprivate(l, NULL); 1340 1341 /* Discard all PCU state; need to start fresh */ 1342 pcu_discard_all(l); 1343 1344 /* map the process's signal trampoline code */ 1345 if ((error = exec_sigcode_map(p, epp->ep_esch->es_emul)) != 0) { 1346 DPRINTF(("%s: map sigcode failed %d\n", __func__, error)); 1347 goto exec_abort; 1348 } 1349 1350 pool_put(&exec_pool, data->ed_argp); 1351 1352 /* notify others that we exec'd */ 1353 KNOTE(&p->p_klist, NOTE_EXEC); 1354 1355 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1356 1357 SDT_PROBE(proc, kernel, , exec__success, epp->ep_kname, 0, 0, 0, 0); 1358 1359 emulexec(l, epp); 1360 1361 /* Allow new references from the debugger/procfs. */ 1362 rw_exit(&p->p_reflock); 1363 if (!no_local_exec_lock) 1364 rw_exit(&exec_lock); 1365 1366 mutex_enter(&proc_lock); 1367 1368 /* posix_spawn(3) reports a single event with implied exec(3) */ 1369 if ((p->p_slflag & PSL_TRACED) && !is_spawn) { 1370 mutex_enter(p->p_lock); 1371 eventswitch(TRAP_EXEC, 0, 0); 1372 mutex_enter(&proc_lock); 1373 } 1374 1375 if (p->p_sflag & PS_STOPEXEC) { 1376 ksiginfoq_t kq; 1377 1378 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1379 p->p_pptr->p_nstopchild++; 1380 p->p_waited = 0; 1381 mutex_enter(p->p_lock); 1382 ksiginfo_queue_init(&kq); 1383 sigclearall(p, &contsigmask, &kq); 1384 lwp_lock(l); 1385 l->l_stat = LSSTOP; 1386 p->p_stat = SSTOP; 1387 p->p_nrlwps--; 1388 lwp_unlock(l); 1389 mutex_exit(p->p_lock); 1390 mutex_exit(&proc_lock); 1391 lwp_lock(l); 1392 spc_lock(l->l_cpu); 1393 mi_switch(l); 1394 ksiginfo_queue_drain(&kq); 1395 } else { 1396 mutex_exit(&proc_lock); 1397 } 1398 1399 exec_path_free(data); 1400 #ifdef TRACE_EXEC 1401 DPRINTF(("%s finished\n", __func__)); 1402 #endif 1403 return EJUSTRETURN; 1404 1405 exec_abort: 1406 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0); 1407 rw_exit(&p->p_reflock); 1408 if (!no_local_exec_lock) 1409 rw_exit(&exec_lock); 1410 1411 exec_path_free(data); 1412 1413 /* 1414 * the old process doesn't exist anymore. exit gracefully. 1415 * get rid of the (new) address space we have created, if any, get rid 1416 * of our namei data and vnode, and exit noting failure 1417 */ 1418 if (vm != NULL) { 1419 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1420 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1421 } 1422 1423 exec_free_emul_arg(epp); 1424 pool_put(&exec_pool, data->ed_argp); 1425 kmem_free(epp->ep_hdr, epp->ep_hdrlen); 1426 if (epp->ep_emul_root != NULL) 1427 vrele(epp->ep_emul_root); 1428 if (epp->ep_interp != NULL) 1429 vrele(epp->ep_interp); 1430 1431 /* Acquire the sched-state mutex (exit1() will release it). */ 1432 if (!is_spawn) { 1433 mutex_enter(p->p_lock); 1434 exit1(l, error, SIGABRT); 1435 } 1436 1437 return error; 1438 } 1439 1440 int 1441 execve1(struct lwp *l, bool has_path, const char *path, int fd, 1442 char * const *args, char * const *envs, 1443 execve_fetch_element_t fetch_element) 1444 { 1445 struct execve_data data; 1446 int error; 1447 1448 error = execve_loadvm(l, has_path, path, fd, args, envs, fetch_element, 1449 &data); 1450 if (error) 1451 return error; 1452 error = execve_runproc(l, &data, false, false); 1453 return error; 1454 } 1455 1456 static size_t 1457 fromptrsz(const struct exec_package *epp) 1458 { 1459 return (epp->ep_flags & EXEC_FROM32) ? sizeof(int) : sizeof(char *); 1460 } 1461 1462 static size_t 1463 ptrsz(const struct exec_package *epp) 1464 { 1465 return (epp->ep_flags & EXEC_32) ? sizeof(int) : sizeof(char *); 1466 } 1467 1468 static size_t 1469 calcargs(struct execve_data * restrict data, const size_t argenvstrlen) 1470 { 1471 struct exec_package * const epp = &data->ed_pack; 1472 1473 const size_t nargenvptrs = 1474 1 + /* long argc */ 1475 data->ed_argc + /* char *argv[] */ 1476 1 + /* \0 */ 1477 data->ed_envc + /* char *env[] */ 1478 1; /* \0 */ 1479 1480 return (nargenvptrs * ptrsz(epp)) /* pointers */ 1481 + argenvstrlen /* strings */ 1482 + epp->ep_esch->es_arglen; /* auxinfo */ 1483 } 1484 1485 static size_t 1486 calcstack(struct execve_data * restrict data, const size_t gaplen) 1487 { 1488 struct exec_package * const epp = &data->ed_pack; 1489 1490 data->ed_szsigcode = epp->ep_esch->es_emul->e_esigcode - 1491 epp->ep_esch->es_emul->e_sigcode; 1492 1493 data->ed_ps_strings_sz = (epp->ep_flags & EXEC_32) ? 1494 sizeof(struct ps_strings32) : sizeof(struct ps_strings); 1495 1496 const size_t sigcode_psstr_sz = 1497 data->ed_szsigcode + /* sigcode */ 1498 data->ed_ps_strings_sz + /* ps_strings */ 1499 STACK_PTHREADSPACE; /* pthread space */ 1500 1501 const size_t stacklen = 1502 data->ed_argslen + 1503 gaplen + 1504 sigcode_psstr_sz; 1505 1506 /* make the stack "safely" aligned */ 1507 return STACK_LEN_ALIGN(stacklen, STACK_ALIGNBYTES); 1508 } 1509 1510 static int 1511 copyoutargs(struct execve_data * restrict data, struct lwp *l, 1512 char * const newstack) 1513 { 1514 struct exec_package * const epp = &data->ed_pack; 1515 struct proc *p = l->l_proc; 1516 int error; 1517 1518 memset(&data->ed_arginfo, 0, sizeof(data->ed_arginfo)); 1519 1520 /* remember information about the process */ 1521 data->ed_arginfo.ps_nargvstr = data->ed_argc; 1522 data->ed_arginfo.ps_nenvstr = data->ed_envc; 1523 1524 /* 1525 * Allocate the stack address passed to the newly execve()'ed process. 1526 * 1527 * The new stack address will be set to the SP (stack pointer) register 1528 * in setregs(). 1529 */ 1530 1531 char *newargs = STACK_ALLOC( 1532 STACK_SHRINK(newstack, data->ed_argslen), data->ed_argslen); 1533 1534 error = (*epp->ep_esch->es_copyargs)(l, epp, 1535 &data->ed_arginfo, &newargs, data->ed_argp); 1536 1537 if (error) { 1538 DPRINTF(("%s: copyargs failed %d\n", __func__, error)); 1539 return error; 1540 } 1541 1542 error = copyoutpsstrs(data, p); 1543 if (error != 0) 1544 return error; 1545 1546 return 0; 1547 } 1548 1549 static int 1550 copyoutpsstrs(struct execve_data * restrict data, struct proc *p) 1551 { 1552 struct exec_package * const epp = &data->ed_pack; 1553 struct ps_strings32 arginfo32; 1554 void *aip; 1555 int error; 1556 1557 /* fill process ps_strings info */ 1558 p->p_psstrp = (vaddr_t)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr, 1559 STACK_PTHREADSPACE), data->ed_ps_strings_sz); 1560 1561 if (epp->ep_flags & EXEC_32) { 1562 aip = &arginfo32; 1563 arginfo32.ps_argvstr = (vaddr_t)data->ed_arginfo.ps_argvstr; 1564 arginfo32.ps_nargvstr = data->ed_arginfo.ps_nargvstr; 1565 arginfo32.ps_envstr = (vaddr_t)data->ed_arginfo.ps_envstr; 1566 arginfo32.ps_nenvstr = data->ed_arginfo.ps_nenvstr; 1567 } else 1568 aip = &data->ed_arginfo; 1569 1570 /* copy out the process's ps_strings structure */ 1571 if ((error = copyout(aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)) 1572 != 0) { 1573 DPRINTF(("%s: ps_strings copyout %p->%p size %zu failed\n", 1574 __func__, aip, (void *)p->p_psstrp, data->ed_ps_strings_sz)); 1575 return error; 1576 } 1577 1578 return 0; 1579 } 1580 1581 static int 1582 copyinargs(struct execve_data * restrict data, char * const *args, 1583 char * const *envs, execve_fetch_element_t fetch_element, char **dpp) 1584 { 1585 struct exec_package * const epp = &data->ed_pack; 1586 char *dp; 1587 size_t i; 1588 int error; 1589 1590 dp = *dpp; 1591 1592 data->ed_argc = 0; 1593 1594 /* copy the fake args list, if there's one, freeing it as we go */ 1595 if (epp->ep_flags & EXEC_HASARGL) { 1596 struct exec_fakearg *fa = epp->ep_fa; 1597 1598 while (fa->fa_arg != NULL) { 1599 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1600 size_t len; 1601 1602 len = strlcpy(dp, fa->fa_arg, maxlen); 1603 /* Count NUL into len. */ 1604 if (len < maxlen) 1605 len++; 1606 else { 1607 while (fa->fa_arg != NULL) { 1608 kmem_free(fa->fa_arg, fa->fa_len); 1609 fa++; 1610 } 1611 kmem_free(epp->ep_fa, epp->ep_fa_len); 1612 epp->ep_flags &= ~EXEC_HASARGL; 1613 return E2BIG; 1614 } 1615 ktrexecarg(fa->fa_arg, len - 1); 1616 dp += len; 1617 1618 kmem_free(fa->fa_arg, fa->fa_len); 1619 fa++; 1620 data->ed_argc++; 1621 } 1622 kmem_free(epp->ep_fa, epp->ep_fa_len); 1623 epp->ep_flags &= ~EXEC_HASARGL; 1624 } 1625 1626 /* 1627 * Read and count argument strings from user. 1628 */ 1629 1630 if (args == NULL) { 1631 DPRINTF(("%s: null args\n", __func__)); 1632 return EINVAL; 1633 } 1634 if (epp->ep_flags & EXEC_SKIPARG) 1635 args = (const void *)((const char *)args + fromptrsz(epp)); 1636 i = 0; 1637 error = copyinargstrs(data, args, fetch_element, &dp, &i, ktr_execarg); 1638 if (error != 0) { 1639 DPRINTF(("%s: copyin arg %d\n", __func__, error)); 1640 return error; 1641 } 1642 data->ed_argc += i; 1643 1644 /* 1645 * Read and count environment strings from user. 1646 */ 1647 1648 data->ed_envc = 0; 1649 /* environment need not be there */ 1650 if (envs == NULL) 1651 goto done; 1652 i = 0; 1653 error = copyinargstrs(data, envs, fetch_element, &dp, &i, ktr_execenv); 1654 if (error != 0) { 1655 DPRINTF(("%s: copyin env %d\n", __func__, error)); 1656 return error; 1657 } 1658 data->ed_envc += i; 1659 1660 done: 1661 *dpp = dp; 1662 1663 return 0; 1664 } 1665 1666 static int 1667 copyinargstrs(struct execve_data * restrict data, char * const *strs, 1668 execve_fetch_element_t fetch_element, char **dpp, size_t *ip, 1669 void (*ktr)(const void *, size_t)) 1670 { 1671 char *dp, *sp; 1672 size_t i; 1673 int error; 1674 1675 dp = *dpp; 1676 1677 i = 0; 1678 while (1) { 1679 const size_t maxlen = ARG_MAX - (dp - data->ed_argp); 1680 size_t len; 1681 1682 if ((error = (*fetch_element)(strs, i, &sp)) != 0) { 1683 return error; 1684 } 1685 if (!sp) 1686 break; 1687 if ((error = copyinstr(sp, dp, maxlen, &len)) != 0) { 1688 if (error == ENAMETOOLONG) 1689 error = E2BIG; 1690 return error; 1691 } 1692 if (__predict_false(ktrace_on)) 1693 (*ktr)(dp, len - 1); 1694 dp += len; 1695 i++; 1696 } 1697 1698 *dpp = dp; 1699 *ip = i; 1700 1701 return 0; 1702 } 1703 1704 /* 1705 * Copy argv and env strings from kernel buffer (argp) to the new stack. 1706 * Those strings are located just after auxinfo. 1707 */ 1708 int 1709 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1710 char **stackp, void *argp) 1711 { 1712 char **cpp, *dp, *sp; 1713 size_t len; 1714 void *nullp; 1715 long argc, envc; 1716 int error; 1717 1718 cpp = (char **)*stackp; 1719 nullp = NULL; 1720 argc = arginfo->ps_nargvstr; 1721 envc = arginfo->ps_nenvstr; 1722 1723 /* argc on stack is long */ 1724 CTASSERT(sizeof(*cpp) == sizeof(argc)); 1725 1726 dp = (char *)(cpp + 1727 1 + /* long argc */ 1728 argc + /* char *argv[] */ 1729 1 + /* \0 */ 1730 envc + /* char *env[] */ 1731 1) + /* \0 */ 1732 pack->ep_esch->es_arglen; /* auxinfo */ 1733 sp = argp; 1734 1735 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) { 1736 COPYPRINTF("", cpp - 1, sizeof(argc)); 1737 return error; 1738 } 1739 1740 /* XXX don't copy them out, remap them! */ 1741 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1742 1743 for (; --argc >= 0; sp += len, dp += len) { 1744 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1745 COPYPRINTF("", cpp - 1, sizeof(dp)); 1746 return error; 1747 } 1748 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1749 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1750 return error; 1751 } 1752 } 1753 1754 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1755 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1756 return error; 1757 } 1758 1759 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1760 1761 for (; --envc >= 0; sp += len, dp += len) { 1762 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) { 1763 COPYPRINTF("", cpp - 1, sizeof(dp)); 1764 return error; 1765 } 1766 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) { 1767 COPYPRINTF("str", dp, (size_t)ARG_MAX); 1768 return error; 1769 } 1770 1771 } 1772 1773 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) { 1774 COPYPRINTF("", cpp - 1, sizeof(nullp)); 1775 return error; 1776 } 1777 1778 *stackp = (char *)cpp; 1779 return 0; 1780 } 1781 1782 1783 /* 1784 * Add execsw[] entries. 1785 */ 1786 int 1787 exec_add(struct execsw *esp, int count) 1788 { 1789 struct exec_entry *it; 1790 int i; 1791 1792 if (count == 0) { 1793 return 0; 1794 } 1795 1796 /* Check for duplicates. */ 1797 rw_enter(&exec_lock, RW_WRITER); 1798 for (i = 0; i < count; i++) { 1799 LIST_FOREACH(it, &ex_head, ex_list) { 1800 /* assume unique (makecmds, probe_func, emulation) */ 1801 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1802 it->ex_sw->u.elf_probe_func == 1803 esp[i].u.elf_probe_func && 1804 it->ex_sw->es_emul == esp[i].es_emul) { 1805 rw_exit(&exec_lock); 1806 return EEXIST; 1807 } 1808 } 1809 } 1810 1811 /* Allocate new entries. */ 1812 for (i = 0; i < count; i++) { 1813 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1814 it->ex_sw = &esp[i]; 1815 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1816 } 1817 1818 /* update execsw[] */ 1819 exec_init(0); 1820 rw_exit(&exec_lock); 1821 return 0; 1822 } 1823 1824 /* 1825 * Remove execsw[] entry. 1826 */ 1827 int 1828 exec_remove(struct execsw *esp, int count) 1829 { 1830 struct exec_entry *it, *next; 1831 int i; 1832 const struct proclist_desc *pd; 1833 proc_t *p; 1834 1835 if (count == 0) { 1836 return 0; 1837 } 1838 1839 /* Abort if any are busy. */ 1840 rw_enter(&exec_lock, RW_WRITER); 1841 for (i = 0; i < count; i++) { 1842 mutex_enter(&proc_lock); 1843 for (pd = proclists; pd->pd_list != NULL; pd++) { 1844 PROCLIST_FOREACH(p, pd->pd_list) { 1845 if (p->p_execsw == &esp[i]) { 1846 mutex_exit(&proc_lock); 1847 rw_exit(&exec_lock); 1848 return EBUSY; 1849 } 1850 } 1851 } 1852 mutex_exit(&proc_lock); 1853 } 1854 1855 /* None are busy, so remove them all. */ 1856 for (i = 0; i < count; i++) { 1857 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1858 next = LIST_NEXT(it, ex_list); 1859 if (it->ex_sw == &esp[i]) { 1860 LIST_REMOVE(it, ex_list); 1861 kmem_free(it, sizeof(*it)); 1862 break; 1863 } 1864 } 1865 } 1866 1867 /* update execsw[] */ 1868 exec_init(0); 1869 rw_exit(&exec_lock); 1870 return 0; 1871 } 1872 1873 /* 1874 * Initialize exec structures. If init_boot is true, also does necessary 1875 * one-time initialization (it's called from main() that way). 1876 * Once system is multiuser, this should be called with exec_lock held, 1877 * i.e. via exec_{add|remove}(). 1878 */ 1879 int 1880 exec_init(int init_boot) 1881 { 1882 const struct execsw **sw; 1883 struct exec_entry *ex; 1884 SLIST_HEAD(,exec_entry) first; 1885 SLIST_HEAD(,exec_entry) any; 1886 SLIST_HEAD(,exec_entry) last; 1887 int i, sz; 1888 1889 if (init_boot) { 1890 /* do one-time initializations */ 1891 vaddr_t vmin = 0, vmax; 1892 1893 rw_init(&exec_lock); 1894 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1895 exec_map = uvm_km_suballoc(kernel_map, &vmin, &vmax, 1896 maxexec*NCARGS, VM_MAP_PAGEABLE, false, NULL); 1897 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1898 "execargs", &exec_palloc, IPL_NONE); 1899 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1900 } else { 1901 KASSERT(rw_write_held(&exec_lock)); 1902 } 1903 1904 /* Sort each entry onto the appropriate queue. */ 1905 SLIST_INIT(&first); 1906 SLIST_INIT(&any); 1907 SLIST_INIT(&last); 1908 sz = 0; 1909 LIST_FOREACH(ex, &ex_head, ex_list) { 1910 switch(ex->ex_sw->es_prio) { 1911 case EXECSW_PRIO_FIRST: 1912 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1913 break; 1914 case EXECSW_PRIO_ANY: 1915 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1916 break; 1917 case EXECSW_PRIO_LAST: 1918 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1919 break; 1920 default: 1921 panic("%s", __func__); 1922 break; 1923 } 1924 sz++; 1925 } 1926 1927 /* 1928 * Create new execsw[]. Ensure we do not try a zero-sized 1929 * allocation. 1930 */ 1931 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1932 i = 0; 1933 SLIST_FOREACH(ex, &first, ex_slist) { 1934 sw[i++] = ex->ex_sw; 1935 } 1936 SLIST_FOREACH(ex, &any, ex_slist) { 1937 sw[i++] = ex->ex_sw; 1938 } 1939 SLIST_FOREACH(ex, &last, ex_slist) { 1940 sw[i++] = ex->ex_sw; 1941 } 1942 1943 /* Replace old execsw[] and free used memory. */ 1944 if (execsw != NULL) { 1945 kmem_free(__UNCONST(execsw), 1946 nexecs * sizeof(struct execsw *) + 1); 1947 } 1948 execsw = sw; 1949 nexecs = sz; 1950 1951 /* Figure out the maximum size of an exec header. */ 1952 exec_maxhdrsz = sizeof(int); 1953 for (i = 0; i < nexecs; i++) { 1954 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1955 exec_maxhdrsz = execsw[i]->es_hdrsz; 1956 } 1957 1958 return 0; 1959 } 1960 1961 static int 1962 exec_sigcode_map(struct proc *p, const struct emul *e) 1963 { 1964 vaddr_t va; 1965 vsize_t sz; 1966 int error; 1967 struct uvm_object *uobj; 1968 1969 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1970 1971 if (e->e_sigobject == NULL || sz == 0) { 1972 return 0; 1973 } 1974 1975 /* 1976 * If we don't have a sigobject for this emulation, create one. 1977 * 1978 * sigobject is an anonymous memory object (just like SYSV shared 1979 * memory) that we keep a permanent reference to and that we map 1980 * in all processes that need this sigcode. The creation is simple, 1981 * we create an object, add a permanent reference to it, map it in 1982 * kernel space, copy out the sigcode to it and unmap it. 1983 * We map it with PROT_READ|PROT_EXEC into the process just 1984 * the way sys_mmap() would map it. 1985 */ 1986 1987 uobj = *e->e_sigobject; 1988 if (uobj == NULL) { 1989 mutex_enter(&sigobject_lock); 1990 if ((uobj = *e->e_sigobject) == NULL) { 1991 uobj = uao_create(sz, 0); 1992 (*uobj->pgops->pgo_reference)(uobj); 1993 va = vm_map_min(kernel_map); 1994 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1995 uobj, 0, 0, 1996 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1997 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1998 printf("kernel mapping failed %d\n", error); 1999 (*uobj->pgops->pgo_detach)(uobj); 2000 mutex_exit(&sigobject_lock); 2001 return error; 2002 } 2003 memcpy((void *)va, e->e_sigcode, sz); 2004 #ifdef PMAP_NEED_PROCWR 2005 pmap_procwr(&proc0, va, sz); 2006 #endif 2007 uvm_unmap(kernel_map, va, va + round_page(sz)); 2008 *e->e_sigobject = uobj; 2009 } 2010 mutex_exit(&sigobject_lock); 2011 } 2012 2013 /* Just a hint to uvm_map where to put it. */ 2014 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 2015 round_page(sz), p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN); 2016 2017 #ifdef __alpha__ 2018 /* 2019 * Tru64 puts /sbin/loader at the end of user virtual memory, 2020 * which causes the above calculation to put the sigcode at 2021 * an invalid address. Put it just below the text instead. 2022 */ 2023 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 2024 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 2025 } 2026 #endif 2027 2028 (*uobj->pgops->pgo_reference)(uobj); 2029 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 2030 uobj, 0, 0, 2031 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 2032 UVM_ADV_RANDOM, 0)); 2033 if (error) { 2034 DPRINTF(("%s, %d: map %p " 2035 "uvm_map %#"PRIxVSIZE"@%#"PRIxVADDR" failed %d\n", 2036 __func__, __LINE__, &p->p_vmspace->vm_map, round_page(sz), 2037 va, error)); 2038 (*uobj->pgops->pgo_detach)(uobj); 2039 return error; 2040 } 2041 p->p_sigctx.ps_sigcode = (void *)va; 2042 return 0; 2043 } 2044 2045 /* 2046 * Release a refcount on spawn_exec_data and destroy memory, if this 2047 * was the last one. 2048 */ 2049 static void 2050 spawn_exec_data_release(struct spawn_exec_data *data) 2051 { 2052 if (atomic_dec_32_nv(&data->sed_refcnt) != 0) 2053 return; 2054 2055 cv_destroy(&data->sed_cv_child_ready); 2056 mutex_destroy(&data->sed_mtx_child); 2057 2058 if (data->sed_actions) 2059 posix_spawn_fa_free(data->sed_actions, 2060 data->sed_actions->len); 2061 if (data->sed_attrs) 2062 kmem_free(data->sed_attrs, 2063 sizeof(*data->sed_attrs)); 2064 kmem_free(data, sizeof(*data)); 2065 } 2066 2067 static int 2068 handle_posix_spawn_file_actions(struct posix_spawn_file_actions *actions) 2069 { 2070 struct lwp *l = curlwp; 2071 register_t retval; 2072 int error, newfd; 2073 2074 if (actions == NULL) 2075 return 0; 2076 2077 for (size_t i = 0; i < actions->len; i++) { 2078 const struct posix_spawn_file_actions_entry *fae = 2079 &actions->fae[i]; 2080 switch (fae->fae_action) { 2081 case FAE_OPEN: 2082 if (fd_getfile(fae->fae_fildes) != NULL) { 2083 error = fd_close(fae->fae_fildes); 2084 if (error) 2085 return error; 2086 } 2087 error = fd_open(fae->fae_path, fae->fae_oflag, 2088 fae->fae_mode, &newfd); 2089 if (error) 2090 return error; 2091 if (newfd != fae->fae_fildes) { 2092 error = dodup(l, newfd, 2093 fae->fae_fildes, 0, &retval); 2094 if (fd_getfile(newfd) != NULL) 2095 fd_close(newfd); 2096 } 2097 break; 2098 case FAE_DUP2: 2099 error = dodup(l, fae->fae_fildes, 2100 fae->fae_newfildes, 0, &retval); 2101 break; 2102 case FAE_CLOSE: 2103 if (fd_getfile(fae->fae_fildes) == NULL) { 2104 return EBADF; 2105 } 2106 error = fd_close(fae->fae_fildes); 2107 break; 2108 } 2109 if (error) 2110 return error; 2111 } 2112 return 0; 2113 } 2114 2115 static int 2116 handle_posix_spawn_attrs(struct posix_spawnattr *attrs, struct proc *parent) 2117 { 2118 struct sigaction sigact; 2119 int error; 2120 struct proc *p = curproc; 2121 struct lwp *l = curlwp; 2122 2123 if (attrs == NULL) 2124 return 0; 2125 2126 memset(&sigact, 0, sizeof(sigact)); 2127 sigact._sa_u._sa_handler = SIG_DFL; 2128 sigact.sa_flags = 0; 2129 2130 /* 2131 * set state to SSTOP so that this proc can be found by pid. 2132 * see proc_enterprp, do_sched_setparam below 2133 */ 2134 mutex_enter(&proc_lock); 2135 /* 2136 * p_stat should be SACTIVE, so we need to adjust the 2137 * parent's p_nstopchild here. For safety, just make 2138 * we're on the good side of SDEAD before we adjust. 2139 */ 2140 int ostat = p->p_stat; 2141 KASSERT(ostat < SSTOP); 2142 p->p_stat = SSTOP; 2143 p->p_waited = 0; 2144 p->p_pptr->p_nstopchild++; 2145 mutex_exit(&proc_lock); 2146 2147 /* Set process group */ 2148 if (attrs->sa_flags & POSIX_SPAWN_SETPGROUP) { 2149 pid_t mypid = p->p_pid; 2150 pid_t pgrp = attrs->sa_pgroup; 2151 2152 if (pgrp == 0) 2153 pgrp = mypid; 2154 2155 error = proc_enterpgrp(parent, mypid, pgrp, false); 2156 if (error) 2157 goto out; 2158 } 2159 2160 /* Set scheduler policy */ 2161 if (attrs->sa_flags & POSIX_SPAWN_SETSCHEDULER) 2162 error = do_sched_setparam(p->p_pid, 0, attrs->sa_schedpolicy, 2163 &attrs->sa_schedparam); 2164 else if (attrs->sa_flags & POSIX_SPAWN_SETSCHEDPARAM) { 2165 error = do_sched_setparam(parent->p_pid, 0, 2166 SCHED_NONE, &attrs->sa_schedparam); 2167 } 2168 if (error) 2169 goto out; 2170 2171 /* Reset user ID's */ 2172 if (attrs->sa_flags & POSIX_SPAWN_RESETIDS) { 2173 error = do_setresuid(l, -1, kauth_cred_getgid(l->l_cred), -1, 2174 ID_E_EQ_R | ID_E_EQ_S); 2175 if (error) 2176 return error; 2177 error = do_setresuid(l, -1, kauth_cred_getuid(l->l_cred), -1, 2178 ID_E_EQ_R | ID_E_EQ_S); 2179 if (error) 2180 goto out; 2181 } 2182 2183 /* Set signal masks/defaults */ 2184 if (attrs->sa_flags & POSIX_SPAWN_SETSIGMASK) { 2185 mutex_enter(p->p_lock); 2186 error = sigprocmask1(l, SIG_SETMASK, &attrs->sa_sigmask, NULL); 2187 mutex_exit(p->p_lock); 2188 if (error) 2189 goto out; 2190 } 2191 2192 if (attrs->sa_flags & POSIX_SPAWN_SETSIGDEF) { 2193 /* 2194 * The following sigaction call is using a sigaction 2195 * version 0 trampoline which is in the compatibility 2196 * code only. This is not a problem because for SIG_DFL 2197 * and SIG_IGN, the trampolines are now ignored. If they 2198 * were not, this would be a problem because we are 2199 * holding the exec_lock, and the compat code needs 2200 * to do the same in order to replace the trampoline 2201 * code of the process. 2202 */ 2203 for (int i = 1; i <= NSIG; i++) { 2204 if (sigismember(&attrs->sa_sigdefault, i)) 2205 sigaction1(l, i, &sigact, NULL, NULL, 0); 2206 } 2207 } 2208 error = 0; 2209 out: 2210 mutex_enter(&proc_lock); 2211 p->p_stat = ostat; 2212 p->p_pptr->p_nstopchild--; 2213 mutex_exit(&proc_lock); 2214 return error; 2215 } 2216 2217 /* 2218 * A child lwp of a posix_spawn operation starts here and ends up in 2219 * cpu_spawn_return, dealing with all filedescriptor and scheduler 2220 * manipulations in between. 2221 * The parent waits for the child, as it is not clear whether the child 2222 * will be able to acquire its own exec_lock. If it can, the parent can 2223 * be released early and continue running in parallel. If not (or if the 2224 * magic debug flag is passed in the scheduler attribute struct), the 2225 * child rides on the parent's exec lock until it is ready to return to 2226 * to userland - and only then releases the parent. This method loses 2227 * concurrency, but improves error reporting. 2228 */ 2229 static void 2230 spawn_return(void *arg) 2231 { 2232 struct spawn_exec_data *spawn_data = arg; 2233 struct lwp *l = curlwp; 2234 struct proc *p = l->l_proc; 2235 int error; 2236 bool have_reflock; 2237 bool parent_is_waiting = true; 2238 2239 /* 2240 * Check if we can release parent early. 2241 * We either need to have no sed_attrs, or sed_attrs does not 2242 * have POSIX_SPAWN_RETURNERROR or one of the flags, that require 2243 * safe access to the parent proc (passed in sed_parent). 2244 * We then try to get the exec_lock, and only if that works, we can 2245 * release the parent here already. 2246 */ 2247 struct posix_spawnattr *attrs = spawn_data->sed_attrs; 2248 if ((!attrs || (attrs->sa_flags 2249 & (POSIX_SPAWN_RETURNERROR|POSIX_SPAWN_SETPGROUP)) == 0) 2250 && rw_tryenter(&exec_lock, RW_READER)) { 2251 parent_is_waiting = false; 2252 mutex_enter(&spawn_data->sed_mtx_child); 2253 cv_signal(&spawn_data->sed_cv_child_ready); 2254 mutex_exit(&spawn_data->sed_mtx_child); 2255 } 2256 2257 /* don't allow debugger access yet */ 2258 rw_enter(&p->p_reflock, RW_WRITER); 2259 have_reflock = true; 2260 2261 /* handle posix_spawn_file_actions */ 2262 error = handle_posix_spawn_file_actions(spawn_data->sed_actions); 2263 if (error) 2264 goto report_error; 2265 2266 /* handle posix_spawnattr */ 2267 error = handle_posix_spawn_attrs(attrs, spawn_data->sed_parent); 2268 if (error) 2269 goto report_error; 2270 2271 /* now do the real exec */ 2272 error = execve_runproc(l, &spawn_data->sed_exec, parent_is_waiting, 2273 true); 2274 have_reflock = false; 2275 if (error == EJUSTRETURN) 2276 error = 0; 2277 else if (error) 2278 goto report_error; 2279 2280 if (parent_is_waiting) { 2281 mutex_enter(&spawn_data->sed_mtx_child); 2282 cv_signal(&spawn_data->sed_cv_child_ready); 2283 mutex_exit(&spawn_data->sed_mtx_child); 2284 } 2285 2286 /* release our refcount on the data */ 2287 spawn_exec_data_release(spawn_data); 2288 2289 if ((p->p_slflag & (PSL_TRACED|PSL_TRACEDCHILD)) == 2290 (PSL_TRACED|PSL_TRACEDCHILD)) { 2291 eventswitchchild(p, TRAP_CHLD, PTRACE_POSIX_SPAWN); 2292 } 2293 2294 /* and finally: leave to userland for the first time */ 2295 cpu_spawn_return(l); 2296 2297 /* NOTREACHED */ 2298 return; 2299 2300 report_error: 2301 if (have_reflock) { 2302 /* 2303 * We have not passed through execve_runproc(), 2304 * which would have released the p_reflock and also 2305 * taken ownership of the sed_exec part of spawn_data, 2306 * so release/free both here. 2307 */ 2308 rw_exit(&p->p_reflock); 2309 execve_free_data(&spawn_data->sed_exec); 2310 } 2311 2312 if (parent_is_waiting) { 2313 /* pass error to parent */ 2314 mutex_enter(&spawn_data->sed_mtx_child); 2315 spawn_data->sed_error = error; 2316 cv_signal(&spawn_data->sed_cv_child_ready); 2317 mutex_exit(&spawn_data->sed_mtx_child); 2318 } else { 2319 rw_exit(&exec_lock); 2320 } 2321 2322 /* release our refcount on the data */ 2323 spawn_exec_data_release(spawn_data); 2324 2325 /* done, exit */ 2326 mutex_enter(p->p_lock); 2327 /* 2328 * Posix explicitly asks for an exit code of 127 if we report 2329 * errors from the child process - so, unfortunately, there 2330 * is no way to report a more exact error code. 2331 * A NetBSD specific workaround is POSIX_SPAWN_RETURNERROR as 2332 * flag bit in the attrp argument to posix_spawn(2), see above. 2333 */ 2334 exit1(l, 127, 0); 2335 } 2336 2337 void 2338 posix_spawn_fa_free(struct posix_spawn_file_actions *fa, size_t len) 2339 { 2340 2341 for (size_t i = 0; i < len; i++) { 2342 struct posix_spawn_file_actions_entry *fae = &fa->fae[i]; 2343 if (fae->fae_action != FAE_OPEN) 2344 continue; 2345 kmem_strfree(fae->fae_path); 2346 } 2347 if (fa->len > 0) 2348 kmem_free(fa->fae, sizeof(*fa->fae) * fa->len); 2349 kmem_free(fa, sizeof(*fa)); 2350 } 2351 2352 static int 2353 posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap, 2354 const struct posix_spawn_file_actions *ufa, rlim_t lim) 2355 { 2356 struct posix_spawn_file_actions *fa; 2357 struct posix_spawn_file_actions_entry *fae; 2358 char *pbuf = NULL; 2359 int error; 2360 size_t i = 0; 2361 2362 fa = kmem_alloc(sizeof(*fa), KM_SLEEP); 2363 error = copyin(ufa, fa, sizeof(*fa)); 2364 if (error || fa->len == 0) { 2365 kmem_free(fa, sizeof(*fa)); 2366 return error; /* 0 if not an error, and len == 0 */ 2367 } 2368 2369 if (fa->len > lim) { 2370 kmem_free(fa, sizeof(*fa)); 2371 return EINVAL; 2372 } 2373 2374 fa->size = fa->len; 2375 size_t fal = fa->len * sizeof(*fae); 2376 fae = fa->fae; 2377 fa->fae = kmem_alloc(fal, KM_SLEEP); 2378 error = copyin(fae, fa->fae, fal); 2379 if (error) 2380 goto out; 2381 2382 pbuf = PNBUF_GET(); 2383 for (; i < fa->len; i++) { 2384 fae = &fa->fae[i]; 2385 if (fae->fae_action != FAE_OPEN) 2386 continue; 2387 error = copyinstr(fae->fae_path, pbuf, MAXPATHLEN, &fal); 2388 if (error) 2389 goto out; 2390 fae->fae_path = kmem_alloc(fal, KM_SLEEP); 2391 memcpy(fae->fae_path, pbuf, fal); 2392 } 2393 PNBUF_PUT(pbuf); 2394 2395 *fap = fa; 2396 return 0; 2397 out: 2398 if (pbuf) 2399 PNBUF_PUT(pbuf); 2400 posix_spawn_fa_free(fa, i); 2401 return error; 2402 } 2403 2404 /* 2405 * N.B. increments nprocs upon success. Callers need to drop nprocs if 2406 * they fail for some other reason. 2407 */ 2408 int 2409 check_posix_spawn(struct lwp *l1) 2410 { 2411 int error, tnprocs, count; 2412 uid_t uid; 2413 struct proc *p1; 2414 2415 p1 = l1->l_proc; 2416 uid = kauth_cred_getuid(l1->l_cred); 2417 tnprocs = atomic_inc_uint_nv(&nprocs); 2418 2419 /* 2420 * Although process entries are dynamically created, we still keep 2421 * a global limit on the maximum number we will create. 2422 */ 2423 if (__predict_false(tnprocs >= maxproc)) 2424 error = -1; 2425 else 2426 error = kauth_authorize_process(l1->l_cred, 2427 KAUTH_PROCESS_FORK, p1, KAUTH_ARG(tnprocs), NULL, NULL); 2428 2429 if (error) { 2430 atomic_dec_uint(&nprocs); 2431 return EAGAIN; 2432 } 2433 2434 /* 2435 * Enforce limits. 2436 */ 2437 count = chgproccnt(uid, 1); 2438 if (kauth_authorize_process(l1->l_cred, KAUTH_PROCESS_RLIMIT, 2439 p1, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS), 2440 &p1->p_rlimit[RLIMIT_NPROC], KAUTH_ARG(RLIMIT_NPROC)) != 0 && 2441 __predict_false(count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) { 2442 (void)chgproccnt(uid, -1); 2443 atomic_dec_uint(&nprocs); 2444 return EAGAIN; 2445 } 2446 2447 return 0; 2448 } 2449 2450 int 2451 do_posix_spawn(struct lwp *l1, pid_t *pid_res, bool *child_ok, const char *path, 2452 struct posix_spawn_file_actions *fa, 2453 struct posix_spawnattr *sa, 2454 char *const *argv, char *const *envp, 2455 execve_fetch_element_t fetch) 2456 { 2457 2458 struct proc *p1, *p2; 2459 struct lwp *l2; 2460 int error; 2461 struct spawn_exec_data *spawn_data; 2462 vaddr_t uaddr; 2463 pid_t pid; 2464 bool have_exec_lock = false; 2465 2466 p1 = l1->l_proc; 2467 2468 /* Allocate and init spawn_data */ 2469 spawn_data = kmem_zalloc(sizeof(*spawn_data), KM_SLEEP); 2470 spawn_data->sed_refcnt = 1; /* only parent so far */ 2471 cv_init(&spawn_data->sed_cv_child_ready, "pspawn"); 2472 mutex_init(&spawn_data->sed_mtx_child, MUTEX_DEFAULT, IPL_NONE); 2473 mutex_enter(&spawn_data->sed_mtx_child); 2474 2475 /* 2476 * Do the first part of the exec now, collect state 2477 * in spawn_data. 2478 */ 2479 error = execve_loadvm(l1, true, path, -1, argv, 2480 envp, fetch, &spawn_data->sed_exec); 2481 if (error == EJUSTRETURN) 2482 error = 0; 2483 else if (error) 2484 goto error_exit; 2485 2486 have_exec_lock = true; 2487 2488 /* 2489 * Allocate virtual address space for the U-area now, while it 2490 * is still easy to abort the fork operation if we're out of 2491 * kernel virtual address space. 2492 */ 2493 uaddr = uvm_uarea_alloc(); 2494 if (__predict_false(uaddr == 0)) { 2495 error = ENOMEM; 2496 goto error_exit; 2497 } 2498 2499 /* 2500 * Allocate new proc. Borrow proc0 vmspace for it, we will 2501 * replace it with its own before returning to userland 2502 * in the child. 2503 */ 2504 p2 = proc_alloc(); 2505 if (p2 == NULL) { 2506 /* We were unable to allocate a process ID. */ 2507 error = EAGAIN; 2508 goto error_exit; 2509 } 2510 2511 /* 2512 * This is a point of no return, we will have to go through 2513 * the child proc to properly clean it up past this point. 2514 */ 2515 pid = p2->p_pid; 2516 2517 /* 2518 * Make a proc table entry for the new process. 2519 * Start by zeroing the section of proc that is zero-initialized, 2520 * then copy the section that is copied directly from the parent. 2521 */ 2522 memset(&p2->p_startzero, 0, 2523 (unsigned) ((char *)&p2->p_endzero - (char *)&p2->p_startzero)); 2524 memcpy(&p2->p_startcopy, &p1->p_startcopy, 2525 (unsigned) ((char *)&p2->p_endcopy - (char *)&p2->p_startcopy)); 2526 p2->p_vmspace = proc0.p_vmspace; 2527 2528 TAILQ_INIT(&p2->p_sigpend.sp_info); 2529 2530 LIST_INIT(&p2->p_lwps); 2531 LIST_INIT(&p2->p_sigwaiters); 2532 2533 /* 2534 * Duplicate sub-structures as needed. 2535 * Increase reference counts on shared objects. 2536 * Inherit flags we want to keep. The flags related to SIGCHLD 2537 * handling are important in order to keep a consistent behaviour 2538 * for the child after the fork. If we are a 32-bit process, the 2539 * child will be too. 2540 */ 2541 p2->p_flag = 2542 p1->p_flag & (PK_SUGID | PK_NOCLDWAIT | PK_CLDSIGIGN | PK_32); 2543 p2->p_emul = p1->p_emul; 2544 p2->p_execsw = p1->p_execsw; 2545 2546 mutex_init(&p2->p_stmutex, MUTEX_DEFAULT, IPL_HIGH); 2547 mutex_init(&p2->p_auxlock, MUTEX_DEFAULT, IPL_NONE); 2548 rw_init(&p2->p_reflock); 2549 cv_init(&p2->p_waitcv, "wait"); 2550 cv_init(&p2->p_lwpcv, "lwpwait"); 2551 2552 p2->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 2553 2554 kauth_proc_fork(p1, p2); 2555 2556 p2->p_raslist = NULL; 2557 p2->p_fd = fd_copy(); 2558 2559 /* XXX racy */ 2560 p2->p_mqueue_cnt = p1->p_mqueue_cnt; 2561 2562 p2->p_cwdi = cwdinit(); 2563 2564 /* 2565 * Note: p_limit (rlimit stuff) is copy-on-write, so normally 2566 * we just need increase pl_refcnt. 2567 */ 2568 if (!p1->p_limit->pl_writeable) { 2569 lim_addref(p1->p_limit); 2570 p2->p_limit = p1->p_limit; 2571 } else { 2572 p2->p_limit = lim_copy(p1->p_limit); 2573 } 2574 2575 p2->p_lflag = 0; 2576 l1->l_vforkwaiting = false; 2577 p2->p_sflag = 0; 2578 p2->p_slflag = 0; 2579 p2->p_pptr = p1; 2580 p2->p_ppid = p1->p_pid; 2581 LIST_INIT(&p2->p_children); 2582 2583 p2->p_aio = NULL; 2584 2585 #ifdef KTRACE 2586 /* 2587 * Copy traceflag and tracefile if enabled. 2588 * If not inherited, these were zeroed above. 2589 */ 2590 if (p1->p_traceflag & KTRFAC_INHERIT) { 2591 mutex_enter(&ktrace_lock); 2592 p2->p_traceflag = p1->p_traceflag; 2593 if ((p2->p_tracep = p1->p_tracep) != NULL) 2594 ktradref(p2); 2595 mutex_exit(&ktrace_lock); 2596 } 2597 #endif 2598 2599 /* 2600 * Create signal actions for the child process. 2601 */ 2602 p2->p_sigacts = sigactsinit(p1, 0); 2603 mutex_enter(p1->p_lock); 2604 p2->p_sflag |= 2605 (p1->p_sflag & (PS_STOPFORK | PS_STOPEXEC | PS_NOCLDSTOP)); 2606 sched_proc_fork(p1, p2); 2607 mutex_exit(p1->p_lock); 2608 2609 p2->p_stflag = p1->p_stflag; 2610 2611 /* 2612 * p_stats. 2613 * Copy parts of p_stats, and zero out the rest. 2614 */ 2615 p2->p_stats = pstatscopy(p1->p_stats); 2616 2617 /* copy over machdep flags to the new proc */ 2618 cpu_proc_fork(p1, p2); 2619 2620 /* 2621 * Prepare remaining parts of spawn data 2622 */ 2623 spawn_data->sed_actions = fa; 2624 spawn_data->sed_attrs = sa; 2625 2626 spawn_data->sed_parent = p1; 2627 2628 /* create LWP */ 2629 lwp_create(l1, p2, uaddr, 0, NULL, 0, spawn_return, spawn_data, 2630 &l2, l1->l_class, &l1->l_sigmask, &l1->l_sigstk); 2631 l2->l_ctxlink = NULL; /* reset ucontext link */ 2632 2633 /* 2634 * Copy the credential so other references don't see our changes. 2635 * Test to see if this is necessary first, since in the common case 2636 * we won't need a private reference. 2637 */ 2638 if (kauth_cred_geteuid(l2->l_cred) != kauth_cred_getsvuid(l2->l_cred) || 2639 kauth_cred_getegid(l2->l_cred) != kauth_cred_getsvgid(l2->l_cred)) { 2640 l2->l_cred = kauth_cred_copy(l2->l_cred); 2641 kauth_cred_setsvuid(l2->l_cred, kauth_cred_geteuid(l2->l_cred)); 2642 kauth_cred_setsvgid(l2->l_cred, kauth_cred_getegid(l2->l_cred)); 2643 } 2644 2645 /* Update the master credentials. */ 2646 if (l2->l_cred != p2->p_cred) { 2647 kauth_cred_t ocred; 2648 2649 kauth_cred_hold(l2->l_cred); 2650 mutex_enter(p2->p_lock); 2651 ocred = p2->p_cred; 2652 p2->p_cred = l2->l_cred; 2653 mutex_exit(p2->p_lock); 2654 kauth_cred_free(ocred); 2655 } 2656 2657 *child_ok = true; 2658 spawn_data->sed_refcnt = 2; /* child gets it as well */ 2659 #if 0 2660 l2->l_nopreempt = 1; /* start it non-preemptable */ 2661 #endif 2662 2663 /* 2664 * It's now safe for the scheduler and other processes to see the 2665 * child process. 2666 */ 2667 mutex_enter(&proc_lock); 2668 2669 if (p1->p_session->s_ttyvp != NULL && p1->p_lflag & PL_CONTROLT) 2670 p2->p_lflag |= PL_CONTROLT; 2671 2672 LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling); 2673 p2->p_exitsig = SIGCHLD; /* signal for parent on exit */ 2674 2675 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) == 2676 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) { 2677 proc_changeparent(p2, p1->p_pptr); 2678 SET(p2->p_slflag, PSL_TRACEDCHILD); 2679 } 2680 2681 p2->p_oppid = p1->p_pid; /* Remember the original parent id. */ 2682 2683 LIST_INSERT_AFTER(p1, p2, p_pglist); 2684 LIST_INSERT_HEAD(&allproc, p2, p_list); 2685 2686 p2->p_trace_enabled = trace_is_enabled(p2); 2687 #ifdef __HAVE_SYSCALL_INTERN 2688 (*p2->p_emul->e_syscall_intern)(p2); 2689 #endif 2690 2691 /* 2692 * Make child runnable, set start time, and add to run queue except 2693 * if the parent requested the child to start in SSTOP state. 2694 */ 2695 mutex_enter(p2->p_lock); 2696 2697 getmicrotime(&p2->p_stats->p_start); 2698 2699 lwp_lock(l2); 2700 KASSERT(p2->p_nrlwps == 1); 2701 KASSERT(l2->l_stat == LSIDL); 2702 p2->p_nrlwps = 1; 2703 p2->p_stat = SACTIVE; 2704 setrunnable(l2); 2705 /* LWP now unlocked */ 2706 2707 mutex_exit(p2->p_lock); 2708 mutex_exit(&proc_lock); 2709 2710 cv_wait(&spawn_data->sed_cv_child_ready, &spawn_data->sed_mtx_child); 2711 error = spawn_data->sed_error; 2712 mutex_exit(&spawn_data->sed_mtx_child); 2713 spawn_exec_data_release(spawn_data); 2714 2715 rw_exit(&p1->p_reflock); 2716 rw_exit(&exec_lock); 2717 have_exec_lock = false; 2718 2719 *pid_res = pid; 2720 2721 if (error) 2722 return error; 2723 2724 if (p1->p_slflag & PSL_TRACED) { 2725 /* Paranoid check */ 2726 mutex_enter(&proc_lock); 2727 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) != 2728 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) { 2729 mutex_exit(&proc_lock); 2730 return 0; 2731 } 2732 2733 mutex_enter(p1->p_lock); 2734 eventswitch(TRAP_CHLD, PTRACE_POSIX_SPAWN, pid); 2735 } 2736 return 0; 2737 2738 error_exit: 2739 if (have_exec_lock) { 2740 execve_free_data(&spawn_data->sed_exec); 2741 rw_exit(&p1->p_reflock); 2742 rw_exit(&exec_lock); 2743 } 2744 mutex_exit(&spawn_data->sed_mtx_child); 2745 spawn_exec_data_release(spawn_data); 2746 2747 return error; 2748 } 2749 2750 int 2751 sys_posix_spawn(struct lwp *l1, const struct sys_posix_spawn_args *uap, 2752 register_t *retval) 2753 { 2754 /* { 2755 syscallarg(pid_t *) pid; 2756 syscallarg(const char *) path; 2757 syscallarg(const struct posix_spawn_file_actions *) file_actions; 2758 syscallarg(const struct posix_spawnattr *) attrp; 2759 syscallarg(char *const *) argv; 2760 syscallarg(char *const *) envp; 2761 } */ 2762 2763 int error; 2764 struct posix_spawn_file_actions *fa = NULL; 2765 struct posix_spawnattr *sa = NULL; 2766 pid_t pid; 2767 bool child_ok = false; 2768 rlim_t max_fileactions; 2769 proc_t *p = l1->l_proc; 2770 2771 /* check_posix_spawn() increments nprocs for us. */ 2772 error = check_posix_spawn(l1); 2773 if (error) { 2774 *retval = error; 2775 return 0; 2776 } 2777 2778 /* copy in file_actions struct */ 2779 if (SCARG(uap, file_actions) != NULL) { 2780 max_fileactions = 2 * uimin(p->p_rlimit[RLIMIT_NOFILE].rlim_cur, 2781 maxfiles); 2782 error = posix_spawn_fa_alloc(&fa, SCARG(uap, file_actions), 2783 max_fileactions); 2784 if (error) 2785 goto error_exit; 2786 } 2787 2788 /* copyin posix_spawnattr struct */ 2789 if (SCARG(uap, attrp) != NULL) { 2790 sa = kmem_alloc(sizeof(*sa), KM_SLEEP); 2791 error = copyin(SCARG(uap, attrp), sa, sizeof(*sa)); 2792 if (error) 2793 goto error_exit; 2794 } 2795 2796 /* 2797 * Do the spawn 2798 */ 2799 error = do_posix_spawn(l1, &pid, &child_ok, SCARG(uap, path), fa, sa, 2800 SCARG(uap, argv), SCARG(uap, envp), execve_fetch_element); 2801 if (error) 2802 goto error_exit; 2803 2804 if (error == 0 && SCARG(uap, pid) != NULL) 2805 error = copyout(&pid, SCARG(uap, pid), sizeof(pid)); 2806 2807 *retval = error; 2808 return 0; 2809 2810 error_exit: 2811 if (!child_ok) { 2812 (void)chgproccnt(kauth_cred_getuid(l1->l_cred), -1); 2813 atomic_dec_uint(&nprocs); 2814 2815 if (sa) 2816 kmem_free(sa, sizeof(*sa)); 2817 if (fa) 2818 posix_spawn_fa_free(fa, fa->len); 2819 } 2820 2821 *retval = error; 2822 return 0; 2823 } 2824 2825 void 2826 exec_free_emul_arg(struct exec_package *epp) 2827 { 2828 if (epp->ep_emul_arg_free != NULL) { 2829 KASSERT(epp->ep_emul_arg != NULL); 2830 (*epp->ep_emul_arg_free)(epp->ep_emul_arg); 2831 epp->ep_emul_arg_free = NULL; 2832 epp->ep_emul_arg = NULL; 2833 } else { 2834 KASSERT(epp->ep_emul_arg == NULL); 2835 } 2836 } 2837 2838 #ifdef DEBUG_EXEC 2839 static void 2840 dump_vmcmds(const struct exec_package * const epp, size_t x, int error) 2841 { 2842 struct exec_vmcmd *vp = &epp->ep_vmcmds.evs_cmds[0]; 2843 size_t j; 2844 2845 if (error == 0) 2846 DPRINTF(("vmcmds %u\n", epp->ep_vmcmds.evs_used)); 2847 else 2848 DPRINTF(("vmcmds %zu/%u, error %d\n", x, 2849 epp->ep_vmcmds.evs_used, error)); 2850 2851 for (j = 0; j < epp->ep_vmcmds.evs_used; j++) { 2852 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#" 2853 PRIxVADDR"/%#"PRIxVSIZE" fd@%#" 2854 PRIxVSIZE" prot=0%o flags=%d\n", j, 2855 vp[j].ev_proc == vmcmd_map_pagedvn ? 2856 "pagedvn" : 2857 vp[j].ev_proc == vmcmd_map_readvn ? 2858 "readvn" : 2859 vp[j].ev_proc == vmcmd_map_zero ? 2860 "zero" : "*unknown*", 2861 vp[j].ev_addr, vp[j].ev_len, 2862 vp[j].ev_offset, vp[j].ev_prot, 2863 vp[j].ev_flags)); 2864 if (error != 0 && j == x) 2865 DPRINTF((" ^--- failed\n")); 2866 } 2867 } 2868 #endif 2869