1 /* $NetBSD: kern_exec.c,v 1.299 2010/07/07 01:30:37 chs Exp $ */ 2 3 /*- 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /*- 30 * Copyright (C) 1993, 1994, 1996 Christopher G. Demetriou 31 * Copyright (C) 1992 Wolfgang Solfrank. 32 * Copyright (C) 1992 TooLs GmbH. 33 * All rights reserved. 34 * 35 * Redistribution and use in source and binary forms, with or without 36 * modification, are permitted provided that the following conditions 37 * are met: 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 2. Redistributions in binary form must reproduce the above copyright 41 * notice, this list of conditions and the following disclaimer in the 42 * documentation and/or other materials provided with the distribution. 43 * 3. All advertising materials mentioning features or use of this software 44 * must display the following acknowledgement: 45 * This product includes software developed by TooLs GmbH. 46 * 4. The name of TooLs GmbH may not be used to endorse or promote products 47 * derived from this software without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 50 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 51 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 52 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 53 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 54 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 55 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 56 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 57 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 58 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 59 */ 60 61 #include <sys/cdefs.h> 62 __KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.299 2010/07/07 01:30:37 chs Exp $"); 63 64 #include "opt_ktrace.h" 65 #include "opt_modular.h" 66 #include "opt_syscall_debug.h" 67 #include "veriexec.h" 68 #include "opt_pax.h" 69 #include "opt_sa.h" 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/filedesc.h> 74 #include <sys/kernel.h> 75 #include <sys/proc.h> 76 #include <sys/mount.h> 77 #include <sys/malloc.h> 78 #include <sys/kmem.h> 79 #include <sys/namei.h> 80 #include <sys/vnode.h> 81 #include <sys/file.h> 82 #include <sys/acct.h> 83 #include <sys/exec.h> 84 #include <sys/ktrace.h> 85 #include <sys/uidinfo.h> 86 #include <sys/wait.h> 87 #include <sys/mman.h> 88 #include <sys/ras.h> 89 #include <sys/signalvar.h> 90 #include <sys/stat.h> 91 #include <sys/syscall.h> 92 #include <sys/kauth.h> 93 #include <sys/lwpctl.h> 94 #include <sys/pax.h> 95 #include <sys/cpu.h> 96 #include <sys/module.h> 97 #include <sys/sa.h> 98 #include <sys/savar.h> 99 #include <sys/syscallvar.h> 100 #include <sys/syscallargs.h> 101 #if NVERIEXEC > 0 102 #include <sys/verified_exec.h> 103 #endif /* NVERIEXEC > 0 */ 104 #include <sys/sdt.h> 105 106 #include <uvm/uvm_extern.h> 107 108 #include <machine/reg.h> 109 110 #include <compat/common/compat_util.h> 111 112 static int exec_sigcode_map(struct proc *, const struct emul *); 113 114 #ifdef DEBUG_EXEC 115 #define DPRINTF(a) uprintf a 116 #else 117 #define DPRINTF(a) 118 #endif /* DEBUG_EXEC */ 119 120 /* 121 * DTrace SDT provider definitions 122 */ 123 SDT_PROBE_DEFINE(proc,,,exec, 124 "char *", NULL, 125 NULL, NULL, NULL, NULL, 126 NULL, NULL, NULL, NULL); 127 SDT_PROBE_DEFINE(proc,,,exec_success, 128 "char *", NULL, 129 NULL, NULL, NULL, NULL, 130 NULL, NULL, NULL, NULL); 131 SDT_PROBE_DEFINE(proc,,,exec_failure, 132 "int", NULL, 133 NULL, NULL, NULL, NULL, 134 NULL, NULL, NULL, NULL); 135 136 /* 137 * Exec function switch: 138 * 139 * Note that each makecmds function is responsible for loading the 140 * exec package with the necessary functions for any exec-type-specific 141 * handling. 142 * 143 * Functions for specific exec types should be defined in their own 144 * header file. 145 */ 146 static const struct execsw **execsw = NULL; 147 static int nexecs; 148 149 u_int exec_maxhdrsz; /* must not be static - used by netbsd32 */ 150 151 /* list of dynamically loaded execsw entries */ 152 static LIST_HEAD(execlist_head, exec_entry) ex_head = 153 LIST_HEAD_INITIALIZER(ex_head); 154 struct exec_entry { 155 LIST_ENTRY(exec_entry) ex_list; 156 SLIST_ENTRY(exec_entry) ex_slist; 157 const struct execsw *ex_sw; 158 }; 159 160 #ifndef __HAVE_SYSCALL_INTERN 161 void syscall(void); 162 #endif 163 164 #ifdef KERN_SA 165 static struct sa_emul saemul_netbsd = { 166 sizeof(ucontext_t), 167 sizeof(struct sa_t), 168 sizeof(struct sa_t *), 169 NULL, 170 NULL, 171 cpu_upcall, 172 (void (*)(struct lwp *, void *))getucontext_sa, 173 sa_ucsp 174 }; 175 #endif /* KERN_SA */ 176 177 /* NetBSD emul struct */ 178 struct emul emul_netbsd = { 179 .e_name = "netbsd", 180 .e_path = NULL, 181 #ifndef __HAVE_MINIMAL_EMUL 182 .e_flags = EMUL_HAS_SYS___syscall, 183 .e_errno = NULL, 184 .e_nosys = SYS_syscall, 185 .e_nsysent = SYS_NSYSENT, 186 #endif 187 .e_sysent = sysent, 188 #ifdef SYSCALL_DEBUG 189 .e_syscallnames = syscallnames, 190 #else 191 .e_syscallnames = NULL, 192 #endif 193 .e_sendsig = sendsig, 194 .e_trapsignal = trapsignal, 195 .e_tracesig = NULL, 196 .e_sigcode = NULL, 197 .e_esigcode = NULL, 198 .e_sigobject = NULL, 199 .e_setregs = setregs, 200 .e_proc_exec = NULL, 201 .e_proc_fork = NULL, 202 .e_proc_exit = NULL, 203 .e_lwp_fork = NULL, 204 .e_lwp_exit = NULL, 205 #ifdef __HAVE_SYSCALL_INTERN 206 .e_syscall_intern = syscall_intern, 207 #else 208 .e_syscall = syscall, 209 #endif 210 .e_sysctlovly = NULL, 211 .e_fault = NULL, 212 .e_vm_default_addr = uvm_default_mapaddr, 213 .e_usertrap = NULL, 214 #ifdef KERN_SA 215 .e_sa = &saemul_netbsd, 216 #else 217 .e_sa = NULL, 218 #endif 219 .e_ucsize = sizeof(ucontext_t), 220 .e_startlwp = startlwp 221 }; 222 223 /* 224 * Exec lock. Used to control access to execsw[] structures. 225 * This must not be static so that netbsd32 can access it, too. 226 */ 227 krwlock_t exec_lock; 228 229 static kmutex_t sigobject_lock; 230 231 static void * 232 exec_pool_alloc(struct pool *pp, int flags) 233 { 234 235 return (void *)uvm_km_alloc(kernel_map, NCARGS, 0, 236 UVM_KMF_PAGEABLE | UVM_KMF_WAITVA); 237 } 238 239 static void 240 exec_pool_free(struct pool *pp, void *addr) 241 { 242 243 uvm_km_free(kernel_map, (vaddr_t)addr, NCARGS, UVM_KMF_PAGEABLE); 244 } 245 246 static struct pool exec_pool; 247 248 static struct pool_allocator exec_palloc = { 249 .pa_alloc = exec_pool_alloc, 250 .pa_free = exec_pool_free, 251 .pa_pagesz = NCARGS 252 }; 253 254 /* 255 * check exec: 256 * given an "executable" described in the exec package's namei info, 257 * see what we can do with it. 258 * 259 * ON ENTRY: 260 * exec package with appropriate namei info 261 * lwp pointer of exec'ing lwp 262 * NO SELF-LOCKED VNODES 263 * 264 * ON EXIT: 265 * error: nothing held, etc. exec header still allocated. 266 * ok: filled exec package, executable's vnode (unlocked). 267 * 268 * EXEC SWITCH ENTRY: 269 * Locked vnode to check, exec package, proc. 270 * 271 * EXEC SWITCH EXIT: 272 * ok: return 0, filled exec package, executable's vnode (unlocked). 273 * error: destructive: 274 * everything deallocated execept exec header. 275 * non-destructive: 276 * error code, executable's vnode (unlocked), 277 * exec header unmodified. 278 */ 279 int 280 /*ARGSUSED*/ 281 check_exec(struct lwp *l, struct exec_package *epp, const char *kpath) 282 { 283 int error, i; 284 struct vnode *vp; 285 struct nameidata nd; 286 size_t resid; 287 288 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | SAVENAME | TRYEMULROOT, 289 UIO_SYSSPACE, kpath); 290 291 /* first get the vnode */ 292 if ((error = namei(&nd)) != 0) 293 return error; 294 epp->ep_vp = vp = nd.ni_vp; 295 /* this cannot overflow as both are size PATH_MAX */ 296 strcpy(epp->ep_resolvedname, nd.ni_cnd.cn_pnbuf); 297 298 /* dump this right away */ 299 #ifdef DIAGNOSTIC 300 /* paranoia (take this out once namei stuff stabilizes) */ 301 memset(nd.ni_cnd.cn_pnbuf, '~', PATH_MAX); 302 #endif 303 PNBUF_PUT(nd.ni_cnd.cn_pnbuf); 304 305 /* check access and type */ 306 if (vp->v_type != VREG) { 307 error = EACCES; 308 goto bad1; 309 } 310 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 311 goto bad1; 312 313 /* get attributes */ 314 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 315 goto bad1; 316 317 /* Check mount point */ 318 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 319 error = EACCES; 320 goto bad1; 321 } 322 if (vp->v_mount->mnt_flag & MNT_NOSUID) 323 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 324 325 /* try to open it */ 326 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 327 goto bad1; 328 329 /* unlock vp, since we need it unlocked from here on out. */ 330 VOP_UNLOCK(vp); 331 332 #if NVERIEXEC > 0 333 error = veriexec_verify(l, vp, epp->ep_resolvedname, 334 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 335 NULL); 336 if (error) 337 goto bad2; 338 #endif /* NVERIEXEC > 0 */ 339 340 #ifdef PAX_SEGVGUARD 341 error = pax_segvguard(l, vp, epp->ep_resolvedname, false); 342 if (error) 343 goto bad2; 344 #endif /* PAX_SEGVGUARD */ 345 346 /* now we have the file, get the exec header */ 347 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 348 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 349 if (error) 350 goto bad2; 351 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 352 353 /* 354 * Set up default address space limits. Can be overridden 355 * by individual exec packages. 356 * 357 * XXX probably should be all done in the exec packages. 358 */ 359 epp->ep_vm_minaddr = VM_MIN_ADDRESS; 360 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 361 /* 362 * set up the vmcmds for creation of the process 363 * address space 364 */ 365 error = ENOEXEC; 366 for (i = 0; i < nexecs; i++) { 367 int newerror; 368 369 epp->ep_esch = execsw[i]; 370 newerror = (*execsw[i]->es_makecmds)(l, epp); 371 372 if (!newerror) { 373 /* Seems ok: check that entry point is sane */ 374 if (epp->ep_entry > VM_MAXUSER_ADDRESS) { 375 error = ENOEXEC; 376 break; 377 } 378 379 /* check limits */ 380 if ((epp->ep_tsize > MAXTSIZ) || 381 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 382 [RLIMIT_DATA].rlim_cur)) { 383 error = ENOMEM; 384 break; 385 } 386 return 0; 387 } 388 389 if (epp->ep_emul_root != NULL) { 390 vrele(epp->ep_emul_root); 391 epp->ep_emul_root = NULL; 392 } 393 if (epp->ep_interp != NULL) { 394 vrele(epp->ep_interp); 395 epp->ep_interp = NULL; 396 } 397 398 /* make sure the first "interesting" error code is saved. */ 399 if (error == ENOEXEC) 400 error = newerror; 401 402 if (epp->ep_flags & EXEC_DESTR) 403 /* Error from "#!" code, tidied up by recursive call */ 404 return error; 405 } 406 407 /* not found, error */ 408 409 /* 410 * free any vmspace-creation commands, 411 * and release their references 412 */ 413 kill_vmcmds(&epp->ep_vmcmds); 414 415 bad2: 416 /* 417 * close and release the vnode, restore the old one, free the 418 * pathname buf, and punt. 419 */ 420 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 421 VOP_CLOSE(vp, FREAD, l->l_cred); 422 vput(vp); 423 return error; 424 425 bad1: 426 /* 427 * free the namei pathname buffer, and put the vnode 428 * (which we don't yet have open). 429 */ 430 vput(vp); /* was still locked */ 431 return error; 432 } 433 434 #ifdef __MACHINE_STACK_GROWS_UP 435 #define STACK_PTHREADSPACE NBPG 436 #else 437 #define STACK_PTHREADSPACE 0 438 #endif 439 440 static int 441 execve_fetch_element(char * const *array, size_t index, char **value) 442 { 443 return copyin(array + index, value, sizeof(*value)); 444 } 445 446 /* 447 * exec system call 448 */ 449 /* ARGSUSED */ 450 int 451 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 452 { 453 /* { 454 syscallarg(const char *) path; 455 syscallarg(char * const *) argp; 456 syscallarg(char * const *) envp; 457 } */ 458 459 return execve1(l, SCARG(uap, path), SCARG(uap, argp), 460 SCARG(uap, envp), execve_fetch_element); 461 } 462 463 /* 464 * Load modules to try and execute an image that we do not understand. 465 * If no execsw entries are present, we load those likely to be needed 466 * in order to run native images only. Otherwise, we autoload all 467 * possible modules that could let us run the binary. XXX lame 468 */ 469 static void 470 exec_autoload(void) 471 { 472 #ifdef MODULAR 473 static const char * const native[] = { 474 "exec_elf32", 475 "exec_elf64", 476 "exec_script", 477 NULL 478 }; 479 static const char * const compat[] = { 480 "exec_elf32", 481 "exec_elf64", 482 "exec_script", 483 "exec_aout", 484 "exec_coff", 485 "exec_ecoff", 486 "compat_aoutm68k", 487 "compat_freebsd", 488 "compat_ibcs2", 489 "compat_irix", 490 "compat_linux", 491 "compat_linux32", 492 "compat_netbsd32", 493 "compat_sunos", 494 "compat_sunos32", 495 "compat_svr4", 496 "compat_svr4_32", 497 "compat_ultrix", 498 NULL 499 }; 500 char const * const *list; 501 int i; 502 503 mutex_enter(&module_lock); 504 list = (nexecs == 0 ? native : compat); 505 for (i = 0; list[i] != NULL; i++) { 506 if (module_autoload(list[i], MODULE_CLASS_MISC) != 0) { 507 continue; 508 } 509 mutex_exit(&module_lock); 510 yield(); 511 mutex_enter(&module_lock); 512 } 513 mutex_exit(&module_lock); 514 #endif 515 } 516 517 int 518 execve1(struct lwp *l, const char *path, char * const *args, 519 char * const *envs, execve_fetch_element_t fetch_element) 520 { 521 int error; 522 struct exec_package pack; 523 struct vattr attr; 524 struct proc *p; 525 char *argp; 526 char *dp, *sp; 527 long argc, envc; 528 size_t i, len; 529 char *stack; 530 struct ps_strings arginfo; 531 struct ps_strings *aip = &arginfo; 532 struct vmspace *vm; 533 struct exec_fakearg *tmpfap; 534 int szsigcode; 535 struct exec_vmcmd *base_vcp; 536 int oldlwpflags; 537 ksiginfo_t ksi; 538 ksiginfoq_t kq; 539 char *pathbuf; 540 char *resolvedpathbuf; 541 const char *commandname; 542 u_int modgen; 543 544 p = l->l_proc; 545 modgen = 0; 546 547 SDT_PROBE(proc,,,exec, path, 0, 0, 0, 0); 548 549 /* 550 * Check if we have exceeded our number of processes limit. 551 * This is so that we handle the case where a root daemon 552 * forked, ran setuid to become the desired user and is trying 553 * to exec. The obvious place to do the reference counting check 554 * is setuid(), but we don't do the reference counting check there 555 * like other OS's do because then all the programs that use setuid() 556 * must be modified to check the return code of setuid() and exit(). 557 * It is dangerous to make setuid() fail, because it fails open and 558 * the program will continue to run as root. If we make it succeed 559 * and return an error code, again we are not enforcing the limit. 560 * The best place to enforce the limit is here, when the process tries 561 * to execute a new image, because eventually the process will need 562 * to call exec in order to do something useful. 563 */ 564 retry: 565 if ((p->p_flag & PK_SUGID) && kauth_authorize_generic(l->l_cred, 566 KAUTH_GENERIC_ISSUSER, NULL) != 0 && chgproccnt(kauth_cred_getuid( 567 l->l_cred), 0) > p->p_rlimit[RLIMIT_NPROC].rlim_cur) 568 return EAGAIN; 569 570 oldlwpflags = l->l_flag & (LW_SA | LW_SA_UPCALL); 571 if (l->l_flag & LW_SA) { 572 lwp_lock(l); 573 l->l_flag &= ~(LW_SA | LW_SA_UPCALL); 574 lwp_unlock(l); 575 } 576 577 /* 578 * Drain existing references and forbid new ones. The process 579 * should be left alone until we're done here. This is necessary 580 * to avoid race conditions - e.g. in ptrace() - that might allow 581 * a local user to illicitly obtain elevated privileges. 582 */ 583 rw_enter(&p->p_reflock, RW_WRITER); 584 585 base_vcp = NULL; 586 /* 587 * Init the namei data to point the file user's program name. 588 * This is done here rather than in check_exec(), so that it's 589 * possible to override this settings if any of makecmd/probe 590 * functions call check_exec() recursively - for example, 591 * see exec_script_makecmds(). 592 */ 593 pathbuf = PNBUF_GET(); 594 error = copyinstr(path, pathbuf, MAXPATHLEN, NULL); 595 if (error) { 596 DPRINTF(("execve: copyinstr path %d", error)); 597 goto clrflg; 598 } 599 resolvedpathbuf = PNBUF_GET(); 600 #ifdef DIAGNOSTIC 601 strcpy(resolvedpathbuf, "/wrong"); 602 #endif 603 604 /* 605 * initialize the fields of the exec package. 606 */ 607 pack.ep_name = path; 608 pack.ep_kname = pathbuf; 609 pack.ep_resolvedname = resolvedpathbuf; 610 pack.ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 611 pack.ep_hdrlen = exec_maxhdrsz; 612 pack.ep_hdrvalid = 0; 613 pack.ep_emul_arg = NULL; 614 pack.ep_vmcmds.evs_cnt = 0; 615 pack.ep_vmcmds.evs_used = 0; 616 pack.ep_vap = &attr; 617 pack.ep_flags = 0; 618 pack.ep_emul_root = NULL; 619 pack.ep_interp = NULL; 620 pack.ep_esch = NULL; 621 pack.ep_pax_flags = 0; 622 623 rw_enter(&exec_lock, RW_READER); 624 625 /* see if we can run it. */ 626 if ((error = check_exec(l, &pack, pathbuf)) != 0) { 627 if (error != ENOENT) { 628 DPRINTF(("execve: check exec failed %d\n", error)); 629 } 630 goto freehdr; 631 } 632 633 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 634 635 /* allocate an argument buffer */ 636 argp = pool_get(&exec_pool, PR_WAITOK); 637 KASSERT(argp != NULL); 638 dp = argp; 639 argc = 0; 640 641 /* copy the fake args list, if there's one, freeing it as we go */ 642 if (pack.ep_flags & EXEC_HASARGL) { 643 tmpfap = pack.ep_fa; 644 while (tmpfap->fa_arg != NULL) { 645 const char *cp; 646 647 cp = tmpfap->fa_arg; 648 while (*cp) 649 *dp++ = *cp++; 650 *dp++ = '\0'; 651 ktrexecarg(tmpfap->fa_arg, cp - tmpfap->fa_arg); 652 653 kmem_free(tmpfap->fa_arg, tmpfap->fa_len); 654 tmpfap++; argc++; 655 } 656 kmem_free(pack.ep_fa, pack.ep_fa_len); 657 pack.ep_flags &= ~EXEC_HASARGL; 658 } 659 660 /* Now get argv & environment */ 661 if (args == NULL) { 662 DPRINTF(("execve: null args\n")); 663 error = EINVAL; 664 goto bad; 665 } 666 /* 'i' will index the argp/envp element to be retrieved */ 667 i = 0; 668 if (pack.ep_flags & EXEC_SKIPARG) 669 i++; 670 671 while (1) { 672 len = argp + ARG_MAX - dp; 673 if ((error = (*fetch_element)(args, i, &sp)) != 0) { 674 DPRINTF(("execve: fetch_element args %d\n", error)); 675 goto bad; 676 } 677 if (!sp) 678 break; 679 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 680 DPRINTF(("execve: copyinstr args %d\n", error)); 681 if (error == ENAMETOOLONG) 682 error = E2BIG; 683 goto bad; 684 } 685 ktrexecarg(dp, len - 1); 686 dp += len; 687 i++; 688 argc++; 689 } 690 691 envc = 0; 692 /* environment need not be there */ 693 if (envs != NULL) { 694 i = 0; 695 while (1) { 696 len = argp + ARG_MAX - dp; 697 if ((error = (*fetch_element)(envs, i, &sp)) != 0) { 698 DPRINTF(("execve: fetch_element env %d\n", error)); 699 goto bad; 700 } 701 if (!sp) 702 break; 703 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 704 DPRINTF(("execve: copyinstr env %d\n", error)); 705 if (error == ENAMETOOLONG) 706 error = E2BIG; 707 goto bad; 708 } 709 ktrexecenv(dp, len - 1); 710 dp += len; 711 i++; 712 envc++; 713 } 714 } 715 716 dp = (char *) ALIGN(dp); 717 718 szsigcode = pack.ep_esch->es_emul->e_esigcode - 719 pack.ep_esch->es_emul->e_sigcode; 720 721 #ifdef __MACHINE_STACK_GROWS_UP 722 /* See big comment lower down */ 723 #define RTLD_GAP 32 724 #else 725 #define RTLD_GAP 0 726 #endif 727 728 /* Now check if args & environ fit into new stack */ 729 if (pack.ep_flags & EXEC_32) 730 len = ((argc + envc + 2 + pack.ep_esch->es_arglen) * 731 sizeof(int) + sizeof(int) + dp + RTLD_GAP + 732 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 733 - argp; 734 else 735 len = ((argc + envc + 2 + pack.ep_esch->es_arglen) * 736 sizeof(char *) + sizeof(int) + dp + RTLD_GAP + 737 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 738 - argp; 739 740 #ifdef PAX_ASLR 741 if (pax_aslr_active(l)) 742 len += (arc4random() % PAGE_SIZE); 743 #endif /* PAX_ASLR */ 744 745 #ifdef STACKLALIGN /* arm, etc. */ 746 len = STACKALIGN(len); /* make the stack "safely" aligned */ 747 #else 748 len = ALIGN(len); /* make the stack "safely" aligned */ 749 #endif 750 751 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 752 DPRINTF(("execve: stack limit exceeded %zu\n", len)); 753 error = ENOMEM; 754 goto bad; 755 } 756 757 /* Get rid of other LWPs. */ 758 if (p->p_sa || p->p_nlwps > 1) { 759 mutex_enter(p->p_lock); 760 exit_lwps(l); 761 mutex_exit(p->p_lock); 762 } 763 KDASSERT(p->p_nlwps == 1); 764 765 /* Destroy any lwpctl info. */ 766 if (p->p_lwpctl != NULL) 767 lwp_ctl_exit(); 768 769 #ifdef KERN_SA 770 /* Release any SA state. */ 771 if (p->p_sa) 772 sa_release(p); 773 #endif /* KERN_SA */ 774 775 /* Remove POSIX timers */ 776 timers_free(p, TIMERS_POSIX); 777 778 /* adjust "active stack depth" for process VSZ */ 779 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 780 781 /* 782 * Do whatever is necessary to prepare the address space 783 * for remapping. Note that this might replace the current 784 * vmspace with another! 785 */ 786 uvmspace_exec(l, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 787 788 /* record proc's vnode, for use by procfs and others */ 789 if (p->p_textvp) 790 vrele(p->p_textvp); 791 vref(pack.ep_vp); 792 p->p_textvp = pack.ep_vp; 793 794 /* Now map address space */ 795 vm = p->p_vmspace; 796 vm->vm_taddr = (void *)pack.ep_taddr; 797 vm->vm_tsize = btoc(pack.ep_tsize); 798 vm->vm_daddr = (void*)pack.ep_daddr; 799 vm->vm_dsize = btoc(pack.ep_dsize); 800 vm->vm_ssize = btoc(pack.ep_ssize); 801 vm->vm_issize = 0; 802 vm->vm_maxsaddr = (void *)pack.ep_maxsaddr; 803 vm->vm_minsaddr = (void *)pack.ep_minsaddr; 804 805 #ifdef PAX_ASLR 806 pax_aslr_init(l, vm); 807 #endif /* PAX_ASLR */ 808 809 /* create the new process's VM space by running the vmcmds */ 810 #ifdef DIAGNOSTIC 811 if (pack.ep_vmcmds.evs_used == 0) 812 panic("execve: no vmcmds"); 813 #endif 814 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 815 struct exec_vmcmd *vcp; 816 817 vcp = &pack.ep_vmcmds.evs_cmds[i]; 818 if (vcp->ev_flags & VMCMD_RELATIVE) { 819 #ifdef DIAGNOSTIC 820 if (base_vcp == NULL) 821 panic("execve: relative vmcmd with no base"); 822 if (vcp->ev_flags & VMCMD_BASE) 823 panic("execve: illegal base & relative vmcmd"); 824 #endif 825 vcp->ev_addr += base_vcp->ev_addr; 826 } 827 error = (*vcp->ev_proc)(l, vcp); 828 #ifdef DEBUG_EXEC 829 if (error) { 830 size_t j; 831 struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0]; 832 for (j = 0; j <= i; j++) 833 uprintf( 834 "vmcmd[%zu] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n", 835 j, vp[j].ev_addr, vp[j].ev_len, 836 vp[j].ev_offset, vp[j].ev_prot, 837 vp[j].ev_flags); 838 } 839 #endif /* DEBUG_EXEC */ 840 if (vcp->ev_flags & VMCMD_BASE) 841 base_vcp = vcp; 842 } 843 844 /* free the vmspace-creation commands, and release their references */ 845 kill_vmcmds(&pack.ep_vmcmds); 846 847 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 848 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 849 vput(pack.ep_vp); 850 851 /* if an error happened, deallocate and punt */ 852 if (error) { 853 DPRINTF(("execve: vmcmd %zu failed: %d\n", i - 1, error)); 854 goto exec_abort; 855 } 856 857 /* remember information about the process */ 858 arginfo.ps_nargvstr = argc; 859 arginfo.ps_nenvstr = envc; 860 861 /* set command name & other accounting info */ 862 commandname = strrchr(pack.ep_resolvedname, '/'); 863 if (commandname != NULL) { 864 commandname++; 865 } else { 866 commandname = pack.ep_resolvedname; 867 } 868 i = min(strlen(commandname), MAXCOMLEN); 869 (void)memcpy(p->p_comm, commandname, i); 870 p->p_comm[i] = '\0'; 871 872 dp = PNBUF_GET(); 873 /* 874 * If the path starts with /, we don't need to do any work. 875 * This handles the majority of the cases. 876 * In the future perhaps we could canonicalize it? 877 */ 878 if (pathbuf[0] == '/') 879 (void)strlcpy(pack.ep_path = dp, pathbuf, MAXPATHLEN); 880 #ifdef notyet 881 /* 882 * Although this works most of the time [since the entry was just 883 * entered in the cache] we don't use it because it theoretically 884 * can fail and it is not the cleanest interface, because there 885 * could be races. When the namei cache is re-written, this can 886 * be changed to use the appropriate function. 887 */ 888 else if (!(error = vnode_to_path(dp, MAXPATHLEN, p->p_textvp, l, p))) 889 pack.ep_path = dp; 890 #endif 891 else { 892 #ifdef notyet 893 printf("Cannot get path for pid %d [%s] (error %d)", 894 (int)p->p_pid, p->p_comm, error); 895 #endif 896 pack.ep_path = NULL; 897 PNBUF_PUT(dp); 898 } 899 900 stack = (char *)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, 901 STACK_PTHREADSPACE + sizeof(struct ps_strings) + szsigcode), 902 len - (sizeof(struct ps_strings) + szsigcode)); 903 904 #ifdef __MACHINE_STACK_GROWS_UP 905 /* 906 * The copyargs call always copies into lower addresses 907 * first, moving towards higher addresses, starting with 908 * the stack pointer that we give. When the stack grows 909 * down, this puts argc/argv/envp very shallow on the 910 * stack, right at the first user stack pointer. 911 * When the stack grows up, the situation is reversed. 912 * 913 * Normally, this is no big deal. But the ld_elf.so _rtld() 914 * function expects to be called with a single pointer to 915 * a region that has a few words it can stash values into, 916 * followed by argc/argv/envp. When the stack grows down, 917 * it's easy to decrement the stack pointer a little bit to 918 * allocate the space for these few words and pass the new 919 * stack pointer to _rtld. When the stack grows up, however, 920 * a few words before argc is part of the signal trampoline, XXX 921 * so we have a problem. 922 * 923 * Instead of changing how _rtld works, we take the easy way 924 * out and steal 32 bytes before we call copyargs. 925 * This extra space was allowed for when 'len' was calculated. 926 */ 927 stack += RTLD_GAP; 928 #endif /* __MACHINE_STACK_GROWS_UP */ 929 930 /* Now copy argc, args & environ to new stack */ 931 error = (*pack.ep_esch->es_copyargs)(l, &pack, &arginfo, &stack, argp); 932 if (pack.ep_path) { 933 PNBUF_PUT(pack.ep_path); 934 pack.ep_path = NULL; 935 } 936 if (error) { 937 DPRINTF(("execve: copyargs failed %d\n", error)); 938 goto exec_abort; 939 } 940 /* Move the stack back to original point */ 941 stack = (char *)STACK_GROW(vm->vm_minsaddr, len); 942 943 /* fill process ps_strings info */ 944 p->p_psstr = (struct ps_strings *) 945 STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, STACK_PTHREADSPACE), 946 sizeof(struct ps_strings)); 947 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 948 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 949 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 950 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 951 952 /* copy out the process's ps_strings structure */ 953 if ((error = copyout(aip, (char *)p->p_psstr, 954 sizeof(arginfo))) != 0) { 955 DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n", 956 aip, (char *)p->p_psstr, (long)sizeof(arginfo))); 957 goto exec_abort; 958 } 959 960 fd_closeexec(); /* handle close on exec */ 961 execsigs(p); /* reset catched signals */ 962 963 l->l_ctxlink = NULL; /* reset ucontext link */ 964 965 966 p->p_acflag &= ~AFORK; 967 mutex_enter(p->p_lock); 968 p->p_flag |= PK_EXEC; 969 mutex_exit(p->p_lock); 970 971 /* 972 * Stop profiling. 973 */ 974 if ((p->p_stflag & PST_PROFIL) != 0) { 975 mutex_spin_enter(&p->p_stmutex); 976 stopprofclock(p); 977 mutex_spin_exit(&p->p_stmutex); 978 } 979 980 /* 981 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 982 * exited and exec()/exit() are the only places it will be cleared. 983 */ 984 if ((p->p_lflag & PL_PPWAIT) != 0) { 985 mutex_enter(proc_lock); 986 p->p_lflag &= ~PL_PPWAIT; 987 cv_broadcast(&p->p_pptr->p_waitcv); 988 mutex_exit(proc_lock); 989 } 990 991 /* 992 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 993 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 994 * out additional references on the process for the moment. 995 */ 996 if ((p->p_slflag & PSL_TRACED) == 0 && 997 998 (((attr.va_mode & S_ISUID) != 0 && 999 kauth_cred_geteuid(l->l_cred) != attr.va_uid) || 1000 1001 ((attr.va_mode & S_ISGID) != 0 && 1002 kauth_cred_getegid(l->l_cred) != attr.va_gid))) { 1003 /* 1004 * Mark the process as SUGID before we do 1005 * anything that might block. 1006 */ 1007 proc_crmod_enter(); 1008 proc_crmod_leave(NULL, NULL, true); 1009 1010 /* Make sure file descriptors 0..2 are in use. */ 1011 if ((error = fd_checkstd()) != 0) { 1012 DPRINTF(("execve: fdcheckstd failed %d\n", error)); 1013 goto exec_abort; 1014 } 1015 1016 /* 1017 * Copy the credential so other references don't see our 1018 * changes. 1019 */ 1020 l->l_cred = kauth_cred_copy(l->l_cred); 1021 #ifdef KTRACE 1022 /* 1023 * If the persistent trace flag isn't set, turn off. 1024 */ 1025 if (p->p_tracep) { 1026 mutex_enter(&ktrace_lock); 1027 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1028 ktrderef(p); 1029 mutex_exit(&ktrace_lock); 1030 } 1031 #endif 1032 if (attr.va_mode & S_ISUID) 1033 kauth_cred_seteuid(l->l_cred, attr.va_uid); 1034 if (attr.va_mode & S_ISGID) 1035 kauth_cred_setegid(l->l_cred, attr.va_gid); 1036 } else { 1037 if (kauth_cred_geteuid(l->l_cred) == 1038 kauth_cred_getuid(l->l_cred) && 1039 kauth_cred_getegid(l->l_cred) == 1040 kauth_cred_getgid(l->l_cred)) 1041 p->p_flag &= ~PK_SUGID; 1042 } 1043 1044 /* 1045 * Copy the credential so other references don't see our changes. 1046 * Test to see if this is necessary first, since in the common case 1047 * we won't need a private reference. 1048 */ 1049 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1050 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1051 l->l_cred = kauth_cred_copy(l->l_cred); 1052 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1053 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1054 } 1055 1056 /* Update the master credentials. */ 1057 if (l->l_cred != p->p_cred) { 1058 kauth_cred_t ocred; 1059 1060 kauth_cred_hold(l->l_cred); 1061 mutex_enter(p->p_lock); 1062 ocred = p->p_cred; 1063 p->p_cred = l->l_cred; 1064 mutex_exit(p->p_lock); 1065 kauth_cred_free(ocred); 1066 } 1067 1068 #if defined(__HAVE_RAS) 1069 /* 1070 * Remove all RASs from the address space. 1071 */ 1072 ras_purgeall(); 1073 #endif 1074 1075 doexechooks(p); 1076 1077 /* setup new registers and do misc. setup. */ 1078 (*pack.ep_esch->es_emul->e_setregs)(l, &pack, (vaddr_t)stack); 1079 if (pack.ep_esch->es_setregs) 1080 (*pack.ep_esch->es_setregs)(l, &pack, (vaddr_t)stack); 1081 1082 /* map the process's signal trampoline code */ 1083 if (exec_sigcode_map(p, pack.ep_esch->es_emul)) { 1084 DPRINTF(("execve: map sigcode failed %d\n", error)); 1085 goto exec_abort; 1086 } 1087 1088 pool_put(&exec_pool, argp); 1089 1090 /* notify others that we exec'd */ 1091 KNOTE(&p->p_klist, NOTE_EXEC); 1092 1093 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1094 1095 SDT_PROBE(proc,,,exec_success, path, 0, 0, 0, 0); 1096 1097 /* The emulation root will usually have been found when we looked 1098 * for the elf interpreter (or similar), if not look now. */ 1099 if (pack.ep_esch->es_emul->e_path != NULL && pack.ep_emul_root == NULL) 1100 emul_find_root(l, &pack); 1101 1102 /* Any old emulation root got removed by fdcloseexec */ 1103 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1104 p->p_cwdi->cwdi_edir = pack.ep_emul_root; 1105 rw_exit(&p->p_cwdi->cwdi_lock); 1106 pack.ep_emul_root = NULL; 1107 if (pack.ep_interp != NULL) 1108 vrele(pack.ep_interp); 1109 1110 /* 1111 * Call emulation specific exec hook. This can setup per-process 1112 * p->p_emuldata or do any other per-process stuff an emulation needs. 1113 * 1114 * If we are executing process of different emulation than the 1115 * original forked process, call e_proc_exit() of the old emulation 1116 * first, then e_proc_exec() of new emulation. If the emulation is 1117 * same, the exec hook code should deallocate any old emulation 1118 * resources held previously by this process. 1119 */ 1120 if (p->p_emul && p->p_emul->e_proc_exit 1121 && p->p_emul != pack.ep_esch->es_emul) 1122 (*p->p_emul->e_proc_exit)(p); 1123 1124 /* 1125 * This is now LWP 1. 1126 */ 1127 mutex_enter(p->p_lock); 1128 p->p_nlwpid = 1; 1129 l->l_lid = 1; 1130 mutex_exit(p->p_lock); 1131 1132 /* 1133 * Call exec hook. Emulation code may NOT store reference to anything 1134 * from &pack. 1135 */ 1136 if (pack.ep_esch->es_emul->e_proc_exec) 1137 (*pack.ep_esch->es_emul->e_proc_exec)(p, &pack); 1138 1139 /* update p_emul, the old value is no longer needed */ 1140 p->p_emul = pack.ep_esch->es_emul; 1141 1142 /* ...and the same for p_execsw */ 1143 p->p_execsw = pack.ep_esch; 1144 1145 #ifdef __HAVE_SYSCALL_INTERN 1146 (*p->p_emul->e_syscall_intern)(p); 1147 #endif 1148 ktremul(); 1149 1150 /* Allow new references from the debugger/procfs. */ 1151 rw_exit(&p->p_reflock); 1152 rw_exit(&exec_lock); 1153 1154 mutex_enter(proc_lock); 1155 1156 if ((p->p_slflag & (PSL_TRACED|PSL_SYSCALL)) == PSL_TRACED) { 1157 KSI_INIT_EMPTY(&ksi); 1158 ksi.ksi_signo = SIGTRAP; 1159 ksi.ksi_lid = l->l_lid; 1160 kpsignal(p, &ksi, NULL); 1161 } 1162 1163 if (p->p_sflag & PS_STOPEXEC) { 1164 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1165 p->p_pptr->p_nstopchild++; 1166 p->p_pptr->p_waited = 0; 1167 mutex_enter(p->p_lock); 1168 ksiginfo_queue_init(&kq); 1169 sigclearall(p, &contsigmask, &kq); 1170 lwp_lock(l); 1171 l->l_stat = LSSTOP; 1172 p->p_stat = SSTOP; 1173 p->p_nrlwps--; 1174 mutex_exit(p->p_lock); 1175 mutex_exit(proc_lock); 1176 mi_switch(l); 1177 ksiginfo_queue_drain(&kq); 1178 KERNEL_LOCK(l->l_biglocks, l); 1179 } else { 1180 mutex_exit(proc_lock); 1181 } 1182 1183 PNBUF_PUT(pathbuf); 1184 PNBUF_PUT(resolvedpathbuf); 1185 return (EJUSTRETURN); 1186 1187 bad: 1188 /* free the vmspace-creation commands, and release their references */ 1189 kill_vmcmds(&pack.ep_vmcmds); 1190 /* kill any opened file descriptor, if necessary */ 1191 if (pack.ep_flags & EXEC_HASFD) { 1192 pack.ep_flags &= ~EXEC_HASFD; 1193 fd_close(pack.ep_fd); 1194 } 1195 /* close and put the exec'd file */ 1196 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 1197 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 1198 vput(pack.ep_vp); 1199 pool_put(&exec_pool, argp); 1200 1201 freehdr: 1202 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1203 if (pack.ep_emul_root != NULL) 1204 vrele(pack.ep_emul_root); 1205 if (pack.ep_interp != NULL) 1206 vrele(pack.ep_interp); 1207 1208 rw_exit(&exec_lock); 1209 1210 PNBUF_PUT(resolvedpathbuf); 1211 1212 clrflg: 1213 lwp_lock(l); 1214 l->l_flag |= oldlwpflags; 1215 lwp_unlock(l); 1216 rw_exit(&p->p_reflock); 1217 1218 PNBUF_PUT(pathbuf); 1219 1220 if (modgen != module_gen && error == ENOEXEC) { 1221 modgen = module_gen; 1222 exec_autoload(); 1223 goto retry; 1224 } 1225 1226 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0); 1227 return error; 1228 1229 exec_abort: 1230 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0); 1231 rw_exit(&p->p_reflock); 1232 rw_exit(&exec_lock); 1233 1234 PNBUF_PUT(pathbuf); 1235 PNBUF_PUT(resolvedpathbuf); 1236 1237 /* 1238 * the old process doesn't exist anymore. exit gracefully. 1239 * get rid of the (new) address space we have created, if any, get rid 1240 * of our namei data and vnode, and exit noting failure 1241 */ 1242 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1243 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1244 if (pack.ep_emul_arg) 1245 free(pack.ep_emul_arg, M_TEMP); 1246 pool_put(&exec_pool, argp); 1247 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1248 if (pack.ep_emul_root != NULL) 1249 vrele(pack.ep_emul_root); 1250 if (pack.ep_interp != NULL) 1251 vrele(pack.ep_interp); 1252 1253 /* Acquire the sched-state mutex (exit1() will release it). */ 1254 mutex_enter(p->p_lock); 1255 exit1(l, W_EXITCODE(error, SIGABRT)); 1256 1257 /* NOTREACHED */ 1258 return 0; 1259 } 1260 1261 1262 int 1263 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1264 char **stackp, void *argp) 1265 { 1266 char **cpp, *dp, *sp; 1267 size_t len; 1268 void *nullp; 1269 long argc, envc; 1270 int error; 1271 1272 cpp = (char **)*stackp; 1273 nullp = NULL; 1274 argc = arginfo->ps_nargvstr; 1275 envc = arginfo->ps_nenvstr; 1276 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) 1277 return error; 1278 1279 dp = (char *) (cpp + argc + envc + 2 + pack->ep_esch->es_arglen); 1280 sp = argp; 1281 1282 /* XXX don't copy them out, remap them! */ 1283 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1284 1285 for (; --argc >= 0; sp += len, dp += len) 1286 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1287 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1288 return error; 1289 1290 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1291 return error; 1292 1293 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1294 1295 for (; --envc >= 0; sp += len, dp += len) 1296 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1297 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1298 return error; 1299 1300 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1301 return error; 1302 1303 *stackp = (char *)cpp; 1304 return 0; 1305 } 1306 1307 1308 /* 1309 * Add execsw[] entries. 1310 */ 1311 int 1312 exec_add(struct execsw *esp, int count) 1313 { 1314 struct exec_entry *it; 1315 int i; 1316 1317 if (count == 0) { 1318 return 0; 1319 } 1320 1321 /* Check for duplicates. */ 1322 rw_enter(&exec_lock, RW_WRITER); 1323 for (i = 0; i < count; i++) { 1324 LIST_FOREACH(it, &ex_head, ex_list) { 1325 /* assume unique (makecmds, probe_func, emulation) */ 1326 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1327 it->ex_sw->u.elf_probe_func == 1328 esp[i].u.elf_probe_func && 1329 it->ex_sw->es_emul == esp[i].es_emul) { 1330 rw_exit(&exec_lock); 1331 return EEXIST; 1332 } 1333 } 1334 } 1335 1336 /* Allocate new entries. */ 1337 for (i = 0; i < count; i++) { 1338 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1339 it->ex_sw = &esp[i]; 1340 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1341 } 1342 1343 /* update execsw[] */ 1344 exec_init(0); 1345 rw_exit(&exec_lock); 1346 return 0; 1347 } 1348 1349 /* 1350 * Remove execsw[] entry. 1351 */ 1352 int 1353 exec_remove(struct execsw *esp, int count) 1354 { 1355 struct exec_entry *it, *next; 1356 int i; 1357 const struct proclist_desc *pd; 1358 proc_t *p; 1359 1360 if (count == 0) { 1361 return 0; 1362 } 1363 1364 /* Abort if any are busy. */ 1365 rw_enter(&exec_lock, RW_WRITER); 1366 for (i = 0; i < count; i++) { 1367 mutex_enter(proc_lock); 1368 for (pd = proclists; pd->pd_list != NULL; pd++) { 1369 PROCLIST_FOREACH(p, pd->pd_list) { 1370 if (p->p_execsw == &esp[i]) { 1371 mutex_exit(proc_lock); 1372 rw_exit(&exec_lock); 1373 return EBUSY; 1374 } 1375 } 1376 } 1377 mutex_exit(proc_lock); 1378 } 1379 1380 /* None are busy, so remove them all. */ 1381 for (i = 0; i < count; i++) { 1382 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1383 next = LIST_NEXT(it, ex_list); 1384 if (it->ex_sw == &esp[i]) { 1385 LIST_REMOVE(it, ex_list); 1386 kmem_free(it, sizeof(*it)); 1387 break; 1388 } 1389 } 1390 } 1391 1392 /* update execsw[] */ 1393 exec_init(0); 1394 rw_exit(&exec_lock); 1395 return 0; 1396 } 1397 1398 /* 1399 * Initialize exec structures. If init_boot is true, also does necessary 1400 * one-time initialization (it's called from main() that way). 1401 * Once system is multiuser, this should be called with exec_lock held, 1402 * i.e. via exec_{add|remove}(). 1403 */ 1404 int 1405 exec_init(int init_boot) 1406 { 1407 const struct execsw **sw; 1408 struct exec_entry *ex; 1409 SLIST_HEAD(,exec_entry) first; 1410 SLIST_HEAD(,exec_entry) any; 1411 SLIST_HEAD(,exec_entry) last; 1412 int i, sz; 1413 1414 if (init_boot) { 1415 /* do one-time initializations */ 1416 rw_init(&exec_lock); 1417 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1418 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1419 "execargs", &exec_palloc, IPL_NONE); 1420 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1421 } else { 1422 KASSERT(rw_write_held(&exec_lock)); 1423 } 1424 1425 /* Sort each entry onto the appropriate queue. */ 1426 SLIST_INIT(&first); 1427 SLIST_INIT(&any); 1428 SLIST_INIT(&last); 1429 sz = 0; 1430 LIST_FOREACH(ex, &ex_head, ex_list) { 1431 switch(ex->ex_sw->es_prio) { 1432 case EXECSW_PRIO_FIRST: 1433 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1434 break; 1435 case EXECSW_PRIO_ANY: 1436 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1437 break; 1438 case EXECSW_PRIO_LAST: 1439 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1440 break; 1441 default: 1442 panic("exec_init"); 1443 break; 1444 } 1445 sz++; 1446 } 1447 1448 /* 1449 * Create new execsw[]. Ensure we do not try a zero-sized 1450 * allocation. 1451 */ 1452 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1453 i = 0; 1454 SLIST_FOREACH(ex, &first, ex_slist) { 1455 sw[i++] = ex->ex_sw; 1456 } 1457 SLIST_FOREACH(ex, &any, ex_slist) { 1458 sw[i++] = ex->ex_sw; 1459 } 1460 SLIST_FOREACH(ex, &last, ex_slist) { 1461 sw[i++] = ex->ex_sw; 1462 } 1463 1464 /* Replace old execsw[] and free used memory. */ 1465 if (execsw != NULL) { 1466 kmem_free(__UNCONST(execsw), 1467 nexecs * sizeof(struct execsw *) + 1); 1468 } 1469 execsw = sw; 1470 nexecs = sz; 1471 1472 /* Figure out the maximum size of an exec header. */ 1473 exec_maxhdrsz = sizeof(int); 1474 for (i = 0; i < nexecs; i++) { 1475 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1476 exec_maxhdrsz = execsw[i]->es_hdrsz; 1477 } 1478 1479 return 0; 1480 } 1481 1482 static int 1483 exec_sigcode_map(struct proc *p, const struct emul *e) 1484 { 1485 vaddr_t va; 1486 vsize_t sz; 1487 int error; 1488 struct uvm_object *uobj; 1489 1490 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1491 1492 if (e->e_sigobject == NULL || sz == 0) { 1493 return 0; 1494 } 1495 1496 /* 1497 * If we don't have a sigobject for this emulation, create one. 1498 * 1499 * sigobject is an anonymous memory object (just like SYSV shared 1500 * memory) that we keep a permanent reference to and that we map 1501 * in all processes that need this sigcode. The creation is simple, 1502 * we create an object, add a permanent reference to it, map it in 1503 * kernel space, copy out the sigcode to it and unmap it. 1504 * We map it with PROT_READ|PROT_EXEC into the process just 1505 * the way sys_mmap() would map it. 1506 */ 1507 1508 uobj = *e->e_sigobject; 1509 if (uobj == NULL) { 1510 mutex_enter(&sigobject_lock); 1511 if ((uobj = *e->e_sigobject) == NULL) { 1512 uobj = uao_create(sz, 0); 1513 (*uobj->pgops->pgo_reference)(uobj); 1514 va = vm_map_min(kernel_map); 1515 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1516 uobj, 0, 0, 1517 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1518 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1519 printf("kernel mapping failed %d\n", error); 1520 (*uobj->pgops->pgo_detach)(uobj); 1521 mutex_exit(&sigobject_lock); 1522 return (error); 1523 } 1524 memcpy((void *)va, e->e_sigcode, sz); 1525 #ifdef PMAP_NEED_PROCWR 1526 pmap_procwr(&proc0, va, sz); 1527 #endif 1528 uvm_unmap(kernel_map, va, va + round_page(sz)); 1529 *e->e_sigobject = uobj; 1530 } 1531 mutex_exit(&sigobject_lock); 1532 } 1533 1534 /* Just a hint to uvm_map where to put it. */ 1535 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1536 round_page(sz)); 1537 1538 #ifdef __alpha__ 1539 /* 1540 * Tru64 puts /sbin/loader at the end of user virtual memory, 1541 * which causes the above calculation to put the sigcode at 1542 * an invalid address. Put it just below the text instead. 1543 */ 1544 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1545 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1546 } 1547 #endif 1548 1549 (*uobj->pgops->pgo_reference)(uobj); 1550 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1551 uobj, 0, 0, 1552 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1553 UVM_ADV_RANDOM, 0)); 1554 if (error) { 1555 (*uobj->pgops->pgo_detach)(uobj); 1556 return (error); 1557 } 1558 p->p_sigctx.ps_sigcode = (void *)va; 1559 return (0); 1560 } 1561