1 /* $NetBSD: kern_exec.c,v 1.298 2010/06/24 13:03:11 hannken 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 1.298 2010/06/24 13:03:11 hannken 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 /* This is now LWP 1 */ 770 l->l_lid = 1; 771 p->p_nlwpid = 1; 772 773 #ifdef KERN_SA 774 /* Release any SA state. */ 775 if (p->p_sa) 776 sa_release(p); 777 #endif /* KERN_SA */ 778 779 /* Remove POSIX timers */ 780 timers_free(p, TIMERS_POSIX); 781 782 /* adjust "active stack depth" for process VSZ */ 783 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 784 785 /* 786 * Do whatever is necessary to prepare the address space 787 * for remapping. Note that this might replace the current 788 * vmspace with another! 789 */ 790 uvmspace_exec(l, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 791 792 /* record proc's vnode, for use by procfs and others */ 793 if (p->p_textvp) 794 vrele(p->p_textvp); 795 vref(pack.ep_vp); 796 p->p_textvp = pack.ep_vp; 797 798 /* Now map address space */ 799 vm = p->p_vmspace; 800 vm->vm_taddr = (void *)pack.ep_taddr; 801 vm->vm_tsize = btoc(pack.ep_tsize); 802 vm->vm_daddr = (void*)pack.ep_daddr; 803 vm->vm_dsize = btoc(pack.ep_dsize); 804 vm->vm_ssize = btoc(pack.ep_ssize); 805 vm->vm_issize = 0; 806 vm->vm_maxsaddr = (void *)pack.ep_maxsaddr; 807 vm->vm_minsaddr = (void *)pack.ep_minsaddr; 808 809 #ifdef PAX_ASLR 810 pax_aslr_init(l, vm); 811 #endif /* PAX_ASLR */ 812 813 /* create the new process's VM space by running the vmcmds */ 814 #ifdef DIAGNOSTIC 815 if (pack.ep_vmcmds.evs_used == 0) 816 panic("execve: no vmcmds"); 817 #endif 818 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 819 struct exec_vmcmd *vcp; 820 821 vcp = &pack.ep_vmcmds.evs_cmds[i]; 822 if (vcp->ev_flags & VMCMD_RELATIVE) { 823 #ifdef DIAGNOSTIC 824 if (base_vcp == NULL) 825 panic("execve: relative vmcmd with no base"); 826 if (vcp->ev_flags & VMCMD_BASE) 827 panic("execve: illegal base & relative vmcmd"); 828 #endif 829 vcp->ev_addr += base_vcp->ev_addr; 830 } 831 error = (*vcp->ev_proc)(l, vcp); 832 #ifdef DEBUG_EXEC 833 if (error) { 834 size_t j; 835 struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0]; 836 for (j = 0; j <= i; j++) 837 uprintf( 838 "vmcmd[%zu] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n", 839 j, vp[j].ev_addr, vp[j].ev_len, 840 vp[j].ev_offset, vp[j].ev_prot, 841 vp[j].ev_flags); 842 } 843 #endif /* DEBUG_EXEC */ 844 if (vcp->ev_flags & VMCMD_BASE) 845 base_vcp = vcp; 846 } 847 848 /* free the vmspace-creation commands, and release their references */ 849 kill_vmcmds(&pack.ep_vmcmds); 850 851 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 852 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 853 vput(pack.ep_vp); 854 855 /* if an error happened, deallocate and punt */ 856 if (error) { 857 DPRINTF(("execve: vmcmd %zu failed: %d\n", i - 1, error)); 858 goto exec_abort; 859 } 860 861 /* remember information about the process */ 862 arginfo.ps_nargvstr = argc; 863 arginfo.ps_nenvstr = envc; 864 865 /* set command name & other accounting info */ 866 commandname = strrchr(pack.ep_resolvedname, '/'); 867 if (commandname != NULL) { 868 commandname++; 869 } else { 870 commandname = pack.ep_resolvedname; 871 } 872 i = min(strlen(commandname), MAXCOMLEN); 873 (void)memcpy(p->p_comm, commandname, i); 874 p->p_comm[i] = '\0'; 875 876 dp = PNBUF_GET(); 877 /* 878 * If the path starts with /, we don't need to do any work. 879 * This handles the majority of the cases. 880 * In the future perhaps we could canonicalize it? 881 */ 882 if (pathbuf[0] == '/') 883 (void)strlcpy(pack.ep_path = dp, pathbuf, MAXPATHLEN); 884 #ifdef notyet 885 /* 886 * Although this works most of the time [since the entry was just 887 * entered in the cache] we don't use it because it theoretically 888 * can fail and it is not the cleanest interface, because there 889 * could be races. When the namei cache is re-written, this can 890 * be changed to use the appropriate function. 891 */ 892 else if (!(error = vnode_to_path(dp, MAXPATHLEN, p->p_textvp, l, p))) 893 pack.ep_path = dp; 894 #endif 895 else { 896 #ifdef notyet 897 printf("Cannot get path for pid %d [%s] (error %d)", 898 (int)p->p_pid, p->p_comm, error); 899 #endif 900 pack.ep_path = NULL; 901 PNBUF_PUT(dp); 902 } 903 904 stack = (char *)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, 905 STACK_PTHREADSPACE + sizeof(struct ps_strings) + szsigcode), 906 len - (sizeof(struct ps_strings) + szsigcode)); 907 908 #ifdef __MACHINE_STACK_GROWS_UP 909 /* 910 * The copyargs call always copies into lower addresses 911 * first, moving towards higher addresses, starting with 912 * the stack pointer that we give. When the stack grows 913 * down, this puts argc/argv/envp very shallow on the 914 * stack, right at the first user stack pointer. 915 * When the stack grows up, the situation is reversed. 916 * 917 * Normally, this is no big deal. But the ld_elf.so _rtld() 918 * function expects to be called with a single pointer to 919 * a region that has a few words it can stash values into, 920 * followed by argc/argv/envp. When the stack grows down, 921 * it's easy to decrement the stack pointer a little bit to 922 * allocate the space for these few words and pass the new 923 * stack pointer to _rtld. When the stack grows up, however, 924 * a few words before argc is part of the signal trampoline, XXX 925 * so we have a problem. 926 * 927 * Instead of changing how _rtld works, we take the easy way 928 * out and steal 32 bytes before we call copyargs. 929 * This extra space was allowed for when 'len' was calculated. 930 */ 931 stack += RTLD_GAP; 932 #endif /* __MACHINE_STACK_GROWS_UP */ 933 934 /* Now copy argc, args & environ to new stack */ 935 error = (*pack.ep_esch->es_copyargs)(l, &pack, &arginfo, &stack, argp); 936 if (pack.ep_path) { 937 PNBUF_PUT(pack.ep_path); 938 pack.ep_path = NULL; 939 } 940 if (error) { 941 DPRINTF(("execve: copyargs failed %d\n", error)); 942 goto exec_abort; 943 } 944 /* Move the stack back to original point */ 945 stack = (char *)STACK_GROW(vm->vm_minsaddr, len); 946 947 /* fill process ps_strings info */ 948 p->p_psstr = (struct ps_strings *) 949 STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, STACK_PTHREADSPACE), 950 sizeof(struct ps_strings)); 951 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 952 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 953 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 954 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 955 956 /* copy out the process's ps_strings structure */ 957 if ((error = copyout(aip, (char *)p->p_psstr, 958 sizeof(arginfo))) != 0) { 959 DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n", 960 aip, (char *)p->p_psstr, (long)sizeof(arginfo))); 961 goto exec_abort; 962 } 963 964 fd_closeexec(); /* handle close on exec */ 965 execsigs(p); /* reset catched signals */ 966 967 l->l_ctxlink = NULL; /* reset ucontext link */ 968 969 970 p->p_acflag &= ~AFORK; 971 mutex_enter(p->p_lock); 972 p->p_flag |= PK_EXEC; 973 mutex_exit(p->p_lock); 974 975 /* 976 * Stop profiling. 977 */ 978 if ((p->p_stflag & PST_PROFIL) != 0) { 979 mutex_spin_enter(&p->p_stmutex); 980 stopprofclock(p); 981 mutex_spin_exit(&p->p_stmutex); 982 } 983 984 /* 985 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 986 * exited and exec()/exit() are the only places it will be cleared. 987 */ 988 if ((p->p_lflag & PL_PPWAIT) != 0) { 989 mutex_enter(proc_lock); 990 p->p_lflag &= ~PL_PPWAIT; 991 cv_broadcast(&p->p_pptr->p_waitcv); 992 mutex_exit(proc_lock); 993 } 994 995 /* 996 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 997 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 998 * out additional references on the process for the moment. 999 */ 1000 if ((p->p_slflag & PSL_TRACED) == 0 && 1001 1002 (((attr.va_mode & S_ISUID) != 0 && 1003 kauth_cred_geteuid(l->l_cred) != attr.va_uid) || 1004 1005 ((attr.va_mode & S_ISGID) != 0 && 1006 kauth_cred_getegid(l->l_cred) != attr.va_gid))) { 1007 /* 1008 * Mark the process as SUGID before we do 1009 * anything that might block. 1010 */ 1011 proc_crmod_enter(); 1012 proc_crmod_leave(NULL, NULL, true); 1013 1014 /* Make sure file descriptors 0..2 are in use. */ 1015 if ((error = fd_checkstd()) != 0) { 1016 DPRINTF(("execve: fdcheckstd failed %d\n", error)); 1017 goto exec_abort; 1018 } 1019 1020 /* 1021 * Copy the credential so other references don't see our 1022 * changes. 1023 */ 1024 l->l_cred = kauth_cred_copy(l->l_cred); 1025 #ifdef KTRACE 1026 /* 1027 * If the persistent trace flag isn't set, turn off. 1028 */ 1029 if (p->p_tracep) { 1030 mutex_enter(&ktrace_lock); 1031 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1032 ktrderef(p); 1033 mutex_exit(&ktrace_lock); 1034 } 1035 #endif 1036 if (attr.va_mode & S_ISUID) 1037 kauth_cred_seteuid(l->l_cred, attr.va_uid); 1038 if (attr.va_mode & S_ISGID) 1039 kauth_cred_setegid(l->l_cred, attr.va_gid); 1040 } else { 1041 if (kauth_cred_geteuid(l->l_cred) == 1042 kauth_cred_getuid(l->l_cred) && 1043 kauth_cred_getegid(l->l_cred) == 1044 kauth_cred_getgid(l->l_cred)) 1045 p->p_flag &= ~PK_SUGID; 1046 } 1047 1048 /* 1049 * Copy the credential so other references don't see our changes. 1050 * Test to see if this is necessary first, since in the common case 1051 * we won't need a private reference. 1052 */ 1053 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1054 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1055 l->l_cred = kauth_cred_copy(l->l_cred); 1056 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1057 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1058 } 1059 1060 /* Update the master credentials. */ 1061 if (l->l_cred != p->p_cred) { 1062 kauth_cred_t ocred; 1063 1064 kauth_cred_hold(l->l_cred); 1065 mutex_enter(p->p_lock); 1066 ocred = p->p_cred; 1067 p->p_cred = l->l_cred; 1068 mutex_exit(p->p_lock); 1069 kauth_cred_free(ocred); 1070 } 1071 1072 #if defined(__HAVE_RAS) 1073 /* 1074 * Remove all RASs from the address space. 1075 */ 1076 ras_purgeall(); 1077 #endif 1078 1079 doexechooks(p); 1080 1081 /* setup new registers and do misc. setup. */ 1082 (*pack.ep_esch->es_emul->e_setregs)(l, &pack, (vaddr_t)stack); 1083 if (pack.ep_esch->es_setregs) 1084 (*pack.ep_esch->es_setregs)(l, &pack, (vaddr_t)stack); 1085 1086 /* map the process's signal trampoline code */ 1087 if (exec_sigcode_map(p, pack.ep_esch->es_emul)) { 1088 DPRINTF(("execve: map sigcode failed %d\n", error)); 1089 goto exec_abort; 1090 } 1091 1092 pool_put(&exec_pool, argp); 1093 1094 /* notify others that we exec'd */ 1095 KNOTE(&p->p_klist, NOTE_EXEC); 1096 1097 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1098 1099 SDT_PROBE(proc,,,exec_success, path, 0, 0, 0, 0); 1100 1101 /* The emulation root will usually have been found when we looked 1102 * for the elf interpreter (or similar), if not look now. */ 1103 if (pack.ep_esch->es_emul->e_path != NULL && pack.ep_emul_root == NULL) 1104 emul_find_root(l, &pack); 1105 1106 /* Any old emulation root got removed by fdcloseexec */ 1107 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1108 p->p_cwdi->cwdi_edir = pack.ep_emul_root; 1109 rw_exit(&p->p_cwdi->cwdi_lock); 1110 pack.ep_emul_root = NULL; 1111 if (pack.ep_interp != NULL) 1112 vrele(pack.ep_interp); 1113 1114 /* 1115 * Call emulation specific exec hook. This can setup per-process 1116 * p->p_emuldata or do any other per-process stuff an emulation needs. 1117 * 1118 * If we are executing process of different emulation than the 1119 * original forked process, call e_proc_exit() of the old emulation 1120 * first, then e_proc_exec() of new emulation. If the emulation is 1121 * same, the exec hook code should deallocate any old emulation 1122 * resources held previously by this process. 1123 */ 1124 if (p->p_emul && p->p_emul->e_proc_exit 1125 && p->p_emul != pack.ep_esch->es_emul) 1126 (*p->p_emul->e_proc_exit)(p); 1127 1128 /* 1129 * Call exec hook. Emulation code may NOT store reference to anything 1130 * from &pack. 1131 */ 1132 if (pack.ep_esch->es_emul->e_proc_exec) 1133 (*pack.ep_esch->es_emul->e_proc_exec)(p, &pack); 1134 1135 /* update p_emul, the old value is no longer needed */ 1136 p->p_emul = pack.ep_esch->es_emul; 1137 1138 /* ...and the same for p_execsw */ 1139 p->p_execsw = pack.ep_esch; 1140 1141 #ifdef __HAVE_SYSCALL_INTERN 1142 (*p->p_emul->e_syscall_intern)(p); 1143 #endif 1144 ktremul(); 1145 1146 /* Allow new references from the debugger/procfs. */ 1147 rw_exit(&p->p_reflock); 1148 rw_exit(&exec_lock); 1149 1150 mutex_enter(proc_lock); 1151 1152 if ((p->p_slflag & (PSL_TRACED|PSL_SYSCALL)) == PSL_TRACED) { 1153 KSI_INIT_EMPTY(&ksi); 1154 ksi.ksi_signo = SIGTRAP; 1155 ksi.ksi_lid = l->l_lid; 1156 kpsignal(p, &ksi, NULL); 1157 } 1158 1159 if (p->p_sflag & PS_STOPEXEC) { 1160 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1161 p->p_pptr->p_nstopchild++; 1162 p->p_pptr->p_waited = 0; 1163 mutex_enter(p->p_lock); 1164 ksiginfo_queue_init(&kq); 1165 sigclearall(p, &contsigmask, &kq); 1166 lwp_lock(l); 1167 l->l_stat = LSSTOP; 1168 p->p_stat = SSTOP; 1169 p->p_nrlwps--; 1170 mutex_exit(p->p_lock); 1171 mutex_exit(proc_lock); 1172 mi_switch(l); 1173 ksiginfo_queue_drain(&kq); 1174 KERNEL_LOCK(l->l_biglocks, l); 1175 } else { 1176 mutex_exit(proc_lock); 1177 } 1178 1179 PNBUF_PUT(pathbuf); 1180 PNBUF_PUT(resolvedpathbuf); 1181 return (EJUSTRETURN); 1182 1183 bad: 1184 /* free the vmspace-creation commands, and release their references */ 1185 kill_vmcmds(&pack.ep_vmcmds); 1186 /* kill any opened file descriptor, if necessary */ 1187 if (pack.ep_flags & EXEC_HASFD) { 1188 pack.ep_flags &= ~EXEC_HASFD; 1189 fd_close(pack.ep_fd); 1190 } 1191 /* close and put the exec'd file */ 1192 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 1193 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 1194 vput(pack.ep_vp); 1195 pool_put(&exec_pool, argp); 1196 1197 freehdr: 1198 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1199 if (pack.ep_emul_root != NULL) 1200 vrele(pack.ep_emul_root); 1201 if (pack.ep_interp != NULL) 1202 vrele(pack.ep_interp); 1203 1204 rw_exit(&exec_lock); 1205 1206 PNBUF_PUT(resolvedpathbuf); 1207 1208 clrflg: 1209 lwp_lock(l); 1210 l->l_flag |= oldlwpflags; 1211 lwp_unlock(l); 1212 rw_exit(&p->p_reflock); 1213 1214 PNBUF_PUT(pathbuf); 1215 1216 if (modgen != module_gen && error == ENOEXEC) { 1217 modgen = module_gen; 1218 exec_autoload(); 1219 goto retry; 1220 } 1221 1222 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0); 1223 return error; 1224 1225 exec_abort: 1226 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0); 1227 rw_exit(&p->p_reflock); 1228 rw_exit(&exec_lock); 1229 1230 PNBUF_PUT(pathbuf); 1231 PNBUF_PUT(resolvedpathbuf); 1232 1233 /* 1234 * the old process doesn't exist anymore. exit gracefully. 1235 * get rid of the (new) address space we have created, if any, get rid 1236 * of our namei data and vnode, and exit noting failure 1237 */ 1238 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1239 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1240 if (pack.ep_emul_arg) 1241 free(pack.ep_emul_arg, M_TEMP); 1242 pool_put(&exec_pool, argp); 1243 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1244 if (pack.ep_emul_root != NULL) 1245 vrele(pack.ep_emul_root); 1246 if (pack.ep_interp != NULL) 1247 vrele(pack.ep_interp); 1248 1249 /* Acquire the sched-state mutex (exit1() will release it). */ 1250 mutex_enter(p->p_lock); 1251 exit1(l, W_EXITCODE(error, SIGABRT)); 1252 1253 /* NOTREACHED */ 1254 return 0; 1255 } 1256 1257 1258 int 1259 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1260 char **stackp, void *argp) 1261 { 1262 char **cpp, *dp, *sp; 1263 size_t len; 1264 void *nullp; 1265 long argc, envc; 1266 int error; 1267 1268 cpp = (char **)*stackp; 1269 nullp = NULL; 1270 argc = arginfo->ps_nargvstr; 1271 envc = arginfo->ps_nenvstr; 1272 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) 1273 return error; 1274 1275 dp = (char *) (cpp + argc + envc + 2 + pack->ep_esch->es_arglen); 1276 sp = argp; 1277 1278 /* XXX don't copy them out, remap them! */ 1279 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1280 1281 for (; --argc >= 0; sp += len, dp += len) 1282 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1283 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1284 return error; 1285 1286 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1287 return error; 1288 1289 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1290 1291 for (; --envc >= 0; sp += len, dp += len) 1292 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1293 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1294 return error; 1295 1296 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1297 return error; 1298 1299 *stackp = (char *)cpp; 1300 return 0; 1301 } 1302 1303 1304 /* 1305 * Add execsw[] entries. 1306 */ 1307 int 1308 exec_add(struct execsw *esp, int count) 1309 { 1310 struct exec_entry *it; 1311 int i; 1312 1313 if (count == 0) { 1314 return 0; 1315 } 1316 1317 /* Check for duplicates. */ 1318 rw_enter(&exec_lock, RW_WRITER); 1319 for (i = 0; i < count; i++) { 1320 LIST_FOREACH(it, &ex_head, ex_list) { 1321 /* assume unique (makecmds, probe_func, emulation) */ 1322 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1323 it->ex_sw->u.elf_probe_func == 1324 esp[i].u.elf_probe_func && 1325 it->ex_sw->es_emul == esp[i].es_emul) { 1326 rw_exit(&exec_lock); 1327 return EEXIST; 1328 } 1329 } 1330 } 1331 1332 /* Allocate new entries. */ 1333 for (i = 0; i < count; i++) { 1334 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1335 it->ex_sw = &esp[i]; 1336 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1337 } 1338 1339 /* update execsw[] */ 1340 exec_init(0); 1341 rw_exit(&exec_lock); 1342 return 0; 1343 } 1344 1345 /* 1346 * Remove execsw[] entry. 1347 */ 1348 int 1349 exec_remove(struct execsw *esp, int count) 1350 { 1351 struct exec_entry *it, *next; 1352 int i; 1353 const struct proclist_desc *pd; 1354 proc_t *p; 1355 1356 if (count == 0) { 1357 return 0; 1358 } 1359 1360 /* Abort if any are busy. */ 1361 rw_enter(&exec_lock, RW_WRITER); 1362 for (i = 0; i < count; i++) { 1363 mutex_enter(proc_lock); 1364 for (pd = proclists; pd->pd_list != NULL; pd++) { 1365 PROCLIST_FOREACH(p, pd->pd_list) { 1366 if (p->p_execsw == &esp[i]) { 1367 mutex_exit(proc_lock); 1368 rw_exit(&exec_lock); 1369 return EBUSY; 1370 } 1371 } 1372 } 1373 mutex_exit(proc_lock); 1374 } 1375 1376 /* None are busy, so remove them all. */ 1377 for (i = 0; i < count; i++) { 1378 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1379 next = LIST_NEXT(it, ex_list); 1380 if (it->ex_sw == &esp[i]) { 1381 LIST_REMOVE(it, ex_list); 1382 kmem_free(it, sizeof(*it)); 1383 break; 1384 } 1385 } 1386 } 1387 1388 /* update execsw[] */ 1389 exec_init(0); 1390 rw_exit(&exec_lock); 1391 return 0; 1392 } 1393 1394 /* 1395 * Initialize exec structures. If init_boot is true, also does necessary 1396 * one-time initialization (it's called from main() that way). 1397 * Once system is multiuser, this should be called with exec_lock held, 1398 * i.e. via exec_{add|remove}(). 1399 */ 1400 int 1401 exec_init(int init_boot) 1402 { 1403 const struct execsw **sw; 1404 struct exec_entry *ex; 1405 SLIST_HEAD(,exec_entry) first; 1406 SLIST_HEAD(,exec_entry) any; 1407 SLIST_HEAD(,exec_entry) last; 1408 int i, sz; 1409 1410 if (init_boot) { 1411 /* do one-time initializations */ 1412 rw_init(&exec_lock); 1413 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1414 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1415 "execargs", &exec_palloc, IPL_NONE); 1416 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1417 } else { 1418 KASSERT(rw_write_held(&exec_lock)); 1419 } 1420 1421 /* Sort each entry onto the appropriate queue. */ 1422 SLIST_INIT(&first); 1423 SLIST_INIT(&any); 1424 SLIST_INIT(&last); 1425 sz = 0; 1426 LIST_FOREACH(ex, &ex_head, ex_list) { 1427 switch(ex->ex_sw->es_prio) { 1428 case EXECSW_PRIO_FIRST: 1429 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1430 break; 1431 case EXECSW_PRIO_ANY: 1432 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1433 break; 1434 case EXECSW_PRIO_LAST: 1435 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1436 break; 1437 default: 1438 panic("exec_init"); 1439 break; 1440 } 1441 sz++; 1442 } 1443 1444 /* 1445 * Create new execsw[]. Ensure we do not try a zero-sized 1446 * allocation. 1447 */ 1448 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1449 i = 0; 1450 SLIST_FOREACH(ex, &first, ex_slist) { 1451 sw[i++] = ex->ex_sw; 1452 } 1453 SLIST_FOREACH(ex, &any, ex_slist) { 1454 sw[i++] = ex->ex_sw; 1455 } 1456 SLIST_FOREACH(ex, &last, ex_slist) { 1457 sw[i++] = ex->ex_sw; 1458 } 1459 1460 /* Replace old execsw[] and free used memory. */ 1461 if (execsw != NULL) { 1462 kmem_free(__UNCONST(execsw), 1463 nexecs * sizeof(struct execsw *) + 1); 1464 } 1465 execsw = sw; 1466 nexecs = sz; 1467 1468 /* Figure out the maximum size of an exec header. */ 1469 exec_maxhdrsz = sizeof(int); 1470 for (i = 0; i < nexecs; i++) { 1471 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1472 exec_maxhdrsz = execsw[i]->es_hdrsz; 1473 } 1474 1475 return 0; 1476 } 1477 1478 static int 1479 exec_sigcode_map(struct proc *p, const struct emul *e) 1480 { 1481 vaddr_t va; 1482 vsize_t sz; 1483 int error; 1484 struct uvm_object *uobj; 1485 1486 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1487 1488 if (e->e_sigobject == NULL || sz == 0) { 1489 return 0; 1490 } 1491 1492 /* 1493 * If we don't have a sigobject for this emulation, create one. 1494 * 1495 * sigobject is an anonymous memory object (just like SYSV shared 1496 * memory) that we keep a permanent reference to and that we map 1497 * in all processes that need this sigcode. The creation is simple, 1498 * we create an object, add a permanent reference to it, map it in 1499 * kernel space, copy out the sigcode to it and unmap it. 1500 * We map it with PROT_READ|PROT_EXEC into the process just 1501 * the way sys_mmap() would map it. 1502 */ 1503 1504 uobj = *e->e_sigobject; 1505 if (uobj == NULL) { 1506 mutex_enter(&sigobject_lock); 1507 if ((uobj = *e->e_sigobject) == NULL) { 1508 uobj = uao_create(sz, 0); 1509 (*uobj->pgops->pgo_reference)(uobj); 1510 va = vm_map_min(kernel_map); 1511 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1512 uobj, 0, 0, 1513 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1514 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1515 printf("kernel mapping failed %d\n", error); 1516 (*uobj->pgops->pgo_detach)(uobj); 1517 mutex_exit(&sigobject_lock); 1518 return (error); 1519 } 1520 memcpy((void *)va, e->e_sigcode, sz); 1521 #ifdef PMAP_NEED_PROCWR 1522 pmap_procwr(&proc0, va, sz); 1523 #endif 1524 uvm_unmap(kernel_map, va, va + round_page(sz)); 1525 *e->e_sigobject = uobj; 1526 } 1527 mutex_exit(&sigobject_lock); 1528 } 1529 1530 /* Just a hint to uvm_map where to put it. */ 1531 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1532 round_page(sz)); 1533 1534 #ifdef __alpha__ 1535 /* 1536 * Tru64 puts /sbin/loader at the end of user virtual memory, 1537 * which causes the above calculation to put the sigcode at 1538 * an invalid address. Put it just below the text instead. 1539 */ 1540 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1541 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1542 } 1543 #endif 1544 1545 (*uobj->pgops->pgo_reference)(uobj); 1546 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1547 uobj, 0, 0, 1548 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1549 UVM_ADV_RANDOM, 0)); 1550 if (error) { 1551 (*uobj->pgops->pgo_detach)(uobj); 1552 return (error); 1553 } 1554 p->p_sigctx.ps_sigcode = (void *)va; 1555 return (0); 1556 } 1557