1 /* $NetBSD: kern_exec.c,v 1.294 2010/03/01 21:10:15 darran 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 1.294 2010/03/01 21:10:15 darran 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) 282 { 283 int error, i; 284 struct vnode *vp; 285 struct nameidata *ndp; 286 size_t resid; 287 288 ndp = epp->ep_ndp; 289 ndp->ni_cnd.cn_nameiop = LOOKUP; 290 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME | TRYEMULROOT; 291 /* first get the vnode */ 292 if ((error = namei(ndp)) != 0) 293 return error; 294 epp->ep_vp = vp = ndp->ni_vp; 295 296 /* check access and type */ 297 if (vp->v_type != VREG) { 298 error = EACCES; 299 goto bad1; 300 } 301 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 302 goto bad1; 303 304 /* get attributes */ 305 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 306 goto bad1; 307 308 /* Check mount point */ 309 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 310 error = EACCES; 311 goto bad1; 312 } 313 if (vp->v_mount->mnt_flag & MNT_NOSUID) 314 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 315 316 /* try to open it */ 317 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 318 goto bad1; 319 320 /* unlock vp, since we need it unlocked from here on out. */ 321 VOP_UNLOCK(vp, 0); 322 323 #if NVERIEXEC > 0 324 error = veriexec_verify(l, vp, ndp->ni_cnd.cn_pnbuf, 325 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 326 NULL); 327 if (error) 328 goto bad2; 329 #endif /* NVERIEXEC > 0 */ 330 331 #ifdef PAX_SEGVGUARD 332 error = pax_segvguard(l, vp, ndp->ni_cnd.cn_pnbuf, false); 333 if (error) 334 goto bad2; 335 #endif /* PAX_SEGVGUARD */ 336 337 /* now we have the file, get the exec header */ 338 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 339 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 340 if (error) 341 goto bad2; 342 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 343 344 /* 345 * Set up default address space limits. Can be overridden 346 * by individual exec packages. 347 * 348 * XXX probably should be all done in the exec packages. 349 */ 350 epp->ep_vm_minaddr = VM_MIN_ADDRESS; 351 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 352 /* 353 * set up the vmcmds for creation of the process 354 * address space 355 */ 356 error = ENOEXEC; 357 for (i = 0; i < nexecs; i++) { 358 int newerror; 359 360 epp->ep_esch = execsw[i]; 361 newerror = (*execsw[i]->es_makecmds)(l, epp); 362 363 if (!newerror) { 364 /* Seems ok: check that entry point is sane */ 365 if (epp->ep_entry > VM_MAXUSER_ADDRESS) { 366 error = ENOEXEC; 367 break; 368 } 369 370 /* check limits */ 371 if ((epp->ep_tsize > MAXTSIZ) || 372 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 373 [RLIMIT_DATA].rlim_cur)) { 374 error = ENOMEM; 375 break; 376 } 377 return 0; 378 } 379 380 if (epp->ep_emul_root != NULL) { 381 vrele(epp->ep_emul_root); 382 epp->ep_emul_root = NULL; 383 } 384 if (epp->ep_interp != NULL) { 385 vrele(epp->ep_interp); 386 epp->ep_interp = NULL; 387 } 388 389 /* make sure the first "interesting" error code is saved. */ 390 if (error == ENOEXEC) 391 error = newerror; 392 393 if (epp->ep_flags & EXEC_DESTR) 394 /* Error from "#!" code, tidied up by recursive call */ 395 return error; 396 } 397 398 /* not found, error */ 399 400 /* 401 * free any vmspace-creation commands, 402 * and release their references 403 */ 404 kill_vmcmds(&epp->ep_vmcmds); 405 406 bad2: 407 /* 408 * close and release the vnode, restore the old one, free the 409 * pathname buf, and punt. 410 */ 411 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 412 VOP_CLOSE(vp, FREAD, l->l_cred); 413 vput(vp); 414 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 415 return error; 416 417 bad1: 418 /* 419 * free the namei pathname buffer, and put the vnode 420 * (which we don't yet have open). 421 */ 422 vput(vp); /* was still locked */ 423 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 424 return error; 425 } 426 427 #ifdef __MACHINE_STACK_GROWS_UP 428 #define STACK_PTHREADSPACE NBPG 429 #else 430 #define STACK_PTHREADSPACE 0 431 #endif 432 433 static int 434 execve_fetch_element(char * const *array, size_t index, char **value) 435 { 436 return copyin(array + index, value, sizeof(*value)); 437 } 438 439 /* 440 * exec system call 441 */ 442 /* ARGSUSED */ 443 int 444 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 445 { 446 /* { 447 syscallarg(const char *) path; 448 syscallarg(char * const *) argp; 449 syscallarg(char * const *) envp; 450 } */ 451 452 return execve1(l, SCARG(uap, path), SCARG(uap, argp), 453 SCARG(uap, envp), execve_fetch_element); 454 } 455 456 /* 457 * Load modules to try and execute an image that we do not understand. 458 * If no execsw entries are present, we load those likely to be needed 459 * in order to run native images only. Otherwise, we autoload all 460 * possible modules that could let us run the binary. XXX lame 461 */ 462 static void 463 exec_autoload(void) 464 { 465 #ifdef MODULAR 466 static const char * const native[] = { 467 "exec_elf32", 468 "exec_elf64", 469 "exec_script", 470 NULL 471 }; 472 static const char * const compat[] = { 473 "exec_elf32", 474 "exec_elf64", 475 "exec_script", 476 "exec_aout", 477 "exec_coff", 478 "exec_ecoff", 479 "compat_aoutm68k", 480 "compat_freebsd", 481 "compat_ibcs2", 482 "compat_irix", 483 "compat_linux", 484 "compat_linux32", 485 "compat_netbsd32", 486 "compat_sunos", 487 "compat_sunos32", 488 "compat_svr4", 489 "compat_svr4_32", 490 "compat_ultrix", 491 NULL 492 }; 493 char const * const *list; 494 int i; 495 496 mutex_enter(&module_lock); 497 list = (nexecs == 0 ? native : compat); 498 for (i = 0; list[i] != NULL; i++) { 499 if (module_autoload(list[i], MODULE_CLASS_MISC) != 0) { 500 continue; 501 } 502 mutex_exit(&module_lock); 503 yield(); 504 mutex_enter(&module_lock); 505 } 506 mutex_exit(&module_lock); 507 #endif 508 } 509 510 int 511 execve1(struct lwp *l, const char *path, char * const *args, 512 char * const *envs, execve_fetch_element_t fetch_element) 513 { 514 int error; 515 struct exec_package pack; 516 struct nameidata nid; 517 struct vattr attr; 518 struct proc *p; 519 char *argp; 520 char *dp, *sp; 521 long argc, envc; 522 size_t i, len; 523 char *stack; 524 struct ps_strings arginfo; 525 struct ps_strings *aip = &arginfo; 526 struct vmspace *vm; 527 struct exec_fakearg *tmpfap; 528 int szsigcode; 529 struct exec_vmcmd *base_vcp; 530 int oldlwpflags; 531 ksiginfo_t ksi; 532 ksiginfoq_t kq; 533 char *pathbuf; 534 size_t pathbuflen; 535 u_int modgen; 536 537 p = l->l_proc; 538 modgen = 0; 539 540 SDT_PROBE(proc,,,exec, path, 0, 0, 0, 0); 541 542 /* 543 * Check if we have exceeded our number of processes limit. 544 * This is so that we handle the case where a root daemon 545 * forked, ran setuid to become the desired user and is trying 546 * to exec. The obvious place to do the reference counting check 547 * is setuid(), but we don't do the reference counting check there 548 * like other OS's do because then all the programs that use setuid() 549 * must be modified to check the return code of setuid() and exit(). 550 * It is dangerous to make setuid() fail, because it fails open and 551 * the program will continue to run as root. If we make it succeed 552 * and return an error code, again we are not enforcing the limit. 553 * The best place to enforce the limit is here, when the process tries 554 * to execute a new image, because eventually the process will need 555 * to call exec in order to do something useful. 556 */ 557 retry: 558 if ((p->p_flag & PK_SUGID) && kauth_authorize_generic(l->l_cred, 559 KAUTH_GENERIC_ISSUSER, NULL) != 0 && chgproccnt(kauth_cred_getuid( 560 l->l_cred), 0) > p->p_rlimit[RLIMIT_NPROC].rlim_cur) 561 return EAGAIN; 562 563 oldlwpflags = l->l_flag & (LW_SA | LW_SA_UPCALL); 564 if (l->l_flag & LW_SA) { 565 lwp_lock(l); 566 l->l_flag &= ~(LW_SA | LW_SA_UPCALL); 567 lwp_unlock(l); 568 } 569 570 /* 571 * Drain existing references and forbid new ones. The process 572 * should be left alone until we're done here. This is necessary 573 * to avoid race conditions - e.g. in ptrace() - that might allow 574 * a local user to illicitly obtain elevated privileges. 575 */ 576 rw_enter(&p->p_reflock, RW_WRITER); 577 578 base_vcp = NULL; 579 /* 580 * Init the namei data to point the file user's program name. 581 * This is done here rather than in check_exec(), so that it's 582 * possible to override this settings if any of makecmd/probe 583 * functions call check_exec() recursively - for example, 584 * see exec_script_makecmds(). 585 */ 586 pathbuf = PNBUF_GET(); 587 error = copyinstr(path, pathbuf, MAXPATHLEN, &pathbuflen); 588 if (error) { 589 DPRINTF(("execve: copyinstr path %d", error)); 590 goto clrflg; 591 } 592 593 NDINIT(&nid, LOOKUP, NOFOLLOW | TRYEMULROOT, UIO_SYSSPACE, pathbuf); 594 595 /* 596 * initialize the fields of the exec package. 597 */ 598 pack.ep_name = path; 599 pack.ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 600 pack.ep_hdrlen = exec_maxhdrsz; 601 pack.ep_hdrvalid = 0; 602 pack.ep_ndp = &nid; 603 pack.ep_emul_arg = NULL; 604 pack.ep_vmcmds.evs_cnt = 0; 605 pack.ep_vmcmds.evs_used = 0; 606 pack.ep_vap = &attr; 607 pack.ep_flags = 0; 608 pack.ep_emul_root = NULL; 609 pack.ep_interp = NULL; 610 pack.ep_esch = NULL; 611 pack.ep_pax_flags = 0; 612 613 rw_enter(&exec_lock, RW_READER); 614 615 /* see if we can run it. */ 616 if ((error = check_exec(l, &pack)) != 0) { 617 if (error != ENOENT) { 618 DPRINTF(("execve: check exec failed %d\n", error)); 619 } 620 goto freehdr; 621 } 622 623 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 624 625 /* allocate an argument buffer */ 626 argp = pool_get(&exec_pool, PR_WAITOK); 627 KASSERT(argp != NULL); 628 dp = argp; 629 argc = 0; 630 631 /* copy the fake args list, if there's one, freeing it as we go */ 632 if (pack.ep_flags & EXEC_HASARGL) { 633 tmpfap = pack.ep_fa; 634 while (tmpfap->fa_arg != NULL) { 635 const char *cp; 636 637 cp = tmpfap->fa_arg; 638 while (*cp) 639 *dp++ = *cp++; 640 *dp++ = '\0'; 641 ktrexecarg(tmpfap->fa_arg, cp - tmpfap->fa_arg); 642 643 kmem_free(tmpfap->fa_arg, tmpfap->fa_len); 644 tmpfap++; argc++; 645 } 646 kmem_free(pack.ep_fa, pack.ep_fa_len); 647 pack.ep_flags &= ~EXEC_HASARGL; 648 } 649 650 /* Now get argv & environment */ 651 if (args == NULL) { 652 DPRINTF(("execve: null args\n")); 653 error = EINVAL; 654 goto bad; 655 } 656 /* 'i' will index the argp/envp element to be retrieved */ 657 i = 0; 658 if (pack.ep_flags & EXEC_SKIPARG) 659 i++; 660 661 while (1) { 662 len = argp + ARG_MAX - dp; 663 if ((error = (*fetch_element)(args, i, &sp)) != 0) { 664 DPRINTF(("execve: fetch_element args %d\n", error)); 665 goto bad; 666 } 667 if (!sp) 668 break; 669 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 670 DPRINTF(("execve: copyinstr args %d\n", error)); 671 if (error == ENAMETOOLONG) 672 error = E2BIG; 673 goto bad; 674 } 675 ktrexecarg(dp, len - 1); 676 dp += len; 677 i++; 678 argc++; 679 } 680 681 envc = 0; 682 /* environment need not be there */ 683 if (envs != NULL) { 684 i = 0; 685 while (1) { 686 len = argp + ARG_MAX - dp; 687 if ((error = (*fetch_element)(envs, i, &sp)) != 0) { 688 DPRINTF(("execve: fetch_element env %d\n", error)); 689 goto bad; 690 } 691 if (!sp) 692 break; 693 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 694 DPRINTF(("execve: copyinstr env %d\n", error)); 695 if (error == ENAMETOOLONG) 696 error = E2BIG; 697 goto bad; 698 } 699 ktrexecenv(dp, len - 1); 700 dp += len; 701 i++; 702 envc++; 703 } 704 } 705 706 dp = (char *) ALIGN(dp); 707 708 szsigcode = pack.ep_esch->es_emul->e_esigcode - 709 pack.ep_esch->es_emul->e_sigcode; 710 711 #ifdef __MACHINE_STACK_GROWS_UP 712 /* See big comment lower down */ 713 #define RTLD_GAP 32 714 #else 715 #define RTLD_GAP 0 716 #endif 717 718 /* Now check if args & environ fit into new stack */ 719 if (pack.ep_flags & EXEC_32) 720 len = ((argc + envc + 2 + pack.ep_esch->es_arglen) * 721 sizeof(int) + sizeof(int) + dp + RTLD_GAP + 722 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 723 - argp; 724 else 725 len = ((argc + envc + 2 + pack.ep_esch->es_arglen) * 726 sizeof(char *) + sizeof(int) + dp + RTLD_GAP + 727 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 728 - argp; 729 730 #ifdef PAX_ASLR 731 if (pax_aslr_active(l)) 732 len += (arc4random() % PAGE_SIZE); 733 #endif /* PAX_ASLR */ 734 735 #ifdef STACKLALIGN /* arm, etc. */ 736 len = STACKALIGN(len); /* make the stack "safely" aligned */ 737 #else 738 len = ALIGN(len); /* make the stack "safely" aligned */ 739 #endif 740 741 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 742 DPRINTF(("execve: stack limit exceeded %zu\n", len)); 743 error = ENOMEM; 744 goto bad; 745 } 746 747 /* Get rid of other LWPs. */ 748 if (p->p_sa || p->p_nlwps > 1) { 749 mutex_enter(p->p_lock); 750 exit_lwps(l); 751 mutex_exit(p->p_lock); 752 } 753 KDASSERT(p->p_nlwps == 1); 754 755 /* Destroy any lwpctl info. */ 756 if (p->p_lwpctl != NULL) 757 lwp_ctl_exit(); 758 759 /* This is now LWP 1 */ 760 l->l_lid = 1; 761 p->p_nlwpid = 1; 762 763 #ifdef KERN_SA 764 /* Release any SA state. */ 765 if (p->p_sa) 766 sa_release(p); 767 #endif /* KERN_SA */ 768 769 /* Remove POSIX timers */ 770 timers_free(p, TIMERS_POSIX); 771 772 /* adjust "active stack depth" for process VSZ */ 773 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 774 775 /* 776 * Do whatever is necessary to prepare the address space 777 * for remapping. Note that this might replace the current 778 * vmspace with another! 779 */ 780 uvmspace_exec(l, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 781 782 /* record proc's vnode, for use by procfs and others */ 783 if (p->p_textvp) 784 vrele(p->p_textvp); 785 vref(pack.ep_vp); 786 p->p_textvp = pack.ep_vp; 787 788 /* Now map address space */ 789 vm = p->p_vmspace; 790 vm->vm_taddr = (void *)pack.ep_taddr; 791 vm->vm_tsize = btoc(pack.ep_tsize); 792 vm->vm_daddr = (void*)pack.ep_daddr; 793 vm->vm_dsize = btoc(pack.ep_dsize); 794 vm->vm_ssize = btoc(pack.ep_ssize); 795 vm->vm_issize = 0; 796 vm->vm_maxsaddr = (void *)pack.ep_maxsaddr; 797 vm->vm_minsaddr = (void *)pack.ep_minsaddr; 798 799 #ifdef PAX_ASLR 800 pax_aslr_init(l, vm); 801 #endif /* PAX_ASLR */ 802 803 /* create the new process's VM space by running the vmcmds */ 804 #ifdef DIAGNOSTIC 805 if (pack.ep_vmcmds.evs_used == 0) 806 panic("execve: no vmcmds"); 807 #endif 808 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 809 struct exec_vmcmd *vcp; 810 811 vcp = &pack.ep_vmcmds.evs_cmds[i]; 812 if (vcp->ev_flags & VMCMD_RELATIVE) { 813 #ifdef DIAGNOSTIC 814 if (base_vcp == NULL) 815 panic("execve: relative vmcmd with no base"); 816 if (vcp->ev_flags & VMCMD_BASE) 817 panic("execve: illegal base & relative vmcmd"); 818 #endif 819 vcp->ev_addr += base_vcp->ev_addr; 820 } 821 error = (*vcp->ev_proc)(l, vcp); 822 #ifdef DEBUG_EXEC 823 if (error) { 824 size_t j; 825 struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0]; 826 for (j = 0; j <= i; j++) 827 uprintf( 828 "vmcmd[%zu] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n", 829 j, vp[j].ev_addr, vp[j].ev_len, 830 vp[j].ev_offset, vp[j].ev_prot, 831 vp[j].ev_flags); 832 } 833 #endif /* DEBUG_EXEC */ 834 if (vcp->ev_flags & VMCMD_BASE) 835 base_vcp = vcp; 836 } 837 838 /* free the vmspace-creation commands, and release their references */ 839 kill_vmcmds(&pack.ep_vmcmds); 840 841 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 842 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 843 vput(pack.ep_vp); 844 845 /* if an error happened, deallocate and punt */ 846 if (error) { 847 DPRINTF(("execve: vmcmd %zu failed: %d\n", i - 1, error)); 848 goto exec_abort; 849 } 850 851 /* remember information about the process */ 852 arginfo.ps_nargvstr = argc; 853 arginfo.ps_nenvstr = envc; 854 855 /* set command name & other accounting info */ 856 i = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 857 (void)memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, i); 858 p->p_comm[i] = '\0'; 859 860 dp = PNBUF_GET(); 861 /* 862 * If the path starts with /, we don't need to do any work. 863 * This handles the majority of the cases. 864 * In the future perhaps we could canonicalize it? 865 */ 866 if (pathbuf[0] == '/') 867 (void)strlcpy(pack.ep_path = dp, pathbuf, MAXPATHLEN); 868 #ifdef notyet 869 /* 870 * Although this works most of the time [since the entry was just 871 * entered in the cache] we don't use it because it theoretically 872 * can fail and it is not the cleanest interface, because there 873 * could be races. When the namei cache is re-written, this can 874 * be changed to use the appropriate function. 875 */ 876 else if (!(error = vnode_to_path(dp, MAXPATHLEN, p->p_textvp, l, p))) 877 pack.ep_path = dp; 878 #endif 879 else { 880 #ifdef notyet 881 printf("Cannot get path for pid %d [%s] (error %d)", 882 (int)p->p_pid, p->p_comm, error); 883 #endif 884 pack.ep_path = NULL; 885 PNBUF_PUT(dp); 886 } 887 888 stack = (char *)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, 889 STACK_PTHREADSPACE + sizeof(struct ps_strings) + szsigcode), 890 len - (sizeof(struct ps_strings) + szsigcode)); 891 892 #ifdef __MACHINE_STACK_GROWS_UP 893 /* 894 * The copyargs call always copies into lower addresses 895 * first, moving towards higher addresses, starting with 896 * the stack pointer that we give. When the stack grows 897 * down, this puts argc/argv/envp very shallow on the 898 * stack, right at the first user stack pointer. 899 * When the stack grows up, the situation is reversed. 900 * 901 * Normally, this is no big deal. But the ld_elf.so _rtld() 902 * function expects to be called with a single pointer to 903 * a region that has a few words it can stash values into, 904 * followed by argc/argv/envp. When the stack grows down, 905 * it's easy to decrement the stack pointer a little bit to 906 * allocate the space for these few words and pass the new 907 * stack pointer to _rtld. When the stack grows up, however, 908 * a few words before argc is part of the signal trampoline, XXX 909 * so we have a problem. 910 * 911 * Instead of changing how _rtld works, we take the easy way 912 * out and steal 32 bytes before we call copyargs. 913 * This extra space was allowed for when 'len' was calculated. 914 */ 915 stack += RTLD_GAP; 916 #endif /* __MACHINE_STACK_GROWS_UP */ 917 918 /* Now copy argc, args & environ to new stack */ 919 error = (*pack.ep_esch->es_copyargs)(l, &pack, &arginfo, &stack, argp); 920 if (pack.ep_path) { 921 PNBUF_PUT(pack.ep_path); 922 pack.ep_path = NULL; 923 } 924 if (error) { 925 DPRINTF(("execve: copyargs failed %d\n", error)); 926 goto exec_abort; 927 } 928 /* Move the stack back to original point */ 929 stack = (char *)STACK_GROW(vm->vm_minsaddr, len); 930 931 /* fill process ps_strings info */ 932 p->p_psstr = (struct ps_strings *) 933 STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, STACK_PTHREADSPACE), 934 sizeof(struct ps_strings)); 935 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 936 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 937 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 938 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 939 940 /* copy out the process's ps_strings structure */ 941 if ((error = copyout(aip, (char *)p->p_psstr, 942 sizeof(arginfo))) != 0) { 943 DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n", 944 aip, (char *)p->p_psstr, (long)sizeof(arginfo))); 945 goto exec_abort; 946 } 947 948 fd_closeexec(); /* handle close on exec */ 949 execsigs(p); /* reset catched signals */ 950 951 l->l_ctxlink = NULL; /* reset ucontext link */ 952 953 954 p->p_acflag &= ~AFORK; 955 mutex_enter(p->p_lock); 956 p->p_flag |= PK_EXEC; 957 mutex_exit(p->p_lock); 958 959 /* 960 * Stop profiling. 961 */ 962 if ((p->p_stflag & PST_PROFIL) != 0) { 963 mutex_spin_enter(&p->p_stmutex); 964 stopprofclock(p); 965 mutex_spin_exit(&p->p_stmutex); 966 } 967 968 /* 969 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 970 * exited and exec()/exit() are the only places it will be cleared. 971 */ 972 if ((p->p_lflag & PL_PPWAIT) != 0) { 973 mutex_enter(proc_lock); 974 p->p_lflag &= ~PL_PPWAIT; 975 cv_broadcast(&p->p_pptr->p_waitcv); 976 mutex_exit(proc_lock); 977 } 978 979 /* 980 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 981 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 982 * out additional references on the process for the moment. 983 */ 984 if ((p->p_slflag & PSL_TRACED) == 0 && 985 986 (((attr.va_mode & S_ISUID) != 0 && 987 kauth_cred_geteuid(l->l_cred) != attr.va_uid) || 988 989 ((attr.va_mode & S_ISGID) != 0 && 990 kauth_cred_getegid(l->l_cred) != attr.va_gid))) { 991 /* 992 * Mark the process as SUGID before we do 993 * anything that might block. 994 */ 995 proc_crmod_enter(); 996 proc_crmod_leave(NULL, NULL, true); 997 998 /* Make sure file descriptors 0..2 are in use. */ 999 if ((error = fd_checkstd()) != 0) { 1000 DPRINTF(("execve: fdcheckstd failed %d\n", error)); 1001 goto exec_abort; 1002 } 1003 1004 /* 1005 * Copy the credential so other references don't see our 1006 * changes. 1007 */ 1008 l->l_cred = kauth_cred_copy(l->l_cred); 1009 #ifdef KTRACE 1010 /* 1011 * If the persistent trace flag isn't set, turn off. 1012 */ 1013 if (p->p_tracep) { 1014 mutex_enter(&ktrace_lock); 1015 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1016 ktrderef(p); 1017 mutex_exit(&ktrace_lock); 1018 } 1019 #endif 1020 if (attr.va_mode & S_ISUID) 1021 kauth_cred_seteuid(l->l_cred, attr.va_uid); 1022 if (attr.va_mode & S_ISGID) 1023 kauth_cred_setegid(l->l_cred, attr.va_gid); 1024 } else { 1025 if (kauth_cred_geteuid(l->l_cred) == 1026 kauth_cred_getuid(l->l_cred) && 1027 kauth_cred_getegid(l->l_cred) == 1028 kauth_cred_getgid(l->l_cred)) 1029 p->p_flag &= ~PK_SUGID; 1030 } 1031 1032 /* 1033 * Copy the credential so other references don't see our changes. 1034 * Test to see if this is necessary first, since in the common case 1035 * we won't need a private reference. 1036 */ 1037 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1038 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1039 l->l_cred = kauth_cred_copy(l->l_cred); 1040 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1041 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1042 } 1043 1044 /* Update the master credentials. */ 1045 if (l->l_cred != p->p_cred) { 1046 kauth_cred_t ocred; 1047 1048 kauth_cred_hold(l->l_cred); 1049 mutex_enter(p->p_lock); 1050 ocred = p->p_cred; 1051 p->p_cred = l->l_cred; 1052 mutex_exit(p->p_lock); 1053 kauth_cred_free(ocred); 1054 } 1055 1056 #if defined(__HAVE_RAS) 1057 /* 1058 * Remove all RASs from the address space. 1059 */ 1060 ras_purgeall(); 1061 #endif 1062 1063 doexechooks(p); 1064 1065 /* setup new registers and do misc. setup. */ 1066 (*pack.ep_esch->es_emul->e_setregs)(l, &pack, (vaddr_t)stack); 1067 if (pack.ep_esch->es_setregs) 1068 (*pack.ep_esch->es_setregs)(l, &pack, (vaddr_t)stack); 1069 1070 /* map the process's signal trampoline code */ 1071 if (exec_sigcode_map(p, pack.ep_esch->es_emul)) { 1072 DPRINTF(("execve: map sigcode failed %d\n", error)); 1073 goto exec_abort; 1074 } 1075 1076 pool_put(&exec_pool, argp); 1077 1078 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1079 1080 /* notify others that we exec'd */ 1081 KNOTE(&p->p_klist, NOTE_EXEC); 1082 1083 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1084 1085 SDT_PROBE(proc,,,exec_success, path, 0, 0, 0, 0); 1086 1087 /* The emulation root will usually have been found when we looked 1088 * for the elf interpreter (or similar), if not look now. */ 1089 if (pack.ep_esch->es_emul->e_path != NULL && pack.ep_emul_root == NULL) 1090 emul_find_root(l, &pack); 1091 1092 /* Any old emulation root got removed by fdcloseexec */ 1093 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1094 p->p_cwdi->cwdi_edir = pack.ep_emul_root; 1095 rw_exit(&p->p_cwdi->cwdi_lock); 1096 pack.ep_emul_root = NULL; 1097 if (pack.ep_interp != NULL) 1098 vrele(pack.ep_interp); 1099 1100 /* 1101 * Call emulation specific exec hook. This can setup per-process 1102 * p->p_emuldata or do any other per-process stuff an emulation needs. 1103 * 1104 * If we are executing process of different emulation than the 1105 * original forked process, call e_proc_exit() of the old emulation 1106 * first, then e_proc_exec() of new emulation. If the emulation is 1107 * same, the exec hook code should deallocate any old emulation 1108 * resources held previously by this process. 1109 */ 1110 if (p->p_emul && p->p_emul->e_proc_exit 1111 && p->p_emul != pack.ep_esch->es_emul) 1112 (*p->p_emul->e_proc_exit)(p); 1113 1114 /* 1115 * Call exec hook. Emulation code may NOT store reference to anything 1116 * from &pack. 1117 */ 1118 if (pack.ep_esch->es_emul->e_proc_exec) 1119 (*pack.ep_esch->es_emul->e_proc_exec)(p, &pack); 1120 1121 /* update p_emul, the old value is no longer needed */ 1122 p->p_emul = pack.ep_esch->es_emul; 1123 1124 /* ...and the same for p_execsw */ 1125 p->p_execsw = pack.ep_esch; 1126 1127 #ifdef __HAVE_SYSCALL_INTERN 1128 (*p->p_emul->e_syscall_intern)(p); 1129 #endif 1130 ktremul(); 1131 1132 /* Allow new references from the debugger/procfs. */ 1133 rw_exit(&p->p_reflock); 1134 rw_exit(&exec_lock); 1135 1136 mutex_enter(proc_lock); 1137 1138 if ((p->p_slflag & (PSL_TRACED|PSL_SYSCALL)) == PSL_TRACED) { 1139 KSI_INIT_EMPTY(&ksi); 1140 ksi.ksi_signo = SIGTRAP; 1141 ksi.ksi_lid = l->l_lid; 1142 kpsignal(p, &ksi, NULL); 1143 } 1144 1145 if (p->p_sflag & PS_STOPEXEC) { 1146 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1147 p->p_pptr->p_nstopchild++; 1148 p->p_pptr->p_waited = 0; 1149 mutex_enter(p->p_lock); 1150 ksiginfo_queue_init(&kq); 1151 sigclearall(p, &contsigmask, &kq); 1152 lwp_lock(l); 1153 l->l_stat = LSSTOP; 1154 p->p_stat = SSTOP; 1155 p->p_nrlwps--; 1156 mutex_exit(p->p_lock); 1157 mutex_exit(proc_lock); 1158 mi_switch(l); 1159 ksiginfo_queue_drain(&kq); 1160 KERNEL_LOCK(l->l_biglocks, l); 1161 } else { 1162 mutex_exit(proc_lock); 1163 } 1164 1165 PNBUF_PUT(pathbuf); 1166 return (EJUSTRETURN); 1167 1168 bad: 1169 /* free the vmspace-creation commands, and release their references */ 1170 kill_vmcmds(&pack.ep_vmcmds); 1171 /* kill any opened file descriptor, if necessary */ 1172 if (pack.ep_flags & EXEC_HASFD) { 1173 pack.ep_flags &= ~EXEC_HASFD; 1174 fd_close(pack.ep_fd); 1175 } 1176 /* close and put the exec'd file */ 1177 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 1178 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 1179 vput(pack.ep_vp); 1180 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1181 pool_put(&exec_pool, argp); 1182 1183 freehdr: 1184 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1185 if (pack.ep_emul_root != NULL) 1186 vrele(pack.ep_emul_root); 1187 if (pack.ep_interp != NULL) 1188 vrele(pack.ep_interp); 1189 1190 rw_exit(&exec_lock); 1191 1192 clrflg: 1193 lwp_lock(l); 1194 l->l_flag |= oldlwpflags; 1195 lwp_unlock(l); 1196 PNBUF_PUT(pathbuf); 1197 rw_exit(&p->p_reflock); 1198 1199 if (modgen != module_gen && error == ENOEXEC) { 1200 modgen = module_gen; 1201 exec_autoload(); 1202 goto retry; 1203 } 1204 1205 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0); 1206 return error; 1207 1208 exec_abort: 1209 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0); 1210 PNBUF_PUT(pathbuf); 1211 rw_exit(&p->p_reflock); 1212 rw_exit(&exec_lock); 1213 1214 /* 1215 * the old process doesn't exist anymore. exit gracefully. 1216 * get rid of the (new) address space we have created, if any, get rid 1217 * of our namei data and vnode, and exit noting failure 1218 */ 1219 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1220 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1221 if (pack.ep_emul_arg) 1222 free(pack.ep_emul_arg, M_TEMP); 1223 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1224 pool_put(&exec_pool, argp); 1225 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1226 if (pack.ep_emul_root != NULL) 1227 vrele(pack.ep_emul_root); 1228 if (pack.ep_interp != NULL) 1229 vrele(pack.ep_interp); 1230 1231 /* Acquire the sched-state mutex (exit1() will release it). */ 1232 mutex_enter(p->p_lock); 1233 exit1(l, W_EXITCODE(error, SIGABRT)); 1234 1235 /* NOTREACHED */ 1236 return 0; 1237 } 1238 1239 1240 int 1241 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1242 char **stackp, void *argp) 1243 { 1244 char **cpp, *dp, *sp; 1245 size_t len; 1246 void *nullp; 1247 long argc, envc; 1248 int error; 1249 1250 cpp = (char **)*stackp; 1251 nullp = NULL; 1252 argc = arginfo->ps_nargvstr; 1253 envc = arginfo->ps_nenvstr; 1254 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) 1255 return error; 1256 1257 dp = (char *) (cpp + argc + envc + 2 + pack->ep_esch->es_arglen); 1258 sp = argp; 1259 1260 /* XXX don't copy them out, remap them! */ 1261 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1262 1263 for (; --argc >= 0; sp += len, dp += len) 1264 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1265 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1266 return error; 1267 1268 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1269 return error; 1270 1271 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1272 1273 for (; --envc >= 0; sp += len, dp += len) 1274 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1275 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1276 return error; 1277 1278 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1279 return error; 1280 1281 *stackp = (char *)cpp; 1282 return 0; 1283 } 1284 1285 1286 /* 1287 * Add execsw[] entries. 1288 */ 1289 int 1290 exec_add(struct execsw *esp, int count) 1291 { 1292 struct exec_entry *it; 1293 int i; 1294 1295 if (count == 0) { 1296 return 0; 1297 } 1298 1299 /* Check for duplicates. */ 1300 rw_enter(&exec_lock, RW_WRITER); 1301 for (i = 0; i < count; i++) { 1302 LIST_FOREACH(it, &ex_head, ex_list) { 1303 /* assume unique (makecmds, probe_func, emulation) */ 1304 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1305 it->ex_sw->u.elf_probe_func == 1306 esp[i].u.elf_probe_func && 1307 it->ex_sw->es_emul == esp[i].es_emul) { 1308 rw_exit(&exec_lock); 1309 return EEXIST; 1310 } 1311 } 1312 } 1313 1314 /* Allocate new entries. */ 1315 for (i = 0; i < count; i++) { 1316 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1317 it->ex_sw = &esp[i]; 1318 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1319 } 1320 1321 /* update execsw[] */ 1322 exec_init(0); 1323 rw_exit(&exec_lock); 1324 return 0; 1325 } 1326 1327 /* 1328 * Remove execsw[] entry. 1329 */ 1330 int 1331 exec_remove(struct execsw *esp, int count) 1332 { 1333 struct exec_entry *it, *next; 1334 int i; 1335 const struct proclist_desc *pd; 1336 proc_t *p; 1337 1338 if (count == 0) { 1339 return 0; 1340 } 1341 1342 /* Abort if any are busy. */ 1343 rw_enter(&exec_lock, RW_WRITER); 1344 for (i = 0; i < count; i++) { 1345 mutex_enter(proc_lock); 1346 for (pd = proclists; pd->pd_list != NULL; pd++) { 1347 PROCLIST_FOREACH(p, pd->pd_list) { 1348 if (p->p_execsw == &esp[i]) { 1349 mutex_exit(proc_lock); 1350 rw_exit(&exec_lock); 1351 return EBUSY; 1352 } 1353 } 1354 } 1355 mutex_exit(proc_lock); 1356 } 1357 1358 /* None are busy, so remove them all. */ 1359 for (i = 0; i < count; i++) { 1360 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1361 next = LIST_NEXT(it, ex_list); 1362 if (it->ex_sw == &esp[i]) { 1363 LIST_REMOVE(it, ex_list); 1364 kmem_free(it, sizeof(*it)); 1365 break; 1366 } 1367 } 1368 } 1369 1370 /* update execsw[] */ 1371 exec_init(0); 1372 rw_exit(&exec_lock); 1373 return 0; 1374 } 1375 1376 /* 1377 * Initialize exec structures. If init_boot is true, also does necessary 1378 * one-time initialization (it's called from main() that way). 1379 * Once system is multiuser, this should be called with exec_lock held, 1380 * i.e. via exec_{add|remove}(). 1381 */ 1382 int 1383 exec_init(int init_boot) 1384 { 1385 const struct execsw **sw; 1386 struct exec_entry *ex; 1387 SLIST_HEAD(,exec_entry) first; 1388 SLIST_HEAD(,exec_entry) any; 1389 SLIST_HEAD(,exec_entry) last; 1390 int i, sz; 1391 1392 if (init_boot) { 1393 /* do one-time initializations */ 1394 rw_init(&exec_lock); 1395 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1396 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1397 "execargs", &exec_palloc, IPL_NONE); 1398 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1399 } else { 1400 KASSERT(rw_write_held(&exec_lock)); 1401 } 1402 1403 /* Sort each entry onto the appropriate queue. */ 1404 SLIST_INIT(&first); 1405 SLIST_INIT(&any); 1406 SLIST_INIT(&last); 1407 sz = 0; 1408 LIST_FOREACH(ex, &ex_head, ex_list) { 1409 switch(ex->ex_sw->es_prio) { 1410 case EXECSW_PRIO_FIRST: 1411 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1412 break; 1413 case EXECSW_PRIO_ANY: 1414 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1415 break; 1416 case EXECSW_PRIO_LAST: 1417 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1418 break; 1419 default: 1420 panic("exec_init"); 1421 break; 1422 } 1423 sz++; 1424 } 1425 1426 /* 1427 * Create new execsw[]. Ensure we do not try a zero-sized 1428 * allocation. 1429 */ 1430 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1431 i = 0; 1432 SLIST_FOREACH(ex, &first, ex_slist) { 1433 sw[i++] = ex->ex_sw; 1434 } 1435 SLIST_FOREACH(ex, &any, ex_slist) { 1436 sw[i++] = ex->ex_sw; 1437 } 1438 SLIST_FOREACH(ex, &last, ex_slist) { 1439 sw[i++] = ex->ex_sw; 1440 } 1441 1442 /* Replace old execsw[] and free used memory. */ 1443 if (execsw != NULL) { 1444 kmem_free(__UNCONST(execsw), 1445 nexecs * sizeof(struct execsw *) + 1); 1446 } 1447 execsw = sw; 1448 nexecs = sz; 1449 1450 /* Figure out the maximum size of an exec header. */ 1451 exec_maxhdrsz = sizeof(int); 1452 for (i = 0; i < nexecs; i++) { 1453 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1454 exec_maxhdrsz = execsw[i]->es_hdrsz; 1455 } 1456 1457 return 0; 1458 } 1459 1460 static int 1461 exec_sigcode_map(struct proc *p, const struct emul *e) 1462 { 1463 vaddr_t va; 1464 vsize_t sz; 1465 int error; 1466 struct uvm_object *uobj; 1467 1468 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1469 1470 if (e->e_sigobject == NULL || sz == 0) { 1471 return 0; 1472 } 1473 1474 /* 1475 * If we don't have a sigobject for this emulation, create one. 1476 * 1477 * sigobject is an anonymous memory object (just like SYSV shared 1478 * memory) that we keep a permanent reference to and that we map 1479 * in all processes that need this sigcode. The creation is simple, 1480 * we create an object, add a permanent reference to it, map it in 1481 * kernel space, copy out the sigcode to it and unmap it. 1482 * We map it with PROT_READ|PROT_EXEC into the process just 1483 * the way sys_mmap() would map it. 1484 */ 1485 1486 uobj = *e->e_sigobject; 1487 if (uobj == NULL) { 1488 mutex_enter(&sigobject_lock); 1489 if ((uobj = *e->e_sigobject) == NULL) { 1490 uobj = uao_create(sz, 0); 1491 (*uobj->pgops->pgo_reference)(uobj); 1492 va = vm_map_min(kernel_map); 1493 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1494 uobj, 0, 0, 1495 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1496 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1497 printf("kernel mapping failed %d\n", error); 1498 (*uobj->pgops->pgo_detach)(uobj); 1499 mutex_exit(&sigobject_lock); 1500 return (error); 1501 } 1502 memcpy((void *)va, e->e_sigcode, sz); 1503 #ifdef PMAP_NEED_PROCWR 1504 pmap_procwr(&proc0, va, sz); 1505 #endif 1506 uvm_unmap(kernel_map, va, va + round_page(sz)); 1507 *e->e_sigobject = uobj; 1508 } 1509 mutex_exit(&sigobject_lock); 1510 } 1511 1512 /* Just a hint to uvm_map where to put it. */ 1513 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1514 round_page(sz)); 1515 1516 #ifdef __alpha__ 1517 /* 1518 * Tru64 puts /sbin/loader at the end of user virtual memory, 1519 * which causes the above calculation to put the sigcode at 1520 * an invalid address. Put it just below the text instead. 1521 */ 1522 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1523 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1524 } 1525 #endif 1526 1527 (*uobj->pgops->pgo_reference)(uobj); 1528 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1529 uobj, 0, 0, 1530 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1531 UVM_ADV_RANDOM, 0)); 1532 if (error) { 1533 (*uobj->pgops->pgo_detach)(uobj); 1534 return (error); 1535 } 1536 p->p_sigctx.ps_sigcode = (void *)va; 1537 return (0); 1538 } 1539