1 /* $NetBSD: kern_exec.c,v 1.288 2009/03/29 01:02:50 mrg 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 1.288 2009/03/29 01:02:50 mrg 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/syscallargs.h> 100 #if NVERIEXEC > 0 101 #include <sys/verified_exec.h> 102 #endif /* NVERIEXEC > 0 */ 103 104 #include <uvm/uvm_extern.h> 105 106 #include <machine/reg.h> 107 108 #include <compat/common/compat_util.h> 109 110 static int exec_sigcode_map(struct proc *, const struct emul *); 111 112 #ifdef DEBUG_EXEC 113 #define DPRINTF(a) uprintf a 114 #else 115 #define DPRINTF(a) 116 #endif /* DEBUG_EXEC */ 117 118 /* 119 * Exec function switch: 120 * 121 * Note that each makecmds function is responsible for loading the 122 * exec package with the necessary functions for any exec-type-specific 123 * handling. 124 * 125 * Functions for specific exec types should be defined in their own 126 * header file. 127 */ 128 static const struct execsw **execsw = NULL; 129 static int nexecs; 130 131 u_int exec_maxhdrsz; /* must not be static - used by netbsd32 */ 132 133 /* list of dynamically loaded execsw entries */ 134 static LIST_HEAD(execlist_head, exec_entry) ex_head = 135 LIST_HEAD_INITIALIZER(ex_head); 136 struct exec_entry { 137 LIST_ENTRY(exec_entry) ex_list; 138 SLIST_ENTRY(exec_entry) ex_slist; 139 const struct execsw *ex_sw; 140 }; 141 142 #ifdef SYSCALL_DEBUG 143 extern const char * const syscallnames[]; 144 #endif 145 146 #ifndef __HAVE_SYSCALL_INTERN 147 void syscall(void); 148 #endif 149 150 #ifdef KERN_SA 151 static struct sa_emul saemul_netbsd = { 152 sizeof(ucontext_t), 153 sizeof(struct sa_t), 154 sizeof(struct sa_t *), 155 NULL, 156 NULL, 157 cpu_upcall, 158 (void (*)(struct lwp *, void *))getucontext_sa, 159 sa_ucsp 160 }; 161 #endif /* KERN_SA */ 162 163 /* NetBSD emul struct */ 164 struct emul emul_netbsd = { 165 "netbsd", 166 NULL, /* emulation path */ 167 #ifndef __HAVE_MINIMAL_EMUL 168 EMUL_HAS_SYS___syscall, 169 NULL, 170 SYS_syscall, 171 SYS_NSYSENT, 172 #endif 173 sysent, 174 #ifdef SYSCALL_DEBUG 175 syscallnames, 176 #else 177 NULL, 178 #endif 179 sendsig, 180 trapsignal, 181 NULL, 182 NULL, 183 NULL, 184 NULL, 185 setregs, 186 NULL, 187 NULL, 188 NULL, 189 NULL, 190 NULL, 191 #ifdef __HAVE_SYSCALL_INTERN 192 syscall_intern, 193 #else 194 syscall, 195 #endif 196 NULL, 197 NULL, 198 199 uvm_default_mapaddr, 200 NULL, 201 #ifdef KERN_SA 202 &saemul_netbsd, 203 #else 204 NULL, 205 #endif 206 sizeof(ucontext_t), 207 startlwp, 208 }; 209 210 /* 211 * Exec lock. Used to control access to execsw[] structures. 212 * This must not be static so that netbsd32 can access it, too. 213 */ 214 krwlock_t exec_lock; 215 216 static kmutex_t sigobject_lock; 217 218 static void * 219 exec_pool_alloc(struct pool *pp, int flags) 220 { 221 222 return (void *)uvm_km_alloc(kernel_map, NCARGS, 0, 223 UVM_KMF_PAGEABLE | UVM_KMF_WAITVA); 224 } 225 226 static void 227 exec_pool_free(struct pool *pp, void *addr) 228 { 229 230 uvm_km_free(kernel_map, (vaddr_t)addr, NCARGS, UVM_KMF_PAGEABLE); 231 } 232 233 static struct pool exec_pool; 234 235 static struct pool_allocator exec_palloc = { 236 .pa_alloc = exec_pool_alloc, 237 .pa_free = exec_pool_free, 238 .pa_pagesz = NCARGS 239 }; 240 241 /* 242 * check exec: 243 * given an "executable" described in the exec package's namei info, 244 * see what we can do with it. 245 * 246 * ON ENTRY: 247 * exec package with appropriate namei info 248 * lwp pointer of exec'ing lwp 249 * NO SELF-LOCKED VNODES 250 * 251 * ON EXIT: 252 * error: nothing held, etc. exec header still allocated. 253 * ok: filled exec package, executable's vnode (unlocked). 254 * 255 * EXEC SWITCH ENTRY: 256 * Locked vnode to check, exec package, proc. 257 * 258 * EXEC SWITCH EXIT: 259 * ok: return 0, filled exec package, executable's vnode (unlocked). 260 * error: destructive: 261 * everything deallocated execept exec header. 262 * non-destructive: 263 * error code, executable's vnode (unlocked), 264 * exec header unmodified. 265 */ 266 int 267 /*ARGSUSED*/ 268 check_exec(struct lwp *l, struct exec_package *epp) 269 { 270 int error, i; 271 struct vnode *vp; 272 struct nameidata *ndp; 273 size_t resid; 274 275 ndp = epp->ep_ndp; 276 ndp->ni_cnd.cn_nameiop = LOOKUP; 277 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME | TRYEMULROOT; 278 /* first get the vnode */ 279 if ((error = namei(ndp)) != 0) 280 return error; 281 epp->ep_vp = vp = ndp->ni_vp; 282 283 /* check access and type */ 284 if (vp->v_type != VREG) { 285 error = EACCES; 286 goto bad1; 287 } 288 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 289 goto bad1; 290 291 /* get attributes */ 292 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 293 goto bad1; 294 295 /* Check mount point */ 296 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 297 error = EACCES; 298 goto bad1; 299 } 300 if (vp->v_mount->mnt_flag & MNT_NOSUID) 301 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 302 303 /* try to open it */ 304 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 305 goto bad1; 306 307 /* unlock vp, since we need it unlocked from here on out. */ 308 VOP_UNLOCK(vp, 0); 309 310 #if NVERIEXEC > 0 311 error = veriexec_verify(l, vp, ndp->ni_cnd.cn_pnbuf, 312 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 313 NULL); 314 if (error) 315 goto bad2; 316 #endif /* NVERIEXEC > 0 */ 317 318 #ifdef PAX_SEGVGUARD 319 error = pax_segvguard(l, vp, ndp->ni_cnd.cn_pnbuf, false); 320 if (error) 321 goto bad2; 322 #endif /* PAX_SEGVGUARD */ 323 324 /* now we have the file, get the exec header */ 325 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 326 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 327 if (error) 328 goto bad2; 329 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 330 331 /* 332 * Set up default address space limits. Can be overridden 333 * by individual exec packages. 334 * 335 * XXX probably should be all done in the exec packages. 336 */ 337 epp->ep_vm_minaddr = VM_MIN_ADDRESS; 338 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 339 /* 340 * set up the vmcmds for creation of the process 341 * address space 342 */ 343 error = ENOEXEC; 344 for (i = 0; i < nexecs; i++) { 345 int newerror; 346 347 epp->ep_esch = execsw[i]; 348 newerror = (*execsw[i]->es_makecmds)(l, epp); 349 350 if (!newerror) { 351 /* Seems ok: check that entry point is sane */ 352 if (epp->ep_entry > VM_MAXUSER_ADDRESS) { 353 error = ENOEXEC; 354 break; 355 } 356 357 /* check limits */ 358 if ((epp->ep_tsize > MAXTSIZ) || 359 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 360 [RLIMIT_DATA].rlim_cur)) { 361 error = ENOMEM; 362 break; 363 } 364 return 0; 365 } 366 367 if (epp->ep_emul_root != NULL) { 368 vrele(epp->ep_emul_root); 369 epp->ep_emul_root = NULL; 370 } 371 if (epp->ep_interp != NULL) { 372 vrele(epp->ep_interp); 373 epp->ep_interp = NULL; 374 } 375 376 /* make sure the first "interesting" error code is saved. */ 377 if (error == ENOEXEC) 378 error = newerror; 379 380 if (epp->ep_flags & EXEC_DESTR) 381 /* Error from "#!" code, tidied up by recursive call */ 382 return error; 383 } 384 385 /* not found, error */ 386 387 /* 388 * free any vmspace-creation commands, 389 * and release their references 390 */ 391 kill_vmcmds(&epp->ep_vmcmds); 392 393 bad2: 394 /* 395 * close and release the vnode, restore the old one, free the 396 * pathname buf, and punt. 397 */ 398 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 399 VOP_CLOSE(vp, FREAD, l->l_cred); 400 vput(vp); 401 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 402 return error; 403 404 bad1: 405 /* 406 * free the namei pathname buffer, and put the vnode 407 * (which we don't yet have open). 408 */ 409 vput(vp); /* was still locked */ 410 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 411 return error; 412 } 413 414 #ifdef __MACHINE_STACK_GROWS_UP 415 #define STACK_PTHREADSPACE NBPG 416 #else 417 #define STACK_PTHREADSPACE 0 418 #endif 419 420 static int 421 execve_fetch_element(char * const *array, size_t index, char **value) 422 { 423 return copyin(array + index, value, sizeof(*value)); 424 } 425 426 /* 427 * exec system call 428 */ 429 /* ARGSUSED */ 430 int 431 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval) 432 { 433 /* { 434 syscallarg(const char *) path; 435 syscallarg(char * const *) argp; 436 syscallarg(char * const *) envp; 437 } */ 438 439 return execve1(l, SCARG(uap, path), SCARG(uap, argp), 440 SCARG(uap, envp), execve_fetch_element); 441 } 442 443 /* 444 * Load modules to try and execute an image that we do not understand. 445 * If no execsw entries are present, we load those likely to be needed 446 * in order to run native images only. Otherwise, we autoload all 447 * possible modules that could let us run the binary. XXX lame 448 */ 449 static void 450 exec_autoload(void) 451 { 452 #ifdef MODULAR 453 static const char * const native[] = { 454 "exec_elf32", 455 "exec_elf64", 456 "exec_script", 457 NULL 458 }; 459 static const char * const compat[] = { 460 "exec_elf32", 461 "exec_elf64", 462 "exec_script", 463 "exec_aout", 464 "exec_coff", 465 "exec_ecoff", 466 "compat_aoutm68k", 467 "compat_freebsd", 468 "compat_ibcs2", 469 "compat_irix", 470 "compat_linux", 471 "compat_linux32", 472 "compat_netbsd32", 473 "compat_sunos", 474 "compat_sunos32", 475 "compat_svr4", 476 "compat_svr4_32", 477 "compat_ultrix", 478 NULL 479 }; 480 char const * const *list; 481 int i; 482 483 mutex_enter(&module_lock); 484 list = (nexecs == 0 ? native : compat); 485 for (i = 0; list[i] != NULL; i++) { 486 if (module_autoload(list[i], MODULE_CLASS_MISC) != 0) { 487 continue; 488 } 489 mutex_exit(&module_lock); 490 yield(); 491 mutex_enter(&module_lock); 492 } 493 mutex_exit(&module_lock); 494 #endif 495 } 496 497 int 498 execve1(struct lwp *l, const char *path, char * const *args, 499 char * const *envs, execve_fetch_element_t fetch_element) 500 { 501 int error; 502 struct exec_package pack; 503 struct nameidata nid; 504 struct vattr attr; 505 struct proc *p; 506 char *argp; 507 char *dp, *sp; 508 long argc, envc; 509 size_t i, len; 510 char *stack; 511 struct ps_strings arginfo; 512 struct ps_strings *aip = &arginfo; 513 struct vmspace *vm; 514 struct exec_fakearg *tmpfap; 515 int szsigcode; 516 struct exec_vmcmd *base_vcp; 517 int oldlwpflags; 518 ksiginfo_t ksi; 519 ksiginfoq_t kq; 520 char *pathbuf; 521 size_t pathbuflen; 522 u_int modgen; 523 524 p = l->l_proc; 525 modgen = 0; 526 527 /* 528 * Check if we have exceeded our number of processes limit. 529 * This is so that we handle the case where a root daemon 530 * forked, ran setuid to become the desired user and is trying 531 * to exec. The obvious place to do the reference counting check 532 * is setuid(), but we don't do the reference counting check there 533 * like other OS's do because then all the programs that use setuid() 534 * must be modified to check the return code of setuid() and exit(). 535 * It is dangerous to make setuid() fail, because it fails open and 536 * the program will continue to run as root. If we make it succeed 537 * and return an error code, again we are not enforcing the limit. 538 * The best place to enforce the limit is here, when the process tries 539 * to execute a new image, because eventually the process will need 540 * to call exec in order to do something useful. 541 */ 542 retry: 543 if ((p->p_flag & PK_SUGID) && kauth_authorize_generic(l->l_cred, 544 KAUTH_GENERIC_ISSUSER, NULL) != 0 && chgproccnt(kauth_cred_getuid( 545 l->l_cred), 0) > p->p_rlimit[RLIMIT_NPROC].rlim_cur) 546 return EAGAIN; 547 548 oldlwpflags = l->l_flag & (LW_SA | LW_SA_UPCALL); 549 if (l->l_flag & LW_SA) { 550 lwp_lock(l); 551 l->l_flag &= ~(LW_SA | LW_SA_UPCALL); 552 lwp_unlock(l); 553 } 554 555 /* 556 * Drain existing references and forbid new ones. The process 557 * should be left alone until we're done here. This is necessary 558 * to avoid race conditions - e.g. in ptrace() - that might allow 559 * a local user to illicitly obtain elevated privileges. 560 */ 561 rw_enter(&p->p_reflock, RW_WRITER); 562 563 base_vcp = NULL; 564 /* 565 * Init the namei data to point the file user's program name. 566 * This is done here rather than in check_exec(), so that it's 567 * possible to override this settings if any of makecmd/probe 568 * functions call check_exec() recursively - for example, 569 * see exec_script_makecmds(). 570 */ 571 pathbuf = PNBUF_GET(); 572 error = copyinstr(path, pathbuf, MAXPATHLEN, &pathbuflen); 573 if (error) { 574 DPRINTF(("execve: copyinstr path %d", error)); 575 goto clrflg; 576 } 577 578 NDINIT(&nid, LOOKUP, NOFOLLOW | TRYEMULROOT, UIO_SYSSPACE, pathbuf); 579 580 /* 581 * initialize the fields of the exec package. 582 */ 583 pack.ep_name = path; 584 pack.ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP); 585 pack.ep_hdrlen = exec_maxhdrsz; 586 pack.ep_hdrvalid = 0; 587 pack.ep_ndp = &nid; 588 pack.ep_emul_arg = NULL; 589 pack.ep_vmcmds.evs_cnt = 0; 590 pack.ep_vmcmds.evs_used = 0; 591 pack.ep_vap = &attr; 592 pack.ep_flags = 0; 593 pack.ep_emul_root = NULL; 594 pack.ep_interp = NULL; 595 pack.ep_esch = NULL; 596 pack.ep_pax_flags = 0; 597 598 rw_enter(&exec_lock, RW_READER); 599 600 /* see if we can run it. */ 601 if ((error = check_exec(l, &pack)) != 0) { 602 if (error != ENOENT) { 603 DPRINTF(("execve: check exec failed %d\n", error)); 604 } 605 goto freehdr; 606 } 607 608 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 609 610 /* allocate an argument buffer */ 611 argp = pool_get(&exec_pool, PR_WAITOK); 612 KASSERT(argp != NULL); 613 dp = argp; 614 argc = 0; 615 616 /* copy the fake args list, if there's one, freeing it as we go */ 617 if (pack.ep_flags & EXEC_HASARGL) { 618 tmpfap = pack.ep_fa; 619 while (tmpfap->fa_arg != NULL) { 620 const char *cp; 621 622 cp = tmpfap->fa_arg; 623 while (*cp) 624 *dp++ = *cp++; 625 *dp++ = '\0'; 626 627 kmem_free(tmpfap->fa_arg, tmpfap->fa_len); 628 tmpfap++; argc++; 629 } 630 kmem_free(pack.ep_fa, pack.ep_fa_len); 631 pack.ep_flags &= ~EXEC_HASARGL; 632 } 633 634 /* Now get argv & environment */ 635 if (args == NULL) { 636 DPRINTF(("execve: null args\n")); 637 error = EINVAL; 638 goto bad; 639 } 640 /* 'i' will index the argp/envp element to be retrieved */ 641 i = 0; 642 if (pack.ep_flags & EXEC_SKIPARG) 643 i++; 644 645 while (1) { 646 len = argp + ARG_MAX - dp; 647 if ((error = (*fetch_element)(args, i, &sp)) != 0) { 648 DPRINTF(("execve: fetch_element args %d\n", error)); 649 goto bad; 650 } 651 if (!sp) 652 break; 653 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 654 DPRINTF(("execve: copyinstr args %d\n", error)); 655 if (error == ENAMETOOLONG) 656 error = E2BIG; 657 goto bad; 658 } 659 ktrexecarg(dp, len - 1); 660 dp += len; 661 i++; 662 argc++; 663 } 664 665 envc = 0; 666 /* environment need not be there */ 667 if (envs != NULL) { 668 i = 0; 669 while (1) { 670 len = argp + ARG_MAX - dp; 671 if ((error = (*fetch_element)(envs, i, &sp)) != 0) { 672 DPRINTF(("execve: fetch_element env %d\n", error)); 673 goto bad; 674 } 675 if (!sp) 676 break; 677 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 678 DPRINTF(("execve: copyinstr env %d\n", error)); 679 if (error == ENAMETOOLONG) 680 error = E2BIG; 681 goto bad; 682 } 683 ktrexecenv(dp, len - 1); 684 dp += len; 685 i++; 686 envc++; 687 } 688 } 689 690 dp = (char *) ALIGN(dp); 691 692 szsigcode = pack.ep_esch->es_emul->e_esigcode - 693 pack.ep_esch->es_emul->e_sigcode; 694 695 #ifdef __MACHINE_STACK_GROWS_UP 696 /* See big comment lower down */ 697 #define RTLD_GAP 32 698 #else 699 #define RTLD_GAP 0 700 #endif 701 702 /* Now check if args & environ fit into new stack */ 703 if (pack.ep_flags & EXEC_32) 704 len = ((argc + envc + 2 + pack.ep_esch->es_arglen) * 705 sizeof(int) + sizeof(int) + dp + RTLD_GAP + 706 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 707 - argp; 708 else 709 len = ((argc + envc + 2 + pack.ep_esch->es_arglen) * 710 sizeof(char *) + sizeof(int) + dp + RTLD_GAP + 711 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 712 - argp; 713 714 #ifdef PAX_ASLR 715 if (pax_aslr_active(l)) 716 len += (arc4random() % PAGE_SIZE); 717 #endif /* PAX_ASLR */ 718 719 #ifdef STACKLALIGN /* arm, etc. */ 720 len = STACKALIGN(len); /* make the stack "safely" aligned */ 721 #else 722 len = ALIGN(len); /* make the stack "safely" aligned */ 723 #endif 724 725 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 726 DPRINTF(("execve: stack limit exceeded %zu\n", len)); 727 error = ENOMEM; 728 goto bad; 729 } 730 731 /* Get rid of other LWPs. */ 732 if (p->p_sa || p->p_nlwps > 1) { 733 mutex_enter(p->p_lock); 734 exit_lwps(l); 735 mutex_exit(p->p_lock); 736 } 737 KDASSERT(p->p_nlwps == 1); 738 739 /* Destroy any lwpctl info. */ 740 if (p->p_lwpctl != NULL) 741 lwp_ctl_exit(); 742 743 /* This is now LWP 1 */ 744 l->l_lid = 1; 745 p->p_nlwpid = 1; 746 747 #ifdef KERN_SA 748 /* Release any SA state. */ 749 if (p->p_sa) 750 sa_release(p); 751 #endif /* KERN_SA */ 752 753 /* Remove POSIX timers */ 754 timers_free(p, TIMERS_POSIX); 755 756 /* adjust "active stack depth" for process VSZ */ 757 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 758 759 /* 760 * Do whatever is necessary to prepare the address space 761 * for remapping. Note that this might replace the current 762 * vmspace with another! 763 */ 764 uvmspace_exec(l, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 765 766 /* record proc's vnode, for use by procfs and others */ 767 if (p->p_textvp) 768 vrele(p->p_textvp); 769 VREF(pack.ep_vp); 770 p->p_textvp = pack.ep_vp; 771 772 /* Now map address space */ 773 vm = p->p_vmspace; 774 vm->vm_taddr = (void *)pack.ep_taddr; 775 vm->vm_tsize = btoc(pack.ep_tsize); 776 vm->vm_daddr = (void*)pack.ep_daddr; 777 vm->vm_dsize = btoc(pack.ep_dsize); 778 vm->vm_ssize = btoc(pack.ep_ssize); 779 vm->vm_issize = 0; 780 vm->vm_maxsaddr = (void *)pack.ep_maxsaddr; 781 vm->vm_minsaddr = (void *)pack.ep_minsaddr; 782 783 #ifdef PAX_ASLR 784 pax_aslr_init(l, vm); 785 #endif /* PAX_ASLR */ 786 787 /* create the new process's VM space by running the vmcmds */ 788 #ifdef DIAGNOSTIC 789 if (pack.ep_vmcmds.evs_used == 0) 790 panic("execve: no vmcmds"); 791 #endif 792 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 793 struct exec_vmcmd *vcp; 794 795 vcp = &pack.ep_vmcmds.evs_cmds[i]; 796 if (vcp->ev_flags & VMCMD_RELATIVE) { 797 #ifdef DIAGNOSTIC 798 if (base_vcp == NULL) 799 panic("execve: relative vmcmd with no base"); 800 if (vcp->ev_flags & VMCMD_BASE) 801 panic("execve: illegal base & relative vmcmd"); 802 #endif 803 vcp->ev_addr += base_vcp->ev_addr; 804 } 805 error = (*vcp->ev_proc)(l, vcp); 806 #ifdef DEBUG_EXEC 807 if (error) { 808 size_t j; 809 struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0]; 810 for (j = 0; j <= i; j++) 811 uprintf( 812 "vmcmd[%zu] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n", 813 j, vp[j].ev_addr, vp[j].ev_len, 814 vp[j].ev_offset, vp[j].ev_prot, 815 vp[j].ev_flags); 816 } 817 #endif /* DEBUG_EXEC */ 818 if (vcp->ev_flags & VMCMD_BASE) 819 base_vcp = vcp; 820 } 821 822 /* free the vmspace-creation commands, and release their references */ 823 kill_vmcmds(&pack.ep_vmcmds); 824 825 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 826 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 827 vput(pack.ep_vp); 828 829 /* if an error happened, deallocate and punt */ 830 if (error) { 831 DPRINTF(("execve: vmcmd %zu failed: %d\n", i - 1, error)); 832 goto exec_abort; 833 } 834 835 /* remember information about the process */ 836 arginfo.ps_nargvstr = argc; 837 arginfo.ps_nenvstr = envc; 838 839 /* set command name & other accounting info */ 840 i = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 841 (void)memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, i); 842 p->p_comm[i] = '\0'; 843 844 dp = PNBUF_GET(); 845 /* 846 * If the path starts with /, we don't need to do any work. 847 * This handles the majority of the cases. 848 * In the future perhaps we could canonicalize it? 849 */ 850 if (pathbuf[0] == '/') 851 (void)strlcpy(pack.ep_path = dp, pathbuf, MAXPATHLEN); 852 #ifdef notyet 853 /* 854 * Although this works most of the time [since the entry was just 855 * entered in the cache] we don't use it because it theoretically 856 * can fail and it is not the cleanest interface, because there 857 * could be races. When the namei cache is re-written, this can 858 * be changed to use the appropriate function. 859 */ 860 else if (!(error = vnode_to_path(dp, MAXPATHLEN, p->p_textvp, l, p))) 861 pack.ep_path = dp; 862 #endif 863 else { 864 #ifdef notyet 865 printf("Cannot get path for pid %d [%s] (error %d)", 866 (int)p->p_pid, p->p_comm, error); 867 #endif 868 pack.ep_path = NULL; 869 PNBUF_PUT(dp); 870 } 871 872 stack = (char *)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, 873 STACK_PTHREADSPACE + sizeof(struct ps_strings) + szsigcode), 874 len - (sizeof(struct ps_strings) + szsigcode)); 875 876 #ifdef __MACHINE_STACK_GROWS_UP 877 /* 878 * The copyargs call always copies into lower addresses 879 * first, moving towards higher addresses, starting with 880 * the stack pointer that we give. When the stack grows 881 * down, this puts argc/argv/envp very shallow on the 882 * stack, right at the first user stack pointer. 883 * When the stack grows up, the situation is reversed. 884 * 885 * Normally, this is no big deal. But the ld_elf.so _rtld() 886 * function expects to be called with a single pointer to 887 * a region that has a few words it can stash values into, 888 * followed by argc/argv/envp. When the stack grows down, 889 * it's easy to decrement the stack pointer a little bit to 890 * allocate the space for these few words and pass the new 891 * stack pointer to _rtld. When the stack grows up, however, 892 * a few words before argc is part of the signal trampoline, XXX 893 * so we have a problem. 894 * 895 * Instead of changing how _rtld works, we take the easy way 896 * out and steal 32 bytes before we call copyargs. 897 * This extra space was allowed for when 'len' was calculated. 898 */ 899 stack += RTLD_GAP; 900 #endif /* __MACHINE_STACK_GROWS_UP */ 901 902 /* Now copy argc, args & environ to new stack */ 903 error = (*pack.ep_esch->es_copyargs)(l, &pack, &arginfo, &stack, argp); 904 if (pack.ep_path) { 905 PNBUF_PUT(pack.ep_path); 906 pack.ep_path = NULL; 907 } 908 if (error) { 909 DPRINTF(("execve: copyargs failed %d\n", error)); 910 goto exec_abort; 911 } 912 /* Move the stack back to original point */ 913 stack = (char *)STACK_GROW(vm->vm_minsaddr, len); 914 915 /* fill process ps_strings info */ 916 p->p_psstr = (struct ps_strings *) 917 STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, STACK_PTHREADSPACE), 918 sizeof(struct ps_strings)); 919 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 920 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 921 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 922 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 923 924 /* copy out the process's ps_strings structure */ 925 if ((error = copyout(aip, (char *)p->p_psstr, 926 sizeof(arginfo))) != 0) { 927 DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n", 928 aip, (char *)p->p_psstr, (long)sizeof(arginfo))); 929 goto exec_abort; 930 } 931 932 fd_closeexec(); /* handle close on exec */ 933 execsigs(p); /* reset catched signals */ 934 935 l->l_ctxlink = NULL; /* reset ucontext link */ 936 937 938 p->p_acflag &= ~AFORK; 939 mutex_enter(p->p_lock); 940 p->p_flag |= PK_EXEC; 941 mutex_exit(p->p_lock); 942 943 /* 944 * Stop profiling. 945 */ 946 if ((p->p_stflag & PST_PROFIL) != 0) { 947 mutex_spin_enter(&p->p_stmutex); 948 stopprofclock(p); 949 mutex_spin_exit(&p->p_stmutex); 950 } 951 952 /* 953 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have 954 * exited and exec()/exit() are the only places it will be cleared. 955 */ 956 if ((p->p_lflag & PL_PPWAIT) != 0) { 957 mutex_enter(proc_lock); 958 p->p_lflag &= ~PL_PPWAIT; 959 cv_broadcast(&p->p_pptr->p_waitcv); 960 mutex_exit(proc_lock); 961 } 962 963 /* 964 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 965 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 966 * out additional references on the process for the moment. 967 */ 968 if ((p->p_slflag & PSL_TRACED) == 0 && 969 970 (((attr.va_mode & S_ISUID) != 0 && 971 kauth_cred_geteuid(l->l_cred) != attr.va_uid) || 972 973 ((attr.va_mode & S_ISGID) != 0 && 974 kauth_cred_getegid(l->l_cred) != attr.va_gid))) { 975 /* 976 * Mark the process as SUGID before we do 977 * anything that might block. 978 */ 979 proc_crmod_enter(); 980 proc_crmod_leave(NULL, NULL, true); 981 982 /* Make sure file descriptors 0..2 are in use. */ 983 if ((error = fd_checkstd()) != 0) { 984 DPRINTF(("execve: fdcheckstd failed %d\n", error)); 985 goto exec_abort; 986 } 987 988 /* 989 * Copy the credential so other references don't see our 990 * changes. 991 */ 992 l->l_cred = kauth_cred_copy(l->l_cred); 993 #ifdef KTRACE 994 /* 995 * If the persistent trace flag isn't set, turn off. 996 */ 997 if (p->p_tracep) { 998 mutex_enter(&ktrace_lock); 999 if (!(p->p_traceflag & KTRFAC_PERSISTENT)) 1000 ktrderef(p); 1001 mutex_exit(&ktrace_lock); 1002 } 1003 #endif 1004 if (attr.va_mode & S_ISUID) 1005 kauth_cred_seteuid(l->l_cred, attr.va_uid); 1006 if (attr.va_mode & S_ISGID) 1007 kauth_cred_setegid(l->l_cred, attr.va_gid); 1008 } else { 1009 if (kauth_cred_geteuid(l->l_cred) == 1010 kauth_cred_getuid(l->l_cred) && 1011 kauth_cred_getegid(l->l_cred) == 1012 kauth_cred_getgid(l->l_cred)) 1013 p->p_flag &= ~PK_SUGID; 1014 } 1015 1016 /* 1017 * Copy the credential so other references don't see our changes. 1018 * Test to see if this is necessary first, since in the common case 1019 * we won't need a private reference. 1020 */ 1021 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 1022 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 1023 l->l_cred = kauth_cred_copy(l->l_cred); 1024 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 1025 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 1026 } 1027 1028 /* Update the master credentials. */ 1029 if (l->l_cred != p->p_cred) { 1030 kauth_cred_t ocred; 1031 1032 kauth_cred_hold(l->l_cred); 1033 mutex_enter(p->p_lock); 1034 ocred = p->p_cred; 1035 p->p_cred = l->l_cred; 1036 mutex_exit(p->p_lock); 1037 kauth_cred_free(ocred); 1038 } 1039 1040 #if defined(__HAVE_RAS) 1041 /* 1042 * Remove all RASs from the address space. 1043 */ 1044 ras_purgeall(); 1045 #endif 1046 1047 doexechooks(p); 1048 1049 /* setup new registers and do misc. setup. */ 1050 (*pack.ep_esch->es_emul->e_setregs)(l, &pack, (u_long) stack); 1051 if (pack.ep_esch->es_setregs) 1052 (*pack.ep_esch->es_setregs)(l, &pack, (u_long) stack); 1053 1054 /* map the process's signal trampoline code */ 1055 if (exec_sigcode_map(p, pack.ep_esch->es_emul)) { 1056 DPRINTF(("execve: map sigcode failed %d\n", error)); 1057 goto exec_abort; 1058 } 1059 1060 pool_put(&exec_pool, argp); 1061 1062 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1063 1064 /* notify others that we exec'd */ 1065 KNOTE(&p->p_klist, NOTE_EXEC); 1066 1067 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1068 1069 /* The emulation root will usually have been found when we looked 1070 * for the elf interpreter (or similar), if not look now. */ 1071 if (pack.ep_esch->es_emul->e_path != NULL && pack.ep_emul_root == NULL) 1072 emul_find_root(l, &pack); 1073 1074 /* Any old emulation root got removed by fdcloseexec */ 1075 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER); 1076 p->p_cwdi->cwdi_edir = pack.ep_emul_root; 1077 rw_exit(&p->p_cwdi->cwdi_lock); 1078 pack.ep_emul_root = NULL; 1079 if (pack.ep_interp != NULL) 1080 vrele(pack.ep_interp); 1081 1082 /* 1083 * Call emulation specific exec hook. This can setup per-process 1084 * p->p_emuldata or do any other per-process stuff an emulation needs. 1085 * 1086 * If we are executing process of different emulation than the 1087 * original forked process, call e_proc_exit() of the old emulation 1088 * first, then e_proc_exec() of new emulation. If the emulation is 1089 * same, the exec hook code should deallocate any old emulation 1090 * resources held previously by this process. 1091 */ 1092 if (p->p_emul && p->p_emul->e_proc_exit 1093 && p->p_emul != pack.ep_esch->es_emul) 1094 (*p->p_emul->e_proc_exit)(p); 1095 1096 /* 1097 * Call exec hook. Emulation code may NOT store reference to anything 1098 * from &pack. 1099 */ 1100 if (pack.ep_esch->es_emul->e_proc_exec) 1101 (*pack.ep_esch->es_emul->e_proc_exec)(p, &pack); 1102 1103 /* update p_emul, the old value is no longer needed */ 1104 p->p_emul = pack.ep_esch->es_emul; 1105 1106 /* ...and the same for p_execsw */ 1107 p->p_execsw = pack.ep_esch; 1108 1109 #ifdef __HAVE_SYSCALL_INTERN 1110 (*p->p_emul->e_syscall_intern)(p); 1111 #endif 1112 ktremul(); 1113 1114 /* Allow new references from the debugger/procfs. */ 1115 rw_exit(&p->p_reflock); 1116 rw_exit(&exec_lock); 1117 1118 mutex_enter(proc_lock); 1119 1120 if ((p->p_slflag & (PSL_TRACED|PSL_SYSCALL)) == PSL_TRACED) { 1121 KSI_INIT_EMPTY(&ksi); 1122 ksi.ksi_signo = SIGTRAP; 1123 ksi.ksi_lid = l->l_lid; 1124 kpsignal(p, &ksi, NULL); 1125 } 1126 1127 if (p->p_sflag & PS_STOPEXEC) { 1128 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1129 p->p_pptr->p_nstopchild++; 1130 p->p_pptr->p_waited = 0; 1131 mutex_enter(p->p_lock); 1132 ksiginfo_queue_init(&kq); 1133 sigclearall(p, &contsigmask, &kq); 1134 lwp_lock(l); 1135 l->l_stat = LSSTOP; 1136 p->p_stat = SSTOP; 1137 p->p_nrlwps--; 1138 mutex_exit(p->p_lock); 1139 mutex_exit(proc_lock); 1140 mi_switch(l); 1141 ksiginfo_queue_drain(&kq); 1142 KERNEL_LOCK(l->l_biglocks, l); 1143 } else { 1144 mutex_exit(proc_lock); 1145 } 1146 1147 PNBUF_PUT(pathbuf); 1148 return (EJUSTRETURN); 1149 1150 bad: 1151 /* free the vmspace-creation commands, and release their references */ 1152 kill_vmcmds(&pack.ep_vmcmds); 1153 /* kill any opened file descriptor, if necessary */ 1154 if (pack.ep_flags & EXEC_HASFD) { 1155 pack.ep_flags &= ~EXEC_HASFD; 1156 fd_close(pack.ep_fd); 1157 } 1158 /* close and put the exec'd file */ 1159 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 1160 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 1161 vput(pack.ep_vp); 1162 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1163 pool_put(&exec_pool, argp); 1164 1165 freehdr: 1166 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1167 if (pack.ep_emul_root != NULL) 1168 vrele(pack.ep_emul_root); 1169 if (pack.ep_interp != NULL) 1170 vrele(pack.ep_interp); 1171 1172 rw_exit(&exec_lock); 1173 1174 clrflg: 1175 lwp_lock(l); 1176 l->l_flag |= oldlwpflags; 1177 lwp_unlock(l); 1178 PNBUF_PUT(pathbuf); 1179 rw_exit(&p->p_reflock); 1180 1181 if (modgen != module_gen && error == ENOEXEC) { 1182 modgen = module_gen; 1183 exec_autoload(); 1184 goto retry; 1185 } 1186 1187 return error; 1188 1189 exec_abort: 1190 PNBUF_PUT(pathbuf); 1191 rw_exit(&p->p_reflock); 1192 rw_exit(&exec_lock); 1193 1194 /* 1195 * the old process doesn't exist anymore. exit gracefully. 1196 * get rid of the (new) address space we have created, if any, get rid 1197 * of our namei data and vnode, and exit noting failure 1198 */ 1199 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1200 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1201 if (pack.ep_emul_arg) 1202 free(pack.ep_emul_arg, M_TEMP); 1203 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1204 pool_put(&exec_pool, argp); 1205 kmem_free(pack.ep_hdr, pack.ep_hdrlen); 1206 if (pack.ep_emul_root != NULL) 1207 vrele(pack.ep_emul_root); 1208 if (pack.ep_interp != NULL) 1209 vrele(pack.ep_interp); 1210 1211 /* Acquire the sched-state mutex (exit1() will release it). */ 1212 mutex_enter(p->p_lock); 1213 exit1(l, W_EXITCODE(error, SIGABRT)); 1214 1215 /* NOTREACHED */ 1216 return 0; 1217 } 1218 1219 1220 int 1221 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1222 char **stackp, void *argp) 1223 { 1224 char **cpp, *dp, *sp; 1225 size_t len; 1226 void *nullp; 1227 long argc, envc; 1228 int error; 1229 1230 cpp = (char **)*stackp; 1231 nullp = NULL; 1232 argc = arginfo->ps_nargvstr; 1233 envc = arginfo->ps_nenvstr; 1234 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) 1235 return error; 1236 1237 dp = (char *) (cpp + argc + envc + 2 + pack->ep_esch->es_arglen); 1238 sp = argp; 1239 1240 /* XXX don't copy them out, remap them! */ 1241 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1242 1243 for (; --argc >= 0; sp += len, dp += len) 1244 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1245 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1246 return error; 1247 1248 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1249 return error; 1250 1251 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1252 1253 for (; --envc >= 0; sp += len, dp += len) 1254 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1255 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1256 return error; 1257 1258 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1259 return error; 1260 1261 *stackp = (char *)cpp; 1262 return 0; 1263 } 1264 1265 1266 /* 1267 * Add execsw[] entries. 1268 */ 1269 int 1270 exec_add(struct execsw *esp, int count) 1271 { 1272 struct exec_entry *it; 1273 int i; 1274 1275 if (count == 0) { 1276 return 0; 1277 } 1278 1279 /* Check for duplicates. */ 1280 rw_enter(&exec_lock, RW_WRITER); 1281 for (i = 0; i < count; i++) { 1282 LIST_FOREACH(it, &ex_head, ex_list) { 1283 /* assume unique (makecmds, probe_func, emulation) */ 1284 if (it->ex_sw->es_makecmds == esp[i].es_makecmds && 1285 it->ex_sw->u.elf_probe_func == 1286 esp[i].u.elf_probe_func && 1287 it->ex_sw->es_emul == esp[i].es_emul) { 1288 rw_exit(&exec_lock); 1289 return EEXIST; 1290 } 1291 } 1292 } 1293 1294 /* Allocate new entries. */ 1295 for (i = 0; i < count; i++) { 1296 it = kmem_alloc(sizeof(*it), KM_SLEEP); 1297 it->ex_sw = &esp[i]; 1298 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1299 } 1300 1301 /* update execsw[] */ 1302 exec_init(0); 1303 rw_exit(&exec_lock); 1304 return 0; 1305 } 1306 1307 /* 1308 * Remove execsw[] entry. 1309 */ 1310 int 1311 exec_remove(struct execsw *esp, int count) 1312 { 1313 struct exec_entry *it, *next; 1314 int i; 1315 const struct proclist_desc *pd; 1316 proc_t *p; 1317 1318 if (count == 0) { 1319 return 0; 1320 } 1321 1322 /* Abort if any are busy. */ 1323 rw_enter(&exec_lock, RW_WRITER); 1324 for (i = 0; i < count; i++) { 1325 mutex_enter(proc_lock); 1326 for (pd = proclists; pd->pd_list != NULL; pd++) { 1327 PROCLIST_FOREACH(p, pd->pd_list) { 1328 if (p->p_execsw == &esp[i]) { 1329 mutex_exit(proc_lock); 1330 rw_exit(&exec_lock); 1331 return EBUSY; 1332 } 1333 } 1334 } 1335 mutex_exit(proc_lock); 1336 } 1337 1338 /* None are busy, so remove them all. */ 1339 for (i = 0; i < count; i++) { 1340 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) { 1341 next = LIST_NEXT(it, ex_list); 1342 if (it->ex_sw == &esp[i]) { 1343 LIST_REMOVE(it, ex_list); 1344 kmem_free(it, sizeof(*it)); 1345 break; 1346 } 1347 } 1348 } 1349 1350 /* update execsw[] */ 1351 exec_init(0); 1352 rw_exit(&exec_lock); 1353 return 0; 1354 } 1355 1356 /* 1357 * Initialize exec structures. If init_boot is true, also does necessary 1358 * one-time initialization (it's called from main() that way). 1359 * Once system is multiuser, this should be called with exec_lock held, 1360 * i.e. via exec_{add|remove}(). 1361 */ 1362 int 1363 exec_init(int init_boot) 1364 { 1365 const struct execsw **sw; 1366 struct exec_entry *ex; 1367 SLIST_HEAD(,exec_entry) first; 1368 SLIST_HEAD(,exec_entry) any; 1369 SLIST_HEAD(,exec_entry) last; 1370 int i, sz; 1371 1372 if (init_boot) { 1373 /* do one-time initializations */ 1374 rw_init(&exec_lock); 1375 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE); 1376 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH, 1377 "execargs", &exec_palloc, IPL_NONE); 1378 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0); 1379 } else { 1380 KASSERT(rw_write_held(&exec_lock)); 1381 } 1382 1383 /* Sort each entry onto the appropriate queue. */ 1384 SLIST_INIT(&first); 1385 SLIST_INIT(&any); 1386 SLIST_INIT(&last); 1387 sz = 0; 1388 LIST_FOREACH(ex, &ex_head, ex_list) { 1389 switch(ex->ex_sw->es_prio) { 1390 case EXECSW_PRIO_FIRST: 1391 SLIST_INSERT_HEAD(&first, ex, ex_slist); 1392 break; 1393 case EXECSW_PRIO_ANY: 1394 SLIST_INSERT_HEAD(&any, ex, ex_slist); 1395 break; 1396 case EXECSW_PRIO_LAST: 1397 SLIST_INSERT_HEAD(&last, ex, ex_slist); 1398 break; 1399 default: 1400 panic("exec_init"); 1401 break; 1402 } 1403 sz++; 1404 } 1405 1406 /* 1407 * Create new execsw[]. Ensure we do not try a zero-sized 1408 * allocation. 1409 */ 1410 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP); 1411 i = 0; 1412 SLIST_FOREACH(ex, &first, ex_slist) { 1413 sw[i++] = ex->ex_sw; 1414 } 1415 SLIST_FOREACH(ex, &any, ex_slist) { 1416 sw[i++] = ex->ex_sw; 1417 } 1418 SLIST_FOREACH(ex, &last, ex_slist) { 1419 sw[i++] = ex->ex_sw; 1420 } 1421 1422 /* Replace old execsw[] and free used memory. */ 1423 if (execsw != NULL) { 1424 kmem_free(__UNCONST(execsw), 1425 nexecs * sizeof(struct execsw *) + 1); 1426 } 1427 execsw = sw; 1428 nexecs = sz; 1429 1430 /* Figure out the maximum size of an exec header. */ 1431 exec_maxhdrsz = sizeof(int); 1432 for (i = 0; i < nexecs; i++) { 1433 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1434 exec_maxhdrsz = execsw[i]->es_hdrsz; 1435 } 1436 1437 return 0; 1438 } 1439 1440 static int 1441 exec_sigcode_map(struct proc *p, const struct emul *e) 1442 { 1443 vaddr_t va; 1444 vsize_t sz; 1445 int error; 1446 struct uvm_object *uobj; 1447 1448 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1449 1450 if (e->e_sigobject == NULL || sz == 0) { 1451 return 0; 1452 } 1453 1454 /* 1455 * If we don't have a sigobject for this emulation, create one. 1456 * 1457 * sigobject is an anonymous memory object (just like SYSV shared 1458 * memory) that we keep a permanent reference to and that we map 1459 * in all processes that need this sigcode. The creation is simple, 1460 * we create an object, add a permanent reference to it, map it in 1461 * kernel space, copy out the sigcode to it and unmap it. 1462 * We map it with PROT_READ|PROT_EXEC into the process just 1463 * the way sys_mmap() would map it. 1464 */ 1465 1466 uobj = *e->e_sigobject; 1467 if (uobj == NULL) { 1468 mutex_enter(&sigobject_lock); 1469 if ((uobj = *e->e_sigobject) == NULL) { 1470 uobj = uao_create(sz, 0); 1471 (*uobj->pgops->pgo_reference)(uobj); 1472 va = vm_map_min(kernel_map); 1473 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1474 uobj, 0, 0, 1475 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1476 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1477 printf("kernel mapping failed %d\n", error); 1478 (*uobj->pgops->pgo_detach)(uobj); 1479 mutex_exit(&sigobject_lock); 1480 return (error); 1481 } 1482 memcpy((void *)va, e->e_sigcode, sz); 1483 #ifdef PMAP_NEED_PROCWR 1484 pmap_procwr(&proc0, va, sz); 1485 #endif 1486 uvm_unmap(kernel_map, va, va + round_page(sz)); 1487 *e->e_sigobject = uobj; 1488 } 1489 mutex_exit(&sigobject_lock); 1490 } 1491 1492 /* Just a hint to uvm_map where to put it. */ 1493 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1494 round_page(sz)); 1495 1496 #ifdef __alpha__ 1497 /* 1498 * Tru64 puts /sbin/loader at the end of user virtual memory, 1499 * which causes the above calculation to put the sigcode at 1500 * an invalid address. Put it just below the text instead. 1501 */ 1502 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1503 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1504 } 1505 #endif 1506 1507 (*uobj->pgops->pgo_reference)(uobj); 1508 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1509 uobj, 0, 0, 1510 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1511 UVM_ADV_RANDOM, 0)); 1512 if (error) { 1513 (*uobj->pgops->pgo_detach)(uobj); 1514 return (error); 1515 } 1516 p->p_sigctx.ps_sigcode = (void *)va; 1517 return (0); 1518 } 1519