Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_exec.c
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1 /* $NetBSD: kern_exec.c,v 1.232.2.4 2011/03/20 20:51:52 bouyer Exp $ */ 2 3 /*- 4 * Copyright (C) 1993, 1994, 1996 Christopher G. Demetriou 5 * Copyright (C) 1992 Wolfgang Solfrank. 6 * Copyright (C) 1992 TooLs GmbH. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by TooLs GmbH. 20 * 4. The name of TooLs GmbH may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.232.2.4 2011/03/20 20:51:52 bouyer Exp $"); 37 38 #include "opt_ktrace.h" 39 #include "opt_syscall_debug.h" 40 #include "opt_compat_netbsd.h" 41 #include "veriexec.h" 42 #include "opt_pax.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/filedesc.h> 47 #include <sys/kernel.h> 48 #include <sys/proc.h> 49 #include <sys/mount.h> 50 #include <sys/malloc.h> 51 #include <sys/namei.h> 52 #include <sys/vnode.h> 53 #include <sys/file.h> 54 #include <sys/acct.h> 55 #include <sys/exec.h> 56 #include <sys/ktrace.h> 57 #include <sys/resourcevar.h> 58 #include <sys/wait.h> 59 #include <sys/mman.h> 60 #include <sys/ras.h> 61 #include <sys/signalvar.h> 62 #include <sys/stat.h> 63 #include <sys/syscall.h> 64 #include <sys/kauth.h> 65 66 #include <sys/sa.h> 67 #include <sys/savar.h> 68 #include <sys/syscallargs.h> 69 #if NVERIEXEC > 0 70 #include <sys/verified_exec.h> 71 #endif /* NVERIEXEC > 0 */ 72 73 #ifdef SYSTRACE 74 #include <sys/systrace.h> 75 #endif /* SYSTRACE */ 76 77 #ifdef PAX_SEGVGUARD 78 #include <sys/pax.h> 79 #endif /* PAX_SEGVGUARD */ 80 81 #include <uvm/uvm_extern.h> 82 83 #include <machine/cpu.h> 84 #include <machine/reg.h> 85 86 static int exec_sigcode_map(struct proc *, const struct emul *); 87 88 #ifdef DEBUG_EXEC 89 #define DPRINTF(a) uprintf a 90 #else 91 #define DPRINTF(a) 92 #endif /* DEBUG_EXEC */ 93 94 MALLOC_DEFINE(M_EXEC, "exec", "argument lists & other mem used by exec"); 95 96 /* 97 * Exec function switch: 98 * 99 * Note that each makecmds function is responsible for loading the 100 * exec package with the necessary functions for any exec-type-specific 101 * handling. 102 * 103 * Functions for specific exec types should be defined in their own 104 * header file. 105 */ 106 extern const struct execsw execsw_builtin[]; 107 extern int nexecs_builtin; 108 static const struct execsw **execsw = NULL; 109 static int nexecs; 110 111 u_int exec_maxhdrsz; /* must not be static - netbsd32 needs it */ 112 113 #ifdef LKM 114 /* list of supported emulations */ 115 static 116 LIST_HEAD(emlist_head, emul_entry) el_head = LIST_HEAD_INITIALIZER(el_head); 117 struct emul_entry { 118 LIST_ENTRY(emul_entry) el_list; 119 const struct emul *el_emul; 120 int ro_entry; 121 }; 122 123 /* list of dynamically loaded execsw entries */ 124 static 125 LIST_HEAD(execlist_head, exec_entry) ex_head = LIST_HEAD_INITIALIZER(ex_head); 126 struct exec_entry { 127 LIST_ENTRY(exec_entry) ex_list; 128 const struct execsw *es; 129 }; 130 131 /* structure used for building execw[] */ 132 struct execsw_entry { 133 struct execsw_entry *next; 134 const struct execsw *es; 135 }; 136 #endif /* LKM */ 137 138 #ifdef SYSCALL_DEBUG 139 extern const char * const syscallnames[]; 140 #endif 141 142 #ifdef COMPAT_16 143 extern char sigcode[], esigcode[]; 144 struct uvm_object *emul_netbsd_object; 145 #endif 146 147 #ifndef __HAVE_SYSCALL_INTERN 148 void syscall(void); 149 #endif 150 151 static const 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, 159 sa_ucsp 160 }; 161 162 /* NetBSD emul struct */ 163 const struct emul emul_netbsd = { 164 "netbsd", 165 NULL, /* emulation path */ 166 #ifndef __HAVE_MINIMAL_EMUL 167 EMUL_HAS_SYS___syscall, 168 NULL, 169 SYS_syscall, 170 SYS_NSYSENT, 171 #endif 172 sysent, 173 #ifdef SYSCALL_DEBUG 174 syscallnames, 175 #else 176 NULL, 177 #endif 178 sendsig, 179 trapsignal, 180 NULL, 181 #ifdef COMPAT_16 182 sigcode, 183 esigcode, 184 &emul_netbsd_object, 185 #else 186 NULL, 187 NULL, 188 NULL, 189 #endif 190 setregs, 191 NULL, 192 NULL, 193 NULL, 194 NULL, 195 NULL, 196 #ifdef __HAVE_SYSCALL_INTERN 197 syscall_intern, 198 #else 199 syscall, 200 #endif 201 NULL, 202 NULL, 203 204 uvm_default_mapaddr, 205 NULL, 206 &saemul_netbsd, 207 }; 208 209 #ifdef LKM 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 struct lock exec_lock; 215 216 static void link_es(struct execsw_entry **, const struct execsw *); 217 #endif /* LKM */ 218 219 /* 220 * check exec: 221 * given an "executable" described in the exec package's namei info, 222 * see what we can do with it. 223 * 224 * ON ENTRY: 225 * exec package with appropriate namei info 226 * lwp pointer of exec'ing lwp 227 * NO SELF-LOCKED VNODES 228 * 229 * ON EXIT: 230 * error: nothing held, etc. exec header still allocated. 231 * ok: filled exec package, executable's vnode (unlocked). 232 * 233 * EXEC SWITCH ENTRY: 234 * Locked vnode to check, exec package, proc. 235 * 236 * EXEC SWITCH EXIT: 237 * ok: return 0, filled exec package, executable's vnode (unlocked). 238 * error: destructive: 239 * everything deallocated execept exec header. 240 * non-destructive: 241 * error code, executable's vnode (unlocked), 242 * exec header unmodified. 243 */ 244 int 245 /*ARGSUSED*/ 246 check_exec(struct lwp *l, struct exec_package *epp) 247 { 248 int error, i; 249 struct vnode *vp; 250 struct nameidata *ndp; 251 size_t resid; 252 253 ndp = epp->ep_ndp; 254 ndp->ni_cnd.cn_nameiop = LOOKUP; 255 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME; 256 /* first get the vnode */ 257 if ((error = namei(ndp)) != 0) 258 return error; 259 epp->ep_vp = vp = ndp->ni_vp; 260 261 /* check access and type */ 262 if (vp->v_type != VREG) { 263 error = EACCES; 264 goto bad1; 265 } 266 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred, l)) != 0) 267 goto bad1; 268 269 /* get attributes */ 270 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred, l)) != 0) 271 goto bad1; 272 273 /* Check mount point */ 274 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 275 error = EACCES; 276 goto bad1; 277 } 278 if (vp->v_mount->mnt_flag & MNT_NOSUID) 279 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 280 281 /* try to open it */ 282 if ((error = VOP_OPEN(vp, FREAD, l->l_cred, l)) != 0) 283 goto bad1; 284 285 /* unlock vp, since we need it unlocked from here on out. */ 286 VOP_UNLOCK(vp, 0); 287 288 #if NVERIEXEC > 0 289 if ((error = veriexec_verify(l, vp, ndp->ni_cnd.cn_pnbuf, 290 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 291 NULL)) != 0) 292 goto bad2; 293 #endif /* NVERIEXEC > 0 */ 294 295 #ifdef PAX_SEGVGUARD 296 error = pax_segvguard(l, vp, ndp->ni_cnd.cn_pnbuf, FALSE); 297 if (error) 298 goto bad2; 299 #endif /* PAX_SEGVGUARD */ 300 301 /* now we have the file, get the exec header */ 302 uvn_attach(vp, VM_PROT_READ); 303 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 304 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 305 if (error) 306 goto bad2; 307 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 308 309 /* 310 * Set up default address space limits. Can be overridden 311 * by individual exec packages. 312 * 313 * XXX probably should be all done in the exec pakages. 314 */ 315 epp->ep_vm_minaddr = VM_MIN_ADDRESS; 316 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 317 /* 318 * set up the vmcmds for creation of the process 319 * address space 320 */ 321 error = ENOEXEC; 322 for (i = 0; i < nexecs && error != 0; i++) { 323 int newerror; 324 325 epp->ep_esch = execsw[i]; 326 newerror = (*execsw[i]->es_makecmds)(l, epp); 327 /* make sure the first "interesting" error code is saved. */ 328 if (!newerror || error == ENOEXEC) 329 error = newerror; 330 331 /* if es_makecmds call was successful, update epp->ep_es */ 332 if (!newerror && (epp->ep_flags & EXEC_HASES) == 0) 333 epp->ep_es = execsw[i]; 334 335 if (epp->ep_flags & EXEC_DESTR && error != 0) 336 return error; 337 } 338 if (!error) { 339 /* check that entry point is sane */ 340 if (epp->ep_entry > VM_MAXUSER_ADDRESS) 341 error = ENOEXEC; 342 343 /* check limits */ 344 if ((epp->ep_tsize > MAXTSIZ) || 345 (epp->ep_dsize > 346 (u_quad_t)l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur)) 347 error = ENOMEM; 348 349 if (!error) 350 return (0); 351 } 352 353 /* 354 * free any vmspace-creation commands, 355 * and release their references 356 */ 357 kill_vmcmds(&epp->ep_vmcmds); 358 359 bad2: 360 /* 361 * close and release the vnode, restore the old one, free the 362 * pathname buf, and punt. 363 */ 364 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 365 VOP_CLOSE(vp, FREAD, l->l_cred, l); 366 vput(vp); 367 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 368 return error; 369 370 bad1: 371 /* 372 * free the namei pathname buffer, and put the vnode 373 * (which we don't yet have open). 374 */ 375 vput(vp); /* was still locked */ 376 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 377 return error; 378 } 379 380 #ifdef __MACHINE_STACK_GROWS_UP 381 #define STACK_PTHREADSPACE NBPG 382 #else 383 #define STACK_PTHREADSPACE 0 384 #endif 385 386 static int 387 execve_fetch_element(char * const *array, size_t index, char **value) 388 { 389 return copyin(array + index, value, sizeof(*value)); 390 } 391 392 /* 393 * exec system call 394 */ 395 /* ARGSUSED */ 396 int 397 sys_execve(struct lwp *l, void *v, register_t *retval) 398 { 399 struct sys_execve_args /* { 400 syscallarg(const char *) path; 401 syscallarg(char * const *) argp; 402 syscallarg(char * const *) envp; 403 } */ *uap = v; 404 405 return execve1(l, SCARG(uap, path), SCARG(uap, argp), 406 SCARG(uap, envp), execve_fetch_element); 407 } 408 409 int 410 execve1(struct lwp *l, const char *path, char * const *args, 411 char * const *envs, execve_fetch_element_t fetch_element) 412 { 413 int error; 414 u_int i; 415 struct exec_package pack; 416 struct nameidata nid; 417 struct vattr attr; 418 struct proc *p; 419 char *argp; 420 char *dp, *sp; 421 long argc, envc; 422 size_t len; 423 char *stack; 424 struct ps_strings arginfo; 425 struct ps_strings *aip = &arginfo; 426 struct vmspace *vm; 427 char **tmpfap; 428 int szsigcode; 429 struct exec_vmcmd *base_vcp; 430 int oldlwpflags; 431 uid_t uid; 432 #ifdef SYSTRACE 433 int wassugid = ISSET(p->p_flag, P_SUGID); 434 char pathbuf[MAXPATHLEN]; 435 size_t pathbuflen; 436 #endif /* SYSTRACE */ 437 438 p = l->l_proc; 439 440 /* 441 * Check if we have exceeded our number of processes limit. 442 * This is so that we handle the case where a root daemon 443 * forked, ran setuid to become the desired user and is trying 444 * to exec. The obvious place to do the reference counting check 445 * is setuid(), but we don't do the reference counting check there 446 * like other OS's do because then all the programs that use setuid() 447 * must be modified to check the return code of setuid() and exit(). 448 * It is dangerous to make setuid() fail, because it fails open and 449 * the program will continue to run as root. If we make it succeed 450 * and return an error code, again we are not enforcing the limit. 451 * The best place to enforce the limit is here, when the process tries 452 * to execute a new image, because eventually the process will need 453 * to call exec in order to do something useful. 454 */ 455 456 if ((p->p_flag & P_SUGID) && (uid = kauth_cred_getuid(l->l_cred)) != 0 457 && chgproccnt(uid, 0) > p->p_rlimit[RLIMIT_NPROC].rlim_cur) 458 return EAGAIN; 459 460 /* Disable scheduler activation upcalls. */ 461 oldlwpflags = l->l_flag & (L_SA | L_SA_UPCALL); 462 if (l->l_flag & L_SA) 463 l->l_flag &= ~(L_SA | L_SA_UPCALL); 464 465 /* 466 * Lock the process and set the P_INEXEC flag to indicate that 467 * it should be left alone until we're done here. This is 468 * necessary to avoid race conditions - e.g. in ptrace() - 469 * that might allow a local user to illicitly obtain elevated 470 * privileges. 471 */ 472 p->p_flag |= P_INEXEC; 473 474 base_vcp = NULL; 475 /* 476 * Init the namei data to point the file user's program name. 477 * This is done here rather than in check_exec(), so that it's 478 * possible to override this settings if any of makecmd/probe 479 * functions call check_exec() recursively - for example, 480 * see exec_script_makecmds(). 481 */ 482 #ifdef SYSTRACE 483 if (ISSET(p->p_flag, P_SYSTRACE)) 484 systrace_execve0(p); 485 486 error = copyinstr(path, pathbuf, sizeof(pathbuf), 487 &pathbuflen); 488 if (error) 489 goto clrflg; 490 491 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, l); 492 #else 493 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, path, l); 494 #endif /* SYSTRACE */ 495 496 /* 497 * initialize the fields of the exec package. 498 */ 499 #ifdef SYSTRACE 500 pack.ep_name = pathbuf; 501 #else 502 pack.ep_name = path; 503 #endif /* SYSTRACE */ 504 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 505 pack.ep_hdrlen = exec_maxhdrsz; 506 pack.ep_hdrvalid = 0; 507 pack.ep_ndp = &nid; 508 pack.ep_emul_arg = NULL; 509 pack.ep_vmcmds.evs_cnt = 0; 510 pack.ep_vmcmds.evs_used = 0; 511 pack.ep_vap = &attr; 512 pack.ep_flags = 0; 513 514 #ifdef LKM 515 lockmgr(&exec_lock, LK_SHARED, NULL); 516 #endif 517 518 /* see if we can run it. */ 519 if ((error = check_exec(l, &pack)) != 0) 520 goto freehdr; 521 522 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 523 524 /* allocate an argument buffer */ 525 argp = (char *) uvm_km_alloc(exec_map, NCARGS, 0, 526 UVM_KMF_PAGEABLE|UVM_KMF_WAITVA); 527 #ifdef DIAGNOSTIC 528 if (argp == NULL) 529 panic("execve: argp == NULL"); 530 #endif 531 dp = argp; 532 argc = 0; 533 534 /* copy the fake args list, if there's one, freeing it as we go */ 535 if (pack.ep_flags & EXEC_HASARGL) { 536 tmpfap = pack.ep_fa; 537 while (*tmpfap != NULL) { 538 char *cp; 539 540 cp = *tmpfap; 541 while (*cp) 542 *dp++ = *cp++; 543 *dp++ = 0; 544 #ifdef KTRACE 545 if (KTRPOINT(p, KTR_EXEC_ARG)) 546 ktrkmem(l, KTR_EXEC_ARG, *tmpfap, cp - *tmpfap); 547 #endif 548 549 FREE(*tmpfap, M_EXEC); 550 tmpfap++; argc++; 551 } 552 FREE(pack.ep_fa, M_EXEC); 553 pack.ep_flags &= ~EXEC_HASARGL; 554 } 555 556 /* Now get argv & environment */ 557 if (args == NULL) { 558 error = EINVAL; 559 goto bad; 560 } 561 /* 'i' will index the argp/envp element to be retrieved */ 562 i = 0; 563 if (pack.ep_flags & EXEC_SKIPARG) 564 i++; 565 566 while (1) { 567 len = argp + ARG_MAX - dp; 568 if ((error = (*fetch_element)(args, i, &sp)) != 0) 569 goto bad; 570 if (!sp) 571 break; 572 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 573 if (error == ENAMETOOLONG) 574 error = E2BIG; 575 goto bad; 576 } 577 #ifdef KTRACE 578 if (KTRPOINT(p, KTR_EXEC_ARG)) 579 ktrkmem(l, KTR_EXEC_ARG, dp, len - 1); 580 #endif 581 dp += len; 582 i++; 583 argc++; 584 } 585 586 envc = 0; 587 /* environment need not be there */ 588 if (envs != NULL) { 589 i = 0; 590 while (1) { 591 len = argp + ARG_MAX - dp; 592 if ((error = (*fetch_element)(envs, i, &sp)) != 0) 593 goto bad; 594 if (!sp) 595 break; 596 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 597 if (error == ENAMETOOLONG) 598 error = E2BIG; 599 goto bad; 600 } 601 #ifdef KTRACE 602 if (KTRPOINT(p, KTR_EXEC_ENV)) 603 ktrkmem(l, KTR_EXEC_ENV, dp, len - 1); 604 #endif 605 dp += len; 606 i++; 607 envc++; 608 } 609 } 610 611 dp = (char *) ALIGN(dp); 612 613 szsigcode = pack.ep_es->es_emul->e_esigcode - 614 pack.ep_es->es_emul->e_sigcode; 615 616 /* Now check if args & environ fit into new stack */ 617 if (pack.ep_flags & EXEC_32) 618 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 619 sizeof(int) + sizeof(int) + dp + STACKGAPLEN + 620 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 621 - argp; 622 else 623 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 624 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN + 625 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 626 - argp; 627 628 len = ALIGN(len); /* make the stack "safely" aligned */ 629 630 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 631 error = ENOMEM; 632 goto bad; 633 } 634 635 /* Get rid of other LWPs/ */ 636 p->p_flag |= P_WEXIT; /* XXX hack. lwp-exit stuff wants to see it. */ 637 exit_lwps(l); 638 p->p_flag &= ~P_WEXIT; 639 KDASSERT(p->p_nlwps == 1); 640 641 /* This is now LWP 1 */ 642 l->l_lid = 1; 643 p->p_nlwpid = 1; 644 645 /* Release any SA state. */ 646 if (p->p_sa) 647 sa_release(p); 648 649 /* Remove POSIX timers */ 650 timers_free(p, TIMERS_POSIX); 651 652 /* adjust "active stack depth" for process VSZ */ 653 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 654 655 /* 656 * Do whatever is necessary to prepare the address space 657 * for remapping. Note that this might replace the current 658 * vmspace with another! 659 */ 660 uvmspace_exec(l, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 661 662 /* record proc's vnode, for use by procfs and others */ 663 if (p->p_textvp) 664 vrele(p->p_textvp); 665 VREF(pack.ep_vp); 666 p->p_textvp = pack.ep_vp; 667 668 /* Now map address space */ 669 vm = p->p_vmspace; 670 vm->vm_taddr = (caddr_t) pack.ep_taddr; 671 vm->vm_tsize = btoc(pack.ep_tsize); 672 vm->vm_daddr = (caddr_t) pack.ep_daddr; 673 vm->vm_dsize = btoc(pack.ep_dsize); 674 vm->vm_ssize = btoc(pack.ep_ssize); 675 vm->vm_maxsaddr = (caddr_t) pack.ep_maxsaddr; 676 vm->vm_minsaddr = (caddr_t) pack.ep_minsaddr; 677 678 /* create the new process's VM space by running the vmcmds */ 679 #ifdef DIAGNOSTIC 680 if (pack.ep_vmcmds.evs_used == 0) 681 panic("execve: no vmcmds"); 682 #endif 683 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 684 struct exec_vmcmd *vcp; 685 686 vcp = &pack.ep_vmcmds.evs_cmds[i]; 687 if (vcp->ev_flags & VMCMD_RELATIVE) { 688 #ifdef DIAGNOSTIC 689 if (base_vcp == NULL) 690 panic("execve: relative vmcmd with no base"); 691 if (vcp->ev_flags & VMCMD_BASE) 692 panic("execve: illegal base & relative vmcmd"); 693 #endif 694 vcp->ev_addr += base_vcp->ev_addr; 695 } 696 error = (*vcp->ev_proc)(l, vcp); 697 #ifdef DEBUG_EXEC 698 if (error) { 699 int j; 700 struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0]; 701 for (j = 0; j <= i; j++) 702 uprintf( 703 "vmcmd[%d] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n", 704 j, vp[j].ev_addr, vp[j].ev_len, 705 vp[j].ev_offset, vp[j].ev_prot, 706 vp[j].ev_flags); 707 } 708 #endif /* DEBUG_EXEC */ 709 if (vcp->ev_flags & VMCMD_BASE) 710 base_vcp = vcp; 711 } 712 713 /* free the vmspace-creation commands, and release their references */ 714 kill_vmcmds(&pack.ep_vmcmds); 715 716 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 717 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred, l); 718 vput(pack.ep_vp); 719 720 /* if an error happened, deallocate and punt */ 721 if (error) { 722 DPRINTF(("execve: vmcmd %i failed: %d\n", i - 1, error)); 723 goto exec_abort; 724 } 725 726 /* remember information about the process */ 727 arginfo.ps_nargvstr = argc; 728 arginfo.ps_nenvstr = envc; 729 730 stack = (char *)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, 731 STACK_PTHREADSPACE + sizeof(struct ps_strings) + szsigcode), 732 len - (sizeof(struct ps_strings) + szsigcode)); 733 #ifdef __MACHINE_STACK_GROWS_UP 734 /* 735 * The copyargs call always copies into lower addresses 736 * first, moving towards higher addresses, starting with 737 * the stack pointer that we give. When the stack grows 738 * down, this puts argc/argv/envp very shallow on the 739 * stack, right at the first user stack pointer, and puts 740 * STACKGAPLEN very deep in the stack. When the stack 741 * grows up, the situation is reversed. 742 * 743 * Normally, this is no big deal. But the ld_elf.so _rtld() 744 * function expects to be called with a single pointer to 745 * a region that has a few words it can stash values into, 746 * followed by argc/argv/envp. When the stack grows down, 747 * it's easy to decrement the stack pointer a little bit to 748 * allocate the space for these few words and pass the new 749 * stack pointer to _rtld. When the stack grows up, however, 750 * a few words before argc is part of the signal trampoline, XXX 751 * so we have a problem. 752 * 753 * Instead of changing how _rtld works, we take the easy way 754 * out and steal 32 bytes before we call copyargs. This 755 * space is effectively stolen from STACKGAPLEN. 756 */ 757 stack += 32; 758 #endif /* __MACHINE_STACK_GROWS_UP */ 759 760 /* Now copy argc, args & environ to new stack */ 761 error = (*pack.ep_es->es_copyargs)(l, &pack, &arginfo, &stack, argp); 762 if (error) { 763 DPRINTF(("execve: copyargs failed %d\n", error)); 764 goto exec_abort; 765 } 766 /* Move the stack back to original point */ 767 stack = (char *)STACK_GROW(vm->vm_minsaddr, len); 768 769 /* fill process ps_strings info */ 770 p->p_psstr = (struct ps_strings *) 771 STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, STACK_PTHREADSPACE), 772 sizeof(struct ps_strings)); 773 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 774 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 775 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 776 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 777 778 /* copy out the process's ps_strings structure */ 779 if ((error = copyout(aip, (char *)p->p_psstr, 780 sizeof(arginfo))) != 0) { 781 DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n", 782 aip, (char *)p->p_psstr, (long)sizeof(arginfo))); 783 goto exec_abort; 784 } 785 786 stopprofclock(p); /* stop profiling */ 787 fdcloseexec(l); /* handle close on exec */ 788 execsigs(p); /* reset catched signals */ 789 790 l->l_ctxlink = NULL; /* reset ucontext link */ 791 792 /* set command name & other accounting info */ 793 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 794 memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len); 795 p->p_comm[len] = 0; 796 p->p_acflag &= ~AFORK; 797 798 p->p_flag |= P_EXEC; 799 if (p->p_flag & P_PPWAIT) { 800 p->p_flag &= ~P_PPWAIT; 801 wakeup((caddr_t) p->p_pptr); 802 } 803 804 /* 805 * deal with set[ug]id. 806 * MNT_NOSUID has already been used to disable s[ug]id. 807 */ 808 if ((p->p_flag & P_TRACED) == 0 && 809 810 (((attr.va_mode & S_ISUID) != 0 && 811 kauth_cred_geteuid(l->l_cred) != attr.va_uid) || 812 813 ((attr.va_mode & S_ISGID) != 0 && 814 kauth_cred_getegid(l->l_cred) != attr.va_gid))) { 815 /* 816 * Mark the process as SUGID before we do 817 * anything that might block. 818 */ 819 p_sugid(p); 820 821 /* Make sure file descriptors 0..2 are in use. */ 822 if ((error = fdcheckstd(l)) != 0) { 823 DPRINTF(("execve: fdcheckstd failed %d\n", error)); 824 goto exec_abort; 825 } 826 827 /* 828 * Copy the credential so other references don't see our 829 * changes. 830 */ 831 l->l_cred = kauth_cred_copy(l->l_cred); 832 #ifdef KTRACE 833 /* 834 * If process is being ktraced, turn off - unless 835 * root set it. 836 */ 837 if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT)) 838 ktrderef(p); 839 #endif 840 if (attr.va_mode & S_ISUID) 841 kauth_cred_seteuid(l->l_cred, attr.va_uid); 842 if (attr.va_mode & S_ISGID) 843 kauth_cred_setegid(l->l_cred, attr.va_gid); 844 } else { 845 if (kauth_cred_geteuid(l->l_cred) == 846 kauth_cred_getuid(l->l_cred) && 847 kauth_cred_getegid(l->l_cred) == 848 kauth_cred_getgid(l->l_cred)) 849 p->p_flag &= ~P_SUGID; 850 } 851 852 /* 853 * Copy the credential so other references don't see our changes. 854 * Test to see if this is necessary first, since in the common case 855 * we won't need a private reference. 856 */ 857 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 858 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 859 l->l_cred = kauth_cred_copy(l->l_cred); 860 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 861 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 862 } 863 864 /* Update the master credentials. */ 865 if (l->l_cred != p->p_cred) { 866 kauth_cred_t ocred; 867 868 kauth_cred_hold(l->l_cred); 869 simple_lock(&p->p_lock); 870 ocred = p->p_cred; 871 p->p_cred = l->l_cred; 872 simple_unlock(&p->p_lock); 873 kauth_cred_free(ocred); 874 } 875 876 #if defined(__HAVE_RAS) 877 /* 878 * Remove all RASs from the address space. 879 */ 880 ras_purgeall(p); 881 #endif 882 883 doexechooks(p); 884 885 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 886 887 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 888 889 /* notify others that we exec'd */ 890 KNOTE(&p->p_klist, NOTE_EXEC); 891 892 /* setup new registers and do misc. setup. */ 893 (*pack.ep_es->es_emul->e_setregs)(l, &pack, (u_long) stack); 894 if (pack.ep_es->es_setregs) 895 (*pack.ep_es->es_setregs)(l, &pack, (u_long) stack); 896 897 /* map the process's signal trampoline code */ 898 if (exec_sigcode_map(p, pack.ep_es->es_emul)) { 899 DPRINTF(("execve: map sigcode failed %d\n", error)); 900 goto exec_abort; 901 } 902 903 if ((p->p_flag & (P_TRACED|P_SYSCALL)) == P_TRACED) 904 psignal(p, SIGTRAP); 905 906 free(pack.ep_hdr, M_EXEC); 907 908 /* 909 * Call emulation specific exec hook. This can setup per-process 910 * p->p_emuldata or do any other per-process stuff an emulation needs. 911 * 912 * If we are executing process of different emulation than the 913 * original forked process, call e_proc_exit() of the old emulation 914 * first, then e_proc_exec() of new emulation. If the emulation is 915 * same, the exec hook code should deallocate any old emulation 916 * resources held previously by this process. 917 */ 918 if (p->p_emul && p->p_emul->e_proc_exit 919 && p->p_emul != pack.ep_es->es_emul) 920 (*p->p_emul->e_proc_exit)(p); 921 922 /* 923 * Call exec hook. Emulation code may NOT store reference to anything 924 * from &pack. 925 */ 926 if (pack.ep_es->es_emul->e_proc_exec) 927 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack); 928 929 /* update p_emul, the old value is no longer needed */ 930 p->p_emul = pack.ep_es->es_emul; 931 932 /* ...and the same for p_execsw */ 933 p->p_execsw = pack.ep_es; 934 935 #ifdef __HAVE_SYSCALL_INTERN 936 (*p->p_emul->e_syscall_intern)(p); 937 #endif 938 #ifdef KTRACE 939 if (KTRPOINT(p, KTR_EMUL)) 940 ktremul(l); 941 #endif 942 943 #ifdef LKM 944 lockmgr(&exec_lock, LK_RELEASE, NULL); 945 #endif 946 p->p_flag &= ~P_INEXEC; 947 948 if (p->p_flag & P_STOPEXEC) { 949 int s; 950 951 sigminusset(&contsigmask, &p->p_sigctx.ps_siglist); 952 SCHED_LOCK(s); 953 p->p_pptr->p_nstopchild++; 954 p->p_stat = SSTOP; 955 l->l_stat = LSSTOP; 956 p->p_nrlwps--; 957 mi_switch(l, NULL); 958 SCHED_ASSERT_UNLOCKED(); 959 splx(s); 960 } 961 962 #ifdef SYSTRACE 963 if (ISSET(p->p_flag, P_SYSTRACE) && 964 wassugid && !ISSET(p->p_flag, P_SUGID)) 965 systrace_execve1(pathbuf, p); 966 #endif /* SYSTRACE */ 967 968 return (EJUSTRETURN); 969 970 bad: 971 p->p_flag &= ~P_INEXEC; 972 /* free the vmspace-creation commands, and release their references */ 973 kill_vmcmds(&pack.ep_vmcmds); 974 /* kill any opened file descriptor, if necessary */ 975 if (pack.ep_flags & EXEC_HASFD) { 976 pack.ep_flags &= ~EXEC_HASFD; 977 (void) fdrelease(l, pack.ep_fd); 978 } 979 /* close and put the exec'd file */ 980 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 981 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred, l); 982 vput(pack.ep_vp); 983 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 984 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 985 986 freehdr: 987 free(pack.ep_hdr, M_EXEC); 988 989 #ifdef SYSTRACE 990 clrflg: 991 #endif /* SYSTRACE */ 992 l->l_flag |= oldlwpflags; 993 p->p_flag &= ~P_INEXEC; 994 #ifdef LKM 995 lockmgr(&exec_lock, LK_RELEASE, NULL); 996 #endif 997 998 return error; 999 1000 exec_abort: 1001 p->p_flag &= ~P_INEXEC; 1002 #ifdef LKM 1003 lockmgr(&exec_lock, LK_RELEASE, NULL); 1004 #endif 1005 1006 /* 1007 * the old process doesn't exist anymore. exit gracefully. 1008 * get rid of the (new) address space we have created, if any, get rid 1009 * of our namei data and vnode, and exit noting failure 1010 */ 1011 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1012 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1013 if (pack.ep_emul_arg) 1014 FREE(pack.ep_emul_arg, M_TEMP); 1015 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1016 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 1017 free(pack.ep_hdr, M_EXEC); 1018 exit1(l, W_EXITCODE(error, SIGABRT)); 1019 1020 /* NOTREACHED */ 1021 return 0; 1022 } 1023 1024 1025 int 1026 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1027 char **stackp, void *argp) 1028 { 1029 char **cpp, *dp, *sp; 1030 size_t len; 1031 void *nullp; 1032 long argc, envc; 1033 int error; 1034 1035 cpp = (char **)*stackp; 1036 nullp = NULL; 1037 argc = arginfo->ps_nargvstr; 1038 envc = arginfo->ps_nenvstr; 1039 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) 1040 return error; 1041 1042 dp = (char *) (cpp + argc + envc + 2 + pack->ep_es->es_arglen); 1043 sp = argp; 1044 1045 /* XXX don't copy them out, remap them! */ 1046 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1047 1048 for (; --argc >= 0; sp += len, dp += len) 1049 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1050 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1051 return error; 1052 1053 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1054 return error; 1055 1056 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1057 1058 for (; --envc >= 0; sp += len, dp += len) 1059 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1060 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1061 return error; 1062 1063 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1064 return error; 1065 1066 *stackp = (char *)cpp; 1067 return 0; 1068 } 1069 1070 #ifdef LKM 1071 /* 1072 * Find an emulation of given name in list of emulations. 1073 * Needs to be called with the exec_lock held. 1074 */ 1075 const struct emul * 1076 emul_search(const char *name) 1077 { 1078 struct emul_entry *it; 1079 1080 LIST_FOREACH(it, &el_head, el_list) { 1081 if (strcmp(name, it->el_emul->e_name) == 0) 1082 return it->el_emul; 1083 } 1084 1085 return NULL; 1086 } 1087 1088 /* 1089 * Add an emulation to list, if it's not there already. 1090 */ 1091 int 1092 emul_register(const struct emul *emul, int ro_entry) 1093 { 1094 struct emul_entry *ee; 1095 int error; 1096 1097 error = 0; 1098 lockmgr(&exec_lock, LK_SHARED, NULL); 1099 1100 if (emul_search(emul->e_name)) { 1101 error = EEXIST; 1102 goto out; 1103 } 1104 1105 MALLOC(ee, struct emul_entry *, sizeof(struct emul_entry), 1106 M_EXEC, M_WAITOK); 1107 ee->el_emul = emul; 1108 ee->ro_entry = ro_entry; 1109 LIST_INSERT_HEAD(&el_head, ee, el_list); 1110 1111 out: 1112 lockmgr(&exec_lock, LK_RELEASE, NULL); 1113 return error; 1114 } 1115 1116 /* 1117 * Remove emulation with name 'name' from list of supported emulations. 1118 */ 1119 int 1120 emul_unregister(const char *name) 1121 { 1122 const struct proclist_desc *pd; 1123 struct emul_entry *it; 1124 int i, error; 1125 struct proc *ptmp; 1126 1127 error = 0; 1128 lockmgr(&exec_lock, LK_SHARED, NULL); 1129 1130 LIST_FOREACH(it, &el_head, el_list) { 1131 if (strcmp(it->el_emul->e_name, name) == 0) 1132 break; 1133 } 1134 1135 if (!it) { 1136 error = ENOENT; 1137 goto out; 1138 } 1139 1140 if (it->ro_entry) { 1141 error = EBUSY; 1142 goto out; 1143 } 1144 1145 /* test if any execw[] entry is still using this */ 1146 for(i=0; i < nexecs; i++) { 1147 if (execsw[i]->es_emul == it->el_emul) { 1148 error = EBUSY; 1149 goto out; 1150 } 1151 } 1152 1153 /* 1154 * Test if any process is running under this emulation - since 1155 * emul_unregister() is running quite sendomly, it's better 1156 * to do expensive check here than to use any locking. 1157 */ 1158 proclist_lock_read(); 1159 for (pd = proclists; pd->pd_list != NULL && !error; pd++) { 1160 PROCLIST_FOREACH(ptmp, pd->pd_list) { 1161 if (ptmp->p_emul == it->el_emul) { 1162 error = EBUSY; 1163 break; 1164 } 1165 } 1166 } 1167 proclist_unlock_read(); 1168 1169 if (error) 1170 goto out; 1171 1172 1173 /* entry is not used, remove it */ 1174 LIST_REMOVE(it, el_list); 1175 FREE(it, M_EXEC); 1176 1177 out: 1178 lockmgr(&exec_lock, LK_RELEASE, NULL); 1179 return error; 1180 } 1181 1182 /* 1183 * Add execsw[] entry. 1184 */ 1185 int 1186 exec_add(struct execsw *esp, const char *e_name) 1187 { 1188 struct exec_entry *it; 1189 int error; 1190 1191 error = 0; 1192 lockmgr(&exec_lock, LK_EXCLUSIVE, NULL); 1193 1194 if (!esp->es_emul) { 1195 esp->es_emul = emul_search(e_name); 1196 if (!esp->es_emul) { 1197 error = ENOENT; 1198 goto out; 1199 } 1200 } 1201 1202 LIST_FOREACH(it, &ex_head, ex_list) { 1203 /* assume tuple (makecmds, probe_func, emulation) is unique */ 1204 if (it->es->es_makecmds == esp->es_makecmds 1205 && it->es->u.elf_probe_func == esp->u.elf_probe_func 1206 && it->es->es_emul == esp->es_emul) { 1207 error = EEXIST; 1208 goto out; 1209 } 1210 } 1211 1212 /* if we got here, the entry doesn't exist yet */ 1213 MALLOC(it, struct exec_entry *, sizeof(struct exec_entry), 1214 M_EXEC, M_WAITOK); 1215 it->es = esp; 1216 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1217 1218 /* update execsw[] */ 1219 exec_init(0); 1220 1221 out: 1222 lockmgr(&exec_lock, LK_RELEASE, NULL); 1223 return error; 1224 } 1225 1226 /* 1227 * Remove execsw[] entry. 1228 */ 1229 int 1230 exec_remove(const struct execsw *esp) 1231 { 1232 struct exec_entry *it; 1233 int error; 1234 1235 error = 0; 1236 lockmgr(&exec_lock, LK_EXCLUSIVE, NULL); 1237 1238 LIST_FOREACH(it, &ex_head, ex_list) { 1239 /* assume tuple (makecmds, probe_func, emulation) is unique */ 1240 if (it->es->es_makecmds == esp->es_makecmds 1241 && it->es->u.elf_probe_func == esp->u.elf_probe_func 1242 && it->es->es_emul == esp->es_emul) 1243 break; 1244 } 1245 if (!it) { 1246 error = ENOENT; 1247 goto out; 1248 } 1249 1250 /* remove item from list and free resources */ 1251 LIST_REMOVE(it, ex_list); 1252 FREE(it, M_EXEC); 1253 1254 /* update execsw[] */ 1255 exec_init(0); 1256 1257 out: 1258 lockmgr(&exec_lock, LK_RELEASE, NULL); 1259 return error; 1260 } 1261 1262 static void 1263 link_es(struct execsw_entry **listp, const struct execsw *esp) 1264 { 1265 struct execsw_entry *et, *e1; 1266 1267 et = (struct execsw_entry *) malloc(sizeof(struct execsw_entry), 1268 M_TEMP, M_WAITOK); 1269 et->next = NULL; 1270 et->es = esp; 1271 if (*listp == NULL) { 1272 *listp = et; 1273 return; 1274 } 1275 1276 switch(et->es->es_prio) { 1277 case EXECSW_PRIO_FIRST: 1278 /* put new entry as the first */ 1279 et->next = *listp; 1280 *listp = et; 1281 break; 1282 case EXECSW_PRIO_ANY: 1283 /* put new entry after all *_FIRST and *_ANY entries */ 1284 for(e1 = *listp; e1->next 1285 && e1->next->es->es_prio != EXECSW_PRIO_LAST; 1286 e1 = e1->next); 1287 et->next = e1->next; 1288 e1->next = et; 1289 break; 1290 case EXECSW_PRIO_LAST: 1291 /* put new entry as the last one */ 1292 for(e1 = *listp; e1->next; e1 = e1->next); 1293 e1->next = et; 1294 break; 1295 default: 1296 #ifdef DIAGNOSTIC 1297 panic("execw[] entry with unknown priority %d found", 1298 et->es->es_prio); 1299 #else 1300 free(et, M_TEMP); 1301 #endif 1302 break; 1303 } 1304 } 1305 1306 /* 1307 * Initialize exec structures. If init_boot is true, also does necessary 1308 * one-time initialization (it's called from main() that way). 1309 * Once system is multiuser, this should be called with exec_lock held, 1310 * i.e. via exec_{add|remove}(). 1311 */ 1312 int 1313 exec_init(int init_boot) 1314 { 1315 const struct execsw **new_es, * const *old_es; 1316 struct execsw_entry *list, *e1; 1317 struct exec_entry *e2; 1318 int i, es_sz; 1319 1320 if (init_boot) { 1321 /* do one-time initializations */ 1322 lockinit(&exec_lock, PWAIT, "execlck", 0, 0); 1323 1324 /* register compiled-in emulations */ 1325 for(i=0; i < nexecs_builtin; i++) { 1326 if (execsw_builtin[i].es_emul) 1327 emul_register(execsw_builtin[i].es_emul, 1); 1328 } 1329 #ifdef DIAGNOSTIC 1330 if (i == 0) 1331 panic("no emulations found in execsw_builtin[]"); 1332 #endif 1333 } 1334 1335 /* 1336 * Build execsw[] array from builtin entries and entries added 1337 * at runtime. 1338 */ 1339 list = NULL; 1340 for(i=0; i < nexecs_builtin; i++) 1341 link_es(&list, &execsw_builtin[i]); 1342 1343 /* Add dynamically loaded entries */ 1344 es_sz = nexecs_builtin; 1345 LIST_FOREACH(e2, &ex_head, ex_list) { 1346 link_es(&list, e2->es); 1347 es_sz++; 1348 } 1349 1350 /* 1351 * Now that we have sorted all execw entries, create new execsw[] 1352 * and free no longer needed memory in the process. 1353 */ 1354 new_es = malloc(es_sz * sizeof(struct execsw *), M_EXEC, M_WAITOK); 1355 for(i=0; list; i++) { 1356 new_es[i] = list->es; 1357 e1 = list->next; 1358 free(list, M_TEMP); 1359 list = e1; 1360 } 1361 1362 /* 1363 * New execsw[] array built, now replace old execsw[] and free 1364 * used memory. 1365 */ 1366 old_es = execsw; 1367 execsw = new_es; 1368 nexecs = es_sz; 1369 if (old_es) 1370 /*XXXUNCONST*/ 1371 free(__UNCONST(old_es), M_EXEC); 1372 1373 /* 1374 * Figure out the maximum size of an exec header. 1375 */ 1376 exec_maxhdrsz = 0; 1377 for (i = 0; i < nexecs; i++) { 1378 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1379 exec_maxhdrsz = execsw[i]->es_hdrsz; 1380 } 1381 1382 return 0; 1383 } 1384 #endif 1385 1386 #ifndef LKM 1387 /* 1388 * Simplified exec_init() for kernels without LKMs. Only initialize 1389 * exec_maxhdrsz and execsw[]. 1390 */ 1391 int 1392 exec_init(int init_boot) 1393 { 1394 int i; 1395 1396 #ifdef DIAGNOSTIC 1397 if (!init_boot) 1398 panic("exec_init(): called with init_boot == 0"); 1399 #endif 1400 1401 /* do one-time initializations */ 1402 nexecs = nexecs_builtin; 1403 execsw = malloc(nexecs*sizeof(struct execsw *), M_EXEC, M_WAITOK); 1404 1405 /* 1406 * Fill in execsw[] and figure out the maximum size of an exec header. 1407 */ 1408 exec_maxhdrsz = 0; 1409 for(i=0; i < nexecs; i++) { 1410 execsw[i] = &execsw_builtin[i]; 1411 if (execsw_builtin[i].es_hdrsz > exec_maxhdrsz) 1412 exec_maxhdrsz = execsw_builtin[i].es_hdrsz; 1413 } 1414 1415 return 0; 1416 1417 } 1418 #endif /* !LKM */ 1419 1420 static int 1421 exec_sigcode_map(struct proc *p, const struct emul *e) 1422 { 1423 vaddr_t va; 1424 vsize_t sz; 1425 int error; 1426 struct uvm_object *uobj; 1427 1428 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1429 1430 if (e->e_sigobject == NULL || sz == 0) { 1431 return 0; 1432 } 1433 1434 /* 1435 * If we don't have a sigobject for this emulation, create one. 1436 * 1437 * sigobject is an anonymous memory object (just like SYSV shared 1438 * memory) that we keep a permanent reference to and that we map 1439 * in all processes that need this sigcode. The creation is simple, 1440 * we create an object, add a permanent reference to it, map it in 1441 * kernel space, copy out the sigcode to it and unmap it. 1442 * We map it with PROT_READ|PROT_EXEC into the process just 1443 * the way sys_mmap() would map it. 1444 */ 1445 1446 uobj = *e->e_sigobject; 1447 if (uobj == NULL) { 1448 uobj = uao_create(sz, 0); 1449 (*uobj->pgops->pgo_reference)(uobj); 1450 va = vm_map_min(kernel_map); 1451 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1452 uobj, 0, 0, 1453 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1454 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1455 printf("kernel mapping failed %d\n", error); 1456 (*uobj->pgops->pgo_detach)(uobj); 1457 return (error); 1458 } 1459 memcpy((void *)va, e->e_sigcode, sz); 1460 #ifdef PMAP_NEED_PROCWR 1461 pmap_procwr(&proc0, va, sz); 1462 #endif 1463 uvm_unmap(kernel_map, va, va + round_page(sz)); 1464 *e->e_sigobject = uobj; 1465 } 1466 1467 /* Just a hint to uvm_map where to put it. */ 1468 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1469 round_page(sz)); 1470 1471 #ifdef __alpha__ 1472 /* 1473 * Tru64 puts /sbin/loader at the end of user virtual memory, 1474 * which causes the above calculation to put the sigcode at 1475 * an invalid address. Put it just below the text instead. 1476 */ 1477 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1478 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1479 } 1480 #endif 1481 1482 (*uobj->pgops->pgo_reference)(uobj); 1483 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1484 uobj, 0, 0, 1485 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1486 UVM_ADV_RANDOM, 0)); 1487 if (error) { 1488 (*uobj->pgops->pgo_detach)(uobj); 1489 return (error); 1490 } 1491 p->p_sigctx.ps_sigcode = (void *)va; 1492 return (0); 1493 }
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