1 /* $NetBSD: kern_exec.c,v 1.257 2007/12/08 19:29:47 pooka 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 1.257 2007/12/08 19:29:47 pooka 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 #include <sys/lwpctl.h> 66 67 #include <sys/syscallargs.h> 68 #if NVERIEXEC > 0 69 #include <sys/verified_exec.h> 70 #endif /* NVERIEXEC > 0 */ 71 72 #ifdef SYSTRACE 73 #include <sys/systrace.h> 74 #endif /* SYSTRACE */ 75 76 #ifdef PAX_SEGVGUARD 77 #include <sys/pax.h> 78 #endif /* PAX_SEGVGUARD */ 79 80 #include <uvm/uvm_extern.h> 81 82 #include <sys/cpu.h> 83 #include <machine/reg.h> 84 85 #include <compat/common/compat_util.h> 86 87 static int exec_sigcode_map(struct proc *, const struct emul *); 88 89 #ifdef DEBUG_EXEC 90 #define DPRINTF(a) uprintf a 91 #else 92 #define DPRINTF(a) 93 #endif /* DEBUG_EXEC */ 94 95 MALLOC_DEFINE(M_EXEC, "exec", "argument lists & other mem used by exec"); 96 97 /* 98 * Exec function switch: 99 * 100 * Note that each makecmds function is responsible for loading the 101 * exec package with the necessary functions for any exec-type-specific 102 * handling. 103 * 104 * Functions for specific exec types should be defined in their own 105 * header file. 106 */ 107 extern const struct execsw execsw_builtin[]; 108 extern int nexecs_builtin; 109 static const struct execsw **execsw = NULL; 110 static int nexecs; 111 112 u_int exec_maxhdrsz; /* must not be static - netbsd32 needs it */ 113 114 #ifdef LKM 115 /* list of supported emulations */ 116 static 117 LIST_HEAD(emlist_head, emul_entry) el_head = LIST_HEAD_INITIALIZER(el_head); 118 struct emul_entry { 119 LIST_ENTRY(emul_entry) el_list; 120 const struct emul *el_emul; 121 int ro_entry; 122 }; 123 124 /* list of dynamically loaded execsw entries */ 125 static 126 LIST_HEAD(execlist_head, exec_entry) ex_head = LIST_HEAD_INITIALIZER(ex_head); 127 struct exec_entry { 128 LIST_ENTRY(exec_entry) ex_list; 129 const struct execsw *es; 130 }; 131 132 /* structure used for building execw[] */ 133 struct execsw_entry { 134 struct execsw_entry *next; 135 const struct execsw *es; 136 }; 137 #endif /* LKM */ 138 139 #ifdef SYSCALL_DEBUG 140 extern const char * const syscallnames[]; 141 #endif 142 143 #ifdef COMPAT_16 144 extern char sigcode[], esigcode[]; 145 struct uvm_object *emul_netbsd_object; 146 #endif 147 148 #ifndef __HAVE_SYSCALL_INTERN 149 void syscall(void); 150 #endif 151 152 /* NetBSD emul struct */ 153 const struct emul emul_netbsd = { 154 "netbsd", 155 NULL, /* emulation path */ 156 #ifndef __HAVE_MINIMAL_EMUL 157 EMUL_HAS_SYS___syscall, 158 NULL, 159 SYS_syscall, 160 SYS_NSYSENT, 161 #endif 162 sysent, 163 #ifdef SYSCALL_DEBUG 164 syscallnames, 165 #else 166 NULL, 167 #endif 168 sendsig, 169 trapsignal, 170 NULL, 171 #ifdef COMPAT_16 172 sigcode, 173 esigcode, 174 &emul_netbsd_object, 175 #else 176 NULL, 177 NULL, 178 NULL, 179 #endif 180 setregs, 181 NULL, 182 NULL, 183 NULL, 184 NULL, 185 NULL, 186 #ifdef __HAVE_SYSCALL_INTERN 187 syscall_intern, 188 #else 189 syscall, 190 #endif 191 NULL, 192 NULL, 193 194 uvm_default_mapaddr, 195 NULL, 196 sizeof(ucontext_t), 197 startlwp, 198 }; 199 200 #ifdef LKM 201 /* 202 * Exec lock. Used to control access to execsw[] structures. 203 * This must not be static so that netbsd32 can access it, too. 204 */ 205 krwlock_t exec_lock; 206 207 static void link_es(struct execsw_entry **, const struct execsw *); 208 #endif /* LKM */ 209 210 /* 211 * check exec: 212 * given an "executable" described in the exec package's namei info, 213 * see what we can do with it. 214 * 215 * ON ENTRY: 216 * exec package with appropriate namei info 217 * lwp pointer of exec'ing lwp 218 * NO SELF-LOCKED VNODES 219 * 220 * ON EXIT: 221 * error: nothing held, etc. exec header still allocated. 222 * ok: filled exec package, executable's vnode (unlocked). 223 * 224 * EXEC SWITCH ENTRY: 225 * Locked vnode to check, exec package, proc. 226 * 227 * EXEC SWITCH EXIT: 228 * ok: return 0, filled exec package, executable's vnode (unlocked). 229 * error: destructive: 230 * everything deallocated execept exec header. 231 * non-destructive: 232 * error code, executable's vnode (unlocked), 233 * exec header unmodified. 234 */ 235 int 236 /*ARGSUSED*/ 237 check_exec(struct lwp *l, struct exec_package *epp) 238 { 239 int error, i; 240 struct vnode *vp; 241 struct nameidata *ndp; 242 size_t resid; 243 244 ndp = epp->ep_ndp; 245 ndp->ni_cnd.cn_nameiop = LOOKUP; 246 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME | TRYEMULROOT; 247 /* first get the vnode */ 248 if ((error = namei(ndp)) != 0) 249 return error; 250 epp->ep_vp = vp = ndp->ni_vp; 251 252 /* check access and type */ 253 if (vp->v_type != VREG) { 254 error = EACCES; 255 goto bad1; 256 } 257 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 258 goto bad1; 259 260 /* get attributes */ 261 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0) 262 goto bad1; 263 264 /* Check mount point */ 265 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 266 error = EACCES; 267 goto bad1; 268 } 269 if (vp->v_mount->mnt_flag & MNT_NOSUID) 270 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 271 272 /* try to open it */ 273 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0) 274 goto bad1; 275 276 /* unlock vp, since we need it unlocked from here on out. */ 277 VOP_UNLOCK(vp, 0); 278 279 #if NVERIEXEC > 0 280 error = veriexec_verify(l, vp, ndp->ni_cnd.cn_pnbuf, 281 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT, 282 NULL); 283 if (error) 284 goto bad2; 285 #endif /* NVERIEXEC > 0 */ 286 287 #ifdef PAX_SEGVGUARD 288 error = pax_segvguard(l, vp, ndp->ni_cnd.cn_pnbuf, false); 289 if (error) 290 goto bad2; 291 #endif /* PAX_SEGVGUARD */ 292 293 /* now we have the file, get the exec header */ 294 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 295 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL); 296 if (error) 297 goto bad2; 298 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 299 300 /* 301 * Set up default address space limits. Can be overridden 302 * by individual exec packages. 303 * 304 * XXX probably should be all done in the exec packages. 305 */ 306 epp->ep_vm_minaddr = VM_MIN_ADDRESS; 307 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 308 /* 309 * set up the vmcmds for creation of the process 310 * address space 311 */ 312 error = ENOEXEC; 313 for (i = 0; i < nexecs; i++) { 314 int newerror; 315 316 epp->ep_esch = execsw[i]; 317 newerror = (*execsw[i]->es_makecmds)(l, epp); 318 319 if (!newerror) { 320 /* Seems ok: check that entry point is sane */ 321 if (epp->ep_entry > VM_MAXUSER_ADDRESS) { 322 error = ENOEXEC; 323 break; 324 } 325 326 /* check limits */ 327 if ((epp->ep_tsize > MAXTSIZ) || 328 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit 329 [RLIMIT_DATA].rlim_cur)) { 330 error = ENOMEM; 331 break; 332 } 333 return 0; 334 } 335 336 if (epp->ep_emul_root != NULL) { 337 vrele(epp->ep_emul_root); 338 epp->ep_emul_root = NULL; 339 } 340 if (epp->ep_interp != NULL) { 341 vrele(epp->ep_interp); 342 epp->ep_interp = NULL; 343 } 344 345 /* make sure the first "interesting" error code is saved. */ 346 if (error == ENOEXEC) 347 error = newerror; 348 349 if (epp->ep_flags & EXEC_DESTR) 350 /* Error from "#!" code, tidied up by recursive call */ 351 return error; 352 } 353 354 /* not found, error */ 355 356 /* 357 * free any vmspace-creation commands, 358 * and release their references 359 */ 360 kill_vmcmds(&epp->ep_vmcmds); 361 362 bad2: 363 /* 364 * close and release the vnode, restore the old one, free the 365 * pathname buf, and punt. 366 */ 367 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 368 VOP_CLOSE(vp, FREAD, l->l_cred); 369 vput(vp); 370 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 371 return error; 372 373 bad1: 374 /* 375 * free the namei pathname buffer, and put the vnode 376 * (which we don't yet have open). 377 */ 378 vput(vp); /* was still locked */ 379 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 380 return error; 381 } 382 383 #ifdef __MACHINE_STACK_GROWS_UP 384 #define STACK_PTHREADSPACE NBPG 385 #else 386 #define STACK_PTHREADSPACE 0 387 #endif 388 389 static int 390 execve_fetch_element(char * const *array, size_t index, char **value) 391 { 392 return copyin(array + index, value, sizeof(*value)); 393 } 394 395 /* 396 * exec system call 397 */ 398 /* ARGSUSED */ 399 int 400 sys_execve(struct lwp *l, void *v, register_t *retval) 401 { 402 struct sys_execve_args /* { 403 syscallarg(const char *) path; 404 syscallarg(char * const *) argp; 405 syscallarg(char * const *) envp; 406 } */ *uap = v; 407 408 return execve1(l, SCARG(uap, path), SCARG(uap, argp), 409 SCARG(uap, envp), execve_fetch_element); 410 } 411 412 int 413 execve1(struct lwp *l, const char *path, char * const *args, 414 char * const *envs, execve_fetch_element_t fetch_element) 415 { 416 int error; 417 struct exec_package pack; 418 struct nameidata nid; 419 struct vattr attr; 420 struct proc *p; 421 char *argp; 422 char *dp, *sp; 423 long argc, envc; 424 size_t i, len; 425 char *stack; 426 struct ps_strings arginfo; 427 struct ps_strings *aip = &arginfo; 428 struct vmspace *vm; 429 char **tmpfap; 430 int szsigcode; 431 struct exec_vmcmd *base_vcp; 432 ksiginfo_t ksi; 433 ksiginfoq_t kq; 434 char pathbuf[MAXPATHLEN]; 435 size_t pathbuflen; 436 #ifdef SYSTRACE 437 int wassugid = ISSET(p->p_flag, PK_SUGID); 438 #endif /* SYSTRACE */ 439 440 p = l->l_proc; 441 442 /* 443 * Drain existing references and forbid new ones. The process 444 * should be left alone until we're done here. This is necessary 445 * to avoid race conditions - e.g. in ptrace() - that might allow 446 * a local user to illicitly obtain elevated privileges. 447 */ 448 rw_enter(&p->p_reflock, RW_WRITER); 449 450 base_vcp = NULL; 451 /* 452 * Init the namei data to point the file user's program name. 453 * This is done here rather than in check_exec(), so that it's 454 * possible to override this settings if any of makecmd/probe 455 * functions call check_exec() recursively - for example, 456 * see exec_script_makecmds(). 457 */ 458 #ifdef SYSTRACE 459 if (ISSET(p->p_flag, PK_SYSTRACE)) 460 systrace_execve0(p); 461 #endif 462 463 error = copyinstr(path, pathbuf, sizeof(pathbuf), &pathbuflen); 464 if (error) { 465 DPRINTF(("execve: copyinstr path %d", error)); 466 goto clrflg; 467 } 468 469 NDINIT(&nid, LOOKUP, NOFOLLOW | TRYEMULROOT, UIO_SYSSPACE, pathbuf); 470 471 /* 472 * initialize the fields of the exec package. 473 */ 474 #ifdef SYSTRACE 475 pack.ep_name = pathbuf; 476 #else 477 pack.ep_name = path; 478 #endif /* SYSTRACE */ 479 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 480 pack.ep_hdrlen = exec_maxhdrsz; 481 pack.ep_hdrvalid = 0; 482 pack.ep_ndp = &nid; 483 pack.ep_emul_arg = NULL; 484 pack.ep_vmcmds.evs_cnt = 0; 485 pack.ep_vmcmds.evs_used = 0; 486 pack.ep_vap = &attr; 487 pack.ep_flags = 0; 488 pack.ep_emul_root = NULL; 489 pack.ep_interp = NULL; 490 pack.ep_esch = NULL; 491 492 #ifdef LKM 493 rw_enter(&exec_lock, RW_READER); 494 #endif 495 496 /* see if we can run it. */ 497 if ((error = check_exec(l, &pack)) != 0) { 498 DPRINTF(("execve: check exec failed %d\n", error)); 499 goto freehdr; 500 } 501 502 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 503 504 /* allocate an argument buffer */ 505 argp = (char *) uvm_km_alloc(exec_map, NCARGS, 0, 506 UVM_KMF_PAGEABLE|UVM_KMF_WAITVA); 507 #ifdef DIAGNOSTIC 508 if (argp == NULL) 509 panic("execve: argp == NULL"); 510 #endif 511 dp = argp; 512 argc = 0; 513 514 /* copy the fake args list, if there's one, freeing it as we go */ 515 if (pack.ep_flags & EXEC_HASARGL) { 516 tmpfap = pack.ep_fa; 517 while (*tmpfap != NULL) { 518 char *cp; 519 520 cp = *tmpfap; 521 while (*cp) 522 *dp++ = *cp++; 523 dp++; 524 525 FREE(*tmpfap, M_EXEC); 526 tmpfap++; argc++; 527 } 528 FREE(pack.ep_fa, M_EXEC); 529 pack.ep_flags &= ~EXEC_HASARGL; 530 } 531 532 /* Now get argv & environment */ 533 if (args == NULL) { 534 DPRINTF(("execve: null args\n")); 535 error = EINVAL; 536 goto bad; 537 } 538 /* 'i' will index the argp/envp element to be retrieved */ 539 i = 0; 540 if (pack.ep_flags & EXEC_SKIPARG) 541 i++; 542 543 while (1) { 544 len = argp + ARG_MAX - dp; 545 if ((error = (*fetch_element)(args, i, &sp)) != 0) { 546 DPRINTF(("execve: fetch_element args %d\n", error)); 547 goto bad; 548 } 549 if (!sp) 550 break; 551 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 552 DPRINTF(("execve: copyinstr args %d\n", error)); 553 if (error == ENAMETOOLONG) 554 error = E2BIG; 555 goto bad; 556 } 557 ktrexecarg(dp, len - 1); 558 dp += len; 559 i++; 560 argc++; 561 } 562 563 envc = 0; 564 /* environment need not be there */ 565 if (envs != NULL) { 566 i = 0; 567 while (1) { 568 len = argp + ARG_MAX - dp; 569 if ((error = (*fetch_element)(envs, i, &sp)) != 0) { 570 DPRINTF(("execve: fetch_element env %d\n", error)); 571 goto bad; 572 } 573 if (!sp) 574 break; 575 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 576 DPRINTF(("execve: copyinstr env %d\n", error)); 577 if (error == ENAMETOOLONG) 578 error = E2BIG; 579 goto bad; 580 } 581 ktrexecenv(dp, len - 1); 582 dp += len; 583 i++; 584 envc++; 585 } 586 } 587 588 dp = (char *) ALIGN(dp); 589 590 szsigcode = pack.ep_esch->es_emul->e_esigcode - 591 pack.ep_esch->es_emul->e_sigcode; 592 593 /* Now check if args & environ fit into new stack */ 594 if (pack.ep_flags & EXEC_32) 595 len = ((argc + envc + 2 + pack.ep_esch->es_arglen) * 596 sizeof(int) + sizeof(int) + dp + STACKGAPLEN + 597 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 598 - argp; 599 else 600 len = ((argc + envc + 2 + pack.ep_esch->es_arglen) * 601 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN + 602 szsigcode + sizeof(struct ps_strings) + STACK_PTHREADSPACE) 603 - argp; 604 605 #ifdef STACKLALIGN /* arm, etc. */ 606 len = STACKALIGN(len); /* make the stack "safely" aligned */ 607 #else 608 len = ALIGN(len); /* make the stack "safely" aligned */ 609 #endif 610 611 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 612 DPRINTF(("execve: stack limit exceeded %zu\n", len)); 613 error = ENOMEM; 614 goto bad; 615 } 616 617 /* Get rid of other LWPs. */ 618 if (p->p_nlwps > 1) { 619 mutex_enter(&p->p_smutex); 620 exit_lwps(l); 621 mutex_exit(&p->p_smutex); 622 } 623 KDASSERT(p->p_nlwps == 1); 624 625 /* Destroy any lwpctl info. */ 626 if (p->p_lwpctl != NULL) 627 lwp_ctl_exit(); 628 629 /* This is now LWP 1 */ 630 l->l_lid = 1; 631 p->p_nlwpid = 1; 632 633 /* Remove POSIX timers */ 634 timers_free(p, TIMERS_POSIX); 635 636 /* adjust "active stack depth" for process VSZ */ 637 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 638 639 /* 640 * Do whatever is necessary to prepare the address space 641 * for remapping. Note that this might replace the current 642 * vmspace with another! 643 */ 644 uvmspace_exec(l, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 645 646 /* record proc's vnode, for use by procfs and others */ 647 if (p->p_textvp) 648 vrele(p->p_textvp); 649 VREF(pack.ep_vp); 650 p->p_textvp = pack.ep_vp; 651 652 /* Now map address space */ 653 vm = p->p_vmspace; 654 vm->vm_taddr = (void *)pack.ep_taddr; 655 vm->vm_tsize = btoc(pack.ep_tsize); 656 vm->vm_daddr = (void*)pack.ep_daddr; 657 vm->vm_dsize = btoc(pack.ep_dsize); 658 vm->vm_ssize = btoc(pack.ep_ssize); 659 vm->vm_maxsaddr = (void *)pack.ep_maxsaddr; 660 vm->vm_minsaddr = (void *)pack.ep_minsaddr; 661 662 /* create the new process's VM space by running the vmcmds */ 663 #ifdef DIAGNOSTIC 664 if (pack.ep_vmcmds.evs_used == 0) 665 panic("execve: no vmcmds"); 666 #endif 667 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 668 struct exec_vmcmd *vcp; 669 670 vcp = &pack.ep_vmcmds.evs_cmds[i]; 671 if (vcp->ev_flags & VMCMD_RELATIVE) { 672 #ifdef DIAGNOSTIC 673 if (base_vcp == NULL) 674 panic("execve: relative vmcmd with no base"); 675 if (vcp->ev_flags & VMCMD_BASE) 676 panic("execve: illegal base & relative vmcmd"); 677 #endif 678 vcp->ev_addr += base_vcp->ev_addr; 679 } 680 error = (*vcp->ev_proc)(l, vcp); 681 #ifdef DEBUG_EXEC 682 if (error) { 683 size_t j; 684 struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0]; 685 for (j = 0; j <= i; j++) 686 uprintf( 687 "vmcmd[%zu] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n", 688 j, vp[j].ev_addr, vp[j].ev_len, 689 vp[j].ev_offset, vp[j].ev_prot, 690 vp[j].ev_flags); 691 } 692 #endif /* DEBUG_EXEC */ 693 if (vcp->ev_flags & VMCMD_BASE) 694 base_vcp = vcp; 695 } 696 697 /* free the vmspace-creation commands, and release their references */ 698 kill_vmcmds(&pack.ep_vmcmds); 699 700 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 701 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 702 vput(pack.ep_vp); 703 704 /* if an error happened, deallocate and punt */ 705 if (error) { 706 DPRINTF(("execve: vmcmd %zu failed: %d\n", i - 1, error)); 707 goto exec_abort; 708 } 709 710 /* remember information about the process */ 711 arginfo.ps_nargvstr = argc; 712 arginfo.ps_nenvstr = envc; 713 714 /* set command name & other accounting info */ 715 i = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 716 (void)memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, i); 717 p->p_comm[i] = '\0'; 718 719 dp = PNBUF_GET(); 720 /* 721 * If the path starts with /, we don't need to do any work. 722 * This handles the majority of the cases. 723 * In the future perhaps we could canonicalize it? 724 */ 725 if (pathbuf[0] == '/') 726 (void)strlcpy(pack.ep_path = dp, pathbuf, MAXPATHLEN); 727 #ifdef notyet 728 /* 729 * Although this works most of the time [since the entry was just 730 * entered in the cache] we don't use it because it theoretically 731 * can fail and it is not the cleanest interface, because there 732 * could be races. When the namei cache is re-written, this can 733 * be changed to use the appropriate function. 734 */ 735 else if (!(error = vnode_to_path(dp, MAXPATHLEN, p->p_textvp, l, p))) 736 pack.ep_path = dp; 737 #endif 738 else { 739 #ifdef notyet 740 printf("Cannot get path for pid %d [%s] (error %d)", 741 (int)p->p_pid, p->p_comm, error); 742 #endif 743 pack.ep_path = NULL; 744 PNBUF_PUT(dp); 745 } 746 747 stack = (char *)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, 748 STACK_PTHREADSPACE + sizeof(struct ps_strings) + szsigcode), 749 len - (sizeof(struct ps_strings) + szsigcode)); 750 #ifdef __MACHINE_STACK_GROWS_UP 751 /* 752 * The copyargs call always copies into lower addresses 753 * first, moving towards higher addresses, starting with 754 * the stack pointer that we give. When the stack grows 755 * down, this puts argc/argv/envp very shallow on the 756 * stack, right at the first user stack pointer, and puts 757 * STACKGAPLEN very deep in the stack. When the stack 758 * grows up, the situation is reversed. 759 * 760 * Normally, this is no big deal. But the ld_elf.so _rtld() 761 * function expects to be called with a single pointer to 762 * a region that has a few words it can stash values into, 763 * followed by argc/argv/envp. When the stack grows down, 764 * it's easy to decrement the stack pointer a little bit to 765 * allocate the space for these few words and pass the new 766 * stack pointer to _rtld. When the stack grows up, however, 767 * a few words before argc is part of the signal trampoline, XXX 768 * so we have a problem. 769 * 770 * Instead of changing how _rtld works, we take the easy way 771 * out and steal 32 bytes before we call copyargs. This 772 * space is effectively stolen from STACKGAPLEN. 773 */ 774 stack += 32; 775 #endif /* __MACHINE_STACK_GROWS_UP */ 776 777 /* Now copy argc, args & environ to new stack */ 778 error = (*pack.ep_esch->es_copyargs)(l, &pack, &arginfo, &stack, argp); 779 if (pack.ep_path) { 780 PNBUF_PUT(pack.ep_path); 781 pack.ep_path = NULL; 782 } 783 if (error) { 784 DPRINTF(("execve: copyargs failed %d\n", error)); 785 goto exec_abort; 786 } 787 /* Move the stack back to original point */ 788 stack = (char *)STACK_GROW(vm->vm_minsaddr, len); 789 790 /* fill process ps_strings info */ 791 p->p_psstr = (struct ps_strings *) 792 STACK_ALLOC(STACK_GROW(vm->vm_minsaddr, STACK_PTHREADSPACE), 793 sizeof(struct ps_strings)); 794 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 795 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 796 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 797 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 798 799 /* copy out the process's ps_strings structure */ 800 if ((error = copyout(aip, (char *)p->p_psstr, 801 sizeof(arginfo))) != 0) { 802 DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n", 803 aip, (char *)p->p_psstr, (long)sizeof(arginfo))); 804 goto exec_abort; 805 } 806 807 fdcloseexec(l); /* handle close on exec */ 808 execsigs(p); /* reset catched signals */ 809 810 l->l_ctxlink = NULL; /* reset ucontext link */ 811 812 813 p->p_acflag &= ~AFORK; 814 p->p_flag |= PK_EXEC; 815 816 /* 817 * Stop profiling. 818 */ 819 if ((p->p_stflag & PST_PROFIL) != 0) { 820 mutex_spin_enter(&p->p_stmutex); 821 stopprofclock(p); 822 mutex_spin_exit(&p->p_stmutex); 823 } 824 825 /* 826 * It's OK to test PS_PPWAIT unlocked here, as other LWPs have 827 * exited and exec()/exit() are the only places it will be cleared. 828 */ 829 if ((p->p_sflag & PS_PPWAIT) != 0) { 830 mutex_enter(&proclist_lock); 831 mutex_enter(&p->p_smutex); 832 p->p_sflag &= ~PS_PPWAIT; 833 cv_broadcast(&p->p_pptr->p_waitcv); 834 mutex_exit(&p->p_smutex); 835 mutex_exit(&proclist_lock); 836 } 837 838 /* 839 * Deal with set[ug]id. MNT_NOSUID has already been used to disable 840 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked 841 * out additional references on the process for the moment. 842 */ 843 if ((p->p_slflag & PSL_TRACED) == 0 && 844 845 (((attr.va_mode & S_ISUID) != 0 && 846 kauth_cred_geteuid(l->l_cred) != attr.va_uid) || 847 848 ((attr.va_mode & S_ISGID) != 0 && 849 kauth_cred_getegid(l->l_cred) != attr.va_gid))) { 850 /* 851 * Mark the process as SUGID before we do 852 * anything that might block. 853 */ 854 proc_crmod_enter(); 855 proc_crmod_leave(NULL, NULL, true); 856 857 /* Make sure file descriptors 0..2 are in use. */ 858 if ((error = fdcheckstd(l)) != 0) { 859 DPRINTF(("execve: fdcheckstd failed %d\n", error)); 860 goto exec_abort; 861 } 862 863 /* 864 * Copy the credential so other references don't see our 865 * changes. 866 */ 867 l->l_cred = kauth_cred_copy(l->l_cred); 868 #ifdef KTRACE 869 /* 870 * If process is being ktraced, turn off - unless 871 * root set it. 872 */ 873 if (p->p_tracep) { 874 mutex_enter(&ktrace_lock); 875 if (!(p->p_traceflag & KTRFAC_ROOT)) 876 ktrderef(p); 877 mutex_exit(&ktrace_lock); 878 } 879 #endif 880 if (attr.va_mode & S_ISUID) 881 kauth_cred_seteuid(l->l_cred, attr.va_uid); 882 if (attr.va_mode & S_ISGID) 883 kauth_cred_setegid(l->l_cred, attr.va_gid); 884 } else { 885 if (kauth_cred_geteuid(l->l_cred) == 886 kauth_cred_getuid(l->l_cred) && 887 kauth_cred_getegid(l->l_cred) == 888 kauth_cred_getgid(l->l_cred)) 889 p->p_flag &= ~PK_SUGID; 890 } 891 892 /* 893 * Copy the credential so other references don't see our changes. 894 * Test to see if this is necessary first, since in the common case 895 * we won't need a private reference. 896 */ 897 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) || 898 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) { 899 l->l_cred = kauth_cred_copy(l->l_cred); 900 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred)); 901 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred)); 902 } 903 904 /* Update the master credentials. */ 905 if (l->l_cred != p->p_cred) { 906 kauth_cred_t ocred; 907 908 kauth_cred_hold(l->l_cred); 909 mutex_enter(&p->p_mutex); 910 ocred = p->p_cred; 911 p->p_cred = l->l_cred; 912 mutex_exit(&p->p_mutex); 913 kauth_cred_free(ocred); 914 } 915 916 #if defined(__HAVE_RAS) 917 /* 918 * Remove all RASs from the address space. 919 */ 920 ras_purgeall(); 921 #endif 922 923 doexechooks(p); 924 925 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 926 927 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 928 929 /* notify others that we exec'd */ 930 KNOTE(&p->p_klist, NOTE_EXEC); 931 932 /* setup new registers and do misc. setup. */ 933 (*pack.ep_esch->es_emul->e_setregs)(l, &pack, (u_long) stack); 934 if (pack.ep_esch->es_setregs) 935 (*pack.ep_esch->es_setregs)(l, &pack, (u_long) stack); 936 937 /* map the process's signal trampoline code */ 938 if (exec_sigcode_map(p, pack.ep_esch->es_emul)) { 939 DPRINTF(("execve: map sigcode failed %d\n", error)); 940 goto exec_abort; 941 } 942 943 free(pack.ep_hdr, M_EXEC); 944 945 /* The emulation root will usually have been found when we looked 946 * for the elf interpreter (or similar), if not look now. */ 947 if (pack.ep_esch->es_emul->e_path != NULL && pack.ep_emul_root == NULL) 948 emul_find_root(l, &pack); 949 950 /* Any old emulation root got removed by fdcloseexec */ 951 p->p_cwdi->cwdi_edir = pack.ep_emul_root; 952 pack.ep_emul_root = NULL; 953 if (pack.ep_interp != NULL) 954 vrele(pack.ep_interp); 955 956 /* 957 * Call emulation specific exec hook. This can setup per-process 958 * p->p_emuldata or do any other per-process stuff an emulation needs. 959 * 960 * If we are executing process of different emulation than the 961 * original forked process, call e_proc_exit() of the old emulation 962 * first, then e_proc_exec() of new emulation. If the emulation is 963 * same, the exec hook code should deallocate any old emulation 964 * resources held previously by this process. 965 */ 966 if (p->p_emul && p->p_emul->e_proc_exit 967 && p->p_emul != pack.ep_esch->es_emul) 968 (*p->p_emul->e_proc_exit)(p); 969 970 /* 971 * Call exec hook. Emulation code may NOT store reference to anything 972 * from &pack. 973 */ 974 if (pack.ep_esch->es_emul->e_proc_exec) 975 (*pack.ep_esch->es_emul->e_proc_exec)(p, &pack); 976 977 /* update p_emul, the old value is no longer needed */ 978 p->p_emul = pack.ep_esch->es_emul; 979 980 /* ...and the same for p_execsw */ 981 p->p_execsw = pack.ep_esch; 982 983 #ifdef __HAVE_SYSCALL_INTERN 984 (*p->p_emul->e_syscall_intern)(p); 985 #endif 986 ktremul(); 987 988 /* Allow new references from the debugger/procfs. */ 989 rw_exit(&p->p_reflock); 990 #ifdef LKM 991 rw_exit(&exec_lock); 992 #endif 993 994 mutex_enter(&proclist_mutex); 995 996 if ((p->p_slflag & (PSL_TRACED|PSL_SYSCALL)) == PSL_TRACED) { 997 KSI_INIT_EMPTY(&ksi); 998 ksi.ksi_signo = SIGTRAP; 999 ksi.ksi_lid = l->l_lid; 1000 kpsignal(p, &ksi, NULL); 1001 } 1002 1003 if (p->p_sflag & PS_STOPEXEC) { 1004 KERNEL_UNLOCK_ALL(l, &l->l_biglocks); 1005 p->p_pptr->p_nstopchild++; 1006 p->p_pptr->p_waited = 0; 1007 mutex_enter(&p->p_smutex); 1008 ksiginfo_queue_init(&kq); 1009 sigclearall(p, &contsigmask, &kq); 1010 lwp_lock(l); 1011 l->l_stat = LSSTOP; 1012 p->p_stat = SSTOP; 1013 p->p_nrlwps--; 1014 mutex_exit(&p->p_smutex); 1015 mutex_exit(&proclist_mutex); 1016 mi_switch(l); 1017 ksiginfo_queue_drain(&kq); 1018 KERNEL_LOCK(l->l_biglocks, l); 1019 } else { 1020 mutex_exit(&proclist_mutex); 1021 } 1022 1023 #ifdef SYSTRACE 1024 /* XXXSMP */ 1025 if (ISSET(p->p_flag, PK_SYSTRACE) && 1026 wassugid && !ISSET(p->p_flag, PK_SUGID)) 1027 systrace_execve1(pathbuf, p); 1028 #endif /* SYSTRACE */ 1029 1030 return (EJUSTRETURN); 1031 1032 bad: 1033 /* free the vmspace-creation commands, and release their references */ 1034 kill_vmcmds(&pack.ep_vmcmds); 1035 /* kill any opened file descriptor, if necessary */ 1036 if (pack.ep_flags & EXEC_HASFD) { 1037 pack.ep_flags &= ~EXEC_HASFD; 1038 (void) fdrelease(l, pack.ep_fd); 1039 } 1040 /* close and put the exec'd file */ 1041 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 1042 VOP_CLOSE(pack.ep_vp, FREAD, l->l_cred); 1043 vput(pack.ep_vp); 1044 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1045 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 1046 1047 freehdr: 1048 free(pack.ep_hdr, M_EXEC); 1049 if (pack.ep_emul_root != NULL) 1050 vrele(pack.ep_emul_root); 1051 if (pack.ep_interp != NULL) 1052 vrele(pack.ep_interp); 1053 1054 clrflg: 1055 rw_exit(&p->p_reflock); 1056 #ifdef LKM 1057 rw_exit(&exec_lock); 1058 #endif 1059 1060 return error; 1061 1062 exec_abort: 1063 rw_exit(&p->p_reflock); 1064 #ifdef LKM 1065 rw_exit(&exec_lock); 1066 #endif 1067 1068 /* 1069 * the old process doesn't exist anymore. exit gracefully. 1070 * get rid of the (new) address space we have created, if any, get rid 1071 * of our namei data and vnode, and exit noting failure 1072 */ 1073 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 1074 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 1075 if (pack.ep_emul_arg) 1076 FREE(pack.ep_emul_arg, M_TEMP); 1077 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 1078 uvm_km_free(exec_map, (vaddr_t) argp, NCARGS, UVM_KMF_PAGEABLE); 1079 free(pack.ep_hdr, M_EXEC); 1080 if (pack.ep_emul_root != NULL) 1081 vrele(pack.ep_emul_root); 1082 if (pack.ep_interp != NULL) 1083 vrele(pack.ep_interp); 1084 1085 /* Acquire the sched-state mutex (exit1() will release it). */ 1086 mutex_enter(&p->p_smutex); 1087 exit1(l, W_EXITCODE(error, SIGABRT)); 1088 1089 /* NOTREACHED */ 1090 return 0; 1091 } 1092 1093 1094 int 1095 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo, 1096 char **stackp, void *argp) 1097 { 1098 char **cpp, *dp, *sp; 1099 size_t len; 1100 void *nullp; 1101 long argc, envc; 1102 int error; 1103 1104 cpp = (char **)*stackp; 1105 nullp = NULL; 1106 argc = arginfo->ps_nargvstr; 1107 envc = arginfo->ps_nenvstr; 1108 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) 1109 return error; 1110 1111 dp = (char *) (cpp + argc + envc + 2 + pack->ep_esch->es_arglen); 1112 sp = argp; 1113 1114 /* XXX don't copy them out, remap them! */ 1115 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 1116 1117 for (; --argc >= 0; sp += len, dp += len) 1118 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1119 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1120 return error; 1121 1122 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1123 return error; 1124 1125 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 1126 1127 for (; --envc >= 0; sp += len, dp += len) 1128 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 1129 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 1130 return error; 1131 1132 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 1133 return error; 1134 1135 *stackp = (char *)cpp; 1136 return 0; 1137 } 1138 1139 #ifdef LKM 1140 /* 1141 * Find an emulation of given name in list of emulations. 1142 * Needs to be called with the exec_lock held. 1143 */ 1144 const struct emul * 1145 emul_search(const char *name) 1146 { 1147 struct emul_entry *it; 1148 1149 LIST_FOREACH(it, &el_head, el_list) { 1150 if (strcmp(name, it->el_emul->e_name) == 0) 1151 return it->el_emul; 1152 } 1153 1154 return NULL; 1155 } 1156 1157 /* 1158 * Add an emulation to list, if it's not there already. 1159 */ 1160 int 1161 emul_register(const struct emul *emul, int ro_entry) 1162 { 1163 struct emul_entry *ee; 1164 int error; 1165 1166 error = 0; 1167 rw_enter(&exec_lock, RW_WRITER); 1168 1169 if (emul_search(emul->e_name)) { 1170 error = EEXIST; 1171 goto out; 1172 } 1173 1174 MALLOC(ee, struct emul_entry *, sizeof(struct emul_entry), 1175 M_EXEC, M_WAITOK); 1176 ee->el_emul = emul; 1177 ee->ro_entry = ro_entry; 1178 LIST_INSERT_HEAD(&el_head, ee, el_list); 1179 1180 out: 1181 rw_exit(&exec_lock); 1182 return error; 1183 } 1184 1185 /* 1186 * Remove emulation with name 'name' from list of supported emulations. 1187 */ 1188 int 1189 emul_unregister(const char *name) 1190 { 1191 const struct proclist_desc *pd; 1192 struct emul_entry *it; 1193 int i, error; 1194 struct proc *ptmp; 1195 1196 error = 0; 1197 rw_enter(&exec_lock, RW_WRITER); 1198 1199 LIST_FOREACH(it, &el_head, el_list) { 1200 if (strcmp(it->el_emul->e_name, name) == 0) 1201 break; 1202 } 1203 1204 if (!it) { 1205 error = ENOENT; 1206 goto out; 1207 } 1208 1209 if (it->ro_entry) { 1210 error = EBUSY; 1211 goto out; 1212 } 1213 1214 /* test if any execw[] entry is still using this */ 1215 for(i=0; i < nexecs; i++) { 1216 if (execsw[i]->es_emul == it->el_emul) { 1217 error = EBUSY; 1218 goto out; 1219 } 1220 } 1221 1222 /* 1223 * Test if any process is running under this emulation - since 1224 * emul_unregister() is running quite sendomly, it's better 1225 * to do expensive check here than to use any locking. 1226 */ 1227 mutex_enter(&proclist_lock); 1228 for (pd = proclists; pd->pd_list != NULL && !error; pd++) { 1229 PROCLIST_FOREACH(ptmp, pd->pd_list) { 1230 if (ptmp->p_emul == it->el_emul) { 1231 error = EBUSY; 1232 break; 1233 } 1234 } 1235 } 1236 mutex_exit(&proclist_lock); 1237 1238 if (error) 1239 goto out; 1240 1241 1242 /* entry is not used, remove it */ 1243 LIST_REMOVE(it, el_list); 1244 FREE(it, M_EXEC); 1245 1246 out: 1247 rw_exit(&exec_lock); 1248 return error; 1249 } 1250 1251 /* 1252 * Add execsw[] entry. 1253 */ 1254 int 1255 exec_add(struct execsw *esp, const char *e_name) 1256 { 1257 struct exec_entry *it; 1258 int error; 1259 1260 error = 0; 1261 rw_enter(&exec_lock, RW_WRITER); 1262 1263 if (!esp->es_emul) { 1264 esp->es_emul = emul_search(e_name); 1265 if (!esp->es_emul) { 1266 error = ENOENT; 1267 goto out; 1268 } 1269 } 1270 1271 LIST_FOREACH(it, &ex_head, ex_list) { 1272 /* assume tuple (makecmds, probe_func, emulation) is unique */ 1273 if (it->es->es_makecmds == esp->es_makecmds 1274 && it->es->u.elf_probe_func == esp->u.elf_probe_func 1275 && it->es->es_emul == esp->es_emul) { 1276 error = EEXIST; 1277 goto out; 1278 } 1279 } 1280 1281 /* if we got here, the entry doesn't exist yet */ 1282 MALLOC(it, struct exec_entry *, sizeof(struct exec_entry), 1283 M_EXEC, M_WAITOK); 1284 it->es = esp; 1285 LIST_INSERT_HEAD(&ex_head, it, ex_list); 1286 1287 /* update execsw[] */ 1288 exec_init(0); 1289 1290 out: 1291 rw_exit(&exec_lock); 1292 return error; 1293 } 1294 1295 /* 1296 * Remove execsw[] entry. 1297 */ 1298 int 1299 exec_remove(const struct execsw *esp) 1300 { 1301 struct exec_entry *it; 1302 int error; 1303 1304 error = 0; 1305 rw_enter(&exec_lock, RW_WRITER); 1306 1307 LIST_FOREACH(it, &ex_head, ex_list) { 1308 /* assume tuple (makecmds, probe_func, emulation) is unique */ 1309 if (it->es->es_makecmds == esp->es_makecmds 1310 && it->es->u.elf_probe_func == esp->u.elf_probe_func 1311 && it->es->es_emul == esp->es_emul) 1312 break; 1313 } 1314 if (!it) { 1315 error = ENOENT; 1316 goto out; 1317 } 1318 1319 /* remove item from list and free resources */ 1320 LIST_REMOVE(it, ex_list); 1321 FREE(it, M_EXEC); 1322 1323 /* update execsw[] */ 1324 exec_init(0); 1325 1326 out: 1327 rw_exit(&exec_lock); 1328 return error; 1329 } 1330 1331 static void 1332 link_es(struct execsw_entry **listp, const struct execsw *esp) 1333 { 1334 struct execsw_entry *et, *e1; 1335 1336 et = (struct execsw_entry *) malloc(sizeof(struct execsw_entry), 1337 M_TEMP, M_WAITOK); 1338 et->next = NULL; 1339 et->es = esp; 1340 if (*listp == NULL) { 1341 *listp = et; 1342 return; 1343 } 1344 1345 switch(et->es->es_prio) { 1346 case EXECSW_PRIO_FIRST: 1347 /* put new entry as the first */ 1348 et->next = *listp; 1349 *listp = et; 1350 break; 1351 case EXECSW_PRIO_ANY: 1352 /* put new entry after all *_FIRST and *_ANY entries */ 1353 for(e1 = *listp; e1->next 1354 && e1->next->es->es_prio != EXECSW_PRIO_LAST; 1355 e1 = e1->next); 1356 et->next = e1->next; 1357 e1->next = et; 1358 break; 1359 case EXECSW_PRIO_LAST: 1360 /* put new entry as the last one */ 1361 for(e1 = *listp; e1->next; e1 = e1->next); 1362 e1->next = et; 1363 break; 1364 default: 1365 #ifdef DIAGNOSTIC 1366 panic("execw[] entry with unknown priority %d found", 1367 et->es->es_prio); 1368 #else 1369 free(et, M_TEMP); 1370 #endif 1371 break; 1372 } 1373 } 1374 1375 /* 1376 * Initialize exec structures. If init_boot is true, also does necessary 1377 * one-time initialization (it's called from main() that way). 1378 * Once system is multiuser, this should be called with exec_lock held, 1379 * i.e. via exec_{add|remove}(). 1380 */ 1381 int 1382 exec_init(int init_boot) 1383 { 1384 const struct execsw **new_es, * const *old_es; 1385 struct execsw_entry *list, *e1; 1386 struct exec_entry *e2; 1387 int i, es_sz; 1388 1389 if (init_boot) { 1390 /* do one-time initializations */ 1391 rw_init(&exec_lock); 1392 1393 /* register compiled-in emulations */ 1394 for(i=0; i < nexecs_builtin; i++) { 1395 if (execsw_builtin[i].es_emul) 1396 emul_register(execsw_builtin[i].es_emul, 1); 1397 } 1398 #ifdef DIAGNOSTIC 1399 if (i == 0) 1400 panic("no emulations found in execsw_builtin[]"); 1401 #endif 1402 } 1403 1404 /* 1405 * Build execsw[] array from builtin entries and entries added 1406 * at runtime. 1407 */ 1408 list = NULL; 1409 for(i=0; i < nexecs_builtin; i++) 1410 link_es(&list, &execsw_builtin[i]); 1411 1412 /* Add dynamically loaded entries */ 1413 es_sz = nexecs_builtin; 1414 LIST_FOREACH(e2, &ex_head, ex_list) { 1415 link_es(&list, e2->es); 1416 es_sz++; 1417 } 1418 1419 /* 1420 * Now that we have sorted all execw entries, create new execsw[] 1421 * and free no longer needed memory in the process. 1422 */ 1423 new_es = malloc(es_sz * sizeof(struct execsw *), M_EXEC, M_WAITOK); 1424 for(i=0; list; i++) { 1425 new_es[i] = list->es; 1426 e1 = list->next; 1427 free(list, M_TEMP); 1428 list = e1; 1429 } 1430 1431 /* 1432 * New execsw[] array built, now replace old execsw[] and free 1433 * used memory. 1434 */ 1435 old_es = execsw; 1436 execsw = new_es; 1437 nexecs = es_sz; 1438 if (old_es) 1439 /*XXXUNCONST*/ 1440 free(__UNCONST(old_es), M_EXEC); 1441 1442 /* 1443 * Figure out the maximum size of an exec header. 1444 */ 1445 exec_maxhdrsz = 0; 1446 for (i = 0; i < nexecs; i++) { 1447 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1448 exec_maxhdrsz = execsw[i]->es_hdrsz; 1449 } 1450 1451 return 0; 1452 } 1453 #endif 1454 1455 #ifndef LKM 1456 /* 1457 * Simplified exec_init() for kernels without LKMs. Only initialize 1458 * exec_maxhdrsz and execsw[]. 1459 */ 1460 int 1461 exec_init(int init_boot) 1462 { 1463 int i; 1464 1465 #ifdef DIAGNOSTIC 1466 if (!init_boot) 1467 panic("exec_init(): called with init_boot == 0"); 1468 #endif 1469 1470 /* do one-time initializations */ 1471 nexecs = nexecs_builtin; 1472 execsw = malloc(nexecs*sizeof(struct execsw *), M_EXEC, M_WAITOK); 1473 1474 /* 1475 * Fill in execsw[] and figure out the maximum size of an exec header. 1476 */ 1477 exec_maxhdrsz = 0; 1478 for(i=0; i < nexecs; i++) { 1479 execsw[i] = &execsw_builtin[i]; 1480 if (execsw_builtin[i].es_hdrsz > exec_maxhdrsz) 1481 exec_maxhdrsz = execsw_builtin[i].es_hdrsz; 1482 } 1483 1484 return 0; 1485 1486 } 1487 #endif /* !LKM */ 1488 1489 static int 1490 exec_sigcode_map(struct proc *p, const struct emul *e) 1491 { 1492 vaddr_t va; 1493 vsize_t sz; 1494 int error; 1495 struct uvm_object *uobj; 1496 1497 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 1498 1499 if (e->e_sigobject == NULL || sz == 0) { 1500 return 0; 1501 } 1502 1503 /* 1504 * If we don't have a sigobject for this emulation, create one. 1505 * 1506 * sigobject is an anonymous memory object (just like SYSV shared 1507 * memory) that we keep a permanent reference to and that we map 1508 * in all processes that need this sigcode. The creation is simple, 1509 * we create an object, add a permanent reference to it, map it in 1510 * kernel space, copy out the sigcode to it and unmap it. 1511 * We map it with PROT_READ|PROT_EXEC into the process just 1512 * the way sys_mmap() would map it. 1513 */ 1514 1515 uobj = *e->e_sigobject; 1516 if (uobj == NULL) { 1517 uobj = uao_create(sz, 0); 1518 (*uobj->pgops->pgo_reference)(uobj); 1519 va = vm_map_min(kernel_map); 1520 if ((error = uvm_map(kernel_map, &va, round_page(sz), 1521 uobj, 0, 0, 1522 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 1523 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 1524 printf("kernel mapping failed %d\n", error); 1525 (*uobj->pgops->pgo_detach)(uobj); 1526 return (error); 1527 } 1528 memcpy((void *)va, e->e_sigcode, sz); 1529 #ifdef PMAP_NEED_PROCWR 1530 pmap_procwr(&proc0, va, sz); 1531 #endif 1532 uvm_unmap(kernel_map, va, va + round_page(sz)); 1533 *e->e_sigobject = uobj; 1534 } 1535 1536 /* Just a hint to uvm_map where to put it. */ 1537 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, 1538 round_page(sz)); 1539 1540 #ifdef __alpha__ 1541 /* 1542 * Tru64 puts /sbin/loader at the end of user virtual memory, 1543 * which causes the above calculation to put the sigcode at 1544 * an invalid address. Put it just below the text instead. 1545 */ 1546 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) { 1547 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz); 1548 } 1549 #endif 1550 1551 (*uobj->pgops->pgo_reference)(uobj); 1552 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz), 1553 uobj, 0, 0, 1554 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE, 1555 UVM_ADV_RANDOM, 0)); 1556 if (error) { 1557 (*uobj->pgops->pgo_detach)(uobj); 1558 return (error); 1559 } 1560 p->p_sigctx.ps_sigcode = (void *)va; 1561 return (0); 1562 } 1563