1 /* $NetBSD: kern_exec.c,v 1.142 2001/06/18 02:00:55 christos 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 "opt_ktrace.h" 36 #include "opt_syscall_debug.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/filedesc.h> 41 #include <sys/kernel.h> 42 #include <sys/proc.h> 43 #include <sys/mount.h> 44 #include <sys/malloc.h> 45 #include <sys/namei.h> 46 #include <sys/vnode.h> 47 #include <sys/file.h> 48 #include <sys/acct.h> 49 #include <sys/exec.h> 50 #include <sys/ktrace.h> 51 #include <sys/resourcevar.h> 52 #include <sys/wait.h> 53 #include <sys/mman.h> 54 #include <sys/signalvar.h> 55 #include <sys/stat.h> 56 #include <sys/syscall.h> 57 58 #include <sys/syscallargs.h> 59 60 #include <uvm/uvm_extern.h> 61 62 #include <machine/cpu.h> 63 #include <machine/reg.h> 64 65 /* 66 * Exec function switch: 67 * 68 * Note that each makecmds function is responsible for loading the 69 * exec package with the necessary functions for any exec-type-specific 70 * handling. 71 * 72 * Functions for specific exec types should be defined in their own 73 * header file. 74 */ 75 extern const struct execsw execsw_builtin[]; 76 extern int nexecs_builtin; 77 static const struct execsw **execsw = NULL; 78 static int nexecs; 79 80 int exec_maxhdrsz; /* must not be static - netbsd32 needs it */ 81 82 #ifdef LKM 83 /* list of supported emulations */ 84 static 85 LIST_HEAD(emlist_head, emul_entry) el_head = LIST_HEAD_INITIALIZER(el_head); 86 struct emul_entry { 87 LIST_ENTRY(emul_entry) el_list; 88 const struct emul *el_emul; 89 int ro_entry; 90 }; 91 92 /* list of dynamically loaded execsw entries */ 93 static 94 LIST_HEAD(execlist_head, exec_entry) ex_head = LIST_HEAD_INITIALIZER(ex_head); 95 struct exec_entry { 96 LIST_ENTRY(exec_entry) ex_list; 97 const struct execsw *es; 98 }; 99 100 /* structure used for building execw[] */ 101 struct execsw_entry { 102 struct execsw_entry *next; 103 const struct execsw *es; 104 }; 105 #endif /* LKM */ 106 107 /* NetBSD emul struct */ 108 extern char sigcode[], esigcode[]; 109 #ifdef SYSCALL_DEBUG 110 extern const char * const syscallnames[]; 111 #endif 112 #ifdef __HAVE_SYSCALL_INTERN 113 void syscall_intern(struct proc *); 114 #else 115 void syscall(void); 116 #endif 117 118 const struct emul emul_netbsd = { 119 "netbsd", 120 NULL, /* emulation path */ 121 #ifndef __HAVE_MINIMAL_EMUL 122 EMUL_HAS_SYS___syscall, 123 NULL, 124 SYS_syscall, 125 SYS_MAXSYSCALL, 126 #endif 127 sysent, 128 #ifdef SYSCALL_DEBUG 129 syscallnames, 130 #else 131 NULL, 132 #endif 133 sendsig, 134 trapsignal, 135 sigcode, 136 esigcode, 137 NULL, 138 NULL, 139 NULL, 140 #ifdef __HAVE_SYSCALL_INTERN 141 syscall_intern, 142 #else 143 syscall, 144 #endif 145 }; 146 147 /* 148 * Exec lock. Used to control access to execsw[] structures. 149 * This must not be static so that netbsd32 can access it, too. 150 */ 151 struct lock exec_lock; 152 153 #ifdef LKM 154 static const struct emul * emul_search(const char *); 155 static void link_es(struct execsw_entry **, const struct execsw *); 156 #endif /* LKM */ 157 158 /* 159 * check exec: 160 * given an "executable" described in the exec package's namei info, 161 * see what we can do with it. 162 * 163 * ON ENTRY: 164 * exec package with appropriate namei info 165 * proc pointer of exec'ing proc 166 * NO SELF-LOCKED VNODES 167 * 168 * ON EXIT: 169 * error: nothing held, etc. exec header still allocated. 170 * ok: filled exec package, executable's vnode (unlocked). 171 * 172 * EXEC SWITCH ENTRY: 173 * Locked vnode to check, exec package, proc. 174 * 175 * EXEC SWITCH EXIT: 176 * ok: return 0, filled exec package, executable's vnode (unlocked). 177 * error: destructive: 178 * everything deallocated execept exec header. 179 * non-destructive: 180 * error code, executable's vnode (unlocked), 181 * exec header unmodified. 182 */ 183 int 184 check_exec(struct proc *p, struct exec_package *epp) 185 { 186 int error, i; 187 struct vnode *vp; 188 struct nameidata *ndp; 189 size_t resid; 190 191 ndp = epp->ep_ndp; 192 ndp->ni_cnd.cn_nameiop = LOOKUP; 193 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME; 194 /* first get the vnode */ 195 if ((error = namei(ndp)) != 0) 196 return error; 197 epp->ep_vp = vp = ndp->ni_vp; 198 199 /* check access and type */ 200 if (vp->v_type != VREG) { 201 error = EACCES; 202 goto bad1; 203 } 204 if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0) 205 goto bad1; 206 207 /* get attributes */ 208 if ((error = VOP_GETATTR(vp, epp->ep_vap, p->p_ucred, p)) != 0) 209 goto bad1; 210 211 /* Check mount point */ 212 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 213 error = EACCES; 214 goto bad1; 215 } 216 if (vp->v_mount->mnt_flag & MNT_NOSUID) 217 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 218 219 /* try to open it */ 220 if ((error = VOP_OPEN(vp, FREAD, p->p_ucred, p)) != 0) 221 goto bad1; 222 223 /* unlock vp, since we need it unlocked from here on out. */ 224 VOP_UNLOCK(vp, 0); 225 226 /* now we have the file, get the exec header */ 227 uvn_attach(vp, VM_PROT_READ); 228 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 229 UIO_SYSSPACE, 0, p->p_ucred, &resid, p); 230 if (error) 231 goto bad2; 232 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 233 234 /* 235 * Set up default address space limits. Can be overridden 236 * by individual exec packages. 237 * 238 * XXX probably shoul be all done in the exec pakages. 239 */ 240 epp->ep_vm_minaddr = VM_MIN_ADDRESS; 241 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 242 /* 243 * set up the vmcmds for creation of the process 244 * address space 245 */ 246 error = ENOEXEC; 247 for (i = 0; i < nexecs && error != 0; i++) { 248 int newerror; 249 250 epp->ep_esch = execsw[i]; 251 newerror = (*execsw[i]->es_check)(p, epp); 252 /* make sure the first "interesting" error code is saved. */ 253 if (!newerror || error == ENOEXEC) 254 error = newerror; 255 256 /* if es_check call was successful, update epp->ep_es */ 257 if (!newerror && (epp->ep_flags & EXEC_HASES) == 0) 258 epp->ep_es = execsw[i]; 259 260 if (epp->ep_flags & EXEC_DESTR && error != 0) 261 return error; 262 } 263 if (!error) { 264 /* check that entry point is sane */ 265 if (epp->ep_entry > VM_MAXUSER_ADDRESS) 266 error = ENOEXEC; 267 268 /* check limits */ 269 if ((epp->ep_tsize > MAXTSIZ) || 270 (epp->ep_dsize > p->p_rlimit[RLIMIT_DATA].rlim_cur)) 271 error = ENOMEM; 272 273 if (!error) 274 return (0); 275 } 276 277 /* 278 * free any vmspace-creation commands, 279 * and release their references 280 */ 281 kill_vmcmds(&epp->ep_vmcmds); 282 283 bad2: 284 /* 285 * close and release the vnode, restore the old one, free the 286 * pathname buf, and punt. 287 */ 288 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 289 VOP_CLOSE(vp, FREAD, p->p_ucred, p); 290 vput(vp); 291 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 292 return error; 293 294 bad1: 295 /* 296 * free the namei pathname buffer, and put the vnode 297 * (which we don't yet have open). 298 */ 299 vput(vp); /* was still locked */ 300 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 301 return error; 302 } 303 304 /* 305 * exec system call 306 */ 307 /* ARGSUSED */ 308 int 309 sys_execve(struct proc *p, void *v, register_t *retval) 310 { 311 struct sys_execve_args /* { 312 syscallarg(const char *) path; 313 syscallarg(char * const *) argp; 314 syscallarg(char * const *) envp; 315 } */ *uap = v; 316 int error, i; 317 struct exec_package pack; 318 struct nameidata nid; 319 struct vattr attr; 320 struct ucred *cred; 321 char *argp; 322 char * const *cpp; 323 char *dp, *sp; 324 long argc, envc; 325 size_t len; 326 char *stack; 327 struct ps_strings arginfo; 328 struct vmspace *vm; 329 char **tmpfap; 330 int szsigcode; 331 struct exec_vmcmd *base_vcp; 332 333 cred = p->p_ucred; 334 base_vcp = NULL; 335 /* 336 * Init the namei data to point the file user's program name. 337 * This is done here rather than in check_exec(), so that it's 338 * possible to override this settings if any of makecmd/probe 339 * functions call check_exec() recursively - for example, 340 * see exec_script_makecmds(). 341 */ 342 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 343 344 /* 345 * initialize the fields of the exec package. 346 */ 347 pack.ep_name = SCARG(uap, path); 348 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 349 pack.ep_hdrlen = exec_maxhdrsz; 350 pack.ep_hdrvalid = 0; 351 pack.ep_ndp = &nid; 352 pack.ep_emul_arg = NULL; 353 pack.ep_vmcmds.evs_cnt = 0; 354 pack.ep_vmcmds.evs_used = 0; 355 pack.ep_vap = &attr; 356 pack.ep_flags = 0; 357 358 lockmgr(&exec_lock, LK_SHARED, NULL); 359 360 /* see if we can run it. */ 361 if ((error = check_exec(p, &pack)) != 0) 362 goto freehdr; 363 364 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 365 366 /* allocate an argument buffer */ 367 argp = (char *) uvm_km_valloc_wait(exec_map, NCARGS); 368 #ifdef DIAGNOSTIC 369 if (argp == (vaddr_t) 0) 370 panic("execve: argp == NULL"); 371 #endif 372 dp = argp; 373 argc = 0; 374 375 /* copy the fake args list, if there's one, freeing it as we go */ 376 if (pack.ep_flags & EXEC_HASARGL) { 377 tmpfap = pack.ep_fa; 378 while (*tmpfap != NULL) { 379 char *cp; 380 381 cp = *tmpfap; 382 while (*cp) 383 *dp++ = *cp++; 384 dp++; 385 386 FREE(*tmpfap, M_EXEC); 387 tmpfap++; argc++; 388 } 389 FREE(pack.ep_fa, M_EXEC); 390 pack.ep_flags &= ~EXEC_HASARGL; 391 } 392 393 /* Now get argv & environment */ 394 if (!(cpp = SCARG(uap, argp))) { 395 error = EINVAL; 396 goto bad; 397 } 398 399 if (pack.ep_flags & EXEC_SKIPARG) 400 cpp++; 401 402 while (1) { 403 len = argp + ARG_MAX - dp; 404 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 405 goto bad; 406 if (!sp) 407 break; 408 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 409 if (error == ENAMETOOLONG) 410 error = E2BIG; 411 goto bad; 412 } 413 dp += len; 414 cpp++; 415 argc++; 416 } 417 418 envc = 0; 419 /* environment need not be there */ 420 if ((cpp = SCARG(uap, envp)) != NULL ) { 421 while (1) { 422 len = argp + ARG_MAX - dp; 423 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 424 goto bad; 425 if (!sp) 426 break; 427 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 428 if (error == ENAMETOOLONG) 429 error = E2BIG; 430 goto bad; 431 } 432 dp += len; 433 cpp++; 434 envc++; 435 } 436 } 437 438 dp = (char *) ALIGN(dp); 439 440 szsigcode = pack.ep_es->es_emul->e_esigcode - 441 pack.ep_es->es_emul->e_sigcode; 442 443 /* Now check if args & environ fit into new stack */ 444 if (pack.ep_flags & EXEC_32) 445 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 446 sizeof(int) + sizeof(int) + dp + STACKGAPLEN + 447 szsigcode + sizeof(struct ps_strings)) - argp; 448 else 449 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 450 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN + 451 szsigcode + sizeof(struct ps_strings)) - argp; 452 453 len = ALIGN(len); /* make the stack "safely" aligned */ 454 455 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 456 error = ENOMEM; 457 goto bad; 458 } 459 460 /* adjust "active stack depth" for process VSZ */ 461 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 462 463 /* 464 * Do whatever is necessary to prepare the address space 465 * for remapping. Note that this might replace the current 466 * vmspace with another! 467 */ 468 uvmspace_exec(p, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 469 470 /* Now map address space */ 471 vm = p->p_vmspace; 472 vm->vm_taddr = (char *) pack.ep_taddr; 473 vm->vm_tsize = btoc(pack.ep_tsize); 474 vm->vm_daddr = (char *) pack.ep_daddr; 475 vm->vm_dsize = btoc(pack.ep_dsize); 476 vm->vm_ssize = btoc(pack.ep_ssize); 477 vm->vm_maxsaddr = (char *) pack.ep_maxsaddr; 478 vm->vm_minsaddr = (char *) pack.ep_minsaddr; 479 480 /* create the new process's VM space by running the vmcmds */ 481 #ifdef DIAGNOSTIC 482 if (pack.ep_vmcmds.evs_used == 0) 483 panic("execve: no vmcmds"); 484 #endif 485 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 486 struct exec_vmcmd *vcp; 487 488 vcp = &pack.ep_vmcmds.evs_cmds[i]; 489 if (vcp->ev_flags & VMCMD_RELATIVE) { 490 #ifdef DIAGNOSTIC 491 if (base_vcp == NULL) 492 panic("execve: relative vmcmd with no base"); 493 if (vcp->ev_flags & VMCMD_BASE) 494 panic("execve: illegal base & relative vmcmd"); 495 #endif 496 vcp->ev_addr += base_vcp->ev_addr; 497 } 498 error = (*vcp->ev_proc)(p, vcp); 499 #ifdef DEBUG 500 if (error) { 501 if (i > 0) 502 printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", i-1, 503 vcp[-1].ev_addr, vcp[-1].ev_len, 504 vcp[-1].ev_offset); 505 printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", i, 506 vcp->ev_addr, vcp->ev_len, vcp->ev_offset); 507 } 508 #endif 509 if (vcp->ev_flags & VMCMD_BASE) 510 base_vcp = vcp; 511 } 512 513 /* free the vmspace-creation commands, and release their references */ 514 kill_vmcmds(&pack.ep_vmcmds); 515 516 /* if an error happened, deallocate and punt */ 517 if (error) { 518 #ifdef DEBUG 519 printf("execve: vmcmd %i failed: %d\n", i-1, error); 520 #endif 521 goto exec_abort; 522 } 523 524 /* remember information about the process */ 525 arginfo.ps_nargvstr = argc; 526 arginfo.ps_nenvstr = envc; 527 528 stack = (char *) (vm->vm_minsaddr - len); 529 /* Now copy argc, args & environ to new stack */ 530 if (!(*pack.ep_es->es_copyargs)(&pack, &arginfo, stack, argp)) { 531 #ifdef DEBUG 532 printf("execve: copyargs failed\n"); 533 #endif 534 goto exec_abort; 535 } 536 537 /* fill process ps_strings info */ 538 p->p_psstr = (struct ps_strings *)(vm->vm_minsaddr 539 - sizeof(struct ps_strings)); 540 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 541 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 542 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 543 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 544 545 /* copy out the process's ps_strings structure */ 546 if (copyout(&arginfo, (char *)p->p_psstr, sizeof(arginfo))) { 547 #ifdef DEBUG 548 printf("execve: ps_strings copyout %p->%p size %ld failed\n", 549 &arginfo, (char *)p->p_psstr, (long)sizeof(arginfo)); 550 #endif 551 goto exec_abort; 552 } 553 554 /* copy out the process's signal trapoline code */ 555 if (szsigcode) { 556 if (copyout((char *)pack.ep_es->es_emul->e_sigcode, 557 p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode, 558 szsigcode)) { 559 #ifdef DEBUG 560 printf("execve: sig trampoline copyout failed\n"); 561 #endif 562 goto exec_abort; 563 } 564 #ifdef PMAP_NEED_PROCWR 565 /* This is code. Let the pmap do what is needed. */ 566 pmap_procwr(p, (vaddr_t)p->p_sigctx.ps_sigcode, szsigcode); 567 #endif 568 } 569 570 stopprofclock(p); /* stop profiling */ 571 fdcloseexec(p); /* handle close on exec */ 572 execsigs(p); /* reset catched signals */ 573 p->p_ctxlink = NULL; /* reset ucontext link */ 574 575 /* set command name & other accounting info */ 576 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 577 memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len); 578 p->p_comm[len] = 0; 579 p->p_acflag &= ~AFORK; 580 581 /* record proc's vnode, for use by procfs and others */ 582 if (p->p_textvp) 583 vrele(p->p_textvp); 584 VREF(pack.ep_vp); 585 p->p_textvp = pack.ep_vp; 586 587 p->p_flag |= P_EXEC; 588 if (p->p_flag & P_PPWAIT) { 589 p->p_flag &= ~P_PPWAIT; 590 wakeup((caddr_t) p->p_pptr); 591 } 592 593 /* 594 * deal with set[ug]id. 595 * MNT_NOSUID has already been used to disable s[ug]id. 596 */ 597 if ((p->p_flag & P_TRACED) == 0 && 598 599 (((attr.va_mode & S_ISUID) != 0 && 600 p->p_ucred->cr_uid != attr.va_uid) || 601 602 ((attr.va_mode & S_ISGID) != 0 && 603 p->p_ucred->cr_gid != attr.va_gid))) { 604 /* 605 * Mark the process as SUGID before we do 606 * anything that might block. 607 */ 608 p_sugid(p); 609 610 p->p_ucred = crcopy(cred); 611 #ifdef KTRACE 612 /* 613 * If process is being ktraced, turn off - unless 614 * root set it. 615 */ 616 if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT)) 617 ktrderef(p); 618 #endif 619 if (attr.va_mode & S_ISUID) 620 p->p_ucred->cr_uid = attr.va_uid; 621 if (attr.va_mode & S_ISGID) 622 p->p_ucred->cr_gid = attr.va_gid; 623 } else 624 p->p_flag &= ~P_SUGID; 625 p->p_cred->p_svuid = p->p_ucred->cr_uid; 626 p->p_cred->p_svgid = p->p_ucred->cr_gid; 627 628 doexechooks(p); 629 630 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 631 632 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 633 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 634 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 635 vput(pack.ep_vp); 636 637 /* setup new registers and do misc. setup. */ 638 (*pack.ep_es->es_setregs)(p, &pack, (u_long) stack); 639 640 if (p->p_flag & P_TRACED) 641 psignal(p, SIGTRAP); 642 643 free(pack.ep_hdr, M_EXEC); 644 645 /* 646 * Call emulation specific exec hook. This can setup setup per-process 647 * p->p_emuldata or do any other per-process stuff an emulation needs. 648 * 649 * If we are executing process of different emulation than the 650 * original forked process, call e_proc_exit() of the old emulation 651 * first, then e_proc_exec() of new emulation. If the emulation is 652 * same, the exec hook code should deallocate any old emulation 653 * resources held previously by this process. 654 */ 655 if (p->p_emul && p->p_emul->e_proc_exit 656 && p->p_emul != pack.ep_es->es_emul) 657 (*p->p_emul->e_proc_exit)(p); 658 659 /* 660 * Call exec hook. Emulation code may NOT store reference to anything 661 * from &pack. 662 */ 663 if (pack.ep_es->es_emul->e_proc_exec) 664 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack); 665 666 /* update p_emul, the old value is no longer needed */ 667 p->p_emul = pack.ep_es->es_emul; 668 #ifdef __HAVE_SYSCALL_INTERN 669 (*p->p_emul->e_syscall_intern)(p); 670 #endif 671 #ifdef KTRACE 672 if (KTRPOINT(p, KTR_EMUL)) 673 ktremul(p); 674 #endif 675 676 lockmgr(&exec_lock, LK_RELEASE, NULL); 677 678 return (EJUSTRETURN); 679 680 bad: 681 /* free the vmspace-creation commands, and release their references */ 682 kill_vmcmds(&pack.ep_vmcmds); 683 /* kill any opened file descriptor, if necessary */ 684 if (pack.ep_flags & EXEC_HASFD) { 685 pack.ep_flags &= ~EXEC_HASFD; 686 (void) fdrelease(p, pack.ep_fd); 687 } 688 /* close and put the exec'd file */ 689 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 690 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 691 vput(pack.ep_vp); 692 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 693 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 694 695 freehdr: 696 lockmgr(&exec_lock, LK_RELEASE, NULL); 697 698 free(pack.ep_hdr, M_EXEC); 699 return error; 700 701 exec_abort: 702 lockmgr(&exec_lock, LK_RELEASE, NULL); 703 704 /* 705 * the old process doesn't exist anymore. exit gracefully. 706 * get rid of the (new) address space we have created, if any, get rid 707 * of our namei data and vnode, and exit noting failure 708 */ 709 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 710 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 711 if (pack.ep_emul_arg) 712 FREE(pack.ep_emul_arg, M_TEMP); 713 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 714 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 715 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 716 vput(pack.ep_vp); 717 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 718 free(pack.ep_hdr, M_EXEC); 719 exit1(p, W_EXITCODE(0, SIGABRT)); 720 exit1(p, -1); 721 722 /* NOTREACHED */ 723 return 0; 724 } 725 726 727 void * 728 copyargs(struct exec_package *pack, struct ps_strings *arginfo, 729 void *stack, void *argp) 730 { 731 char **cpp, *dp, *sp; 732 size_t len; 733 void *nullp; 734 long argc, envc; 735 736 cpp = stack; 737 nullp = NULL; 738 argc = arginfo->ps_nargvstr; 739 envc = arginfo->ps_nenvstr; 740 if (copyout(&argc, cpp++, sizeof(argc))) 741 return NULL; 742 743 dp = (char *) (cpp + argc + envc + 2 + pack->ep_es->es_arglen); 744 sp = argp; 745 746 /* XXX don't copy them out, remap them! */ 747 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 748 749 for (; --argc >= 0; sp += len, dp += len) 750 if (copyout(&dp, cpp++, sizeof(dp)) || 751 copyoutstr(sp, dp, ARG_MAX, &len)) 752 return NULL; 753 754 if (copyout(&nullp, cpp++, sizeof(nullp))) 755 return NULL; 756 757 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 758 759 for (; --envc >= 0; sp += len, dp += len) 760 if (copyout(&dp, cpp++, sizeof(dp)) || 761 copyoutstr(sp, dp, ARG_MAX, &len)) 762 return NULL; 763 764 if (copyout(&nullp, cpp++, sizeof(nullp))) 765 return NULL; 766 767 return cpp; 768 } 769 770 #ifdef LKM 771 /* 772 * Find an emulation of given name in list of emulations. 773 */ 774 static const struct emul * 775 emul_search(const char *name) 776 { 777 struct emul_entry *it; 778 779 LIST_FOREACH(it, &el_head, el_list) { 780 if (strcmp(name, it->el_emul->e_name) == 0) 781 return it->el_emul; 782 } 783 784 return NULL; 785 } 786 787 /* 788 * Add an emulation to list, if it's not there already. 789 */ 790 int 791 emul_register(const struct emul *emul, int ro_entry) 792 { 793 struct emul_entry *ee; 794 int error; 795 796 error = 0; 797 lockmgr(&exec_lock, LK_SHARED, NULL); 798 799 if (emul_search(emul->e_name)) { 800 error = EEXIST; 801 goto out; 802 } 803 804 MALLOC(ee, struct emul_entry *, sizeof(struct emul_entry), 805 M_EXEC, M_WAITOK); 806 ee->el_emul = emul; 807 ee->ro_entry = ro_entry; 808 LIST_INSERT_HEAD(&el_head, ee, el_list); 809 810 out: 811 lockmgr(&exec_lock, LK_RELEASE, NULL); 812 return error; 813 } 814 815 /* 816 * Remove emulation with name 'name' from list of supported emulations. 817 */ 818 int 819 emul_unregister(const char *name) 820 { 821 const struct proclist_desc *pd; 822 struct emul_entry *it; 823 int i, error; 824 struct proc *ptmp; 825 826 error = 0; 827 lockmgr(&exec_lock, LK_SHARED, NULL); 828 829 LIST_FOREACH(it, &el_head, el_list) { 830 if (strcmp(it->el_emul->e_name, name) == 0) 831 break; 832 } 833 834 if (!it) { 835 error = ENOENT; 836 goto out; 837 } 838 839 if (it->ro_entry) { 840 error = EBUSY; 841 goto out; 842 } 843 844 /* test if any execw[] entry is still using this */ 845 for(i=0; i < nexecs; i++) { 846 if (execsw[i]->es_emul == it->el_emul) { 847 error = EBUSY; 848 goto out; 849 } 850 } 851 852 /* 853 * Test if any process is running under this emulation - since 854 * emul_unregister() is running quite sendomly, it's better 855 * to do expensive check here than to use any locking. 856 */ 857 proclist_lock_read(); 858 for (pd = proclists; pd->pd_list != NULL && !error; pd++) { 859 LIST_FOREACH(ptmp, pd->pd_list, p_list) { 860 if (ptmp->p_emul == it->el_emul) { 861 error = EBUSY; 862 break; 863 } 864 } 865 } 866 proclist_unlock_read(); 867 868 if (error) 869 goto out; 870 871 872 /* entry is not used, remove it */ 873 LIST_REMOVE(it, el_list); 874 FREE(it, M_EXEC); 875 876 out: 877 lockmgr(&exec_lock, LK_RELEASE, NULL); 878 return error; 879 } 880 881 /* 882 * Add execsw[] entry. 883 */ 884 int 885 exec_add(struct execsw *esp, const char *e_name) 886 { 887 struct exec_entry *it; 888 int error; 889 890 error = 0; 891 lockmgr(&exec_lock, LK_EXCLUSIVE, NULL); 892 893 if (!esp->es_emul) { 894 esp->es_emul = emul_search(e_name); 895 if (!esp->es_emul) { 896 error = ENOENT; 897 goto out; 898 } 899 } 900 901 LIST_FOREACH(it, &ex_head, ex_list) { 902 /* assume tuple (makecmds, probe_func, emulation) is unique */ 903 if (it->es->es_check == esp->es_check 904 && it->es->u.elf_probe_func == esp->u.elf_probe_func 905 && it->es->es_emul == esp->es_emul) { 906 error = EEXIST; 907 goto out; 908 } 909 } 910 911 /* if we got here, the entry doesn't exist yet */ 912 MALLOC(it, struct exec_entry *, sizeof(struct exec_entry), 913 M_EXEC, M_WAITOK); 914 it->es = esp; 915 LIST_INSERT_HEAD(&ex_head, it, ex_list); 916 917 /* update execsw[] */ 918 exec_init(0); 919 920 out: 921 lockmgr(&exec_lock, LK_RELEASE, NULL); 922 return error; 923 } 924 925 /* 926 * Remove execsw[] entry. 927 */ 928 int 929 exec_remove(const struct execsw *esp) 930 { 931 struct exec_entry *it; 932 int error; 933 934 error = 0; 935 lockmgr(&exec_lock, LK_EXCLUSIVE, NULL); 936 937 LIST_FOREACH(it, &ex_head, ex_list) { 938 /* assume tuple (makecmds, probe_func, emulation) is unique */ 939 if (it->es->es_check == esp->es_check 940 && it->es->u.elf_probe_func == esp->u.elf_probe_func 941 && it->es->es_emul == esp->es_emul) 942 break; 943 } 944 if (!it) { 945 error = ENOENT; 946 goto out; 947 } 948 949 /* remove item from list and free resources */ 950 LIST_REMOVE(it, ex_list); 951 FREE(it, M_EXEC); 952 953 /* update execsw[] */ 954 exec_init(0); 955 956 out: 957 lockmgr(&exec_lock, LK_RELEASE, NULL); 958 return error; 959 } 960 961 static void 962 link_es(struct execsw_entry **listp, const struct execsw *esp) 963 { 964 struct execsw_entry *et, *e1; 965 966 MALLOC(et, struct execsw_entry *, sizeof(struct execsw_entry), 967 M_TEMP, M_WAITOK); 968 et->next = NULL; 969 et->es = esp; 970 if (*listp == NULL) { 971 *listp = et; 972 return; 973 } 974 975 switch(et->es->es_prio) { 976 case EXECSW_PRIO_FIRST: 977 /* put new entry as the first */ 978 et->next = *listp; 979 *listp = et; 980 break; 981 case EXECSW_PRIO_ANY: 982 /* put new entry after all *_FIRST and *_ANY entries */ 983 for(e1 = *listp; e1->next 984 && e1->next->es->es_prio != EXECSW_PRIO_LAST; 985 e1 = e1->next); 986 et->next = e1->next; 987 e1->next = et; 988 break; 989 case EXECSW_PRIO_LAST: 990 /* put new entry as the last one */ 991 for(e1 = *listp; e1->next; e1 = e1->next); 992 e1->next = et; 993 break; 994 default: 995 #ifdef DIAGNOSTIC 996 panic("execw[] entry with unknown priority %d found\n", 997 et->es->es_prio); 998 #endif 999 break; 1000 } 1001 } 1002 1003 /* 1004 * Initialize exec structures. If init_boot is true, also does necessary 1005 * one-time initialization (it's called from main() that way). 1006 * Once system is multiuser, this should be called with exec_lock hold, 1007 * i.e. via exec_{add|remove}(). 1008 */ 1009 int 1010 exec_init(int init_boot) 1011 { 1012 const struct execsw **new_es, * const *old_es; 1013 struct execsw_entry *list, *e1; 1014 struct exec_entry *e2; 1015 int i, es_sz; 1016 1017 if (init_boot) { 1018 /* do one-time initializations */ 1019 lockinit(&exec_lock, PWAIT, "execlck", 0, 0); 1020 1021 /* register compiled-in emulations */ 1022 for(i=0; i < nexecs_builtin; i++) { 1023 if (execsw_builtin[i].es_emul) 1024 emul_register(execsw_builtin[i].es_emul, 1); 1025 } 1026 #ifdef DIAGNOSTIC 1027 if (i == 0) 1028 panic("no emulations found in execsw_builtin[]\n"); 1029 #endif 1030 } 1031 1032 /* 1033 * Build execsw[] array from builtin entries and entries added 1034 * at runtime. 1035 */ 1036 list = NULL; 1037 for(i=0; i < nexecs_builtin; i++) 1038 link_es(&list, &execsw_builtin[i]); 1039 1040 /* Add dynamically loaded entries */ 1041 es_sz = nexecs_builtin; 1042 LIST_FOREACH(e2, &ex_head, ex_list) { 1043 link_es(&list, e2->es); 1044 es_sz++; 1045 } 1046 1047 /* 1048 * Now that we have sorted all execw entries, create new execsw[] 1049 * and free no longer needed memory in the process. 1050 */ 1051 new_es = malloc(es_sz * sizeof(struct execsw *), M_EXEC, M_WAITOK); 1052 for(i=0; list; i++) { 1053 new_es[i] = list->es; 1054 e1 = list->next; 1055 FREE(list, M_TEMP); 1056 list = e1; 1057 } 1058 1059 /* 1060 * New execsw[] array built, now replace old execsw[] and free 1061 * used memory. 1062 */ 1063 old_es = execsw; 1064 execsw = new_es; 1065 nexecs = es_sz; 1066 if (old_es) 1067 free((void *)old_es, M_EXEC); 1068 1069 /* 1070 * Figure out the maximum size of an exec header. 1071 */ 1072 exec_maxhdrsz = 0; 1073 for (i = 0; i < nexecs; i++) { 1074 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1075 exec_maxhdrsz = execsw[i]->es_hdrsz; 1076 } 1077 1078 return 0; 1079 } 1080 #endif 1081 1082 #ifndef LKM 1083 /* 1084 * Simplified exec_init() for kernels without LKMs. Only initialize 1085 * exec_maxhdrsz and execsw[]. 1086 */ 1087 int 1088 exec_init(int init_boot) 1089 { 1090 int i; 1091 1092 #ifdef DIAGNOSTIC 1093 if (!init_boot) 1094 panic("exec_init(): called with init_boot == 0"); 1095 #endif 1096 1097 /* do one-time initializations */ 1098 lockinit(&exec_lock, PWAIT, "execlck", 0, 0); 1099 1100 nexecs = nexecs_builtin; 1101 execsw = malloc(nexecs*sizeof(struct execsw *), M_EXEC, M_WAITOK); 1102 1103 /* 1104 * Fill in execsw[] and figure out the maximum size of an exec header. 1105 */ 1106 exec_maxhdrsz = 0; 1107 for(i=0; i < nexecs; i++) { 1108 execsw[i] = &execsw_builtin[i]; 1109 if (execsw_builtin[i].es_hdrsz > exec_maxhdrsz) 1110 exec_maxhdrsz = execsw_builtin[i].es_hdrsz; 1111 } 1112 1113 return 0; 1114 1115 } 1116 #endif /* !LKM */ 1117