1 /* $NetBSD: kern_exec.c,v 1.150 2002/01/12 14:20:30 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 <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.150 2002/01/12 14:20:30 christos Exp $"); 37 38 #include "opt_ktrace.h" 39 #include "opt_syscall_debug.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/filedesc.h> 44 #include <sys/kernel.h> 45 #include <sys/proc.h> 46 #include <sys/mount.h> 47 #include <sys/malloc.h> 48 #include <sys/namei.h> 49 #include <sys/vnode.h> 50 #include <sys/file.h> 51 #include <sys/acct.h> 52 #include <sys/exec.h> 53 #include <sys/ktrace.h> 54 #include <sys/resourcevar.h> 55 #include <sys/wait.h> 56 #include <sys/mman.h> 57 #include <sys/signalvar.h> 58 #include <sys/stat.h> 59 #include <sys/syscall.h> 60 61 #include <sys/syscallargs.h> 62 63 #include <uvm/uvm_extern.h> 64 65 #include <machine/cpu.h> 66 #include <machine/reg.h> 67 68 #ifdef DEBUG_EXEC 69 #define DPRINTF(a) uprintf a 70 #else 71 #define DPRINTF(a) 72 #endif /* DEBUG_EXEC */ 73 74 /* 75 * Exec function switch: 76 * 77 * Note that each makecmds function is responsible for loading the 78 * exec package with the necessary functions for any exec-type-specific 79 * handling. 80 * 81 * Functions for specific exec types should be defined in their own 82 * header file. 83 */ 84 extern const struct execsw execsw_builtin[]; 85 extern int nexecs_builtin; 86 static const struct execsw **execsw = NULL; 87 static int nexecs; 88 89 int exec_maxhdrsz; /* must not be static - netbsd32 needs it */ 90 91 #ifdef LKM 92 /* list of supported emulations */ 93 static 94 LIST_HEAD(emlist_head, emul_entry) el_head = LIST_HEAD_INITIALIZER(el_head); 95 struct emul_entry { 96 LIST_ENTRY(emul_entry) el_list; 97 const struct emul *el_emul; 98 int ro_entry; 99 }; 100 101 /* list of dynamically loaded execsw entries */ 102 static 103 LIST_HEAD(execlist_head, exec_entry) ex_head = LIST_HEAD_INITIALIZER(ex_head); 104 struct exec_entry { 105 LIST_ENTRY(exec_entry) ex_list; 106 const struct execsw *es; 107 }; 108 109 /* structure used for building execw[] */ 110 struct execsw_entry { 111 struct execsw_entry *next; 112 const struct execsw *es; 113 }; 114 #endif /* LKM */ 115 116 /* NetBSD emul struct */ 117 extern char sigcode[], esigcode[]; 118 #ifdef SYSCALL_DEBUG 119 extern const char * const syscallnames[]; 120 #endif 121 #ifdef __HAVE_SYSCALL_INTERN 122 void syscall_intern(struct proc *); 123 #else 124 void syscall(void); 125 #endif 126 127 const struct emul emul_netbsd = { 128 "netbsd", 129 NULL, /* emulation path */ 130 #ifndef __HAVE_MINIMAL_EMUL 131 EMUL_HAS_SYS___syscall, 132 NULL, 133 SYS_syscall, 134 SYS_MAXSYSCALL, 135 #endif 136 sysent, 137 #ifdef SYSCALL_DEBUG 138 syscallnames, 139 #else 140 NULL, 141 #endif 142 sendsig, 143 trapsignal, 144 sigcode, 145 esigcode, 146 setregs, 147 NULL, 148 NULL, 149 NULL, 150 #ifdef __HAVE_SYSCALL_INTERN 151 syscall_intern, 152 #else 153 syscall, 154 #endif 155 }; 156 157 #ifdef LKM 158 /* 159 * Exec lock. Used to control access to execsw[] structures. 160 * This must not be static so that netbsd32 can access it, too. 161 */ 162 struct lock exec_lock; 163 164 static const struct emul * emul_search(const char *); 165 static void link_es(struct execsw_entry **, const struct execsw *); 166 #endif /* LKM */ 167 168 /* 169 * check exec: 170 * given an "executable" described in the exec package's namei info, 171 * see what we can do with it. 172 * 173 * ON ENTRY: 174 * exec package with appropriate namei info 175 * proc pointer of exec'ing proc 176 * NO SELF-LOCKED VNODES 177 * 178 * ON EXIT: 179 * error: nothing held, etc. exec header still allocated. 180 * ok: filled exec package, executable's vnode (unlocked). 181 * 182 * EXEC SWITCH ENTRY: 183 * Locked vnode to check, exec package, proc. 184 * 185 * EXEC SWITCH EXIT: 186 * ok: return 0, filled exec package, executable's vnode (unlocked). 187 * error: destructive: 188 * everything deallocated execept exec header. 189 * non-destructive: 190 * error code, executable's vnode (unlocked), 191 * exec header unmodified. 192 */ 193 int 194 check_exec(struct proc *p, struct exec_package *epp) 195 { 196 int error, i; 197 struct vnode *vp; 198 struct nameidata *ndp; 199 size_t resid; 200 201 ndp = epp->ep_ndp; 202 ndp->ni_cnd.cn_nameiop = LOOKUP; 203 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME; 204 /* first get the vnode */ 205 if ((error = namei(ndp)) != 0) 206 return error; 207 epp->ep_vp = vp = ndp->ni_vp; 208 209 /* check access and type */ 210 if (vp->v_type != VREG) { 211 error = EACCES; 212 goto bad1; 213 } 214 if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0) 215 goto bad1; 216 217 /* get attributes */ 218 if ((error = VOP_GETATTR(vp, epp->ep_vap, p->p_ucred, p)) != 0) 219 goto bad1; 220 221 /* Check mount point */ 222 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 223 error = EACCES; 224 goto bad1; 225 } 226 if (vp->v_mount->mnt_flag & MNT_NOSUID) 227 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 228 229 /* try to open it */ 230 if ((error = VOP_OPEN(vp, FREAD, p->p_ucred, p)) != 0) 231 goto bad1; 232 233 /* unlock vp, since we need it unlocked from here on out. */ 234 VOP_UNLOCK(vp, 0); 235 236 /* now we have the file, get the exec header */ 237 uvn_attach(vp, VM_PROT_READ); 238 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 239 UIO_SYSSPACE, 0, p->p_ucred, &resid, p); 240 if (error) 241 goto bad2; 242 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 243 244 /* 245 * Set up default address space limits. Can be overridden 246 * by individual exec packages. 247 * 248 * XXX probably shoul be all done in the exec pakages. 249 */ 250 epp->ep_vm_minaddr = VM_MIN_ADDRESS; 251 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS; 252 /* 253 * set up the vmcmds for creation of the process 254 * address space 255 */ 256 error = ENOEXEC; 257 for (i = 0; i < nexecs && error != 0; i++) { 258 int newerror; 259 260 epp->ep_esch = execsw[i]; 261 newerror = (*execsw[i]->es_check)(p, epp); 262 /* make sure the first "interesting" error code is saved. */ 263 if (!newerror || error == ENOEXEC) 264 error = newerror; 265 266 /* if es_check call was successful, update epp->ep_es */ 267 if (!newerror && (epp->ep_flags & EXEC_HASES) == 0) 268 epp->ep_es = execsw[i]; 269 270 if (epp->ep_flags & EXEC_DESTR && error != 0) 271 return error; 272 } 273 if (!error) { 274 /* check that entry point is sane */ 275 if (epp->ep_entry > VM_MAXUSER_ADDRESS) 276 error = ENOEXEC; 277 278 /* check limits */ 279 if ((epp->ep_tsize > MAXTSIZ) || 280 (epp->ep_dsize > p->p_rlimit[RLIMIT_DATA].rlim_cur)) 281 error = ENOMEM; 282 283 if (!error) 284 return (0); 285 } 286 287 /* 288 * free any vmspace-creation commands, 289 * and release their references 290 */ 291 kill_vmcmds(&epp->ep_vmcmds); 292 293 bad2: 294 /* 295 * close and release the vnode, restore the old one, free the 296 * pathname buf, and punt. 297 */ 298 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 299 VOP_CLOSE(vp, FREAD, p->p_ucred, p); 300 vput(vp); 301 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 302 return error; 303 304 bad1: 305 /* 306 * free the namei pathname buffer, and put the vnode 307 * (which we don't yet have open). 308 */ 309 vput(vp); /* was still locked */ 310 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 311 return error; 312 } 313 314 /* 315 * exec system call 316 */ 317 /* ARGSUSED */ 318 int 319 sys_execve(struct proc *p, void *v, register_t *retval) 320 { 321 struct sys_execve_args /* { 322 syscallarg(const char *) path; 323 syscallarg(char * const *) argp; 324 syscallarg(char * const *) envp; 325 } */ *uap = v; 326 int error, i; 327 struct exec_package pack; 328 struct nameidata nid; 329 struct vattr attr; 330 struct ucred *cred; 331 char *argp; 332 char * const *cpp; 333 char *dp, *sp; 334 long argc, envc; 335 size_t len; 336 char *stack; 337 struct ps_strings arginfo; 338 struct vmspace *vm; 339 char **tmpfap; 340 int szsigcode; 341 struct exec_vmcmd *base_vcp; 342 343 /* 344 * Lock the process and set the P_INEXEC flag to indicate that 345 * it should be left alone until we're done here. This is 346 * necessary to avoid race conditions - e.g. in ptrace() - 347 * that might allow a local user to illicitly obtain elevated 348 * privileges. 349 */ 350 p->p_flag |= P_INEXEC; 351 352 cred = p->p_ucred; 353 base_vcp = NULL; 354 /* 355 * Init the namei data to point the file user's program name. 356 * This is done here rather than in check_exec(), so that it's 357 * possible to override this settings if any of makecmd/probe 358 * functions call check_exec() recursively - for example, 359 * see exec_script_makecmds(). 360 */ 361 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 362 363 /* 364 * initialize the fields of the exec package. 365 */ 366 pack.ep_name = SCARG(uap, path); 367 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 368 pack.ep_hdrlen = exec_maxhdrsz; 369 pack.ep_hdrvalid = 0; 370 pack.ep_ndp = &nid; 371 pack.ep_emul_arg = NULL; 372 pack.ep_vmcmds.evs_cnt = 0; 373 pack.ep_vmcmds.evs_used = 0; 374 pack.ep_vap = &attr; 375 pack.ep_flags = 0; 376 377 #ifdef LKM 378 lockmgr(&exec_lock, LK_SHARED, NULL); 379 #endif 380 381 /* see if we can run it. */ 382 if ((error = check_exec(p, &pack)) != 0) 383 goto freehdr; 384 385 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 386 387 /* allocate an argument buffer */ 388 argp = (char *) uvm_km_valloc_wait(exec_map, NCARGS); 389 #ifdef DIAGNOSTIC 390 if (argp == (vaddr_t) 0) 391 panic("execve: argp == NULL"); 392 #endif 393 dp = argp; 394 argc = 0; 395 396 /* copy the fake args list, if there's one, freeing it as we go */ 397 if (pack.ep_flags & EXEC_HASARGL) { 398 tmpfap = pack.ep_fa; 399 while (*tmpfap != NULL) { 400 char *cp; 401 402 cp = *tmpfap; 403 while (*cp) 404 *dp++ = *cp++; 405 dp++; 406 407 FREE(*tmpfap, M_EXEC); 408 tmpfap++; argc++; 409 } 410 FREE(pack.ep_fa, M_EXEC); 411 pack.ep_flags &= ~EXEC_HASARGL; 412 } 413 414 /* Now get argv & environment */ 415 if (!(cpp = SCARG(uap, argp))) { 416 error = EINVAL; 417 goto bad; 418 } 419 420 if (pack.ep_flags & EXEC_SKIPARG) 421 cpp++; 422 423 while (1) { 424 len = argp + ARG_MAX - dp; 425 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 426 goto bad; 427 if (!sp) 428 break; 429 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 430 if (error == ENAMETOOLONG) 431 error = E2BIG; 432 goto bad; 433 } 434 dp += len; 435 cpp++; 436 argc++; 437 } 438 439 envc = 0; 440 /* environment need not be there */ 441 if ((cpp = SCARG(uap, envp)) != NULL ) { 442 while (1) { 443 len = argp + ARG_MAX - dp; 444 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 445 goto bad; 446 if (!sp) 447 break; 448 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 449 if (error == ENAMETOOLONG) 450 error = E2BIG; 451 goto bad; 452 } 453 dp += len; 454 cpp++; 455 envc++; 456 } 457 } 458 459 dp = (char *) ALIGN(dp); 460 461 szsigcode = pack.ep_es->es_emul->e_esigcode - 462 pack.ep_es->es_emul->e_sigcode; 463 464 /* Now check if args & environ fit into new stack */ 465 if (pack.ep_flags & EXEC_32) 466 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 467 sizeof(int) + sizeof(int) + dp + STACKGAPLEN + 468 szsigcode + sizeof(struct ps_strings)) - argp; 469 else 470 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 471 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN + 472 szsigcode + sizeof(struct ps_strings)) - argp; 473 474 len = ALIGN(len); /* make the stack "safely" aligned */ 475 476 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 477 error = ENOMEM; 478 goto bad; 479 } 480 481 /* adjust "active stack depth" for process VSZ */ 482 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 483 484 /* 485 * Do whatever is necessary to prepare the address space 486 * for remapping. Note that this might replace the current 487 * vmspace with another! 488 */ 489 uvmspace_exec(p, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 490 491 /* Now map address space */ 492 vm = p->p_vmspace; 493 vm->vm_taddr = (char *) pack.ep_taddr; 494 vm->vm_tsize = btoc(pack.ep_tsize); 495 vm->vm_daddr = (char *) pack.ep_daddr; 496 vm->vm_dsize = btoc(pack.ep_dsize); 497 vm->vm_ssize = btoc(pack.ep_ssize); 498 vm->vm_maxsaddr = (char *) pack.ep_maxsaddr; 499 vm->vm_minsaddr = (char *) pack.ep_minsaddr; 500 501 /* create the new process's VM space by running the vmcmds */ 502 #ifdef DIAGNOSTIC 503 if (pack.ep_vmcmds.evs_used == 0) 504 panic("execve: no vmcmds"); 505 #endif 506 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 507 struct exec_vmcmd *vcp; 508 509 vcp = &pack.ep_vmcmds.evs_cmds[i]; 510 if (vcp->ev_flags & VMCMD_RELATIVE) { 511 #ifdef DIAGNOSTIC 512 if (base_vcp == NULL) 513 panic("execve: relative vmcmd with no base"); 514 if (vcp->ev_flags & VMCMD_BASE) 515 panic("execve: illegal base & relative vmcmd"); 516 #endif 517 vcp->ev_addr += base_vcp->ev_addr; 518 } 519 error = (*vcp->ev_proc)(p, vcp); 520 #ifdef DEBUG_EXEC 521 if (error) { 522 int j; 523 struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0]; 524 for (j = 0; j <= i; j++) 525 uprintf( 526 "vmcmd[%d] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n", 527 j, vp[j].ev_addr, vp[j].ev_len, 528 vp[j].ev_offset, vp[j].ev_prot, 529 vp[j].ev_flags); 530 } 531 #endif /* DEBUG_EXEC */ 532 if (vcp->ev_flags & VMCMD_BASE) 533 base_vcp = vcp; 534 } 535 536 /* free the vmspace-creation commands, and release their references */ 537 kill_vmcmds(&pack.ep_vmcmds); 538 539 /* if an error happened, deallocate and punt */ 540 if (error) { 541 DPRINTF(("execve: vmcmd %i failed: %d\n", i - 1, error)); 542 goto exec_abort; 543 } 544 545 /* remember information about the process */ 546 arginfo.ps_nargvstr = argc; 547 arginfo.ps_nenvstr = envc; 548 549 stack = (char *) (vm->vm_minsaddr - len); 550 /* Now copy argc, args & environ to new stack */ 551 error = (*pack.ep_es->es_copyargs)(&pack, &arginfo, &stack, argp); 552 if (error) { 553 DPRINTF(("execve: copyargs failed %d\n", error)); 554 goto exec_abort; 555 } 556 /* Move the stack back to original point */ 557 stack = (char *) (vm->vm_minsaddr - len); 558 559 /* fill process ps_strings info */ 560 p->p_psstr = (struct ps_strings *)(vm->vm_minsaddr 561 - sizeof(struct ps_strings)); 562 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 563 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 564 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 565 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 566 567 /* copy out the process's ps_strings structure */ 568 if ((error = copyout(&arginfo, (char *)p->p_psstr, 569 sizeof(arginfo))) != 0) { 570 DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n", 571 &arginfo, (char *)p->p_psstr, (long)sizeof(arginfo))); 572 goto exec_abort; 573 } 574 575 /* copy out the process's signal trapoline code */ 576 if (szsigcode) { 577 if ((error = copyout((char *)pack.ep_es->es_emul->e_sigcode, 578 p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode, 579 szsigcode)) != 0) { 580 DPRINTF(("execve: sig trampoline copyout failed\n")); 581 goto exec_abort; 582 } 583 #ifdef PMAP_NEED_PROCWR 584 /* This is code. Let the pmap do what is needed. */ 585 pmap_procwr(p, (vaddr_t)p->p_sigctx.ps_sigcode, szsigcode); 586 #endif 587 } 588 589 stopprofclock(p); /* stop profiling */ 590 fdcloseexec(p); /* handle close on exec */ 591 execsigs(p); /* reset catched signals */ 592 p->p_ctxlink = NULL; /* reset ucontext link */ 593 594 /* set command name & other accounting info */ 595 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 596 memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len); 597 p->p_comm[len] = 0; 598 p->p_acflag &= ~AFORK; 599 600 /* record proc's vnode, for use by procfs and others */ 601 if (p->p_textvp) 602 vrele(p->p_textvp); 603 VREF(pack.ep_vp); 604 p->p_textvp = pack.ep_vp; 605 606 p->p_flag |= P_EXEC; 607 if (p->p_flag & P_PPWAIT) { 608 p->p_flag &= ~P_PPWAIT; 609 wakeup((caddr_t) p->p_pptr); 610 } 611 612 /* 613 * deal with set[ug]id. 614 * MNT_NOSUID has already been used to disable s[ug]id. 615 */ 616 if ((p->p_flag & P_TRACED) == 0 && 617 618 (((attr.va_mode & S_ISUID) != 0 && 619 p->p_ucred->cr_uid != attr.va_uid) || 620 621 ((attr.va_mode & S_ISGID) != 0 && 622 p->p_ucred->cr_gid != attr.va_gid))) { 623 /* 624 * Mark the process as SUGID before we do 625 * anything that might block. 626 */ 627 p_sugid(p); 628 629 p->p_ucred = crcopy(cred); 630 #ifdef KTRACE 631 /* 632 * If process is being ktraced, turn off - unless 633 * root set it. 634 */ 635 if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT)) 636 ktrderef(p); 637 #endif 638 if (attr.va_mode & S_ISUID) 639 p->p_ucred->cr_uid = attr.va_uid; 640 if (attr.va_mode & S_ISGID) 641 p->p_ucred->cr_gid = attr.va_gid; 642 } else 643 p->p_flag &= ~P_SUGID; 644 p->p_cred->p_svuid = p->p_ucred->cr_uid; 645 p->p_cred->p_svgid = p->p_ucred->cr_gid; 646 647 doexechooks(p); 648 649 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 650 651 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 652 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 653 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 654 vput(pack.ep_vp); 655 656 /* setup new registers and do misc. setup. */ 657 (*pack.ep_es->es_emul->e_setregs)(p, &pack, (u_long) stack); 658 if (pack.ep_es->es_setregs) 659 (*pack.ep_es->es_setregs)(p, &pack, (u_long) stack); 660 661 if (p->p_flag & P_TRACED) 662 psignal(p, SIGTRAP); 663 664 free(pack.ep_hdr, M_EXEC); 665 666 /* 667 * Call emulation specific exec hook. This can setup setup per-process 668 * p->p_emuldata or do any other per-process stuff an emulation needs. 669 * 670 * If we are executing process of different emulation than the 671 * original forked process, call e_proc_exit() of the old emulation 672 * first, then e_proc_exec() of new emulation. If the emulation is 673 * same, the exec hook code should deallocate any old emulation 674 * resources held previously by this process. 675 */ 676 if (p->p_emul && p->p_emul->e_proc_exit 677 && p->p_emul != pack.ep_es->es_emul) 678 (*p->p_emul->e_proc_exit)(p); 679 680 /* 681 * Call exec hook. Emulation code may NOT store reference to anything 682 * from &pack. 683 */ 684 if (pack.ep_es->es_emul->e_proc_exec) 685 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack); 686 687 /* update p_emul, the old value is no longer needed */ 688 p->p_emul = pack.ep_es->es_emul; 689 690 /* ...and the same for p_execsw */ 691 p->p_execsw = pack.ep_es; 692 693 #ifdef __HAVE_SYSCALL_INTERN 694 (*p->p_emul->e_syscall_intern)(p); 695 #endif 696 #ifdef KTRACE 697 if (KTRPOINT(p, KTR_EMUL)) 698 ktremul(p); 699 #endif 700 701 #ifdef LKM 702 lockmgr(&exec_lock, LK_RELEASE, NULL); 703 #endif 704 p->p_flag &= ~P_INEXEC; 705 return (EJUSTRETURN); 706 707 bad: 708 p->p_flag &= ~P_INEXEC; 709 /* free the vmspace-creation commands, and release their references */ 710 kill_vmcmds(&pack.ep_vmcmds); 711 /* kill any opened file descriptor, if necessary */ 712 if (pack.ep_flags & EXEC_HASFD) { 713 pack.ep_flags &= ~EXEC_HASFD; 714 (void) fdrelease(p, pack.ep_fd); 715 } 716 /* close and put the exec'd file */ 717 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 718 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 719 vput(pack.ep_vp); 720 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 721 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 722 723 freehdr: 724 p->p_flag &= ~P_INEXEC; 725 #ifdef LKM 726 lockmgr(&exec_lock, LK_RELEASE, NULL); 727 #endif 728 729 free(pack.ep_hdr, M_EXEC); 730 return error; 731 732 exec_abort: 733 p->p_flag &= ~P_INEXEC; 734 #ifdef LKM 735 lockmgr(&exec_lock, LK_RELEASE, NULL); 736 #endif 737 738 /* 739 * the old process doesn't exist anymore. exit gracefully. 740 * get rid of the (new) address space we have created, if any, get rid 741 * of our namei data and vnode, and exit noting failure 742 */ 743 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 744 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 745 if (pack.ep_emul_arg) 746 FREE(pack.ep_emul_arg, M_TEMP); 747 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 748 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 749 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 750 vput(pack.ep_vp); 751 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 752 free(pack.ep_hdr, M_EXEC); 753 exit1(p, W_EXITCODE(error, SIGABRT)); 754 755 /* NOTREACHED */ 756 return 0; 757 } 758 759 760 int 761 copyargs(struct exec_package *pack, struct ps_strings *arginfo, 762 char **stackp, void *argp) 763 { 764 char **cpp, *dp, *sp; 765 size_t len; 766 void *nullp; 767 long argc, envc; 768 int error; 769 770 cpp = (char **)*stackp; 771 nullp = NULL; 772 argc = arginfo->ps_nargvstr; 773 envc = arginfo->ps_nenvstr; 774 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) 775 return error; 776 777 dp = (char *) (cpp + argc + envc + 2 + pack->ep_es->es_arglen); 778 sp = argp; 779 780 /* XXX don't copy them out, remap them! */ 781 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 782 783 for (; --argc >= 0; sp += len, dp += len) 784 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 785 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 786 return error; 787 788 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 789 return error; 790 791 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 792 793 for (; --envc >= 0; sp += len, dp += len) 794 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 795 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 796 return error; 797 798 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 799 return error; 800 801 *stackp = (char *)cpp; 802 return 0; 803 } 804 805 #ifdef LKM 806 /* 807 * Find an emulation of given name in list of emulations. 808 */ 809 static const struct emul * 810 emul_search(const char *name) 811 { 812 struct emul_entry *it; 813 814 LIST_FOREACH(it, &el_head, el_list) { 815 if (strcmp(name, it->el_emul->e_name) == 0) 816 return it->el_emul; 817 } 818 819 return NULL; 820 } 821 822 /* 823 * Add an emulation to list, if it's not there already. 824 */ 825 int 826 emul_register(const struct emul *emul, int ro_entry) 827 { 828 struct emul_entry *ee; 829 int error; 830 831 error = 0; 832 lockmgr(&exec_lock, LK_SHARED, NULL); 833 834 if (emul_search(emul->e_name)) { 835 error = EEXIST; 836 goto out; 837 } 838 839 MALLOC(ee, struct emul_entry *, sizeof(struct emul_entry), 840 M_EXEC, M_WAITOK); 841 ee->el_emul = emul; 842 ee->ro_entry = ro_entry; 843 LIST_INSERT_HEAD(&el_head, ee, el_list); 844 845 out: 846 lockmgr(&exec_lock, LK_RELEASE, NULL); 847 return error; 848 } 849 850 /* 851 * Remove emulation with name 'name' from list of supported emulations. 852 */ 853 int 854 emul_unregister(const char *name) 855 { 856 const struct proclist_desc *pd; 857 struct emul_entry *it; 858 int i, error; 859 struct proc *ptmp; 860 861 error = 0; 862 lockmgr(&exec_lock, LK_SHARED, NULL); 863 864 LIST_FOREACH(it, &el_head, el_list) { 865 if (strcmp(it->el_emul->e_name, name) == 0) 866 break; 867 } 868 869 if (!it) { 870 error = ENOENT; 871 goto out; 872 } 873 874 if (it->ro_entry) { 875 error = EBUSY; 876 goto out; 877 } 878 879 /* test if any execw[] entry is still using this */ 880 for(i=0; i < nexecs; i++) { 881 if (execsw[i]->es_emul == it->el_emul) { 882 error = EBUSY; 883 goto out; 884 } 885 } 886 887 /* 888 * Test if any process is running under this emulation - since 889 * emul_unregister() is running quite sendomly, it's better 890 * to do expensive check here than to use any locking. 891 */ 892 proclist_lock_read(); 893 for (pd = proclists; pd->pd_list != NULL && !error; pd++) { 894 LIST_FOREACH(ptmp, pd->pd_list, p_list) { 895 if (ptmp->p_emul == it->el_emul) { 896 error = EBUSY; 897 break; 898 } 899 } 900 } 901 proclist_unlock_read(); 902 903 if (error) 904 goto out; 905 906 907 /* entry is not used, remove it */ 908 LIST_REMOVE(it, el_list); 909 FREE(it, M_EXEC); 910 911 out: 912 lockmgr(&exec_lock, LK_RELEASE, NULL); 913 return error; 914 } 915 916 /* 917 * Add execsw[] entry. 918 */ 919 int 920 exec_add(struct execsw *esp, const char *e_name) 921 { 922 struct exec_entry *it; 923 int error; 924 925 error = 0; 926 lockmgr(&exec_lock, LK_EXCLUSIVE, NULL); 927 928 if (!esp->es_emul) { 929 esp->es_emul = emul_search(e_name); 930 if (!esp->es_emul) { 931 error = ENOENT; 932 goto out; 933 } 934 } 935 936 LIST_FOREACH(it, &ex_head, ex_list) { 937 /* assume tuple (makecmds, probe_func, emulation) is unique */ 938 if (it->es->es_check == esp->es_check 939 && it->es->u.elf_probe_func == esp->u.elf_probe_func 940 && it->es->es_emul == esp->es_emul) { 941 error = EEXIST; 942 goto out; 943 } 944 } 945 946 /* if we got here, the entry doesn't exist yet */ 947 MALLOC(it, struct exec_entry *, sizeof(struct exec_entry), 948 M_EXEC, M_WAITOK); 949 it->es = esp; 950 LIST_INSERT_HEAD(&ex_head, it, ex_list); 951 952 /* update execsw[] */ 953 exec_init(0); 954 955 out: 956 lockmgr(&exec_lock, LK_RELEASE, NULL); 957 return error; 958 } 959 960 /* 961 * Remove execsw[] entry. 962 */ 963 int 964 exec_remove(const struct execsw *esp) 965 { 966 struct exec_entry *it; 967 int error; 968 969 error = 0; 970 lockmgr(&exec_lock, LK_EXCLUSIVE, NULL); 971 972 LIST_FOREACH(it, &ex_head, ex_list) { 973 /* assume tuple (makecmds, probe_func, emulation) is unique */ 974 if (it->es->es_check == esp->es_check 975 && it->es->u.elf_probe_func == esp->u.elf_probe_func 976 && it->es->es_emul == esp->es_emul) 977 break; 978 } 979 if (!it) { 980 error = ENOENT; 981 goto out; 982 } 983 984 /* remove item from list and free resources */ 985 LIST_REMOVE(it, ex_list); 986 FREE(it, M_EXEC); 987 988 /* update execsw[] */ 989 exec_init(0); 990 991 out: 992 lockmgr(&exec_lock, LK_RELEASE, NULL); 993 return error; 994 } 995 996 static void 997 link_es(struct execsw_entry **listp, const struct execsw *esp) 998 { 999 struct execsw_entry *et, *e1; 1000 1001 MALLOC(et, struct execsw_entry *, sizeof(struct execsw_entry), 1002 M_TEMP, M_WAITOK); 1003 et->next = NULL; 1004 et->es = esp; 1005 if (*listp == NULL) { 1006 *listp = et; 1007 return; 1008 } 1009 1010 switch(et->es->es_prio) { 1011 case EXECSW_PRIO_FIRST: 1012 /* put new entry as the first */ 1013 et->next = *listp; 1014 *listp = et; 1015 break; 1016 case EXECSW_PRIO_ANY: 1017 /* put new entry after all *_FIRST and *_ANY entries */ 1018 for(e1 = *listp; e1->next 1019 && e1->next->es->es_prio != EXECSW_PRIO_LAST; 1020 e1 = e1->next); 1021 et->next = e1->next; 1022 e1->next = et; 1023 break; 1024 case EXECSW_PRIO_LAST: 1025 /* put new entry as the last one */ 1026 for(e1 = *listp; e1->next; e1 = e1->next); 1027 e1->next = et; 1028 break; 1029 default: 1030 #ifdef DIAGNOSTIC 1031 panic("execw[] entry with unknown priority %d found\n", 1032 et->es->es_prio); 1033 #endif 1034 break; 1035 } 1036 } 1037 1038 /* 1039 * Initialize exec structures. If init_boot is true, also does necessary 1040 * one-time initialization (it's called from main() that way). 1041 * Once system is multiuser, this should be called with exec_lock held, 1042 * i.e. via exec_{add|remove}(). 1043 */ 1044 int 1045 exec_init(int init_boot) 1046 { 1047 const struct execsw **new_es, * const *old_es; 1048 struct execsw_entry *list, *e1; 1049 struct exec_entry *e2; 1050 int i, es_sz; 1051 1052 if (init_boot) { 1053 /* do one-time initializations */ 1054 lockinit(&exec_lock, PWAIT, "execlck", 0, 0); 1055 1056 /* register compiled-in emulations */ 1057 for(i=0; i < nexecs_builtin; i++) { 1058 if (execsw_builtin[i].es_emul) 1059 emul_register(execsw_builtin[i].es_emul, 1); 1060 } 1061 #ifdef DIAGNOSTIC 1062 if (i == 0) 1063 panic("no emulations found in execsw_builtin[]\n"); 1064 #endif 1065 } 1066 1067 /* 1068 * Build execsw[] array from builtin entries and entries added 1069 * at runtime. 1070 */ 1071 list = NULL; 1072 for(i=0; i < nexecs_builtin; i++) 1073 link_es(&list, &execsw_builtin[i]); 1074 1075 /* Add dynamically loaded entries */ 1076 es_sz = nexecs_builtin; 1077 LIST_FOREACH(e2, &ex_head, ex_list) { 1078 link_es(&list, e2->es); 1079 es_sz++; 1080 } 1081 1082 /* 1083 * Now that we have sorted all execw entries, create new execsw[] 1084 * and free no longer needed memory in the process. 1085 */ 1086 new_es = malloc(es_sz * sizeof(struct execsw *), M_EXEC, M_WAITOK); 1087 for(i=0; list; i++) { 1088 new_es[i] = list->es; 1089 e1 = list->next; 1090 FREE(list, M_TEMP); 1091 list = e1; 1092 } 1093 1094 /* 1095 * New execsw[] array built, now replace old execsw[] and free 1096 * used memory. 1097 */ 1098 old_es = execsw; 1099 execsw = new_es; 1100 nexecs = es_sz; 1101 if (old_es) 1102 free((void *)old_es, M_EXEC); 1103 1104 /* 1105 * Figure out the maximum size of an exec header. 1106 */ 1107 exec_maxhdrsz = 0; 1108 for (i = 0; i < nexecs; i++) { 1109 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1110 exec_maxhdrsz = execsw[i]->es_hdrsz; 1111 } 1112 1113 return 0; 1114 } 1115 #endif 1116 1117 #ifndef LKM 1118 /* 1119 * Simplified exec_init() for kernels without LKMs. Only initialize 1120 * exec_maxhdrsz and execsw[]. 1121 */ 1122 int 1123 exec_init(int init_boot) 1124 { 1125 int i; 1126 1127 #ifdef DIAGNOSTIC 1128 if (!init_boot) 1129 panic("exec_init(): called with init_boot == 0"); 1130 #endif 1131 1132 /* do one-time initializations */ 1133 nexecs = nexecs_builtin; 1134 execsw = malloc(nexecs*sizeof(struct execsw *), M_EXEC, M_WAITOK); 1135 1136 /* 1137 * Fill in execsw[] and figure out the maximum size of an exec header. 1138 */ 1139 exec_maxhdrsz = 0; 1140 for(i=0; i < nexecs; i++) { 1141 execsw[i] = &execsw_builtin[i]; 1142 if (execsw_builtin[i].es_hdrsz > exec_maxhdrsz) 1143 exec_maxhdrsz = execsw_builtin[i].es_hdrsz; 1144 } 1145 1146 return 0; 1147 1148 } 1149 #endif /* !LKM */ 1150