1 /* $NetBSD: kern_exec.c,v 1.155 2002/08/28 07:16:35 gmcgarry 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 1.155 2002/08/28 07:16:35 gmcgarry 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/ras.h> 58 #include <sys/signalvar.h> 59 #include <sys/stat.h> 60 #include <sys/syscall.h> 61 62 #include <sys/syscallargs.h> 63 64 #include <uvm/uvm_extern.h> 65 66 #include <machine/cpu.h> 67 #include <machine/reg.h> 68 69 #ifdef DEBUG_EXEC 70 #define DPRINTF(a) uprintf a 71 #else 72 #define DPRINTF(a) 73 #endif /* DEBUG_EXEC */ 74 75 /* 76 * Exec function switch: 77 * 78 * Note that each makecmds function is responsible for loading the 79 * exec package with the necessary functions for any exec-type-specific 80 * handling. 81 * 82 * Functions for specific exec types should be defined in their own 83 * header file. 84 */ 85 extern const struct execsw execsw_builtin[]; 86 extern int nexecs_builtin; 87 static const struct execsw **execsw = NULL; 88 static int nexecs; 89 90 u_int exec_maxhdrsz; /* must not be static - netbsd32 needs it */ 91 92 #ifdef LKM 93 /* list of supported emulations */ 94 static 95 LIST_HEAD(emlist_head, emul_entry) el_head = LIST_HEAD_INITIALIZER(el_head); 96 struct emul_entry { 97 LIST_ENTRY(emul_entry) el_list; 98 const struct emul *el_emul; 99 int ro_entry; 100 }; 101 102 /* list of dynamically loaded execsw entries */ 103 static 104 LIST_HEAD(execlist_head, exec_entry) ex_head = LIST_HEAD_INITIALIZER(ex_head); 105 struct exec_entry { 106 LIST_ENTRY(exec_entry) ex_list; 107 const struct execsw *es; 108 }; 109 110 /* structure used for building execw[] */ 111 struct execsw_entry { 112 struct execsw_entry *next; 113 const struct execsw *es; 114 }; 115 #endif /* LKM */ 116 117 /* NetBSD emul struct */ 118 extern char sigcode[], esigcode[]; 119 #ifdef SYSCALL_DEBUG 120 extern const char * const syscallnames[]; 121 #endif 122 #ifdef __HAVE_SYSCALL_INTERN 123 void syscall_intern(struct proc *); 124 #else 125 void syscall(void); 126 #endif 127 128 const struct emul emul_netbsd = { 129 "netbsd", 130 NULL, /* emulation path */ 131 #ifndef __HAVE_MINIMAL_EMUL 132 EMUL_HAS_SYS___syscall, 133 NULL, 134 SYS_syscall, 135 SYS_MAXSYSCALL, 136 #endif 137 sysent, 138 #ifdef SYSCALL_DEBUG 139 syscallnames, 140 #else 141 NULL, 142 #endif 143 sendsig, 144 trapsignal, 145 sigcode, 146 esigcode, 147 setregs, 148 NULL, 149 NULL, 150 NULL, 151 #ifdef __HAVE_SYSCALL_INTERN 152 syscall_intern, 153 #else 154 syscall, 155 #endif 156 }; 157 158 #ifdef LKM 159 /* 160 * Exec lock. Used to control access to execsw[] structures. 161 * This must not be static so that netbsd32 can access it, too. 162 */ 163 struct lock exec_lock; 164 165 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 > 281 (u_quad_t)p->p_rlimit[RLIMIT_DATA].rlim_cur)) 282 error = ENOMEM; 283 284 if (!error) 285 return (0); 286 } 287 288 /* 289 * free any vmspace-creation commands, 290 * and release their references 291 */ 292 kill_vmcmds(&epp->ep_vmcmds); 293 294 bad2: 295 /* 296 * close and release the vnode, restore the old one, free the 297 * pathname buf, and punt. 298 */ 299 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 300 VOP_CLOSE(vp, FREAD, p->p_ucred, p); 301 vput(vp); 302 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 303 return error; 304 305 bad1: 306 /* 307 * free the namei pathname buffer, and put the vnode 308 * (which we don't yet have open). 309 */ 310 vput(vp); /* was still locked */ 311 PNBUF_PUT(ndp->ni_cnd.cn_pnbuf); 312 return error; 313 } 314 315 /* 316 * exec system call 317 */ 318 /* ARGSUSED */ 319 int 320 sys_execve(struct proc *p, void *v, register_t *retval) 321 { 322 struct sys_execve_args /* { 323 syscallarg(const char *) path; 324 syscallarg(char * const *) argp; 325 syscallarg(char * const *) envp; 326 } */ *uap = v; 327 int error; 328 u_int i; 329 struct exec_package pack; 330 struct nameidata nid; 331 struct vattr attr; 332 struct ucred *cred; 333 char *argp; 334 char * const *cpp; 335 char *dp, *sp; 336 long argc, envc; 337 size_t len; 338 char *stack; 339 struct ps_strings arginfo; 340 struct vmspace *vm; 341 char **tmpfap; 342 int szsigcode; 343 struct exec_vmcmd *base_vcp; 344 345 /* 346 * Lock the process and set the P_INEXEC flag to indicate that 347 * it should be left alone until we're done here. This is 348 * necessary to avoid race conditions - e.g. in ptrace() - 349 * that might allow a local user to illicitly obtain elevated 350 * privileges. 351 */ 352 p->p_flag |= P_INEXEC; 353 354 cred = p->p_ucred; 355 base_vcp = NULL; 356 /* 357 * Init the namei data to point the file user's program name. 358 * This is done here rather than in check_exec(), so that it's 359 * possible to override this settings if any of makecmd/probe 360 * functions call check_exec() recursively - for example, 361 * see exec_script_makecmds(). 362 */ 363 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 364 365 /* 366 * initialize the fields of the exec package. 367 */ 368 pack.ep_name = SCARG(uap, path); 369 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 370 pack.ep_hdrlen = exec_maxhdrsz; 371 pack.ep_hdrvalid = 0; 372 pack.ep_ndp = &nid; 373 pack.ep_emul_arg = NULL; 374 pack.ep_vmcmds.evs_cnt = 0; 375 pack.ep_vmcmds.evs_used = 0; 376 pack.ep_vap = &attr; 377 pack.ep_flags = 0; 378 379 #ifdef LKM 380 lockmgr(&exec_lock, LK_SHARED, NULL); 381 #endif 382 383 /* see if we can run it. */ 384 if ((error = check_exec(p, &pack)) != 0) 385 goto freehdr; 386 387 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 388 389 /* allocate an argument buffer */ 390 argp = (char *) uvm_km_valloc_wait(exec_map, NCARGS); 391 #ifdef DIAGNOSTIC 392 if (argp == (vaddr_t) 0) 393 panic("execve: argp == NULL"); 394 #endif 395 dp = argp; 396 argc = 0; 397 398 /* copy the fake args list, if there's one, freeing it as we go */ 399 if (pack.ep_flags & EXEC_HASARGL) { 400 tmpfap = pack.ep_fa; 401 while (*tmpfap != NULL) { 402 char *cp; 403 404 cp = *tmpfap; 405 while (*cp) 406 *dp++ = *cp++; 407 dp++; 408 409 FREE(*tmpfap, M_EXEC); 410 tmpfap++; argc++; 411 } 412 FREE(pack.ep_fa, M_EXEC); 413 pack.ep_flags &= ~EXEC_HASARGL; 414 } 415 416 /* Now get argv & environment */ 417 if (!(cpp = SCARG(uap, argp))) { 418 error = EINVAL; 419 goto bad; 420 } 421 422 if (pack.ep_flags & EXEC_SKIPARG) 423 cpp++; 424 425 while (1) { 426 len = argp + ARG_MAX - dp; 427 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 428 goto bad; 429 if (!sp) 430 break; 431 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 432 if (error == ENAMETOOLONG) 433 error = E2BIG; 434 goto bad; 435 } 436 dp += len; 437 cpp++; 438 argc++; 439 } 440 441 envc = 0; 442 /* environment need not be there */ 443 if ((cpp = SCARG(uap, envp)) != NULL ) { 444 while (1) { 445 len = argp + ARG_MAX - dp; 446 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 447 goto bad; 448 if (!sp) 449 break; 450 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 451 if (error == ENAMETOOLONG) 452 error = E2BIG; 453 goto bad; 454 } 455 dp += len; 456 cpp++; 457 envc++; 458 } 459 } 460 461 dp = (char *) ALIGN(dp); 462 463 szsigcode = pack.ep_es->es_emul->e_esigcode - 464 pack.ep_es->es_emul->e_sigcode; 465 466 /* Now check if args & environ fit into new stack */ 467 if (pack.ep_flags & EXEC_32) 468 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 469 sizeof(int) + sizeof(int) + dp + STACKGAPLEN + 470 szsigcode + sizeof(struct ps_strings)) - argp; 471 else 472 len = ((argc + envc + 2 + pack.ep_es->es_arglen) * 473 sizeof(char *) + sizeof(int) + dp + STACKGAPLEN + 474 szsigcode + sizeof(struct ps_strings)) - argp; 475 476 len = ALIGN(len); /* make the stack "safely" aligned */ 477 478 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 479 error = ENOMEM; 480 goto bad; 481 } 482 483 /* adjust "active stack depth" for process VSZ */ 484 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 485 486 /* 487 * Do whatever is necessary to prepare the address space 488 * for remapping. Note that this might replace the current 489 * vmspace with another! 490 */ 491 uvmspace_exec(p, pack.ep_vm_minaddr, pack.ep_vm_maxaddr); 492 493 /* Now map address space */ 494 vm = p->p_vmspace; 495 vm->vm_taddr = (char *) pack.ep_taddr; 496 vm->vm_tsize = btoc(pack.ep_tsize); 497 vm->vm_daddr = (char *) pack.ep_daddr; 498 vm->vm_dsize = btoc(pack.ep_dsize); 499 vm->vm_ssize = btoc(pack.ep_ssize); 500 vm->vm_maxsaddr = (char *) pack.ep_maxsaddr; 501 vm->vm_minsaddr = (char *) pack.ep_minsaddr; 502 503 /* create the new process's VM space by running the vmcmds */ 504 #ifdef DIAGNOSTIC 505 if (pack.ep_vmcmds.evs_used == 0) 506 panic("execve: no vmcmds"); 507 #endif 508 for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) { 509 struct exec_vmcmd *vcp; 510 511 vcp = &pack.ep_vmcmds.evs_cmds[i]; 512 if (vcp->ev_flags & VMCMD_RELATIVE) { 513 #ifdef DIAGNOSTIC 514 if (base_vcp == NULL) 515 panic("execve: relative vmcmd with no base"); 516 if (vcp->ev_flags & VMCMD_BASE) 517 panic("execve: illegal base & relative vmcmd"); 518 #endif 519 vcp->ev_addr += base_vcp->ev_addr; 520 } 521 error = (*vcp->ev_proc)(p, vcp); 522 #ifdef DEBUG_EXEC 523 if (error) { 524 int j; 525 struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0]; 526 for (j = 0; j <= i; j++) 527 uprintf( 528 "vmcmd[%d] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n", 529 j, vp[j].ev_addr, vp[j].ev_len, 530 vp[j].ev_offset, vp[j].ev_prot, 531 vp[j].ev_flags); 532 } 533 #endif /* DEBUG_EXEC */ 534 if (vcp->ev_flags & VMCMD_BASE) 535 base_vcp = vcp; 536 } 537 538 /* free the vmspace-creation commands, and release their references */ 539 kill_vmcmds(&pack.ep_vmcmds); 540 541 /* if an error happened, deallocate and punt */ 542 if (error) { 543 DPRINTF(("execve: vmcmd %i failed: %d\n", i - 1, error)); 544 goto exec_abort; 545 } 546 547 /* remember information about the process */ 548 arginfo.ps_nargvstr = argc; 549 arginfo.ps_nenvstr = envc; 550 551 stack = (char *) (vm->vm_minsaddr - len); 552 /* Now copy argc, args & environ to new stack */ 553 error = (*pack.ep_es->es_copyargs)(p, &pack, &arginfo, &stack, argp); 554 if (error) { 555 DPRINTF(("execve: copyargs failed %d\n", error)); 556 goto exec_abort; 557 } 558 /* Move the stack back to original point */ 559 stack = (char *) (vm->vm_minsaddr - len); 560 561 /* fill process ps_strings info */ 562 p->p_psstr = (struct ps_strings *)(vm->vm_minsaddr 563 - sizeof(struct ps_strings)); 564 p->p_psargv = offsetof(struct ps_strings, ps_argvstr); 565 p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr); 566 p->p_psenv = offsetof(struct ps_strings, ps_envstr); 567 p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr); 568 569 /* copy out the process's ps_strings structure */ 570 if ((error = copyout(&arginfo, (char *)p->p_psstr, 571 sizeof(arginfo))) != 0) { 572 DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n", 573 &arginfo, (char *)p->p_psstr, (long)sizeof(arginfo))); 574 goto exec_abort; 575 } 576 577 /* copy out the process's signal trapoline code */ 578 if (szsigcode) { 579 if ((error = copyout((char *)pack.ep_es->es_emul->e_sigcode, 580 p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode, 581 szsigcode)) != 0) { 582 DPRINTF(("execve: sig trampoline copyout failed\n")); 583 goto exec_abort; 584 } 585 #ifdef PMAP_NEED_PROCWR 586 /* This is code. Let the pmap do what is needed. */ 587 pmap_procwr(p, (vaddr_t)p->p_sigctx.ps_sigcode, szsigcode); 588 #endif 589 } 590 591 stopprofclock(p); /* stop profiling */ 592 fdcloseexec(p); /* handle close on exec */ 593 execsigs(p); /* reset catched signals */ 594 p->p_ctxlink = NULL; /* reset ucontext link */ 595 596 /* set command name & other accounting info */ 597 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 598 memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len); 599 p->p_comm[len] = 0; 600 p->p_acflag &= ~AFORK; 601 602 /* record proc's vnode, for use by procfs and others */ 603 if (p->p_textvp) 604 vrele(p->p_textvp); 605 VREF(pack.ep_vp); 606 p->p_textvp = pack.ep_vp; 607 608 p->p_flag |= P_EXEC; 609 if (p->p_flag & P_PPWAIT) { 610 p->p_flag &= ~P_PPWAIT; 611 wakeup((caddr_t) p->p_pptr); 612 } 613 614 /* 615 * deal with set[ug]id. 616 * MNT_NOSUID has already been used to disable s[ug]id. 617 */ 618 if ((p->p_flag & P_TRACED) == 0 && 619 620 (((attr.va_mode & S_ISUID) != 0 && 621 p->p_ucred->cr_uid != attr.va_uid) || 622 623 ((attr.va_mode & S_ISGID) != 0 && 624 p->p_ucred->cr_gid != attr.va_gid))) { 625 /* 626 * Mark the process as SUGID before we do 627 * anything that might block. 628 */ 629 p_sugid(p); 630 631 /* Make sure file descriptors 0..2 are in use. */ 632 if ((error = fdcheckstd(p)) != 0) 633 goto exec_abort; 634 635 p->p_ucred = crcopy(cred); 636 #ifdef KTRACE 637 /* 638 * If process is being ktraced, turn off - unless 639 * root set it. 640 */ 641 if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT)) 642 ktrderef(p); 643 #endif 644 if (attr.va_mode & S_ISUID) 645 p->p_ucred->cr_uid = attr.va_uid; 646 if (attr.va_mode & S_ISGID) 647 p->p_ucred->cr_gid = attr.va_gid; 648 } else 649 p->p_flag &= ~P_SUGID; 650 p->p_cred->p_svuid = p->p_ucred->cr_uid; 651 p->p_cred->p_svgid = p->p_ucred->cr_gid; 652 653 #if defined(__HAVE_RAS) 654 /* 655 * Remove all RASs from the address space. 656 */ 657 ras_purgeall(p); 658 #endif 659 660 doexechooks(p); 661 662 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 663 664 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 665 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 666 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 667 vput(pack.ep_vp); 668 669 /* setup new registers and do misc. setup. */ 670 (*pack.ep_es->es_emul->e_setregs)(p, &pack, (u_long) stack); 671 if (pack.ep_es->es_setregs) 672 (*pack.ep_es->es_setregs)(p, &pack, (u_long) stack); 673 674 if (p->p_flag & P_TRACED) 675 psignal(p, SIGTRAP); 676 677 free(pack.ep_hdr, M_EXEC); 678 679 /* 680 * Call emulation specific exec hook. This can setup setup per-process 681 * p->p_emuldata or do any other per-process stuff an emulation needs. 682 * 683 * If we are executing process of different emulation than the 684 * original forked process, call e_proc_exit() of the old emulation 685 * first, then e_proc_exec() of new emulation. If the emulation is 686 * same, the exec hook code should deallocate any old emulation 687 * resources held previously by this process. 688 */ 689 if (p->p_emul && p->p_emul->e_proc_exit 690 && p->p_emul != pack.ep_es->es_emul) 691 (*p->p_emul->e_proc_exit)(p); 692 693 /* 694 * Call exec hook. Emulation code may NOT store reference to anything 695 * from &pack. 696 */ 697 if (pack.ep_es->es_emul->e_proc_exec) 698 (*pack.ep_es->es_emul->e_proc_exec)(p, &pack); 699 700 /* update p_emul, the old value is no longer needed */ 701 p->p_emul = pack.ep_es->es_emul; 702 703 /* ...and the same for p_execsw */ 704 p->p_execsw = pack.ep_es; 705 706 #ifdef __HAVE_SYSCALL_INTERN 707 (*p->p_emul->e_syscall_intern)(p); 708 #endif 709 #ifdef KTRACE 710 if (KTRPOINT(p, KTR_EMUL)) 711 ktremul(p); 712 #endif 713 714 #ifdef LKM 715 lockmgr(&exec_lock, LK_RELEASE, NULL); 716 #endif 717 p->p_flag &= ~P_INEXEC; 718 return (EJUSTRETURN); 719 720 bad: 721 p->p_flag &= ~P_INEXEC; 722 /* free the vmspace-creation commands, and release their references */ 723 kill_vmcmds(&pack.ep_vmcmds); 724 /* kill any opened file descriptor, if necessary */ 725 if (pack.ep_flags & EXEC_HASFD) { 726 pack.ep_flags &= ~EXEC_HASFD; 727 (void) fdrelease(p, pack.ep_fd); 728 } 729 /* close and put the exec'd file */ 730 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 731 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 732 vput(pack.ep_vp); 733 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 734 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 735 736 freehdr: 737 p->p_flag &= ~P_INEXEC; 738 #ifdef LKM 739 lockmgr(&exec_lock, LK_RELEASE, NULL); 740 #endif 741 742 free(pack.ep_hdr, M_EXEC); 743 return error; 744 745 exec_abort: 746 p->p_flag &= ~P_INEXEC; 747 #ifdef LKM 748 lockmgr(&exec_lock, LK_RELEASE, NULL); 749 #endif 750 751 /* 752 * the old process doesn't exist anymore. exit gracefully. 753 * get rid of the (new) address space we have created, if any, get rid 754 * of our namei data and vnode, and exit noting failure 755 */ 756 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 757 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 758 if (pack.ep_emul_arg) 759 FREE(pack.ep_emul_arg, M_TEMP); 760 PNBUF_PUT(nid.ni_cnd.cn_pnbuf); 761 vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY); 762 VOP_CLOSE(pack.ep_vp, FREAD, cred, p); 763 vput(pack.ep_vp); 764 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 765 free(pack.ep_hdr, M_EXEC); 766 exit1(p, W_EXITCODE(error, SIGABRT)); 767 768 /* NOTREACHED */ 769 return 0; 770 } 771 772 773 int 774 copyargs(struct proc *p, struct exec_package *pack, struct ps_strings *arginfo, 775 char **stackp, void *argp) 776 { 777 char **cpp, *dp, *sp; 778 size_t len; 779 void *nullp; 780 long argc, envc; 781 int error; 782 783 cpp = (char **)*stackp; 784 nullp = NULL; 785 argc = arginfo->ps_nargvstr; 786 envc = arginfo->ps_nenvstr; 787 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) 788 return error; 789 790 dp = (char *) (cpp + argc + envc + 2 + pack->ep_es->es_arglen); 791 sp = argp; 792 793 /* XXX don't copy them out, remap them! */ 794 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 795 796 for (; --argc >= 0; sp += len, dp += len) 797 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 798 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 799 return error; 800 801 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 802 return error; 803 804 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 805 806 for (; --envc >= 0; sp += len, dp += len) 807 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 || 808 (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) 809 return error; 810 811 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) 812 return error; 813 814 *stackp = (char *)cpp; 815 return 0; 816 } 817 818 #ifdef LKM 819 /* 820 * Find an emulation of given name in list of emulations. 821 * Needs to be called with the exec_lock held. 822 */ 823 const struct emul * 824 emul_search(const char *name) 825 { 826 struct emul_entry *it; 827 828 LIST_FOREACH(it, &el_head, el_list) { 829 if (strcmp(name, it->el_emul->e_name) == 0) 830 return it->el_emul; 831 } 832 833 return NULL; 834 } 835 836 /* 837 * Add an emulation to list, if it's not there already. 838 */ 839 int 840 emul_register(const struct emul *emul, int ro_entry) 841 { 842 struct emul_entry *ee; 843 int error; 844 845 error = 0; 846 lockmgr(&exec_lock, LK_SHARED, NULL); 847 848 if (emul_search(emul->e_name)) { 849 error = EEXIST; 850 goto out; 851 } 852 853 MALLOC(ee, struct emul_entry *, sizeof(struct emul_entry), 854 M_EXEC, M_WAITOK); 855 ee->el_emul = emul; 856 ee->ro_entry = ro_entry; 857 LIST_INSERT_HEAD(&el_head, ee, el_list); 858 859 out: 860 lockmgr(&exec_lock, LK_RELEASE, NULL); 861 return error; 862 } 863 864 /* 865 * Remove emulation with name 'name' from list of supported emulations. 866 */ 867 int 868 emul_unregister(const char *name) 869 { 870 const struct proclist_desc *pd; 871 struct emul_entry *it; 872 int i, error; 873 struct proc *ptmp; 874 875 error = 0; 876 lockmgr(&exec_lock, LK_SHARED, NULL); 877 878 LIST_FOREACH(it, &el_head, el_list) { 879 if (strcmp(it->el_emul->e_name, name) == 0) 880 break; 881 } 882 883 if (!it) { 884 error = ENOENT; 885 goto out; 886 } 887 888 if (it->ro_entry) { 889 error = EBUSY; 890 goto out; 891 } 892 893 /* test if any execw[] entry is still using this */ 894 for(i=0; i < nexecs; i++) { 895 if (execsw[i]->es_emul == it->el_emul) { 896 error = EBUSY; 897 goto out; 898 } 899 } 900 901 /* 902 * Test if any process is running under this emulation - since 903 * emul_unregister() is running quite sendomly, it's better 904 * to do expensive check here than to use any locking. 905 */ 906 proclist_lock_read(); 907 for (pd = proclists; pd->pd_list != NULL && !error; pd++) { 908 LIST_FOREACH(ptmp, pd->pd_list, p_list) { 909 if (ptmp->p_emul == it->el_emul) { 910 error = EBUSY; 911 break; 912 } 913 } 914 } 915 proclist_unlock_read(); 916 917 if (error) 918 goto out; 919 920 921 /* entry is not used, remove it */ 922 LIST_REMOVE(it, el_list); 923 FREE(it, M_EXEC); 924 925 out: 926 lockmgr(&exec_lock, LK_RELEASE, NULL); 927 return error; 928 } 929 930 /* 931 * Add execsw[] entry. 932 */ 933 int 934 exec_add(struct execsw *esp, const char *e_name) 935 { 936 struct exec_entry *it; 937 int error; 938 939 error = 0; 940 lockmgr(&exec_lock, LK_EXCLUSIVE, NULL); 941 942 if (!esp->es_emul) { 943 esp->es_emul = emul_search(e_name); 944 if (!esp->es_emul) { 945 error = ENOENT; 946 goto out; 947 } 948 } 949 950 LIST_FOREACH(it, &ex_head, ex_list) { 951 /* assume tuple (makecmds, probe_func, emulation) is unique */ 952 if (it->es->es_check == esp->es_check 953 && it->es->u.elf_probe_func == esp->u.elf_probe_func 954 && it->es->es_emul == esp->es_emul) { 955 error = EEXIST; 956 goto out; 957 } 958 } 959 960 /* if we got here, the entry doesn't exist yet */ 961 MALLOC(it, struct exec_entry *, sizeof(struct exec_entry), 962 M_EXEC, M_WAITOK); 963 it->es = esp; 964 LIST_INSERT_HEAD(&ex_head, it, ex_list); 965 966 /* update execsw[] */ 967 exec_init(0); 968 969 out: 970 lockmgr(&exec_lock, LK_RELEASE, NULL); 971 return error; 972 } 973 974 /* 975 * Remove execsw[] entry. 976 */ 977 int 978 exec_remove(const struct execsw *esp) 979 { 980 struct exec_entry *it; 981 int error; 982 983 error = 0; 984 lockmgr(&exec_lock, LK_EXCLUSIVE, NULL); 985 986 LIST_FOREACH(it, &ex_head, ex_list) { 987 /* assume tuple (makecmds, probe_func, emulation) is unique */ 988 if (it->es->es_check == esp->es_check 989 && it->es->u.elf_probe_func == esp->u.elf_probe_func 990 && it->es->es_emul == esp->es_emul) 991 break; 992 } 993 if (!it) { 994 error = ENOENT; 995 goto out; 996 } 997 998 /* remove item from list and free resources */ 999 LIST_REMOVE(it, ex_list); 1000 FREE(it, M_EXEC); 1001 1002 /* update execsw[] */ 1003 exec_init(0); 1004 1005 out: 1006 lockmgr(&exec_lock, LK_RELEASE, NULL); 1007 return error; 1008 } 1009 1010 static void 1011 link_es(struct execsw_entry **listp, const struct execsw *esp) 1012 { 1013 struct execsw_entry *et, *e1; 1014 1015 MALLOC(et, struct execsw_entry *, sizeof(struct execsw_entry), 1016 M_TEMP, M_WAITOK); 1017 et->next = NULL; 1018 et->es = esp; 1019 if (*listp == NULL) { 1020 *listp = et; 1021 return; 1022 } 1023 1024 switch(et->es->es_prio) { 1025 case EXECSW_PRIO_FIRST: 1026 /* put new entry as the first */ 1027 et->next = *listp; 1028 *listp = et; 1029 break; 1030 case EXECSW_PRIO_ANY: 1031 /* put new entry after all *_FIRST and *_ANY entries */ 1032 for(e1 = *listp; e1->next 1033 && e1->next->es->es_prio != EXECSW_PRIO_LAST; 1034 e1 = e1->next); 1035 et->next = e1->next; 1036 e1->next = et; 1037 break; 1038 case EXECSW_PRIO_LAST: 1039 /* put new entry as the last one */ 1040 for(e1 = *listp; e1->next; e1 = e1->next); 1041 e1->next = et; 1042 break; 1043 default: 1044 #ifdef DIAGNOSTIC 1045 panic("execw[] entry with unknown priority %d found\n", 1046 et->es->es_prio); 1047 #endif 1048 break; 1049 } 1050 } 1051 1052 /* 1053 * Initialize exec structures. If init_boot is true, also does necessary 1054 * one-time initialization (it's called from main() that way). 1055 * Once system is multiuser, this should be called with exec_lock held, 1056 * i.e. via exec_{add|remove}(). 1057 */ 1058 int 1059 exec_init(int init_boot) 1060 { 1061 const struct execsw **new_es, * const *old_es; 1062 struct execsw_entry *list, *e1; 1063 struct exec_entry *e2; 1064 int i, es_sz; 1065 1066 if (init_boot) { 1067 /* do one-time initializations */ 1068 lockinit(&exec_lock, PWAIT, "execlck", 0, 0); 1069 1070 /* register compiled-in emulations */ 1071 for(i=0; i < nexecs_builtin; i++) { 1072 if (execsw_builtin[i].es_emul) 1073 emul_register(execsw_builtin[i].es_emul, 1); 1074 } 1075 #ifdef DIAGNOSTIC 1076 if (i == 0) 1077 panic("no emulations found in execsw_builtin[]\n"); 1078 #endif 1079 } 1080 1081 /* 1082 * Build execsw[] array from builtin entries and entries added 1083 * at runtime. 1084 */ 1085 list = NULL; 1086 for(i=0; i < nexecs_builtin; i++) 1087 link_es(&list, &execsw_builtin[i]); 1088 1089 /* Add dynamically loaded entries */ 1090 es_sz = nexecs_builtin; 1091 LIST_FOREACH(e2, &ex_head, ex_list) { 1092 link_es(&list, e2->es); 1093 es_sz++; 1094 } 1095 1096 /* 1097 * Now that we have sorted all execw entries, create new execsw[] 1098 * and free no longer needed memory in the process. 1099 */ 1100 new_es = malloc(es_sz * sizeof(struct execsw *), M_EXEC, M_WAITOK); 1101 for(i=0; list; i++) { 1102 new_es[i] = list->es; 1103 e1 = list->next; 1104 FREE(list, M_TEMP); 1105 list = e1; 1106 } 1107 1108 /* 1109 * New execsw[] array built, now replace old execsw[] and free 1110 * used memory. 1111 */ 1112 old_es = execsw; 1113 execsw = new_es; 1114 nexecs = es_sz; 1115 if (old_es) 1116 free((void *)old_es, M_EXEC); 1117 1118 /* 1119 * Figure out the maximum size of an exec header. 1120 */ 1121 exec_maxhdrsz = 0; 1122 for (i = 0; i < nexecs; i++) { 1123 if (execsw[i]->es_hdrsz > exec_maxhdrsz) 1124 exec_maxhdrsz = execsw[i]->es_hdrsz; 1125 } 1126 1127 return 0; 1128 } 1129 #endif 1130 1131 #ifndef LKM 1132 /* 1133 * Simplified exec_init() for kernels without LKMs. Only initialize 1134 * exec_maxhdrsz and execsw[]. 1135 */ 1136 int 1137 exec_init(int init_boot) 1138 { 1139 int i; 1140 1141 #ifdef DIAGNOSTIC 1142 if (!init_boot) 1143 panic("exec_init(): called with init_boot == 0"); 1144 #endif 1145 1146 /* do one-time initializations */ 1147 nexecs = nexecs_builtin; 1148 execsw = malloc(nexecs*sizeof(struct execsw *), M_EXEC, M_WAITOK); 1149 1150 /* 1151 * Fill in execsw[] and figure out the maximum size of an exec header. 1152 */ 1153 exec_maxhdrsz = 0; 1154 for(i=0; i < nexecs; i++) { 1155 execsw[i] = &execsw_builtin[i]; 1156 if (execsw_builtin[i].es_hdrsz > exec_maxhdrsz) 1157 exec_maxhdrsz = execsw_builtin[i].es_hdrsz; 1158 } 1159 1160 return 0; 1161 1162 } 1163 #endif /* !LKM */ 1164