1 /* $OpenBSD: kern_exec.c,v 1.149 2014/11/18 02:37:31 tedu Exp $ */ 2 /* $NetBSD: kern_exec.c,v 1.75 1996/02/09 18:59:28 christos Exp $ */ 3 4 /*- 5 * Copyright (C) 1993, 1994 Christopher G. Demetriou 6 * Copyright (C) 1992 Wolfgang Solfrank. 7 * Copyright (C) 1992 TooLs GmbH. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by TooLs GmbH. 21 * 4. The name of TooLs GmbH may not be used to endorse or promote products 22 * derived from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 29 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 30 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 32 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 33 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/filedesc.h> 39 #include <sys/kernel.h> 40 #include <sys/proc.h> 41 #include <sys/mount.h> 42 #include <sys/malloc.h> 43 #include <sys/pool.h> 44 #include <sys/namei.h> 45 #include <sys/vnode.h> 46 #include <sys/file.h> 47 #include <sys/acct.h> 48 #include <sys/exec.h> 49 #include <sys/ktrace.h> 50 #include <sys/resourcevar.h> 51 #include <sys/wait.h> 52 #include <sys/mman.h> 53 #include <sys/signalvar.h> 54 #include <sys/stat.h> 55 #include <sys/conf.h> 56 #ifdef SYSVSHM 57 #include <sys/shm.h> 58 #endif 59 60 #include <sys/syscallargs.h> 61 62 #include <machine/reg.h> 63 64 #ifdef __HAVE_MD_TCB 65 # include <machine/tcb.h> 66 #endif 67 68 #include "systrace.h" 69 70 #if NSYSTRACE > 0 71 #include <dev/systrace.h> 72 #endif 73 74 const struct kmem_va_mode kv_exec = { 75 .kv_wait = 1, 76 .kv_map = &exec_map 77 }; 78 79 /* 80 * Map the shared signal code. 81 */ 82 int exec_sigcode_map(struct process *, struct emul *); 83 84 /* 85 * If non-zero, stackgap_random specifies the upper limit of the random gap size 86 * added to the fixed stack gap. Must be n^2. 87 */ 88 int stackgap_random = STACKGAP_RANDOM; 89 90 /* 91 * check exec: 92 * given an "executable" described in the exec package's namei info, 93 * see what we can do with it. 94 * 95 * ON ENTRY: 96 * exec package with appropriate namei info 97 * proc pointer of exec'ing proc 98 * NO SELF-LOCKED VNODES 99 * 100 * ON EXIT: 101 * error: nothing held, etc. exec header still allocated. 102 * ok: filled exec package, one locked vnode. 103 * 104 * EXEC SWITCH ENTRY: 105 * Locked vnode to check, exec package, proc. 106 * 107 * EXEC SWITCH EXIT: 108 * ok: return 0, filled exec package, one locked vnode. 109 * error: destructive: 110 * everything deallocated except exec header. 111 * non-destructive: 112 * error code, locked vnode, exec header unmodified 113 */ 114 int 115 check_exec(struct proc *p, struct exec_package *epp) 116 { 117 int error, i; 118 struct vnode *vp; 119 struct nameidata *ndp; 120 size_t resid; 121 122 ndp = epp->ep_ndp; 123 ndp->ni_cnd.cn_nameiop = LOOKUP; 124 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME; 125 /* first get the vnode */ 126 if ((error = namei(ndp)) != 0) 127 return (error); 128 epp->ep_vp = vp = ndp->ni_vp; 129 130 /* check for regular file */ 131 if (vp->v_type == VDIR) { 132 error = EISDIR; 133 goto bad1; 134 } 135 if (vp->v_type != VREG) { 136 error = EACCES; 137 goto bad1; 138 } 139 140 /* get attributes */ 141 if ((error = VOP_GETATTR(vp, epp->ep_vap, p->p_ucred, p)) != 0) 142 goto bad1; 143 144 /* Check mount point */ 145 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 146 error = EACCES; 147 goto bad1; 148 } 149 150 if ((vp->v_mount->mnt_flag & MNT_NOSUID)) 151 epp->ep_vap->va_mode &= ~(VSUID | VSGID); 152 153 /* check access. for root we have to see if any exec bit on */ 154 if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0) 155 goto bad1; 156 if ((epp->ep_vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0) { 157 error = EACCES; 158 goto bad1; 159 } 160 161 /* try to open it */ 162 if ((error = VOP_OPEN(vp, FREAD, p->p_ucred, p)) != 0) 163 goto bad1; 164 165 /* unlock vp, we need it unlocked from here */ 166 VOP_UNLOCK(vp, 0, p); 167 168 /* now we have the file, get the exec header */ 169 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 170 UIO_SYSSPACE, 0, p->p_ucred, &resid, p); 171 if (error) 172 goto bad2; 173 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 174 175 /* 176 * set up the vmcmds for creation of the process 177 * address space 178 */ 179 error = ENOEXEC; 180 for (i = 0; i < nexecs && error != 0; i++) { 181 int newerror; 182 183 if (execsw[i].es_check == NULL) 184 continue; 185 newerror = (*execsw[i].es_check)(p, epp); 186 if (!newerror && !(epp->ep_emul->e_flags & EMUL_ENABLED)) 187 newerror = EPERM; 188 /* make sure the first "interesting" error code is saved. */ 189 if (!newerror || error == ENOEXEC) 190 error = newerror; 191 if (epp->ep_flags & EXEC_DESTR && error != 0) 192 return (error); 193 } 194 if (!error) { 195 /* check that entry point is sane */ 196 if (epp->ep_entry > VM_MAXUSER_ADDRESS) { 197 error = ENOEXEC; 198 } 199 200 /* check limits */ 201 if ((epp->ep_tsize > MAXTSIZ) || 202 (epp->ep_dsize > p->p_rlimit[RLIMIT_DATA].rlim_cur)) 203 error = ENOMEM; 204 205 if (!error) 206 return (0); 207 } 208 209 /* 210 * free any vmspace-creation commands, 211 * and release their references 212 */ 213 kill_vmcmds(&epp->ep_vmcmds); 214 215 bad2: 216 /* 217 * close the vnode, free the pathname buf, and punt. 218 */ 219 vn_close(vp, FREAD, p->p_ucred, p); 220 pool_put(&namei_pool, ndp->ni_cnd.cn_pnbuf); 221 return (error); 222 223 bad1: 224 /* 225 * free the namei pathname buffer, and put the vnode 226 * (which we don't yet have open). 227 */ 228 pool_put(&namei_pool, ndp->ni_cnd.cn_pnbuf); 229 vput(vp); 230 return (error); 231 } 232 233 /* 234 * exec system call 235 */ 236 /* ARGSUSED */ 237 int 238 sys_execve(struct proc *p, void *v, register_t *retval) 239 { 240 struct sys_execve_args /* { 241 syscallarg(const char *) path; 242 syscallarg(char *const *) argp; 243 syscallarg(char *const *) envp; 244 } */ *uap = v; 245 int error; 246 struct exec_package pack; 247 struct nameidata nid; 248 struct vattr attr; 249 struct ucred *cred = p->p_ucred; 250 char *argp; 251 char * const *cpp, *dp, *sp; 252 struct process *pr = p->p_p; 253 long argc, envc; 254 size_t len, sgap; 255 #ifdef MACHINE_STACK_GROWS_UP 256 size_t slen; 257 #endif 258 char *stack; 259 struct ps_strings arginfo; 260 struct vmspace *vm = pr->ps_vmspace; 261 char **tmpfap; 262 extern struct emul emul_native; 263 #if NSYSTRACE > 0 264 int wassugid = ISSET(pr->ps_flags, PS_SUGID | PS_SUGIDEXEC); 265 size_t pathbuflen; 266 #endif 267 char *pathbuf = NULL; 268 struct vnode *otvp; 269 270 /* get other threads to stop */ 271 if ((error = single_thread_set(p, SINGLE_UNWIND, 1))) 272 return (error); 273 274 /* 275 * Cheap solution to complicated problems. 276 * Mark this process as "leave me alone, I'm execing". 277 */ 278 atomic_setbits_int(&pr->ps_flags, PS_INEXEC); 279 280 #if NSYSTRACE > 0 281 if (ISSET(p->p_flag, P_SYSTRACE)) { 282 systrace_execve0(p); 283 pathbuf = pool_get(&namei_pool, PR_WAITOK); 284 error = copyinstr(SCARG(uap, path), pathbuf, MAXPATHLEN, 285 &pathbuflen); 286 if (error != 0) 287 goto clrflag; 288 } 289 #endif 290 if (pathbuf != NULL) { 291 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, p); 292 } else { 293 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, 294 SCARG(uap, path), p); 295 } 296 297 /* 298 * initialize the fields of the exec package. 299 */ 300 if (pathbuf != NULL) 301 pack.ep_name = pathbuf; 302 else 303 pack.ep_name = (char *)SCARG(uap, path); 304 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 305 pack.ep_hdrlen = exec_maxhdrsz; 306 pack.ep_hdrvalid = 0; 307 pack.ep_ndp = &nid; 308 pack.ep_interp = NULL; 309 pack.ep_emul_arg = NULL; 310 VMCMDSET_INIT(&pack.ep_vmcmds); 311 pack.ep_vap = &attr; 312 pack.ep_emul = &emul_native; 313 pack.ep_flags = 0; 314 315 /* see if we can run it. */ 316 if ((error = check_exec(p, &pack)) != 0) { 317 goto freehdr; 318 } 319 320 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 321 322 /* allocate an argument buffer */ 323 argp = km_alloc(NCARGS, &kv_exec, &kp_pageable, &kd_waitok); 324 #ifdef DIAGNOSTIC 325 if (argp == NULL) 326 panic("execve: argp == NULL"); 327 #endif 328 dp = argp; 329 argc = 0; 330 331 /* copy the fake args list, if there's one, freeing it as we go */ 332 if (pack.ep_flags & EXEC_HASARGL) { 333 tmpfap = pack.ep_fa; 334 while (*tmpfap != NULL) { 335 char *cp; 336 337 cp = *tmpfap; 338 while (*cp) 339 *dp++ = *cp++; 340 *dp++ = '\0'; 341 342 free(*tmpfap, M_EXEC, 0); 343 tmpfap++; argc++; 344 } 345 free(pack.ep_fa, M_EXEC, 0); 346 pack.ep_flags &= ~EXEC_HASARGL; 347 } 348 349 /* Now get argv & environment */ 350 if (!(cpp = SCARG(uap, argp))) { 351 error = EFAULT; 352 goto bad; 353 } 354 355 if (pack.ep_flags & EXEC_SKIPARG) 356 cpp++; 357 358 while (1) { 359 len = argp + ARG_MAX - dp; 360 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 361 goto bad; 362 if (!sp) 363 break; 364 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 365 if (error == ENAMETOOLONG) 366 error = E2BIG; 367 goto bad; 368 } 369 dp += len; 370 cpp++; 371 argc++; 372 } 373 374 envc = 0; 375 /* environment does not need to be there */ 376 if ((cpp = SCARG(uap, envp)) != NULL ) { 377 while (1) { 378 len = argp + ARG_MAX - dp; 379 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 380 goto bad; 381 if (!sp) 382 break; 383 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 384 if (error == ENAMETOOLONG) 385 error = E2BIG; 386 goto bad; 387 } 388 dp += len; 389 cpp++; 390 envc++; 391 } 392 } 393 394 dp = (char *)(((long)dp + _STACKALIGNBYTES) & ~_STACKALIGNBYTES); 395 396 sgap = STACKGAPLEN; 397 if (stackgap_random != 0) { 398 sgap += arc4random() & (stackgap_random - 1); 399 sgap = (sgap + _STACKALIGNBYTES) & ~_STACKALIGNBYTES; 400 } 401 402 /* Now check if args & environ fit into new stack */ 403 len = ((argc + envc + 2 + pack.ep_emul->e_arglen) * sizeof(char *) + 404 sizeof(long) + dp + sgap + sizeof(struct ps_strings)) - argp; 405 406 len = (len + _STACKALIGNBYTES) &~ _STACKALIGNBYTES; 407 408 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 409 error = ENOMEM; 410 goto bad; 411 } 412 413 /* adjust "active stack depth" for process VSZ */ 414 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 415 416 /* 417 * we're committed: any further errors will kill the process, so 418 * kill the other threads now. 419 */ 420 single_thread_set(p, SINGLE_EXIT, 0); 421 422 /* 423 * Prepare vmspace for remapping. Note that uvmspace_exec can replace 424 * pr_vmspace! 425 */ 426 uvmspace_exec(p, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS); 427 428 vm = pr->ps_vmspace; 429 /* Now map address space */ 430 vm->vm_taddr = (char *)trunc_page(pack.ep_taddr); 431 vm->vm_tsize = atop(round_page(pack.ep_taddr + pack.ep_tsize) - 432 trunc_page(pack.ep_taddr)); 433 vm->vm_daddr = (char *)trunc_page(pack.ep_daddr); 434 vm->vm_dsize = atop(round_page(pack.ep_daddr + pack.ep_dsize) - 435 trunc_page(pack.ep_daddr)); 436 vm->vm_dused = 0; 437 vm->vm_ssize = atop(round_page(pack.ep_ssize)); 438 vm->vm_maxsaddr = (char *)pack.ep_maxsaddr; 439 vm->vm_minsaddr = (char *)pack.ep_minsaddr; 440 441 /* create the new process's VM space by running the vmcmds */ 442 #ifdef DIAGNOSTIC 443 if (pack.ep_vmcmds.evs_used == 0) 444 panic("execve: no vmcmds"); 445 #endif 446 error = exec_process_vmcmds(p, &pack); 447 448 /* if an error happened, deallocate and punt */ 449 if (error) 450 goto exec_abort; 451 452 /* remember information about the process */ 453 arginfo.ps_nargvstr = argc; 454 arginfo.ps_nenvstr = envc; 455 456 #ifdef MACHINE_STACK_GROWS_UP 457 stack = (char *)USRSTACK + sizeof(arginfo) + sgap; 458 slen = len - sizeof(arginfo) - sgap; 459 #else 460 stack = (char *)(USRSTACK - len); 461 #endif 462 /* Now copy argc, args & environ to new stack */ 463 if (!(*pack.ep_emul->e_copyargs)(&pack, &arginfo, stack, argp)) 464 goto exec_abort; 465 466 /* copy out the process's ps_strings structure */ 467 if (copyout(&arginfo, (char *)PS_STRINGS, sizeof(arginfo))) 468 goto exec_abort; 469 470 stopprofclock(pr); /* stop profiling */ 471 fdcloseexec(p); /* handle close on exec */ 472 execsigs(p); /* reset caught signals */ 473 TCB_SET(p, NULL); /* reset the TCB address */ 474 475 /* set command name & other accounting info */ 476 memset(p->p_comm, 0, sizeof(p->p_comm)); 477 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 478 bcopy(nid.ni_cnd.cn_nameptr, p->p_comm, len); 479 pr->ps_acflag &= ~AFORK; 480 481 /* record proc's vnode, for use by sysctl */ 482 otvp = pr->ps_textvp; 483 vref(pack.ep_vp); 484 pr->ps_textvp = pack.ep_vp; 485 if (otvp) 486 vrele(otvp); 487 488 atomic_setbits_int(&pr->ps_flags, PS_EXEC); 489 if (pr->ps_flags & PS_PPWAIT) { 490 atomic_clearbits_int(&pr->ps_flags, PS_PPWAIT); 491 atomic_clearbits_int(&pr->ps_pptr->ps_flags, PS_ISPWAIT); 492 wakeup(pr->ps_pptr); 493 } 494 495 /* 496 * If process does execve() while it has a mismatched real, 497 * effective, or saved uid/gid, we set PS_SUGIDEXEC. 498 */ 499 if (cred->cr_uid != cred->cr_ruid || 500 cred->cr_uid != cred->cr_svuid || 501 cred->cr_gid != cred->cr_rgid || 502 cred->cr_gid != cred->cr_svgid) 503 atomic_setbits_int(&pr->ps_flags, PS_SUGIDEXEC); 504 else 505 atomic_clearbits_int(&pr->ps_flags, PS_SUGIDEXEC); 506 507 /* 508 * deal with set[ug]id. 509 * MNT_NOEXEC has already been used to disable s[ug]id. 510 */ 511 if ((attr.va_mode & (VSUID | VSGID)) && proc_cansugid(p)) { 512 int i; 513 514 atomic_setbits_int(&pr->ps_flags, PS_SUGID|PS_SUGIDEXEC); 515 516 #ifdef KTRACE 517 /* 518 * If process is being ktraced, turn off - unless 519 * root set it. 520 */ 521 if (pr->ps_tracevp && !(pr->ps_traceflag & KTRFAC_ROOT)) 522 ktrcleartrace(pr); 523 #endif 524 p->p_ucred = cred = crcopy(cred); 525 if (attr.va_mode & VSUID) 526 cred->cr_uid = attr.va_uid; 527 if (attr.va_mode & VSGID) 528 cred->cr_gid = attr.va_gid; 529 530 /* 531 * For set[ug]id processes, a few caveats apply to 532 * stdin, stdout, and stderr. 533 */ 534 error = 0; 535 fdplock(p->p_fd); 536 for (i = 0; i < 3; i++) { 537 struct file *fp = NULL; 538 539 /* 540 * NOTE - This will never return NULL because of 541 * immature fds. The file descriptor table is not 542 * shared because we're suid. 543 */ 544 fp = fd_getfile(p->p_fd, i); 545 546 /* 547 * Ensure that stdin, stdout, and stderr are already 548 * allocated. We do not want userland to accidentally 549 * allocate descriptors in this range which has implied 550 * meaning to libc. 551 */ 552 if (fp == NULL) { 553 short flags = FREAD | (i == 0 ? 0 : FWRITE); 554 struct vnode *vp; 555 int indx; 556 557 if ((error = falloc(p, &fp, &indx)) != 0) 558 break; 559 #ifdef DIAGNOSTIC 560 if (indx != i) 561 panic("sys_execve: falloc indx != i"); 562 #endif 563 if ((error = cdevvp(getnulldev(), &vp)) != 0) { 564 fdremove(p->p_fd, indx); 565 closef(fp, p); 566 break; 567 } 568 if ((error = VOP_OPEN(vp, flags, cred, p)) != 0) { 569 fdremove(p->p_fd, indx); 570 closef(fp, p); 571 vrele(vp); 572 break; 573 } 574 if (flags & FWRITE) 575 vp->v_writecount++; 576 fp->f_flag = flags; 577 fp->f_type = DTYPE_VNODE; 578 fp->f_ops = &vnops; 579 fp->f_data = (caddr_t)vp; 580 FILE_SET_MATURE(fp, p); 581 } 582 } 583 fdpunlock(p->p_fd); 584 if (error) 585 goto exec_abort; 586 } else 587 atomic_clearbits_int(&pr->ps_flags, PS_SUGID); 588 589 /* 590 * Reset the saved ugids and update the process's copy of the 591 * creds if the creds have been changed 592 */ 593 if (cred->cr_uid != cred->cr_svuid || 594 cred->cr_gid != cred->cr_svgid) { 595 /* make sure we have unshared ucreds */ 596 p->p_ucred = cred = crcopy(cred); 597 cred->cr_svuid = cred->cr_uid; 598 cred->cr_svgid = cred->cr_gid; 599 } 600 601 if (pr->ps_ucred != cred) { 602 struct ucred *ocred; 603 604 ocred = pr->ps_ucred; 605 crhold(cred); 606 pr->ps_ucred = cred; 607 crfree(ocred); 608 } 609 610 if (pr->ps_flags & PS_SUGIDEXEC) { 611 int i, s = splclock(); 612 613 timeout_del(&pr->ps_realit_to); 614 for (i = 0; i < nitems(pr->ps_timer); i++) { 615 timerclear(&pr->ps_timer[i].it_interval); 616 timerclear(&pr->ps_timer[i].it_value); 617 } 618 splx(s); 619 } 620 621 /* reset CPU time usage for the thread, but not the process */ 622 timespecclear(&p->p_tu.tu_runtime); 623 p->p_tu.tu_uticks = p->p_tu.tu_sticks = p->p_tu.tu_iticks = 0; 624 625 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 626 627 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 628 vn_close(pack.ep_vp, FREAD, cred, p); 629 630 /* 631 * notify others that we exec'd 632 */ 633 KNOTE(&pr->ps_klist, NOTE_EXEC); 634 635 /* setup new registers and do misc. setup. */ 636 if (pack.ep_emul->e_fixup != NULL) { 637 if ((*pack.ep_emul->e_fixup)(p, &pack) != 0) 638 goto free_pack_abort; 639 } 640 #ifdef MACHINE_STACK_GROWS_UP 641 (*pack.ep_emul->e_setregs)(p, &pack, (u_long)stack + slen, retval); 642 #else 643 (*pack.ep_emul->e_setregs)(p, &pack, (u_long)stack, retval); 644 #endif 645 646 /* map the process's signal trampoline code */ 647 if (exec_sigcode_map(pr, pack.ep_emul)) 648 goto free_pack_abort; 649 650 #ifdef __HAVE_EXEC_MD_MAP 651 /* perform md specific mappings that process might need */ 652 if (exec_md_map(p, &pack)) 653 goto free_pack_abort; 654 #endif 655 656 if (pr->ps_flags & PS_TRACED) 657 psignal(p, SIGTRAP); 658 659 free(pack.ep_hdr, M_EXEC, 0); 660 661 /* 662 * Call emulation specific exec hook. This can setup per-process 663 * p->p_emuldata or do any other per-process stuff an emulation needs. 664 * 665 * If we are executing process of different emulation than the 666 * original forked process, call e_proc_exit() of the old emulation 667 * first, then e_proc_exec() of new emulation. If the emulation is 668 * same, the exec hook code should deallocate any old emulation 669 * resources held previously by this process. 670 */ 671 if (pr->ps_emul && pr->ps_emul->e_proc_exit && 672 pr->ps_emul != pack.ep_emul) 673 (*pr->ps_emul->e_proc_exit)(p); 674 675 p->p_descfd = 255; 676 if ((pack.ep_flags & EXEC_HASFD) && pack.ep_fd < 255) 677 p->p_descfd = pack.ep_fd; 678 679 /* 680 * Call exec hook. Emulation code may NOT store reference to anything 681 * from &pack. 682 */ 683 if (pack.ep_emul->e_proc_exec) 684 (*pack.ep_emul->e_proc_exec)(p, &pack); 685 686 /* update ps_emul, the old value is no longer needed */ 687 pr->ps_emul = pack.ep_emul; 688 689 #ifdef KTRACE 690 if (KTRPOINT(p, KTR_EMUL)) 691 ktremul(p); 692 #endif 693 694 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 695 single_thread_clear(p, P_SUSPSIG); 696 697 #if NSYSTRACE > 0 698 if (ISSET(p->p_flag, P_SYSTRACE) && 699 wassugid && !ISSET(pr->ps_flags, PS_SUGID | PS_SUGIDEXEC)) 700 systrace_execve1(pathbuf, p); 701 #endif 702 703 if (pathbuf != NULL) 704 pool_put(&namei_pool, pathbuf); 705 706 return (0); 707 708 bad: 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 fdplock(p->p_fd); 715 (void) fdrelease(p, pack.ep_fd); 716 fdpunlock(p->p_fd); 717 } 718 if (pack.ep_interp != NULL) 719 pool_put(&namei_pool, pack.ep_interp); 720 if (pack.ep_emul_arg != NULL) 721 free(pack.ep_emul_arg, M_TEMP, 0); 722 /* close and put the exec'd file */ 723 vn_close(pack.ep_vp, FREAD, cred, p); 724 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 725 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 726 727 freehdr: 728 free(pack.ep_hdr, M_EXEC, 0); 729 #if NSYSTRACE > 0 730 clrflag: 731 #endif 732 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 733 single_thread_clear(p, P_SUSPSIG); 734 735 if (pathbuf != NULL) 736 pool_put(&namei_pool, pathbuf); 737 738 return (error); 739 740 exec_abort: 741 /* 742 * the old process doesn't exist anymore. exit gracefully. 743 * get rid of the (new) address space we have created, if any, get rid 744 * of our namei data and vnode, and exit noting failure 745 */ 746 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 747 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 748 if (pack.ep_interp != NULL) 749 pool_put(&namei_pool, pack.ep_interp); 750 if (pack.ep_emul_arg != NULL) 751 free(pack.ep_emul_arg, M_TEMP, 0); 752 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 753 vn_close(pack.ep_vp, FREAD, cred, p); 754 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 755 756 free_pack_abort: 757 free(pack.ep_hdr, M_EXEC, 0); 758 exit1(p, W_EXITCODE(0, SIGABRT), EXIT_NORMAL); 759 760 /* NOTREACHED */ 761 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 762 if (pathbuf != NULL) 763 pool_put(&namei_pool, pathbuf); 764 765 return (0); 766 } 767 768 769 void * 770 copyargs(struct exec_package *pack, struct ps_strings *arginfo, void *stack, 771 void *argp) 772 { 773 char **cpp = stack; 774 char *dp, *sp; 775 size_t len; 776 void *nullp = NULL; 777 long argc = arginfo->ps_nargvstr; 778 int envc = arginfo->ps_nenvstr; 779 780 if (copyout(&argc, cpp++, sizeof(argc))) 781 return (NULL); 782 783 dp = (char *) (cpp + argc + envc + 2 + pack->ep_emul->e_arglen); 784 sp = argp; 785 786 /* XXX don't copy them out, remap them! */ 787 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 788 789 for (; --argc >= 0; sp += len, dp += len) 790 if (copyout(&dp, cpp++, sizeof(dp)) || 791 copyoutstr(sp, dp, ARG_MAX, &len)) 792 return (NULL); 793 794 if (copyout(&nullp, cpp++, sizeof(nullp))) 795 return (NULL); 796 797 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 798 799 for (; --envc >= 0; sp += len, dp += len) 800 if (copyout(&dp, cpp++, sizeof(dp)) || 801 copyoutstr(sp, dp, ARG_MAX, &len)) 802 return (NULL); 803 804 if (copyout(&nullp, cpp++, sizeof(nullp))) 805 return (NULL); 806 807 return (cpp); 808 } 809 810 int 811 exec_sigcode_map(struct process *pr, struct emul *e) 812 { 813 vsize_t sz; 814 815 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 816 817 /* 818 * If we don't have a sigobject for this emulation, create one. 819 * 820 * sigobject is an anonymous memory object (just like SYSV shared 821 * memory) that we keep a permanent reference to and that we map 822 * in all processes that need this sigcode. The creation is simple, 823 * we create an object, add a permanent reference to it, map it in 824 * kernel space, copy out the sigcode to it and unmap it. 825 * Then we map it with PROT_READ|PROT_EXEC into the process just 826 * the way sys_mmap would map it. 827 */ 828 if (e->e_sigobject == NULL) { 829 vaddr_t va; 830 int r; 831 832 e->e_sigobject = uao_create(sz, 0); 833 uao_reference(e->e_sigobject); /* permanent reference */ 834 835 if ((r = uvm_map(kernel_map, &va, round_page(sz), e->e_sigobject, 836 0, 0, UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE, 837 UVM_INH_SHARE, POSIX_MADV_RANDOM, 0)))) { 838 uao_detach(e->e_sigobject); 839 return (ENOMEM); 840 } 841 memcpy((void *)va, e->e_sigcode, sz); 842 uvm_unmap(kernel_map, va, va + round_page(sz)); 843 } 844 845 pr->ps_sigcode = 0; /* no hint */ 846 uao_reference(e->e_sigobject); 847 if (uvm_map(&pr->ps_vmspace->vm_map, &pr->ps_sigcode, round_page(sz), 848 e->e_sigobject, 0, 0, UVM_MAPFLAG(PROT_READ | PROT_EXEC, 849 PROT_READ | PROT_EXEC, UVM_INH_SHARE, POSIX_MADV_RANDOM, 0))) { 850 uao_detach(e->e_sigobject); 851 return (ENOMEM); 852 } 853 854 return (0); 855 } 856