1 /* $OpenBSD: kern_exec.c,v 1.142 2014/05/15 03:52:25 guenther 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 <uvm/uvm_extern.h> 63 64 #include <machine/reg.h> 65 66 #ifdef __HAVE_MD_TCB 67 # include <machine/tcb.h> 68 #endif 69 70 #include <dev/rndvar.h> 71 72 #include "systrace.h" 73 74 #if NSYSTRACE > 0 75 #include <dev/systrace.h> 76 #endif 77 78 /* 79 * Map the shared signal code. 80 */ 81 int exec_sigcode_map(struct process *, struct emul *); 82 83 /* 84 * If non-zero, stackgap_random specifies the upper limit of the random gap size 85 * added to the fixed stack gap. Must be n^2. 86 */ 87 int stackgap_random = STACKGAP_RANDOM; 88 89 /* 90 * check exec: 91 * given an "executable" described in the exec package's namei info, 92 * see what we can do with it. 93 * 94 * ON ENTRY: 95 * exec package with appropriate namei info 96 * proc pointer of exec'ing proc 97 * NO SELF-LOCKED VNODES 98 * 99 * ON EXIT: 100 * error: nothing held, etc. exec header still allocated. 101 * ok: filled exec package, one locked vnode. 102 * 103 * EXEC SWITCH ENTRY: 104 * Locked vnode to check, exec package, proc. 105 * 106 * EXEC SWITCH EXIT: 107 * ok: return 0, filled exec package, one locked vnode. 108 * error: destructive: 109 * everything deallocated except exec header. 110 * non-destructive: 111 * error code, locked vnode, exec header unmodified 112 */ 113 int 114 check_exec(struct proc *p, struct exec_package *epp) 115 { 116 int error, i; 117 struct vnode *vp; 118 struct nameidata *ndp; 119 size_t resid; 120 121 ndp = epp->ep_ndp; 122 ndp->ni_cnd.cn_nameiop = LOOKUP; 123 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME; 124 /* first get the vnode */ 125 if ((error = namei(ndp)) != 0) 126 return (error); 127 epp->ep_vp = vp = ndp->ni_vp; 128 129 /* check for regular file */ 130 if (vp->v_type == VDIR) { 131 error = EISDIR; 132 goto bad1; 133 } 134 if (vp->v_type != VREG) { 135 error = EACCES; 136 goto bad1; 137 } 138 139 /* get attributes */ 140 if ((error = VOP_GETATTR(vp, epp->ep_vap, p->p_ucred, p)) != 0) 141 goto bad1; 142 143 /* Check mount point */ 144 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 145 error = EACCES; 146 goto bad1; 147 } 148 149 if ((vp->v_mount->mnt_flag & MNT_NOSUID)) 150 epp->ep_vap->va_mode &= ~(VSUID | VSGID); 151 152 /* check access. for root we have to see if any exec bit on */ 153 if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0) 154 goto bad1; 155 if ((epp->ep_vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0) { 156 error = EACCES; 157 goto bad1; 158 } 159 160 /* try to open it */ 161 if ((error = VOP_OPEN(vp, FREAD, p->p_ucred, p)) != 0) 162 goto bad1; 163 164 /* unlock vp, we need it unlocked from here */ 165 VOP_UNLOCK(vp, 0, p); 166 167 /* now we have the file, get the exec header */ 168 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 169 UIO_SYSSPACE, 0, p->p_ucred, &resid, p); 170 if (error) 171 goto bad2; 172 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 173 174 /* 175 * set up the vmcmds for creation of the process 176 * address space 177 */ 178 error = ENOEXEC; 179 for (i = 0; i < nexecs && error != 0; i++) { 180 int newerror; 181 182 if (execsw[i].es_check == NULL) 183 continue; 184 newerror = (*execsw[i].es_check)(p, epp); 185 if (!newerror && !(epp->ep_emul->e_flags & EMUL_ENABLED)) 186 newerror = EPERM; 187 /* make sure the first "interesting" error code is saved. */ 188 if (!newerror || error == ENOEXEC) 189 error = newerror; 190 if (epp->ep_flags & EXEC_DESTR && error != 0) 191 return (error); 192 } 193 if (!error) { 194 /* check that entry point is sane */ 195 if (epp->ep_entry > VM_MAXUSER_ADDRESS) { 196 error = ENOEXEC; 197 } 198 199 /* check limits */ 200 if ((epp->ep_tsize > MAXTSIZ) || 201 (epp->ep_dsize > p->p_rlimit[RLIMIT_DATA].rlim_cur)) 202 error = ENOMEM; 203 204 if (!error) 205 return (0); 206 } 207 208 /* 209 * free any vmspace-creation commands, 210 * and release their references 211 */ 212 kill_vmcmds(&epp->ep_vmcmds); 213 214 bad2: 215 /* 216 * close the vnode, free the pathname buf, and punt. 217 */ 218 vn_close(vp, FREAD, p->p_ucred, p); 219 pool_put(&namei_pool, ndp->ni_cnd.cn_pnbuf); 220 return (error); 221 222 bad1: 223 /* 224 * free the namei pathname buffer, and put the vnode 225 * (which we don't yet have open). 226 */ 227 pool_put(&namei_pool, ndp->ni_cnd.cn_pnbuf); 228 vput(vp); 229 return (error); 230 } 231 232 /* 233 * exec system call 234 */ 235 /* ARGSUSED */ 236 int 237 sys_execve(struct proc *p, void *v, register_t *retval) 238 { 239 struct sys_execve_args /* { 240 syscallarg(const char *) path; 241 syscallarg(char *const *) argp; 242 syscallarg(char *const *) envp; 243 } */ *uap = v; 244 int error; 245 struct exec_package pack; 246 struct nameidata nid; 247 struct vattr attr; 248 struct ucred *cred = p->p_ucred; 249 char *argp; 250 char * const *cpp, *dp, *sp; 251 struct process *pr = p->p_p; 252 long argc, envc; 253 size_t len, sgap; 254 #ifdef MACHINE_STACK_GROWS_UP 255 size_t slen; 256 #endif 257 char *stack; 258 struct ps_strings arginfo; 259 struct vmspace *vm = pr->ps_vmspace; 260 char **tmpfap; 261 extern struct emul emul_native; 262 #if NSYSTRACE > 0 263 int wassugid = ISSET(pr->ps_flags, PS_SUGID | PS_SUGIDEXEC); 264 size_t pathbuflen; 265 #endif 266 char *pathbuf = NULL; 267 struct vnode *otvp; 268 269 /* get other threads to stop */ 270 if ((error = single_thread_set(p, SINGLE_UNWIND, 1))) 271 return (error); 272 273 /* 274 * Cheap solution to complicated problems. 275 * Mark this process as "leave me alone, I'm execing". 276 */ 277 atomic_setbits_int(&pr->ps_flags, PS_INEXEC); 278 279 #if NSYSTRACE > 0 280 if (ISSET(p->p_flag, P_SYSTRACE)) { 281 systrace_execve0(p); 282 pathbuf = pool_get(&namei_pool, PR_WAITOK); 283 error = copyinstr(SCARG(uap, path), pathbuf, MAXPATHLEN, 284 &pathbuflen); 285 if (error != 0) 286 goto clrflag; 287 } 288 #endif 289 if (pathbuf != NULL) { 290 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, p); 291 } else { 292 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, 293 SCARG(uap, path), p); 294 } 295 296 /* 297 * initialize the fields of the exec package. 298 */ 299 if (pathbuf != NULL) 300 pack.ep_name = pathbuf; 301 else 302 pack.ep_name = (char *)SCARG(uap, path); 303 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 304 pack.ep_hdrlen = exec_maxhdrsz; 305 pack.ep_hdrvalid = 0; 306 pack.ep_ndp = &nid; 307 pack.ep_interp = NULL; 308 pack.ep_emul_arg = NULL; 309 VMCMDSET_INIT(&pack.ep_vmcmds); 310 pack.ep_vap = &attr; 311 pack.ep_emul = &emul_native; 312 pack.ep_flags = 0; 313 314 /* see if we can run it. */ 315 if ((error = check_exec(p, &pack)) != 0) { 316 goto freehdr; 317 } 318 319 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 320 321 /* allocate an argument buffer */ 322 argp = (char *) uvm_km_valloc_wait(exec_map, NCARGS); 323 #ifdef DIAGNOSTIC 324 if (argp == NULL) 325 panic("execve: argp == NULL"); 326 #endif 327 dp = argp; 328 argc = 0; 329 330 /* copy the fake args list, if there's one, freeing it as we go */ 331 if (pack.ep_flags & EXEC_HASARGL) { 332 tmpfap = pack.ep_fa; 333 while (*tmpfap != NULL) { 334 char *cp; 335 336 cp = *tmpfap; 337 while (*cp) 338 *dp++ = *cp++; 339 *dp++ = '\0'; 340 341 free(*tmpfap, M_EXEC); 342 tmpfap++; argc++; 343 } 344 free(pack.ep_fa, M_EXEC); 345 pack.ep_flags &= ~EXEC_HASARGL; 346 } 347 348 /* Now get argv & environment */ 349 if (!(cpp = SCARG(uap, argp))) { 350 error = EFAULT; 351 goto bad; 352 } 353 354 if (pack.ep_flags & EXEC_SKIPARG) 355 cpp++; 356 357 while (1) { 358 len = argp + ARG_MAX - dp; 359 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 360 goto bad; 361 if (!sp) 362 break; 363 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 364 if (error == ENAMETOOLONG) 365 error = E2BIG; 366 goto bad; 367 } 368 dp += len; 369 cpp++; 370 argc++; 371 } 372 373 envc = 0; 374 /* environment does not need to be there */ 375 if ((cpp = SCARG(uap, envp)) != NULL ) { 376 while (1) { 377 len = argp + ARG_MAX - dp; 378 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 379 goto bad; 380 if (!sp) 381 break; 382 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 383 if (error == ENAMETOOLONG) 384 error = E2BIG; 385 goto bad; 386 } 387 dp += len; 388 cpp++; 389 envc++; 390 } 391 } 392 393 dp = (char *)(((long)dp + _STACKALIGNBYTES) & ~_STACKALIGNBYTES); 394 395 sgap = STACKGAPLEN; 396 if (stackgap_random != 0) { 397 sgap += arc4random() & (stackgap_random - 1); 398 sgap = (sgap + _STACKALIGNBYTES) & ~_STACKALIGNBYTES; 399 } 400 401 /* Now check if args & environ fit into new stack */ 402 len = ((argc + envc + 2 + pack.ep_emul->e_arglen) * sizeof(char *) + 403 sizeof(long) + dp + sgap + sizeof(struct ps_strings)) - argp; 404 405 len = (len + _STACKALIGNBYTES) &~ _STACKALIGNBYTES; 406 407 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 408 error = ENOMEM; 409 goto bad; 410 } 411 412 /* adjust "active stack depth" for process VSZ */ 413 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 414 415 /* 416 * we're committed: any further errors will kill the process, so 417 * kill the other threads now. 418 */ 419 single_thread_set(p, SINGLE_EXIT, 0); 420 421 /* 422 * Prepare vmspace for remapping. Note that uvmspace_exec can replace 423 * pr_vmspace! 424 */ 425 uvmspace_exec(p, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS); 426 427 vm = pr->ps_vmspace; 428 /* Now map address space */ 429 vm->vm_taddr = (char *)pack.ep_taddr; 430 vm->vm_tsize = atop(round_page(pack.ep_tsize)); 431 vm->vm_daddr = (char *)pack.ep_daddr; 432 vm->vm_dsize = atop(round_page(pack.ep_dsize)); 433 vm->vm_dused = 0; 434 vm->vm_ssize = atop(round_page(pack.ep_ssize)); 435 vm->vm_maxsaddr = (char *)pack.ep_maxsaddr; 436 vm->vm_minsaddr = (char *)pack.ep_minsaddr; 437 438 /* create the new process's VM space by running the vmcmds */ 439 #ifdef DIAGNOSTIC 440 if (pack.ep_vmcmds.evs_used == 0) 441 panic("execve: no vmcmds"); 442 #endif 443 error = exec_process_vmcmds(p, &pack); 444 445 /* if an error happened, deallocate and punt */ 446 if (error) 447 goto exec_abort; 448 449 /* remember information about the process */ 450 arginfo.ps_nargvstr = argc; 451 arginfo.ps_nenvstr = envc; 452 453 #ifdef MACHINE_STACK_GROWS_UP 454 stack = (char *)USRSTACK + sizeof(arginfo) + sgap; 455 slen = len - sizeof(arginfo) - sgap; 456 #else 457 stack = (char *)(USRSTACK - len); 458 #endif 459 /* Now copy argc, args & environ to new stack */ 460 if (!(*pack.ep_emul->e_copyargs)(&pack, &arginfo, stack, argp)) 461 goto exec_abort; 462 463 /* copy out the process's ps_strings structure */ 464 if (copyout(&arginfo, (char *)PS_STRINGS, sizeof(arginfo))) 465 goto exec_abort; 466 467 stopprofclock(pr); /* stop profiling */ 468 fdcloseexec(p); /* handle close on exec */ 469 execsigs(p); /* reset caught signals */ 470 TCB_SET(p, NULL); /* reset the TCB address */ 471 472 /* set command name & other accounting info */ 473 memset(p->p_comm, 0, sizeof(p->p_comm)); 474 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 475 bcopy(nid.ni_cnd.cn_nameptr, p->p_comm, len); 476 pr->ps_acflag &= ~AFORK; 477 478 /* record proc's vnode, for use by procfs and others */ 479 otvp = pr->ps_textvp; 480 vref(pack.ep_vp); 481 pr->ps_textvp = pack.ep_vp; 482 if (otvp) 483 vrele(otvp); 484 485 atomic_setbits_int(&pr->ps_flags, PS_EXEC); 486 if (pr->ps_flags & PS_PPWAIT) { 487 atomic_clearbits_int(&pr->ps_flags, PS_PPWAIT); 488 atomic_clearbits_int(&pr->ps_pptr->ps_flags, PS_ISPWAIT); 489 wakeup(pr->ps_pptr); 490 } 491 492 /* 493 * If process does execve() while it has a mismatched real, 494 * effective, or saved uid/gid, we set PS_SUGIDEXEC. 495 */ 496 if (cred->cr_uid != cred->cr_ruid || 497 cred->cr_uid != cred->cr_svuid || 498 cred->cr_gid != cred->cr_rgid || 499 cred->cr_gid != cred->cr_svgid) 500 atomic_setbits_int(&pr->ps_flags, PS_SUGIDEXEC); 501 else 502 atomic_clearbits_int(&pr->ps_flags, PS_SUGIDEXEC); 503 504 /* 505 * deal with set[ug]id. 506 * MNT_NOEXEC has already been used to disable s[ug]id. 507 */ 508 if ((attr.va_mode & (VSUID | VSGID)) && proc_cansugid(p)) { 509 int i; 510 511 atomic_setbits_int(&pr->ps_flags, PS_SUGID|PS_SUGIDEXEC); 512 513 #ifdef KTRACE 514 /* 515 * If process is being ktraced, turn off - unless 516 * root set it. 517 */ 518 if (pr->ps_tracevp && !(pr->ps_traceflag & KTRFAC_ROOT)) 519 ktrcleartrace(pr); 520 #endif 521 p->p_ucred = cred = crcopy(cred); 522 if (attr.va_mode & VSUID) 523 cred->cr_uid = attr.va_uid; 524 if (attr.va_mode & VSGID) 525 cred->cr_gid = attr.va_gid; 526 527 /* 528 * For set[ug]id processes, a few caveats apply to 529 * stdin, stdout, and stderr. 530 */ 531 error = 0; 532 fdplock(p->p_fd); 533 for (i = 0; i < 3; i++) { 534 struct file *fp = NULL; 535 536 /* 537 * NOTE - This will never return NULL because of 538 * immature fds. The file descriptor table is not 539 * shared because we're suid. 540 */ 541 fp = fd_getfile(p->p_fd, i); 542 #ifdef PROCFS 543 /* 544 * Close descriptors that are writing to procfs. 545 */ 546 if (fp && fp->f_type == DTYPE_VNODE && 547 ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS && 548 (fp->f_flag & FWRITE)) { 549 fdrelease(p, i); 550 fp = NULL; 551 } 552 #endif 553 554 /* 555 * Ensure that stdin, stdout, and stderr are already 556 * allocated. We do not want userland to accidentally 557 * allocate descriptors in this range which has implied 558 * meaning to libc. 559 */ 560 if (fp == NULL) { 561 short flags = FREAD | (i == 0 ? 0 : FWRITE); 562 struct vnode *vp; 563 int indx; 564 565 if ((error = falloc(p, &fp, &indx)) != 0) 566 break; 567 #ifdef DIAGNOSTIC 568 if (indx != i) 569 panic("sys_execve: falloc indx != i"); 570 #endif 571 if ((error = cdevvp(getnulldev(), &vp)) != 0) { 572 fdremove(p->p_fd, indx); 573 closef(fp, p); 574 break; 575 } 576 if ((error = VOP_OPEN(vp, flags, cred, p)) != 0) { 577 fdremove(p->p_fd, indx); 578 closef(fp, p); 579 vrele(vp); 580 break; 581 } 582 if (flags & FWRITE) 583 vp->v_writecount++; 584 fp->f_flag = flags; 585 fp->f_type = DTYPE_VNODE; 586 fp->f_ops = &vnops; 587 fp->f_data = (caddr_t)vp; 588 FILE_SET_MATURE(fp, p); 589 } 590 } 591 fdpunlock(p->p_fd); 592 if (error) 593 goto exec_abort; 594 } else 595 atomic_clearbits_int(&pr->ps_flags, PS_SUGID); 596 597 /* 598 * Reset the saved ugids and update the process's copy of the 599 * creds if the creds have been changed 600 */ 601 if (cred->cr_uid != cred->cr_svuid || 602 cred->cr_gid != cred->cr_svgid) { 603 /* make sure we have unshared ucreds */ 604 p->p_ucred = cred = crcopy(cred); 605 cred->cr_svuid = cred->cr_uid; 606 cred->cr_svgid = cred->cr_gid; 607 } 608 609 if (pr->ps_ucred != cred) { 610 struct ucred *ocred; 611 612 ocred = pr->ps_ucred; 613 crhold(cred); 614 pr->ps_ucred = cred; 615 crfree(ocred); 616 } 617 618 if (pr->ps_flags & PS_SUGIDEXEC) { 619 int i, s = splclock(); 620 621 timeout_del(&pr->ps_realit_to); 622 for (i = 0; i < nitems(pr->ps_timer); i++) { 623 timerclear(&pr->ps_timer[i].it_interval); 624 timerclear(&pr->ps_timer[i].it_value); 625 } 626 splx(s); 627 } 628 629 /* reset CPU time usage for the thread, but not the process */ 630 timespecclear(&p->p_tu.tu_runtime); 631 p->p_tu.tu_uticks = p->p_tu.tu_sticks = p->p_tu.tu_iticks = 0; 632 633 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 634 635 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 636 vn_close(pack.ep_vp, FREAD, cred, p); 637 638 /* 639 * notify others that we exec'd 640 */ 641 KNOTE(&pr->ps_klist, NOTE_EXEC); 642 643 /* setup new registers and do misc. setup. */ 644 if (pack.ep_emul->e_fixup != NULL) { 645 if ((*pack.ep_emul->e_fixup)(p, &pack) != 0) 646 goto free_pack_abort; 647 } 648 #ifdef MACHINE_STACK_GROWS_UP 649 (*pack.ep_emul->e_setregs)(p, &pack, (u_long)stack + slen, retval); 650 #else 651 (*pack.ep_emul->e_setregs)(p, &pack, (u_long)stack, retval); 652 #endif 653 654 /* map the process's signal trampoline code */ 655 if (exec_sigcode_map(pr, pack.ep_emul)) 656 goto free_pack_abort; 657 658 #ifdef __HAVE_EXEC_MD_MAP 659 /* perform md specific mappings that process might need */ 660 if (exec_md_map(p, &pack)) 661 goto free_pack_abort; 662 #endif 663 664 if (pr->ps_flags & PS_TRACED) 665 psignal(p, SIGTRAP); 666 667 free(pack.ep_hdr, M_EXEC); 668 669 /* 670 * Call emulation specific exec hook. This can setup per-process 671 * p->p_emuldata or do any other per-process stuff an emulation needs. 672 * 673 * If we are executing process of different emulation than the 674 * original forked process, call e_proc_exit() of the old emulation 675 * first, then e_proc_exec() of new emulation. If the emulation is 676 * same, the exec hook code should deallocate any old emulation 677 * resources held previously by this process. 678 */ 679 if (pr->ps_emul && pr->ps_emul->e_proc_exit && 680 pr->ps_emul != pack.ep_emul) 681 (*pr->ps_emul->e_proc_exit)(p); 682 683 p->p_descfd = 255; 684 if ((pack.ep_flags & EXEC_HASFD) && pack.ep_fd < 255) 685 p->p_descfd = pack.ep_fd; 686 687 /* 688 * Call exec hook. Emulation code may NOT store reference to anything 689 * from &pack. 690 */ 691 if (pack.ep_emul->e_proc_exec) 692 (*pack.ep_emul->e_proc_exec)(p, &pack); 693 694 /* update ps_emul, the old value is no longer needed */ 695 pr->ps_emul = pack.ep_emul; 696 697 #ifdef KTRACE 698 if (KTRPOINT(p, KTR_EMUL)) 699 ktremul(p); 700 #endif 701 702 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 703 single_thread_clear(p, P_SUSPSIG); 704 705 #if NSYSTRACE > 0 706 if (ISSET(p->p_flag, P_SYSTRACE) && 707 wassugid && !ISSET(pr->ps_flags, PS_SUGID | PS_SUGIDEXEC)) 708 systrace_execve1(pathbuf, p); 709 #endif 710 711 if (pathbuf != NULL) 712 pool_put(&namei_pool, pathbuf); 713 714 return (0); 715 716 bad: 717 /* free the vmspace-creation commands, and release their references */ 718 kill_vmcmds(&pack.ep_vmcmds); 719 /* kill any opened file descriptor, if necessary */ 720 if (pack.ep_flags & EXEC_HASFD) { 721 pack.ep_flags &= ~EXEC_HASFD; 722 fdplock(p->p_fd); 723 (void) fdrelease(p, pack.ep_fd); 724 fdpunlock(p->p_fd); 725 } 726 if (pack.ep_interp != NULL) 727 pool_put(&namei_pool, pack.ep_interp); 728 if (pack.ep_emul_arg != NULL) 729 free(pack.ep_emul_arg, M_TEMP); 730 /* close and put the exec'd file */ 731 vn_close(pack.ep_vp, FREAD, cred, p); 732 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 733 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 734 735 freehdr: 736 free(pack.ep_hdr, M_EXEC); 737 #if NSYSTRACE > 0 738 clrflag: 739 #endif 740 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 741 single_thread_clear(p, P_SUSPSIG); 742 743 if (pathbuf != NULL) 744 pool_put(&namei_pool, pathbuf); 745 746 return (error); 747 748 exec_abort: 749 /* 750 * the old process doesn't exist anymore. exit gracefully. 751 * get rid of the (new) address space we have created, if any, get rid 752 * of our namei data and vnode, and exit noting failure 753 */ 754 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 755 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 756 if (pack.ep_interp != NULL) 757 pool_put(&namei_pool, pack.ep_interp); 758 if (pack.ep_emul_arg != NULL) 759 free(pack.ep_emul_arg, M_TEMP); 760 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 761 vn_close(pack.ep_vp, FREAD, cred, p); 762 uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS); 763 764 free_pack_abort: 765 free(pack.ep_hdr, M_EXEC); 766 exit1(p, W_EXITCODE(0, SIGABRT), EXIT_NORMAL); 767 768 /* NOTREACHED */ 769 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 770 if (pathbuf != NULL) 771 pool_put(&namei_pool, pathbuf); 772 773 return (0); 774 } 775 776 777 void * 778 copyargs(struct exec_package *pack, struct ps_strings *arginfo, void *stack, 779 void *argp) 780 { 781 char **cpp = stack; 782 char *dp, *sp; 783 size_t len; 784 void *nullp = NULL; 785 long argc = arginfo->ps_nargvstr; 786 int envc = arginfo->ps_nenvstr; 787 788 if (copyout(&argc, cpp++, sizeof(argc))) 789 return (NULL); 790 791 dp = (char *) (cpp + argc + envc + 2 + pack->ep_emul->e_arglen); 792 sp = argp; 793 794 /* XXX don't copy them out, remap them! */ 795 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 796 797 for (; --argc >= 0; sp += len, dp += len) 798 if (copyout(&dp, cpp++, sizeof(dp)) || 799 copyoutstr(sp, dp, ARG_MAX, &len)) 800 return (NULL); 801 802 if (copyout(&nullp, cpp++, sizeof(nullp))) 803 return (NULL); 804 805 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 806 807 for (; --envc >= 0; sp += len, dp += len) 808 if (copyout(&dp, cpp++, sizeof(dp)) || 809 copyoutstr(sp, dp, ARG_MAX, &len)) 810 return (NULL); 811 812 if (copyout(&nullp, cpp++, sizeof(nullp))) 813 return (NULL); 814 815 return (cpp); 816 } 817 818 int 819 exec_sigcode_map(struct process *pr, struct emul *e) 820 { 821 vsize_t sz; 822 823 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 824 825 /* 826 * If we don't have a sigobject for this emulation, create one. 827 * 828 * sigobject is an anonymous memory object (just like SYSV shared 829 * memory) that we keep a permanent reference to and that we map 830 * in all processes that need this sigcode. The creation is simple, 831 * we create an object, add a permanent reference to it, map it in 832 * kernel space, copy out the sigcode to it and unmap it. 833 * Then we map it with PROT_READ|PROT_EXEC into the process just 834 * the way sys_mmap would map it. 835 */ 836 if (e->e_sigobject == NULL) { 837 vaddr_t va; 838 int r; 839 840 e->e_sigobject = uao_create(sz, 0); 841 uao_reference(e->e_sigobject); /* permanent reference */ 842 843 if ((r = uvm_map(kernel_map, &va, round_page(sz), e->e_sigobject, 844 0, 0, UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, 845 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) { 846 uao_detach(e->e_sigobject); 847 return (ENOMEM); 848 } 849 memcpy((void *)va, e->e_sigcode, sz); 850 uvm_unmap(kernel_map, va, va + round_page(sz)); 851 } 852 853 pr->ps_sigcode = 0; /* no hint */ 854 uao_reference(e->e_sigobject); 855 if (uvm_map(&pr->ps_vmspace->vm_map, &pr->ps_sigcode, round_page(sz), 856 e->e_sigobject, 0, 0, UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, 857 UVM_INH_SHARE, UVM_ADV_RANDOM, 0))) { 858 uao_detach(e->e_sigobject); 859 return (ENOMEM); 860 } 861 862 return (0); 863 } 864