1 /* $OpenBSD: kern_exec.c,v 1.189 2017/08/29 02:51:27 deraadt 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 #include <sys/pledge.h> 57 #ifdef SYSVSHM 58 #include <sys/shm.h> 59 #endif 60 61 #include <sys/syscallargs.h> 62 63 #include <uvm/uvm_extern.h> 64 #include <machine/tcb.h> 65 66 const struct kmem_va_mode kv_exec = { 67 .kv_wait = 1, 68 .kv_map = &exec_map 69 }; 70 71 /* 72 * Map the shared signal code. 73 */ 74 int exec_sigcode_map(struct process *, struct emul *); 75 76 /* 77 * If non-zero, stackgap_random specifies the upper limit of the random gap size 78 * added to the fixed stack position. Must be n^2. 79 */ 80 int stackgap_random = STACKGAP_RANDOM; 81 82 /* 83 * check exec: 84 * given an "executable" described in the exec package's namei info, 85 * see what we can do with it. 86 * 87 * ON ENTRY: 88 * exec package with appropriate namei info 89 * proc pointer of exec'ing proc 90 * NO SELF-LOCKED VNODES 91 * 92 * ON EXIT: 93 * error: nothing held, etc. exec header still allocated. 94 * ok: filled exec package, one locked vnode. 95 * 96 * EXEC SWITCH ENTRY: 97 * Locked vnode to check, exec package, proc. 98 * 99 * EXEC SWITCH EXIT: 100 * ok: return 0, filled exec package, one locked vnode. 101 * error: destructive: 102 * everything deallocated except exec header. 103 * non-destructive: 104 * error code, locked vnode, exec header unmodified 105 */ 106 int 107 check_exec(struct proc *p, struct exec_package *epp) 108 { 109 int error, i; 110 struct vnode *vp; 111 struct nameidata *ndp; 112 size_t resid; 113 114 ndp = epp->ep_ndp; 115 ndp->ni_cnd.cn_nameiop = LOOKUP; 116 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME; 117 /* first get the vnode */ 118 if ((error = namei(ndp)) != 0) 119 return (error); 120 epp->ep_vp = vp = ndp->ni_vp; 121 122 /* check for regular file */ 123 if (vp->v_type == VDIR) { 124 error = EISDIR; 125 goto bad1; 126 } 127 if (vp->v_type != VREG) { 128 error = EACCES; 129 goto bad1; 130 } 131 132 /* get attributes */ 133 if ((error = VOP_GETATTR(vp, epp->ep_vap, p->p_ucred, p)) != 0) 134 goto bad1; 135 136 /* Check mount point */ 137 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 138 error = EACCES; 139 goto bad1; 140 } 141 142 if ((vp->v_mount->mnt_flag & MNT_NOSUID)) 143 epp->ep_vap->va_mode &= ~(VSUID | VSGID); 144 145 /* check access. for root we have to see if any exec bit on */ 146 if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0) 147 goto bad1; 148 if ((epp->ep_vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0) { 149 error = EACCES; 150 goto bad1; 151 } 152 153 /* try to open it */ 154 if ((error = VOP_OPEN(vp, FREAD, p->p_ucred, p)) != 0) 155 goto bad1; 156 157 /* unlock vp, we need it unlocked from here */ 158 VOP_UNLOCK(vp, p); 159 160 /* now we have the file, get the exec header */ 161 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 162 UIO_SYSSPACE, 0, p->p_ucred, &resid, p); 163 if (error) 164 goto bad2; 165 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 166 167 /* 168 * set up the vmcmds for creation of the process 169 * address space 170 */ 171 error = ENOEXEC; 172 for (i = 0; i < nexecs && error != 0; i++) { 173 int newerror; 174 175 if (execsw[i].es_check == NULL) 176 continue; 177 newerror = (*execsw[i].es_check)(p, epp); 178 if (!newerror && !(epp->ep_emul->e_flags & EMUL_ENABLED)) 179 newerror = EPERM; 180 /* make sure the first "interesting" error code is saved. */ 181 if (!newerror || error == ENOEXEC) 182 error = newerror; 183 if (epp->ep_flags & EXEC_DESTR && error != 0) 184 return (error); 185 } 186 if (!error) { 187 /* check that entry point is sane */ 188 if (epp->ep_entry > VM_MAXUSER_ADDRESS) { 189 error = ENOEXEC; 190 } 191 192 /* check limits */ 193 if ((epp->ep_tsize > MAXTSIZ) || 194 (epp->ep_dsize > p->p_rlimit[RLIMIT_DATA].rlim_cur)) 195 error = ENOMEM; 196 197 if (!error) 198 return (0); 199 } 200 201 /* 202 * free any vmspace-creation commands, 203 * and release their references 204 */ 205 kill_vmcmds(&epp->ep_vmcmds); 206 207 bad2: 208 /* 209 * close the vnode, free the pathname buf, and punt. 210 */ 211 vn_close(vp, FREAD, p->p_ucred, p); 212 pool_put(&namei_pool, ndp->ni_cnd.cn_pnbuf); 213 return (error); 214 215 bad1: 216 /* 217 * free the namei pathname buffer, and put the vnode 218 * (which we don't yet have open). 219 */ 220 pool_put(&namei_pool, ndp->ni_cnd.cn_pnbuf); 221 vput(vp); 222 return (error); 223 } 224 225 /* 226 * exec system call 227 */ 228 int 229 sys_execve(struct proc *p, void *v, register_t *retval) 230 { 231 struct sys_execve_args /* { 232 syscallarg(const char *) path; 233 syscallarg(char *const *) argp; 234 syscallarg(char *const *) envp; 235 } */ *uap = v; 236 int error; 237 struct exec_package pack; 238 struct nameidata nid; 239 struct vattr attr; 240 struct ucred *cred = p->p_ucred; 241 char *argp; 242 char * const *cpp, *dp, *sp; 243 #ifdef KTRACE 244 char *env_start; 245 #endif 246 struct process *pr = p->p_p; 247 long argc, envc; 248 size_t len, sgap; 249 #ifdef MACHINE_STACK_GROWS_UP 250 size_t slen; 251 #endif 252 char *stack; 253 struct ps_strings arginfo; 254 struct vmspace *vm; 255 char **tmpfap; 256 extern struct emul emul_native; 257 struct vnode *otvp; 258 259 /* get other threads to stop */ 260 if ((error = single_thread_set(p, SINGLE_UNWIND, 1))) 261 return (error); 262 263 /* 264 * Cheap solution to complicated problems. 265 * Mark this process as "leave me alone, I'm execing". 266 */ 267 atomic_setbits_int(&pr->ps_flags, PS_INEXEC); 268 269 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 270 nid.ni_pledge = PLEDGE_EXEC; 271 272 /* 273 * initialize the fields of the exec package. 274 */ 275 pack.ep_name = (char *)SCARG(uap, path); 276 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 277 pack.ep_hdrlen = exec_maxhdrsz; 278 pack.ep_hdrvalid = 0; 279 pack.ep_ndp = &nid; 280 pack.ep_interp = NULL; 281 pack.ep_emul_arg = NULL; 282 VMCMDSET_INIT(&pack.ep_vmcmds); 283 pack.ep_vap = &attr; 284 pack.ep_emul = &emul_native; 285 pack.ep_flags = 0; 286 287 /* see if we can run it. */ 288 if ((error = check_exec(p, &pack)) != 0) { 289 goto freehdr; 290 } 291 292 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 293 294 /* allocate an argument buffer */ 295 argp = km_alloc(NCARGS, &kv_exec, &kp_pageable, &kd_waitok); 296 #ifdef DIAGNOSTIC 297 if (argp == NULL) 298 panic("execve: argp == NULL"); 299 #endif 300 dp = argp; 301 argc = 0; 302 303 /* copy the fake args list, if there's one, freeing it as we go */ 304 if (pack.ep_flags & EXEC_HASARGL) { 305 tmpfap = pack.ep_fa; 306 while (*tmpfap != NULL) { 307 char *cp; 308 309 cp = *tmpfap; 310 while (*cp) 311 *dp++ = *cp++; 312 *dp++ = '\0'; 313 314 free(*tmpfap, M_EXEC, 0); 315 tmpfap++; argc++; 316 } 317 free(pack.ep_fa, M_EXEC, 0); 318 pack.ep_flags &= ~EXEC_HASARGL; 319 } 320 321 /* Now get argv & environment */ 322 if (!(cpp = SCARG(uap, argp))) { 323 error = EFAULT; 324 goto bad; 325 } 326 327 if (pack.ep_flags & EXEC_SKIPARG) 328 cpp++; 329 330 while (1) { 331 len = argp + ARG_MAX - dp; 332 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 333 goto bad; 334 if (!sp) 335 break; 336 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 337 if (error == ENAMETOOLONG) 338 error = E2BIG; 339 goto bad; 340 } 341 dp += len; 342 cpp++; 343 argc++; 344 } 345 346 /* must have at least one argument */ 347 if (argc == 0) { 348 error = EINVAL; 349 goto bad; 350 } 351 352 #ifdef KTRACE 353 if (KTRPOINT(p, KTR_EXECARGS)) 354 ktrexec(p, KTR_EXECARGS, argp, dp - argp); 355 #endif 356 357 envc = 0; 358 /* environment does not need to be there */ 359 if ((cpp = SCARG(uap, envp)) != NULL ) { 360 #ifdef KTRACE 361 env_start = dp; 362 #endif 363 while (1) { 364 len = argp + ARG_MAX - dp; 365 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 366 goto bad; 367 if (!sp) 368 break; 369 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 370 if (error == ENAMETOOLONG) 371 error = E2BIG; 372 goto bad; 373 } 374 dp += len; 375 cpp++; 376 envc++; 377 } 378 379 #ifdef KTRACE 380 if (KTRPOINT(p, KTR_EXECENV)) 381 ktrexec(p, KTR_EXECENV, env_start, dp - env_start); 382 #endif 383 } 384 385 dp = (char *)(((long)dp + _STACKALIGNBYTES) & ~_STACKALIGNBYTES); 386 387 sgap = STACKGAPLEN; 388 389 /* 390 * If we have enabled random stackgap, the stack itself has already 391 * been moved from a random location, but is still aligned to a page 392 * boundary. Provide the lower bits of random placement now. 393 */ 394 if (stackgap_random != 0) { 395 sgap += arc4random() & PAGE_MASK; 396 sgap = (sgap + _STACKALIGNBYTES) & ~_STACKALIGNBYTES; 397 } 398 399 /* Now check if args & environ fit into new stack */ 400 len = ((argc + envc + 2 + pack.ep_emul->e_arglen) * sizeof(char *) + 401 sizeof(long) + dp + sgap + sizeof(struct ps_strings)) - argp; 402 403 len = (len + _STACKALIGNBYTES) &~ _STACKALIGNBYTES; 404 405 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 406 error = ENOMEM; 407 goto bad; 408 } 409 410 /* adjust "active stack depth" for process VSZ */ 411 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 412 413 /* 414 * we're committed: any further errors will kill the process, so 415 * kill the other threads now. 416 */ 417 single_thread_set(p, SINGLE_EXIT, 0); 418 419 /* 420 * Prepare vmspace for remapping. Note that uvmspace_exec can replace 421 * ps_vmspace! 422 */ 423 uvmspace_exec(p, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS); 424 425 vm = pr->ps_vmspace; 426 /* Now map address space */ 427 vm->vm_taddr = (char *)trunc_page(pack.ep_taddr); 428 vm->vm_tsize = atop(round_page(pack.ep_taddr + pack.ep_tsize) - 429 trunc_page(pack.ep_taddr)); 430 vm->vm_daddr = (char *)trunc_page(pack.ep_daddr); 431 vm->vm_dsize = atop(round_page(pack.ep_daddr + pack.ep_dsize) - 432 trunc_page(pack.ep_daddr)); 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 /* old "stackgap" is gone now */ 450 pr->ps_stackgap = 0; 451 452 #ifdef MACHINE_STACK_GROWS_UP 453 pr->ps_strings = (vaddr_t)vm->vm_maxsaddr + sgap; 454 if (uvm_map_protect(&vm->vm_map, (vaddr_t)vm->vm_maxsaddr, 455 trunc_page(pr->ps_strings), PROT_NONE, TRUE)) 456 goto exec_abort; 457 #else 458 pr->ps_strings = (vaddr_t)vm->vm_minsaddr - sizeof(arginfo) - sgap; 459 if (uvm_map_protect(&vm->vm_map, 460 round_page(pr->ps_strings + sizeof(arginfo)), 461 (vaddr_t)vm->vm_minsaddr, PROT_NONE, TRUE)) 462 goto exec_abort; 463 #endif 464 465 /* remember information about the process */ 466 arginfo.ps_nargvstr = argc; 467 arginfo.ps_nenvstr = envc; 468 469 #ifdef MACHINE_STACK_GROWS_UP 470 stack = (char *)vm->vm_maxsaddr + sizeof(arginfo) + sgap; 471 slen = len - sizeof(arginfo) - sgap; 472 #else 473 stack = (char *)(vm->vm_minsaddr - len); 474 #endif 475 /* Now copy argc, args & environ to new stack */ 476 if (!(*pack.ep_emul->e_copyargs)(&pack, &arginfo, stack, argp)) 477 goto exec_abort; 478 479 /* copy out the process's ps_strings structure */ 480 if (copyout(&arginfo, (char *)pr->ps_strings, sizeof(arginfo))) 481 goto exec_abort; 482 483 stopprofclock(pr); /* stop profiling */ 484 fdcloseexec(p); /* handle close on exec */ 485 execsigs(p); /* reset caught signals */ 486 TCB_SET(p, NULL); /* reset the TCB address */ 487 pr->ps_kbind_addr = 0; /* reset the kbind bits */ 488 pr->ps_kbind_cookie = 0; 489 arc4random_buf(&pr->ps_sigcookie, sizeof pr->ps_sigcookie); 490 491 /* set command name & other accounting info */ 492 memset(pr->ps_comm, 0, sizeof(pr->ps_comm)); 493 len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN); 494 memcpy(pr->ps_comm, nid.ni_cnd.cn_nameptr, len); 495 pr->ps_acflag &= ~AFORK; 496 497 /* record proc's vnode, for use by sysctl */ 498 otvp = pr->ps_textvp; 499 vref(pack.ep_vp); 500 pr->ps_textvp = pack.ep_vp; 501 if (otvp) 502 vrele(otvp); 503 504 atomic_setbits_int(&pr->ps_flags, PS_EXEC); 505 if (pr->ps_flags & PS_PPWAIT) { 506 atomic_clearbits_int(&pr->ps_flags, PS_PPWAIT); 507 atomic_clearbits_int(&pr->ps_pptr->ps_flags, PS_ISPWAIT); 508 wakeup(pr->ps_pptr); 509 } 510 511 /* 512 * If process does execve() while it has a mismatched real, 513 * effective, or saved uid/gid, we set PS_SUGIDEXEC. 514 */ 515 if (cred->cr_uid != cred->cr_ruid || 516 cred->cr_uid != cred->cr_svuid || 517 cred->cr_gid != cred->cr_rgid || 518 cred->cr_gid != cred->cr_svgid) 519 atomic_setbits_int(&pr->ps_flags, PS_SUGIDEXEC); 520 else 521 atomic_clearbits_int(&pr->ps_flags, PS_SUGIDEXEC); 522 523 atomic_clearbits_int(&pr->ps_flags, PS_PLEDGE); 524 525 /* 526 * deal with set[ug]id. 527 * MNT_NOEXEC has already been used to disable s[ug]id. 528 */ 529 if ((attr.va_mode & (VSUID | VSGID)) && proc_cansugid(p)) { 530 int i; 531 532 atomic_setbits_int(&pr->ps_flags, PS_SUGID|PS_SUGIDEXEC); 533 534 #ifdef KTRACE 535 /* 536 * If process is being ktraced, turn off - unless 537 * root set it. 538 */ 539 if (pr->ps_tracevp && !(pr->ps_traceflag & KTRFAC_ROOT)) 540 ktrcleartrace(pr); 541 #endif 542 p->p_ucred = cred = crcopy(cred); 543 if (attr.va_mode & VSUID) 544 cred->cr_uid = attr.va_uid; 545 if (attr.va_mode & VSGID) 546 cred->cr_gid = attr.va_gid; 547 548 /* 549 * For set[ug]id processes, a few caveats apply to 550 * stdin, stdout, and stderr. 551 */ 552 error = 0; 553 fdplock(p->p_fd); 554 for (i = 0; i < 3; i++) { 555 struct file *fp = NULL; 556 557 /* 558 * NOTE - This will never return NULL because of 559 * immature fds. The file descriptor table is not 560 * shared because we're suid. 561 */ 562 fp = fd_getfile(p->p_fd, i); 563 564 /* 565 * Ensure that stdin, stdout, and stderr are already 566 * allocated. We do not want userland to accidentally 567 * allocate descriptors in this range which has implied 568 * meaning to libc. 569 */ 570 if (fp == NULL) { 571 short flags = FREAD | (i == 0 ? 0 : FWRITE); 572 struct vnode *vp; 573 int indx; 574 575 if ((error = falloc(p, 0, &fp, &indx)) != 0) 576 break; 577 #ifdef DIAGNOSTIC 578 if (indx != i) 579 panic("sys_execve: falloc indx != i"); 580 #endif 581 if ((error = cdevvp(getnulldev(), &vp)) != 0) { 582 fdremove(p->p_fd, indx); 583 closef(fp, p); 584 break; 585 } 586 if ((error = VOP_OPEN(vp, flags, cred, p)) != 0) { 587 fdremove(p->p_fd, indx); 588 closef(fp, p); 589 vrele(vp); 590 break; 591 } 592 if (flags & FWRITE) 593 vp->v_writecount++; 594 fp->f_flag = flags; 595 fp->f_type = DTYPE_VNODE; 596 fp->f_ops = &vnops; 597 fp->f_data = (caddr_t)vp; 598 FILE_SET_MATURE(fp, p); 599 } 600 } 601 fdpunlock(p->p_fd); 602 if (error) 603 goto exec_abort; 604 } else 605 atomic_clearbits_int(&pr->ps_flags, PS_SUGID); 606 607 /* 608 * Reset the saved ugids and update the process's copy of the 609 * creds if the creds have been changed 610 */ 611 if (cred->cr_uid != cred->cr_svuid || 612 cred->cr_gid != cred->cr_svgid) { 613 /* make sure we have unshared ucreds */ 614 p->p_ucred = cred = crcopy(cred); 615 cred->cr_svuid = cred->cr_uid; 616 cred->cr_svgid = cred->cr_gid; 617 } 618 619 if (pr->ps_ucred != cred) { 620 struct ucred *ocred; 621 622 ocred = pr->ps_ucred; 623 crhold(cred); 624 pr->ps_ucred = cred; 625 crfree(ocred); 626 } 627 628 if (pr->ps_flags & PS_SUGIDEXEC) { 629 int i, s = splclock(); 630 631 timeout_del(&pr->ps_realit_to); 632 for (i = 0; i < nitems(pr->ps_timer); i++) { 633 timerclear(&pr->ps_timer[i].it_interval); 634 timerclear(&pr->ps_timer[i].it_value); 635 } 636 splx(s); 637 } 638 639 /* reset CPU time usage for the thread, but not the process */ 640 timespecclear(&p->p_tu.tu_runtime); 641 p->p_tu.tu_uticks = p->p_tu.tu_sticks = p->p_tu.tu_iticks = 0; 642 643 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 644 645 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 646 vn_close(pack.ep_vp, FREAD, cred, p); 647 648 /* 649 * notify others that we exec'd 650 */ 651 KNOTE(&pr->ps_klist, NOTE_EXEC); 652 653 /* setup new registers and do misc. setup. */ 654 if (pack.ep_emul->e_fixup != NULL) { 655 if ((*pack.ep_emul->e_fixup)(p, &pack) != 0) 656 goto free_pack_abort; 657 } 658 #ifdef MACHINE_STACK_GROWS_UP 659 (*pack.ep_emul->e_setregs)(p, &pack, (u_long)stack + slen, retval); 660 #else 661 (*pack.ep_emul->e_setregs)(p, &pack, (u_long)stack, retval); 662 #endif 663 664 /* map the process's signal trampoline code */ 665 if (exec_sigcode_map(pr, pack.ep_emul)) 666 goto free_pack_abort; 667 668 #ifdef __HAVE_EXEC_MD_MAP 669 /* perform md specific mappings that process might need */ 670 if (exec_md_map(p, &pack)) 671 goto free_pack_abort; 672 #endif 673 674 if (pr->ps_flags & PS_TRACED) 675 psignal(p, SIGTRAP); 676 677 free(pack.ep_hdr, M_EXEC, pack.ep_hdrlen); 678 679 p->p_descfd = 255; 680 if ((pack.ep_flags & EXEC_HASFD) && pack.ep_fd < 255) 681 p->p_descfd = pack.ep_fd; 682 683 if (pack.ep_flags & EXEC_WXNEEDED) 684 p->p_p->ps_flags |= PS_WXNEEDED; 685 else 686 p->p_p->ps_flags &= ~PS_WXNEEDED; 687 688 /* update ps_emul, the old value is no longer needed */ 689 pr->ps_emul = pack.ep_emul; 690 691 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 692 single_thread_clear(p, P_SUSPSIG); 693 694 return (0); 695 696 bad: 697 /* free the vmspace-creation commands, and release their references */ 698 kill_vmcmds(&pack.ep_vmcmds); 699 /* kill any opened file descriptor, if necessary */ 700 if (pack.ep_flags & EXEC_HASFD) { 701 pack.ep_flags &= ~EXEC_HASFD; 702 fdplock(p->p_fd); 703 (void) fdrelease(p, pack.ep_fd); 704 fdpunlock(p->p_fd); 705 } 706 if (pack.ep_interp != NULL) 707 pool_put(&namei_pool, pack.ep_interp); 708 if (pack.ep_emul_arg != NULL) 709 free(pack.ep_emul_arg, M_TEMP, pack.ep_emul_argsize); 710 /* close and put the exec'd file */ 711 vn_close(pack.ep_vp, FREAD, cred, p); 712 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 713 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 714 715 freehdr: 716 free(pack.ep_hdr, M_EXEC, pack.ep_hdrlen); 717 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 718 single_thread_clear(p, P_SUSPSIG); 719 720 return (error); 721 722 exec_abort: 723 /* 724 * the old process doesn't exist anymore. exit gracefully. 725 * get rid of the (new) address space we have created, if any, get rid 726 * of our namei data and vnode, and exit noting failure 727 */ 728 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS, 729 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS); 730 if (pack.ep_interp != NULL) 731 pool_put(&namei_pool, pack.ep_interp); 732 if (pack.ep_emul_arg != NULL) 733 free(pack.ep_emul_arg, M_TEMP, pack.ep_emul_argsize); 734 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 735 vn_close(pack.ep_vp, FREAD, cred, p); 736 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 737 738 free_pack_abort: 739 free(pack.ep_hdr, M_EXEC, pack.ep_hdrlen); 740 exit1(p, W_EXITCODE(0, SIGABRT), EXIT_NORMAL); 741 742 /* NOTREACHED */ 743 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 744 745 return (0); 746 } 747 748 749 void * 750 copyargs(struct exec_package *pack, struct ps_strings *arginfo, void *stack, 751 void *argp) 752 { 753 char **cpp = stack; 754 char *dp, *sp; 755 size_t len; 756 void *nullp = NULL; 757 long argc = arginfo->ps_nargvstr; 758 int envc = arginfo->ps_nenvstr; 759 760 if (copyout(&argc, cpp++, sizeof(argc))) 761 return (NULL); 762 763 dp = (char *) (cpp + argc + envc + 2 + pack->ep_emul->e_arglen); 764 sp = argp; 765 766 /* XXX don't copy them out, remap them! */ 767 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 768 769 for (; --argc >= 0; sp += len, dp += len) 770 if (copyout(&dp, cpp++, sizeof(dp)) || 771 copyoutstr(sp, dp, ARG_MAX, &len)) 772 return (NULL); 773 774 if (copyout(&nullp, cpp++, sizeof(nullp))) 775 return (NULL); 776 777 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 778 779 for (; --envc >= 0; sp += len, dp += len) 780 if (copyout(&dp, cpp++, sizeof(dp)) || 781 copyoutstr(sp, dp, ARG_MAX, &len)) 782 return (NULL); 783 784 if (copyout(&nullp, cpp++, sizeof(nullp))) 785 return (NULL); 786 787 return (cpp); 788 } 789 790 int 791 exec_sigcode_map(struct process *pr, struct emul *e) 792 { 793 vsize_t sz; 794 795 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode; 796 797 /* 798 * If we don't have a sigobject for this emulation, create one. 799 * 800 * sigobject is an anonymous memory object (just like SYSV shared 801 * memory) that we keep a permanent reference to and that we map 802 * in all processes that need this sigcode. The creation is simple, 803 * we create an object, add a permanent reference to it, map it in 804 * kernel space, copy out the sigcode to it and unmap it. 805 * Then we map it with PROT_READ|PROT_EXEC into the process just 806 * the way sys_mmap would map it. 807 */ 808 if (e->e_sigobject == NULL) { 809 extern int sigfillsiz; 810 extern u_char sigfill[]; 811 size_t off; 812 vaddr_t va; 813 int r; 814 815 e->e_sigobject = uao_create(sz, 0); 816 uao_reference(e->e_sigobject); /* permanent reference */ 817 818 if ((r = uvm_map(kernel_map, &va, round_page(sz), e->e_sigobject, 819 0, 0, UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE, 820 MAP_INHERIT_SHARE, MADV_RANDOM, 0)))) { 821 uao_detach(e->e_sigobject); 822 return (ENOMEM); 823 } 824 825 for (off = 0; off < round_page(sz); off += sigfillsiz) 826 memcpy((caddr_t)va + off, sigfill, sigfillsiz); 827 memcpy((caddr_t)va, e->e_sigcode, sz); 828 uvm_unmap(kernel_map, va, va + round_page(sz)); 829 } 830 831 pr->ps_sigcode = 0; /* no hint */ 832 uao_reference(e->e_sigobject); 833 if (uvm_map(&pr->ps_vmspace->vm_map, &pr->ps_sigcode, round_page(sz), 834 e->e_sigobject, 0, 0, UVM_MAPFLAG(PROT_READ | PROT_EXEC, 835 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_INHERIT_COPY, 836 MADV_RANDOM, UVM_FLAG_COPYONW))) { 837 uao_detach(e->e_sigobject); 838 return (ENOMEM); 839 } 840 841 /* Calculate PC at point of sigreturn entry */ 842 pr->ps_sigcoderet = pr->ps_sigcode + 843 (pr->ps_emul->e_esigret - pr->ps_emul->e_sigcode); 844 845 return (0); 846 } 847