1 /* $OpenBSD: kern_exec.c,v 1.252 2023/10/30 07:13:10 claudio 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/proc.h> 40 #include <sys/user.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/fcntl.h> 47 #include <sys/file.h> 48 #include <sys/acct.h> 49 #include <sys/exec.h> 50 #include <sys/exec_elf.h> 51 #include <sys/ktrace.h> 52 #include <sys/resourcevar.h> 53 #include <sys/mman.h> 54 #include <sys/signalvar.h> 55 #include <sys/stat.h> 56 #include <sys/conf.h> 57 #include <sys/pledge.h> 58 #ifdef SYSVSHM 59 #include <sys/shm.h> 60 #endif 61 62 #include <sys/syscallargs.h> 63 64 #include <uvm/uvm_extern.h> 65 #include <machine/tcb.h> 66 67 #include <sys/timetc.h> 68 69 struct uvm_object *sigobject; /* shared sigcode object */ 70 vaddr_t sigcode_va; 71 vsize_t sigcode_sz; 72 struct uvm_object *timekeep_object; 73 struct timekeep *timekeep; 74 75 void unveil_destroy(struct process *ps); 76 77 const struct kmem_va_mode kv_exec = { 78 .kv_wait = 1, 79 .kv_map = &exec_map 80 }; 81 82 /* 83 * Map the shared signal code. 84 */ 85 int exec_sigcode_map(struct process *); 86 87 /* 88 * Map the shared timekeep page. 89 */ 90 int exec_timekeep_map(struct process *); 91 92 /* 93 * If non-zero, stackgap_random specifies the upper limit of the random gap size 94 * added to the fixed stack position. Must be n^2. 95 */ 96 int stackgap_random = STACKGAP_RANDOM; 97 98 /* 99 * check exec: 100 * given an "executable" described in the exec package's namei info, 101 * see what we can do with it. 102 * 103 * ON ENTRY: 104 * exec package with appropriate namei info 105 * proc pointer of exec'ing proc 106 * NO SELF-LOCKED VNODES 107 * 108 * ON EXIT: 109 * error: nothing held, etc. exec header still allocated. 110 * ok: filled exec package, one locked vnode. 111 * 112 * EXEC SWITCH ENTRY: 113 * Locked vnode to check, exec package, proc. 114 * 115 * EXEC SWITCH EXIT: 116 * ok: return 0, filled exec package, one locked vnode. 117 * error: destructive: 118 * everything deallocated except exec header. 119 * non-destructive: 120 * error code, locked vnode, exec header unmodified 121 */ 122 int 123 check_exec(struct proc *p, struct exec_package *epp) 124 { 125 int error, i; 126 struct vnode *vp; 127 struct nameidata *ndp; 128 size_t resid; 129 130 ndp = epp->ep_ndp; 131 ndp->ni_cnd.cn_nameiop = LOOKUP; 132 ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME; 133 if (epp->ep_flags & EXEC_INDIR) 134 ndp->ni_cnd.cn_flags |= BYPASSUNVEIL; 135 /* first get the vnode */ 136 if ((error = namei(ndp)) != 0) 137 return (error); 138 epp->ep_vp = vp = ndp->ni_vp; 139 140 /* check for regular file */ 141 if (vp->v_type != VREG) { 142 error = EACCES; 143 goto bad1; 144 } 145 146 /* get attributes */ 147 if ((error = VOP_GETATTR(vp, epp->ep_vap, p->p_ucred, p)) != 0) 148 goto bad1; 149 150 /* Check mount point */ 151 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 152 error = EACCES; 153 goto bad1; 154 } 155 156 /* SUID programs may not be started with execpromises */ 157 if ((epp->ep_vap->va_mode & (VSUID | VSGID)) && 158 (p->p_p->ps_flags & PS_EXECPLEDGE)) { 159 error = EACCES; 160 goto bad1; 161 } 162 163 if ((vp->v_mount->mnt_flag & MNT_NOSUID)) 164 epp->ep_vap->va_mode &= ~(VSUID | VSGID); 165 166 /* check access. for root we have to see if any exec bit on */ 167 if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0) 168 goto bad1; 169 if ((epp->ep_vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0) { 170 error = EACCES; 171 goto bad1; 172 } 173 174 /* try to open it */ 175 if ((error = VOP_OPEN(vp, FREAD, p->p_ucred, p)) != 0) 176 goto bad1; 177 178 /* unlock vp, we need it unlocked from here */ 179 VOP_UNLOCK(vp); 180 181 /* now we have the file, get the exec header */ 182 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0, 183 UIO_SYSSPACE, 0, p->p_ucred, &resid, p); 184 if (error) 185 goto bad2; 186 epp->ep_hdrvalid = epp->ep_hdrlen - resid; 187 188 /* 189 * set up the vmcmds for creation of the process 190 * address space 191 */ 192 error = ENOEXEC; 193 for (i = 0; i < nexecs && error != 0; i++) { 194 int newerror; 195 196 if (execsw[i].es_check == NULL) 197 continue; 198 newerror = (*execsw[i].es_check)(p, epp); 199 /* make sure the first "interesting" error code is saved. */ 200 if (!newerror || error == ENOEXEC) 201 error = newerror; 202 if (epp->ep_flags & EXEC_DESTR && error != 0) 203 return (error); 204 } 205 if (!error) { 206 /* check that entry point is sane */ 207 if (epp->ep_entry > VM_MAXUSER_ADDRESS) { 208 error = ENOEXEC; 209 } 210 211 /* check limits */ 212 if ((epp->ep_tsize > MAXTSIZ) || 213 (epp->ep_dsize > lim_cur(RLIMIT_DATA))) 214 error = ENOMEM; 215 216 if (!error) 217 return (0); 218 } 219 220 /* 221 * free any vmspace-creation commands, 222 * and release their references 223 */ 224 kill_vmcmds(&epp->ep_vmcmds); 225 226 bad2: 227 /* 228 * close the vnode, free the pathname buf, and punt. 229 */ 230 vn_close(vp, FREAD, p->p_ucred, p); 231 pool_put(&namei_pool, ndp->ni_cnd.cn_pnbuf); 232 return (error); 233 234 bad1: 235 /* 236 * free the namei pathname buffer, and put the vnode 237 * (which we don't yet have open). 238 */ 239 pool_put(&namei_pool, ndp->ni_cnd.cn_pnbuf); 240 vput(vp); 241 return (error); 242 } 243 244 /* 245 * exec system call 246 */ 247 int 248 sys_execve(struct proc *p, void *v, register_t *retval) 249 { 250 struct sys_execve_args /* { 251 syscallarg(const char *) path; 252 syscallarg(char *const *) argp; 253 syscallarg(char *const *) envp; 254 } */ *uap = v; 255 int error; 256 struct exec_package pack; 257 struct nameidata nid; 258 struct vattr attr; 259 struct ucred *cred = p->p_ucred; 260 char *argp; 261 char * const *cpp, *dp, *sp; 262 #ifdef KTRACE 263 char *env_start; 264 #endif 265 struct process *pr = p->p_p; 266 long argc, envc; 267 size_t len, sgap, dstsize; 268 #ifdef MACHINE_STACK_GROWS_UP 269 size_t slen; 270 #endif 271 vaddr_t pc = PROC_PC(p); 272 char *stack; 273 struct ps_strings arginfo; 274 struct vmspace *vm = p->p_vmspace; 275 struct vnode *otvp; 276 277 if (vm->vm_execve && 278 (pc >= vm->vm_execve_end || pc < vm->vm_execve)) { 279 printf("%s(%d): execve %lx outside %lx-%lx\n", pr->ps_comm, 280 pr->ps_pid, pc, vm->vm_execve, vm->vm_execve_end); 281 p->p_p->ps_acflag |= AEXECVE; 282 sigabort(p); 283 return (0); 284 } 285 286 /* 287 * Get other threads to stop, if contested return ERESTART, 288 * so the syscall is restarted after halting in userret. 289 */ 290 if (single_thread_set(p, SINGLE_UNWIND | SINGLE_DEEP)) 291 return (ERESTART); 292 293 /* 294 * Cheap solution to complicated problems. 295 * Mark this process as "leave me alone, I'm execing". 296 */ 297 atomic_setbits_int(&pr->ps_flags, PS_INEXEC); 298 299 NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 300 nid.ni_pledge = PLEDGE_EXEC; 301 nid.ni_unveil = UNVEIL_EXEC; 302 303 /* 304 * initialize the fields of the exec package. 305 */ 306 pack.ep_name = (char *)SCARG(uap, path); 307 pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK); 308 pack.ep_hdrlen = exec_maxhdrsz; 309 pack.ep_hdrvalid = 0; 310 pack.ep_ndp = &nid; 311 pack.ep_interp = NULL; 312 pack.ep_args = NULL; 313 pack.ep_auxinfo = NULL; 314 VMCMDSET_INIT(&pack.ep_vmcmds); 315 pack.ep_vap = &attr; 316 pack.ep_flags = 0; 317 318 /* see if we can run it. */ 319 if ((error = check_exec(p, &pack)) != 0) { 320 goto freehdr; 321 } 322 323 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */ 324 325 /* allocate an argument buffer */ 326 argp = km_alloc(NCARGS, &kv_exec, &kp_pageable, &kd_waitok); 327 #ifdef DIAGNOSTIC 328 if (argp == NULL) 329 panic("execve: argp == NULL"); 330 #endif 331 dp = argp; 332 argc = 0; 333 334 /* 335 * Copy the fake args list, if there's one, freeing it as we go. 336 * exec_script_makecmds() allocates either 2 or 3 fake args bounded 337 * by MAXINTERP + MAXPATHLEN < NCARGS so no overflow can happen. 338 */ 339 if (pack.ep_flags & EXEC_HASARGL) { 340 dstsize = NCARGS; 341 for(; pack.ep_fa[argc] != NULL; argc++) { 342 len = strlcpy(dp, pack.ep_fa[argc], dstsize); 343 len++; 344 dp += len; dstsize -= len; 345 if (pack.ep_fa[argc+1] != NULL) 346 free(pack.ep_fa[argc], M_EXEC, len); 347 else 348 free(pack.ep_fa[argc], M_EXEC, MAXPATHLEN); 349 } 350 free(pack.ep_fa, M_EXEC, 4 * sizeof(char *)); 351 pack.ep_flags &= ~EXEC_HASARGL; 352 } 353 354 /* Now get argv & environment */ 355 if (!(cpp = SCARG(uap, argp))) { 356 error = EFAULT; 357 goto bad; 358 } 359 360 if (pack.ep_flags & EXEC_SKIPARG) 361 cpp++; 362 363 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 argc++; 377 } 378 379 /* must have at least one argument */ 380 if (argc == 0) { 381 error = EINVAL; 382 goto bad; 383 } 384 385 #ifdef KTRACE 386 if (KTRPOINT(p, KTR_EXECARGS)) 387 ktrexec(p, KTR_EXECARGS, argp, dp - argp); 388 #endif 389 390 envc = 0; 391 /* environment does not need to be there */ 392 if ((cpp = SCARG(uap, envp)) != NULL ) { 393 #ifdef KTRACE 394 env_start = dp; 395 #endif 396 while (1) { 397 len = argp + ARG_MAX - dp; 398 if ((error = copyin(cpp, &sp, sizeof(sp))) != 0) 399 goto bad; 400 if (!sp) 401 break; 402 if ((error = copyinstr(sp, dp, len, &len)) != 0) { 403 if (error == ENAMETOOLONG) 404 error = E2BIG; 405 goto bad; 406 } 407 dp += len; 408 cpp++; 409 envc++; 410 } 411 412 #ifdef KTRACE 413 if (KTRPOINT(p, KTR_EXECENV)) 414 ktrexec(p, KTR_EXECENV, env_start, dp - env_start); 415 #endif 416 } 417 418 dp = (char *)(((long)dp + _STACKALIGNBYTES) & ~_STACKALIGNBYTES); 419 420 /* 421 * If we have enabled random stackgap, the stack itself has already 422 * been moved from a random location, but is still aligned to a page 423 * boundary. Provide the lower bits of random placement now. 424 */ 425 if (stackgap_random == 0) { 426 sgap = 0; 427 } else { 428 sgap = arc4random() & PAGE_MASK; 429 sgap = (sgap + _STACKALIGNBYTES) & ~_STACKALIGNBYTES; 430 } 431 432 /* Now check if args & environ fit into new stack */ 433 len = ((argc + envc + 2 + ELF_AUX_WORDS) * sizeof(char *) + 434 sizeof(long) + dp + sgap + sizeof(struct ps_strings)) - argp; 435 436 len = (len + _STACKALIGNBYTES) &~ _STACKALIGNBYTES; 437 438 if (len > pack.ep_ssize) { /* in effect, compare to initial limit */ 439 error = ENOMEM; 440 goto bad; 441 } 442 443 /* adjust "active stack depth" for process VSZ */ 444 pack.ep_ssize = len; /* maybe should go elsewhere, but... */ 445 446 /* 447 * we're committed: any further errors will kill the process, so 448 * kill the other threads now. 449 */ 450 single_thread_set(p, SINGLE_EXIT); 451 452 /* 453 * Prepare vmspace for remapping. Note that uvmspace_exec can replace 454 * ps_vmspace! 455 */ 456 uvmspace_exec(p, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS); 457 458 vm = pr->ps_vmspace; 459 /* Now map address space */ 460 vm->vm_taddr = (char *)trunc_page(pack.ep_taddr); 461 vm->vm_tsize = atop(round_page(pack.ep_taddr + pack.ep_tsize) - 462 trunc_page(pack.ep_taddr)); 463 vm->vm_daddr = (char *)trunc_page(pack.ep_daddr); 464 vm->vm_dsize = atop(round_page(pack.ep_daddr + pack.ep_dsize) - 465 trunc_page(pack.ep_daddr)); 466 vm->vm_dused = 0; 467 vm->vm_ssize = atop(round_page(pack.ep_ssize)); 468 vm->vm_maxsaddr = (char *)pack.ep_maxsaddr; 469 vm->vm_minsaddr = (char *)pack.ep_minsaddr; 470 471 /* create the new process's VM space by running the vmcmds */ 472 #ifdef DIAGNOSTIC 473 if (pack.ep_vmcmds.evs_used == 0) 474 panic("execve: no vmcmds"); 475 #endif 476 error = exec_process_vmcmds(p, &pack); 477 478 /* if an error happened, deallocate and punt */ 479 if (error) 480 goto exec_abort; 481 482 #ifdef MACHINE_STACK_GROWS_UP 483 pr->ps_strings = (vaddr_t)vm->vm_maxsaddr + sgap; 484 if (uvm_map_protect(&vm->vm_map, (vaddr_t)vm->vm_maxsaddr, 485 trunc_page(pr->ps_strings), PROT_NONE, 0, TRUE, FALSE)) 486 goto exec_abort; 487 #else 488 pr->ps_strings = (vaddr_t)vm->vm_minsaddr - sizeof(arginfo) - sgap; 489 if (uvm_map_protect(&vm->vm_map, 490 round_page(pr->ps_strings + sizeof(arginfo)), 491 (vaddr_t)vm->vm_minsaddr, PROT_NONE, 0, TRUE, FALSE)) 492 goto exec_abort; 493 #endif 494 495 memset(&arginfo, 0, sizeof(arginfo)); 496 497 /* remember information about the process */ 498 arginfo.ps_nargvstr = argc; 499 arginfo.ps_nenvstr = envc; 500 501 #ifdef MACHINE_STACK_GROWS_UP 502 stack = (char *)vm->vm_maxsaddr + sizeof(arginfo) + sgap; 503 slen = len - sizeof(arginfo) - sgap; 504 #else 505 stack = (char *)(vm->vm_minsaddr - len); 506 #endif 507 /* Now copy argc, args & environ to new stack */ 508 if (!copyargs(&pack, &arginfo, stack, argp)) 509 goto exec_abort; 510 511 pr->ps_auxinfo = (vaddr_t)pack.ep_auxinfo; 512 513 /* copy out the process's ps_strings structure */ 514 if (copyout(&arginfo, (char *)pr->ps_strings, sizeof(arginfo))) 515 goto exec_abort; 516 517 stopprofclock(pr); /* stop profiling */ 518 fdcloseexec(p); /* handle close on exec */ 519 execsigs(p); /* reset caught signals */ 520 TCB_SET(p, NULL); /* reset the TCB address */ 521 pr->ps_kbind_addr = 0; /* reset the kbind bits */ 522 pr->ps_kbind_cookie = 0; 523 arc4random_buf(&pr->ps_sigcookie, sizeof pr->ps_sigcookie); 524 525 /* set command name & other accounting info */ 526 memset(pr->ps_comm, 0, sizeof(pr->ps_comm)); 527 strlcpy(pr->ps_comm, nid.ni_cnd.cn_nameptr, sizeof(pr->ps_comm)); 528 pr->ps_acflag &= ~AFORK; 529 530 /* record proc's vnode, for use by sysctl */ 531 otvp = pr->ps_textvp; 532 vref(pack.ep_vp); 533 pr->ps_textvp = pack.ep_vp; 534 if (otvp) 535 vrele(otvp); 536 537 if (pack.ep_flags & EXEC_NOBTCFI) 538 atomic_setbits_int(&p->p_p->ps_flags, PS_NOBTCFI); 539 else 540 atomic_clearbits_int(&p->p_p->ps_flags, PS_NOBTCFI); 541 542 atomic_setbits_int(&pr->ps_flags, PS_EXEC); 543 if (pr->ps_flags & PS_PPWAIT) { 544 atomic_clearbits_int(&pr->ps_flags, PS_PPWAIT); 545 atomic_clearbits_int(&pr->ps_pptr->ps_flags, PS_ISPWAIT); 546 wakeup(pr->ps_pptr); 547 } 548 549 /* 550 * If process does execve() while it has a mismatched real, 551 * effective, or saved uid/gid, we set PS_SUGIDEXEC. 552 */ 553 if (cred->cr_uid != cred->cr_ruid || 554 cred->cr_uid != cred->cr_svuid || 555 cred->cr_gid != cred->cr_rgid || 556 cred->cr_gid != cred->cr_svgid) 557 atomic_setbits_int(&pr->ps_flags, PS_SUGIDEXEC); 558 else 559 atomic_clearbits_int(&pr->ps_flags, PS_SUGIDEXEC); 560 561 if (pr->ps_flags & PS_EXECPLEDGE) { 562 pr->ps_pledge = pr->ps_execpledge; 563 atomic_setbits_int(&pr->ps_flags, PS_PLEDGE); 564 } else { 565 atomic_clearbits_int(&pr->ps_flags, PS_PLEDGE); 566 pr->ps_pledge = 0; 567 /* XXX XXX XXX XXX */ 568 /* Clear our unveil paths out so the child 569 * starts afresh 570 */ 571 unveil_destroy(pr); 572 pr->ps_uvdone = 0; 573 } 574 575 /* 576 * deal with set[ug]id. 577 * MNT_NOEXEC has already been used to disable s[ug]id. 578 */ 579 if ((attr.va_mode & (VSUID | VSGID)) && proc_cansugid(p)) { 580 int i; 581 582 atomic_setbits_int(&pr->ps_flags, PS_SUGID|PS_SUGIDEXEC); 583 584 #ifdef KTRACE 585 /* 586 * If process is being ktraced, turn off - unless 587 * root set it. 588 */ 589 if (pr->ps_tracevp && !(pr->ps_traceflag & KTRFAC_ROOT)) 590 ktrcleartrace(pr); 591 #endif 592 p->p_ucred = cred = crcopy(cred); 593 if (attr.va_mode & VSUID) 594 cred->cr_uid = attr.va_uid; 595 if (attr.va_mode & VSGID) 596 cred->cr_gid = attr.va_gid; 597 598 /* 599 * For set[ug]id processes, a few caveats apply to 600 * stdin, stdout, and stderr. 601 */ 602 error = 0; 603 fdplock(p->p_fd); 604 for (i = 0; i < 3; i++) { 605 struct file *fp = NULL; 606 607 /* 608 * NOTE - This will never return NULL because of 609 * immature fds. The file descriptor table is not 610 * shared because we're suid. 611 */ 612 fp = fd_getfile(p->p_fd, i); 613 614 /* 615 * Ensure that stdin, stdout, and stderr are already 616 * allocated. We do not want userland to accidentally 617 * allocate descriptors in this range which has implied 618 * meaning to libc. 619 */ 620 if (fp == NULL) { 621 short flags = FREAD | (i == 0 ? 0 : FWRITE); 622 struct vnode *vp; 623 int indx; 624 625 if ((error = falloc(p, &fp, &indx)) != 0) 626 break; 627 #ifdef DIAGNOSTIC 628 if (indx != i) 629 panic("sys_execve: falloc indx != i"); 630 #endif 631 if ((error = cdevvp(getnulldev(), &vp)) != 0) { 632 fdremove(p->p_fd, indx); 633 closef(fp, p); 634 break; 635 } 636 if ((error = VOP_OPEN(vp, flags, cred, p)) != 0) { 637 fdremove(p->p_fd, indx); 638 closef(fp, p); 639 vrele(vp); 640 break; 641 } 642 if (flags & FWRITE) 643 vp->v_writecount++; 644 fp->f_flag = flags; 645 fp->f_type = DTYPE_VNODE; 646 fp->f_ops = &vnops; 647 fp->f_data = (caddr_t)vp; 648 fdinsert(p->p_fd, indx, 0, fp); 649 } 650 FRELE(fp, p); 651 } 652 fdpunlock(p->p_fd); 653 if (error) 654 goto exec_abort; 655 } else 656 atomic_clearbits_int(&pr->ps_flags, PS_SUGID); 657 658 /* 659 * Reset the saved ugids and update the process's copy of the 660 * creds if the creds have been changed 661 */ 662 if (cred->cr_uid != cred->cr_svuid || 663 cred->cr_gid != cred->cr_svgid) { 664 /* make sure we have unshared ucreds */ 665 p->p_ucred = cred = crcopy(cred); 666 cred->cr_svuid = cred->cr_uid; 667 cred->cr_svgid = cred->cr_gid; 668 } 669 670 if (pr->ps_ucred != cred) { 671 struct ucred *ocred; 672 673 ocred = pr->ps_ucred; 674 crhold(cred); 675 pr->ps_ucred = cred; 676 crfree(ocred); 677 } 678 679 if (pr->ps_flags & PS_SUGIDEXEC) { 680 cancel_all_itimers(); 681 } 682 683 /* reset CPU time usage for the thread, but not the process */ 684 timespecclear(&p->p_tu.tu_runtime); 685 p->p_tu.tu_uticks = p->p_tu.tu_sticks = p->p_tu.tu_iticks = 0; 686 687 memset(p->p_name, 0, sizeof p->p_name); 688 689 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 690 691 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 692 vn_close(pack.ep_vp, FREAD, cred, p); 693 694 /* 695 * notify others that we exec'd 696 */ 697 knote_locked(&pr->ps_klist, NOTE_EXEC); 698 699 /* map the process's timekeep page, needs to be before exec_elf_fixup */ 700 if (exec_timekeep_map(pr)) 701 goto free_pack_abort; 702 703 /* setup new registers and do misc. setup. */ 704 if (exec_elf_fixup(p, &pack) != 0) 705 goto free_pack_abort; 706 #ifdef MACHINE_STACK_GROWS_UP 707 setregs(p, &pack, (u_long)stack + slen, &arginfo); 708 #else 709 setregs(p, &pack, (u_long)stack, &arginfo); 710 #endif 711 712 /* map the process's signal trampoline code */ 713 if (exec_sigcode_map(pr)) 714 goto free_pack_abort; 715 716 #ifdef __HAVE_EXEC_MD_MAP 717 /* perform md specific mappings that process might need */ 718 if (exec_md_map(p, &pack)) 719 goto free_pack_abort; 720 #endif 721 722 if (pr->ps_flags & PS_TRACED) 723 psignal(p, SIGTRAP); 724 725 free(pack.ep_hdr, M_EXEC, pack.ep_hdrlen); 726 727 p->p_descfd = 255; 728 if ((pack.ep_flags & EXEC_HASFD) && pack.ep_fd < 255) 729 p->p_descfd = pack.ep_fd; 730 731 if (pack.ep_flags & EXEC_WXNEEDED) 732 atomic_setbits_int(&p->p_p->ps_flags, PS_WXNEEDED); 733 else 734 atomic_clearbits_int(&p->p_p->ps_flags, PS_WXNEEDED); 735 736 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 737 single_thread_clear(p, P_SUSPSIG); 738 739 /* setregs() sets up all the registers, so just 'return' */ 740 return EJUSTRETURN; 741 742 bad: 743 /* free the vmspace-creation commands, and release their references */ 744 kill_vmcmds(&pack.ep_vmcmds); 745 /* kill any opened file descriptor, if necessary */ 746 if (pack.ep_flags & EXEC_HASFD) { 747 pack.ep_flags &= ~EXEC_HASFD; 748 fdplock(p->p_fd); 749 /* fdrelease unlocks p->p_fd. */ 750 (void) fdrelease(p, pack.ep_fd); 751 } 752 if (pack.ep_interp != NULL) 753 pool_put(&namei_pool, pack.ep_interp); 754 free(pack.ep_args, M_TEMP, sizeof *pack.ep_args); 755 /* close and put the exec'd file */ 756 vn_close(pack.ep_vp, FREAD, cred, p); 757 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 758 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 759 760 freehdr: 761 free(pack.ep_hdr, M_EXEC, pack.ep_hdrlen); 762 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 763 single_thread_clear(p, P_SUSPSIG); 764 765 return (error); 766 767 exec_abort: 768 /* 769 * the old process doesn't exist anymore. exit gracefully. 770 * get rid of the (new) address space we have created, if any, get rid 771 * of our namei data and vnode, and exit noting failure 772 */ 773 uvm_unmap(&vm->vm_map, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS); 774 if (pack.ep_interp != NULL) 775 pool_put(&namei_pool, pack.ep_interp); 776 free(pack.ep_args, M_TEMP, sizeof *pack.ep_args); 777 pool_put(&namei_pool, nid.ni_cnd.cn_pnbuf); 778 vn_close(pack.ep_vp, FREAD, cred, p); 779 km_free(argp, NCARGS, &kv_exec, &kp_pageable); 780 781 free_pack_abort: 782 free(pack.ep_hdr, M_EXEC, pack.ep_hdrlen); 783 exit1(p, 0, SIGABRT, EXIT_NORMAL); 784 785 /* NOTREACHED */ 786 atomic_clearbits_int(&pr->ps_flags, PS_INEXEC); 787 788 return (0); 789 } 790 791 792 int 793 copyargs(struct exec_package *pack, struct ps_strings *arginfo, void *stack, 794 void *argp) 795 { 796 char **cpp = stack; 797 char *dp, *sp; 798 size_t len; 799 void *nullp = NULL; 800 long argc = arginfo->ps_nargvstr; 801 int envc = arginfo->ps_nenvstr; 802 803 if (copyout(&argc, cpp++, sizeof(argc))) 804 return (0); 805 806 dp = (char *) (cpp + argc + envc + 2 + ELF_AUX_WORDS); 807 sp = argp; 808 809 /* XXX don't copy them out, remap them! */ 810 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 811 812 for (; --argc >= 0; sp += len, dp += len) 813 if (copyout(&dp, cpp++, sizeof(dp)) || 814 copyoutstr(sp, dp, ARG_MAX, &len)) 815 return (0); 816 817 if (copyout(&nullp, cpp++, sizeof(nullp))) 818 return (0); 819 820 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 821 822 for (; --envc >= 0; sp += len, dp += len) 823 if (copyout(&dp, cpp++, sizeof(dp)) || 824 copyoutstr(sp, dp, ARG_MAX, &len)) 825 return (0); 826 827 if (copyout(&nullp, cpp++, sizeof(nullp))) 828 return (0); 829 830 /* if this process needs auxinfo, note where to place it */ 831 if (pack->ep_args != NULL) 832 pack->ep_auxinfo = cpp; 833 834 return (1); 835 } 836 837 int 838 exec_sigcode_map(struct process *pr) 839 { 840 extern char sigcode[], esigcode[], sigcoderet[]; 841 vsize_t sz; 842 843 sz = (vaddr_t)esigcode - (vaddr_t)sigcode; 844 845 /* 846 * If we don't have a sigobject yet, create one. 847 * 848 * sigobject is an anonymous memory object (just like SYSV shared 849 * memory) that we keep a permanent reference to and that we map 850 * in all processes that need this sigcode. The creation is simple, 851 * we create an object, add a permanent reference to it, map it in 852 * kernel space, copy out the sigcode to it and unmap it. Then we map 853 * it with PROT_EXEC into the process just the way sys_mmap would map it. 854 */ 855 if (sigobject == NULL) { 856 extern int sigfillsiz; 857 extern u_char sigfill[]; 858 size_t off, left; 859 vaddr_t va; 860 int r; 861 862 sigobject = uao_create(sz, 0); 863 uao_reference(sigobject); /* permanent reference */ 864 865 if ((r = uvm_map(kernel_map, &va, round_page(sz), sigobject, 866 0, 0, UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE, 867 MAP_INHERIT_SHARE, MADV_RANDOM, 0)))) { 868 uao_detach(sigobject); 869 return (ENOMEM); 870 } 871 872 for (off = 0, left = round_page(sz); left != 0; 873 off += sigfillsiz) { 874 size_t chunk = ulmin(left, sigfillsiz); 875 memcpy((caddr_t)va + off, sigfill, chunk); 876 left -= chunk; 877 } 878 memcpy((caddr_t)va, sigcode, sz); 879 880 (void) uvm_map_protect(kernel_map, va, round_page(sz), 881 PROT_READ, 0, FALSE, FALSE); 882 sigcode_va = va; 883 sigcode_sz = round_page(sz); 884 } 885 886 pr->ps_sigcode = 0; /* no hint */ 887 uao_reference(sigobject); 888 if (uvm_map(&pr->ps_vmspace->vm_map, &pr->ps_sigcode, round_page(sz), 889 sigobject, 0, 0, UVM_MAPFLAG(PROT_EXEC, 890 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_INHERIT_COPY, 891 MADV_RANDOM, UVM_FLAG_COPYONW | UVM_FLAG_SYSCALL))) { 892 uao_detach(sigobject); 893 return (ENOMEM); 894 } 895 uvm_map_immutable(&pr->ps_vmspace->vm_map, pr->ps_sigcode, 896 pr->ps_sigcode + round_page(sz), 1); 897 898 /* Calculate PC at point of sigreturn entry */ 899 pr->ps_sigcoderet = pr->ps_sigcode + (sigcoderet - sigcode); 900 901 return (0); 902 } 903 904 int 905 exec_timekeep_map(struct process *pr) 906 { 907 size_t timekeep_sz = round_page(sizeof(struct timekeep)); 908 909 /* 910 * Similar to the sigcode object 911 */ 912 if (timekeep_object == NULL) { 913 vaddr_t va = 0; 914 915 timekeep_object = uao_create(timekeep_sz, 0); 916 uao_reference(timekeep_object); 917 918 if (uvm_map(kernel_map, &va, timekeep_sz, timekeep_object, 919 0, 0, UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE, 920 MAP_INHERIT_SHARE, MADV_RANDOM, 0))) { 921 uao_detach(timekeep_object); 922 timekeep_object = NULL; 923 return (ENOMEM); 924 } 925 if (uvm_fault_wire(kernel_map, va, va + timekeep_sz, 926 PROT_READ | PROT_WRITE)) { 927 uvm_unmap(kernel_map, va, va + timekeep_sz); 928 uao_detach(timekeep_object); 929 timekeep_object = NULL; 930 return (ENOMEM); 931 } 932 933 timekeep = (struct timekeep *)va; 934 timekeep->tk_version = TK_VERSION; 935 } 936 937 pr->ps_timekeep = 0; /* no hint */ 938 uao_reference(timekeep_object); 939 if (uvm_map(&pr->ps_vmspace->vm_map, &pr->ps_timekeep, timekeep_sz, 940 timekeep_object, 0, 0, UVM_MAPFLAG(PROT_READ, PROT_READ, 941 MAP_INHERIT_COPY, MADV_RANDOM, 0))) { 942 uao_detach(timekeep_object); 943 return (ENOMEM); 944 } 945 uvm_map_immutable(&pr->ps_vmspace->vm_map, pr->ps_timekeep, 946 pr->ps_timekeep + timekeep_sz, 1); 947 948 return (0); 949 } 950