1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1993, David Greenman 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_capsicum.h" 33 #include "opt_hwpmc_hooks.h" 34 #include "opt_ktrace.h" 35 #include "opt_vm.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/acct.h> 40 #include <sys/asan.h> 41 #include <sys/capsicum.h> 42 #include <sys/compressor.h> 43 #include <sys/eventhandler.h> 44 #include <sys/exec.h> 45 #include <sys/fcntl.h> 46 #include <sys/filedesc.h> 47 #include <sys/imgact.h> 48 #include <sys/imgact_elf.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/malloc.h> 52 #include <sys/mman.h> 53 #include <sys/mount.h> 54 #include <sys/mutex.h> 55 #include <sys/namei.h> 56 #include <sys/priv.h> 57 #include <sys/proc.h> 58 #include <sys/ptrace.h> 59 #include <sys/reg.h> 60 #include <sys/resourcevar.h> 61 #include <sys/rwlock.h> 62 #include <sys/sched.h> 63 #include <sys/sdt.h> 64 #include <sys/sf_buf.h> 65 #include <sys/shm.h> 66 #include <sys/signalvar.h> 67 #include <sys/smp.h> 68 #include <sys/stat.h> 69 #include <sys/syscallsubr.h> 70 #include <sys/sysctl.h> 71 #include <sys/sysent.h> 72 #include <sys/sysproto.h> 73 #include <sys/timers.h> 74 #include <sys/umtxvar.h> 75 #include <sys/vnode.h> 76 #include <sys/wait.h> 77 #ifdef KTRACE 78 #include <sys/ktrace.h> 79 #endif 80 81 #include <vm/vm.h> 82 #include <vm/vm_param.h> 83 #include <vm/pmap.h> 84 #include <vm/vm_page.h> 85 #include <vm/vm_map.h> 86 #include <vm/vm_kern.h> 87 #include <vm/vm_extern.h> 88 #include <vm/vm_object.h> 89 #include <vm/vm_pager.h> 90 91 #ifdef HWPMC_HOOKS 92 #include <sys/pmckern.h> 93 #endif 94 95 #include <security/audit/audit.h> 96 #include <security/mac/mac_framework.h> 97 98 #ifdef KDTRACE_HOOKS 99 #include <sys/dtrace_bsd.h> 100 dtrace_execexit_func_t dtrace_fasttrap_exec; 101 #endif 102 103 SDT_PROVIDER_DECLARE(proc); 104 SDT_PROBE_DEFINE1(proc, , , exec, "char *"); 105 SDT_PROBE_DEFINE1(proc, , , exec__failure, "int"); 106 SDT_PROBE_DEFINE1(proc, , , exec__success, "char *"); 107 108 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments"); 109 110 int coredump_pack_fileinfo = 1; 111 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN, 112 &coredump_pack_fileinfo, 0, 113 "Enable file path packing in 'procstat -f' coredump notes"); 114 115 int coredump_pack_vmmapinfo = 1; 116 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN, 117 &coredump_pack_vmmapinfo, 0, 118 "Enable file path packing in 'procstat -v' coredump notes"); 119 120 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS); 121 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS); 122 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS); 123 static int do_execve(struct thread *td, struct image_args *args, 124 struct mac *mac_p, struct vmspace *oldvmspace); 125 126 /* XXX This should be vm_size_t. */ 127 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD| 128 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU", 129 "Location of process' ps_strings structure"); 130 131 /* XXX This should be vm_size_t. */ 132 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD| 133 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU", 134 "Top of process stack"); 135 136 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE, 137 NULL, 0, sysctl_kern_stackprot, "I", 138 "Stack memory permissions"); 139 140 u_long ps_arg_cache_limit = PAGE_SIZE / 16; 141 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW, 142 &ps_arg_cache_limit, 0, 143 "Process' command line characters cache limit"); 144 145 static int disallow_high_osrel; 146 SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW, 147 &disallow_high_osrel, 0, 148 "Disallow execution of binaries built for higher version of the world"); 149 150 static int map_at_zero = 0; 151 SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0, 152 "Permit processes to map an object at virtual address 0."); 153 154 static int core_dump_can_intr = 1; 155 SYSCTL_INT(_kern, OID_AUTO, core_dump_can_intr, CTLFLAG_RWTUN, 156 &core_dump_can_intr, 0, 157 "Core dumping interruptible with SIGKILL"); 158 159 static int 160 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS) 161 { 162 struct proc *p; 163 vm_offset_t ps_strings; 164 165 p = curproc; 166 #ifdef SCTL_MASK32 167 if (req->flags & SCTL_MASK32) { 168 unsigned int val; 169 val = (unsigned int)PROC_PS_STRINGS(p); 170 return (SYSCTL_OUT(req, &val, sizeof(val))); 171 } 172 #endif 173 ps_strings = PROC_PS_STRINGS(p); 174 return (SYSCTL_OUT(req, &ps_strings, sizeof(ps_strings))); 175 } 176 177 static int 178 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS) 179 { 180 struct proc *p; 181 vm_offset_t val; 182 183 p = curproc; 184 #ifdef SCTL_MASK32 185 if (req->flags & SCTL_MASK32) { 186 unsigned int val32; 187 188 val32 = round_page((unsigned int)p->p_vmspace->vm_stacktop); 189 return (SYSCTL_OUT(req, &val32, sizeof(val32))); 190 } 191 #endif 192 val = round_page(p->p_vmspace->vm_stacktop); 193 return (SYSCTL_OUT(req, &val, sizeof(val))); 194 } 195 196 static int 197 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS) 198 { 199 struct proc *p; 200 201 p = curproc; 202 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot, 203 sizeof(p->p_sysent->sv_stackprot))); 204 } 205 206 /* 207 * Each of the items is a pointer to a `const struct execsw', hence the 208 * double pointer here. 209 */ 210 static const struct execsw **execsw; 211 212 #ifndef _SYS_SYSPROTO_H_ 213 struct execve_args { 214 char *fname; 215 char **argv; 216 char **envv; 217 }; 218 #endif 219 220 int 221 sys_execve(struct thread *td, struct execve_args *uap) 222 { 223 struct image_args args; 224 struct vmspace *oldvmspace; 225 int error; 226 227 error = pre_execve(td, &oldvmspace); 228 if (error != 0) 229 return (error); 230 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, 231 uap->argv, uap->envv); 232 if (error == 0) 233 error = kern_execve(td, &args, NULL, oldvmspace); 234 post_execve(td, error, oldvmspace); 235 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 236 return (error); 237 } 238 239 #ifndef _SYS_SYSPROTO_H_ 240 struct fexecve_args { 241 int fd; 242 char **argv; 243 char **envv; 244 }; 245 #endif 246 int 247 sys_fexecve(struct thread *td, struct fexecve_args *uap) 248 { 249 struct image_args args; 250 struct vmspace *oldvmspace; 251 int error; 252 253 error = pre_execve(td, &oldvmspace); 254 if (error != 0) 255 return (error); 256 error = exec_copyin_args(&args, NULL, UIO_SYSSPACE, 257 uap->argv, uap->envv); 258 if (error == 0) { 259 args.fd = uap->fd; 260 error = kern_execve(td, &args, NULL, oldvmspace); 261 } 262 post_execve(td, error, oldvmspace); 263 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 264 return (error); 265 } 266 267 #ifndef _SYS_SYSPROTO_H_ 268 struct __mac_execve_args { 269 char *fname; 270 char **argv; 271 char **envv; 272 struct mac *mac_p; 273 }; 274 #endif 275 276 int 277 sys___mac_execve(struct thread *td, struct __mac_execve_args *uap) 278 { 279 #ifdef MAC 280 struct image_args args; 281 struct vmspace *oldvmspace; 282 int error; 283 284 error = pre_execve(td, &oldvmspace); 285 if (error != 0) 286 return (error); 287 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, 288 uap->argv, uap->envv); 289 if (error == 0) 290 error = kern_execve(td, &args, uap->mac_p, oldvmspace); 291 post_execve(td, error, oldvmspace); 292 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 293 return (error); 294 #else 295 return (ENOSYS); 296 #endif 297 } 298 299 int 300 pre_execve(struct thread *td, struct vmspace **oldvmspace) 301 { 302 struct proc *p; 303 int error; 304 305 KASSERT(td == curthread, ("non-current thread %p", td)); 306 error = 0; 307 p = td->td_proc; 308 if ((p->p_flag & P_HADTHREADS) != 0) { 309 PROC_LOCK(p); 310 if (thread_single(p, SINGLE_BOUNDARY) != 0) 311 error = ERESTART; 312 PROC_UNLOCK(p); 313 } 314 KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0, 315 ("nested execve")); 316 *oldvmspace = p->p_vmspace; 317 return (error); 318 } 319 320 void 321 post_execve(struct thread *td, int error, struct vmspace *oldvmspace) 322 { 323 struct proc *p; 324 325 KASSERT(td == curthread, ("non-current thread %p", td)); 326 p = td->td_proc; 327 if ((p->p_flag & P_HADTHREADS) != 0) { 328 PROC_LOCK(p); 329 /* 330 * If success, we upgrade to SINGLE_EXIT state to 331 * force other threads to suicide. 332 */ 333 if (error == EJUSTRETURN) 334 thread_single(p, SINGLE_EXIT); 335 else 336 thread_single_end(p, SINGLE_BOUNDARY); 337 PROC_UNLOCK(p); 338 } 339 exec_cleanup(td, oldvmspace); 340 } 341 342 /* 343 * kern_execve() has the astonishing property of not always returning to 344 * the caller. If sufficiently bad things happen during the call to 345 * do_execve(), it can end up calling exit1(); as a result, callers must 346 * avoid doing anything which they might need to undo (e.g., allocating 347 * memory). 348 */ 349 int 350 kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 351 struct vmspace *oldvmspace) 352 { 353 354 TSEXEC(td->td_proc->p_pid, args->begin_argv); 355 AUDIT_ARG_ARGV(args->begin_argv, args->argc, 356 exec_args_get_begin_envv(args) - args->begin_argv); 357 AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc, 358 args->endp - exec_args_get_begin_envv(args)); 359 360 /* Must have at least one argument. */ 361 if (args->argc == 0) { 362 exec_free_args(args); 363 return (EINVAL); 364 } 365 return (do_execve(td, args, mac_p, oldvmspace)); 366 } 367 368 static void 369 execve_nosetid(struct image_params *imgp) 370 { 371 imgp->credential_setid = false; 372 if (imgp->newcred != NULL) { 373 crfree(imgp->newcred); 374 imgp->newcred = NULL; 375 } 376 } 377 378 /* 379 * In-kernel implementation of execve(). All arguments are assumed to be 380 * userspace pointers from the passed thread. 381 */ 382 static int 383 do_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 384 struct vmspace *oldvmspace) 385 { 386 struct proc *p = td->td_proc; 387 struct nameidata nd; 388 struct ucred *oldcred; 389 struct uidinfo *euip = NULL; 390 uintptr_t stack_base; 391 struct image_params image_params, *imgp; 392 struct vattr attr; 393 int (*img_first)(struct image_params *); 394 struct pargs *oldargs = NULL, *newargs = NULL; 395 struct sigacts *oldsigacts = NULL, *newsigacts = NULL; 396 #ifdef KTRACE 397 struct ktr_io_params *kiop; 398 #endif 399 struct vnode *oldtextvp, *newtextvp; 400 struct vnode *oldtextdvp, *newtextdvp; 401 char *oldbinname, *newbinname; 402 bool credential_changing; 403 #ifdef MAC 404 struct label *interpvplabel = NULL; 405 bool will_transition; 406 #endif 407 #ifdef HWPMC_HOOKS 408 struct pmckern_procexec pe; 409 #endif 410 int error, i, orig_osrel; 411 uint32_t orig_fctl0; 412 Elf_Brandinfo *orig_brandinfo; 413 size_t freepath_size; 414 static const char fexecv_proc_title[] = "(fexecv)"; 415 416 imgp = &image_params; 417 oldtextvp = oldtextdvp = NULL; 418 newtextvp = newtextdvp = NULL; 419 newbinname = oldbinname = NULL; 420 #ifdef KTRACE 421 kiop = NULL; 422 #endif 423 424 /* 425 * Lock the process and set the P_INEXEC flag to indicate that 426 * it should be left alone until we're done here. This is 427 * necessary to avoid race conditions - e.g. in ptrace() - 428 * that might allow a local user to illicitly obtain elevated 429 * privileges. 430 */ 431 PROC_LOCK(p); 432 KASSERT((p->p_flag & P_INEXEC) == 0, 433 ("%s(): process already has P_INEXEC flag", __func__)); 434 p->p_flag |= P_INEXEC; 435 PROC_UNLOCK(p); 436 437 /* 438 * Initialize part of the common data 439 */ 440 bzero(imgp, sizeof(*imgp)); 441 imgp->proc = p; 442 imgp->attr = &attr; 443 imgp->args = args; 444 oldcred = p->p_ucred; 445 orig_osrel = p->p_osrel; 446 orig_fctl0 = p->p_fctl0; 447 orig_brandinfo = p->p_elf_brandinfo; 448 449 #ifdef MAC 450 error = mac_execve_enter(imgp, mac_p); 451 if (error) 452 goto exec_fail; 453 #endif 454 455 SDT_PROBE1(proc, , , exec, args->fname); 456 457 interpret: 458 if (args->fname != NULL) { 459 #ifdef CAPABILITY_MODE 460 /* 461 * While capability mode can't reach this point via direct 462 * path arguments to execve(), we also don't allow 463 * interpreters to be used in capability mode (for now). 464 * Catch indirect lookups and return a permissions error. 465 */ 466 if (IN_CAPABILITY_MODE(td)) { 467 error = ECAPMODE; 468 goto exec_fail; 469 } 470 #endif 471 472 /* 473 * Translate the file name. namei() returns a vnode 474 * pointer in ni_vp among other things. 475 */ 476 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | 477 AUDITVNODE1 | WANTPARENT, UIO_SYSSPACE, 478 args->fname); 479 480 error = namei(&nd); 481 if (error) 482 goto exec_fail; 483 484 newtextvp = nd.ni_vp; 485 newtextdvp = nd.ni_dvp; 486 nd.ni_dvp = NULL; 487 newbinname = malloc(nd.ni_cnd.cn_namelen + 1, M_PARGS, 488 M_WAITOK); 489 memcpy(newbinname, nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 490 newbinname[nd.ni_cnd.cn_namelen] = '\0'; 491 imgp->vp = newtextvp; 492 493 /* 494 * Do the best to calculate the full path to the image file. 495 */ 496 if (args->fname[0] == '/') { 497 imgp->execpath = args->fname; 498 } else { 499 VOP_UNLOCK(imgp->vp); 500 freepath_size = MAXPATHLEN; 501 if (vn_fullpath_hardlink(newtextvp, newtextdvp, 502 newbinname, nd.ni_cnd.cn_namelen, &imgp->execpath, 503 &imgp->freepath, &freepath_size) != 0) 504 imgp->execpath = args->fname; 505 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 506 } 507 } else { 508 AUDIT_ARG_FD(args->fd); 509 510 /* 511 * If the descriptors was not opened with O_PATH, then 512 * we require that it was opened with O_EXEC or 513 * O_RDONLY. In either case, exec_check_permissions() 514 * below checks _current_ file access mode regardless 515 * of the permissions additionally checked at the 516 * open(2). 517 */ 518 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, 519 &newtextvp); 520 if (error != 0) 521 goto exec_fail; 522 523 if (vn_fullpath(newtextvp, &imgp->execpath, 524 &imgp->freepath) != 0) 525 imgp->execpath = args->fname; 526 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 527 AUDIT_ARG_VNODE1(newtextvp); 528 imgp->vp = newtextvp; 529 } 530 531 /* 532 * Check file permissions. Also 'opens' file and sets its vnode to 533 * text mode. 534 */ 535 error = exec_check_permissions(imgp); 536 if (error) 537 goto exec_fail_dealloc; 538 539 imgp->object = imgp->vp->v_object; 540 if (imgp->object != NULL) 541 vm_object_reference(imgp->object); 542 543 error = exec_map_first_page(imgp); 544 if (error) 545 goto exec_fail_dealloc; 546 547 imgp->proc->p_osrel = 0; 548 imgp->proc->p_fctl0 = 0; 549 imgp->proc->p_elf_brandinfo = NULL; 550 551 /* 552 * Implement image setuid/setgid. 553 * 554 * Determine new credentials before attempting image activators 555 * so that it can be used by process_exec handlers to determine 556 * credential/setid changes. 557 * 558 * Don't honor setuid/setgid if the filesystem prohibits it or if 559 * the process is being traced. 560 * 561 * We disable setuid/setgid/etc in capability mode on the basis 562 * that most setugid applications are not written with that 563 * environment in mind, and will therefore almost certainly operate 564 * incorrectly. In principle there's no reason that setugid 565 * applications might not be useful in capability mode, so we may want 566 * to reconsider this conservative design choice in the future. 567 * 568 * XXXMAC: For the time being, use NOSUID to also prohibit 569 * transitions on the file system. 570 */ 571 credential_changing = false; 572 credential_changing |= (attr.va_mode & S_ISUID) && 573 oldcred->cr_uid != attr.va_uid; 574 credential_changing |= (attr.va_mode & S_ISGID) && 575 oldcred->cr_gid != attr.va_gid; 576 #ifdef MAC 577 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp, 578 interpvplabel, imgp) != 0; 579 credential_changing |= will_transition; 580 #endif 581 582 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */ 583 if (credential_changing) 584 imgp->proc->p_pdeathsig = 0; 585 586 if (credential_changing && 587 #ifdef CAPABILITY_MODE 588 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) && 589 #endif 590 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 && 591 (p->p_flag & P_TRACED) == 0) { 592 imgp->credential_setid = true; 593 VOP_UNLOCK(imgp->vp); 594 imgp->newcred = crdup(oldcred); 595 if (attr.va_mode & S_ISUID) { 596 euip = uifind(attr.va_uid); 597 change_euid(imgp->newcred, euip); 598 } 599 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 600 if (attr.va_mode & S_ISGID) 601 change_egid(imgp->newcred, attr.va_gid); 602 /* 603 * Implement correct POSIX saved-id behavior. 604 * 605 * XXXMAC: Note that the current logic will save the 606 * uid and gid if a MAC domain transition occurs, even 607 * though maybe it shouldn't. 608 */ 609 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 610 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 611 } else { 612 /* 613 * Implement correct POSIX saved-id behavior. 614 * 615 * XXX: It's not clear that the existing behavior is 616 * POSIX-compliant. A number of sources indicate that the 617 * saved uid/gid should only be updated if the new ruid is 618 * not equal to the old ruid, or the new euid is not equal 619 * to the old euid and the new euid is not equal to the old 620 * ruid. The FreeBSD code always updates the saved uid/gid. 621 * Also, this code uses the new (replaced) euid and egid as 622 * the source, which may or may not be the right ones to use. 623 */ 624 if (oldcred->cr_svuid != oldcred->cr_uid || 625 oldcred->cr_svgid != oldcred->cr_gid) { 626 VOP_UNLOCK(imgp->vp); 627 imgp->newcred = crdup(oldcred); 628 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 629 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 630 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 631 } 632 } 633 /* The new credentials are installed into the process later. */ 634 635 /* 636 * If the current process has a special image activator it 637 * wants to try first, call it. For example, emulating shell 638 * scripts differently. 639 */ 640 error = -1; 641 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL) 642 error = img_first(imgp); 643 644 /* 645 * Loop through the list of image activators, calling each one. 646 * An activator returns -1 if there is no match, 0 on success, 647 * and an error otherwise. 648 */ 649 for (i = 0; error == -1 && execsw[i]; ++i) { 650 if (execsw[i]->ex_imgact == NULL || 651 execsw[i]->ex_imgact == img_first) { 652 continue; 653 } 654 error = (*execsw[i]->ex_imgact)(imgp); 655 } 656 657 if (error) { 658 if (error == -1) 659 error = ENOEXEC; 660 goto exec_fail_dealloc; 661 } 662 663 /* 664 * Special interpreter operation, cleanup and loop up to try to 665 * activate the interpreter. 666 */ 667 if (imgp->interpreted) { 668 exec_unmap_first_page(imgp); 669 /* 670 * The text reference needs to be removed for scripts. 671 * There is a short period before we determine that 672 * something is a script where text reference is active. 673 * The vnode lock is held over this entire period 674 * so nothing should illegitimately be blocked. 675 */ 676 MPASS(imgp->textset); 677 VOP_UNSET_TEXT_CHECKED(newtextvp); 678 imgp->textset = false; 679 /* free name buffer and old vnode */ 680 #ifdef MAC 681 mac_execve_interpreter_enter(newtextvp, &interpvplabel); 682 #endif 683 if (imgp->opened) { 684 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td); 685 imgp->opened = false; 686 } 687 vput(newtextvp); 688 imgp->vp = newtextvp = NULL; 689 if (args->fname != NULL) { 690 if (newtextdvp != NULL) { 691 vrele(newtextdvp); 692 newtextdvp = NULL; 693 } 694 NDFREE_PNBUF(&nd); 695 free(newbinname, M_PARGS); 696 newbinname = NULL; 697 } 698 vm_object_deallocate(imgp->object); 699 imgp->object = NULL; 700 execve_nosetid(imgp); 701 imgp->execpath = NULL; 702 free(imgp->freepath, M_TEMP); 703 imgp->freepath = NULL; 704 /* set new name to that of the interpreter */ 705 args->fname = imgp->interpreter_name; 706 goto interpret; 707 } 708 709 /* 710 * NB: We unlock the vnode here because it is believed that none 711 * of the sv_copyout_strings/sv_fixup operations require the vnode. 712 */ 713 VOP_UNLOCK(imgp->vp); 714 715 if (disallow_high_osrel && 716 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { 717 error = ENOEXEC; 718 uprintf("Osrel %d for image %s too high\n", p->p_osrel, 719 imgp->execpath != NULL ? imgp->execpath : "<unresolved>"); 720 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 721 goto exec_fail_dealloc; 722 } 723 724 /* 725 * Copy out strings (args and env) and initialize stack base. 726 */ 727 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); 728 if (error != 0) { 729 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 730 goto exec_fail_dealloc; 731 } 732 733 /* 734 * Stack setup. 735 */ 736 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); 737 if (error != 0) { 738 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 739 goto exec_fail_dealloc; 740 } 741 742 /* 743 * For security and other reasons, the file descriptor table cannot be 744 * shared after an exec. 745 */ 746 fdunshare(td); 747 pdunshare(td); 748 /* close files on exec */ 749 fdcloseexec(td); 750 751 /* 752 * Malloc things before we need locks. 753 */ 754 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; 755 /* Cache arguments if they fit inside our allowance */ 756 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { 757 newargs = pargs_alloc(i); 758 bcopy(imgp->args->begin_argv, newargs->ar_args, i); 759 } 760 761 /* 762 * For security and other reasons, signal handlers cannot 763 * be shared after an exec. The new process gets a copy of the old 764 * handlers. In execsigs(), the new process will have its signals 765 * reset. 766 */ 767 if (sigacts_shared(p->p_sigacts)) { 768 oldsigacts = p->p_sigacts; 769 newsigacts = sigacts_alloc(); 770 sigacts_copy(newsigacts, oldsigacts); 771 } 772 773 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 774 775 PROC_LOCK(p); 776 if (oldsigacts) 777 p->p_sigacts = newsigacts; 778 /* Stop profiling */ 779 stopprofclock(p); 780 781 /* reset caught signals */ 782 execsigs(p); 783 784 /* name this process - nameiexec(p, ndp) */ 785 bzero(p->p_comm, sizeof(p->p_comm)); 786 if (args->fname) 787 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, 788 min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); 789 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) 790 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); 791 bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); 792 #ifdef KTR 793 sched_clear_tdname(td); 794 #endif 795 796 /* 797 * mark as execed, wakeup the process that vforked (if any) and tell 798 * it that it now has its own resources back 799 */ 800 p->p_flag |= P_EXEC; 801 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) 802 p->p_flag2 &= ~P2_NOTRACE; 803 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) 804 p->p_flag2 &= ~P2_STKGAP_DISABLE; 805 if (p->p_flag & P_PPWAIT) { 806 p->p_flag &= ~(P_PPWAIT | P_PPTRACE); 807 cv_broadcast(&p->p_pwait); 808 /* STOPs are no longer ignored, arrange for AST */ 809 signotify(td); 810 } 811 812 if ((imgp->sysent->sv_setid_allowed != NULL && 813 !(*imgp->sysent->sv_setid_allowed)(td, imgp)) || 814 (p->p_flag2 & P2_NO_NEW_PRIVS) != 0) 815 execve_nosetid(imgp); 816 817 /* 818 * Implement image setuid/setgid installation. 819 */ 820 if (imgp->credential_setid) { 821 /* 822 * Turn off syscall tracing for set-id programs, except for 823 * root. Record any set-id flags first to make sure that 824 * we do not regain any tracing during a possible block. 825 */ 826 setsugid(p); 827 #ifdef KTRACE 828 kiop = ktrprocexec(p); 829 #endif 830 /* 831 * Close any file descriptors 0..2 that reference procfs, 832 * then make sure file descriptors 0..2 are in use. 833 * 834 * Both fdsetugidsafety() and fdcheckstd() may call functions 835 * taking sleepable locks, so temporarily drop our locks. 836 */ 837 PROC_UNLOCK(p); 838 VOP_UNLOCK(imgp->vp); 839 fdsetugidsafety(td); 840 error = fdcheckstd(td); 841 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 842 if (error != 0) 843 goto exec_fail_dealloc; 844 PROC_LOCK(p); 845 #ifdef MAC 846 if (will_transition) { 847 mac_vnode_execve_transition(oldcred, imgp->newcred, 848 imgp->vp, interpvplabel, imgp); 849 } 850 #endif 851 } else { 852 if (oldcred->cr_uid == oldcred->cr_ruid && 853 oldcred->cr_gid == oldcred->cr_rgid) 854 p->p_flag &= ~P_SUGID; 855 } 856 /* 857 * Set the new credentials. 858 */ 859 if (imgp->newcred != NULL) { 860 proc_set_cred(p, imgp->newcred); 861 crfree(oldcred); 862 oldcred = NULL; 863 } 864 865 /* 866 * Store the vp for use in kern.proc.pathname. This vnode was 867 * referenced by namei() or by fexecve variant of fname handling. 868 */ 869 oldtextvp = p->p_textvp; 870 p->p_textvp = newtextvp; 871 oldtextdvp = p->p_textdvp; 872 p->p_textdvp = newtextdvp; 873 newtextdvp = NULL; 874 oldbinname = p->p_binname; 875 p->p_binname = newbinname; 876 newbinname = NULL; 877 878 #ifdef KDTRACE_HOOKS 879 /* 880 * Tell the DTrace fasttrap provider about the exec if it 881 * has declared an interest. 882 */ 883 if (dtrace_fasttrap_exec) 884 dtrace_fasttrap_exec(p); 885 #endif 886 887 /* 888 * Notify others that we exec'd, and clear the P_INEXEC flag 889 * as we're now a bona fide freshly-execed process. 890 */ 891 KNOTE_LOCKED(p->p_klist, NOTE_EXEC); 892 p->p_flag &= ~P_INEXEC; 893 894 /* clear "fork but no exec" flag, as we _are_ execing */ 895 p->p_acflag &= ~AFORK; 896 897 /* 898 * Free any previous argument cache and replace it with 899 * the new argument cache, if any. 900 */ 901 oldargs = p->p_args; 902 p->p_args = newargs; 903 newargs = NULL; 904 905 PROC_UNLOCK(p); 906 907 #ifdef HWPMC_HOOKS 908 /* 909 * Check if system-wide sampling is in effect or if the 910 * current process is using PMCs. If so, do exec() time 911 * processing. This processing needs to happen AFTER the 912 * P_INEXEC flag is cleared. 913 */ 914 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { 915 VOP_UNLOCK(imgp->vp); 916 pe.pm_credentialschanged = credential_changing; 917 pe.pm_entryaddr = imgp->entry_addr; 918 919 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); 920 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 921 } 922 #endif 923 924 /* Set values passed into the program in registers. */ 925 (*p->p_sysent->sv_setregs)(td, imgp, stack_base); 926 927 VOP_MMAPPED(imgp->vp); 928 929 SDT_PROBE1(proc, , , exec__success, args->fname); 930 931 exec_fail_dealloc: 932 if (error != 0) { 933 p->p_osrel = orig_osrel; 934 p->p_fctl0 = orig_fctl0; 935 p->p_elf_brandinfo = orig_brandinfo; 936 } 937 938 if (imgp->firstpage != NULL) 939 exec_unmap_first_page(imgp); 940 941 if (imgp->vp != NULL) { 942 if (imgp->opened) 943 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); 944 if (imgp->textset) 945 VOP_UNSET_TEXT_CHECKED(imgp->vp); 946 if (error != 0) 947 vput(imgp->vp); 948 else 949 VOP_UNLOCK(imgp->vp); 950 if (args->fname != NULL) 951 NDFREE_PNBUF(&nd); 952 if (newtextdvp != NULL) 953 vrele(newtextdvp); 954 free(newbinname, M_PARGS); 955 } 956 957 if (imgp->object != NULL) 958 vm_object_deallocate(imgp->object); 959 960 free(imgp->freepath, M_TEMP); 961 962 if (error == 0) { 963 if (p->p_ptevents & PTRACE_EXEC) { 964 PROC_LOCK(p); 965 if (p->p_ptevents & PTRACE_EXEC) 966 td->td_dbgflags |= TDB_EXEC; 967 PROC_UNLOCK(p); 968 } 969 } else { 970 exec_fail: 971 /* we're done here, clear P_INEXEC */ 972 PROC_LOCK(p); 973 p->p_flag &= ~P_INEXEC; 974 PROC_UNLOCK(p); 975 976 SDT_PROBE1(proc, , , exec__failure, error); 977 } 978 979 if (imgp->newcred != NULL && oldcred != NULL) 980 crfree(imgp->newcred); 981 982 #ifdef MAC 983 mac_execve_exit(imgp); 984 mac_execve_interpreter_exit(interpvplabel); 985 #endif 986 exec_free_args(args); 987 988 /* 989 * Handle deferred decrement of ref counts. 990 */ 991 if (oldtextvp != NULL) 992 vrele(oldtextvp); 993 if (oldtextdvp != NULL) 994 vrele(oldtextdvp); 995 free(oldbinname, M_PARGS); 996 #ifdef KTRACE 997 ktr_io_params_free(kiop); 998 #endif 999 pargs_drop(oldargs); 1000 pargs_drop(newargs); 1001 if (oldsigacts != NULL) 1002 sigacts_free(oldsigacts); 1003 if (euip != NULL) 1004 uifree(euip); 1005 1006 if (error && imgp->vmspace_destroyed) { 1007 /* sorry, no more process anymore. exit gracefully */ 1008 exec_cleanup(td, oldvmspace); 1009 exit1(td, 0, SIGABRT); 1010 /* NOT REACHED */ 1011 } 1012 1013 #ifdef KTRACE 1014 if (error == 0) 1015 ktrprocctor(p); 1016 #endif 1017 1018 /* 1019 * We don't want cpu_set_syscall_retval() to overwrite any of 1020 * the register values put in place by exec_setregs(). 1021 * Implementations of cpu_set_syscall_retval() will leave 1022 * registers unmodified when returning EJUSTRETURN. 1023 */ 1024 return (error == 0 ? EJUSTRETURN : error); 1025 } 1026 1027 void 1028 exec_cleanup(struct thread *td, struct vmspace *oldvmspace) 1029 { 1030 if ((td->td_pflags & TDP_EXECVMSPC) != 0) { 1031 KASSERT(td->td_proc->p_vmspace != oldvmspace, 1032 ("oldvmspace still used")); 1033 vmspace_free(oldvmspace); 1034 td->td_pflags &= ~TDP_EXECVMSPC; 1035 } 1036 } 1037 1038 int 1039 exec_map_first_page(struct image_params *imgp) 1040 { 1041 vm_object_t object; 1042 vm_page_t m; 1043 int error; 1044 1045 if (imgp->firstpage != NULL) 1046 exec_unmap_first_page(imgp); 1047 1048 object = imgp->vp->v_object; 1049 if (object == NULL) 1050 return (EACCES); 1051 #if VM_NRESERVLEVEL > 0 1052 if ((object->flags & OBJ_COLORED) == 0) { 1053 VM_OBJECT_WLOCK(object); 1054 vm_object_color(object, 0); 1055 VM_OBJECT_WUNLOCK(object); 1056 } 1057 #endif 1058 error = vm_page_grab_valid_unlocked(&m, object, 0, 1059 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | 1060 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 1061 1062 if (error != VM_PAGER_OK) 1063 return (EIO); 1064 imgp->firstpage = sf_buf_alloc(m, 0); 1065 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); 1066 1067 return (0); 1068 } 1069 1070 void 1071 exec_unmap_first_page(struct image_params *imgp) 1072 { 1073 vm_page_t m; 1074 1075 if (imgp->firstpage != NULL) { 1076 m = sf_buf_page(imgp->firstpage); 1077 sf_buf_free(imgp->firstpage); 1078 imgp->firstpage = NULL; 1079 vm_page_unwire(m, PQ_ACTIVE); 1080 } 1081 } 1082 1083 void 1084 exec_onexec_old(struct thread *td) 1085 { 1086 sigfastblock_clear(td); 1087 umtx_exec(td->td_proc); 1088 } 1089 1090 /* 1091 * This is an optimization which removes the unmanaged shared page 1092 * mapping. In combination with pmap_remove_pages(), which cleans all 1093 * managed mappings in the process' vmspace pmap, no work will be left 1094 * for pmap_remove(min, max). 1095 */ 1096 void 1097 exec_free_abi_mappings(struct proc *p) 1098 { 1099 struct vmspace *vmspace; 1100 1101 vmspace = p->p_vmspace; 1102 if (refcount_load(&vmspace->vm_refcnt) != 1) 1103 return; 1104 1105 if (!PROC_HAS_SHP(p)) 1106 return; 1107 1108 pmap_remove(vmspace_pmap(vmspace), vmspace->vm_shp_base, 1109 vmspace->vm_shp_base + p->p_sysent->sv_shared_page_len); 1110 } 1111 1112 /* 1113 * Run down the current address space and install a new one. 1114 */ 1115 int 1116 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) 1117 { 1118 int error; 1119 struct proc *p = imgp->proc; 1120 struct vmspace *vmspace = p->p_vmspace; 1121 struct thread *td = curthread; 1122 vm_offset_t sv_minuser; 1123 vm_map_t map; 1124 1125 imgp->vmspace_destroyed = true; 1126 imgp->sysent = sv; 1127 1128 if (p->p_sysent->sv_onexec_old != NULL) 1129 p->p_sysent->sv_onexec_old(td); 1130 itimers_exec(p); 1131 1132 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); 1133 1134 /* 1135 * Blow away entire process VM, if address space not shared, 1136 * otherwise, create a new VM space so that other threads are 1137 * not disrupted 1138 */ 1139 map = &vmspace->vm_map; 1140 if (map_at_zero) 1141 sv_minuser = sv->sv_minuser; 1142 else 1143 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); 1144 if (refcount_load(&vmspace->vm_refcnt) == 1 && 1145 vm_map_min(map) == sv_minuser && 1146 vm_map_max(map) == sv->sv_maxuser && 1147 cpu_exec_vmspace_reuse(p, map)) { 1148 exec_free_abi_mappings(p); 1149 shmexit(vmspace); 1150 pmap_remove_pages(vmspace_pmap(vmspace)); 1151 vm_map_remove(map, vm_map_min(map), vm_map_max(map)); 1152 /* 1153 * An exec terminates mlockall(MCL_FUTURE). 1154 * ASLR and W^X states must be re-evaluated. 1155 */ 1156 vm_map_lock(map); 1157 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | 1158 MAP_ASLR_IGNSTART | MAP_ASLR_STACK | MAP_WXORX); 1159 vm_map_unlock(map); 1160 } else { 1161 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); 1162 if (error) 1163 return (error); 1164 vmspace = p->p_vmspace; 1165 map = &vmspace->vm_map; 1166 } 1167 map->flags |= imgp->map_flags; 1168 1169 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0); 1170 } 1171 1172 /* 1173 * Compute the stack size limit and map the main process stack. 1174 * Map the shared page. 1175 */ 1176 int 1177 exec_map_stack(struct image_params *imgp) 1178 { 1179 struct rlimit rlim_stack; 1180 struct sysentvec *sv; 1181 struct proc *p; 1182 vm_map_t map; 1183 struct vmspace *vmspace; 1184 vm_offset_t stack_addr, stack_top; 1185 vm_offset_t sharedpage_addr; 1186 u_long ssiz; 1187 int error, find_space, stack_off; 1188 vm_prot_t stack_prot; 1189 vm_object_t obj; 1190 1191 p = imgp->proc; 1192 sv = p->p_sysent; 1193 1194 if (imgp->stack_sz != 0) { 1195 ssiz = trunc_page(imgp->stack_sz); 1196 PROC_LOCK(p); 1197 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); 1198 PROC_UNLOCK(p); 1199 if (ssiz > rlim_stack.rlim_max) 1200 ssiz = rlim_stack.rlim_max; 1201 if (ssiz > rlim_stack.rlim_cur) { 1202 rlim_stack.rlim_cur = ssiz; 1203 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); 1204 } 1205 } else if (sv->sv_maxssiz != NULL) { 1206 ssiz = *sv->sv_maxssiz; 1207 } else { 1208 ssiz = maxssiz; 1209 } 1210 1211 vmspace = p->p_vmspace; 1212 map = &vmspace->vm_map; 1213 1214 stack_prot = sv->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? 1215 imgp->stack_prot : sv->sv_stackprot; 1216 if ((map->flags & MAP_ASLR_STACK) != 0) { 1217 stack_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1218 lim_max(curthread, RLIMIT_DATA)); 1219 find_space = VMFS_ANY_SPACE; 1220 } else { 1221 stack_addr = sv->sv_usrstack - ssiz; 1222 find_space = VMFS_NO_SPACE; 1223 } 1224 error = vm_map_find(map, NULL, 0, &stack_addr, (vm_size_t)ssiz, 1225 sv->sv_usrstack, find_space, stack_prot, VM_PROT_ALL, 1226 MAP_STACK_GROWS_DOWN); 1227 if (error != KERN_SUCCESS) { 1228 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " 1229 "failed, mach error %d errno %d\n", (uintmax_t)ssiz, 1230 stack_prot, error, vm_mmap_to_errno(error)); 1231 return (vm_mmap_to_errno(error)); 1232 } 1233 1234 stack_top = stack_addr + ssiz; 1235 if ((map->flags & MAP_ASLR_STACK) != 0) { 1236 /* Randomize within the first page of the stack. */ 1237 arc4rand(&stack_off, sizeof(stack_off), 0); 1238 stack_top -= rounddown2(stack_off & PAGE_MASK, sizeof(void *)); 1239 } 1240 1241 /* Map a shared page */ 1242 obj = sv->sv_shared_page_obj; 1243 if (obj == NULL) { 1244 sharedpage_addr = 0; 1245 goto out; 1246 } 1247 1248 /* 1249 * If randomization is disabled then the shared page will 1250 * be mapped at address specified in sysentvec. 1251 * Otherwise any address above .data section can be selected. 1252 * Same logic is used for stack address randomization. 1253 * If the address randomization is applied map a guard page 1254 * at the top of UVA. 1255 */ 1256 vm_object_reference(obj); 1257 if ((imgp->imgp_flags & IMGP_ASLR_SHARED_PAGE) != 0) { 1258 sharedpage_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1259 lim_max(curthread, RLIMIT_DATA)); 1260 1261 error = vm_map_fixed(map, NULL, 0, 1262 sv->sv_maxuser - PAGE_SIZE, PAGE_SIZE, 1263 VM_PROT_NONE, VM_PROT_NONE, MAP_CREATE_GUARD); 1264 if (error != KERN_SUCCESS) { 1265 /* 1266 * This is not fatal, so let's just print a warning 1267 * and continue. 1268 */ 1269 uprintf("%s: Mapping guard page at the top of UVA failed" 1270 " mach error %d errno %d", 1271 __func__, error, vm_mmap_to_errno(error)); 1272 } 1273 1274 error = vm_map_find(map, obj, 0, 1275 &sharedpage_addr, sv->sv_shared_page_len, 1276 sv->sv_maxuser, VMFS_ANY_SPACE, 1277 VM_PROT_READ | VM_PROT_EXECUTE, 1278 VM_PROT_READ | VM_PROT_EXECUTE, 1279 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1280 } else { 1281 sharedpage_addr = sv->sv_shared_page_base; 1282 vm_map_fixed(map, obj, 0, 1283 sharedpage_addr, sv->sv_shared_page_len, 1284 VM_PROT_READ | VM_PROT_EXECUTE, 1285 VM_PROT_READ | VM_PROT_EXECUTE, 1286 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1287 } 1288 if (error != KERN_SUCCESS) { 1289 uprintf("%s: mapping shared page at addr: %p" 1290 "failed, mach error %d errno %d\n", __func__, 1291 (void *)sharedpage_addr, error, vm_mmap_to_errno(error)); 1292 vm_object_deallocate(obj); 1293 return (vm_mmap_to_errno(error)); 1294 } 1295 out: 1296 /* 1297 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they 1298 * are still used to enforce the stack rlimit on the process stack. 1299 */ 1300 vmspace->vm_maxsaddr = (char *)stack_addr; 1301 vmspace->vm_stacktop = stack_top; 1302 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; 1303 vmspace->vm_shp_base = sharedpage_addr; 1304 1305 return (0); 1306 } 1307 1308 /* 1309 * Copy out argument and environment strings from the old process address 1310 * space into the temporary string buffer. 1311 */ 1312 int 1313 exec_copyin_args(struct image_args *args, const char *fname, 1314 enum uio_seg segflg, char **argv, char **envv) 1315 { 1316 u_long arg, env; 1317 int error; 1318 1319 bzero(args, sizeof(*args)); 1320 if (argv == NULL) 1321 return (EFAULT); 1322 1323 /* 1324 * Allocate demand-paged memory for the file name, argument, and 1325 * environment strings. 1326 */ 1327 error = exec_alloc_args(args); 1328 if (error != 0) 1329 return (error); 1330 1331 /* 1332 * Copy the file name. 1333 */ 1334 error = exec_args_add_fname(args, fname, segflg); 1335 if (error != 0) 1336 goto err_exit; 1337 1338 /* 1339 * extract arguments first 1340 */ 1341 for (;;) { 1342 error = fueword(argv++, &arg); 1343 if (error == -1) { 1344 error = EFAULT; 1345 goto err_exit; 1346 } 1347 if (arg == 0) 1348 break; 1349 error = exec_args_add_arg(args, (char *)(uintptr_t)arg, 1350 UIO_USERSPACE); 1351 if (error != 0) 1352 goto err_exit; 1353 } 1354 1355 /* 1356 * extract environment strings 1357 */ 1358 if (envv) { 1359 for (;;) { 1360 error = fueword(envv++, &env); 1361 if (error == -1) { 1362 error = EFAULT; 1363 goto err_exit; 1364 } 1365 if (env == 0) 1366 break; 1367 error = exec_args_add_env(args, 1368 (char *)(uintptr_t)env, UIO_USERSPACE); 1369 if (error != 0) 1370 goto err_exit; 1371 } 1372 } 1373 1374 return (0); 1375 1376 err_exit: 1377 exec_free_args(args); 1378 return (error); 1379 } 1380 1381 struct exec_args_kva { 1382 vm_offset_t addr; 1383 u_int gen; 1384 SLIST_ENTRY(exec_args_kva) next; 1385 }; 1386 1387 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); 1388 1389 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; 1390 static struct mtx exec_args_kva_mtx; 1391 static u_int exec_args_gen; 1392 1393 static void 1394 exec_prealloc_args_kva(void *arg __unused) 1395 { 1396 struct exec_args_kva *argkva; 1397 u_int i; 1398 1399 SLIST_INIT(&exec_args_kva_freelist); 1400 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); 1401 for (i = 0; i < exec_map_entries; i++) { 1402 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); 1403 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); 1404 argkva->gen = exec_args_gen; 1405 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1406 } 1407 } 1408 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); 1409 1410 static vm_offset_t 1411 exec_alloc_args_kva(void **cookie) 1412 { 1413 struct exec_args_kva *argkva; 1414 1415 argkva = (void *)atomic_readandclear_ptr( 1416 (uintptr_t *)DPCPU_PTR(exec_args_kva)); 1417 if (argkva == NULL) { 1418 mtx_lock(&exec_args_kva_mtx); 1419 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) 1420 (void)mtx_sleep(&exec_args_kva_freelist, 1421 &exec_args_kva_mtx, 0, "execkva", 0); 1422 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); 1423 mtx_unlock(&exec_args_kva_mtx); 1424 } 1425 kasan_mark((void *)argkva->addr, exec_map_entry_size, 1426 exec_map_entry_size, 0); 1427 *(struct exec_args_kva **)cookie = argkva; 1428 return (argkva->addr); 1429 } 1430 1431 static void 1432 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) 1433 { 1434 vm_offset_t base; 1435 1436 base = argkva->addr; 1437 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size, 1438 KASAN_EXEC_ARGS_FREED); 1439 if (argkva->gen != gen) { 1440 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, 1441 MADV_FREE); 1442 argkva->gen = gen; 1443 } 1444 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), 1445 (uintptr_t)NULL, (uintptr_t)argkva)) { 1446 mtx_lock(&exec_args_kva_mtx); 1447 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1448 wakeup_one(&exec_args_kva_freelist); 1449 mtx_unlock(&exec_args_kva_mtx); 1450 } 1451 } 1452 1453 static void 1454 exec_free_args_kva(void *cookie) 1455 { 1456 1457 exec_release_args_kva(cookie, exec_args_gen); 1458 } 1459 1460 static void 1461 exec_args_kva_lowmem(void *arg __unused) 1462 { 1463 SLIST_HEAD(, exec_args_kva) head; 1464 struct exec_args_kva *argkva; 1465 u_int gen; 1466 int i; 1467 1468 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; 1469 1470 /* 1471 * Force an madvise of each KVA range. Any currently allocated ranges 1472 * will have MADV_FREE applied once they are freed. 1473 */ 1474 SLIST_INIT(&head); 1475 mtx_lock(&exec_args_kva_mtx); 1476 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); 1477 mtx_unlock(&exec_args_kva_mtx); 1478 while ((argkva = SLIST_FIRST(&head)) != NULL) { 1479 SLIST_REMOVE_HEAD(&head, next); 1480 exec_release_args_kva(argkva, gen); 1481 } 1482 1483 CPU_FOREACH(i) { 1484 argkva = (void *)atomic_readandclear_ptr( 1485 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); 1486 if (argkva != NULL) 1487 exec_release_args_kva(argkva, gen); 1488 } 1489 } 1490 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, 1491 EVENTHANDLER_PRI_ANY); 1492 1493 /* 1494 * Allocate temporary demand-paged, zero-filled memory for the file name, 1495 * argument, and environment strings. 1496 */ 1497 int 1498 exec_alloc_args(struct image_args *args) 1499 { 1500 1501 args->buf = (char *)exec_alloc_args_kva(&args->bufkva); 1502 return (0); 1503 } 1504 1505 void 1506 exec_free_args(struct image_args *args) 1507 { 1508 1509 if (args->buf != NULL) { 1510 exec_free_args_kva(args->bufkva); 1511 args->buf = NULL; 1512 } 1513 if (args->fname_buf != NULL) { 1514 free(args->fname_buf, M_TEMP); 1515 args->fname_buf = NULL; 1516 } 1517 } 1518 1519 /* 1520 * A set to functions to fill struct image args. 1521 * 1522 * NOTE: exec_args_add_fname() must be called (possibly with a NULL 1523 * fname) before the other functions. All exec_args_add_arg() calls must 1524 * be made before any exec_args_add_env() calls. exec_args_adjust_args() 1525 * may be called any time after exec_args_add_fname(). 1526 * 1527 * exec_args_add_fname() - install path to be executed 1528 * exec_args_add_arg() - append an argument string 1529 * exec_args_add_env() - append an env string 1530 * exec_args_adjust_args() - adjust location of the argument list to 1531 * allow new arguments to be prepended 1532 */ 1533 int 1534 exec_args_add_fname(struct image_args *args, const char *fname, 1535 enum uio_seg segflg) 1536 { 1537 int error; 1538 size_t length; 1539 1540 KASSERT(args->fname == NULL, ("fname already appended")); 1541 KASSERT(args->endp == NULL, ("already appending to args")); 1542 1543 if (fname != NULL) { 1544 args->fname = args->buf; 1545 error = segflg == UIO_SYSSPACE ? 1546 copystr(fname, args->fname, PATH_MAX, &length) : 1547 copyinstr(fname, args->fname, PATH_MAX, &length); 1548 if (error != 0) 1549 return (error == ENAMETOOLONG ? E2BIG : error); 1550 } else 1551 length = 0; 1552 1553 /* Set up for _arg_*()/_env_*() */ 1554 args->endp = args->buf + length; 1555 /* begin_argv must be set and kept updated */ 1556 args->begin_argv = args->endp; 1557 KASSERT(exec_map_entry_size - length >= ARG_MAX, 1558 ("too little space remaining for arguments %zu < %zu", 1559 exec_map_entry_size - length, (size_t)ARG_MAX)); 1560 args->stringspace = ARG_MAX; 1561 1562 return (0); 1563 } 1564 1565 static int 1566 exec_args_add_str(struct image_args *args, const char *str, 1567 enum uio_seg segflg, int *countp) 1568 { 1569 int error; 1570 size_t length; 1571 1572 KASSERT(args->endp != NULL, ("endp not initialized")); 1573 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1574 1575 error = (segflg == UIO_SYSSPACE) ? 1576 copystr(str, args->endp, args->stringspace, &length) : 1577 copyinstr(str, args->endp, args->stringspace, &length); 1578 if (error != 0) 1579 return (error == ENAMETOOLONG ? E2BIG : error); 1580 args->stringspace -= length; 1581 args->endp += length; 1582 (*countp)++; 1583 1584 return (0); 1585 } 1586 1587 int 1588 exec_args_add_arg(struct image_args *args, const char *argp, 1589 enum uio_seg segflg) 1590 { 1591 1592 KASSERT(args->envc == 0, ("appending args after env")); 1593 1594 return (exec_args_add_str(args, argp, segflg, &args->argc)); 1595 } 1596 1597 int 1598 exec_args_add_env(struct image_args *args, const char *envp, 1599 enum uio_seg segflg) 1600 { 1601 1602 if (args->envc == 0) 1603 args->begin_envv = args->endp; 1604 1605 return (exec_args_add_str(args, envp, segflg, &args->envc)); 1606 } 1607 1608 int 1609 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) 1610 { 1611 ssize_t offset; 1612 1613 KASSERT(args->endp != NULL, ("endp not initialized")); 1614 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1615 1616 offset = extend - consume; 1617 if (args->stringspace < offset) 1618 return (E2BIG); 1619 memmove(args->begin_argv + extend, args->begin_argv + consume, 1620 args->endp - args->begin_argv + consume); 1621 if (args->envc > 0) 1622 args->begin_envv += offset; 1623 args->endp += offset; 1624 args->stringspace -= offset; 1625 return (0); 1626 } 1627 1628 char * 1629 exec_args_get_begin_envv(struct image_args *args) 1630 { 1631 1632 KASSERT(args->endp != NULL, ("endp not initialized")); 1633 1634 if (args->envc > 0) 1635 return (args->begin_envv); 1636 return (args->endp); 1637 } 1638 1639 /* 1640 * Copy strings out to the new process address space, constructing new arg 1641 * and env vector tables. Return a pointer to the base so that it can be used 1642 * as the initial stack pointer. 1643 */ 1644 int 1645 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 1646 { 1647 int argc, envc; 1648 char **vectp; 1649 char *stringp; 1650 uintptr_t destp, ustringp; 1651 struct ps_strings *arginfo; 1652 struct proc *p; 1653 struct sysentvec *sysent; 1654 size_t execpath_len; 1655 int error, szsigcode; 1656 char canary[sizeof(long) * 8]; 1657 1658 p = imgp->proc; 1659 sysent = p->p_sysent; 1660 1661 destp = PROC_PS_STRINGS(p); 1662 arginfo = imgp->ps_strings = (void *)destp; 1663 1664 /* 1665 * Install sigcode. 1666 */ 1667 if (sysent->sv_shared_page_base == 0 && sysent->sv_szsigcode != NULL) { 1668 szsigcode = *(sysent->sv_szsigcode); 1669 destp -= szsigcode; 1670 destp = rounddown2(destp, sizeof(void *)); 1671 error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode); 1672 if (error != 0) 1673 return (error); 1674 } 1675 1676 /* 1677 * Copy the image path for the rtld. 1678 */ 1679 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 1680 execpath_len = strlen(imgp->execpath) + 1; 1681 destp -= execpath_len; 1682 destp = rounddown2(destp, sizeof(void *)); 1683 imgp->execpathp = (void *)destp; 1684 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 1685 if (error != 0) 1686 return (error); 1687 } 1688 1689 /* 1690 * Prepare the canary for SSP. 1691 */ 1692 arc4rand(canary, sizeof(canary), 0); 1693 destp -= sizeof(canary); 1694 imgp->canary = (void *)destp; 1695 error = copyout(canary, imgp->canary, sizeof(canary)); 1696 if (error != 0) 1697 return (error); 1698 imgp->canarylen = sizeof(canary); 1699 1700 /* 1701 * Prepare the pagesizes array. 1702 */ 1703 imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES; 1704 destp -= imgp->pagesizeslen; 1705 destp = rounddown2(destp, sizeof(void *)); 1706 imgp->pagesizes = (void *)destp; 1707 error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen); 1708 if (error != 0) 1709 return (error); 1710 1711 /* 1712 * Allocate room for the argument and environment strings. 1713 */ 1714 destp -= ARG_MAX - imgp->args->stringspace; 1715 destp = rounddown2(destp, sizeof(void *)); 1716 ustringp = destp; 1717 1718 if (imgp->auxargs) { 1719 /* 1720 * Allocate room on the stack for the ELF auxargs 1721 * array. It has up to AT_COUNT entries. 1722 */ 1723 destp -= AT_COUNT * sizeof(Elf_Auxinfo); 1724 destp = rounddown2(destp, sizeof(void *)); 1725 } 1726 1727 vectp = (char **)destp; 1728 1729 /* 1730 * Allocate room for the argv[] and env vectors including the 1731 * terminating NULL pointers. 1732 */ 1733 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 1734 1735 /* 1736 * vectp also becomes our initial stack base 1737 */ 1738 *stack_base = (uintptr_t)vectp; 1739 1740 stringp = imgp->args->begin_argv; 1741 argc = imgp->args->argc; 1742 envc = imgp->args->envc; 1743 1744 /* 1745 * Copy out strings - arguments and environment. 1746 */ 1747 error = copyout(stringp, (void *)ustringp, 1748 ARG_MAX - imgp->args->stringspace); 1749 if (error != 0) 1750 return (error); 1751 1752 /* 1753 * Fill in "ps_strings" struct for ps, w, etc. 1754 */ 1755 imgp->argv = vectp; 1756 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 1757 suword32(&arginfo->ps_nargvstr, argc) != 0) 1758 return (EFAULT); 1759 1760 /* 1761 * Fill in argument portion of vector table. 1762 */ 1763 for (; argc > 0; --argc) { 1764 if (suword(vectp++, ustringp) != 0) 1765 return (EFAULT); 1766 while (*stringp++ != 0) 1767 ustringp++; 1768 ustringp++; 1769 } 1770 1771 /* a null vector table pointer separates the argp's from the envp's */ 1772 if (suword(vectp++, 0) != 0) 1773 return (EFAULT); 1774 1775 imgp->envv = vectp; 1776 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 1777 suword32(&arginfo->ps_nenvstr, envc) != 0) 1778 return (EFAULT); 1779 1780 /* 1781 * Fill in environment portion of vector table. 1782 */ 1783 for (; envc > 0; --envc) { 1784 if (suword(vectp++, ustringp) != 0) 1785 return (EFAULT); 1786 while (*stringp++ != 0) 1787 ustringp++; 1788 ustringp++; 1789 } 1790 1791 /* end of vector table is a null pointer */ 1792 if (suword(vectp, 0) != 0) 1793 return (EFAULT); 1794 1795 if (imgp->auxargs) { 1796 vectp++; 1797 error = imgp->sysent->sv_copyout_auxargs(imgp, 1798 (uintptr_t)vectp); 1799 if (error != 0) 1800 return (error); 1801 } 1802 1803 return (0); 1804 } 1805 1806 /* 1807 * Check permissions of file to execute. 1808 * Called with imgp->vp locked. 1809 * Return 0 for success or error code on failure. 1810 */ 1811 int 1812 exec_check_permissions(struct image_params *imgp) 1813 { 1814 struct vnode *vp = imgp->vp; 1815 struct vattr *attr = imgp->attr; 1816 struct thread *td; 1817 int error; 1818 1819 td = curthread; 1820 1821 /* Get file attributes */ 1822 error = VOP_GETATTR(vp, attr, td->td_ucred); 1823 if (error) 1824 return (error); 1825 1826 #ifdef MAC 1827 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); 1828 if (error) 1829 return (error); 1830 #endif 1831 1832 /* 1833 * 1) Check if file execution is disabled for the filesystem that 1834 * this file resides on. 1835 * 2) Ensure that at least one execute bit is on. Otherwise, a 1836 * privileged user will always succeed, and we don't want this 1837 * to happen unless the file really is executable. 1838 * 3) Ensure that the file is a regular file. 1839 */ 1840 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || 1841 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || 1842 (attr->va_type != VREG)) 1843 return (EACCES); 1844 1845 /* 1846 * Zero length files can't be exec'd 1847 */ 1848 if (attr->va_size == 0) 1849 return (ENOEXEC); 1850 1851 /* 1852 * Check for execute permission to file based on current credentials. 1853 */ 1854 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); 1855 if (error) 1856 return (error); 1857 1858 /* 1859 * Check number of open-for-writes on the file and deny execution 1860 * if there are any. 1861 * 1862 * Add a text reference now so no one can write to the 1863 * executable while we're activating it. 1864 * 1865 * Remember if this was set before and unset it in case this is not 1866 * actually an executable image. 1867 */ 1868 error = VOP_SET_TEXT(vp); 1869 if (error != 0) 1870 return (error); 1871 imgp->textset = true; 1872 1873 /* 1874 * Call filesystem specific open routine (which does nothing in the 1875 * general case). 1876 */ 1877 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); 1878 if (error == 0) 1879 imgp->opened = true; 1880 return (error); 1881 } 1882 1883 /* 1884 * Exec handler registration 1885 */ 1886 int 1887 exec_register(const struct execsw *execsw_arg) 1888 { 1889 const struct execsw **es, **xs, **newexecsw; 1890 u_int count = 2; /* New slot and trailing NULL */ 1891 1892 if (execsw) 1893 for (es = execsw; *es; es++) 1894 count++; 1895 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1896 xs = newexecsw; 1897 if (execsw) 1898 for (es = execsw; *es; es++) 1899 *xs++ = *es; 1900 *xs++ = execsw_arg; 1901 *xs = NULL; 1902 if (execsw) 1903 free(execsw, M_TEMP); 1904 execsw = newexecsw; 1905 return (0); 1906 } 1907 1908 int 1909 exec_unregister(const struct execsw *execsw_arg) 1910 { 1911 const struct execsw **es, **xs, **newexecsw; 1912 int count = 1; 1913 1914 if (execsw == NULL) 1915 panic("unregister with no handlers left?\n"); 1916 1917 for (es = execsw; *es; es++) { 1918 if (*es == execsw_arg) 1919 break; 1920 } 1921 if (*es == NULL) 1922 return (ENOENT); 1923 for (es = execsw; *es; es++) 1924 if (*es != execsw_arg) 1925 count++; 1926 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1927 xs = newexecsw; 1928 for (es = execsw; *es; es++) 1929 if (*es != execsw_arg) 1930 *xs++ = *es; 1931 *xs = NULL; 1932 if (execsw) 1933 free(execsw, M_TEMP); 1934 execsw = newexecsw; 1935 return (0); 1936 } 1937 1938 /* 1939 * Write out a core segment to the compression stream. 1940 */ 1941 static int 1942 compress_chunk(struct coredump_params *cp, char *base, char *buf, size_t len) 1943 { 1944 size_t chunk_len; 1945 int error; 1946 1947 while (len > 0) { 1948 chunk_len = MIN(len, CORE_BUF_SIZE); 1949 1950 /* 1951 * We can get EFAULT error here. 1952 * In that case zero out the current chunk of the segment. 1953 */ 1954 error = copyin(base, buf, chunk_len); 1955 if (error != 0) 1956 bzero(buf, chunk_len); 1957 error = compressor_write(cp->comp, buf, chunk_len); 1958 if (error != 0) 1959 break; 1960 base += chunk_len; 1961 len -= chunk_len; 1962 } 1963 return (error); 1964 } 1965 1966 int 1967 core_write(struct coredump_params *cp, const void *base, size_t len, 1968 off_t offset, enum uio_seg seg, size_t *resid) 1969 { 1970 1971 return (vn_rdwr_inchunks(UIO_WRITE, cp->vp, __DECONST(void *, base), 1972 len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED, 1973 cp->active_cred, cp->file_cred, resid, cp->td)); 1974 } 1975 1976 int 1977 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp, 1978 void *tmpbuf) 1979 { 1980 vm_map_t map; 1981 struct mount *mp; 1982 size_t resid, runlen; 1983 int error; 1984 bool success; 1985 1986 KASSERT((uintptr_t)base % PAGE_SIZE == 0, 1987 ("%s: user address %p is not page-aligned", __func__, base)); 1988 1989 if (cp->comp != NULL) 1990 return (compress_chunk(cp, base, tmpbuf, len)); 1991 1992 map = &cp->td->td_proc->p_vmspace->vm_map; 1993 for (; len > 0; base += runlen, offset += runlen, len -= runlen) { 1994 /* 1995 * Attempt to page in all virtual pages in the range. If a 1996 * virtual page is not backed by the pager, it is represented as 1997 * a hole in the file. This can occur with zero-filled 1998 * anonymous memory or truncated files, for example. 1999 */ 2000 for (runlen = 0; runlen < len; runlen += PAGE_SIZE) { 2001 if (core_dump_can_intr && curproc_sigkilled()) 2002 return (EINTR); 2003 error = vm_fault(map, (uintptr_t)base + runlen, 2004 VM_PROT_READ, VM_FAULT_NOFILL, NULL); 2005 if (runlen == 0) 2006 success = error == KERN_SUCCESS; 2007 else if ((error == KERN_SUCCESS) != success) 2008 break; 2009 } 2010 2011 if (success) { 2012 error = core_write(cp, base, runlen, offset, 2013 UIO_USERSPACE, &resid); 2014 if (error != 0) { 2015 if (error != EFAULT) 2016 break; 2017 2018 /* 2019 * EFAULT may be returned if the user mapping 2020 * could not be accessed, e.g., because a mapped 2021 * file has been truncated. Skip the page if no 2022 * progress was made, to protect against a 2023 * hypothetical scenario where vm_fault() was 2024 * successful but core_write() returns EFAULT 2025 * anyway. 2026 */ 2027 runlen -= resid; 2028 if (runlen == 0) { 2029 success = false; 2030 runlen = PAGE_SIZE; 2031 } 2032 } 2033 } 2034 if (!success) { 2035 error = vn_start_write(cp->vp, &mp, V_WAIT); 2036 if (error != 0) 2037 break; 2038 vn_lock(cp->vp, LK_EXCLUSIVE | LK_RETRY); 2039 error = vn_truncate_locked(cp->vp, offset + runlen, 2040 false, cp->td->td_ucred); 2041 VOP_UNLOCK(cp->vp); 2042 vn_finished_write(mp); 2043 if (error != 0) 2044 break; 2045 } 2046 } 2047 return (error); 2048 } 2049 2050 /* 2051 * Drain into a core file. 2052 */ 2053 int 2054 sbuf_drain_core_output(void *arg, const char *data, int len) 2055 { 2056 struct coredump_params *cp; 2057 struct proc *p; 2058 int error, locked; 2059 2060 cp = arg; 2061 p = cp->td->td_proc; 2062 2063 /* 2064 * Some kern_proc out routines that print to this sbuf may 2065 * call us with the process lock held. Draining with the 2066 * non-sleepable lock held is unsafe. The lock is needed for 2067 * those routines when dumping a live process. In our case we 2068 * can safely release the lock before draining and acquire 2069 * again after. 2070 */ 2071 locked = PROC_LOCKED(p); 2072 if (locked) 2073 PROC_UNLOCK(p); 2074 if (cp->comp != NULL) 2075 error = compressor_write(cp->comp, __DECONST(char *, data), 2076 len); 2077 else 2078 error = core_write(cp, __DECONST(void *, data), len, cp->offset, 2079 UIO_SYSSPACE, NULL); 2080 if (locked) 2081 PROC_LOCK(p); 2082 if (error != 0) 2083 return (-error); 2084 cp->offset += len; 2085 return (len); 2086 } 2087