1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 struct pargs *oldargs = NULL, *newargs = NULL; 394 struct sigacts *oldsigacts = NULL, *newsigacts = NULL; 395 #ifdef KTRACE 396 struct ktr_io_params *kiop; 397 #endif 398 struct vnode *oldtextvp, *newtextvp; 399 struct vnode *oldtextdvp, *newtextdvp; 400 char *oldbinname, *newbinname; 401 bool credential_changing; 402 #ifdef MAC 403 struct label *interpvplabel = NULL; 404 bool will_transition; 405 #endif 406 #ifdef HWPMC_HOOKS 407 struct pmckern_procexec pe; 408 #endif 409 int error, i, orig_osrel; 410 uint32_t orig_fctl0; 411 Elf_Brandinfo *orig_brandinfo; 412 size_t freepath_size; 413 static const char fexecv_proc_title[] = "(fexecv)"; 414 415 imgp = &image_params; 416 oldtextvp = oldtextdvp = NULL; 417 newtextvp = newtextdvp = NULL; 418 newbinname = oldbinname = NULL; 419 #ifdef KTRACE 420 kiop = NULL; 421 #endif 422 423 /* 424 * Lock the process and set the P_INEXEC flag to indicate that 425 * it should be left alone until we're done here. This is 426 * necessary to avoid race conditions - e.g. in ptrace() - 427 * that might allow a local user to illicitly obtain elevated 428 * privileges. 429 */ 430 PROC_LOCK(p); 431 KASSERT((p->p_flag & P_INEXEC) == 0, 432 ("%s(): process already has P_INEXEC flag", __func__)); 433 p->p_flag |= P_INEXEC; 434 PROC_UNLOCK(p); 435 436 /* 437 * Initialize part of the common data 438 */ 439 bzero(imgp, sizeof(*imgp)); 440 imgp->proc = p; 441 imgp->attr = &attr; 442 imgp->args = args; 443 oldcred = p->p_ucred; 444 orig_osrel = p->p_osrel; 445 orig_fctl0 = p->p_fctl0; 446 orig_brandinfo = p->p_elf_brandinfo; 447 448 #ifdef MAC 449 error = mac_execve_enter(imgp, mac_p); 450 if (error) 451 goto exec_fail; 452 #endif 453 454 SDT_PROBE1(proc, , , exec, args->fname); 455 456 interpret: 457 if (args->fname != NULL) { 458 #ifdef CAPABILITY_MODE 459 /* 460 * While capability mode can't reach this point via direct 461 * path arguments to execve(), we also don't allow 462 * interpreters to be used in capability mode (for now). 463 * Catch indirect lookups and return a permissions error. 464 */ 465 if (IN_CAPABILITY_MODE(td)) { 466 error = ECAPMODE; 467 goto exec_fail; 468 } 469 #endif 470 471 /* 472 * Translate the file name. namei() returns a vnode 473 * pointer in ni_vp among other things. 474 */ 475 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | 476 AUDITVNODE1 | WANTPARENT, UIO_SYSSPACE, 477 args->fname); 478 479 error = namei(&nd); 480 if (error) 481 goto exec_fail; 482 483 newtextvp = nd.ni_vp; 484 newtextdvp = nd.ni_dvp; 485 nd.ni_dvp = NULL; 486 newbinname = malloc(nd.ni_cnd.cn_namelen + 1, M_PARGS, 487 M_WAITOK); 488 memcpy(newbinname, nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 489 newbinname[nd.ni_cnd.cn_namelen] = '\0'; 490 imgp->vp = newtextvp; 491 492 /* 493 * Do the best to calculate the full path to the image file. 494 */ 495 if (args->fname[0] == '/') { 496 imgp->execpath = args->fname; 497 } else { 498 VOP_UNLOCK(imgp->vp); 499 freepath_size = MAXPATHLEN; 500 if (vn_fullpath_hardlink(newtextvp, newtextdvp, 501 newbinname, nd.ni_cnd.cn_namelen, &imgp->execpath, 502 &imgp->freepath, &freepath_size) != 0) 503 imgp->execpath = args->fname; 504 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 505 } 506 } else if (imgp->interpreter_vp) { 507 /* 508 * An image activator has already provided an open vnode 509 */ 510 newtextvp = imgp->interpreter_vp; 511 imgp->interpreter_vp = NULL; 512 if (vn_fullpath(newtextvp, &imgp->execpath, 513 &imgp->freepath) != 0) 514 imgp->execpath = args->fname; 515 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 516 AUDIT_ARG_VNODE1(newtextvp); 517 imgp->vp = newtextvp; 518 } else { 519 AUDIT_ARG_FD(args->fd); 520 521 /* 522 * If the descriptors was not opened with O_PATH, then 523 * we require that it was opened with O_EXEC or 524 * O_RDONLY. In either case, exec_check_permissions() 525 * below checks _current_ file access mode regardless 526 * of the permissions additionally checked at the 527 * open(2). 528 */ 529 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, 530 &newtextvp); 531 if (error != 0) 532 goto exec_fail; 533 534 if (vn_fullpath(newtextvp, &imgp->execpath, 535 &imgp->freepath) != 0) 536 imgp->execpath = args->fname; 537 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 538 AUDIT_ARG_VNODE1(newtextvp); 539 imgp->vp = newtextvp; 540 } 541 542 /* 543 * Check file permissions. Also 'opens' file and sets its vnode to 544 * text mode. 545 */ 546 error = exec_check_permissions(imgp); 547 if (error) 548 goto exec_fail_dealloc; 549 550 imgp->object = imgp->vp->v_object; 551 if (imgp->object != NULL) 552 vm_object_reference(imgp->object); 553 554 error = exec_map_first_page(imgp); 555 if (error) 556 goto exec_fail_dealloc; 557 558 imgp->proc->p_osrel = 0; 559 imgp->proc->p_fctl0 = 0; 560 imgp->proc->p_elf_brandinfo = NULL; 561 562 /* 563 * Implement image setuid/setgid. 564 * 565 * Determine new credentials before attempting image activators 566 * so that it can be used by process_exec handlers to determine 567 * credential/setid changes. 568 * 569 * Don't honor setuid/setgid if the filesystem prohibits it or if 570 * the process is being traced. 571 * 572 * We disable setuid/setgid/etc in capability mode on the basis 573 * that most setugid applications are not written with that 574 * environment in mind, and will therefore almost certainly operate 575 * incorrectly. In principle there's no reason that setugid 576 * applications might not be useful in capability mode, so we may want 577 * to reconsider this conservative design choice in the future. 578 * 579 * XXXMAC: For the time being, use NOSUID to also prohibit 580 * transitions on the file system. 581 */ 582 credential_changing = false; 583 credential_changing |= (attr.va_mode & S_ISUID) && 584 oldcred->cr_uid != attr.va_uid; 585 credential_changing |= (attr.va_mode & S_ISGID) && 586 oldcred->cr_gid != attr.va_gid; 587 #ifdef MAC 588 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp, 589 interpvplabel, imgp) != 0; 590 credential_changing |= will_transition; 591 #endif 592 593 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */ 594 if (credential_changing) 595 imgp->proc->p_pdeathsig = 0; 596 597 if (credential_changing && 598 #ifdef CAPABILITY_MODE 599 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) && 600 #endif 601 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 && 602 (p->p_flag & P_TRACED) == 0) { 603 imgp->credential_setid = true; 604 VOP_UNLOCK(imgp->vp); 605 imgp->newcred = crdup(oldcred); 606 if (attr.va_mode & S_ISUID) { 607 euip = uifind(attr.va_uid); 608 change_euid(imgp->newcred, euip); 609 } 610 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 611 if (attr.va_mode & S_ISGID) 612 change_egid(imgp->newcred, attr.va_gid); 613 /* 614 * Implement correct POSIX saved-id behavior. 615 * 616 * XXXMAC: Note that the current logic will save the 617 * uid and gid if a MAC domain transition occurs, even 618 * though maybe it shouldn't. 619 */ 620 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 621 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 622 } else { 623 /* 624 * Implement correct POSIX saved-id behavior. 625 * 626 * XXX: It's not clear that the existing behavior is 627 * POSIX-compliant. A number of sources indicate that the 628 * saved uid/gid should only be updated if the new ruid is 629 * not equal to the old ruid, or the new euid is not equal 630 * to the old euid and the new euid is not equal to the old 631 * ruid. The FreeBSD code always updates the saved uid/gid. 632 * Also, this code uses the new (replaced) euid and egid as 633 * the source, which may or may not be the right ones to use. 634 */ 635 if (oldcred->cr_svuid != oldcred->cr_uid || 636 oldcred->cr_svgid != oldcred->cr_gid) { 637 VOP_UNLOCK(imgp->vp); 638 imgp->newcred = crdup(oldcred); 639 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 640 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 641 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 642 } 643 } 644 /* The new credentials are installed into the process later. */ 645 646 /* 647 * Loop through the list of image activators, calling each one. 648 * An activator returns -1 if there is no match, 0 on success, 649 * and an error otherwise. 650 */ 651 error = -1; 652 for (i = 0; error == -1 && execsw[i]; ++i) { 653 if (execsw[i]->ex_imgact == NULL) 654 continue; 655 error = (*execsw[i]->ex_imgact)(imgp); 656 } 657 658 if (error) { 659 if (error == -1) 660 error = ENOEXEC; 661 goto exec_fail_dealloc; 662 } 663 664 /* 665 * Special interpreter operation, cleanup and loop up to try to 666 * activate the interpreter. 667 */ 668 if (imgp->interpreted) { 669 exec_unmap_first_page(imgp); 670 /* 671 * The text reference needs to be removed for scripts. 672 * There is a short period before we determine that 673 * something is a script where text reference is active. 674 * The vnode lock is held over this entire period 675 * so nothing should illegitimately be blocked. 676 */ 677 MPASS(imgp->textset); 678 VOP_UNSET_TEXT_CHECKED(newtextvp); 679 imgp->textset = false; 680 /* free name buffer and old vnode */ 681 #ifdef MAC 682 mac_execve_interpreter_enter(newtextvp, &interpvplabel); 683 #endif 684 if (imgp->opened) { 685 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td); 686 imgp->opened = false; 687 } 688 vput(newtextvp); 689 imgp->vp = newtextvp = NULL; 690 if (args->fname != NULL) { 691 if (newtextdvp != NULL) { 692 vrele(newtextdvp); 693 newtextdvp = NULL; 694 } 695 NDFREE_PNBUF(&nd); 696 free(newbinname, M_PARGS); 697 newbinname = NULL; 698 } 699 vm_object_deallocate(imgp->object); 700 imgp->object = NULL; 701 execve_nosetid(imgp); 702 imgp->execpath = NULL; 703 free(imgp->freepath, M_TEMP); 704 imgp->freepath = NULL; 705 /* set new name to that of the interpreter */ 706 if (imgp->interpreter_vp) { 707 args->fname = NULL; 708 } else { 709 args->fname = imgp->interpreter_name; 710 } 711 goto interpret; 712 } 713 714 /* 715 * NB: We unlock the vnode here because it is believed that none 716 * of the sv_copyout_strings/sv_fixup operations require the vnode. 717 */ 718 VOP_UNLOCK(imgp->vp); 719 720 if (disallow_high_osrel && 721 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { 722 error = ENOEXEC; 723 uprintf("Osrel %d for image %s too high\n", p->p_osrel, 724 imgp->execpath != NULL ? imgp->execpath : "<unresolved>"); 725 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 726 goto exec_fail_dealloc; 727 } 728 729 /* 730 * Copy out strings (args and env) and initialize stack base. 731 */ 732 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); 733 if (error != 0) { 734 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 735 goto exec_fail_dealloc; 736 } 737 738 /* 739 * Stack setup. 740 */ 741 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); 742 if (error != 0) { 743 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 744 goto exec_fail_dealloc; 745 } 746 747 /* 748 * For security and other reasons, the file descriptor table cannot be 749 * shared after an exec. 750 */ 751 fdunshare(td); 752 pdunshare(td); 753 /* close files on exec */ 754 fdcloseexec(td); 755 756 /* 757 * Malloc things before we need locks. 758 */ 759 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; 760 /* Cache arguments if they fit inside our allowance */ 761 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { 762 newargs = pargs_alloc(i); 763 bcopy(imgp->args->begin_argv, newargs->ar_args, i); 764 } 765 766 /* 767 * For security and other reasons, signal handlers cannot 768 * be shared after an exec. The new process gets a copy of the old 769 * handlers. In execsigs(), the new process will have its signals 770 * reset. 771 */ 772 if (sigacts_shared(p->p_sigacts)) { 773 oldsigacts = p->p_sigacts; 774 newsigacts = sigacts_alloc(); 775 sigacts_copy(newsigacts, oldsigacts); 776 } 777 778 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 779 780 PROC_LOCK(p); 781 if (oldsigacts) 782 p->p_sigacts = newsigacts; 783 /* Stop profiling */ 784 stopprofclock(p); 785 786 /* reset caught signals */ 787 execsigs(p); 788 789 /* name this process - nameiexec(p, ndp) */ 790 bzero(p->p_comm, sizeof(p->p_comm)); 791 if (args->fname) 792 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, 793 min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); 794 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) 795 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); 796 bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); 797 #ifdef KTR 798 sched_clear_tdname(td); 799 #endif 800 801 /* 802 * mark as execed, wakeup the process that vforked (if any) and tell 803 * it that it now has its own resources back 804 */ 805 p->p_flag |= P_EXEC; 806 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) 807 p->p_flag2 &= ~P2_NOTRACE; 808 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) 809 p->p_flag2 &= ~P2_STKGAP_DISABLE; 810 if (p->p_flag & P_PPWAIT) { 811 p->p_flag &= ~(P_PPWAIT | P_PPTRACE); 812 cv_broadcast(&p->p_pwait); 813 /* STOPs are no longer ignored, arrange for AST */ 814 signotify(td); 815 } 816 817 if ((imgp->sysent->sv_setid_allowed != NULL && 818 !(*imgp->sysent->sv_setid_allowed)(td, imgp)) || 819 (p->p_flag2 & P2_NO_NEW_PRIVS) != 0) 820 execve_nosetid(imgp); 821 822 /* 823 * Implement image setuid/setgid installation. 824 */ 825 if (imgp->credential_setid) { 826 /* 827 * Turn off syscall tracing for set-id programs, except for 828 * root. Record any set-id flags first to make sure that 829 * we do not regain any tracing during a possible block. 830 */ 831 setsugid(p); 832 #ifdef KTRACE 833 kiop = ktrprocexec(p); 834 #endif 835 /* 836 * Close any file descriptors 0..2 that reference procfs, 837 * then make sure file descriptors 0..2 are in use. 838 * 839 * Both fdsetugidsafety() and fdcheckstd() may call functions 840 * taking sleepable locks, so temporarily drop our locks. 841 */ 842 PROC_UNLOCK(p); 843 VOP_UNLOCK(imgp->vp); 844 fdsetugidsafety(td); 845 error = fdcheckstd(td); 846 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 847 if (error != 0) 848 goto exec_fail_dealloc; 849 PROC_LOCK(p); 850 #ifdef MAC 851 if (will_transition) { 852 mac_vnode_execve_transition(oldcred, imgp->newcred, 853 imgp->vp, interpvplabel, imgp); 854 } 855 #endif 856 } else { 857 if (oldcred->cr_uid == oldcred->cr_ruid && 858 oldcred->cr_gid == oldcred->cr_rgid) 859 p->p_flag &= ~P_SUGID; 860 } 861 /* 862 * Set the new credentials. 863 */ 864 if (imgp->newcred != NULL) { 865 proc_set_cred(p, imgp->newcred); 866 crfree(oldcred); 867 oldcred = NULL; 868 } 869 870 /* 871 * Store the vp for use in kern.proc.pathname. This vnode was 872 * referenced by namei() or by fexecve variant of fname handling. 873 */ 874 oldtextvp = p->p_textvp; 875 p->p_textvp = newtextvp; 876 oldtextdvp = p->p_textdvp; 877 p->p_textdvp = newtextdvp; 878 newtextdvp = NULL; 879 oldbinname = p->p_binname; 880 p->p_binname = newbinname; 881 newbinname = NULL; 882 883 #ifdef KDTRACE_HOOKS 884 /* 885 * Tell the DTrace fasttrap provider about the exec if it 886 * has declared an interest. 887 */ 888 if (dtrace_fasttrap_exec) 889 dtrace_fasttrap_exec(p); 890 #endif 891 892 /* 893 * Notify others that we exec'd, and clear the P_INEXEC flag 894 * as we're now a bona fide freshly-execed process. 895 */ 896 KNOTE_LOCKED(p->p_klist, NOTE_EXEC); 897 p->p_flag &= ~P_INEXEC; 898 899 /* clear "fork but no exec" flag, as we _are_ execing */ 900 p->p_acflag &= ~AFORK; 901 902 /* 903 * Free any previous argument cache and replace it with 904 * the new argument cache, if any. 905 */ 906 oldargs = p->p_args; 907 p->p_args = newargs; 908 newargs = NULL; 909 910 PROC_UNLOCK(p); 911 912 #ifdef HWPMC_HOOKS 913 /* 914 * Check if system-wide sampling is in effect or if the 915 * current process is using PMCs. If so, do exec() time 916 * processing. This processing needs to happen AFTER the 917 * P_INEXEC flag is cleared. 918 */ 919 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { 920 VOP_UNLOCK(imgp->vp); 921 pe.pm_credentialschanged = credential_changing; 922 pe.pm_entryaddr = imgp->entry_addr; 923 924 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); 925 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 926 } 927 #endif 928 929 /* Set values passed into the program in registers. */ 930 (*p->p_sysent->sv_setregs)(td, imgp, stack_base); 931 932 VOP_MMAPPED(imgp->vp); 933 934 SDT_PROBE1(proc, , , exec__success, args->fname); 935 936 exec_fail_dealloc: 937 if (error != 0) { 938 p->p_osrel = orig_osrel; 939 p->p_fctl0 = orig_fctl0; 940 p->p_elf_brandinfo = orig_brandinfo; 941 } 942 943 if (imgp->firstpage != NULL) 944 exec_unmap_first_page(imgp); 945 946 if (imgp->vp != NULL) { 947 if (imgp->opened) 948 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); 949 if (imgp->textset) 950 VOP_UNSET_TEXT_CHECKED(imgp->vp); 951 if (error != 0) 952 vput(imgp->vp); 953 else 954 VOP_UNLOCK(imgp->vp); 955 if (args->fname != NULL) 956 NDFREE_PNBUF(&nd); 957 if (newtextdvp != NULL) 958 vrele(newtextdvp); 959 free(newbinname, M_PARGS); 960 } 961 962 if (imgp->object != NULL) 963 vm_object_deallocate(imgp->object); 964 965 free(imgp->freepath, M_TEMP); 966 967 if (error == 0) { 968 if (p->p_ptevents & PTRACE_EXEC) { 969 PROC_LOCK(p); 970 if (p->p_ptevents & PTRACE_EXEC) 971 td->td_dbgflags |= TDB_EXEC; 972 PROC_UNLOCK(p); 973 } 974 } else { 975 exec_fail: 976 /* we're done here, clear P_INEXEC */ 977 PROC_LOCK(p); 978 p->p_flag &= ~P_INEXEC; 979 PROC_UNLOCK(p); 980 981 SDT_PROBE1(proc, , , exec__failure, error); 982 } 983 984 if (imgp->newcred != NULL && oldcred != NULL) 985 crfree(imgp->newcred); 986 987 #ifdef MAC 988 mac_execve_exit(imgp); 989 mac_execve_interpreter_exit(interpvplabel); 990 #endif 991 exec_free_args(args); 992 993 /* 994 * Handle deferred decrement of ref counts. 995 */ 996 if (oldtextvp != NULL) 997 vrele(oldtextvp); 998 if (oldtextdvp != NULL) 999 vrele(oldtextdvp); 1000 free(oldbinname, M_PARGS); 1001 #ifdef KTRACE 1002 ktr_io_params_free(kiop); 1003 #endif 1004 pargs_drop(oldargs); 1005 pargs_drop(newargs); 1006 if (oldsigacts != NULL) 1007 sigacts_free(oldsigacts); 1008 if (euip != NULL) 1009 uifree(euip); 1010 1011 if (error && imgp->vmspace_destroyed) { 1012 /* sorry, no more process anymore. exit gracefully */ 1013 exec_cleanup(td, oldvmspace); 1014 exit1(td, 0, SIGABRT); 1015 /* NOT REACHED */ 1016 } 1017 1018 #ifdef KTRACE 1019 if (error == 0) 1020 ktrprocctor(p); 1021 #endif 1022 1023 /* 1024 * We don't want cpu_set_syscall_retval() to overwrite any of 1025 * the register values put in place by exec_setregs(). 1026 * Implementations of cpu_set_syscall_retval() will leave 1027 * registers unmodified when returning EJUSTRETURN. 1028 */ 1029 return (error == 0 ? EJUSTRETURN : error); 1030 } 1031 1032 void 1033 exec_cleanup(struct thread *td, struct vmspace *oldvmspace) 1034 { 1035 if ((td->td_pflags & TDP_EXECVMSPC) != 0) { 1036 KASSERT(td->td_proc->p_vmspace != oldvmspace, 1037 ("oldvmspace still used")); 1038 vmspace_free(oldvmspace); 1039 td->td_pflags &= ~TDP_EXECVMSPC; 1040 } 1041 } 1042 1043 int 1044 exec_map_first_page(struct image_params *imgp) 1045 { 1046 vm_object_t object; 1047 vm_page_t m; 1048 int error; 1049 1050 if (imgp->firstpage != NULL) 1051 exec_unmap_first_page(imgp); 1052 1053 object = imgp->vp->v_object; 1054 if (object == NULL) 1055 return (EACCES); 1056 #if VM_NRESERVLEVEL > 0 1057 if ((object->flags & OBJ_COLORED) == 0) { 1058 VM_OBJECT_WLOCK(object); 1059 vm_object_color(object, 0); 1060 VM_OBJECT_WUNLOCK(object); 1061 } 1062 #endif 1063 error = vm_page_grab_valid_unlocked(&m, object, 0, 1064 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | 1065 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 1066 1067 if (error != VM_PAGER_OK) 1068 return (EIO); 1069 imgp->firstpage = sf_buf_alloc(m, 0); 1070 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); 1071 1072 return (0); 1073 } 1074 1075 void 1076 exec_unmap_first_page(struct image_params *imgp) 1077 { 1078 vm_page_t m; 1079 1080 if (imgp->firstpage != NULL) { 1081 m = sf_buf_page(imgp->firstpage); 1082 sf_buf_free(imgp->firstpage); 1083 imgp->firstpage = NULL; 1084 vm_page_unwire(m, PQ_ACTIVE); 1085 } 1086 } 1087 1088 void 1089 exec_onexec_old(struct thread *td) 1090 { 1091 sigfastblock_clear(td); 1092 umtx_exec(td->td_proc); 1093 } 1094 1095 /* 1096 * This is an optimization which removes the unmanaged shared page 1097 * mapping. In combination with pmap_remove_pages(), which cleans all 1098 * managed mappings in the process' vmspace pmap, no work will be left 1099 * for pmap_remove(min, max). 1100 */ 1101 void 1102 exec_free_abi_mappings(struct proc *p) 1103 { 1104 struct vmspace *vmspace; 1105 1106 vmspace = p->p_vmspace; 1107 if (refcount_load(&vmspace->vm_refcnt) != 1) 1108 return; 1109 1110 if (!PROC_HAS_SHP(p)) 1111 return; 1112 1113 pmap_remove(vmspace_pmap(vmspace), vmspace->vm_shp_base, 1114 vmspace->vm_shp_base + p->p_sysent->sv_shared_page_len); 1115 } 1116 1117 /* 1118 * Run down the current address space and install a new one. 1119 */ 1120 int 1121 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) 1122 { 1123 int error; 1124 struct proc *p = imgp->proc; 1125 struct vmspace *vmspace = p->p_vmspace; 1126 struct thread *td = curthread; 1127 vm_offset_t sv_minuser; 1128 vm_map_t map; 1129 1130 imgp->vmspace_destroyed = true; 1131 imgp->sysent = sv; 1132 1133 if (p->p_sysent->sv_onexec_old != NULL) 1134 p->p_sysent->sv_onexec_old(td); 1135 itimers_exec(p); 1136 1137 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); 1138 1139 /* 1140 * Blow away entire process VM, if address space not shared, 1141 * otherwise, create a new VM space so that other threads are 1142 * not disrupted 1143 */ 1144 map = &vmspace->vm_map; 1145 if (map_at_zero) 1146 sv_minuser = sv->sv_minuser; 1147 else 1148 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); 1149 if (refcount_load(&vmspace->vm_refcnt) == 1 && 1150 vm_map_min(map) == sv_minuser && 1151 vm_map_max(map) == sv->sv_maxuser && 1152 cpu_exec_vmspace_reuse(p, map)) { 1153 exec_free_abi_mappings(p); 1154 shmexit(vmspace); 1155 pmap_remove_pages(vmspace_pmap(vmspace)); 1156 vm_map_remove(map, vm_map_min(map), vm_map_max(map)); 1157 /* 1158 * An exec terminates mlockall(MCL_FUTURE). 1159 * ASLR and W^X states must be re-evaluated. 1160 */ 1161 vm_map_lock(map); 1162 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | 1163 MAP_ASLR_IGNSTART | MAP_ASLR_STACK | MAP_WXORX); 1164 vm_map_unlock(map); 1165 } else { 1166 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); 1167 if (error) 1168 return (error); 1169 vmspace = p->p_vmspace; 1170 map = &vmspace->vm_map; 1171 } 1172 map->flags |= imgp->map_flags; 1173 1174 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0); 1175 } 1176 1177 /* 1178 * Compute the stack size limit and map the main process stack. 1179 * Map the shared page. 1180 */ 1181 int 1182 exec_map_stack(struct image_params *imgp) 1183 { 1184 struct rlimit rlim_stack; 1185 struct sysentvec *sv; 1186 struct proc *p; 1187 vm_map_t map; 1188 struct vmspace *vmspace; 1189 vm_offset_t stack_addr, stack_top; 1190 vm_offset_t sharedpage_addr; 1191 u_long ssiz; 1192 int error, find_space, stack_off; 1193 vm_prot_t stack_prot; 1194 vm_object_t obj; 1195 1196 p = imgp->proc; 1197 sv = p->p_sysent; 1198 1199 if (imgp->stack_sz != 0) { 1200 ssiz = trunc_page(imgp->stack_sz); 1201 PROC_LOCK(p); 1202 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); 1203 PROC_UNLOCK(p); 1204 if (ssiz > rlim_stack.rlim_max) 1205 ssiz = rlim_stack.rlim_max; 1206 if (ssiz > rlim_stack.rlim_cur) { 1207 rlim_stack.rlim_cur = ssiz; 1208 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); 1209 } 1210 } else if (sv->sv_maxssiz != NULL) { 1211 ssiz = *sv->sv_maxssiz; 1212 } else { 1213 ssiz = maxssiz; 1214 } 1215 1216 vmspace = p->p_vmspace; 1217 map = &vmspace->vm_map; 1218 1219 stack_prot = sv->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? 1220 imgp->stack_prot : sv->sv_stackprot; 1221 if ((map->flags & MAP_ASLR_STACK) != 0) { 1222 stack_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1223 lim_max(curthread, RLIMIT_DATA)); 1224 find_space = VMFS_ANY_SPACE; 1225 } else { 1226 stack_addr = sv->sv_usrstack - ssiz; 1227 find_space = VMFS_NO_SPACE; 1228 } 1229 error = vm_map_find(map, NULL, 0, &stack_addr, (vm_size_t)ssiz, 1230 sv->sv_usrstack, find_space, stack_prot, VM_PROT_ALL, 1231 MAP_STACK_GROWS_DOWN); 1232 if (error != KERN_SUCCESS) { 1233 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " 1234 "failed, mach error %d errno %d\n", (uintmax_t)ssiz, 1235 stack_prot, error, vm_mmap_to_errno(error)); 1236 return (vm_mmap_to_errno(error)); 1237 } 1238 1239 stack_top = stack_addr + ssiz; 1240 if ((map->flags & MAP_ASLR_STACK) != 0) { 1241 /* Randomize within the first page of the stack. */ 1242 arc4rand(&stack_off, sizeof(stack_off), 0); 1243 stack_top -= rounddown2(stack_off & PAGE_MASK, sizeof(void *)); 1244 } 1245 1246 /* Map a shared page */ 1247 obj = sv->sv_shared_page_obj; 1248 if (obj == NULL) { 1249 sharedpage_addr = 0; 1250 goto out; 1251 } 1252 1253 /* 1254 * If randomization is disabled then the shared page will 1255 * be mapped at address specified in sysentvec. 1256 * Otherwise any address above .data section can be selected. 1257 * Same logic is used for stack address randomization. 1258 * If the address randomization is applied map a guard page 1259 * at the top of UVA. 1260 */ 1261 vm_object_reference(obj); 1262 if ((imgp->imgp_flags & IMGP_ASLR_SHARED_PAGE) != 0) { 1263 sharedpage_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1264 lim_max(curthread, RLIMIT_DATA)); 1265 1266 error = vm_map_fixed(map, NULL, 0, 1267 sv->sv_maxuser - PAGE_SIZE, PAGE_SIZE, 1268 VM_PROT_NONE, VM_PROT_NONE, MAP_CREATE_GUARD); 1269 if (error != KERN_SUCCESS) { 1270 /* 1271 * This is not fatal, so let's just print a warning 1272 * and continue. 1273 */ 1274 uprintf("%s: Mapping guard page at the top of UVA failed" 1275 " mach error %d errno %d", 1276 __func__, error, vm_mmap_to_errno(error)); 1277 } 1278 1279 error = vm_map_find(map, obj, 0, 1280 &sharedpage_addr, sv->sv_shared_page_len, 1281 sv->sv_maxuser, VMFS_ANY_SPACE, 1282 VM_PROT_READ | VM_PROT_EXECUTE, 1283 VM_PROT_READ | VM_PROT_EXECUTE, 1284 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1285 } else { 1286 sharedpage_addr = sv->sv_shared_page_base; 1287 vm_map_fixed(map, obj, 0, 1288 sharedpage_addr, sv->sv_shared_page_len, 1289 VM_PROT_READ | VM_PROT_EXECUTE, 1290 VM_PROT_READ | VM_PROT_EXECUTE, 1291 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1292 } 1293 if (error != KERN_SUCCESS) { 1294 uprintf("%s: mapping shared page at addr: %p" 1295 "failed, mach error %d errno %d\n", __func__, 1296 (void *)sharedpage_addr, error, vm_mmap_to_errno(error)); 1297 vm_object_deallocate(obj); 1298 return (vm_mmap_to_errno(error)); 1299 } 1300 out: 1301 /* 1302 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they 1303 * are still used to enforce the stack rlimit on the process stack. 1304 */ 1305 vmspace->vm_maxsaddr = (char *)stack_addr; 1306 vmspace->vm_stacktop = stack_top; 1307 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; 1308 vmspace->vm_shp_base = sharedpage_addr; 1309 1310 return (0); 1311 } 1312 1313 /* 1314 * Copy out argument and environment strings from the old process address 1315 * space into the temporary string buffer. 1316 */ 1317 int 1318 exec_copyin_args(struct image_args *args, const char *fname, 1319 enum uio_seg segflg, char **argv, char **envv) 1320 { 1321 u_long arg, env; 1322 int error; 1323 1324 bzero(args, sizeof(*args)); 1325 if (argv == NULL) 1326 return (EFAULT); 1327 1328 /* 1329 * Allocate demand-paged memory for the file name, argument, and 1330 * environment strings. 1331 */ 1332 error = exec_alloc_args(args); 1333 if (error != 0) 1334 return (error); 1335 1336 /* 1337 * Copy the file name. 1338 */ 1339 error = exec_args_add_fname(args, fname, segflg); 1340 if (error != 0) 1341 goto err_exit; 1342 1343 /* 1344 * extract arguments first 1345 */ 1346 for (;;) { 1347 error = fueword(argv++, &arg); 1348 if (error == -1) { 1349 error = EFAULT; 1350 goto err_exit; 1351 } 1352 if (arg == 0) 1353 break; 1354 error = exec_args_add_arg(args, (char *)(uintptr_t)arg, 1355 UIO_USERSPACE); 1356 if (error != 0) 1357 goto err_exit; 1358 } 1359 1360 /* 1361 * extract environment strings 1362 */ 1363 if (envv) { 1364 for (;;) { 1365 error = fueword(envv++, &env); 1366 if (error == -1) { 1367 error = EFAULT; 1368 goto err_exit; 1369 } 1370 if (env == 0) 1371 break; 1372 error = exec_args_add_env(args, 1373 (char *)(uintptr_t)env, UIO_USERSPACE); 1374 if (error != 0) 1375 goto err_exit; 1376 } 1377 } 1378 1379 return (0); 1380 1381 err_exit: 1382 exec_free_args(args); 1383 return (error); 1384 } 1385 1386 struct exec_args_kva { 1387 vm_offset_t addr; 1388 u_int gen; 1389 SLIST_ENTRY(exec_args_kva) next; 1390 }; 1391 1392 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); 1393 1394 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; 1395 static struct mtx exec_args_kva_mtx; 1396 static u_int exec_args_gen; 1397 1398 static void 1399 exec_prealloc_args_kva(void *arg __unused) 1400 { 1401 struct exec_args_kva *argkva; 1402 u_int i; 1403 1404 SLIST_INIT(&exec_args_kva_freelist); 1405 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); 1406 for (i = 0; i < exec_map_entries; i++) { 1407 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); 1408 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); 1409 argkva->gen = exec_args_gen; 1410 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1411 } 1412 } 1413 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); 1414 1415 static vm_offset_t 1416 exec_alloc_args_kva(void **cookie) 1417 { 1418 struct exec_args_kva *argkva; 1419 1420 argkva = (void *)atomic_readandclear_ptr( 1421 (uintptr_t *)DPCPU_PTR(exec_args_kva)); 1422 if (argkva == NULL) { 1423 mtx_lock(&exec_args_kva_mtx); 1424 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) 1425 (void)mtx_sleep(&exec_args_kva_freelist, 1426 &exec_args_kva_mtx, 0, "execkva", 0); 1427 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); 1428 mtx_unlock(&exec_args_kva_mtx); 1429 } 1430 kasan_mark((void *)argkva->addr, exec_map_entry_size, 1431 exec_map_entry_size, 0); 1432 *(struct exec_args_kva **)cookie = argkva; 1433 return (argkva->addr); 1434 } 1435 1436 static void 1437 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) 1438 { 1439 vm_offset_t base; 1440 1441 base = argkva->addr; 1442 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size, 1443 KASAN_EXEC_ARGS_FREED); 1444 if (argkva->gen != gen) { 1445 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, 1446 MADV_FREE); 1447 argkva->gen = gen; 1448 } 1449 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), 1450 (uintptr_t)NULL, (uintptr_t)argkva)) { 1451 mtx_lock(&exec_args_kva_mtx); 1452 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1453 wakeup_one(&exec_args_kva_freelist); 1454 mtx_unlock(&exec_args_kva_mtx); 1455 } 1456 } 1457 1458 static void 1459 exec_free_args_kva(void *cookie) 1460 { 1461 1462 exec_release_args_kva(cookie, exec_args_gen); 1463 } 1464 1465 static void 1466 exec_args_kva_lowmem(void *arg __unused) 1467 { 1468 SLIST_HEAD(, exec_args_kva) head; 1469 struct exec_args_kva *argkva; 1470 u_int gen; 1471 int i; 1472 1473 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; 1474 1475 /* 1476 * Force an madvise of each KVA range. Any currently allocated ranges 1477 * will have MADV_FREE applied once they are freed. 1478 */ 1479 SLIST_INIT(&head); 1480 mtx_lock(&exec_args_kva_mtx); 1481 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); 1482 mtx_unlock(&exec_args_kva_mtx); 1483 while ((argkva = SLIST_FIRST(&head)) != NULL) { 1484 SLIST_REMOVE_HEAD(&head, next); 1485 exec_release_args_kva(argkva, gen); 1486 } 1487 1488 CPU_FOREACH(i) { 1489 argkva = (void *)atomic_readandclear_ptr( 1490 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); 1491 if (argkva != NULL) 1492 exec_release_args_kva(argkva, gen); 1493 } 1494 } 1495 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, 1496 EVENTHANDLER_PRI_ANY); 1497 1498 /* 1499 * Allocate temporary demand-paged, zero-filled memory for the file name, 1500 * argument, and environment strings. 1501 */ 1502 int 1503 exec_alloc_args(struct image_args *args) 1504 { 1505 1506 args->buf = (char *)exec_alloc_args_kva(&args->bufkva); 1507 return (0); 1508 } 1509 1510 void 1511 exec_free_args(struct image_args *args) 1512 { 1513 1514 if (args->buf != NULL) { 1515 exec_free_args_kva(args->bufkva); 1516 args->buf = NULL; 1517 } 1518 if (args->fname_buf != NULL) { 1519 free(args->fname_buf, M_TEMP); 1520 args->fname_buf = NULL; 1521 } 1522 } 1523 1524 /* 1525 * A set to functions to fill struct image args. 1526 * 1527 * NOTE: exec_args_add_fname() must be called (possibly with a NULL 1528 * fname) before the other functions. All exec_args_add_arg() calls must 1529 * be made before any exec_args_add_env() calls. exec_args_adjust_args() 1530 * may be called any time after exec_args_add_fname(). 1531 * 1532 * exec_args_add_fname() - install path to be executed 1533 * exec_args_add_arg() - append an argument string 1534 * exec_args_add_env() - append an env string 1535 * exec_args_adjust_args() - adjust location of the argument list to 1536 * allow new arguments to be prepended 1537 */ 1538 int 1539 exec_args_add_fname(struct image_args *args, const char *fname, 1540 enum uio_seg segflg) 1541 { 1542 int error; 1543 size_t length; 1544 1545 KASSERT(args->fname == NULL, ("fname already appended")); 1546 KASSERT(args->endp == NULL, ("already appending to args")); 1547 1548 if (fname != NULL) { 1549 args->fname = args->buf; 1550 error = segflg == UIO_SYSSPACE ? 1551 copystr(fname, args->fname, PATH_MAX, &length) : 1552 copyinstr(fname, args->fname, PATH_MAX, &length); 1553 if (error != 0) 1554 return (error == ENAMETOOLONG ? E2BIG : error); 1555 } else 1556 length = 0; 1557 1558 /* Set up for _arg_*()/_env_*() */ 1559 args->endp = args->buf + length; 1560 /* begin_argv must be set and kept updated */ 1561 args->begin_argv = args->endp; 1562 KASSERT(exec_map_entry_size - length >= ARG_MAX, 1563 ("too little space remaining for arguments %zu < %zu", 1564 exec_map_entry_size - length, (size_t)ARG_MAX)); 1565 args->stringspace = ARG_MAX; 1566 1567 return (0); 1568 } 1569 1570 static int 1571 exec_args_add_str(struct image_args *args, const char *str, 1572 enum uio_seg segflg, int *countp) 1573 { 1574 int error; 1575 size_t length; 1576 1577 KASSERT(args->endp != NULL, ("endp not initialized")); 1578 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1579 1580 error = (segflg == UIO_SYSSPACE) ? 1581 copystr(str, args->endp, args->stringspace, &length) : 1582 copyinstr(str, args->endp, args->stringspace, &length); 1583 if (error != 0) 1584 return (error == ENAMETOOLONG ? E2BIG : error); 1585 args->stringspace -= length; 1586 args->endp += length; 1587 (*countp)++; 1588 1589 return (0); 1590 } 1591 1592 int 1593 exec_args_add_arg(struct image_args *args, const char *argp, 1594 enum uio_seg segflg) 1595 { 1596 1597 KASSERT(args->envc == 0, ("appending args after env")); 1598 1599 return (exec_args_add_str(args, argp, segflg, &args->argc)); 1600 } 1601 1602 int 1603 exec_args_add_env(struct image_args *args, const char *envp, 1604 enum uio_seg segflg) 1605 { 1606 1607 if (args->envc == 0) 1608 args->begin_envv = args->endp; 1609 1610 return (exec_args_add_str(args, envp, segflg, &args->envc)); 1611 } 1612 1613 int 1614 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) 1615 { 1616 ssize_t offset; 1617 1618 KASSERT(args->endp != NULL, ("endp not initialized")); 1619 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1620 1621 offset = extend - consume; 1622 if (args->stringspace < offset) 1623 return (E2BIG); 1624 memmove(args->begin_argv + extend, args->begin_argv + consume, 1625 args->endp - args->begin_argv + consume); 1626 if (args->envc > 0) 1627 args->begin_envv += offset; 1628 args->endp += offset; 1629 args->stringspace -= offset; 1630 return (0); 1631 } 1632 1633 char * 1634 exec_args_get_begin_envv(struct image_args *args) 1635 { 1636 1637 KASSERT(args->endp != NULL, ("endp not initialized")); 1638 1639 if (args->envc > 0) 1640 return (args->begin_envv); 1641 return (args->endp); 1642 } 1643 1644 /* 1645 * Copy strings out to the new process address space, constructing new arg 1646 * and env vector tables. Return a pointer to the base so that it can be used 1647 * as the initial stack pointer. 1648 */ 1649 int 1650 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 1651 { 1652 int argc, envc; 1653 char **vectp; 1654 char *stringp; 1655 uintptr_t destp, ustringp; 1656 struct ps_strings *arginfo; 1657 struct proc *p; 1658 struct sysentvec *sysent; 1659 size_t execpath_len; 1660 int error, szsigcode; 1661 char canary[sizeof(long) * 8]; 1662 1663 p = imgp->proc; 1664 sysent = p->p_sysent; 1665 1666 destp = PROC_PS_STRINGS(p); 1667 arginfo = imgp->ps_strings = (void *)destp; 1668 1669 /* 1670 * Install sigcode. 1671 */ 1672 if (sysent->sv_shared_page_base == 0 && sysent->sv_szsigcode != NULL) { 1673 szsigcode = *(sysent->sv_szsigcode); 1674 destp -= szsigcode; 1675 destp = rounddown2(destp, sizeof(void *)); 1676 error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode); 1677 if (error != 0) 1678 return (error); 1679 } 1680 1681 /* 1682 * Copy the image path for the rtld. 1683 */ 1684 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 1685 execpath_len = strlen(imgp->execpath) + 1; 1686 destp -= execpath_len; 1687 destp = rounddown2(destp, sizeof(void *)); 1688 imgp->execpathp = (void *)destp; 1689 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 1690 if (error != 0) 1691 return (error); 1692 } 1693 1694 /* 1695 * Prepare the canary for SSP. 1696 */ 1697 arc4rand(canary, sizeof(canary), 0); 1698 destp -= sizeof(canary); 1699 imgp->canary = (void *)destp; 1700 error = copyout(canary, imgp->canary, sizeof(canary)); 1701 if (error != 0) 1702 return (error); 1703 imgp->canarylen = sizeof(canary); 1704 1705 /* 1706 * Prepare the pagesizes array. 1707 */ 1708 imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES; 1709 destp -= imgp->pagesizeslen; 1710 destp = rounddown2(destp, sizeof(void *)); 1711 imgp->pagesizes = (void *)destp; 1712 error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen); 1713 if (error != 0) 1714 return (error); 1715 1716 /* 1717 * Allocate room for the argument and environment strings. 1718 */ 1719 destp -= ARG_MAX - imgp->args->stringspace; 1720 destp = rounddown2(destp, sizeof(void *)); 1721 ustringp = destp; 1722 1723 if (imgp->auxargs) { 1724 /* 1725 * Allocate room on the stack for the ELF auxargs 1726 * array. It has up to AT_COUNT entries. 1727 */ 1728 destp -= AT_COUNT * sizeof(Elf_Auxinfo); 1729 destp = rounddown2(destp, sizeof(void *)); 1730 } 1731 1732 vectp = (char **)destp; 1733 1734 /* 1735 * Allocate room for the argv[] and env vectors including the 1736 * terminating NULL pointers. 1737 */ 1738 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 1739 1740 /* 1741 * vectp also becomes our initial stack base 1742 */ 1743 *stack_base = (uintptr_t)vectp; 1744 1745 stringp = imgp->args->begin_argv; 1746 argc = imgp->args->argc; 1747 envc = imgp->args->envc; 1748 1749 /* 1750 * Copy out strings - arguments and environment. 1751 */ 1752 error = copyout(stringp, (void *)ustringp, 1753 ARG_MAX - imgp->args->stringspace); 1754 if (error != 0) 1755 return (error); 1756 1757 /* 1758 * Fill in "ps_strings" struct for ps, w, etc. 1759 */ 1760 imgp->argv = vectp; 1761 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 1762 suword32(&arginfo->ps_nargvstr, argc) != 0) 1763 return (EFAULT); 1764 1765 /* 1766 * Fill in argument portion of vector table. 1767 */ 1768 for (; argc > 0; --argc) { 1769 if (suword(vectp++, ustringp) != 0) 1770 return (EFAULT); 1771 while (*stringp++ != 0) 1772 ustringp++; 1773 ustringp++; 1774 } 1775 1776 /* a null vector table pointer separates the argp's from the envp's */ 1777 if (suword(vectp++, 0) != 0) 1778 return (EFAULT); 1779 1780 imgp->envv = vectp; 1781 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 1782 suword32(&arginfo->ps_nenvstr, envc) != 0) 1783 return (EFAULT); 1784 1785 /* 1786 * Fill in environment portion of vector table. 1787 */ 1788 for (; envc > 0; --envc) { 1789 if (suword(vectp++, ustringp) != 0) 1790 return (EFAULT); 1791 while (*stringp++ != 0) 1792 ustringp++; 1793 ustringp++; 1794 } 1795 1796 /* end of vector table is a null pointer */ 1797 if (suword(vectp, 0) != 0) 1798 return (EFAULT); 1799 1800 if (imgp->auxargs) { 1801 vectp++; 1802 error = imgp->sysent->sv_copyout_auxargs(imgp, 1803 (uintptr_t)vectp); 1804 if (error != 0) 1805 return (error); 1806 } 1807 1808 return (0); 1809 } 1810 1811 /* 1812 * Check permissions of file to execute. 1813 * Called with imgp->vp locked. 1814 * Return 0 for success or error code on failure. 1815 */ 1816 int 1817 exec_check_permissions(struct image_params *imgp) 1818 { 1819 struct vnode *vp = imgp->vp; 1820 struct vattr *attr = imgp->attr; 1821 struct thread *td; 1822 int error; 1823 1824 td = curthread; 1825 1826 /* Get file attributes */ 1827 error = VOP_GETATTR(vp, attr, td->td_ucred); 1828 if (error) 1829 return (error); 1830 1831 #ifdef MAC 1832 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); 1833 if (error) 1834 return (error); 1835 #endif 1836 1837 /* 1838 * 1) Check if file execution is disabled for the filesystem that 1839 * this file resides on. 1840 * 2) Ensure that at least one execute bit is on. Otherwise, a 1841 * privileged user will always succeed, and we don't want this 1842 * to happen unless the file really is executable. 1843 * 3) Ensure that the file is a regular file. 1844 */ 1845 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || 1846 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || 1847 (attr->va_type != VREG)) 1848 return (EACCES); 1849 1850 /* 1851 * Zero length files can't be exec'd 1852 */ 1853 if (attr->va_size == 0) 1854 return (ENOEXEC); 1855 1856 /* 1857 * Check for execute permission to file based on current credentials. 1858 */ 1859 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); 1860 if (error) 1861 return (error); 1862 1863 /* 1864 * Check number of open-for-writes on the file and deny execution 1865 * if there are any. 1866 * 1867 * Add a text reference now so no one can write to the 1868 * executable while we're activating it. 1869 * 1870 * Remember if this was set before and unset it in case this is not 1871 * actually an executable image. 1872 */ 1873 error = VOP_SET_TEXT(vp); 1874 if (error != 0) 1875 return (error); 1876 imgp->textset = true; 1877 1878 /* 1879 * Call filesystem specific open routine (which does nothing in the 1880 * general case). 1881 */ 1882 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); 1883 if (error == 0) 1884 imgp->opened = true; 1885 return (error); 1886 } 1887 1888 /* 1889 * Exec handler registration 1890 */ 1891 int 1892 exec_register(const struct execsw *execsw_arg) 1893 { 1894 const struct execsw **es, **xs, **newexecsw; 1895 u_int count = 2; /* New slot and trailing NULL */ 1896 1897 if (execsw) 1898 for (es = execsw; *es; es++) 1899 count++; 1900 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1901 xs = newexecsw; 1902 if (execsw) 1903 for (es = execsw; *es; es++) 1904 *xs++ = *es; 1905 *xs++ = execsw_arg; 1906 *xs = NULL; 1907 if (execsw) 1908 free(execsw, M_TEMP); 1909 execsw = newexecsw; 1910 return (0); 1911 } 1912 1913 int 1914 exec_unregister(const struct execsw *execsw_arg) 1915 { 1916 const struct execsw **es, **xs, **newexecsw; 1917 int count = 1; 1918 1919 if (execsw == NULL) 1920 panic("unregister with no handlers left?\n"); 1921 1922 for (es = execsw; *es; es++) { 1923 if (*es == execsw_arg) 1924 break; 1925 } 1926 if (*es == NULL) 1927 return (ENOENT); 1928 for (es = execsw; *es; es++) 1929 if (*es != execsw_arg) 1930 count++; 1931 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1932 xs = newexecsw; 1933 for (es = execsw; *es; es++) 1934 if (*es != execsw_arg) 1935 *xs++ = *es; 1936 *xs = NULL; 1937 if (execsw) 1938 free(execsw, M_TEMP); 1939 execsw = newexecsw; 1940 return (0); 1941 } 1942 1943 /* 1944 * Write out a core segment to the compression stream. 1945 */ 1946 static int 1947 compress_chunk(struct coredump_params *cp, char *base, char *buf, size_t len) 1948 { 1949 size_t chunk_len; 1950 int error; 1951 1952 while (len > 0) { 1953 chunk_len = MIN(len, CORE_BUF_SIZE); 1954 1955 /* 1956 * We can get EFAULT error here. 1957 * In that case zero out the current chunk of the segment. 1958 */ 1959 error = copyin(base, buf, chunk_len); 1960 if (error != 0) 1961 bzero(buf, chunk_len); 1962 error = compressor_write(cp->comp, buf, chunk_len); 1963 if (error != 0) 1964 break; 1965 base += chunk_len; 1966 len -= chunk_len; 1967 } 1968 return (error); 1969 } 1970 1971 int 1972 core_write(struct coredump_params *cp, const void *base, size_t len, 1973 off_t offset, enum uio_seg seg, size_t *resid) 1974 { 1975 1976 return (vn_rdwr_inchunks(UIO_WRITE, cp->vp, __DECONST(void *, base), 1977 len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED, 1978 cp->active_cred, cp->file_cred, resid, cp->td)); 1979 } 1980 1981 int 1982 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp, 1983 void *tmpbuf) 1984 { 1985 vm_map_t map; 1986 struct mount *mp; 1987 size_t resid, runlen; 1988 int error; 1989 bool success; 1990 1991 KASSERT((uintptr_t)base % PAGE_SIZE == 0, 1992 ("%s: user address %p is not page-aligned", __func__, base)); 1993 1994 if (cp->comp != NULL) 1995 return (compress_chunk(cp, base, tmpbuf, len)); 1996 1997 map = &cp->td->td_proc->p_vmspace->vm_map; 1998 for (; len > 0; base += runlen, offset += runlen, len -= runlen) { 1999 /* 2000 * Attempt to page in all virtual pages in the range. If a 2001 * virtual page is not backed by the pager, it is represented as 2002 * a hole in the file. This can occur with zero-filled 2003 * anonymous memory or truncated files, for example. 2004 */ 2005 for (runlen = 0; runlen < len; runlen += PAGE_SIZE) { 2006 if (core_dump_can_intr && curproc_sigkilled()) 2007 return (EINTR); 2008 error = vm_fault(map, (uintptr_t)base + runlen, 2009 VM_PROT_READ, VM_FAULT_NOFILL, NULL); 2010 if (runlen == 0) 2011 success = error == KERN_SUCCESS; 2012 else if ((error == KERN_SUCCESS) != success) 2013 break; 2014 } 2015 2016 if (success) { 2017 error = core_write(cp, base, runlen, offset, 2018 UIO_USERSPACE, &resid); 2019 if (error != 0) { 2020 if (error != EFAULT) 2021 break; 2022 2023 /* 2024 * EFAULT may be returned if the user mapping 2025 * could not be accessed, e.g., because a mapped 2026 * file has been truncated. Skip the page if no 2027 * progress was made, to protect against a 2028 * hypothetical scenario where vm_fault() was 2029 * successful but core_write() returns EFAULT 2030 * anyway. 2031 */ 2032 runlen -= resid; 2033 if (runlen == 0) { 2034 success = false; 2035 runlen = PAGE_SIZE; 2036 } 2037 } 2038 } 2039 if (!success) { 2040 error = vn_start_write(cp->vp, &mp, V_WAIT); 2041 if (error != 0) 2042 break; 2043 vn_lock(cp->vp, LK_EXCLUSIVE | LK_RETRY); 2044 error = vn_truncate_locked(cp->vp, offset + runlen, 2045 false, cp->td->td_ucred); 2046 VOP_UNLOCK(cp->vp); 2047 vn_finished_write(mp); 2048 if (error != 0) 2049 break; 2050 } 2051 } 2052 return (error); 2053 } 2054 2055 /* 2056 * Drain into a core file. 2057 */ 2058 int 2059 sbuf_drain_core_output(void *arg, const char *data, int len) 2060 { 2061 struct coredump_params *cp; 2062 struct proc *p; 2063 int error, locked; 2064 2065 cp = arg; 2066 p = cp->td->td_proc; 2067 2068 /* 2069 * Some kern_proc out routines that print to this sbuf may 2070 * call us with the process lock held. Draining with the 2071 * non-sleepable lock held is unsafe. The lock is needed for 2072 * those routines when dumping a live process. In our case we 2073 * can safely release the lock before draining and acquire 2074 * again after. 2075 */ 2076 locked = PROC_LOCKED(p); 2077 if (locked) 2078 PROC_UNLOCK(p); 2079 if (cp->comp != NULL) 2080 error = compressor_write(cp->comp, __DECONST(char *, data), 2081 len); 2082 else 2083 error = core_write(cp, __DECONST(void *, data), len, cp->offset, 2084 UIO_SYSSPACE, NULL); 2085 if (locked) 2086 PROC_LOCK(p); 2087 if (error != 0) 2088 return (-error); 2089 cp->offset += len; 2090 return (len); 2091 } 2092