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 #include "opt_capsicum.h" 31 #include "opt_hwpmc_hooks.h" 32 #include "opt_ktrace.h" 33 #include "opt_vm.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/acct.h> 38 #include <sys/asan.h> 39 #include <sys/capsicum.h> 40 #include <sys/compressor.h> 41 #include <sys/eventhandler.h> 42 #include <sys/exec.h> 43 #include <sys/fcntl.h> 44 #include <sys/filedesc.h> 45 #include <sys/imgact.h> 46 #include <sys/imgact_elf.h> 47 #include <sys/kernel.h> 48 #include <sys/lock.h> 49 #include <sys/malloc.h> 50 #include <sys/mman.h> 51 #include <sys/mount.h> 52 #include <sys/mutex.h> 53 #include <sys/namei.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/ptrace.h> 57 #include <sys/reg.h> 58 #include <sys/resourcevar.h> 59 #include <sys/rwlock.h> 60 #include <sys/sched.h> 61 #include <sys/sdt.h> 62 #include <sys/sf_buf.h> 63 #include <sys/shm.h> 64 #include <sys/signalvar.h> 65 #include <sys/smp.h> 66 #include <sys/stat.h> 67 #include <sys/syscallsubr.h> 68 #include <sys/sysctl.h> 69 #include <sys/sysent.h> 70 #include <sys/sysproto.h> 71 #include <sys/timers.h> 72 #include <sys/umtxvar.h> 73 #include <sys/vnode.h> 74 #include <sys/wait.h> 75 #ifdef KTRACE 76 #include <sys/ktrace.h> 77 #endif 78 79 #include <vm/vm.h> 80 #include <vm/vm_param.h> 81 #include <vm/pmap.h> 82 #include <vm/vm_page.h> 83 #include <vm/vm_map.h> 84 #include <vm/vm_kern.h> 85 #include <vm/vm_extern.h> 86 #include <vm/vm_object.h> 87 #include <vm/vm_pager.h> 88 89 #ifdef HWPMC_HOOKS 90 #include <sys/pmckern.h> 91 #endif 92 93 #include <security/audit/audit.h> 94 #include <security/mac/mac_framework.h> 95 96 #ifdef KDTRACE_HOOKS 97 #include <sys/dtrace_bsd.h> 98 dtrace_execexit_func_t dtrace_fasttrap_exec; 99 #endif 100 101 SDT_PROVIDER_DECLARE(proc); 102 SDT_PROBE_DEFINE1(proc, , , exec, "char *"); 103 SDT_PROBE_DEFINE1(proc, , , exec__failure, "int"); 104 SDT_PROBE_DEFINE1(proc, , , exec__success, "char *"); 105 106 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments"); 107 108 int coredump_pack_fileinfo = 1; 109 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN, 110 &coredump_pack_fileinfo, 0, 111 "Enable file path packing in 'procstat -f' coredump notes"); 112 113 int coredump_pack_vmmapinfo = 1; 114 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN, 115 &coredump_pack_vmmapinfo, 0, 116 "Enable file path packing in 'procstat -v' coredump notes"); 117 118 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS); 119 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS); 120 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS); 121 static int do_execve(struct thread *td, struct image_args *args, 122 struct mac *mac_p, struct vmspace *oldvmspace); 123 124 /* XXX This should be vm_size_t. */ 125 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD| 126 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU", 127 "Location of process' ps_strings structure"); 128 129 /* XXX This should be vm_size_t. */ 130 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD| 131 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU", 132 "Top of process stack"); 133 134 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE, 135 NULL, 0, sysctl_kern_stackprot, "I", 136 "Stack memory permissions"); 137 138 u_long ps_arg_cache_limit = PAGE_SIZE / 16; 139 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW, 140 &ps_arg_cache_limit, 0, 141 "Process' command line characters cache limit"); 142 143 static int disallow_high_osrel; 144 SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW, 145 &disallow_high_osrel, 0, 146 "Disallow execution of binaries built for higher version of the world"); 147 148 static int map_at_zero = 0; 149 SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0, 150 "Permit processes to map an object at virtual address 0."); 151 152 static int core_dump_can_intr = 1; 153 SYSCTL_INT(_kern, OID_AUTO, core_dump_can_intr, CTLFLAG_RWTUN, 154 &core_dump_can_intr, 0, 155 "Core dumping interruptible with SIGKILL"); 156 157 static int 158 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS) 159 { 160 struct proc *p; 161 vm_offset_t ps_strings; 162 163 p = curproc; 164 #ifdef SCTL_MASK32 165 if (req->flags & SCTL_MASK32) { 166 unsigned int val; 167 val = (unsigned int)PROC_PS_STRINGS(p); 168 return (SYSCTL_OUT(req, &val, sizeof(val))); 169 } 170 #endif 171 ps_strings = PROC_PS_STRINGS(p); 172 return (SYSCTL_OUT(req, &ps_strings, sizeof(ps_strings))); 173 } 174 175 static int 176 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS) 177 { 178 struct proc *p; 179 vm_offset_t val; 180 181 p = curproc; 182 #ifdef SCTL_MASK32 183 if (req->flags & SCTL_MASK32) { 184 unsigned int val32; 185 186 val32 = round_page((unsigned int)p->p_vmspace->vm_stacktop); 187 return (SYSCTL_OUT(req, &val32, sizeof(val32))); 188 } 189 #endif 190 val = round_page(p->p_vmspace->vm_stacktop); 191 return (SYSCTL_OUT(req, &val, sizeof(val))); 192 } 193 194 static int 195 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS) 196 { 197 struct proc *p; 198 199 p = curproc; 200 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot, 201 sizeof(p->p_sysent->sv_stackprot))); 202 } 203 204 /* 205 * Each of the items is a pointer to a `const struct execsw', hence the 206 * double pointer here. 207 */ 208 static const struct execsw **execsw; 209 210 #ifndef _SYS_SYSPROTO_H_ 211 struct execve_args { 212 char *fname; 213 char **argv; 214 char **envv; 215 }; 216 #endif 217 218 int 219 sys_execve(struct thread *td, struct execve_args *uap) 220 { 221 struct image_args args; 222 struct vmspace *oldvmspace; 223 int error; 224 225 error = pre_execve(td, &oldvmspace); 226 if (error != 0) 227 return (error); 228 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, 229 uap->argv, uap->envv); 230 if (error == 0) 231 error = kern_execve(td, &args, NULL, oldvmspace); 232 post_execve(td, error, oldvmspace); 233 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 234 return (error); 235 } 236 237 #ifndef _SYS_SYSPROTO_H_ 238 struct fexecve_args { 239 int fd; 240 char **argv; 241 char **envv; 242 }; 243 #endif 244 int 245 sys_fexecve(struct thread *td, struct fexecve_args *uap) 246 { 247 struct image_args args; 248 struct vmspace *oldvmspace; 249 int error; 250 251 error = pre_execve(td, &oldvmspace); 252 if (error != 0) 253 return (error); 254 error = exec_copyin_args(&args, NULL, UIO_SYSSPACE, 255 uap->argv, uap->envv); 256 if (error == 0) { 257 args.fd = uap->fd; 258 error = kern_execve(td, &args, NULL, oldvmspace); 259 } 260 post_execve(td, error, oldvmspace); 261 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 262 return (error); 263 } 264 265 #ifndef _SYS_SYSPROTO_H_ 266 struct __mac_execve_args { 267 char *fname; 268 char **argv; 269 char **envv; 270 struct mac *mac_p; 271 }; 272 #endif 273 274 int 275 sys___mac_execve(struct thread *td, struct __mac_execve_args *uap) 276 { 277 #ifdef MAC 278 struct image_args args; 279 struct vmspace *oldvmspace; 280 int error; 281 282 error = pre_execve(td, &oldvmspace); 283 if (error != 0) 284 return (error); 285 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, 286 uap->argv, uap->envv); 287 if (error == 0) 288 error = kern_execve(td, &args, uap->mac_p, oldvmspace); 289 post_execve(td, error, oldvmspace); 290 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 291 return (error); 292 #else 293 return (ENOSYS); 294 #endif 295 } 296 297 int 298 pre_execve(struct thread *td, struct vmspace **oldvmspace) 299 { 300 struct proc *p; 301 int error; 302 303 KASSERT(td == curthread, ("non-current thread %p", td)); 304 error = 0; 305 p = td->td_proc; 306 if ((p->p_flag & P_HADTHREADS) != 0) { 307 PROC_LOCK(p); 308 if (thread_single(p, SINGLE_BOUNDARY) != 0) 309 error = ERESTART; 310 PROC_UNLOCK(p); 311 } 312 KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0, 313 ("nested execve")); 314 *oldvmspace = p->p_vmspace; 315 return (error); 316 } 317 318 void 319 post_execve(struct thread *td, int error, struct vmspace *oldvmspace) 320 { 321 struct proc *p; 322 323 KASSERT(td == curthread, ("non-current thread %p", td)); 324 p = td->td_proc; 325 if ((p->p_flag & P_HADTHREADS) != 0) { 326 PROC_LOCK(p); 327 /* 328 * If success, we upgrade to SINGLE_EXIT state to 329 * force other threads to suicide. 330 */ 331 if (error == EJUSTRETURN) 332 thread_single(p, SINGLE_EXIT); 333 else 334 thread_single_end(p, SINGLE_BOUNDARY); 335 PROC_UNLOCK(p); 336 } 337 exec_cleanup(td, oldvmspace); 338 } 339 340 /* 341 * kern_execve() has the astonishing property of not always returning to 342 * the caller. If sufficiently bad things happen during the call to 343 * do_execve(), it can end up calling exit1(); as a result, callers must 344 * avoid doing anything which they might need to undo (e.g., allocating 345 * memory). 346 */ 347 int 348 kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 349 struct vmspace *oldvmspace) 350 { 351 352 TSEXEC(td->td_proc->p_pid, args->begin_argv); 353 AUDIT_ARG_ARGV(args->begin_argv, args->argc, 354 exec_args_get_begin_envv(args) - args->begin_argv); 355 AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc, 356 args->endp - exec_args_get_begin_envv(args)); 357 #ifdef KTRACE 358 if (KTRPOINT(td, KTR_ARGS)) { 359 ktrdata(KTR_ARGS, args->begin_argv, 360 exec_args_get_begin_envv(args) - args->begin_argv); 361 } 362 if (KTRPOINT(td, KTR_ENVS)) { 363 ktrdata(KTR_ENVS, exec_args_get_begin_envv(args), 364 args->endp - exec_args_get_begin_envv(args)); 365 } 366 #endif 367 /* Must have at least one argument. */ 368 if (args->argc == 0) { 369 exec_free_args(args); 370 return (EINVAL); 371 } 372 return (do_execve(td, args, mac_p, oldvmspace)); 373 } 374 375 static void 376 execve_nosetid(struct image_params *imgp) 377 { 378 imgp->credential_setid = false; 379 if (imgp->newcred != NULL) { 380 crfree(imgp->newcred); 381 imgp->newcred = NULL; 382 } 383 } 384 385 /* 386 * In-kernel implementation of execve(). All arguments are assumed to be 387 * userspace pointers from the passed thread. 388 */ 389 static int 390 do_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 391 struct vmspace *oldvmspace) 392 { 393 struct proc *p = td->td_proc; 394 struct nameidata nd; 395 struct ucred *oldcred; 396 struct uidinfo *euip = NULL; 397 uintptr_t stack_base; 398 struct image_params image_params, *imgp; 399 struct vattr attr; 400 struct pargs *oldargs = NULL, *newargs = NULL; 401 struct sigacts *oldsigacts = NULL, *newsigacts = NULL; 402 #ifdef KTRACE 403 struct ktr_io_params *kiop; 404 #endif 405 struct vnode *oldtextvp, *newtextvp; 406 struct vnode *oldtextdvp, *newtextdvp; 407 char *oldbinname, *newbinname; 408 bool credential_changing; 409 #ifdef MAC 410 struct label *interpvplabel = NULL; 411 bool will_transition; 412 #endif 413 #ifdef HWPMC_HOOKS 414 struct pmckern_procexec pe; 415 #endif 416 int error, i, orig_osrel; 417 uint32_t orig_fctl0; 418 Elf_Brandinfo *orig_brandinfo; 419 size_t freepath_size; 420 static const char fexecv_proc_title[] = "(fexecv)"; 421 422 imgp = &image_params; 423 oldtextvp = oldtextdvp = NULL; 424 newtextvp = newtextdvp = NULL; 425 newbinname = oldbinname = NULL; 426 #ifdef KTRACE 427 kiop = NULL; 428 #endif 429 430 /* 431 * Lock the process and set the P_INEXEC flag to indicate that 432 * it should be left alone until we're done here. This is 433 * necessary to avoid race conditions - e.g. in ptrace() - 434 * that might allow a local user to illicitly obtain elevated 435 * privileges. 436 */ 437 PROC_LOCK(p); 438 KASSERT((p->p_flag & P_INEXEC) == 0, 439 ("%s(): process already has P_INEXEC flag", __func__)); 440 p->p_flag |= P_INEXEC; 441 PROC_UNLOCK(p); 442 443 /* 444 * Initialize part of the common data 445 */ 446 bzero(imgp, sizeof(*imgp)); 447 imgp->proc = p; 448 imgp->attr = &attr; 449 imgp->args = args; 450 oldcred = p->p_ucred; 451 orig_osrel = p->p_osrel; 452 orig_fctl0 = p->p_fctl0; 453 orig_brandinfo = p->p_elf_brandinfo; 454 455 #ifdef MAC 456 error = mac_execve_enter(imgp, mac_p); 457 if (error) 458 goto exec_fail; 459 #endif 460 461 SDT_PROBE1(proc, , , exec, args->fname); 462 463 interpret: 464 if (args->fname != NULL) { 465 #ifdef CAPABILITY_MODE 466 if (CAP_TRACING(td)) 467 ktrcapfail(CAPFAIL_NAMEI, args->fname); 468 /* 469 * While capability mode can't reach this point via direct 470 * path arguments to execve(), we also don't allow 471 * interpreters to be used in capability mode (for now). 472 * Catch indirect lookups and return a permissions error. 473 */ 474 if (IN_CAPABILITY_MODE(td)) { 475 error = ECAPMODE; 476 goto exec_fail; 477 } 478 #endif 479 480 /* 481 * Translate the file name. namei() returns a vnode 482 * pointer in ni_vp among other things. 483 */ 484 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | 485 AUDITVNODE1 | WANTPARENT, UIO_SYSSPACE, 486 args->fname); 487 488 error = namei(&nd); 489 if (error) 490 goto exec_fail; 491 492 newtextvp = nd.ni_vp; 493 newtextdvp = nd.ni_dvp; 494 nd.ni_dvp = NULL; 495 newbinname = malloc(nd.ni_cnd.cn_namelen + 1, M_PARGS, 496 M_WAITOK); 497 memcpy(newbinname, nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 498 newbinname[nd.ni_cnd.cn_namelen] = '\0'; 499 imgp->vp = newtextvp; 500 501 /* 502 * Do the best to calculate the full path to the image file. 503 */ 504 if (args->fname[0] == '/') { 505 imgp->execpath = args->fname; 506 } else { 507 VOP_UNLOCK(imgp->vp); 508 freepath_size = MAXPATHLEN; 509 if (vn_fullpath_hardlink(newtextvp, newtextdvp, 510 newbinname, nd.ni_cnd.cn_namelen, &imgp->execpath, 511 &imgp->freepath, &freepath_size) != 0) 512 imgp->execpath = args->fname; 513 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 514 } 515 } else if (imgp->interpreter_vp) { 516 /* 517 * An image activator has already provided an open vnode 518 */ 519 newtextvp = imgp->interpreter_vp; 520 imgp->interpreter_vp = NULL; 521 if (vn_fullpath(newtextvp, &imgp->execpath, 522 &imgp->freepath) != 0) 523 imgp->execpath = args->fname; 524 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 525 AUDIT_ARG_VNODE1(newtextvp); 526 imgp->vp = newtextvp; 527 } else { 528 AUDIT_ARG_FD(args->fd); 529 530 /* 531 * If the descriptors was not opened with O_PATH, then 532 * we require that it was opened with O_EXEC or 533 * O_RDONLY. In either case, exec_check_permissions() 534 * below checks _current_ file access mode regardless 535 * of the permissions additionally checked at the 536 * open(2). 537 */ 538 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, 539 &newtextvp); 540 if (error != 0) 541 goto exec_fail; 542 543 if (vn_fullpath(newtextvp, &imgp->execpath, 544 &imgp->freepath) != 0) 545 imgp->execpath = args->fname; 546 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 547 AUDIT_ARG_VNODE1(newtextvp); 548 imgp->vp = newtextvp; 549 } 550 551 /* 552 * Check file permissions. Also 'opens' file and sets its vnode to 553 * text mode. 554 */ 555 error = exec_check_permissions(imgp); 556 if (error) 557 goto exec_fail_dealloc; 558 559 imgp->object = imgp->vp->v_object; 560 if (imgp->object != NULL) 561 vm_object_reference(imgp->object); 562 563 error = exec_map_first_page(imgp); 564 if (error) 565 goto exec_fail_dealloc; 566 567 imgp->proc->p_osrel = 0; 568 imgp->proc->p_fctl0 = 0; 569 imgp->proc->p_elf_brandinfo = NULL; 570 571 /* 572 * Implement image setuid/setgid. 573 * 574 * Determine new credentials before attempting image activators 575 * so that it can be used by process_exec handlers to determine 576 * credential/setid changes. 577 * 578 * Don't honor setuid/setgid if the filesystem prohibits it or if 579 * the process is being traced. 580 * 581 * We disable setuid/setgid/etc in capability mode on the basis 582 * that most setugid applications are not written with that 583 * environment in mind, and will therefore almost certainly operate 584 * incorrectly. In principle there's no reason that setugid 585 * applications might not be useful in capability mode, so we may want 586 * to reconsider this conservative design choice in the future. 587 * 588 * XXXMAC: For the time being, use NOSUID to also prohibit 589 * transitions on the file system. 590 */ 591 credential_changing = false; 592 credential_changing |= (attr.va_mode & S_ISUID) && 593 oldcred->cr_uid != attr.va_uid; 594 credential_changing |= (attr.va_mode & S_ISGID) && 595 oldcred->cr_gid != attr.va_gid; 596 #ifdef MAC 597 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp, 598 interpvplabel, imgp) != 0; 599 credential_changing |= will_transition; 600 #endif 601 602 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */ 603 if (credential_changing) 604 imgp->proc->p_pdeathsig = 0; 605 606 if (credential_changing && 607 #ifdef CAPABILITY_MODE 608 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) && 609 #endif 610 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 && 611 (p->p_flag & P_TRACED) == 0) { 612 imgp->credential_setid = true; 613 VOP_UNLOCK(imgp->vp); 614 imgp->newcred = crdup(oldcred); 615 if (attr.va_mode & S_ISUID) { 616 euip = uifind(attr.va_uid); 617 change_euid(imgp->newcred, euip); 618 } 619 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 620 if (attr.va_mode & S_ISGID) 621 change_egid(imgp->newcred, attr.va_gid); 622 /* 623 * Implement correct POSIX saved-id behavior. 624 * 625 * XXXMAC: Note that the current logic will save the 626 * uid and gid if a MAC domain transition occurs, even 627 * though maybe it shouldn't. 628 */ 629 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 630 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 631 } else { 632 /* 633 * Implement correct POSIX saved-id behavior. 634 * 635 * XXX: It's not clear that the existing behavior is 636 * POSIX-compliant. A number of sources indicate that the 637 * saved uid/gid should only be updated if the new ruid is 638 * not equal to the old ruid, or the new euid is not equal 639 * to the old euid and the new euid is not equal to the old 640 * ruid. The FreeBSD code always updates the saved uid/gid. 641 * Also, this code uses the new (replaced) euid and egid as 642 * the source, which may or may not be the right ones to use. 643 */ 644 if (oldcred->cr_svuid != oldcred->cr_uid || 645 oldcred->cr_svgid != oldcred->cr_gid) { 646 VOP_UNLOCK(imgp->vp); 647 imgp->newcred = crdup(oldcred); 648 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 649 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 650 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 651 } 652 } 653 /* The new credentials are installed into the process later. */ 654 655 /* 656 * Loop through the list of image activators, calling each one. 657 * An activator returns -1 if there is no match, 0 on success, 658 * and an error otherwise. 659 */ 660 error = -1; 661 for (i = 0; error == -1 && execsw[i]; ++i) { 662 if (execsw[i]->ex_imgact == NULL) 663 continue; 664 error = (*execsw[i]->ex_imgact)(imgp); 665 } 666 667 if (error) { 668 if (error == -1) 669 error = ENOEXEC; 670 goto exec_fail_dealloc; 671 } 672 673 /* 674 * Special interpreter operation, cleanup and loop up to try to 675 * activate the interpreter. 676 */ 677 if (imgp->interpreted) { 678 exec_unmap_first_page(imgp); 679 /* 680 * The text reference needs to be removed for scripts. 681 * There is a short period before we determine that 682 * something is a script where text reference is active. 683 * The vnode lock is held over this entire period 684 * so nothing should illegitimately be blocked. 685 */ 686 MPASS(imgp->textset); 687 VOP_UNSET_TEXT_CHECKED(newtextvp); 688 imgp->textset = false; 689 /* free name buffer and old vnode */ 690 #ifdef MAC 691 mac_execve_interpreter_enter(newtextvp, &interpvplabel); 692 #endif 693 if (imgp->opened) { 694 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td); 695 imgp->opened = false; 696 } 697 vput(newtextvp); 698 imgp->vp = newtextvp = NULL; 699 if (args->fname != NULL) { 700 if (newtextdvp != NULL) { 701 vrele(newtextdvp); 702 newtextdvp = NULL; 703 } 704 NDFREE_PNBUF(&nd); 705 free(newbinname, M_PARGS); 706 newbinname = NULL; 707 } 708 vm_object_deallocate(imgp->object); 709 imgp->object = NULL; 710 execve_nosetid(imgp); 711 imgp->execpath = NULL; 712 free(imgp->freepath, M_TEMP); 713 imgp->freepath = NULL; 714 /* set new name to that of the interpreter */ 715 if (imgp->interpreter_vp) { 716 args->fname = NULL; 717 } else { 718 args->fname = imgp->interpreter_name; 719 } 720 goto interpret; 721 } 722 723 /* 724 * NB: We unlock the vnode here because it is believed that none 725 * of the sv_copyout_strings/sv_fixup operations require the vnode. 726 */ 727 VOP_UNLOCK(imgp->vp); 728 729 if (disallow_high_osrel && 730 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { 731 error = ENOEXEC; 732 uprintf("Osrel %d for image %s too high\n", p->p_osrel, 733 imgp->execpath != NULL ? imgp->execpath : "<unresolved>"); 734 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 735 goto exec_fail_dealloc; 736 } 737 738 /* 739 * Copy out strings (args and env) and initialize stack base. 740 */ 741 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); 742 if (error != 0) { 743 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 744 goto exec_fail_dealloc; 745 } 746 747 /* 748 * Stack setup. 749 */ 750 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); 751 if (error != 0) { 752 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 753 goto exec_fail_dealloc; 754 } 755 756 /* 757 * For security and other reasons, the file descriptor table cannot be 758 * shared after an exec. 759 */ 760 fdunshare(td); 761 pdunshare(td); 762 /* close files on exec */ 763 fdcloseexec(td); 764 765 /* 766 * Malloc things before we need locks. 767 */ 768 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; 769 /* Cache arguments if they fit inside our allowance */ 770 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { 771 newargs = pargs_alloc(i); 772 bcopy(imgp->args->begin_argv, newargs->ar_args, i); 773 } 774 775 /* 776 * For security and other reasons, signal handlers cannot 777 * be shared after an exec. The new process gets a copy of the old 778 * handlers. In execsigs(), the new process will have its signals 779 * reset. 780 */ 781 if (sigacts_shared(p->p_sigacts)) { 782 oldsigacts = p->p_sigacts; 783 newsigacts = sigacts_alloc(); 784 sigacts_copy(newsigacts, oldsigacts); 785 } 786 787 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 788 789 PROC_LOCK(p); 790 if (oldsigacts) 791 p->p_sigacts = newsigacts; 792 /* Stop profiling */ 793 stopprofclock(p); 794 795 /* reset caught signals */ 796 execsigs(p); 797 798 /* name this process - nameiexec(p, ndp) */ 799 bzero(p->p_comm, sizeof(p->p_comm)); 800 if (args->fname) 801 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, 802 min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); 803 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) 804 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); 805 bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); 806 #ifdef KTR 807 sched_clear_tdname(td); 808 #endif 809 810 /* 811 * mark as execed, wakeup the process that vforked (if any) and tell 812 * it that it now has its own resources back 813 */ 814 p->p_flag |= P_EXEC; 815 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) 816 p->p_flag2 &= ~P2_NOTRACE; 817 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) 818 p->p_flag2 &= ~P2_STKGAP_DISABLE; 819 p->p_flag2 &= ~(P2_MEMBAR_PRIVE | P2_MEMBAR_PRIVE_SYNCORE | 820 P2_MEMBAR_GLOBE); 821 if (p->p_flag & P_PPWAIT) { 822 p->p_flag &= ~(P_PPWAIT | P_PPTRACE); 823 cv_broadcast(&p->p_pwait); 824 /* STOPs are no longer ignored, arrange for AST */ 825 signotify(td); 826 } 827 828 if ((imgp->sysent->sv_setid_allowed != NULL && 829 !(*imgp->sysent->sv_setid_allowed)(td, imgp)) || 830 (p->p_flag2 & P2_NO_NEW_PRIVS) != 0) 831 execve_nosetid(imgp); 832 833 /* 834 * Implement image setuid/setgid installation. 835 */ 836 if (imgp->credential_setid) { 837 /* 838 * Turn off syscall tracing for set-id programs, except for 839 * root. Record any set-id flags first to make sure that 840 * we do not regain any tracing during a possible block. 841 */ 842 setsugid(p); 843 #ifdef KTRACE 844 kiop = ktrprocexec(p); 845 #endif 846 /* 847 * Close any file descriptors 0..2 that reference procfs, 848 * then make sure file descriptors 0..2 are in use. 849 * 850 * Both fdsetugidsafety() and fdcheckstd() may call functions 851 * taking sleepable locks, so temporarily drop our locks. 852 */ 853 PROC_UNLOCK(p); 854 VOP_UNLOCK(imgp->vp); 855 fdsetugidsafety(td); 856 error = fdcheckstd(td); 857 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 858 if (error != 0) 859 goto exec_fail_dealloc; 860 PROC_LOCK(p); 861 #ifdef MAC 862 if (will_transition) { 863 mac_vnode_execve_transition(oldcred, imgp->newcred, 864 imgp->vp, interpvplabel, imgp); 865 } 866 #endif 867 } else { 868 if (oldcred->cr_uid == oldcred->cr_ruid && 869 oldcred->cr_gid == oldcred->cr_rgid) 870 p->p_flag &= ~P_SUGID; 871 } 872 /* 873 * Set the new credentials. 874 */ 875 if (imgp->newcred != NULL) { 876 proc_set_cred(p, imgp->newcred); 877 crfree(oldcred); 878 oldcred = NULL; 879 } 880 881 /* 882 * Store the vp for use in kern.proc.pathname. This vnode was 883 * referenced by namei() or by fexecve variant of fname handling. 884 */ 885 oldtextvp = p->p_textvp; 886 p->p_textvp = newtextvp; 887 oldtextdvp = p->p_textdvp; 888 p->p_textdvp = newtextdvp; 889 newtextdvp = NULL; 890 oldbinname = p->p_binname; 891 p->p_binname = newbinname; 892 newbinname = NULL; 893 894 #ifdef KDTRACE_HOOKS 895 /* 896 * Tell the DTrace fasttrap provider about the exec if it 897 * has declared an interest. 898 */ 899 if (dtrace_fasttrap_exec) 900 dtrace_fasttrap_exec(p); 901 #endif 902 903 /* 904 * Notify others that we exec'd, and clear the P_INEXEC flag 905 * as we're now a bona fide freshly-execed process. 906 */ 907 KNOTE_LOCKED(p->p_klist, NOTE_EXEC); 908 p->p_flag &= ~P_INEXEC; 909 910 /* clear "fork but no exec" flag, as we _are_ execing */ 911 p->p_acflag &= ~AFORK; 912 913 /* 914 * Free any previous argument cache and replace it with 915 * the new argument cache, if any. 916 */ 917 oldargs = p->p_args; 918 p->p_args = newargs; 919 newargs = NULL; 920 921 PROC_UNLOCK(p); 922 923 #ifdef HWPMC_HOOKS 924 /* 925 * Check if system-wide sampling is in effect or if the 926 * current process is using PMCs. If so, do exec() time 927 * processing. This processing needs to happen AFTER the 928 * P_INEXEC flag is cleared. 929 */ 930 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { 931 VOP_UNLOCK(imgp->vp); 932 pe.pm_credentialschanged = credential_changing; 933 pe.pm_baseaddr = imgp->reloc_base; 934 pe.pm_dynaddr = imgp->et_dyn_addr; 935 936 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); 937 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 938 } 939 #endif 940 941 /* Set values passed into the program in registers. */ 942 (*p->p_sysent->sv_setregs)(td, imgp, stack_base); 943 944 VOP_MMAPPED(imgp->vp); 945 946 SDT_PROBE1(proc, , , exec__success, args->fname); 947 948 exec_fail_dealloc: 949 if (error != 0) { 950 p->p_osrel = orig_osrel; 951 p->p_fctl0 = orig_fctl0; 952 p->p_elf_brandinfo = orig_brandinfo; 953 } 954 955 if (imgp->firstpage != NULL) 956 exec_unmap_first_page(imgp); 957 958 if (imgp->vp != NULL) { 959 if (imgp->opened) 960 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); 961 if (imgp->textset) 962 VOP_UNSET_TEXT_CHECKED(imgp->vp); 963 if (error != 0) 964 vput(imgp->vp); 965 else 966 VOP_UNLOCK(imgp->vp); 967 if (args->fname != NULL) 968 NDFREE_PNBUF(&nd); 969 if (newtextdvp != NULL) 970 vrele(newtextdvp); 971 free(newbinname, M_PARGS); 972 } 973 974 if (imgp->object != NULL) 975 vm_object_deallocate(imgp->object); 976 977 free(imgp->freepath, M_TEMP); 978 979 if (error == 0) { 980 if (p->p_ptevents & PTRACE_EXEC) { 981 PROC_LOCK(p); 982 if (p->p_ptevents & PTRACE_EXEC) 983 td->td_dbgflags |= TDB_EXEC; 984 PROC_UNLOCK(p); 985 } 986 } else { 987 exec_fail: 988 /* we're done here, clear P_INEXEC */ 989 PROC_LOCK(p); 990 p->p_flag &= ~P_INEXEC; 991 PROC_UNLOCK(p); 992 993 SDT_PROBE1(proc, , , exec__failure, error); 994 } 995 996 if (imgp->newcred != NULL && oldcred != NULL) 997 crfree(imgp->newcred); 998 999 #ifdef MAC 1000 mac_execve_exit(imgp); 1001 mac_execve_interpreter_exit(interpvplabel); 1002 #endif 1003 exec_free_args(args); 1004 1005 /* 1006 * Handle deferred decrement of ref counts. 1007 */ 1008 if (oldtextvp != NULL) 1009 vrele(oldtextvp); 1010 if (oldtextdvp != NULL) 1011 vrele(oldtextdvp); 1012 free(oldbinname, M_PARGS); 1013 #ifdef KTRACE 1014 ktr_io_params_free(kiop); 1015 #endif 1016 pargs_drop(oldargs); 1017 pargs_drop(newargs); 1018 if (oldsigacts != NULL) 1019 sigacts_free(oldsigacts); 1020 if (euip != NULL) 1021 uifree(euip); 1022 1023 if (error && imgp->vmspace_destroyed) { 1024 /* sorry, no more process anymore. exit gracefully */ 1025 exec_cleanup(td, oldvmspace); 1026 exit1(td, 0, SIGABRT); 1027 /* NOT REACHED */ 1028 } 1029 1030 #ifdef KTRACE 1031 if (error == 0) 1032 ktrprocctor(p); 1033 #endif 1034 1035 /* 1036 * We don't want cpu_set_syscall_retval() to overwrite any of 1037 * the register values put in place by exec_setregs(). 1038 * Implementations of cpu_set_syscall_retval() will leave 1039 * registers unmodified when returning EJUSTRETURN. 1040 */ 1041 return (error == 0 ? EJUSTRETURN : error); 1042 } 1043 1044 void 1045 exec_cleanup(struct thread *td, struct vmspace *oldvmspace) 1046 { 1047 if ((td->td_pflags & TDP_EXECVMSPC) != 0) { 1048 KASSERT(td->td_proc->p_vmspace != oldvmspace, 1049 ("oldvmspace still used")); 1050 vmspace_free(oldvmspace); 1051 td->td_pflags &= ~TDP_EXECVMSPC; 1052 } 1053 } 1054 1055 int 1056 exec_map_first_page(struct image_params *imgp) 1057 { 1058 vm_object_t object; 1059 vm_page_t m; 1060 int error; 1061 1062 if (imgp->firstpage != NULL) 1063 exec_unmap_first_page(imgp); 1064 1065 object = imgp->vp->v_object; 1066 if (object == NULL) 1067 return (EACCES); 1068 #if VM_NRESERVLEVEL > 0 1069 if ((object->flags & OBJ_COLORED) == 0) { 1070 VM_OBJECT_WLOCK(object); 1071 vm_object_color(object, 0); 1072 VM_OBJECT_WUNLOCK(object); 1073 } 1074 #endif 1075 error = vm_page_grab_valid_unlocked(&m, object, 0, 1076 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | 1077 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 1078 1079 if (error != VM_PAGER_OK) 1080 return (EIO); 1081 imgp->firstpage = sf_buf_alloc(m, 0); 1082 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); 1083 1084 return (0); 1085 } 1086 1087 void 1088 exec_unmap_first_page(struct image_params *imgp) 1089 { 1090 vm_page_t m; 1091 1092 if (imgp->firstpage != NULL) { 1093 m = sf_buf_page(imgp->firstpage); 1094 sf_buf_free(imgp->firstpage); 1095 imgp->firstpage = NULL; 1096 vm_page_unwire(m, PQ_ACTIVE); 1097 } 1098 } 1099 1100 void 1101 exec_onexec_old(struct thread *td) 1102 { 1103 sigfastblock_clear(td); 1104 umtx_exec(td->td_proc); 1105 } 1106 1107 /* 1108 * This is an optimization which removes the unmanaged shared page 1109 * mapping. In combination with pmap_remove_pages(), which cleans all 1110 * managed mappings in the process' vmspace pmap, no work will be left 1111 * for pmap_remove(min, max). 1112 */ 1113 void 1114 exec_free_abi_mappings(struct proc *p) 1115 { 1116 struct vmspace *vmspace; 1117 1118 vmspace = p->p_vmspace; 1119 if (refcount_load(&vmspace->vm_refcnt) != 1) 1120 return; 1121 1122 if (!PROC_HAS_SHP(p)) 1123 return; 1124 1125 pmap_remove(vmspace_pmap(vmspace), vmspace->vm_shp_base, 1126 vmspace->vm_shp_base + p->p_sysent->sv_shared_page_len); 1127 } 1128 1129 /* 1130 * Run down the current address space and install a new one. 1131 */ 1132 int 1133 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) 1134 { 1135 int error; 1136 struct proc *p = imgp->proc; 1137 struct vmspace *vmspace = p->p_vmspace; 1138 struct thread *td = curthread; 1139 vm_offset_t sv_minuser; 1140 vm_map_t map; 1141 1142 imgp->vmspace_destroyed = true; 1143 imgp->sysent = sv; 1144 1145 if (p->p_sysent->sv_onexec_old != NULL) 1146 p->p_sysent->sv_onexec_old(td); 1147 itimers_exec(p); 1148 1149 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); 1150 1151 /* 1152 * Blow away entire process VM, if address space not shared, 1153 * otherwise, create a new VM space so that other threads are 1154 * not disrupted 1155 */ 1156 map = &vmspace->vm_map; 1157 if (map_at_zero) 1158 sv_minuser = sv->sv_minuser; 1159 else 1160 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); 1161 if (refcount_load(&vmspace->vm_refcnt) == 1 && 1162 vm_map_min(map) == sv_minuser && 1163 vm_map_max(map) == sv->sv_maxuser && 1164 cpu_exec_vmspace_reuse(p, map)) { 1165 exec_free_abi_mappings(p); 1166 shmexit(vmspace); 1167 pmap_remove_pages(vmspace_pmap(vmspace)); 1168 vm_map_remove(map, vm_map_min(map), vm_map_max(map)); 1169 /* 1170 * An exec terminates mlockall(MCL_FUTURE). 1171 * ASLR and W^X states must be re-evaluated. 1172 */ 1173 vm_map_lock(map); 1174 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | 1175 MAP_ASLR_IGNSTART | MAP_ASLR_STACK | MAP_WXORX); 1176 vm_map_unlock(map); 1177 } else { 1178 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); 1179 if (error) 1180 return (error); 1181 vmspace = p->p_vmspace; 1182 map = &vmspace->vm_map; 1183 } 1184 map->flags |= imgp->map_flags; 1185 1186 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0); 1187 } 1188 1189 /* 1190 * Compute the stack size limit and map the main process stack. 1191 * Map the shared page. 1192 */ 1193 int 1194 exec_map_stack(struct image_params *imgp) 1195 { 1196 struct rlimit rlim_stack; 1197 struct sysentvec *sv; 1198 struct proc *p; 1199 vm_map_t map; 1200 struct vmspace *vmspace; 1201 vm_offset_t stack_addr, stack_top; 1202 vm_offset_t sharedpage_addr; 1203 u_long ssiz; 1204 int error, find_space, stack_off; 1205 vm_prot_t stack_prot; 1206 vm_object_t obj; 1207 1208 p = imgp->proc; 1209 sv = p->p_sysent; 1210 1211 if (imgp->stack_sz != 0) { 1212 ssiz = trunc_page(imgp->stack_sz); 1213 PROC_LOCK(p); 1214 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); 1215 PROC_UNLOCK(p); 1216 if (ssiz > rlim_stack.rlim_max) 1217 ssiz = rlim_stack.rlim_max; 1218 if (ssiz > rlim_stack.rlim_cur) { 1219 rlim_stack.rlim_cur = ssiz; 1220 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); 1221 } 1222 } else if (sv->sv_maxssiz != NULL) { 1223 ssiz = *sv->sv_maxssiz; 1224 } else { 1225 ssiz = maxssiz; 1226 } 1227 1228 vmspace = p->p_vmspace; 1229 map = &vmspace->vm_map; 1230 1231 stack_prot = sv->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? 1232 imgp->stack_prot : sv->sv_stackprot; 1233 if ((map->flags & MAP_ASLR_STACK) != 0) { 1234 stack_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1235 lim_max(curthread, RLIMIT_DATA)); 1236 find_space = VMFS_ANY_SPACE; 1237 } else { 1238 stack_addr = sv->sv_usrstack - ssiz; 1239 find_space = VMFS_NO_SPACE; 1240 } 1241 error = vm_map_find(map, NULL, 0, &stack_addr, (vm_size_t)ssiz, 1242 sv->sv_usrstack, find_space, stack_prot, VM_PROT_ALL, 1243 MAP_STACK_AREA); 1244 if (error != KERN_SUCCESS) { 1245 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " 1246 "failed, mach error %d errno %d\n", (uintmax_t)ssiz, 1247 stack_prot, error, vm_mmap_to_errno(error)); 1248 return (vm_mmap_to_errno(error)); 1249 } 1250 1251 stack_top = stack_addr + ssiz; 1252 if ((map->flags & MAP_ASLR_STACK) != 0) { 1253 /* Randomize within the first page of the stack. */ 1254 arc4rand(&stack_off, sizeof(stack_off), 0); 1255 stack_top -= rounddown2(stack_off & PAGE_MASK, sizeof(void *)); 1256 } 1257 1258 /* Map a shared page */ 1259 obj = sv->sv_shared_page_obj; 1260 if (obj == NULL) { 1261 sharedpage_addr = 0; 1262 goto out; 1263 } 1264 1265 /* 1266 * If randomization is disabled then the shared page will 1267 * be mapped at address specified in sysentvec. 1268 * Otherwise any address above .data section can be selected. 1269 * Same logic is used for stack address randomization. 1270 * If the address randomization is applied map a guard page 1271 * at the top of UVA. 1272 */ 1273 vm_object_reference(obj); 1274 if ((imgp->imgp_flags & IMGP_ASLR_SHARED_PAGE) != 0) { 1275 sharedpage_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1276 lim_max(curthread, RLIMIT_DATA)); 1277 1278 error = vm_map_fixed(map, NULL, 0, 1279 sv->sv_maxuser - PAGE_SIZE, PAGE_SIZE, 1280 VM_PROT_NONE, VM_PROT_NONE, MAP_CREATE_GUARD); 1281 if (error != KERN_SUCCESS) { 1282 /* 1283 * This is not fatal, so let's just print a warning 1284 * and continue. 1285 */ 1286 uprintf("%s: Mapping guard page at the top of UVA failed" 1287 " mach error %d errno %d", 1288 __func__, error, vm_mmap_to_errno(error)); 1289 } 1290 1291 error = vm_map_find(map, obj, 0, 1292 &sharedpage_addr, sv->sv_shared_page_len, 1293 sv->sv_maxuser, VMFS_ANY_SPACE, 1294 VM_PROT_READ | VM_PROT_EXECUTE, 1295 VM_PROT_READ | VM_PROT_EXECUTE, 1296 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1297 } else { 1298 sharedpage_addr = sv->sv_shared_page_base; 1299 vm_map_fixed(map, obj, 0, 1300 sharedpage_addr, sv->sv_shared_page_len, 1301 VM_PROT_READ | VM_PROT_EXECUTE, 1302 VM_PROT_READ | VM_PROT_EXECUTE, 1303 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1304 } 1305 if (error != KERN_SUCCESS) { 1306 uprintf("%s: mapping shared page at addr: %p" 1307 "failed, mach error %d errno %d\n", __func__, 1308 (void *)sharedpage_addr, error, vm_mmap_to_errno(error)); 1309 vm_object_deallocate(obj); 1310 return (vm_mmap_to_errno(error)); 1311 } 1312 out: 1313 /* 1314 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they 1315 * are still used to enforce the stack rlimit on the process stack. 1316 */ 1317 vmspace->vm_maxsaddr = (char *)stack_addr; 1318 vmspace->vm_stacktop = stack_top; 1319 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; 1320 vmspace->vm_shp_base = sharedpage_addr; 1321 1322 return (0); 1323 } 1324 1325 /* 1326 * Copy out argument and environment strings from the old process address 1327 * space into the temporary string buffer. 1328 */ 1329 int 1330 exec_copyin_args(struct image_args *args, const char *fname, 1331 enum uio_seg segflg, char **argv, char **envv) 1332 { 1333 u_long arg, env; 1334 int error; 1335 1336 bzero(args, sizeof(*args)); 1337 if (argv == NULL) 1338 return (EFAULT); 1339 1340 /* 1341 * Allocate demand-paged memory for the file name, argument, and 1342 * environment strings. 1343 */ 1344 error = exec_alloc_args(args); 1345 if (error != 0) 1346 return (error); 1347 1348 /* 1349 * Copy the file name. 1350 */ 1351 error = exec_args_add_fname(args, fname, segflg); 1352 if (error != 0) 1353 goto err_exit; 1354 1355 /* 1356 * extract arguments first 1357 */ 1358 for (;;) { 1359 error = fueword(argv++, &arg); 1360 if (error == -1) { 1361 error = EFAULT; 1362 goto err_exit; 1363 } 1364 if (arg == 0) 1365 break; 1366 error = exec_args_add_arg(args, (char *)(uintptr_t)arg, 1367 UIO_USERSPACE); 1368 if (error != 0) 1369 goto err_exit; 1370 } 1371 1372 /* 1373 * extract environment strings 1374 */ 1375 if (envv) { 1376 for (;;) { 1377 error = fueword(envv++, &env); 1378 if (error == -1) { 1379 error = EFAULT; 1380 goto err_exit; 1381 } 1382 if (env == 0) 1383 break; 1384 error = exec_args_add_env(args, 1385 (char *)(uintptr_t)env, UIO_USERSPACE); 1386 if (error != 0) 1387 goto err_exit; 1388 } 1389 } 1390 1391 return (0); 1392 1393 err_exit: 1394 exec_free_args(args); 1395 return (error); 1396 } 1397 1398 struct exec_args_kva { 1399 vm_offset_t addr; 1400 u_int gen; 1401 SLIST_ENTRY(exec_args_kva) next; 1402 }; 1403 1404 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); 1405 1406 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; 1407 static struct mtx exec_args_kva_mtx; 1408 static u_int exec_args_gen; 1409 1410 static void 1411 exec_prealloc_args_kva(void *arg __unused) 1412 { 1413 struct exec_args_kva *argkva; 1414 u_int i; 1415 1416 SLIST_INIT(&exec_args_kva_freelist); 1417 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); 1418 for (i = 0; i < exec_map_entries; i++) { 1419 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); 1420 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); 1421 argkva->gen = exec_args_gen; 1422 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1423 } 1424 } 1425 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); 1426 1427 static vm_offset_t 1428 exec_alloc_args_kva(void **cookie) 1429 { 1430 struct exec_args_kva *argkva; 1431 1432 argkva = (void *)atomic_readandclear_ptr( 1433 (uintptr_t *)DPCPU_PTR(exec_args_kva)); 1434 if (argkva == NULL) { 1435 mtx_lock(&exec_args_kva_mtx); 1436 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) 1437 (void)mtx_sleep(&exec_args_kva_freelist, 1438 &exec_args_kva_mtx, 0, "execkva", 0); 1439 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); 1440 mtx_unlock(&exec_args_kva_mtx); 1441 } 1442 kasan_mark((void *)argkva->addr, exec_map_entry_size, 1443 exec_map_entry_size, 0); 1444 *(struct exec_args_kva **)cookie = argkva; 1445 return (argkva->addr); 1446 } 1447 1448 static void 1449 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) 1450 { 1451 vm_offset_t base; 1452 1453 base = argkva->addr; 1454 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size, 1455 KASAN_EXEC_ARGS_FREED); 1456 if (argkva->gen != gen) { 1457 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, 1458 MADV_FREE); 1459 argkva->gen = gen; 1460 } 1461 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), 1462 (uintptr_t)NULL, (uintptr_t)argkva)) { 1463 mtx_lock(&exec_args_kva_mtx); 1464 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1465 wakeup_one(&exec_args_kva_freelist); 1466 mtx_unlock(&exec_args_kva_mtx); 1467 } 1468 } 1469 1470 static void 1471 exec_free_args_kva(void *cookie) 1472 { 1473 1474 exec_release_args_kva(cookie, exec_args_gen); 1475 } 1476 1477 static void 1478 exec_args_kva_lowmem(void *arg __unused) 1479 { 1480 SLIST_HEAD(, exec_args_kva) head; 1481 struct exec_args_kva *argkva; 1482 u_int gen; 1483 int i; 1484 1485 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; 1486 1487 /* 1488 * Force an madvise of each KVA range. Any currently allocated ranges 1489 * will have MADV_FREE applied once they are freed. 1490 */ 1491 SLIST_INIT(&head); 1492 mtx_lock(&exec_args_kva_mtx); 1493 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); 1494 mtx_unlock(&exec_args_kva_mtx); 1495 while ((argkva = SLIST_FIRST(&head)) != NULL) { 1496 SLIST_REMOVE_HEAD(&head, next); 1497 exec_release_args_kva(argkva, gen); 1498 } 1499 1500 CPU_FOREACH(i) { 1501 argkva = (void *)atomic_readandclear_ptr( 1502 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); 1503 if (argkva != NULL) 1504 exec_release_args_kva(argkva, gen); 1505 } 1506 } 1507 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, 1508 EVENTHANDLER_PRI_ANY); 1509 1510 /* 1511 * Allocate temporary demand-paged, zero-filled memory for the file name, 1512 * argument, and environment strings. 1513 */ 1514 int 1515 exec_alloc_args(struct image_args *args) 1516 { 1517 1518 args->buf = (char *)exec_alloc_args_kva(&args->bufkva); 1519 return (0); 1520 } 1521 1522 void 1523 exec_free_args(struct image_args *args) 1524 { 1525 1526 if (args->buf != NULL) { 1527 exec_free_args_kva(args->bufkva); 1528 args->buf = NULL; 1529 } 1530 if (args->fname_buf != NULL) { 1531 free(args->fname_buf, M_TEMP); 1532 args->fname_buf = NULL; 1533 } 1534 } 1535 1536 /* 1537 * A set to functions to fill struct image args. 1538 * 1539 * NOTE: exec_args_add_fname() must be called (possibly with a NULL 1540 * fname) before the other functions. All exec_args_add_arg() calls must 1541 * be made before any exec_args_add_env() calls. exec_args_adjust_args() 1542 * may be called any time after exec_args_add_fname(). 1543 * 1544 * exec_args_add_fname() - install path to be executed 1545 * exec_args_add_arg() - append an argument string 1546 * exec_args_add_env() - append an env string 1547 * exec_args_adjust_args() - adjust location of the argument list to 1548 * allow new arguments to be prepended 1549 */ 1550 int 1551 exec_args_add_fname(struct image_args *args, const char *fname, 1552 enum uio_seg segflg) 1553 { 1554 int error; 1555 size_t length; 1556 1557 KASSERT(args->fname == NULL, ("fname already appended")); 1558 KASSERT(args->endp == NULL, ("already appending to args")); 1559 1560 if (fname != NULL) { 1561 args->fname = args->buf; 1562 error = segflg == UIO_SYSSPACE ? 1563 copystr(fname, args->fname, PATH_MAX, &length) : 1564 copyinstr(fname, args->fname, PATH_MAX, &length); 1565 if (error != 0) 1566 return (error == ENAMETOOLONG ? E2BIG : error); 1567 } else 1568 length = 0; 1569 1570 /* Set up for _arg_*()/_env_*() */ 1571 args->endp = args->buf + length; 1572 /* begin_argv must be set and kept updated */ 1573 args->begin_argv = args->endp; 1574 KASSERT(exec_map_entry_size - length >= ARG_MAX, 1575 ("too little space remaining for arguments %zu < %zu", 1576 exec_map_entry_size - length, (size_t)ARG_MAX)); 1577 args->stringspace = ARG_MAX; 1578 1579 return (0); 1580 } 1581 1582 static int 1583 exec_args_add_str(struct image_args *args, const char *str, 1584 enum uio_seg segflg, int *countp) 1585 { 1586 int error; 1587 size_t length; 1588 1589 KASSERT(args->endp != NULL, ("endp not initialized")); 1590 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1591 1592 error = (segflg == UIO_SYSSPACE) ? 1593 copystr(str, args->endp, args->stringspace, &length) : 1594 copyinstr(str, args->endp, args->stringspace, &length); 1595 if (error != 0) 1596 return (error == ENAMETOOLONG ? E2BIG : error); 1597 args->stringspace -= length; 1598 args->endp += length; 1599 (*countp)++; 1600 1601 return (0); 1602 } 1603 1604 int 1605 exec_args_add_arg(struct image_args *args, const char *argp, 1606 enum uio_seg segflg) 1607 { 1608 1609 KASSERT(args->envc == 0, ("appending args after env")); 1610 1611 return (exec_args_add_str(args, argp, segflg, &args->argc)); 1612 } 1613 1614 int 1615 exec_args_add_env(struct image_args *args, const char *envp, 1616 enum uio_seg segflg) 1617 { 1618 1619 if (args->envc == 0) 1620 args->begin_envv = args->endp; 1621 1622 return (exec_args_add_str(args, envp, segflg, &args->envc)); 1623 } 1624 1625 int 1626 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) 1627 { 1628 ssize_t offset; 1629 1630 KASSERT(args->endp != NULL, ("endp not initialized")); 1631 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1632 1633 offset = extend - consume; 1634 if (args->stringspace < offset) 1635 return (E2BIG); 1636 memmove(args->begin_argv + extend, args->begin_argv + consume, 1637 args->endp - args->begin_argv + consume); 1638 if (args->envc > 0) 1639 args->begin_envv += offset; 1640 args->endp += offset; 1641 args->stringspace -= offset; 1642 return (0); 1643 } 1644 1645 char * 1646 exec_args_get_begin_envv(struct image_args *args) 1647 { 1648 1649 KASSERT(args->endp != NULL, ("endp not initialized")); 1650 1651 if (args->envc > 0) 1652 return (args->begin_envv); 1653 return (args->endp); 1654 } 1655 1656 /* 1657 * Copy strings out to the new process address space, constructing new arg 1658 * and env vector tables. Return a pointer to the base so that it can be used 1659 * as the initial stack pointer. 1660 */ 1661 int 1662 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 1663 { 1664 int argc, envc; 1665 char **vectp; 1666 char *stringp; 1667 uintptr_t destp, ustringp; 1668 struct ps_strings *arginfo; 1669 struct proc *p; 1670 struct sysentvec *sysent; 1671 size_t execpath_len; 1672 int error, szsigcode; 1673 char canary[sizeof(long) * 8]; 1674 1675 p = imgp->proc; 1676 sysent = p->p_sysent; 1677 1678 destp = PROC_PS_STRINGS(p); 1679 arginfo = imgp->ps_strings = (void *)destp; 1680 1681 /* 1682 * Install sigcode. 1683 */ 1684 if (sysent->sv_shared_page_base == 0 && sysent->sv_szsigcode != NULL) { 1685 szsigcode = *(sysent->sv_szsigcode); 1686 destp -= szsigcode; 1687 destp = rounddown2(destp, sizeof(void *)); 1688 error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode); 1689 if (error != 0) 1690 return (error); 1691 } 1692 1693 /* 1694 * Copy the image path for the rtld. 1695 */ 1696 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 1697 execpath_len = strlen(imgp->execpath) + 1; 1698 destp -= execpath_len; 1699 destp = rounddown2(destp, sizeof(void *)); 1700 imgp->execpathp = (void *)destp; 1701 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 1702 if (error != 0) 1703 return (error); 1704 } 1705 1706 /* 1707 * Prepare the canary for SSP. 1708 */ 1709 arc4rand(canary, sizeof(canary), 0); 1710 destp -= sizeof(canary); 1711 imgp->canary = (void *)destp; 1712 error = copyout(canary, imgp->canary, sizeof(canary)); 1713 if (error != 0) 1714 return (error); 1715 imgp->canarylen = sizeof(canary); 1716 1717 /* 1718 * Prepare the pagesizes array. 1719 */ 1720 imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES; 1721 destp -= imgp->pagesizeslen; 1722 destp = rounddown2(destp, sizeof(void *)); 1723 imgp->pagesizes = (void *)destp; 1724 error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen); 1725 if (error != 0) 1726 return (error); 1727 1728 /* 1729 * Allocate room for the argument and environment strings. 1730 */ 1731 destp -= ARG_MAX - imgp->args->stringspace; 1732 destp = rounddown2(destp, sizeof(void *)); 1733 ustringp = destp; 1734 1735 if (imgp->auxargs) { 1736 /* 1737 * Allocate room on the stack for the ELF auxargs 1738 * array. It has up to AT_COUNT entries. 1739 */ 1740 destp -= AT_COUNT * sizeof(Elf_Auxinfo); 1741 destp = rounddown2(destp, sizeof(void *)); 1742 } 1743 1744 vectp = (char **)destp; 1745 1746 /* 1747 * Allocate room for the argv[] and env vectors including the 1748 * terminating NULL pointers. 1749 */ 1750 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 1751 1752 /* 1753 * vectp also becomes our initial stack base 1754 */ 1755 *stack_base = (uintptr_t)vectp; 1756 1757 stringp = imgp->args->begin_argv; 1758 argc = imgp->args->argc; 1759 envc = imgp->args->envc; 1760 1761 /* 1762 * Copy out strings - arguments and environment. 1763 */ 1764 error = copyout(stringp, (void *)ustringp, 1765 ARG_MAX - imgp->args->stringspace); 1766 if (error != 0) 1767 return (error); 1768 1769 /* 1770 * Fill in "ps_strings" struct for ps, w, etc. 1771 */ 1772 imgp->argv = vectp; 1773 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 1774 suword32(&arginfo->ps_nargvstr, argc) != 0) 1775 return (EFAULT); 1776 1777 /* 1778 * Fill in argument portion of vector table. 1779 */ 1780 for (; argc > 0; --argc) { 1781 if (suword(vectp++, ustringp) != 0) 1782 return (EFAULT); 1783 while (*stringp++ != 0) 1784 ustringp++; 1785 ustringp++; 1786 } 1787 1788 /* a null vector table pointer separates the argp's from the envp's */ 1789 if (suword(vectp++, 0) != 0) 1790 return (EFAULT); 1791 1792 imgp->envv = vectp; 1793 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 1794 suword32(&arginfo->ps_nenvstr, envc) != 0) 1795 return (EFAULT); 1796 1797 /* 1798 * Fill in environment portion of vector table. 1799 */ 1800 for (; envc > 0; --envc) { 1801 if (suword(vectp++, ustringp) != 0) 1802 return (EFAULT); 1803 while (*stringp++ != 0) 1804 ustringp++; 1805 ustringp++; 1806 } 1807 1808 /* end of vector table is a null pointer */ 1809 if (suword(vectp, 0) != 0) 1810 return (EFAULT); 1811 1812 if (imgp->auxargs) { 1813 vectp++; 1814 error = imgp->sysent->sv_copyout_auxargs(imgp, 1815 (uintptr_t)vectp); 1816 if (error != 0) 1817 return (error); 1818 } 1819 1820 return (0); 1821 } 1822 1823 /* 1824 * Check permissions of file to execute. 1825 * Called with imgp->vp locked. 1826 * Return 0 for success or error code on failure. 1827 */ 1828 int 1829 exec_check_permissions(struct image_params *imgp) 1830 { 1831 struct vnode *vp = imgp->vp; 1832 struct vattr *attr = imgp->attr; 1833 struct thread *td; 1834 int error; 1835 1836 td = curthread; 1837 1838 /* Get file attributes */ 1839 error = VOP_GETATTR(vp, attr, td->td_ucred); 1840 if (error) 1841 return (error); 1842 1843 #ifdef MAC 1844 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); 1845 if (error) 1846 return (error); 1847 #endif 1848 1849 /* 1850 * 1) Check if file execution is disabled for the filesystem that 1851 * this file resides on. 1852 * 2) Ensure that at least one execute bit is on. Otherwise, a 1853 * privileged user will always succeed, and we don't want this 1854 * to happen unless the file really is executable. 1855 * 3) Ensure that the file is a regular file. 1856 */ 1857 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || 1858 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || 1859 (attr->va_type != VREG)) 1860 return (EACCES); 1861 1862 /* 1863 * Zero length files can't be exec'd 1864 */ 1865 if (attr->va_size == 0) 1866 return (ENOEXEC); 1867 1868 /* 1869 * Check for execute permission to file based on current credentials. 1870 */ 1871 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); 1872 if (error) 1873 return (error); 1874 1875 /* 1876 * Check number of open-for-writes on the file and deny execution 1877 * if there are any. 1878 * 1879 * Add a text reference now so no one can write to the 1880 * executable while we're activating it. 1881 * 1882 * Remember if this was set before and unset it in case this is not 1883 * actually an executable image. 1884 */ 1885 error = VOP_SET_TEXT(vp); 1886 if (error != 0) 1887 return (error); 1888 imgp->textset = true; 1889 1890 /* 1891 * Call filesystem specific open routine (which does nothing in the 1892 * general case). 1893 */ 1894 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); 1895 if (error == 0) 1896 imgp->opened = true; 1897 return (error); 1898 } 1899 1900 /* 1901 * Exec handler registration 1902 */ 1903 int 1904 exec_register(const struct execsw *execsw_arg) 1905 { 1906 const struct execsw **es, **xs, **newexecsw; 1907 u_int count = 2; /* New slot and trailing NULL */ 1908 1909 if (execsw) 1910 for (es = execsw; *es; es++) 1911 count++; 1912 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1913 xs = newexecsw; 1914 if (execsw) 1915 for (es = execsw; *es; es++) 1916 *xs++ = *es; 1917 *xs++ = execsw_arg; 1918 *xs = NULL; 1919 if (execsw) 1920 free(execsw, M_TEMP); 1921 execsw = newexecsw; 1922 return (0); 1923 } 1924 1925 int 1926 exec_unregister(const struct execsw *execsw_arg) 1927 { 1928 const struct execsw **es, **xs, **newexecsw; 1929 int count = 1; 1930 1931 if (execsw == NULL) 1932 panic("unregister with no handlers left?\n"); 1933 1934 for (es = execsw; *es; es++) { 1935 if (*es == execsw_arg) 1936 break; 1937 } 1938 if (*es == NULL) 1939 return (ENOENT); 1940 for (es = execsw; *es; es++) 1941 if (*es != execsw_arg) 1942 count++; 1943 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1944 xs = newexecsw; 1945 for (es = execsw; *es; es++) 1946 if (*es != execsw_arg) 1947 *xs++ = *es; 1948 *xs = NULL; 1949 if (execsw) 1950 free(execsw, M_TEMP); 1951 execsw = newexecsw; 1952 return (0); 1953 } 1954 1955 /* 1956 * Write out a core segment to the compression stream. 1957 */ 1958 static int 1959 compress_chunk(struct coredump_params *cp, char *base, char *buf, size_t len) 1960 { 1961 size_t chunk_len; 1962 int error; 1963 1964 error = 0; 1965 while (len > 0) { 1966 chunk_len = MIN(len, CORE_BUF_SIZE); 1967 1968 /* 1969 * We can get EFAULT error here. 1970 * In that case zero out the current chunk of the segment. 1971 */ 1972 error = copyin(base, buf, chunk_len); 1973 if (error != 0) 1974 bzero(buf, chunk_len); 1975 error = compressor_write(cp->comp, buf, chunk_len); 1976 if (error != 0) 1977 break; 1978 base += chunk_len; 1979 len -= chunk_len; 1980 } 1981 return (error); 1982 } 1983 1984 int 1985 core_write(struct coredump_params *cp, const void *base, size_t len, 1986 off_t offset, enum uio_seg seg, size_t *resid) 1987 { 1988 1989 return (vn_rdwr_inchunks(UIO_WRITE, cp->vp, __DECONST(void *, base), 1990 len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED, 1991 cp->active_cred, cp->file_cred, resid, cp->td)); 1992 } 1993 1994 int 1995 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp, 1996 void *tmpbuf) 1997 { 1998 vm_map_t map; 1999 struct mount *mp; 2000 size_t resid, runlen; 2001 int error; 2002 bool success; 2003 2004 KASSERT((uintptr_t)base % PAGE_SIZE == 0, 2005 ("%s: user address %p is not page-aligned", __func__, base)); 2006 2007 if (cp->comp != NULL) 2008 return (compress_chunk(cp, base, tmpbuf, len)); 2009 2010 error = 0; 2011 map = &cp->td->td_proc->p_vmspace->vm_map; 2012 for (; len > 0; base += runlen, offset += runlen, len -= runlen) { 2013 /* 2014 * Attempt to page in all virtual pages in the range. If a 2015 * virtual page is not backed by the pager, it is represented as 2016 * a hole in the file. This can occur with zero-filled 2017 * anonymous memory or truncated files, for example. 2018 */ 2019 for (runlen = 0; runlen < len; runlen += PAGE_SIZE) { 2020 if (core_dump_can_intr && curproc_sigkilled()) 2021 return (EINTR); 2022 error = vm_fault(map, (uintptr_t)base + runlen, 2023 VM_PROT_READ, VM_FAULT_NOFILL, NULL); 2024 if (runlen == 0) 2025 success = error == KERN_SUCCESS; 2026 else if ((error == KERN_SUCCESS) != success) 2027 break; 2028 } 2029 2030 if (success) { 2031 error = core_write(cp, base, runlen, offset, 2032 UIO_USERSPACE, &resid); 2033 if (error != 0) { 2034 if (error != EFAULT) 2035 break; 2036 2037 /* 2038 * EFAULT may be returned if the user mapping 2039 * could not be accessed, e.g., because a mapped 2040 * file has been truncated. Skip the page if no 2041 * progress was made, to protect against a 2042 * hypothetical scenario where vm_fault() was 2043 * successful but core_write() returns EFAULT 2044 * anyway. 2045 */ 2046 runlen -= resid; 2047 if (runlen == 0) { 2048 success = false; 2049 runlen = PAGE_SIZE; 2050 } 2051 } 2052 } 2053 if (!success) { 2054 error = vn_start_write(cp->vp, &mp, V_WAIT); 2055 if (error != 0) 2056 break; 2057 vn_lock(cp->vp, LK_EXCLUSIVE | LK_RETRY); 2058 error = vn_truncate_locked(cp->vp, offset + runlen, 2059 false, cp->td->td_ucred); 2060 VOP_UNLOCK(cp->vp); 2061 vn_finished_write(mp); 2062 if (error != 0) 2063 break; 2064 } 2065 } 2066 return (error); 2067 } 2068 2069 /* 2070 * Drain into a core file. 2071 */ 2072 int 2073 sbuf_drain_core_output(void *arg, const char *data, int len) 2074 { 2075 struct coredump_params *cp; 2076 struct proc *p; 2077 int error, locked; 2078 2079 cp = arg; 2080 p = cp->td->td_proc; 2081 2082 /* 2083 * Some kern_proc out routines that print to this sbuf may 2084 * call us with the process lock held. Draining with the 2085 * non-sleepable lock held is unsafe. The lock is needed for 2086 * those routines when dumping a live process. In our case we 2087 * can safely release the lock before draining and acquire 2088 * again after. 2089 */ 2090 locked = PROC_LOCKED(p); 2091 if (locked) 2092 PROC_UNLOCK(p); 2093 if (cp->comp != NULL) 2094 error = compressor_write(cp->comp, __DECONST(char *, data), 2095 len); 2096 else 2097 error = core_write(cp, __DECONST(void *, data), len, cp->offset, 2098 UIO_SYSSPACE, NULL); 2099 if (locked) 2100 PROC_LOCK(p); 2101 if (error != 0) 2102 return (-error); 2103 cp->offset += len; 2104 return (len); 2105 } 2106