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)); 357 358 /* Must have at least one argument. */ 359 if (args->argc == 0) { 360 exec_free_args(args); 361 return (EINVAL); 362 } 363 return (do_execve(td, args, mac_p, oldvmspace)); 364 } 365 366 static void 367 execve_nosetid(struct image_params *imgp) 368 { 369 imgp->credential_setid = false; 370 if (imgp->newcred != NULL) { 371 crfree(imgp->newcred); 372 imgp->newcred = NULL; 373 } 374 } 375 376 /* 377 * In-kernel implementation of execve(). All arguments are assumed to be 378 * userspace pointers from the passed thread. 379 */ 380 static int 381 do_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 382 struct vmspace *oldvmspace) 383 { 384 struct proc *p = td->td_proc; 385 struct nameidata nd; 386 struct ucred *oldcred; 387 struct uidinfo *euip = NULL; 388 uintptr_t stack_base; 389 struct image_params image_params, *imgp; 390 struct vattr attr; 391 struct pargs *oldargs = NULL, *newargs = NULL; 392 struct sigacts *oldsigacts = NULL, *newsigacts = NULL; 393 #ifdef KTRACE 394 struct ktr_io_params *kiop; 395 #endif 396 struct vnode *oldtextvp, *newtextvp; 397 struct vnode *oldtextdvp, *newtextdvp; 398 char *oldbinname, *newbinname; 399 bool credential_changing; 400 #ifdef MAC 401 struct label *interpvplabel = NULL; 402 bool will_transition; 403 #endif 404 #ifdef HWPMC_HOOKS 405 struct pmckern_procexec pe; 406 #endif 407 int error, i, orig_osrel; 408 uint32_t orig_fctl0; 409 Elf_Brandinfo *orig_brandinfo; 410 size_t freepath_size; 411 static const char fexecv_proc_title[] = "(fexecv)"; 412 413 imgp = &image_params; 414 oldtextvp = oldtextdvp = NULL; 415 newtextvp = newtextdvp = NULL; 416 newbinname = oldbinname = NULL; 417 #ifdef KTRACE 418 kiop = NULL; 419 #endif 420 421 /* 422 * Lock the process and set the P_INEXEC flag to indicate that 423 * it should be left alone until we're done here. This is 424 * necessary to avoid race conditions - e.g. in ptrace() - 425 * that might allow a local user to illicitly obtain elevated 426 * privileges. 427 */ 428 PROC_LOCK(p); 429 KASSERT((p->p_flag & P_INEXEC) == 0, 430 ("%s(): process already has P_INEXEC flag", __func__)); 431 p->p_flag |= P_INEXEC; 432 PROC_UNLOCK(p); 433 434 /* 435 * Initialize part of the common data 436 */ 437 bzero(imgp, sizeof(*imgp)); 438 imgp->proc = p; 439 imgp->attr = &attr; 440 imgp->args = args; 441 oldcred = p->p_ucred; 442 orig_osrel = p->p_osrel; 443 orig_fctl0 = p->p_fctl0; 444 orig_brandinfo = p->p_elf_brandinfo; 445 446 #ifdef MAC 447 error = mac_execve_enter(imgp, mac_p); 448 if (error) 449 goto exec_fail; 450 #endif 451 452 SDT_PROBE1(proc, , , exec, args->fname); 453 454 interpret: 455 if (args->fname != NULL) { 456 #ifdef CAPABILITY_MODE 457 /* 458 * While capability mode can't reach this point via direct 459 * path arguments to execve(), we also don't allow 460 * interpreters to be used in capability mode (for now). 461 * Catch indirect lookups and return a permissions error. 462 */ 463 if (IN_CAPABILITY_MODE(td)) { 464 error = ECAPMODE; 465 goto exec_fail; 466 } 467 #endif 468 469 /* 470 * Translate the file name. namei() returns a vnode 471 * pointer in ni_vp among other things. 472 */ 473 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | 474 AUDITVNODE1 | WANTPARENT, UIO_SYSSPACE, 475 args->fname); 476 477 error = namei(&nd); 478 if (error) 479 goto exec_fail; 480 481 newtextvp = nd.ni_vp; 482 newtextdvp = nd.ni_dvp; 483 nd.ni_dvp = NULL; 484 newbinname = malloc(nd.ni_cnd.cn_namelen + 1, M_PARGS, 485 M_WAITOK); 486 memcpy(newbinname, nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 487 newbinname[nd.ni_cnd.cn_namelen] = '\0'; 488 imgp->vp = newtextvp; 489 490 /* 491 * Do the best to calculate the full path to the image file. 492 */ 493 if (args->fname[0] == '/') { 494 imgp->execpath = args->fname; 495 } else { 496 VOP_UNLOCK(imgp->vp); 497 freepath_size = MAXPATHLEN; 498 if (vn_fullpath_hardlink(newtextvp, newtextdvp, 499 newbinname, nd.ni_cnd.cn_namelen, &imgp->execpath, 500 &imgp->freepath, &freepath_size) != 0) 501 imgp->execpath = args->fname; 502 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 503 } 504 } else if (imgp->interpreter_vp) { 505 /* 506 * An image activator has already provided an open vnode 507 */ 508 newtextvp = imgp->interpreter_vp; 509 imgp->interpreter_vp = NULL; 510 if (vn_fullpath(newtextvp, &imgp->execpath, 511 &imgp->freepath) != 0) 512 imgp->execpath = args->fname; 513 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 514 AUDIT_ARG_VNODE1(newtextvp); 515 imgp->vp = newtextvp; 516 } else { 517 AUDIT_ARG_FD(args->fd); 518 519 /* 520 * If the descriptors was not opened with O_PATH, then 521 * we require that it was opened with O_EXEC or 522 * O_RDONLY. In either case, exec_check_permissions() 523 * below checks _current_ file access mode regardless 524 * of the permissions additionally checked at the 525 * open(2). 526 */ 527 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, 528 &newtextvp); 529 if (error != 0) 530 goto exec_fail; 531 532 if (vn_fullpath(newtextvp, &imgp->execpath, 533 &imgp->freepath) != 0) 534 imgp->execpath = args->fname; 535 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 536 AUDIT_ARG_VNODE1(newtextvp); 537 imgp->vp = newtextvp; 538 } 539 540 /* 541 * Check file permissions. Also 'opens' file and sets its vnode to 542 * text mode. 543 */ 544 error = exec_check_permissions(imgp); 545 if (error) 546 goto exec_fail_dealloc; 547 548 imgp->object = imgp->vp->v_object; 549 if (imgp->object != NULL) 550 vm_object_reference(imgp->object); 551 552 error = exec_map_first_page(imgp); 553 if (error) 554 goto exec_fail_dealloc; 555 556 imgp->proc->p_osrel = 0; 557 imgp->proc->p_fctl0 = 0; 558 imgp->proc->p_elf_brandinfo = NULL; 559 560 /* 561 * Implement image setuid/setgid. 562 * 563 * Determine new credentials before attempting image activators 564 * so that it can be used by process_exec handlers to determine 565 * credential/setid changes. 566 * 567 * Don't honor setuid/setgid if the filesystem prohibits it or if 568 * the process is being traced. 569 * 570 * We disable setuid/setgid/etc in capability mode on the basis 571 * that most setugid applications are not written with that 572 * environment in mind, and will therefore almost certainly operate 573 * incorrectly. In principle there's no reason that setugid 574 * applications might not be useful in capability mode, so we may want 575 * to reconsider this conservative design choice in the future. 576 * 577 * XXXMAC: For the time being, use NOSUID to also prohibit 578 * transitions on the file system. 579 */ 580 credential_changing = false; 581 credential_changing |= (attr.va_mode & S_ISUID) && 582 oldcred->cr_uid != attr.va_uid; 583 credential_changing |= (attr.va_mode & S_ISGID) && 584 oldcred->cr_gid != attr.va_gid; 585 #ifdef MAC 586 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp, 587 interpvplabel, imgp) != 0; 588 credential_changing |= will_transition; 589 #endif 590 591 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */ 592 if (credential_changing) 593 imgp->proc->p_pdeathsig = 0; 594 595 if (credential_changing && 596 #ifdef CAPABILITY_MODE 597 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) && 598 #endif 599 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 && 600 (p->p_flag & P_TRACED) == 0) { 601 imgp->credential_setid = true; 602 VOP_UNLOCK(imgp->vp); 603 imgp->newcred = crdup(oldcred); 604 if (attr.va_mode & S_ISUID) { 605 euip = uifind(attr.va_uid); 606 change_euid(imgp->newcred, euip); 607 } 608 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 609 if (attr.va_mode & S_ISGID) 610 change_egid(imgp->newcred, attr.va_gid); 611 /* 612 * Implement correct POSIX saved-id behavior. 613 * 614 * XXXMAC: Note that the current logic will save the 615 * uid and gid if a MAC domain transition occurs, even 616 * though maybe it shouldn't. 617 */ 618 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 619 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 620 } else { 621 /* 622 * Implement correct POSIX saved-id behavior. 623 * 624 * XXX: It's not clear that the existing behavior is 625 * POSIX-compliant. A number of sources indicate that the 626 * saved uid/gid should only be updated if the new ruid is 627 * not equal to the old ruid, or the new euid is not equal 628 * to the old euid and the new euid is not equal to the old 629 * ruid. The FreeBSD code always updates the saved uid/gid. 630 * Also, this code uses the new (replaced) euid and egid as 631 * the source, which may or may not be the right ones to use. 632 */ 633 if (oldcred->cr_svuid != oldcred->cr_uid || 634 oldcred->cr_svgid != oldcred->cr_gid) { 635 VOP_UNLOCK(imgp->vp); 636 imgp->newcred = crdup(oldcred); 637 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 638 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 639 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 640 } 641 } 642 /* The new credentials are installed into the process later. */ 643 644 /* 645 * Loop through the list of image activators, calling each one. 646 * An activator returns -1 if there is no match, 0 on success, 647 * and an error otherwise. 648 */ 649 error = -1; 650 for (i = 0; error == -1 && execsw[i]; ++i) { 651 if (execsw[i]->ex_imgact == NULL) 652 continue; 653 error = (*execsw[i]->ex_imgact)(imgp); 654 } 655 656 if (error) { 657 if (error == -1) 658 error = ENOEXEC; 659 goto exec_fail_dealloc; 660 } 661 662 /* 663 * Special interpreter operation, cleanup and loop up to try to 664 * activate the interpreter. 665 */ 666 if (imgp->interpreted) { 667 exec_unmap_first_page(imgp); 668 /* 669 * The text reference needs to be removed for scripts. 670 * There is a short period before we determine that 671 * something is a script where text reference is active. 672 * The vnode lock is held over this entire period 673 * so nothing should illegitimately be blocked. 674 */ 675 MPASS(imgp->textset); 676 VOP_UNSET_TEXT_CHECKED(newtextvp); 677 imgp->textset = false; 678 /* free name buffer and old vnode */ 679 #ifdef MAC 680 mac_execve_interpreter_enter(newtextvp, &interpvplabel); 681 #endif 682 if (imgp->opened) { 683 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td); 684 imgp->opened = false; 685 } 686 vput(newtextvp); 687 imgp->vp = newtextvp = NULL; 688 if (args->fname != NULL) { 689 if (newtextdvp != NULL) { 690 vrele(newtextdvp); 691 newtextdvp = NULL; 692 } 693 NDFREE_PNBUF(&nd); 694 free(newbinname, M_PARGS); 695 newbinname = NULL; 696 } 697 vm_object_deallocate(imgp->object); 698 imgp->object = NULL; 699 execve_nosetid(imgp); 700 imgp->execpath = NULL; 701 free(imgp->freepath, M_TEMP); 702 imgp->freepath = NULL; 703 /* set new name to that of the interpreter */ 704 if (imgp->interpreter_vp) { 705 args->fname = NULL; 706 } else { 707 args->fname = imgp->interpreter_name; 708 } 709 goto interpret; 710 } 711 712 /* 713 * NB: We unlock the vnode here because it is believed that none 714 * of the sv_copyout_strings/sv_fixup operations require the vnode. 715 */ 716 VOP_UNLOCK(imgp->vp); 717 718 if (disallow_high_osrel && 719 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { 720 error = ENOEXEC; 721 uprintf("Osrel %d for image %s too high\n", p->p_osrel, 722 imgp->execpath != NULL ? imgp->execpath : "<unresolved>"); 723 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 724 goto exec_fail_dealloc; 725 } 726 727 /* 728 * Copy out strings (args and env) and initialize stack base. 729 */ 730 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); 731 if (error != 0) { 732 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 733 goto exec_fail_dealloc; 734 } 735 736 /* 737 * Stack setup. 738 */ 739 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); 740 if (error != 0) { 741 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 742 goto exec_fail_dealloc; 743 } 744 745 /* 746 * For security and other reasons, the file descriptor table cannot be 747 * shared after an exec. 748 */ 749 fdunshare(td); 750 pdunshare(td); 751 /* close files on exec */ 752 fdcloseexec(td); 753 754 /* 755 * Malloc things before we need locks. 756 */ 757 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; 758 /* Cache arguments if they fit inside our allowance */ 759 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { 760 newargs = pargs_alloc(i); 761 bcopy(imgp->args->begin_argv, newargs->ar_args, i); 762 } 763 764 /* 765 * For security and other reasons, signal handlers cannot 766 * be shared after an exec. The new process gets a copy of the old 767 * handlers. In execsigs(), the new process will have its signals 768 * reset. 769 */ 770 if (sigacts_shared(p->p_sigacts)) { 771 oldsigacts = p->p_sigacts; 772 newsigacts = sigacts_alloc(); 773 sigacts_copy(newsigacts, oldsigacts); 774 } 775 776 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 777 778 PROC_LOCK(p); 779 if (oldsigacts) 780 p->p_sigacts = newsigacts; 781 /* Stop profiling */ 782 stopprofclock(p); 783 784 /* reset caught signals */ 785 execsigs(p); 786 787 /* name this process - nameiexec(p, ndp) */ 788 bzero(p->p_comm, sizeof(p->p_comm)); 789 if (args->fname) 790 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, 791 min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); 792 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) 793 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); 794 bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); 795 #ifdef KTR 796 sched_clear_tdname(td); 797 #endif 798 799 /* 800 * mark as execed, wakeup the process that vforked (if any) and tell 801 * it that it now has its own resources back 802 */ 803 p->p_flag |= P_EXEC; 804 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) 805 p->p_flag2 &= ~P2_NOTRACE; 806 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) 807 p->p_flag2 &= ~P2_STKGAP_DISABLE; 808 p->p_flag2 &= ~(P2_MEMBAR_PRIVE | P2_MEMBAR_PRIVE_SYNCORE | 809 P2_MEMBAR_GLOBE); 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_baseaddr = imgp->reloc_base; 923 pe.pm_dynaddr = imgp->et_dyn_addr; 924 925 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); 926 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 927 } 928 #endif 929 930 /* Set values passed into the program in registers. */ 931 (*p->p_sysent->sv_setregs)(td, imgp, stack_base); 932 933 VOP_MMAPPED(imgp->vp); 934 935 SDT_PROBE1(proc, , , exec__success, args->fname); 936 937 exec_fail_dealloc: 938 if (error != 0) { 939 p->p_osrel = orig_osrel; 940 p->p_fctl0 = orig_fctl0; 941 p->p_elf_brandinfo = orig_brandinfo; 942 } 943 944 if (imgp->firstpage != NULL) 945 exec_unmap_first_page(imgp); 946 947 if (imgp->vp != NULL) { 948 if (imgp->opened) 949 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); 950 if (imgp->textset) 951 VOP_UNSET_TEXT_CHECKED(imgp->vp); 952 if (error != 0) 953 vput(imgp->vp); 954 else 955 VOP_UNLOCK(imgp->vp); 956 if (args->fname != NULL) 957 NDFREE_PNBUF(&nd); 958 if (newtextdvp != NULL) 959 vrele(newtextdvp); 960 free(newbinname, M_PARGS); 961 } 962 963 if (imgp->object != NULL) 964 vm_object_deallocate(imgp->object); 965 966 free(imgp->freepath, M_TEMP); 967 968 if (error == 0) { 969 if (p->p_ptevents & PTRACE_EXEC) { 970 PROC_LOCK(p); 971 if (p->p_ptevents & PTRACE_EXEC) 972 td->td_dbgflags |= TDB_EXEC; 973 PROC_UNLOCK(p); 974 } 975 } else { 976 exec_fail: 977 /* we're done here, clear P_INEXEC */ 978 PROC_LOCK(p); 979 p->p_flag &= ~P_INEXEC; 980 PROC_UNLOCK(p); 981 982 SDT_PROBE1(proc, , , exec__failure, error); 983 } 984 985 if (imgp->newcred != NULL && oldcred != NULL) 986 crfree(imgp->newcred); 987 988 #ifdef MAC 989 mac_execve_exit(imgp); 990 mac_execve_interpreter_exit(interpvplabel); 991 #endif 992 exec_free_args(args); 993 994 /* 995 * Handle deferred decrement of ref counts. 996 */ 997 if (oldtextvp != NULL) 998 vrele(oldtextvp); 999 if (oldtextdvp != NULL) 1000 vrele(oldtextdvp); 1001 free(oldbinname, M_PARGS); 1002 #ifdef KTRACE 1003 ktr_io_params_free(kiop); 1004 #endif 1005 pargs_drop(oldargs); 1006 pargs_drop(newargs); 1007 if (oldsigacts != NULL) 1008 sigacts_free(oldsigacts); 1009 if (euip != NULL) 1010 uifree(euip); 1011 1012 if (error && imgp->vmspace_destroyed) { 1013 /* sorry, no more process anymore. exit gracefully */ 1014 exec_cleanup(td, oldvmspace); 1015 exit1(td, 0, SIGABRT); 1016 /* NOT REACHED */ 1017 } 1018 1019 #ifdef KTRACE 1020 if (error == 0) 1021 ktrprocctor(p); 1022 #endif 1023 1024 /* 1025 * We don't want cpu_set_syscall_retval() to overwrite any of 1026 * the register values put in place by exec_setregs(). 1027 * Implementations of cpu_set_syscall_retval() will leave 1028 * registers unmodified when returning EJUSTRETURN. 1029 */ 1030 return (error == 0 ? EJUSTRETURN : error); 1031 } 1032 1033 void 1034 exec_cleanup(struct thread *td, struct vmspace *oldvmspace) 1035 { 1036 if ((td->td_pflags & TDP_EXECVMSPC) != 0) { 1037 KASSERT(td->td_proc->p_vmspace != oldvmspace, 1038 ("oldvmspace still used")); 1039 vmspace_free(oldvmspace); 1040 td->td_pflags &= ~TDP_EXECVMSPC; 1041 } 1042 } 1043 1044 int 1045 exec_map_first_page(struct image_params *imgp) 1046 { 1047 vm_object_t object; 1048 vm_page_t m; 1049 int error; 1050 1051 if (imgp->firstpage != NULL) 1052 exec_unmap_first_page(imgp); 1053 1054 object = imgp->vp->v_object; 1055 if (object == NULL) 1056 return (EACCES); 1057 #if VM_NRESERVLEVEL > 0 1058 if ((object->flags & OBJ_COLORED) == 0) { 1059 VM_OBJECT_WLOCK(object); 1060 vm_object_color(object, 0); 1061 VM_OBJECT_WUNLOCK(object); 1062 } 1063 #endif 1064 error = vm_page_grab_valid_unlocked(&m, object, 0, 1065 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | 1066 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 1067 1068 if (error != VM_PAGER_OK) 1069 return (EIO); 1070 imgp->firstpage = sf_buf_alloc(m, 0); 1071 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); 1072 1073 return (0); 1074 } 1075 1076 void 1077 exec_unmap_first_page(struct image_params *imgp) 1078 { 1079 vm_page_t m; 1080 1081 if (imgp->firstpage != NULL) { 1082 m = sf_buf_page(imgp->firstpage); 1083 sf_buf_free(imgp->firstpage); 1084 imgp->firstpage = NULL; 1085 vm_page_unwire(m, PQ_ACTIVE); 1086 } 1087 } 1088 1089 void 1090 exec_onexec_old(struct thread *td) 1091 { 1092 sigfastblock_clear(td); 1093 umtx_exec(td->td_proc); 1094 } 1095 1096 /* 1097 * This is an optimization which removes the unmanaged shared page 1098 * mapping. In combination with pmap_remove_pages(), which cleans all 1099 * managed mappings in the process' vmspace pmap, no work will be left 1100 * for pmap_remove(min, max). 1101 */ 1102 void 1103 exec_free_abi_mappings(struct proc *p) 1104 { 1105 struct vmspace *vmspace; 1106 1107 vmspace = p->p_vmspace; 1108 if (refcount_load(&vmspace->vm_refcnt) != 1) 1109 return; 1110 1111 if (!PROC_HAS_SHP(p)) 1112 return; 1113 1114 pmap_remove(vmspace_pmap(vmspace), vmspace->vm_shp_base, 1115 vmspace->vm_shp_base + p->p_sysent->sv_shared_page_len); 1116 } 1117 1118 /* 1119 * Run down the current address space and install a new one. 1120 */ 1121 int 1122 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) 1123 { 1124 int error; 1125 struct proc *p = imgp->proc; 1126 struct vmspace *vmspace = p->p_vmspace; 1127 struct thread *td = curthread; 1128 vm_offset_t sv_minuser; 1129 vm_map_t map; 1130 1131 imgp->vmspace_destroyed = true; 1132 imgp->sysent = sv; 1133 1134 if (p->p_sysent->sv_onexec_old != NULL) 1135 p->p_sysent->sv_onexec_old(td); 1136 itimers_exec(p); 1137 1138 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); 1139 1140 /* 1141 * Blow away entire process VM, if address space not shared, 1142 * otherwise, create a new VM space so that other threads are 1143 * not disrupted 1144 */ 1145 map = &vmspace->vm_map; 1146 if (map_at_zero) 1147 sv_minuser = sv->sv_minuser; 1148 else 1149 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); 1150 if (refcount_load(&vmspace->vm_refcnt) == 1 && 1151 vm_map_min(map) == sv_minuser && 1152 vm_map_max(map) == sv->sv_maxuser && 1153 cpu_exec_vmspace_reuse(p, map)) { 1154 exec_free_abi_mappings(p); 1155 shmexit(vmspace); 1156 pmap_remove_pages(vmspace_pmap(vmspace)); 1157 vm_map_remove(map, vm_map_min(map), vm_map_max(map)); 1158 /* 1159 * An exec terminates mlockall(MCL_FUTURE). 1160 * ASLR and W^X states must be re-evaluated. 1161 */ 1162 vm_map_lock(map); 1163 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | 1164 MAP_ASLR_IGNSTART | MAP_ASLR_STACK | MAP_WXORX); 1165 vm_map_unlock(map); 1166 } else { 1167 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); 1168 if (error) 1169 return (error); 1170 vmspace = p->p_vmspace; 1171 map = &vmspace->vm_map; 1172 } 1173 map->flags |= imgp->map_flags; 1174 1175 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0); 1176 } 1177 1178 /* 1179 * Compute the stack size limit and map the main process stack. 1180 * Map the shared page. 1181 */ 1182 int 1183 exec_map_stack(struct image_params *imgp) 1184 { 1185 struct rlimit rlim_stack; 1186 struct sysentvec *sv; 1187 struct proc *p; 1188 vm_map_t map; 1189 struct vmspace *vmspace; 1190 vm_offset_t stack_addr, stack_top; 1191 vm_offset_t sharedpage_addr; 1192 u_long ssiz; 1193 int error, find_space, stack_off; 1194 vm_prot_t stack_prot; 1195 vm_object_t obj; 1196 1197 p = imgp->proc; 1198 sv = p->p_sysent; 1199 1200 if (imgp->stack_sz != 0) { 1201 ssiz = trunc_page(imgp->stack_sz); 1202 PROC_LOCK(p); 1203 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); 1204 PROC_UNLOCK(p); 1205 if (ssiz > rlim_stack.rlim_max) 1206 ssiz = rlim_stack.rlim_max; 1207 if (ssiz > rlim_stack.rlim_cur) { 1208 rlim_stack.rlim_cur = ssiz; 1209 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); 1210 } 1211 } else if (sv->sv_maxssiz != NULL) { 1212 ssiz = *sv->sv_maxssiz; 1213 } else { 1214 ssiz = maxssiz; 1215 } 1216 1217 vmspace = p->p_vmspace; 1218 map = &vmspace->vm_map; 1219 1220 stack_prot = sv->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? 1221 imgp->stack_prot : sv->sv_stackprot; 1222 if ((map->flags & MAP_ASLR_STACK) != 0) { 1223 stack_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1224 lim_max(curthread, RLIMIT_DATA)); 1225 find_space = VMFS_ANY_SPACE; 1226 } else { 1227 stack_addr = sv->sv_usrstack - ssiz; 1228 find_space = VMFS_NO_SPACE; 1229 } 1230 error = vm_map_find(map, NULL, 0, &stack_addr, (vm_size_t)ssiz, 1231 sv->sv_usrstack, find_space, stack_prot, VM_PROT_ALL, 1232 MAP_STACK_GROWS_DOWN); 1233 if (error != KERN_SUCCESS) { 1234 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " 1235 "failed, mach error %d errno %d\n", (uintmax_t)ssiz, 1236 stack_prot, error, vm_mmap_to_errno(error)); 1237 return (vm_mmap_to_errno(error)); 1238 } 1239 1240 stack_top = stack_addr + ssiz; 1241 if ((map->flags & MAP_ASLR_STACK) != 0) { 1242 /* Randomize within the first page of the stack. */ 1243 arc4rand(&stack_off, sizeof(stack_off), 0); 1244 stack_top -= rounddown2(stack_off & PAGE_MASK, sizeof(void *)); 1245 } 1246 1247 /* Map a shared page */ 1248 obj = sv->sv_shared_page_obj; 1249 if (obj == NULL) { 1250 sharedpage_addr = 0; 1251 goto out; 1252 } 1253 1254 /* 1255 * If randomization is disabled then the shared page will 1256 * be mapped at address specified in sysentvec. 1257 * Otherwise any address above .data section can be selected. 1258 * Same logic is used for stack address randomization. 1259 * If the address randomization is applied map a guard page 1260 * at the top of UVA. 1261 */ 1262 vm_object_reference(obj); 1263 if ((imgp->imgp_flags & IMGP_ASLR_SHARED_PAGE) != 0) { 1264 sharedpage_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1265 lim_max(curthread, RLIMIT_DATA)); 1266 1267 error = vm_map_fixed(map, NULL, 0, 1268 sv->sv_maxuser - PAGE_SIZE, PAGE_SIZE, 1269 VM_PROT_NONE, VM_PROT_NONE, MAP_CREATE_GUARD); 1270 if (error != KERN_SUCCESS) { 1271 /* 1272 * This is not fatal, so let's just print a warning 1273 * and continue. 1274 */ 1275 uprintf("%s: Mapping guard page at the top of UVA failed" 1276 " mach error %d errno %d", 1277 __func__, error, vm_mmap_to_errno(error)); 1278 } 1279 1280 error = vm_map_find(map, obj, 0, 1281 &sharedpage_addr, sv->sv_shared_page_len, 1282 sv->sv_maxuser, VMFS_ANY_SPACE, 1283 VM_PROT_READ | VM_PROT_EXECUTE, 1284 VM_PROT_READ | VM_PROT_EXECUTE, 1285 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1286 } else { 1287 sharedpage_addr = sv->sv_shared_page_base; 1288 vm_map_fixed(map, obj, 0, 1289 sharedpage_addr, sv->sv_shared_page_len, 1290 VM_PROT_READ | VM_PROT_EXECUTE, 1291 VM_PROT_READ | VM_PROT_EXECUTE, 1292 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1293 } 1294 if (error != KERN_SUCCESS) { 1295 uprintf("%s: mapping shared page at addr: %p" 1296 "failed, mach error %d errno %d\n", __func__, 1297 (void *)sharedpage_addr, error, vm_mmap_to_errno(error)); 1298 vm_object_deallocate(obj); 1299 return (vm_mmap_to_errno(error)); 1300 } 1301 out: 1302 /* 1303 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they 1304 * are still used to enforce the stack rlimit on the process stack. 1305 */ 1306 vmspace->vm_maxsaddr = (char *)stack_addr; 1307 vmspace->vm_stacktop = stack_top; 1308 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; 1309 vmspace->vm_shp_base = sharedpage_addr; 1310 1311 return (0); 1312 } 1313 1314 /* 1315 * Copy out argument and environment strings from the old process address 1316 * space into the temporary string buffer. 1317 */ 1318 int 1319 exec_copyin_args(struct image_args *args, const char *fname, 1320 enum uio_seg segflg, char **argv, char **envv) 1321 { 1322 u_long arg, env; 1323 int error; 1324 1325 bzero(args, sizeof(*args)); 1326 if (argv == NULL) 1327 return (EFAULT); 1328 1329 /* 1330 * Allocate demand-paged memory for the file name, argument, and 1331 * environment strings. 1332 */ 1333 error = exec_alloc_args(args); 1334 if (error != 0) 1335 return (error); 1336 1337 /* 1338 * Copy the file name. 1339 */ 1340 error = exec_args_add_fname(args, fname, segflg); 1341 if (error != 0) 1342 goto err_exit; 1343 1344 /* 1345 * extract arguments first 1346 */ 1347 for (;;) { 1348 error = fueword(argv++, &arg); 1349 if (error == -1) { 1350 error = EFAULT; 1351 goto err_exit; 1352 } 1353 if (arg == 0) 1354 break; 1355 error = exec_args_add_arg(args, (char *)(uintptr_t)arg, 1356 UIO_USERSPACE); 1357 if (error != 0) 1358 goto err_exit; 1359 } 1360 1361 /* 1362 * extract environment strings 1363 */ 1364 if (envv) { 1365 for (;;) { 1366 error = fueword(envv++, &env); 1367 if (error == -1) { 1368 error = EFAULT; 1369 goto err_exit; 1370 } 1371 if (env == 0) 1372 break; 1373 error = exec_args_add_env(args, 1374 (char *)(uintptr_t)env, UIO_USERSPACE); 1375 if (error != 0) 1376 goto err_exit; 1377 } 1378 } 1379 1380 return (0); 1381 1382 err_exit: 1383 exec_free_args(args); 1384 return (error); 1385 } 1386 1387 struct exec_args_kva { 1388 vm_offset_t addr; 1389 u_int gen; 1390 SLIST_ENTRY(exec_args_kva) next; 1391 }; 1392 1393 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); 1394 1395 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; 1396 static struct mtx exec_args_kva_mtx; 1397 static u_int exec_args_gen; 1398 1399 static void 1400 exec_prealloc_args_kva(void *arg __unused) 1401 { 1402 struct exec_args_kva *argkva; 1403 u_int i; 1404 1405 SLIST_INIT(&exec_args_kva_freelist); 1406 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); 1407 for (i = 0; i < exec_map_entries; i++) { 1408 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); 1409 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); 1410 argkva->gen = exec_args_gen; 1411 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1412 } 1413 } 1414 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); 1415 1416 static vm_offset_t 1417 exec_alloc_args_kva(void **cookie) 1418 { 1419 struct exec_args_kva *argkva; 1420 1421 argkva = (void *)atomic_readandclear_ptr( 1422 (uintptr_t *)DPCPU_PTR(exec_args_kva)); 1423 if (argkva == NULL) { 1424 mtx_lock(&exec_args_kva_mtx); 1425 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) 1426 (void)mtx_sleep(&exec_args_kva_freelist, 1427 &exec_args_kva_mtx, 0, "execkva", 0); 1428 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); 1429 mtx_unlock(&exec_args_kva_mtx); 1430 } 1431 kasan_mark((void *)argkva->addr, exec_map_entry_size, 1432 exec_map_entry_size, 0); 1433 *(struct exec_args_kva **)cookie = argkva; 1434 return (argkva->addr); 1435 } 1436 1437 static void 1438 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) 1439 { 1440 vm_offset_t base; 1441 1442 base = argkva->addr; 1443 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size, 1444 KASAN_EXEC_ARGS_FREED); 1445 if (argkva->gen != gen) { 1446 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, 1447 MADV_FREE); 1448 argkva->gen = gen; 1449 } 1450 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), 1451 (uintptr_t)NULL, (uintptr_t)argkva)) { 1452 mtx_lock(&exec_args_kva_mtx); 1453 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1454 wakeup_one(&exec_args_kva_freelist); 1455 mtx_unlock(&exec_args_kva_mtx); 1456 } 1457 } 1458 1459 static void 1460 exec_free_args_kva(void *cookie) 1461 { 1462 1463 exec_release_args_kva(cookie, exec_args_gen); 1464 } 1465 1466 static void 1467 exec_args_kva_lowmem(void *arg __unused) 1468 { 1469 SLIST_HEAD(, exec_args_kva) head; 1470 struct exec_args_kva *argkva; 1471 u_int gen; 1472 int i; 1473 1474 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; 1475 1476 /* 1477 * Force an madvise of each KVA range. Any currently allocated ranges 1478 * will have MADV_FREE applied once they are freed. 1479 */ 1480 SLIST_INIT(&head); 1481 mtx_lock(&exec_args_kva_mtx); 1482 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); 1483 mtx_unlock(&exec_args_kva_mtx); 1484 while ((argkva = SLIST_FIRST(&head)) != NULL) { 1485 SLIST_REMOVE_HEAD(&head, next); 1486 exec_release_args_kva(argkva, gen); 1487 } 1488 1489 CPU_FOREACH(i) { 1490 argkva = (void *)atomic_readandclear_ptr( 1491 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); 1492 if (argkva != NULL) 1493 exec_release_args_kva(argkva, gen); 1494 } 1495 } 1496 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, 1497 EVENTHANDLER_PRI_ANY); 1498 1499 /* 1500 * Allocate temporary demand-paged, zero-filled memory for the file name, 1501 * argument, and environment strings. 1502 */ 1503 int 1504 exec_alloc_args(struct image_args *args) 1505 { 1506 1507 args->buf = (char *)exec_alloc_args_kva(&args->bufkva); 1508 return (0); 1509 } 1510 1511 void 1512 exec_free_args(struct image_args *args) 1513 { 1514 1515 if (args->buf != NULL) { 1516 exec_free_args_kva(args->bufkva); 1517 args->buf = NULL; 1518 } 1519 if (args->fname_buf != NULL) { 1520 free(args->fname_buf, M_TEMP); 1521 args->fname_buf = NULL; 1522 } 1523 } 1524 1525 /* 1526 * A set to functions to fill struct image args. 1527 * 1528 * NOTE: exec_args_add_fname() must be called (possibly with a NULL 1529 * fname) before the other functions. All exec_args_add_arg() calls must 1530 * be made before any exec_args_add_env() calls. exec_args_adjust_args() 1531 * may be called any time after exec_args_add_fname(). 1532 * 1533 * exec_args_add_fname() - install path to be executed 1534 * exec_args_add_arg() - append an argument string 1535 * exec_args_add_env() - append an env string 1536 * exec_args_adjust_args() - adjust location of the argument list to 1537 * allow new arguments to be prepended 1538 */ 1539 int 1540 exec_args_add_fname(struct image_args *args, const char *fname, 1541 enum uio_seg segflg) 1542 { 1543 int error; 1544 size_t length; 1545 1546 KASSERT(args->fname == NULL, ("fname already appended")); 1547 KASSERT(args->endp == NULL, ("already appending to args")); 1548 1549 if (fname != NULL) { 1550 args->fname = args->buf; 1551 error = segflg == UIO_SYSSPACE ? 1552 copystr(fname, args->fname, PATH_MAX, &length) : 1553 copyinstr(fname, args->fname, PATH_MAX, &length); 1554 if (error != 0) 1555 return (error == ENAMETOOLONG ? E2BIG : error); 1556 } else 1557 length = 0; 1558 1559 /* Set up for _arg_*()/_env_*() */ 1560 args->endp = args->buf + length; 1561 /* begin_argv must be set and kept updated */ 1562 args->begin_argv = args->endp; 1563 KASSERT(exec_map_entry_size - length >= ARG_MAX, 1564 ("too little space remaining for arguments %zu < %zu", 1565 exec_map_entry_size - length, (size_t)ARG_MAX)); 1566 args->stringspace = ARG_MAX; 1567 1568 return (0); 1569 } 1570 1571 static int 1572 exec_args_add_str(struct image_args *args, const char *str, 1573 enum uio_seg segflg, int *countp) 1574 { 1575 int error; 1576 size_t length; 1577 1578 KASSERT(args->endp != NULL, ("endp not initialized")); 1579 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1580 1581 error = (segflg == UIO_SYSSPACE) ? 1582 copystr(str, args->endp, args->stringspace, &length) : 1583 copyinstr(str, args->endp, args->stringspace, &length); 1584 if (error != 0) 1585 return (error == ENAMETOOLONG ? E2BIG : error); 1586 args->stringspace -= length; 1587 args->endp += length; 1588 (*countp)++; 1589 1590 return (0); 1591 } 1592 1593 int 1594 exec_args_add_arg(struct image_args *args, const char *argp, 1595 enum uio_seg segflg) 1596 { 1597 1598 KASSERT(args->envc == 0, ("appending args after env")); 1599 1600 return (exec_args_add_str(args, argp, segflg, &args->argc)); 1601 } 1602 1603 int 1604 exec_args_add_env(struct image_args *args, const char *envp, 1605 enum uio_seg segflg) 1606 { 1607 1608 if (args->envc == 0) 1609 args->begin_envv = args->endp; 1610 1611 return (exec_args_add_str(args, envp, segflg, &args->envc)); 1612 } 1613 1614 int 1615 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) 1616 { 1617 ssize_t offset; 1618 1619 KASSERT(args->endp != NULL, ("endp not initialized")); 1620 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1621 1622 offset = extend - consume; 1623 if (args->stringspace < offset) 1624 return (E2BIG); 1625 memmove(args->begin_argv + extend, args->begin_argv + consume, 1626 args->endp - args->begin_argv + consume); 1627 if (args->envc > 0) 1628 args->begin_envv += offset; 1629 args->endp += offset; 1630 args->stringspace -= offset; 1631 return (0); 1632 } 1633 1634 char * 1635 exec_args_get_begin_envv(struct image_args *args) 1636 { 1637 1638 KASSERT(args->endp != NULL, ("endp not initialized")); 1639 1640 if (args->envc > 0) 1641 return (args->begin_envv); 1642 return (args->endp); 1643 } 1644 1645 /* 1646 * Copy strings out to the new process address space, constructing new arg 1647 * and env vector tables. Return a pointer to the base so that it can be used 1648 * as the initial stack pointer. 1649 */ 1650 int 1651 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 1652 { 1653 int argc, envc; 1654 char **vectp; 1655 char *stringp; 1656 uintptr_t destp, ustringp; 1657 struct ps_strings *arginfo; 1658 struct proc *p; 1659 struct sysentvec *sysent; 1660 size_t execpath_len; 1661 int error, szsigcode; 1662 char canary[sizeof(long) * 8]; 1663 1664 p = imgp->proc; 1665 sysent = p->p_sysent; 1666 1667 destp = PROC_PS_STRINGS(p); 1668 arginfo = imgp->ps_strings = (void *)destp; 1669 1670 /* 1671 * Install sigcode. 1672 */ 1673 if (sysent->sv_shared_page_base == 0 && sysent->sv_szsigcode != NULL) { 1674 szsigcode = *(sysent->sv_szsigcode); 1675 destp -= szsigcode; 1676 destp = rounddown2(destp, sizeof(void *)); 1677 error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode); 1678 if (error != 0) 1679 return (error); 1680 } 1681 1682 /* 1683 * Copy the image path for the rtld. 1684 */ 1685 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 1686 execpath_len = strlen(imgp->execpath) + 1; 1687 destp -= execpath_len; 1688 destp = rounddown2(destp, sizeof(void *)); 1689 imgp->execpathp = (void *)destp; 1690 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 1691 if (error != 0) 1692 return (error); 1693 } 1694 1695 /* 1696 * Prepare the canary for SSP. 1697 */ 1698 arc4rand(canary, sizeof(canary), 0); 1699 destp -= sizeof(canary); 1700 imgp->canary = (void *)destp; 1701 error = copyout(canary, imgp->canary, sizeof(canary)); 1702 if (error != 0) 1703 return (error); 1704 imgp->canarylen = sizeof(canary); 1705 1706 /* 1707 * Prepare the pagesizes array. 1708 */ 1709 imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES; 1710 destp -= imgp->pagesizeslen; 1711 destp = rounddown2(destp, sizeof(void *)); 1712 imgp->pagesizes = (void *)destp; 1713 error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen); 1714 if (error != 0) 1715 return (error); 1716 1717 /* 1718 * Allocate room for the argument and environment strings. 1719 */ 1720 destp -= ARG_MAX - imgp->args->stringspace; 1721 destp = rounddown2(destp, sizeof(void *)); 1722 ustringp = destp; 1723 1724 if (imgp->auxargs) { 1725 /* 1726 * Allocate room on the stack for the ELF auxargs 1727 * array. It has up to AT_COUNT entries. 1728 */ 1729 destp -= AT_COUNT * sizeof(Elf_Auxinfo); 1730 destp = rounddown2(destp, sizeof(void *)); 1731 } 1732 1733 vectp = (char **)destp; 1734 1735 /* 1736 * Allocate room for the argv[] and env vectors including the 1737 * terminating NULL pointers. 1738 */ 1739 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 1740 1741 /* 1742 * vectp also becomes our initial stack base 1743 */ 1744 *stack_base = (uintptr_t)vectp; 1745 1746 stringp = imgp->args->begin_argv; 1747 argc = imgp->args->argc; 1748 envc = imgp->args->envc; 1749 1750 /* 1751 * Copy out strings - arguments and environment. 1752 */ 1753 error = copyout(stringp, (void *)ustringp, 1754 ARG_MAX - imgp->args->stringspace); 1755 if (error != 0) 1756 return (error); 1757 1758 /* 1759 * Fill in "ps_strings" struct for ps, w, etc. 1760 */ 1761 imgp->argv = vectp; 1762 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 1763 suword32(&arginfo->ps_nargvstr, argc) != 0) 1764 return (EFAULT); 1765 1766 /* 1767 * Fill in argument portion of vector table. 1768 */ 1769 for (; argc > 0; --argc) { 1770 if (suword(vectp++, ustringp) != 0) 1771 return (EFAULT); 1772 while (*stringp++ != 0) 1773 ustringp++; 1774 ustringp++; 1775 } 1776 1777 /* a null vector table pointer separates the argp's from the envp's */ 1778 if (suword(vectp++, 0) != 0) 1779 return (EFAULT); 1780 1781 imgp->envv = vectp; 1782 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 1783 suword32(&arginfo->ps_nenvstr, envc) != 0) 1784 return (EFAULT); 1785 1786 /* 1787 * Fill in environment portion of vector table. 1788 */ 1789 for (; envc > 0; --envc) { 1790 if (suword(vectp++, ustringp) != 0) 1791 return (EFAULT); 1792 while (*stringp++ != 0) 1793 ustringp++; 1794 ustringp++; 1795 } 1796 1797 /* end of vector table is a null pointer */ 1798 if (suword(vectp, 0) != 0) 1799 return (EFAULT); 1800 1801 if (imgp->auxargs) { 1802 vectp++; 1803 error = imgp->sysent->sv_copyout_auxargs(imgp, 1804 (uintptr_t)vectp); 1805 if (error != 0) 1806 return (error); 1807 } 1808 1809 return (0); 1810 } 1811 1812 /* 1813 * Check permissions of file to execute. 1814 * Called with imgp->vp locked. 1815 * Return 0 for success or error code on failure. 1816 */ 1817 int 1818 exec_check_permissions(struct image_params *imgp) 1819 { 1820 struct vnode *vp = imgp->vp; 1821 struct vattr *attr = imgp->attr; 1822 struct thread *td; 1823 int error; 1824 1825 td = curthread; 1826 1827 /* Get file attributes */ 1828 error = VOP_GETATTR(vp, attr, td->td_ucred); 1829 if (error) 1830 return (error); 1831 1832 #ifdef MAC 1833 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); 1834 if (error) 1835 return (error); 1836 #endif 1837 1838 /* 1839 * 1) Check if file execution is disabled for the filesystem that 1840 * this file resides on. 1841 * 2) Ensure that at least one execute bit is on. Otherwise, a 1842 * privileged user will always succeed, and we don't want this 1843 * to happen unless the file really is executable. 1844 * 3) Ensure that the file is a regular file. 1845 */ 1846 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || 1847 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || 1848 (attr->va_type != VREG)) 1849 return (EACCES); 1850 1851 /* 1852 * Zero length files can't be exec'd 1853 */ 1854 if (attr->va_size == 0) 1855 return (ENOEXEC); 1856 1857 /* 1858 * Check for execute permission to file based on current credentials. 1859 */ 1860 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); 1861 if (error) 1862 return (error); 1863 1864 /* 1865 * Check number of open-for-writes on the file and deny execution 1866 * if there are any. 1867 * 1868 * Add a text reference now so no one can write to the 1869 * executable while we're activating it. 1870 * 1871 * Remember if this was set before and unset it in case this is not 1872 * actually an executable image. 1873 */ 1874 error = VOP_SET_TEXT(vp); 1875 if (error != 0) 1876 return (error); 1877 imgp->textset = true; 1878 1879 /* 1880 * Call filesystem specific open routine (which does nothing in the 1881 * general case). 1882 */ 1883 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); 1884 if (error == 0) 1885 imgp->opened = true; 1886 return (error); 1887 } 1888 1889 /* 1890 * Exec handler registration 1891 */ 1892 int 1893 exec_register(const struct execsw *execsw_arg) 1894 { 1895 const struct execsw **es, **xs, **newexecsw; 1896 u_int count = 2; /* New slot and trailing NULL */ 1897 1898 if (execsw) 1899 for (es = execsw; *es; es++) 1900 count++; 1901 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1902 xs = newexecsw; 1903 if (execsw) 1904 for (es = execsw; *es; es++) 1905 *xs++ = *es; 1906 *xs++ = execsw_arg; 1907 *xs = NULL; 1908 if (execsw) 1909 free(execsw, M_TEMP); 1910 execsw = newexecsw; 1911 return (0); 1912 } 1913 1914 int 1915 exec_unregister(const struct execsw *execsw_arg) 1916 { 1917 const struct execsw **es, **xs, **newexecsw; 1918 int count = 1; 1919 1920 if (execsw == NULL) 1921 panic("unregister with no handlers left?\n"); 1922 1923 for (es = execsw; *es; es++) { 1924 if (*es == execsw_arg) 1925 break; 1926 } 1927 if (*es == NULL) 1928 return (ENOENT); 1929 for (es = execsw; *es; es++) 1930 if (*es != execsw_arg) 1931 count++; 1932 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1933 xs = newexecsw; 1934 for (es = execsw; *es; es++) 1935 if (*es != execsw_arg) 1936 *xs++ = *es; 1937 *xs = NULL; 1938 if (execsw) 1939 free(execsw, M_TEMP); 1940 execsw = newexecsw; 1941 return (0); 1942 } 1943 1944 /* 1945 * Write out a core segment to the compression stream. 1946 */ 1947 static int 1948 compress_chunk(struct coredump_params *cp, char *base, char *buf, size_t len) 1949 { 1950 size_t chunk_len; 1951 int error; 1952 1953 while (len > 0) { 1954 chunk_len = MIN(len, CORE_BUF_SIZE); 1955 1956 /* 1957 * We can get EFAULT error here. 1958 * In that case zero out the current chunk of the segment. 1959 */ 1960 error = copyin(base, buf, chunk_len); 1961 if (error != 0) 1962 bzero(buf, chunk_len); 1963 error = compressor_write(cp->comp, buf, chunk_len); 1964 if (error != 0) 1965 break; 1966 base += chunk_len; 1967 len -= chunk_len; 1968 } 1969 return (error); 1970 } 1971 1972 int 1973 core_write(struct coredump_params *cp, const void *base, size_t len, 1974 off_t offset, enum uio_seg seg, size_t *resid) 1975 { 1976 1977 return (vn_rdwr_inchunks(UIO_WRITE, cp->vp, __DECONST(void *, base), 1978 len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED, 1979 cp->active_cred, cp->file_cred, resid, cp->td)); 1980 } 1981 1982 int 1983 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp, 1984 void *tmpbuf) 1985 { 1986 vm_map_t map; 1987 struct mount *mp; 1988 size_t resid, runlen; 1989 int error; 1990 bool success; 1991 1992 KASSERT((uintptr_t)base % PAGE_SIZE == 0, 1993 ("%s: user address %p is not page-aligned", __func__, base)); 1994 1995 if (cp->comp != NULL) 1996 return (compress_chunk(cp, base, tmpbuf, len)); 1997 1998 map = &cp->td->td_proc->p_vmspace->vm_map; 1999 for (; len > 0; base += runlen, offset += runlen, len -= runlen) { 2000 /* 2001 * Attempt to page in all virtual pages in the range. If a 2002 * virtual page is not backed by the pager, it is represented as 2003 * a hole in the file. This can occur with zero-filled 2004 * anonymous memory or truncated files, for example. 2005 */ 2006 for (runlen = 0; runlen < len; runlen += PAGE_SIZE) { 2007 if (core_dump_can_intr && curproc_sigkilled()) 2008 return (EINTR); 2009 error = vm_fault(map, (uintptr_t)base + runlen, 2010 VM_PROT_READ, VM_FAULT_NOFILL, NULL); 2011 if (runlen == 0) 2012 success = error == KERN_SUCCESS; 2013 else if ((error == KERN_SUCCESS) != success) 2014 break; 2015 } 2016 2017 if (success) { 2018 error = core_write(cp, base, runlen, offset, 2019 UIO_USERSPACE, &resid); 2020 if (error != 0) { 2021 if (error != EFAULT) 2022 break; 2023 2024 /* 2025 * EFAULT may be returned if the user mapping 2026 * could not be accessed, e.g., because a mapped 2027 * file has been truncated. Skip the page if no 2028 * progress was made, to protect against a 2029 * hypothetical scenario where vm_fault() was 2030 * successful but core_write() returns EFAULT 2031 * anyway. 2032 */ 2033 runlen -= resid; 2034 if (runlen == 0) { 2035 success = false; 2036 runlen = PAGE_SIZE; 2037 } 2038 } 2039 } 2040 if (!success) { 2041 error = vn_start_write(cp->vp, &mp, V_WAIT); 2042 if (error != 0) 2043 break; 2044 vn_lock(cp->vp, LK_EXCLUSIVE | LK_RETRY); 2045 error = vn_truncate_locked(cp->vp, offset + runlen, 2046 false, cp->td->td_ucred); 2047 VOP_UNLOCK(cp->vp); 2048 vn_finished_write(mp); 2049 if (error != 0) 2050 break; 2051 } 2052 } 2053 return (error); 2054 } 2055 2056 /* 2057 * Drain into a core file. 2058 */ 2059 int 2060 sbuf_drain_core_output(void *arg, const char *data, int len) 2061 { 2062 struct coredump_params *cp; 2063 struct proc *p; 2064 int error, locked; 2065 2066 cp = arg; 2067 p = cp->td->td_proc; 2068 2069 /* 2070 * Some kern_proc out routines that print to this sbuf may 2071 * call us with the process lock held. Draining with the 2072 * non-sleepable lock held is unsafe. The lock is needed for 2073 * those routines when dumping a live process. In our case we 2074 * can safely release the lock before draining and acquire 2075 * again after. 2076 */ 2077 locked = PROC_LOCKED(p); 2078 if (locked) 2079 PROC_UNLOCK(p); 2080 if (cp->comp != NULL) 2081 error = compressor_write(cp->comp, __DECONST(char *, data), 2082 len); 2083 else 2084 error = core_write(cp, __DECONST(void *, data), len, cp->offset, 2085 UIO_SYSSPACE, NULL); 2086 if (locked) 2087 PROC_LOCK(p); 2088 if (error != 0) 2089 return (-error); 2090 cp->offset += len; 2091 return (len); 2092 } 2093