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_hwt_hooks.h" 33 #include "opt_ktrace.h" 34 #include "opt_vm.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/acct.h> 39 #include <sys/asan.h> 40 #include <sys/capsicum.h> 41 #include <sys/compressor.h> 42 #include <sys/eventhandler.h> 43 #include <sys/exec.h> 44 #include <sys/fcntl.h> 45 #include <sys/filedesc.h> 46 #include <sys/imgact.h> 47 #include <sys/imgact_elf.h> 48 #include <sys/kernel.h> 49 #include <sys/lock.h> 50 #include <sys/malloc.h> 51 #include <sys/mman.h> 52 #include <sys/mount.h> 53 #include <sys/mutex.h> 54 #include <sys/namei.h> 55 #include <sys/priv.h> 56 #include <sys/proc.h> 57 #include <sys/ptrace.h> 58 #include <sys/reg.h> 59 #include <sys/resourcevar.h> 60 #include <sys/rwlock.h> 61 #include <sys/sched.h> 62 #include <sys/sdt.h> 63 #include <sys/sf_buf.h> 64 #include <sys/shm.h> 65 #include <sys/signalvar.h> 66 #include <sys/smp.h> 67 #include <sys/stat.h> 68 #include <sys/syscallsubr.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysent.h> 71 #include <sys/sysproto.h> 72 #include <sys/timers.h> 73 #include <sys/ucoredump.h> 74 #include <sys/umtxvar.h> 75 #include <sys/vnode.h> 76 #include <sys/wait.h> 77 #ifdef KTRACE 78 #include <sys/ktrace.h> 79 #endif 80 81 #include <vm/vm.h> 82 #include <vm/vm_param.h> 83 #include <vm/pmap.h> 84 #include <vm/vm_page.h> 85 #include <vm/vm_map.h> 86 #include <vm/vm_kern.h> 87 #include <vm/vm_extern.h> 88 #include <vm/vm_object.h> 89 #include <vm/vm_pager.h> 90 91 #ifdef HWPMC_HOOKS 92 #include <sys/pmckern.h> 93 #endif 94 95 #ifdef HWT_HOOKS 96 #include <dev/hwt/hwt_hook.h> 97 #endif 98 99 #include <security/audit/audit.h> 100 #include <security/mac/mac_framework.h> 101 102 #ifdef KDTRACE_HOOKS 103 #include <sys/dtrace_bsd.h> 104 dtrace_execexit_func_t dtrace_fasttrap_exec; 105 #endif 106 107 SDT_PROVIDER_DECLARE(proc); 108 SDT_PROBE_DEFINE1(proc, , , exec, "char *"); 109 SDT_PROBE_DEFINE1(proc, , , exec__failure, "int"); 110 SDT_PROBE_DEFINE1(proc, , , exec__success, "char *"); 111 112 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments"); 113 114 int coredump_pack_fileinfo = 1; 115 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN, 116 &coredump_pack_fileinfo, 0, 117 "Enable file path packing in 'procstat -f' coredump notes"); 118 119 int coredump_pack_vmmapinfo = 1; 120 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN, 121 &coredump_pack_vmmapinfo, 0, 122 "Enable file path packing in 'procstat -v' coredump notes"); 123 124 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS); 125 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS); 126 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS); 127 static int do_execve(struct thread *td, struct image_args *args, 128 struct mac *mac_p, struct vmspace *oldvmspace); 129 130 /* XXX This should be vm_size_t. */ 131 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD| 132 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU", 133 "Location of process' ps_strings structure"); 134 135 /* XXX This should be vm_size_t. */ 136 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD| 137 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU", 138 "Top of process stack"); 139 140 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE, 141 NULL, 0, sysctl_kern_stackprot, "I", 142 "Stack memory permissions"); 143 144 u_long ps_arg_cache_limit = PAGE_SIZE / 16; 145 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW, 146 &ps_arg_cache_limit, 0, 147 "Process' command line characters cache limit"); 148 149 static int disallow_high_osrel; 150 SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW, 151 &disallow_high_osrel, 0, 152 "Disallow execution of binaries built for higher version of the world"); 153 154 static int map_at_zero = 0; 155 SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0, 156 "Permit processes to map an object at virtual address 0."); 157 158 static int core_dump_can_intr = 1; 159 SYSCTL_INT(_kern, OID_AUTO, core_dump_can_intr, CTLFLAG_RWTUN, 160 &core_dump_can_intr, 0, 161 "Core dumping interruptible with SIGKILL"); 162 163 static int 164 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS) 165 { 166 struct proc *p; 167 vm_offset_t ps_strings; 168 169 p = curproc; 170 #ifdef SCTL_MASK32 171 if (req->flags & SCTL_MASK32) { 172 unsigned int val; 173 val = (unsigned int)PROC_PS_STRINGS(p); 174 return (SYSCTL_OUT(req, &val, sizeof(val))); 175 } 176 #endif 177 ps_strings = PROC_PS_STRINGS(p); 178 return (SYSCTL_OUT(req, &ps_strings, sizeof(ps_strings))); 179 } 180 181 static int 182 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS) 183 { 184 struct proc *p; 185 vm_offset_t val; 186 187 p = curproc; 188 #ifdef SCTL_MASK32 189 if (req->flags & SCTL_MASK32) { 190 unsigned int val32; 191 192 val32 = round_page((unsigned int)p->p_vmspace->vm_stacktop); 193 return (SYSCTL_OUT(req, &val32, sizeof(val32))); 194 } 195 #endif 196 val = round_page(p->p_vmspace->vm_stacktop); 197 return (SYSCTL_OUT(req, &val, sizeof(val))); 198 } 199 200 static int 201 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS) 202 { 203 struct proc *p; 204 205 p = curproc; 206 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot, 207 sizeof(p->p_sysent->sv_stackprot))); 208 } 209 210 /* 211 * Each of the items is a pointer to a `const struct execsw', hence the 212 * double pointer here. 213 */ 214 static const struct execsw **execsw; 215 216 #ifndef _SYS_SYSPROTO_H_ 217 struct execve_args { 218 char *fname; 219 char **argv; 220 char **envv; 221 }; 222 #endif 223 224 int 225 sys_execve(struct thread *td, struct execve_args *uap) 226 { 227 struct image_args args; 228 struct vmspace *oldvmspace; 229 int error; 230 231 error = pre_execve(td, &oldvmspace); 232 if (error != 0) 233 return (error); 234 error = exec_copyin_args(&args, uap->fname, uap->argv, uap->envv); 235 if (error == 0) 236 error = kern_execve(td, &args, NULL, oldvmspace); 237 post_execve(td, error, oldvmspace); 238 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 239 return (error); 240 } 241 242 #ifndef _SYS_SYSPROTO_H_ 243 struct fexecve_args { 244 int fd; 245 char **argv; 246 char **envv; 247 }; 248 #endif 249 int 250 sys_fexecve(struct thread *td, struct fexecve_args *uap) 251 { 252 struct image_args args; 253 struct vmspace *oldvmspace; 254 int error; 255 256 error = pre_execve(td, &oldvmspace); 257 if (error != 0) 258 return (error); 259 error = exec_copyin_args(&args, NULL, uap->argv, uap->envv); 260 if (error == 0) { 261 args.fd = uap->fd; 262 error = kern_execve(td, &args, NULL, oldvmspace); 263 } 264 post_execve(td, error, oldvmspace); 265 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 266 return (error); 267 } 268 269 #ifndef _SYS_SYSPROTO_H_ 270 struct __mac_execve_args { 271 char *fname; 272 char **argv; 273 char **envv; 274 struct mac *mac_p; 275 }; 276 #endif 277 278 int 279 sys___mac_execve(struct thread *td, struct __mac_execve_args *uap) 280 { 281 #ifdef MAC 282 struct image_args args; 283 struct vmspace *oldvmspace; 284 int error; 285 286 error = pre_execve(td, &oldvmspace); 287 if (error != 0) 288 return (error); 289 error = exec_copyin_args(&args, uap->fname, uap->argv, uap->envv); 290 if (error == 0) 291 error = kern_execve(td, &args, uap->mac_p, oldvmspace); 292 post_execve(td, error, oldvmspace); 293 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 294 return (error); 295 #else 296 return (ENOSYS); 297 #endif 298 } 299 300 int 301 pre_execve(struct thread *td, struct vmspace **oldvmspace) 302 { 303 struct proc *p; 304 int error; 305 306 KASSERT(td == curthread, ("non-current thread %p", td)); 307 error = 0; 308 p = td->td_proc; 309 if ((p->p_flag & P_HADTHREADS) != 0) { 310 PROC_LOCK(p); 311 if (thread_single(p, SINGLE_BOUNDARY) != 0) 312 error = ERESTART; 313 PROC_UNLOCK(p); 314 } 315 KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0, 316 ("nested execve")); 317 *oldvmspace = p->p_vmspace; 318 return (error); 319 } 320 321 void 322 post_execve(struct thread *td, int error, struct vmspace *oldvmspace) 323 { 324 struct proc *p; 325 326 KASSERT(td == curthread, ("non-current thread %p", td)); 327 p = td->td_proc; 328 if ((p->p_flag & P_HADTHREADS) != 0) { 329 PROC_LOCK(p); 330 /* 331 * If success, we upgrade to SINGLE_EXIT state to 332 * force other threads to suicide. 333 */ 334 if (error == EJUSTRETURN) 335 thread_single(p, SINGLE_EXIT); 336 else 337 thread_single_end(p, SINGLE_BOUNDARY); 338 PROC_UNLOCK(p); 339 } 340 exec_cleanup(td, oldvmspace); 341 } 342 343 /* 344 * kern_execve() has the astonishing property of not always returning to 345 * the caller. If sufficiently bad things happen during the call to 346 * do_execve(), it can end up calling exit1(); as a result, callers must 347 * avoid doing anything which they might need to undo (e.g., allocating 348 * memory). 349 */ 350 int 351 kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 352 struct vmspace *oldvmspace) 353 { 354 355 TSEXEC(td->td_proc->p_pid, args->begin_argv); 356 AUDIT_ARG_ARGV(args->begin_argv, args->argc, 357 exec_args_get_begin_envv(args) - args->begin_argv); 358 AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc, 359 args->endp - exec_args_get_begin_envv(args)); 360 #ifdef KTRACE 361 if (KTRPOINT(td, KTR_ARGS)) { 362 ktrdata(KTR_ARGS, args->begin_argv, 363 exec_args_get_begin_envv(args) - args->begin_argv); 364 } 365 if (KTRPOINT(td, KTR_ENVS)) { 366 ktrdata(KTR_ENVS, exec_args_get_begin_envv(args), 367 args->endp - exec_args_get_begin_envv(args)); 368 } 369 #endif 370 /* Must have at least one argument. */ 371 if (args->argc == 0) { 372 exec_free_args(args); 373 return (EINVAL); 374 } 375 return (do_execve(td, args, mac_p, oldvmspace)); 376 } 377 378 static void 379 execve_nosetid(struct image_params *imgp) 380 { 381 imgp->credential_setid = false; 382 if (imgp->newcred != NULL) { 383 crfree(imgp->newcred); 384 imgp->newcred = NULL; 385 } 386 } 387 388 /* 389 * In-kernel implementation of execve(). All arguments are assumed to be 390 * userspace pointers from the passed thread. 391 */ 392 static int 393 do_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 394 struct vmspace *oldvmspace) 395 { 396 struct proc *p = td->td_proc; 397 struct nameidata nd; 398 struct ucred *oldcred; 399 struct uidinfo *euip = NULL; 400 uintptr_t stack_base; 401 struct image_params image_params, *imgp; 402 struct vattr attr; 403 struct pargs *oldargs = NULL, *newargs = NULL; 404 struct sigacts *oldsigacts = NULL, *newsigacts = NULL; 405 #ifdef KTRACE 406 struct ktr_io_params *kiop; 407 #endif 408 struct vnode *oldtextvp, *newtextvp; 409 struct vnode *oldtextdvp, *newtextdvp; 410 char *oldbinname, *newbinname; 411 bool credential_changing; 412 #ifdef MAC 413 struct label *interpvplabel = NULL; 414 bool will_transition; 415 #endif 416 #ifdef HWPMC_HOOKS 417 struct pmckern_procexec pe; 418 #endif 419 int error, i, orig_osrel; 420 uint32_t orig_fctl0; 421 Elf_Brandinfo *orig_brandinfo; 422 size_t freepath_size; 423 static const char fexecv_proc_title[] = "(fexecv)"; 424 425 imgp = &image_params; 426 oldtextvp = oldtextdvp = NULL; 427 newtextvp = newtextdvp = NULL; 428 newbinname = oldbinname = NULL; 429 #ifdef KTRACE 430 kiop = NULL; 431 #endif 432 433 /* 434 * Lock the process and set the P_INEXEC flag to indicate that 435 * it should be left alone until we're done here. This is 436 * necessary to avoid race conditions - e.g. in ptrace() - 437 * that might allow a local user to illicitly obtain elevated 438 * privileges. 439 */ 440 PROC_LOCK(p); 441 KASSERT((p->p_flag & P_INEXEC) == 0, 442 ("%s(): process already has P_INEXEC flag", __func__)); 443 p->p_flag |= P_INEXEC; 444 PROC_UNLOCK(p); 445 446 /* 447 * Initialize part of the common data 448 */ 449 bzero(imgp, sizeof(*imgp)); 450 imgp->proc = p; 451 imgp->attr = &attr; 452 imgp->args = args; 453 oldcred = p->p_ucred; 454 orig_osrel = p->p_osrel; 455 orig_fctl0 = p->p_fctl0; 456 orig_brandinfo = p->p_elf_brandinfo; 457 458 #ifdef MAC 459 error = mac_execve_enter(imgp, mac_p); 460 if (error) 461 goto exec_fail; 462 #endif 463 464 SDT_PROBE1(proc, , , exec, args->fname); 465 466 interpret: 467 if (args->fname != NULL) { 468 #ifdef CAPABILITY_MODE 469 if (CAP_TRACING(td)) 470 ktrcapfail(CAPFAIL_NAMEI, args->fname); 471 /* 472 * While capability mode can't reach this point via direct 473 * path arguments to execve(), we also don't allow 474 * interpreters to be used in capability mode (for now). 475 * Catch indirect lookups and return a permissions error. 476 */ 477 if (IN_CAPABILITY_MODE(td)) { 478 error = ECAPMODE; 479 goto exec_fail; 480 } 481 #endif 482 483 /* 484 * Translate the file name. namei() returns a vnode 485 * pointer in ni_vp among other things. 486 */ 487 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | 488 AUDITVNODE1 | WANTPARENT, UIO_SYSSPACE, 489 args->fname); 490 491 error = namei(&nd); 492 if (error) 493 goto exec_fail; 494 495 newtextvp = nd.ni_vp; 496 newtextdvp = nd.ni_dvp; 497 nd.ni_dvp = NULL; 498 newbinname = malloc(nd.ni_cnd.cn_namelen + 1, M_PARGS, 499 M_WAITOK); 500 memcpy(newbinname, nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 501 newbinname[nd.ni_cnd.cn_namelen] = '\0'; 502 imgp->vp = newtextvp; 503 504 /* 505 * Do the best to calculate the full path to the image file. 506 */ 507 if (args->fname[0] == '/') { 508 imgp->execpath = args->fname; 509 } else { 510 VOP_UNLOCK(imgp->vp); 511 freepath_size = MAXPATHLEN; 512 if (vn_fullpath_hardlink(newtextvp, newtextdvp, 513 newbinname, nd.ni_cnd.cn_namelen, &imgp->execpath, 514 &imgp->freepath, &freepath_size) != 0) 515 imgp->execpath = args->fname; 516 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 517 } 518 } else if (imgp->interpreter_vp) { 519 /* 520 * An image activator has already provided an open vnode 521 */ 522 newtextvp = imgp->interpreter_vp; 523 imgp->interpreter_vp = NULL; 524 if (vn_fullpath(newtextvp, &imgp->execpath, 525 &imgp->freepath) != 0) 526 imgp->execpath = args->fname; 527 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 528 AUDIT_ARG_VNODE1(newtextvp); 529 imgp->vp = newtextvp; 530 } else { 531 AUDIT_ARG_FD(args->fd); 532 533 /* 534 * If the descriptors was not opened with O_PATH, then 535 * we require that it was opened with O_EXEC or 536 * O_RDONLY. In either case, exec_check_permissions() 537 * below checks _current_ file access mode regardless 538 * of the permissions additionally checked at the 539 * open(2). 540 */ 541 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, 542 &newtextvp); 543 if (error != 0) 544 goto exec_fail; 545 546 if (vn_fullpath(newtextvp, &imgp->execpath, 547 &imgp->freepath) != 0) 548 imgp->execpath = args->fname; 549 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 550 AUDIT_ARG_VNODE1(newtextvp); 551 imgp->vp = newtextvp; 552 } 553 554 /* 555 * Check file permissions. Also 'opens' file and sets its vnode to 556 * text mode. 557 */ 558 error = exec_check_permissions(imgp); 559 if (error) 560 goto exec_fail_dealloc; 561 562 imgp->object = imgp->vp->v_object; 563 if (imgp->object != NULL) 564 vm_object_reference(imgp->object); 565 566 error = exec_map_first_page(imgp); 567 if (error) 568 goto exec_fail_dealloc; 569 570 imgp->proc->p_osrel = 0; 571 imgp->proc->p_fctl0 = 0; 572 imgp->proc->p_elf_brandinfo = NULL; 573 574 /* 575 * Implement image setuid/setgid. 576 * 577 * Determine new credentials before attempting image activators 578 * so that it can be used by process_exec handlers to determine 579 * credential/setid changes. 580 * 581 * Don't honor setuid/setgid if the filesystem prohibits it or if 582 * the process is being traced. 583 * 584 * We disable setuid/setgid/etc in capability mode on the basis 585 * that most setugid applications are not written with that 586 * environment in mind, and will therefore almost certainly operate 587 * incorrectly. In principle there's no reason that setugid 588 * applications might not be useful in capability mode, so we may want 589 * to reconsider this conservative design choice in the future. 590 * 591 * XXXMAC: For the time being, use NOSUID to also prohibit 592 * transitions on the file system. 593 */ 594 credential_changing = false; 595 credential_changing |= (attr.va_mode & S_ISUID) && 596 oldcred->cr_uid != attr.va_uid; 597 credential_changing |= (attr.va_mode & S_ISGID) && 598 oldcred->cr_gid != attr.va_gid; 599 #ifdef MAC 600 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp, 601 interpvplabel, imgp) != 0; 602 credential_changing |= will_transition; 603 #endif 604 605 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */ 606 if (credential_changing) 607 imgp->proc->p_pdeathsig = 0; 608 609 if (credential_changing && 610 #ifdef CAPABILITY_MODE 611 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) && 612 #endif 613 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 && 614 (p->p_flag & P_TRACED) == 0) { 615 imgp->credential_setid = true; 616 VOP_UNLOCK(imgp->vp); 617 imgp->newcred = crdup(oldcred); 618 if (attr.va_mode & S_ISUID) { 619 euip = uifind(attr.va_uid); 620 change_euid(imgp->newcred, euip); 621 } 622 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 623 if (attr.va_mode & S_ISGID) 624 change_egid(imgp->newcred, attr.va_gid); 625 /* 626 * Implement correct POSIX saved-id behavior. 627 * 628 * XXXMAC: Note that the current logic will save the 629 * uid and gid if a MAC domain transition occurs, even 630 * though maybe it shouldn't. 631 */ 632 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 633 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 634 } else { 635 /* 636 * Implement correct POSIX saved-id behavior. 637 * 638 * XXX: It's not clear that the existing behavior is 639 * POSIX-compliant. A number of sources indicate that the 640 * saved uid/gid should only be updated if the new ruid is 641 * not equal to the old ruid, or the new euid is not equal 642 * to the old euid and the new euid is not equal to the old 643 * ruid. The FreeBSD code always updates the saved uid/gid. 644 * Also, this code uses the new (replaced) euid and egid as 645 * the source, which may or may not be the right ones to use. 646 */ 647 if (oldcred->cr_svuid != oldcred->cr_uid || 648 oldcred->cr_svgid != oldcred->cr_gid) { 649 VOP_UNLOCK(imgp->vp); 650 imgp->newcred = crdup(oldcred); 651 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 652 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 653 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 654 } 655 } 656 /* The new credentials are installed into the process later. */ 657 658 /* 659 * Loop through the list of image activators, calling each one. 660 * An activator returns -1 if there is no match, 0 on success, 661 * and an error otherwise. 662 */ 663 error = -1; 664 for (i = 0; error == -1 && execsw[i]; ++i) { 665 if (execsw[i]->ex_imgact == NULL) 666 continue; 667 error = (*execsw[i]->ex_imgact)(imgp); 668 } 669 670 if (error) { 671 if (error == -1) 672 error = ENOEXEC; 673 goto exec_fail_dealloc; 674 } 675 676 /* 677 * Special interpreter operation, cleanup and loop up to try to 678 * activate the interpreter. 679 */ 680 if (imgp->interpreted) { 681 exec_unmap_first_page(imgp); 682 /* 683 * The text reference needs to be removed for scripts. 684 * There is a short period before we determine that 685 * something is a script where text reference is active. 686 * The vnode lock is held over this entire period 687 * so nothing should illegitimately be blocked. 688 */ 689 MPASS(imgp->textset); 690 VOP_UNSET_TEXT_CHECKED(newtextvp); 691 imgp->textset = false; 692 /* free name buffer and old vnode */ 693 #ifdef MAC 694 mac_execve_interpreter_enter(newtextvp, &interpvplabel); 695 #endif 696 if (imgp->opened) { 697 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td); 698 imgp->opened = false; 699 } 700 vput(newtextvp); 701 imgp->vp = newtextvp = NULL; 702 if (args->fname != NULL) { 703 if (newtextdvp != NULL) { 704 vrele(newtextdvp); 705 newtextdvp = NULL; 706 } 707 NDFREE_PNBUF(&nd); 708 free(newbinname, M_PARGS); 709 newbinname = NULL; 710 } 711 vm_object_deallocate(imgp->object); 712 imgp->object = NULL; 713 execve_nosetid(imgp); 714 imgp->execpath = NULL; 715 free(imgp->freepath, M_TEMP); 716 imgp->freepath = NULL; 717 /* set new name to that of the interpreter */ 718 if (imgp->interpreter_vp) { 719 args->fname = NULL; 720 } else { 721 args->fname = imgp->interpreter_name; 722 } 723 goto interpret; 724 } 725 726 /* 727 * NB: We unlock the vnode here because it is believed that none 728 * of the sv_copyout_strings/sv_fixup operations require the vnode. 729 */ 730 VOP_UNLOCK(imgp->vp); 731 732 if (disallow_high_osrel && 733 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { 734 error = ENOEXEC; 735 uprintf("Osrel %d for image %s too high\n", p->p_osrel, 736 imgp->execpath != NULL ? imgp->execpath : "<unresolved>"); 737 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 738 goto exec_fail_dealloc; 739 } 740 741 /* 742 * Copy out strings (args and env) and initialize stack base. 743 */ 744 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); 745 if (error != 0) { 746 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 747 goto exec_fail_dealloc; 748 } 749 750 /* 751 * Stack setup. 752 */ 753 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); 754 if (error != 0) { 755 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 756 goto exec_fail_dealloc; 757 } 758 759 /* 760 * For security and other reasons, the file descriptor table cannot be 761 * shared after an exec. 762 */ 763 fdunshare(td); 764 pdunshare(td); 765 /* close files on exec */ 766 fdcloseexec(td); 767 768 /* 769 * Malloc things before we need locks. 770 */ 771 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; 772 /* Cache arguments if they fit inside our allowance */ 773 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { 774 newargs = pargs_alloc(i); 775 bcopy(imgp->args->begin_argv, newargs->ar_args, i); 776 } 777 778 /* 779 * For security and other reasons, signal handlers cannot 780 * be shared after an exec. The new process gets a copy of the old 781 * handlers. In execsigs(), the new process will have its signals 782 * reset. 783 */ 784 if (sigacts_shared(p->p_sigacts)) { 785 oldsigacts = p->p_sigacts; 786 newsigacts = sigacts_alloc(); 787 sigacts_copy(newsigacts, oldsigacts); 788 } 789 790 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 791 792 PROC_LOCK(p); 793 if (oldsigacts) 794 p->p_sigacts = newsigacts; 795 /* Stop profiling */ 796 stopprofclock(p); 797 798 /* reset caught signals */ 799 execsigs(p); 800 801 /* name this process - nameiexec(p, ndp) */ 802 bzero(p->p_comm, sizeof(p->p_comm)); 803 if (args->fname) 804 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, 805 min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); 806 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) 807 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); 808 bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); 809 #ifdef KTR 810 sched_clear_tdname(td); 811 #endif 812 813 /* 814 * mark as execed, wakeup the process that vforked (if any) and tell 815 * it that it now has its own resources back 816 */ 817 p->p_flag |= P_EXEC; 818 td->td_pflags2 &= ~TDP2_UEXTERR; 819 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) 820 p->p_flag2 &= ~P2_NOTRACE; 821 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) 822 p->p_flag2 &= ~P2_STKGAP_DISABLE; 823 p->p_flag2 &= ~(P2_MEMBAR_PRIVE | P2_MEMBAR_PRIVE_SYNCORE | 824 P2_MEMBAR_GLOBE); 825 if (p->p_flag & P_PPWAIT) { 826 p->p_flag &= ~(P_PPWAIT | P_PPTRACE); 827 cv_broadcast(&p->p_pwait); 828 /* STOPs are no longer ignored, arrange for AST */ 829 signotify(td); 830 } 831 832 if ((imgp->sysent->sv_setid_allowed != NULL && 833 !(*imgp->sysent->sv_setid_allowed)(td, imgp)) || 834 (p->p_flag2 & P2_NO_NEW_PRIVS) != 0) 835 execve_nosetid(imgp); 836 837 /* 838 * Implement image setuid/setgid installation. 839 */ 840 if (imgp->credential_setid) { 841 /* 842 * Turn off syscall tracing for set-id programs, except for 843 * root. Record any set-id flags first to make sure that 844 * we do not regain any tracing during a possible block. 845 */ 846 setsugid(p); 847 #ifdef KTRACE 848 kiop = ktrprocexec(p); 849 #endif 850 /* 851 * Close any file descriptors 0..2 that reference procfs, 852 * then make sure file descriptors 0..2 are in use. 853 * 854 * Both fdsetugidsafety() and fdcheckstd() may call functions 855 * taking sleepable locks, so temporarily drop our locks. 856 */ 857 PROC_UNLOCK(p); 858 VOP_UNLOCK(imgp->vp); 859 fdsetugidsafety(td); 860 error = fdcheckstd(td); 861 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 862 if (error != 0) 863 goto exec_fail_dealloc; 864 PROC_LOCK(p); 865 #ifdef MAC 866 if (will_transition) { 867 mac_vnode_execve_transition(oldcred, imgp->newcred, 868 imgp->vp, interpvplabel, imgp); 869 } 870 #endif 871 } else { 872 if (oldcred->cr_uid == oldcred->cr_ruid && 873 oldcred->cr_gid == oldcred->cr_rgid) 874 p->p_flag &= ~P_SUGID; 875 } 876 /* 877 * Set the new credentials. 878 */ 879 if (imgp->newcred != NULL) { 880 proc_set_cred(p, imgp->newcred); 881 crfree(oldcred); 882 oldcred = NULL; 883 } 884 885 /* 886 * Store the vp for use in kern.proc.pathname. This vnode was 887 * referenced by namei() or by fexecve variant of fname handling. 888 */ 889 oldtextvp = p->p_textvp; 890 p->p_textvp = newtextvp; 891 oldtextdvp = p->p_textdvp; 892 p->p_textdvp = newtextdvp; 893 newtextdvp = NULL; 894 oldbinname = p->p_binname; 895 p->p_binname = newbinname; 896 newbinname = NULL; 897 898 #ifdef KDTRACE_HOOKS 899 /* 900 * Tell the DTrace fasttrap provider about the exec if it 901 * has declared an interest. 902 */ 903 if (dtrace_fasttrap_exec) 904 dtrace_fasttrap_exec(p); 905 #endif 906 907 /* 908 * Notify others that we exec'd, and clear the P_INEXEC flag 909 * as we're now a bona fide freshly-execed process. 910 */ 911 KNOTE_LOCKED(p->p_klist, NOTE_EXEC); 912 p->p_flag &= ~P_INEXEC; 913 914 /* clear "fork but no exec" flag, as we _are_ execing */ 915 p->p_acflag &= ~AFORK; 916 917 /* 918 * Free any previous argument cache and replace it with 919 * the new argument cache, if any. 920 */ 921 oldargs = p->p_args; 922 p->p_args = newargs; 923 newargs = NULL; 924 925 PROC_UNLOCK(p); 926 927 #ifdef HWPMC_HOOKS 928 /* 929 * Check if system-wide sampling is in effect or if the 930 * current process is using PMCs. If so, do exec() time 931 * processing. This processing needs to happen AFTER the 932 * P_INEXEC flag is cleared. 933 */ 934 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { 935 VOP_UNLOCK(imgp->vp); 936 pe.pm_credentialschanged = credential_changing; 937 pe.pm_baseaddr = imgp->reloc_base; 938 pe.pm_dynaddr = imgp->et_dyn_addr; 939 940 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); 941 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 942 } 943 #endif 944 945 #ifdef HWT_HOOKS 946 if ((td->td_proc->p_flag2 & P2_HWT) != 0) { 947 struct hwt_record_entry ent; 948 949 VOP_UNLOCK(imgp->vp); 950 ent.fullpath = imgp->execpath; 951 ent.addr = imgp->et_dyn_addr; 952 ent.baseaddr = imgp->reloc_base; 953 ent.record_type = HWT_RECORD_EXECUTABLE; 954 HWT_CALL_HOOK(td, HWT_EXEC, &ent); 955 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 956 } 957 #endif 958 959 /* Set values passed into the program in registers. */ 960 (*p->p_sysent->sv_setregs)(td, imgp, stack_base); 961 962 VOP_MMAPPED(imgp->vp); 963 964 SDT_PROBE1(proc, , , exec__success, args->fname); 965 966 exec_fail_dealloc: 967 if (error != 0) { 968 p->p_osrel = orig_osrel; 969 p->p_fctl0 = orig_fctl0; 970 p->p_elf_brandinfo = orig_brandinfo; 971 } 972 973 if (imgp->firstpage != NULL) 974 exec_unmap_first_page(imgp); 975 976 if (imgp->vp != NULL) { 977 if (imgp->opened) 978 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); 979 if (imgp->textset) 980 VOP_UNSET_TEXT_CHECKED(imgp->vp); 981 if (error != 0) 982 vput(imgp->vp); 983 else 984 VOP_UNLOCK(imgp->vp); 985 if (args->fname != NULL) 986 NDFREE_PNBUF(&nd); 987 if (newtextdvp != NULL) 988 vrele(newtextdvp); 989 free(newbinname, M_PARGS); 990 } 991 992 if (imgp->object != NULL) 993 vm_object_deallocate(imgp->object); 994 995 free(imgp->freepath, M_TEMP); 996 997 if (error == 0) { 998 if (p->p_ptevents & PTRACE_EXEC) { 999 PROC_LOCK(p); 1000 if (p->p_ptevents & PTRACE_EXEC) 1001 td->td_dbgflags |= TDB_EXEC; 1002 PROC_UNLOCK(p); 1003 } 1004 } else { 1005 exec_fail: 1006 /* we're done here, clear P_INEXEC */ 1007 PROC_LOCK(p); 1008 p->p_flag &= ~P_INEXEC; 1009 PROC_UNLOCK(p); 1010 1011 SDT_PROBE1(proc, , , exec__failure, error); 1012 } 1013 1014 if (imgp->newcred != NULL && oldcred != NULL) 1015 crfree(imgp->newcred); 1016 1017 #ifdef MAC 1018 mac_execve_exit(imgp); 1019 mac_execve_interpreter_exit(interpvplabel); 1020 #endif 1021 exec_free_args(args); 1022 1023 /* 1024 * Handle deferred decrement of ref counts. 1025 */ 1026 if (oldtextvp != NULL) 1027 vrele(oldtextvp); 1028 if (oldtextdvp != NULL) 1029 vrele(oldtextdvp); 1030 free(oldbinname, M_PARGS); 1031 #ifdef KTRACE 1032 ktr_io_params_free(kiop); 1033 #endif 1034 pargs_drop(oldargs); 1035 pargs_drop(newargs); 1036 if (oldsigacts != NULL) 1037 sigacts_free(oldsigacts); 1038 if (euip != NULL) 1039 uifree(euip); 1040 1041 if (error && imgp->vmspace_destroyed) { 1042 /* sorry, no more process anymore. exit gracefully */ 1043 exec_cleanup(td, oldvmspace); 1044 exit1(td, 0, SIGABRT); 1045 /* NOT REACHED */ 1046 } 1047 1048 #ifdef KTRACE 1049 if (error == 0) 1050 ktrprocctor(p); 1051 #endif 1052 1053 /* 1054 * We don't want cpu_set_syscall_retval() to overwrite any of 1055 * the register values put in place by exec_setregs(). 1056 * Implementations of cpu_set_syscall_retval() will leave 1057 * registers unmodified when returning EJUSTRETURN. 1058 */ 1059 return (error == 0 ? EJUSTRETURN : error); 1060 } 1061 1062 void 1063 exec_cleanup(struct thread *td, struct vmspace *oldvmspace) 1064 { 1065 if ((td->td_pflags & TDP_EXECVMSPC) != 0) { 1066 KASSERT(td->td_proc->p_vmspace != oldvmspace, 1067 ("oldvmspace still used")); 1068 vmspace_free(oldvmspace); 1069 td->td_pflags &= ~TDP_EXECVMSPC; 1070 } 1071 } 1072 1073 int 1074 exec_map_first_page(struct image_params *imgp) 1075 { 1076 vm_object_t object; 1077 vm_page_t m; 1078 int error; 1079 1080 if (imgp->firstpage != NULL) 1081 exec_unmap_first_page(imgp); 1082 1083 object = imgp->vp->v_object; 1084 if (object == NULL) 1085 return (EACCES); 1086 #if VM_NRESERVLEVEL > 0 1087 if ((object->flags & OBJ_COLORED) == 0) { 1088 VM_OBJECT_WLOCK(object); 1089 vm_object_color(object, 0); 1090 VM_OBJECT_WUNLOCK(object); 1091 } 1092 #endif 1093 error = vm_page_grab_valid_unlocked(&m, object, 0, 1094 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | 1095 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 1096 1097 if (error != VM_PAGER_OK) 1098 return (EIO); 1099 imgp->firstpage = sf_buf_alloc(m, 0); 1100 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); 1101 1102 return (0); 1103 } 1104 1105 void 1106 exec_unmap_first_page(struct image_params *imgp) 1107 { 1108 vm_page_t m; 1109 1110 if (imgp->firstpage != NULL) { 1111 m = sf_buf_page(imgp->firstpage); 1112 sf_buf_free(imgp->firstpage); 1113 imgp->firstpage = NULL; 1114 vm_page_unwire(m, PQ_ACTIVE); 1115 } 1116 } 1117 1118 void 1119 exec_onexec_old(struct thread *td) 1120 { 1121 sigfastblock_clear(td); 1122 umtx_exec(td->td_proc); 1123 } 1124 1125 /* 1126 * This is an optimization which removes the unmanaged shared page 1127 * mapping. In combination with pmap_remove_pages(), which cleans all 1128 * managed mappings in the process' vmspace pmap, no work will be left 1129 * for pmap_remove(min, max). 1130 */ 1131 void 1132 exec_free_abi_mappings(struct proc *p) 1133 { 1134 struct vmspace *vmspace; 1135 1136 vmspace = p->p_vmspace; 1137 if (refcount_load(&vmspace->vm_refcnt) != 1) 1138 return; 1139 1140 if (!PROC_HAS_SHP(p)) 1141 return; 1142 1143 pmap_remove(vmspace_pmap(vmspace), vmspace->vm_shp_base, 1144 vmspace->vm_shp_base + p->p_sysent->sv_shared_page_len); 1145 } 1146 1147 /* 1148 * Run down the current address space and install a new one. 1149 */ 1150 int 1151 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) 1152 { 1153 int error; 1154 struct proc *p = imgp->proc; 1155 struct vmspace *vmspace = p->p_vmspace; 1156 struct thread *td = curthread; 1157 vm_offset_t sv_minuser; 1158 vm_map_t map; 1159 1160 imgp->vmspace_destroyed = true; 1161 imgp->sysent = sv; 1162 1163 if (p->p_sysent->sv_onexec_old != NULL) 1164 p->p_sysent->sv_onexec_old(td); 1165 itimers_exec(p); 1166 1167 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); 1168 1169 /* 1170 * Blow away entire process VM, if address space not shared, 1171 * otherwise, create a new VM space so that other threads are 1172 * not disrupted 1173 */ 1174 map = &vmspace->vm_map; 1175 if (map_at_zero) 1176 sv_minuser = sv->sv_minuser; 1177 else 1178 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); 1179 if (refcount_load(&vmspace->vm_refcnt) == 1 && 1180 vm_map_min(map) == sv_minuser && 1181 vm_map_max(map) == sv->sv_maxuser && 1182 cpu_exec_vmspace_reuse(p, map)) { 1183 exec_free_abi_mappings(p); 1184 shmexit(vmspace); 1185 pmap_remove_pages(vmspace_pmap(vmspace)); 1186 vm_map_remove(map, vm_map_min(map), vm_map_max(map)); 1187 /* 1188 * An exec terminates mlockall(MCL_FUTURE). 1189 * ASLR and W^X states must be re-evaluated. 1190 */ 1191 vm_map_lock(map); 1192 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | 1193 MAP_ASLR_IGNSTART | MAP_ASLR_STACK | MAP_WXORX); 1194 vm_map_unlock(map); 1195 } else { 1196 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); 1197 if (error) 1198 return (error); 1199 vmspace = p->p_vmspace; 1200 map = &vmspace->vm_map; 1201 } 1202 map->flags |= imgp->map_flags; 1203 1204 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0); 1205 } 1206 1207 /* 1208 * Compute the stack size limit and map the main process stack. 1209 * Map the shared page. 1210 */ 1211 int 1212 exec_map_stack(struct image_params *imgp) 1213 { 1214 struct rlimit rlim_stack; 1215 struct sysentvec *sv; 1216 struct proc *p; 1217 vm_map_t map; 1218 struct vmspace *vmspace; 1219 vm_offset_t stack_addr, stack_top; 1220 vm_offset_t sharedpage_addr; 1221 u_long ssiz; 1222 int error, find_space, stack_off; 1223 vm_prot_t stack_prot; 1224 vm_object_t obj; 1225 1226 p = imgp->proc; 1227 sv = p->p_sysent; 1228 1229 if (imgp->stack_sz != 0) { 1230 ssiz = trunc_page(imgp->stack_sz); 1231 PROC_LOCK(p); 1232 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); 1233 PROC_UNLOCK(p); 1234 if (ssiz > rlim_stack.rlim_max) 1235 ssiz = rlim_stack.rlim_max; 1236 if (ssiz > rlim_stack.rlim_cur) { 1237 rlim_stack.rlim_cur = ssiz; 1238 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); 1239 } 1240 } else if (sv->sv_maxssiz != NULL) { 1241 ssiz = *sv->sv_maxssiz; 1242 } else { 1243 ssiz = maxssiz; 1244 } 1245 1246 vmspace = p->p_vmspace; 1247 map = &vmspace->vm_map; 1248 1249 stack_prot = sv->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? 1250 imgp->stack_prot : sv->sv_stackprot; 1251 if ((map->flags & MAP_ASLR_STACK) != 0) { 1252 stack_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1253 lim_max(curthread, RLIMIT_DATA)); 1254 find_space = VMFS_ANY_SPACE; 1255 } else { 1256 stack_addr = sv->sv_usrstack - ssiz; 1257 find_space = VMFS_NO_SPACE; 1258 } 1259 error = vm_map_find(map, NULL, 0, &stack_addr, (vm_size_t)ssiz, 1260 sv->sv_usrstack, find_space, stack_prot, VM_PROT_ALL, 1261 MAP_STACK_AREA); 1262 if (error != KERN_SUCCESS) { 1263 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " 1264 "failed, mach error %d errno %d\n", (uintmax_t)ssiz, 1265 stack_prot, error, vm_mmap_to_errno(error)); 1266 return (vm_mmap_to_errno(error)); 1267 } 1268 1269 stack_top = stack_addr + ssiz; 1270 if ((map->flags & MAP_ASLR_STACK) != 0) { 1271 /* Randomize within the first page of the stack. */ 1272 arc4rand(&stack_off, sizeof(stack_off), 0); 1273 stack_top -= rounddown2(stack_off & PAGE_MASK, sizeof(void *)); 1274 } 1275 1276 /* Map a shared page */ 1277 obj = sv->sv_shared_page_obj; 1278 if (obj == NULL) { 1279 sharedpage_addr = 0; 1280 goto out; 1281 } 1282 1283 /* 1284 * If randomization is disabled then the shared page will 1285 * be mapped at address specified in sysentvec. 1286 * Otherwise any address above .data section can be selected. 1287 * Same logic is used for stack address randomization. 1288 * If the address randomization is applied map a guard page 1289 * at the top of UVA. 1290 */ 1291 vm_object_reference(obj); 1292 if ((imgp->imgp_flags & IMGP_ASLR_SHARED_PAGE) != 0) { 1293 sharedpage_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1294 lim_max(curthread, RLIMIT_DATA)); 1295 1296 error = vm_map_fixed(map, NULL, 0, 1297 sv->sv_maxuser - PAGE_SIZE, PAGE_SIZE, 1298 VM_PROT_NONE, VM_PROT_NONE, MAP_CREATE_GUARD); 1299 if (error != KERN_SUCCESS) { 1300 /* 1301 * This is not fatal, so let's just print a warning 1302 * and continue. 1303 */ 1304 uprintf("%s: Mapping guard page at the top of UVA failed" 1305 " mach error %d errno %d", 1306 __func__, error, vm_mmap_to_errno(error)); 1307 } 1308 1309 error = vm_map_find(map, obj, 0, 1310 &sharedpage_addr, sv->sv_shared_page_len, 1311 sv->sv_maxuser, VMFS_ANY_SPACE, 1312 VM_PROT_READ | VM_PROT_EXECUTE, 1313 VM_PROT_READ | VM_PROT_EXECUTE, 1314 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1315 } else { 1316 sharedpage_addr = sv->sv_shared_page_base; 1317 vm_map_fixed(map, obj, 0, 1318 sharedpage_addr, sv->sv_shared_page_len, 1319 VM_PROT_READ | VM_PROT_EXECUTE, 1320 VM_PROT_READ | VM_PROT_EXECUTE, 1321 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1322 } 1323 if (error != KERN_SUCCESS) { 1324 uprintf("%s: mapping shared page at addr: %p" 1325 "failed, mach error %d errno %d\n", __func__, 1326 (void *)sharedpage_addr, error, vm_mmap_to_errno(error)); 1327 vm_object_deallocate(obj); 1328 return (vm_mmap_to_errno(error)); 1329 } 1330 out: 1331 /* 1332 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they 1333 * are still used to enforce the stack rlimit on the process stack. 1334 */ 1335 vmspace->vm_maxsaddr = (char *)stack_addr; 1336 vmspace->vm_stacktop = stack_top; 1337 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; 1338 vmspace->vm_shp_base = sharedpage_addr; 1339 1340 return (0); 1341 } 1342 1343 /* 1344 * Copy out argument and environment strings from the old process address 1345 * space into the temporary string buffer. 1346 */ 1347 int 1348 exec_copyin_args(struct image_args *args, const char *fname, 1349 char **argv, char **envv) 1350 { 1351 u_long arg, env; 1352 int error; 1353 1354 bzero(args, sizeof(*args)); 1355 if (argv == NULL) 1356 return (EFAULT); 1357 1358 /* 1359 * Allocate demand-paged memory for the file name, argument, and 1360 * environment strings. 1361 */ 1362 error = exec_alloc_args(args); 1363 if (error != 0) 1364 return (error); 1365 1366 /* 1367 * Copy the file name. 1368 */ 1369 error = exec_args_add_fname(args, fname, UIO_USERSPACE); 1370 if (error != 0) 1371 goto err_exit; 1372 1373 /* 1374 * extract arguments first 1375 */ 1376 for (;;) { 1377 error = fueword(argv++, &arg); 1378 if (error == -1) { 1379 error = EFAULT; 1380 goto err_exit; 1381 } 1382 if (arg == 0) 1383 break; 1384 error = exec_args_add_arg(args, (char *)(uintptr_t)arg, 1385 UIO_USERSPACE); 1386 if (error != 0) 1387 goto err_exit; 1388 } 1389 1390 /* 1391 * extract environment strings 1392 */ 1393 if (envv) { 1394 for (;;) { 1395 error = fueword(envv++, &env); 1396 if (error == -1) { 1397 error = EFAULT; 1398 goto err_exit; 1399 } 1400 if (env == 0) 1401 break; 1402 error = exec_args_add_env(args, 1403 (char *)(uintptr_t)env, UIO_USERSPACE); 1404 if (error != 0) 1405 goto err_exit; 1406 } 1407 } 1408 1409 return (0); 1410 1411 err_exit: 1412 exec_free_args(args); 1413 return (error); 1414 } 1415 1416 struct exec_args_kva { 1417 vm_offset_t addr; 1418 u_int gen; 1419 SLIST_ENTRY(exec_args_kva) next; 1420 }; 1421 1422 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); 1423 1424 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; 1425 static struct mtx exec_args_kva_mtx; 1426 static u_int exec_args_gen; 1427 1428 static void 1429 exec_prealloc_args_kva(void *arg __unused) 1430 { 1431 struct exec_args_kva *argkva; 1432 u_int i; 1433 1434 SLIST_INIT(&exec_args_kva_freelist); 1435 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); 1436 for (i = 0; i < exec_map_entries; i++) { 1437 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); 1438 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); 1439 argkva->gen = exec_args_gen; 1440 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1441 } 1442 } 1443 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); 1444 1445 static vm_offset_t 1446 exec_alloc_args_kva(void **cookie) 1447 { 1448 struct exec_args_kva *argkva; 1449 1450 argkva = (void *)atomic_readandclear_ptr( 1451 (uintptr_t *)DPCPU_PTR(exec_args_kva)); 1452 if (argkva == NULL) { 1453 mtx_lock(&exec_args_kva_mtx); 1454 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) 1455 (void)mtx_sleep(&exec_args_kva_freelist, 1456 &exec_args_kva_mtx, 0, "execkva", 0); 1457 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); 1458 mtx_unlock(&exec_args_kva_mtx); 1459 } 1460 kasan_mark((void *)argkva->addr, exec_map_entry_size, 1461 exec_map_entry_size, 0); 1462 *(struct exec_args_kva **)cookie = argkva; 1463 return (argkva->addr); 1464 } 1465 1466 static void 1467 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) 1468 { 1469 vm_offset_t base; 1470 1471 base = argkva->addr; 1472 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size, 1473 KASAN_EXEC_ARGS_FREED); 1474 if (argkva->gen != gen) { 1475 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, 1476 MADV_FREE); 1477 argkva->gen = gen; 1478 } 1479 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), 1480 (uintptr_t)NULL, (uintptr_t)argkva)) { 1481 mtx_lock(&exec_args_kva_mtx); 1482 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1483 wakeup_one(&exec_args_kva_freelist); 1484 mtx_unlock(&exec_args_kva_mtx); 1485 } 1486 } 1487 1488 static void 1489 exec_free_args_kva(void *cookie) 1490 { 1491 1492 exec_release_args_kva(cookie, exec_args_gen); 1493 } 1494 1495 static void 1496 exec_args_kva_lowmem(void *arg __unused, int flags __unused) 1497 { 1498 SLIST_HEAD(, exec_args_kva) head; 1499 struct exec_args_kva *argkva; 1500 u_int gen; 1501 int i; 1502 1503 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; 1504 1505 /* 1506 * Force an madvise of each KVA range. Any currently allocated ranges 1507 * will have MADV_FREE applied once they are freed. 1508 */ 1509 SLIST_INIT(&head); 1510 mtx_lock(&exec_args_kva_mtx); 1511 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); 1512 mtx_unlock(&exec_args_kva_mtx); 1513 while ((argkva = SLIST_FIRST(&head)) != NULL) { 1514 SLIST_REMOVE_HEAD(&head, next); 1515 exec_release_args_kva(argkva, gen); 1516 } 1517 1518 CPU_FOREACH(i) { 1519 argkva = (void *)atomic_readandclear_ptr( 1520 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); 1521 if (argkva != NULL) 1522 exec_release_args_kva(argkva, gen); 1523 } 1524 } 1525 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, 1526 EVENTHANDLER_PRI_ANY); 1527 1528 /* 1529 * Allocate temporary demand-paged, zero-filled memory for the file name, 1530 * argument, and environment strings. 1531 */ 1532 int 1533 exec_alloc_args(struct image_args *args) 1534 { 1535 1536 args->buf = (char *)exec_alloc_args_kva(&args->bufkva); 1537 return (0); 1538 } 1539 1540 void 1541 exec_free_args(struct image_args *args) 1542 { 1543 1544 if (args->buf != NULL) { 1545 exec_free_args_kva(args->bufkva); 1546 args->buf = NULL; 1547 } 1548 if (args->fname_buf != NULL) { 1549 free(args->fname_buf, M_TEMP); 1550 args->fname_buf = NULL; 1551 } 1552 } 1553 1554 /* 1555 * A set to functions to fill struct image args. 1556 * 1557 * NOTE: exec_args_add_fname() must be called (possibly with a NULL 1558 * fname) before the other functions. All exec_args_add_arg() calls must 1559 * be made before any exec_args_add_env() calls. exec_args_adjust_args() 1560 * may be called any time after exec_args_add_fname(). 1561 * 1562 * exec_args_add_fname() - install path to be executed 1563 * exec_args_add_arg() - append an argument string 1564 * exec_args_add_env() - append an env string 1565 * exec_args_adjust_args() - adjust location of the argument list to 1566 * allow new arguments to be prepended 1567 */ 1568 int 1569 exec_args_add_fname(struct image_args *args, const char *fname, 1570 enum uio_seg segflg) 1571 { 1572 int error; 1573 size_t length; 1574 1575 KASSERT(args->fname == NULL, ("fname already appended")); 1576 KASSERT(args->endp == NULL, ("already appending to args")); 1577 1578 if (fname != NULL) { 1579 args->fname = args->buf; 1580 error = segflg == UIO_SYSSPACE ? 1581 copystr(fname, args->fname, PATH_MAX, &length) : 1582 copyinstr(fname, args->fname, PATH_MAX, &length); 1583 if (error != 0) 1584 return (error == ENAMETOOLONG ? E2BIG : error); 1585 } else 1586 length = 0; 1587 1588 /* Set up for _arg_*()/_env_*() */ 1589 args->endp = args->buf + length; 1590 /* begin_argv must be set and kept updated */ 1591 args->begin_argv = args->endp; 1592 KASSERT(exec_map_entry_size - length >= ARG_MAX, 1593 ("too little space remaining for arguments %zu < %zu", 1594 exec_map_entry_size - length, (size_t)ARG_MAX)); 1595 args->stringspace = ARG_MAX; 1596 1597 return (0); 1598 } 1599 1600 static int 1601 exec_args_add_str(struct image_args *args, const char *str, 1602 enum uio_seg segflg, int *countp) 1603 { 1604 int error; 1605 size_t length; 1606 1607 KASSERT(args->endp != NULL, ("endp not initialized")); 1608 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1609 1610 error = (segflg == UIO_SYSSPACE) ? 1611 copystr(str, args->endp, args->stringspace, &length) : 1612 copyinstr(str, args->endp, args->stringspace, &length); 1613 if (error != 0) 1614 return (error == ENAMETOOLONG ? E2BIG : error); 1615 args->stringspace -= length; 1616 args->endp += length; 1617 (*countp)++; 1618 1619 return (0); 1620 } 1621 1622 int 1623 exec_args_add_arg(struct image_args *args, const char *argp, 1624 enum uio_seg segflg) 1625 { 1626 1627 KASSERT(args->envc == 0, ("appending args after env")); 1628 1629 return (exec_args_add_str(args, argp, segflg, &args->argc)); 1630 } 1631 1632 int 1633 exec_args_add_env(struct image_args *args, const char *envp, 1634 enum uio_seg segflg) 1635 { 1636 1637 if (args->envc == 0) 1638 args->begin_envv = args->endp; 1639 1640 return (exec_args_add_str(args, envp, segflg, &args->envc)); 1641 } 1642 1643 int 1644 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) 1645 { 1646 ssize_t offset; 1647 1648 KASSERT(args->endp != NULL, ("endp not initialized")); 1649 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1650 1651 offset = extend - consume; 1652 if (args->stringspace < offset) 1653 return (E2BIG); 1654 memmove(args->begin_argv + extend, args->begin_argv + consume, 1655 args->endp - args->begin_argv + consume); 1656 if (args->envc > 0) 1657 args->begin_envv += offset; 1658 args->endp += offset; 1659 args->stringspace -= offset; 1660 return (0); 1661 } 1662 1663 char * 1664 exec_args_get_begin_envv(struct image_args *args) 1665 { 1666 1667 KASSERT(args->endp != NULL, ("endp not initialized")); 1668 1669 if (args->envc > 0) 1670 return (args->begin_envv); 1671 return (args->endp); 1672 } 1673 1674 /* 1675 * Copy strings out to the new process address space, constructing new arg 1676 * and env vector tables. Return a pointer to the base so that it can be used 1677 * as the initial stack pointer. 1678 */ 1679 int 1680 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 1681 { 1682 int argc, envc; 1683 char **vectp; 1684 char *stringp; 1685 uintptr_t destp, ustringp; 1686 struct ps_strings *arginfo; 1687 struct proc *p; 1688 struct sysentvec *sysent; 1689 size_t execpath_len; 1690 int error, szsigcode; 1691 char canary[sizeof(long) * 8]; 1692 1693 p = imgp->proc; 1694 sysent = p->p_sysent; 1695 1696 destp = PROC_PS_STRINGS(p); 1697 arginfo = imgp->ps_strings = (void *)destp; 1698 1699 /* 1700 * Install sigcode. 1701 */ 1702 if (sysent->sv_shared_page_base == 0 && sysent->sv_szsigcode != NULL) { 1703 szsigcode = *(sysent->sv_szsigcode); 1704 destp -= szsigcode; 1705 destp = rounddown2(destp, sizeof(void *)); 1706 error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode); 1707 if (error != 0) 1708 return (error); 1709 } 1710 1711 /* 1712 * Copy the image path for the rtld. 1713 */ 1714 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 1715 execpath_len = strlen(imgp->execpath) + 1; 1716 destp -= execpath_len; 1717 destp = rounddown2(destp, sizeof(void *)); 1718 imgp->execpathp = (void *)destp; 1719 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 1720 if (error != 0) 1721 return (error); 1722 } 1723 1724 /* 1725 * Prepare the canary for SSP. 1726 */ 1727 arc4rand(canary, sizeof(canary), 0); 1728 destp -= sizeof(canary); 1729 imgp->canary = (void *)destp; 1730 error = copyout(canary, imgp->canary, sizeof(canary)); 1731 if (error != 0) 1732 return (error); 1733 imgp->canarylen = sizeof(canary); 1734 1735 /* 1736 * Prepare the pagesizes array. 1737 */ 1738 imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES; 1739 destp -= imgp->pagesizeslen; 1740 destp = rounddown2(destp, sizeof(void *)); 1741 imgp->pagesizes = (void *)destp; 1742 error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen); 1743 if (error != 0) 1744 return (error); 1745 1746 /* 1747 * Allocate room for the argument and environment strings. 1748 */ 1749 destp -= ARG_MAX - imgp->args->stringspace; 1750 destp = rounddown2(destp, sizeof(void *)); 1751 ustringp = destp; 1752 1753 if (imgp->auxargs) { 1754 /* 1755 * Allocate room on the stack for the ELF auxargs 1756 * array. It has up to AT_COUNT entries. 1757 */ 1758 destp -= AT_COUNT * sizeof(Elf_Auxinfo); 1759 destp = rounddown2(destp, sizeof(void *)); 1760 } 1761 1762 vectp = (char **)destp; 1763 1764 /* 1765 * Allocate room for the argv[] and env vectors including the 1766 * terminating NULL pointers. 1767 */ 1768 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 1769 1770 /* 1771 * vectp also becomes our initial stack base 1772 */ 1773 *stack_base = (uintptr_t)vectp; 1774 1775 stringp = imgp->args->begin_argv; 1776 argc = imgp->args->argc; 1777 envc = imgp->args->envc; 1778 1779 /* 1780 * Copy out strings - arguments and environment. 1781 */ 1782 error = copyout(stringp, (void *)ustringp, 1783 ARG_MAX - imgp->args->stringspace); 1784 if (error != 0) 1785 return (error); 1786 1787 /* 1788 * Fill in "ps_strings" struct for ps, w, etc. 1789 */ 1790 imgp->argv = vectp; 1791 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 1792 suword32(&arginfo->ps_nargvstr, argc) != 0) 1793 return (EFAULT); 1794 1795 /* 1796 * Fill in argument portion of vector table. 1797 */ 1798 for (; argc > 0; --argc) { 1799 if (suword(vectp++, ustringp) != 0) 1800 return (EFAULT); 1801 while (*stringp++ != 0) 1802 ustringp++; 1803 ustringp++; 1804 } 1805 1806 /* a null vector table pointer separates the argp's from the envp's */ 1807 if (suword(vectp++, 0) != 0) 1808 return (EFAULT); 1809 1810 imgp->envv = vectp; 1811 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 1812 suword32(&arginfo->ps_nenvstr, envc) != 0) 1813 return (EFAULT); 1814 1815 /* 1816 * Fill in environment portion of vector table. 1817 */ 1818 for (; envc > 0; --envc) { 1819 if (suword(vectp++, ustringp) != 0) 1820 return (EFAULT); 1821 while (*stringp++ != 0) 1822 ustringp++; 1823 ustringp++; 1824 } 1825 1826 /* end of vector table is a null pointer */ 1827 if (suword(vectp, 0) != 0) 1828 return (EFAULT); 1829 1830 if (imgp->auxargs) { 1831 vectp++; 1832 error = imgp->sysent->sv_copyout_auxargs(imgp, 1833 (uintptr_t)vectp); 1834 if (error != 0) 1835 return (error); 1836 } 1837 1838 return (0); 1839 } 1840 1841 /* 1842 * Check permissions of file to execute. 1843 * Called with imgp->vp locked. 1844 * Return 0 for success or error code on failure. 1845 */ 1846 int 1847 exec_check_permissions(struct image_params *imgp) 1848 { 1849 struct vnode *vp = imgp->vp; 1850 struct vattr *attr = imgp->attr; 1851 struct thread *td; 1852 int error; 1853 1854 td = curthread; 1855 1856 /* Get file attributes */ 1857 error = VOP_GETATTR(vp, attr, td->td_ucred); 1858 if (error) 1859 return (error); 1860 1861 #ifdef MAC 1862 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); 1863 if (error) 1864 return (error); 1865 #endif 1866 1867 /* 1868 * 1) Check if file execution is disabled for the filesystem that 1869 * this file resides on. 1870 * 2) Ensure that at least one execute bit is on. Otherwise, a 1871 * privileged user will always succeed, and we don't want this 1872 * to happen unless the file really is executable. 1873 * 3) Ensure that the file is a regular file. 1874 */ 1875 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || 1876 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || 1877 (attr->va_type != VREG)) 1878 return (EACCES); 1879 1880 /* 1881 * Zero length files can't be exec'd 1882 */ 1883 if (attr->va_size == 0) 1884 return (ENOEXEC); 1885 1886 /* 1887 * Check for execute permission to file based on current credentials. 1888 */ 1889 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); 1890 if (error) 1891 return (error); 1892 1893 /* 1894 * Check number of open-for-writes on the file and deny execution 1895 * if there are any. 1896 * 1897 * Add a text reference now so no one can write to the 1898 * executable while we're activating it. 1899 * 1900 * Remember if this was set before and unset it in case this is not 1901 * actually an executable image. 1902 */ 1903 error = VOP_SET_TEXT(vp); 1904 if (error != 0) 1905 return (error); 1906 imgp->textset = true; 1907 1908 /* 1909 * Call filesystem specific open routine (which does nothing in the 1910 * general case). 1911 */ 1912 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); 1913 if (error == 0) 1914 imgp->opened = true; 1915 return (error); 1916 } 1917 1918 /* 1919 * Exec handler registration 1920 */ 1921 int 1922 exec_register(const struct execsw *execsw_arg) 1923 { 1924 const struct execsw **es, **xs, **newexecsw; 1925 u_int count = 2; /* New slot and trailing NULL */ 1926 1927 if (execsw) 1928 for (es = execsw; *es; es++) 1929 count++; 1930 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1931 xs = newexecsw; 1932 if (execsw) 1933 for (es = execsw; *es; es++) 1934 *xs++ = *es; 1935 *xs++ = execsw_arg; 1936 *xs = NULL; 1937 if (execsw) 1938 free(execsw, M_TEMP); 1939 execsw = newexecsw; 1940 return (0); 1941 } 1942 1943 int 1944 exec_unregister(const struct execsw *execsw_arg) 1945 { 1946 const struct execsw **es, **xs, **newexecsw; 1947 int count = 1; 1948 1949 if (execsw == NULL) 1950 panic("unregister with no handlers left?\n"); 1951 1952 for (es = execsw; *es; es++) { 1953 if (*es == execsw_arg) 1954 break; 1955 } 1956 if (*es == NULL) 1957 return (ENOENT); 1958 for (es = execsw; *es; es++) 1959 if (*es != execsw_arg) 1960 count++; 1961 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1962 xs = newexecsw; 1963 for (es = execsw; *es; es++) 1964 if (*es != execsw_arg) 1965 *xs++ = *es; 1966 *xs = NULL; 1967 if (execsw) 1968 free(execsw, M_TEMP); 1969 execsw = newexecsw; 1970 return (0); 1971 } 1972 1973 /* 1974 * Write out a core segment to the compression stream. 1975 */ 1976 static int 1977 compress_chunk(struct coredump_params *cp, char *base, char *buf, size_t len) 1978 { 1979 size_t chunk_len; 1980 int error; 1981 1982 error = 0; 1983 while (len > 0) { 1984 chunk_len = MIN(len, CORE_BUF_SIZE); 1985 1986 /* 1987 * We can get EFAULT error here. 1988 * In that case zero out the current chunk of the segment. 1989 */ 1990 error = copyin(base, buf, chunk_len); 1991 if (error != 0) 1992 bzero(buf, chunk_len); 1993 error = compressor_write(cp->comp, buf, chunk_len); 1994 if (error != 0) 1995 break; 1996 base += chunk_len; 1997 len -= chunk_len; 1998 } 1999 return (error); 2000 } 2001 2002 int 2003 core_write(struct coredump_params *cp, const void *base, size_t len, 2004 off_t offset, enum uio_seg seg, size_t *resid) 2005 { 2006 return ((*cp->cdw->write_fn)(cp->cdw, base, len, offset, seg, 2007 cp->active_cred, resid, cp->td)); 2008 } 2009 2010 static int 2011 core_extend(struct coredump_params *cp, off_t newsz) 2012 { 2013 return ((*cp->cdw->extend_fn)(cp->cdw, newsz, cp->active_cred)); 2014 } 2015 2016 int 2017 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp, 2018 void *tmpbuf) 2019 { 2020 vm_map_t map; 2021 size_t resid, runlen; 2022 int error; 2023 bool success; 2024 2025 KASSERT((uintptr_t)base % PAGE_SIZE == 0, 2026 ("%s: user address %p is not page-aligned", __func__, base)); 2027 2028 if (cp->comp != NULL) 2029 return (compress_chunk(cp, base, tmpbuf, len)); 2030 2031 error = 0; 2032 map = &cp->td->td_proc->p_vmspace->vm_map; 2033 for (; len > 0; base += runlen, offset += runlen, len -= runlen) { 2034 /* 2035 * Attempt to page in all virtual pages in the range. If a 2036 * virtual page is not backed by the pager, it is represented as 2037 * a hole in the file. This can occur with zero-filled 2038 * anonymous memory or truncated files, for example. 2039 */ 2040 for (runlen = 0; runlen < len; runlen += PAGE_SIZE) { 2041 if (core_dump_can_intr && curproc_sigkilled()) 2042 return (EINTR); 2043 error = vm_fault(map, (uintptr_t)base + runlen, 2044 VM_PROT_READ, VM_FAULT_NOFILL, NULL); 2045 if (runlen == 0) 2046 success = error == KERN_SUCCESS; 2047 else if ((error == KERN_SUCCESS) != success) 2048 break; 2049 } 2050 2051 if (success) { 2052 error = core_write(cp, base, runlen, offset, 2053 UIO_USERSPACE, &resid); 2054 if (error != 0) { 2055 if (error != EFAULT) 2056 break; 2057 2058 /* 2059 * EFAULT may be returned if the user mapping 2060 * could not be accessed, e.g., because a mapped 2061 * file has been truncated. Skip the page if no 2062 * progress was made, to protect against a 2063 * hypothetical scenario where vm_fault() was 2064 * successful but core_write() returns EFAULT 2065 * anyway. 2066 */ 2067 runlen -= resid; 2068 if (runlen == 0) { 2069 success = false; 2070 runlen = PAGE_SIZE; 2071 } 2072 } 2073 } 2074 if (!success) { 2075 error = core_extend(cp, offset + runlen); 2076 if (error != 0) 2077 break; 2078 } 2079 } 2080 return (error); 2081 } 2082 2083 /* 2084 * Drain into a core file. 2085 */ 2086 int 2087 sbuf_drain_core_output(void *arg, const char *data, int len) 2088 { 2089 struct coredump_params *cp; 2090 struct proc *p; 2091 int error, locked; 2092 2093 cp = arg; 2094 p = cp->td->td_proc; 2095 2096 /* 2097 * Some kern_proc out routines that print to this sbuf may 2098 * call us with the process lock held. Draining with the 2099 * non-sleepable lock held is unsafe. The lock is needed for 2100 * those routines when dumping a live process. In our case we 2101 * can safely release the lock before draining and acquire 2102 * again after. 2103 */ 2104 locked = PROC_LOCKED(p); 2105 if (locked) 2106 PROC_UNLOCK(p); 2107 if (cp->comp != NULL) 2108 error = compressor_write(cp->comp, __DECONST(char *, data), 2109 len); 2110 else 2111 error = core_write(cp, __DECONST(void *, data), len, cp->offset, 2112 UIO_SYSSPACE, NULL); 2113 if (locked) 2114 PROC_LOCK(p); 2115 if (error != 0) 2116 return (-error); 2117 cp->offset += len; 2118 return (len); 2119 } 2120