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