1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1993, David Greenman 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 #include "opt_capsicum.h" 31 #include "opt_hwpmc_hooks.h" 32 #include "opt_ktrace.h" 33 #include "opt_vm.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/acct.h> 38 #include <sys/asan.h> 39 #include <sys/capsicum.h> 40 #include <sys/compressor.h> 41 #include <sys/eventhandler.h> 42 #include <sys/exec.h> 43 #include <sys/fcntl.h> 44 #include <sys/filedesc.h> 45 #include <sys/imgact.h> 46 #include <sys/imgact_elf.h> 47 #include <sys/kernel.h> 48 #include <sys/lock.h> 49 #include <sys/malloc.h> 50 #include <sys/mman.h> 51 #include <sys/mount.h> 52 #include <sys/mutex.h> 53 #include <sys/namei.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/ptrace.h> 57 #include <sys/reg.h> 58 #include <sys/resourcevar.h> 59 #include <sys/rwlock.h> 60 #include <sys/sched.h> 61 #include <sys/sdt.h> 62 #include <sys/sf_buf.h> 63 #include <sys/shm.h> 64 #include <sys/signalvar.h> 65 #include <sys/smp.h> 66 #include <sys/stat.h> 67 #include <sys/syscallsubr.h> 68 #include <sys/sysctl.h> 69 #include <sys/sysent.h> 70 #include <sys/sysproto.h> 71 #include <sys/timers.h> 72 #include <sys/umtxvar.h> 73 #include <sys/vnode.h> 74 #include <sys/wait.h> 75 #ifdef KTRACE 76 #include <sys/ktrace.h> 77 #endif 78 79 #include <vm/vm.h> 80 #include <vm/vm_param.h> 81 #include <vm/pmap.h> 82 #include <vm/vm_page.h> 83 #include <vm/vm_map.h> 84 #include <vm/vm_kern.h> 85 #include <vm/vm_extern.h> 86 #include <vm/vm_object.h> 87 #include <vm/vm_pager.h> 88 89 #ifdef HWPMC_HOOKS 90 #include <sys/pmckern.h> 91 #endif 92 93 #include <security/audit/audit.h> 94 #include <security/mac/mac_framework.h> 95 96 #ifdef KDTRACE_HOOKS 97 #include <sys/dtrace_bsd.h> 98 dtrace_execexit_func_t dtrace_fasttrap_exec; 99 #endif 100 101 SDT_PROVIDER_DECLARE(proc); 102 SDT_PROBE_DEFINE1(proc, , , exec, "char *"); 103 SDT_PROBE_DEFINE1(proc, , , exec__failure, "int"); 104 SDT_PROBE_DEFINE1(proc, , , exec__success, "char *"); 105 106 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments"); 107 108 int coredump_pack_fileinfo = 1; 109 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN, 110 &coredump_pack_fileinfo, 0, 111 "Enable file path packing in 'procstat -f' coredump notes"); 112 113 int coredump_pack_vmmapinfo = 1; 114 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN, 115 &coredump_pack_vmmapinfo, 0, 116 "Enable file path packing in 'procstat -v' coredump notes"); 117 118 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS); 119 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS); 120 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS); 121 static int do_execve(struct thread *td, struct image_args *args, 122 struct mac *mac_p, struct vmspace *oldvmspace); 123 124 /* XXX This should be vm_size_t. */ 125 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD| 126 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU", 127 "Location of process' ps_strings structure"); 128 129 /* XXX This should be vm_size_t. */ 130 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD| 131 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU", 132 "Top of process stack"); 133 134 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE, 135 NULL, 0, sysctl_kern_stackprot, "I", 136 "Stack memory permissions"); 137 138 u_long ps_arg_cache_limit = PAGE_SIZE / 16; 139 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW, 140 &ps_arg_cache_limit, 0, 141 "Process' command line characters cache limit"); 142 143 static int disallow_high_osrel; 144 SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW, 145 &disallow_high_osrel, 0, 146 "Disallow execution of binaries built for higher version of the world"); 147 148 static int map_at_zero = 0; 149 SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0, 150 "Permit processes to map an object at virtual address 0."); 151 152 static int core_dump_can_intr = 1; 153 SYSCTL_INT(_kern, OID_AUTO, core_dump_can_intr, CTLFLAG_RWTUN, 154 &core_dump_can_intr, 0, 155 "Core dumping interruptible with SIGKILL"); 156 157 static int 158 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS) 159 { 160 struct proc *p; 161 vm_offset_t ps_strings; 162 163 p = curproc; 164 #ifdef SCTL_MASK32 165 if (req->flags & SCTL_MASK32) { 166 unsigned int val; 167 val = (unsigned int)PROC_PS_STRINGS(p); 168 return (SYSCTL_OUT(req, &val, sizeof(val))); 169 } 170 #endif 171 ps_strings = PROC_PS_STRINGS(p); 172 return (SYSCTL_OUT(req, &ps_strings, sizeof(ps_strings))); 173 } 174 175 static int 176 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS) 177 { 178 struct proc *p; 179 vm_offset_t val; 180 181 p = curproc; 182 #ifdef SCTL_MASK32 183 if (req->flags & SCTL_MASK32) { 184 unsigned int val32; 185 186 val32 = round_page((unsigned int)p->p_vmspace->vm_stacktop); 187 return (SYSCTL_OUT(req, &val32, sizeof(val32))); 188 } 189 #endif 190 val = round_page(p->p_vmspace->vm_stacktop); 191 return (SYSCTL_OUT(req, &val, sizeof(val))); 192 } 193 194 static int 195 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS) 196 { 197 struct proc *p; 198 199 p = curproc; 200 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot, 201 sizeof(p->p_sysent->sv_stackprot))); 202 } 203 204 /* 205 * Each of the items is a pointer to a `const struct execsw', hence the 206 * double pointer here. 207 */ 208 static const struct execsw **execsw; 209 210 #ifndef _SYS_SYSPROTO_H_ 211 struct execve_args { 212 char *fname; 213 char **argv; 214 char **envv; 215 }; 216 #endif 217 218 int 219 sys_execve(struct thread *td, struct execve_args *uap) 220 { 221 struct image_args args; 222 struct vmspace *oldvmspace; 223 int error; 224 225 error = pre_execve(td, &oldvmspace); 226 if (error != 0) 227 return (error); 228 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, 229 uap->argv, uap->envv); 230 if (error == 0) 231 error = kern_execve(td, &args, NULL, oldvmspace); 232 post_execve(td, error, oldvmspace); 233 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 234 return (error); 235 } 236 237 #ifndef _SYS_SYSPROTO_H_ 238 struct fexecve_args { 239 int fd; 240 char **argv; 241 char **envv; 242 }; 243 #endif 244 int 245 sys_fexecve(struct thread *td, struct fexecve_args *uap) 246 { 247 struct image_args args; 248 struct vmspace *oldvmspace; 249 int error; 250 251 error = pre_execve(td, &oldvmspace); 252 if (error != 0) 253 return (error); 254 error = exec_copyin_args(&args, NULL, UIO_SYSSPACE, 255 uap->argv, uap->envv); 256 if (error == 0) { 257 args.fd = uap->fd; 258 error = kern_execve(td, &args, NULL, oldvmspace); 259 } 260 post_execve(td, error, oldvmspace); 261 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 262 return (error); 263 } 264 265 #ifndef _SYS_SYSPROTO_H_ 266 struct __mac_execve_args { 267 char *fname; 268 char **argv; 269 char **envv; 270 struct mac *mac_p; 271 }; 272 #endif 273 274 int 275 sys___mac_execve(struct thread *td, struct __mac_execve_args *uap) 276 { 277 #ifdef MAC 278 struct image_args args; 279 struct vmspace *oldvmspace; 280 int error; 281 282 error = pre_execve(td, &oldvmspace); 283 if (error != 0) 284 return (error); 285 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, 286 uap->argv, uap->envv); 287 if (error == 0) 288 error = kern_execve(td, &args, uap->mac_p, oldvmspace); 289 post_execve(td, error, oldvmspace); 290 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 291 return (error); 292 #else 293 return (ENOSYS); 294 #endif 295 } 296 297 int 298 pre_execve(struct thread *td, struct vmspace **oldvmspace) 299 { 300 struct proc *p; 301 int error; 302 303 KASSERT(td == curthread, ("non-current thread %p", td)); 304 error = 0; 305 p = td->td_proc; 306 if ((p->p_flag & P_HADTHREADS) != 0) { 307 PROC_LOCK(p); 308 if (thread_single(p, SINGLE_BOUNDARY) != 0) 309 error = ERESTART; 310 PROC_UNLOCK(p); 311 } 312 KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0, 313 ("nested execve")); 314 *oldvmspace = p->p_vmspace; 315 return (error); 316 } 317 318 void 319 post_execve(struct thread *td, int error, struct vmspace *oldvmspace) 320 { 321 struct proc *p; 322 323 KASSERT(td == curthread, ("non-current thread %p", td)); 324 p = td->td_proc; 325 if ((p->p_flag & P_HADTHREADS) != 0) { 326 PROC_LOCK(p); 327 /* 328 * If success, we upgrade to SINGLE_EXIT state to 329 * force other threads to suicide. 330 */ 331 if (error == EJUSTRETURN) 332 thread_single(p, SINGLE_EXIT); 333 else 334 thread_single_end(p, SINGLE_BOUNDARY); 335 PROC_UNLOCK(p); 336 } 337 exec_cleanup(td, oldvmspace); 338 } 339 340 /* 341 * kern_execve() has the astonishing property of not always returning to 342 * the caller. If sufficiently bad things happen during the call to 343 * do_execve(), it can end up calling exit1(); as a result, callers must 344 * avoid doing anything which they might need to undo (e.g., allocating 345 * memory). 346 */ 347 int 348 kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 349 struct vmspace *oldvmspace) 350 { 351 352 TSEXEC(td->td_proc->p_pid, args->begin_argv); 353 AUDIT_ARG_ARGV(args->begin_argv, args->argc, 354 exec_args_get_begin_envv(args) - args->begin_argv); 355 AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc, 356 args->endp - exec_args_get_begin_envv(args)); 357 358 /* Must have at least one argument. */ 359 if (args->argc == 0) { 360 exec_free_args(args); 361 return (EINVAL); 362 } 363 return (do_execve(td, args, mac_p, oldvmspace)); 364 } 365 366 static void 367 execve_nosetid(struct image_params *imgp) 368 { 369 imgp->credential_setid = false; 370 if (imgp->newcred != NULL) { 371 crfree(imgp->newcred); 372 imgp->newcred = NULL; 373 } 374 } 375 376 /* 377 * In-kernel implementation of execve(). All arguments are assumed to be 378 * userspace pointers from the passed thread. 379 */ 380 static int 381 do_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 382 struct vmspace *oldvmspace) 383 { 384 struct proc *p = td->td_proc; 385 struct nameidata nd; 386 struct ucred *oldcred; 387 struct uidinfo *euip = NULL; 388 uintptr_t stack_base; 389 struct image_params image_params, *imgp; 390 struct vattr attr; 391 struct pargs *oldargs = NULL, *newargs = NULL; 392 struct sigacts *oldsigacts = NULL, *newsigacts = NULL; 393 #ifdef KTRACE 394 struct ktr_io_params *kiop; 395 #endif 396 struct vnode *oldtextvp, *newtextvp; 397 struct vnode *oldtextdvp, *newtextdvp; 398 char *oldbinname, *newbinname; 399 bool credential_changing; 400 #ifdef MAC 401 struct label *interpvplabel = NULL; 402 bool will_transition; 403 #endif 404 #ifdef HWPMC_HOOKS 405 struct pmckern_procexec pe; 406 #endif 407 int error, i, orig_osrel; 408 uint32_t orig_fctl0; 409 Elf_Brandinfo *orig_brandinfo; 410 size_t freepath_size; 411 static const char fexecv_proc_title[] = "(fexecv)"; 412 413 imgp = &image_params; 414 oldtextvp = oldtextdvp = NULL; 415 newtextvp = newtextdvp = NULL; 416 newbinname = oldbinname = NULL; 417 #ifdef KTRACE 418 kiop = NULL; 419 #endif 420 421 /* 422 * Lock the process and set the P_INEXEC flag to indicate that 423 * it should be left alone until we're done here. This is 424 * necessary to avoid race conditions - e.g. in ptrace() - 425 * that might allow a local user to illicitly obtain elevated 426 * privileges. 427 */ 428 PROC_LOCK(p); 429 KASSERT((p->p_flag & P_INEXEC) == 0, 430 ("%s(): process already has P_INEXEC flag", __func__)); 431 p->p_flag |= P_INEXEC; 432 PROC_UNLOCK(p); 433 434 /* 435 * Initialize part of the common data 436 */ 437 bzero(imgp, sizeof(*imgp)); 438 imgp->proc = p; 439 imgp->attr = &attr; 440 imgp->args = args; 441 oldcred = p->p_ucred; 442 orig_osrel = p->p_osrel; 443 orig_fctl0 = p->p_fctl0; 444 orig_brandinfo = p->p_elf_brandinfo; 445 446 #ifdef MAC 447 error = mac_execve_enter(imgp, mac_p); 448 if (error) 449 goto exec_fail; 450 #endif 451 452 SDT_PROBE1(proc, , , exec, args->fname); 453 454 interpret: 455 if (args->fname != NULL) { 456 #ifdef CAPABILITY_MODE 457 if (CAP_TRACING(td)) 458 ktrcapfail(CAPFAIL_NAMEI, args->fname); 459 /* 460 * While capability mode can't reach this point via direct 461 * path arguments to execve(), we also don't allow 462 * interpreters to be used in capability mode (for now). 463 * Catch indirect lookups and return a permissions error. 464 */ 465 if (IN_CAPABILITY_MODE(td)) { 466 error = ECAPMODE; 467 goto exec_fail; 468 } 469 #endif 470 471 /* 472 * Translate the file name. namei() returns a vnode 473 * pointer in ni_vp among other things. 474 */ 475 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | 476 AUDITVNODE1 | WANTPARENT, UIO_SYSSPACE, 477 args->fname); 478 479 error = namei(&nd); 480 if (error) 481 goto exec_fail; 482 483 newtextvp = nd.ni_vp; 484 newtextdvp = nd.ni_dvp; 485 nd.ni_dvp = NULL; 486 newbinname = malloc(nd.ni_cnd.cn_namelen + 1, M_PARGS, 487 M_WAITOK); 488 memcpy(newbinname, nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 489 newbinname[nd.ni_cnd.cn_namelen] = '\0'; 490 imgp->vp = newtextvp; 491 492 /* 493 * Do the best to calculate the full path to the image file. 494 */ 495 if (args->fname[0] == '/') { 496 imgp->execpath = args->fname; 497 } else { 498 VOP_UNLOCK(imgp->vp); 499 freepath_size = MAXPATHLEN; 500 if (vn_fullpath_hardlink(newtextvp, newtextdvp, 501 newbinname, nd.ni_cnd.cn_namelen, &imgp->execpath, 502 &imgp->freepath, &freepath_size) != 0) 503 imgp->execpath = args->fname; 504 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 505 } 506 } else if (imgp->interpreter_vp) { 507 /* 508 * An image activator has already provided an open vnode 509 */ 510 newtextvp = imgp->interpreter_vp; 511 imgp->interpreter_vp = NULL; 512 if (vn_fullpath(newtextvp, &imgp->execpath, 513 &imgp->freepath) != 0) 514 imgp->execpath = args->fname; 515 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 516 AUDIT_ARG_VNODE1(newtextvp); 517 imgp->vp = newtextvp; 518 } else { 519 AUDIT_ARG_FD(args->fd); 520 521 /* 522 * If the descriptors was not opened with O_PATH, then 523 * we require that it was opened with O_EXEC or 524 * O_RDONLY. In either case, exec_check_permissions() 525 * below checks _current_ file access mode regardless 526 * of the permissions additionally checked at the 527 * open(2). 528 */ 529 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, 530 &newtextvp); 531 if (error != 0) 532 goto exec_fail; 533 534 if (vn_fullpath(newtextvp, &imgp->execpath, 535 &imgp->freepath) != 0) 536 imgp->execpath = args->fname; 537 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 538 AUDIT_ARG_VNODE1(newtextvp); 539 imgp->vp = newtextvp; 540 } 541 542 /* 543 * Check file permissions. Also 'opens' file and sets its vnode to 544 * text mode. 545 */ 546 error = exec_check_permissions(imgp); 547 if (error) 548 goto exec_fail_dealloc; 549 550 imgp->object = imgp->vp->v_object; 551 if (imgp->object != NULL) 552 vm_object_reference(imgp->object); 553 554 error = exec_map_first_page(imgp); 555 if (error) 556 goto exec_fail_dealloc; 557 558 imgp->proc->p_osrel = 0; 559 imgp->proc->p_fctl0 = 0; 560 imgp->proc->p_elf_brandinfo = NULL; 561 562 /* 563 * Implement image setuid/setgid. 564 * 565 * Determine new credentials before attempting image activators 566 * so that it can be used by process_exec handlers to determine 567 * credential/setid changes. 568 * 569 * Don't honor setuid/setgid if the filesystem prohibits it or if 570 * the process is being traced. 571 * 572 * We disable setuid/setgid/etc in capability mode on the basis 573 * that most setugid applications are not written with that 574 * environment in mind, and will therefore almost certainly operate 575 * incorrectly. In principle there's no reason that setugid 576 * applications might not be useful in capability mode, so we may want 577 * to reconsider this conservative design choice in the future. 578 * 579 * XXXMAC: For the time being, use NOSUID to also prohibit 580 * transitions on the file system. 581 */ 582 credential_changing = false; 583 credential_changing |= (attr.va_mode & S_ISUID) && 584 oldcred->cr_uid != attr.va_uid; 585 credential_changing |= (attr.va_mode & S_ISGID) && 586 oldcred->cr_gid != attr.va_gid; 587 #ifdef MAC 588 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp, 589 interpvplabel, imgp) != 0; 590 credential_changing |= will_transition; 591 #endif 592 593 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */ 594 if (credential_changing) 595 imgp->proc->p_pdeathsig = 0; 596 597 if (credential_changing && 598 #ifdef CAPABILITY_MODE 599 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) && 600 #endif 601 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 && 602 (p->p_flag & P_TRACED) == 0) { 603 imgp->credential_setid = true; 604 VOP_UNLOCK(imgp->vp); 605 imgp->newcred = crdup(oldcred); 606 if (attr.va_mode & S_ISUID) { 607 euip = uifind(attr.va_uid); 608 change_euid(imgp->newcred, euip); 609 } 610 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 611 if (attr.va_mode & S_ISGID) 612 change_egid(imgp->newcred, attr.va_gid); 613 /* 614 * Implement correct POSIX saved-id behavior. 615 * 616 * XXXMAC: Note that the current logic will save the 617 * uid and gid if a MAC domain transition occurs, even 618 * though maybe it shouldn't. 619 */ 620 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 621 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 622 } else { 623 /* 624 * Implement correct POSIX saved-id behavior. 625 * 626 * XXX: It's not clear that the existing behavior is 627 * POSIX-compliant. A number of sources indicate that the 628 * saved uid/gid should only be updated if the new ruid is 629 * not equal to the old ruid, or the new euid is not equal 630 * to the old euid and the new euid is not equal to the old 631 * ruid. The FreeBSD code always updates the saved uid/gid. 632 * Also, this code uses the new (replaced) euid and egid as 633 * the source, which may or may not be the right ones to use. 634 */ 635 if (oldcred->cr_svuid != oldcred->cr_uid || 636 oldcred->cr_svgid != oldcred->cr_gid) { 637 VOP_UNLOCK(imgp->vp); 638 imgp->newcred = crdup(oldcred); 639 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 640 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 641 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 642 } 643 } 644 /* The new credentials are installed into the process later. */ 645 646 /* 647 * Loop through the list of image activators, calling each one. 648 * An activator returns -1 if there is no match, 0 on success, 649 * and an error otherwise. 650 */ 651 error = -1; 652 for (i = 0; error == -1 && execsw[i]; ++i) { 653 if (execsw[i]->ex_imgact == NULL) 654 continue; 655 error = (*execsw[i]->ex_imgact)(imgp); 656 } 657 658 if (error) { 659 if (error == -1) 660 error = ENOEXEC; 661 goto exec_fail_dealloc; 662 } 663 664 /* 665 * Special interpreter operation, cleanup and loop up to try to 666 * activate the interpreter. 667 */ 668 if (imgp->interpreted) { 669 exec_unmap_first_page(imgp); 670 /* 671 * The text reference needs to be removed for scripts. 672 * There is a short period before we determine that 673 * something is a script where text reference is active. 674 * The vnode lock is held over this entire period 675 * so nothing should illegitimately be blocked. 676 */ 677 MPASS(imgp->textset); 678 VOP_UNSET_TEXT_CHECKED(newtextvp); 679 imgp->textset = false; 680 /* free name buffer and old vnode */ 681 #ifdef MAC 682 mac_execve_interpreter_enter(newtextvp, &interpvplabel); 683 #endif 684 if (imgp->opened) { 685 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td); 686 imgp->opened = false; 687 } 688 vput(newtextvp); 689 imgp->vp = newtextvp = NULL; 690 if (args->fname != NULL) { 691 if (newtextdvp != NULL) { 692 vrele(newtextdvp); 693 newtextdvp = NULL; 694 } 695 NDFREE_PNBUF(&nd); 696 free(newbinname, M_PARGS); 697 newbinname = NULL; 698 } 699 vm_object_deallocate(imgp->object); 700 imgp->object = NULL; 701 execve_nosetid(imgp); 702 imgp->execpath = NULL; 703 free(imgp->freepath, M_TEMP); 704 imgp->freepath = NULL; 705 /* set new name to that of the interpreter */ 706 if (imgp->interpreter_vp) { 707 args->fname = NULL; 708 } else { 709 args->fname = imgp->interpreter_name; 710 } 711 goto interpret; 712 } 713 714 /* 715 * NB: We unlock the vnode here because it is believed that none 716 * of the sv_copyout_strings/sv_fixup operations require the vnode. 717 */ 718 VOP_UNLOCK(imgp->vp); 719 720 if (disallow_high_osrel && 721 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { 722 error = ENOEXEC; 723 uprintf("Osrel %d for image %s too high\n", p->p_osrel, 724 imgp->execpath != NULL ? imgp->execpath : "<unresolved>"); 725 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 726 goto exec_fail_dealloc; 727 } 728 729 /* 730 * Copy out strings (args and env) and initialize stack base. 731 */ 732 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); 733 if (error != 0) { 734 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 735 goto exec_fail_dealloc; 736 } 737 738 /* 739 * Stack setup. 740 */ 741 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); 742 if (error != 0) { 743 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 744 goto exec_fail_dealloc; 745 } 746 747 /* 748 * For security and other reasons, the file descriptor table cannot be 749 * shared after an exec. 750 */ 751 fdunshare(td); 752 pdunshare(td); 753 /* close files on exec */ 754 fdcloseexec(td); 755 756 /* 757 * Malloc things before we need locks. 758 */ 759 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; 760 /* Cache arguments if they fit inside our allowance */ 761 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { 762 newargs = pargs_alloc(i); 763 bcopy(imgp->args->begin_argv, newargs->ar_args, i); 764 } 765 766 /* 767 * For security and other reasons, signal handlers cannot 768 * be shared after an exec. The new process gets a copy of the old 769 * handlers. In execsigs(), the new process will have its signals 770 * reset. 771 */ 772 if (sigacts_shared(p->p_sigacts)) { 773 oldsigacts = p->p_sigacts; 774 newsigacts = sigacts_alloc(); 775 sigacts_copy(newsigacts, oldsigacts); 776 } 777 778 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 779 780 PROC_LOCK(p); 781 if (oldsigacts) 782 p->p_sigacts = newsigacts; 783 /* Stop profiling */ 784 stopprofclock(p); 785 786 /* reset caught signals */ 787 execsigs(p); 788 789 /* name this process - nameiexec(p, ndp) */ 790 bzero(p->p_comm, sizeof(p->p_comm)); 791 if (args->fname) 792 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, 793 min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); 794 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) 795 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); 796 bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); 797 #ifdef KTR 798 sched_clear_tdname(td); 799 #endif 800 801 /* 802 * mark as execed, wakeup the process that vforked (if any) and tell 803 * it that it now has its own resources back 804 */ 805 p->p_flag |= P_EXEC; 806 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) 807 p->p_flag2 &= ~P2_NOTRACE; 808 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) 809 p->p_flag2 &= ~P2_STKGAP_DISABLE; 810 p->p_flag2 &= ~(P2_MEMBAR_PRIVE | P2_MEMBAR_PRIVE_SYNCORE | 811 P2_MEMBAR_GLOBE); 812 if (p->p_flag & P_PPWAIT) { 813 p->p_flag &= ~(P_PPWAIT | P_PPTRACE); 814 cv_broadcast(&p->p_pwait); 815 /* STOPs are no longer ignored, arrange for AST */ 816 signotify(td); 817 } 818 819 if ((imgp->sysent->sv_setid_allowed != NULL && 820 !(*imgp->sysent->sv_setid_allowed)(td, imgp)) || 821 (p->p_flag2 & P2_NO_NEW_PRIVS) != 0) 822 execve_nosetid(imgp); 823 824 /* 825 * Implement image setuid/setgid installation. 826 */ 827 if (imgp->credential_setid) { 828 /* 829 * Turn off syscall tracing for set-id programs, except for 830 * root. Record any set-id flags first to make sure that 831 * we do not regain any tracing during a possible block. 832 */ 833 setsugid(p); 834 #ifdef KTRACE 835 kiop = ktrprocexec(p); 836 #endif 837 /* 838 * Close any file descriptors 0..2 that reference procfs, 839 * then make sure file descriptors 0..2 are in use. 840 * 841 * Both fdsetugidsafety() and fdcheckstd() may call functions 842 * taking sleepable locks, so temporarily drop our locks. 843 */ 844 PROC_UNLOCK(p); 845 VOP_UNLOCK(imgp->vp); 846 fdsetugidsafety(td); 847 error = fdcheckstd(td); 848 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 849 if (error != 0) 850 goto exec_fail_dealloc; 851 PROC_LOCK(p); 852 #ifdef MAC 853 if (will_transition) { 854 mac_vnode_execve_transition(oldcred, imgp->newcred, 855 imgp->vp, interpvplabel, imgp); 856 } 857 #endif 858 } else { 859 if (oldcred->cr_uid == oldcred->cr_ruid && 860 oldcred->cr_gid == oldcred->cr_rgid) 861 p->p_flag &= ~P_SUGID; 862 } 863 /* 864 * Set the new credentials. 865 */ 866 if (imgp->newcred != NULL) { 867 proc_set_cred(p, imgp->newcred); 868 crfree(oldcred); 869 oldcred = NULL; 870 } 871 872 /* 873 * Store the vp for use in kern.proc.pathname. This vnode was 874 * referenced by namei() or by fexecve variant of fname handling. 875 */ 876 oldtextvp = p->p_textvp; 877 p->p_textvp = newtextvp; 878 oldtextdvp = p->p_textdvp; 879 p->p_textdvp = newtextdvp; 880 newtextdvp = NULL; 881 oldbinname = p->p_binname; 882 p->p_binname = newbinname; 883 newbinname = NULL; 884 885 #ifdef KDTRACE_HOOKS 886 /* 887 * Tell the DTrace fasttrap provider about the exec if it 888 * has declared an interest. 889 */ 890 if (dtrace_fasttrap_exec) 891 dtrace_fasttrap_exec(p); 892 #endif 893 894 /* 895 * Notify others that we exec'd, and clear the P_INEXEC flag 896 * as we're now a bona fide freshly-execed process. 897 */ 898 KNOTE_LOCKED(p->p_klist, NOTE_EXEC); 899 p->p_flag &= ~P_INEXEC; 900 901 /* clear "fork but no exec" flag, as we _are_ execing */ 902 p->p_acflag &= ~AFORK; 903 904 /* 905 * Free any previous argument cache and replace it with 906 * the new argument cache, if any. 907 */ 908 oldargs = p->p_args; 909 p->p_args = newargs; 910 newargs = NULL; 911 912 PROC_UNLOCK(p); 913 914 #ifdef HWPMC_HOOKS 915 /* 916 * Check if system-wide sampling is in effect or if the 917 * current process is using PMCs. If so, do exec() time 918 * processing. This processing needs to happen AFTER the 919 * P_INEXEC flag is cleared. 920 */ 921 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { 922 VOP_UNLOCK(imgp->vp); 923 pe.pm_credentialschanged = credential_changing; 924 pe.pm_baseaddr = imgp->reloc_base; 925 pe.pm_dynaddr = imgp->et_dyn_addr; 926 927 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); 928 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 929 } 930 #endif 931 932 /* Set values passed into the program in registers. */ 933 (*p->p_sysent->sv_setregs)(td, imgp, stack_base); 934 935 VOP_MMAPPED(imgp->vp); 936 937 SDT_PROBE1(proc, , , exec__success, args->fname); 938 939 exec_fail_dealloc: 940 if (error != 0) { 941 p->p_osrel = orig_osrel; 942 p->p_fctl0 = orig_fctl0; 943 p->p_elf_brandinfo = orig_brandinfo; 944 } 945 946 if (imgp->firstpage != NULL) 947 exec_unmap_first_page(imgp); 948 949 if (imgp->vp != NULL) { 950 if (imgp->opened) 951 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); 952 if (imgp->textset) 953 VOP_UNSET_TEXT_CHECKED(imgp->vp); 954 if (error != 0) 955 vput(imgp->vp); 956 else 957 VOP_UNLOCK(imgp->vp); 958 if (args->fname != NULL) 959 NDFREE_PNBUF(&nd); 960 if (newtextdvp != NULL) 961 vrele(newtextdvp); 962 free(newbinname, M_PARGS); 963 } 964 965 if (imgp->object != NULL) 966 vm_object_deallocate(imgp->object); 967 968 free(imgp->freepath, M_TEMP); 969 970 if (error == 0) { 971 if (p->p_ptevents & PTRACE_EXEC) { 972 PROC_LOCK(p); 973 if (p->p_ptevents & PTRACE_EXEC) 974 td->td_dbgflags |= TDB_EXEC; 975 PROC_UNLOCK(p); 976 } 977 } else { 978 exec_fail: 979 /* we're done here, clear P_INEXEC */ 980 PROC_LOCK(p); 981 p->p_flag &= ~P_INEXEC; 982 PROC_UNLOCK(p); 983 984 SDT_PROBE1(proc, , , exec__failure, error); 985 } 986 987 if (imgp->newcred != NULL && oldcred != NULL) 988 crfree(imgp->newcred); 989 990 #ifdef MAC 991 mac_execve_exit(imgp); 992 mac_execve_interpreter_exit(interpvplabel); 993 #endif 994 exec_free_args(args); 995 996 /* 997 * Handle deferred decrement of ref counts. 998 */ 999 if (oldtextvp != NULL) 1000 vrele(oldtextvp); 1001 if (oldtextdvp != NULL) 1002 vrele(oldtextdvp); 1003 free(oldbinname, M_PARGS); 1004 #ifdef KTRACE 1005 ktr_io_params_free(kiop); 1006 #endif 1007 pargs_drop(oldargs); 1008 pargs_drop(newargs); 1009 if (oldsigacts != NULL) 1010 sigacts_free(oldsigacts); 1011 if (euip != NULL) 1012 uifree(euip); 1013 1014 if (error && imgp->vmspace_destroyed) { 1015 /* sorry, no more process anymore. exit gracefully */ 1016 exec_cleanup(td, oldvmspace); 1017 exit1(td, 0, SIGABRT); 1018 /* NOT REACHED */ 1019 } 1020 1021 #ifdef KTRACE 1022 if (error == 0) 1023 ktrprocctor(p); 1024 #endif 1025 1026 /* 1027 * We don't want cpu_set_syscall_retval() to overwrite any of 1028 * the register values put in place by exec_setregs(). 1029 * Implementations of cpu_set_syscall_retval() will leave 1030 * registers unmodified when returning EJUSTRETURN. 1031 */ 1032 return (error == 0 ? EJUSTRETURN : error); 1033 } 1034 1035 void 1036 exec_cleanup(struct thread *td, struct vmspace *oldvmspace) 1037 { 1038 if ((td->td_pflags & TDP_EXECVMSPC) != 0) { 1039 KASSERT(td->td_proc->p_vmspace != oldvmspace, 1040 ("oldvmspace still used")); 1041 vmspace_free(oldvmspace); 1042 td->td_pflags &= ~TDP_EXECVMSPC; 1043 } 1044 } 1045 1046 int 1047 exec_map_first_page(struct image_params *imgp) 1048 { 1049 vm_object_t object; 1050 vm_page_t m; 1051 int error; 1052 1053 if (imgp->firstpage != NULL) 1054 exec_unmap_first_page(imgp); 1055 1056 object = imgp->vp->v_object; 1057 if (object == NULL) 1058 return (EACCES); 1059 #if VM_NRESERVLEVEL > 0 1060 if ((object->flags & OBJ_COLORED) == 0) { 1061 VM_OBJECT_WLOCK(object); 1062 vm_object_color(object, 0); 1063 VM_OBJECT_WUNLOCK(object); 1064 } 1065 #endif 1066 error = vm_page_grab_valid_unlocked(&m, object, 0, 1067 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | 1068 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 1069 1070 if (error != VM_PAGER_OK) 1071 return (EIO); 1072 imgp->firstpage = sf_buf_alloc(m, 0); 1073 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); 1074 1075 return (0); 1076 } 1077 1078 void 1079 exec_unmap_first_page(struct image_params *imgp) 1080 { 1081 vm_page_t m; 1082 1083 if (imgp->firstpage != NULL) { 1084 m = sf_buf_page(imgp->firstpage); 1085 sf_buf_free(imgp->firstpage); 1086 imgp->firstpage = NULL; 1087 vm_page_unwire(m, PQ_ACTIVE); 1088 } 1089 } 1090 1091 void 1092 exec_onexec_old(struct thread *td) 1093 { 1094 sigfastblock_clear(td); 1095 umtx_exec(td->td_proc); 1096 } 1097 1098 /* 1099 * This is an optimization which removes the unmanaged shared page 1100 * mapping. In combination with pmap_remove_pages(), which cleans all 1101 * managed mappings in the process' vmspace pmap, no work will be left 1102 * for pmap_remove(min, max). 1103 */ 1104 void 1105 exec_free_abi_mappings(struct proc *p) 1106 { 1107 struct vmspace *vmspace; 1108 1109 vmspace = p->p_vmspace; 1110 if (refcount_load(&vmspace->vm_refcnt) != 1) 1111 return; 1112 1113 if (!PROC_HAS_SHP(p)) 1114 return; 1115 1116 pmap_remove(vmspace_pmap(vmspace), vmspace->vm_shp_base, 1117 vmspace->vm_shp_base + p->p_sysent->sv_shared_page_len); 1118 } 1119 1120 /* 1121 * Run down the current address space and install a new one. 1122 */ 1123 int 1124 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) 1125 { 1126 int error; 1127 struct proc *p = imgp->proc; 1128 struct vmspace *vmspace = p->p_vmspace; 1129 struct thread *td = curthread; 1130 vm_offset_t sv_minuser; 1131 vm_map_t map; 1132 1133 imgp->vmspace_destroyed = true; 1134 imgp->sysent = sv; 1135 1136 if (p->p_sysent->sv_onexec_old != NULL) 1137 p->p_sysent->sv_onexec_old(td); 1138 itimers_exec(p); 1139 1140 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); 1141 1142 /* 1143 * Blow away entire process VM, if address space not shared, 1144 * otherwise, create a new VM space so that other threads are 1145 * not disrupted 1146 */ 1147 map = &vmspace->vm_map; 1148 if (map_at_zero) 1149 sv_minuser = sv->sv_minuser; 1150 else 1151 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); 1152 if (refcount_load(&vmspace->vm_refcnt) == 1 && 1153 vm_map_min(map) == sv_minuser && 1154 vm_map_max(map) == sv->sv_maxuser && 1155 cpu_exec_vmspace_reuse(p, map)) { 1156 exec_free_abi_mappings(p); 1157 shmexit(vmspace); 1158 pmap_remove_pages(vmspace_pmap(vmspace)); 1159 vm_map_remove(map, vm_map_min(map), vm_map_max(map)); 1160 /* 1161 * An exec terminates mlockall(MCL_FUTURE). 1162 * ASLR and W^X states must be re-evaluated. 1163 */ 1164 vm_map_lock(map); 1165 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | 1166 MAP_ASLR_IGNSTART | MAP_ASLR_STACK | MAP_WXORX); 1167 vm_map_unlock(map); 1168 } else { 1169 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); 1170 if (error) 1171 return (error); 1172 vmspace = p->p_vmspace; 1173 map = &vmspace->vm_map; 1174 } 1175 map->flags |= imgp->map_flags; 1176 1177 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0); 1178 } 1179 1180 /* 1181 * Compute the stack size limit and map the main process stack. 1182 * Map the shared page. 1183 */ 1184 int 1185 exec_map_stack(struct image_params *imgp) 1186 { 1187 struct rlimit rlim_stack; 1188 struct sysentvec *sv; 1189 struct proc *p; 1190 vm_map_t map; 1191 struct vmspace *vmspace; 1192 vm_offset_t stack_addr, stack_top; 1193 vm_offset_t sharedpage_addr; 1194 u_long ssiz; 1195 int error, find_space, stack_off; 1196 vm_prot_t stack_prot; 1197 vm_object_t obj; 1198 1199 p = imgp->proc; 1200 sv = p->p_sysent; 1201 1202 if (imgp->stack_sz != 0) { 1203 ssiz = trunc_page(imgp->stack_sz); 1204 PROC_LOCK(p); 1205 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); 1206 PROC_UNLOCK(p); 1207 if (ssiz > rlim_stack.rlim_max) 1208 ssiz = rlim_stack.rlim_max; 1209 if (ssiz > rlim_stack.rlim_cur) { 1210 rlim_stack.rlim_cur = ssiz; 1211 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); 1212 } 1213 } else if (sv->sv_maxssiz != NULL) { 1214 ssiz = *sv->sv_maxssiz; 1215 } else { 1216 ssiz = maxssiz; 1217 } 1218 1219 vmspace = p->p_vmspace; 1220 map = &vmspace->vm_map; 1221 1222 stack_prot = sv->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? 1223 imgp->stack_prot : sv->sv_stackprot; 1224 if ((map->flags & MAP_ASLR_STACK) != 0) { 1225 stack_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1226 lim_max(curthread, RLIMIT_DATA)); 1227 find_space = VMFS_ANY_SPACE; 1228 } else { 1229 stack_addr = sv->sv_usrstack - ssiz; 1230 find_space = VMFS_NO_SPACE; 1231 } 1232 error = vm_map_find(map, NULL, 0, &stack_addr, (vm_size_t)ssiz, 1233 sv->sv_usrstack, find_space, stack_prot, VM_PROT_ALL, 1234 MAP_STACK_GROWS_DOWN); 1235 if (error != KERN_SUCCESS) { 1236 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " 1237 "failed, mach error %d errno %d\n", (uintmax_t)ssiz, 1238 stack_prot, error, vm_mmap_to_errno(error)); 1239 return (vm_mmap_to_errno(error)); 1240 } 1241 1242 stack_top = stack_addr + ssiz; 1243 if ((map->flags & MAP_ASLR_STACK) != 0) { 1244 /* Randomize within the first page of the stack. */ 1245 arc4rand(&stack_off, sizeof(stack_off), 0); 1246 stack_top -= rounddown2(stack_off & PAGE_MASK, sizeof(void *)); 1247 } 1248 1249 /* Map a shared page */ 1250 obj = sv->sv_shared_page_obj; 1251 if (obj == NULL) { 1252 sharedpage_addr = 0; 1253 goto out; 1254 } 1255 1256 /* 1257 * If randomization is disabled then the shared page will 1258 * be mapped at address specified in sysentvec. 1259 * Otherwise any address above .data section can be selected. 1260 * Same logic is used for stack address randomization. 1261 * If the address randomization is applied map a guard page 1262 * at the top of UVA. 1263 */ 1264 vm_object_reference(obj); 1265 if ((imgp->imgp_flags & IMGP_ASLR_SHARED_PAGE) != 0) { 1266 sharedpage_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1267 lim_max(curthread, RLIMIT_DATA)); 1268 1269 error = vm_map_fixed(map, NULL, 0, 1270 sv->sv_maxuser - PAGE_SIZE, PAGE_SIZE, 1271 VM_PROT_NONE, VM_PROT_NONE, MAP_CREATE_GUARD); 1272 if (error != KERN_SUCCESS) { 1273 /* 1274 * This is not fatal, so let's just print a warning 1275 * and continue. 1276 */ 1277 uprintf("%s: Mapping guard page at the top of UVA failed" 1278 " mach error %d errno %d", 1279 __func__, error, vm_mmap_to_errno(error)); 1280 } 1281 1282 error = vm_map_find(map, obj, 0, 1283 &sharedpage_addr, sv->sv_shared_page_len, 1284 sv->sv_maxuser, VMFS_ANY_SPACE, 1285 VM_PROT_READ | VM_PROT_EXECUTE, 1286 VM_PROT_READ | VM_PROT_EXECUTE, 1287 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1288 } else { 1289 sharedpage_addr = sv->sv_shared_page_base; 1290 vm_map_fixed(map, obj, 0, 1291 sharedpage_addr, sv->sv_shared_page_len, 1292 VM_PROT_READ | VM_PROT_EXECUTE, 1293 VM_PROT_READ | VM_PROT_EXECUTE, 1294 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1295 } 1296 if (error != KERN_SUCCESS) { 1297 uprintf("%s: mapping shared page at addr: %p" 1298 "failed, mach error %d errno %d\n", __func__, 1299 (void *)sharedpage_addr, error, vm_mmap_to_errno(error)); 1300 vm_object_deallocate(obj); 1301 return (vm_mmap_to_errno(error)); 1302 } 1303 out: 1304 /* 1305 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they 1306 * are still used to enforce the stack rlimit on the process stack. 1307 */ 1308 vmspace->vm_maxsaddr = (char *)stack_addr; 1309 vmspace->vm_stacktop = stack_top; 1310 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; 1311 vmspace->vm_shp_base = sharedpage_addr; 1312 1313 return (0); 1314 } 1315 1316 /* 1317 * Copy out argument and environment strings from the old process address 1318 * space into the temporary string buffer. 1319 */ 1320 int 1321 exec_copyin_args(struct image_args *args, const char *fname, 1322 enum uio_seg segflg, char **argv, char **envv) 1323 { 1324 u_long arg, env; 1325 int error; 1326 1327 bzero(args, sizeof(*args)); 1328 if (argv == NULL) 1329 return (EFAULT); 1330 1331 /* 1332 * Allocate demand-paged memory for the file name, argument, and 1333 * environment strings. 1334 */ 1335 error = exec_alloc_args(args); 1336 if (error != 0) 1337 return (error); 1338 1339 /* 1340 * Copy the file name. 1341 */ 1342 error = exec_args_add_fname(args, fname, segflg); 1343 if (error != 0) 1344 goto err_exit; 1345 1346 /* 1347 * extract arguments first 1348 */ 1349 for (;;) { 1350 error = fueword(argv++, &arg); 1351 if (error == -1) { 1352 error = EFAULT; 1353 goto err_exit; 1354 } 1355 if (arg == 0) 1356 break; 1357 error = exec_args_add_arg(args, (char *)(uintptr_t)arg, 1358 UIO_USERSPACE); 1359 if (error != 0) 1360 goto err_exit; 1361 } 1362 1363 /* 1364 * extract environment strings 1365 */ 1366 if (envv) { 1367 for (;;) { 1368 error = fueword(envv++, &env); 1369 if (error == -1) { 1370 error = EFAULT; 1371 goto err_exit; 1372 } 1373 if (env == 0) 1374 break; 1375 error = exec_args_add_env(args, 1376 (char *)(uintptr_t)env, UIO_USERSPACE); 1377 if (error != 0) 1378 goto err_exit; 1379 } 1380 } 1381 1382 return (0); 1383 1384 err_exit: 1385 exec_free_args(args); 1386 return (error); 1387 } 1388 1389 struct exec_args_kva { 1390 vm_offset_t addr; 1391 u_int gen; 1392 SLIST_ENTRY(exec_args_kva) next; 1393 }; 1394 1395 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); 1396 1397 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; 1398 static struct mtx exec_args_kva_mtx; 1399 static u_int exec_args_gen; 1400 1401 static void 1402 exec_prealloc_args_kva(void *arg __unused) 1403 { 1404 struct exec_args_kva *argkva; 1405 u_int i; 1406 1407 SLIST_INIT(&exec_args_kva_freelist); 1408 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); 1409 for (i = 0; i < exec_map_entries; i++) { 1410 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); 1411 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); 1412 argkva->gen = exec_args_gen; 1413 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1414 } 1415 } 1416 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); 1417 1418 static vm_offset_t 1419 exec_alloc_args_kva(void **cookie) 1420 { 1421 struct exec_args_kva *argkva; 1422 1423 argkva = (void *)atomic_readandclear_ptr( 1424 (uintptr_t *)DPCPU_PTR(exec_args_kva)); 1425 if (argkva == NULL) { 1426 mtx_lock(&exec_args_kva_mtx); 1427 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) 1428 (void)mtx_sleep(&exec_args_kva_freelist, 1429 &exec_args_kva_mtx, 0, "execkva", 0); 1430 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); 1431 mtx_unlock(&exec_args_kva_mtx); 1432 } 1433 kasan_mark((void *)argkva->addr, exec_map_entry_size, 1434 exec_map_entry_size, 0); 1435 *(struct exec_args_kva **)cookie = argkva; 1436 return (argkva->addr); 1437 } 1438 1439 static void 1440 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) 1441 { 1442 vm_offset_t base; 1443 1444 base = argkva->addr; 1445 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size, 1446 KASAN_EXEC_ARGS_FREED); 1447 if (argkva->gen != gen) { 1448 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, 1449 MADV_FREE); 1450 argkva->gen = gen; 1451 } 1452 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), 1453 (uintptr_t)NULL, (uintptr_t)argkva)) { 1454 mtx_lock(&exec_args_kva_mtx); 1455 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1456 wakeup_one(&exec_args_kva_freelist); 1457 mtx_unlock(&exec_args_kva_mtx); 1458 } 1459 } 1460 1461 static void 1462 exec_free_args_kva(void *cookie) 1463 { 1464 1465 exec_release_args_kva(cookie, exec_args_gen); 1466 } 1467 1468 static void 1469 exec_args_kva_lowmem(void *arg __unused) 1470 { 1471 SLIST_HEAD(, exec_args_kva) head; 1472 struct exec_args_kva *argkva; 1473 u_int gen; 1474 int i; 1475 1476 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; 1477 1478 /* 1479 * Force an madvise of each KVA range. Any currently allocated ranges 1480 * will have MADV_FREE applied once they are freed. 1481 */ 1482 SLIST_INIT(&head); 1483 mtx_lock(&exec_args_kva_mtx); 1484 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); 1485 mtx_unlock(&exec_args_kva_mtx); 1486 while ((argkva = SLIST_FIRST(&head)) != NULL) { 1487 SLIST_REMOVE_HEAD(&head, next); 1488 exec_release_args_kva(argkva, gen); 1489 } 1490 1491 CPU_FOREACH(i) { 1492 argkva = (void *)atomic_readandclear_ptr( 1493 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); 1494 if (argkva != NULL) 1495 exec_release_args_kva(argkva, gen); 1496 } 1497 } 1498 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, 1499 EVENTHANDLER_PRI_ANY); 1500 1501 /* 1502 * Allocate temporary demand-paged, zero-filled memory for the file name, 1503 * argument, and environment strings. 1504 */ 1505 int 1506 exec_alloc_args(struct image_args *args) 1507 { 1508 1509 args->buf = (char *)exec_alloc_args_kva(&args->bufkva); 1510 return (0); 1511 } 1512 1513 void 1514 exec_free_args(struct image_args *args) 1515 { 1516 1517 if (args->buf != NULL) { 1518 exec_free_args_kva(args->bufkva); 1519 args->buf = NULL; 1520 } 1521 if (args->fname_buf != NULL) { 1522 free(args->fname_buf, M_TEMP); 1523 args->fname_buf = NULL; 1524 } 1525 } 1526 1527 /* 1528 * A set to functions to fill struct image args. 1529 * 1530 * NOTE: exec_args_add_fname() must be called (possibly with a NULL 1531 * fname) before the other functions. All exec_args_add_arg() calls must 1532 * be made before any exec_args_add_env() calls. exec_args_adjust_args() 1533 * may be called any time after exec_args_add_fname(). 1534 * 1535 * exec_args_add_fname() - install path to be executed 1536 * exec_args_add_arg() - append an argument string 1537 * exec_args_add_env() - append an env string 1538 * exec_args_adjust_args() - adjust location of the argument list to 1539 * allow new arguments to be prepended 1540 */ 1541 int 1542 exec_args_add_fname(struct image_args *args, const char *fname, 1543 enum uio_seg segflg) 1544 { 1545 int error; 1546 size_t length; 1547 1548 KASSERT(args->fname == NULL, ("fname already appended")); 1549 KASSERT(args->endp == NULL, ("already appending to args")); 1550 1551 if (fname != NULL) { 1552 args->fname = args->buf; 1553 error = segflg == UIO_SYSSPACE ? 1554 copystr(fname, args->fname, PATH_MAX, &length) : 1555 copyinstr(fname, args->fname, PATH_MAX, &length); 1556 if (error != 0) 1557 return (error == ENAMETOOLONG ? E2BIG : error); 1558 } else 1559 length = 0; 1560 1561 /* Set up for _arg_*()/_env_*() */ 1562 args->endp = args->buf + length; 1563 /* begin_argv must be set and kept updated */ 1564 args->begin_argv = args->endp; 1565 KASSERT(exec_map_entry_size - length >= ARG_MAX, 1566 ("too little space remaining for arguments %zu < %zu", 1567 exec_map_entry_size - length, (size_t)ARG_MAX)); 1568 args->stringspace = ARG_MAX; 1569 1570 return (0); 1571 } 1572 1573 static int 1574 exec_args_add_str(struct image_args *args, const char *str, 1575 enum uio_seg segflg, int *countp) 1576 { 1577 int error; 1578 size_t length; 1579 1580 KASSERT(args->endp != NULL, ("endp not initialized")); 1581 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1582 1583 error = (segflg == UIO_SYSSPACE) ? 1584 copystr(str, args->endp, args->stringspace, &length) : 1585 copyinstr(str, args->endp, args->stringspace, &length); 1586 if (error != 0) 1587 return (error == ENAMETOOLONG ? E2BIG : error); 1588 args->stringspace -= length; 1589 args->endp += length; 1590 (*countp)++; 1591 1592 return (0); 1593 } 1594 1595 int 1596 exec_args_add_arg(struct image_args *args, const char *argp, 1597 enum uio_seg segflg) 1598 { 1599 1600 KASSERT(args->envc == 0, ("appending args after env")); 1601 1602 return (exec_args_add_str(args, argp, segflg, &args->argc)); 1603 } 1604 1605 int 1606 exec_args_add_env(struct image_args *args, const char *envp, 1607 enum uio_seg segflg) 1608 { 1609 1610 if (args->envc == 0) 1611 args->begin_envv = args->endp; 1612 1613 return (exec_args_add_str(args, envp, segflg, &args->envc)); 1614 } 1615 1616 int 1617 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) 1618 { 1619 ssize_t offset; 1620 1621 KASSERT(args->endp != NULL, ("endp not initialized")); 1622 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1623 1624 offset = extend - consume; 1625 if (args->stringspace < offset) 1626 return (E2BIG); 1627 memmove(args->begin_argv + extend, args->begin_argv + consume, 1628 args->endp - args->begin_argv + consume); 1629 if (args->envc > 0) 1630 args->begin_envv += offset; 1631 args->endp += offset; 1632 args->stringspace -= offset; 1633 return (0); 1634 } 1635 1636 char * 1637 exec_args_get_begin_envv(struct image_args *args) 1638 { 1639 1640 KASSERT(args->endp != NULL, ("endp not initialized")); 1641 1642 if (args->envc > 0) 1643 return (args->begin_envv); 1644 return (args->endp); 1645 } 1646 1647 /* 1648 * Copy strings out to the new process address space, constructing new arg 1649 * and env vector tables. Return a pointer to the base so that it can be used 1650 * as the initial stack pointer. 1651 */ 1652 int 1653 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 1654 { 1655 int argc, envc; 1656 char **vectp; 1657 char *stringp; 1658 uintptr_t destp, ustringp; 1659 struct ps_strings *arginfo; 1660 struct proc *p; 1661 struct sysentvec *sysent; 1662 size_t execpath_len; 1663 int error, szsigcode; 1664 char canary[sizeof(long) * 8]; 1665 1666 p = imgp->proc; 1667 sysent = p->p_sysent; 1668 1669 destp = PROC_PS_STRINGS(p); 1670 arginfo = imgp->ps_strings = (void *)destp; 1671 1672 /* 1673 * Install sigcode. 1674 */ 1675 if (sysent->sv_shared_page_base == 0 && sysent->sv_szsigcode != NULL) { 1676 szsigcode = *(sysent->sv_szsigcode); 1677 destp -= szsigcode; 1678 destp = rounddown2(destp, sizeof(void *)); 1679 error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode); 1680 if (error != 0) 1681 return (error); 1682 } 1683 1684 /* 1685 * Copy the image path for the rtld. 1686 */ 1687 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 1688 execpath_len = strlen(imgp->execpath) + 1; 1689 destp -= execpath_len; 1690 destp = rounddown2(destp, sizeof(void *)); 1691 imgp->execpathp = (void *)destp; 1692 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 1693 if (error != 0) 1694 return (error); 1695 } 1696 1697 /* 1698 * Prepare the canary for SSP. 1699 */ 1700 arc4rand(canary, sizeof(canary), 0); 1701 destp -= sizeof(canary); 1702 imgp->canary = (void *)destp; 1703 error = copyout(canary, imgp->canary, sizeof(canary)); 1704 if (error != 0) 1705 return (error); 1706 imgp->canarylen = sizeof(canary); 1707 1708 /* 1709 * Prepare the pagesizes array. 1710 */ 1711 imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES; 1712 destp -= imgp->pagesizeslen; 1713 destp = rounddown2(destp, sizeof(void *)); 1714 imgp->pagesizes = (void *)destp; 1715 error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen); 1716 if (error != 0) 1717 return (error); 1718 1719 /* 1720 * Allocate room for the argument and environment strings. 1721 */ 1722 destp -= ARG_MAX - imgp->args->stringspace; 1723 destp = rounddown2(destp, sizeof(void *)); 1724 ustringp = destp; 1725 1726 if (imgp->auxargs) { 1727 /* 1728 * Allocate room on the stack for the ELF auxargs 1729 * array. It has up to AT_COUNT entries. 1730 */ 1731 destp -= AT_COUNT * sizeof(Elf_Auxinfo); 1732 destp = rounddown2(destp, sizeof(void *)); 1733 } 1734 1735 vectp = (char **)destp; 1736 1737 /* 1738 * Allocate room for the argv[] and env vectors including the 1739 * terminating NULL pointers. 1740 */ 1741 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 1742 1743 /* 1744 * vectp also becomes our initial stack base 1745 */ 1746 *stack_base = (uintptr_t)vectp; 1747 1748 stringp = imgp->args->begin_argv; 1749 argc = imgp->args->argc; 1750 envc = imgp->args->envc; 1751 1752 /* 1753 * Copy out strings - arguments and environment. 1754 */ 1755 error = copyout(stringp, (void *)ustringp, 1756 ARG_MAX - imgp->args->stringspace); 1757 if (error != 0) 1758 return (error); 1759 1760 /* 1761 * Fill in "ps_strings" struct for ps, w, etc. 1762 */ 1763 imgp->argv = vectp; 1764 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 1765 suword32(&arginfo->ps_nargvstr, argc) != 0) 1766 return (EFAULT); 1767 1768 /* 1769 * Fill in argument portion of vector table. 1770 */ 1771 for (; argc > 0; --argc) { 1772 if (suword(vectp++, ustringp) != 0) 1773 return (EFAULT); 1774 while (*stringp++ != 0) 1775 ustringp++; 1776 ustringp++; 1777 } 1778 1779 /* a null vector table pointer separates the argp's from the envp's */ 1780 if (suword(vectp++, 0) != 0) 1781 return (EFAULT); 1782 1783 imgp->envv = vectp; 1784 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 1785 suword32(&arginfo->ps_nenvstr, envc) != 0) 1786 return (EFAULT); 1787 1788 /* 1789 * Fill in environment portion of vector table. 1790 */ 1791 for (; envc > 0; --envc) { 1792 if (suword(vectp++, ustringp) != 0) 1793 return (EFAULT); 1794 while (*stringp++ != 0) 1795 ustringp++; 1796 ustringp++; 1797 } 1798 1799 /* end of vector table is a null pointer */ 1800 if (suword(vectp, 0) != 0) 1801 return (EFAULT); 1802 1803 if (imgp->auxargs) { 1804 vectp++; 1805 error = imgp->sysent->sv_copyout_auxargs(imgp, 1806 (uintptr_t)vectp); 1807 if (error != 0) 1808 return (error); 1809 } 1810 1811 return (0); 1812 } 1813 1814 /* 1815 * Check permissions of file to execute. 1816 * Called with imgp->vp locked. 1817 * Return 0 for success or error code on failure. 1818 */ 1819 int 1820 exec_check_permissions(struct image_params *imgp) 1821 { 1822 struct vnode *vp = imgp->vp; 1823 struct vattr *attr = imgp->attr; 1824 struct thread *td; 1825 int error; 1826 1827 td = curthread; 1828 1829 /* Get file attributes */ 1830 error = VOP_GETATTR(vp, attr, td->td_ucred); 1831 if (error) 1832 return (error); 1833 1834 #ifdef MAC 1835 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); 1836 if (error) 1837 return (error); 1838 #endif 1839 1840 /* 1841 * 1) Check if file execution is disabled for the filesystem that 1842 * this file resides on. 1843 * 2) Ensure that at least one execute bit is on. Otherwise, a 1844 * privileged user will always succeed, and we don't want this 1845 * to happen unless the file really is executable. 1846 * 3) Ensure that the file is a regular file. 1847 */ 1848 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || 1849 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || 1850 (attr->va_type != VREG)) 1851 return (EACCES); 1852 1853 /* 1854 * Zero length files can't be exec'd 1855 */ 1856 if (attr->va_size == 0) 1857 return (ENOEXEC); 1858 1859 /* 1860 * Check for execute permission to file based on current credentials. 1861 */ 1862 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); 1863 if (error) 1864 return (error); 1865 1866 /* 1867 * Check number of open-for-writes on the file and deny execution 1868 * if there are any. 1869 * 1870 * Add a text reference now so no one can write to the 1871 * executable while we're activating it. 1872 * 1873 * Remember if this was set before and unset it in case this is not 1874 * actually an executable image. 1875 */ 1876 error = VOP_SET_TEXT(vp); 1877 if (error != 0) 1878 return (error); 1879 imgp->textset = true; 1880 1881 /* 1882 * Call filesystem specific open routine (which does nothing in the 1883 * general case). 1884 */ 1885 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); 1886 if (error == 0) 1887 imgp->opened = true; 1888 return (error); 1889 } 1890 1891 /* 1892 * Exec handler registration 1893 */ 1894 int 1895 exec_register(const struct execsw *execsw_arg) 1896 { 1897 const struct execsw **es, **xs, **newexecsw; 1898 u_int count = 2; /* New slot and trailing NULL */ 1899 1900 if (execsw) 1901 for (es = execsw; *es; es++) 1902 count++; 1903 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1904 xs = newexecsw; 1905 if (execsw) 1906 for (es = execsw; *es; es++) 1907 *xs++ = *es; 1908 *xs++ = execsw_arg; 1909 *xs = NULL; 1910 if (execsw) 1911 free(execsw, M_TEMP); 1912 execsw = newexecsw; 1913 return (0); 1914 } 1915 1916 int 1917 exec_unregister(const struct execsw *execsw_arg) 1918 { 1919 const struct execsw **es, **xs, **newexecsw; 1920 int count = 1; 1921 1922 if (execsw == NULL) 1923 panic("unregister with no handlers left?\n"); 1924 1925 for (es = execsw; *es; es++) { 1926 if (*es == execsw_arg) 1927 break; 1928 } 1929 if (*es == NULL) 1930 return (ENOENT); 1931 for (es = execsw; *es; es++) 1932 if (*es != execsw_arg) 1933 count++; 1934 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1935 xs = newexecsw; 1936 for (es = execsw; *es; es++) 1937 if (*es != execsw_arg) 1938 *xs++ = *es; 1939 *xs = NULL; 1940 if (execsw) 1941 free(execsw, M_TEMP); 1942 execsw = newexecsw; 1943 return (0); 1944 } 1945 1946 /* 1947 * Write out a core segment to the compression stream. 1948 */ 1949 static int 1950 compress_chunk(struct coredump_params *cp, char *base, char *buf, size_t len) 1951 { 1952 size_t chunk_len; 1953 int error; 1954 1955 while (len > 0) { 1956 chunk_len = MIN(len, CORE_BUF_SIZE); 1957 1958 /* 1959 * We can get EFAULT error here. 1960 * In that case zero out the current chunk of the segment. 1961 */ 1962 error = copyin(base, buf, chunk_len); 1963 if (error != 0) 1964 bzero(buf, chunk_len); 1965 error = compressor_write(cp->comp, buf, chunk_len); 1966 if (error != 0) 1967 break; 1968 base += chunk_len; 1969 len -= chunk_len; 1970 } 1971 return (error); 1972 } 1973 1974 int 1975 core_write(struct coredump_params *cp, const void *base, size_t len, 1976 off_t offset, enum uio_seg seg, size_t *resid) 1977 { 1978 1979 return (vn_rdwr_inchunks(UIO_WRITE, cp->vp, __DECONST(void *, base), 1980 len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED, 1981 cp->active_cred, cp->file_cred, resid, cp->td)); 1982 } 1983 1984 int 1985 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp, 1986 void *tmpbuf) 1987 { 1988 vm_map_t map; 1989 struct mount *mp; 1990 size_t resid, runlen; 1991 int error; 1992 bool success; 1993 1994 KASSERT((uintptr_t)base % PAGE_SIZE == 0, 1995 ("%s: user address %p is not page-aligned", __func__, base)); 1996 1997 if (cp->comp != NULL) 1998 return (compress_chunk(cp, base, tmpbuf, len)); 1999 2000 map = &cp->td->td_proc->p_vmspace->vm_map; 2001 for (; len > 0; base += runlen, offset += runlen, len -= runlen) { 2002 /* 2003 * Attempt to page in all virtual pages in the range. If a 2004 * virtual page is not backed by the pager, it is represented as 2005 * a hole in the file. This can occur with zero-filled 2006 * anonymous memory or truncated files, for example. 2007 */ 2008 for (runlen = 0; runlen < len; runlen += PAGE_SIZE) { 2009 if (core_dump_can_intr && curproc_sigkilled()) 2010 return (EINTR); 2011 error = vm_fault(map, (uintptr_t)base + runlen, 2012 VM_PROT_READ, VM_FAULT_NOFILL, NULL); 2013 if (runlen == 0) 2014 success = error == KERN_SUCCESS; 2015 else if ((error == KERN_SUCCESS) != success) 2016 break; 2017 } 2018 2019 if (success) { 2020 error = core_write(cp, base, runlen, offset, 2021 UIO_USERSPACE, &resid); 2022 if (error != 0) { 2023 if (error != EFAULT) 2024 break; 2025 2026 /* 2027 * EFAULT may be returned if the user mapping 2028 * could not be accessed, e.g., because a mapped 2029 * file has been truncated. Skip the page if no 2030 * progress was made, to protect against a 2031 * hypothetical scenario where vm_fault() was 2032 * successful but core_write() returns EFAULT 2033 * anyway. 2034 */ 2035 runlen -= resid; 2036 if (runlen == 0) { 2037 success = false; 2038 runlen = PAGE_SIZE; 2039 } 2040 } 2041 } 2042 if (!success) { 2043 error = vn_start_write(cp->vp, &mp, V_WAIT); 2044 if (error != 0) 2045 break; 2046 vn_lock(cp->vp, LK_EXCLUSIVE | LK_RETRY); 2047 error = vn_truncate_locked(cp->vp, offset + runlen, 2048 false, cp->td->td_ucred); 2049 VOP_UNLOCK(cp->vp); 2050 vn_finished_write(mp); 2051 if (error != 0) 2052 break; 2053 } 2054 } 2055 return (error); 2056 } 2057 2058 /* 2059 * Drain into a core file. 2060 */ 2061 int 2062 sbuf_drain_core_output(void *arg, const char *data, int len) 2063 { 2064 struct coredump_params *cp; 2065 struct proc *p; 2066 int error, locked; 2067 2068 cp = arg; 2069 p = cp->td->td_proc; 2070 2071 /* 2072 * Some kern_proc out routines that print to this sbuf may 2073 * call us with the process lock held. Draining with the 2074 * non-sleepable lock held is unsafe. The lock is needed for 2075 * those routines when dumping a live process. In our case we 2076 * can safely release the lock before draining and acquire 2077 * again after. 2078 */ 2079 locked = PROC_LOCKED(p); 2080 if (locked) 2081 PROC_UNLOCK(p); 2082 if (cp->comp != NULL) 2083 error = compressor_write(cp->comp, __DECONST(char *, data), 2084 len); 2085 else 2086 error = core_write(cp, __DECONST(void *, data), len, cp->offset, 2087 UIO_SYSSPACE, NULL); 2088 if (locked) 2089 PROC_LOCK(p); 2090 if (error != 0) 2091 return (-error); 2092 cp->offset += len; 2093 return (len); 2094 } 2095