Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_exec.c
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1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 __FBSDID("$FreeBSD$"); 31 32 #include "opt_capsicum.h" 33 #include "opt_hwpmc_hooks.h" 34 #include "opt_ktrace.h" 35 #include "opt_vm.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/acct.h> 40 #include <sys/asan.h> 41 #include <sys/capsicum.h> 42 #include <sys/compressor.h> 43 #include <sys/eventhandler.h> 44 #include <sys/exec.h> 45 #include <sys/fcntl.h> 46 #include <sys/filedesc.h> 47 #include <sys/imgact.h> 48 #include <sys/imgact_elf.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/malloc.h> 52 #include <sys/mman.h> 53 #include <sys/mount.h> 54 #include <sys/mutex.h> 55 #include <sys/namei.h> 56 #include <sys/priv.h> 57 #include <sys/proc.h> 58 #include <sys/ptrace.h> 59 #include <sys/reg.h> 60 #include <sys/resourcevar.h> 61 #include <sys/rwlock.h> 62 #include <sys/sched.h> 63 #include <sys/sdt.h> 64 #include <sys/sf_buf.h> 65 #include <sys/shm.h> 66 #include <sys/signalvar.h> 67 #include <sys/smp.h> 68 #include <sys/stat.h> 69 #include <sys/syscallsubr.h> 70 #include <sys/sysctl.h> 71 #include <sys/sysent.h> 72 #include <sys/sysproto.h> 73 #include <sys/timers.h> 74 #include <sys/umtxvar.h> 75 #include <sys/vnode.h> 76 #include <sys/wait.h> 77 #ifdef KTRACE 78 #include <sys/ktrace.h> 79 #endif 80 81 #include <vm/vm.h> 82 #include <vm/vm_param.h> 83 #include <vm/pmap.h> 84 #include <vm/vm_page.h> 85 #include <vm/vm_map.h> 86 #include <vm/vm_kern.h> 87 #include <vm/vm_extern.h> 88 #include <vm/vm_object.h> 89 #include <vm/vm_pager.h> 90 91 #ifdef HWPMC_HOOKS 92 #include <sys/pmckern.h> 93 #endif 94 95 #include <security/audit/audit.h> 96 #include <security/mac/mac_framework.h> 97 98 #ifdef KDTRACE_HOOKS 99 #include <sys/dtrace_bsd.h> 100 dtrace_execexit_func_t dtrace_fasttrap_exec; 101 #endif 102 103 SDT_PROVIDER_DECLARE(proc); 104 SDT_PROBE_DEFINE1(proc, , , exec, "char *"); 105 SDT_PROBE_DEFINE1(proc, , , exec__failure, "int"); 106 SDT_PROBE_DEFINE1(proc, , , exec__success, "char *"); 107 108 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments"); 109 110 int coredump_pack_fileinfo = 1; 111 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN, 112 &coredump_pack_fileinfo, 0, 113 "Enable file path packing in 'procstat -f' coredump notes"); 114 115 int coredump_pack_vmmapinfo = 1; 116 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN, 117 &coredump_pack_vmmapinfo, 0, 118 "Enable file path packing in 'procstat -v' coredump notes"); 119 120 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS); 121 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS); 122 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS); 123 static int do_execve(struct thread *td, struct image_args *args, 124 struct mac *mac_p, struct vmspace *oldvmspace); 125 126 /* XXX This should be vm_size_t. */ 127 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD| 128 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU", 129 "Location of process' ps_strings structure"); 130 131 /* XXX This should be vm_size_t. */ 132 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD| 133 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU", 134 "Top of process stack"); 135 136 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE, 137 NULL, 0, sysctl_kern_stackprot, "I", 138 "Stack memory permissions"); 139 140 u_long ps_arg_cache_limit = PAGE_SIZE / 16; 141 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW, 142 &ps_arg_cache_limit, 0, 143 "Process' command line characters cache limit"); 144 145 static int disallow_high_osrel; 146 SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW, 147 &disallow_high_osrel, 0, 148 "Disallow execution of binaries built for higher version of the world"); 149 150 static int map_at_zero = 0; 151 SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0, 152 "Permit processes to map an object at virtual address 0."); 153 154 static int core_dump_can_intr = 1; 155 SYSCTL_INT(_kern, OID_AUTO, core_dump_can_intr, CTLFLAG_RWTUN, 156 &core_dump_can_intr, 0, 157 "Core dumping interruptible with SIGKILL"); 158 159 static int 160 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS) 161 { 162 struct proc *p; 163 vm_offset_t ps_strings; 164 165 p = curproc; 166 #ifdef SCTL_MASK32 167 if (req->flags & SCTL_MASK32) { 168 unsigned int val; 169 val = (unsigned int)PROC_PS_STRINGS(p); 170 return (SYSCTL_OUT(req, &val, sizeof(val))); 171 } 172 #endif 173 ps_strings = PROC_PS_STRINGS(p); 174 return (SYSCTL_OUT(req, &ps_strings, sizeof(ps_strings))); 175 } 176 177 static int 178 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS) 179 { 180 struct proc *p; 181 vm_offset_t val; 182 183 p = curproc; 184 #ifdef SCTL_MASK32 185 if (req->flags & SCTL_MASK32) { 186 unsigned int val32; 187 188 val32 = round_page((unsigned int)p->p_vmspace->vm_stacktop); 189 return (SYSCTL_OUT(req, &val32, sizeof(val32))); 190 } 191 #endif 192 val = round_page(p->p_vmspace->vm_stacktop); 193 return (SYSCTL_OUT(req, &val, sizeof(val))); 194 } 195 196 static int 197 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS) 198 { 199 struct proc *p; 200 201 p = curproc; 202 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot, 203 sizeof(p->p_sysent->sv_stackprot))); 204 } 205 206 /* 207 * Each of the items is a pointer to a `const struct execsw', hence the 208 * double pointer here. 209 */ 210 static const struct execsw **execsw; 211 212 #ifndef _SYS_SYSPROTO_H_ 213 struct execve_args { 214 char *fname; 215 char **argv; 216 char **envv; 217 }; 218 #endif 219 220 int 221 sys_execve(struct thread *td, struct execve_args *uap) 222 { 223 struct image_args args; 224 struct vmspace *oldvmspace; 225 int error; 226 227 error = pre_execve(td, &oldvmspace); 228 if (error != 0) 229 return (error); 230 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, 231 uap->argv, uap->envv); 232 if (error == 0) 233 error = kern_execve(td, &args, NULL, oldvmspace); 234 post_execve(td, error, oldvmspace); 235 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 236 return (error); 237 } 238 239 #ifndef _SYS_SYSPROTO_H_ 240 struct fexecve_args { 241 int fd; 242 char **argv; 243 char **envv; 244 }; 245 #endif 246 int 247 sys_fexecve(struct thread *td, struct fexecve_args *uap) 248 { 249 struct image_args args; 250 struct vmspace *oldvmspace; 251 int error; 252 253 error = pre_execve(td, &oldvmspace); 254 if (error != 0) 255 return (error); 256 error = exec_copyin_args(&args, NULL, UIO_SYSSPACE, 257 uap->argv, uap->envv); 258 if (error == 0) { 259 args.fd = uap->fd; 260 error = kern_execve(td, &args, NULL, oldvmspace); 261 } 262 post_execve(td, error, oldvmspace); 263 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 264 return (error); 265 } 266 267 #ifndef _SYS_SYSPROTO_H_ 268 struct __mac_execve_args { 269 char *fname; 270 char **argv; 271 char **envv; 272 struct mac *mac_p; 273 }; 274 #endif 275 276 int 277 sys___mac_execve(struct thread *td, struct __mac_execve_args *uap) 278 { 279 #ifdef MAC 280 struct image_args args; 281 struct vmspace *oldvmspace; 282 int error; 283 284 error = pre_execve(td, &oldvmspace); 285 if (error != 0) 286 return (error); 287 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE, 288 uap->argv, uap->envv); 289 if (error == 0) 290 error = kern_execve(td, &args, uap->mac_p, oldvmspace); 291 post_execve(td, error, oldvmspace); 292 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td); 293 return (error); 294 #else 295 return (ENOSYS); 296 #endif 297 } 298 299 int 300 pre_execve(struct thread *td, struct vmspace **oldvmspace) 301 { 302 struct proc *p; 303 int error; 304 305 KASSERT(td == curthread, ("non-current thread %p", td)); 306 error = 0; 307 p = td->td_proc; 308 if ((p->p_flag & P_HADTHREADS) != 0) { 309 PROC_LOCK(p); 310 if (thread_single(p, SINGLE_BOUNDARY) != 0) 311 error = ERESTART; 312 PROC_UNLOCK(p); 313 } 314 KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0, 315 ("nested execve")); 316 *oldvmspace = p->p_vmspace; 317 return (error); 318 } 319 320 void 321 post_execve(struct thread *td, int error, struct vmspace *oldvmspace) 322 { 323 struct proc *p; 324 325 KASSERT(td == curthread, ("non-current thread %p", td)); 326 p = td->td_proc; 327 if ((p->p_flag & P_HADTHREADS) != 0) { 328 PROC_LOCK(p); 329 /* 330 * If success, we upgrade to SINGLE_EXIT state to 331 * force other threads to suicide. 332 */ 333 if (error == EJUSTRETURN) 334 thread_single(p, SINGLE_EXIT); 335 else 336 thread_single_end(p, SINGLE_BOUNDARY); 337 PROC_UNLOCK(p); 338 } 339 exec_cleanup(td, oldvmspace); 340 } 341 342 /* 343 * kern_execve() has the astonishing property of not always returning to 344 * the caller. If sufficiently bad things happen during the call to 345 * do_execve(), it can end up calling exit1(); as a result, callers must 346 * avoid doing anything which they might need to undo (e.g., allocating 347 * memory). 348 */ 349 int 350 kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 351 struct vmspace *oldvmspace) 352 { 353 354 TSEXEC(td->td_proc->p_pid, args->begin_argv); 355 AUDIT_ARG_ARGV(args->begin_argv, args->argc, 356 exec_args_get_begin_envv(args) - args->begin_argv); 357 AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc, 358 args->endp - exec_args_get_begin_envv(args)); 359 360 /* Must have at least one argument. */ 361 if (args->argc == 0) { 362 exec_free_args(args); 363 return (EINVAL); 364 } 365 return (do_execve(td, args, mac_p, oldvmspace)); 366 } 367 368 static void 369 execve_nosetid(struct image_params *imgp) 370 { 371 imgp->credential_setid = false; 372 if (imgp->newcred != NULL) { 373 crfree(imgp->newcred); 374 imgp->newcred = NULL; 375 } 376 } 377 378 /* 379 * In-kernel implementation of execve(). All arguments are assumed to be 380 * userspace pointers from the passed thread. 381 */ 382 static int 383 do_execve(struct thread *td, struct image_args *args, struct mac *mac_p, 384 struct vmspace *oldvmspace) 385 { 386 struct proc *p = td->td_proc; 387 struct nameidata nd; 388 struct ucred *oldcred; 389 struct uidinfo *euip = NULL; 390 uintptr_t stack_base; 391 struct image_params image_params, *imgp; 392 struct vattr attr; 393 int (*img_first)(struct image_params *); 394 struct pargs *oldargs = NULL, *newargs = NULL; 395 struct sigacts *oldsigacts = NULL, *newsigacts = NULL; 396 #ifdef KTRACE 397 struct ktr_io_params *kiop; 398 #endif 399 struct vnode *oldtextvp, *newtextvp; 400 struct vnode *oldtextdvp, *newtextdvp; 401 char *oldbinname, *newbinname; 402 bool credential_changing; 403 #ifdef MAC 404 struct label *interpvplabel = NULL; 405 bool will_transition; 406 #endif 407 #ifdef HWPMC_HOOKS 408 struct pmckern_procexec pe; 409 #endif 410 int error, i, orig_osrel; 411 uint32_t orig_fctl0; 412 Elf_Brandinfo *orig_brandinfo; 413 size_t freepath_size; 414 static const char fexecv_proc_title[] = "(fexecv)"; 415 416 imgp = &image_params; 417 oldtextvp = oldtextdvp = NULL; 418 newtextvp = newtextdvp = NULL; 419 newbinname = oldbinname = NULL; 420 #ifdef KTRACE 421 kiop = NULL; 422 #endif 423 424 /* 425 * Lock the process and set the P_INEXEC flag to indicate that 426 * it should be left alone until we're done here. This is 427 * necessary to avoid race conditions - e.g. in ptrace() - 428 * that might allow a local user to illicitly obtain elevated 429 * privileges. 430 */ 431 PROC_LOCK(p); 432 KASSERT((p->p_flag & P_INEXEC) == 0, 433 ("%s(): process already has P_INEXEC flag", __func__)); 434 p->p_flag |= P_INEXEC; 435 PROC_UNLOCK(p); 436 437 /* 438 * Initialize part of the common data 439 */ 440 bzero(imgp, sizeof(*imgp)); 441 imgp->proc = p; 442 imgp->attr = &attr; 443 imgp->args = args; 444 oldcred = p->p_ucred; 445 orig_osrel = p->p_osrel; 446 orig_fctl0 = p->p_fctl0; 447 orig_brandinfo = p->p_elf_brandinfo; 448 449 #ifdef MAC 450 error = mac_execve_enter(imgp, mac_p); 451 if (error) 452 goto exec_fail; 453 #endif 454 455 SDT_PROBE1(proc, , , exec, args->fname); 456 457 interpret: 458 if (args->fname != NULL) { 459 #ifdef CAPABILITY_MODE 460 /* 461 * While capability mode can't reach this point via direct 462 * path arguments to execve(), we also don't allow 463 * interpreters to be used in capability mode (for now). 464 * Catch indirect lookups and return a permissions error. 465 */ 466 if (IN_CAPABILITY_MODE(td)) { 467 error = ECAPMODE; 468 goto exec_fail; 469 } 470 #endif 471 472 /* 473 * Translate the file name. namei() returns a vnode 474 * pointer in ni_vp among other things. 475 */ 476 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW | 477 AUDITVNODE1 | WANTPARENT, UIO_SYSSPACE, 478 args->fname); 479 480 error = namei(&nd); 481 if (error) 482 goto exec_fail; 483 484 newtextvp = nd.ni_vp; 485 newtextdvp = nd.ni_dvp; 486 nd.ni_dvp = NULL; 487 newbinname = malloc(nd.ni_cnd.cn_namelen + 1, M_PARGS, 488 M_WAITOK); 489 memcpy(newbinname, nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen); 490 newbinname[nd.ni_cnd.cn_namelen] = '\0'; 491 imgp->vp = newtextvp; 492 493 /* 494 * Do the best to calculate the full path to the image file. 495 */ 496 if (args->fname[0] == '/') { 497 imgp->execpath = args->fname; 498 } else { 499 VOP_UNLOCK(imgp->vp); 500 freepath_size = MAXPATHLEN; 501 if (vn_fullpath_hardlink(newtextvp, newtextdvp, 502 newbinname, nd.ni_cnd.cn_namelen, &imgp->execpath, 503 &imgp->freepath, &freepath_size) != 0) 504 imgp->execpath = args->fname; 505 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 506 } 507 } else if (imgp->interpreter_vp) { 508 /* 509 * An image activator has already provided an open vnode 510 */ 511 newtextvp = imgp->interpreter_vp; 512 imgp->interpreter_vp = NULL; 513 if (vn_fullpath(newtextvp, &imgp->execpath, 514 &imgp->freepath) != 0) 515 imgp->execpath = args->fname; 516 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 517 AUDIT_ARG_VNODE1(newtextvp); 518 imgp->vp = newtextvp; 519 } else { 520 AUDIT_ARG_FD(args->fd); 521 522 /* 523 * If the descriptors was not opened with O_PATH, then 524 * we require that it was opened with O_EXEC or 525 * O_RDONLY. In either case, exec_check_permissions() 526 * below checks _current_ file access mode regardless 527 * of the permissions additionally checked at the 528 * open(2). 529 */ 530 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, 531 &newtextvp); 532 if (error != 0) 533 goto exec_fail; 534 535 if (vn_fullpath(newtextvp, &imgp->execpath, 536 &imgp->freepath) != 0) 537 imgp->execpath = args->fname; 538 vn_lock(newtextvp, LK_SHARED | LK_RETRY); 539 AUDIT_ARG_VNODE1(newtextvp); 540 imgp->vp = newtextvp; 541 } 542 543 /* 544 * Check file permissions. Also 'opens' file and sets its vnode to 545 * text mode. 546 */ 547 error = exec_check_permissions(imgp); 548 if (error) 549 goto exec_fail_dealloc; 550 551 imgp->object = imgp->vp->v_object; 552 if (imgp->object != NULL) 553 vm_object_reference(imgp->object); 554 555 error = exec_map_first_page(imgp); 556 if (error) 557 goto exec_fail_dealloc; 558 559 imgp->proc->p_osrel = 0; 560 imgp->proc->p_fctl0 = 0; 561 imgp->proc->p_elf_brandinfo = NULL; 562 563 /* 564 * Implement image setuid/setgid. 565 * 566 * Determine new credentials before attempting image activators 567 * so that it can be used by process_exec handlers to determine 568 * credential/setid changes. 569 * 570 * Don't honor setuid/setgid if the filesystem prohibits it or if 571 * the process is being traced. 572 * 573 * We disable setuid/setgid/etc in capability mode on the basis 574 * that most setugid applications are not written with that 575 * environment in mind, and will therefore almost certainly operate 576 * incorrectly. In principle there's no reason that setugid 577 * applications might not be useful in capability mode, so we may want 578 * to reconsider this conservative design choice in the future. 579 * 580 * XXXMAC: For the time being, use NOSUID to also prohibit 581 * transitions on the file system. 582 */ 583 credential_changing = false; 584 credential_changing |= (attr.va_mode & S_ISUID) && 585 oldcred->cr_uid != attr.va_uid; 586 credential_changing |= (attr.va_mode & S_ISGID) && 587 oldcred->cr_gid != attr.va_gid; 588 #ifdef MAC 589 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp, 590 interpvplabel, imgp) != 0; 591 credential_changing |= will_transition; 592 #endif 593 594 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */ 595 if (credential_changing) 596 imgp->proc->p_pdeathsig = 0; 597 598 if (credential_changing && 599 #ifdef CAPABILITY_MODE 600 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) && 601 #endif 602 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 && 603 (p->p_flag & P_TRACED) == 0) { 604 imgp->credential_setid = true; 605 VOP_UNLOCK(imgp->vp); 606 imgp->newcred = crdup(oldcred); 607 if (attr.va_mode & S_ISUID) { 608 euip = uifind(attr.va_uid); 609 change_euid(imgp->newcred, euip); 610 } 611 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 612 if (attr.va_mode & S_ISGID) 613 change_egid(imgp->newcred, attr.va_gid); 614 /* 615 * Implement correct POSIX saved-id behavior. 616 * 617 * XXXMAC: Note that the current logic will save the 618 * uid and gid if a MAC domain transition occurs, even 619 * though maybe it shouldn't. 620 */ 621 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 622 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 623 } else { 624 /* 625 * Implement correct POSIX saved-id behavior. 626 * 627 * XXX: It's not clear that the existing behavior is 628 * POSIX-compliant. A number of sources indicate that the 629 * saved uid/gid should only be updated if the new ruid is 630 * not equal to the old ruid, or the new euid is not equal 631 * to the old euid and the new euid is not equal to the old 632 * ruid. The FreeBSD code always updates the saved uid/gid. 633 * Also, this code uses the new (replaced) euid and egid as 634 * the source, which may or may not be the right ones to use. 635 */ 636 if (oldcred->cr_svuid != oldcred->cr_uid || 637 oldcred->cr_svgid != oldcred->cr_gid) { 638 VOP_UNLOCK(imgp->vp); 639 imgp->newcred = crdup(oldcred); 640 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 641 change_svuid(imgp->newcred, imgp->newcred->cr_uid); 642 change_svgid(imgp->newcred, imgp->newcred->cr_gid); 643 } 644 } 645 /* The new credentials are installed into the process later. */ 646 647 /* 648 * If the current process has a special image activator it 649 * wants to try first, call it. For example, emulating shell 650 * scripts differently. 651 */ 652 error = -1; 653 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL) 654 error = img_first(imgp); 655 656 /* 657 * Loop through the list of image activators, calling each one. 658 * An activator returns -1 if there is no match, 0 on success, 659 * and an error otherwise. 660 */ 661 for (i = 0; error == -1 && execsw[i]; ++i) { 662 if (execsw[i]->ex_imgact == NULL || 663 execsw[i]->ex_imgact == img_first) { 664 continue; 665 } 666 error = (*execsw[i]->ex_imgact)(imgp); 667 } 668 669 if (error) { 670 if (error == -1) 671 error = ENOEXEC; 672 goto exec_fail_dealloc; 673 } 674 675 /* 676 * Special interpreter operation, cleanup and loop up to try to 677 * activate the interpreter. 678 */ 679 if (imgp->interpreted) { 680 exec_unmap_first_page(imgp); 681 /* 682 * The text reference needs to be removed for scripts. 683 * There is a short period before we determine that 684 * something is a script where text reference is active. 685 * The vnode lock is held over this entire period 686 * so nothing should illegitimately be blocked. 687 */ 688 MPASS(imgp->textset); 689 VOP_UNSET_TEXT_CHECKED(newtextvp); 690 imgp->textset = false; 691 /* free name buffer and old vnode */ 692 #ifdef MAC 693 mac_execve_interpreter_enter(newtextvp, &interpvplabel); 694 #endif 695 if (imgp->opened) { 696 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td); 697 imgp->opened = false; 698 } 699 vput(newtextvp); 700 imgp->vp = newtextvp = NULL; 701 if (args->fname != NULL) { 702 if (newtextdvp != NULL) { 703 vrele(newtextdvp); 704 newtextdvp = NULL; 705 } 706 NDFREE_PNBUF(&nd); 707 free(newbinname, M_PARGS); 708 newbinname = NULL; 709 } 710 vm_object_deallocate(imgp->object); 711 imgp->object = NULL; 712 execve_nosetid(imgp); 713 imgp->execpath = NULL; 714 free(imgp->freepath, M_TEMP); 715 imgp->freepath = NULL; 716 /* set new name to that of the interpreter */ 717 if (imgp->interpreter_vp) { 718 args->fname = NULL; 719 } else { 720 args->fname = imgp->interpreter_name; 721 } 722 goto interpret; 723 } 724 725 /* 726 * NB: We unlock the vnode here because it is believed that none 727 * of the sv_copyout_strings/sv_fixup operations require the vnode. 728 */ 729 VOP_UNLOCK(imgp->vp); 730 731 if (disallow_high_osrel && 732 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { 733 error = ENOEXEC; 734 uprintf("Osrel %d for image %s too high\n", p->p_osrel, 735 imgp->execpath != NULL ? imgp->execpath : "<unresolved>"); 736 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 737 goto exec_fail_dealloc; 738 } 739 740 /* 741 * Copy out strings (args and env) and initialize stack base. 742 */ 743 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); 744 if (error != 0) { 745 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 746 goto exec_fail_dealloc; 747 } 748 749 /* 750 * Stack setup. 751 */ 752 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); 753 if (error != 0) { 754 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 755 goto exec_fail_dealloc; 756 } 757 758 /* 759 * For security and other reasons, the file descriptor table cannot be 760 * shared after an exec. 761 */ 762 fdunshare(td); 763 pdunshare(td); 764 /* close files on exec */ 765 fdcloseexec(td); 766 767 /* 768 * Malloc things before we need locks. 769 */ 770 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; 771 /* Cache arguments if they fit inside our allowance */ 772 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { 773 newargs = pargs_alloc(i); 774 bcopy(imgp->args->begin_argv, newargs->ar_args, i); 775 } 776 777 /* 778 * For security and other reasons, signal handlers cannot 779 * be shared after an exec. The new process gets a copy of the old 780 * handlers. In execsigs(), the new process will have its signals 781 * reset. 782 */ 783 if (sigacts_shared(p->p_sigacts)) { 784 oldsigacts = p->p_sigacts; 785 newsigacts = sigacts_alloc(); 786 sigacts_copy(newsigacts, oldsigacts); 787 } 788 789 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 790 791 PROC_LOCK(p); 792 if (oldsigacts) 793 p->p_sigacts = newsigacts; 794 /* Stop profiling */ 795 stopprofclock(p); 796 797 /* reset caught signals */ 798 execsigs(p); 799 800 /* name this process - nameiexec(p, ndp) */ 801 bzero(p->p_comm, sizeof(p->p_comm)); 802 if (args->fname) 803 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, 804 min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); 805 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) 806 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); 807 bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); 808 #ifdef KTR 809 sched_clear_tdname(td); 810 #endif 811 812 /* 813 * mark as execed, wakeup the process that vforked (if any) and tell 814 * it that it now has its own resources back 815 */ 816 p->p_flag |= P_EXEC; 817 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) 818 p->p_flag2 &= ~P2_NOTRACE; 819 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) 820 p->p_flag2 &= ~P2_STKGAP_DISABLE; 821 if (p->p_flag & P_PPWAIT) { 822 p->p_flag &= ~(P_PPWAIT | P_PPTRACE); 823 cv_broadcast(&p->p_pwait); 824 /* STOPs are no longer ignored, arrange for AST */ 825 signotify(td); 826 } 827 828 if ((imgp->sysent->sv_setid_allowed != NULL && 829 !(*imgp->sysent->sv_setid_allowed)(td, imgp)) || 830 (p->p_flag2 & P2_NO_NEW_PRIVS) != 0) 831 execve_nosetid(imgp); 832 833 /* 834 * Implement image setuid/setgid installation. 835 */ 836 if (imgp->credential_setid) { 837 /* 838 * Turn off syscall tracing for set-id programs, except for 839 * root. Record any set-id flags first to make sure that 840 * we do not regain any tracing during a possible block. 841 */ 842 setsugid(p); 843 #ifdef KTRACE 844 kiop = ktrprocexec(p); 845 #endif 846 /* 847 * Close any file descriptors 0..2 that reference procfs, 848 * then make sure file descriptors 0..2 are in use. 849 * 850 * Both fdsetugidsafety() and fdcheckstd() may call functions 851 * taking sleepable locks, so temporarily drop our locks. 852 */ 853 PROC_UNLOCK(p); 854 VOP_UNLOCK(imgp->vp); 855 fdsetugidsafety(td); 856 error = fdcheckstd(td); 857 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 858 if (error != 0) 859 goto exec_fail_dealloc; 860 PROC_LOCK(p); 861 #ifdef MAC 862 if (will_transition) { 863 mac_vnode_execve_transition(oldcred, imgp->newcred, 864 imgp->vp, interpvplabel, imgp); 865 } 866 #endif 867 } else { 868 if (oldcred->cr_uid == oldcred->cr_ruid && 869 oldcred->cr_gid == oldcred->cr_rgid) 870 p->p_flag &= ~P_SUGID; 871 } 872 /* 873 * Set the new credentials. 874 */ 875 if (imgp->newcred != NULL) { 876 proc_set_cred(p, imgp->newcred); 877 crfree(oldcred); 878 oldcred = NULL; 879 } 880 881 /* 882 * Store the vp for use in kern.proc.pathname. This vnode was 883 * referenced by namei() or by fexecve variant of fname handling. 884 */ 885 oldtextvp = p->p_textvp; 886 p->p_textvp = newtextvp; 887 oldtextdvp = p->p_textdvp; 888 p->p_textdvp = newtextdvp; 889 newtextdvp = NULL; 890 oldbinname = p->p_binname; 891 p->p_binname = newbinname; 892 newbinname = NULL; 893 894 #ifdef KDTRACE_HOOKS 895 /* 896 * Tell the DTrace fasttrap provider about the exec if it 897 * has declared an interest. 898 */ 899 if (dtrace_fasttrap_exec) 900 dtrace_fasttrap_exec(p); 901 #endif 902 903 /* 904 * Notify others that we exec'd, and clear the P_INEXEC flag 905 * as we're now a bona fide freshly-execed process. 906 */ 907 KNOTE_LOCKED(p->p_klist, NOTE_EXEC); 908 p->p_flag &= ~P_INEXEC; 909 910 /* clear "fork but no exec" flag, as we _are_ execing */ 911 p->p_acflag &= ~AFORK; 912 913 /* 914 * Free any previous argument cache and replace it with 915 * the new argument cache, if any. 916 */ 917 oldargs = p->p_args; 918 p->p_args = newargs; 919 newargs = NULL; 920 921 PROC_UNLOCK(p); 922 923 #ifdef HWPMC_HOOKS 924 /* 925 * Check if system-wide sampling is in effect or if the 926 * current process is using PMCs. If so, do exec() time 927 * processing. This processing needs to happen AFTER the 928 * P_INEXEC flag is cleared. 929 */ 930 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { 931 VOP_UNLOCK(imgp->vp); 932 pe.pm_credentialschanged = credential_changing; 933 pe.pm_entryaddr = imgp->entry_addr; 934 935 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); 936 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 937 } 938 #endif 939 940 /* Set values passed into the program in registers. */ 941 (*p->p_sysent->sv_setregs)(td, imgp, stack_base); 942 943 VOP_MMAPPED(imgp->vp); 944 945 SDT_PROBE1(proc, , , exec__success, args->fname); 946 947 exec_fail_dealloc: 948 if (error != 0) { 949 p->p_osrel = orig_osrel; 950 p->p_fctl0 = orig_fctl0; 951 p->p_elf_brandinfo = orig_brandinfo; 952 } 953 954 if (imgp->firstpage != NULL) 955 exec_unmap_first_page(imgp); 956 957 if (imgp->vp != NULL) { 958 if (imgp->opened) 959 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); 960 if (imgp->textset) 961 VOP_UNSET_TEXT_CHECKED(imgp->vp); 962 if (error != 0) 963 vput(imgp->vp); 964 else 965 VOP_UNLOCK(imgp->vp); 966 if (args->fname != NULL) 967 NDFREE_PNBUF(&nd); 968 if (newtextdvp != NULL) 969 vrele(newtextdvp); 970 free(newbinname, M_PARGS); 971 } 972 973 if (imgp->object != NULL) 974 vm_object_deallocate(imgp->object); 975 976 free(imgp->freepath, M_TEMP); 977 978 if (error == 0) { 979 if (p->p_ptevents & PTRACE_EXEC) { 980 PROC_LOCK(p); 981 if (p->p_ptevents & PTRACE_EXEC) 982 td->td_dbgflags |= TDB_EXEC; 983 PROC_UNLOCK(p); 984 } 985 } else { 986 exec_fail: 987 /* we're done here, clear P_INEXEC */ 988 PROC_LOCK(p); 989 p->p_flag &= ~P_INEXEC; 990 PROC_UNLOCK(p); 991 992 SDT_PROBE1(proc, , , exec__failure, error); 993 } 994 995 if (imgp->newcred != NULL && oldcred != NULL) 996 crfree(imgp->newcred); 997 998 #ifdef MAC 999 mac_execve_exit(imgp); 1000 mac_execve_interpreter_exit(interpvplabel); 1001 #endif 1002 exec_free_args(args); 1003 1004 /* 1005 * Handle deferred decrement of ref counts. 1006 */ 1007 if (oldtextvp != NULL) 1008 vrele(oldtextvp); 1009 if (oldtextdvp != NULL) 1010 vrele(oldtextdvp); 1011 free(oldbinname, M_PARGS); 1012 #ifdef KTRACE 1013 ktr_io_params_free(kiop); 1014 #endif 1015 pargs_drop(oldargs); 1016 pargs_drop(newargs); 1017 if (oldsigacts != NULL) 1018 sigacts_free(oldsigacts); 1019 if (euip != NULL) 1020 uifree(euip); 1021 1022 if (error && imgp->vmspace_destroyed) { 1023 /* sorry, no more process anymore. exit gracefully */ 1024 exec_cleanup(td, oldvmspace); 1025 exit1(td, 0, SIGABRT); 1026 /* NOT REACHED */ 1027 } 1028 1029 #ifdef KTRACE 1030 if (error == 0) 1031 ktrprocctor(p); 1032 #endif 1033 1034 /* 1035 * We don't want cpu_set_syscall_retval() to overwrite any of 1036 * the register values put in place by exec_setregs(). 1037 * Implementations of cpu_set_syscall_retval() will leave 1038 * registers unmodified when returning EJUSTRETURN. 1039 */ 1040 return (error == 0 ? EJUSTRETURN : error); 1041 } 1042 1043 void 1044 exec_cleanup(struct thread *td, struct vmspace *oldvmspace) 1045 { 1046 if ((td->td_pflags & TDP_EXECVMSPC) != 0) { 1047 KASSERT(td->td_proc->p_vmspace != oldvmspace, 1048 ("oldvmspace still used")); 1049 vmspace_free(oldvmspace); 1050 td->td_pflags &= ~TDP_EXECVMSPC; 1051 } 1052 } 1053 1054 int 1055 exec_map_first_page(struct image_params *imgp) 1056 { 1057 vm_object_t object; 1058 vm_page_t m; 1059 int error; 1060 1061 if (imgp->firstpage != NULL) 1062 exec_unmap_first_page(imgp); 1063 1064 object = imgp->vp->v_object; 1065 if (object == NULL) 1066 return (EACCES); 1067 #if VM_NRESERVLEVEL > 0 1068 if ((object->flags & OBJ_COLORED) == 0) { 1069 VM_OBJECT_WLOCK(object); 1070 vm_object_color(object, 0); 1071 VM_OBJECT_WUNLOCK(object); 1072 } 1073 #endif 1074 error = vm_page_grab_valid_unlocked(&m, object, 0, 1075 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | 1076 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 1077 1078 if (error != VM_PAGER_OK) 1079 return (EIO); 1080 imgp->firstpage = sf_buf_alloc(m, 0); 1081 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); 1082 1083 return (0); 1084 } 1085 1086 void 1087 exec_unmap_first_page(struct image_params *imgp) 1088 { 1089 vm_page_t m; 1090 1091 if (imgp->firstpage != NULL) { 1092 m = sf_buf_page(imgp->firstpage); 1093 sf_buf_free(imgp->firstpage); 1094 imgp->firstpage = NULL; 1095 vm_page_unwire(m, PQ_ACTIVE); 1096 } 1097 } 1098 1099 void 1100 exec_onexec_old(struct thread *td) 1101 { 1102 sigfastblock_clear(td); 1103 umtx_exec(td->td_proc); 1104 } 1105 1106 /* 1107 * This is an optimization which removes the unmanaged shared page 1108 * mapping. In combination with pmap_remove_pages(), which cleans all 1109 * managed mappings in the process' vmspace pmap, no work will be left 1110 * for pmap_remove(min, max). 1111 */ 1112 void 1113 exec_free_abi_mappings(struct proc *p) 1114 { 1115 struct vmspace *vmspace; 1116 1117 vmspace = p->p_vmspace; 1118 if (refcount_load(&vmspace->vm_refcnt) != 1) 1119 return; 1120 1121 if (!PROC_HAS_SHP(p)) 1122 return; 1123 1124 pmap_remove(vmspace_pmap(vmspace), vmspace->vm_shp_base, 1125 vmspace->vm_shp_base + p->p_sysent->sv_shared_page_len); 1126 } 1127 1128 /* 1129 * Run down the current address space and install a new one. 1130 */ 1131 int 1132 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) 1133 { 1134 int error; 1135 struct proc *p = imgp->proc; 1136 struct vmspace *vmspace = p->p_vmspace; 1137 struct thread *td = curthread; 1138 vm_offset_t sv_minuser; 1139 vm_map_t map; 1140 1141 imgp->vmspace_destroyed = true; 1142 imgp->sysent = sv; 1143 1144 if (p->p_sysent->sv_onexec_old != NULL) 1145 p->p_sysent->sv_onexec_old(td); 1146 itimers_exec(p); 1147 1148 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); 1149 1150 /* 1151 * Blow away entire process VM, if address space not shared, 1152 * otherwise, create a new VM space so that other threads are 1153 * not disrupted 1154 */ 1155 map = &vmspace->vm_map; 1156 if (map_at_zero) 1157 sv_minuser = sv->sv_minuser; 1158 else 1159 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); 1160 if (refcount_load(&vmspace->vm_refcnt) == 1 && 1161 vm_map_min(map) == sv_minuser && 1162 vm_map_max(map) == sv->sv_maxuser && 1163 cpu_exec_vmspace_reuse(p, map)) { 1164 exec_free_abi_mappings(p); 1165 shmexit(vmspace); 1166 pmap_remove_pages(vmspace_pmap(vmspace)); 1167 vm_map_remove(map, vm_map_min(map), vm_map_max(map)); 1168 /* 1169 * An exec terminates mlockall(MCL_FUTURE). 1170 * ASLR and W^X states must be re-evaluated. 1171 */ 1172 vm_map_lock(map); 1173 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | 1174 MAP_ASLR_IGNSTART | MAP_ASLR_STACK | MAP_WXORX); 1175 vm_map_unlock(map); 1176 } else { 1177 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); 1178 if (error) 1179 return (error); 1180 vmspace = p->p_vmspace; 1181 map = &vmspace->vm_map; 1182 } 1183 map->flags |= imgp->map_flags; 1184 1185 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0); 1186 } 1187 1188 /* 1189 * Compute the stack size limit and map the main process stack. 1190 * Map the shared page. 1191 */ 1192 int 1193 exec_map_stack(struct image_params *imgp) 1194 { 1195 struct rlimit rlim_stack; 1196 struct sysentvec *sv; 1197 struct proc *p; 1198 vm_map_t map; 1199 struct vmspace *vmspace; 1200 vm_offset_t stack_addr, stack_top; 1201 vm_offset_t sharedpage_addr; 1202 u_long ssiz; 1203 int error, find_space, stack_off; 1204 vm_prot_t stack_prot; 1205 vm_object_t obj; 1206 1207 p = imgp->proc; 1208 sv = p->p_sysent; 1209 1210 if (imgp->stack_sz != 0) { 1211 ssiz = trunc_page(imgp->stack_sz); 1212 PROC_LOCK(p); 1213 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); 1214 PROC_UNLOCK(p); 1215 if (ssiz > rlim_stack.rlim_max) 1216 ssiz = rlim_stack.rlim_max; 1217 if (ssiz > rlim_stack.rlim_cur) { 1218 rlim_stack.rlim_cur = ssiz; 1219 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); 1220 } 1221 } else if (sv->sv_maxssiz != NULL) { 1222 ssiz = *sv->sv_maxssiz; 1223 } else { 1224 ssiz = maxssiz; 1225 } 1226 1227 vmspace = p->p_vmspace; 1228 map = &vmspace->vm_map; 1229 1230 stack_prot = sv->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? 1231 imgp->stack_prot : sv->sv_stackprot; 1232 if ((map->flags & MAP_ASLR_STACK) != 0) { 1233 stack_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1234 lim_max(curthread, RLIMIT_DATA)); 1235 find_space = VMFS_ANY_SPACE; 1236 } else { 1237 stack_addr = sv->sv_usrstack - ssiz; 1238 find_space = VMFS_NO_SPACE; 1239 } 1240 error = vm_map_find(map, NULL, 0, &stack_addr, (vm_size_t)ssiz, 1241 sv->sv_usrstack, find_space, stack_prot, VM_PROT_ALL, 1242 MAP_STACK_GROWS_DOWN); 1243 if (error != KERN_SUCCESS) { 1244 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " 1245 "failed, mach error %d errno %d\n", (uintmax_t)ssiz, 1246 stack_prot, error, vm_mmap_to_errno(error)); 1247 return (vm_mmap_to_errno(error)); 1248 } 1249 1250 stack_top = stack_addr + ssiz; 1251 if ((map->flags & MAP_ASLR_STACK) != 0) { 1252 /* Randomize within the first page of the stack. */ 1253 arc4rand(&stack_off, sizeof(stack_off), 0); 1254 stack_top -= rounddown2(stack_off & PAGE_MASK, sizeof(void *)); 1255 } 1256 1257 /* Map a shared page */ 1258 obj = sv->sv_shared_page_obj; 1259 if (obj == NULL) { 1260 sharedpage_addr = 0; 1261 goto out; 1262 } 1263 1264 /* 1265 * If randomization is disabled then the shared page will 1266 * be mapped at address specified in sysentvec. 1267 * Otherwise any address above .data section can be selected. 1268 * Same logic is used for stack address randomization. 1269 * If the address randomization is applied map a guard page 1270 * at the top of UVA. 1271 */ 1272 vm_object_reference(obj); 1273 if ((imgp->imgp_flags & IMGP_ASLR_SHARED_PAGE) != 0) { 1274 sharedpage_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1275 lim_max(curthread, RLIMIT_DATA)); 1276 1277 error = vm_map_fixed(map, NULL, 0, 1278 sv->sv_maxuser - PAGE_SIZE, PAGE_SIZE, 1279 VM_PROT_NONE, VM_PROT_NONE, MAP_CREATE_GUARD); 1280 if (error != KERN_SUCCESS) { 1281 /* 1282 * This is not fatal, so let's just print a warning 1283 * and continue. 1284 */ 1285 uprintf("%s: Mapping guard page at the top of UVA failed" 1286 " mach error %d errno %d", 1287 __func__, error, vm_mmap_to_errno(error)); 1288 } 1289 1290 error = vm_map_find(map, obj, 0, 1291 &sharedpage_addr, sv->sv_shared_page_len, 1292 sv->sv_maxuser, VMFS_ANY_SPACE, 1293 VM_PROT_READ | VM_PROT_EXECUTE, 1294 VM_PROT_READ | VM_PROT_EXECUTE, 1295 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1296 } else { 1297 sharedpage_addr = sv->sv_shared_page_base; 1298 vm_map_fixed(map, obj, 0, 1299 sharedpage_addr, sv->sv_shared_page_len, 1300 VM_PROT_READ | VM_PROT_EXECUTE, 1301 VM_PROT_READ | VM_PROT_EXECUTE, 1302 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1303 } 1304 if (error != KERN_SUCCESS) { 1305 uprintf("%s: mapping shared page at addr: %p" 1306 "failed, mach error %d errno %d\n", __func__, 1307 (void *)sharedpage_addr, error, vm_mmap_to_errno(error)); 1308 vm_object_deallocate(obj); 1309 return (vm_mmap_to_errno(error)); 1310 } 1311 out: 1312 /* 1313 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they 1314 * are still used to enforce the stack rlimit on the process stack. 1315 */ 1316 vmspace->vm_maxsaddr = (char *)stack_addr; 1317 vmspace->vm_stacktop = stack_top; 1318 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; 1319 vmspace->vm_shp_base = sharedpage_addr; 1320 1321 return (0); 1322 } 1323 1324 /* 1325 * Copy out argument and environment strings from the old process address 1326 * space into the temporary string buffer. 1327 */ 1328 int 1329 exec_copyin_args(struct image_args *args, const char *fname, 1330 enum uio_seg segflg, char **argv, char **envv) 1331 { 1332 u_long arg, env; 1333 int error; 1334 1335 bzero(args, sizeof(*args)); 1336 if (argv == NULL) 1337 return (EFAULT); 1338 1339 /* 1340 * Allocate demand-paged memory for the file name, argument, and 1341 * environment strings. 1342 */ 1343 error = exec_alloc_args(args); 1344 if (error != 0) 1345 return (error); 1346 1347 /* 1348 * Copy the file name. 1349 */ 1350 error = exec_args_add_fname(args, fname, segflg); 1351 if (error != 0) 1352 goto err_exit; 1353 1354 /* 1355 * extract arguments first 1356 */ 1357 for (;;) { 1358 error = fueword(argv++, &arg); 1359 if (error == -1) { 1360 error = EFAULT; 1361 goto err_exit; 1362 } 1363 if (arg == 0) 1364 break; 1365 error = exec_args_add_arg(args, (char *)(uintptr_t)arg, 1366 UIO_USERSPACE); 1367 if (error != 0) 1368 goto err_exit; 1369 } 1370 1371 /* 1372 * extract environment strings 1373 */ 1374 if (envv) { 1375 for (;;) { 1376 error = fueword(envv++, &env); 1377 if (error == -1) { 1378 error = EFAULT; 1379 goto err_exit; 1380 } 1381 if (env == 0) 1382 break; 1383 error = exec_args_add_env(args, 1384 (char *)(uintptr_t)env, UIO_USERSPACE); 1385 if (error != 0) 1386 goto err_exit; 1387 } 1388 } 1389 1390 return (0); 1391 1392 err_exit: 1393 exec_free_args(args); 1394 return (error); 1395 } 1396 1397 struct exec_args_kva { 1398 vm_offset_t addr; 1399 u_int gen; 1400 SLIST_ENTRY(exec_args_kva) next; 1401 }; 1402 1403 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); 1404 1405 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; 1406 static struct mtx exec_args_kva_mtx; 1407 static u_int exec_args_gen; 1408 1409 static void 1410 exec_prealloc_args_kva(void *arg __unused) 1411 { 1412 struct exec_args_kva *argkva; 1413 u_int i; 1414 1415 SLIST_INIT(&exec_args_kva_freelist); 1416 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); 1417 for (i = 0; i < exec_map_entries; i++) { 1418 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); 1419 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); 1420 argkva->gen = exec_args_gen; 1421 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1422 } 1423 } 1424 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); 1425 1426 static vm_offset_t 1427 exec_alloc_args_kva(void **cookie) 1428 { 1429 struct exec_args_kva *argkva; 1430 1431 argkva = (void *)atomic_readandclear_ptr( 1432 (uintptr_t *)DPCPU_PTR(exec_args_kva)); 1433 if (argkva == NULL) { 1434 mtx_lock(&exec_args_kva_mtx); 1435 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) 1436 (void)mtx_sleep(&exec_args_kva_freelist, 1437 &exec_args_kva_mtx, 0, "execkva", 0); 1438 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); 1439 mtx_unlock(&exec_args_kva_mtx); 1440 } 1441 kasan_mark((void *)argkva->addr, exec_map_entry_size, 1442 exec_map_entry_size, 0); 1443 *(struct exec_args_kva **)cookie = argkva; 1444 return (argkva->addr); 1445 } 1446 1447 static void 1448 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) 1449 { 1450 vm_offset_t base; 1451 1452 base = argkva->addr; 1453 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size, 1454 KASAN_EXEC_ARGS_FREED); 1455 if (argkva->gen != gen) { 1456 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, 1457 MADV_FREE); 1458 argkva->gen = gen; 1459 } 1460 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), 1461 (uintptr_t)NULL, (uintptr_t)argkva)) { 1462 mtx_lock(&exec_args_kva_mtx); 1463 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1464 wakeup_one(&exec_args_kva_freelist); 1465 mtx_unlock(&exec_args_kva_mtx); 1466 } 1467 } 1468 1469 static void 1470 exec_free_args_kva(void *cookie) 1471 { 1472 1473 exec_release_args_kva(cookie, exec_args_gen); 1474 } 1475 1476 static void 1477 exec_args_kva_lowmem(void *arg __unused) 1478 { 1479 SLIST_HEAD(, exec_args_kva) head; 1480 struct exec_args_kva *argkva; 1481 u_int gen; 1482 int i; 1483 1484 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; 1485 1486 /* 1487 * Force an madvise of each KVA range. Any currently allocated ranges 1488 * will have MADV_FREE applied once they are freed. 1489 */ 1490 SLIST_INIT(&head); 1491 mtx_lock(&exec_args_kva_mtx); 1492 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); 1493 mtx_unlock(&exec_args_kva_mtx); 1494 while ((argkva = SLIST_FIRST(&head)) != NULL) { 1495 SLIST_REMOVE_HEAD(&head, next); 1496 exec_release_args_kva(argkva, gen); 1497 } 1498 1499 CPU_FOREACH(i) { 1500 argkva = (void *)atomic_readandclear_ptr( 1501 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); 1502 if (argkva != NULL) 1503 exec_release_args_kva(argkva, gen); 1504 } 1505 } 1506 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, 1507 EVENTHANDLER_PRI_ANY); 1508 1509 /* 1510 * Allocate temporary demand-paged, zero-filled memory for the file name, 1511 * argument, and environment strings. 1512 */ 1513 int 1514 exec_alloc_args(struct image_args *args) 1515 { 1516 1517 args->buf = (char *)exec_alloc_args_kva(&args->bufkva); 1518 return (0); 1519 } 1520 1521 void 1522 exec_free_args(struct image_args *args) 1523 { 1524 1525 if (args->buf != NULL) { 1526 exec_free_args_kva(args->bufkva); 1527 args->buf = NULL; 1528 } 1529 if (args->fname_buf != NULL) { 1530 free(args->fname_buf, M_TEMP); 1531 args->fname_buf = NULL; 1532 } 1533 } 1534 1535 /* 1536 * A set to functions to fill struct image args. 1537 * 1538 * NOTE: exec_args_add_fname() must be called (possibly with a NULL 1539 * fname) before the other functions. All exec_args_add_arg() calls must 1540 * be made before any exec_args_add_env() calls. exec_args_adjust_args() 1541 * may be called any time after exec_args_add_fname(). 1542 * 1543 * exec_args_add_fname() - install path to be executed 1544 * exec_args_add_arg() - append an argument string 1545 * exec_args_add_env() - append an env string 1546 * exec_args_adjust_args() - adjust location of the argument list to 1547 * allow new arguments to be prepended 1548 */ 1549 int 1550 exec_args_add_fname(struct image_args *args, const char *fname, 1551 enum uio_seg segflg) 1552 { 1553 int error; 1554 size_t length; 1555 1556 KASSERT(args->fname == NULL, ("fname already appended")); 1557 KASSERT(args->endp == NULL, ("already appending to args")); 1558 1559 if (fname != NULL) { 1560 args->fname = args->buf; 1561 error = segflg == UIO_SYSSPACE ? 1562 copystr(fname, args->fname, PATH_MAX, &length) : 1563 copyinstr(fname, args->fname, PATH_MAX, &length); 1564 if (error != 0) 1565 return (error == ENAMETOOLONG ? E2BIG : error); 1566 } else 1567 length = 0; 1568 1569 /* Set up for _arg_*()/_env_*() */ 1570 args->endp = args->buf + length; 1571 /* begin_argv must be set and kept updated */ 1572 args->begin_argv = args->endp; 1573 KASSERT(exec_map_entry_size - length >= ARG_MAX, 1574 ("too little space remaining for arguments %zu < %zu", 1575 exec_map_entry_size - length, (size_t)ARG_MAX)); 1576 args->stringspace = ARG_MAX; 1577 1578 return (0); 1579 } 1580 1581 static int 1582 exec_args_add_str(struct image_args *args, const char *str, 1583 enum uio_seg segflg, int *countp) 1584 { 1585 int error; 1586 size_t length; 1587 1588 KASSERT(args->endp != NULL, ("endp not initialized")); 1589 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1590 1591 error = (segflg == UIO_SYSSPACE) ? 1592 copystr(str, args->endp, args->stringspace, &length) : 1593 copyinstr(str, args->endp, args->stringspace, &length); 1594 if (error != 0) 1595 return (error == ENAMETOOLONG ? E2BIG : error); 1596 args->stringspace -= length; 1597 args->endp += length; 1598 (*countp)++; 1599 1600 return (0); 1601 } 1602 1603 int 1604 exec_args_add_arg(struct image_args *args, const char *argp, 1605 enum uio_seg segflg) 1606 { 1607 1608 KASSERT(args->envc == 0, ("appending args after env")); 1609 1610 return (exec_args_add_str(args, argp, segflg, &args->argc)); 1611 } 1612 1613 int 1614 exec_args_add_env(struct image_args *args, const char *envp, 1615 enum uio_seg segflg) 1616 { 1617 1618 if (args->envc == 0) 1619 args->begin_envv = args->endp; 1620 1621 return (exec_args_add_str(args, envp, segflg, &args->envc)); 1622 } 1623 1624 int 1625 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) 1626 { 1627 ssize_t offset; 1628 1629 KASSERT(args->endp != NULL, ("endp not initialized")); 1630 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1631 1632 offset = extend - consume; 1633 if (args->stringspace < offset) 1634 return (E2BIG); 1635 memmove(args->begin_argv + extend, args->begin_argv + consume, 1636 args->endp - args->begin_argv + consume); 1637 if (args->envc > 0) 1638 args->begin_envv += offset; 1639 args->endp += offset; 1640 args->stringspace -= offset; 1641 return (0); 1642 } 1643 1644 char * 1645 exec_args_get_begin_envv(struct image_args *args) 1646 { 1647 1648 KASSERT(args->endp != NULL, ("endp not initialized")); 1649 1650 if (args->envc > 0) 1651 return (args->begin_envv); 1652 return (args->endp); 1653 } 1654 1655 /* 1656 * Copy strings out to the new process address space, constructing new arg 1657 * and env vector tables. Return a pointer to the base so that it can be used 1658 * as the initial stack pointer. 1659 */ 1660 int 1661 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 1662 { 1663 int argc, envc; 1664 char **vectp; 1665 char *stringp; 1666 uintptr_t destp, ustringp; 1667 struct ps_strings *arginfo; 1668 struct proc *p; 1669 struct sysentvec *sysent; 1670 size_t execpath_len; 1671 int error, szsigcode; 1672 char canary[sizeof(long) * 8]; 1673 1674 p = imgp->proc; 1675 sysent = p->p_sysent; 1676 1677 destp = PROC_PS_STRINGS(p); 1678 arginfo = imgp->ps_strings = (void *)destp; 1679 1680 /* 1681 * Install sigcode. 1682 */ 1683 if (sysent->sv_shared_page_base == 0 && sysent->sv_szsigcode != NULL) { 1684 szsigcode = *(sysent->sv_szsigcode); 1685 destp -= szsigcode; 1686 destp = rounddown2(destp, sizeof(void *)); 1687 error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode); 1688 if (error != 0) 1689 return (error); 1690 } 1691 1692 /* 1693 * Copy the image path for the rtld. 1694 */ 1695 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 1696 execpath_len = strlen(imgp->execpath) + 1; 1697 destp -= execpath_len; 1698 destp = rounddown2(destp, sizeof(void *)); 1699 imgp->execpathp = (void *)destp; 1700 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 1701 if (error != 0) 1702 return (error); 1703 } 1704 1705 /* 1706 * Prepare the canary for SSP. 1707 */ 1708 arc4rand(canary, sizeof(canary), 0); 1709 destp -= sizeof(canary); 1710 imgp->canary = (void *)destp; 1711 error = copyout(canary, imgp->canary, sizeof(canary)); 1712 if (error != 0) 1713 return (error); 1714 imgp->canarylen = sizeof(canary); 1715 1716 /* 1717 * Prepare the pagesizes array. 1718 */ 1719 imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES; 1720 destp -= imgp->pagesizeslen; 1721 destp = rounddown2(destp, sizeof(void *)); 1722 imgp->pagesizes = (void *)destp; 1723 error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen); 1724 if (error != 0) 1725 return (error); 1726 1727 /* 1728 * Allocate room for the argument and environment strings. 1729 */ 1730 destp -= ARG_MAX - imgp->args->stringspace; 1731 destp = rounddown2(destp, sizeof(void *)); 1732 ustringp = destp; 1733 1734 if (imgp->auxargs) { 1735 /* 1736 * Allocate room on the stack for the ELF auxargs 1737 * array. It has up to AT_COUNT entries. 1738 */ 1739 destp -= AT_COUNT * sizeof(Elf_Auxinfo); 1740 destp = rounddown2(destp, sizeof(void *)); 1741 } 1742 1743 vectp = (char **)destp; 1744 1745 /* 1746 * Allocate room for the argv[] and env vectors including the 1747 * terminating NULL pointers. 1748 */ 1749 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 1750 1751 /* 1752 * vectp also becomes our initial stack base 1753 */ 1754 *stack_base = (uintptr_t)vectp; 1755 1756 stringp = imgp->args->begin_argv; 1757 argc = imgp->args->argc; 1758 envc = imgp->args->envc; 1759 1760 /* 1761 * Copy out strings - arguments and environment. 1762 */ 1763 error = copyout(stringp, (void *)ustringp, 1764 ARG_MAX - imgp->args->stringspace); 1765 if (error != 0) 1766 return (error); 1767 1768 /* 1769 * Fill in "ps_strings" struct for ps, w, etc. 1770 */ 1771 imgp->argv = vectp; 1772 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 1773 suword32(&arginfo->ps_nargvstr, argc) != 0) 1774 return (EFAULT); 1775 1776 /* 1777 * Fill in argument portion of vector table. 1778 */ 1779 for (; argc > 0; --argc) { 1780 if (suword(vectp++, ustringp) != 0) 1781 return (EFAULT); 1782 while (*stringp++ != 0) 1783 ustringp++; 1784 ustringp++; 1785 } 1786 1787 /* a null vector table pointer separates the argp's from the envp's */ 1788 if (suword(vectp++, 0) != 0) 1789 return (EFAULT); 1790 1791 imgp->envv = vectp; 1792 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 1793 suword32(&arginfo->ps_nenvstr, envc) != 0) 1794 return (EFAULT); 1795 1796 /* 1797 * Fill in environment portion of vector table. 1798 */ 1799 for (; envc > 0; --envc) { 1800 if (suword(vectp++, ustringp) != 0) 1801 return (EFAULT); 1802 while (*stringp++ != 0) 1803 ustringp++; 1804 ustringp++; 1805 } 1806 1807 /* end of vector table is a null pointer */ 1808 if (suword(vectp, 0) != 0) 1809 return (EFAULT); 1810 1811 if (imgp->auxargs) { 1812 vectp++; 1813 error = imgp->sysent->sv_copyout_auxargs(imgp, 1814 (uintptr_t)vectp); 1815 if (error != 0) 1816 return (error); 1817 } 1818 1819 return (0); 1820 } 1821 1822 /* 1823 * Check permissions of file to execute. 1824 * Called with imgp->vp locked. 1825 * Return 0 for success or error code on failure. 1826 */ 1827 int 1828 exec_check_permissions(struct image_params *imgp) 1829 { 1830 struct vnode *vp = imgp->vp; 1831 struct vattr *attr = imgp->attr; 1832 struct thread *td; 1833 int error; 1834 1835 td = curthread; 1836 1837 /* Get file attributes */ 1838 error = VOP_GETATTR(vp, attr, td->td_ucred); 1839 if (error) 1840 return (error); 1841 1842 #ifdef MAC 1843 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); 1844 if (error) 1845 return (error); 1846 #endif 1847 1848 /* 1849 * 1) Check if file execution is disabled for the filesystem that 1850 * this file resides on. 1851 * 2) Ensure that at least one execute bit is on. Otherwise, a 1852 * privileged user will always succeed, and we don't want this 1853 * to happen unless the file really is executable. 1854 * 3) Ensure that the file is a regular file. 1855 */ 1856 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || 1857 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || 1858 (attr->va_type != VREG)) 1859 return (EACCES); 1860 1861 /* 1862 * Zero length files can't be exec'd 1863 */ 1864 if (attr->va_size == 0) 1865 return (ENOEXEC); 1866 1867 /* 1868 * Check for execute permission to file based on current credentials. 1869 */ 1870 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); 1871 if (error) 1872 return (error); 1873 1874 /* 1875 * Check number of open-for-writes on the file and deny execution 1876 * if there are any. 1877 * 1878 * Add a text reference now so no one can write to the 1879 * executable while we're activating it. 1880 * 1881 * Remember if this was set before and unset it in case this is not 1882 * actually an executable image. 1883 */ 1884 error = VOP_SET_TEXT(vp); 1885 if (error != 0) 1886 return (error); 1887 imgp->textset = true; 1888 1889 /* 1890 * Call filesystem specific open routine (which does nothing in the 1891 * general case). 1892 */ 1893 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); 1894 if (error == 0) 1895 imgp->opened = true; 1896 return (error); 1897 } 1898 1899 /* 1900 * Exec handler registration 1901 */ 1902 int 1903 exec_register(const struct execsw *execsw_arg) 1904 { 1905 const struct execsw **es, **xs, **newexecsw; 1906 u_int count = 2; /* New slot and trailing NULL */ 1907 1908 if (execsw) 1909 for (es = execsw; *es; es++) 1910 count++; 1911 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1912 xs = newexecsw; 1913 if (execsw) 1914 for (es = execsw; *es; es++) 1915 *xs++ = *es; 1916 *xs++ = execsw_arg; 1917 *xs = NULL; 1918 if (execsw) 1919 free(execsw, M_TEMP); 1920 execsw = newexecsw; 1921 return (0); 1922 } 1923 1924 int 1925 exec_unregister(const struct execsw *execsw_arg) 1926 { 1927 const struct execsw **es, **xs, **newexecsw; 1928 int count = 1; 1929 1930 if (execsw == NULL) 1931 panic("unregister with no handlers left?\n"); 1932 1933 for (es = execsw; *es; es++) { 1934 if (*es == execsw_arg) 1935 break; 1936 } 1937 if (*es == NULL) 1938 return (ENOENT); 1939 for (es = execsw; *es; es++) 1940 if (*es != execsw_arg) 1941 count++; 1942 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1943 xs = newexecsw; 1944 for (es = execsw; *es; es++) 1945 if (*es != execsw_arg) 1946 *xs++ = *es; 1947 *xs = NULL; 1948 if (execsw) 1949 free(execsw, M_TEMP); 1950 execsw = newexecsw; 1951 return (0); 1952 } 1953 1954 /* 1955 * Write out a core segment to the compression stream. 1956 */ 1957 static int 1958 compress_chunk(struct coredump_params *cp, char *base, char *buf, size_t len) 1959 { 1960 size_t chunk_len; 1961 int error; 1962 1963 while (len > 0) { 1964 chunk_len = MIN(len, CORE_BUF_SIZE); 1965 1966 /* 1967 * We can get EFAULT error here. 1968 * In that case zero out the current chunk of the segment. 1969 */ 1970 error = copyin(base, buf, chunk_len); 1971 if (error != 0) 1972 bzero(buf, chunk_len); 1973 error = compressor_write(cp->comp, buf, chunk_len); 1974 if (error != 0) 1975 break; 1976 base += chunk_len; 1977 len -= chunk_len; 1978 } 1979 return (error); 1980 } 1981 1982 int 1983 core_write(struct coredump_params *cp, const void *base, size_t len, 1984 off_t offset, enum uio_seg seg, size_t *resid) 1985 { 1986 1987 return (vn_rdwr_inchunks(UIO_WRITE, cp->vp, __DECONST(void *, base), 1988 len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED, 1989 cp->active_cred, cp->file_cred, resid, cp->td)); 1990 } 1991 1992 int 1993 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp, 1994 void *tmpbuf) 1995 { 1996 vm_map_t map; 1997 struct mount *mp; 1998 size_t resid, runlen; 1999 int error; 2000 bool success; 2001 2002 KASSERT((uintptr_t)base % PAGE_SIZE == 0, 2003 ("%s: user address %p is not page-aligned", __func__, base)); 2004 2005 if (cp->comp != NULL) 2006 return (compress_chunk(cp, base, tmpbuf, len)); 2007 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 }
Cache object: f3234e262ce2b260410e659e47f53989
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