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 SAVENAME | AUDITVNODE1 | WANTPARENT, UIO_SYSSPACE, 478 args->fname, td); 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(&nd, NDF_ONLY_PNBUF); 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 /* ABI enforces the use of Capsicum. Switch into capabilities mode. */ 741 if (SV_PROC_FLAG(p, SV_CAPSICUM)) 742 sys_cap_enter(td, NULL); 743 744 /* 745 * Copy out strings (args and env) and initialize stack base. 746 */ 747 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base); 748 if (error != 0) { 749 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 750 goto exec_fail_dealloc; 751 } 752 753 /* 754 * Stack setup. 755 */ 756 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp); 757 if (error != 0) { 758 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 759 goto exec_fail_dealloc; 760 } 761 762 if (args->fdp != NULL) { 763 /* Install a brand new file descriptor table. */ 764 fdinstall_remapped(td, args->fdp); 765 args->fdp = NULL; 766 } else { 767 /* 768 * Keep on using the existing file descriptor table. For 769 * security and other reasons, the file descriptor table 770 * cannot be shared after an exec. 771 */ 772 fdunshare(td); 773 pdunshare(td); 774 /* close files on exec */ 775 fdcloseexec(td); 776 } 777 778 /* 779 * Malloc things before we need locks. 780 */ 781 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv; 782 /* Cache arguments if they fit inside our allowance */ 783 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) { 784 newargs = pargs_alloc(i); 785 bcopy(imgp->args->begin_argv, newargs->ar_args, i); 786 } 787 788 /* 789 * For security and other reasons, signal handlers cannot 790 * be shared after an exec. The new process gets a copy of the old 791 * handlers. In execsigs(), the new process will have its signals 792 * reset. 793 */ 794 if (sigacts_shared(p->p_sigacts)) { 795 oldsigacts = p->p_sigacts; 796 newsigacts = sigacts_alloc(); 797 sigacts_copy(newsigacts, oldsigacts); 798 } 799 800 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 801 802 PROC_LOCK(p); 803 if (oldsigacts) 804 p->p_sigacts = newsigacts; 805 /* Stop profiling */ 806 stopprofclock(p); 807 808 /* reset caught signals */ 809 execsigs(p); 810 811 /* name this process - nameiexec(p, ndp) */ 812 bzero(p->p_comm, sizeof(p->p_comm)); 813 if (args->fname) 814 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm, 815 min(nd.ni_cnd.cn_namelen, MAXCOMLEN)); 816 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0) 817 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title)); 818 bcopy(p->p_comm, td->td_name, sizeof(td->td_name)); 819 #ifdef KTR 820 sched_clear_tdname(td); 821 #endif 822 823 /* 824 * mark as execed, wakeup the process that vforked (if any) and tell 825 * it that it now has its own resources back 826 */ 827 p->p_flag |= P_EXEC; 828 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0) 829 p->p_flag2 &= ~P2_NOTRACE; 830 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0) 831 p->p_flag2 &= ~P2_STKGAP_DISABLE; 832 if (p->p_flag & P_PPWAIT) { 833 p->p_flag &= ~(P_PPWAIT | P_PPTRACE); 834 cv_broadcast(&p->p_pwait); 835 /* STOPs are no longer ignored, arrange for AST */ 836 signotify(td); 837 } 838 839 if ((imgp->sysent->sv_setid_allowed != NULL && 840 !(*imgp->sysent->sv_setid_allowed)(td, imgp)) || 841 (p->p_flag2 & P2_NO_NEW_PRIVS) != 0) 842 execve_nosetid(imgp); 843 844 /* 845 * Implement image setuid/setgid installation. 846 */ 847 if (imgp->credential_setid) { 848 /* 849 * Turn off syscall tracing for set-id programs, except for 850 * root. Record any set-id flags first to make sure that 851 * we do not regain any tracing during a possible block. 852 */ 853 setsugid(p); 854 #ifdef KTRACE 855 kiop = ktrprocexec(p); 856 #endif 857 /* 858 * Close any file descriptors 0..2 that reference procfs, 859 * then make sure file descriptors 0..2 are in use. 860 * 861 * Both fdsetugidsafety() and fdcheckstd() may call functions 862 * taking sleepable locks, so temporarily drop our locks. 863 */ 864 PROC_UNLOCK(p); 865 VOP_UNLOCK(imgp->vp); 866 fdsetugidsafety(td); 867 error = fdcheckstd(td); 868 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 869 if (error != 0) 870 goto exec_fail_dealloc; 871 PROC_LOCK(p); 872 #ifdef MAC 873 if (will_transition) { 874 mac_vnode_execve_transition(oldcred, imgp->newcred, 875 imgp->vp, interpvplabel, imgp); 876 } 877 #endif 878 } else { 879 if (oldcred->cr_uid == oldcred->cr_ruid && 880 oldcred->cr_gid == oldcred->cr_rgid) 881 p->p_flag &= ~P_SUGID; 882 } 883 /* 884 * Set the new credentials. 885 */ 886 if (imgp->newcred != NULL) { 887 proc_set_cred(p, imgp->newcred); 888 crfree(oldcred); 889 oldcred = NULL; 890 } 891 892 /* 893 * Store the vp for use in kern.proc.pathname. This vnode was 894 * referenced by namei() or by fexecve variant of fname handling. 895 */ 896 oldtextvp = p->p_textvp; 897 p->p_textvp = newtextvp; 898 oldtextdvp = p->p_textdvp; 899 p->p_textdvp = newtextdvp; 900 newtextdvp = NULL; 901 oldbinname = p->p_binname; 902 p->p_binname = newbinname; 903 newbinname = NULL; 904 905 #ifdef KDTRACE_HOOKS 906 /* 907 * Tell the DTrace fasttrap provider about the exec if it 908 * has declared an interest. 909 */ 910 if (dtrace_fasttrap_exec) 911 dtrace_fasttrap_exec(p); 912 #endif 913 914 /* 915 * Notify others that we exec'd, and clear the P_INEXEC flag 916 * as we're now a bona fide freshly-execed process. 917 */ 918 KNOTE_LOCKED(p->p_klist, NOTE_EXEC); 919 p->p_flag &= ~P_INEXEC; 920 921 /* clear "fork but no exec" flag, as we _are_ execing */ 922 p->p_acflag &= ~AFORK; 923 924 /* 925 * Free any previous argument cache and replace it with 926 * the new argument cache, if any. 927 */ 928 oldargs = p->p_args; 929 p->p_args = newargs; 930 newargs = NULL; 931 932 PROC_UNLOCK(p); 933 934 #ifdef HWPMC_HOOKS 935 /* 936 * Check if system-wide sampling is in effect or if the 937 * current process is using PMCs. If so, do exec() time 938 * processing. This processing needs to happen AFTER the 939 * P_INEXEC flag is cleared. 940 */ 941 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) { 942 VOP_UNLOCK(imgp->vp); 943 pe.pm_credentialschanged = credential_changing; 944 pe.pm_entryaddr = imgp->entry_addr; 945 946 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe); 947 vn_lock(imgp->vp, LK_SHARED | LK_RETRY); 948 } 949 #endif 950 951 /* Set values passed into the program in registers. */ 952 (*p->p_sysent->sv_setregs)(td, imgp, stack_base); 953 954 VOP_MMAPPED(imgp->vp); 955 956 SDT_PROBE1(proc, , , exec__success, args->fname); 957 958 exec_fail_dealloc: 959 if (error != 0) { 960 p->p_osrel = orig_osrel; 961 p->p_fctl0 = orig_fctl0; 962 p->p_elf_brandinfo = orig_brandinfo; 963 } 964 965 if (imgp->firstpage != NULL) 966 exec_unmap_first_page(imgp); 967 968 if (imgp->vp != NULL) { 969 if (imgp->opened) 970 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td); 971 if (imgp->textset) 972 VOP_UNSET_TEXT_CHECKED(imgp->vp); 973 if (error != 0) 974 vput(imgp->vp); 975 else 976 VOP_UNLOCK(imgp->vp); 977 if (args->fname != NULL) 978 NDFREE(&nd, NDF_ONLY_PNBUF); 979 if (newtextdvp != NULL) 980 vrele(newtextdvp); 981 free(newbinname, M_PARGS); 982 } 983 984 if (imgp->object != NULL) 985 vm_object_deallocate(imgp->object); 986 987 free(imgp->freepath, M_TEMP); 988 989 if (error == 0) { 990 if (p->p_ptevents & PTRACE_EXEC) { 991 PROC_LOCK(p); 992 if (p->p_ptevents & PTRACE_EXEC) 993 td->td_dbgflags |= TDB_EXEC; 994 PROC_UNLOCK(p); 995 } 996 } else { 997 exec_fail: 998 /* we're done here, clear P_INEXEC */ 999 PROC_LOCK(p); 1000 p->p_flag &= ~P_INEXEC; 1001 PROC_UNLOCK(p); 1002 1003 SDT_PROBE1(proc, , , exec__failure, error); 1004 } 1005 1006 if (imgp->newcred != NULL && oldcred != NULL) 1007 crfree(imgp->newcred); 1008 1009 #ifdef MAC 1010 mac_execve_exit(imgp); 1011 mac_execve_interpreter_exit(interpvplabel); 1012 #endif 1013 exec_free_args(args); 1014 1015 /* 1016 * Handle deferred decrement of ref counts. 1017 */ 1018 if (oldtextvp != NULL) 1019 vrele(oldtextvp); 1020 if (oldtextdvp != NULL) 1021 vrele(oldtextdvp); 1022 free(oldbinname, M_PARGS); 1023 #ifdef KTRACE 1024 ktr_io_params_free(kiop); 1025 #endif 1026 pargs_drop(oldargs); 1027 pargs_drop(newargs); 1028 if (oldsigacts != NULL) 1029 sigacts_free(oldsigacts); 1030 if (euip != NULL) 1031 uifree(euip); 1032 1033 if (error && imgp->vmspace_destroyed) { 1034 /* sorry, no more process anymore. exit gracefully */ 1035 exec_cleanup(td, oldvmspace); 1036 exit1(td, 0, SIGABRT); 1037 /* NOT REACHED */ 1038 } 1039 1040 #ifdef KTRACE 1041 if (error == 0) 1042 ktrprocctor(p); 1043 #endif 1044 1045 /* 1046 * We don't want cpu_set_syscall_retval() to overwrite any of 1047 * the register values put in place by exec_setregs(). 1048 * Implementations of cpu_set_syscall_retval() will leave 1049 * registers unmodified when returning EJUSTRETURN. 1050 */ 1051 return (error == 0 ? EJUSTRETURN : error); 1052 } 1053 1054 void 1055 exec_cleanup(struct thread *td, struct vmspace *oldvmspace) 1056 { 1057 if ((td->td_pflags & TDP_EXECVMSPC) != 0) { 1058 KASSERT(td->td_proc->p_vmspace != oldvmspace, 1059 ("oldvmspace still used")); 1060 vmspace_free(oldvmspace); 1061 td->td_pflags &= ~TDP_EXECVMSPC; 1062 } 1063 } 1064 1065 int 1066 exec_map_first_page(struct image_params *imgp) 1067 { 1068 vm_object_t object; 1069 vm_page_t m; 1070 int error; 1071 1072 if (imgp->firstpage != NULL) 1073 exec_unmap_first_page(imgp); 1074 1075 object = imgp->vp->v_object; 1076 if (object == NULL) 1077 return (EACCES); 1078 #if VM_NRESERVLEVEL > 0 1079 if ((object->flags & OBJ_COLORED) == 0) { 1080 VM_OBJECT_WLOCK(object); 1081 vm_object_color(object, 0); 1082 VM_OBJECT_WUNLOCK(object); 1083 } 1084 #endif 1085 error = vm_page_grab_valid_unlocked(&m, object, 0, 1086 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) | 1087 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 1088 1089 if (error != VM_PAGER_OK) 1090 return (EIO); 1091 imgp->firstpage = sf_buf_alloc(m, 0); 1092 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage); 1093 1094 return (0); 1095 } 1096 1097 void 1098 exec_unmap_first_page(struct image_params *imgp) 1099 { 1100 vm_page_t m; 1101 1102 if (imgp->firstpage != NULL) { 1103 m = sf_buf_page(imgp->firstpage); 1104 sf_buf_free(imgp->firstpage); 1105 imgp->firstpage = NULL; 1106 vm_page_unwire(m, PQ_ACTIVE); 1107 } 1108 } 1109 1110 void 1111 exec_onexec_old(struct thread *td) 1112 { 1113 sigfastblock_clear(td); 1114 umtx_exec(td->td_proc); 1115 } 1116 1117 /* 1118 * This is an optimization which removes the unmanaged shared page 1119 * mapping. In combination with pmap_remove_pages(), which cleans all 1120 * managed mappings in the process' vmspace pmap, no work will be left 1121 * for pmap_remove(min, max). 1122 */ 1123 void 1124 exec_free_abi_mappings(struct proc *p) 1125 { 1126 struct vmspace *vmspace; 1127 struct sysentvec *sv; 1128 1129 vmspace = p->p_vmspace; 1130 if (refcount_load(&vmspace->vm_refcnt) != 1) 1131 return; 1132 1133 sv = p->p_sysent; 1134 if (sv->sv_shared_page_obj == NULL) 1135 return; 1136 1137 pmap_remove(vmspace_pmap(vmspace), sv->sv_shared_page_base, 1138 sv->sv_shared_page_base + sv->sv_shared_page_len); 1139 } 1140 1141 /* 1142 * Run down the current address space and install a new one. Map the shared 1143 * page. 1144 */ 1145 int 1146 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv) 1147 { 1148 int error; 1149 struct proc *p = imgp->proc; 1150 struct vmspace *vmspace = p->p_vmspace; 1151 struct thread *td = curthread; 1152 vm_object_t obj; 1153 vm_offset_t sv_minuser; 1154 vm_map_t map; 1155 1156 imgp->vmspace_destroyed = true; 1157 imgp->sysent = sv; 1158 1159 if (p->p_sysent->sv_onexec_old != NULL) 1160 p->p_sysent->sv_onexec_old(td); 1161 itimers_exec(p); 1162 1163 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp); 1164 1165 /* 1166 * Blow away entire process VM, if address space not shared, 1167 * otherwise, create a new VM space so that other threads are 1168 * not disrupted 1169 */ 1170 map = &vmspace->vm_map; 1171 if (map_at_zero) 1172 sv_minuser = sv->sv_minuser; 1173 else 1174 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE); 1175 if (refcount_load(&vmspace->vm_refcnt) == 1 && 1176 vm_map_min(map) == sv_minuser && 1177 vm_map_max(map) == sv->sv_maxuser && 1178 cpu_exec_vmspace_reuse(p, map)) { 1179 exec_free_abi_mappings(p); 1180 shmexit(vmspace); 1181 pmap_remove_pages(vmspace_pmap(vmspace)); 1182 vm_map_remove(map, vm_map_min(map), vm_map_max(map)); 1183 /* 1184 * An exec terminates mlockall(MCL_FUTURE). 1185 * ASLR and W^X states must be re-evaluated. 1186 */ 1187 vm_map_lock(map); 1188 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR | 1189 MAP_ASLR_IGNSTART | MAP_ASLR_STACK | MAP_WXORX); 1190 vm_map_unlock(map); 1191 } else { 1192 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser); 1193 if (error) 1194 return (error); 1195 vmspace = p->p_vmspace; 1196 map = &vmspace->vm_map; 1197 } 1198 map->flags |= imgp->map_flags; 1199 1200 /* Map a shared page */ 1201 obj = sv->sv_shared_page_obj; 1202 if (obj != NULL) { 1203 vm_object_reference(obj); 1204 error = vm_map_fixed(map, obj, 0, 1205 sv->sv_shared_page_base, sv->sv_shared_page_len, 1206 VM_PROT_READ | VM_PROT_EXECUTE, 1207 VM_PROT_READ | VM_PROT_EXECUTE, 1208 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE); 1209 if (error != KERN_SUCCESS) { 1210 vm_object_deallocate(obj); 1211 return (vm_mmap_to_errno(error)); 1212 } 1213 } 1214 1215 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0); 1216 } 1217 1218 /* 1219 * Compute the stack size limit and map the main process stack. 1220 */ 1221 int 1222 exec_map_stack(struct image_params *imgp) 1223 { 1224 struct rlimit rlim_stack; 1225 struct sysentvec *sv; 1226 struct proc *p; 1227 vm_map_t map; 1228 struct vmspace *vmspace; 1229 vm_offset_t stack_addr, stack_top; 1230 u_long ssiz; 1231 int error, find_space, stack_off; 1232 vm_prot_t stack_prot; 1233 1234 p = imgp->proc; 1235 sv = p->p_sysent; 1236 1237 if (imgp->stack_sz != 0) { 1238 ssiz = trunc_page(imgp->stack_sz); 1239 PROC_LOCK(p); 1240 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack); 1241 PROC_UNLOCK(p); 1242 if (ssiz > rlim_stack.rlim_max) 1243 ssiz = rlim_stack.rlim_max; 1244 if (ssiz > rlim_stack.rlim_cur) { 1245 rlim_stack.rlim_cur = ssiz; 1246 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack); 1247 } 1248 } else if (sv->sv_maxssiz != NULL) { 1249 ssiz = *sv->sv_maxssiz; 1250 } else { 1251 ssiz = maxssiz; 1252 } 1253 1254 vmspace = p->p_vmspace; 1255 map = &vmspace->vm_map; 1256 1257 stack_prot = sv->sv_shared_page_obj != NULL && imgp->stack_prot != 0 ? 1258 imgp->stack_prot : sv->sv_stackprot; 1259 if ((map->flags & MAP_ASLR_STACK) != 0) { 1260 stack_addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 1261 lim_max(curthread, RLIMIT_DATA)); 1262 find_space = VMFS_ANY_SPACE; 1263 } else { 1264 stack_addr = sv->sv_usrstack - ssiz; 1265 find_space = VMFS_NO_SPACE; 1266 } 1267 error = vm_map_find(map, NULL, 0, &stack_addr, (vm_size_t)ssiz, 1268 sv->sv_usrstack, find_space, stack_prot, VM_PROT_ALL, 1269 MAP_STACK_GROWS_DOWN); 1270 if (error != KERN_SUCCESS) { 1271 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x " 1272 "failed, mach error %d errno %d\n", (uintmax_t)ssiz, 1273 stack_prot, error, vm_mmap_to_errno(error)); 1274 return (vm_mmap_to_errno(error)); 1275 } 1276 1277 stack_top = stack_addr + ssiz; 1278 if ((map->flags & MAP_ASLR_STACK) != 0) { 1279 /* Randomize within the first page of the stack. */ 1280 arc4rand(&stack_off, sizeof(stack_off), 0); 1281 stack_top -= rounddown2(stack_off & PAGE_MASK, sizeof(void *)); 1282 } 1283 1284 /* 1285 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they 1286 * are still used to enforce the stack rlimit on the process stack. 1287 */ 1288 vmspace->vm_maxsaddr = (char *)stack_addr; 1289 vmspace->vm_stacktop = stack_top; 1290 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT; 1291 1292 return (0); 1293 } 1294 1295 /* 1296 * Copy out argument and environment strings from the old process address 1297 * space into the temporary string buffer. 1298 */ 1299 int 1300 exec_copyin_args(struct image_args *args, const char *fname, 1301 enum uio_seg segflg, char **argv, char **envv) 1302 { 1303 u_long arg, env; 1304 int error; 1305 1306 bzero(args, sizeof(*args)); 1307 if (argv == NULL) 1308 return (EFAULT); 1309 1310 /* 1311 * Allocate demand-paged memory for the file name, argument, and 1312 * environment strings. 1313 */ 1314 error = exec_alloc_args(args); 1315 if (error != 0) 1316 return (error); 1317 1318 /* 1319 * Copy the file name. 1320 */ 1321 error = exec_args_add_fname(args, fname, segflg); 1322 if (error != 0) 1323 goto err_exit; 1324 1325 /* 1326 * extract arguments first 1327 */ 1328 for (;;) { 1329 error = fueword(argv++, &arg); 1330 if (error == -1) { 1331 error = EFAULT; 1332 goto err_exit; 1333 } 1334 if (arg == 0) 1335 break; 1336 error = exec_args_add_arg(args, (char *)(uintptr_t)arg, 1337 UIO_USERSPACE); 1338 if (error != 0) 1339 goto err_exit; 1340 } 1341 1342 /* 1343 * extract environment strings 1344 */ 1345 if (envv) { 1346 for (;;) { 1347 error = fueword(envv++, &env); 1348 if (error == -1) { 1349 error = EFAULT; 1350 goto err_exit; 1351 } 1352 if (env == 0) 1353 break; 1354 error = exec_args_add_env(args, 1355 (char *)(uintptr_t)env, UIO_USERSPACE); 1356 if (error != 0) 1357 goto err_exit; 1358 } 1359 } 1360 1361 return (0); 1362 1363 err_exit: 1364 exec_free_args(args); 1365 return (error); 1366 } 1367 1368 int 1369 exec_copyin_data_fds(struct thread *td, struct image_args *args, 1370 const void *data, size_t datalen, const int *fds, size_t fdslen) 1371 { 1372 struct filedesc *ofdp; 1373 const char *p; 1374 int *kfds; 1375 int error; 1376 1377 memset(args, '\0', sizeof(*args)); 1378 ofdp = td->td_proc->p_fd; 1379 if (datalen >= ARG_MAX || fdslen >= ofdp->fd_nfiles) 1380 return (E2BIG); 1381 error = exec_alloc_args(args); 1382 if (error != 0) 1383 return (error); 1384 1385 args->begin_argv = args->buf; 1386 args->stringspace = ARG_MAX; 1387 1388 if (datalen > 0) { 1389 /* 1390 * Argument buffer has been provided. Copy it into the 1391 * kernel as a single string and add a terminating null 1392 * byte. 1393 */ 1394 error = copyin(data, args->begin_argv, datalen); 1395 if (error != 0) 1396 goto err_exit; 1397 args->begin_argv[datalen] = '\0'; 1398 args->endp = args->begin_argv + datalen + 1; 1399 args->stringspace -= datalen + 1; 1400 1401 /* 1402 * Traditional argument counting. Count the number of 1403 * null bytes. 1404 */ 1405 for (p = args->begin_argv; p < args->endp; ++p) 1406 if (*p == '\0') 1407 ++args->argc; 1408 } else { 1409 /* No argument buffer provided. */ 1410 args->endp = args->begin_argv; 1411 } 1412 1413 /* Create new file descriptor table. */ 1414 kfds = malloc(fdslen * sizeof(int), M_TEMP, M_WAITOK); 1415 error = copyin(fds, kfds, fdslen * sizeof(int)); 1416 if (error != 0) { 1417 free(kfds, M_TEMP); 1418 goto err_exit; 1419 } 1420 error = fdcopy_remapped(ofdp, kfds, fdslen, &args->fdp); 1421 free(kfds, M_TEMP); 1422 if (error != 0) 1423 goto err_exit; 1424 1425 return (0); 1426 err_exit: 1427 exec_free_args(args); 1428 return (error); 1429 } 1430 1431 struct exec_args_kva { 1432 vm_offset_t addr; 1433 u_int gen; 1434 SLIST_ENTRY(exec_args_kva) next; 1435 }; 1436 1437 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva); 1438 1439 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist; 1440 static struct mtx exec_args_kva_mtx; 1441 static u_int exec_args_gen; 1442 1443 static void 1444 exec_prealloc_args_kva(void *arg __unused) 1445 { 1446 struct exec_args_kva *argkva; 1447 u_int i; 1448 1449 SLIST_INIT(&exec_args_kva_freelist); 1450 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF); 1451 for (i = 0; i < exec_map_entries; i++) { 1452 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK); 1453 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size); 1454 argkva->gen = exec_args_gen; 1455 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1456 } 1457 } 1458 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL); 1459 1460 static vm_offset_t 1461 exec_alloc_args_kva(void **cookie) 1462 { 1463 struct exec_args_kva *argkva; 1464 1465 argkva = (void *)atomic_readandclear_ptr( 1466 (uintptr_t *)DPCPU_PTR(exec_args_kva)); 1467 if (argkva == NULL) { 1468 mtx_lock(&exec_args_kva_mtx); 1469 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL) 1470 (void)mtx_sleep(&exec_args_kva_freelist, 1471 &exec_args_kva_mtx, 0, "execkva", 0); 1472 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next); 1473 mtx_unlock(&exec_args_kva_mtx); 1474 } 1475 kasan_mark((void *)argkva->addr, exec_map_entry_size, 1476 exec_map_entry_size, 0); 1477 *(struct exec_args_kva **)cookie = argkva; 1478 return (argkva->addr); 1479 } 1480 1481 static void 1482 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen) 1483 { 1484 vm_offset_t base; 1485 1486 base = argkva->addr; 1487 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size, 1488 KASAN_EXEC_ARGS_FREED); 1489 if (argkva->gen != gen) { 1490 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size, 1491 MADV_FREE); 1492 argkva->gen = gen; 1493 } 1494 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva), 1495 (uintptr_t)NULL, (uintptr_t)argkva)) { 1496 mtx_lock(&exec_args_kva_mtx); 1497 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next); 1498 wakeup_one(&exec_args_kva_freelist); 1499 mtx_unlock(&exec_args_kva_mtx); 1500 } 1501 } 1502 1503 static void 1504 exec_free_args_kva(void *cookie) 1505 { 1506 1507 exec_release_args_kva(cookie, exec_args_gen); 1508 } 1509 1510 static void 1511 exec_args_kva_lowmem(void *arg __unused) 1512 { 1513 SLIST_HEAD(, exec_args_kva) head; 1514 struct exec_args_kva *argkva; 1515 u_int gen; 1516 int i; 1517 1518 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1; 1519 1520 /* 1521 * Force an madvise of each KVA range. Any currently allocated ranges 1522 * will have MADV_FREE applied once they are freed. 1523 */ 1524 SLIST_INIT(&head); 1525 mtx_lock(&exec_args_kva_mtx); 1526 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva); 1527 mtx_unlock(&exec_args_kva_mtx); 1528 while ((argkva = SLIST_FIRST(&head)) != NULL) { 1529 SLIST_REMOVE_HEAD(&head, next); 1530 exec_release_args_kva(argkva, gen); 1531 } 1532 1533 CPU_FOREACH(i) { 1534 argkva = (void *)atomic_readandclear_ptr( 1535 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva)); 1536 if (argkva != NULL) 1537 exec_release_args_kva(argkva, gen); 1538 } 1539 } 1540 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL, 1541 EVENTHANDLER_PRI_ANY); 1542 1543 /* 1544 * Allocate temporary demand-paged, zero-filled memory for the file name, 1545 * argument, and environment strings. 1546 */ 1547 int 1548 exec_alloc_args(struct image_args *args) 1549 { 1550 1551 args->buf = (char *)exec_alloc_args_kva(&args->bufkva); 1552 return (0); 1553 } 1554 1555 void 1556 exec_free_args(struct image_args *args) 1557 { 1558 1559 if (args->buf != NULL) { 1560 exec_free_args_kva(args->bufkva); 1561 args->buf = NULL; 1562 } 1563 if (args->fname_buf != NULL) { 1564 free(args->fname_buf, M_TEMP); 1565 args->fname_buf = NULL; 1566 } 1567 if (args->fdp != NULL) 1568 fdescfree_remapped(args->fdp); 1569 } 1570 1571 /* 1572 * A set to functions to fill struct image args. 1573 * 1574 * NOTE: exec_args_add_fname() must be called (possibly with a NULL 1575 * fname) before the other functions. All exec_args_add_arg() calls must 1576 * be made before any exec_args_add_env() calls. exec_args_adjust_args() 1577 * may be called any time after exec_args_add_fname(). 1578 * 1579 * exec_args_add_fname() - install path to be executed 1580 * exec_args_add_arg() - append an argument string 1581 * exec_args_add_env() - append an env string 1582 * exec_args_adjust_args() - adjust location of the argument list to 1583 * allow new arguments to be prepended 1584 */ 1585 int 1586 exec_args_add_fname(struct image_args *args, const char *fname, 1587 enum uio_seg segflg) 1588 { 1589 int error; 1590 size_t length; 1591 1592 KASSERT(args->fname == NULL, ("fname already appended")); 1593 KASSERT(args->endp == NULL, ("already appending to args")); 1594 1595 if (fname != NULL) { 1596 args->fname = args->buf; 1597 error = segflg == UIO_SYSSPACE ? 1598 copystr(fname, args->fname, PATH_MAX, &length) : 1599 copyinstr(fname, args->fname, PATH_MAX, &length); 1600 if (error != 0) 1601 return (error == ENAMETOOLONG ? E2BIG : error); 1602 } else 1603 length = 0; 1604 1605 /* Set up for _arg_*()/_env_*() */ 1606 args->endp = args->buf + length; 1607 /* begin_argv must be set and kept updated */ 1608 args->begin_argv = args->endp; 1609 KASSERT(exec_map_entry_size - length >= ARG_MAX, 1610 ("too little space remaining for arguments %zu < %zu", 1611 exec_map_entry_size - length, (size_t)ARG_MAX)); 1612 args->stringspace = ARG_MAX; 1613 1614 return (0); 1615 } 1616 1617 static int 1618 exec_args_add_str(struct image_args *args, const char *str, 1619 enum uio_seg segflg, int *countp) 1620 { 1621 int error; 1622 size_t length; 1623 1624 KASSERT(args->endp != NULL, ("endp not initialized")); 1625 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1626 1627 error = (segflg == UIO_SYSSPACE) ? 1628 copystr(str, args->endp, args->stringspace, &length) : 1629 copyinstr(str, args->endp, args->stringspace, &length); 1630 if (error != 0) 1631 return (error == ENAMETOOLONG ? E2BIG : error); 1632 args->stringspace -= length; 1633 args->endp += length; 1634 (*countp)++; 1635 1636 return (0); 1637 } 1638 1639 int 1640 exec_args_add_arg(struct image_args *args, const char *argp, 1641 enum uio_seg segflg) 1642 { 1643 1644 KASSERT(args->envc == 0, ("appending args after env")); 1645 1646 return (exec_args_add_str(args, argp, segflg, &args->argc)); 1647 } 1648 1649 int 1650 exec_args_add_env(struct image_args *args, const char *envp, 1651 enum uio_seg segflg) 1652 { 1653 1654 if (args->envc == 0) 1655 args->begin_envv = args->endp; 1656 1657 return (exec_args_add_str(args, envp, segflg, &args->envc)); 1658 } 1659 1660 int 1661 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend) 1662 { 1663 ssize_t offset; 1664 1665 KASSERT(args->endp != NULL, ("endp not initialized")); 1666 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized")); 1667 1668 offset = extend - consume; 1669 if (args->stringspace < offset) 1670 return (E2BIG); 1671 memmove(args->begin_argv + extend, args->begin_argv + consume, 1672 args->endp - args->begin_argv + consume); 1673 if (args->envc > 0) 1674 args->begin_envv += offset; 1675 args->endp += offset; 1676 args->stringspace -= offset; 1677 return (0); 1678 } 1679 1680 char * 1681 exec_args_get_begin_envv(struct image_args *args) 1682 { 1683 1684 KASSERT(args->endp != NULL, ("endp not initialized")); 1685 1686 if (args->envc > 0) 1687 return (args->begin_envv); 1688 return (args->endp); 1689 } 1690 1691 /* 1692 * Copy strings out to the new process address space, constructing new arg 1693 * and env vector tables. Return a pointer to the base so that it can be used 1694 * as the initial stack pointer. 1695 */ 1696 int 1697 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 1698 { 1699 int argc, envc; 1700 char **vectp; 1701 char *stringp; 1702 uintptr_t destp, ustringp; 1703 struct ps_strings *arginfo; 1704 struct proc *p; 1705 struct sysentvec *sysent; 1706 size_t execpath_len; 1707 int error, szsigcode; 1708 char canary[sizeof(long) * 8]; 1709 1710 p = imgp->proc; 1711 sysent = p->p_sysent; 1712 1713 destp = PROC_PS_STRINGS(p); 1714 arginfo = imgp->ps_strings = (void *)destp; 1715 1716 /* 1717 * Install sigcode. 1718 */ 1719 if (sysent->sv_sigcode_base == 0 && sysent->sv_szsigcode != NULL) { 1720 szsigcode = *(sysent->sv_szsigcode); 1721 destp -= szsigcode; 1722 destp = rounddown2(destp, sizeof(void *)); 1723 error = copyout(sysent->sv_sigcode, (void *)destp, szsigcode); 1724 if (error != 0) 1725 return (error); 1726 } 1727 1728 /* 1729 * Copy the image path for the rtld. 1730 */ 1731 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 1732 execpath_len = strlen(imgp->execpath) + 1; 1733 destp -= execpath_len; 1734 destp = rounddown2(destp, sizeof(void *)); 1735 imgp->execpathp = (void *)destp; 1736 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 1737 if (error != 0) 1738 return (error); 1739 } 1740 1741 /* 1742 * Prepare the canary for SSP. 1743 */ 1744 arc4rand(canary, sizeof(canary), 0); 1745 destp -= sizeof(canary); 1746 imgp->canary = (void *)destp; 1747 error = copyout(canary, imgp->canary, sizeof(canary)); 1748 if (error != 0) 1749 return (error); 1750 imgp->canarylen = sizeof(canary); 1751 1752 /* 1753 * Prepare the pagesizes array. 1754 */ 1755 imgp->pagesizeslen = sizeof(pagesizes[0]) * MAXPAGESIZES; 1756 destp -= imgp->pagesizeslen; 1757 destp = rounddown2(destp, sizeof(void *)); 1758 imgp->pagesizes = (void *)destp; 1759 error = copyout(pagesizes, imgp->pagesizes, imgp->pagesizeslen); 1760 if (error != 0) 1761 return (error); 1762 1763 /* 1764 * Allocate room for the argument and environment strings. 1765 */ 1766 destp -= ARG_MAX - imgp->args->stringspace; 1767 destp = rounddown2(destp, sizeof(void *)); 1768 ustringp = destp; 1769 1770 if (imgp->auxargs) { 1771 /* 1772 * Allocate room on the stack for the ELF auxargs 1773 * array. It has up to AT_COUNT entries. 1774 */ 1775 destp -= AT_COUNT * sizeof(Elf_Auxinfo); 1776 destp = rounddown2(destp, sizeof(void *)); 1777 } 1778 1779 vectp = (char **)destp; 1780 1781 /* 1782 * Allocate room for the argv[] and env vectors including the 1783 * terminating NULL pointers. 1784 */ 1785 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 1786 1787 /* 1788 * vectp also becomes our initial stack base 1789 */ 1790 *stack_base = (uintptr_t)vectp; 1791 1792 stringp = imgp->args->begin_argv; 1793 argc = imgp->args->argc; 1794 envc = imgp->args->envc; 1795 1796 /* 1797 * Copy out strings - arguments and environment. 1798 */ 1799 error = copyout(stringp, (void *)ustringp, 1800 ARG_MAX - imgp->args->stringspace); 1801 if (error != 0) 1802 return (error); 1803 1804 /* 1805 * Fill in "ps_strings" struct for ps, w, etc. 1806 */ 1807 imgp->argv = vectp; 1808 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 1809 suword32(&arginfo->ps_nargvstr, argc) != 0) 1810 return (EFAULT); 1811 1812 /* 1813 * Fill in argument portion of vector table. 1814 */ 1815 for (; argc > 0; --argc) { 1816 if (suword(vectp++, ustringp) != 0) 1817 return (EFAULT); 1818 while (*stringp++ != 0) 1819 ustringp++; 1820 ustringp++; 1821 } 1822 1823 /* a null vector table pointer separates the argp's from the envp's */ 1824 if (suword(vectp++, 0) != 0) 1825 return (EFAULT); 1826 1827 imgp->envv = vectp; 1828 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 1829 suword32(&arginfo->ps_nenvstr, envc) != 0) 1830 return (EFAULT); 1831 1832 /* 1833 * Fill in environment portion of vector table. 1834 */ 1835 for (; envc > 0; --envc) { 1836 if (suword(vectp++, ustringp) != 0) 1837 return (EFAULT); 1838 while (*stringp++ != 0) 1839 ustringp++; 1840 ustringp++; 1841 } 1842 1843 /* end of vector table is a null pointer */ 1844 if (suword(vectp, 0) != 0) 1845 return (EFAULT); 1846 1847 if (imgp->auxargs) { 1848 vectp++; 1849 error = imgp->sysent->sv_copyout_auxargs(imgp, 1850 (uintptr_t)vectp); 1851 if (error != 0) 1852 return (error); 1853 } 1854 1855 return (0); 1856 } 1857 1858 /* 1859 * Check permissions of file to execute. 1860 * Called with imgp->vp locked. 1861 * Return 0 for success or error code on failure. 1862 */ 1863 int 1864 exec_check_permissions(struct image_params *imgp) 1865 { 1866 struct vnode *vp = imgp->vp; 1867 struct vattr *attr = imgp->attr; 1868 struct thread *td; 1869 int error; 1870 1871 td = curthread; 1872 1873 /* Get file attributes */ 1874 error = VOP_GETATTR(vp, attr, td->td_ucred); 1875 if (error) 1876 return (error); 1877 1878 #ifdef MAC 1879 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp); 1880 if (error) 1881 return (error); 1882 #endif 1883 1884 /* 1885 * 1) Check if file execution is disabled for the filesystem that 1886 * this file resides on. 1887 * 2) Ensure that at least one execute bit is on. Otherwise, a 1888 * privileged user will always succeed, and we don't want this 1889 * to happen unless the file really is executable. 1890 * 3) Ensure that the file is a regular file. 1891 */ 1892 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) || 1893 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 || 1894 (attr->va_type != VREG)) 1895 return (EACCES); 1896 1897 /* 1898 * Zero length files can't be exec'd 1899 */ 1900 if (attr->va_size == 0) 1901 return (ENOEXEC); 1902 1903 /* 1904 * Check for execute permission to file based on current credentials. 1905 */ 1906 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td); 1907 if (error) 1908 return (error); 1909 1910 /* 1911 * Check number of open-for-writes on the file and deny execution 1912 * if there are any. 1913 * 1914 * Add a text reference now so no one can write to the 1915 * executable while we're activating it. 1916 * 1917 * Remember if this was set before and unset it in case this is not 1918 * actually an executable image. 1919 */ 1920 error = VOP_SET_TEXT(vp); 1921 if (error != 0) 1922 return (error); 1923 imgp->textset = true; 1924 1925 /* 1926 * Call filesystem specific open routine (which does nothing in the 1927 * general case). 1928 */ 1929 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL); 1930 if (error == 0) 1931 imgp->opened = true; 1932 return (error); 1933 } 1934 1935 /* 1936 * Exec handler registration 1937 */ 1938 int 1939 exec_register(const struct execsw *execsw_arg) 1940 { 1941 const struct execsw **es, **xs, **newexecsw; 1942 u_int count = 2; /* New slot and trailing NULL */ 1943 1944 if (execsw) 1945 for (es = execsw; *es; es++) 1946 count++; 1947 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1948 xs = newexecsw; 1949 if (execsw) 1950 for (es = execsw; *es; es++) 1951 *xs++ = *es; 1952 *xs++ = execsw_arg; 1953 *xs = NULL; 1954 if (execsw) 1955 free(execsw, M_TEMP); 1956 execsw = newexecsw; 1957 return (0); 1958 } 1959 1960 int 1961 exec_unregister(const struct execsw *execsw_arg) 1962 { 1963 const struct execsw **es, **xs, **newexecsw; 1964 int count = 1; 1965 1966 if (execsw == NULL) 1967 panic("unregister with no handlers left?\n"); 1968 1969 for (es = execsw; *es; es++) { 1970 if (*es == execsw_arg) 1971 break; 1972 } 1973 if (*es == NULL) 1974 return (ENOENT); 1975 for (es = execsw; *es; es++) 1976 if (*es != execsw_arg) 1977 count++; 1978 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK); 1979 xs = newexecsw; 1980 for (es = execsw; *es; es++) 1981 if (*es != execsw_arg) 1982 *xs++ = *es; 1983 *xs = NULL; 1984 if (execsw) 1985 free(execsw, M_TEMP); 1986 execsw = newexecsw; 1987 return (0); 1988 } 1989 1990 /* 1991 * Write out a core segment to the compression stream. 1992 */ 1993 static int 1994 compress_chunk(struct coredump_params *cp, char *base, char *buf, size_t len) 1995 { 1996 size_t chunk_len; 1997 int error; 1998 1999 while (len > 0) { 2000 chunk_len = MIN(len, CORE_BUF_SIZE); 2001 2002 /* 2003 * We can get EFAULT error here. 2004 * In that case zero out the current chunk of the segment. 2005 */ 2006 error = copyin(base, buf, chunk_len); 2007 if (error != 0) 2008 bzero(buf, chunk_len); 2009 error = compressor_write(cp->comp, buf, chunk_len); 2010 if (error != 0) 2011 break; 2012 base += chunk_len; 2013 len -= chunk_len; 2014 } 2015 return (error); 2016 } 2017 2018 int 2019 core_write(struct coredump_params *cp, const void *base, size_t len, 2020 off_t offset, enum uio_seg seg, size_t *resid) 2021 { 2022 2023 return (vn_rdwr_inchunks(UIO_WRITE, cp->vp, __DECONST(void *, base), 2024 len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED, 2025 cp->active_cred, cp->file_cred, resid, cp->td)); 2026 } 2027 2028 int 2029 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp, 2030 void *tmpbuf) 2031 { 2032 vm_map_t map; 2033 struct mount *mp; 2034 size_t resid, runlen; 2035 int error; 2036 bool success; 2037 2038 KASSERT((uintptr_t)base % PAGE_SIZE == 0, 2039 ("%s: user address %p is not page-aligned", __func__, base)); 2040 2041 if (cp->comp != NULL) 2042 return (compress_chunk(cp, base, tmpbuf, len)); 2043 2044 map = &cp->td->td_proc->p_vmspace->vm_map; 2045 for (; len > 0; base += runlen, offset += runlen, len -= runlen) { 2046 /* 2047 * Attempt to page in all virtual pages in the range. If a 2048 * virtual page is not backed by the pager, it is represented as 2049 * a hole in the file. This can occur with zero-filled 2050 * anonymous memory or truncated files, for example. 2051 */ 2052 for (runlen = 0; runlen < len; runlen += PAGE_SIZE) { 2053 if (core_dump_can_intr && curproc_sigkilled()) 2054 return (EINTR); 2055 error = vm_fault(map, (uintptr_t)base + runlen, 2056 VM_PROT_READ, VM_FAULT_NOFILL, NULL); 2057 if (runlen == 0) 2058 success = error == KERN_SUCCESS; 2059 else if ((error == KERN_SUCCESS) != success) 2060 break; 2061 } 2062 2063 if (success) { 2064 error = core_write(cp, base, runlen, offset, 2065 UIO_USERSPACE, &resid); 2066 if (error != 0) { 2067 if (error != EFAULT) 2068 break; 2069 2070 /* 2071 * EFAULT may be returned if the user mapping 2072 * could not be accessed, e.g., because a mapped 2073 * file has been truncated. Skip the page if no 2074 * progress was made, to protect against a 2075 * hypothetical scenario where vm_fault() was 2076 * successful but core_write() returns EFAULT 2077 * anyway. 2078 */ 2079 runlen -= resid; 2080 if (runlen == 0) { 2081 success = false; 2082 runlen = PAGE_SIZE; 2083 } 2084 } 2085 } 2086 if (!success) { 2087 error = vn_start_write(cp->vp, &mp, V_WAIT); 2088 if (error != 0) 2089 break; 2090 vn_lock(cp->vp, LK_EXCLUSIVE | LK_RETRY); 2091 error = vn_truncate_locked(cp->vp, offset + runlen, 2092 false, cp->td->td_ucred); 2093 VOP_UNLOCK(cp->vp); 2094 vn_finished_write(mp); 2095 if (error != 0) 2096 break; 2097 } 2098 } 2099 return (error); 2100 } 2101 2102 /* 2103 * Drain into a core file. 2104 */ 2105 int 2106 sbuf_drain_core_output(void *arg, const char *data, int len) 2107 { 2108 struct coredump_params *cp; 2109 struct proc *p; 2110 int error, locked; 2111 2112 cp = arg; 2113 p = cp->td->td_proc; 2114 2115 /* 2116 * Some kern_proc out routines that print to this sbuf may 2117 * call us with the process lock held. Draining with the 2118 * non-sleepable lock held is unsafe. The lock is needed for 2119 * those routines when dumping a live process. In our case we 2120 * can safely release the lock before draining and acquire 2121 * again after. 2122 */ 2123 locked = PROC_LOCKED(p); 2124 if (locked) 2125 PROC_UNLOCK(p); 2126 if (cp->comp != NULL) 2127 error = compressor_write(cp->comp, __DECONST(char *, data), len); 2128 else 2129 error = core_write(cp, __DECONST(void *, data), len, cp->offset, 2130 UIO_SYSSPACE, NULL); 2131 if (locked) 2132 PROC_LOCK(p); 2133 if (error != 0) 2134 return (-error); 2135 cp->offset += len; 2136 return (len); 2137 }
Cache object: 07b7b7e85f41bc62dbe58f75fffab33e
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