1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$ 39 * 40 * @(#)vm_mmap.c 8.4 (Berkeley) 1/12/94 41 * $FreeBSD: src/sys/vm/vm_mmap.c,v 1.108.2.6 2002/07/02 20:06:19 dillon Exp $ 42 * $DragonFly: src/sys/vm/vm_mmap.c,v 1.30 2006/06/05 07:26:11 dillon Exp $ 43 */ 44 45 /* 46 * Mapped file (mmap) interface to VM 47 */ 48 49 #include <sys/param.h> 50 #include <sys/kernel.h> 51 #include <sys/systm.h> 52 #include <sys/sysproto.h> 53 #include <sys/filedesc.h> 54 #include <sys/kern_syscall.h> 55 #include <sys/proc.h> 56 #include <sys/resource.h> 57 #include <sys/resourcevar.h> 58 #include <sys/vnode.h> 59 #include <sys/fcntl.h> 60 #include <sys/file.h> 61 #include <sys/mman.h> 62 #include <sys/conf.h> 63 #include <sys/stat.h> 64 #include <sys/vmmeter.h> 65 #include <sys/sysctl.h> 66 67 #include <vm/vm.h> 68 #include <vm/vm_param.h> 69 #include <sys/lock.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_map.h> 72 #include <vm/vm_object.h> 73 #include <vm/vm_page.h> 74 #include <vm/vm_pager.h> 75 #include <vm/vm_pageout.h> 76 #include <vm/vm_extern.h> 77 #include <vm/vm_page.h> 78 #include <vm/vm_kern.h> 79 80 #include <sys/file2.h> 81 #include <sys/thread2.h> 82 83 static int max_proc_mmap; 84 SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, ""); 85 86 /* 87 * Set the maximum number of vm_map_entry structures per process. Roughly 88 * speaking vm_map_entry structures are tiny, so allowing them to eat 1/100 89 * of our KVM malloc space still results in generous limits. We want a 90 * default that is good enough to prevent the kernel running out of resources 91 * if attacked from compromised user account but generous enough such that 92 * multi-threaded processes are not unduly inconvenienced. 93 */ 94 95 static void vmmapentry_rsrc_init (void *); 96 SYSINIT(vmmersrc, SI_SUB_KVM_RSRC, SI_ORDER_FIRST, vmmapentry_rsrc_init, NULL) 97 98 static void 99 vmmapentry_rsrc_init(void *dummy) 100 { 101 max_proc_mmap = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 102 sizeof(struct vm_map_entry); 103 max_proc_mmap /= 100; 104 } 105 106 /* ARGSUSED */ 107 int 108 sys_sbrk(struct sbrk_args *uap) 109 { 110 /* Not yet implemented */ 111 return (EOPNOTSUPP); 112 } 113 114 /* 115 * sstk_args(int incr) 116 */ 117 /* ARGSUSED */ 118 int 119 sys_sstk(struct sstk_args *uap) 120 { 121 /* Not yet implemented */ 122 return (EOPNOTSUPP); 123 } 124 125 /* 126 * mmap_args(void *addr, size_t len, int prot, int flags, int fd, 127 * long pad, off_t pos) 128 * 129 * Memory Map (mmap) system call. Note that the file offset 130 * and address are allowed to be NOT page aligned, though if 131 * the MAP_FIXED flag it set, both must have the same remainder 132 * modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not 133 * page-aligned, the actual mapping starts at trunc_page(addr) 134 * and the return value is adjusted up by the page offset. 135 * 136 * Generally speaking, only character devices which are themselves 137 * memory-based, such as a video framebuffer, can be mmap'd. Otherwise 138 * there would be no cache coherency between a descriptor and a VM mapping 139 * both to the same character device. 140 * 141 * Block devices can be mmap'd no matter what they represent. Cache coherency 142 * is maintained as long as you do not write directly to the underlying 143 * character device. 144 */ 145 146 int 147 kern_mmap(caddr_t uaddr, size_t ulen, int uprot, int uflags, int fd, 148 off_t upos, void **res) 149 { 150 struct thread *td = curthread; 151 struct proc *p = td->td_proc; 152 struct file *fp = NULL; 153 struct vnode *vp; 154 vm_offset_t addr; 155 vm_size_t size, pageoff; 156 vm_prot_t prot, maxprot; 157 void *handle; 158 int flags, error; 159 int disablexworkaround; 160 off_t pos; 161 struct vmspace *vms = p->p_vmspace; 162 vm_object_t obj; 163 164 KKASSERT(p); 165 166 addr = (vm_offset_t) uaddr; 167 size = ulen; 168 prot = uprot & VM_PROT_ALL; 169 flags = uflags; 170 pos = upos; 171 172 /* make sure mapping fits into numeric range etc */ 173 if ((ssize_t) ulen < 0 || 174 ((flags & MAP_ANON) && fd != -1)) 175 return (EINVAL); 176 177 if (flags & MAP_STACK) { 178 if ((fd != -1) || 179 ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE))) 180 return (EINVAL); 181 flags |= MAP_ANON; 182 pos = 0; 183 } 184 185 /* 186 * Align the file position to a page boundary, 187 * and save its page offset component. 188 */ 189 pageoff = (pos & PAGE_MASK); 190 pos -= pageoff; 191 192 /* Adjust size for rounding (on both ends). */ 193 size += pageoff; /* low end... */ 194 size = (vm_size_t) round_page(size); /* hi end */ 195 196 /* 197 * Check for illegal addresses. Watch out for address wrap... Note 198 * that VM_*_ADDRESS are not constants due to casts (argh). 199 */ 200 if (flags & MAP_FIXED) { 201 /* 202 * The specified address must have the same remainder 203 * as the file offset taken modulo PAGE_SIZE, so it 204 * should be aligned after adjustment by pageoff. 205 */ 206 addr -= pageoff; 207 if (addr & PAGE_MASK) 208 return (EINVAL); 209 /* Address range must be all in user VM space. */ 210 if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS) 211 return (EINVAL); 212 #ifndef i386 213 if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS) 214 return (EINVAL); 215 #endif 216 if (addr + size < addr) 217 return (EINVAL); 218 } 219 /* 220 * XXX for non-fixed mappings where no hint is provided or 221 * the hint would fall in the potential heap space, 222 * place it after the end of the largest possible heap. 223 * 224 * There should really be a pmap call to determine a reasonable 225 * location. 226 */ 227 else if (addr == 0 || 228 (addr >= round_page((vm_offset_t)vms->vm_taddr) && 229 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) 230 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz); 231 232 if (flags & MAP_ANON) { 233 /* 234 * Mapping blank space is trivial. 235 */ 236 handle = NULL; 237 maxprot = VM_PROT_ALL; 238 pos = 0; 239 } else { 240 /* 241 * Mapping file, get fp for validation. Obtain vnode and make 242 * sure it is of appropriate type. 243 */ 244 fp = holdfp(p->p_fd, fd, -1); 245 if (fp == NULL) 246 return (EBADF); 247 if (fp->f_type != DTYPE_VNODE) { 248 error = EINVAL; 249 goto done; 250 } 251 /* 252 * POSIX shared-memory objects are defined to have 253 * kernel persistence, and are not defined to support 254 * read(2)/write(2) -- or even open(2). Thus, we can 255 * use MAP_ASYNC to trade on-disk coherence for speed. 256 * The shm_open(3) library routine turns on the FPOSIXSHM 257 * flag to request this behavior. 258 */ 259 if (fp->f_flag & FPOSIXSHM) 260 flags |= MAP_NOSYNC; 261 vp = (struct vnode *) fp->f_data; 262 if (vp->v_type != VREG && vp->v_type != VCHR) { 263 error = EINVAL; 264 goto done; 265 } 266 if (vp->v_type == VREG) { 267 /* 268 * Get the proper underlying object 269 */ 270 if ((obj = vp->v_object) == NULL) { 271 error = EINVAL; 272 goto done; 273 } 274 KKASSERT(vp == (struct vnode *)obj->handle); 275 } 276 277 /* 278 * XXX hack to handle use of /dev/zero to map anon memory (ala 279 * SunOS). 280 */ 281 if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) { 282 handle = NULL; 283 maxprot = VM_PROT_ALL; 284 flags |= MAP_ANON; 285 pos = 0; 286 } else { 287 /* 288 * cdevs does not provide private mappings of any kind. 289 */ 290 /* 291 * However, for XIG X server to continue to work, 292 * we should allow the superuser to do it anyway. 293 * We only allow it at securelevel < 1. 294 * (Because the XIG X server writes directly to video 295 * memory via /dev/mem, it should never work at any 296 * other securelevel. 297 * XXX this will have to go 298 */ 299 if (securelevel >= 1) 300 disablexworkaround = 1; 301 else 302 disablexworkaround = suser(td); 303 if (vp->v_type == VCHR && disablexworkaround && 304 (flags & (MAP_PRIVATE|MAP_COPY))) { 305 error = EINVAL; 306 goto done; 307 } 308 /* 309 * Ensure that file and memory protections are 310 * compatible. Note that we only worry about 311 * writability if mapping is shared; in this case, 312 * current and max prot are dictated by the open file. 313 * XXX use the vnode instead? Problem is: what 314 * credentials do we use for determination? What if 315 * proc does a setuid? 316 */ 317 maxprot = VM_PROT_EXECUTE; /* ??? */ 318 if (fp->f_flag & FREAD) { 319 maxprot |= VM_PROT_READ; 320 } else if (prot & PROT_READ) { 321 error = EACCES; 322 goto done; 323 } 324 /* 325 * If we are sharing potential changes (either via 326 * MAP_SHARED or via the implicit sharing of character 327 * device mappings), and we are trying to get write 328 * permission although we opened it without asking 329 * for it, bail out. Check for superuser, only if 330 * we're at securelevel < 1, to allow the XIG X server 331 * to continue to work. 332 */ 333 334 if ((flags & MAP_SHARED) != 0 || 335 (vp->v_type == VCHR && disablexworkaround)) { 336 if ((fp->f_flag & FWRITE) != 0) { 337 struct vattr va; 338 if ((error = VOP_GETATTR(vp, &va))) { 339 goto done; 340 } 341 if ((va.va_flags & 342 (IMMUTABLE|APPEND)) == 0) { 343 maxprot |= VM_PROT_WRITE; 344 } else if (prot & PROT_WRITE) { 345 error = EPERM; 346 goto done; 347 } 348 } else if ((prot & PROT_WRITE) != 0) { 349 error = EACCES; 350 goto done; 351 } 352 } else { 353 maxprot |= VM_PROT_WRITE; 354 } 355 handle = (void *)vp; 356 } 357 } 358 359 /* 360 * Do not allow more then a certain number of vm_map_entry structures 361 * per process. Scale with the number of rforks sharing the map 362 * to make the limit reasonable for threads. 363 */ 364 if (max_proc_mmap && 365 vms->vm_map.nentries >= max_proc_mmap * vms->vm_refcnt) { 366 error = ENOMEM; 367 goto done; 368 } 369 370 error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot, 371 flags, handle, pos); 372 if (error == 0) 373 *res = (void *)(addr + pageoff); 374 done: 375 if (fp) 376 fdrop(fp); 377 return (error); 378 } 379 380 int 381 sys_mmap(struct mmap_args *uap) 382 { 383 int error; 384 385 error = kern_mmap(uap->addr, uap->len, uap->prot, uap->flags, 386 uap->fd, uap->pos, &uap->sysmsg_resultp); 387 388 return (error); 389 } 390 391 /* 392 * msync_args(void *addr, int len, int flags) 393 */ 394 int 395 sys_msync(struct msync_args *uap) 396 { 397 struct proc *p = curproc; 398 vm_offset_t addr; 399 vm_size_t size, pageoff; 400 int flags; 401 vm_map_t map; 402 int rv; 403 404 addr = (vm_offset_t) uap->addr; 405 size = uap->len; 406 flags = uap->flags; 407 408 pageoff = (addr & PAGE_MASK); 409 addr -= pageoff; 410 size += pageoff; 411 size = (vm_size_t) round_page(size); 412 if (addr + size < addr) 413 return(EINVAL); 414 415 if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE)) 416 return (EINVAL); 417 418 map = &p->p_vmspace->vm_map; 419 420 /* 421 * XXX Gak! If size is zero we are supposed to sync "all modified 422 * pages with the region containing addr". Unfortunately, we don't 423 * really keep track of individual mmaps so we approximate by flushing 424 * the range of the map entry containing addr. This can be incorrect 425 * if the region splits or is coalesced with a neighbor. 426 */ 427 if (size == 0) { 428 vm_map_entry_t entry; 429 430 vm_map_lock_read(map); 431 rv = vm_map_lookup_entry(map, addr, &entry); 432 vm_map_unlock_read(map); 433 if (rv == FALSE) 434 return (EINVAL); 435 addr = entry->start; 436 size = entry->end - entry->start; 437 } 438 439 /* 440 * Clean the pages and interpret the return value. 441 */ 442 rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0, 443 (flags & MS_INVALIDATE) != 0); 444 445 switch (rv) { 446 case KERN_SUCCESS: 447 break; 448 case KERN_INVALID_ADDRESS: 449 return (EINVAL); /* Sun returns ENOMEM? */ 450 case KERN_FAILURE: 451 return (EIO); 452 default: 453 return (EINVAL); 454 } 455 456 return (0); 457 } 458 459 /* 460 * munmap_args(void *addr, size_t len) 461 */ 462 int 463 sys_munmap(struct munmap_args *uap) 464 { 465 struct proc *p = curproc; 466 vm_offset_t addr; 467 vm_size_t size, pageoff; 468 vm_map_t map; 469 470 addr = (vm_offset_t) uap->addr; 471 size = uap->len; 472 473 pageoff = (addr & PAGE_MASK); 474 addr -= pageoff; 475 size += pageoff; 476 size = (vm_size_t) round_page(size); 477 if (addr + size < addr) 478 return(EINVAL); 479 480 if (size == 0) 481 return (0); 482 483 /* 484 * Check for illegal addresses. Watch out for address wrap... Note 485 * that VM_*_ADDRESS are not constants due to casts (argh). 486 */ 487 if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS) 488 return (EINVAL); 489 #ifndef i386 490 if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS) 491 return (EINVAL); 492 #endif 493 map = &p->p_vmspace->vm_map; 494 /* 495 * Make sure entire range is allocated. 496 */ 497 if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE)) 498 return (EINVAL); 499 /* returns nothing but KERN_SUCCESS anyway */ 500 vm_map_remove(map, addr, addr + size); 501 return (0); 502 } 503 504 /* 505 * mprotect_args(const void *addr, size_t len, int prot) 506 */ 507 int 508 sys_mprotect(struct mprotect_args *uap) 509 { 510 struct proc *p = curproc; 511 vm_offset_t addr; 512 vm_size_t size, pageoff; 513 vm_prot_t prot; 514 515 addr = (vm_offset_t) uap->addr; 516 size = uap->len; 517 prot = uap->prot & VM_PROT_ALL; 518 #if defined(VM_PROT_READ_IS_EXEC) 519 if (prot & VM_PROT_READ) 520 prot |= VM_PROT_EXECUTE; 521 #endif 522 523 pageoff = (addr & PAGE_MASK); 524 addr -= pageoff; 525 size += pageoff; 526 size = (vm_size_t) round_page(size); 527 if (addr + size < addr) 528 return(EINVAL); 529 530 switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot, 531 FALSE)) { 532 case KERN_SUCCESS: 533 return (0); 534 case KERN_PROTECTION_FAILURE: 535 return (EACCES); 536 } 537 return (EINVAL); 538 } 539 540 /* 541 * minherit_args(void *addr, size_t len, int inherit) 542 */ 543 int 544 sys_minherit(struct minherit_args *uap) 545 { 546 struct proc *p = curproc; 547 vm_offset_t addr; 548 vm_size_t size, pageoff; 549 vm_inherit_t inherit; 550 551 addr = (vm_offset_t)uap->addr; 552 size = uap->len; 553 inherit = uap->inherit; 554 555 pageoff = (addr & PAGE_MASK); 556 addr -= pageoff; 557 size += pageoff; 558 size = (vm_size_t) round_page(size); 559 if (addr + size < addr) 560 return(EINVAL); 561 562 switch (vm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size, 563 inherit)) { 564 case KERN_SUCCESS: 565 return (0); 566 case KERN_PROTECTION_FAILURE: 567 return (EACCES); 568 } 569 return (EINVAL); 570 } 571 572 /* 573 * madvise_args(void *addr, size_t len, int behav) 574 */ 575 /* ARGSUSED */ 576 int 577 sys_madvise(struct madvise_args *uap) 578 { 579 struct proc *p = curproc; 580 vm_offset_t start, end; 581 582 /* 583 * Check for illegal behavior 584 */ 585 if (uap->behav < 0 || uap->behav > MADV_CORE) 586 return (EINVAL); 587 /* 588 * Check for illegal addresses. Watch out for address wrap... Note 589 * that VM_*_ADDRESS are not constants due to casts (argh). 590 */ 591 if (VM_MAXUSER_ADDRESS > 0 && 592 ((vm_offset_t) uap->addr + uap->len) > VM_MAXUSER_ADDRESS) 593 return (EINVAL); 594 #ifndef i386 595 if (VM_MIN_ADDRESS > 0 && uap->addr < VM_MIN_ADDRESS) 596 return (EINVAL); 597 #endif 598 if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr) 599 return (EINVAL); 600 601 /* 602 * Since this routine is only advisory, we default to conservative 603 * behavior. 604 */ 605 start = trunc_page((vm_offset_t) uap->addr); 606 end = round_page((vm_offset_t) uap->addr + uap->len); 607 608 if (vm_map_madvise(&p->p_vmspace->vm_map, start, end, uap->behav)) 609 return (EINVAL); 610 return (0); 611 } 612 613 /* 614 * mincore_args(const void *addr, size_t len, char *vec) 615 */ 616 /* ARGSUSED */ 617 int 618 sys_mincore(struct mincore_args *uap) 619 { 620 struct proc *p = curproc; 621 vm_offset_t addr, first_addr; 622 vm_offset_t end, cend; 623 pmap_t pmap; 624 vm_map_t map; 625 char *vec; 626 int error; 627 int vecindex, lastvecindex; 628 vm_map_entry_t current; 629 vm_map_entry_t entry; 630 int mincoreinfo; 631 unsigned int timestamp; 632 633 /* 634 * Make sure that the addresses presented are valid for user 635 * mode. 636 */ 637 first_addr = addr = trunc_page((vm_offset_t) uap->addr); 638 end = addr + (vm_size_t)round_page(uap->len); 639 if (VM_MAXUSER_ADDRESS > 0 && end > VM_MAXUSER_ADDRESS) 640 return (EINVAL); 641 if (end < addr) 642 return (EINVAL); 643 644 /* 645 * Address of byte vector 646 */ 647 vec = uap->vec; 648 649 map = &p->p_vmspace->vm_map; 650 pmap = vmspace_pmap(p->p_vmspace); 651 652 vm_map_lock_read(map); 653 RestartScan: 654 timestamp = map->timestamp; 655 656 if (!vm_map_lookup_entry(map, addr, &entry)) 657 entry = entry->next; 658 659 /* 660 * Do this on a map entry basis so that if the pages are not 661 * in the current processes address space, we can easily look 662 * up the pages elsewhere. 663 */ 664 lastvecindex = -1; 665 for(current = entry; 666 (current != &map->header) && (current->start < end); 667 current = current->next) { 668 669 /* 670 * ignore submaps (for now) or null objects 671 */ 672 if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) || 673 current->object.vm_object == NULL) 674 continue; 675 676 /* 677 * limit this scan to the current map entry and the 678 * limits for the mincore call 679 */ 680 if (addr < current->start) 681 addr = current->start; 682 cend = current->end; 683 if (cend > end) 684 cend = end; 685 686 /* 687 * scan this entry one page at a time 688 */ 689 while (addr < cend) { 690 /* 691 * Check pmap first, it is likely faster, also 692 * it can provide info as to whether we are the 693 * one referencing or modifying the page. 694 */ 695 mincoreinfo = pmap_mincore(pmap, addr); 696 if (!mincoreinfo) { 697 vm_pindex_t pindex; 698 vm_ooffset_t offset; 699 vm_page_t m; 700 701 /* 702 * calculate the page index into the object 703 */ 704 offset = current->offset + (addr - current->start); 705 pindex = OFF_TO_IDX(offset); 706 707 /* 708 * if the page is resident, then gather 709 * information about it. spl protection is 710 * required to maintain the object 711 * association. And XXX what if the page is 712 * busy? What's the deal with that? 713 */ 714 crit_enter(); 715 m = vm_page_lookup(current->object.vm_object, 716 pindex); 717 if (m && m->valid) { 718 mincoreinfo = MINCORE_INCORE; 719 if (m->dirty || 720 pmap_is_modified(m)) 721 mincoreinfo |= MINCORE_MODIFIED_OTHER; 722 if ((m->flags & PG_REFERENCED) || 723 pmap_ts_referenced(m)) { 724 vm_page_flag_set(m, PG_REFERENCED); 725 mincoreinfo |= MINCORE_REFERENCED_OTHER; 726 } 727 } 728 crit_exit(); 729 } 730 731 /* 732 * subyte may page fault. In case it needs to modify 733 * the map, we release the lock. 734 */ 735 vm_map_unlock_read(map); 736 737 /* 738 * calculate index into user supplied byte vector 739 */ 740 vecindex = OFF_TO_IDX(addr - first_addr); 741 742 /* 743 * If we have skipped map entries, we need to make sure that 744 * the byte vector is zeroed for those skipped entries. 745 */ 746 while((lastvecindex + 1) < vecindex) { 747 error = subyte( vec + lastvecindex, 0); 748 if (error) { 749 return (EFAULT); 750 } 751 ++lastvecindex; 752 } 753 754 /* 755 * Pass the page information to the user 756 */ 757 error = subyte( vec + vecindex, mincoreinfo); 758 if (error) { 759 return (EFAULT); 760 } 761 762 /* 763 * If the map has changed, due to the subyte, the previous 764 * output may be invalid. 765 */ 766 vm_map_lock_read(map); 767 if (timestamp != map->timestamp) 768 goto RestartScan; 769 770 lastvecindex = vecindex; 771 addr += PAGE_SIZE; 772 } 773 } 774 775 /* 776 * subyte may page fault. In case it needs to modify 777 * the map, we release the lock. 778 */ 779 vm_map_unlock_read(map); 780 781 /* 782 * Zero the last entries in the byte vector. 783 */ 784 vecindex = OFF_TO_IDX(end - first_addr); 785 while((lastvecindex + 1) < vecindex) { 786 error = subyte( vec + lastvecindex, 0); 787 if (error) { 788 return (EFAULT); 789 } 790 ++lastvecindex; 791 } 792 793 /* 794 * If the map has changed, due to the subyte, the previous 795 * output may be invalid. 796 */ 797 vm_map_lock_read(map); 798 if (timestamp != map->timestamp) 799 goto RestartScan; 800 vm_map_unlock_read(map); 801 802 return (0); 803 } 804 805 /* 806 * mlock_args(const void *addr, size_t len) 807 */ 808 int 809 sys_mlock(struct mlock_args *uap) 810 { 811 vm_offset_t addr; 812 vm_size_t size, pageoff; 813 int error; 814 struct proc *p = curproc; 815 816 addr = (vm_offset_t) uap->addr; 817 size = uap->len; 818 819 pageoff = (addr & PAGE_MASK); 820 addr -= pageoff; 821 size += pageoff; 822 size = (vm_size_t) round_page(size); 823 824 /* disable wrap around */ 825 if (addr + size < addr) 826 return (EINVAL); 827 828 if (atop(size) + vmstats.v_wire_count > vm_page_max_wired) 829 return (EAGAIN); 830 831 #ifdef pmap_wired_count 832 if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) > 833 p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur) 834 return (ENOMEM); 835 #else 836 error = suser_cred(p->p_ucred, 0); 837 if (error) 838 return (error); 839 #endif 840 841 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, FALSE); 842 return (error == KERN_SUCCESS ? 0 : ENOMEM); 843 } 844 845 /* 846 * mlockall_args(int how) 847 */ 848 int 849 sys_mlockall(struct mlockall_args *uap) 850 { 851 return 0; 852 } 853 854 /* 855 * munlockall_args(void) 856 */ 857 int 858 sys_munlockall(struct munlockall_args *uap) 859 { 860 return 0; 861 } 862 863 /* 864 * munlock_args(const void *addr, size_t len) 865 */ 866 int 867 sys_munlock(struct munlock_args *uap) 868 { 869 struct thread *td = curthread; 870 struct proc *p = td->td_proc; 871 vm_offset_t addr; 872 vm_size_t size, pageoff; 873 int error; 874 875 addr = (vm_offset_t) uap->addr; 876 size = uap->len; 877 878 pageoff = (addr & PAGE_MASK); 879 addr -= pageoff; 880 size += pageoff; 881 size = (vm_size_t) round_page(size); 882 883 /* disable wrap around */ 884 if (addr + size < addr) 885 return (EINVAL); 886 887 #ifndef pmap_wired_count 888 error = suser(td); 889 if (error) 890 return (error); 891 #endif 892 893 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, TRUE); 894 return (error == KERN_SUCCESS ? 0 : ENOMEM); 895 } 896 897 /* 898 * Internal version of mmap. 899 * Currently used by mmap, exec, and sys5 shared memory. 900 * Handle is either a vnode pointer or NULL for MAP_ANON. 901 */ 902 int 903 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot, 904 vm_prot_t maxprot, int flags, 905 void *handle, 906 vm_ooffset_t foff) 907 { 908 boolean_t fitit; 909 vm_object_t object; 910 struct vnode *vp = NULL; 911 objtype_t type; 912 int rv = KERN_SUCCESS; 913 off_t objsize; 914 int docow; 915 struct thread *td = curthread; /* XXX */ 916 struct proc *p = td->td_proc; 917 918 KKASSERT(p); 919 920 if (size == 0) 921 return (0); 922 923 objsize = size = round_page(size); 924 925 if (p->p_vmspace->vm_map.size + size > 926 p->p_rlimit[RLIMIT_VMEM].rlim_cur) { 927 return(ENOMEM); 928 } 929 930 /* 931 * We currently can only deal with page aligned file offsets. 932 * The check is here rather than in the syscall because the 933 * kernel calls this function internally for other mmaping 934 * operations (such as in exec) and non-aligned offsets will 935 * cause pmap inconsistencies...so we want to be sure to 936 * disallow this in all cases. 937 */ 938 if (foff & PAGE_MASK) 939 return (EINVAL); 940 941 if ((flags & MAP_FIXED) == 0) { 942 fitit = TRUE; 943 *addr = round_page(*addr); 944 } else { 945 if (*addr != trunc_page(*addr)) 946 return (EINVAL); 947 fitit = FALSE; 948 vm_map_remove(map, *addr, *addr + size); 949 } 950 951 /* 952 * Lookup/allocate object. 953 */ 954 if (flags & MAP_ANON) { 955 type = OBJT_DEFAULT; 956 /* 957 * Unnamed anonymous regions always start at 0. 958 */ 959 if (handle == 0) 960 foff = 0; 961 } else { 962 vp = (struct vnode *) handle; 963 if (vp->v_type == VCHR) { 964 type = OBJT_DEVICE; 965 handle = (void *)(intptr_t)vp->v_rdev; 966 } else { 967 struct vattr vat; 968 int error; 969 970 error = VOP_GETATTR(vp, &vat); 971 if (error) 972 return (error); 973 objsize = vat.va_size; 974 type = OBJT_VNODE; 975 /* 976 * if it is a regular file without any references 977 * we do not need to sync it. 978 */ 979 if (vp->v_type == VREG && vat.va_nlink == 0) { 980 flags |= MAP_NOSYNC; 981 } 982 } 983 } 984 985 if (handle == NULL) { 986 object = NULL; 987 docow = 0; 988 } else { 989 object = vm_pager_allocate(type, handle, objsize, prot, foff); 990 if (object == NULL) 991 return (type == OBJT_DEVICE ? EINVAL : ENOMEM); 992 docow = MAP_PREFAULT_PARTIAL; 993 } 994 995 /* 996 * Force device mappings to be shared. 997 */ 998 if (type == OBJT_DEVICE || type == OBJT_PHYS) { 999 flags &= ~(MAP_PRIVATE|MAP_COPY); 1000 flags |= MAP_SHARED; 1001 } 1002 1003 if ((flags & (MAP_ANON|MAP_SHARED)) == 0) 1004 docow |= MAP_COPY_ON_WRITE; 1005 if (flags & MAP_NOSYNC) 1006 docow |= MAP_DISABLE_SYNCER; 1007 if (flags & MAP_NOCORE) 1008 docow |= MAP_DISABLE_COREDUMP; 1009 1010 #if defined(VM_PROT_READ_IS_EXEC) 1011 if (prot & VM_PROT_READ) 1012 prot |= VM_PROT_EXECUTE; 1013 1014 if (maxprot & VM_PROT_READ) 1015 maxprot |= VM_PROT_EXECUTE; 1016 #endif 1017 1018 if (fitit) { 1019 *addr = pmap_addr_hint(object, *addr, size); 1020 } 1021 1022 if (flags & MAP_STACK) 1023 rv = vm_map_stack (map, *addr, size, prot, 1024 maxprot, docow); 1025 else 1026 rv = vm_map_find(map, object, foff, addr, size, fitit, 1027 prot, maxprot, docow); 1028 1029 if (rv != KERN_SUCCESS) { 1030 /* 1031 * Lose the object reference. Will destroy the 1032 * object if it's an unnamed anonymous mapping 1033 * or named anonymous without other references. 1034 */ 1035 vm_object_deallocate(object); 1036 goto out; 1037 } 1038 1039 /* 1040 * Shared memory is also shared with children. 1041 */ 1042 if (flags & (MAP_SHARED|MAP_INHERIT)) { 1043 rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE); 1044 if (rv != KERN_SUCCESS) { 1045 vm_map_remove(map, *addr, *addr + size); 1046 goto out; 1047 } 1048 } 1049 out: 1050 switch (rv) { 1051 case KERN_SUCCESS: 1052 return (0); 1053 case KERN_INVALID_ADDRESS: 1054 case KERN_NO_SPACE: 1055 return (ENOMEM); 1056 case KERN_PROTECTION_FAILURE: 1057 return (EACCES); 1058 default: 1059 return (EINVAL); 1060 } 1061 } 1062