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 1.39 2007/04/30 07:18:57 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/priv.h> 57 #include <sys/resource.h> 58 #include <sys/resourcevar.h> 59 #include <sys/vnode.h> 60 #include <sys/fcntl.h> 61 #include <sys/file.h> 62 #include <sys/mman.h> 63 #include <sys/conf.h> 64 #include <sys/stat.h> 65 #include <sys/vmmeter.h> 66 #include <sys/sysctl.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_param.h> 70 #include <sys/lock.h> 71 #include <vm/pmap.h> 72 #include <vm/vm_map.h> 73 #include <vm/vm_object.h> 74 #include <vm/vm_page.h> 75 #include <vm/vm_pager.h> 76 #include <vm/vm_pageout.h> 77 #include <vm/vm_extern.h> 78 #include <vm/vm_page.h> 79 #include <vm/vm_kern.h> 80 81 #include <sys/file2.h> 82 #include <sys/thread2.h> 83 84 static int max_proc_mmap; 85 SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, ""); 86 int vkernel_enable; 87 SYSCTL_INT(_vm, OID_AUTO, vkernel_enable, CTLFLAG_RW, &vkernel_enable, 0, ""); 88 89 /* 90 * Set the maximum number of vm_map_entry structures per process. Roughly 91 * speaking vm_map_entry structures are tiny, so allowing them to eat 1/100 92 * of our KVM malloc space still results in generous limits. We want a 93 * default that is good enough to prevent the kernel running out of resources 94 * if attacked from compromised user account but generous enough such that 95 * multi-threaded processes are not unduly inconvenienced. 96 */ 97 98 static void vmmapentry_rsrc_init (void *); 99 SYSINIT(vmmersrc, SI_BOOT1_POST, SI_ORDER_ANY, vmmapentry_rsrc_init, NULL) 100 101 static void 102 vmmapentry_rsrc_init(void *dummy) 103 { 104 max_proc_mmap = KvaSize / sizeof(struct vm_map_entry); 105 max_proc_mmap /= 100; 106 } 107 108 /* ARGSUSED */ 109 int 110 sys_sbrk(struct sbrk_args *uap) 111 { 112 /* Not yet implemented */ 113 return (EOPNOTSUPP); 114 } 115 116 /* 117 * sstk_args(int incr) 118 */ 119 /* ARGSUSED */ 120 int 121 sys_sstk(struct sstk_args *uap) 122 { 123 /* Not yet implemented */ 124 return (EOPNOTSUPP); 125 } 126 127 /* 128 * mmap_args(void *addr, size_t len, int prot, int flags, int fd, 129 * long pad, off_t pos) 130 * 131 * Memory Map (mmap) system call. Note that the file offset 132 * and address are allowed to be NOT page aligned, though if 133 * the MAP_FIXED flag it set, both must have the same remainder 134 * modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not 135 * page-aligned, the actual mapping starts at trunc_page(addr) 136 * and the return value is adjusted up by the page offset. 137 * 138 * Generally speaking, only character devices which are themselves 139 * memory-based, such as a video framebuffer, can be mmap'd. Otherwise 140 * there would be no cache coherency between a descriptor and a VM mapping 141 * both to the same character device. 142 * 143 * Block devices can be mmap'd no matter what they represent. Cache coherency 144 * is maintained as long as you do not write directly to the underlying 145 * character device. 146 */ 147 148 int 149 kern_mmap(struct vmspace *vms, caddr_t uaddr, size_t ulen, 150 int uprot, int uflags, int fd, off_t upos, void **res) 151 { 152 struct thread *td = curthread; 153 struct proc *p = td->td_proc; 154 struct file *fp = NULL; 155 struct vnode *vp; 156 vm_offset_t addr; 157 vm_size_t size, pageoff; 158 vm_prot_t prot, maxprot; 159 void *handle; 160 int flags, error; 161 int disablexworkaround; 162 off_t pos; 163 vm_object_t obj; 164 165 KKASSERT(p); 166 167 addr = (vm_offset_t) uaddr; 168 size = ulen; 169 prot = uprot & VM_PROT_ALL; 170 flags = uflags; 171 pos = upos; 172 173 /* make sure mapping fits into numeric range etc */ 174 if ((ssize_t) ulen < 0 || ((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 * Virtual page tables cannot be used with MAP_STACK. Apart from 187 * it not making any sense, the aux union is used by both 188 * types. 189 * 190 * Because the virtual page table is stored in the backing object 191 * and might be updated by the kernel, the mapping must be R+W. 192 */ 193 if (flags & MAP_VPAGETABLE) { 194 if (vkernel_enable == 0) 195 return (EOPNOTSUPP); 196 if (flags & MAP_STACK) 197 return (EINVAL); 198 if ((prot & (PROT_READ|PROT_WRITE)) != (PROT_READ|PROT_WRITE)) 199 return (EINVAL); 200 } 201 202 /* 203 * Align the file position to a page boundary, 204 * and save its page offset component. 205 */ 206 pageoff = (pos & PAGE_MASK); 207 pos -= pageoff; 208 209 /* Adjust size for rounding (on both ends). */ 210 size += pageoff; /* low end... */ 211 size = (vm_size_t) round_page(size); /* hi end */ 212 213 /* 214 * Check for illegal addresses. Watch out for address wrap... Note 215 * that VM_*_ADDRESS are not constants due to casts (argh). 216 */ 217 if (flags & MAP_FIXED) { 218 /* 219 * The specified address must have the same remainder 220 * as the file offset taken modulo PAGE_SIZE, so it 221 * should be aligned after adjustment by pageoff. 222 */ 223 addr -= pageoff; 224 if (addr & PAGE_MASK) 225 return (EINVAL); 226 /* Address range must be all in user VM space. */ 227 if (VM_MAX_USER_ADDRESS > 0 && addr + size > VM_MAX_USER_ADDRESS) 228 return (EINVAL); 229 if (VM_MIN_USER_ADDRESS > 0 && addr < VM_MIN_USER_ADDRESS) 230 return (EINVAL); 231 if (addr + size < addr) 232 return (EINVAL); 233 } else if ((flags & MAP_TRYFIXED) == 0) { 234 /* 235 * XXX for non-fixed mappings where no hint is provided or 236 * the hint would fall in the potential heap space, 237 * place it after the end of the largest possible heap. 238 * 239 * There should really be a pmap call to determine a reasonable 240 * location. 241 */ 242 if (addr == 0 || 243 (addr >= round_page((vm_offset_t)vms->vm_taddr) && 244 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) 245 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz); 246 } 247 248 if (flags & MAP_ANON) { 249 /* 250 * Mapping blank space is trivial. 251 */ 252 handle = NULL; 253 maxprot = VM_PROT_ALL; 254 pos = 0; 255 } else { 256 /* 257 * Mapping file, get fp for validation. Obtain vnode and make 258 * sure it is of appropriate type. 259 */ 260 fp = holdfp(p->p_fd, fd, -1); 261 if (fp == NULL) 262 return (EBADF); 263 if (fp->f_type != DTYPE_VNODE) { 264 error = EINVAL; 265 goto done; 266 } 267 /* 268 * POSIX shared-memory objects are defined to have 269 * kernel persistence, and are not defined to support 270 * read(2)/write(2) -- or even open(2). Thus, we can 271 * use MAP_ASYNC to trade on-disk coherence for speed. 272 * The shm_open(3) library routine turns on the FPOSIXSHM 273 * flag to request this behavior. 274 */ 275 if (fp->f_flag & FPOSIXSHM) 276 flags |= MAP_NOSYNC; 277 vp = (struct vnode *) fp->f_data; 278 279 /* 280 * Validate the vnode for the operation. 281 */ 282 switch(vp->v_type) { 283 case VREG: 284 /* 285 * Get the proper underlying object 286 */ 287 if ((obj = vp->v_object) == NULL) { 288 error = EINVAL; 289 goto done; 290 } 291 KKASSERT((struct vnode *)obj->handle == vp); 292 break; 293 case VCHR: 294 /* 295 * Make sure a device has not been revoked. 296 * Mappability is handled by the device layer. 297 */ 298 if (vp->v_rdev == NULL) { 299 error = EBADF; 300 goto done; 301 } 302 break; 303 default: 304 /* 305 * Nothing else is mappable. 306 */ 307 error = EINVAL; 308 goto done; 309 } 310 311 /* 312 * XXX hack to handle use of /dev/zero to map anon memory (ala 313 * SunOS). 314 */ 315 if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) { 316 handle = NULL; 317 maxprot = VM_PROT_ALL; 318 flags |= MAP_ANON; 319 pos = 0; 320 } else { 321 /* 322 * cdevs does not provide private mappings of any kind. 323 */ 324 /* 325 * However, for XIG X server to continue to work, 326 * we should allow the superuser to do it anyway. 327 * We only allow it at securelevel < 1. 328 * (Because the XIG X server writes directly to video 329 * memory via /dev/mem, it should never work at any 330 * other securelevel. 331 * XXX this will have to go 332 */ 333 if (securelevel >= 1) 334 disablexworkaround = 1; 335 else 336 disablexworkaround = priv_check(td, PRIV_ROOT); 337 if (vp->v_type == VCHR && disablexworkaround && 338 (flags & (MAP_PRIVATE|MAP_COPY))) { 339 error = EINVAL; 340 goto done; 341 } 342 /* 343 * Ensure that file and memory protections are 344 * compatible. Note that we only worry about 345 * writability if mapping is shared; in this case, 346 * current and max prot are dictated by the open file. 347 * XXX use the vnode instead? Problem is: what 348 * credentials do we use for determination? What if 349 * proc does a setuid? 350 */ 351 maxprot = VM_PROT_EXECUTE; /* ??? */ 352 if (fp->f_flag & FREAD) { 353 maxprot |= VM_PROT_READ; 354 } else if (prot & PROT_READ) { 355 error = EACCES; 356 goto done; 357 } 358 /* 359 * If we are sharing potential changes (either via 360 * MAP_SHARED or via the implicit sharing of character 361 * device mappings), and we are trying to get write 362 * permission although we opened it without asking 363 * for it, bail out. Check for superuser, only if 364 * we're at securelevel < 1, to allow the XIG X server 365 * to continue to work. 366 */ 367 368 if ((flags & MAP_SHARED) != 0 || 369 (vp->v_type == VCHR && disablexworkaround)) { 370 if ((fp->f_flag & FWRITE) != 0) { 371 struct vattr va; 372 if ((error = VOP_GETATTR(vp, &va))) { 373 goto done; 374 } 375 if ((va.va_flags & 376 (IMMUTABLE|APPEND)) == 0) { 377 maxprot |= VM_PROT_WRITE; 378 } else if (prot & PROT_WRITE) { 379 error = EPERM; 380 goto done; 381 } 382 } else if ((prot & PROT_WRITE) != 0) { 383 error = EACCES; 384 goto done; 385 } 386 } else { 387 maxprot |= VM_PROT_WRITE; 388 } 389 handle = (void *)vp; 390 } 391 } 392 393 /* 394 * Do not allow more then a certain number of vm_map_entry structures 395 * per process. Scale with the number of rforks sharing the map 396 * to make the limit reasonable for threads. 397 */ 398 if (max_proc_mmap && 399 vms->vm_map.nentries >= max_proc_mmap * vms->vm_sysref.refcnt) { 400 error = ENOMEM; 401 goto done; 402 } 403 404 error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot, 405 flags, handle, pos); 406 if (error == 0) 407 *res = (void *)(addr + pageoff); 408 done: 409 if (fp) 410 fdrop(fp); 411 return (error); 412 } 413 414 int 415 sys_mmap(struct mmap_args *uap) 416 { 417 int error; 418 419 error = kern_mmap(curproc->p_vmspace, uap->addr, uap->len, 420 uap->prot, uap->flags, 421 uap->fd, uap->pos, &uap->sysmsg_resultp); 422 423 return (error); 424 } 425 426 /* 427 * msync_args(void *addr, int len, int flags) 428 */ 429 int 430 sys_msync(struct msync_args *uap) 431 { 432 struct proc *p = curproc; 433 vm_offset_t addr; 434 vm_size_t size, pageoff; 435 int flags; 436 vm_map_t map; 437 int rv; 438 439 addr = (vm_offset_t) uap->addr; 440 size = uap->len; 441 flags = uap->flags; 442 443 pageoff = (addr & PAGE_MASK); 444 addr -= pageoff; 445 size += pageoff; 446 size = (vm_size_t) round_page(size); 447 if (addr + size < addr) 448 return(EINVAL); 449 450 if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE)) 451 return (EINVAL); 452 453 map = &p->p_vmspace->vm_map; 454 455 /* 456 * XXX Gak! If size is zero we are supposed to sync "all modified 457 * pages with the region containing addr". Unfortunately, we don't 458 * really keep track of individual mmaps so we approximate by flushing 459 * the range of the map entry containing addr. This can be incorrect 460 * if the region splits or is coalesced with a neighbor. 461 */ 462 if (size == 0) { 463 vm_map_entry_t entry; 464 465 vm_map_lock_read(map); 466 rv = vm_map_lookup_entry(map, addr, &entry); 467 vm_map_unlock_read(map); 468 if (rv == FALSE) 469 return (EINVAL); 470 addr = entry->start; 471 size = entry->end - entry->start; 472 } 473 474 /* 475 * Clean the pages and interpret the return value. 476 */ 477 rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0, 478 (flags & MS_INVALIDATE) != 0); 479 480 switch (rv) { 481 case KERN_SUCCESS: 482 break; 483 case KERN_INVALID_ADDRESS: 484 return (EINVAL); /* Sun returns ENOMEM? */ 485 case KERN_FAILURE: 486 return (EIO); 487 default: 488 return (EINVAL); 489 } 490 491 return (0); 492 } 493 494 /* 495 * munmap_args(void *addr, size_t len) 496 */ 497 int 498 sys_munmap(struct munmap_args *uap) 499 { 500 struct proc *p = curproc; 501 vm_offset_t addr; 502 vm_size_t size, pageoff; 503 vm_map_t map; 504 505 addr = (vm_offset_t) uap->addr; 506 size = uap->len; 507 508 pageoff = (addr & PAGE_MASK); 509 addr -= pageoff; 510 size += pageoff; 511 size = (vm_size_t) round_page(size); 512 if (addr + size < addr) 513 return(EINVAL); 514 515 if (size == 0) 516 return (0); 517 518 /* 519 * Check for illegal addresses. Watch out for address wrap... Note 520 * that VM_*_ADDRESS are not constants due to casts (argh). 521 */ 522 if (VM_MAX_USER_ADDRESS > 0 && addr + size > VM_MAX_USER_ADDRESS) 523 return (EINVAL); 524 if (VM_MIN_USER_ADDRESS > 0 && addr < VM_MIN_USER_ADDRESS) 525 return (EINVAL); 526 map = &p->p_vmspace->vm_map; 527 /* 528 * Make sure entire range is allocated. 529 */ 530 if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE)) 531 return (EINVAL); 532 /* returns nothing but KERN_SUCCESS anyway */ 533 vm_map_remove(map, addr, addr + size); 534 return (0); 535 } 536 537 /* 538 * mprotect_args(const void *addr, size_t len, int prot) 539 */ 540 int 541 sys_mprotect(struct mprotect_args *uap) 542 { 543 struct proc *p = curproc; 544 vm_offset_t addr; 545 vm_size_t size, pageoff; 546 vm_prot_t prot; 547 548 addr = (vm_offset_t) uap->addr; 549 size = uap->len; 550 prot = uap->prot & VM_PROT_ALL; 551 #if defined(VM_PROT_READ_IS_EXEC) 552 if (prot & VM_PROT_READ) 553 prot |= VM_PROT_EXECUTE; 554 #endif 555 556 pageoff = (addr & PAGE_MASK); 557 addr -= pageoff; 558 size += pageoff; 559 size = (vm_size_t) round_page(size); 560 if (addr + size < addr) 561 return(EINVAL); 562 563 switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot, 564 FALSE)) { 565 case KERN_SUCCESS: 566 return (0); 567 case KERN_PROTECTION_FAILURE: 568 return (EACCES); 569 } 570 return (EINVAL); 571 } 572 573 /* 574 * minherit_args(void *addr, size_t len, int inherit) 575 */ 576 int 577 sys_minherit(struct minherit_args *uap) 578 { 579 struct proc *p = curproc; 580 vm_offset_t addr; 581 vm_size_t size, pageoff; 582 vm_inherit_t inherit; 583 584 addr = (vm_offset_t)uap->addr; 585 size = uap->len; 586 inherit = uap->inherit; 587 588 pageoff = (addr & PAGE_MASK); 589 addr -= pageoff; 590 size += pageoff; 591 size = (vm_size_t) round_page(size); 592 if (addr + size < addr) 593 return(EINVAL); 594 595 switch (vm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size, 596 inherit)) { 597 case KERN_SUCCESS: 598 return (0); 599 case KERN_PROTECTION_FAILURE: 600 return (EACCES); 601 } 602 return (EINVAL); 603 } 604 605 /* 606 * madvise_args(void *addr, size_t len, int behav) 607 */ 608 /* ARGSUSED */ 609 int 610 sys_madvise(struct madvise_args *uap) 611 { 612 struct proc *p = curproc; 613 vm_offset_t start, end; 614 615 /* 616 * Check for illegal behavior 617 */ 618 if (uap->behav < 0 || uap->behav >= MADV_CONTROL_END) 619 return (EINVAL); 620 /* 621 * Check for illegal addresses. Watch out for address wrap... Note 622 * that VM_*_ADDRESS are not constants due to casts (argh). 623 */ 624 if (VM_MAX_USER_ADDRESS > 0 && 625 ((vm_offset_t) uap->addr + uap->len) > VM_MAX_USER_ADDRESS) 626 return (EINVAL); 627 if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS) 628 return (EINVAL); 629 if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr) 630 return (EINVAL); 631 632 /* 633 * Since this routine is only advisory, we default to conservative 634 * behavior. 635 */ 636 start = trunc_page((vm_offset_t) uap->addr); 637 end = round_page((vm_offset_t) uap->addr + uap->len); 638 639 return (vm_map_madvise(&p->p_vmspace->vm_map, start, end, 640 uap->behav, 0)); 641 } 642 643 /* 644 * mcontrol_args(void *addr, size_t len, int behav, off_t value) 645 */ 646 /* ARGSUSED */ 647 int 648 sys_mcontrol(struct mcontrol_args *uap) 649 { 650 struct proc *p = curproc; 651 vm_offset_t start, end; 652 653 /* 654 * Check for illegal behavior 655 */ 656 if (uap->behav < 0 || uap->behav > MADV_CONTROL_END) 657 return (EINVAL); 658 /* 659 * Check for illegal addresses. Watch out for address wrap... Note 660 * that VM_*_ADDRESS are not constants due to casts (argh). 661 */ 662 if (VM_MAX_USER_ADDRESS > 0 && 663 ((vm_offset_t) uap->addr + uap->len) > VM_MAX_USER_ADDRESS) 664 return (EINVAL); 665 if (VM_MIN_USER_ADDRESS > 0 && uap->addr < VM_MIN_USER_ADDRESS) 666 return (EINVAL); 667 if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr) 668 return (EINVAL); 669 670 /* 671 * Since this routine is only advisory, we default to conservative 672 * behavior. 673 */ 674 start = trunc_page((vm_offset_t) uap->addr); 675 end = round_page((vm_offset_t) uap->addr + uap->len); 676 677 return (vm_map_madvise(&p->p_vmspace->vm_map, start, end, 678 uap->behav, uap->value)); 679 } 680 681 682 /* 683 * mincore_args(const void *addr, size_t len, char *vec) 684 */ 685 /* ARGSUSED */ 686 int 687 sys_mincore(struct mincore_args *uap) 688 { 689 struct proc *p = curproc; 690 vm_offset_t addr, first_addr; 691 vm_offset_t end, cend; 692 pmap_t pmap; 693 vm_map_t map; 694 char *vec; 695 int error; 696 int vecindex, lastvecindex; 697 vm_map_entry_t current; 698 vm_map_entry_t entry; 699 int mincoreinfo; 700 unsigned int timestamp; 701 702 /* 703 * Make sure that the addresses presented are valid for user 704 * mode. 705 */ 706 first_addr = addr = trunc_page((vm_offset_t) uap->addr); 707 end = addr + (vm_size_t)round_page(uap->len); 708 if (VM_MAX_USER_ADDRESS > 0 && end > VM_MAX_USER_ADDRESS) 709 return (EINVAL); 710 if (end < addr) 711 return (EINVAL); 712 713 /* 714 * Address of byte vector 715 */ 716 vec = uap->vec; 717 718 map = &p->p_vmspace->vm_map; 719 pmap = vmspace_pmap(p->p_vmspace); 720 721 vm_map_lock_read(map); 722 RestartScan: 723 timestamp = map->timestamp; 724 725 if (!vm_map_lookup_entry(map, addr, &entry)) 726 entry = entry->next; 727 728 /* 729 * Do this on a map entry basis so that if the pages are not 730 * in the current processes address space, we can easily look 731 * up the pages elsewhere. 732 */ 733 lastvecindex = -1; 734 for(current = entry; 735 (current != &map->header) && (current->start < end); 736 current = current->next) { 737 738 /* 739 * ignore submaps (for now) or null objects 740 */ 741 if (current->maptype != VM_MAPTYPE_NORMAL && 742 current->maptype != VM_MAPTYPE_VPAGETABLE) { 743 continue; 744 } 745 if (current->object.vm_object == NULL) 746 continue; 747 748 /* 749 * limit this scan to the current map entry and the 750 * limits for the mincore call 751 */ 752 if (addr < current->start) 753 addr = current->start; 754 cend = current->end; 755 if (cend > end) 756 cend = end; 757 758 /* 759 * scan this entry one page at a time 760 */ 761 while (addr < cend) { 762 /* 763 * Check pmap first, it is likely faster, also 764 * it can provide info as to whether we are the 765 * one referencing or modifying the page. 766 * 767 * If we have to check the VM object, only mess 768 * around with normal maps. Do not mess around 769 * with virtual page tables (XXX). 770 */ 771 mincoreinfo = pmap_mincore(pmap, addr); 772 if (mincoreinfo == 0 && 773 current->maptype == VM_MAPTYPE_NORMAL) { 774 vm_pindex_t pindex; 775 vm_ooffset_t offset; 776 vm_page_t m; 777 778 /* 779 * calculate the page index into the object 780 */ 781 offset = current->offset + (addr - current->start); 782 pindex = OFF_TO_IDX(offset); 783 784 /* 785 * if the page is resident, then gather 786 * information about it. spl protection is 787 * required to maintain the object 788 * association. And XXX what if the page is 789 * busy? What's the deal with that? 790 */ 791 crit_enter(); 792 m = vm_page_lookup(current->object.vm_object, 793 pindex); 794 if (m && m->valid) { 795 mincoreinfo = MINCORE_INCORE; 796 if (m->dirty || 797 pmap_is_modified(m)) 798 mincoreinfo |= MINCORE_MODIFIED_OTHER; 799 if ((m->flags & PG_REFERENCED) || 800 pmap_ts_referenced(m)) { 801 vm_page_flag_set(m, PG_REFERENCED); 802 mincoreinfo |= MINCORE_REFERENCED_OTHER; 803 } 804 } 805 crit_exit(); 806 } 807 808 /* 809 * subyte may page fault. In case it needs to modify 810 * the map, we release the lock. 811 */ 812 vm_map_unlock_read(map); 813 814 /* 815 * calculate index into user supplied byte vector 816 */ 817 vecindex = OFF_TO_IDX(addr - first_addr); 818 819 /* 820 * If we have skipped map entries, we need to make sure that 821 * the byte vector is zeroed for those skipped entries. 822 */ 823 while((lastvecindex + 1) < vecindex) { 824 error = subyte( vec + lastvecindex, 0); 825 if (error) { 826 return (EFAULT); 827 } 828 ++lastvecindex; 829 } 830 831 /* 832 * Pass the page information to the user 833 */ 834 error = subyte( vec + vecindex, mincoreinfo); 835 if (error) { 836 return (EFAULT); 837 } 838 839 /* 840 * If the map has changed, due to the subyte, the previous 841 * output may be invalid. 842 */ 843 vm_map_lock_read(map); 844 if (timestamp != map->timestamp) 845 goto RestartScan; 846 847 lastvecindex = vecindex; 848 addr += PAGE_SIZE; 849 } 850 } 851 852 /* 853 * subyte may page fault. In case it needs to modify 854 * the map, we release the lock. 855 */ 856 vm_map_unlock_read(map); 857 858 /* 859 * Zero the last entries in the byte vector. 860 */ 861 vecindex = OFF_TO_IDX(end - first_addr); 862 while((lastvecindex + 1) < vecindex) { 863 error = subyte( vec + lastvecindex, 0); 864 if (error) { 865 return (EFAULT); 866 } 867 ++lastvecindex; 868 } 869 870 /* 871 * If the map has changed, due to the subyte, the previous 872 * output may be invalid. 873 */ 874 vm_map_lock_read(map); 875 if (timestamp != map->timestamp) 876 goto RestartScan; 877 vm_map_unlock_read(map); 878 879 return (0); 880 } 881 882 /* 883 * mlock_args(const void *addr, size_t len) 884 */ 885 int 886 sys_mlock(struct mlock_args *uap) 887 { 888 vm_offset_t addr; 889 vm_size_t size, pageoff; 890 int error; 891 struct proc *p = curproc; 892 893 addr = (vm_offset_t) uap->addr; 894 size = uap->len; 895 896 pageoff = (addr & PAGE_MASK); 897 addr -= pageoff; 898 size += pageoff; 899 size = (vm_size_t) round_page(size); 900 901 /* disable wrap around */ 902 if (addr + size < addr) 903 return (EINVAL); 904 905 if (atop(size) + vmstats.v_wire_count > vm_page_max_wired) 906 return (EAGAIN); 907 908 #ifdef pmap_wired_count 909 if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) > 910 p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur) 911 return (ENOMEM); 912 #else 913 error = priv_check_cred(p->p_ucred, PRIV_ROOT, 0); 914 if (error) 915 return (error); 916 #endif 917 918 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, FALSE); 919 return (error == KERN_SUCCESS ? 0 : ENOMEM); 920 } 921 922 /* 923 * mlockall_args(int how) 924 */ 925 int 926 sys_mlockall(struct mlockall_args *uap) 927 { 928 return 0; 929 } 930 931 /* 932 * munlockall_args(void) 933 */ 934 int 935 sys_munlockall(struct munlockall_args *uap) 936 { 937 return 0; 938 } 939 940 /* 941 * munlock_args(const void *addr, size_t len) 942 */ 943 int 944 sys_munlock(struct munlock_args *uap) 945 { 946 struct thread *td = curthread; 947 struct proc *p = td->td_proc; 948 vm_offset_t addr; 949 vm_size_t size, pageoff; 950 int error; 951 952 addr = (vm_offset_t) uap->addr; 953 size = uap->len; 954 955 pageoff = (addr & PAGE_MASK); 956 addr -= pageoff; 957 size += pageoff; 958 size = (vm_size_t) round_page(size); 959 960 /* disable wrap around */ 961 if (addr + size < addr) 962 return (EINVAL); 963 964 #ifndef pmap_wired_count 965 error = priv_check(td, PRIV_ROOT); 966 if (error) 967 return (error); 968 #endif 969 970 error = vm_map_unwire(&p->p_vmspace->vm_map, addr, addr + size, TRUE); 971 return (error == KERN_SUCCESS ? 0 : ENOMEM); 972 } 973 974 /* 975 * Internal version of mmap. 976 * Currently used by mmap, exec, and sys5 shared memory. 977 * Handle is either a vnode pointer or NULL for MAP_ANON. 978 */ 979 int 980 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot, 981 vm_prot_t maxprot, int flags, 982 void *handle, 983 vm_ooffset_t foff) 984 { 985 boolean_t fitit; 986 vm_object_t object; 987 struct vnode *vp; 988 struct thread *td = curthread; 989 struct proc *p; 990 objtype_t type; 991 int rv = KERN_SUCCESS; 992 off_t objsize; 993 int docow; 994 995 if (size == 0) 996 return (0); 997 998 objsize = size = round_page(size); 999 1000 /* 1001 * XXX messy code, fixme 1002 */ 1003 if ((p = curproc) != NULL && map == &p->p_vmspace->vm_map) { 1004 if (map->size + size > p->p_rlimit[RLIMIT_VMEM].rlim_cur) 1005 return(ENOMEM); 1006 } 1007 1008 /* 1009 * We currently can only deal with page aligned file offsets. 1010 * The check is here rather than in the syscall because the 1011 * kernel calls this function internally for other mmaping 1012 * operations (such as in exec) and non-aligned offsets will 1013 * cause pmap inconsistencies...so we want to be sure to 1014 * disallow this in all cases. 1015 */ 1016 if (foff & PAGE_MASK) 1017 return (EINVAL); 1018 1019 if ((flags & MAP_FIXED) == 0) { 1020 fitit = TRUE; 1021 *addr = round_page(*addr); 1022 } else { 1023 if (*addr != trunc_page(*addr)) 1024 return (EINVAL); 1025 fitit = FALSE; 1026 vm_map_remove(map, *addr, *addr + size); 1027 } 1028 1029 /* 1030 * Lookup/allocate object. 1031 */ 1032 if (flags & MAP_ANON) { 1033 type = OBJT_DEFAULT; 1034 /* 1035 * Unnamed anonymous regions always start at 0. 1036 */ 1037 if (handle == NULL) 1038 foff = 0; 1039 vp = NULL; 1040 } else { 1041 vp = (struct vnode *)handle; 1042 if (vp->v_type == VCHR) { 1043 type = OBJT_DEVICE; 1044 handle = (void *)(intptr_t)vp->v_rdev; 1045 } else { 1046 struct vattr vat; 1047 int error; 1048 1049 error = VOP_GETATTR(vp, &vat); 1050 if (error) 1051 return (error); 1052 objsize = vat.va_size; 1053 type = OBJT_VNODE; 1054 /* 1055 * if it is a regular file without any references 1056 * we do not need to sync it. 1057 */ 1058 if (vp->v_type == VREG && vat.va_nlink == 0) { 1059 flags |= MAP_NOSYNC; 1060 } 1061 } 1062 } 1063 1064 if (handle == NULL) { 1065 object = NULL; 1066 docow = 0; 1067 } else { 1068 object = vm_pager_allocate(type, handle, objsize, prot, foff); 1069 if (object == NULL) 1070 return (type == OBJT_DEVICE ? EINVAL : ENOMEM); 1071 docow = MAP_PREFAULT_PARTIAL; 1072 } 1073 1074 /* 1075 * Force device mappings to be shared. 1076 */ 1077 if (type == OBJT_DEVICE || type == OBJT_PHYS) { 1078 flags &= ~(MAP_PRIVATE|MAP_COPY); 1079 flags |= MAP_SHARED; 1080 } 1081 1082 if ((flags & (MAP_ANON|MAP_SHARED)) == 0) 1083 docow |= MAP_COPY_ON_WRITE; 1084 if (flags & MAP_NOSYNC) 1085 docow |= MAP_DISABLE_SYNCER; 1086 if (flags & MAP_NOCORE) 1087 docow |= MAP_DISABLE_COREDUMP; 1088 1089 #if defined(VM_PROT_READ_IS_EXEC) 1090 if (prot & VM_PROT_READ) 1091 prot |= VM_PROT_EXECUTE; 1092 1093 if (maxprot & VM_PROT_READ) 1094 maxprot |= VM_PROT_EXECUTE; 1095 #endif 1096 1097 if (fitit) { 1098 *addr = pmap_addr_hint(object, *addr, size); 1099 } 1100 1101 /* 1102 * Stack mappings need special attention. Mappings that use virtual 1103 * page tables will default to storing the page table at offset 0. 1104 */ 1105 if (flags & MAP_STACK) { 1106 rv = vm_map_stack (map, *addr, size, prot, maxprot, docow); 1107 } else if (flags & MAP_VPAGETABLE) { 1108 rv = vm_map_find(map, object, foff, addr, size, fitit, 1109 VM_MAPTYPE_VPAGETABLE, prot, maxprot, docow); 1110 } else { 1111 rv = vm_map_find(map, object, foff, addr, size, fitit, 1112 VM_MAPTYPE_NORMAL, prot, maxprot, docow); 1113 } 1114 1115 if (rv != KERN_SUCCESS) { 1116 /* 1117 * Lose the object reference. Will destroy the 1118 * object if it's an unnamed anonymous mapping 1119 * or named anonymous without other references. 1120 */ 1121 vm_object_deallocate(object); 1122 goto out; 1123 } 1124 1125 /* 1126 * Shared memory is also shared with children. 1127 */ 1128 if (flags & (MAP_SHARED|MAP_INHERIT)) { 1129 rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE); 1130 if (rv != KERN_SUCCESS) { 1131 vm_map_remove(map, *addr, *addr + size); 1132 goto out; 1133 } 1134 } 1135 1136 /* 1137 * Set the access time on the vnode 1138 */ 1139 if (vp != NULL) 1140 vn_mark_atime(vp, td); 1141 out: 1142 switch (rv) { 1143 case KERN_SUCCESS: 1144 return (0); 1145 case KERN_INVALID_ADDRESS: 1146 case KERN_NO_SPACE: 1147 return (ENOMEM); 1148 case KERN_PROTECTION_FAILURE: 1149 return (EACCES); 1150 default: 1151 return (EINVAL); 1152 } 1153 } 1154