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sys/vm/vm_mmap.c
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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: releng/5.0/sys/vm/vm_mmap.c 107370 2002-11-28 08:01:39Z alc $ 42 */ 43 44 /* 45 * Mapped file (mmap) interface to VM 46 */ 47 48 #include "opt_compat.h" 49 #include "opt_mac.h" 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/kernel.h> 54 #include <sys/lock.h> 55 #include <sys/mutex.h> 56 #include <sys/sysproto.h> 57 #include <sys/filedesc.h> 58 #include <sys/proc.h> 59 #include <sys/resource.h> 60 #include <sys/resourcevar.h> 61 #include <sys/vnode.h> 62 #include <sys/fcntl.h> 63 #include <sys/file.h> 64 #include <sys/mac.h> 65 #include <sys/mman.h> 66 #include <sys/conf.h> 67 #include <sys/stat.h> 68 #include <sys/vmmeter.h> 69 #include <sys/sysctl.h> 70 71 #include <vm/vm.h> 72 #include <vm/vm_param.h> 73 #include <vm/pmap.h> 74 #include <vm/vm_map.h> 75 #include <vm/vm_object.h> 76 #include <vm/vm_page.h> 77 #include <vm/vm_pager.h> 78 #include <vm/vm_pageout.h> 79 #include <vm/vm_extern.h> 80 #include <vm/vm_page.h> 81 #include <vm/vm_kern.h> 82 83 #ifndef _SYS_SYSPROTO_H_ 84 struct sbrk_args { 85 int incr; 86 }; 87 #endif 88 89 static int max_proc_mmap; 90 SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, ""); 91 92 /* 93 * Set the maximum number of vm_map_entry structures per process. Roughly 94 * speaking vm_map_entry structures are tiny, so allowing them to eat 1/100 95 * of our KVM malloc space still results in generous limits. We want a 96 * default that is good enough to prevent the kernel running out of resources 97 * if attacked from compromised user account but generous enough such that 98 * multi-threaded processes are not unduly inconvenienced. 99 */ 100 static void vmmapentry_rsrc_init(void *); 101 SYSINIT(vmmersrc, SI_SUB_KVM_RSRC, SI_ORDER_FIRST, vmmapentry_rsrc_init, NULL) 102 103 static void 104 vmmapentry_rsrc_init(dummy) 105 void *dummy; 106 { 107 max_proc_mmap = vm_kmem_size / sizeof(struct vm_map_entry); 108 max_proc_mmap /= 100; 109 } 110 111 /* 112 * MPSAFE 113 */ 114 /* ARGSUSED */ 115 int 116 sbrk(td, uap) 117 struct thread *td; 118 struct sbrk_args *uap; 119 { 120 /* Not yet implemented */ 121 /* mtx_lock(&Giant); */ 122 /* mtx_unlock(&Giant); */ 123 return (EOPNOTSUPP); 124 } 125 126 #ifndef _SYS_SYSPROTO_H_ 127 struct sstk_args { 128 int incr; 129 }; 130 #endif 131 132 /* 133 * MPSAFE 134 */ 135 /* ARGSUSED */ 136 int 137 sstk(td, uap) 138 struct thread *td; 139 struct sstk_args *uap; 140 { 141 /* Not yet implemented */ 142 /* mtx_lock(&Giant); */ 143 /* mtx_unlock(&Giant); */ 144 return (EOPNOTSUPP); 145 } 146 147 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 148 #ifndef _SYS_SYSPROTO_H_ 149 struct getpagesize_args { 150 int dummy; 151 }; 152 #endif 153 154 /* ARGSUSED */ 155 int 156 ogetpagesize(td, uap) 157 struct thread *td; 158 struct getpagesize_args *uap; 159 { 160 /* MP SAFE */ 161 td->td_retval[0] = PAGE_SIZE; 162 return (0); 163 } 164 #endif /* COMPAT_43 || COMPAT_SUNOS */ 165 166 167 /* 168 * Memory Map (mmap) system call. Note that the file offset 169 * and address are allowed to be NOT page aligned, though if 170 * the MAP_FIXED flag it set, both must have the same remainder 171 * modulo the PAGE_SIZE (POSIX 1003.1b). If the address is not 172 * page-aligned, the actual mapping starts at trunc_page(addr) 173 * and the return value is adjusted up by the page offset. 174 * 175 * Generally speaking, only character devices which are themselves 176 * memory-based, such as a video framebuffer, can be mmap'd. Otherwise 177 * there would be no cache coherency between a descriptor and a VM mapping 178 * both to the same character device. 179 * 180 * Block devices can be mmap'd no matter what they represent. Cache coherency 181 * is maintained as long as you do not write directly to the underlying 182 * character device. 183 */ 184 #ifndef _SYS_SYSPROTO_H_ 185 struct mmap_args { 186 void *addr; 187 size_t len; 188 int prot; 189 int flags; 190 int fd; 191 long pad; 192 off_t pos; 193 }; 194 #endif 195 196 /* 197 * MPSAFE 198 */ 199 int 200 mmap(td, uap) 201 struct thread *td; 202 struct mmap_args *uap; 203 { 204 struct file *fp = NULL; 205 struct vnode *vp; 206 vm_offset_t addr; 207 vm_size_t size, pageoff; 208 vm_prot_t prot, maxprot; 209 void *handle; 210 int flags, error; 211 int disablexworkaround; 212 off_t pos; 213 struct vmspace *vms = td->td_proc->p_vmspace; 214 vm_object_t obj; 215 216 addr = (vm_offset_t) uap->addr; 217 size = uap->len; 218 prot = uap->prot & VM_PROT_ALL; 219 flags = uap->flags; 220 pos = uap->pos; 221 222 vp = NULL; 223 fp = NULL; 224 /* make sure mapping fits into numeric range etc */ 225 if ((ssize_t) uap->len < 0 || 226 ((flags & MAP_ANON) && uap->fd != -1)) 227 return (EINVAL); 228 229 if (flags & MAP_STACK) { 230 if ((uap->fd != -1) || 231 ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE))) 232 return (EINVAL); 233 flags |= MAP_ANON; 234 pos = 0; 235 } 236 237 /* 238 * Align the file position to a page boundary, 239 * and save its page offset component. 240 */ 241 pageoff = (pos & PAGE_MASK); 242 pos -= pageoff; 243 244 /* Adjust size for rounding (on both ends). */ 245 size += pageoff; /* low end... */ 246 size = (vm_size_t) round_page(size); /* hi end */ 247 248 /* 249 * Check for illegal addresses. Watch out for address wrap... Note 250 * that VM_*_ADDRESS are not constants due to casts (argh). 251 */ 252 if (flags & MAP_FIXED) { 253 /* 254 * The specified address must have the same remainder 255 * as the file offset taken modulo PAGE_SIZE, so it 256 * should be aligned after adjustment by pageoff. 257 */ 258 addr -= pageoff; 259 if (addr & PAGE_MASK) 260 return (EINVAL); 261 /* Address range must be all in user VM space. */ 262 if (addr < vm_map_min(&vms->vm_map) || 263 addr + size > vm_map_max(&vms->vm_map)) 264 return (EINVAL); 265 if (addr + size < addr) 266 return (EINVAL); 267 } 268 /* 269 * XXX for non-fixed mappings where no hint is provided or 270 * the hint would fall in the potential heap space, 271 * place it after the end of the largest possible heap. 272 * 273 * There should really be a pmap call to determine a reasonable 274 * location. 275 */ 276 else if (addr == 0 || 277 (addr >= round_page((vm_offset_t)vms->vm_taddr) && 278 addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) 279 addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz); 280 281 mtx_lock(&Giant); /* syscall marked mp-safe but isn't */ 282 if (flags & MAP_ANON) { 283 /* 284 * Mapping blank space is trivial. 285 */ 286 handle = NULL; 287 maxprot = VM_PROT_ALL; 288 pos = 0; 289 } else { 290 /* 291 * Mapping file, get fp for validation. Obtain vnode and make 292 * sure it is of appropriate type. 293 * don't let the descriptor disappear on us if we block 294 */ 295 if ((error = fget(td, uap->fd, &fp)) != 0) 296 goto done; 297 if (fp->f_type != DTYPE_VNODE) { 298 error = EINVAL; 299 goto done; 300 } 301 302 /* 303 * POSIX shared-memory objects are defined to have 304 * kernel persistence, and are not defined to support 305 * read(2)/write(2) -- or even open(2). Thus, we can 306 * use MAP_ASYNC to trade on-disk coherence for speed. 307 * The shm_open(3) library routine turns on the FPOSIXSHM 308 * flag to request this behavior. 309 */ 310 if (fp->f_flag & FPOSIXSHM) 311 flags |= MAP_NOSYNC; 312 vp = (struct vnode *) fp->f_data; 313 error = vget(vp, LK_EXCLUSIVE, td); 314 if (error) 315 goto done; 316 if (vp->v_type != VREG && vp->v_type != VCHR) { 317 error = EINVAL; 318 goto done; 319 } 320 if (vp->v_type == VREG) { 321 /* 322 * Get the proper underlying object 323 */ 324 if (VOP_GETVOBJECT(vp, &obj) != 0) { 325 error = EINVAL; 326 goto done; 327 } 328 if (obj->handle != vp) { 329 vput(vp); 330 vp = (struct vnode*)obj->handle; 331 vget(vp, LK_EXCLUSIVE, td); 332 } 333 } 334 /* 335 * XXX hack to handle use of /dev/zero to map anon memory (ala 336 * SunOS). 337 */ 338 if ((vp->v_type == VCHR) && 339 (vp->v_rdev->si_devsw->d_flags & D_MMAP_ANON)) { 340 handle = NULL; 341 maxprot = VM_PROT_ALL; 342 flags |= MAP_ANON; 343 pos = 0; 344 } else { 345 /* 346 * cdevs does not provide private mappings of any kind. 347 */ 348 /* 349 * However, for XIG X server to continue to work, 350 * we should allow the superuser to do it anyway. 351 * We only allow it at securelevel < 1. 352 * (Because the XIG X server writes directly to video 353 * memory via /dev/mem, it should never work at any 354 * other securelevel. 355 * XXX this will have to go 356 */ 357 if (securelevel_ge(td->td_ucred, 1)) 358 disablexworkaround = 1; 359 else 360 disablexworkaround = suser(td); 361 if (vp->v_type == VCHR && disablexworkaround && 362 (flags & (MAP_PRIVATE|MAP_COPY))) { 363 error = EINVAL; 364 goto done; 365 } 366 /* 367 * Ensure that file and memory protections are 368 * compatible. Note that we only worry about 369 * writability if mapping is shared; in this case, 370 * current and max prot are dictated by the open file. 371 * XXX use the vnode instead? Problem is: what 372 * credentials do we use for determination? What if 373 * proc does a setuid? 374 */ 375 maxprot = VM_PROT_EXECUTE; /* ??? */ 376 if (fp->f_flag & FREAD) { 377 maxprot |= VM_PROT_READ; 378 } else if (prot & PROT_READ) { 379 error = EACCES; 380 goto done; 381 } 382 /* 383 * If we are sharing potential changes (either via 384 * MAP_SHARED or via the implicit sharing of character 385 * device mappings), and we are trying to get write 386 * permission although we opened it without asking 387 * for it, bail out. Check for superuser, only if 388 * we're at securelevel < 1, to allow the XIG X server 389 * to continue to work. 390 */ 391 if ((flags & MAP_SHARED) != 0 || 392 (vp->v_type == VCHR && disablexworkaround)) { 393 if ((fp->f_flag & FWRITE) != 0) { 394 struct vattr va; 395 if ((error = 396 VOP_GETATTR(vp, &va, 397 td->td_ucred, td))) { 398 goto done; 399 } 400 if ((va.va_flags & 401 (SF_SNAPSHOT|IMMUTABLE|APPEND)) == 0) { 402 maxprot |= VM_PROT_WRITE; 403 } else if (prot & PROT_WRITE) { 404 error = EPERM; 405 goto done; 406 } 407 } else if ((prot & PROT_WRITE) != 0) { 408 error = EACCES; 409 goto done; 410 } 411 } else { 412 maxprot |= VM_PROT_WRITE; 413 } 414 415 handle = (void *)vp; 416 } 417 } 418 419 /* 420 * Do not allow more then a certain number of vm_map_entry structures 421 * per process. Scale with the number of rforks sharing the map 422 * to make the limit reasonable for threads. 423 */ 424 if (max_proc_mmap && 425 vms->vm_map.nentries >= max_proc_mmap * vms->vm_refcnt) { 426 error = ENOMEM; 427 goto done; 428 } 429 430 mtx_unlock(&Giant); 431 error = 0; 432 #ifdef MAC 433 if (handle != NULL && (flags & MAP_SHARED) != 0) { 434 error = mac_check_vnode_mmap(td->td_ucred, 435 (struct vnode *)handle, prot); 436 } 437 #endif 438 if (error == 0) 439 error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot, 440 flags, handle, pos); 441 mtx_lock(&Giant); 442 if (error == 0) 443 td->td_retval[0] = (register_t) (addr + pageoff); 444 done: 445 if (vp) 446 vput(vp); 447 mtx_unlock(&Giant); 448 if (fp) 449 fdrop(fp, td); 450 451 return (error); 452 } 453 454 #ifdef COMPAT_43 455 #ifndef _SYS_SYSPROTO_H_ 456 struct ommap_args { 457 caddr_t addr; 458 int len; 459 int prot; 460 int flags; 461 int fd; 462 long pos; 463 }; 464 #endif 465 int 466 ommap(td, uap) 467 struct thread *td; 468 struct ommap_args *uap; 469 { 470 struct mmap_args nargs; 471 static const char cvtbsdprot[8] = { 472 0, 473 PROT_EXEC, 474 PROT_WRITE, 475 PROT_EXEC | PROT_WRITE, 476 PROT_READ, 477 PROT_EXEC | PROT_READ, 478 PROT_WRITE | PROT_READ, 479 PROT_EXEC | PROT_WRITE | PROT_READ, 480 }; 481 482 #define OMAP_ANON 0x0002 483 #define OMAP_COPY 0x0020 484 #define OMAP_SHARED 0x0010 485 #define OMAP_FIXED 0x0100 486 487 nargs.addr = uap->addr; 488 nargs.len = uap->len; 489 nargs.prot = cvtbsdprot[uap->prot & 0x7]; 490 nargs.flags = 0; 491 if (uap->flags & OMAP_ANON) 492 nargs.flags |= MAP_ANON; 493 if (uap->flags & OMAP_COPY) 494 nargs.flags |= MAP_COPY; 495 if (uap->flags & OMAP_SHARED) 496 nargs.flags |= MAP_SHARED; 497 else 498 nargs.flags |= MAP_PRIVATE; 499 if (uap->flags & OMAP_FIXED) 500 nargs.flags |= MAP_FIXED; 501 nargs.fd = uap->fd; 502 nargs.pos = uap->pos; 503 return (mmap(td, &nargs)); 504 } 505 #endif /* COMPAT_43 */ 506 507 508 #ifndef _SYS_SYSPROTO_H_ 509 struct msync_args { 510 void *addr; 511 int len; 512 int flags; 513 }; 514 #endif 515 /* 516 * MPSAFE 517 */ 518 int 519 msync(td, uap) 520 struct thread *td; 521 struct msync_args *uap; 522 { 523 vm_offset_t addr; 524 vm_size_t size, pageoff; 525 int flags; 526 vm_map_t map; 527 int rv; 528 529 addr = (vm_offset_t) uap->addr; 530 size = uap->len; 531 flags = uap->flags; 532 533 pageoff = (addr & PAGE_MASK); 534 addr -= pageoff; 535 size += pageoff; 536 size = (vm_size_t) round_page(size); 537 if (addr + size < addr) 538 return (EINVAL); 539 540 if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE)) 541 return (EINVAL); 542 543 mtx_lock(&Giant); 544 545 map = &td->td_proc->p_vmspace->vm_map; 546 547 /* 548 * XXX Gak! If size is zero we are supposed to sync "all modified 549 * pages with the region containing addr". Unfortunately, we don't 550 * really keep track of individual mmaps so we approximate by flushing 551 * the range of the map entry containing addr. This can be incorrect 552 * if the region splits or is coalesced with a neighbor. 553 */ 554 if (size == 0) { 555 vm_map_entry_t entry; 556 557 vm_map_lock_read(map); 558 rv = vm_map_lookup_entry(map, addr, &entry); 559 vm_map_unlock_read(map); 560 if (rv == FALSE) { 561 rv = -1; 562 goto done2; 563 } 564 addr = entry->start; 565 size = entry->end - entry->start; 566 } 567 568 /* 569 * Clean the pages and interpret the return value. 570 */ 571 rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0, 572 (flags & MS_INVALIDATE) != 0); 573 574 done2: 575 mtx_unlock(&Giant); 576 577 switch (rv) { 578 case KERN_SUCCESS: 579 return (0); 580 case KERN_INVALID_ADDRESS: 581 return (EINVAL); /* Sun returns ENOMEM? */ 582 case KERN_FAILURE: 583 return (EIO); 584 default: 585 return (EINVAL); 586 } 587 } 588 589 #ifndef _SYS_SYSPROTO_H_ 590 struct munmap_args { 591 void *addr; 592 size_t len; 593 }; 594 #endif 595 /* 596 * MPSAFE 597 */ 598 int 599 munmap(td, uap) 600 struct thread *td; 601 struct munmap_args *uap; 602 { 603 vm_offset_t addr; 604 vm_size_t size, pageoff; 605 vm_map_t map; 606 607 addr = (vm_offset_t) uap->addr; 608 size = uap->len; 609 610 pageoff = (addr & PAGE_MASK); 611 addr -= pageoff; 612 size += pageoff; 613 size = (vm_size_t) round_page(size); 614 if (addr + size < addr) 615 return (EINVAL); 616 617 if (size == 0) 618 return (0); 619 620 /* 621 * Check for illegal addresses. Watch out for address wrap... 622 */ 623 map = &td->td_proc->p_vmspace->vm_map; 624 if (addr < vm_map_min(map) || addr + size > vm_map_max(map)) 625 return (EINVAL); 626 /* 627 * Make sure entire range is allocated. 628 */ 629 if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE)) 630 return (EINVAL); 631 632 /* returns nothing but KERN_SUCCESS anyway */ 633 (void) vm_map_remove(map, addr, addr + size); 634 return (0); 635 } 636 637 #if 0 638 void 639 munmapfd(td, fd) 640 struct thread *td; 641 int fd; 642 { 643 /* 644 * XXX should unmap any regions mapped to this file 645 */ 646 FILEDESC_LOCK(p->p_fd); 647 td->td_proc->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED; 648 FILEDESC_UNLOCK(p->p_fd); 649 } 650 #endif 651 652 #ifndef _SYS_SYSPROTO_H_ 653 struct mprotect_args { 654 const void *addr; 655 size_t len; 656 int prot; 657 }; 658 #endif 659 /* 660 * MPSAFE 661 */ 662 int 663 mprotect(td, uap) 664 struct thread *td; 665 struct mprotect_args *uap; 666 { 667 vm_offset_t addr; 668 vm_size_t size, pageoff; 669 vm_prot_t prot; 670 671 addr = (vm_offset_t) uap->addr; 672 size = uap->len; 673 prot = uap->prot & VM_PROT_ALL; 674 #if defined(VM_PROT_READ_IS_EXEC) 675 if (prot & VM_PROT_READ) 676 prot |= VM_PROT_EXECUTE; 677 #endif 678 679 pageoff = (addr & PAGE_MASK); 680 addr -= pageoff; 681 size += pageoff; 682 size = (vm_size_t) round_page(size); 683 if (addr + size < addr) 684 return (EINVAL); 685 686 switch (vm_map_protect(&td->td_proc->p_vmspace->vm_map, addr, 687 addr + size, prot, FALSE)) { 688 case KERN_SUCCESS: 689 return (0); 690 case KERN_PROTECTION_FAILURE: 691 return (EACCES); 692 } 693 return (EINVAL); 694 } 695 696 #ifndef _SYS_SYSPROTO_H_ 697 struct minherit_args { 698 void *addr; 699 size_t len; 700 int inherit; 701 }; 702 #endif 703 /* 704 * MPSAFE 705 */ 706 int 707 minherit(td, uap) 708 struct thread *td; 709 struct minherit_args *uap; 710 { 711 vm_offset_t addr; 712 vm_size_t size, pageoff; 713 vm_inherit_t inherit; 714 715 addr = (vm_offset_t)uap->addr; 716 size = uap->len; 717 inherit = uap->inherit; 718 719 pageoff = (addr & PAGE_MASK); 720 addr -= pageoff; 721 size += pageoff; 722 size = (vm_size_t) round_page(size); 723 if (addr + size < addr) 724 return (EINVAL); 725 726 switch (vm_map_inherit(&td->td_proc->p_vmspace->vm_map, addr, 727 addr + size, inherit)) { 728 case KERN_SUCCESS: 729 return (0); 730 case KERN_PROTECTION_FAILURE: 731 return (EACCES); 732 } 733 return (EINVAL); 734 } 735 736 #ifndef _SYS_SYSPROTO_H_ 737 struct madvise_args { 738 void *addr; 739 size_t len; 740 int behav; 741 }; 742 #endif 743 744 /* 745 * MPSAFE 746 */ 747 /* ARGSUSED */ 748 int 749 madvise(td, uap) 750 struct thread *td; 751 struct madvise_args *uap; 752 { 753 vm_offset_t start, end; 754 vm_map_t map; 755 756 /* 757 * Check for illegal behavior 758 */ 759 if (uap->behav < 0 || uap->behav > MADV_CORE) 760 return (EINVAL); 761 /* 762 * Check for illegal addresses. Watch out for address wrap... Note 763 * that VM_*_ADDRESS are not constants due to casts (argh). 764 */ 765 map = &td->td_proc->p_vmspace->vm_map; 766 if ((vm_offset_t)uap->addr < vm_map_min(map) || 767 (vm_offset_t)uap->addr + uap->len > vm_map_max(map)) 768 return (EINVAL); 769 if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr) 770 return (EINVAL); 771 772 /* 773 * Since this routine is only advisory, we default to conservative 774 * behavior. 775 */ 776 start = trunc_page((vm_offset_t) uap->addr); 777 end = round_page((vm_offset_t) uap->addr + uap->len); 778 779 if (vm_map_madvise(map, start, end, uap->behav)) 780 return (EINVAL); 781 return (0); 782 } 783 784 #ifndef _SYS_SYSPROTO_H_ 785 struct mincore_args { 786 const void *addr; 787 size_t len; 788 char *vec; 789 }; 790 #endif 791 792 /* 793 * MPSAFE 794 */ 795 /* ARGSUSED */ 796 int 797 mincore(td, uap) 798 struct thread *td; 799 struct mincore_args *uap; 800 { 801 vm_offset_t addr, first_addr; 802 vm_offset_t end, cend; 803 pmap_t pmap; 804 vm_map_t map; 805 char *vec; 806 int error = 0; 807 int vecindex, lastvecindex; 808 vm_map_entry_t current; 809 vm_map_entry_t entry; 810 int mincoreinfo; 811 unsigned int timestamp; 812 813 /* 814 * Make sure that the addresses presented are valid for user 815 * mode. 816 */ 817 first_addr = addr = trunc_page((vm_offset_t) uap->addr); 818 end = addr + (vm_size_t)round_page(uap->len); 819 map = &td->td_proc->p_vmspace->vm_map; 820 if (end > vm_map_max(map) || end < addr) 821 return (EINVAL); 822 823 /* 824 * Address of byte vector 825 */ 826 vec = uap->vec; 827 828 mtx_lock(&Giant); 829 pmap = vmspace_pmap(td->td_proc->p_vmspace); 830 831 vm_map_lock_read(map); 832 RestartScan: 833 timestamp = map->timestamp; 834 835 if (!vm_map_lookup_entry(map, addr, &entry)) 836 entry = entry->next; 837 838 /* 839 * Do this on a map entry basis so that if the pages are not 840 * in the current processes address space, we can easily look 841 * up the pages elsewhere. 842 */ 843 lastvecindex = -1; 844 for (current = entry; 845 (current != &map->header) && (current->start < end); 846 current = current->next) { 847 848 /* 849 * ignore submaps (for now) or null objects 850 */ 851 if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) || 852 current->object.vm_object == NULL) 853 continue; 854 855 /* 856 * limit this scan to the current map entry and the 857 * limits for the mincore call 858 */ 859 if (addr < current->start) 860 addr = current->start; 861 cend = current->end; 862 if (cend > end) 863 cend = end; 864 865 /* 866 * scan this entry one page at a time 867 */ 868 while (addr < cend) { 869 /* 870 * Check pmap first, it is likely faster, also 871 * it can provide info as to whether we are the 872 * one referencing or modifying the page. 873 */ 874 mincoreinfo = pmap_mincore(pmap, addr); 875 if (!mincoreinfo) { 876 vm_pindex_t pindex; 877 vm_ooffset_t offset; 878 vm_page_t m; 879 /* 880 * calculate the page index into the object 881 */ 882 offset = current->offset + (addr - current->start); 883 pindex = OFF_TO_IDX(offset); 884 m = vm_page_lookup(current->object.vm_object, 885 pindex); 886 vm_page_lock_queues(); 887 /* 888 * if the page is resident, then gather information about 889 * it. 890 */ 891 if (m) { 892 mincoreinfo = MINCORE_INCORE; 893 if (m->dirty || 894 pmap_is_modified(m)) 895 mincoreinfo |= MINCORE_MODIFIED_OTHER; 896 if ((m->flags & PG_REFERENCED) || 897 pmap_ts_referenced(m)) { 898 vm_page_flag_set(m, PG_REFERENCED); 899 mincoreinfo |= MINCORE_REFERENCED_OTHER; 900 } 901 } 902 vm_page_unlock_queues(); 903 } 904 905 /* 906 * subyte may page fault. In case it needs to modify 907 * the map, we release the lock. 908 */ 909 vm_map_unlock_read(map); 910 911 /* 912 * calculate index into user supplied byte vector 913 */ 914 vecindex = OFF_TO_IDX(addr - first_addr); 915 916 /* 917 * If we have skipped map entries, we need to make sure that 918 * the byte vector is zeroed for those skipped entries. 919 */ 920 while ((lastvecindex + 1) < vecindex) { 921 error = subyte(vec + lastvecindex, 0); 922 if (error) { 923 error = EFAULT; 924 goto done2; 925 } 926 ++lastvecindex; 927 } 928 929 /* 930 * Pass the page information to the user 931 */ 932 error = subyte(vec + vecindex, mincoreinfo); 933 if (error) { 934 error = EFAULT; 935 goto done2; 936 } 937 938 /* 939 * If the map has changed, due to the subyte, the previous 940 * output may be invalid. 941 */ 942 vm_map_lock_read(map); 943 if (timestamp != map->timestamp) 944 goto RestartScan; 945 946 lastvecindex = vecindex; 947 addr += PAGE_SIZE; 948 } 949 } 950 951 /* 952 * subyte may page fault. In case it needs to modify 953 * the map, we release the lock. 954 */ 955 vm_map_unlock_read(map); 956 957 /* 958 * Zero the last entries in the byte vector. 959 */ 960 vecindex = OFF_TO_IDX(end - first_addr); 961 while ((lastvecindex + 1) < vecindex) { 962 error = subyte(vec + lastvecindex, 0); 963 if (error) { 964 error = EFAULT; 965 goto done2; 966 } 967 ++lastvecindex; 968 } 969 970 /* 971 * If the map has changed, due to the subyte, the previous 972 * output may be invalid. 973 */ 974 vm_map_lock_read(map); 975 if (timestamp != map->timestamp) 976 goto RestartScan; 977 vm_map_unlock_read(map); 978 done2: 979 mtx_unlock(&Giant); 980 return (error); 981 } 982 983 #ifndef _SYS_SYSPROTO_H_ 984 struct mlock_args { 985 const void *addr; 986 size_t len; 987 }; 988 #endif 989 /* 990 * MPSAFE 991 */ 992 int 993 mlock(td, uap) 994 struct thread *td; 995 struct mlock_args *uap; 996 { 997 vm_offset_t addr; 998 vm_size_t size, pageoff; 999 int error; 1000 1001 addr = (vm_offset_t) uap->addr; 1002 size = uap->len; 1003 1004 pageoff = (addr & PAGE_MASK); 1005 addr -= pageoff; 1006 size += pageoff; 1007 size = (vm_size_t) round_page(size); 1008 1009 /* disable wrap around */ 1010 if (addr + size < addr) 1011 return (EINVAL); 1012 1013 if (atop(size) + cnt.v_wire_count > vm_page_max_wired) 1014 return (EAGAIN); 1015 1016 #ifdef pmap_wired_count 1017 if (size + ptoa(pmap_wired_count(vm_map_pmap(&td->td_proc->p_vmspace->vm_map))) > 1018 td->td_proc->p_rlimit[RLIMIT_MEMLOCK].rlim_cur) 1019 return (ENOMEM); 1020 #else 1021 error = suser(td); 1022 if (error) 1023 return (error); 1024 #endif 1025 1026 error = vm_map_wire(&td->td_proc->p_vmspace->vm_map, addr, 1027 addr + size, TRUE); 1028 return (error == KERN_SUCCESS ? 0 : ENOMEM); 1029 } 1030 1031 #ifndef _SYS_SYSPROTO_H_ 1032 struct mlockall_args { 1033 int how; 1034 }; 1035 #endif 1036 1037 /* 1038 * MPSAFE 1039 */ 1040 int 1041 mlockall(td, uap) 1042 struct thread *td; 1043 struct mlockall_args *uap; 1044 { 1045 /* mtx_lock(&Giant); */ 1046 /* mtx_unlock(&Giant); */ 1047 return 0; 1048 } 1049 1050 #ifndef _SYS_SYSPROTO_H_ 1051 struct munlockall_args { 1052 int how; 1053 }; 1054 #endif 1055 1056 /* 1057 * MPSAFE 1058 */ 1059 int 1060 munlockall(td, uap) 1061 struct thread *td; 1062 struct munlockall_args *uap; 1063 { 1064 /* mtx_lock(&Giant); */ 1065 /* mtx_unlock(&Giant); */ 1066 return 0; 1067 } 1068 1069 #ifndef _SYS_SYSPROTO_H_ 1070 struct munlock_args { 1071 const void *addr; 1072 size_t len; 1073 }; 1074 #endif 1075 /* 1076 * MPSAFE 1077 */ 1078 int 1079 munlock(td, uap) 1080 struct thread *td; 1081 struct munlock_args *uap; 1082 { 1083 vm_offset_t addr; 1084 vm_size_t size, pageoff; 1085 int error; 1086 1087 addr = (vm_offset_t) uap->addr; 1088 size = uap->len; 1089 1090 pageoff = (addr & PAGE_MASK); 1091 addr -= pageoff; 1092 size += pageoff; 1093 size = (vm_size_t) round_page(size); 1094 1095 /* disable wrap around */ 1096 if (addr + size < addr) 1097 return (EINVAL); 1098 1099 #ifndef pmap_wired_count 1100 error = suser(td); 1101 if (error) 1102 return (error); 1103 #endif 1104 1105 error = vm_map_unwire(&td->td_proc->p_vmspace->vm_map, addr, 1106 addr + size, TRUE); 1107 return (error == KERN_SUCCESS ? 0 : ENOMEM); 1108 } 1109 1110 /* 1111 * vm_mmap() 1112 * 1113 * MPSAFE 1114 * 1115 * Internal version of mmap. Currently used by mmap, exec, and sys5 1116 * shared memory. Handle is either a vnode pointer or NULL for MAP_ANON. 1117 */ 1118 int 1119 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot, 1120 vm_prot_t maxprot, int flags, 1121 void *handle, 1122 vm_ooffset_t foff) 1123 { 1124 boolean_t fitit; 1125 vm_object_t object; 1126 struct vnode *vp = NULL; 1127 objtype_t type; 1128 int rv = KERN_SUCCESS; 1129 vm_ooffset_t objsize; 1130 int docow; 1131 struct thread *td = curthread; 1132 1133 if (size == 0) 1134 return (0); 1135 1136 objsize = size = round_page(size); 1137 1138 if (td->td_proc->p_vmspace->vm_map.size + size > 1139 td->td_proc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 1140 return(ENOMEM); 1141 } 1142 1143 /* 1144 * We currently can only deal with page aligned file offsets. 1145 * The check is here rather than in the syscall because the 1146 * kernel calls this function internally for other mmaping 1147 * operations (such as in exec) and non-aligned offsets will 1148 * cause pmap inconsistencies...so we want to be sure to 1149 * disallow this in all cases. 1150 */ 1151 if (foff & PAGE_MASK) 1152 return (EINVAL); 1153 1154 if ((flags & MAP_FIXED) == 0) { 1155 fitit = TRUE; 1156 *addr = round_page(*addr); 1157 } else { 1158 if (*addr != trunc_page(*addr)) 1159 return (EINVAL); 1160 fitit = FALSE; 1161 (void) vm_map_remove(map, *addr, *addr + size); 1162 } 1163 1164 /* 1165 * Lookup/allocate object. 1166 */ 1167 if (flags & MAP_ANON) { 1168 type = OBJT_DEFAULT; 1169 /* 1170 * Unnamed anonymous regions always start at 0. 1171 */ 1172 if (handle == 0) 1173 foff = 0; 1174 } else { 1175 vp = (struct vnode *) handle; 1176 mtx_lock(&Giant); 1177 ASSERT_VOP_LOCKED(vp, "vm_mmap"); 1178 if (vp->v_type == VCHR) { 1179 type = OBJT_DEVICE; 1180 handle = (void *)(intptr_t)vp->v_rdev; 1181 } else { 1182 struct vattr vat; 1183 int error; 1184 1185 error = VOP_GETATTR(vp, &vat, td->td_ucred, td); 1186 if (error) { 1187 mtx_unlock(&Giant); 1188 return (error); 1189 } 1190 objsize = round_page(vat.va_size); 1191 type = OBJT_VNODE; 1192 /* 1193 * if it is a regular file without any references 1194 * we do not need to sync it. 1195 */ 1196 if (vp->v_type == VREG && vat.va_nlink == 0) { 1197 flags |= MAP_NOSYNC; 1198 } 1199 } 1200 mtx_unlock(&Giant); 1201 } 1202 1203 if (handle == NULL) { 1204 object = NULL; 1205 docow = 0; 1206 } else { 1207 object = vm_pager_allocate(type, 1208 handle, objsize, prot, foff); 1209 if (object == NULL) { 1210 return (type == OBJT_DEVICE ? EINVAL : ENOMEM); 1211 } 1212 docow = MAP_PREFAULT_PARTIAL; 1213 } 1214 1215 /* 1216 * Force device mappings to be shared. 1217 */ 1218 if (type == OBJT_DEVICE || type == OBJT_PHYS) { 1219 flags &= ~(MAP_PRIVATE|MAP_COPY); 1220 flags |= MAP_SHARED; 1221 } 1222 1223 if ((flags & (MAP_ANON|MAP_SHARED)) == 0) 1224 docow |= MAP_COPY_ON_WRITE; 1225 if (flags & MAP_NOSYNC) 1226 docow |= MAP_DISABLE_SYNCER; 1227 if (flags & MAP_NOCORE) 1228 docow |= MAP_DISABLE_COREDUMP; 1229 1230 #if defined(VM_PROT_READ_IS_EXEC) 1231 if (prot & VM_PROT_READ) 1232 prot |= VM_PROT_EXECUTE; 1233 1234 if (maxprot & VM_PROT_READ) 1235 maxprot |= VM_PROT_EXECUTE; 1236 #endif 1237 1238 if (fitit) 1239 *addr = pmap_addr_hint(object, *addr, size); 1240 1241 if (flags & MAP_STACK) 1242 rv = vm_map_stack (map, *addr, size, prot, 1243 maxprot, docow); 1244 else 1245 rv = vm_map_find(map, object, foff, addr, size, fitit, 1246 prot, maxprot, docow); 1247 1248 if (rv != KERN_SUCCESS) { 1249 /* 1250 * Lose the object reference. Will destroy the 1251 * object if it's an unnamed anonymous mapping 1252 * or named anonymous without other references. 1253 */ 1254 vm_object_deallocate(object); 1255 } else if (flags & MAP_SHARED) { 1256 /* 1257 * Shared memory is also shared with children. 1258 */ 1259 rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE); 1260 if (rv != KERN_SUCCESS) 1261 (void) vm_map_remove(map, *addr, *addr + size); 1262 } 1263 switch (rv) { 1264 case KERN_SUCCESS: 1265 return (0); 1266 case KERN_INVALID_ADDRESS: 1267 case KERN_NO_SPACE: 1268 return (ENOMEM); 1269 case KERN_PROTECTION_FAILURE: 1270 return (EACCES); 1271 default: 1272 return (EINVAL); 1273 } 1274 }
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