1 /* $NetBSD: uvm_map.c,v 1.205 2005/12/11 12:25:29 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Charles D. Cranor and Washington University. 5 * Copyright (c) 1991, 1993, The Regents of the University of California. 6 * 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * The Mach Operating System project at Carnegie-Mellon University. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Charles D. Cranor, 23 * Washington University, the University of California, Berkeley and 24 * its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vm_map.c 8.3 (Berkeley) 1/12/94 42 * from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 chs Exp 43 * 44 * 45 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 46 * All rights reserved. 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69 /* 70 * uvm_map.c: uvm map operations 71 */ 72 73 #include <sys/cdefs.h> 74 __KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.205 2005/12/11 12:25:29 christos Exp $"); 75 76 #include "opt_ddb.h" 77 #include "opt_uvmhist.h" 78 #include "opt_uvm.h" 79 #include "opt_sysv.h" 80 81 #include <sys/param.h> 82 #include <sys/systm.h> 83 #include <sys/mman.h> 84 #include <sys/proc.h> 85 #include <sys/malloc.h> 86 #include <sys/pool.h> 87 #include <sys/kernel.h> 88 #include <sys/mount.h> 89 #include <sys/vnode.h> 90 91 #ifdef SYSVSHM 92 #include <sys/shm.h> 93 #endif 94 95 #define UVM_MAP_C 96 #include <uvm/uvm.h> 97 #undef RB_AUGMENT 98 #define RB_AUGMENT(x) uvm_rb_augment(x) 99 100 #ifdef DDB 101 #include <uvm/uvm_ddb.h> 102 #endif 103 104 #ifndef UVMMAP_NOCOUNTERS 105 #include <sys/device.h> 106 struct evcnt map_ubackmerge = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 107 "uvmmap", "ubackmerge"); 108 struct evcnt map_uforwmerge = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 109 "uvmmap", "uforwmerge"); 110 struct evcnt map_ubimerge = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 111 "uvmmap", "ubimerge"); 112 struct evcnt map_unomerge = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 113 "uvmmap", "unomerge"); 114 struct evcnt map_kbackmerge = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 115 "uvmmap", "kbackmerge"); 116 struct evcnt map_kforwmerge = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 117 "uvmmap", "kforwmerge"); 118 struct evcnt map_kbimerge = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 119 "uvmmap", "kbimerge"); 120 struct evcnt map_knomerge = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 121 "uvmmap", "knomerge"); 122 struct evcnt uvm_map_call = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 123 "uvmmap", "map_call"); 124 struct evcnt uvm_mlk_call = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 125 "uvmmap", "mlk_call"); 126 struct evcnt uvm_mlk_hint = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, 127 "uvmmap", "mlk_hint"); 128 129 EVCNT_ATTACH_STATIC(map_ubackmerge); 130 EVCNT_ATTACH_STATIC(map_uforwmerge); 131 EVCNT_ATTACH_STATIC(map_ubimerge); 132 EVCNT_ATTACH_STATIC(map_unomerge); 133 EVCNT_ATTACH_STATIC(map_kbackmerge); 134 EVCNT_ATTACH_STATIC(map_kforwmerge); 135 EVCNT_ATTACH_STATIC(map_kbimerge); 136 EVCNT_ATTACH_STATIC(map_knomerge); 137 EVCNT_ATTACH_STATIC(uvm_map_call); 138 EVCNT_ATTACH_STATIC(uvm_mlk_call); 139 EVCNT_ATTACH_STATIC(uvm_mlk_hint); 140 141 #define UVMCNT_INCR(ev) ev.ev_count++ 142 #define UVMCNT_DECR(ev) ev.ev_count-- 143 #else 144 #define UVMCNT_INCR(ev) 145 #define UVMCNT_DECR(ev) 146 #endif 147 148 const char vmmapbsy[] = "vmmapbsy"; 149 150 /* 151 * pool for vmspace structures. 152 */ 153 154 POOL_INIT(uvm_vmspace_pool, sizeof(struct vmspace), 0, 0, 0, "vmsppl", 155 &pool_allocator_nointr); 156 157 /* 158 * pool for dynamically-allocated map entries. 159 */ 160 161 POOL_INIT(uvm_map_entry_pool, sizeof(struct vm_map_entry), 0, 0, 0, "vmmpepl", 162 &pool_allocator_nointr); 163 164 MALLOC_DEFINE(M_VMMAP, "VM map", "VM map structures"); 165 MALLOC_DEFINE(M_VMPMAP, "VM pmap", "VM pmap"); 166 167 #ifdef PMAP_GROWKERNEL 168 /* 169 * This global represents the end of the kernel virtual address 170 * space. If we want to exceed this, we must grow the kernel 171 * virtual address space dynamically. 172 * 173 * Note, this variable is locked by kernel_map's lock. 174 */ 175 vaddr_t uvm_maxkaddr; 176 #endif 177 178 /* 179 * macros 180 */ 181 182 /* 183 * VM_MAP_USE_KMAPENT: determine if uvm_kmapent_alloc/free is used 184 * for the vm_map. 185 */ 186 extern struct vm_map *pager_map; /* XXX */ 187 #define VM_MAP_USE_KMAPENT(map) \ 188 (((map)->flags & VM_MAP_INTRSAFE) || (map) == kernel_map) 189 190 /* 191 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging 192 */ 193 194 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \ 195 prot, maxprot, inh, adv, wire) \ 196 ((ent)->etype == (type) && \ 197 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE | UVM_MAP_QUANTUM)) \ 198 == 0 && \ 199 (ent)->object.uvm_obj == (uobj) && \ 200 (ent)->protection == (prot) && \ 201 (ent)->max_protection == (maxprot) && \ 202 (ent)->inheritance == (inh) && \ 203 (ent)->advice == (adv) && \ 204 (ent)->wired_count == (wire)) 205 206 /* 207 * uvm_map_entry_link: insert entry into a map 208 * 209 * => map must be locked 210 */ 211 #define uvm_map_entry_link(map, after_where, entry) do { \ 212 KASSERT(entry->start < entry->end); \ 213 (map)->nentries++; \ 214 (entry)->prev = (after_where); \ 215 (entry)->next = (after_where)->next; \ 216 (entry)->prev->next = (entry); \ 217 (entry)->next->prev = (entry); \ 218 uvm_rb_insert((map), (entry)); \ 219 } while (/*CONSTCOND*/ 0) 220 221 /* 222 * uvm_map_entry_unlink: remove entry from a map 223 * 224 * => map must be locked 225 */ 226 #define uvm_map_entry_unlink(map, entry) do { \ 227 (map)->nentries--; \ 228 (entry)->next->prev = (entry)->prev; \ 229 (entry)->prev->next = (entry)->next; \ 230 uvm_rb_remove((map), (entry)); \ 231 } while (/*CONSTCOND*/ 0) 232 233 /* 234 * SAVE_HINT: saves the specified entry as the hint for future lookups. 235 * 236 * => map need not be locked (protected by hint_lock). 237 */ 238 #define SAVE_HINT(map,check,value) do { \ 239 simple_lock(&(map)->hint_lock); \ 240 if ((map)->hint == (check)) \ 241 (map)->hint = (value); \ 242 simple_unlock(&(map)->hint_lock); \ 243 } while (/*CONSTCOND*/ 0) 244 245 /* 246 * VM_MAP_RANGE_CHECK: check and correct range 247 * 248 * => map must at least be read locked 249 */ 250 251 #define VM_MAP_RANGE_CHECK(map, start, end) do { \ 252 if (start < vm_map_min(map)) \ 253 start = vm_map_min(map); \ 254 if (end > vm_map_max(map)) \ 255 end = vm_map_max(map); \ 256 if (start > end) \ 257 start = end; \ 258 } while (/*CONSTCOND*/ 0) 259 260 /* 261 * local prototypes 262 */ 263 264 static struct vm_map_entry * 265 uvm_mapent_alloc(struct vm_map *, int); 266 static struct vm_map_entry * 267 uvm_mapent_alloc_split(struct vm_map *, 268 const struct vm_map_entry *, int, 269 struct uvm_mapent_reservation *); 270 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *); 271 static void uvm_mapent_free(struct vm_map_entry *); 272 static struct vm_map_entry * 273 uvm_kmapent_alloc(struct vm_map *, int); 274 static void uvm_kmapent_free(struct vm_map_entry *); 275 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *); 276 static void uvm_map_reference_amap(struct vm_map_entry *, int); 277 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int, 278 struct vm_map_entry *); 279 static void uvm_map_unreference_amap(struct vm_map_entry *, int); 280 281 int _uvm_tree_sanity(struct vm_map *, const char *); 282 static vsize_t uvm_rb_subtree_space(const struct vm_map_entry *); 283 284 static __inline int 285 uvm_compare(const struct vm_map_entry *a, const struct vm_map_entry *b) 286 { 287 288 if (a->start < b->start) 289 return (-1); 290 else if (a->start > b->start) 291 return (1); 292 293 return (0); 294 } 295 296 static __inline void 297 uvm_rb_augment(struct vm_map_entry *entry) 298 { 299 300 entry->space = uvm_rb_subtree_space(entry); 301 } 302 303 RB_PROTOTYPE(uvm_tree, vm_map_entry, rb_entry, uvm_compare); 304 305 RB_GENERATE(uvm_tree, vm_map_entry, rb_entry, uvm_compare); 306 307 static __inline vsize_t 308 uvm_rb_space(const struct vm_map *map, const struct vm_map_entry *entry) 309 { 310 /* XXX map is not used */ 311 312 KASSERT(entry->next != NULL); 313 return entry->next->start - entry->end; 314 } 315 316 static vsize_t 317 uvm_rb_subtree_space(const struct vm_map_entry *entry) 318 { 319 vaddr_t space, tmp; 320 321 space = entry->ownspace; 322 if (RB_LEFT(entry, rb_entry)) { 323 tmp = RB_LEFT(entry, rb_entry)->space; 324 if (tmp > space) 325 space = tmp; 326 } 327 328 if (RB_RIGHT(entry, rb_entry)) { 329 tmp = RB_RIGHT(entry, rb_entry)->space; 330 if (tmp > space) 331 space = tmp; 332 } 333 334 return (space); 335 } 336 337 static __inline void 338 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry) 339 { 340 /* We need to traverse to the very top */ 341 do { 342 entry->ownspace = uvm_rb_space(map, entry); 343 entry->space = uvm_rb_subtree_space(entry); 344 } while ((entry = RB_PARENT(entry, rb_entry)) != NULL); 345 } 346 347 static void 348 uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry) 349 { 350 vaddr_t space = uvm_rb_space(map, entry); 351 struct vm_map_entry *tmp; 352 353 entry->ownspace = entry->space = space; 354 tmp = RB_INSERT(uvm_tree, &(map)->rbhead, entry); 355 #ifdef DIAGNOSTIC 356 if (tmp != NULL) 357 panic("uvm_rb_insert: duplicate entry?"); 358 #endif 359 uvm_rb_fixup(map, entry); 360 if (entry->prev != &map->header) 361 uvm_rb_fixup(map, entry->prev); 362 } 363 364 static void 365 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry) 366 { 367 struct vm_map_entry *parent; 368 369 parent = RB_PARENT(entry, rb_entry); 370 RB_REMOVE(uvm_tree, &(map)->rbhead, entry); 371 if (entry->prev != &map->header) 372 uvm_rb_fixup(map, entry->prev); 373 if (parent) 374 uvm_rb_fixup(map, parent); 375 } 376 377 #ifdef DEBUG 378 int uvm_debug_check_rbtree = 0; 379 #define uvm_tree_sanity(x,y) \ 380 if (uvm_debug_check_rbtree) \ 381 _uvm_tree_sanity(x,y) 382 #else 383 #define uvm_tree_sanity(x,y) 384 #endif 385 386 int 387 _uvm_tree_sanity(struct vm_map *map, const char *name) 388 { 389 struct vm_map_entry *tmp, *trtmp; 390 int n = 0, i = 1; 391 392 RB_FOREACH(tmp, uvm_tree, &map->rbhead) { 393 if (tmp->ownspace != uvm_rb_space(map, tmp)) { 394 printf("%s: %d/%d ownspace %lx != %lx %s\n", 395 name, n + 1, map->nentries, 396 (ulong)tmp->ownspace, (ulong)uvm_rb_space(map, tmp), 397 tmp->next == &map->header ? "(last)" : ""); 398 goto error; 399 } 400 } 401 trtmp = NULL; 402 RB_FOREACH(tmp, uvm_tree, &map->rbhead) { 403 if (tmp->space != uvm_rb_subtree_space(tmp)) { 404 printf("%s: space %lx != %lx\n", 405 name, (ulong)tmp->space, 406 (ulong)uvm_rb_subtree_space(tmp)); 407 goto error; 408 } 409 if (trtmp != NULL && trtmp->start >= tmp->start) { 410 printf("%s: corrupt: 0x%lx >= 0x%lx\n", 411 name, trtmp->start, tmp->start); 412 goto error; 413 } 414 n++; 415 416 trtmp = tmp; 417 } 418 419 if (n != map->nentries) { 420 printf("%s: nentries: %d vs %d\n", 421 name, n, map->nentries); 422 goto error; 423 } 424 425 for (tmp = map->header.next; tmp && tmp != &map->header; 426 tmp = tmp->next, i++) { 427 trtmp = RB_FIND(uvm_tree, &map->rbhead, tmp); 428 if (trtmp != tmp) { 429 printf("%s: lookup: %d: %p - %p: %p\n", 430 name, i, tmp, trtmp, 431 RB_PARENT(tmp, rb_entry)); 432 goto error; 433 } 434 } 435 436 return (0); 437 error: 438 #if defined(DDB) && __GNUC__ < 4 439 /* handy breakpoint location for error case */ 440 __asm(".globl treesanity_label\ntreesanity_label:"); 441 #endif 442 return (-1); 443 } 444 445 #ifdef DIAGNOSTIC 446 static struct vm_map *uvm_kmapent_map(struct vm_map_entry *); 447 #endif 448 449 /* 450 * uvm_mapent_alloc: allocate a map entry 451 */ 452 453 static struct vm_map_entry * 454 uvm_mapent_alloc(struct vm_map *map, int flags) 455 { 456 struct vm_map_entry *me; 457 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK; 458 UVMHIST_FUNC("uvm_mapent_alloc"); UVMHIST_CALLED(maphist); 459 460 if (VM_MAP_USE_KMAPENT(map)) { 461 me = uvm_kmapent_alloc(map, flags); 462 } else { 463 me = pool_get(&uvm_map_entry_pool, pflags); 464 if (__predict_false(me == NULL)) 465 return NULL; 466 me->flags = 0; 467 } 468 469 UVMHIST_LOG(maphist, "<- new entry=0x%x [kentry=%d]", me, 470 ((map->flags & VM_MAP_INTRSAFE) != 0 || map == kernel_map), 0, 0); 471 return (me); 472 } 473 474 /* 475 * uvm_mapent_alloc_split: allocate a map entry for clipping. 476 */ 477 478 static struct vm_map_entry * 479 uvm_mapent_alloc_split(struct vm_map *map, 480 const struct vm_map_entry *old_entry, int flags, 481 struct uvm_mapent_reservation *umr) 482 { 483 struct vm_map_entry *me; 484 485 KASSERT(!VM_MAP_USE_KMAPENT(map) || 486 (old_entry->flags & UVM_MAP_QUANTUM) || !UMR_EMPTY(umr)); 487 488 if (old_entry->flags & UVM_MAP_QUANTUM) { 489 int s; 490 struct vm_map_kernel *vmk = vm_map_to_kernel(map); 491 492 s = splvm(); 493 simple_lock(&uvm.kentry_lock); 494 me = vmk->vmk_merged_entries; 495 KASSERT(me); 496 vmk->vmk_merged_entries = me->next; 497 simple_unlock(&uvm.kentry_lock); 498 splx(s); 499 KASSERT(me->flags & UVM_MAP_QUANTUM); 500 } else { 501 me = uvm_mapent_alloc(map, flags); 502 } 503 504 return me; 505 } 506 507 /* 508 * uvm_mapent_free: free map entry 509 */ 510 511 static void 512 uvm_mapent_free(struct vm_map_entry *me) 513 { 514 UVMHIST_FUNC("uvm_mapent_free"); UVMHIST_CALLED(maphist); 515 516 UVMHIST_LOG(maphist,"<- freeing map entry=0x%x [flags=%d]", 517 me, me->flags, 0, 0); 518 if (me->flags & UVM_MAP_KERNEL) { 519 uvm_kmapent_free(me); 520 } else { 521 pool_put(&uvm_map_entry_pool, me); 522 } 523 } 524 525 /* 526 * uvm_mapent_free_merged: free merged map entry 527 * 528 * => keep the entry if needed. 529 * => caller shouldn't hold map locked if VM_MAP_USE_KMAPENT(map) is true. 530 */ 531 532 static void 533 uvm_mapent_free_merged(struct vm_map *map, struct vm_map_entry *me) 534 { 535 536 KASSERT(!(me->flags & UVM_MAP_KERNEL) || uvm_kmapent_map(me) == map); 537 538 if (me->flags & UVM_MAP_QUANTUM) { 539 /* 540 * keep this entry for later splitting. 541 */ 542 struct vm_map_kernel *vmk; 543 int s; 544 545 KASSERT(VM_MAP_IS_KERNEL(map)); 546 KASSERT(!VM_MAP_USE_KMAPENT(map) || 547 (me->flags & UVM_MAP_KERNEL)); 548 549 vmk = vm_map_to_kernel(map); 550 s = splvm(); 551 simple_lock(&uvm.kentry_lock); 552 me->next = vmk->vmk_merged_entries; 553 vmk->vmk_merged_entries = me; 554 simple_unlock(&uvm.kentry_lock); 555 splx(s); 556 } else { 557 uvm_mapent_free(me); 558 } 559 } 560 561 /* 562 * uvm_mapent_copy: copy a map entry, preserving flags 563 */ 564 565 static __inline void 566 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst) 567 { 568 569 memcpy(dst, src, ((char *)&src->uvm_map_entry_stop_copy) - 570 ((char *)src)); 571 } 572 573 /* 574 * uvm_map_entry_unwire: unwire a map entry 575 * 576 * => map should be locked by caller 577 */ 578 579 static __inline void 580 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry) 581 { 582 583 entry->wired_count = 0; 584 uvm_fault_unwire_locked(map, entry->start, entry->end); 585 } 586 587 588 /* 589 * wrapper for calling amap_ref() 590 */ 591 static __inline void 592 uvm_map_reference_amap(struct vm_map_entry *entry, int flags) 593 { 594 595 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff, 596 (entry->end - entry->start) >> PAGE_SHIFT, flags); 597 } 598 599 600 /* 601 * wrapper for calling amap_unref() 602 */ 603 static __inline void 604 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags) 605 { 606 607 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff, 608 (entry->end - entry->start) >> PAGE_SHIFT, flags); 609 } 610 611 612 /* 613 * uvm_map_init: init mapping system at boot time. note that we allocate 614 * and init the static pool of struct vm_map_entry *'s for the kernel here. 615 */ 616 617 void 618 uvm_map_init(void) 619 { 620 #if defined(UVMHIST) 621 static struct uvm_history_ent maphistbuf[100]; 622 static struct uvm_history_ent pdhistbuf[100]; 623 #endif 624 625 /* 626 * first, init logging system. 627 */ 628 629 UVMHIST_FUNC("uvm_map_init"); 630 UVMHIST_INIT_STATIC(maphist, maphistbuf); 631 UVMHIST_INIT_STATIC(pdhist, pdhistbuf); 632 UVMHIST_CALLED(maphist); 633 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0); 634 635 /* 636 * initialize the global lock for kernel map entry. 637 * 638 * XXX is it worth to have per-map lock instead? 639 */ 640 641 simple_lock_init(&uvm.kentry_lock); 642 } 643 644 /* 645 * clippers 646 */ 647 648 /* 649 * uvm_map_clip_start: ensure that the entry begins at or after 650 * the starting address, if it doesn't we split the entry. 651 * 652 * => caller should use UVM_MAP_CLIP_START macro rather than calling 653 * this directly 654 * => map must be locked by caller 655 */ 656 657 void 658 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry, 659 vaddr_t start, struct uvm_mapent_reservation *umr) 660 { 661 struct vm_map_entry *new_entry; 662 vaddr_t new_adj; 663 664 /* uvm_map_simplify_entry(map, entry); */ /* XXX */ 665 666 uvm_tree_sanity(map, "clip_start entry"); 667 668 /* 669 * Split off the front portion. note that we must insert the new 670 * entry BEFORE this one, so that this entry has the specified 671 * starting address. 672 */ 673 new_entry = uvm_mapent_alloc_split(map, entry, 0, umr); 674 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 675 676 new_entry->end = start; 677 new_adj = start - new_entry->start; 678 if (entry->object.uvm_obj) 679 entry->offset += new_adj; /* shift start over */ 680 681 /* Does not change order for the RB tree */ 682 entry->start = start; 683 684 if (new_entry->aref.ar_amap) { 685 amap_splitref(&new_entry->aref, &entry->aref, new_adj); 686 } 687 688 uvm_map_entry_link(map, entry->prev, new_entry); 689 690 if (UVM_ET_ISSUBMAP(entry)) { 691 /* ... unlikely to happen, but play it safe */ 692 uvm_map_reference(new_entry->object.sub_map); 693 } else { 694 if (UVM_ET_ISOBJ(entry) && 695 entry->object.uvm_obj->pgops && 696 entry->object.uvm_obj->pgops->pgo_reference) 697 entry->object.uvm_obj->pgops->pgo_reference( 698 entry->object.uvm_obj); 699 } 700 701 uvm_tree_sanity(map, "clip_start leave"); 702 } 703 704 /* 705 * uvm_map_clip_end: ensure that the entry ends at or before 706 * the ending address, if it does't we split the reference 707 * 708 * => caller should use UVM_MAP_CLIP_END macro rather than calling 709 * this directly 710 * => map must be locked by caller 711 */ 712 713 void 714 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end, 715 struct uvm_mapent_reservation *umr) 716 { 717 struct vm_map_entry * new_entry; 718 vaddr_t new_adj; /* #bytes we move start forward */ 719 720 uvm_tree_sanity(map, "clip_end entry"); 721 722 /* 723 * Create a new entry and insert it 724 * AFTER the specified entry 725 */ 726 new_entry = uvm_mapent_alloc_split(map, entry, 0, umr); 727 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 728 729 new_entry->start = entry->end = end; 730 new_adj = end - entry->start; 731 if (new_entry->object.uvm_obj) 732 new_entry->offset += new_adj; 733 734 if (entry->aref.ar_amap) 735 amap_splitref(&entry->aref, &new_entry->aref, new_adj); 736 737 uvm_rb_fixup(map, entry); 738 739 uvm_map_entry_link(map, entry, new_entry); 740 741 if (UVM_ET_ISSUBMAP(entry)) { 742 /* ... unlikely to happen, but play it safe */ 743 uvm_map_reference(new_entry->object.sub_map); 744 } else { 745 if (UVM_ET_ISOBJ(entry) && 746 entry->object.uvm_obj->pgops && 747 entry->object.uvm_obj->pgops->pgo_reference) 748 entry->object.uvm_obj->pgops->pgo_reference( 749 entry->object.uvm_obj); 750 } 751 752 uvm_tree_sanity(map, "clip_end leave"); 753 } 754 755 756 /* 757 * M A P - m a i n e n t r y p o i n t 758 */ 759 /* 760 * uvm_map: establish a valid mapping in a map 761 * 762 * => assume startp is page aligned. 763 * => assume size is a multiple of PAGE_SIZE. 764 * => assume sys_mmap provides enough of a "hint" to have us skip 765 * over text/data/bss area. 766 * => map must be unlocked (we will lock it) 767 * => <uobj,uoffset> value meanings (4 cases): 768 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER 769 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER 770 * [3] <uobj,uoffset> == normal mapping 771 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA 772 * 773 * case [4] is for kernel mappings where we don't know the offset until 774 * we've found a virtual address. note that kernel object offsets are 775 * always relative to vm_map_min(kernel_map). 776 * 777 * => if `align' is non-zero, we align the virtual address to the specified 778 * alignment. 779 * this is provided as a mechanism for large pages. 780 * 781 * => XXXCDC: need way to map in external amap? 782 */ 783 784 int 785 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size, 786 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags) 787 { 788 struct uvm_map_args args; 789 struct vm_map_entry *new_entry; 790 int error; 791 792 KASSERT((flags & UVM_FLAG_QUANTUM) == 0 || VM_MAP_IS_KERNEL(map)); 793 KASSERT((size & PAGE_MASK) == 0); 794 795 /* 796 * for pager_map, allocate the new entry first to avoid sleeping 797 * for memory while we have the map locked. 798 * 799 * besides, because we allocates entries for in-kernel maps 800 * a bit differently (cf. uvm_kmapent_alloc/free), we need to 801 * allocate them before locking the map. 802 */ 803 804 new_entry = NULL; 805 if (VM_MAP_USE_KMAPENT(map) || (flags & UVM_FLAG_QUANTUM) || 806 map == pager_map) { 807 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT)); 808 if (__predict_false(new_entry == NULL)) 809 return ENOMEM; 810 if (flags & UVM_FLAG_QUANTUM) 811 new_entry->flags |= UVM_MAP_QUANTUM; 812 } 813 if (map == pager_map) 814 flags |= UVM_FLAG_NOMERGE; 815 816 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align, 817 flags, &args); 818 if (!error) { 819 error = uvm_map_enter(map, &args, new_entry); 820 *startp = args.uma_start; 821 } else if (new_entry) { 822 uvm_mapent_free(new_entry); 823 } 824 825 #if defined(DEBUG) 826 if (!error && VM_MAP_IS_KERNEL(map)) { 827 uvm_km_check_empty(*startp, *startp + size, 828 (map->flags & VM_MAP_INTRSAFE) != 0); 829 } 830 #endif /* defined(DEBUG) */ 831 832 return error; 833 } 834 835 int 836 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size, 837 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags, 838 struct uvm_map_args *args) 839 { 840 struct vm_map_entry *prev_entry; 841 vm_prot_t prot = UVM_PROTECTION(flags); 842 vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 843 844 UVMHIST_FUNC("uvm_map_prepare"); 845 UVMHIST_CALLED(maphist); 846 847 UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)", 848 map, start, size, flags); 849 UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0); 850 851 /* 852 * detect a popular device driver bug. 853 */ 854 855 KASSERT(doing_shutdown || curlwp != NULL || 856 (map->flags & VM_MAP_INTRSAFE)); 857 858 /* 859 * zero-sized mapping doesn't make any sense. 860 */ 861 KASSERT(size > 0); 862 863 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0); 864 865 uvm_tree_sanity(map, "map entry"); 866 867 /* 868 * check sanity of protection code 869 */ 870 871 if ((prot & maxprot) != prot) { 872 UVMHIST_LOG(maphist, "<- prot. failure: prot=0x%x, max=0x%x", 873 prot, maxprot,0,0); 874 return EACCES; 875 } 876 877 /* 878 * figure out where to put new VM range 879 */ 880 881 retry: 882 if (vm_map_lock_try(map) == FALSE) { 883 if (flags & UVM_FLAG_TRYLOCK) { 884 return EAGAIN; 885 } 886 vm_map_lock(map); /* could sleep here */ 887 } 888 if ((prev_entry = uvm_map_findspace(map, start, size, &start, 889 uobj, uoffset, align, flags)) == NULL) { 890 unsigned int timestamp; 891 892 if ((flags & UVM_FLAG_WAITVA) == 0) { 893 UVMHIST_LOG(maphist,"<- uvm_map_findspace failed!", 894 0,0,0,0); 895 vm_map_unlock(map); 896 return ENOMEM; 897 } 898 timestamp = map->timestamp; 899 UVMHIST_LOG(maphist,"waiting va timestamp=0x%x", 900 timestamp,0,0,0); 901 simple_lock(&map->flags_lock); 902 map->flags |= VM_MAP_WANTVA; 903 simple_unlock(&map->flags_lock); 904 vm_map_unlock(map); 905 906 /* 907 * wait until someone does unmap. 908 * XXX fragile locking 909 */ 910 911 simple_lock(&map->flags_lock); 912 while ((map->flags & VM_MAP_WANTVA) != 0 && 913 map->timestamp == timestamp) { 914 ltsleep(&map->header, PVM, "vmmapva", 0, 915 &map->flags_lock); 916 } 917 simple_unlock(&map->flags_lock); 918 goto retry; 919 } 920 921 #ifdef PMAP_GROWKERNEL 922 /* 923 * If the kernel pmap can't map the requested space, 924 * then allocate more resources for it. 925 */ 926 if (map == kernel_map && uvm_maxkaddr < (start + size)) 927 uvm_maxkaddr = pmap_growkernel(start + size); 928 #endif 929 930 UVMCNT_INCR(uvm_map_call); 931 932 /* 933 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER 934 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in 935 * either case we want to zero it before storing it in the map entry 936 * (because it looks strange and confusing when debugging...) 937 * 938 * if uobj is not null 939 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping 940 * and we do not need to change uoffset. 941 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset 942 * now (based on the starting address of the map). this case is 943 * for kernel object mappings where we don't know the offset until 944 * the virtual address is found (with uvm_map_findspace). the 945 * offset is the distance we are from the start of the map. 946 */ 947 948 if (uobj == NULL) { 949 uoffset = 0; 950 } else { 951 if (uoffset == UVM_UNKNOWN_OFFSET) { 952 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj)); 953 uoffset = start - vm_map_min(kernel_map); 954 } 955 } 956 957 args->uma_flags = flags; 958 args->uma_prev = prev_entry; 959 args->uma_start = start; 960 args->uma_size = size; 961 args->uma_uobj = uobj; 962 args->uma_uoffset = uoffset; 963 964 return 0; 965 } 966 967 int 968 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args, 969 struct vm_map_entry *new_entry) 970 { 971 struct vm_map_entry *prev_entry = args->uma_prev; 972 struct vm_map_entry *dead = NULL; 973 974 const uvm_flag_t flags = args->uma_flags; 975 const vm_prot_t prot = UVM_PROTECTION(flags); 976 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 977 const vm_inherit_t inherit = UVM_INHERIT(flags); 978 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ? 979 AMAP_EXTEND_NOWAIT : 0; 980 const int advice = UVM_ADVICE(flags); 981 const int meflagval = (flags & UVM_FLAG_QUANTUM) ? 982 UVM_MAP_QUANTUM : 0; 983 984 vaddr_t start = args->uma_start; 985 vsize_t size = args->uma_size; 986 struct uvm_object *uobj = args->uma_uobj; 987 voff_t uoffset = args->uma_uoffset; 988 989 const int kmap = (vm_map_pmap(map) == pmap_kernel()); 990 int merged = 0; 991 int error; 992 int newetype; 993 994 UVMHIST_FUNC("uvm_map_enter"); 995 UVMHIST_CALLED(maphist); 996 997 UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)", 998 map, start, size, flags); 999 UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0); 1000 1001 if (flags & UVM_FLAG_QUANTUM) { 1002 KASSERT(new_entry); 1003 KASSERT(new_entry->flags & UVM_MAP_QUANTUM); 1004 } 1005 1006 if (uobj) 1007 newetype = UVM_ET_OBJ; 1008 else 1009 newetype = 0; 1010 1011 if (flags & UVM_FLAG_COPYONW) { 1012 newetype |= UVM_ET_COPYONWRITE; 1013 if ((flags & UVM_FLAG_OVERLAY) == 0) 1014 newetype |= UVM_ET_NEEDSCOPY; 1015 } 1016 1017 /* 1018 * try and insert in map by extending previous entry, if possible. 1019 * XXX: we don't try and pull back the next entry. might be useful 1020 * for a stack, but we are currently allocating our stack in advance. 1021 */ 1022 1023 if (flags & UVM_FLAG_NOMERGE) 1024 goto nomerge; 1025 1026 if (prev_entry->end == start && 1027 prev_entry != &map->header && 1028 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, meflagval, 1029 prot, maxprot, inherit, advice, 0)) { 1030 1031 if (uobj && prev_entry->offset + 1032 (prev_entry->end - prev_entry->start) != uoffset) 1033 goto forwardmerge; 1034 1035 /* 1036 * can't extend a shared amap. note: no need to lock amap to 1037 * look at refs since we don't care about its exact value. 1038 * if it is one (i.e. we have only reference) it will stay there 1039 */ 1040 1041 if (prev_entry->aref.ar_amap && 1042 amap_refs(prev_entry->aref.ar_amap) != 1) { 1043 goto forwardmerge; 1044 } 1045 1046 if (prev_entry->aref.ar_amap) { 1047 error = amap_extend(prev_entry, size, 1048 amapwaitflag | AMAP_EXTEND_FORWARDS); 1049 if (error) 1050 goto nomerge; 1051 } 1052 1053 if (kmap) 1054 UVMCNT_INCR(map_kbackmerge); 1055 else 1056 UVMCNT_INCR(map_ubackmerge); 1057 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0); 1058 1059 /* 1060 * drop our reference to uobj since we are extending a reference 1061 * that we already have (the ref count can not drop to zero). 1062 */ 1063 1064 if (uobj && uobj->pgops->pgo_detach) 1065 uobj->pgops->pgo_detach(uobj); 1066 1067 prev_entry->end += size; 1068 uvm_rb_fixup(map, prev_entry); 1069 1070 uvm_tree_sanity(map, "map backmerged"); 1071 1072 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0); 1073 merged++; 1074 } 1075 1076 forwardmerge: 1077 if (prev_entry->next->start == (start + size) && 1078 prev_entry->next != &map->header && 1079 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, meflagval, 1080 prot, maxprot, inherit, advice, 0)) { 1081 1082 if (uobj && prev_entry->next->offset != uoffset + size) 1083 goto nomerge; 1084 1085 /* 1086 * can't extend a shared amap. note: no need to lock amap to 1087 * look at refs since we don't care about its exact value. 1088 * if it is one (i.e. we have only reference) it will stay there. 1089 * 1090 * note that we also can't merge two amaps, so if we 1091 * merged with the previous entry which has an amap, 1092 * and the next entry also has an amap, we give up. 1093 * 1094 * Interesting cases: 1095 * amap, new, amap -> give up second merge (single fwd extend) 1096 * amap, new, none -> double forward extend (extend again here) 1097 * none, new, amap -> double backward extend (done here) 1098 * uobj, new, amap -> single backward extend (done here) 1099 * 1100 * XXX should we attempt to deal with someone refilling 1101 * the deallocated region between two entries that are 1102 * backed by the same amap (ie, arefs is 2, "prev" and 1103 * "next" refer to it, and adding this allocation will 1104 * close the hole, thus restoring arefs to 1 and 1105 * deallocating the "next" vm_map_entry)? -- @@@ 1106 */ 1107 1108 if (prev_entry->next->aref.ar_amap && 1109 (amap_refs(prev_entry->next->aref.ar_amap) != 1 || 1110 (merged && prev_entry->aref.ar_amap))) { 1111 goto nomerge; 1112 } 1113 1114 if (merged) { 1115 /* 1116 * Try to extend the amap of the previous entry to 1117 * cover the next entry as well. If it doesn't work 1118 * just skip on, don't actually give up, since we've 1119 * already completed the back merge. 1120 */ 1121 if (prev_entry->aref.ar_amap) { 1122 if (amap_extend(prev_entry, 1123 prev_entry->next->end - 1124 prev_entry->next->start, 1125 amapwaitflag | AMAP_EXTEND_FORWARDS)) 1126 goto nomerge; 1127 } 1128 1129 /* 1130 * Try to extend the amap of the *next* entry 1131 * back to cover the new allocation *and* the 1132 * previous entry as well (the previous merge 1133 * didn't have an amap already otherwise we 1134 * wouldn't be checking here for an amap). If 1135 * it doesn't work just skip on, again, don't 1136 * actually give up, since we've already 1137 * completed the back merge. 1138 */ 1139 else if (prev_entry->next->aref.ar_amap) { 1140 if (amap_extend(prev_entry->next, 1141 prev_entry->end - 1142 prev_entry->start, 1143 amapwaitflag | AMAP_EXTEND_BACKWARDS)) 1144 goto nomerge; 1145 } 1146 } else { 1147 /* 1148 * Pull the next entry's amap backwards to cover this 1149 * new allocation. 1150 */ 1151 if (prev_entry->next->aref.ar_amap) { 1152 error = amap_extend(prev_entry->next, size, 1153 amapwaitflag | AMAP_EXTEND_BACKWARDS); 1154 if (error) 1155 goto nomerge; 1156 } 1157 } 1158 1159 if (merged) { 1160 if (kmap) { 1161 UVMCNT_DECR(map_kbackmerge); 1162 UVMCNT_INCR(map_kbimerge); 1163 } else { 1164 UVMCNT_DECR(map_ubackmerge); 1165 UVMCNT_INCR(map_ubimerge); 1166 } 1167 } else { 1168 if (kmap) 1169 UVMCNT_INCR(map_kforwmerge); 1170 else 1171 UVMCNT_INCR(map_uforwmerge); 1172 } 1173 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0); 1174 1175 /* 1176 * drop our reference to uobj since we are extending a reference 1177 * that we already have (the ref count can not drop to zero). 1178 * (if merged, we've already detached) 1179 */ 1180 if (uobj && uobj->pgops->pgo_detach && !merged) 1181 uobj->pgops->pgo_detach(uobj); 1182 1183 if (merged) { 1184 dead = prev_entry->next; 1185 prev_entry->end = dead->end; 1186 uvm_map_entry_unlink(map, dead); 1187 if (dead->aref.ar_amap != NULL) { 1188 prev_entry->aref = dead->aref; 1189 dead->aref.ar_amap = NULL; 1190 } 1191 } else { 1192 prev_entry->next->start -= size; 1193 if (prev_entry != &map->header) 1194 uvm_rb_fixup(map, prev_entry); 1195 if (uobj) 1196 prev_entry->next->offset = uoffset; 1197 } 1198 1199 uvm_tree_sanity(map, "map forwardmerged"); 1200 1201 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0); 1202 merged++; 1203 } 1204 1205 nomerge: 1206 if (!merged) { 1207 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0); 1208 if (kmap) 1209 UVMCNT_INCR(map_knomerge); 1210 else 1211 UVMCNT_INCR(map_unomerge); 1212 1213 /* 1214 * allocate new entry and link it in. 1215 */ 1216 1217 if (new_entry == NULL) { 1218 new_entry = uvm_mapent_alloc(map, 1219 (flags & UVM_FLAG_NOWAIT)); 1220 if (__predict_false(new_entry == NULL)) { 1221 error = ENOMEM; 1222 goto done; 1223 } 1224 } 1225 new_entry->start = start; 1226 new_entry->end = new_entry->start + size; 1227 new_entry->object.uvm_obj = uobj; 1228 new_entry->offset = uoffset; 1229 1230 new_entry->etype = newetype; 1231 1232 if (flags & UVM_FLAG_NOMERGE) { 1233 new_entry->flags |= UVM_MAP_NOMERGE; 1234 } 1235 1236 new_entry->protection = prot; 1237 new_entry->max_protection = maxprot; 1238 new_entry->inheritance = inherit; 1239 new_entry->wired_count = 0; 1240 new_entry->advice = advice; 1241 if (flags & UVM_FLAG_OVERLAY) { 1242 1243 /* 1244 * to_add: for BSS we overallocate a little since we 1245 * are likely to extend 1246 */ 1247 1248 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ? 1249 UVM_AMAP_CHUNK << PAGE_SHIFT : 0; 1250 struct vm_amap *amap = amap_alloc(size, to_add, 1251 (flags & UVM_FLAG_NOWAIT) ? M_NOWAIT : M_WAITOK); 1252 if (__predict_false(amap == NULL)) { 1253 error = ENOMEM; 1254 goto done; 1255 } 1256 new_entry->aref.ar_pageoff = 0; 1257 new_entry->aref.ar_amap = amap; 1258 } else { 1259 new_entry->aref.ar_pageoff = 0; 1260 new_entry->aref.ar_amap = NULL; 1261 } 1262 uvm_map_entry_link(map, prev_entry, new_entry); 1263 1264 /* 1265 * Update the free space hint 1266 */ 1267 1268 if ((map->first_free == prev_entry) && 1269 (prev_entry->end >= new_entry->start)) 1270 map->first_free = new_entry; 1271 1272 new_entry = NULL; 1273 } 1274 1275 map->size += size; 1276 1277 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 1278 1279 error = 0; 1280 done: 1281 vm_map_unlock(map); 1282 if (new_entry) { 1283 if (error == 0) { 1284 KDASSERT(merged); 1285 uvm_mapent_free_merged(map, new_entry); 1286 } else { 1287 uvm_mapent_free(new_entry); 1288 } 1289 } 1290 if (dead) { 1291 KDASSERT(merged); 1292 uvm_mapent_free_merged(map, dead); 1293 } 1294 return error; 1295 } 1296 1297 /* 1298 * uvm_map_lookup_entry: find map entry at or before an address 1299 * 1300 * => map must at least be read-locked by caller 1301 * => entry is returned in "entry" 1302 * => return value is true if address is in the returned entry 1303 */ 1304 1305 boolean_t 1306 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address, 1307 struct vm_map_entry **entry /* OUT */) 1308 { 1309 struct vm_map_entry *cur; 1310 boolean_t use_tree = FALSE; 1311 UVMHIST_FUNC("uvm_map_lookup_entry"); 1312 UVMHIST_CALLED(maphist); 1313 1314 UVMHIST_LOG(maphist,"(map=0x%x,addr=0x%x,ent=0x%x)", 1315 map, address, entry, 0); 1316 1317 /* 1318 * start looking either from the head of the 1319 * list, or from the hint. 1320 */ 1321 1322 simple_lock(&map->hint_lock); 1323 cur = map->hint; 1324 simple_unlock(&map->hint_lock); 1325 1326 if (cur == &map->header) 1327 cur = cur->next; 1328 1329 UVMCNT_INCR(uvm_mlk_call); 1330 if (address >= cur->start) { 1331 1332 /* 1333 * go from hint to end of list. 1334 * 1335 * but first, make a quick check to see if 1336 * we are already looking at the entry we 1337 * want (which is usually the case). 1338 * note also that we don't need to save the hint 1339 * here... it is the same hint (unless we are 1340 * at the header, in which case the hint didn't 1341 * buy us anything anyway). 1342 */ 1343 1344 if (cur != &map->header && cur->end > address) { 1345 UVMCNT_INCR(uvm_mlk_hint); 1346 *entry = cur; 1347 UVMHIST_LOG(maphist,"<- got it via hint (0x%x)", 1348 cur, 0, 0, 0); 1349 return (TRUE); 1350 } 1351 1352 if (map->nentries > 30) 1353 use_tree = TRUE; 1354 } else { 1355 1356 /* 1357 * invalid hint. use tree. 1358 */ 1359 use_tree = TRUE; 1360 } 1361 1362 uvm_tree_sanity(map, __func__); 1363 1364 if (use_tree) { 1365 struct vm_map_entry *prev = &map->header; 1366 cur = RB_ROOT(&map->rbhead); 1367 1368 /* 1369 * Simple lookup in the tree. Happens when the hint is 1370 * invalid, or nentries reach a threshold. 1371 */ 1372 while (cur) { 1373 if (address >= cur->start) { 1374 if (address < cur->end) { 1375 *entry = cur; 1376 goto got; 1377 } 1378 prev = cur; 1379 cur = RB_RIGHT(cur, rb_entry); 1380 } else 1381 cur = RB_LEFT(cur, rb_entry); 1382 } 1383 *entry = prev; 1384 goto failed; 1385 } 1386 1387 /* 1388 * search linearly 1389 */ 1390 1391 while (cur != &map->header) { 1392 if (cur->end > address) { 1393 if (address >= cur->start) { 1394 /* 1395 * save this lookup for future 1396 * hints, and return 1397 */ 1398 1399 *entry = cur; 1400 got: 1401 SAVE_HINT(map, map->hint, *entry); 1402 UVMHIST_LOG(maphist,"<- search got it (0x%x)", 1403 cur, 0, 0, 0); 1404 KDASSERT((*entry)->start <= address); 1405 KDASSERT(address < (*entry)->end); 1406 return (TRUE); 1407 } 1408 break; 1409 } 1410 cur = cur->next; 1411 } 1412 *entry = cur->prev; 1413 failed: 1414 SAVE_HINT(map, map->hint, *entry); 1415 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0); 1416 KDASSERT((*entry) == &map->header || (*entry)->end <= address); 1417 KDASSERT((*entry)->next == &map->header || 1418 address < (*entry)->next->start); 1419 return (FALSE); 1420 } 1421 1422 /* 1423 * See if the range between start and start + length fits in the gap 1424 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't 1425 * fit, and -1 address wraps around. 1426 */ 1427 static int 1428 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset, 1429 vsize_t align, int topdown, struct vm_map_entry *entry) 1430 { 1431 vaddr_t end; 1432 1433 #ifdef PMAP_PREFER 1434 /* 1435 * push start address forward as needed to avoid VAC alias problems. 1436 * we only do this if a valid offset is specified. 1437 */ 1438 1439 if (uoffset != UVM_UNKNOWN_OFFSET) 1440 PMAP_PREFER(uoffset, start, length, topdown); 1441 #endif 1442 if (align != 0) { 1443 if ((*start & (align - 1)) != 0) { 1444 if (topdown) 1445 *start &= ~(align - 1); 1446 else 1447 *start = roundup(*start, align); 1448 } 1449 /* 1450 * XXX Should we PMAP_PREFER() here again? 1451 * eh...i think we're okay 1452 */ 1453 } 1454 1455 /* 1456 * Find the end of the proposed new region. Be sure we didn't 1457 * wrap around the address; if so, we lose. Otherwise, if the 1458 * proposed new region fits before the next entry, we win. 1459 */ 1460 1461 end = *start + length; 1462 if (end < *start) 1463 return (-1); 1464 1465 if (entry->next->start >= end && *start >= entry->end) 1466 return (1); 1467 1468 return (0); 1469 } 1470 1471 /* 1472 * uvm_map_findspace: find "length" sized space in "map". 1473 * 1474 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is 1475 * set in "flags" (in which case we insist on using "hint"). 1476 * => "result" is VA returned 1477 * => uobj/uoffset are to be used to handle VAC alignment, if required 1478 * => if "align" is non-zero, we attempt to align to that value. 1479 * => caller must at least have read-locked map 1480 * => returns NULL on failure, or pointer to prev. map entry if success 1481 * => note this is a cross between the old vm_map_findspace and vm_map_find 1482 */ 1483 1484 struct vm_map_entry * 1485 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length, 1486 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset, 1487 vsize_t align, int flags) 1488 { 1489 struct vm_map_entry *entry; 1490 struct vm_map_entry *child, *prev, *tmp; 1491 vaddr_t orig_hint; 1492 const int topdown = map->flags & VM_MAP_TOPDOWN; 1493 UVMHIST_FUNC("uvm_map_findspace"); 1494 UVMHIST_CALLED(maphist); 1495 1496 UVMHIST_LOG(maphist, "(map=0x%x, hint=0x%x, len=%d, flags=0x%x)", 1497 map, hint, length, flags); 1498 KASSERT((align & (align - 1)) == 0); 1499 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1500 1501 uvm_tree_sanity(map, "map_findspace entry"); 1502 1503 /* 1504 * remember the original hint. if we are aligning, then we 1505 * may have to try again with no alignment constraint if 1506 * we fail the first time. 1507 */ 1508 1509 orig_hint = hint; 1510 if (hint < vm_map_min(map)) { /* check ranges ... */ 1511 if (flags & UVM_FLAG_FIXED) { 1512 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0); 1513 return (NULL); 1514 } 1515 hint = vm_map_min(map); 1516 } 1517 if (hint > vm_map_max(map)) { 1518 UVMHIST_LOG(maphist,"<- VA 0x%x > range [0x%x->0x%x]", 1519 hint, vm_map_min(map), vm_map_max(map), 0); 1520 return (NULL); 1521 } 1522 1523 /* 1524 * Look for the first possible address; if there's already 1525 * something at this address, we have to start after it. 1526 */ 1527 1528 /* 1529 * @@@: there are four, no, eight cases to consider. 1530 * 1531 * 0: found, fixed, bottom up -> fail 1532 * 1: found, fixed, top down -> fail 1533 * 2: found, not fixed, bottom up -> start after entry->end, 1534 * loop up 1535 * 3: found, not fixed, top down -> start before entry->start, 1536 * loop down 1537 * 4: not found, fixed, bottom up -> check entry->next->start, fail 1538 * 5: not found, fixed, top down -> check entry->next->start, fail 1539 * 6: not found, not fixed, bottom up -> check entry->next->start, 1540 * loop up 1541 * 7: not found, not fixed, top down -> check entry->next->start, 1542 * loop down 1543 * 1544 * as you can see, it reduces to roughly five cases, and that 1545 * adding top down mapping only adds one unique case (without 1546 * it, there would be four cases). 1547 */ 1548 1549 if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) { 1550 entry = map->first_free; 1551 } else { 1552 if (uvm_map_lookup_entry(map, hint, &entry)) { 1553 /* "hint" address already in use ... */ 1554 if (flags & UVM_FLAG_FIXED) { 1555 UVMHIST_LOG(maphist, "<- fixed & VA in use", 1556 0, 0, 0, 0); 1557 return (NULL); 1558 } 1559 if (topdown) 1560 /* Start from lower gap. */ 1561 entry = entry->prev; 1562 } else if (flags & UVM_FLAG_FIXED) { 1563 if (entry->next->start >= hint + length && 1564 hint + length > hint) 1565 goto found; 1566 1567 /* "hint" address is gap but too small */ 1568 UVMHIST_LOG(maphist, "<- fixed mapping failed", 1569 0, 0, 0, 0); 1570 return (NULL); /* only one shot at it ... */ 1571 } else { 1572 /* 1573 * See if given hint fits in this gap. 1574 */ 1575 switch (uvm_map_space_avail(&hint, length, 1576 uoffset, align, topdown, entry)) { 1577 case 1: 1578 goto found; 1579 case -1: 1580 goto wraparound; 1581 } 1582 1583 if (topdown) { 1584 /* 1585 * Still there is a chance to fit 1586 * if hint > entry->end. 1587 */ 1588 } else { 1589 /* Start from higher gap. */ 1590 entry = entry->next; 1591 if (entry == &map->header) 1592 goto notfound; 1593 goto nextgap; 1594 } 1595 } 1596 } 1597 1598 /* 1599 * Note that all UVM_FLAGS_FIXED case is already handled. 1600 */ 1601 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1602 1603 /* Try to find the space in the red-black tree */ 1604 1605 /* Check slot before any entry */ 1606 hint = topdown ? entry->next->start - length : entry->end; 1607 switch (uvm_map_space_avail(&hint, length, uoffset, align, 1608 topdown, entry)) { 1609 case 1: 1610 goto found; 1611 case -1: 1612 goto wraparound; 1613 } 1614 1615 nextgap: 1616 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1617 /* If there is not enough space in the whole tree, we fail */ 1618 tmp = RB_ROOT(&map->rbhead); 1619 if (tmp == NULL || tmp->space < length) 1620 goto notfound; 1621 1622 prev = NULL; /* previous candidate */ 1623 1624 /* Find an entry close to hint that has enough space */ 1625 for (; tmp;) { 1626 KASSERT(tmp->next->start == tmp->end + tmp->ownspace); 1627 if (topdown) { 1628 if (tmp->next->start < hint + length && 1629 (prev == NULL || tmp->end > prev->end)) { 1630 if (tmp->ownspace >= length) 1631 prev = tmp; 1632 else if ((child = RB_LEFT(tmp, rb_entry)) 1633 != NULL && child->space >= length) 1634 prev = tmp; 1635 } 1636 } else { 1637 if (tmp->end >= hint && 1638 (prev == NULL || tmp->end < prev->end)) { 1639 if (tmp->ownspace >= length) 1640 prev = tmp; 1641 else if ((child = RB_RIGHT(tmp, rb_entry)) 1642 != NULL && child->space >= length) 1643 prev = tmp; 1644 } 1645 } 1646 if (tmp->next->start < hint + length) 1647 child = RB_RIGHT(tmp, rb_entry); 1648 else if (tmp->end > hint) 1649 child = RB_LEFT(tmp, rb_entry); 1650 else { 1651 if (tmp->ownspace >= length) 1652 break; 1653 if (topdown) 1654 child = RB_LEFT(tmp, rb_entry); 1655 else 1656 child = RB_RIGHT(tmp, rb_entry); 1657 } 1658 if (child == NULL || child->space < length) 1659 break; 1660 tmp = child; 1661 } 1662 1663 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) { 1664 /* 1665 * Check if the entry that we found satifies the 1666 * space requirement 1667 */ 1668 if (topdown) { 1669 if (hint > tmp->next->start - length) 1670 hint = tmp->next->start - length; 1671 } else { 1672 if (hint < tmp->end) 1673 hint = tmp->end; 1674 } 1675 switch (uvm_map_space_avail(&hint, length, uoffset, align, 1676 topdown, tmp)) { 1677 case 1: 1678 entry = tmp; 1679 goto found; 1680 case -1: 1681 goto wraparound; 1682 } 1683 if (tmp->ownspace >= length) 1684 goto listsearch; 1685 } 1686 if (prev == NULL) 1687 goto notfound; 1688 1689 if (topdown) { 1690 KASSERT(orig_hint >= prev->next->start - length || 1691 prev->next->start - length > prev->next->start); 1692 hint = prev->next->start - length; 1693 } else { 1694 KASSERT(orig_hint <= prev->end); 1695 hint = prev->end; 1696 } 1697 switch (uvm_map_space_avail(&hint, length, uoffset, align, 1698 topdown, prev)) { 1699 case 1: 1700 entry = prev; 1701 goto found; 1702 case -1: 1703 goto wraparound; 1704 } 1705 if (prev->ownspace >= length) 1706 goto listsearch; 1707 1708 if (topdown) 1709 tmp = RB_LEFT(prev, rb_entry); 1710 else 1711 tmp = RB_RIGHT(prev, rb_entry); 1712 for (;;) { 1713 KASSERT(tmp && tmp->space >= length); 1714 if (topdown) 1715 child = RB_RIGHT(tmp, rb_entry); 1716 else 1717 child = RB_LEFT(tmp, rb_entry); 1718 if (child && child->space >= length) { 1719 tmp = child; 1720 continue; 1721 } 1722 if (tmp->ownspace >= length) 1723 break; 1724 if (topdown) 1725 tmp = RB_LEFT(tmp, rb_entry); 1726 else 1727 tmp = RB_RIGHT(tmp, rb_entry); 1728 } 1729 1730 if (topdown) { 1731 KASSERT(orig_hint >= tmp->next->start - length || 1732 tmp->next->start - length > tmp->next->start); 1733 hint = tmp->next->start - length; 1734 } else { 1735 KASSERT(orig_hint <= tmp->end); 1736 hint = tmp->end; 1737 } 1738 switch (uvm_map_space_avail(&hint, length, uoffset, align, 1739 topdown, tmp)) { 1740 case 1: 1741 entry = tmp; 1742 goto found; 1743 case -1: 1744 goto wraparound; 1745 } 1746 1747 /* 1748 * The tree fails to find an entry because of offset or alignment 1749 * restrictions. Search the list instead. 1750 */ 1751 listsearch: 1752 /* 1753 * Look through the rest of the map, trying to fit a new region in 1754 * the gap between existing regions, or after the very last region. 1755 * note: entry->end = base VA of current gap, 1756 * entry->next->start = VA of end of current gap 1757 */ 1758 1759 for (;;) { 1760 /* Update hint for current gap. */ 1761 hint = topdown ? entry->next->start - length : entry->end; 1762 1763 /* See if it fits. */ 1764 switch (uvm_map_space_avail(&hint, length, uoffset, align, 1765 topdown, entry)) { 1766 case 1: 1767 goto found; 1768 case -1: 1769 goto wraparound; 1770 } 1771 1772 /* Advance to next/previous gap */ 1773 if (topdown) { 1774 if (entry == &map->header) { 1775 UVMHIST_LOG(maphist, "<- failed (off start)", 1776 0,0,0,0); 1777 goto notfound; 1778 } 1779 entry = entry->prev; 1780 } else { 1781 entry = entry->next; 1782 if (entry == &map->header) { 1783 UVMHIST_LOG(maphist, "<- failed (off end)", 1784 0,0,0,0); 1785 goto notfound; 1786 } 1787 } 1788 } 1789 1790 found: 1791 SAVE_HINT(map, map->hint, entry); 1792 *result = hint; 1793 UVMHIST_LOG(maphist,"<- got it! (result=0x%x)", hint, 0,0,0); 1794 KASSERT( topdown || hint >= orig_hint); 1795 KASSERT(!topdown || hint <= orig_hint); 1796 KASSERT(entry->end <= hint); 1797 KASSERT(hint + length <= entry->next->start); 1798 return (entry); 1799 1800 wraparound: 1801 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0); 1802 1803 return (NULL); 1804 1805 notfound: 1806 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0); 1807 1808 return (NULL); 1809 } 1810 1811 /* 1812 * U N M A P - m a i n h e l p e r f u n c t i o n s 1813 */ 1814 1815 /* 1816 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop") 1817 * 1818 * => caller must check alignment and size 1819 * => map must be locked by caller 1820 * => we return a list of map entries that we've remove from the map 1821 * in "entry_list" 1822 */ 1823 1824 void 1825 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end, 1826 struct vm_map_entry **entry_list /* OUT */, 1827 struct uvm_mapent_reservation *umr, int flags) 1828 { 1829 struct vm_map_entry *entry, *first_entry, *next; 1830 vaddr_t len; 1831 UVMHIST_FUNC("uvm_unmap_remove"); UVMHIST_CALLED(maphist); 1832 1833 UVMHIST_LOG(maphist,"(map=0x%x, start=0x%x, end=0x%x)", 1834 map, start, end, 0); 1835 VM_MAP_RANGE_CHECK(map, start, end); 1836 1837 uvm_tree_sanity(map, "unmap_remove entry"); 1838 1839 /* 1840 * find first entry 1841 */ 1842 1843 if (uvm_map_lookup_entry(map, start, &first_entry) == TRUE) { 1844 /* clip and go... */ 1845 entry = first_entry; 1846 UVM_MAP_CLIP_START(map, entry, start, umr); 1847 /* critical! prevents stale hint */ 1848 SAVE_HINT(map, entry, entry->prev); 1849 } else { 1850 entry = first_entry->next; 1851 } 1852 1853 /* 1854 * Save the free space hint 1855 */ 1856 1857 if (map->first_free->start >= start) 1858 map->first_free = entry->prev; 1859 1860 /* 1861 * note: we now re-use first_entry for a different task. we remove 1862 * a number of map entries from the map and save them in a linked 1863 * list headed by "first_entry". once we remove them from the map 1864 * the caller should unlock the map and drop the references to the 1865 * backing objects [c.f. uvm_unmap_detach]. the object is to 1866 * separate unmapping from reference dropping. why? 1867 * [1] the map has to be locked for unmapping 1868 * [2] the map need not be locked for reference dropping 1869 * [3] dropping references may trigger pager I/O, and if we hit 1870 * a pager that does synchronous I/O we may have to wait for it. 1871 * [4] we would like all waiting for I/O to occur with maps unlocked 1872 * so that we don't block other threads. 1873 */ 1874 1875 first_entry = NULL; 1876 *entry_list = NULL; 1877 1878 /* 1879 * break up the area into map entry sized regions and unmap. note 1880 * that all mappings have to be removed before we can even consider 1881 * dropping references to amaps or VM objects (otherwise we could end 1882 * up with a mapping to a page on the free list which would be very bad) 1883 */ 1884 1885 while ((entry != &map->header) && (entry->start < end)) { 1886 KASSERT((entry->flags & UVM_MAP_FIRST) == 0); 1887 1888 UVM_MAP_CLIP_END(map, entry, end, umr); 1889 next = entry->next; 1890 len = entry->end - entry->start; 1891 1892 /* 1893 * unwire before removing addresses from the pmap; otherwise 1894 * unwiring will put the entries back into the pmap (XXX). 1895 */ 1896 1897 if (VM_MAPENT_ISWIRED(entry)) { 1898 uvm_map_entry_unwire(map, entry); 1899 } 1900 if (flags & UVM_FLAG_VAONLY) { 1901 1902 /* nothing */ 1903 1904 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) { 1905 1906 /* 1907 * if the map is non-pageable, any pages mapped there 1908 * must be wired and entered with pmap_kenter_pa(), 1909 * and we should free any such pages immediately. 1910 * this is mostly used for kmem_map and mb_map. 1911 */ 1912 1913 if ((entry->flags & UVM_MAP_KMAPENT) == 0) { 1914 uvm_km_pgremove_intrsafe(entry->start, 1915 entry->end); 1916 pmap_kremove(entry->start, len); 1917 } 1918 } else if (UVM_ET_ISOBJ(entry) && 1919 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) { 1920 KASSERT(vm_map_pmap(map) == pmap_kernel()); 1921 1922 /* 1923 * note: kernel object mappings are currently used in 1924 * two ways: 1925 * [1] "normal" mappings of pages in the kernel object 1926 * [2] uvm_km_valloc'd allocations in which we 1927 * pmap_enter in some non-kernel-object page 1928 * (e.g. vmapbuf). 1929 * 1930 * for case [1], we need to remove the mapping from 1931 * the pmap and then remove the page from the kernel 1932 * object (because, once pages in a kernel object are 1933 * unmapped they are no longer needed, unlike, say, 1934 * a vnode where you might want the data to persist 1935 * until flushed out of a queue). 1936 * 1937 * for case [2], we need to remove the mapping from 1938 * the pmap. there shouldn't be any pages at the 1939 * specified offset in the kernel object [but it 1940 * doesn't hurt to call uvm_km_pgremove just to be 1941 * safe?] 1942 * 1943 * uvm_km_pgremove currently does the following: 1944 * for pages in the kernel object in range: 1945 * - drops the swap slot 1946 * - uvm_pagefree the page 1947 */ 1948 1949 /* 1950 * remove mappings from pmap and drop the pages 1951 * from the object. offsets are always relative 1952 * to vm_map_min(kernel_map). 1953 */ 1954 1955 pmap_remove(pmap_kernel(), entry->start, 1956 entry->start + len); 1957 uvm_km_pgremove(entry->start, entry->end); 1958 1959 /* 1960 * null out kernel_object reference, we've just 1961 * dropped it 1962 */ 1963 1964 entry->etype &= ~UVM_ET_OBJ; 1965 entry->object.uvm_obj = NULL; 1966 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) { 1967 1968 /* 1969 * remove mappings the standard way. 1970 */ 1971 1972 pmap_remove(map->pmap, entry->start, entry->end); 1973 } 1974 1975 #if defined(DEBUG) 1976 if ((entry->flags & UVM_MAP_KMAPENT) == 0) { 1977 1978 /* 1979 * check if there's remaining mapping, 1980 * which is a bug in caller. 1981 */ 1982 1983 vaddr_t va; 1984 for (va = entry->start; va < entry->end; 1985 va += PAGE_SIZE) { 1986 if (pmap_extract(vm_map_pmap(map), va, NULL)) { 1987 panic("uvm_unmap_remove: has mapping"); 1988 } 1989 } 1990 1991 if (VM_MAP_IS_KERNEL(map)) { 1992 uvm_km_check_empty(entry->start, entry->end, 1993 (map->flags & VM_MAP_INTRSAFE) != 0); 1994 } 1995 } 1996 #endif /* defined(DEBUG) */ 1997 1998 /* 1999 * remove entry from map and put it on our list of entries 2000 * that we've nuked. then go to next entry. 2001 */ 2002 2003 UVMHIST_LOG(maphist, " removed map entry 0x%x", entry, 0, 0,0); 2004 2005 /* critical! prevents stale hint */ 2006 SAVE_HINT(map, entry, entry->prev); 2007 2008 uvm_map_entry_unlink(map, entry); 2009 KASSERT(map->size >= len); 2010 map->size -= len; 2011 entry->prev = NULL; 2012 entry->next = first_entry; 2013 first_entry = entry; 2014 entry = next; 2015 } 2016 if ((map->flags & VM_MAP_DYING) == 0) { 2017 pmap_update(vm_map_pmap(map)); 2018 } 2019 2020 uvm_tree_sanity(map, "unmap_remove leave"); 2021 2022 /* 2023 * now we've cleaned up the map and are ready for the caller to drop 2024 * references to the mapped objects. 2025 */ 2026 2027 *entry_list = first_entry; 2028 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 2029 2030 simple_lock(&map->flags_lock); 2031 if (map->flags & VM_MAP_WANTVA) { 2032 map->flags &= ~VM_MAP_WANTVA; 2033 wakeup(&map->header); 2034 } 2035 simple_unlock(&map->flags_lock); 2036 } 2037 2038 /* 2039 * uvm_unmap_detach: drop references in a chain of map entries 2040 * 2041 * => we will free the map entries as we traverse the list. 2042 */ 2043 2044 void 2045 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags) 2046 { 2047 struct vm_map_entry *next_entry; 2048 UVMHIST_FUNC("uvm_unmap_detach"); UVMHIST_CALLED(maphist); 2049 2050 while (first_entry) { 2051 KASSERT(!VM_MAPENT_ISWIRED(first_entry)); 2052 UVMHIST_LOG(maphist, 2053 " detach 0x%x: amap=0x%x, obj=0x%x, submap?=%d", 2054 first_entry, first_entry->aref.ar_amap, 2055 first_entry->object.uvm_obj, 2056 UVM_ET_ISSUBMAP(first_entry)); 2057 2058 /* 2059 * drop reference to amap, if we've got one 2060 */ 2061 2062 if (first_entry->aref.ar_amap) 2063 uvm_map_unreference_amap(first_entry, flags); 2064 2065 /* 2066 * drop reference to our backing object, if we've got one 2067 */ 2068 2069 KASSERT(!UVM_ET_ISSUBMAP(first_entry)); 2070 if (UVM_ET_ISOBJ(first_entry) && 2071 first_entry->object.uvm_obj->pgops->pgo_detach) { 2072 (*first_entry->object.uvm_obj->pgops->pgo_detach) 2073 (first_entry->object.uvm_obj); 2074 } 2075 next_entry = first_entry->next; 2076 uvm_mapent_free(first_entry); 2077 first_entry = next_entry; 2078 } 2079 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 2080 } 2081 2082 /* 2083 * E X T R A C T I O N F U N C T I O N S 2084 */ 2085 2086 /* 2087 * uvm_map_reserve: reserve space in a vm_map for future use. 2088 * 2089 * => we reserve space in a map by putting a dummy map entry in the 2090 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE) 2091 * => map should be unlocked (we will write lock it) 2092 * => we return true if we were able to reserve space 2093 * => XXXCDC: should be inline? 2094 */ 2095 2096 int 2097 uvm_map_reserve(struct vm_map *map, vsize_t size, 2098 vaddr_t offset /* hint for pmap_prefer */, 2099 vsize_t align /* alignment hint */, 2100 vaddr_t *raddr /* IN:hint, OUT: reserved VA */) 2101 { 2102 UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist); 2103 2104 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x, offset=0x%x,addr=0x%x)", 2105 map,size,offset,raddr); 2106 2107 size = round_page(size); 2108 if (*raddr < vm_map_min(map)) 2109 *raddr = vm_map_min(map); /* hint */ 2110 2111 /* 2112 * reserve some virtual space. 2113 */ 2114 2115 if (uvm_map(map, raddr, size, NULL, offset, 0, 2116 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE, 2117 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE)) != 0) { 2118 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 2119 return (FALSE); 2120 } 2121 2122 UVMHIST_LOG(maphist, "<- done (*raddr=0x%x)", *raddr,0,0,0); 2123 return (TRUE); 2124 } 2125 2126 /* 2127 * uvm_map_replace: replace a reserved (blank) area of memory with 2128 * real mappings. 2129 * 2130 * => caller must WRITE-LOCK the map 2131 * => we return TRUE if replacement was a success 2132 * => we expect the newents chain to have nnewents entrys on it and 2133 * we expect newents->prev to point to the last entry on the list 2134 * => note newents is allowed to be NULL 2135 */ 2136 2137 int 2138 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end, 2139 struct vm_map_entry *newents, int nnewents) 2140 { 2141 struct vm_map_entry *oldent, *last; 2142 2143 uvm_tree_sanity(map, "map_replace entry"); 2144 2145 /* 2146 * first find the blank map entry at the specified address 2147 */ 2148 2149 if (!uvm_map_lookup_entry(map, start, &oldent)) { 2150 return (FALSE); 2151 } 2152 2153 /* 2154 * check to make sure we have a proper blank entry 2155 */ 2156 2157 if (oldent->start != start || oldent->end != end || 2158 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) { 2159 return (FALSE); 2160 } 2161 2162 #ifdef DIAGNOSTIC 2163 2164 /* 2165 * sanity check the newents chain 2166 */ 2167 2168 { 2169 struct vm_map_entry *tmpent = newents; 2170 int nent = 0; 2171 vaddr_t cur = start; 2172 2173 while (tmpent) { 2174 nent++; 2175 if (tmpent->start < cur) 2176 panic("uvm_map_replace1"); 2177 if (tmpent->start > tmpent->end || tmpent->end > end) { 2178 printf("tmpent->start=0x%lx, tmpent->end=0x%lx, end=0x%lx\n", 2179 tmpent->start, tmpent->end, end); 2180 panic("uvm_map_replace2"); 2181 } 2182 cur = tmpent->end; 2183 if (tmpent->next) { 2184 if (tmpent->next->prev != tmpent) 2185 panic("uvm_map_replace3"); 2186 } else { 2187 if (newents->prev != tmpent) 2188 panic("uvm_map_replace4"); 2189 } 2190 tmpent = tmpent->next; 2191 } 2192 if (nent != nnewents) 2193 panic("uvm_map_replace5"); 2194 } 2195 #endif 2196 2197 /* 2198 * map entry is a valid blank! replace it. (this does all the 2199 * work of map entry link/unlink...). 2200 */ 2201 2202 if (newents) { 2203 last = newents->prev; 2204 2205 /* critical: flush stale hints out of map */ 2206 SAVE_HINT(map, map->hint, newents); 2207 if (map->first_free == oldent) 2208 map->first_free = last; 2209 2210 last->next = oldent->next; 2211 last->next->prev = last; 2212 2213 /* Fix RB tree */ 2214 uvm_rb_remove(map, oldent); 2215 2216 newents->prev = oldent->prev; 2217 newents->prev->next = newents; 2218 map->nentries = map->nentries + (nnewents - 1); 2219 2220 /* Fixup the RB tree */ 2221 { 2222 int i; 2223 struct vm_map_entry *tmp; 2224 2225 tmp = newents; 2226 for (i = 0; i < nnewents && tmp; i++) { 2227 uvm_rb_insert(map, tmp); 2228 tmp = tmp->next; 2229 } 2230 } 2231 } else { 2232 2233 /* critical: flush stale hints out of map */ 2234 SAVE_HINT(map, map->hint, oldent->prev); 2235 if (map->first_free == oldent) 2236 map->first_free = oldent->prev; 2237 2238 /* NULL list of new entries: just remove the old one */ 2239 uvm_map_entry_unlink(map, oldent); 2240 } 2241 2242 uvm_tree_sanity(map, "map_replace leave"); 2243 2244 /* 2245 * now we can free the old blank entry, unlock the map and return. 2246 */ 2247 2248 uvm_mapent_free(oldent); 2249 return (TRUE); 2250 } 2251 2252 /* 2253 * uvm_map_extract: extract a mapping from a map and put it somewhere 2254 * (maybe removing the old mapping) 2255 * 2256 * => maps should be unlocked (we will write lock them) 2257 * => returns 0 on success, error code otherwise 2258 * => start must be page aligned 2259 * => len must be page sized 2260 * => flags: 2261 * UVM_EXTRACT_REMOVE: remove mappings from srcmap 2262 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only) 2263 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs 2264 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go 2265 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<< 2266 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only 2267 * be used from within the kernel in a kernel level map <<< 2268 */ 2269 2270 int 2271 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len, 2272 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags) 2273 { 2274 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge; 2275 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry, 2276 *deadentry, *oldentry; 2277 vsize_t elen; 2278 int nchain, error, copy_ok; 2279 UVMHIST_FUNC("uvm_map_extract"); UVMHIST_CALLED(maphist); 2280 2281 UVMHIST_LOG(maphist,"(srcmap=0x%x,start=0x%x, len=0x%x", srcmap, start, 2282 len,0); 2283 UVMHIST_LOG(maphist," ...,dstmap=0x%x, flags=0x%x)", dstmap,flags,0,0); 2284 2285 uvm_tree_sanity(srcmap, "map_extract src enter"); 2286 uvm_tree_sanity(dstmap, "map_extract dst enter"); 2287 2288 /* 2289 * step 0: sanity check: start must be on a page boundary, length 2290 * must be page sized. can't ask for CONTIG/QREF if you asked for 2291 * REMOVE. 2292 */ 2293 2294 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0); 2295 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 || 2296 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0); 2297 2298 /* 2299 * step 1: reserve space in the target map for the extracted area 2300 */ 2301 2302 dstaddr = vm_map_min(dstmap); 2303 if (uvm_map_reserve(dstmap, len, start, 0, &dstaddr) == FALSE) 2304 return (ENOMEM); 2305 *dstaddrp = dstaddr; /* pass address back to caller */ 2306 UVMHIST_LOG(maphist, " dstaddr=0x%x", dstaddr,0,0,0); 2307 2308 /* 2309 * step 2: setup for the extraction process loop by init'ing the 2310 * map entry chain, locking src map, and looking up the first useful 2311 * entry in the map. 2312 */ 2313 2314 end = start + len; 2315 newend = dstaddr + len; 2316 chain = endchain = NULL; 2317 nchain = 0; 2318 vm_map_lock(srcmap); 2319 2320 if (uvm_map_lookup_entry(srcmap, start, &entry)) { 2321 2322 /* "start" is within an entry */ 2323 if (flags & UVM_EXTRACT_QREF) { 2324 2325 /* 2326 * for quick references we don't clip the entry, so 2327 * the entry may map space "before" the starting 2328 * virtual address... this is the "fudge" factor 2329 * (which can be non-zero only the first time 2330 * through the "while" loop in step 3). 2331 */ 2332 2333 fudge = start - entry->start; 2334 } else { 2335 2336 /* 2337 * normal reference: we clip the map to fit (thus 2338 * fudge is zero) 2339 */ 2340 2341 UVM_MAP_CLIP_START(srcmap, entry, start, NULL); 2342 SAVE_HINT(srcmap, srcmap->hint, entry->prev); 2343 fudge = 0; 2344 } 2345 } else { 2346 2347 /* "start" is not within an entry ... skip to next entry */ 2348 if (flags & UVM_EXTRACT_CONTIG) { 2349 error = EINVAL; 2350 goto bad; /* definite hole here ... */ 2351 } 2352 2353 entry = entry->next; 2354 fudge = 0; 2355 } 2356 2357 /* save values from srcmap for step 6 */ 2358 orig_entry = entry; 2359 orig_fudge = fudge; 2360 2361 /* 2362 * step 3: now start looping through the map entries, extracting 2363 * as we go. 2364 */ 2365 2366 while (entry->start < end && entry != &srcmap->header) { 2367 2368 /* if we are not doing a quick reference, clip it */ 2369 if ((flags & UVM_EXTRACT_QREF) == 0) 2370 UVM_MAP_CLIP_END(srcmap, entry, end, NULL); 2371 2372 /* clear needs_copy (allow chunking) */ 2373 if (UVM_ET_ISNEEDSCOPY(entry)) { 2374 amap_copy(srcmap, entry, M_NOWAIT, TRUE, start, end); 2375 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */ 2376 error = ENOMEM; 2377 goto bad; 2378 } 2379 2380 /* amap_copy could clip (during chunk)! update fudge */ 2381 if (fudge) { 2382 fudge = start - entry->start; 2383 orig_fudge = fudge; 2384 } 2385 } 2386 2387 /* calculate the offset of this from "start" */ 2388 oldoffset = (entry->start + fudge) - start; 2389 2390 /* allocate a new map entry */ 2391 newentry = uvm_mapent_alloc(dstmap, 0); 2392 if (newentry == NULL) { 2393 error = ENOMEM; 2394 goto bad; 2395 } 2396 2397 /* set up new map entry */ 2398 newentry->next = NULL; 2399 newentry->prev = endchain; 2400 newentry->start = dstaddr + oldoffset; 2401 newentry->end = 2402 newentry->start + (entry->end - (entry->start + fudge)); 2403 if (newentry->end > newend || newentry->end < newentry->start) 2404 newentry->end = newend; 2405 newentry->object.uvm_obj = entry->object.uvm_obj; 2406 if (newentry->object.uvm_obj) { 2407 if (newentry->object.uvm_obj->pgops->pgo_reference) 2408 newentry->object.uvm_obj->pgops-> 2409 pgo_reference(newentry->object.uvm_obj); 2410 newentry->offset = entry->offset + fudge; 2411 } else { 2412 newentry->offset = 0; 2413 } 2414 newentry->etype = entry->etype; 2415 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ? 2416 entry->max_protection : entry->protection; 2417 newentry->max_protection = entry->max_protection; 2418 newentry->inheritance = entry->inheritance; 2419 newentry->wired_count = 0; 2420 newentry->aref.ar_amap = entry->aref.ar_amap; 2421 if (newentry->aref.ar_amap) { 2422 newentry->aref.ar_pageoff = 2423 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT); 2424 uvm_map_reference_amap(newentry, AMAP_SHARED | 2425 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0)); 2426 } else { 2427 newentry->aref.ar_pageoff = 0; 2428 } 2429 newentry->advice = entry->advice; 2430 2431 /* now link it on the chain */ 2432 nchain++; 2433 if (endchain == NULL) { 2434 chain = endchain = newentry; 2435 } else { 2436 endchain->next = newentry; 2437 endchain = newentry; 2438 } 2439 2440 /* end of 'while' loop! */ 2441 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end && 2442 (entry->next == &srcmap->header || 2443 entry->next->start != entry->end)) { 2444 error = EINVAL; 2445 goto bad; 2446 } 2447 entry = entry->next; 2448 fudge = 0; 2449 } 2450 2451 /* 2452 * step 4: close off chain (in format expected by uvm_map_replace) 2453 */ 2454 2455 if (chain) 2456 chain->prev = endchain; 2457 2458 /* 2459 * step 5: attempt to lock the dest map so we can pmap_copy. 2460 * note usage of copy_ok: 2461 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5) 2462 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7 2463 */ 2464 2465 if (srcmap == dstmap || vm_map_lock_try(dstmap) == TRUE) { 2466 copy_ok = 1; 2467 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2468 nchain)) { 2469 if (srcmap != dstmap) 2470 vm_map_unlock(dstmap); 2471 error = EIO; 2472 goto bad; 2473 } 2474 } else { 2475 copy_ok = 0; 2476 /* replace defered until step 7 */ 2477 } 2478 2479 /* 2480 * step 6: traverse the srcmap a second time to do the following: 2481 * - if we got a lock on the dstmap do pmap_copy 2482 * - if UVM_EXTRACT_REMOVE remove the entries 2483 * we make use of orig_entry and orig_fudge (saved in step 2) 2484 */ 2485 2486 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) { 2487 2488 /* purge possible stale hints from srcmap */ 2489 if (flags & UVM_EXTRACT_REMOVE) { 2490 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev); 2491 if (srcmap->first_free->start >= start) 2492 srcmap->first_free = orig_entry->prev; 2493 } 2494 2495 entry = orig_entry; 2496 fudge = orig_fudge; 2497 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */ 2498 2499 while (entry->start < end && entry != &srcmap->header) { 2500 if (copy_ok) { 2501 oldoffset = (entry->start + fudge) - start; 2502 elen = MIN(end, entry->end) - 2503 (entry->start + fudge); 2504 pmap_copy(dstmap->pmap, srcmap->pmap, 2505 dstaddr + oldoffset, elen, 2506 entry->start + fudge); 2507 } 2508 2509 /* we advance "entry" in the following if statement */ 2510 if (flags & UVM_EXTRACT_REMOVE) { 2511 pmap_remove(srcmap->pmap, entry->start, 2512 entry->end); 2513 oldentry = entry; /* save entry */ 2514 entry = entry->next; /* advance */ 2515 uvm_map_entry_unlink(srcmap, oldentry); 2516 /* add to dead list */ 2517 oldentry->next = deadentry; 2518 deadentry = oldentry; 2519 } else { 2520 entry = entry->next; /* advance */ 2521 } 2522 2523 /* end of 'while' loop */ 2524 fudge = 0; 2525 } 2526 pmap_update(srcmap->pmap); 2527 2528 /* 2529 * unlock dstmap. we will dispose of deadentry in 2530 * step 7 if needed 2531 */ 2532 2533 if (copy_ok && srcmap != dstmap) 2534 vm_map_unlock(dstmap); 2535 2536 } else { 2537 deadentry = NULL; 2538 } 2539 2540 /* 2541 * step 7: we are done with the source map, unlock. if copy_ok 2542 * is 0 then we have not replaced the dummy mapping in dstmap yet 2543 * and we need to do so now. 2544 */ 2545 2546 vm_map_unlock(srcmap); 2547 if ((flags & UVM_EXTRACT_REMOVE) && deadentry) 2548 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */ 2549 2550 /* now do the replacement if we didn't do it in step 5 */ 2551 if (copy_ok == 0) { 2552 vm_map_lock(dstmap); 2553 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2554 nchain); 2555 vm_map_unlock(dstmap); 2556 2557 if (error == FALSE) { 2558 error = EIO; 2559 goto bad2; 2560 } 2561 } 2562 2563 uvm_tree_sanity(srcmap, "map_extract src leave"); 2564 uvm_tree_sanity(dstmap, "map_extract dst leave"); 2565 2566 return (0); 2567 2568 /* 2569 * bad: failure recovery 2570 */ 2571 bad: 2572 vm_map_unlock(srcmap); 2573 bad2: /* src already unlocked */ 2574 if (chain) 2575 uvm_unmap_detach(chain, 2576 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0); 2577 2578 uvm_tree_sanity(srcmap, "map_extract src err leave"); 2579 uvm_tree_sanity(dstmap, "map_extract dst err leave"); 2580 2581 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */ 2582 return (error); 2583 } 2584 2585 /* end of extraction functions */ 2586 2587 /* 2588 * uvm_map_submap: punch down part of a map into a submap 2589 * 2590 * => only the kernel_map is allowed to be submapped 2591 * => the purpose of submapping is to break up the locking granularity 2592 * of a larger map 2593 * => the range specified must have been mapped previously with a uvm_map() 2594 * call [with uobj==NULL] to create a blank map entry in the main map. 2595 * [And it had better still be blank!] 2596 * => maps which contain submaps should never be copied or forked. 2597 * => to remove a submap, use uvm_unmap() on the main map 2598 * and then uvm_map_deallocate() the submap. 2599 * => main map must be unlocked. 2600 * => submap must have been init'd and have a zero reference count. 2601 * [need not be locked as we don't actually reference it] 2602 */ 2603 2604 int 2605 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end, 2606 struct vm_map *submap) 2607 { 2608 struct vm_map_entry *entry; 2609 struct uvm_mapent_reservation umr; 2610 int error; 2611 2612 uvm_mapent_reserve(map, &umr, 2, 0); 2613 2614 vm_map_lock(map); 2615 VM_MAP_RANGE_CHECK(map, start, end); 2616 2617 if (uvm_map_lookup_entry(map, start, &entry)) { 2618 UVM_MAP_CLIP_START(map, entry, start, &umr); 2619 UVM_MAP_CLIP_END(map, entry, end, &umr); /* to be safe */ 2620 } else { 2621 entry = NULL; 2622 } 2623 2624 if (entry != NULL && 2625 entry->start == start && entry->end == end && 2626 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL && 2627 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) { 2628 entry->etype |= UVM_ET_SUBMAP; 2629 entry->object.sub_map = submap; 2630 entry->offset = 0; 2631 uvm_map_reference(submap); 2632 error = 0; 2633 } else { 2634 error = EINVAL; 2635 } 2636 vm_map_unlock(map); 2637 2638 uvm_mapent_unreserve(map, &umr); 2639 2640 return error; 2641 } 2642 2643 /* 2644 * uvm_map_setup_kernel: init in-kernel map 2645 * 2646 * => map must not be in service yet. 2647 */ 2648 2649 void 2650 uvm_map_setup_kernel(struct vm_map_kernel *map, 2651 vaddr_t vmin, vaddr_t vmax, int flags) 2652 { 2653 2654 uvm_map_setup(&map->vmk_map, vmin, vmax, flags); 2655 2656 LIST_INIT(&map->vmk_kentry_free); 2657 map->vmk_merged_entries = NULL; 2658 } 2659 2660 2661 /* 2662 * uvm_map_protect: change map protection 2663 * 2664 * => set_max means set max_protection. 2665 * => map must be unlocked. 2666 */ 2667 2668 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \ 2669 ~VM_PROT_WRITE : VM_PROT_ALL) 2670 2671 int 2672 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end, 2673 vm_prot_t new_prot, boolean_t set_max) 2674 { 2675 struct vm_map_entry *current, *entry; 2676 int error = 0; 2677 UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist); 2678 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_prot=0x%x)", 2679 map, start, end, new_prot); 2680 2681 vm_map_lock(map); 2682 VM_MAP_RANGE_CHECK(map, start, end); 2683 if (uvm_map_lookup_entry(map, start, &entry)) { 2684 UVM_MAP_CLIP_START(map, entry, start, NULL); 2685 } else { 2686 entry = entry->next; 2687 } 2688 2689 /* 2690 * make a first pass to check for protection violations. 2691 */ 2692 2693 current = entry; 2694 while ((current != &map->header) && (current->start < end)) { 2695 if (UVM_ET_ISSUBMAP(current)) { 2696 error = EINVAL; 2697 goto out; 2698 } 2699 if ((new_prot & current->max_protection) != new_prot) { 2700 error = EACCES; 2701 goto out; 2702 } 2703 /* 2704 * Don't allow VM_PROT_EXECUTE to be set on entries that 2705 * point to vnodes that are associated with a NOEXEC file 2706 * system. 2707 */ 2708 if (UVM_ET_ISOBJ(current) && 2709 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) { 2710 struct vnode *vp = 2711 (struct vnode *) current->object.uvm_obj; 2712 2713 if ((new_prot & VM_PROT_EXECUTE) != 0 && 2714 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { 2715 error = EACCES; 2716 goto out; 2717 } 2718 } 2719 current = current->next; 2720 } 2721 2722 /* go back and fix up protections (no need to clip this time). */ 2723 2724 current = entry; 2725 while ((current != &map->header) && (current->start < end)) { 2726 vm_prot_t old_prot; 2727 2728 UVM_MAP_CLIP_END(map, current, end, NULL); 2729 old_prot = current->protection; 2730 if (set_max) 2731 current->protection = 2732 (current->max_protection = new_prot) & old_prot; 2733 else 2734 current->protection = new_prot; 2735 2736 /* 2737 * update physical map if necessary. worry about copy-on-write 2738 * here -- CHECK THIS XXX 2739 */ 2740 2741 if (current->protection != old_prot) { 2742 /* update pmap! */ 2743 pmap_protect(map->pmap, current->start, current->end, 2744 current->protection & MASK(entry)); 2745 2746 /* 2747 * If this entry points at a vnode, and the 2748 * protection includes VM_PROT_EXECUTE, mark 2749 * the vnode as VEXECMAP. 2750 */ 2751 if (UVM_ET_ISOBJ(current)) { 2752 struct uvm_object *uobj = 2753 current->object.uvm_obj; 2754 2755 if (UVM_OBJ_IS_VNODE(uobj) && 2756 (current->protection & VM_PROT_EXECUTE)) 2757 vn_markexec((struct vnode *) uobj); 2758 } 2759 } 2760 2761 /* 2762 * If the map is configured to lock any future mappings, 2763 * wire this entry now if the old protection was VM_PROT_NONE 2764 * and the new protection is not VM_PROT_NONE. 2765 */ 2766 2767 if ((map->flags & VM_MAP_WIREFUTURE) != 0 && 2768 VM_MAPENT_ISWIRED(entry) == 0 && 2769 old_prot == VM_PROT_NONE && 2770 new_prot != VM_PROT_NONE) { 2771 if (uvm_map_pageable(map, entry->start, 2772 entry->end, FALSE, 2773 UVM_LK_ENTER|UVM_LK_EXIT) != 0) { 2774 2775 /* 2776 * If locking the entry fails, remember the 2777 * error if it's the first one. Note we 2778 * still continue setting the protection in 2779 * the map, but will return the error 2780 * condition regardless. 2781 * 2782 * XXX Ignore what the actual error is, 2783 * XXX just call it a resource shortage 2784 * XXX so that it doesn't get confused 2785 * XXX what uvm_map_protect() itself would 2786 * XXX normally return. 2787 */ 2788 2789 error = ENOMEM; 2790 } 2791 } 2792 current = current->next; 2793 } 2794 pmap_update(map->pmap); 2795 2796 out: 2797 vm_map_unlock(map); 2798 2799 UVMHIST_LOG(maphist, "<- done, error=%d",error,0,0,0); 2800 return error; 2801 } 2802 2803 #undef MASK 2804 2805 /* 2806 * uvm_map_inherit: set inheritance code for range of addrs in map. 2807 * 2808 * => map must be unlocked 2809 * => note that the inherit code is used during a "fork". see fork 2810 * code for details. 2811 */ 2812 2813 int 2814 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end, 2815 vm_inherit_t new_inheritance) 2816 { 2817 struct vm_map_entry *entry, *temp_entry; 2818 UVMHIST_FUNC("uvm_map_inherit"); UVMHIST_CALLED(maphist); 2819 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_inh=0x%x)", 2820 map, start, end, new_inheritance); 2821 2822 switch (new_inheritance) { 2823 case MAP_INHERIT_NONE: 2824 case MAP_INHERIT_COPY: 2825 case MAP_INHERIT_SHARE: 2826 break; 2827 default: 2828 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 2829 return EINVAL; 2830 } 2831 2832 vm_map_lock(map); 2833 VM_MAP_RANGE_CHECK(map, start, end); 2834 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 2835 entry = temp_entry; 2836 UVM_MAP_CLIP_START(map, entry, start, NULL); 2837 } else { 2838 entry = temp_entry->next; 2839 } 2840 while ((entry != &map->header) && (entry->start < end)) { 2841 UVM_MAP_CLIP_END(map, entry, end, NULL); 2842 entry->inheritance = new_inheritance; 2843 entry = entry->next; 2844 } 2845 vm_map_unlock(map); 2846 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 2847 return 0; 2848 } 2849 2850 /* 2851 * uvm_map_advice: set advice code for range of addrs in map. 2852 * 2853 * => map must be unlocked 2854 */ 2855 2856 int 2857 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice) 2858 { 2859 struct vm_map_entry *entry, *temp_entry; 2860 UVMHIST_FUNC("uvm_map_advice"); UVMHIST_CALLED(maphist); 2861 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_adv=0x%x)", 2862 map, start, end, new_advice); 2863 2864 vm_map_lock(map); 2865 VM_MAP_RANGE_CHECK(map, start, end); 2866 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 2867 entry = temp_entry; 2868 UVM_MAP_CLIP_START(map, entry, start, NULL); 2869 } else { 2870 entry = temp_entry->next; 2871 } 2872 2873 /* 2874 * XXXJRT: disallow holes? 2875 */ 2876 2877 while ((entry != &map->header) && (entry->start < end)) { 2878 UVM_MAP_CLIP_END(map, entry, end, NULL); 2879 2880 switch (new_advice) { 2881 case MADV_NORMAL: 2882 case MADV_RANDOM: 2883 case MADV_SEQUENTIAL: 2884 /* nothing special here */ 2885 break; 2886 2887 default: 2888 vm_map_unlock(map); 2889 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 2890 return EINVAL; 2891 } 2892 entry->advice = new_advice; 2893 entry = entry->next; 2894 } 2895 2896 vm_map_unlock(map); 2897 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 2898 return 0; 2899 } 2900 2901 /* 2902 * uvm_map_pageable: sets the pageability of a range in a map. 2903 * 2904 * => wires map entries. should not be used for transient page locking. 2905 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). 2906 * => regions sepcified as not pageable require lock-down (wired) memory 2907 * and page tables. 2908 * => map must never be read-locked 2909 * => if islocked is TRUE, map is already write-locked 2910 * => we always unlock the map, since we must downgrade to a read-lock 2911 * to call uvm_fault_wire() 2912 * => XXXCDC: check this and try and clean it up. 2913 */ 2914 2915 int 2916 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end, 2917 boolean_t new_pageable, int lockflags) 2918 { 2919 struct vm_map_entry *entry, *start_entry, *failed_entry; 2920 int rv; 2921 #ifdef DIAGNOSTIC 2922 u_int timestamp_save; 2923 #endif 2924 UVMHIST_FUNC("uvm_map_pageable"); UVMHIST_CALLED(maphist); 2925 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_pageable=0x%x)", 2926 map, start, end, new_pageable); 2927 KASSERT(map->flags & VM_MAP_PAGEABLE); 2928 2929 if ((lockflags & UVM_LK_ENTER) == 0) 2930 vm_map_lock(map); 2931 VM_MAP_RANGE_CHECK(map, start, end); 2932 2933 /* 2934 * only one pageability change may take place at one time, since 2935 * uvm_fault_wire assumes it will be called only once for each 2936 * wiring/unwiring. therefore, we have to make sure we're actually 2937 * changing the pageability for the entire region. we do so before 2938 * making any changes. 2939 */ 2940 2941 if (uvm_map_lookup_entry(map, start, &start_entry) == FALSE) { 2942 if ((lockflags & UVM_LK_EXIT) == 0) 2943 vm_map_unlock(map); 2944 2945 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0); 2946 return EFAULT; 2947 } 2948 entry = start_entry; 2949 2950 /* 2951 * handle wiring and unwiring separately. 2952 */ 2953 2954 if (new_pageable) { /* unwire */ 2955 UVM_MAP_CLIP_START(map, entry, start, NULL); 2956 2957 /* 2958 * unwiring. first ensure that the range to be unwired is 2959 * really wired down and that there are no holes. 2960 */ 2961 2962 while ((entry != &map->header) && (entry->start < end)) { 2963 if (entry->wired_count == 0 || 2964 (entry->end < end && 2965 (entry->next == &map->header || 2966 entry->next->start > entry->end))) { 2967 if ((lockflags & UVM_LK_EXIT) == 0) 2968 vm_map_unlock(map); 2969 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0); 2970 return EINVAL; 2971 } 2972 entry = entry->next; 2973 } 2974 2975 /* 2976 * POSIX 1003.1b - a single munlock call unlocks a region, 2977 * regardless of the number of mlock calls made on that 2978 * region. 2979 */ 2980 2981 entry = start_entry; 2982 while ((entry != &map->header) && (entry->start < end)) { 2983 UVM_MAP_CLIP_END(map, entry, end, NULL); 2984 if (VM_MAPENT_ISWIRED(entry)) 2985 uvm_map_entry_unwire(map, entry); 2986 entry = entry->next; 2987 } 2988 if ((lockflags & UVM_LK_EXIT) == 0) 2989 vm_map_unlock(map); 2990 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 2991 return 0; 2992 } 2993 2994 /* 2995 * wire case: in two passes [XXXCDC: ugly block of code here] 2996 * 2997 * 1: holding the write lock, we create any anonymous maps that need 2998 * to be created. then we clip each map entry to the region to 2999 * be wired and increment its wiring count. 3000 * 3001 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 3002 * in the pages for any newly wired area (wired_count == 1). 3003 * 3004 * downgrading to a read lock for uvm_fault_wire avoids a possible 3005 * deadlock with another thread that may have faulted on one of 3006 * the pages to be wired (it would mark the page busy, blocking 3007 * us, then in turn block on the map lock that we hold). because 3008 * of problems in the recursive lock package, we cannot upgrade 3009 * to a write lock in vm_map_lookup. thus, any actions that 3010 * require the write lock must be done beforehand. because we 3011 * keep the read lock on the map, the copy-on-write status of the 3012 * entries we modify here cannot change. 3013 */ 3014 3015 while ((entry != &map->header) && (entry->start < end)) { 3016 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3017 3018 /* 3019 * perform actions of vm_map_lookup that need the 3020 * write lock on the map: create an anonymous map 3021 * for a copy-on-write region, or an anonymous map 3022 * for a zero-fill region. (XXXCDC: submap case 3023 * ok?) 3024 */ 3025 3026 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3027 if (UVM_ET_ISNEEDSCOPY(entry) && 3028 ((entry->max_protection & VM_PROT_WRITE) || 3029 (entry->object.uvm_obj == NULL))) { 3030 amap_copy(map, entry, M_WAITOK, TRUE, 3031 start, end); 3032 /* XXXCDC: wait OK? */ 3033 } 3034 } 3035 } 3036 UVM_MAP_CLIP_START(map, entry, start, NULL); 3037 UVM_MAP_CLIP_END(map, entry, end, NULL); 3038 entry->wired_count++; 3039 3040 /* 3041 * Check for holes 3042 */ 3043 3044 if (entry->protection == VM_PROT_NONE || 3045 (entry->end < end && 3046 (entry->next == &map->header || 3047 entry->next->start > entry->end))) { 3048 3049 /* 3050 * found one. amap creation actions do not need to 3051 * be undone, but the wired counts need to be restored. 3052 */ 3053 3054 while (entry != &map->header && entry->end > start) { 3055 entry->wired_count--; 3056 entry = entry->prev; 3057 } 3058 if ((lockflags & UVM_LK_EXIT) == 0) 3059 vm_map_unlock(map); 3060 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0); 3061 return EINVAL; 3062 } 3063 entry = entry->next; 3064 } 3065 3066 /* 3067 * Pass 2. 3068 */ 3069 3070 #ifdef DIAGNOSTIC 3071 timestamp_save = map->timestamp; 3072 #endif 3073 vm_map_busy(map); 3074 vm_map_downgrade(map); 3075 3076 rv = 0; 3077 entry = start_entry; 3078 while (entry != &map->header && entry->start < end) { 3079 if (entry->wired_count == 1) { 3080 rv = uvm_fault_wire(map, entry->start, entry->end, 3081 VM_FAULT_WIREMAX, entry->max_protection); 3082 if (rv) { 3083 3084 /* 3085 * wiring failed. break out of the loop. 3086 * we'll clean up the map below, once we 3087 * have a write lock again. 3088 */ 3089 3090 break; 3091 } 3092 } 3093 entry = entry->next; 3094 } 3095 3096 if (rv) { /* failed? */ 3097 3098 /* 3099 * Get back to an exclusive (write) lock. 3100 */ 3101 3102 vm_map_upgrade(map); 3103 vm_map_unbusy(map); 3104 3105 #ifdef DIAGNOSTIC 3106 if (timestamp_save != map->timestamp) 3107 panic("uvm_map_pageable: stale map"); 3108 #endif 3109 3110 /* 3111 * first drop the wiring count on all the entries 3112 * which haven't actually been wired yet. 3113 */ 3114 3115 failed_entry = entry; 3116 while (entry != &map->header && entry->start < end) { 3117 entry->wired_count--; 3118 entry = entry->next; 3119 } 3120 3121 /* 3122 * now, unwire all the entries that were successfully 3123 * wired above. 3124 */ 3125 3126 entry = start_entry; 3127 while (entry != failed_entry) { 3128 entry->wired_count--; 3129 if (VM_MAPENT_ISWIRED(entry) == 0) 3130 uvm_map_entry_unwire(map, entry); 3131 entry = entry->next; 3132 } 3133 if ((lockflags & UVM_LK_EXIT) == 0) 3134 vm_map_unlock(map); 3135 UVMHIST_LOG(maphist, "<- done (RV=%d)", rv,0,0,0); 3136 return (rv); 3137 } 3138 3139 /* We are holding a read lock here. */ 3140 if ((lockflags & UVM_LK_EXIT) == 0) { 3141 vm_map_unbusy(map); 3142 vm_map_unlock_read(map); 3143 } else { 3144 3145 /* 3146 * Get back to an exclusive (write) lock. 3147 */ 3148 3149 vm_map_upgrade(map); 3150 vm_map_unbusy(map); 3151 } 3152 3153 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3154 return 0; 3155 } 3156 3157 /* 3158 * uvm_map_pageable_all: special case of uvm_map_pageable - affects 3159 * all mapped regions. 3160 * 3161 * => map must not be locked. 3162 * => if no flags are specified, all regions are unwired. 3163 * => XXXJRT: has some of the same problems as uvm_map_pageable() above. 3164 */ 3165 3166 int 3167 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit) 3168 { 3169 struct vm_map_entry *entry, *failed_entry; 3170 vsize_t size; 3171 int rv; 3172 #ifdef DIAGNOSTIC 3173 u_int timestamp_save; 3174 #endif 3175 UVMHIST_FUNC("uvm_map_pageable_all"); UVMHIST_CALLED(maphist); 3176 UVMHIST_LOG(maphist,"(map=0x%x,flags=0x%x)", map, flags, 0, 0); 3177 3178 KASSERT(map->flags & VM_MAP_PAGEABLE); 3179 3180 vm_map_lock(map); 3181 3182 /* 3183 * handle wiring and unwiring separately. 3184 */ 3185 3186 if (flags == 0) { /* unwire */ 3187 3188 /* 3189 * POSIX 1003.1b -- munlockall unlocks all regions, 3190 * regardless of how many times mlockall has been called. 3191 */ 3192 3193 for (entry = map->header.next; entry != &map->header; 3194 entry = entry->next) { 3195 if (VM_MAPENT_ISWIRED(entry)) 3196 uvm_map_entry_unwire(map, entry); 3197 } 3198 vm_map_modflags(map, 0, VM_MAP_WIREFUTURE); 3199 vm_map_unlock(map); 3200 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3201 return 0; 3202 } 3203 3204 if (flags & MCL_FUTURE) { 3205 3206 /* 3207 * must wire all future mappings; remember this. 3208 */ 3209 3210 vm_map_modflags(map, VM_MAP_WIREFUTURE, 0); 3211 } 3212 3213 if ((flags & MCL_CURRENT) == 0) { 3214 3215 /* 3216 * no more work to do! 3217 */ 3218 3219 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0); 3220 vm_map_unlock(map); 3221 return 0; 3222 } 3223 3224 /* 3225 * wire case: in three passes [XXXCDC: ugly block of code here] 3226 * 3227 * 1: holding the write lock, count all pages mapped by non-wired 3228 * entries. if this would cause us to go over our limit, we fail. 3229 * 3230 * 2: still holding the write lock, we create any anonymous maps that 3231 * need to be created. then we increment its wiring count. 3232 * 3233 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault 3234 * in the pages for any newly wired area (wired_count == 1). 3235 * 3236 * downgrading to a read lock for uvm_fault_wire avoids a possible 3237 * deadlock with another thread that may have faulted on one of 3238 * the pages to be wired (it would mark the page busy, blocking 3239 * us, then in turn block on the map lock that we hold). because 3240 * of problems in the recursive lock package, we cannot upgrade 3241 * to a write lock in vm_map_lookup. thus, any actions that 3242 * require the write lock must be done beforehand. because we 3243 * keep the read lock on the map, the copy-on-write status of the 3244 * entries we modify here cannot change. 3245 */ 3246 3247 for (size = 0, entry = map->header.next; entry != &map->header; 3248 entry = entry->next) { 3249 if (entry->protection != VM_PROT_NONE && 3250 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3251 size += entry->end - entry->start; 3252 } 3253 } 3254 3255 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) { 3256 vm_map_unlock(map); 3257 return ENOMEM; 3258 } 3259 3260 if (limit != 0 && 3261 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) { 3262 vm_map_unlock(map); 3263 return ENOMEM; 3264 } 3265 3266 /* 3267 * Pass 2. 3268 */ 3269 3270 for (entry = map->header.next; entry != &map->header; 3271 entry = entry->next) { 3272 if (entry->protection == VM_PROT_NONE) 3273 continue; 3274 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3275 3276 /* 3277 * perform actions of vm_map_lookup that need the 3278 * write lock on the map: create an anonymous map 3279 * for a copy-on-write region, or an anonymous map 3280 * for a zero-fill region. (XXXCDC: submap case 3281 * ok?) 3282 */ 3283 3284 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3285 if (UVM_ET_ISNEEDSCOPY(entry) && 3286 ((entry->max_protection & VM_PROT_WRITE) || 3287 (entry->object.uvm_obj == NULL))) { 3288 amap_copy(map, entry, M_WAITOK, TRUE, 3289 entry->start, entry->end); 3290 /* XXXCDC: wait OK? */ 3291 } 3292 } 3293 } 3294 entry->wired_count++; 3295 } 3296 3297 /* 3298 * Pass 3. 3299 */ 3300 3301 #ifdef DIAGNOSTIC 3302 timestamp_save = map->timestamp; 3303 #endif 3304 vm_map_busy(map); 3305 vm_map_downgrade(map); 3306 3307 rv = 0; 3308 for (entry = map->header.next; entry != &map->header; 3309 entry = entry->next) { 3310 if (entry->wired_count == 1) { 3311 rv = uvm_fault_wire(map, entry->start, entry->end, 3312 VM_FAULT_WIREMAX, entry->max_protection); 3313 if (rv) { 3314 3315 /* 3316 * wiring failed. break out of the loop. 3317 * we'll clean up the map below, once we 3318 * have a write lock again. 3319 */ 3320 3321 break; 3322 } 3323 } 3324 } 3325 3326 if (rv) { 3327 3328 /* 3329 * Get back an exclusive (write) lock. 3330 */ 3331 3332 vm_map_upgrade(map); 3333 vm_map_unbusy(map); 3334 3335 #ifdef DIAGNOSTIC 3336 if (timestamp_save != map->timestamp) 3337 panic("uvm_map_pageable_all: stale map"); 3338 #endif 3339 3340 /* 3341 * first drop the wiring count on all the entries 3342 * which haven't actually been wired yet. 3343 * 3344 * Skip VM_PROT_NONE entries like we did above. 3345 */ 3346 3347 failed_entry = entry; 3348 for (/* nothing */; entry != &map->header; 3349 entry = entry->next) { 3350 if (entry->protection == VM_PROT_NONE) 3351 continue; 3352 entry->wired_count--; 3353 } 3354 3355 /* 3356 * now, unwire all the entries that were successfully 3357 * wired above. 3358 * 3359 * Skip VM_PROT_NONE entries like we did above. 3360 */ 3361 3362 for (entry = map->header.next; entry != failed_entry; 3363 entry = entry->next) { 3364 if (entry->protection == VM_PROT_NONE) 3365 continue; 3366 entry->wired_count--; 3367 if (VM_MAPENT_ISWIRED(entry)) 3368 uvm_map_entry_unwire(map, entry); 3369 } 3370 vm_map_unlock(map); 3371 UVMHIST_LOG(maphist,"<- done (RV=%d)", rv,0,0,0); 3372 return (rv); 3373 } 3374 3375 /* We are holding a read lock here. */ 3376 vm_map_unbusy(map); 3377 vm_map_unlock_read(map); 3378 3379 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3380 return 0; 3381 } 3382 3383 /* 3384 * uvm_map_clean: clean out a map range 3385 * 3386 * => valid flags: 3387 * if (flags & PGO_CLEANIT): dirty pages are cleaned first 3388 * if (flags & PGO_SYNCIO): dirty pages are written synchronously 3389 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean 3390 * if (flags & PGO_FREE): any cached pages are freed after clean 3391 * => returns an error if any part of the specified range isn't mapped 3392 * => never a need to flush amap layer since the anonymous memory has 3393 * no permanent home, but may deactivate pages there 3394 * => called from sys_msync() and sys_madvise() 3395 * => caller must not write-lock map (read OK). 3396 * => we may sleep while cleaning if SYNCIO [with map read-locked] 3397 */ 3398 3399 int 3400 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 3401 { 3402 struct vm_map_entry *current, *entry; 3403 struct uvm_object *uobj; 3404 struct vm_amap *amap; 3405 struct vm_anon *anon; 3406 struct vm_page *pg; 3407 vaddr_t offset; 3408 vsize_t size; 3409 voff_t uoff; 3410 int error, refs; 3411 UVMHIST_FUNC("uvm_map_clean"); UVMHIST_CALLED(maphist); 3412 3413 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,flags=0x%x)", 3414 map, start, end, flags); 3415 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) != 3416 (PGO_FREE|PGO_DEACTIVATE)); 3417 3418 vm_map_lock_read(map); 3419 VM_MAP_RANGE_CHECK(map, start, end); 3420 if (uvm_map_lookup_entry(map, start, &entry) == FALSE) { 3421 vm_map_unlock_read(map); 3422 return EFAULT; 3423 } 3424 3425 /* 3426 * Make a first pass to check for holes and wiring problems. 3427 */ 3428 3429 for (current = entry; current->start < end; current = current->next) { 3430 if (UVM_ET_ISSUBMAP(current)) { 3431 vm_map_unlock_read(map); 3432 return EINVAL; 3433 } 3434 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) { 3435 vm_map_unlock_read(map); 3436 return EBUSY; 3437 } 3438 if (end <= current->end) { 3439 break; 3440 } 3441 if (current->end != current->next->start) { 3442 vm_map_unlock_read(map); 3443 return EFAULT; 3444 } 3445 } 3446 3447 error = 0; 3448 for (current = entry; start < end; current = current->next) { 3449 amap = current->aref.ar_amap; /* top layer */ 3450 uobj = current->object.uvm_obj; /* bottom layer */ 3451 KASSERT(start >= current->start); 3452 3453 /* 3454 * No amap cleaning necessary if: 3455 * 3456 * (1) There's no amap. 3457 * 3458 * (2) We're not deactivating or freeing pages. 3459 */ 3460 3461 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) 3462 goto flush_object; 3463 3464 amap_lock(amap); 3465 offset = start - current->start; 3466 size = MIN(end, current->end) - start; 3467 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) { 3468 anon = amap_lookup(¤t->aref, offset); 3469 if (anon == NULL) 3470 continue; 3471 3472 simple_lock(&anon->an_lock); 3473 pg = anon->an_page; 3474 if (pg == NULL) { 3475 simple_unlock(&anon->an_lock); 3476 continue; 3477 } 3478 3479 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) { 3480 3481 /* 3482 * In these first 3 cases, we just deactivate the page. 3483 */ 3484 3485 case PGO_CLEANIT|PGO_FREE: 3486 case PGO_CLEANIT|PGO_DEACTIVATE: 3487 case PGO_DEACTIVATE: 3488 deactivate_it: 3489 /* 3490 * skip the page if it's loaned or wired, 3491 * since it shouldn't be on a paging queue 3492 * at all in these cases. 3493 */ 3494 3495 uvm_lock_pageq(); 3496 if (pg->loan_count != 0 || 3497 pg->wire_count != 0) { 3498 uvm_unlock_pageq(); 3499 simple_unlock(&anon->an_lock); 3500 continue; 3501 } 3502 KASSERT(pg->uanon == anon); 3503 pmap_clear_reference(pg); 3504 uvm_pagedeactivate(pg); 3505 uvm_unlock_pageq(); 3506 simple_unlock(&anon->an_lock); 3507 continue; 3508 3509 case PGO_FREE: 3510 3511 /* 3512 * If there are multiple references to 3513 * the amap, just deactivate the page. 3514 */ 3515 3516 if (amap_refs(amap) > 1) 3517 goto deactivate_it; 3518 3519 /* skip the page if it's wired */ 3520 if (pg->wire_count != 0) { 3521 simple_unlock(&anon->an_lock); 3522 continue; 3523 } 3524 amap_unadd(¤t->aref, offset); 3525 refs = --anon->an_ref; 3526 simple_unlock(&anon->an_lock); 3527 if (refs == 0) 3528 uvm_anfree(anon); 3529 continue; 3530 } 3531 } 3532 amap_unlock(amap); 3533 3534 flush_object: 3535 /* 3536 * flush pages if we've got a valid backing object. 3537 * note that we must always clean object pages before 3538 * freeing them since otherwise we could reveal stale 3539 * data from files. 3540 */ 3541 3542 uoff = current->offset + (start - current->start); 3543 size = MIN(end, current->end) - start; 3544 if (uobj != NULL) { 3545 simple_lock(&uobj->vmobjlock); 3546 if (uobj->pgops->pgo_put != NULL) 3547 error = (uobj->pgops->pgo_put)(uobj, uoff, 3548 uoff + size, flags | PGO_CLEANIT); 3549 else 3550 error = 0; 3551 } 3552 start += size; 3553 } 3554 vm_map_unlock_read(map); 3555 return (error); 3556 } 3557 3558 3559 /* 3560 * uvm_map_checkprot: check protection in map 3561 * 3562 * => must allow specified protection in a fully allocated region. 3563 * => map must be read or write locked by caller. 3564 */ 3565 3566 boolean_t 3567 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end, 3568 vm_prot_t protection) 3569 { 3570 struct vm_map_entry *entry; 3571 struct vm_map_entry *tmp_entry; 3572 3573 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) { 3574 return (FALSE); 3575 } 3576 entry = tmp_entry; 3577 while (start < end) { 3578 if (entry == &map->header) { 3579 return (FALSE); 3580 } 3581 3582 /* 3583 * no holes allowed 3584 */ 3585 3586 if (start < entry->start) { 3587 return (FALSE); 3588 } 3589 3590 /* 3591 * check protection associated with entry 3592 */ 3593 3594 if ((entry->protection & protection) != protection) { 3595 return (FALSE); 3596 } 3597 start = entry->end; 3598 entry = entry->next; 3599 } 3600 return (TRUE); 3601 } 3602 3603 /* 3604 * uvmspace_alloc: allocate a vmspace structure. 3605 * 3606 * - structure includes vm_map and pmap 3607 * - XXX: no locking on this structure 3608 * - refcnt set to 1, rest must be init'd by caller 3609 */ 3610 struct vmspace * 3611 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax) 3612 { 3613 struct vmspace *vm; 3614 UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist); 3615 3616 vm = pool_get(&uvm_vmspace_pool, PR_WAITOK); 3617 uvmspace_init(vm, NULL, vmin, vmax); 3618 UVMHIST_LOG(maphist,"<- done (vm=0x%x)", vm,0,0,0); 3619 return (vm); 3620 } 3621 3622 /* 3623 * uvmspace_init: initialize a vmspace structure. 3624 * 3625 * - XXX: no locking on this structure 3626 * - refcnt set to 1, rest must be init'd by caller 3627 */ 3628 void 3629 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, vaddr_t vmax) 3630 { 3631 UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist); 3632 3633 memset(vm, 0, sizeof(*vm)); 3634 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE 3635 #ifdef __USING_TOPDOWN_VM 3636 | VM_MAP_TOPDOWN 3637 #endif 3638 ); 3639 if (pmap) 3640 pmap_reference(pmap); 3641 else 3642 pmap = pmap_create(); 3643 vm->vm_map.pmap = pmap; 3644 vm->vm_refcnt = 1; 3645 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 3646 } 3647 3648 /* 3649 * uvmspace_share: share a vmspace between two processes 3650 * 3651 * - used for vfork, threads(?) 3652 */ 3653 3654 void 3655 uvmspace_share(struct proc *p1, struct proc *p2) 3656 { 3657 struct simplelock *slock = &p1->p_vmspace->vm_map.ref_lock; 3658 3659 p2->p_vmspace = p1->p_vmspace; 3660 simple_lock(slock); 3661 p1->p_vmspace->vm_refcnt++; 3662 simple_unlock(slock); 3663 } 3664 3665 /* 3666 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace 3667 * 3668 * - XXX: no locking on vmspace 3669 */ 3670 3671 void 3672 uvmspace_unshare(struct lwp *l) 3673 { 3674 struct proc *p = l->l_proc; 3675 struct vmspace *nvm, *ovm = p->p_vmspace; 3676 3677 if (ovm->vm_refcnt == 1) 3678 /* nothing to do: vmspace isn't shared in the first place */ 3679 return; 3680 3681 /* make a new vmspace, still holding old one */ 3682 nvm = uvmspace_fork(ovm); 3683 3684 pmap_deactivate(l); /* unbind old vmspace */ 3685 p->p_vmspace = nvm; 3686 pmap_activate(l); /* switch to new vmspace */ 3687 3688 uvmspace_free(ovm); /* drop reference to old vmspace */ 3689 } 3690 3691 /* 3692 * uvmspace_exec: the process wants to exec a new program 3693 */ 3694 3695 void 3696 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end) 3697 { 3698 struct proc *p = l->l_proc; 3699 struct vmspace *nvm, *ovm = p->p_vmspace; 3700 struct vm_map *map = &ovm->vm_map; 3701 3702 #ifdef __sparc__ 3703 /* XXX cgd 960926: the sparc #ifdef should be a MD hook */ 3704 kill_user_windows(l); /* before stack addresses go away */ 3705 #endif 3706 3707 /* 3708 * see if more than one process is using this vmspace... 3709 */ 3710 3711 if (ovm->vm_refcnt == 1) { 3712 3713 /* 3714 * if p is the only process using its vmspace then we can safely 3715 * recycle that vmspace for the program that is being exec'd. 3716 */ 3717 3718 #ifdef SYSVSHM 3719 /* 3720 * SYSV SHM semantics require us to kill all segments on an exec 3721 */ 3722 3723 if (ovm->vm_shm) 3724 shmexit(ovm); 3725 #endif 3726 3727 /* 3728 * POSIX 1003.1b -- "lock future mappings" is revoked 3729 * when a process execs another program image. 3730 */ 3731 3732 vm_map_modflags(map, 0, VM_MAP_WIREFUTURE); 3733 3734 /* 3735 * now unmap the old program 3736 */ 3737 3738 pmap_remove_all(map->pmap); 3739 uvm_unmap(map, vm_map_min(map), vm_map_max(map)); 3740 KASSERT(map->header.prev == &map->header); 3741 KASSERT(map->nentries == 0); 3742 3743 /* 3744 * resize the map 3745 */ 3746 3747 vm_map_setmin(map, start); 3748 vm_map_setmax(map, end); 3749 } else { 3750 3751 /* 3752 * p's vmspace is being shared, so we can't reuse it for p since 3753 * it is still being used for others. allocate a new vmspace 3754 * for p 3755 */ 3756 3757 nvm = uvmspace_alloc(start, end); 3758 3759 /* 3760 * install new vmspace and drop our ref to the old one. 3761 */ 3762 3763 pmap_deactivate(l); 3764 p->p_vmspace = nvm; 3765 pmap_activate(l); 3766 3767 uvmspace_free(ovm); 3768 } 3769 } 3770 3771 /* 3772 * uvmspace_free: free a vmspace data structure 3773 */ 3774 3775 void 3776 uvmspace_free(struct vmspace *vm) 3777 { 3778 struct vm_map_entry *dead_entries; 3779 struct vm_map *map = &vm->vm_map; 3780 int n; 3781 3782 UVMHIST_FUNC("uvmspace_free"); UVMHIST_CALLED(maphist); 3783 3784 UVMHIST_LOG(maphist,"(vm=0x%x) ref=%d", vm, vm->vm_refcnt,0,0); 3785 simple_lock(&map->ref_lock); 3786 n = --vm->vm_refcnt; 3787 simple_unlock(&map->ref_lock); 3788 if (n > 0) 3789 return; 3790 3791 /* 3792 * at this point, there should be no other references to the map. 3793 * delete all of the mappings, then destroy the pmap. 3794 */ 3795 3796 map->flags |= VM_MAP_DYING; 3797 pmap_remove_all(map->pmap); 3798 #ifdef SYSVSHM 3799 /* Get rid of any SYSV shared memory segments. */ 3800 if (vm->vm_shm != NULL) 3801 shmexit(vm); 3802 #endif 3803 if (map->nentries) { 3804 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map), 3805 &dead_entries, NULL, 0); 3806 if (dead_entries != NULL) 3807 uvm_unmap_detach(dead_entries, 0); 3808 } 3809 KASSERT(map->nentries == 0); 3810 KASSERT(map->size == 0); 3811 pmap_destroy(map->pmap); 3812 pool_put(&uvm_vmspace_pool, vm); 3813 } 3814 3815 /* 3816 * F O R K - m a i n e n t r y p o i n t 3817 */ 3818 /* 3819 * uvmspace_fork: fork a process' main map 3820 * 3821 * => create a new vmspace for child process from parent. 3822 * => parent's map must not be locked. 3823 */ 3824 3825 struct vmspace * 3826 uvmspace_fork(struct vmspace *vm1) 3827 { 3828 struct vmspace *vm2; 3829 struct vm_map *old_map = &vm1->vm_map; 3830 struct vm_map *new_map; 3831 struct vm_map_entry *old_entry; 3832 struct vm_map_entry *new_entry; 3833 UVMHIST_FUNC("uvmspace_fork"); UVMHIST_CALLED(maphist); 3834 3835 vm_map_lock(old_map); 3836 3837 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map)); 3838 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy, 3839 (caddr_t) (vm1 + 1) - (caddr_t) &vm1->vm_startcopy); 3840 new_map = &vm2->vm_map; /* XXX */ 3841 3842 old_entry = old_map->header.next; 3843 new_map->size = old_map->size; 3844 3845 /* 3846 * go entry-by-entry 3847 */ 3848 3849 while (old_entry != &old_map->header) { 3850 3851 /* 3852 * first, some sanity checks on the old entry 3853 */ 3854 3855 KASSERT(!UVM_ET_ISSUBMAP(old_entry)); 3856 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) || 3857 !UVM_ET_ISNEEDSCOPY(old_entry)); 3858 3859 switch (old_entry->inheritance) { 3860 case MAP_INHERIT_NONE: 3861 3862 /* 3863 * drop the mapping, modify size 3864 */ 3865 new_map->size -= old_entry->end - old_entry->start; 3866 break; 3867 3868 case MAP_INHERIT_SHARE: 3869 3870 /* 3871 * share the mapping: this means we want the old and 3872 * new entries to share amaps and backing objects. 3873 */ 3874 /* 3875 * if the old_entry needs a new amap (due to prev fork) 3876 * then we need to allocate it now so that we have 3877 * something we own to share with the new_entry. [in 3878 * other words, we need to clear needs_copy] 3879 */ 3880 3881 if (UVM_ET_ISNEEDSCOPY(old_entry)) { 3882 /* get our own amap, clears needs_copy */ 3883 amap_copy(old_map, old_entry, M_WAITOK, FALSE, 3884 0, 0); 3885 /* XXXCDC: WAITOK??? */ 3886 } 3887 3888 new_entry = uvm_mapent_alloc(new_map, 0); 3889 /* old_entry -> new_entry */ 3890 uvm_mapent_copy(old_entry, new_entry); 3891 3892 /* new pmap has nothing wired in it */ 3893 new_entry->wired_count = 0; 3894 3895 /* 3896 * gain reference to object backing the map (can't 3897 * be a submap, already checked this case). 3898 */ 3899 3900 if (new_entry->aref.ar_amap) 3901 uvm_map_reference_amap(new_entry, AMAP_SHARED); 3902 3903 if (new_entry->object.uvm_obj && 3904 new_entry->object.uvm_obj->pgops->pgo_reference) 3905 new_entry->object.uvm_obj-> 3906 pgops->pgo_reference( 3907 new_entry->object.uvm_obj); 3908 3909 /* insert entry at end of new_map's entry list */ 3910 uvm_map_entry_link(new_map, new_map->header.prev, 3911 new_entry); 3912 3913 break; 3914 3915 case MAP_INHERIT_COPY: 3916 3917 /* 3918 * copy-on-write the mapping (using mmap's 3919 * MAP_PRIVATE semantics) 3920 * 3921 * allocate new_entry, adjust reference counts. 3922 * (note that new references are read-only). 3923 */ 3924 3925 new_entry = uvm_mapent_alloc(new_map, 0); 3926 /* old_entry -> new_entry */ 3927 uvm_mapent_copy(old_entry, new_entry); 3928 3929 if (new_entry->aref.ar_amap) 3930 uvm_map_reference_amap(new_entry, 0); 3931 3932 if (new_entry->object.uvm_obj && 3933 new_entry->object.uvm_obj->pgops->pgo_reference) 3934 new_entry->object.uvm_obj->pgops->pgo_reference 3935 (new_entry->object.uvm_obj); 3936 3937 /* new pmap has nothing wired in it */ 3938 new_entry->wired_count = 0; 3939 3940 new_entry->etype |= 3941 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 3942 uvm_map_entry_link(new_map, new_map->header.prev, 3943 new_entry); 3944 3945 /* 3946 * the new entry will need an amap. it will either 3947 * need to be copied from the old entry or created 3948 * from scratch (if the old entry does not have an 3949 * amap). can we defer this process until later 3950 * (by setting "needs_copy") or do we need to copy 3951 * the amap now? 3952 * 3953 * we must copy the amap now if any of the following 3954 * conditions hold: 3955 * 1. the old entry has an amap and that amap is 3956 * being shared. this means that the old (parent) 3957 * process is sharing the amap with another 3958 * process. if we do not clear needs_copy here 3959 * we will end up in a situation where both the 3960 * parent and child process are refering to the 3961 * same amap with "needs_copy" set. if the 3962 * parent write-faults, the fault routine will 3963 * clear "needs_copy" in the parent by allocating 3964 * a new amap. this is wrong because the 3965 * parent is supposed to be sharing the old amap 3966 * and the new amap will break that. 3967 * 3968 * 2. if the old entry has an amap and a non-zero 3969 * wire count then we are going to have to call 3970 * amap_cow_now to avoid page faults in the 3971 * parent process. since amap_cow_now requires 3972 * "needs_copy" to be clear we might as well 3973 * clear it here as well. 3974 * 3975 */ 3976 3977 if (old_entry->aref.ar_amap != NULL) { 3978 if ((amap_flags(old_entry->aref.ar_amap) & 3979 AMAP_SHARED) != 0 || 3980 VM_MAPENT_ISWIRED(old_entry)) { 3981 3982 amap_copy(new_map, new_entry, M_WAITOK, 3983 FALSE, 0, 0); 3984 /* XXXCDC: M_WAITOK ... ok? */ 3985 } 3986 } 3987 3988 /* 3989 * if the parent's entry is wired down, then the 3990 * parent process does not want page faults on 3991 * access to that memory. this means that we 3992 * cannot do copy-on-write because we can't write 3993 * protect the old entry. in this case we 3994 * resolve all copy-on-write faults now, using 3995 * amap_cow_now. note that we have already 3996 * allocated any needed amap (above). 3997 */ 3998 3999 if (VM_MAPENT_ISWIRED(old_entry)) { 4000 4001 /* 4002 * resolve all copy-on-write faults now 4003 * (note that there is nothing to do if 4004 * the old mapping does not have an amap). 4005 */ 4006 if (old_entry->aref.ar_amap) 4007 amap_cow_now(new_map, new_entry); 4008 4009 } else { 4010 4011 /* 4012 * setup mappings to trigger copy-on-write faults 4013 * we must write-protect the parent if it has 4014 * an amap and it is not already "needs_copy"... 4015 * if it is already "needs_copy" then the parent 4016 * has already been write-protected by a previous 4017 * fork operation. 4018 */ 4019 4020 if (old_entry->aref.ar_amap && 4021 !UVM_ET_ISNEEDSCOPY(old_entry)) { 4022 if (old_entry->max_protection & VM_PROT_WRITE) { 4023 pmap_protect(old_map->pmap, 4024 old_entry->start, 4025 old_entry->end, 4026 old_entry->protection & 4027 ~VM_PROT_WRITE); 4028 pmap_update(old_map->pmap); 4029 } 4030 old_entry->etype |= UVM_ET_NEEDSCOPY; 4031 } 4032 } 4033 break; 4034 } /* end of switch statement */ 4035 old_entry = old_entry->next; 4036 } 4037 4038 vm_map_unlock(old_map); 4039 4040 #ifdef SYSVSHM 4041 if (vm1->vm_shm) 4042 shmfork(vm1, vm2); 4043 #endif 4044 4045 #ifdef PMAP_FORK 4046 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap); 4047 #endif 4048 4049 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4050 return (vm2); 4051 } 4052 4053 4054 /* 4055 * in-kernel map entry allocation. 4056 */ 4057 4058 int ukh_alloc, ukh_free; 4059 int uke_alloc, uke_free; 4060 4061 struct uvm_kmapent_hdr { 4062 LIST_ENTRY(uvm_kmapent_hdr) ukh_listq; 4063 int ukh_nused; 4064 struct vm_map_entry *ukh_freelist; 4065 struct vm_map *ukh_map; 4066 struct vm_map_entry ukh_entries[0]; 4067 }; 4068 4069 #define UVM_KMAPENT_CHUNK \ 4070 ((PAGE_SIZE - sizeof(struct uvm_kmapent_hdr)) \ 4071 / sizeof(struct vm_map_entry)) 4072 4073 #define UVM_KHDR_FIND(entry) \ 4074 ((struct uvm_kmapent_hdr *)(((vaddr_t)entry) & ~PAGE_MASK)) 4075 4076 4077 #ifdef DIAGNOSTIC 4078 static struct vm_map * 4079 uvm_kmapent_map(struct vm_map_entry *entry) 4080 { 4081 const struct uvm_kmapent_hdr *ukh; 4082 4083 ukh = UVM_KHDR_FIND(entry); 4084 return ukh->ukh_map; 4085 } 4086 #endif 4087 4088 static __inline struct vm_map_entry * 4089 uvm_kmapent_get(struct uvm_kmapent_hdr *ukh) 4090 { 4091 struct vm_map_entry *entry; 4092 4093 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4094 KASSERT(ukh->ukh_nused >= 0); 4095 4096 entry = ukh->ukh_freelist; 4097 if (entry) { 4098 KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT)) 4099 == UVM_MAP_KERNEL); 4100 ukh->ukh_freelist = entry->next; 4101 ukh->ukh_nused++; 4102 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4103 } else { 4104 KASSERT(ukh->ukh_nused == UVM_KMAPENT_CHUNK); 4105 } 4106 4107 return entry; 4108 } 4109 4110 static __inline void 4111 uvm_kmapent_put(struct uvm_kmapent_hdr *ukh, struct vm_map_entry *entry) 4112 { 4113 4114 KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT)) 4115 == UVM_MAP_KERNEL); 4116 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4117 KASSERT(ukh->ukh_nused > 0); 4118 KASSERT(ukh->ukh_freelist != NULL || 4119 ukh->ukh_nused == UVM_KMAPENT_CHUNK); 4120 KASSERT(ukh->ukh_freelist == NULL || 4121 ukh->ukh_nused < UVM_KMAPENT_CHUNK); 4122 4123 ukh->ukh_nused--; 4124 entry->next = ukh->ukh_freelist; 4125 ukh->ukh_freelist = entry; 4126 } 4127 4128 /* 4129 * uvm_kmapent_alloc: allocate a map entry for in-kernel map 4130 */ 4131 4132 static struct vm_map_entry * 4133 uvm_kmapent_alloc(struct vm_map *map, int flags) 4134 { 4135 struct vm_page *pg; 4136 struct uvm_map_args args; 4137 struct uvm_kmapent_hdr *ukh; 4138 struct vm_map_entry *entry; 4139 uvm_flag_t mapflags = UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 4140 UVM_INH_NONE, UVM_ADV_RANDOM, flags | UVM_FLAG_NOMERGE); 4141 vaddr_t va; 4142 int error; 4143 int i; 4144 int s; 4145 4146 KDASSERT(UVM_KMAPENT_CHUNK > 2); 4147 KDASSERT(kernel_map != NULL); 4148 KASSERT(vm_map_pmap(map) == pmap_kernel()); 4149 4150 uke_alloc++; 4151 entry = NULL; 4152 again: 4153 /* 4154 * try to grab an entry from freelist. 4155 */ 4156 s = splvm(); 4157 simple_lock(&uvm.kentry_lock); 4158 ukh = LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free); 4159 if (ukh) { 4160 entry = uvm_kmapent_get(ukh); 4161 if (ukh->ukh_nused == UVM_KMAPENT_CHUNK) 4162 LIST_REMOVE(ukh, ukh_listq); 4163 } 4164 simple_unlock(&uvm.kentry_lock); 4165 splx(s); 4166 4167 if (entry) 4168 return entry; 4169 4170 /* 4171 * there's no free entry for this vm_map. 4172 * now we need to allocate some vm_map_entry. 4173 * for simplicity, always allocate one page chunk of them at once. 4174 */ 4175 4176 pg = uvm_pagealloc(NULL, 0, NULL, 0); 4177 if (__predict_false(pg == NULL)) { 4178 if (flags & UVM_FLAG_NOWAIT) 4179 return NULL; 4180 uvm_wait("kme_alloc"); 4181 goto again; 4182 } 4183 4184 error = uvm_map_prepare(map, 0, PAGE_SIZE, NULL, 0, 0, mapflags, &args); 4185 if (error) { 4186 uvm_pagefree(pg); 4187 return NULL; 4188 } 4189 4190 va = args.uma_start; 4191 4192 pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), VM_PROT_READ|VM_PROT_WRITE); 4193 pmap_update(vm_map_pmap(map)); 4194 4195 ukh = (void *)va; 4196 4197 /* 4198 * use the first entry for ukh itsself. 4199 */ 4200 4201 entry = &ukh->ukh_entries[0]; 4202 entry->flags = UVM_MAP_KERNEL | UVM_MAP_KMAPENT; 4203 error = uvm_map_enter(map, &args, entry); 4204 KASSERT(error == 0); 4205 4206 ukh->ukh_nused = UVM_KMAPENT_CHUNK; 4207 ukh->ukh_map = map; 4208 ukh->ukh_freelist = NULL; 4209 for (i = UVM_KMAPENT_CHUNK - 1; i >= 2; i--) { 4210 struct vm_map_entry *xentry = &ukh->ukh_entries[i]; 4211 4212 xentry->flags = UVM_MAP_KERNEL; 4213 uvm_kmapent_put(ukh, xentry); 4214 } 4215 KASSERT(ukh->ukh_nused == 2); 4216 4217 s = splvm(); 4218 simple_lock(&uvm.kentry_lock); 4219 LIST_INSERT_HEAD(&vm_map_to_kernel(map)->vmk_kentry_free, 4220 ukh, ukh_listq); 4221 simple_unlock(&uvm.kentry_lock); 4222 splx(s); 4223 4224 /* 4225 * return second entry. 4226 */ 4227 4228 entry = &ukh->ukh_entries[1]; 4229 entry->flags = UVM_MAP_KERNEL; 4230 ukh_alloc++; 4231 return entry; 4232 } 4233 4234 /* 4235 * uvm_mapent_free: free map entry for in-kernel map 4236 */ 4237 4238 static void 4239 uvm_kmapent_free(struct vm_map_entry *entry) 4240 { 4241 struct uvm_kmapent_hdr *ukh; 4242 struct vm_page *pg; 4243 struct vm_map *map; 4244 struct pmap *pmap; 4245 vaddr_t va; 4246 paddr_t pa; 4247 struct vm_map_entry *deadentry; 4248 int s; 4249 4250 uke_free++; 4251 ukh = UVM_KHDR_FIND(entry); 4252 map = ukh->ukh_map; 4253 4254 s = splvm(); 4255 simple_lock(&uvm.kentry_lock); 4256 uvm_kmapent_put(ukh, entry); 4257 if (ukh->ukh_nused > 1) { 4258 if (ukh->ukh_nused == UVM_KMAPENT_CHUNK - 1) 4259 LIST_INSERT_HEAD( 4260 &vm_map_to_kernel(map)->vmk_kentry_free, 4261 ukh, ukh_listq); 4262 simple_unlock(&uvm.kentry_lock); 4263 splx(s); 4264 return; 4265 } 4266 4267 /* 4268 * now we can free this ukh. 4269 * 4270 * however, keep an empty ukh to avoid ping-pong. 4271 */ 4272 4273 if (LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free) == ukh && 4274 LIST_NEXT(ukh, ukh_listq) == NULL) { 4275 simple_unlock(&uvm.kentry_lock); 4276 splx(s); 4277 return; 4278 } 4279 LIST_REMOVE(ukh, ukh_listq); 4280 simple_unlock(&uvm.kentry_lock); 4281 splx(s); 4282 4283 KASSERT(ukh->ukh_nused == 1); 4284 4285 /* 4286 * remove map entry for ukh itsself. 4287 */ 4288 4289 va = (vaddr_t)ukh; 4290 KASSERT((va & PAGE_MASK) == 0); 4291 vm_map_lock(map); 4292 uvm_unmap_remove(map, va, va + PAGE_SIZE, &deadentry, NULL, 0); 4293 KASSERT(deadentry->flags & UVM_MAP_KERNEL); 4294 KASSERT(deadentry->flags & UVM_MAP_KMAPENT); 4295 KASSERT(deadentry->next == NULL); 4296 KASSERT(deadentry == &ukh->ukh_entries[0]); 4297 4298 /* 4299 * unmap the page from pmap and free it. 4300 */ 4301 4302 pmap = vm_map_pmap(map); 4303 KASSERT(pmap == pmap_kernel()); 4304 if (!pmap_extract(pmap, va, &pa)) 4305 panic("%s: no mapping", __func__); 4306 pmap_kremove(va, PAGE_SIZE); 4307 vm_map_unlock(map); 4308 pg = PHYS_TO_VM_PAGE(pa); 4309 uvm_pagefree(pg); 4310 ukh_free++; 4311 } 4312 4313 /* 4314 * map entry reservation 4315 */ 4316 4317 /* 4318 * uvm_mapent_reserve: reserve map entries for clipping before locking map. 4319 * 4320 * => needed when unmapping entries allocated without UVM_FLAG_QUANTUM. 4321 * => caller shouldn't hold map locked. 4322 */ 4323 int 4324 uvm_mapent_reserve(struct vm_map *map, struct uvm_mapent_reservation *umr, 4325 int nentries, int flags) 4326 { 4327 4328 umr->umr_nentries = 0; 4329 4330 if ((flags & UVM_FLAG_QUANTUM) != 0) 4331 return 0; 4332 4333 if (!VM_MAP_USE_KMAPENT(map)) 4334 return 0; 4335 4336 while (nentries--) { 4337 struct vm_map_entry *ent; 4338 ent = uvm_kmapent_alloc(map, flags); 4339 if (!ent) { 4340 uvm_mapent_unreserve(map, umr); 4341 return ENOMEM; 4342 } 4343 UMR_PUTENTRY(umr, ent); 4344 } 4345 4346 return 0; 4347 } 4348 4349 /* 4350 * uvm_mapent_unreserve: 4351 * 4352 * => caller shouldn't hold map locked. 4353 * => never fail or sleep. 4354 */ 4355 void 4356 uvm_mapent_unreserve(struct vm_map *map, struct uvm_mapent_reservation *umr) 4357 { 4358 4359 while (!UMR_EMPTY(umr)) 4360 uvm_kmapent_free(UMR_GETENTRY(umr)); 4361 } 4362 4363 /* 4364 * uvm_mapent_trymerge: try to merge an entry with its neighbors. 4365 * 4366 * => called with map locked. 4367 * => return non zero if successfully merged. 4368 */ 4369 4370 int 4371 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags) 4372 { 4373 struct uvm_object *uobj; 4374 struct vm_map_entry *next; 4375 struct vm_map_entry *prev; 4376 vsize_t size; 4377 int merged = 0; 4378 boolean_t copying; 4379 int newetype; 4380 4381 if (VM_MAP_USE_KMAPENT(map)) { 4382 return 0; 4383 } 4384 if (entry->aref.ar_amap != NULL) { 4385 return 0; 4386 } 4387 if ((entry->flags & UVM_MAP_NOMERGE) != 0) { 4388 return 0; 4389 } 4390 4391 uobj = entry->object.uvm_obj; 4392 size = entry->end - entry->start; 4393 copying = (flags & UVM_MERGE_COPYING) != 0; 4394 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype; 4395 4396 next = entry->next; 4397 if (next != &map->header && 4398 next->start == entry->end && 4399 ((copying && next->aref.ar_amap != NULL && 4400 amap_refs(next->aref.ar_amap) == 1) || 4401 (!copying && next->aref.ar_amap == NULL)) && 4402 UVM_ET_ISCOMPATIBLE(next, newetype, 4403 uobj, entry->flags, entry->protection, 4404 entry->max_protection, entry->inheritance, entry->advice, 4405 entry->wired_count) && 4406 (uobj == NULL || entry->offset + size == next->offset)) { 4407 int error; 4408 4409 if (copying) { 4410 error = amap_extend(next, size, 4411 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS); 4412 } else { 4413 error = 0; 4414 } 4415 if (error == 0) { 4416 if (uobj) { 4417 if (uobj->pgops->pgo_detach) { 4418 uobj->pgops->pgo_detach(uobj); 4419 } 4420 } 4421 4422 entry->end = next->end; 4423 uvm_map_entry_unlink(map, next); 4424 if (copying) { 4425 entry->aref = next->aref; 4426 entry->etype &= ~UVM_ET_NEEDSCOPY; 4427 } 4428 uvm_tree_sanity(map, "trymerge forwardmerge"); 4429 uvm_mapent_free_merged(map, next); 4430 merged++; 4431 } 4432 } 4433 4434 prev = entry->prev; 4435 if (prev != &map->header && 4436 prev->end == entry->start && 4437 ((copying && !merged && prev->aref.ar_amap != NULL && 4438 amap_refs(prev->aref.ar_amap) == 1) || 4439 (!copying && prev->aref.ar_amap == NULL)) && 4440 UVM_ET_ISCOMPATIBLE(prev, newetype, 4441 uobj, entry->flags, entry->protection, 4442 entry->max_protection, entry->inheritance, entry->advice, 4443 entry->wired_count) && 4444 (uobj == NULL || 4445 prev->offset + prev->end - prev->start == entry->offset)) { 4446 int error; 4447 4448 if (copying) { 4449 error = amap_extend(prev, size, 4450 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS); 4451 } else { 4452 error = 0; 4453 } 4454 if (error == 0) { 4455 if (uobj) { 4456 if (uobj->pgops->pgo_detach) { 4457 uobj->pgops->pgo_detach(uobj); 4458 } 4459 entry->offset = prev->offset; 4460 } 4461 4462 entry->start = prev->start; 4463 uvm_map_entry_unlink(map, prev); 4464 if (copying) { 4465 entry->aref = prev->aref; 4466 entry->etype &= ~UVM_ET_NEEDSCOPY; 4467 } 4468 uvm_tree_sanity(map, "trymerge backmerge"); 4469 uvm_mapent_free_merged(map, prev); 4470 merged++; 4471 } 4472 } 4473 4474 return merged; 4475 } 4476 4477 #if defined(DDB) 4478 4479 /* 4480 * DDB hooks 4481 */ 4482 4483 /* 4484 * uvm_map_printit: actually prints the map 4485 */ 4486 4487 void 4488 uvm_map_printit(struct vm_map *map, boolean_t full, 4489 void (*pr)(const char *, ...)) 4490 { 4491 struct vm_map_entry *entry; 4492 4493 (*pr)("MAP %p: [0x%lx->0x%lx]\n", map, vm_map_min(map), 4494 vm_map_max(map)); 4495 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=0x%x\n", 4496 map->nentries, map->size, map->ref_count, map->timestamp, 4497 map->flags); 4498 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap, 4499 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap)); 4500 if (!full) 4501 return; 4502 for (entry = map->header.next; entry != &map->header; 4503 entry = entry->next) { 4504 (*pr)(" - %p: 0x%lx->0x%lx: obj=%p/0x%llx, amap=%p/%d\n", 4505 entry, entry->start, entry->end, entry->object.uvm_obj, 4506 (long long)entry->offset, entry->aref.ar_amap, 4507 entry->aref.ar_pageoff); 4508 (*pr)( 4509 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, " 4510 "wc=%d, adv=%d\n", 4511 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F', 4512 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F', 4513 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F', 4514 entry->protection, entry->max_protection, 4515 entry->inheritance, entry->wired_count, entry->advice); 4516 } 4517 } 4518 4519 /* 4520 * uvm_object_printit: actually prints the object 4521 */ 4522 4523 void 4524 uvm_object_printit(struct uvm_object *uobj, boolean_t full, 4525 void (*pr)(const char *, ...)) 4526 { 4527 struct vm_page *pg; 4528 int cnt = 0; 4529 4530 (*pr)("OBJECT %p: locked=%d, pgops=%p, npages=%d, ", 4531 uobj, uobj->vmobjlock.lock_data, uobj->pgops, uobj->uo_npages); 4532 if (UVM_OBJ_IS_KERN_OBJECT(uobj)) 4533 (*pr)("refs=<SYSTEM>\n"); 4534 else 4535 (*pr)("refs=%d\n", uobj->uo_refs); 4536 4537 if (!full) { 4538 return; 4539 } 4540 (*pr)(" PAGES <pg,offset>:\n "); 4541 TAILQ_FOREACH(pg, &uobj->memq, listq) { 4542 cnt++; 4543 (*pr)("<%p,0x%llx> ", pg, (long long)pg->offset); 4544 if ((cnt % 3) == 0) { 4545 (*pr)("\n "); 4546 } 4547 } 4548 if ((cnt % 3) != 0) { 4549 (*pr)("\n"); 4550 } 4551 } 4552 4553 /* 4554 * uvm_page_printit: actually print the page 4555 */ 4556 4557 static const char page_flagbits[] = 4558 "\20\1BUSY\2WANTED\3TABLED\4CLEAN\5PAGEOUT\6RELEASED\7FAKE\10RDONLY" 4559 "\11ZERO\15PAGER1"; 4560 static const char page_pqflagbits[] = 4561 "\20\1FREE\2INACTIVE\3ACTIVE\5ANON\6AOBJ"; 4562 4563 void 4564 uvm_page_printit(struct vm_page *pg, boolean_t full, 4565 void (*pr)(const char *, ...)) 4566 { 4567 struct vm_page *tpg; 4568 struct uvm_object *uobj; 4569 struct pglist *pgl; 4570 char pgbuf[128]; 4571 char pqbuf[128]; 4572 4573 (*pr)("PAGE %p:\n", pg); 4574 bitmask_snprintf(pg->flags, page_flagbits, pgbuf, sizeof(pgbuf)); 4575 bitmask_snprintf(pg->pqflags, page_pqflagbits, pqbuf, sizeof(pqbuf)); 4576 (*pr)(" flags=%s, pqflags=%s, wire_count=%d, pa=0x%lx\n", 4577 pgbuf, pqbuf, pg->wire_count, (long)VM_PAGE_TO_PHYS(pg)); 4578 (*pr)(" uobject=%p, uanon=%p, offset=0x%llx loan_count=%d\n", 4579 pg->uobject, pg->uanon, (long long)pg->offset, pg->loan_count); 4580 #if defined(UVM_PAGE_TRKOWN) 4581 if (pg->flags & PG_BUSY) 4582 (*pr)(" owning process = %d, tag=%s\n", 4583 pg->owner, pg->owner_tag); 4584 else 4585 (*pr)(" page not busy, no owner\n"); 4586 #else 4587 (*pr)(" [page ownership tracking disabled]\n"); 4588 #endif 4589 4590 if (!full) 4591 return; 4592 4593 /* cross-verify object/anon */ 4594 if ((pg->pqflags & PQ_FREE) == 0) { 4595 if (pg->pqflags & PQ_ANON) { 4596 if (pg->uanon == NULL || pg->uanon->an_page != pg) 4597 (*pr)(" >>> ANON DOES NOT POINT HERE <<< (%p)\n", 4598 (pg->uanon) ? pg->uanon->an_page : NULL); 4599 else 4600 (*pr)(" anon backpointer is OK\n"); 4601 } else { 4602 uobj = pg->uobject; 4603 if (uobj) { 4604 (*pr)(" checking object list\n"); 4605 TAILQ_FOREACH(tpg, &uobj->memq, listq) { 4606 if (tpg == pg) { 4607 break; 4608 } 4609 } 4610 if (tpg) 4611 (*pr)(" page found on object list\n"); 4612 else 4613 (*pr)(" >>> PAGE NOT FOUND ON OBJECT LIST! <<<\n"); 4614 } 4615 } 4616 } 4617 4618 /* cross-verify page queue */ 4619 if (pg->pqflags & PQ_FREE) { 4620 int fl = uvm_page_lookup_freelist(pg); 4621 int color = VM_PGCOLOR_BUCKET(pg); 4622 pgl = &uvm.page_free[fl].pgfl_buckets[color].pgfl_queues[ 4623 ((pg)->flags & PG_ZERO) ? PGFL_ZEROS : PGFL_UNKNOWN]; 4624 } else if (pg->pqflags & PQ_INACTIVE) { 4625 pgl = &uvm.page_inactive; 4626 } else if (pg->pqflags & PQ_ACTIVE) { 4627 pgl = &uvm.page_active; 4628 } else { 4629 pgl = NULL; 4630 } 4631 4632 if (pgl) { 4633 (*pr)(" checking pageq list\n"); 4634 TAILQ_FOREACH(tpg, pgl, pageq) { 4635 if (tpg == pg) { 4636 break; 4637 } 4638 } 4639 if (tpg) 4640 (*pr)(" page found on pageq list\n"); 4641 else 4642 (*pr)(" >>> PAGE NOT FOUND ON PAGEQ LIST! <<<\n"); 4643 } 4644 } 4645 #endif 4646