1 /* $NetBSD: uvm_map.c,v 1.388 2021/04/17 21:37:21 mrg 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. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vm_map.c 8.3 (Berkeley) 1/12/94 37 * from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 chs Exp 38 * 39 * 40 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 41 * All rights reserved. 42 * 43 * Permission to use, copy, modify and distribute this software and 44 * its documentation is hereby granted, provided that both the copyright 45 * notice and this permission notice appear in all copies of the 46 * software, derivative works or modified versions, and any portions 47 * thereof, and that both notices appear in supporting documentation. 48 * 49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 51 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 52 * 53 * Carnegie Mellon requests users of this software to return to 54 * 55 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 56 * School of Computer Science 57 * Carnegie Mellon University 58 * Pittsburgh PA 15213-3890 59 * 60 * any improvements or extensions that they make and grant Carnegie the 61 * rights to redistribute these changes. 62 */ 63 64 /* 65 * uvm_map.c: uvm map operations 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.388 2021/04/17 21:37:21 mrg Exp $"); 70 71 #include "opt_ddb.h" 72 #include "opt_pax.h" 73 #include "opt_uvmhist.h" 74 #include "opt_uvm.h" 75 #include "opt_sysv.h" 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/mman.h> 80 #include <sys/proc.h> 81 #include <sys/pool.h> 82 #include <sys/kernel.h> 83 #include <sys/mount.h> 84 #include <sys/pax.h> 85 #include <sys/vnode.h> 86 #include <sys/filedesc.h> 87 #include <sys/lockdebug.h> 88 #include <sys/atomic.h> 89 #include <sys/sysctl.h> 90 #ifndef __USER_VA0_IS_SAFE 91 #include <sys/kauth.h> 92 #include "opt_user_va0_disable_default.h" 93 #endif 94 95 #include <sys/shm.h> 96 97 #include <uvm/uvm.h> 98 #include <uvm/uvm_readahead.h> 99 100 #if defined(DDB) || defined(DEBUGPRINT) 101 #include <uvm/uvm_ddb.h> 102 #endif 103 104 #ifdef UVMHIST 105 #ifndef UVMHIST_MAPHIST_SIZE 106 #define UVMHIST_MAPHIST_SIZE 100 107 #endif 108 static struct kern_history_ent maphistbuf[UVMHIST_MAPHIST_SIZE]; 109 UVMHIST_DEFINE(maphist) = UVMHIST_INITIALIZER(maphist, maphistbuf); 110 #endif 111 112 #if !defined(UVMMAP_COUNTERS) 113 114 #define UVMMAP_EVCNT_DEFINE(name) /* nothing */ 115 #define UVMMAP_EVCNT_INCR(ev) /* nothing */ 116 #define UVMMAP_EVCNT_DECR(ev) /* nothing */ 117 118 #else /* defined(UVMMAP_NOCOUNTERS) */ 119 120 #include <sys/evcnt.h> 121 #define UVMMAP_EVCNT_DEFINE(name) \ 122 struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \ 123 "uvmmap", #name); \ 124 EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name); 125 #define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++ 126 #define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count-- 127 128 #endif /* defined(UVMMAP_NOCOUNTERS) */ 129 130 UVMMAP_EVCNT_DEFINE(ubackmerge) 131 UVMMAP_EVCNT_DEFINE(uforwmerge) 132 UVMMAP_EVCNT_DEFINE(ubimerge) 133 UVMMAP_EVCNT_DEFINE(unomerge) 134 UVMMAP_EVCNT_DEFINE(kbackmerge) 135 UVMMAP_EVCNT_DEFINE(kforwmerge) 136 UVMMAP_EVCNT_DEFINE(kbimerge) 137 UVMMAP_EVCNT_DEFINE(knomerge) 138 UVMMAP_EVCNT_DEFINE(map_call) 139 UVMMAP_EVCNT_DEFINE(mlk_call) 140 UVMMAP_EVCNT_DEFINE(mlk_hint) 141 UVMMAP_EVCNT_DEFINE(mlk_tree) 142 UVMMAP_EVCNT_DEFINE(mlk_treeloop) 143 144 const char vmmapbsy[] = "vmmapbsy"; 145 146 /* 147 * cache for vmspace structures. 148 */ 149 150 static struct pool_cache uvm_vmspace_cache; 151 152 /* 153 * cache for dynamically-allocated map entries. 154 */ 155 156 static struct pool_cache uvm_map_entry_cache; 157 158 #ifdef PMAP_GROWKERNEL 159 /* 160 * This global represents the end of the kernel virtual address 161 * space. If we want to exceed this, we must grow the kernel 162 * virtual address space dynamically. 163 * 164 * Note, this variable is locked by kernel_map's lock. 165 */ 166 vaddr_t uvm_maxkaddr; 167 #endif 168 169 #ifndef __USER_VA0_IS_SAFE 170 #ifndef __USER_VA0_DISABLE_DEFAULT 171 #define __USER_VA0_DISABLE_DEFAULT 1 172 #endif 173 #ifdef USER_VA0_DISABLE_DEFAULT /* kernel config option overrides */ 174 #undef __USER_VA0_DISABLE_DEFAULT 175 #define __USER_VA0_DISABLE_DEFAULT USER_VA0_DISABLE_DEFAULT 176 #endif 177 int user_va0_disable = __USER_VA0_DISABLE_DEFAULT; 178 #endif 179 180 /* 181 * macros 182 */ 183 184 /* 185 * uvm_map_align_va: round down or up virtual address 186 */ 187 static __inline void 188 uvm_map_align_va(vaddr_t *vap, vsize_t align, int topdown) 189 { 190 191 KASSERT(powerof2(align)); 192 193 if (align != 0 && (*vap & (align - 1)) != 0) { 194 if (topdown) 195 *vap = rounddown2(*vap, align); 196 else 197 *vap = roundup2(*vap, align); 198 } 199 } 200 201 /* 202 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging 203 */ 204 extern struct vm_map *pager_map; 205 206 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \ 207 prot, maxprot, inh, adv, wire) \ 208 ((ent)->etype == (type) && \ 209 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE)) == 0 && \ 210 (ent)->object.uvm_obj == (uobj) && \ 211 (ent)->protection == (prot) && \ 212 (ent)->max_protection == (maxprot) && \ 213 (ent)->inheritance == (inh) && \ 214 (ent)->advice == (adv) && \ 215 (ent)->wired_count == (wire)) 216 217 /* 218 * uvm_map_entry_link: insert entry into a map 219 * 220 * => map must be locked 221 */ 222 #define uvm_map_entry_link(map, after_where, entry) do { \ 223 uvm_mapent_check(entry); \ 224 (map)->nentries++; \ 225 (entry)->prev = (after_where); \ 226 (entry)->next = (after_where)->next; \ 227 (entry)->prev->next = (entry); \ 228 (entry)->next->prev = (entry); \ 229 uvm_rb_insert((map), (entry)); \ 230 } while (/*CONSTCOND*/ 0) 231 232 /* 233 * uvm_map_entry_unlink: remove entry from a map 234 * 235 * => map must be locked 236 */ 237 #define uvm_map_entry_unlink(map, entry) do { \ 238 KASSERT((entry) != (map)->first_free); \ 239 KASSERT((entry) != (map)->hint); \ 240 uvm_mapent_check(entry); \ 241 (map)->nentries--; \ 242 (entry)->next->prev = (entry)->prev; \ 243 (entry)->prev->next = (entry)->next; \ 244 uvm_rb_remove((map), (entry)); \ 245 } while (/*CONSTCOND*/ 0) 246 247 /* 248 * SAVE_HINT: saves the specified entry as the hint for future lookups. 249 * 250 * => map need not be locked. 251 */ 252 #define SAVE_HINT(map, check, value) do { \ 253 if ((map)->hint == (check)) \ 254 (map)->hint = (value); \ 255 } while (/*CONSTCOND*/ 0) 256 257 /* 258 * clear_hints: ensure that hints don't point to the entry. 259 * 260 * => map must be write-locked. 261 */ 262 static void 263 clear_hints(struct vm_map *map, struct vm_map_entry *ent) 264 { 265 266 SAVE_HINT(map, ent, ent->prev); 267 if (map->first_free == ent) { 268 map->first_free = ent->prev; 269 } 270 } 271 272 /* 273 * VM_MAP_RANGE_CHECK: check and correct range 274 * 275 * => map must at least be read locked 276 */ 277 278 #define VM_MAP_RANGE_CHECK(map, start, end) do { \ 279 if (start < vm_map_min(map)) \ 280 start = vm_map_min(map); \ 281 if (end > vm_map_max(map)) \ 282 end = vm_map_max(map); \ 283 if (start > end) \ 284 start = end; \ 285 } while (/*CONSTCOND*/ 0) 286 287 /* 288 * local prototypes 289 */ 290 291 static struct vm_map_entry * 292 uvm_mapent_alloc(struct vm_map *, int); 293 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *); 294 static void uvm_mapent_free(struct vm_map_entry *); 295 #if defined(DEBUG) 296 static void _uvm_mapent_check(const struct vm_map_entry *, int); 297 #define uvm_mapent_check(map) _uvm_mapent_check(map, __LINE__) 298 #else /* defined(DEBUG) */ 299 #define uvm_mapent_check(e) /* nothing */ 300 #endif /* defined(DEBUG) */ 301 302 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *); 303 static void uvm_map_reference_amap(struct vm_map_entry *, int); 304 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int, 305 int, struct vm_map_entry *); 306 static void uvm_map_unreference_amap(struct vm_map_entry *, int); 307 308 int _uvm_map_sanity(struct vm_map *); 309 int _uvm_tree_sanity(struct vm_map *); 310 static vsize_t uvm_rb_maxgap(const struct vm_map_entry *); 311 312 #define ROOT_ENTRY(map) ((struct vm_map_entry *)(map)->rb_tree.rbt_root) 313 #define LEFT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_left) 314 #define RIGHT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_right) 315 #define PARENT_ENTRY(map, entry) \ 316 (ROOT_ENTRY(map) == (entry) \ 317 ? NULL : (struct vm_map_entry *)RB_FATHER(&(entry)->rb_node)) 318 319 /* 320 * These get filled in if/when SYSVSHM shared memory code is loaded 321 * 322 * We do this with function pointers rather the #ifdef SYSVSHM so the 323 * SYSVSHM code can be loaded and unloaded 324 */ 325 void (*uvm_shmexit)(struct vmspace *) = NULL; 326 void (*uvm_shmfork)(struct vmspace *, struct vmspace *) = NULL; 327 328 static int 329 uvm_map_compare_nodes(void *ctx, const void *nparent, const void *nkey) 330 { 331 const struct vm_map_entry *eparent = nparent; 332 const struct vm_map_entry *ekey = nkey; 333 334 KASSERT(eparent->start < ekey->start || eparent->start >= ekey->end); 335 KASSERT(ekey->start < eparent->start || ekey->start >= eparent->end); 336 337 if (eparent->start < ekey->start) 338 return -1; 339 if (eparent->end >= ekey->start) 340 return 1; 341 return 0; 342 } 343 344 static int 345 uvm_map_compare_key(void *ctx, const void *nparent, const void *vkey) 346 { 347 const struct vm_map_entry *eparent = nparent; 348 const vaddr_t va = *(const vaddr_t *) vkey; 349 350 if (eparent->start < va) 351 return -1; 352 if (eparent->end >= va) 353 return 1; 354 return 0; 355 } 356 357 static const rb_tree_ops_t uvm_map_tree_ops = { 358 .rbto_compare_nodes = uvm_map_compare_nodes, 359 .rbto_compare_key = uvm_map_compare_key, 360 .rbto_node_offset = offsetof(struct vm_map_entry, rb_node), 361 .rbto_context = NULL 362 }; 363 364 /* 365 * uvm_rb_gap: return the gap size between our entry and next entry. 366 */ 367 static inline vsize_t 368 uvm_rb_gap(const struct vm_map_entry *entry) 369 { 370 371 KASSERT(entry->next != NULL); 372 return entry->next->start - entry->end; 373 } 374 375 static vsize_t 376 uvm_rb_maxgap(const struct vm_map_entry *entry) 377 { 378 struct vm_map_entry *child; 379 vsize_t maxgap = entry->gap; 380 381 /* 382 * We need maxgap to be the largest gap of us or any of our 383 * descendents. Since each of our children's maxgap is the 384 * cached value of their largest gap of themselves or their 385 * descendents, we can just use that value and avoid recursing 386 * down the tree to calculate it. 387 */ 388 if ((child = LEFT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 389 maxgap = child->maxgap; 390 391 if ((child = RIGHT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 392 maxgap = child->maxgap; 393 394 return maxgap; 395 } 396 397 static void 398 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry) 399 { 400 struct vm_map_entry *parent; 401 402 KASSERT(entry->gap == uvm_rb_gap(entry)); 403 entry->maxgap = uvm_rb_maxgap(entry); 404 405 while ((parent = PARENT_ENTRY(map, entry)) != NULL) { 406 struct vm_map_entry *brother; 407 vsize_t maxgap = parent->gap; 408 unsigned int which; 409 410 KDASSERT(parent->gap == uvm_rb_gap(parent)); 411 if (maxgap < entry->maxgap) 412 maxgap = entry->maxgap; 413 /* 414 * Since we work towards the root, we know entry's maxgap 415 * value is OK, but its brothers may now be out-of-date due 416 * to rebalancing. So refresh it. 417 */ 418 which = RB_POSITION(&entry->rb_node) ^ RB_DIR_OTHER; 419 brother = (struct vm_map_entry *)parent->rb_node.rb_nodes[which]; 420 if (brother != NULL) { 421 KDASSERT(brother->gap == uvm_rb_gap(brother)); 422 brother->maxgap = uvm_rb_maxgap(brother); 423 if (maxgap < brother->maxgap) 424 maxgap = brother->maxgap; 425 } 426 427 parent->maxgap = maxgap; 428 entry = parent; 429 } 430 } 431 432 static void 433 uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry) 434 { 435 struct vm_map_entry *ret __diagused; 436 437 entry->gap = entry->maxgap = uvm_rb_gap(entry); 438 if (entry->prev != &map->header) 439 entry->prev->gap = uvm_rb_gap(entry->prev); 440 441 ret = rb_tree_insert_node(&map->rb_tree, entry); 442 KASSERTMSG(ret == entry, 443 "uvm_rb_insert: map %p: duplicate entry %p", map, ret); 444 445 /* 446 * If the previous entry is not our immediate left child, then it's an 447 * ancestor and will be fixed up on the way to the root. We don't 448 * have to check entry->prev against &map->header since &map->header 449 * will never be in the tree. 450 */ 451 uvm_rb_fixup(map, 452 LEFT_ENTRY(entry) == entry->prev ? entry->prev : entry); 453 } 454 455 static void 456 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry) 457 { 458 struct vm_map_entry *prev_parent = NULL, *next_parent = NULL; 459 460 /* 461 * If we are removing an interior node, then an adjacent node will 462 * be used to replace its position in the tree. Therefore we will 463 * need to fixup the tree starting at the parent of the replacement 464 * node. So record their parents for later use. 465 */ 466 if (entry->prev != &map->header) 467 prev_parent = PARENT_ENTRY(map, entry->prev); 468 if (entry->next != &map->header) 469 next_parent = PARENT_ENTRY(map, entry->next); 470 471 rb_tree_remove_node(&map->rb_tree, entry); 472 473 /* 474 * If the previous node has a new parent, fixup the tree starting 475 * at the previous node's old parent. 476 */ 477 if (entry->prev != &map->header) { 478 /* 479 * Update the previous entry's gap due to our absence. 480 */ 481 entry->prev->gap = uvm_rb_gap(entry->prev); 482 uvm_rb_fixup(map, entry->prev); 483 if (prev_parent != NULL 484 && prev_parent != entry 485 && prev_parent != PARENT_ENTRY(map, entry->prev)) 486 uvm_rb_fixup(map, prev_parent); 487 } 488 489 /* 490 * If the next node has a new parent, fixup the tree starting 491 * at the next node's old parent. 492 */ 493 if (entry->next != &map->header) { 494 uvm_rb_fixup(map, entry->next); 495 if (next_parent != NULL 496 && next_parent != entry 497 && next_parent != PARENT_ENTRY(map, entry->next)) 498 uvm_rb_fixup(map, next_parent); 499 } 500 } 501 502 #if defined(DEBUG) 503 int uvm_debug_check_map = 0; 504 int uvm_debug_check_rbtree = 0; 505 #define uvm_map_check(map, name) \ 506 _uvm_map_check((map), (name), __FILE__, __LINE__) 507 static void 508 _uvm_map_check(struct vm_map *map, const char *name, 509 const char *file, int line) 510 { 511 512 if ((uvm_debug_check_map && _uvm_map_sanity(map)) || 513 (uvm_debug_check_rbtree && _uvm_tree_sanity(map))) { 514 panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)", 515 name, map, file, line); 516 } 517 } 518 #else /* defined(DEBUG) */ 519 #define uvm_map_check(map, name) /* nothing */ 520 #endif /* defined(DEBUG) */ 521 522 #if defined(DEBUG) || defined(DDB) 523 int 524 _uvm_map_sanity(struct vm_map *map) 525 { 526 bool first_free_found = false; 527 bool hint_found = false; 528 const struct vm_map_entry *e; 529 struct vm_map_entry *hint = map->hint; 530 531 e = &map->header; 532 for (;;) { 533 if (map->first_free == e) { 534 first_free_found = true; 535 } else if (!first_free_found && e->next->start > e->end) { 536 printf("first_free %p should be %p\n", 537 map->first_free, e); 538 return -1; 539 } 540 if (hint == e) { 541 hint_found = true; 542 } 543 544 e = e->next; 545 if (e == &map->header) { 546 break; 547 } 548 } 549 if (!first_free_found) { 550 printf("stale first_free\n"); 551 return -1; 552 } 553 if (!hint_found) { 554 printf("stale hint\n"); 555 return -1; 556 } 557 return 0; 558 } 559 560 int 561 _uvm_tree_sanity(struct vm_map *map) 562 { 563 struct vm_map_entry *tmp, *trtmp; 564 int n = 0, i = 1; 565 566 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 567 if (tmp->gap != uvm_rb_gap(tmp)) { 568 printf("%d/%d gap %#lx != %#lx %s\n", 569 n + 1, map->nentries, 570 (ulong)tmp->gap, (ulong)uvm_rb_gap(tmp), 571 tmp->next == &map->header ? "(last)" : ""); 572 goto error; 573 } 574 /* 575 * If any entries are out of order, tmp->gap will be unsigned 576 * and will likely exceed the size of the map. 577 */ 578 if (tmp->gap >= vm_map_max(map) - vm_map_min(map)) { 579 printf("too large gap %zu\n", (size_t)tmp->gap); 580 goto error; 581 } 582 n++; 583 } 584 585 if (n != map->nentries) { 586 printf("nentries: %d vs %d\n", n, map->nentries); 587 goto error; 588 } 589 590 trtmp = NULL; 591 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 592 if (tmp->maxgap != uvm_rb_maxgap(tmp)) { 593 printf("maxgap %#lx != %#lx\n", 594 (ulong)tmp->maxgap, 595 (ulong)uvm_rb_maxgap(tmp)); 596 goto error; 597 } 598 if (trtmp != NULL && trtmp->start >= tmp->start) { 599 printf("corrupt: 0x%"PRIxVADDR"x >= 0x%"PRIxVADDR"x\n", 600 trtmp->start, tmp->start); 601 goto error; 602 } 603 604 trtmp = tmp; 605 } 606 607 for (tmp = map->header.next; tmp != &map->header; 608 tmp = tmp->next, i++) { 609 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_LEFT); 610 if (trtmp == NULL) 611 trtmp = &map->header; 612 if (tmp->prev != trtmp) { 613 printf("lookup: %d: %p->prev=%p: %p\n", 614 i, tmp, tmp->prev, trtmp); 615 goto error; 616 } 617 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_RIGHT); 618 if (trtmp == NULL) 619 trtmp = &map->header; 620 if (tmp->next != trtmp) { 621 printf("lookup: %d: %p->next=%p: %p\n", 622 i, tmp, tmp->next, trtmp); 623 goto error; 624 } 625 trtmp = rb_tree_find_node(&map->rb_tree, &tmp->start); 626 if (trtmp != tmp) { 627 printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp, 628 PARENT_ENTRY(map, tmp)); 629 goto error; 630 } 631 } 632 633 return (0); 634 error: 635 return (-1); 636 } 637 #endif /* defined(DEBUG) || defined(DDB) */ 638 639 /* 640 * vm_map_lock: acquire an exclusive (write) lock on a map. 641 * 642 * => The locking protocol provides for guaranteed upgrade from shared -> 643 * exclusive by whichever thread currently has the map marked busy. 644 * See "LOCKING PROTOCOL NOTES" in uvm_map.h. This is horrible; among 645 * other problems, it defeats any fairness guarantees provided by RW 646 * locks. 647 */ 648 649 void 650 vm_map_lock(struct vm_map *map) 651 { 652 653 for (;;) { 654 rw_enter(&map->lock, RW_WRITER); 655 if (map->busy == NULL || map->busy == curlwp) { 656 break; 657 } 658 mutex_enter(&map->misc_lock); 659 rw_exit(&map->lock); 660 if (map->busy != NULL) { 661 cv_wait(&map->cv, &map->misc_lock); 662 } 663 mutex_exit(&map->misc_lock); 664 } 665 map->timestamp++; 666 } 667 668 /* 669 * vm_map_lock_try: try to lock a map, failing if it is already locked. 670 */ 671 672 bool 673 vm_map_lock_try(struct vm_map *map) 674 { 675 676 if (!rw_tryenter(&map->lock, RW_WRITER)) { 677 return false; 678 } 679 if (map->busy != NULL) { 680 rw_exit(&map->lock); 681 return false; 682 } 683 map->timestamp++; 684 return true; 685 } 686 687 /* 688 * vm_map_unlock: release an exclusive lock on a map. 689 */ 690 691 void 692 vm_map_unlock(struct vm_map *map) 693 { 694 695 KASSERT(rw_write_held(&map->lock)); 696 KASSERT(map->busy == NULL || map->busy == curlwp); 697 rw_exit(&map->lock); 698 } 699 700 /* 701 * vm_map_unbusy: mark the map as unbusy, and wake any waiters that 702 * want an exclusive lock. 703 */ 704 705 void 706 vm_map_unbusy(struct vm_map *map) 707 { 708 709 KASSERT(map->busy == curlwp); 710 711 /* 712 * Safe to clear 'busy' and 'waiters' with only a read lock held: 713 * 714 * o they can only be set with a write lock held 715 * o writers are blocked out with a read or write hold 716 * o at any time, only one thread owns the set of values 717 */ 718 mutex_enter(&map->misc_lock); 719 map->busy = NULL; 720 cv_broadcast(&map->cv); 721 mutex_exit(&map->misc_lock); 722 } 723 724 /* 725 * vm_map_lock_read: acquire a shared (read) lock on a map. 726 */ 727 728 void 729 vm_map_lock_read(struct vm_map *map) 730 { 731 732 rw_enter(&map->lock, RW_READER); 733 } 734 735 /* 736 * vm_map_unlock_read: release a shared lock on a map. 737 */ 738 739 void 740 vm_map_unlock_read(struct vm_map *map) 741 { 742 743 rw_exit(&map->lock); 744 } 745 746 /* 747 * vm_map_busy: mark a map as busy. 748 * 749 * => the caller must hold the map write locked 750 */ 751 752 void 753 vm_map_busy(struct vm_map *map) 754 { 755 756 KASSERT(rw_write_held(&map->lock)); 757 KASSERT(map->busy == NULL); 758 759 map->busy = curlwp; 760 } 761 762 /* 763 * vm_map_locked_p: return true if the map is write locked. 764 * 765 * => only for debug purposes like KASSERTs. 766 * => should not be used to verify that a map is not locked. 767 */ 768 769 bool 770 vm_map_locked_p(struct vm_map *map) 771 { 772 773 return rw_write_held(&map->lock); 774 } 775 776 /* 777 * uvm_mapent_alloc: allocate a map entry 778 */ 779 780 static struct vm_map_entry * 781 uvm_mapent_alloc(struct vm_map *map, int flags) 782 { 783 struct vm_map_entry *me; 784 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK; 785 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 786 787 me = pool_cache_get(&uvm_map_entry_cache, pflags); 788 if (__predict_false(me == NULL)) { 789 return NULL; 790 } 791 me->flags = 0; 792 793 UVMHIST_LOG(maphist, "<- new entry=%#jx [kentry=%jd]", (uintptr_t)me, 794 (map == kernel_map), 0, 0); 795 return me; 796 } 797 798 /* 799 * uvm_mapent_free: free map entry 800 */ 801 802 static void 803 uvm_mapent_free(struct vm_map_entry *me) 804 { 805 UVMHIST_FUNC(__func__); 806 UVMHIST_CALLARGS(maphist,"<- freeing map entry=%#jx [flags=%#jx]", 807 (uintptr_t)me, me->flags, 0, 0); 808 pool_cache_put(&uvm_map_entry_cache, me); 809 } 810 811 /* 812 * uvm_mapent_copy: copy a map entry, preserving flags 813 */ 814 815 static inline void 816 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst) 817 { 818 819 memcpy(dst, src, sizeof(*dst)); 820 dst->flags = 0; 821 } 822 823 #if defined(DEBUG) 824 static void 825 _uvm_mapent_check(const struct vm_map_entry *entry, int line) 826 { 827 828 if (entry->start >= entry->end) { 829 goto bad; 830 } 831 if (UVM_ET_ISOBJ(entry)) { 832 if (entry->object.uvm_obj == NULL) { 833 goto bad; 834 } 835 } else if (UVM_ET_ISSUBMAP(entry)) { 836 if (entry->object.sub_map == NULL) { 837 goto bad; 838 } 839 } else { 840 if (entry->object.uvm_obj != NULL || 841 entry->object.sub_map != NULL) { 842 goto bad; 843 } 844 } 845 if (!UVM_ET_ISOBJ(entry)) { 846 if (entry->offset != 0) { 847 goto bad; 848 } 849 } 850 851 return; 852 853 bad: 854 panic("%s: bad entry %p, line %d", __func__, entry, line); 855 } 856 #endif /* defined(DEBUG) */ 857 858 /* 859 * uvm_map_entry_unwire: unwire a map entry 860 * 861 * => map should be locked by caller 862 */ 863 864 static inline void 865 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry) 866 { 867 868 entry->wired_count = 0; 869 uvm_fault_unwire_locked(map, entry->start, entry->end); 870 } 871 872 873 /* 874 * wrapper for calling amap_ref() 875 */ 876 static inline void 877 uvm_map_reference_amap(struct vm_map_entry *entry, int flags) 878 { 879 880 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff, 881 (entry->end - entry->start) >> PAGE_SHIFT, flags); 882 } 883 884 885 /* 886 * wrapper for calling amap_unref() 887 */ 888 static inline void 889 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags) 890 { 891 892 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff, 893 (entry->end - entry->start) >> PAGE_SHIFT, flags); 894 } 895 896 897 /* 898 * uvm_map_init: init mapping system at boot time. 899 */ 900 901 void 902 uvm_map_init(void) 903 { 904 /* 905 * first, init logging system. 906 */ 907 908 UVMHIST_FUNC(__func__); 909 UVMHIST_LINK_STATIC(maphist); 910 UVMHIST_LINK_STATIC(pdhist); 911 UVMHIST_CALLED(maphist); 912 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0); 913 914 /* 915 * initialize the global lock for kernel map entry. 916 */ 917 918 mutex_init(&uvm_kentry_lock, MUTEX_DRIVER, IPL_VM); 919 } 920 921 /* 922 * uvm_map_init_caches: init mapping system caches. 923 */ 924 void 925 uvm_map_init_caches(void) 926 { 927 /* 928 * initialize caches. 929 */ 930 931 pool_cache_bootstrap(&uvm_map_entry_cache, sizeof(struct vm_map_entry), 932 coherency_unit, 0, PR_LARGECACHE, "vmmpepl", NULL, IPL_NONE, NULL, 933 NULL, NULL); 934 pool_cache_bootstrap(&uvm_vmspace_cache, sizeof(struct vmspace), 935 0, 0, 0, "vmsppl", NULL, IPL_NONE, NULL, NULL, NULL); 936 } 937 938 /* 939 * clippers 940 */ 941 942 /* 943 * uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy. 944 */ 945 946 static void 947 uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2, 948 vaddr_t splitat) 949 { 950 vaddr_t adj; 951 952 KASSERT(entry1->start < splitat); 953 KASSERT(splitat < entry1->end); 954 955 adj = splitat - entry1->start; 956 entry1->end = entry2->start = splitat; 957 958 if (entry1->aref.ar_amap) { 959 amap_splitref(&entry1->aref, &entry2->aref, adj); 960 } 961 if (UVM_ET_ISSUBMAP(entry1)) { 962 /* ... unlikely to happen, but play it safe */ 963 uvm_map_reference(entry1->object.sub_map); 964 } else if (UVM_ET_ISOBJ(entry1)) { 965 KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */ 966 entry2->offset += adj; 967 if (entry1->object.uvm_obj->pgops && 968 entry1->object.uvm_obj->pgops->pgo_reference) 969 entry1->object.uvm_obj->pgops->pgo_reference( 970 entry1->object.uvm_obj); 971 } 972 } 973 974 /* 975 * uvm_map_clip_start: ensure that the entry begins at or after 976 * the starting address, if it doesn't we split the entry. 977 * 978 * => caller should use UVM_MAP_CLIP_START macro rather than calling 979 * this directly 980 * => map must be locked by caller 981 */ 982 983 void 984 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry, 985 vaddr_t start) 986 { 987 struct vm_map_entry *new_entry; 988 989 /* uvm_map_simplify_entry(map, entry); */ /* XXX */ 990 991 uvm_map_check(map, "clip_start entry"); 992 uvm_mapent_check(entry); 993 994 /* 995 * Split off the front portion. note that we must insert the new 996 * entry BEFORE this one, so that this entry has the specified 997 * starting address. 998 */ 999 new_entry = uvm_mapent_alloc(map, 0); 1000 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1001 uvm_mapent_splitadj(new_entry, entry, start); 1002 uvm_map_entry_link(map, entry->prev, new_entry); 1003 1004 uvm_map_check(map, "clip_start leave"); 1005 } 1006 1007 /* 1008 * uvm_map_clip_end: ensure that the entry ends at or before 1009 * the ending address, if it does't we split the reference 1010 * 1011 * => caller should use UVM_MAP_CLIP_END macro rather than calling 1012 * this directly 1013 * => map must be locked by caller 1014 */ 1015 1016 void 1017 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end) 1018 { 1019 struct vm_map_entry *new_entry; 1020 1021 uvm_map_check(map, "clip_end entry"); 1022 uvm_mapent_check(entry); 1023 1024 /* 1025 * Create a new entry and insert it 1026 * AFTER the specified entry 1027 */ 1028 new_entry = uvm_mapent_alloc(map, 0); 1029 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1030 uvm_mapent_splitadj(entry, new_entry, end); 1031 uvm_map_entry_link(map, entry, new_entry); 1032 1033 uvm_map_check(map, "clip_end leave"); 1034 } 1035 1036 /* 1037 * M A P - m a i n e n t r y p o i n t 1038 */ 1039 /* 1040 * uvm_map: establish a valid mapping in a map 1041 * 1042 * => assume startp is page aligned. 1043 * => assume size is a multiple of PAGE_SIZE. 1044 * => assume sys_mmap provides enough of a "hint" to have us skip 1045 * over text/data/bss area. 1046 * => map must be unlocked (we will lock it) 1047 * => <uobj,uoffset> value meanings (4 cases): 1048 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER 1049 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER 1050 * [3] <uobj,uoffset> == normal mapping 1051 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA 1052 * 1053 * case [4] is for kernel mappings where we don't know the offset until 1054 * we've found a virtual address. note that kernel object offsets are 1055 * always relative to vm_map_min(kernel_map). 1056 * 1057 * => if `align' is non-zero, we align the virtual address to the specified 1058 * alignment. 1059 * this is provided as a mechanism for large pages. 1060 * 1061 * => XXXCDC: need way to map in external amap? 1062 */ 1063 1064 int 1065 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size, 1066 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags) 1067 { 1068 struct uvm_map_args args; 1069 struct vm_map_entry *new_entry; 1070 int error; 1071 1072 KASSERT((size & PAGE_MASK) == 0); 1073 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1074 1075 /* 1076 * for pager_map, allocate the new entry first to avoid sleeping 1077 * for memory while we have the map locked. 1078 */ 1079 1080 new_entry = NULL; 1081 if (map == pager_map) { 1082 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT)); 1083 if (__predict_false(new_entry == NULL)) 1084 return ENOMEM; 1085 } 1086 if (map == pager_map) 1087 flags |= UVM_FLAG_NOMERGE; 1088 1089 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align, 1090 flags, &args); 1091 if (!error) { 1092 error = uvm_map_enter(map, &args, new_entry); 1093 *startp = args.uma_start; 1094 } else if (new_entry) { 1095 uvm_mapent_free(new_entry); 1096 } 1097 1098 #if defined(DEBUG) 1099 if (!error && VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) { 1100 uvm_km_check_empty(map, *startp, *startp + size); 1101 } 1102 #endif /* defined(DEBUG) */ 1103 1104 return error; 1105 } 1106 1107 /* 1108 * uvm_map_prepare: 1109 * 1110 * called with map unlocked. 1111 * on success, returns the map locked. 1112 */ 1113 1114 int 1115 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size, 1116 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags, 1117 struct uvm_map_args *args) 1118 { 1119 struct vm_map_entry *prev_entry; 1120 vm_prot_t prot = UVM_PROTECTION(flags); 1121 vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1122 1123 UVMHIST_FUNC(__func__); 1124 UVMHIST_CALLARGS(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)", 1125 (uintptr_t)map, start, size, flags); 1126 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj, 1127 uoffset,0,0); 1128 1129 /* 1130 * detect a popular device driver bug. 1131 */ 1132 1133 KASSERT(doing_shutdown || curlwp != NULL); 1134 1135 /* 1136 * zero-sized mapping doesn't make any sense. 1137 */ 1138 KASSERT(size > 0); 1139 1140 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0); 1141 1142 uvm_map_check(map, "map entry"); 1143 1144 /* 1145 * check sanity of protection code 1146 */ 1147 1148 if ((prot & maxprot) != prot) { 1149 UVMHIST_LOG(maphist, "<- prot. failure: prot=%#jx, max=%#jx", 1150 prot, maxprot,0,0); 1151 return EACCES; 1152 } 1153 1154 /* 1155 * figure out where to put new VM range 1156 */ 1157 retry: 1158 if (vm_map_lock_try(map) == false) { 1159 if ((flags & UVM_FLAG_TRYLOCK) != 0) { 1160 return EAGAIN; 1161 } 1162 vm_map_lock(map); /* could sleep here */ 1163 } 1164 if (flags & UVM_FLAG_UNMAP) { 1165 KASSERT(flags & UVM_FLAG_FIXED); 1166 KASSERT((flags & UVM_FLAG_NOWAIT) == 0); 1167 1168 /* 1169 * Set prev_entry to what it will need to be after any existing 1170 * entries are removed later in uvm_map_enter(). 1171 */ 1172 1173 if (uvm_map_lookup_entry(map, start, &prev_entry)) { 1174 if (start == prev_entry->start) 1175 prev_entry = prev_entry->prev; 1176 else 1177 UVM_MAP_CLIP_END(map, prev_entry, start); 1178 SAVE_HINT(map, map->hint, prev_entry); 1179 } 1180 } else { 1181 prev_entry = uvm_map_findspace(map, start, size, &start, 1182 uobj, uoffset, align, flags); 1183 } 1184 if (prev_entry == NULL) { 1185 unsigned int timestamp; 1186 1187 timestamp = map->timestamp; 1188 UVMHIST_LOG(maphist,"waiting va timestamp=%#jx", 1189 timestamp,0,0,0); 1190 map->flags |= VM_MAP_WANTVA; 1191 vm_map_unlock(map); 1192 1193 /* 1194 * try to reclaim kva and wait until someone does unmap. 1195 * fragile locking here, so we awaken every second to 1196 * recheck the condition. 1197 */ 1198 1199 mutex_enter(&map->misc_lock); 1200 while ((map->flags & VM_MAP_WANTVA) != 0 && 1201 map->timestamp == timestamp) { 1202 if ((flags & UVM_FLAG_WAITVA) == 0) { 1203 mutex_exit(&map->misc_lock); 1204 UVMHIST_LOG(maphist, 1205 "<- uvm_map_findspace failed!", 0,0,0,0); 1206 return ENOMEM; 1207 } else { 1208 cv_timedwait(&map->cv, &map->misc_lock, hz); 1209 } 1210 } 1211 mutex_exit(&map->misc_lock); 1212 goto retry; 1213 } 1214 1215 #ifdef PMAP_GROWKERNEL 1216 /* 1217 * If the kernel pmap can't map the requested space, 1218 * then allocate more resources for it. 1219 */ 1220 if (map == kernel_map && uvm_maxkaddr < (start + size)) 1221 uvm_maxkaddr = pmap_growkernel(start + size); 1222 #endif 1223 1224 UVMMAP_EVCNT_INCR(map_call); 1225 1226 /* 1227 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER 1228 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in 1229 * either case we want to zero it before storing it in the map entry 1230 * (because it looks strange and confusing when debugging...) 1231 * 1232 * if uobj is not null 1233 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping 1234 * and we do not need to change uoffset. 1235 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset 1236 * now (based on the starting address of the map). this case is 1237 * for kernel object mappings where we don't know the offset until 1238 * the virtual address is found (with uvm_map_findspace). the 1239 * offset is the distance we are from the start of the map. 1240 */ 1241 1242 if (uobj == NULL) { 1243 uoffset = 0; 1244 } else { 1245 if (uoffset == UVM_UNKNOWN_OFFSET) { 1246 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj)); 1247 uoffset = start - vm_map_min(kernel_map); 1248 } 1249 } 1250 1251 args->uma_flags = flags; 1252 args->uma_prev = prev_entry; 1253 args->uma_start = start; 1254 args->uma_size = size; 1255 args->uma_uobj = uobj; 1256 args->uma_uoffset = uoffset; 1257 1258 UVMHIST_LOG(maphist, "<- done!", 0,0,0,0); 1259 return 0; 1260 } 1261 1262 /* 1263 * uvm_map_enter: 1264 * 1265 * called with map locked. 1266 * unlock the map before returning. 1267 */ 1268 1269 int 1270 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args, 1271 struct vm_map_entry *new_entry) 1272 { 1273 struct vm_map_entry *prev_entry = args->uma_prev; 1274 struct vm_map_entry *dead = NULL, *dead_entries = NULL; 1275 1276 const uvm_flag_t flags = args->uma_flags; 1277 const vm_prot_t prot = UVM_PROTECTION(flags); 1278 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1279 const vm_inherit_t inherit = UVM_INHERIT(flags); 1280 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ? 1281 AMAP_EXTEND_NOWAIT : 0; 1282 const int advice = UVM_ADVICE(flags); 1283 1284 vaddr_t start = args->uma_start; 1285 vsize_t size = args->uma_size; 1286 struct uvm_object *uobj = args->uma_uobj; 1287 voff_t uoffset = args->uma_uoffset; 1288 1289 const int kmap = (vm_map_pmap(map) == pmap_kernel()); 1290 int merged = 0; 1291 int error; 1292 int newetype; 1293 1294 UVMHIST_FUNC(__func__); 1295 UVMHIST_CALLARGS(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)", 1296 (uintptr_t)map, start, size, flags); 1297 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj, 1298 uoffset,0,0); 1299 1300 KASSERT(map->hint == prev_entry); /* bimerge case assumes this */ 1301 KASSERT(vm_map_locked_p(map)); 1302 KASSERT((flags & (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)) != 1303 (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)); 1304 1305 if (uobj) 1306 newetype = UVM_ET_OBJ; 1307 else 1308 newetype = 0; 1309 1310 if (flags & UVM_FLAG_COPYONW) { 1311 newetype |= UVM_ET_COPYONWRITE; 1312 if ((flags & UVM_FLAG_OVERLAY) == 0) 1313 newetype |= UVM_ET_NEEDSCOPY; 1314 } 1315 1316 /* 1317 * For mappings with unmap, remove any old entries now. Adding the new 1318 * entry cannot fail because that can only happen if UVM_FLAG_NOWAIT 1319 * is set, and we do not support nowait and unmap together. 1320 */ 1321 1322 if (flags & UVM_FLAG_UNMAP) { 1323 KASSERT(flags & UVM_FLAG_FIXED); 1324 uvm_unmap_remove(map, start, start + size, &dead_entries, 0); 1325 #ifdef DEBUG 1326 struct vm_map_entry *tmp_entry __diagused; 1327 bool rv __diagused; 1328 1329 rv = uvm_map_lookup_entry(map, start, &tmp_entry); 1330 KASSERT(!rv); 1331 KASSERTMSG(prev_entry == tmp_entry, 1332 "args %p prev_entry %p tmp_entry %p", 1333 args, prev_entry, tmp_entry); 1334 #endif 1335 SAVE_HINT(map, map->hint, prev_entry); 1336 } 1337 1338 /* 1339 * try and insert in map by extending previous entry, if possible. 1340 * XXX: we don't try and pull back the next entry. might be useful 1341 * for a stack, but we are currently allocating our stack in advance. 1342 */ 1343 1344 if (flags & UVM_FLAG_NOMERGE) 1345 goto nomerge; 1346 1347 if (prev_entry->end == start && 1348 prev_entry != &map->header && 1349 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, 0, 1350 prot, maxprot, inherit, advice, 0)) { 1351 1352 if (uobj && prev_entry->offset + 1353 (prev_entry->end - prev_entry->start) != uoffset) 1354 goto forwardmerge; 1355 1356 /* 1357 * can't extend a shared amap. note: no need to lock amap to 1358 * look at refs since we don't care about its exact value. 1359 * if it is one (i.e. we have only reference) it will stay there 1360 */ 1361 1362 if (prev_entry->aref.ar_amap && 1363 amap_refs(prev_entry->aref.ar_amap) != 1) { 1364 goto forwardmerge; 1365 } 1366 1367 if (prev_entry->aref.ar_amap) { 1368 error = amap_extend(prev_entry, size, 1369 amapwaitflag | AMAP_EXTEND_FORWARDS); 1370 if (error) 1371 goto nomerge; 1372 } 1373 1374 if (kmap) { 1375 UVMMAP_EVCNT_INCR(kbackmerge); 1376 } else { 1377 UVMMAP_EVCNT_INCR(ubackmerge); 1378 } 1379 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0); 1380 1381 /* 1382 * drop our reference to uobj since we are extending a reference 1383 * that we already have (the ref count can not drop to zero). 1384 */ 1385 1386 if (uobj && uobj->pgops->pgo_detach) 1387 uobj->pgops->pgo_detach(uobj); 1388 1389 /* 1390 * Now that we've merged the entries, note that we've grown 1391 * and our gap has shrunk. Then fix the tree. 1392 */ 1393 prev_entry->end += size; 1394 prev_entry->gap -= size; 1395 uvm_rb_fixup(map, prev_entry); 1396 1397 uvm_map_check(map, "map backmerged"); 1398 1399 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0); 1400 merged++; 1401 } 1402 1403 forwardmerge: 1404 if (prev_entry->next->start == (start + size) && 1405 prev_entry->next != &map->header && 1406 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, 0, 1407 prot, maxprot, inherit, advice, 0)) { 1408 1409 if (uobj && prev_entry->next->offset != uoffset + size) 1410 goto nomerge; 1411 1412 /* 1413 * can't extend a shared amap. note: no need to lock amap to 1414 * look at refs since we don't care about its exact value. 1415 * if it is one (i.e. we have only reference) it will stay there. 1416 * 1417 * note that we also can't merge two amaps, so if we 1418 * merged with the previous entry which has an amap, 1419 * and the next entry also has an amap, we give up. 1420 * 1421 * Interesting cases: 1422 * amap, new, amap -> give up second merge (single fwd extend) 1423 * amap, new, none -> double forward extend (extend again here) 1424 * none, new, amap -> double backward extend (done here) 1425 * uobj, new, amap -> single backward extend (done here) 1426 * 1427 * XXX should we attempt to deal with someone refilling 1428 * the deallocated region between two entries that are 1429 * backed by the same amap (ie, arefs is 2, "prev" and 1430 * "next" refer to it, and adding this allocation will 1431 * close the hole, thus restoring arefs to 1 and 1432 * deallocating the "next" vm_map_entry)? -- @@@ 1433 */ 1434 1435 if (prev_entry->next->aref.ar_amap && 1436 (amap_refs(prev_entry->next->aref.ar_amap) != 1 || 1437 (merged && prev_entry->aref.ar_amap))) { 1438 goto nomerge; 1439 } 1440 1441 if (merged) { 1442 /* 1443 * Try to extend the amap of the previous entry to 1444 * cover the next entry as well. If it doesn't work 1445 * just skip on, don't actually give up, since we've 1446 * already completed the back merge. 1447 */ 1448 if (prev_entry->aref.ar_amap) { 1449 if (amap_extend(prev_entry, 1450 prev_entry->next->end - 1451 prev_entry->next->start, 1452 amapwaitflag | AMAP_EXTEND_FORWARDS)) 1453 goto nomerge; 1454 } 1455 1456 /* 1457 * Try to extend the amap of the *next* entry 1458 * back to cover the new allocation *and* the 1459 * previous entry as well (the previous merge 1460 * didn't have an amap already otherwise we 1461 * wouldn't be checking here for an amap). If 1462 * it doesn't work just skip on, again, don't 1463 * actually give up, since we've already 1464 * completed the back merge. 1465 */ 1466 else if (prev_entry->next->aref.ar_amap) { 1467 if (amap_extend(prev_entry->next, 1468 prev_entry->end - 1469 prev_entry->start, 1470 amapwaitflag | AMAP_EXTEND_BACKWARDS)) 1471 goto nomerge; 1472 } 1473 } else { 1474 /* 1475 * Pull the next entry's amap backwards to cover this 1476 * new allocation. 1477 */ 1478 if (prev_entry->next->aref.ar_amap) { 1479 error = amap_extend(prev_entry->next, size, 1480 amapwaitflag | AMAP_EXTEND_BACKWARDS); 1481 if (error) 1482 goto nomerge; 1483 } 1484 } 1485 1486 if (merged) { 1487 if (kmap) { 1488 UVMMAP_EVCNT_DECR(kbackmerge); 1489 UVMMAP_EVCNT_INCR(kbimerge); 1490 } else { 1491 UVMMAP_EVCNT_DECR(ubackmerge); 1492 UVMMAP_EVCNT_INCR(ubimerge); 1493 } 1494 } else { 1495 if (kmap) { 1496 UVMMAP_EVCNT_INCR(kforwmerge); 1497 } else { 1498 UVMMAP_EVCNT_INCR(uforwmerge); 1499 } 1500 } 1501 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0); 1502 1503 /* 1504 * drop our reference to uobj since we are extending a reference 1505 * that we already have (the ref count can not drop to zero). 1506 */ 1507 if (uobj && uobj->pgops->pgo_detach) 1508 uobj->pgops->pgo_detach(uobj); 1509 1510 if (merged) { 1511 dead = prev_entry->next; 1512 prev_entry->end = dead->end; 1513 uvm_map_entry_unlink(map, dead); 1514 if (dead->aref.ar_amap != NULL) { 1515 prev_entry->aref = dead->aref; 1516 dead->aref.ar_amap = NULL; 1517 } 1518 } else { 1519 prev_entry->next->start -= size; 1520 if (prev_entry != &map->header) { 1521 prev_entry->gap -= size; 1522 KASSERT(prev_entry->gap == uvm_rb_gap(prev_entry)); 1523 uvm_rb_fixup(map, prev_entry); 1524 } 1525 if (uobj) 1526 prev_entry->next->offset = uoffset; 1527 } 1528 1529 uvm_map_check(map, "map forwardmerged"); 1530 1531 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0); 1532 merged++; 1533 } 1534 1535 nomerge: 1536 if (!merged) { 1537 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0); 1538 if (kmap) { 1539 UVMMAP_EVCNT_INCR(knomerge); 1540 } else { 1541 UVMMAP_EVCNT_INCR(unomerge); 1542 } 1543 1544 /* 1545 * allocate new entry and link it in. 1546 */ 1547 1548 if (new_entry == NULL) { 1549 new_entry = uvm_mapent_alloc(map, 1550 (flags & UVM_FLAG_NOWAIT)); 1551 if (__predict_false(new_entry == NULL)) { 1552 error = ENOMEM; 1553 goto done; 1554 } 1555 } 1556 new_entry->start = start; 1557 new_entry->end = new_entry->start + size; 1558 new_entry->object.uvm_obj = uobj; 1559 new_entry->offset = uoffset; 1560 1561 new_entry->etype = newetype; 1562 1563 if (flags & UVM_FLAG_NOMERGE) { 1564 new_entry->flags |= UVM_MAP_NOMERGE; 1565 } 1566 1567 new_entry->protection = prot; 1568 new_entry->max_protection = maxprot; 1569 new_entry->inheritance = inherit; 1570 new_entry->wired_count = 0; 1571 new_entry->advice = advice; 1572 if (flags & UVM_FLAG_OVERLAY) { 1573 1574 /* 1575 * to_add: for BSS we overallocate a little since we 1576 * are likely to extend 1577 */ 1578 1579 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ? 1580 UVM_AMAP_CHUNK << PAGE_SHIFT : 0; 1581 struct vm_amap *amap = amap_alloc(size, to_add, 1582 (flags & UVM_FLAG_NOWAIT)); 1583 if (__predict_false(amap == NULL)) { 1584 error = ENOMEM; 1585 goto done; 1586 } 1587 new_entry->aref.ar_pageoff = 0; 1588 new_entry->aref.ar_amap = amap; 1589 } else { 1590 new_entry->aref.ar_pageoff = 0; 1591 new_entry->aref.ar_amap = NULL; 1592 } 1593 uvm_map_entry_link(map, prev_entry, new_entry); 1594 1595 /* 1596 * Update the free space hint 1597 */ 1598 1599 if ((map->first_free == prev_entry) && 1600 (prev_entry->end >= new_entry->start)) 1601 map->first_free = new_entry; 1602 1603 new_entry = NULL; 1604 } 1605 1606 map->size += size; 1607 1608 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 1609 1610 error = 0; 1611 1612 done: 1613 vm_map_unlock(map); 1614 1615 if (new_entry) { 1616 uvm_mapent_free(new_entry); 1617 } 1618 if (dead) { 1619 KDASSERT(merged); 1620 uvm_mapent_free(dead); 1621 } 1622 if (dead_entries) 1623 uvm_unmap_detach(dead_entries, 0); 1624 1625 return error; 1626 } 1627 1628 /* 1629 * uvm_map_lookup_entry_bytree: lookup an entry in tree 1630 */ 1631 1632 static inline bool 1633 uvm_map_lookup_entry_bytree(struct vm_map *map, vaddr_t address, 1634 struct vm_map_entry **entry /* OUT */) 1635 { 1636 struct vm_map_entry *prev = &map->header; 1637 struct vm_map_entry *cur = ROOT_ENTRY(map); 1638 1639 while (cur) { 1640 UVMMAP_EVCNT_INCR(mlk_treeloop); 1641 if (address >= cur->start) { 1642 if (address < cur->end) { 1643 *entry = cur; 1644 return true; 1645 } 1646 prev = cur; 1647 cur = RIGHT_ENTRY(cur); 1648 } else 1649 cur = LEFT_ENTRY(cur); 1650 } 1651 *entry = prev; 1652 return false; 1653 } 1654 1655 /* 1656 * uvm_map_lookup_entry: find map entry at or before an address 1657 * 1658 * => map must at least be read-locked by caller 1659 * => entry is returned in "entry" 1660 * => return value is true if address is in the returned entry 1661 */ 1662 1663 bool 1664 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address, 1665 struct vm_map_entry **entry /* OUT */) 1666 { 1667 struct vm_map_entry *cur; 1668 UVMHIST_FUNC(__func__); 1669 UVMHIST_CALLARGS(maphist,"(map=%#jx,addr=%#jx,ent=%#jx)", 1670 (uintptr_t)map, address, (uintptr_t)entry, 0); 1671 1672 /* 1673 * make a quick check to see if we are already looking at 1674 * the entry we want (which is usually the case). note also 1675 * that we don't need to save the hint here... it is the 1676 * same hint (unless we are at the header, in which case the 1677 * hint didn't buy us anything anyway). 1678 */ 1679 1680 cur = map->hint; 1681 UVMMAP_EVCNT_INCR(mlk_call); 1682 if (cur != &map->header && 1683 address >= cur->start && cur->end > address) { 1684 UVMMAP_EVCNT_INCR(mlk_hint); 1685 *entry = cur; 1686 UVMHIST_LOG(maphist,"<- got it via hint (%#jx)", 1687 (uintptr_t)cur, 0, 0, 0); 1688 uvm_mapent_check(*entry); 1689 return (true); 1690 } 1691 uvm_map_check(map, __func__); 1692 1693 /* 1694 * lookup in the tree. 1695 */ 1696 1697 UVMMAP_EVCNT_INCR(mlk_tree); 1698 if (__predict_true(uvm_map_lookup_entry_bytree(map, address, entry))) { 1699 SAVE_HINT(map, map->hint, *entry); 1700 UVMHIST_LOG(maphist,"<- search got it (%#jx)", 1701 (uintptr_t)cur, 0, 0, 0); 1702 KDASSERT((*entry)->start <= address); 1703 KDASSERT(address < (*entry)->end); 1704 uvm_mapent_check(*entry); 1705 return (true); 1706 } 1707 1708 SAVE_HINT(map, map->hint, *entry); 1709 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0); 1710 KDASSERT((*entry) == &map->header || (*entry)->end <= address); 1711 KDASSERT((*entry)->next == &map->header || 1712 address < (*entry)->next->start); 1713 return (false); 1714 } 1715 1716 /* 1717 * See if the range between start and start + length fits in the gap 1718 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't 1719 * fit, and -1 address wraps around. 1720 */ 1721 static int 1722 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset, 1723 vsize_t align, int flags, int topdown, struct vm_map_entry *entry) 1724 { 1725 vaddr_t end; 1726 1727 #ifdef PMAP_PREFER 1728 /* 1729 * push start address forward as needed to avoid VAC alias problems. 1730 * we only do this if a valid offset is specified. 1731 */ 1732 1733 if (uoffset != UVM_UNKNOWN_OFFSET) 1734 PMAP_PREFER(uoffset, start, length, topdown); 1735 #endif 1736 if ((flags & UVM_FLAG_COLORMATCH) != 0) { 1737 KASSERT(align < uvmexp.ncolors); 1738 if (uvmexp.ncolors > 1) { 1739 const u_int colormask = uvmexp.colormask; 1740 const u_int colorsize = colormask + 1; 1741 vaddr_t hint = atop(*start); 1742 const u_int color = hint & colormask; 1743 if (color != align) { 1744 hint -= color; /* adjust to color boundary */ 1745 KASSERT((hint & colormask) == 0); 1746 if (topdown) { 1747 if (align > color) 1748 hint -= colorsize; 1749 } else { 1750 if (align < color) 1751 hint += colorsize; 1752 } 1753 *start = ptoa(hint + align); /* adjust to color */ 1754 } 1755 } 1756 } else { 1757 KASSERT(powerof2(align)); 1758 uvm_map_align_va(start, align, topdown); 1759 /* 1760 * XXX Should we PMAP_PREFER() here again? 1761 * eh...i think we're okay 1762 */ 1763 } 1764 1765 /* 1766 * Find the end of the proposed new region. Be sure we didn't 1767 * wrap around the address; if so, we lose. Otherwise, if the 1768 * proposed new region fits before the next entry, we win. 1769 */ 1770 1771 end = *start + length; 1772 if (end < *start) 1773 return (-1); 1774 1775 if (entry->next->start >= end && *start >= entry->end) 1776 return (1); 1777 1778 return (0); 1779 } 1780 1781 /* 1782 * uvm_map_findspace: find "length" sized space in "map". 1783 * 1784 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is 1785 * set in "flags" (in which case we insist on using "hint"). 1786 * => "result" is VA returned 1787 * => uobj/uoffset are to be used to handle VAC alignment, if required 1788 * => if "align" is non-zero, we attempt to align to that value. 1789 * => caller must at least have read-locked map 1790 * => returns NULL on failure, or pointer to prev. map entry if success 1791 * => note this is a cross between the old vm_map_findspace and vm_map_find 1792 */ 1793 1794 struct vm_map_entry * 1795 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length, 1796 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset, 1797 vsize_t align, int flags) 1798 { 1799 struct vm_map_entry *entry; 1800 struct vm_map_entry *child, *prev, *tmp; 1801 vaddr_t orig_hint __diagused; 1802 const int topdown = map->flags & VM_MAP_TOPDOWN; 1803 UVMHIST_FUNC(__func__); 1804 UVMHIST_CALLARGS(maphist, "(map=%#jx, hint=%#jx, len=%ju, flags=%#jx)", 1805 (uintptr_t)map, hint, length, flags); 1806 1807 KASSERT((flags & UVM_FLAG_COLORMATCH) != 0 || powerof2(align)); 1808 KASSERT((flags & UVM_FLAG_COLORMATCH) == 0 || align < uvmexp.ncolors); 1809 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1810 1811 uvm_map_check(map, "map_findspace entry"); 1812 1813 /* 1814 * remember the original hint. if we are aligning, then we 1815 * may have to try again with no alignment constraint if 1816 * we fail the first time. 1817 */ 1818 1819 orig_hint = hint; 1820 if (hint < vm_map_min(map)) { /* check ranges ... */ 1821 if (flags & UVM_FLAG_FIXED) { 1822 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0); 1823 return (NULL); 1824 } 1825 hint = vm_map_min(map); 1826 } 1827 if (hint > vm_map_max(map)) { 1828 UVMHIST_LOG(maphist,"<- VA %#jx > range [%#jx->%#jx]", 1829 hint, vm_map_min(map), vm_map_max(map), 0); 1830 return (NULL); 1831 } 1832 1833 /* 1834 * hint may not be aligned properly; we need round up or down it 1835 * before proceeding further. 1836 */ 1837 if ((flags & UVM_FLAG_COLORMATCH) == 0) 1838 uvm_map_align_va(&hint, align, topdown); 1839 1840 /* 1841 * Look for the first possible address; if there's already 1842 * something at this address, we have to start after it. 1843 */ 1844 1845 /* 1846 * @@@: there are four, no, eight cases to consider. 1847 * 1848 * 0: found, fixed, bottom up -> fail 1849 * 1: found, fixed, top down -> fail 1850 * 2: found, not fixed, bottom up -> start after entry->end, 1851 * loop up 1852 * 3: found, not fixed, top down -> start before entry->start, 1853 * loop down 1854 * 4: not found, fixed, bottom up -> check entry->next->start, fail 1855 * 5: not found, fixed, top down -> check entry->next->start, fail 1856 * 6: not found, not fixed, bottom up -> check entry->next->start, 1857 * loop up 1858 * 7: not found, not fixed, top down -> check entry->next->start, 1859 * loop down 1860 * 1861 * as you can see, it reduces to roughly five cases, and that 1862 * adding top down mapping only adds one unique case (without 1863 * it, there would be four cases). 1864 */ 1865 1866 if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) { 1867 entry = map->first_free; 1868 } else { 1869 if (uvm_map_lookup_entry(map, hint, &entry)) { 1870 /* "hint" address already in use ... */ 1871 if (flags & UVM_FLAG_FIXED) { 1872 UVMHIST_LOG(maphist, "<- fixed & VA in use", 1873 0, 0, 0, 0); 1874 return (NULL); 1875 } 1876 if (topdown) 1877 /* Start from lower gap. */ 1878 entry = entry->prev; 1879 } else if (flags & UVM_FLAG_FIXED) { 1880 if (entry->next->start >= hint + length && 1881 hint + length > hint) 1882 goto found; 1883 1884 /* "hint" address is gap but too small */ 1885 UVMHIST_LOG(maphist, "<- fixed mapping failed", 1886 0, 0, 0, 0); 1887 return (NULL); /* only one shot at it ... */ 1888 } else { 1889 /* 1890 * See if given hint fits in this gap. 1891 */ 1892 switch (uvm_map_space_avail(&hint, length, 1893 uoffset, align, flags, topdown, entry)) { 1894 case 1: 1895 goto found; 1896 case -1: 1897 goto wraparound; 1898 } 1899 1900 if (topdown) { 1901 /* 1902 * Still there is a chance to fit 1903 * if hint > entry->end. 1904 */ 1905 } else { 1906 /* Start from higher gap. */ 1907 entry = entry->next; 1908 if (entry == &map->header) 1909 goto notfound; 1910 goto nextgap; 1911 } 1912 } 1913 } 1914 1915 /* 1916 * Note that all UVM_FLAGS_FIXED case is already handled. 1917 */ 1918 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1919 1920 /* Try to find the space in the red-black tree */ 1921 1922 /* Check slot before any entry */ 1923 hint = topdown ? entry->next->start - length : entry->end; 1924 switch (uvm_map_space_avail(&hint, length, uoffset, align, flags, 1925 topdown, entry)) { 1926 case 1: 1927 goto found; 1928 case -1: 1929 goto wraparound; 1930 } 1931 1932 nextgap: 1933 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1934 /* If there is not enough space in the whole tree, we fail */ 1935 tmp = ROOT_ENTRY(map); 1936 if (tmp == NULL || tmp->maxgap < length) 1937 goto notfound; 1938 1939 prev = NULL; /* previous candidate */ 1940 1941 /* Find an entry close to hint that has enough space */ 1942 for (; tmp;) { 1943 KASSERT(tmp->next->start == tmp->end + tmp->gap); 1944 if (topdown) { 1945 if (tmp->next->start < hint + length && 1946 (prev == NULL || tmp->end > prev->end)) { 1947 if (tmp->gap >= length) 1948 prev = tmp; 1949 else if ((child = LEFT_ENTRY(tmp)) != NULL 1950 && child->maxgap >= length) 1951 prev = tmp; 1952 } 1953 } else { 1954 if (tmp->end >= hint && 1955 (prev == NULL || tmp->end < prev->end)) { 1956 if (tmp->gap >= length) 1957 prev = tmp; 1958 else if ((child = RIGHT_ENTRY(tmp)) != NULL 1959 && child->maxgap >= length) 1960 prev = tmp; 1961 } 1962 } 1963 if (tmp->next->start < hint + length) 1964 child = RIGHT_ENTRY(tmp); 1965 else if (tmp->end > hint) 1966 child = LEFT_ENTRY(tmp); 1967 else { 1968 if (tmp->gap >= length) 1969 break; 1970 if (topdown) 1971 child = LEFT_ENTRY(tmp); 1972 else 1973 child = RIGHT_ENTRY(tmp); 1974 } 1975 if (child == NULL || child->maxgap < length) 1976 break; 1977 tmp = child; 1978 } 1979 1980 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) { 1981 /* 1982 * Check if the entry that we found satifies the 1983 * space requirement 1984 */ 1985 if (topdown) { 1986 if (hint > tmp->next->start - length) 1987 hint = tmp->next->start - length; 1988 } else { 1989 if (hint < tmp->end) 1990 hint = tmp->end; 1991 } 1992 switch (uvm_map_space_avail(&hint, length, uoffset, align, 1993 flags, topdown, tmp)) { 1994 case 1: 1995 entry = tmp; 1996 goto found; 1997 case -1: 1998 goto wraparound; 1999 } 2000 if (tmp->gap >= length) 2001 goto listsearch; 2002 } 2003 if (prev == NULL) 2004 goto notfound; 2005 2006 if (topdown) { 2007 KASSERT(orig_hint >= prev->next->start - length || 2008 prev->next->start - length > prev->next->start); 2009 hint = prev->next->start - length; 2010 } else { 2011 KASSERT(orig_hint <= prev->end); 2012 hint = prev->end; 2013 } 2014 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2015 flags, topdown, prev)) { 2016 case 1: 2017 entry = prev; 2018 goto found; 2019 case -1: 2020 goto wraparound; 2021 } 2022 if (prev->gap >= length) 2023 goto listsearch; 2024 2025 if (topdown) 2026 tmp = LEFT_ENTRY(prev); 2027 else 2028 tmp = RIGHT_ENTRY(prev); 2029 for (;;) { 2030 KASSERT(tmp && tmp->maxgap >= length); 2031 if (topdown) 2032 child = RIGHT_ENTRY(tmp); 2033 else 2034 child = LEFT_ENTRY(tmp); 2035 if (child && child->maxgap >= length) { 2036 tmp = child; 2037 continue; 2038 } 2039 if (tmp->gap >= length) 2040 break; 2041 if (topdown) 2042 tmp = LEFT_ENTRY(tmp); 2043 else 2044 tmp = RIGHT_ENTRY(tmp); 2045 } 2046 2047 if (topdown) { 2048 KASSERT(orig_hint >= tmp->next->start - length || 2049 tmp->next->start - length > tmp->next->start); 2050 hint = tmp->next->start - length; 2051 } else { 2052 KASSERT(orig_hint <= tmp->end); 2053 hint = tmp->end; 2054 } 2055 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2056 flags, topdown, tmp)) { 2057 case 1: 2058 entry = tmp; 2059 goto found; 2060 case -1: 2061 goto wraparound; 2062 } 2063 2064 /* 2065 * The tree fails to find an entry because of offset or alignment 2066 * restrictions. Search the list instead. 2067 */ 2068 listsearch: 2069 /* 2070 * Look through the rest of the map, trying to fit a new region in 2071 * the gap between existing regions, or after the very last region. 2072 * note: entry->end = base VA of current gap, 2073 * entry->next->start = VA of end of current gap 2074 */ 2075 2076 for (;;) { 2077 /* Update hint for current gap. */ 2078 hint = topdown ? entry->next->start - length : entry->end; 2079 2080 /* See if it fits. */ 2081 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2082 flags, topdown, entry)) { 2083 case 1: 2084 goto found; 2085 case -1: 2086 goto wraparound; 2087 } 2088 2089 /* Advance to next/previous gap */ 2090 if (topdown) { 2091 if (entry == &map->header) { 2092 UVMHIST_LOG(maphist, "<- failed (off start)", 2093 0,0,0,0); 2094 goto notfound; 2095 } 2096 entry = entry->prev; 2097 } else { 2098 entry = entry->next; 2099 if (entry == &map->header) { 2100 UVMHIST_LOG(maphist, "<- failed (off end)", 2101 0,0,0,0); 2102 goto notfound; 2103 } 2104 } 2105 } 2106 2107 found: 2108 SAVE_HINT(map, map->hint, entry); 2109 *result = hint; 2110 UVMHIST_LOG(maphist,"<- got it! (result=%#jx)", hint, 0,0,0); 2111 KASSERTMSG( topdown || hint >= orig_hint, "hint: %#jx, orig_hint: %#jx", 2112 (uintmax_t)hint, (uintmax_t)orig_hint); 2113 KASSERTMSG(!topdown || hint <= orig_hint, "hint: %#jx, orig_hint: %#jx", 2114 (uintmax_t)hint, (uintmax_t)orig_hint); 2115 KASSERT(entry->end <= hint); 2116 KASSERT(hint + length <= entry->next->start); 2117 return (entry); 2118 2119 wraparound: 2120 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0); 2121 2122 return (NULL); 2123 2124 notfound: 2125 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0); 2126 2127 return (NULL); 2128 } 2129 2130 /* 2131 * U N M A P - m a i n h e l p e r f u n c t i o n s 2132 */ 2133 2134 /* 2135 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop") 2136 * 2137 * => caller must check alignment and size 2138 * => map must be locked by caller 2139 * => we return a list of map entries that we've remove from the map 2140 * in "entry_list" 2141 */ 2142 2143 void 2144 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end, 2145 struct vm_map_entry **entry_list /* OUT */, int flags) 2146 { 2147 struct vm_map_entry *entry, *first_entry, *next; 2148 vaddr_t len; 2149 UVMHIST_FUNC(__func__); 2150 UVMHIST_CALLARGS(maphist,"(map=%#jx, start=%#jx, end=%#jx)", 2151 (uintptr_t)map, start, end, 0); 2152 VM_MAP_RANGE_CHECK(map, start, end); 2153 2154 uvm_map_check(map, "unmap_remove entry"); 2155 2156 /* 2157 * find first entry 2158 */ 2159 2160 if (uvm_map_lookup_entry(map, start, &first_entry) == true) { 2161 /* clip and go... */ 2162 entry = first_entry; 2163 UVM_MAP_CLIP_START(map, entry, start); 2164 /* critical! prevents stale hint */ 2165 SAVE_HINT(map, entry, entry->prev); 2166 } else { 2167 entry = first_entry->next; 2168 } 2169 2170 /* 2171 * save the free space hint 2172 */ 2173 2174 if (map->first_free != &map->header && map->first_free->start >= start) 2175 map->first_free = entry->prev; 2176 2177 /* 2178 * note: we now re-use first_entry for a different task. we remove 2179 * a number of map entries from the map and save them in a linked 2180 * list headed by "first_entry". once we remove them from the map 2181 * the caller should unlock the map and drop the references to the 2182 * backing objects [c.f. uvm_unmap_detach]. the object is to 2183 * separate unmapping from reference dropping. why? 2184 * [1] the map has to be locked for unmapping 2185 * [2] the map need not be locked for reference dropping 2186 * [3] dropping references may trigger pager I/O, and if we hit 2187 * a pager that does synchronous I/O we may have to wait for it. 2188 * [4] we would like all waiting for I/O to occur with maps unlocked 2189 * so that we don't block other threads. 2190 */ 2191 2192 first_entry = NULL; 2193 *entry_list = NULL; 2194 2195 /* 2196 * break up the area into map entry sized regions and unmap. note 2197 * that all mappings have to be removed before we can even consider 2198 * dropping references to amaps or VM objects (otherwise we could end 2199 * up with a mapping to a page on the free list which would be very bad) 2200 */ 2201 2202 while ((entry != &map->header) && (entry->start < end)) { 2203 KASSERT((entry->flags & UVM_MAP_STATIC) == 0); 2204 2205 UVM_MAP_CLIP_END(map, entry, end); 2206 next = entry->next; 2207 len = entry->end - entry->start; 2208 2209 /* 2210 * unwire before removing addresses from the pmap; otherwise 2211 * unwiring will put the entries back into the pmap (XXX). 2212 */ 2213 2214 if (VM_MAPENT_ISWIRED(entry)) { 2215 uvm_map_entry_unwire(map, entry); 2216 } 2217 if (flags & UVM_FLAG_VAONLY) { 2218 2219 /* nothing */ 2220 2221 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) { 2222 2223 /* 2224 * if the map is non-pageable, any pages mapped there 2225 * must be wired and entered with pmap_kenter_pa(), 2226 * and we should free any such pages immediately. 2227 * this is mostly used for kmem_map. 2228 */ 2229 KASSERT(vm_map_pmap(map) == pmap_kernel()); 2230 2231 uvm_km_pgremove_intrsafe(map, entry->start, entry->end); 2232 } else if (UVM_ET_ISOBJ(entry) && 2233 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) { 2234 panic("%s: kernel object %p %p\n", 2235 __func__, map, entry); 2236 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) { 2237 /* 2238 * remove mappings the standard way. lock object 2239 * and/or amap to ensure vm_page state does not 2240 * change while in pmap_remove(). 2241 */ 2242 2243 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */ 2244 uvm_map_lock_entry(entry, RW_WRITER); 2245 #else 2246 uvm_map_lock_entry(entry, RW_READER); 2247 #endif 2248 pmap_remove(map->pmap, entry->start, entry->end); 2249 2250 /* 2251 * note: if map is dying, leave pmap_update() for 2252 * later. if the map is to be reused (exec) then 2253 * pmap_update() will be called. if the map is 2254 * being disposed of (exit) then pmap_destroy() 2255 * will be called. 2256 */ 2257 2258 if ((map->flags & VM_MAP_DYING) == 0) { 2259 pmap_update(vm_map_pmap(map)); 2260 } else { 2261 KASSERT(vm_map_pmap(map) != pmap_kernel()); 2262 } 2263 2264 uvm_map_unlock_entry(entry); 2265 } 2266 2267 #if defined(UVMDEBUG) 2268 /* 2269 * check if there's remaining mapping, 2270 * which is a bug in caller. 2271 */ 2272 2273 vaddr_t va; 2274 for (va = entry->start; va < entry->end; 2275 va += PAGE_SIZE) { 2276 if (pmap_extract(vm_map_pmap(map), va, NULL)) { 2277 panic("%s: %#"PRIxVADDR" has mapping", 2278 __func__, va); 2279 } 2280 } 2281 2282 if (VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) { 2283 uvm_km_check_empty(map, entry->start, 2284 entry->end); 2285 } 2286 #endif /* defined(UVMDEBUG) */ 2287 2288 /* 2289 * remove entry from map and put it on our list of entries 2290 * that we've nuked. then go to next entry. 2291 */ 2292 2293 UVMHIST_LOG(maphist, " removed map entry %#jx", 2294 (uintptr_t)entry, 0, 0, 0); 2295 2296 /* critical! prevents stale hint */ 2297 SAVE_HINT(map, entry, entry->prev); 2298 2299 uvm_map_entry_unlink(map, entry); 2300 KASSERT(map->size >= len); 2301 map->size -= len; 2302 entry->prev = NULL; 2303 entry->next = first_entry; 2304 first_entry = entry; 2305 entry = next; 2306 } 2307 2308 uvm_map_check(map, "unmap_remove leave"); 2309 2310 /* 2311 * now we've cleaned up the map and are ready for the caller to drop 2312 * references to the mapped objects. 2313 */ 2314 2315 *entry_list = first_entry; 2316 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 2317 2318 if (map->flags & VM_MAP_WANTVA) { 2319 mutex_enter(&map->misc_lock); 2320 map->flags &= ~VM_MAP_WANTVA; 2321 cv_broadcast(&map->cv); 2322 mutex_exit(&map->misc_lock); 2323 } 2324 } 2325 2326 /* 2327 * uvm_unmap_detach: drop references in a chain of map entries 2328 * 2329 * => we will free the map entries as we traverse the list. 2330 */ 2331 2332 void 2333 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags) 2334 { 2335 struct vm_map_entry *next_entry; 2336 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 2337 2338 while (first_entry) { 2339 KASSERT(!VM_MAPENT_ISWIRED(first_entry)); 2340 UVMHIST_LOG(maphist, 2341 " detach %#jx: amap=%#jx, obj=%#jx, submap?=%jd", 2342 (uintptr_t)first_entry, 2343 (uintptr_t)first_entry->aref.ar_amap, 2344 (uintptr_t)first_entry->object.uvm_obj, 2345 UVM_ET_ISSUBMAP(first_entry)); 2346 2347 /* 2348 * drop reference to amap, if we've got one 2349 */ 2350 2351 if (first_entry->aref.ar_amap) 2352 uvm_map_unreference_amap(first_entry, flags); 2353 2354 /* 2355 * drop reference to our backing object, if we've got one 2356 */ 2357 2358 KASSERT(!UVM_ET_ISSUBMAP(first_entry)); 2359 if (UVM_ET_ISOBJ(first_entry) && 2360 first_entry->object.uvm_obj->pgops->pgo_detach) { 2361 (*first_entry->object.uvm_obj->pgops->pgo_detach) 2362 (first_entry->object.uvm_obj); 2363 } 2364 next_entry = first_entry->next; 2365 uvm_mapent_free(first_entry); 2366 first_entry = next_entry; 2367 } 2368 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 2369 } 2370 2371 /* 2372 * E X T R A C T I O N F U N C T I O N S 2373 */ 2374 2375 /* 2376 * uvm_map_reserve: reserve space in a vm_map for future use. 2377 * 2378 * => we reserve space in a map by putting a dummy map entry in the 2379 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE) 2380 * => map should be unlocked (we will write lock it) 2381 * => we return true if we were able to reserve space 2382 * => XXXCDC: should be inline? 2383 */ 2384 2385 int 2386 uvm_map_reserve(struct vm_map *map, vsize_t size, 2387 vaddr_t offset /* hint for pmap_prefer */, 2388 vsize_t align /* alignment */, 2389 vaddr_t *raddr /* IN:hint, OUT: reserved VA */, 2390 uvm_flag_t flags /* UVM_FLAG_FIXED or UVM_FLAG_COLORMATCH or 0 */) 2391 { 2392 UVMHIST_FUNC(__func__); 2393 UVMHIST_CALLARGS(maphist, "(map=%#jx, size=%#jx, offset=%#jx, addr=%#jx)", 2394 (uintptr_t)map, size, offset, (uintptr_t)raddr); 2395 2396 size = round_page(size); 2397 2398 /* 2399 * reserve some virtual space. 2400 */ 2401 2402 if (uvm_map(map, raddr, size, NULL, offset, align, 2403 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE, 2404 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) { 2405 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 2406 return (false); 2407 } 2408 2409 UVMHIST_LOG(maphist, "<- done (*raddr=%#jx)", *raddr,0,0,0); 2410 return (true); 2411 } 2412 2413 /* 2414 * uvm_map_replace: replace a reserved (blank) area of memory with 2415 * real mappings. 2416 * 2417 * => caller must WRITE-LOCK the map 2418 * => we return true if replacement was a success 2419 * => we expect the newents chain to have nnewents entrys on it and 2420 * we expect newents->prev to point to the last entry on the list 2421 * => note newents is allowed to be NULL 2422 */ 2423 2424 static int 2425 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end, 2426 struct vm_map_entry *newents, int nnewents, vsize_t nsize, 2427 struct vm_map_entry **oldentryp) 2428 { 2429 struct vm_map_entry *oldent, *last; 2430 2431 uvm_map_check(map, "map_replace entry"); 2432 2433 /* 2434 * first find the blank map entry at the specified address 2435 */ 2436 2437 if (!uvm_map_lookup_entry(map, start, &oldent)) { 2438 return (false); 2439 } 2440 2441 /* 2442 * check to make sure we have a proper blank entry 2443 */ 2444 2445 if (end < oldent->end) { 2446 UVM_MAP_CLIP_END(map, oldent, end); 2447 } 2448 if (oldent->start != start || oldent->end != end || 2449 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) { 2450 return (false); 2451 } 2452 2453 #ifdef DIAGNOSTIC 2454 2455 /* 2456 * sanity check the newents chain 2457 */ 2458 2459 { 2460 struct vm_map_entry *tmpent = newents; 2461 int nent = 0; 2462 vsize_t sz = 0; 2463 vaddr_t cur = start; 2464 2465 while (tmpent) { 2466 nent++; 2467 sz += tmpent->end - tmpent->start; 2468 if (tmpent->start < cur) 2469 panic("uvm_map_replace1"); 2470 if (tmpent->start >= tmpent->end || tmpent->end > end) { 2471 panic("uvm_map_replace2: " 2472 "tmpent->start=%#"PRIxVADDR 2473 ", tmpent->end=%#"PRIxVADDR 2474 ", end=%#"PRIxVADDR, 2475 tmpent->start, tmpent->end, end); 2476 } 2477 cur = tmpent->end; 2478 if (tmpent->next) { 2479 if (tmpent->next->prev != tmpent) 2480 panic("uvm_map_replace3"); 2481 } else { 2482 if (newents->prev != tmpent) 2483 panic("uvm_map_replace4"); 2484 } 2485 tmpent = tmpent->next; 2486 } 2487 if (nent != nnewents) 2488 panic("uvm_map_replace5"); 2489 if (sz != nsize) 2490 panic("uvm_map_replace6"); 2491 } 2492 #endif 2493 2494 /* 2495 * map entry is a valid blank! replace it. (this does all the 2496 * work of map entry link/unlink...). 2497 */ 2498 2499 if (newents) { 2500 last = newents->prev; 2501 2502 /* critical: flush stale hints out of map */ 2503 SAVE_HINT(map, map->hint, newents); 2504 if (map->first_free == oldent) 2505 map->first_free = last; 2506 2507 last->next = oldent->next; 2508 last->next->prev = last; 2509 2510 /* Fix RB tree */ 2511 uvm_rb_remove(map, oldent); 2512 2513 newents->prev = oldent->prev; 2514 newents->prev->next = newents; 2515 map->nentries = map->nentries + (nnewents - 1); 2516 2517 /* Fixup the RB tree */ 2518 { 2519 int i; 2520 struct vm_map_entry *tmp; 2521 2522 tmp = newents; 2523 for (i = 0; i < nnewents && tmp; i++) { 2524 uvm_rb_insert(map, tmp); 2525 tmp = tmp->next; 2526 } 2527 } 2528 } else { 2529 /* NULL list of new entries: just remove the old one */ 2530 clear_hints(map, oldent); 2531 uvm_map_entry_unlink(map, oldent); 2532 } 2533 map->size -= end - start - nsize; 2534 2535 uvm_map_check(map, "map_replace leave"); 2536 2537 /* 2538 * now we can free the old blank entry and return. 2539 */ 2540 2541 *oldentryp = oldent; 2542 return (true); 2543 } 2544 2545 /* 2546 * uvm_map_extract: extract a mapping from a map and put it somewhere 2547 * (maybe removing the old mapping) 2548 * 2549 * => maps should be unlocked (we will write lock them) 2550 * => returns 0 on success, error code otherwise 2551 * => start must be page aligned 2552 * => len must be page sized 2553 * => flags: 2554 * UVM_EXTRACT_REMOVE: remove mappings from srcmap 2555 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only) 2556 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs 2557 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go 2558 * UVM_EXTRACT_PROT_ALL: set prot to UVM_PROT_ALL as we go 2559 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<< 2560 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only 2561 * be used from within the kernel in a kernel level map <<< 2562 */ 2563 2564 int 2565 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len, 2566 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags) 2567 { 2568 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge; 2569 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry, 2570 *deadentry, *oldentry; 2571 struct vm_map_entry *resentry = NULL; /* a dummy reservation entry */ 2572 vsize_t elen __unused; 2573 int nchain, error, copy_ok; 2574 vsize_t nsize; 2575 UVMHIST_FUNC(__func__); 2576 UVMHIST_CALLARGS(maphist,"(srcmap=%#jx,start=%#jx, len=%#jx", 2577 (uintptr_t)srcmap, start, len, 0); 2578 UVMHIST_LOG(maphist," ...,dstmap=%#jx, flags=%#jx)", 2579 (uintptr_t)dstmap, flags, 0, 0); 2580 2581 /* 2582 * step 0: sanity check: start must be on a page boundary, length 2583 * must be page sized. can't ask for CONTIG/QREF if you asked for 2584 * REMOVE. 2585 */ 2586 2587 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0); 2588 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 || 2589 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0); 2590 2591 /* 2592 * step 1: reserve space in the target map for the extracted area 2593 */ 2594 2595 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2596 dstaddr = vm_map_min(dstmap); 2597 if (!uvm_map_reserve(dstmap, len, start, 2598 atop(start) & uvmexp.colormask, &dstaddr, 2599 UVM_FLAG_COLORMATCH)) 2600 return (ENOMEM); 2601 KASSERT((atop(start ^ dstaddr) & uvmexp.colormask) == 0); 2602 *dstaddrp = dstaddr; /* pass address back to caller */ 2603 UVMHIST_LOG(maphist, " dstaddr=%#jx", dstaddr,0,0,0); 2604 } else { 2605 dstaddr = *dstaddrp; 2606 } 2607 2608 /* 2609 * step 2: setup for the extraction process loop by init'ing the 2610 * map entry chain, locking src map, and looking up the first useful 2611 * entry in the map. 2612 */ 2613 2614 end = start + len; 2615 newend = dstaddr + len; 2616 chain = endchain = NULL; 2617 nchain = 0; 2618 nsize = 0; 2619 vm_map_lock(srcmap); 2620 2621 if (uvm_map_lookup_entry(srcmap, start, &entry)) { 2622 2623 /* "start" is within an entry */ 2624 if (flags & UVM_EXTRACT_QREF) { 2625 2626 /* 2627 * for quick references we don't clip the entry, so 2628 * the entry may map space "before" the starting 2629 * virtual address... this is the "fudge" factor 2630 * (which can be non-zero only the first time 2631 * through the "while" loop in step 3). 2632 */ 2633 2634 fudge = start - entry->start; 2635 } else { 2636 2637 /* 2638 * normal reference: we clip the map to fit (thus 2639 * fudge is zero) 2640 */ 2641 2642 UVM_MAP_CLIP_START(srcmap, entry, start); 2643 SAVE_HINT(srcmap, srcmap->hint, entry->prev); 2644 fudge = 0; 2645 } 2646 } else { 2647 2648 /* "start" is not within an entry ... skip to next entry */ 2649 if (flags & UVM_EXTRACT_CONTIG) { 2650 error = EINVAL; 2651 goto bad; /* definite hole here ... */ 2652 } 2653 2654 entry = entry->next; 2655 fudge = 0; 2656 } 2657 2658 /* save values from srcmap for step 6 */ 2659 orig_entry = entry; 2660 orig_fudge = fudge; 2661 2662 /* 2663 * step 3: now start looping through the map entries, extracting 2664 * as we go. 2665 */ 2666 2667 while (entry->start < end && entry != &srcmap->header) { 2668 2669 /* if we are not doing a quick reference, clip it */ 2670 if ((flags & UVM_EXTRACT_QREF) == 0) 2671 UVM_MAP_CLIP_END(srcmap, entry, end); 2672 2673 /* clear needs_copy (allow chunking) */ 2674 if (UVM_ET_ISNEEDSCOPY(entry)) { 2675 amap_copy(srcmap, entry, 2676 AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end); 2677 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */ 2678 error = ENOMEM; 2679 goto bad; 2680 } 2681 2682 /* amap_copy could clip (during chunk)! update fudge */ 2683 if (fudge) { 2684 fudge = start - entry->start; 2685 orig_fudge = fudge; 2686 } 2687 } 2688 2689 /* calculate the offset of this from "start" */ 2690 oldoffset = (entry->start + fudge) - start; 2691 2692 /* allocate a new map entry */ 2693 newentry = uvm_mapent_alloc(dstmap, 0); 2694 if (newentry == NULL) { 2695 error = ENOMEM; 2696 goto bad; 2697 } 2698 2699 /* set up new map entry */ 2700 newentry->next = NULL; 2701 newentry->prev = endchain; 2702 newentry->start = dstaddr + oldoffset; 2703 newentry->end = 2704 newentry->start + (entry->end - (entry->start + fudge)); 2705 if (newentry->end > newend || newentry->end < newentry->start) 2706 newentry->end = newend; 2707 newentry->object.uvm_obj = entry->object.uvm_obj; 2708 if (newentry->object.uvm_obj) { 2709 if (newentry->object.uvm_obj->pgops->pgo_reference) 2710 newentry->object.uvm_obj->pgops-> 2711 pgo_reference(newentry->object.uvm_obj); 2712 newentry->offset = entry->offset + fudge; 2713 } else { 2714 newentry->offset = 0; 2715 } 2716 newentry->etype = entry->etype; 2717 if (flags & UVM_EXTRACT_PROT_ALL) { 2718 newentry->protection = newentry->max_protection = 2719 UVM_PROT_ALL; 2720 } else { 2721 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ? 2722 entry->max_protection : entry->protection; 2723 newentry->max_protection = entry->max_protection; 2724 } 2725 newentry->inheritance = entry->inheritance; 2726 newentry->wired_count = 0; 2727 newentry->aref.ar_amap = entry->aref.ar_amap; 2728 if (newentry->aref.ar_amap) { 2729 newentry->aref.ar_pageoff = 2730 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT); 2731 uvm_map_reference_amap(newentry, AMAP_SHARED | 2732 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0)); 2733 } else { 2734 newentry->aref.ar_pageoff = 0; 2735 } 2736 newentry->advice = entry->advice; 2737 if ((flags & UVM_EXTRACT_QREF) != 0) { 2738 newentry->flags |= UVM_MAP_NOMERGE; 2739 } 2740 2741 /* now link it on the chain */ 2742 nchain++; 2743 nsize += newentry->end - newentry->start; 2744 if (endchain == NULL) { 2745 chain = endchain = newentry; 2746 } else { 2747 endchain->next = newentry; 2748 endchain = newentry; 2749 } 2750 2751 /* end of 'while' loop! */ 2752 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end && 2753 (entry->next == &srcmap->header || 2754 entry->next->start != entry->end)) { 2755 error = EINVAL; 2756 goto bad; 2757 } 2758 entry = entry->next; 2759 fudge = 0; 2760 } 2761 2762 /* 2763 * step 4: close off chain (in format expected by uvm_map_replace) 2764 */ 2765 2766 if (chain) 2767 chain->prev = endchain; 2768 2769 /* 2770 * step 5: attempt to lock the dest map so we can pmap_copy. 2771 * note usage of copy_ok: 2772 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5) 2773 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7 2774 */ 2775 2776 if (srcmap == dstmap || vm_map_lock_try(dstmap) == true) { 2777 copy_ok = 1; 2778 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2779 nchain, nsize, &resentry)) { 2780 if (srcmap != dstmap) 2781 vm_map_unlock(dstmap); 2782 error = EIO; 2783 goto bad; 2784 } 2785 } else { 2786 copy_ok = 0; 2787 /* replace defered until step 7 */ 2788 } 2789 2790 /* 2791 * step 6: traverse the srcmap a second time to do the following: 2792 * - if we got a lock on the dstmap do pmap_copy 2793 * - if UVM_EXTRACT_REMOVE remove the entries 2794 * we make use of orig_entry and orig_fudge (saved in step 2) 2795 */ 2796 2797 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) { 2798 2799 /* purge possible stale hints from srcmap */ 2800 if (flags & UVM_EXTRACT_REMOVE) { 2801 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev); 2802 if (srcmap->first_free != &srcmap->header && 2803 srcmap->first_free->start >= start) 2804 srcmap->first_free = orig_entry->prev; 2805 } 2806 2807 entry = orig_entry; 2808 fudge = orig_fudge; 2809 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */ 2810 2811 while (entry->start < end && entry != &srcmap->header) { 2812 if (copy_ok) { 2813 oldoffset = (entry->start + fudge) - start; 2814 elen = MIN(end, entry->end) - 2815 (entry->start + fudge); 2816 pmap_copy(dstmap->pmap, srcmap->pmap, 2817 dstaddr + oldoffset, elen, 2818 entry->start + fudge); 2819 } 2820 2821 /* we advance "entry" in the following if statement */ 2822 if (flags & UVM_EXTRACT_REMOVE) { 2823 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */ 2824 uvm_map_lock_entry(entry, RW_WRITER); 2825 #else 2826 uvm_map_lock_entry(entry, RW_READER); 2827 #endif 2828 pmap_remove(srcmap->pmap, entry->start, 2829 entry->end); 2830 uvm_map_unlock_entry(entry); 2831 oldentry = entry; /* save entry */ 2832 entry = entry->next; /* advance */ 2833 uvm_map_entry_unlink(srcmap, oldentry); 2834 /* add to dead list */ 2835 oldentry->next = deadentry; 2836 deadentry = oldentry; 2837 } else { 2838 entry = entry->next; /* advance */ 2839 } 2840 2841 /* end of 'while' loop */ 2842 fudge = 0; 2843 } 2844 pmap_update(srcmap->pmap); 2845 2846 /* 2847 * unlock dstmap. we will dispose of deadentry in 2848 * step 7 if needed 2849 */ 2850 2851 if (copy_ok && srcmap != dstmap) 2852 vm_map_unlock(dstmap); 2853 2854 } else { 2855 deadentry = NULL; 2856 } 2857 2858 /* 2859 * step 7: we are done with the source map, unlock. if copy_ok 2860 * is 0 then we have not replaced the dummy mapping in dstmap yet 2861 * and we need to do so now. 2862 */ 2863 2864 vm_map_unlock(srcmap); 2865 if ((flags & UVM_EXTRACT_REMOVE) && deadentry) 2866 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */ 2867 2868 /* now do the replacement if we didn't do it in step 5 */ 2869 if (copy_ok == 0) { 2870 vm_map_lock(dstmap); 2871 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2872 nchain, nsize, &resentry); 2873 vm_map_unlock(dstmap); 2874 2875 if (error == false) { 2876 error = EIO; 2877 goto bad2; 2878 } 2879 } 2880 2881 if (resentry != NULL) 2882 uvm_mapent_free(resentry); 2883 2884 return (0); 2885 2886 /* 2887 * bad: failure recovery 2888 */ 2889 bad: 2890 vm_map_unlock(srcmap); 2891 bad2: /* src already unlocked */ 2892 if (chain) 2893 uvm_unmap_detach(chain, 2894 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0); 2895 2896 if (resentry != NULL) 2897 uvm_mapent_free(resentry); 2898 2899 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2900 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */ 2901 } 2902 return (error); 2903 } 2904 2905 /* end of extraction functions */ 2906 2907 /* 2908 * uvm_map_submap: punch down part of a map into a submap 2909 * 2910 * => only the kernel_map is allowed to be submapped 2911 * => the purpose of submapping is to break up the locking granularity 2912 * of a larger map 2913 * => the range specified must have been mapped previously with a uvm_map() 2914 * call [with uobj==NULL] to create a blank map entry in the main map. 2915 * [And it had better still be blank!] 2916 * => maps which contain submaps should never be copied or forked. 2917 * => to remove a submap, use uvm_unmap() on the main map 2918 * and then uvm_map_deallocate() the submap. 2919 * => main map must be unlocked. 2920 * => submap must have been init'd and have a zero reference count. 2921 * [need not be locked as we don't actually reference it] 2922 */ 2923 2924 int 2925 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end, 2926 struct vm_map *submap) 2927 { 2928 struct vm_map_entry *entry; 2929 int error; 2930 2931 vm_map_lock(map); 2932 VM_MAP_RANGE_CHECK(map, start, end); 2933 2934 if (uvm_map_lookup_entry(map, start, &entry)) { 2935 UVM_MAP_CLIP_START(map, entry, start); 2936 UVM_MAP_CLIP_END(map, entry, end); /* to be safe */ 2937 } else { 2938 entry = NULL; 2939 } 2940 2941 if (entry != NULL && 2942 entry->start == start && entry->end == end && 2943 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL && 2944 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) { 2945 entry->etype |= UVM_ET_SUBMAP; 2946 entry->object.sub_map = submap; 2947 entry->offset = 0; 2948 uvm_map_reference(submap); 2949 error = 0; 2950 } else { 2951 error = EINVAL; 2952 } 2953 vm_map_unlock(map); 2954 2955 return error; 2956 } 2957 2958 /* 2959 * uvm_map_protect_user: change map protection on behalf of the user. 2960 * Enforces PAX settings as necessary. 2961 */ 2962 int 2963 uvm_map_protect_user(struct lwp *l, vaddr_t start, vaddr_t end, 2964 vm_prot_t new_prot) 2965 { 2966 int error; 2967 2968 if ((error = PAX_MPROTECT_VALIDATE(l, new_prot))) 2969 return error; 2970 2971 return uvm_map_protect(&l->l_proc->p_vmspace->vm_map, start, end, 2972 new_prot, false); 2973 } 2974 2975 2976 /* 2977 * uvm_map_protect: change map protection 2978 * 2979 * => set_max means set max_protection. 2980 * => map must be unlocked. 2981 */ 2982 2983 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \ 2984 ~VM_PROT_WRITE : VM_PROT_ALL) 2985 2986 int 2987 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end, 2988 vm_prot_t new_prot, bool set_max) 2989 { 2990 struct vm_map_entry *current, *entry; 2991 int error = 0; 2992 UVMHIST_FUNC(__func__); 2993 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_prot=%#jx)", 2994 (uintptr_t)map, start, end, new_prot); 2995 2996 vm_map_lock(map); 2997 VM_MAP_RANGE_CHECK(map, start, end); 2998 if (uvm_map_lookup_entry(map, start, &entry)) { 2999 UVM_MAP_CLIP_START(map, entry, start); 3000 } else { 3001 entry = entry->next; 3002 } 3003 3004 /* 3005 * make a first pass to check for protection violations. 3006 */ 3007 3008 current = entry; 3009 while ((current != &map->header) && (current->start < end)) { 3010 if (UVM_ET_ISSUBMAP(current)) { 3011 error = EINVAL; 3012 goto out; 3013 } 3014 if ((new_prot & current->max_protection) != new_prot) { 3015 error = EACCES; 3016 goto out; 3017 } 3018 /* 3019 * Don't allow VM_PROT_EXECUTE to be set on entries that 3020 * point to vnodes that are associated with a NOEXEC file 3021 * system. 3022 */ 3023 if (UVM_ET_ISOBJ(current) && 3024 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) { 3025 struct vnode *vp = 3026 (struct vnode *) current->object.uvm_obj; 3027 3028 if ((new_prot & VM_PROT_EXECUTE) != 0 && 3029 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { 3030 error = EACCES; 3031 goto out; 3032 } 3033 } 3034 3035 current = current->next; 3036 } 3037 3038 /* go back and fix up protections (no need to clip this time). */ 3039 3040 current = entry; 3041 while ((current != &map->header) && (current->start < end)) { 3042 vm_prot_t old_prot; 3043 3044 UVM_MAP_CLIP_END(map, current, end); 3045 old_prot = current->protection; 3046 if (set_max) 3047 current->protection = 3048 (current->max_protection = new_prot) & old_prot; 3049 else 3050 current->protection = new_prot; 3051 3052 /* 3053 * update physical map if necessary. worry about copy-on-write 3054 * here -- CHECK THIS XXX 3055 */ 3056 3057 if (current->protection != old_prot) { 3058 /* update pmap! */ 3059 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */ 3060 uvm_map_lock_entry(current, RW_WRITER); 3061 #else 3062 uvm_map_lock_entry(current, RW_READER); 3063 #endif 3064 pmap_protect(map->pmap, current->start, current->end, 3065 current->protection & MASK(current)); 3066 uvm_map_unlock_entry(current); 3067 3068 /* 3069 * If this entry points at a vnode, and the 3070 * protection includes VM_PROT_EXECUTE, mark 3071 * the vnode as VEXECMAP. 3072 */ 3073 if (UVM_ET_ISOBJ(current)) { 3074 struct uvm_object *uobj = 3075 current->object.uvm_obj; 3076 3077 if (UVM_OBJ_IS_VNODE(uobj) && 3078 (current->protection & VM_PROT_EXECUTE)) { 3079 vn_markexec((struct vnode *) uobj); 3080 } 3081 } 3082 } 3083 3084 /* 3085 * If the map is configured to lock any future mappings, 3086 * wire this entry now if the old protection was VM_PROT_NONE 3087 * and the new protection is not VM_PROT_NONE. 3088 */ 3089 3090 if ((map->flags & VM_MAP_WIREFUTURE) != 0 && 3091 VM_MAPENT_ISWIRED(current) == 0 && 3092 old_prot == VM_PROT_NONE && 3093 new_prot != VM_PROT_NONE) { 3094 3095 /* 3096 * We must call pmap_update() here because the 3097 * pmap_protect() call above might have removed some 3098 * pmap entries and uvm_map_pageable() might create 3099 * some new pmap entries that rely on the prior 3100 * removals being completely finished. 3101 */ 3102 3103 pmap_update(map->pmap); 3104 3105 if (uvm_map_pageable(map, current->start, 3106 current->end, false, 3107 UVM_LK_ENTER|UVM_LK_EXIT) != 0) { 3108 3109 /* 3110 * If locking the entry fails, remember the 3111 * error if it's the first one. Note we 3112 * still continue setting the protection in 3113 * the map, but will return the error 3114 * condition regardless. 3115 * 3116 * XXX Ignore what the actual error is, 3117 * XXX just call it a resource shortage 3118 * XXX so that it doesn't get confused 3119 * XXX what uvm_map_protect() itself would 3120 * XXX normally return. 3121 */ 3122 3123 error = ENOMEM; 3124 } 3125 } 3126 current = current->next; 3127 } 3128 pmap_update(map->pmap); 3129 3130 out: 3131 vm_map_unlock(map); 3132 3133 UVMHIST_LOG(maphist, "<- done, error=%jd",error,0,0,0); 3134 return error; 3135 } 3136 3137 #undef MASK 3138 3139 /* 3140 * uvm_map_inherit: set inheritance code for range of addrs in map. 3141 * 3142 * => map must be unlocked 3143 * => note that the inherit code is used during a "fork". see fork 3144 * code for details. 3145 */ 3146 3147 int 3148 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end, 3149 vm_inherit_t new_inheritance) 3150 { 3151 struct vm_map_entry *entry, *temp_entry; 3152 UVMHIST_FUNC(__func__); 3153 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_inh=%#jx)", 3154 (uintptr_t)map, start, end, new_inheritance); 3155 3156 switch (new_inheritance) { 3157 case MAP_INHERIT_NONE: 3158 case MAP_INHERIT_COPY: 3159 case MAP_INHERIT_SHARE: 3160 case MAP_INHERIT_ZERO: 3161 break; 3162 default: 3163 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3164 return EINVAL; 3165 } 3166 3167 vm_map_lock(map); 3168 VM_MAP_RANGE_CHECK(map, start, end); 3169 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3170 entry = temp_entry; 3171 UVM_MAP_CLIP_START(map, entry, start); 3172 } else { 3173 entry = temp_entry->next; 3174 } 3175 while ((entry != &map->header) && (entry->start < end)) { 3176 UVM_MAP_CLIP_END(map, entry, end); 3177 entry->inheritance = new_inheritance; 3178 entry = entry->next; 3179 } 3180 vm_map_unlock(map); 3181 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3182 return 0; 3183 } 3184 3185 /* 3186 * uvm_map_advice: set advice code for range of addrs in map. 3187 * 3188 * => map must be unlocked 3189 */ 3190 3191 int 3192 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice) 3193 { 3194 struct vm_map_entry *entry, *temp_entry; 3195 UVMHIST_FUNC(__func__); 3196 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_adv=%#jx)", 3197 (uintptr_t)map, start, end, new_advice); 3198 3199 vm_map_lock(map); 3200 VM_MAP_RANGE_CHECK(map, start, end); 3201 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3202 entry = temp_entry; 3203 UVM_MAP_CLIP_START(map, entry, start); 3204 } else { 3205 entry = temp_entry->next; 3206 } 3207 3208 /* 3209 * XXXJRT: disallow holes? 3210 */ 3211 3212 while ((entry != &map->header) && (entry->start < end)) { 3213 UVM_MAP_CLIP_END(map, entry, end); 3214 3215 switch (new_advice) { 3216 case MADV_NORMAL: 3217 case MADV_RANDOM: 3218 case MADV_SEQUENTIAL: 3219 /* nothing special here */ 3220 break; 3221 3222 default: 3223 vm_map_unlock(map); 3224 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3225 return EINVAL; 3226 } 3227 entry->advice = new_advice; 3228 entry = entry->next; 3229 } 3230 3231 vm_map_unlock(map); 3232 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3233 return 0; 3234 } 3235 3236 /* 3237 * uvm_map_willneed: apply MADV_WILLNEED 3238 */ 3239 3240 int 3241 uvm_map_willneed(struct vm_map *map, vaddr_t start, vaddr_t end) 3242 { 3243 struct vm_map_entry *entry; 3244 UVMHIST_FUNC(__func__); 3245 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx)", 3246 (uintptr_t)map, start, end, 0); 3247 3248 vm_map_lock_read(map); 3249 VM_MAP_RANGE_CHECK(map, start, end); 3250 if (!uvm_map_lookup_entry(map, start, &entry)) { 3251 entry = entry->next; 3252 } 3253 while (entry->start < end) { 3254 struct vm_amap * const amap = entry->aref.ar_amap; 3255 struct uvm_object * const uobj = entry->object.uvm_obj; 3256 3257 KASSERT(entry != &map->header); 3258 KASSERT(start < entry->end); 3259 /* 3260 * For now, we handle only the easy but commonly-requested case. 3261 * ie. start prefetching of backing uobj pages. 3262 * 3263 * XXX It might be useful to pmap_enter() the already-in-core 3264 * pages by inventing a "weak" mode for uvm_fault() which would 3265 * only do the PGO_LOCKED pgo_get(). 3266 */ 3267 if (UVM_ET_ISOBJ(entry) && amap == NULL && uobj != NULL) { 3268 off_t offset; 3269 off_t size; 3270 3271 offset = entry->offset; 3272 if (start < entry->start) { 3273 offset += entry->start - start; 3274 } 3275 size = entry->offset + (entry->end - entry->start); 3276 if (entry->end < end) { 3277 size -= end - entry->end; 3278 } 3279 uvm_readahead(uobj, offset, size); 3280 } 3281 entry = entry->next; 3282 } 3283 vm_map_unlock_read(map); 3284 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3285 return 0; 3286 } 3287 3288 /* 3289 * uvm_map_pageable: sets the pageability of a range in a map. 3290 * 3291 * => wires map entries. should not be used for transient page locking. 3292 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). 3293 * => regions specified as not pageable require lock-down (wired) memory 3294 * and page tables. 3295 * => map must never be read-locked 3296 * => if islocked is true, map is already write-locked 3297 * => we always unlock the map, since we must downgrade to a read-lock 3298 * to call uvm_fault_wire() 3299 * => XXXCDC: check this and try and clean it up. 3300 */ 3301 3302 int 3303 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end, 3304 bool new_pageable, int lockflags) 3305 { 3306 struct vm_map_entry *entry, *start_entry, *failed_entry; 3307 int rv; 3308 #ifdef DIAGNOSTIC 3309 u_int timestamp_save; 3310 #endif 3311 UVMHIST_FUNC(__func__); 3312 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_pageable=%ju)", 3313 (uintptr_t)map, start, end, new_pageable); 3314 KASSERT(map->flags & VM_MAP_PAGEABLE); 3315 3316 if ((lockflags & UVM_LK_ENTER) == 0) 3317 vm_map_lock(map); 3318 VM_MAP_RANGE_CHECK(map, start, end); 3319 3320 /* 3321 * only one pageability change may take place at one time, since 3322 * uvm_fault_wire assumes it will be called only once for each 3323 * wiring/unwiring. therefore, we have to make sure we're actually 3324 * changing the pageability for the entire region. we do so before 3325 * making any changes. 3326 */ 3327 3328 if (uvm_map_lookup_entry(map, start, &start_entry) == false) { 3329 if ((lockflags & UVM_LK_EXIT) == 0) 3330 vm_map_unlock(map); 3331 3332 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0); 3333 return EFAULT; 3334 } 3335 entry = start_entry; 3336 3337 if (start == end) { /* nothing required */ 3338 if ((lockflags & UVM_LK_EXIT) == 0) 3339 vm_map_unlock(map); 3340 3341 UVMHIST_LOG(maphist,"<- done (nothing)",0,0,0,0); 3342 return 0; 3343 } 3344 3345 /* 3346 * handle wiring and unwiring separately. 3347 */ 3348 3349 if (new_pageable) { /* unwire */ 3350 UVM_MAP_CLIP_START(map, entry, start); 3351 3352 /* 3353 * unwiring. first ensure that the range to be unwired is 3354 * really wired down and that there are no holes. 3355 */ 3356 3357 while ((entry != &map->header) && (entry->start < end)) { 3358 if (entry->wired_count == 0 || 3359 (entry->end < end && 3360 (entry->next == &map->header || 3361 entry->next->start > entry->end))) { 3362 if ((lockflags & UVM_LK_EXIT) == 0) 3363 vm_map_unlock(map); 3364 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0); 3365 return EINVAL; 3366 } 3367 entry = entry->next; 3368 } 3369 3370 /* 3371 * POSIX 1003.1b - a single munlock call unlocks a region, 3372 * regardless of the number of mlock calls made on that 3373 * region. 3374 */ 3375 3376 entry = start_entry; 3377 while ((entry != &map->header) && (entry->start < end)) { 3378 UVM_MAP_CLIP_END(map, entry, end); 3379 if (VM_MAPENT_ISWIRED(entry)) 3380 uvm_map_entry_unwire(map, entry); 3381 entry = entry->next; 3382 } 3383 if ((lockflags & UVM_LK_EXIT) == 0) 3384 vm_map_unlock(map); 3385 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3386 return 0; 3387 } 3388 3389 /* 3390 * wire case: in two passes [XXXCDC: ugly block of code here] 3391 * 3392 * 1: holding the write lock, we create any anonymous maps that need 3393 * to be created. then we clip each map entry to the region to 3394 * be wired and increment its wiring count. 3395 * 3396 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 3397 * in the pages for any newly wired area (wired_count == 1). 3398 * 3399 * downgrading to a read lock for uvm_fault_wire avoids a possible 3400 * deadlock with another thread that may have faulted on one of 3401 * the pages to be wired (it would mark the page busy, blocking 3402 * us, then in turn block on the map lock that we hold). because 3403 * of problems in the recursive lock package, we cannot upgrade 3404 * to a write lock in vm_map_lookup. thus, any actions that 3405 * require the write lock must be done beforehand. because we 3406 * keep the read lock on the map, the copy-on-write status of the 3407 * entries we modify here cannot change. 3408 */ 3409 3410 while ((entry != &map->header) && (entry->start < end)) { 3411 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3412 3413 /* 3414 * perform actions of vm_map_lookup that need the 3415 * write lock on the map: create an anonymous map 3416 * for a copy-on-write region, or an anonymous map 3417 * for a zero-fill region. (XXXCDC: submap case 3418 * ok?) 3419 */ 3420 3421 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3422 if (UVM_ET_ISNEEDSCOPY(entry) && 3423 ((entry->max_protection & VM_PROT_WRITE) || 3424 (entry->object.uvm_obj == NULL))) { 3425 amap_copy(map, entry, 0, start, end); 3426 /* XXXCDC: wait OK? */ 3427 } 3428 } 3429 } 3430 UVM_MAP_CLIP_START(map, entry, start); 3431 UVM_MAP_CLIP_END(map, entry, end); 3432 entry->wired_count++; 3433 3434 /* 3435 * Check for holes 3436 */ 3437 3438 if (entry->protection == VM_PROT_NONE || 3439 (entry->end < end && 3440 (entry->next == &map->header || 3441 entry->next->start > entry->end))) { 3442 3443 /* 3444 * found one. amap creation actions do not need to 3445 * be undone, but the wired counts need to be restored. 3446 */ 3447 3448 while (entry != &map->header && entry->end > start) { 3449 entry->wired_count--; 3450 entry = entry->prev; 3451 } 3452 if ((lockflags & UVM_LK_EXIT) == 0) 3453 vm_map_unlock(map); 3454 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0); 3455 return EINVAL; 3456 } 3457 entry = entry->next; 3458 } 3459 3460 /* 3461 * Pass 2. 3462 */ 3463 3464 #ifdef DIAGNOSTIC 3465 timestamp_save = map->timestamp; 3466 #endif 3467 vm_map_busy(map); 3468 vm_map_unlock(map); 3469 3470 rv = 0; 3471 entry = start_entry; 3472 while (entry != &map->header && entry->start < end) { 3473 if (entry->wired_count == 1) { 3474 rv = uvm_fault_wire(map, entry->start, entry->end, 3475 entry->max_protection, 1); 3476 if (rv) { 3477 3478 /* 3479 * wiring failed. break out of the loop. 3480 * we'll clean up the map below, once we 3481 * have a write lock again. 3482 */ 3483 3484 break; 3485 } 3486 } 3487 entry = entry->next; 3488 } 3489 3490 if (rv) { /* failed? */ 3491 3492 /* 3493 * Get back to an exclusive (write) lock. 3494 */ 3495 3496 vm_map_lock(map); 3497 vm_map_unbusy(map); 3498 3499 #ifdef DIAGNOSTIC 3500 if (timestamp_save + 1 != map->timestamp) 3501 panic("uvm_map_pageable: stale map"); 3502 #endif 3503 3504 /* 3505 * first drop the wiring count on all the entries 3506 * which haven't actually been wired yet. 3507 */ 3508 3509 failed_entry = entry; 3510 while (entry != &map->header && entry->start < end) { 3511 entry->wired_count--; 3512 entry = entry->next; 3513 } 3514 3515 /* 3516 * now, unwire all the entries that were successfully 3517 * wired above. 3518 */ 3519 3520 entry = start_entry; 3521 while (entry != failed_entry) { 3522 entry->wired_count--; 3523 if (VM_MAPENT_ISWIRED(entry) == 0) 3524 uvm_map_entry_unwire(map, entry); 3525 entry = entry->next; 3526 } 3527 if ((lockflags & UVM_LK_EXIT) == 0) 3528 vm_map_unlock(map); 3529 UVMHIST_LOG(maphist, "<- done (RV=%jd)", rv,0,0,0); 3530 return (rv); 3531 } 3532 3533 if ((lockflags & UVM_LK_EXIT) == 0) { 3534 vm_map_unbusy(map); 3535 } else { 3536 3537 /* 3538 * Get back to an exclusive (write) lock. 3539 */ 3540 3541 vm_map_lock(map); 3542 vm_map_unbusy(map); 3543 } 3544 3545 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3546 return 0; 3547 } 3548 3549 /* 3550 * uvm_map_pageable_all: special case of uvm_map_pageable - affects 3551 * all mapped regions. 3552 * 3553 * => map must not be locked. 3554 * => if no flags are specified, all regions are unwired. 3555 * => XXXJRT: has some of the same problems as uvm_map_pageable() above. 3556 */ 3557 3558 int 3559 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit) 3560 { 3561 struct vm_map_entry *entry, *failed_entry; 3562 vsize_t size; 3563 int rv; 3564 #ifdef DIAGNOSTIC 3565 u_int timestamp_save; 3566 #endif 3567 UVMHIST_FUNC(__func__); 3568 UVMHIST_CALLARGS(maphist,"(map=%#jx,flags=%#jx)", (uintptr_t)map, flags, 3569 0, 0); 3570 3571 KASSERT(map->flags & VM_MAP_PAGEABLE); 3572 3573 vm_map_lock(map); 3574 3575 /* 3576 * handle wiring and unwiring separately. 3577 */ 3578 3579 if (flags == 0) { /* unwire */ 3580 3581 /* 3582 * POSIX 1003.1b -- munlockall unlocks all regions, 3583 * regardless of how many times mlockall has been called. 3584 */ 3585 3586 for (entry = map->header.next; entry != &map->header; 3587 entry = entry->next) { 3588 if (VM_MAPENT_ISWIRED(entry)) 3589 uvm_map_entry_unwire(map, entry); 3590 } 3591 map->flags &= ~VM_MAP_WIREFUTURE; 3592 vm_map_unlock(map); 3593 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3594 return 0; 3595 } 3596 3597 if (flags & MCL_FUTURE) { 3598 3599 /* 3600 * must wire all future mappings; remember this. 3601 */ 3602 3603 map->flags |= VM_MAP_WIREFUTURE; 3604 } 3605 3606 if ((flags & MCL_CURRENT) == 0) { 3607 3608 /* 3609 * no more work to do! 3610 */ 3611 3612 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0); 3613 vm_map_unlock(map); 3614 return 0; 3615 } 3616 3617 /* 3618 * wire case: in three passes [XXXCDC: ugly block of code here] 3619 * 3620 * 1: holding the write lock, count all pages mapped by non-wired 3621 * entries. if this would cause us to go over our limit, we fail. 3622 * 3623 * 2: still holding the write lock, we create any anonymous maps that 3624 * need to be created. then we increment its wiring count. 3625 * 3626 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault 3627 * in the pages for any newly wired area (wired_count == 1). 3628 * 3629 * downgrading to a read lock for uvm_fault_wire avoids a possible 3630 * deadlock with another thread that may have faulted on one of 3631 * the pages to be wired (it would mark the page busy, blocking 3632 * us, then in turn block on the map lock that we hold). because 3633 * of problems in the recursive lock package, we cannot upgrade 3634 * to a write lock in vm_map_lookup. thus, any actions that 3635 * require the write lock must be done beforehand. because we 3636 * keep the read lock on the map, the copy-on-write status of the 3637 * entries we modify here cannot change. 3638 */ 3639 3640 for (size = 0, entry = map->header.next; entry != &map->header; 3641 entry = entry->next) { 3642 if (entry->protection != VM_PROT_NONE && 3643 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3644 size += entry->end - entry->start; 3645 } 3646 } 3647 3648 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) { 3649 vm_map_unlock(map); 3650 return ENOMEM; 3651 } 3652 3653 if (limit != 0 && 3654 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) { 3655 vm_map_unlock(map); 3656 return ENOMEM; 3657 } 3658 3659 /* 3660 * Pass 2. 3661 */ 3662 3663 for (entry = map->header.next; entry != &map->header; 3664 entry = entry->next) { 3665 if (entry->protection == VM_PROT_NONE) 3666 continue; 3667 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3668 3669 /* 3670 * perform actions of vm_map_lookup that need the 3671 * write lock on the map: create an anonymous map 3672 * for a copy-on-write region, or an anonymous map 3673 * for a zero-fill region. (XXXCDC: submap case 3674 * ok?) 3675 */ 3676 3677 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3678 if (UVM_ET_ISNEEDSCOPY(entry) && 3679 ((entry->max_protection & VM_PROT_WRITE) || 3680 (entry->object.uvm_obj == NULL))) { 3681 amap_copy(map, entry, 0, entry->start, 3682 entry->end); 3683 /* XXXCDC: wait OK? */ 3684 } 3685 } 3686 } 3687 entry->wired_count++; 3688 } 3689 3690 /* 3691 * Pass 3. 3692 */ 3693 3694 #ifdef DIAGNOSTIC 3695 timestamp_save = map->timestamp; 3696 #endif 3697 vm_map_busy(map); 3698 vm_map_unlock(map); 3699 3700 rv = 0; 3701 for (entry = map->header.next; entry != &map->header; 3702 entry = entry->next) { 3703 if (entry->wired_count == 1) { 3704 rv = uvm_fault_wire(map, entry->start, entry->end, 3705 entry->max_protection, 1); 3706 if (rv) { 3707 3708 /* 3709 * wiring failed. break out of the loop. 3710 * we'll clean up the map below, once we 3711 * have a write lock again. 3712 */ 3713 3714 break; 3715 } 3716 } 3717 } 3718 3719 if (rv) { 3720 3721 /* 3722 * Get back an exclusive (write) lock. 3723 */ 3724 3725 vm_map_lock(map); 3726 vm_map_unbusy(map); 3727 3728 #ifdef DIAGNOSTIC 3729 if (timestamp_save + 1 != map->timestamp) 3730 panic("uvm_map_pageable_all: stale map"); 3731 #endif 3732 3733 /* 3734 * first drop the wiring count on all the entries 3735 * which haven't actually been wired yet. 3736 * 3737 * Skip VM_PROT_NONE entries like we did above. 3738 */ 3739 3740 failed_entry = entry; 3741 for (/* nothing */; entry != &map->header; 3742 entry = entry->next) { 3743 if (entry->protection == VM_PROT_NONE) 3744 continue; 3745 entry->wired_count--; 3746 } 3747 3748 /* 3749 * now, unwire all the entries that were successfully 3750 * wired above. 3751 * 3752 * Skip VM_PROT_NONE entries like we did above. 3753 */ 3754 3755 for (entry = map->header.next; entry != failed_entry; 3756 entry = entry->next) { 3757 if (entry->protection == VM_PROT_NONE) 3758 continue; 3759 entry->wired_count--; 3760 if (VM_MAPENT_ISWIRED(entry)) 3761 uvm_map_entry_unwire(map, entry); 3762 } 3763 vm_map_unlock(map); 3764 UVMHIST_LOG(maphist,"<- done (RV=%jd)", rv,0,0,0); 3765 return (rv); 3766 } 3767 3768 vm_map_unbusy(map); 3769 3770 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3771 return 0; 3772 } 3773 3774 /* 3775 * uvm_map_clean: clean out a map range 3776 * 3777 * => valid flags: 3778 * if (flags & PGO_CLEANIT): dirty pages are cleaned first 3779 * if (flags & PGO_SYNCIO): dirty pages are written synchronously 3780 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean 3781 * if (flags & PGO_FREE): any cached pages are freed after clean 3782 * => returns an error if any part of the specified range isn't mapped 3783 * => never a need to flush amap layer since the anonymous memory has 3784 * no permanent home, but may deactivate pages there 3785 * => called from sys_msync() and sys_madvise() 3786 * => caller must not write-lock map (read OK). 3787 * => we may sleep while cleaning if SYNCIO [with map read-locked] 3788 */ 3789 3790 int 3791 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 3792 { 3793 struct vm_map_entry *current, *entry; 3794 struct uvm_object *uobj; 3795 struct vm_amap *amap; 3796 struct vm_anon *anon; 3797 struct vm_page *pg; 3798 vaddr_t offset; 3799 vsize_t size; 3800 voff_t uoff; 3801 int error, refs; 3802 UVMHIST_FUNC(__func__); 3803 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,flags=%#jx)", 3804 (uintptr_t)map, start, end, flags); 3805 3806 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) != 3807 (PGO_FREE|PGO_DEACTIVATE)); 3808 3809 vm_map_lock_read(map); 3810 VM_MAP_RANGE_CHECK(map, start, end); 3811 if (uvm_map_lookup_entry(map, start, &entry) == false) { 3812 vm_map_unlock_read(map); 3813 return EFAULT; 3814 } 3815 3816 /* 3817 * Make a first pass to check for holes and wiring problems. 3818 */ 3819 3820 for (current = entry; current->start < end; current = current->next) { 3821 if (UVM_ET_ISSUBMAP(current)) { 3822 vm_map_unlock_read(map); 3823 return EINVAL; 3824 } 3825 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) { 3826 vm_map_unlock_read(map); 3827 return EBUSY; 3828 } 3829 if (end <= current->end) { 3830 break; 3831 } 3832 if (current->end != current->next->start) { 3833 vm_map_unlock_read(map); 3834 return EFAULT; 3835 } 3836 } 3837 3838 error = 0; 3839 for (current = entry; start < end; current = current->next) { 3840 amap = current->aref.ar_amap; /* upper layer */ 3841 uobj = current->object.uvm_obj; /* lower layer */ 3842 KASSERT(start >= current->start); 3843 3844 /* 3845 * No amap cleaning necessary if: 3846 * 3847 * (1) There's no amap. 3848 * 3849 * (2) We're not deactivating or freeing pages. 3850 */ 3851 3852 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) 3853 goto flush_object; 3854 3855 offset = start - current->start; 3856 size = MIN(end, current->end) - start; 3857 3858 amap_lock(amap, RW_WRITER); 3859 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) { 3860 anon = amap_lookup(¤t->aref, offset); 3861 if (anon == NULL) 3862 continue; 3863 3864 KASSERT(anon->an_lock == amap->am_lock); 3865 pg = anon->an_page; 3866 if (pg == NULL) { 3867 continue; 3868 } 3869 if (pg->flags & PG_BUSY) { 3870 continue; 3871 } 3872 3873 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) { 3874 3875 /* 3876 * In these first 3 cases, we just deactivate the page. 3877 */ 3878 3879 case PGO_CLEANIT|PGO_FREE: 3880 case PGO_CLEANIT|PGO_DEACTIVATE: 3881 case PGO_DEACTIVATE: 3882 deactivate_it: 3883 /* 3884 * skip the page if it's loaned or wired, 3885 * since it shouldn't be on a paging queue 3886 * at all in these cases. 3887 */ 3888 3889 if (pg->loan_count != 0 || 3890 pg->wire_count != 0) { 3891 continue; 3892 } 3893 KASSERT(pg->uanon == anon); 3894 uvm_pagelock(pg); 3895 uvm_pagedeactivate(pg); 3896 uvm_pageunlock(pg); 3897 continue; 3898 3899 case PGO_FREE: 3900 3901 /* 3902 * If there are multiple references to 3903 * the amap, just deactivate the page. 3904 */ 3905 3906 if (amap_refs(amap) > 1) 3907 goto deactivate_it; 3908 3909 /* skip the page if it's wired */ 3910 if (pg->wire_count != 0) { 3911 continue; 3912 } 3913 amap_unadd(¤t->aref, offset); 3914 refs = --anon->an_ref; 3915 if (refs == 0) { 3916 uvm_anfree(anon); 3917 } 3918 continue; 3919 } 3920 } 3921 amap_unlock(amap); 3922 3923 flush_object: 3924 /* 3925 * flush pages if we've got a valid backing object. 3926 * note that we must always clean object pages before 3927 * freeing them since otherwise we could reveal stale 3928 * data from files. 3929 */ 3930 3931 uoff = current->offset + (start - current->start); 3932 size = MIN(end, current->end) - start; 3933 if (uobj != NULL) { 3934 rw_enter(uobj->vmobjlock, RW_WRITER); 3935 if (uobj->pgops->pgo_put != NULL) 3936 error = (uobj->pgops->pgo_put)(uobj, uoff, 3937 uoff + size, flags | PGO_CLEANIT); 3938 else 3939 error = 0; 3940 } 3941 start += size; 3942 } 3943 vm_map_unlock_read(map); 3944 return (error); 3945 } 3946 3947 3948 /* 3949 * uvm_map_checkprot: check protection in map 3950 * 3951 * => must allow specified protection in a fully allocated region. 3952 * => map must be read or write locked by caller. 3953 */ 3954 3955 bool 3956 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end, 3957 vm_prot_t protection) 3958 { 3959 struct vm_map_entry *entry; 3960 struct vm_map_entry *tmp_entry; 3961 3962 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) { 3963 return (false); 3964 } 3965 entry = tmp_entry; 3966 while (start < end) { 3967 if (entry == &map->header) { 3968 return (false); 3969 } 3970 3971 /* 3972 * no holes allowed 3973 */ 3974 3975 if (start < entry->start) { 3976 return (false); 3977 } 3978 3979 /* 3980 * check protection associated with entry 3981 */ 3982 3983 if ((entry->protection & protection) != protection) { 3984 return (false); 3985 } 3986 start = entry->end; 3987 entry = entry->next; 3988 } 3989 return (true); 3990 } 3991 3992 /* 3993 * uvmspace_alloc: allocate a vmspace structure. 3994 * 3995 * - structure includes vm_map and pmap 3996 * - XXX: no locking on this structure 3997 * - refcnt set to 1, rest must be init'd by caller 3998 */ 3999 struct vmspace * 4000 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax, bool topdown) 4001 { 4002 struct vmspace *vm; 4003 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 4004 4005 vm = pool_cache_get(&uvm_vmspace_cache, PR_WAITOK); 4006 uvmspace_init(vm, NULL, vmin, vmax, topdown); 4007 UVMHIST_LOG(maphist,"<- done (vm=%#jx)", (uintptr_t)vm, 0, 0, 0); 4008 return (vm); 4009 } 4010 4011 /* 4012 * uvmspace_init: initialize a vmspace structure. 4013 * 4014 * - XXX: no locking on this structure 4015 * - refcnt set to 1, rest must be init'd by caller 4016 */ 4017 void 4018 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, 4019 vaddr_t vmax, bool topdown) 4020 { 4021 UVMHIST_FUNC(__func__); 4022 UVMHIST_CALLARGS(maphist, "(vm=%#jx, pmap=%#jx, vmin=%#jx, vmax=%#jx", 4023 (uintptr_t)vm, (uintptr_t)pmap, vmin, vmax); 4024 UVMHIST_LOG(maphist, " topdown=%ju)", topdown, 0, 0, 0); 4025 4026 memset(vm, 0, sizeof(*vm)); 4027 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE 4028 | (topdown ? VM_MAP_TOPDOWN : 0) 4029 ); 4030 if (pmap) 4031 pmap_reference(pmap); 4032 else 4033 pmap = pmap_create(); 4034 vm->vm_map.pmap = pmap; 4035 vm->vm_refcnt = 1; 4036 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4037 } 4038 4039 /* 4040 * uvmspace_share: share a vmspace between two processes 4041 * 4042 * - used for vfork, threads(?) 4043 */ 4044 4045 void 4046 uvmspace_share(struct proc *p1, struct proc *p2) 4047 { 4048 4049 uvmspace_addref(p1->p_vmspace); 4050 p2->p_vmspace = p1->p_vmspace; 4051 } 4052 4053 #if 0 4054 4055 /* 4056 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace 4057 * 4058 * - XXX: no locking on vmspace 4059 */ 4060 4061 void 4062 uvmspace_unshare(struct lwp *l) 4063 { 4064 struct proc *p = l->l_proc; 4065 struct vmspace *nvm, *ovm = p->p_vmspace; 4066 4067 if (ovm->vm_refcnt == 1) 4068 /* nothing to do: vmspace isn't shared in the first place */ 4069 return; 4070 4071 /* make a new vmspace, still holding old one */ 4072 nvm = uvmspace_fork(ovm); 4073 4074 kpreempt_disable(); 4075 pmap_deactivate(l); /* unbind old vmspace */ 4076 p->p_vmspace = nvm; 4077 pmap_activate(l); /* switch to new vmspace */ 4078 kpreempt_enable(); 4079 4080 uvmspace_free(ovm); /* drop reference to old vmspace */ 4081 } 4082 4083 #endif 4084 4085 4086 /* 4087 * uvmspace_spawn: a new process has been spawned and needs a vmspace 4088 */ 4089 4090 void 4091 uvmspace_spawn(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown) 4092 { 4093 struct proc *p = l->l_proc; 4094 struct vmspace *nvm; 4095 4096 #ifdef __HAVE_CPU_VMSPACE_EXEC 4097 cpu_vmspace_exec(l, start, end); 4098 #endif 4099 4100 nvm = uvmspace_alloc(start, end, topdown); 4101 kpreempt_disable(); 4102 p->p_vmspace = nvm; 4103 pmap_activate(l); 4104 kpreempt_enable(); 4105 } 4106 4107 /* 4108 * uvmspace_exec: the process wants to exec a new program 4109 */ 4110 4111 void 4112 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown) 4113 { 4114 struct proc *p = l->l_proc; 4115 struct vmspace *nvm, *ovm = p->p_vmspace; 4116 struct vm_map *map; 4117 int flags; 4118 4119 KASSERT(ovm != NULL); 4120 #ifdef __HAVE_CPU_VMSPACE_EXEC 4121 cpu_vmspace_exec(l, start, end); 4122 #endif 4123 4124 map = &ovm->vm_map; 4125 /* 4126 * see if more than one process is using this vmspace... 4127 */ 4128 4129 if (ovm->vm_refcnt == 1 4130 && topdown == ((ovm->vm_map.flags & VM_MAP_TOPDOWN) != 0)) { 4131 4132 /* 4133 * if p is the only process using its vmspace then we can safely 4134 * recycle that vmspace for the program that is being exec'd. 4135 * But only if TOPDOWN matches the requested value for the new 4136 * vm space! 4137 */ 4138 4139 /* 4140 * SYSV SHM semantics require us to kill all segments on an exec 4141 */ 4142 if (uvm_shmexit && ovm->vm_shm) 4143 (*uvm_shmexit)(ovm); 4144 4145 /* 4146 * POSIX 1003.1b -- "lock future mappings" is revoked 4147 * when a process execs another program image. 4148 */ 4149 4150 map->flags &= ~VM_MAP_WIREFUTURE; 4151 4152 /* 4153 * now unmap the old program. 4154 * 4155 * XXX set VM_MAP_DYING for the duration, so pmap_update() 4156 * is not called until the pmap has been totally cleared out 4157 * after pmap_remove_all(), or it can confuse some pmap 4158 * implementations. it would be nice to handle this by 4159 * deferring the pmap_update() while it is known the address 4160 * space is not visible to any user LWP other than curlwp, 4161 * but there isn't an elegant way of inferring that right 4162 * now. 4163 */ 4164 4165 flags = pmap_remove_all(map->pmap) ? UVM_FLAG_VAONLY : 0; 4166 map->flags |= VM_MAP_DYING; 4167 uvm_unmap1(map, vm_map_min(map), vm_map_max(map), flags); 4168 map->flags &= ~VM_MAP_DYING; 4169 pmap_update(map->pmap); 4170 KASSERT(map->header.prev == &map->header); 4171 KASSERT(map->nentries == 0); 4172 4173 /* 4174 * resize the map 4175 */ 4176 4177 vm_map_setmin(map, start); 4178 vm_map_setmax(map, end); 4179 } else { 4180 4181 /* 4182 * p's vmspace is being shared, so we can't reuse it for p since 4183 * it is still being used for others. allocate a new vmspace 4184 * for p 4185 */ 4186 4187 nvm = uvmspace_alloc(start, end, topdown); 4188 4189 /* 4190 * install new vmspace and drop our ref to the old one. 4191 */ 4192 4193 kpreempt_disable(); 4194 pmap_deactivate(l); 4195 p->p_vmspace = nvm; 4196 pmap_activate(l); 4197 kpreempt_enable(); 4198 4199 uvmspace_free(ovm); 4200 } 4201 } 4202 4203 /* 4204 * uvmspace_addref: add a reference to a vmspace. 4205 */ 4206 4207 void 4208 uvmspace_addref(struct vmspace *vm) 4209 { 4210 4211 KASSERT((vm->vm_map.flags & VM_MAP_DYING) == 0); 4212 KASSERT(vm->vm_refcnt > 0); 4213 atomic_inc_uint(&vm->vm_refcnt); 4214 } 4215 4216 /* 4217 * uvmspace_free: free a vmspace data structure 4218 */ 4219 4220 void 4221 uvmspace_free(struct vmspace *vm) 4222 { 4223 struct vm_map_entry *dead_entries; 4224 struct vm_map *map = &vm->vm_map; 4225 int flags; 4226 4227 UVMHIST_FUNC(__func__); 4228 UVMHIST_CALLARGS(maphist,"(vm=%#jx) ref=%jd", (uintptr_t)vm, 4229 vm->vm_refcnt, 0, 0); 4230 if (atomic_dec_uint_nv(&vm->vm_refcnt) > 0) 4231 return; 4232 4233 /* 4234 * at this point, there should be no other references to the map. 4235 * delete all of the mappings, then destroy the pmap. 4236 */ 4237 4238 map->flags |= VM_MAP_DYING; 4239 flags = pmap_remove_all(map->pmap) ? UVM_FLAG_VAONLY : 0; 4240 4241 /* Get rid of any SYSV shared memory segments. */ 4242 if (uvm_shmexit && vm->vm_shm != NULL) 4243 (*uvm_shmexit)(vm); 4244 4245 if (map->nentries) { 4246 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map), 4247 &dead_entries, flags); 4248 if (dead_entries != NULL) 4249 uvm_unmap_detach(dead_entries, 0); 4250 } 4251 KASSERT(map->nentries == 0); 4252 KASSERT(map->size == 0); 4253 4254 mutex_destroy(&map->misc_lock); 4255 rw_destroy(&map->lock); 4256 cv_destroy(&map->cv); 4257 pmap_destroy(map->pmap); 4258 pool_cache_put(&uvm_vmspace_cache, vm); 4259 } 4260 4261 static struct vm_map_entry * 4262 uvm_mapent_clone(struct vm_map *new_map, struct vm_map_entry *old_entry, 4263 int flags) 4264 { 4265 struct vm_map_entry *new_entry; 4266 4267 new_entry = uvm_mapent_alloc(new_map, 0); 4268 /* old_entry -> new_entry */ 4269 uvm_mapent_copy(old_entry, new_entry); 4270 4271 /* new pmap has nothing wired in it */ 4272 new_entry->wired_count = 0; 4273 4274 /* 4275 * gain reference to object backing the map (can't 4276 * be a submap, already checked this case). 4277 */ 4278 4279 if (new_entry->aref.ar_amap) 4280 uvm_map_reference_amap(new_entry, flags); 4281 4282 if (new_entry->object.uvm_obj && 4283 new_entry->object.uvm_obj->pgops->pgo_reference) 4284 new_entry->object.uvm_obj->pgops->pgo_reference( 4285 new_entry->object.uvm_obj); 4286 4287 /* insert entry at end of new_map's entry list */ 4288 uvm_map_entry_link(new_map, new_map->header.prev, 4289 new_entry); 4290 4291 return new_entry; 4292 } 4293 4294 /* 4295 * share the mapping: this means we want the old and 4296 * new entries to share amaps and backing objects. 4297 */ 4298 static void 4299 uvm_mapent_forkshared(struct vm_map *new_map, struct vm_map *old_map, 4300 struct vm_map_entry *old_entry) 4301 { 4302 /* 4303 * if the old_entry needs a new amap (due to prev fork) 4304 * then we need to allocate it now so that we have 4305 * something we own to share with the new_entry. [in 4306 * other words, we need to clear needs_copy] 4307 */ 4308 4309 if (UVM_ET_ISNEEDSCOPY(old_entry)) { 4310 /* get our own amap, clears needs_copy */ 4311 amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK, 4312 0, 0); 4313 /* XXXCDC: WAITOK??? */ 4314 } 4315 4316 uvm_mapent_clone(new_map, old_entry, AMAP_SHARED); 4317 } 4318 4319 4320 static void 4321 uvm_mapent_forkcopy(struct vm_map *new_map, struct vm_map *old_map, 4322 struct vm_map_entry *old_entry) 4323 { 4324 struct vm_map_entry *new_entry; 4325 4326 /* 4327 * copy-on-write the mapping (using mmap's 4328 * MAP_PRIVATE semantics) 4329 * 4330 * allocate new_entry, adjust reference counts. 4331 * (note that new references are read-only). 4332 */ 4333 4334 new_entry = uvm_mapent_clone(new_map, old_entry, 0); 4335 4336 new_entry->etype |= 4337 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4338 4339 /* 4340 * the new entry will need an amap. it will either 4341 * need to be copied from the old entry or created 4342 * from scratch (if the old entry does not have an 4343 * amap). can we defer this process until later 4344 * (by setting "needs_copy") or do we need to copy 4345 * the amap now? 4346 * 4347 * we must copy the amap now if any of the following 4348 * conditions hold: 4349 * 1. the old entry has an amap and that amap is 4350 * being shared. this means that the old (parent) 4351 * process is sharing the amap with another 4352 * process. if we do not clear needs_copy here 4353 * we will end up in a situation where both the 4354 * parent and child process are refering to the 4355 * same amap with "needs_copy" set. if the 4356 * parent write-faults, the fault routine will 4357 * clear "needs_copy" in the parent by allocating 4358 * a new amap. this is wrong because the 4359 * parent is supposed to be sharing the old amap 4360 * and the new amap will break that. 4361 * 4362 * 2. if the old entry has an amap and a non-zero 4363 * wire count then we are going to have to call 4364 * amap_cow_now to avoid page faults in the 4365 * parent process. since amap_cow_now requires 4366 * "needs_copy" to be clear we might as well 4367 * clear it here as well. 4368 * 4369 */ 4370 4371 if (old_entry->aref.ar_amap != NULL) { 4372 if ((amap_flags(old_entry->aref.ar_amap) & AMAP_SHARED) != 0 || 4373 VM_MAPENT_ISWIRED(old_entry)) { 4374 4375 amap_copy(new_map, new_entry, 4376 AMAP_COPY_NOCHUNK, 0, 0); 4377 /* XXXCDC: M_WAITOK ... ok? */ 4378 } 4379 } 4380 4381 /* 4382 * if the parent's entry is wired down, then the 4383 * parent process does not want page faults on 4384 * access to that memory. this means that we 4385 * cannot do copy-on-write because we can't write 4386 * protect the old entry. in this case we 4387 * resolve all copy-on-write faults now, using 4388 * amap_cow_now. note that we have already 4389 * allocated any needed amap (above). 4390 */ 4391 4392 if (VM_MAPENT_ISWIRED(old_entry)) { 4393 4394 /* 4395 * resolve all copy-on-write faults now 4396 * (note that there is nothing to do if 4397 * the old mapping does not have an amap). 4398 */ 4399 if (old_entry->aref.ar_amap) 4400 amap_cow_now(new_map, new_entry); 4401 4402 } else { 4403 /* 4404 * setup mappings to trigger copy-on-write faults 4405 * we must write-protect the parent if it has 4406 * an amap and it is not already "needs_copy"... 4407 * if it is already "needs_copy" then the parent 4408 * has already been write-protected by a previous 4409 * fork operation. 4410 */ 4411 if (old_entry->aref.ar_amap && 4412 !UVM_ET_ISNEEDSCOPY(old_entry)) { 4413 if (old_entry->max_protection & VM_PROT_WRITE) { 4414 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */ 4415 uvm_map_lock_entry(old_entry, RW_WRITER); 4416 #else 4417 uvm_map_lock_entry(old_entry, RW_READER); 4418 #endif 4419 pmap_protect(old_map->pmap, 4420 old_entry->start, old_entry->end, 4421 old_entry->protection & ~VM_PROT_WRITE); 4422 uvm_map_unlock_entry(old_entry); 4423 } 4424 old_entry->etype |= UVM_ET_NEEDSCOPY; 4425 } 4426 } 4427 } 4428 4429 /* 4430 * zero the mapping: the new entry will be zero initialized 4431 */ 4432 static void 4433 uvm_mapent_forkzero(struct vm_map *new_map, struct vm_map *old_map, 4434 struct vm_map_entry *old_entry) 4435 { 4436 struct vm_map_entry *new_entry; 4437 4438 new_entry = uvm_mapent_clone(new_map, old_entry, 0); 4439 4440 new_entry->etype |= 4441 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4442 4443 if (new_entry->aref.ar_amap) { 4444 uvm_map_unreference_amap(new_entry, 0); 4445 new_entry->aref.ar_pageoff = 0; 4446 new_entry->aref.ar_amap = NULL; 4447 } 4448 4449 if (UVM_ET_ISOBJ(new_entry)) { 4450 if (new_entry->object.uvm_obj->pgops->pgo_detach) 4451 new_entry->object.uvm_obj->pgops->pgo_detach( 4452 new_entry->object.uvm_obj); 4453 new_entry->object.uvm_obj = NULL; 4454 new_entry->etype &= ~UVM_ET_OBJ; 4455 } 4456 } 4457 4458 /* 4459 * F O R K - m a i n e n t r y p o i n t 4460 */ 4461 /* 4462 * uvmspace_fork: fork a process' main map 4463 * 4464 * => create a new vmspace for child process from parent. 4465 * => parent's map must not be locked. 4466 */ 4467 4468 struct vmspace * 4469 uvmspace_fork(struct vmspace *vm1) 4470 { 4471 struct vmspace *vm2; 4472 struct vm_map *old_map = &vm1->vm_map; 4473 struct vm_map *new_map; 4474 struct vm_map_entry *old_entry; 4475 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 4476 4477 vm_map_lock(old_map); 4478 4479 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map), 4480 vm1->vm_map.flags & VM_MAP_TOPDOWN); 4481 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy, 4482 (char *) (vm1 + 1) - (char *) &vm1->vm_startcopy); 4483 new_map = &vm2->vm_map; /* XXX */ 4484 4485 old_entry = old_map->header.next; 4486 new_map->size = old_map->size; 4487 4488 /* 4489 * go entry-by-entry 4490 */ 4491 4492 while (old_entry != &old_map->header) { 4493 4494 /* 4495 * first, some sanity checks on the old entry 4496 */ 4497 4498 KASSERT(!UVM_ET_ISSUBMAP(old_entry)); 4499 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) || 4500 !UVM_ET_ISNEEDSCOPY(old_entry)); 4501 4502 switch (old_entry->inheritance) { 4503 case MAP_INHERIT_NONE: 4504 /* 4505 * drop the mapping, modify size 4506 */ 4507 new_map->size -= old_entry->end - old_entry->start; 4508 break; 4509 4510 case MAP_INHERIT_SHARE: 4511 uvm_mapent_forkshared(new_map, old_map, old_entry); 4512 break; 4513 4514 case MAP_INHERIT_COPY: 4515 uvm_mapent_forkcopy(new_map, old_map, old_entry); 4516 break; 4517 4518 case MAP_INHERIT_ZERO: 4519 uvm_mapent_forkzero(new_map, old_map, old_entry); 4520 break; 4521 default: 4522 KASSERT(0); 4523 break; 4524 } 4525 old_entry = old_entry->next; 4526 } 4527 4528 pmap_update(old_map->pmap); 4529 vm_map_unlock(old_map); 4530 4531 if (uvm_shmfork && vm1->vm_shm) 4532 (*uvm_shmfork)(vm1, vm2); 4533 4534 #ifdef PMAP_FORK 4535 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap); 4536 #endif 4537 4538 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4539 return (vm2); 4540 } 4541 4542 4543 /* 4544 * uvm_mapent_trymerge: try to merge an entry with its neighbors. 4545 * 4546 * => called with map locked. 4547 * => return non zero if successfully merged. 4548 */ 4549 4550 int 4551 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags) 4552 { 4553 struct uvm_object *uobj; 4554 struct vm_map_entry *next; 4555 struct vm_map_entry *prev; 4556 vsize_t size; 4557 int merged = 0; 4558 bool copying; 4559 int newetype; 4560 4561 if (entry->aref.ar_amap != NULL) { 4562 return 0; 4563 } 4564 if ((entry->flags & UVM_MAP_NOMERGE) != 0) { 4565 return 0; 4566 } 4567 4568 uobj = entry->object.uvm_obj; 4569 size = entry->end - entry->start; 4570 copying = (flags & UVM_MERGE_COPYING) != 0; 4571 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype; 4572 4573 next = entry->next; 4574 if (next != &map->header && 4575 next->start == entry->end && 4576 ((copying && next->aref.ar_amap != NULL && 4577 amap_refs(next->aref.ar_amap) == 1) || 4578 (!copying && next->aref.ar_amap == NULL)) && 4579 UVM_ET_ISCOMPATIBLE(next, newetype, 4580 uobj, entry->flags, entry->protection, 4581 entry->max_protection, entry->inheritance, entry->advice, 4582 entry->wired_count) && 4583 (uobj == NULL || entry->offset + size == next->offset)) { 4584 int error; 4585 4586 if (copying) { 4587 error = amap_extend(next, size, 4588 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS); 4589 } else { 4590 error = 0; 4591 } 4592 if (error == 0) { 4593 if (uobj) { 4594 if (uobj->pgops->pgo_detach) { 4595 uobj->pgops->pgo_detach(uobj); 4596 } 4597 } 4598 4599 entry->end = next->end; 4600 clear_hints(map, next); 4601 uvm_map_entry_unlink(map, next); 4602 if (copying) { 4603 entry->aref = next->aref; 4604 entry->etype &= ~UVM_ET_NEEDSCOPY; 4605 } 4606 uvm_map_check(map, "trymerge forwardmerge"); 4607 uvm_mapent_free(next); 4608 merged++; 4609 } 4610 } 4611 4612 prev = entry->prev; 4613 if (prev != &map->header && 4614 prev->end == entry->start && 4615 ((copying && !merged && prev->aref.ar_amap != NULL && 4616 amap_refs(prev->aref.ar_amap) == 1) || 4617 (!copying && prev->aref.ar_amap == NULL)) && 4618 UVM_ET_ISCOMPATIBLE(prev, newetype, 4619 uobj, entry->flags, entry->protection, 4620 entry->max_protection, entry->inheritance, entry->advice, 4621 entry->wired_count) && 4622 (uobj == NULL || 4623 prev->offset + prev->end - prev->start == entry->offset)) { 4624 int error; 4625 4626 if (copying) { 4627 error = amap_extend(prev, size, 4628 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS); 4629 } else { 4630 error = 0; 4631 } 4632 if (error == 0) { 4633 if (uobj) { 4634 if (uobj->pgops->pgo_detach) { 4635 uobj->pgops->pgo_detach(uobj); 4636 } 4637 entry->offset = prev->offset; 4638 } 4639 4640 entry->start = prev->start; 4641 clear_hints(map, prev); 4642 uvm_map_entry_unlink(map, prev); 4643 if (copying) { 4644 entry->aref = prev->aref; 4645 entry->etype &= ~UVM_ET_NEEDSCOPY; 4646 } 4647 uvm_map_check(map, "trymerge backmerge"); 4648 uvm_mapent_free(prev); 4649 merged++; 4650 } 4651 } 4652 4653 return merged; 4654 } 4655 4656 /* 4657 * uvm_map_setup: init map 4658 * 4659 * => map must not be in service yet. 4660 */ 4661 4662 void 4663 uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags) 4664 { 4665 4666 rb_tree_init(&map->rb_tree, &uvm_map_tree_ops); 4667 map->header.next = map->header.prev = &map->header; 4668 map->nentries = 0; 4669 map->size = 0; 4670 map->ref_count = 1; 4671 vm_map_setmin(map, vmin); 4672 vm_map_setmax(map, vmax); 4673 map->flags = flags; 4674 map->first_free = &map->header; 4675 map->hint = &map->header; 4676 map->timestamp = 0; 4677 map->busy = NULL; 4678 4679 rw_init(&map->lock); 4680 cv_init(&map->cv, "vm_map"); 4681 mutex_init(&map->misc_lock, MUTEX_DRIVER, IPL_NONE); 4682 } 4683 4684 /* 4685 * U N M A P - m a i n e n t r y p o i n t 4686 */ 4687 4688 /* 4689 * uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop") 4690 * 4691 * => caller must check alignment and size 4692 * => map must be unlocked (we will lock it) 4693 * => flags is UVM_FLAG_QUANTUM or 0. 4694 */ 4695 4696 void 4697 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 4698 { 4699 struct vm_map_entry *dead_entries; 4700 UVMHIST_FUNC(__func__); 4701 UVMHIST_CALLARGS(maphist, " (map=%#jx, start=%#jx, end=%#jx)", 4702 (uintptr_t)map, start, end, 0); 4703 4704 KASSERTMSG(start < end, 4705 "%s: map %p: start %#jx < end %#jx", __func__, map, 4706 (uintmax_t)start, (uintmax_t)end); 4707 if (map == kernel_map) { 4708 LOCKDEBUG_MEM_CHECK((void *)start, end - start); 4709 } 4710 4711 /* 4712 * work now done by helper functions. wipe the pmap's and then 4713 * detach from the dead entries... 4714 */ 4715 vm_map_lock(map); 4716 uvm_unmap_remove(map, start, end, &dead_entries, flags); 4717 vm_map_unlock(map); 4718 4719 if (dead_entries != NULL) 4720 uvm_unmap_detach(dead_entries, 0); 4721 4722 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 4723 } 4724 4725 4726 /* 4727 * uvm_map_reference: add reference to a map 4728 * 4729 * => map need not be locked 4730 */ 4731 4732 void 4733 uvm_map_reference(struct vm_map *map) 4734 { 4735 4736 atomic_inc_uint(&map->ref_count); 4737 } 4738 4739 void 4740 uvm_map_lock_entry(struct vm_map_entry *entry, krw_t op) 4741 { 4742 4743 if (entry->aref.ar_amap != NULL) { 4744 amap_lock(entry->aref.ar_amap, op); 4745 } 4746 if (UVM_ET_ISOBJ(entry)) { 4747 rw_enter(entry->object.uvm_obj->vmobjlock, op); 4748 } 4749 } 4750 4751 void 4752 uvm_map_unlock_entry(struct vm_map_entry *entry) 4753 { 4754 4755 if (UVM_ET_ISOBJ(entry)) { 4756 rw_exit(entry->object.uvm_obj->vmobjlock); 4757 } 4758 if (entry->aref.ar_amap != NULL) { 4759 amap_unlock(entry->aref.ar_amap); 4760 } 4761 } 4762 4763 #define UVM_VOADDR_TYPE_MASK 0x3UL 4764 #define UVM_VOADDR_TYPE_UOBJ 0x1UL 4765 #define UVM_VOADDR_TYPE_ANON 0x2UL 4766 #define UVM_VOADDR_OBJECT_MASK ~UVM_VOADDR_TYPE_MASK 4767 4768 #define UVM_VOADDR_GET_TYPE(voa) \ 4769 ((voa)->object & UVM_VOADDR_TYPE_MASK) 4770 #define UVM_VOADDR_GET_OBJECT(voa) \ 4771 ((voa)->object & UVM_VOADDR_OBJECT_MASK) 4772 #define UVM_VOADDR_SET_OBJECT(voa, obj, type) \ 4773 do { \ 4774 KASSERT(((uintptr_t)(obj) & UVM_VOADDR_TYPE_MASK) == 0); \ 4775 (voa)->object = ((uintptr_t)(obj)) | (type); \ 4776 } while (/*CONSTCOND*/0) 4777 4778 #define UVM_VOADDR_GET_UOBJ(voa) \ 4779 ((struct uvm_object *)UVM_VOADDR_GET_OBJECT(voa)) 4780 #define UVM_VOADDR_SET_UOBJ(voa, uobj) \ 4781 UVM_VOADDR_SET_OBJECT(voa, uobj, UVM_VOADDR_TYPE_UOBJ) 4782 4783 #define UVM_VOADDR_GET_ANON(voa) \ 4784 ((struct vm_anon *)UVM_VOADDR_GET_OBJECT(voa)) 4785 #define UVM_VOADDR_SET_ANON(voa, anon) \ 4786 UVM_VOADDR_SET_OBJECT(voa, anon, UVM_VOADDR_TYPE_ANON) 4787 4788 /* 4789 * uvm_voaddr_acquire: returns the virtual object address corresponding 4790 * to the specified virtual address. 4791 * 4792 * => resolves COW so the true page identity is tracked. 4793 * 4794 * => acquires a reference on the page's owner (uvm_object or vm_anon) 4795 */ 4796 bool 4797 uvm_voaddr_acquire(struct vm_map * const map, vaddr_t const va, 4798 struct uvm_voaddr * const voaddr) 4799 { 4800 struct vm_map_entry *entry; 4801 struct vm_anon *anon = NULL; 4802 bool result = false; 4803 bool exclusive = false; 4804 void (*unlock_fn)(struct vm_map *); 4805 4806 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 4807 UVMHIST_LOG(maphist,"(map=%#jx,va=%#jx)", (uintptr_t)map, va, 0, 0); 4808 4809 const vaddr_t start = trunc_page(va); 4810 const vaddr_t end = round_page(va+1); 4811 4812 lookup_again: 4813 if (__predict_false(exclusive)) { 4814 vm_map_lock(map); 4815 unlock_fn = vm_map_unlock; 4816 } else { 4817 vm_map_lock_read(map); 4818 unlock_fn = vm_map_unlock_read; 4819 } 4820 4821 if (__predict_false(!uvm_map_lookup_entry(map, start, &entry))) { 4822 unlock_fn(map); 4823 UVMHIST_LOG(maphist,"<- done (no entry)",0,0,0,0); 4824 return false; 4825 } 4826 4827 if (__predict_false(entry->protection == VM_PROT_NONE)) { 4828 unlock_fn(map); 4829 UVMHIST_LOG(maphist,"<- done (PROT_NONE)",0,0,0,0); 4830 return false; 4831 } 4832 4833 /* 4834 * We have a fast path for the common case of "no COW resolution 4835 * needed" whereby we have taken a read lock on the map and if 4836 * we don't encounter any need to create a vm_anon then great! 4837 * But if we do, we loop around again, instead taking an exclusive 4838 * lock so that we can perform the fault. 4839 * 4840 * In the event that we have to resolve the fault, we do nearly the 4841 * same work as uvm_map_pageable() does: 4842 * 4843 * 1: holding the write lock, we create any anonymous maps that need 4844 * to be created. however, we do NOT need to clip the map entries 4845 * in this case. 4846 * 4847 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 4848 * in the page (assuming the entry is not already wired). this 4849 * is done because we need the vm_anon to be present. 4850 */ 4851 if (__predict_true(!VM_MAPENT_ISWIRED(entry))) { 4852 4853 bool need_fault = false; 4854 4855 /* 4856 * perform the action of vm_map_lookup that need the 4857 * write lock on the map: create an anonymous map for 4858 * a copy-on-write region, or an anonymous map for 4859 * a zero-fill region. 4860 */ 4861 if (__predict_false(UVM_ET_ISSUBMAP(entry))) { 4862 unlock_fn(map); 4863 UVMHIST_LOG(maphist,"<- done (submap)",0,0,0,0); 4864 return false; 4865 } 4866 if (__predict_false(UVM_ET_ISNEEDSCOPY(entry) && 4867 ((entry->max_protection & VM_PROT_WRITE) || 4868 (entry->object.uvm_obj == NULL)))) { 4869 if (!exclusive) { 4870 /* need to take the slow path */ 4871 KASSERT(unlock_fn == vm_map_unlock_read); 4872 vm_map_unlock_read(map); 4873 exclusive = true; 4874 goto lookup_again; 4875 } 4876 need_fault = true; 4877 amap_copy(map, entry, 0, start, end); 4878 /* XXXCDC: wait OK? */ 4879 } 4880 4881 /* 4882 * do a quick check to see if the fault has already 4883 * been resolved to the upper layer. 4884 */ 4885 if (__predict_true(entry->aref.ar_amap != NULL && 4886 need_fault == false)) { 4887 amap_lock(entry->aref.ar_amap, RW_WRITER); 4888 anon = amap_lookup(&entry->aref, start - entry->start); 4889 if (__predict_true(anon != NULL)) { 4890 /* amap unlocked below */ 4891 goto found_anon; 4892 } 4893 amap_unlock(entry->aref.ar_amap); 4894 need_fault = true; 4895 } 4896 4897 /* 4898 * we predict this test as false because if we reach 4899 * this point, then we are likely dealing with a 4900 * shared memory region backed by a uvm_object, in 4901 * which case a fault to create the vm_anon is not 4902 * necessary. 4903 */ 4904 if (__predict_false(need_fault)) { 4905 if (exclusive) { 4906 vm_map_busy(map); 4907 vm_map_unlock(map); 4908 unlock_fn = vm_map_unbusy; 4909 } 4910 4911 if (uvm_fault_wire(map, start, end, 4912 entry->max_protection, 1)) { 4913 /* wiring failed */ 4914 unlock_fn(map); 4915 UVMHIST_LOG(maphist,"<- done (wire failed)", 4916 0,0,0,0); 4917 return false; 4918 } 4919 4920 /* 4921 * now that we have resolved the fault, we can unwire 4922 * the page. 4923 */ 4924 if (exclusive) { 4925 vm_map_lock(map); 4926 vm_map_unbusy(map); 4927 unlock_fn = vm_map_unlock; 4928 } 4929 4930 uvm_fault_unwire_locked(map, start, end); 4931 } 4932 } 4933 4934 /* check the upper layer */ 4935 if (entry->aref.ar_amap) { 4936 amap_lock(entry->aref.ar_amap, RW_WRITER); 4937 anon = amap_lookup(&entry->aref, start - entry->start); 4938 if (anon) { 4939 found_anon: KASSERT(anon->an_lock == entry->aref.ar_amap->am_lock); 4940 anon->an_ref++; 4941 rw_obj_hold(anon->an_lock); 4942 KASSERT(anon->an_ref != 0); 4943 UVM_VOADDR_SET_ANON(voaddr, anon); 4944 voaddr->offset = va & PAGE_MASK; 4945 result = true; 4946 } 4947 amap_unlock(entry->aref.ar_amap); 4948 } 4949 4950 /* check the lower layer */ 4951 if (!result && UVM_ET_ISOBJ(entry)) { 4952 struct uvm_object *uobj = entry->object.uvm_obj; 4953 4954 KASSERT(uobj != NULL); 4955 (*uobj->pgops->pgo_reference)(uobj); 4956 UVM_VOADDR_SET_UOBJ(voaddr, uobj); 4957 voaddr->offset = entry->offset + (va - entry->start); 4958 result = true; 4959 } 4960 4961 unlock_fn(map); 4962 4963 if (result) { 4964 UVMHIST_LOG(maphist, 4965 "<- done OK (type=%jd,owner=%#jx,offset=%#jx)", 4966 UVM_VOADDR_GET_TYPE(voaddr), 4967 UVM_VOADDR_GET_OBJECT(voaddr), 4968 voaddr->offset, 0); 4969 } else { 4970 UVMHIST_LOG(maphist,"<- done (failed)",0,0,0,0); 4971 } 4972 4973 return result; 4974 } 4975 4976 /* 4977 * uvm_voaddr_release: release the references held by the 4978 * vitual object address. 4979 */ 4980 void 4981 uvm_voaddr_release(struct uvm_voaddr * const voaddr) 4982 { 4983 4984 switch (UVM_VOADDR_GET_TYPE(voaddr)) { 4985 case UVM_VOADDR_TYPE_UOBJ: { 4986 struct uvm_object * const uobj = UVM_VOADDR_GET_UOBJ(voaddr); 4987 4988 KASSERT(uobj != NULL); 4989 KASSERT(uobj->pgops->pgo_detach != NULL); 4990 (*uobj->pgops->pgo_detach)(uobj); 4991 break; 4992 } 4993 case UVM_VOADDR_TYPE_ANON: { 4994 struct vm_anon * const anon = UVM_VOADDR_GET_ANON(voaddr); 4995 krwlock_t *lock; 4996 4997 KASSERT(anon != NULL); 4998 rw_enter((lock = anon->an_lock), RW_WRITER); 4999 KASSERT(anon->an_ref > 0); 5000 if (--anon->an_ref == 0) { 5001 uvm_anfree(anon); 5002 } 5003 rw_exit(lock); 5004 rw_obj_free(lock); 5005 break; 5006 } 5007 default: 5008 panic("uvm_voaddr_release: bad type"); 5009 } 5010 memset(voaddr, 0, sizeof(*voaddr)); 5011 } 5012 5013 /* 5014 * uvm_voaddr_compare: compare two uvm_voaddr objects. 5015 * 5016 * => memcmp() semantics 5017 */ 5018 int 5019 uvm_voaddr_compare(const struct uvm_voaddr * const voaddr1, 5020 const struct uvm_voaddr * const voaddr2) 5021 { 5022 const uintptr_t type1 = UVM_VOADDR_GET_TYPE(voaddr1); 5023 const uintptr_t type2 = UVM_VOADDR_GET_TYPE(voaddr2); 5024 5025 KASSERT(type1 == UVM_VOADDR_TYPE_UOBJ || 5026 type1 == UVM_VOADDR_TYPE_ANON); 5027 5028 KASSERT(type2 == UVM_VOADDR_TYPE_UOBJ || 5029 type2 == UVM_VOADDR_TYPE_ANON); 5030 5031 if (type1 < type2) 5032 return -1; 5033 if (type1 > type2) 5034 return 1; 5035 5036 const uintptr_t addr1 = UVM_VOADDR_GET_OBJECT(voaddr1); 5037 const uintptr_t addr2 = UVM_VOADDR_GET_OBJECT(voaddr2); 5038 5039 if (addr1 < addr2) 5040 return -1; 5041 if (addr1 > addr2) 5042 return 1; 5043 5044 if (voaddr1->offset < voaddr2->offset) 5045 return -1; 5046 if (voaddr1->offset > voaddr2->offset) 5047 return 1; 5048 5049 return 0; 5050 } 5051 5052 #if defined(DDB) || defined(DEBUGPRINT) 5053 5054 /* 5055 * uvm_map_printit: actually prints the map 5056 */ 5057 5058 void 5059 uvm_map_printit(struct vm_map *map, bool full, 5060 void (*pr)(const char *, ...)) 5061 { 5062 struct vm_map_entry *entry; 5063 5064 (*pr)("MAP %p: [%#lx->%#lx]\n", map, vm_map_min(map), 5065 vm_map_max(map)); 5066 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=%#x\n", 5067 map->nentries, map->size, map->ref_count, map->timestamp, 5068 map->flags); 5069 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap, 5070 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap)); 5071 if (!full) 5072 return; 5073 for (entry = map->header.next; entry != &map->header; 5074 entry = entry->next) { 5075 (*pr)(" - %p: %#lx->%#lx: obj=%p/%#llx, amap=%p/%d\n", 5076 entry, entry->start, entry->end, entry->object.uvm_obj, 5077 (long long)entry->offset, entry->aref.ar_amap, 5078 entry->aref.ar_pageoff); 5079 (*pr)( 5080 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, " 5081 "wc=%d, adv=%d\n", 5082 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F', 5083 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F', 5084 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F', 5085 entry->protection, entry->max_protection, 5086 entry->inheritance, entry->wired_count, entry->advice); 5087 } 5088 } 5089 5090 void 5091 uvm_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 5092 { 5093 struct vm_map *map; 5094 5095 for (map = kernel_map;;) { 5096 struct vm_map_entry *entry; 5097 5098 if (!uvm_map_lookup_entry_bytree(map, (vaddr_t)addr, &entry)) { 5099 break; 5100 } 5101 (*pr)("%p is %p+%zu from VMMAP %p\n", 5102 (void *)addr, (void *)entry->start, 5103 (size_t)(addr - (uintptr_t)entry->start), map); 5104 if (!UVM_ET_ISSUBMAP(entry)) { 5105 break; 5106 } 5107 map = entry->object.sub_map; 5108 } 5109 } 5110 5111 #endif /* DDB || DEBUGPRINT */ 5112 5113 #ifndef __USER_VA0_IS_SAFE 5114 static int 5115 sysctl_user_va0_disable(SYSCTLFN_ARGS) 5116 { 5117 struct sysctlnode node; 5118 int t, error; 5119 5120 node = *rnode; 5121 node.sysctl_data = &t; 5122 t = user_va0_disable; 5123 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 5124 if (error || newp == NULL) 5125 return (error); 5126 5127 if (!t && user_va0_disable && 5128 kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MAP_VA_ZERO, 0, 5129 NULL, NULL, NULL)) 5130 return EPERM; 5131 5132 user_va0_disable = !!t; 5133 return 0; 5134 } 5135 #endif 5136 5137 static int 5138 fill_vmentry(struct lwp *l, struct proc *p, struct kinfo_vmentry *kve, 5139 struct vm_map *m, struct vm_map_entry *e) 5140 { 5141 #ifndef _RUMPKERNEL 5142 int error; 5143 5144 memset(kve, 0, sizeof(*kve)); 5145 KASSERT(e != NULL); 5146 if (UVM_ET_ISOBJ(e)) { 5147 struct uvm_object *uobj = e->object.uvm_obj; 5148 KASSERT(uobj != NULL); 5149 kve->kve_ref_count = uobj->uo_refs; 5150 kve->kve_count = uobj->uo_npages; 5151 if (UVM_OBJ_IS_VNODE(uobj)) { 5152 struct vattr va; 5153 struct vnode *vp = (struct vnode *)uobj; 5154 vn_lock(vp, LK_SHARED | LK_RETRY); 5155 error = VOP_GETATTR(vp, &va, l->l_cred); 5156 VOP_UNLOCK(vp); 5157 kve->kve_type = KVME_TYPE_VNODE; 5158 if (error == 0) { 5159 kve->kve_vn_size = vp->v_size; 5160 kve->kve_vn_type = (int)vp->v_type; 5161 kve->kve_vn_mode = va.va_mode; 5162 kve->kve_vn_rdev = va.va_rdev; 5163 kve->kve_vn_fileid = va.va_fileid; 5164 kve->kve_vn_fsid = va.va_fsid; 5165 error = vnode_to_path(kve->kve_path, 5166 sizeof(kve->kve_path) / 2, vp, l, p); 5167 #ifdef DIAGNOSTIC 5168 if (error) 5169 printf("%s: vp %p error %d\n", __func__, 5170 vp, error); 5171 #endif 5172 } 5173 } else if (UVM_OBJ_IS_KERN_OBJECT(uobj)) { 5174 kve->kve_type = KVME_TYPE_KERN; 5175 } else if (UVM_OBJ_IS_DEVICE(uobj)) { 5176 kve->kve_type = KVME_TYPE_DEVICE; 5177 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 5178 kve->kve_type = KVME_TYPE_ANON; 5179 } else { 5180 kve->kve_type = KVME_TYPE_OBJECT; 5181 } 5182 } else if (UVM_ET_ISSUBMAP(e)) { 5183 struct vm_map *map = e->object.sub_map; 5184 KASSERT(map != NULL); 5185 kve->kve_ref_count = map->ref_count; 5186 kve->kve_count = map->nentries; 5187 kve->kve_type = KVME_TYPE_SUBMAP; 5188 } else 5189 kve->kve_type = KVME_TYPE_UNKNOWN; 5190 5191 kve->kve_start = e->start; 5192 kve->kve_end = e->end; 5193 kve->kve_offset = e->offset; 5194 kve->kve_wired_count = e->wired_count; 5195 kve->kve_inheritance = e->inheritance; 5196 kve->kve_attributes = 0; /* unused */ 5197 kve->kve_advice = e->advice; 5198 #define PROT(p) (((p) & VM_PROT_READ) ? KVME_PROT_READ : 0) | \ 5199 (((p) & VM_PROT_WRITE) ? KVME_PROT_WRITE : 0) | \ 5200 (((p) & VM_PROT_EXECUTE) ? KVME_PROT_EXEC : 0) 5201 kve->kve_protection = PROT(e->protection); 5202 kve->kve_max_protection = PROT(e->max_protection); 5203 kve->kve_flags |= (e->etype & UVM_ET_COPYONWRITE) 5204 ? KVME_FLAG_COW : 0; 5205 kve->kve_flags |= (e->etype & UVM_ET_NEEDSCOPY) 5206 ? KVME_FLAG_NEEDS_COPY : 0; 5207 kve->kve_flags |= (m->flags & VM_MAP_TOPDOWN) 5208 ? KVME_FLAG_GROWS_DOWN : KVME_FLAG_GROWS_UP; 5209 kve->kve_flags |= (m->flags & VM_MAP_PAGEABLE) 5210 ? KVME_FLAG_PAGEABLE : 0; 5211 #endif 5212 return 0; 5213 } 5214 5215 static int 5216 fill_vmentries(struct lwp *l, pid_t pid, u_int elem_size, void *oldp, 5217 size_t *oldlenp) 5218 { 5219 int error; 5220 struct proc *p; 5221 struct kinfo_vmentry *vme; 5222 struct vmspace *vm; 5223 struct vm_map *map; 5224 struct vm_map_entry *entry; 5225 char *dp; 5226 size_t count, vmesize; 5227 5228 if (elem_size == 0 || elem_size > 2 * sizeof(*vme)) 5229 return EINVAL; 5230 5231 if (oldp) { 5232 if (*oldlenp > 10UL * 1024UL * 1024UL) 5233 return E2BIG; 5234 count = *oldlenp / elem_size; 5235 if (count == 0) 5236 return ENOMEM; 5237 vmesize = count * sizeof(*vme); 5238 } else 5239 vmesize = 0; 5240 5241 if ((error = proc_find_locked(l, &p, pid)) != 0) 5242 return error; 5243 5244 vme = NULL; 5245 count = 0; 5246 5247 if ((error = proc_vmspace_getref(p, &vm)) != 0) 5248 goto out; 5249 5250 map = &vm->vm_map; 5251 vm_map_lock_read(map); 5252 5253 dp = oldp; 5254 if (oldp) 5255 vme = kmem_alloc(vmesize, KM_SLEEP); 5256 for (entry = map->header.next; entry != &map->header; 5257 entry = entry->next) { 5258 if (oldp && (dp - (char *)oldp) < vmesize) { 5259 error = fill_vmentry(l, p, &vme[count], map, entry); 5260 if (error) 5261 goto out; 5262 dp += elem_size; 5263 } 5264 count++; 5265 } 5266 vm_map_unlock_read(map); 5267 uvmspace_free(vm); 5268 5269 out: 5270 if (pid != -1) 5271 mutex_exit(p->p_lock); 5272 if (error == 0) { 5273 const u_int esize = uimin(sizeof(*vme), elem_size); 5274 dp = oldp; 5275 for (size_t i = 0; i < count; i++) { 5276 if (oldp && (dp - (char *)oldp) < vmesize) { 5277 error = sysctl_copyout(l, &vme[i], dp, esize); 5278 if (error) 5279 break; 5280 dp += elem_size; 5281 } else 5282 break; 5283 } 5284 count *= elem_size; 5285 if (oldp != NULL && *oldlenp < count) 5286 error = ENOSPC; 5287 *oldlenp = count; 5288 } 5289 if (vme) 5290 kmem_free(vme, vmesize); 5291 return error; 5292 } 5293 5294 static int 5295 sysctl_vmproc(SYSCTLFN_ARGS) 5296 { 5297 int error; 5298 5299 if (namelen == 1 && name[0] == CTL_QUERY) 5300 return (sysctl_query(SYSCTLFN_CALL(rnode))); 5301 5302 if (namelen == 0) 5303 return EINVAL; 5304 5305 switch (name[0]) { 5306 case VM_PROC_MAP: 5307 if (namelen != 3) 5308 return EINVAL; 5309 sysctl_unlock(); 5310 error = fill_vmentries(l, name[1], name[2], oldp, oldlenp); 5311 sysctl_relock(); 5312 return error; 5313 default: 5314 return EINVAL; 5315 } 5316 } 5317 5318 SYSCTL_SETUP(sysctl_uvmmap_setup, "sysctl uvmmap setup") 5319 { 5320 5321 sysctl_createv(clog, 0, NULL, NULL, 5322 CTLFLAG_PERMANENT, 5323 CTLTYPE_STRUCT, "proc", 5324 SYSCTL_DESCR("Process vm information"), 5325 sysctl_vmproc, 0, NULL, 0, 5326 CTL_VM, VM_PROC, CTL_EOL); 5327 #ifndef __USER_VA0_IS_SAFE 5328 sysctl_createv(clog, 0, NULL, NULL, 5329 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 5330 CTLTYPE_INT, "user_va0_disable", 5331 SYSCTL_DESCR("Disable VA 0"), 5332 sysctl_user_va0_disable, 0, &user_va0_disable, 0, 5333 CTL_VM, CTL_CREATE, CTL_EOL); 5334 #endif 5335 } 5336