1 /* $NetBSD: uvm_map.c,v 1.354 2018/02/06 09:20:29 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 1.354 2018/02/06 09:20:29 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 #ifndef UVMHIST_PDHIST_SIZE 109 #define UVMHIST_PDHIST_SIZE 100 110 #endif 111 static struct kern_history_ent maphistbuf[UVMHIST_MAPHIST_SIZE]; 112 UVMHIST_DEFINE(maphist) = UVMHIST_INITIALIZER(maphist, maphistbuf); 113 #endif 114 115 #if !defined(UVMMAP_COUNTERS) 116 117 #define UVMMAP_EVCNT_DEFINE(name) /* nothing */ 118 #define UVMMAP_EVCNT_INCR(ev) /* nothing */ 119 #define UVMMAP_EVCNT_DECR(ev) /* nothing */ 120 121 #else /* defined(UVMMAP_NOCOUNTERS) */ 122 123 #include <sys/evcnt.h> 124 #define UVMMAP_EVCNT_DEFINE(name) \ 125 struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \ 126 "uvmmap", #name); \ 127 EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name); 128 #define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++ 129 #define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count-- 130 131 #endif /* defined(UVMMAP_NOCOUNTERS) */ 132 133 UVMMAP_EVCNT_DEFINE(ubackmerge) 134 UVMMAP_EVCNT_DEFINE(uforwmerge) 135 UVMMAP_EVCNT_DEFINE(ubimerge) 136 UVMMAP_EVCNT_DEFINE(unomerge) 137 UVMMAP_EVCNT_DEFINE(kbackmerge) 138 UVMMAP_EVCNT_DEFINE(kforwmerge) 139 UVMMAP_EVCNT_DEFINE(kbimerge) 140 UVMMAP_EVCNT_DEFINE(knomerge) 141 UVMMAP_EVCNT_DEFINE(map_call) 142 UVMMAP_EVCNT_DEFINE(mlk_call) 143 UVMMAP_EVCNT_DEFINE(mlk_hint) 144 UVMMAP_EVCNT_DEFINE(mlk_list) 145 UVMMAP_EVCNT_DEFINE(mlk_tree) 146 UVMMAP_EVCNT_DEFINE(mlk_treeloop) 147 UVMMAP_EVCNT_DEFINE(mlk_listloop) 148 149 const char vmmapbsy[] = "vmmapbsy"; 150 151 /* 152 * cache for vmspace structures. 153 */ 154 155 static struct pool_cache uvm_vmspace_cache; 156 157 /* 158 * cache for dynamically-allocated map entries. 159 */ 160 161 static struct pool_cache uvm_map_entry_cache; 162 163 #ifdef PMAP_GROWKERNEL 164 /* 165 * This global represents the end of the kernel virtual address 166 * space. If we want to exceed this, we must grow the kernel 167 * virtual address space dynamically. 168 * 169 * Note, this variable is locked by kernel_map's lock. 170 */ 171 vaddr_t uvm_maxkaddr; 172 #endif 173 174 #ifndef __USER_VA0_IS_SAFE 175 #ifndef __USER_VA0_DISABLE_DEFAULT 176 #define __USER_VA0_DISABLE_DEFAULT 1 177 #endif 178 #ifdef USER_VA0_DISABLE_DEFAULT /* kernel config option overrides */ 179 #undef __USER_VA0_DISABLE_DEFAULT 180 #define __USER_VA0_DISABLE_DEFAULT USER_VA0_DISABLE_DEFAULT 181 #endif 182 int user_va0_disable = __USER_VA0_DISABLE_DEFAULT; 183 #endif 184 185 /* 186 * macros 187 */ 188 189 /* 190 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging 191 */ 192 extern struct vm_map *pager_map; 193 194 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \ 195 prot, maxprot, inh, adv, wire) \ 196 ((ent)->etype == (type) && \ 197 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE)) == 0 && \ 198 (ent)->object.uvm_obj == (uobj) && \ 199 (ent)->protection == (prot) && \ 200 (ent)->max_protection == (maxprot) && \ 201 (ent)->inheritance == (inh) && \ 202 (ent)->advice == (adv) && \ 203 (ent)->wired_count == (wire)) 204 205 /* 206 * uvm_map_entry_link: insert entry into a map 207 * 208 * => map must be locked 209 */ 210 #define uvm_map_entry_link(map, after_where, entry) do { \ 211 uvm_mapent_check(entry); \ 212 (map)->nentries++; \ 213 (entry)->prev = (after_where); \ 214 (entry)->next = (after_where)->next; \ 215 (entry)->prev->next = (entry); \ 216 (entry)->next->prev = (entry); \ 217 uvm_rb_insert((map), (entry)); \ 218 } while (/*CONSTCOND*/ 0) 219 220 /* 221 * uvm_map_entry_unlink: remove entry from a map 222 * 223 * => map must be locked 224 */ 225 #define uvm_map_entry_unlink(map, entry) do { \ 226 KASSERT((entry) != (map)->first_free); \ 227 KASSERT((entry) != (map)->hint); \ 228 uvm_mapent_check(entry); \ 229 (map)->nentries--; \ 230 (entry)->next->prev = (entry)->prev; \ 231 (entry)->prev->next = (entry)->next; \ 232 uvm_rb_remove((map), (entry)); \ 233 } while (/*CONSTCOND*/ 0) 234 235 /* 236 * SAVE_HINT: saves the specified entry as the hint for future lookups. 237 * 238 * => map need not be locked. 239 */ 240 #define SAVE_HINT(map, check, value) do { \ 241 if ((map)->hint == (check)) \ 242 (map)->hint = (value); \ 243 } while (/*CONSTCOND*/ 0) 244 245 /* 246 * clear_hints: ensure that hints don't point to the entry. 247 * 248 * => map must be write-locked. 249 */ 250 static void 251 clear_hints(struct vm_map *map, struct vm_map_entry *ent) 252 { 253 254 SAVE_HINT(map, ent, ent->prev); 255 if (map->first_free == ent) { 256 map->first_free = ent->prev; 257 } 258 } 259 260 /* 261 * VM_MAP_RANGE_CHECK: check and correct range 262 * 263 * => map must at least be read locked 264 */ 265 266 #define VM_MAP_RANGE_CHECK(map, start, end) do { \ 267 if (start < vm_map_min(map)) \ 268 start = vm_map_min(map); \ 269 if (end > vm_map_max(map)) \ 270 end = vm_map_max(map); \ 271 if (start > end) \ 272 start = end; \ 273 } while (/*CONSTCOND*/ 0) 274 275 /* 276 * local prototypes 277 */ 278 279 static struct vm_map_entry * 280 uvm_mapent_alloc(struct vm_map *, int); 281 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *); 282 static void uvm_mapent_free(struct vm_map_entry *); 283 #if defined(DEBUG) 284 static void _uvm_mapent_check(const struct vm_map_entry *, const char *, 285 int); 286 #define uvm_mapent_check(map) _uvm_mapent_check(map, __FILE__, __LINE__) 287 #else /* defined(DEBUG) */ 288 #define uvm_mapent_check(e) /* nothing */ 289 #endif /* defined(DEBUG) */ 290 291 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *); 292 static void uvm_map_reference_amap(struct vm_map_entry *, int); 293 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int, 294 int, struct vm_map_entry *); 295 static void uvm_map_unreference_amap(struct vm_map_entry *, int); 296 297 int _uvm_map_sanity(struct vm_map *); 298 int _uvm_tree_sanity(struct vm_map *); 299 static vsize_t uvm_rb_maxgap(const struct vm_map_entry *); 300 301 #define ROOT_ENTRY(map) ((struct vm_map_entry *)(map)->rb_tree.rbt_root) 302 #define LEFT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_left) 303 #define RIGHT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_right) 304 #define PARENT_ENTRY(map, entry) \ 305 (ROOT_ENTRY(map) == (entry) \ 306 ? NULL : (struct vm_map_entry *)RB_FATHER(&(entry)->rb_node)) 307 308 /* 309 * These get filled in if/when SYSVSHM shared memory code is loaded 310 * 311 * We do this with function pointers rather the #ifdef SYSVSHM so the 312 * SYSVSHM code can be loaded and unloaded 313 */ 314 void (*uvm_shmexit)(struct vmspace *) = NULL; 315 void (*uvm_shmfork)(struct vmspace *, struct vmspace *) = NULL; 316 317 static int 318 uvm_map_compare_nodes(void *ctx, const void *nparent, const void *nkey) 319 { 320 const struct vm_map_entry *eparent = nparent; 321 const struct vm_map_entry *ekey = nkey; 322 323 KASSERT(eparent->start < ekey->start || eparent->start >= ekey->end); 324 KASSERT(ekey->start < eparent->start || ekey->start >= eparent->end); 325 326 if (eparent->start < ekey->start) 327 return -1; 328 if (eparent->end >= ekey->start) 329 return 1; 330 return 0; 331 } 332 333 static int 334 uvm_map_compare_key(void *ctx, const void *nparent, const void *vkey) 335 { 336 const struct vm_map_entry *eparent = nparent; 337 const vaddr_t va = *(const vaddr_t *) vkey; 338 339 if (eparent->start < va) 340 return -1; 341 if (eparent->end >= va) 342 return 1; 343 return 0; 344 } 345 346 static const rb_tree_ops_t uvm_map_tree_ops = { 347 .rbto_compare_nodes = uvm_map_compare_nodes, 348 .rbto_compare_key = uvm_map_compare_key, 349 .rbto_node_offset = offsetof(struct vm_map_entry, rb_node), 350 .rbto_context = NULL 351 }; 352 353 /* 354 * uvm_rb_gap: return the gap size between our entry and next entry. 355 */ 356 static inline vsize_t 357 uvm_rb_gap(const struct vm_map_entry *entry) 358 { 359 360 KASSERT(entry->next != NULL); 361 return entry->next->start - entry->end; 362 } 363 364 static vsize_t 365 uvm_rb_maxgap(const struct vm_map_entry *entry) 366 { 367 struct vm_map_entry *child; 368 vsize_t maxgap = entry->gap; 369 370 /* 371 * We need maxgap to be the largest gap of us or any of our 372 * descendents. Since each of our children's maxgap is the 373 * cached value of their largest gap of themselves or their 374 * descendents, we can just use that value and avoid recursing 375 * down the tree to calculate it. 376 */ 377 if ((child = LEFT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 378 maxgap = child->maxgap; 379 380 if ((child = RIGHT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 381 maxgap = child->maxgap; 382 383 return maxgap; 384 } 385 386 static void 387 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry) 388 { 389 struct vm_map_entry *parent; 390 391 KASSERT(entry->gap == uvm_rb_gap(entry)); 392 entry->maxgap = uvm_rb_maxgap(entry); 393 394 while ((parent = PARENT_ENTRY(map, entry)) != NULL) { 395 struct vm_map_entry *brother; 396 vsize_t maxgap = parent->gap; 397 unsigned int which; 398 399 KDASSERT(parent->gap == uvm_rb_gap(parent)); 400 if (maxgap < entry->maxgap) 401 maxgap = entry->maxgap; 402 /* 403 * Since we work towards the root, we know entry's maxgap 404 * value is OK, but its brothers may now be out-of-date due 405 * to rebalancing. So refresh it. 406 */ 407 which = RB_POSITION(&entry->rb_node) ^ RB_DIR_OTHER; 408 brother = (struct vm_map_entry *)parent->rb_node.rb_nodes[which]; 409 if (brother != NULL) { 410 KDASSERT(brother->gap == uvm_rb_gap(brother)); 411 brother->maxgap = uvm_rb_maxgap(brother); 412 if (maxgap < brother->maxgap) 413 maxgap = brother->maxgap; 414 } 415 416 parent->maxgap = maxgap; 417 entry = parent; 418 } 419 } 420 421 static void 422 uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry) 423 { 424 struct vm_map_entry *ret __diagused; 425 426 entry->gap = entry->maxgap = uvm_rb_gap(entry); 427 if (entry->prev != &map->header) 428 entry->prev->gap = uvm_rb_gap(entry->prev); 429 430 ret = rb_tree_insert_node(&map->rb_tree, entry); 431 KASSERTMSG(ret == entry, 432 "uvm_rb_insert: map %p: duplicate entry %p", map, ret); 433 434 /* 435 * If the previous entry is not our immediate left child, then it's an 436 * ancestor and will be fixed up on the way to the root. We don't 437 * have to check entry->prev against &map->header since &map->header 438 * will never be in the tree. 439 */ 440 uvm_rb_fixup(map, 441 LEFT_ENTRY(entry) == entry->prev ? entry->prev : entry); 442 } 443 444 static void 445 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry) 446 { 447 struct vm_map_entry *prev_parent = NULL, *next_parent = NULL; 448 449 /* 450 * If we are removing an interior node, then an adjacent node will 451 * be used to replace its position in the tree. Therefore we will 452 * need to fixup the tree starting at the parent of the replacement 453 * node. So record their parents for later use. 454 */ 455 if (entry->prev != &map->header) 456 prev_parent = PARENT_ENTRY(map, entry->prev); 457 if (entry->next != &map->header) 458 next_parent = PARENT_ENTRY(map, entry->next); 459 460 rb_tree_remove_node(&map->rb_tree, entry); 461 462 /* 463 * If the previous node has a new parent, fixup the tree starting 464 * at the previous node's old parent. 465 */ 466 if (entry->prev != &map->header) { 467 /* 468 * Update the previous entry's gap due to our absence. 469 */ 470 entry->prev->gap = uvm_rb_gap(entry->prev); 471 uvm_rb_fixup(map, entry->prev); 472 if (prev_parent != NULL 473 && prev_parent != entry 474 && prev_parent != PARENT_ENTRY(map, entry->prev)) 475 uvm_rb_fixup(map, prev_parent); 476 } 477 478 /* 479 * If the next node has a new parent, fixup the tree starting 480 * at the next node's old parent. 481 */ 482 if (entry->next != &map->header) { 483 uvm_rb_fixup(map, entry->next); 484 if (next_parent != NULL 485 && next_parent != entry 486 && next_parent != PARENT_ENTRY(map, entry->next)) 487 uvm_rb_fixup(map, next_parent); 488 } 489 } 490 491 #if defined(DEBUG) 492 int uvm_debug_check_map = 0; 493 int uvm_debug_check_rbtree = 0; 494 #define uvm_map_check(map, name) \ 495 _uvm_map_check((map), (name), __FILE__, __LINE__) 496 static void 497 _uvm_map_check(struct vm_map *map, const char *name, 498 const char *file, int line) 499 { 500 501 if ((uvm_debug_check_map && _uvm_map_sanity(map)) || 502 (uvm_debug_check_rbtree && _uvm_tree_sanity(map))) { 503 panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)", 504 name, map, file, line); 505 } 506 } 507 #else /* defined(DEBUG) */ 508 #define uvm_map_check(map, name) /* nothing */ 509 #endif /* defined(DEBUG) */ 510 511 #if defined(DEBUG) || defined(DDB) 512 int 513 _uvm_map_sanity(struct vm_map *map) 514 { 515 bool first_free_found = false; 516 bool hint_found = false; 517 const struct vm_map_entry *e; 518 struct vm_map_entry *hint = map->hint; 519 520 e = &map->header; 521 for (;;) { 522 if (map->first_free == e) { 523 first_free_found = true; 524 } else if (!first_free_found && e->next->start > e->end) { 525 printf("first_free %p should be %p\n", 526 map->first_free, e); 527 return -1; 528 } 529 if (hint == e) { 530 hint_found = true; 531 } 532 533 e = e->next; 534 if (e == &map->header) { 535 break; 536 } 537 } 538 if (!first_free_found) { 539 printf("stale first_free\n"); 540 return -1; 541 } 542 if (!hint_found) { 543 printf("stale hint\n"); 544 return -1; 545 } 546 return 0; 547 } 548 549 int 550 _uvm_tree_sanity(struct vm_map *map) 551 { 552 struct vm_map_entry *tmp, *trtmp; 553 int n = 0, i = 1; 554 555 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 556 if (tmp->gap != uvm_rb_gap(tmp)) { 557 printf("%d/%d gap %#lx != %#lx %s\n", 558 n + 1, map->nentries, 559 (ulong)tmp->gap, (ulong)uvm_rb_gap(tmp), 560 tmp->next == &map->header ? "(last)" : ""); 561 goto error; 562 } 563 /* 564 * If any entries are out of order, tmp->gap will be unsigned 565 * and will likely exceed the size of the map. 566 */ 567 if (tmp->gap >= vm_map_max(map) - vm_map_min(map)) { 568 printf("too large gap %zu\n", (size_t)tmp->gap); 569 goto error; 570 } 571 n++; 572 } 573 574 if (n != map->nentries) { 575 printf("nentries: %d vs %d\n", n, map->nentries); 576 goto error; 577 } 578 579 trtmp = NULL; 580 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 581 if (tmp->maxgap != uvm_rb_maxgap(tmp)) { 582 printf("maxgap %#lx != %#lx\n", 583 (ulong)tmp->maxgap, 584 (ulong)uvm_rb_maxgap(tmp)); 585 goto error; 586 } 587 if (trtmp != NULL && trtmp->start >= tmp->start) { 588 printf("corrupt: 0x%"PRIxVADDR"x >= 0x%"PRIxVADDR"x\n", 589 trtmp->start, tmp->start); 590 goto error; 591 } 592 593 trtmp = tmp; 594 } 595 596 for (tmp = map->header.next; tmp != &map->header; 597 tmp = tmp->next, i++) { 598 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_LEFT); 599 if (trtmp == NULL) 600 trtmp = &map->header; 601 if (tmp->prev != trtmp) { 602 printf("lookup: %d: %p->prev=%p: %p\n", 603 i, tmp, tmp->prev, trtmp); 604 goto error; 605 } 606 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_RIGHT); 607 if (trtmp == NULL) 608 trtmp = &map->header; 609 if (tmp->next != trtmp) { 610 printf("lookup: %d: %p->next=%p: %p\n", 611 i, tmp, tmp->next, trtmp); 612 goto error; 613 } 614 trtmp = rb_tree_find_node(&map->rb_tree, &tmp->start); 615 if (trtmp != tmp) { 616 printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp, 617 PARENT_ENTRY(map, tmp)); 618 goto error; 619 } 620 } 621 622 return (0); 623 error: 624 return (-1); 625 } 626 #endif /* defined(DEBUG) || defined(DDB) */ 627 628 /* 629 * vm_map_lock: acquire an exclusive (write) lock on a map. 630 * 631 * => The locking protocol provides for guaranteed upgrade from shared -> 632 * exclusive by whichever thread currently has the map marked busy. 633 * See "LOCKING PROTOCOL NOTES" in uvm_map.h. This is horrible; among 634 * other problems, it defeats any fairness guarantees provided by RW 635 * locks. 636 */ 637 638 void 639 vm_map_lock(struct vm_map *map) 640 { 641 642 for (;;) { 643 rw_enter(&map->lock, RW_WRITER); 644 if (map->busy == NULL || map->busy == curlwp) { 645 break; 646 } 647 mutex_enter(&map->misc_lock); 648 rw_exit(&map->lock); 649 if (map->busy != NULL) { 650 cv_wait(&map->cv, &map->misc_lock); 651 } 652 mutex_exit(&map->misc_lock); 653 } 654 map->timestamp++; 655 } 656 657 /* 658 * vm_map_lock_try: try to lock a map, failing if it is already locked. 659 */ 660 661 bool 662 vm_map_lock_try(struct vm_map *map) 663 { 664 665 if (!rw_tryenter(&map->lock, RW_WRITER)) { 666 return false; 667 } 668 if (map->busy != NULL) { 669 rw_exit(&map->lock); 670 return false; 671 } 672 map->timestamp++; 673 return true; 674 } 675 676 /* 677 * vm_map_unlock: release an exclusive lock on a map. 678 */ 679 680 void 681 vm_map_unlock(struct vm_map *map) 682 { 683 684 KASSERT(rw_write_held(&map->lock)); 685 KASSERT(map->busy == NULL || map->busy == curlwp); 686 rw_exit(&map->lock); 687 } 688 689 /* 690 * vm_map_unbusy: mark the map as unbusy, and wake any waiters that 691 * want an exclusive lock. 692 */ 693 694 void 695 vm_map_unbusy(struct vm_map *map) 696 { 697 698 KASSERT(map->busy == curlwp); 699 700 /* 701 * Safe to clear 'busy' and 'waiters' with only a read lock held: 702 * 703 * o they can only be set with a write lock held 704 * o writers are blocked out with a read or write hold 705 * o at any time, only one thread owns the set of values 706 */ 707 mutex_enter(&map->misc_lock); 708 map->busy = NULL; 709 cv_broadcast(&map->cv); 710 mutex_exit(&map->misc_lock); 711 } 712 713 /* 714 * vm_map_lock_read: acquire a shared (read) lock on a map. 715 */ 716 717 void 718 vm_map_lock_read(struct vm_map *map) 719 { 720 721 rw_enter(&map->lock, RW_READER); 722 } 723 724 /* 725 * vm_map_unlock_read: release a shared lock on a map. 726 */ 727 728 void 729 vm_map_unlock_read(struct vm_map *map) 730 { 731 732 rw_exit(&map->lock); 733 } 734 735 /* 736 * vm_map_busy: mark a map as busy. 737 * 738 * => the caller must hold the map write locked 739 */ 740 741 void 742 vm_map_busy(struct vm_map *map) 743 { 744 745 KASSERT(rw_write_held(&map->lock)); 746 KASSERT(map->busy == NULL); 747 748 map->busy = curlwp; 749 } 750 751 /* 752 * vm_map_locked_p: return true if the map is write locked. 753 * 754 * => only for debug purposes like KASSERTs. 755 * => should not be used to verify that a map is not locked. 756 */ 757 758 bool 759 vm_map_locked_p(struct vm_map *map) 760 { 761 762 return rw_write_held(&map->lock); 763 } 764 765 /* 766 * uvm_mapent_alloc: allocate a map entry 767 */ 768 769 static struct vm_map_entry * 770 uvm_mapent_alloc(struct vm_map *map, int flags) 771 { 772 struct vm_map_entry *me; 773 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK; 774 UVMHIST_FUNC("uvm_mapent_alloc"); UVMHIST_CALLED(maphist); 775 776 me = pool_cache_get(&uvm_map_entry_cache, pflags); 777 if (__predict_false(me == NULL)) { 778 return NULL; 779 } 780 me->flags = 0; 781 782 UVMHIST_LOG(maphist, "<- new entry=%#jx [kentry=%jd]", (uintptr_t)me, 783 (map == kernel_map), 0, 0); 784 return me; 785 } 786 787 /* 788 * uvm_mapent_free: free map entry 789 */ 790 791 static void 792 uvm_mapent_free(struct vm_map_entry *me) 793 { 794 UVMHIST_FUNC("uvm_mapent_free"); UVMHIST_CALLED(maphist); 795 796 UVMHIST_LOG(maphist,"<- freeing map entry=%#jx [flags=%jd]", 797 (uintptr_t)me, me->flags, 0, 0); 798 pool_cache_put(&uvm_map_entry_cache, me); 799 } 800 801 /* 802 * uvm_mapent_copy: copy a map entry, preserving flags 803 */ 804 805 static inline void 806 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst) 807 { 808 809 memcpy(dst, src, ((char *)&src->uvm_map_entry_stop_copy) - 810 ((char *)src)); 811 } 812 813 #if defined(DEBUG) 814 static void 815 _uvm_mapent_check(const struct vm_map_entry *entry, const char *file, int line) 816 { 817 818 if (entry->start >= entry->end) { 819 goto bad; 820 } 821 if (UVM_ET_ISOBJ(entry)) { 822 if (entry->object.uvm_obj == NULL) { 823 goto bad; 824 } 825 } else if (UVM_ET_ISSUBMAP(entry)) { 826 if (entry->object.sub_map == NULL) { 827 goto bad; 828 } 829 } else { 830 if (entry->object.uvm_obj != NULL || 831 entry->object.sub_map != NULL) { 832 goto bad; 833 } 834 } 835 if (!UVM_ET_ISOBJ(entry)) { 836 if (entry->offset != 0) { 837 goto bad; 838 } 839 } 840 841 return; 842 843 bad: 844 panic("%s: bad entry %p (%s:%d)", __func__, entry, file, line); 845 } 846 #endif /* defined(DEBUG) */ 847 848 /* 849 * uvm_map_entry_unwire: unwire a map entry 850 * 851 * => map should be locked by caller 852 */ 853 854 static inline void 855 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry) 856 { 857 858 entry->wired_count = 0; 859 uvm_fault_unwire_locked(map, entry->start, entry->end); 860 } 861 862 863 /* 864 * wrapper for calling amap_ref() 865 */ 866 static inline void 867 uvm_map_reference_amap(struct vm_map_entry *entry, int flags) 868 { 869 870 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff, 871 (entry->end - entry->start) >> PAGE_SHIFT, flags); 872 } 873 874 875 /* 876 * wrapper for calling amap_unref() 877 */ 878 static inline void 879 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags) 880 { 881 882 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff, 883 (entry->end - entry->start) >> PAGE_SHIFT, flags); 884 } 885 886 887 /* 888 * uvm_map_init: init mapping system at boot time. 889 */ 890 891 void 892 uvm_map_init(void) 893 { 894 #if defined(UVMHIST) 895 static struct kern_history_ent pdhistbuf[UVMHIST_PDHIST_SIZE]; 896 #endif 897 898 /* 899 * first, init logging system. 900 */ 901 902 UVMHIST_FUNC("uvm_map_init"); 903 UVMHIST_LINK_STATIC(maphist); 904 UVMHIST_INIT_STATIC(pdhist, pdhistbuf); 905 UVMHIST_CALLED(maphist); 906 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0); 907 908 /* 909 * initialize the global lock for kernel map entry. 910 */ 911 912 mutex_init(&uvm_kentry_lock, MUTEX_DRIVER, IPL_VM); 913 } 914 915 /* 916 * uvm_map_init_caches: init mapping system caches. 917 */ 918 void 919 uvm_map_init_caches(void) 920 { 921 /* 922 * initialize caches. 923 */ 924 925 pool_cache_bootstrap(&uvm_map_entry_cache, sizeof(struct vm_map_entry), 926 0, 0, 0, "vmmpepl", NULL, IPL_NONE, NULL, NULL, NULL); 927 pool_cache_bootstrap(&uvm_vmspace_cache, sizeof(struct vmspace), 928 0, 0, 0, "vmsppl", NULL, IPL_NONE, NULL, NULL, NULL); 929 } 930 931 /* 932 * clippers 933 */ 934 935 /* 936 * uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy. 937 */ 938 939 static void 940 uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2, 941 vaddr_t splitat) 942 { 943 vaddr_t adj; 944 945 KASSERT(entry1->start < splitat); 946 KASSERT(splitat < entry1->end); 947 948 adj = splitat - entry1->start; 949 entry1->end = entry2->start = splitat; 950 951 if (entry1->aref.ar_amap) { 952 amap_splitref(&entry1->aref, &entry2->aref, adj); 953 } 954 if (UVM_ET_ISSUBMAP(entry1)) { 955 /* ... unlikely to happen, but play it safe */ 956 uvm_map_reference(entry1->object.sub_map); 957 } else if (UVM_ET_ISOBJ(entry1)) { 958 KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */ 959 entry2->offset += adj; 960 if (entry1->object.uvm_obj->pgops && 961 entry1->object.uvm_obj->pgops->pgo_reference) 962 entry1->object.uvm_obj->pgops->pgo_reference( 963 entry1->object.uvm_obj); 964 } 965 } 966 967 /* 968 * uvm_map_clip_start: ensure that the entry begins at or after 969 * the starting address, if it doesn't we split the entry. 970 * 971 * => caller should use UVM_MAP_CLIP_START macro rather than calling 972 * this directly 973 * => map must be locked by caller 974 */ 975 976 void 977 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry, 978 vaddr_t start) 979 { 980 struct vm_map_entry *new_entry; 981 982 /* uvm_map_simplify_entry(map, entry); */ /* XXX */ 983 984 uvm_map_check(map, "clip_start entry"); 985 uvm_mapent_check(entry); 986 987 /* 988 * Split off the front portion. note that we must insert the new 989 * entry BEFORE this one, so that this entry has the specified 990 * starting address. 991 */ 992 new_entry = uvm_mapent_alloc(map, 0); 993 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 994 uvm_mapent_splitadj(new_entry, entry, start); 995 uvm_map_entry_link(map, entry->prev, new_entry); 996 997 uvm_map_check(map, "clip_start leave"); 998 } 999 1000 /* 1001 * uvm_map_clip_end: ensure that the entry ends at or before 1002 * the ending address, if it does't we split the reference 1003 * 1004 * => caller should use UVM_MAP_CLIP_END macro rather than calling 1005 * this directly 1006 * => map must be locked by caller 1007 */ 1008 1009 void 1010 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end) 1011 { 1012 struct vm_map_entry *new_entry; 1013 1014 uvm_map_check(map, "clip_end entry"); 1015 uvm_mapent_check(entry); 1016 1017 /* 1018 * Create a new entry and insert it 1019 * AFTER the specified entry 1020 */ 1021 new_entry = uvm_mapent_alloc(map, 0); 1022 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1023 uvm_mapent_splitadj(entry, new_entry, end); 1024 uvm_map_entry_link(map, entry, new_entry); 1025 1026 uvm_map_check(map, "clip_end leave"); 1027 } 1028 1029 /* 1030 * M A P - m a i n e n t r y p o i n t 1031 */ 1032 /* 1033 * uvm_map: establish a valid mapping in a map 1034 * 1035 * => assume startp is page aligned. 1036 * => assume size is a multiple of PAGE_SIZE. 1037 * => assume sys_mmap provides enough of a "hint" to have us skip 1038 * over text/data/bss area. 1039 * => map must be unlocked (we will lock it) 1040 * => <uobj,uoffset> value meanings (4 cases): 1041 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER 1042 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER 1043 * [3] <uobj,uoffset> == normal mapping 1044 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA 1045 * 1046 * case [4] is for kernel mappings where we don't know the offset until 1047 * we've found a virtual address. note that kernel object offsets are 1048 * always relative to vm_map_min(kernel_map). 1049 * 1050 * => if `align' is non-zero, we align the virtual address to the specified 1051 * alignment. 1052 * this is provided as a mechanism for large pages. 1053 * 1054 * => XXXCDC: need way to map in external amap? 1055 */ 1056 1057 int 1058 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size, 1059 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags) 1060 { 1061 struct uvm_map_args args; 1062 struct vm_map_entry *new_entry; 1063 int error; 1064 1065 KASSERT((size & PAGE_MASK) == 0); 1066 1067 #ifndef __USER_VA0_IS_SAFE 1068 if ((flags & UVM_FLAG_FIXED) && *startp == 0 && 1069 !VM_MAP_IS_KERNEL(map) && user_va0_disable) { 1070 uprintf("%s: process wants to map virtual address 0; see " 1071 "vm.user_va0_disable in sysctl(7).\n", __func__); 1072 return EACCES; 1073 } 1074 #endif 1075 1076 /* 1077 * for pager_map, allocate the new entry first to avoid sleeping 1078 * for memory while we have the map locked. 1079 */ 1080 1081 new_entry = NULL; 1082 if (map == pager_map) { 1083 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT)); 1084 if (__predict_false(new_entry == NULL)) 1085 return ENOMEM; 1086 } 1087 if (map == pager_map) 1088 flags |= UVM_FLAG_NOMERGE; 1089 1090 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align, 1091 flags, &args); 1092 if (!error) { 1093 error = uvm_map_enter(map, &args, new_entry); 1094 *startp = args.uma_start; 1095 } else if (new_entry) { 1096 uvm_mapent_free(new_entry); 1097 } 1098 1099 #if defined(DEBUG) 1100 if (!error && VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) { 1101 uvm_km_check_empty(map, *startp, *startp + size); 1102 } 1103 #endif /* defined(DEBUG) */ 1104 1105 return error; 1106 } 1107 1108 /* 1109 * uvm_map_prepare: 1110 * 1111 * called with map unlocked. 1112 * on success, returns the map locked. 1113 */ 1114 1115 int 1116 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size, 1117 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags, 1118 struct uvm_map_args *args) 1119 { 1120 struct vm_map_entry *prev_entry; 1121 vm_prot_t prot = UVM_PROTECTION(flags); 1122 vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1123 1124 UVMHIST_FUNC("uvm_map_prepare"); 1125 UVMHIST_CALLED(maphist); 1126 1127 UVMHIST_LOG(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)", 1128 (uintptr_t)map, start, size, flags); 1129 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj, 1130 uoffset,0,0); 1131 1132 /* 1133 * detect a popular device driver bug. 1134 */ 1135 1136 KASSERT(doing_shutdown || curlwp != NULL); 1137 1138 /* 1139 * zero-sized mapping doesn't make any sense. 1140 */ 1141 KASSERT(size > 0); 1142 1143 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0); 1144 1145 uvm_map_check(map, "map entry"); 1146 1147 /* 1148 * check sanity of protection code 1149 */ 1150 1151 if ((prot & maxprot) != prot) { 1152 UVMHIST_LOG(maphist, "<- prot. failure: prot=%#jx, max=%#jx", 1153 prot, maxprot,0,0); 1154 return EACCES; 1155 } 1156 1157 /* 1158 * figure out where to put new VM range 1159 */ 1160 retry: 1161 if (vm_map_lock_try(map) == false) { 1162 if ((flags & UVM_FLAG_TRYLOCK) != 0) { 1163 return EAGAIN; 1164 } 1165 vm_map_lock(map); /* could sleep here */ 1166 } 1167 if (flags & UVM_FLAG_UNMAP) { 1168 KASSERT(flags & UVM_FLAG_FIXED); 1169 KASSERT((flags & UVM_FLAG_NOWAIT) == 0); 1170 1171 /* 1172 * Set prev_entry to what it will need to be after any existing 1173 * entries are removed later in uvm_map_enter(). 1174 */ 1175 1176 if (uvm_map_lookup_entry(map, start, &prev_entry)) { 1177 if (start == prev_entry->start) 1178 prev_entry = prev_entry->prev; 1179 else 1180 UVM_MAP_CLIP_END(map, prev_entry, start); 1181 SAVE_HINT(map, map->hint, prev_entry); 1182 } 1183 } else { 1184 prev_entry = uvm_map_findspace(map, start, size, &start, 1185 uobj, uoffset, align, flags); 1186 } 1187 if (prev_entry == NULL) { 1188 unsigned int timestamp; 1189 1190 timestamp = map->timestamp; 1191 UVMHIST_LOG(maphist,"waiting va timestamp=%#jx", 1192 timestamp,0,0,0); 1193 map->flags |= VM_MAP_WANTVA; 1194 vm_map_unlock(map); 1195 1196 /* 1197 * try to reclaim kva and wait until someone does unmap. 1198 * fragile locking here, so we awaken every second to 1199 * recheck the condition. 1200 */ 1201 1202 mutex_enter(&map->misc_lock); 1203 while ((map->flags & VM_MAP_WANTVA) != 0 && 1204 map->timestamp == timestamp) { 1205 if ((flags & UVM_FLAG_WAITVA) == 0) { 1206 mutex_exit(&map->misc_lock); 1207 UVMHIST_LOG(maphist, 1208 "<- uvm_map_findspace failed!", 0,0,0,0); 1209 return ENOMEM; 1210 } else { 1211 cv_timedwait(&map->cv, &map->misc_lock, hz); 1212 } 1213 } 1214 mutex_exit(&map->misc_lock); 1215 goto retry; 1216 } 1217 1218 #ifdef PMAP_GROWKERNEL 1219 /* 1220 * If the kernel pmap can't map the requested space, 1221 * then allocate more resources for it. 1222 */ 1223 if (map == kernel_map && uvm_maxkaddr < (start + size)) 1224 uvm_maxkaddr = pmap_growkernel(start + size); 1225 #endif 1226 1227 UVMMAP_EVCNT_INCR(map_call); 1228 1229 /* 1230 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER 1231 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in 1232 * either case we want to zero it before storing it in the map entry 1233 * (because it looks strange and confusing when debugging...) 1234 * 1235 * if uobj is not null 1236 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping 1237 * and we do not need to change uoffset. 1238 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset 1239 * now (based on the starting address of the map). this case is 1240 * for kernel object mappings where we don't know the offset until 1241 * the virtual address is found (with uvm_map_findspace). the 1242 * offset is the distance we are from the start of the map. 1243 */ 1244 1245 if (uobj == NULL) { 1246 uoffset = 0; 1247 } else { 1248 if (uoffset == UVM_UNKNOWN_OFFSET) { 1249 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj)); 1250 uoffset = start - vm_map_min(kernel_map); 1251 } 1252 } 1253 1254 args->uma_flags = flags; 1255 args->uma_prev = prev_entry; 1256 args->uma_start = start; 1257 args->uma_size = size; 1258 args->uma_uobj = uobj; 1259 args->uma_uoffset = uoffset; 1260 1261 UVMHIST_LOG(maphist, "<- done!", 0,0,0,0); 1262 return 0; 1263 } 1264 1265 /* 1266 * uvm_map_enter: 1267 * 1268 * called with map locked. 1269 * unlock the map before returning. 1270 */ 1271 1272 int 1273 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args, 1274 struct vm_map_entry *new_entry) 1275 { 1276 struct vm_map_entry *prev_entry = args->uma_prev; 1277 struct vm_map_entry *dead = NULL, *dead_entries = NULL; 1278 1279 const uvm_flag_t flags = args->uma_flags; 1280 const vm_prot_t prot = UVM_PROTECTION(flags); 1281 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1282 const vm_inherit_t inherit = UVM_INHERIT(flags); 1283 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ? 1284 AMAP_EXTEND_NOWAIT : 0; 1285 const int advice = UVM_ADVICE(flags); 1286 1287 vaddr_t start = args->uma_start; 1288 vsize_t size = args->uma_size; 1289 struct uvm_object *uobj = args->uma_uobj; 1290 voff_t uoffset = args->uma_uoffset; 1291 1292 const int kmap = (vm_map_pmap(map) == pmap_kernel()); 1293 int merged = 0; 1294 int error; 1295 int newetype; 1296 1297 UVMHIST_FUNC("uvm_map_enter"); 1298 UVMHIST_CALLED(maphist); 1299 1300 UVMHIST_LOG(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)", 1301 (uintptr_t)map, start, size, flags); 1302 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj, 1303 uoffset,0,0); 1304 1305 KASSERT(map->hint == prev_entry); /* bimerge case assumes this */ 1306 KASSERT(vm_map_locked_p(map)); 1307 KASSERT((flags & (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)) != 1308 (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)); 1309 1310 if (uobj) 1311 newetype = UVM_ET_OBJ; 1312 else 1313 newetype = 0; 1314 1315 if (flags & UVM_FLAG_COPYONW) { 1316 newetype |= UVM_ET_COPYONWRITE; 1317 if ((flags & UVM_FLAG_OVERLAY) == 0) 1318 newetype |= UVM_ET_NEEDSCOPY; 1319 } 1320 1321 /* 1322 * For mappings with unmap, remove any old entries now. Adding the new 1323 * entry cannot fail because that can only happen if UVM_FLAG_NOWAIT 1324 * is set, and we do not support nowait and unmap together. 1325 */ 1326 1327 if (flags & UVM_FLAG_UNMAP) { 1328 KASSERT(flags & UVM_FLAG_FIXED); 1329 uvm_unmap_remove(map, start, start + size, &dead_entries, 0); 1330 #ifdef DEBUG 1331 struct vm_map_entry *tmp_entry __diagused; 1332 bool rv __diagused; 1333 1334 rv = uvm_map_lookup_entry(map, start, &tmp_entry); 1335 KASSERT(!rv); 1336 KASSERTMSG(prev_entry == tmp_entry, 1337 "args %p prev_entry %p tmp_entry %p", 1338 args, prev_entry, tmp_entry); 1339 #endif 1340 SAVE_HINT(map, map->hint, prev_entry); 1341 } 1342 1343 /* 1344 * try and insert in map by extending previous entry, if possible. 1345 * XXX: we don't try and pull back the next entry. might be useful 1346 * for a stack, but we are currently allocating our stack in advance. 1347 */ 1348 1349 if (flags & UVM_FLAG_NOMERGE) 1350 goto nomerge; 1351 1352 if (prev_entry->end == start && 1353 prev_entry != &map->header && 1354 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, 0, 1355 prot, maxprot, inherit, advice, 0)) { 1356 1357 if (uobj && prev_entry->offset + 1358 (prev_entry->end - prev_entry->start) != uoffset) 1359 goto forwardmerge; 1360 1361 /* 1362 * can't extend a shared amap. note: no need to lock amap to 1363 * look at refs since we don't care about its exact value. 1364 * if it is one (i.e. we have only reference) it will stay there 1365 */ 1366 1367 if (prev_entry->aref.ar_amap && 1368 amap_refs(prev_entry->aref.ar_amap) != 1) { 1369 goto forwardmerge; 1370 } 1371 1372 if (prev_entry->aref.ar_amap) { 1373 error = amap_extend(prev_entry, size, 1374 amapwaitflag | AMAP_EXTEND_FORWARDS); 1375 if (error) 1376 goto nomerge; 1377 } 1378 1379 if (kmap) { 1380 UVMMAP_EVCNT_INCR(kbackmerge); 1381 } else { 1382 UVMMAP_EVCNT_INCR(ubackmerge); 1383 } 1384 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0); 1385 1386 /* 1387 * drop our reference to uobj since we are extending a reference 1388 * that we already have (the ref count can not drop to zero). 1389 */ 1390 1391 if (uobj && uobj->pgops->pgo_detach) 1392 uobj->pgops->pgo_detach(uobj); 1393 1394 /* 1395 * Now that we've merged the entries, note that we've grown 1396 * and our gap has shrunk. Then fix the tree. 1397 */ 1398 prev_entry->end += size; 1399 prev_entry->gap -= size; 1400 uvm_rb_fixup(map, prev_entry); 1401 1402 uvm_map_check(map, "map backmerged"); 1403 1404 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0); 1405 merged++; 1406 } 1407 1408 forwardmerge: 1409 if (prev_entry->next->start == (start + size) && 1410 prev_entry->next != &map->header && 1411 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, 0, 1412 prot, maxprot, inherit, advice, 0)) { 1413 1414 if (uobj && prev_entry->next->offset != uoffset + size) 1415 goto nomerge; 1416 1417 /* 1418 * can't extend a shared amap. note: no need to lock amap to 1419 * look at refs since we don't care about its exact value. 1420 * if it is one (i.e. we have only reference) it will stay there. 1421 * 1422 * note that we also can't merge two amaps, so if we 1423 * merged with the previous entry which has an amap, 1424 * and the next entry also has an amap, we give up. 1425 * 1426 * Interesting cases: 1427 * amap, new, amap -> give up second merge (single fwd extend) 1428 * amap, new, none -> double forward extend (extend again here) 1429 * none, new, amap -> double backward extend (done here) 1430 * uobj, new, amap -> single backward extend (done here) 1431 * 1432 * XXX should we attempt to deal with someone refilling 1433 * the deallocated region between two entries that are 1434 * backed by the same amap (ie, arefs is 2, "prev" and 1435 * "next" refer to it, and adding this allocation will 1436 * close the hole, thus restoring arefs to 1 and 1437 * deallocating the "next" vm_map_entry)? -- @@@ 1438 */ 1439 1440 if (prev_entry->next->aref.ar_amap && 1441 (amap_refs(prev_entry->next->aref.ar_amap) != 1 || 1442 (merged && prev_entry->aref.ar_amap))) { 1443 goto nomerge; 1444 } 1445 1446 if (merged) { 1447 /* 1448 * Try to extend the amap of the previous entry to 1449 * cover the next entry as well. If it doesn't work 1450 * just skip on, don't actually give up, since we've 1451 * already completed the back merge. 1452 */ 1453 if (prev_entry->aref.ar_amap) { 1454 if (amap_extend(prev_entry, 1455 prev_entry->next->end - 1456 prev_entry->next->start, 1457 amapwaitflag | AMAP_EXTEND_FORWARDS)) 1458 goto nomerge; 1459 } 1460 1461 /* 1462 * Try to extend the amap of the *next* entry 1463 * back to cover the new allocation *and* the 1464 * previous entry as well (the previous merge 1465 * didn't have an amap already otherwise we 1466 * wouldn't be checking here for an amap). If 1467 * it doesn't work just skip on, again, don't 1468 * actually give up, since we've already 1469 * completed the back merge. 1470 */ 1471 else if (prev_entry->next->aref.ar_amap) { 1472 if (amap_extend(prev_entry->next, 1473 prev_entry->end - 1474 prev_entry->start, 1475 amapwaitflag | AMAP_EXTEND_BACKWARDS)) 1476 goto nomerge; 1477 } 1478 } else { 1479 /* 1480 * Pull the next entry's amap backwards to cover this 1481 * new allocation. 1482 */ 1483 if (prev_entry->next->aref.ar_amap) { 1484 error = amap_extend(prev_entry->next, size, 1485 amapwaitflag | AMAP_EXTEND_BACKWARDS); 1486 if (error) 1487 goto nomerge; 1488 } 1489 } 1490 1491 if (merged) { 1492 if (kmap) { 1493 UVMMAP_EVCNT_DECR(kbackmerge); 1494 UVMMAP_EVCNT_INCR(kbimerge); 1495 } else { 1496 UVMMAP_EVCNT_DECR(ubackmerge); 1497 UVMMAP_EVCNT_INCR(ubimerge); 1498 } 1499 } else { 1500 if (kmap) { 1501 UVMMAP_EVCNT_INCR(kforwmerge); 1502 } else { 1503 UVMMAP_EVCNT_INCR(uforwmerge); 1504 } 1505 } 1506 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0); 1507 1508 /* 1509 * drop our reference to uobj since we are extending a reference 1510 * that we already have (the ref count can not drop to zero). 1511 */ 1512 if (uobj && uobj->pgops->pgo_detach) 1513 uobj->pgops->pgo_detach(uobj); 1514 1515 if (merged) { 1516 dead = prev_entry->next; 1517 prev_entry->end = dead->end; 1518 uvm_map_entry_unlink(map, dead); 1519 if (dead->aref.ar_amap != NULL) { 1520 prev_entry->aref = dead->aref; 1521 dead->aref.ar_amap = NULL; 1522 } 1523 } else { 1524 prev_entry->next->start -= size; 1525 if (prev_entry != &map->header) { 1526 prev_entry->gap -= size; 1527 KASSERT(prev_entry->gap == uvm_rb_gap(prev_entry)); 1528 uvm_rb_fixup(map, prev_entry); 1529 } 1530 if (uobj) 1531 prev_entry->next->offset = uoffset; 1532 } 1533 1534 uvm_map_check(map, "map forwardmerged"); 1535 1536 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0); 1537 merged++; 1538 } 1539 1540 nomerge: 1541 if (!merged) { 1542 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0); 1543 if (kmap) { 1544 UVMMAP_EVCNT_INCR(knomerge); 1545 } else { 1546 UVMMAP_EVCNT_INCR(unomerge); 1547 } 1548 1549 /* 1550 * allocate new entry and link it in. 1551 */ 1552 1553 if (new_entry == NULL) { 1554 new_entry = uvm_mapent_alloc(map, 1555 (flags & UVM_FLAG_NOWAIT)); 1556 if (__predict_false(new_entry == NULL)) { 1557 error = ENOMEM; 1558 goto done; 1559 } 1560 } 1561 new_entry->start = start; 1562 new_entry->end = new_entry->start + size; 1563 new_entry->object.uvm_obj = uobj; 1564 new_entry->offset = uoffset; 1565 1566 new_entry->etype = newetype; 1567 1568 if (flags & UVM_FLAG_NOMERGE) { 1569 new_entry->flags |= UVM_MAP_NOMERGE; 1570 } 1571 1572 new_entry->protection = prot; 1573 new_entry->max_protection = maxprot; 1574 new_entry->inheritance = inherit; 1575 new_entry->wired_count = 0; 1576 new_entry->advice = advice; 1577 if (flags & UVM_FLAG_OVERLAY) { 1578 1579 /* 1580 * to_add: for BSS we overallocate a little since we 1581 * are likely to extend 1582 */ 1583 1584 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ? 1585 UVM_AMAP_CHUNK << PAGE_SHIFT : 0; 1586 struct vm_amap *amap = amap_alloc(size, to_add, 1587 (flags & UVM_FLAG_NOWAIT)); 1588 if (__predict_false(amap == NULL)) { 1589 error = ENOMEM; 1590 goto done; 1591 } 1592 new_entry->aref.ar_pageoff = 0; 1593 new_entry->aref.ar_amap = amap; 1594 } else { 1595 new_entry->aref.ar_pageoff = 0; 1596 new_entry->aref.ar_amap = NULL; 1597 } 1598 uvm_map_entry_link(map, prev_entry, new_entry); 1599 1600 /* 1601 * Update the free space hint 1602 */ 1603 1604 if ((map->first_free == prev_entry) && 1605 (prev_entry->end >= new_entry->start)) 1606 map->first_free = new_entry; 1607 1608 new_entry = NULL; 1609 } 1610 1611 map->size += size; 1612 1613 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 1614 1615 error = 0; 1616 1617 done: 1618 vm_map_unlock(map); 1619 1620 if (new_entry) { 1621 uvm_mapent_free(new_entry); 1622 } 1623 if (dead) { 1624 KDASSERT(merged); 1625 uvm_mapent_free(dead); 1626 } 1627 if (dead_entries) 1628 uvm_unmap_detach(dead_entries, 0); 1629 1630 return error; 1631 } 1632 1633 /* 1634 * uvm_map_lookup_entry_bytree: lookup an entry in tree 1635 */ 1636 1637 static inline bool 1638 uvm_map_lookup_entry_bytree(struct vm_map *map, vaddr_t address, 1639 struct vm_map_entry **entry /* OUT */) 1640 { 1641 struct vm_map_entry *prev = &map->header; 1642 struct vm_map_entry *cur = ROOT_ENTRY(map); 1643 1644 while (cur) { 1645 UVMMAP_EVCNT_INCR(mlk_treeloop); 1646 if (address >= cur->start) { 1647 if (address < cur->end) { 1648 *entry = cur; 1649 return true; 1650 } 1651 prev = cur; 1652 cur = RIGHT_ENTRY(cur); 1653 } else 1654 cur = LEFT_ENTRY(cur); 1655 } 1656 *entry = prev; 1657 return false; 1658 } 1659 1660 /* 1661 * uvm_map_lookup_entry: find map entry at or before an address 1662 * 1663 * => map must at least be read-locked by caller 1664 * => entry is returned in "entry" 1665 * => return value is true if address is in the returned entry 1666 */ 1667 1668 bool 1669 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address, 1670 struct vm_map_entry **entry /* OUT */) 1671 { 1672 struct vm_map_entry *cur; 1673 bool use_tree = false; 1674 UVMHIST_FUNC("uvm_map_lookup_entry"); 1675 UVMHIST_CALLED(maphist); 1676 1677 UVMHIST_LOG(maphist,"(map=%#jx,addr=%#jx,ent=%#jx)", 1678 (uintptr_t)map, address, (uintptr_t)entry, 0); 1679 1680 /* 1681 * start looking either from the head of the 1682 * list, or from the hint. 1683 */ 1684 1685 cur = map->hint; 1686 1687 if (cur == &map->header) 1688 cur = cur->next; 1689 1690 UVMMAP_EVCNT_INCR(mlk_call); 1691 if (address >= cur->start) { 1692 1693 /* 1694 * go from hint to end of list. 1695 * 1696 * but first, make a quick check to see if 1697 * we are already looking at the entry we 1698 * want (which is usually the case). 1699 * note also that we don't need to save the hint 1700 * here... it is the same hint (unless we are 1701 * at the header, in which case the hint didn't 1702 * buy us anything anyway). 1703 */ 1704 1705 if (cur != &map->header && cur->end > address) { 1706 UVMMAP_EVCNT_INCR(mlk_hint); 1707 *entry = cur; 1708 UVMHIST_LOG(maphist,"<- got it via hint (%#jx)", 1709 (uintptr_t)cur, 0, 0, 0); 1710 uvm_mapent_check(*entry); 1711 return (true); 1712 } 1713 1714 if (map->nentries > 15) 1715 use_tree = true; 1716 } else { 1717 1718 /* 1719 * invalid hint. use tree. 1720 */ 1721 use_tree = true; 1722 } 1723 1724 uvm_map_check(map, __func__); 1725 1726 if (use_tree) { 1727 /* 1728 * Simple lookup in the tree. Happens when the hint is 1729 * invalid, or nentries reach a threshold. 1730 */ 1731 UVMMAP_EVCNT_INCR(mlk_tree); 1732 if (uvm_map_lookup_entry_bytree(map, address, entry)) { 1733 goto got; 1734 } else { 1735 goto failed; 1736 } 1737 } 1738 1739 /* 1740 * search linearly 1741 */ 1742 1743 UVMMAP_EVCNT_INCR(mlk_list); 1744 while (cur != &map->header) { 1745 UVMMAP_EVCNT_INCR(mlk_listloop); 1746 if (cur->end > address) { 1747 if (address >= cur->start) { 1748 /* 1749 * save this lookup for future 1750 * hints, and return 1751 */ 1752 1753 *entry = cur; 1754 got: 1755 SAVE_HINT(map, map->hint, *entry); 1756 UVMHIST_LOG(maphist,"<- search got it (%#jx)", 1757 (uintptr_t)cur, 0, 0, 0); 1758 KDASSERT((*entry)->start <= address); 1759 KDASSERT(address < (*entry)->end); 1760 uvm_mapent_check(*entry); 1761 return (true); 1762 } 1763 break; 1764 } 1765 cur = cur->next; 1766 } 1767 *entry = cur->prev; 1768 failed: 1769 SAVE_HINT(map, map->hint, *entry); 1770 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0); 1771 KDASSERT((*entry) == &map->header || (*entry)->end <= address); 1772 KDASSERT((*entry)->next == &map->header || 1773 address < (*entry)->next->start); 1774 return (false); 1775 } 1776 1777 /* 1778 * See if the range between start and start + length fits in the gap 1779 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't 1780 * fit, and -1 address wraps around. 1781 */ 1782 static int 1783 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset, 1784 vsize_t align, int flags, int topdown, struct vm_map_entry *entry) 1785 { 1786 vaddr_t end; 1787 1788 #ifdef PMAP_PREFER 1789 /* 1790 * push start address forward as needed to avoid VAC alias problems. 1791 * we only do this if a valid offset is specified. 1792 */ 1793 1794 if (uoffset != UVM_UNKNOWN_OFFSET) 1795 PMAP_PREFER(uoffset, start, length, topdown); 1796 #endif 1797 if ((flags & UVM_FLAG_COLORMATCH) != 0) { 1798 KASSERT(align < uvmexp.ncolors); 1799 if (uvmexp.ncolors > 1) { 1800 const u_int colormask = uvmexp.colormask; 1801 const u_int colorsize = colormask + 1; 1802 vaddr_t hint = atop(*start); 1803 const u_int color = hint & colormask; 1804 if (color != align) { 1805 hint -= color; /* adjust to color boundary */ 1806 KASSERT((hint & colormask) == 0); 1807 if (topdown) { 1808 if (align > color) 1809 hint -= colorsize; 1810 } else { 1811 if (align < color) 1812 hint += colorsize; 1813 } 1814 *start = ptoa(hint + align); /* adjust to color */ 1815 } 1816 } 1817 } else if (align != 0) { 1818 if ((*start & (align - 1)) != 0) { 1819 if (topdown) 1820 *start &= ~(align - 1); 1821 else 1822 *start = roundup(*start, align); 1823 } 1824 /* 1825 * XXX Should we PMAP_PREFER() here again? 1826 * eh...i think we're okay 1827 */ 1828 } 1829 1830 /* 1831 * Find the end of the proposed new region. Be sure we didn't 1832 * wrap around the address; if so, we lose. Otherwise, if the 1833 * proposed new region fits before the next entry, we win. 1834 */ 1835 1836 end = *start + length; 1837 if (end < *start) 1838 return (-1); 1839 1840 if (entry->next->start >= end && *start >= entry->end) 1841 return (1); 1842 1843 return (0); 1844 } 1845 1846 /* 1847 * uvm_map_findspace: find "length" sized space in "map". 1848 * 1849 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is 1850 * set in "flags" (in which case we insist on using "hint"). 1851 * => "result" is VA returned 1852 * => uobj/uoffset are to be used to handle VAC alignment, if required 1853 * => if "align" is non-zero, we attempt to align to that value. 1854 * => caller must at least have read-locked map 1855 * => returns NULL on failure, or pointer to prev. map entry if success 1856 * => note this is a cross between the old vm_map_findspace and vm_map_find 1857 */ 1858 1859 struct vm_map_entry * 1860 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length, 1861 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset, 1862 vsize_t align, int flags) 1863 { 1864 struct vm_map_entry *entry; 1865 struct vm_map_entry *child, *prev, *tmp; 1866 vaddr_t orig_hint __diagused; 1867 const int topdown = map->flags & VM_MAP_TOPDOWN; 1868 UVMHIST_FUNC("uvm_map_findspace"); 1869 UVMHIST_CALLED(maphist); 1870 1871 UVMHIST_LOG(maphist, "(map=%#jx, hint=%#jx, len=%ju, flags=%#jx)", 1872 (uintptr_t)map, hint, length, flags); 1873 KASSERT((flags & UVM_FLAG_COLORMATCH) != 0 || (align & (align - 1)) == 0); 1874 KASSERT((flags & UVM_FLAG_COLORMATCH) == 0 || align < uvmexp.ncolors); 1875 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1876 1877 uvm_map_check(map, "map_findspace entry"); 1878 1879 /* 1880 * remember the original hint. if we are aligning, then we 1881 * may have to try again with no alignment constraint if 1882 * we fail the first time. 1883 */ 1884 1885 orig_hint = hint; 1886 if (hint < vm_map_min(map)) { /* check ranges ... */ 1887 if (flags & UVM_FLAG_FIXED) { 1888 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0); 1889 return (NULL); 1890 } 1891 hint = vm_map_min(map); 1892 } 1893 if (hint > vm_map_max(map)) { 1894 UVMHIST_LOG(maphist,"<- VA %#jx > range [%#jx->%#jx]", 1895 hint, vm_map_min(map), vm_map_max(map), 0); 1896 return (NULL); 1897 } 1898 1899 /* 1900 * Look for the first possible address; if there's already 1901 * something at this address, we have to start after it. 1902 */ 1903 1904 /* 1905 * @@@: there are four, no, eight cases to consider. 1906 * 1907 * 0: found, fixed, bottom up -> fail 1908 * 1: found, fixed, top down -> fail 1909 * 2: found, not fixed, bottom up -> start after entry->end, 1910 * loop up 1911 * 3: found, not fixed, top down -> start before entry->start, 1912 * loop down 1913 * 4: not found, fixed, bottom up -> check entry->next->start, fail 1914 * 5: not found, fixed, top down -> check entry->next->start, fail 1915 * 6: not found, not fixed, bottom up -> check entry->next->start, 1916 * loop up 1917 * 7: not found, not fixed, top down -> check entry->next->start, 1918 * loop down 1919 * 1920 * as you can see, it reduces to roughly five cases, and that 1921 * adding top down mapping only adds one unique case (without 1922 * it, there would be four cases). 1923 */ 1924 1925 if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) { 1926 entry = map->first_free; 1927 } else { 1928 if (uvm_map_lookup_entry(map, hint, &entry)) { 1929 /* "hint" address already in use ... */ 1930 if (flags & UVM_FLAG_FIXED) { 1931 UVMHIST_LOG(maphist, "<- fixed & VA in use", 1932 0, 0, 0, 0); 1933 return (NULL); 1934 } 1935 if (topdown) 1936 /* Start from lower gap. */ 1937 entry = entry->prev; 1938 } else if (flags & UVM_FLAG_FIXED) { 1939 if (entry->next->start >= hint + length && 1940 hint + length > hint) 1941 goto found; 1942 1943 /* "hint" address is gap but too small */ 1944 UVMHIST_LOG(maphist, "<- fixed mapping failed", 1945 0, 0, 0, 0); 1946 return (NULL); /* only one shot at it ... */ 1947 } else { 1948 /* 1949 * See if given hint fits in this gap. 1950 */ 1951 switch (uvm_map_space_avail(&hint, length, 1952 uoffset, align, flags, topdown, entry)) { 1953 case 1: 1954 goto found; 1955 case -1: 1956 goto wraparound; 1957 } 1958 1959 if (topdown) { 1960 /* 1961 * Still there is a chance to fit 1962 * if hint > entry->end. 1963 */ 1964 } else { 1965 /* Start from higher gap. */ 1966 entry = entry->next; 1967 if (entry == &map->header) 1968 goto notfound; 1969 goto nextgap; 1970 } 1971 } 1972 } 1973 1974 /* 1975 * Note that all UVM_FLAGS_FIXED case is already handled. 1976 */ 1977 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1978 1979 /* Try to find the space in the red-black tree */ 1980 1981 /* Check slot before any entry */ 1982 hint = topdown ? entry->next->start - length : entry->end; 1983 switch (uvm_map_space_avail(&hint, length, uoffset, align, flags, 1984 topdown, entry)) { 1985 case 1: 1986 goto found; 1987 case -1: 1988 goto wraparound; 1989 } 1990 1991 nextgap: 1992 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1993 /* If there is not enough space in the whole tree, we fail */ 1994 tmp = ROOT_ENTRY(map); 1995 if (tmp == NULL || tmp->maxgap < length) 1996 goto notfound; 1997 1998 prev = NULL; /* previous candidate */ 1999 2000 /* Find an entry close to hint that has enough space */ 2001 for (; tmp;) { 2002 KASSERT(tmp->next->start == tmp->end + tmp->gap); 2003 if (topdown) { 2004 if (tmp->next->start < hint + length && 2005 (prev == NULL || tmp->end > prev->end)) { 2006 if (tmp->gap >= length) 2007 prev = tmp; 2008 else if ((child = LEFT_ENTRY(tmp)) != NULL 2009 && child->maxgap >= length) 2010 prev = tmp; 2011 } 2012 } else { 2013 if (tmp->end >= hint && 2014 (prev == NULL || tmp->end < prev->end)) { 2015 if (tmp->gap >= length) 2016 prev = tmp; 2017 else if ((child = RIGHT_ENTRY(tmp)) != NULL 2018 && child->maxgap >= length) 2019 prev = tmp; 2020 } 2021 } 2022 if (tmp->next->start < hint + length) 2023 child = RIGHT_ENTRY(tmp); 2024 else if (tmp->end > hint) 2025 child = LEFT_ENTRY(tmp); 2026 else { 2027 if (tmp->gap >= length) 2028 break; 2029 if (topdown) 2030 child = LEFT_ENTRY(tmp); 2031 else 2032 child = RIGHT_ENTRY(tmp); 2033 } 2034 if (child == NULL || child->maxgap < length) 2035 break; 2036 tmp = child; 2037 } 2038 2039 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) { 2040 /* 2041 * Check if the entry that we found satifies the 2042 * space requirement 2043 */ 2044 if (topdown) { 2045 if (hint > tmp->next->start - length) 2046 hint = tmp->next->start - length; 2047 } else { 2048 if (hint < tmp->end) 2049 hint = tmp->end; 2050 } 2051 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2052 flags, topdown, tmp)) { 2053 case 1: 2054 entry = tmp; 2055 goto found; 2056 case -1: 2057 goto wraparound; 2058 } 2059 if (tmp->gap >= length) 2060 goto listsearch; 2061 } 2062 if (prev == NULL) 2063 goto notfound; 2064 2065 if (topdown) { 2066 KASSERT(orig_hint >= prev->next->start - length || 2067 prev->next->start - length > prev->next->start); 2068 hint = prev->next->start - length; 2069 } else { 2070 KASSERT(orig_hint <= prev->end); 2071 hint = prev->end; 2072 } 2073 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2074 flags, topdown, prev)) { 2075 case 1: 2076 entry = prev; 2077 goto found; 2078 case -1: 2079 goto wraparound; 2080 } 2081 if (prev->gap >= length) 2082 goto listsearch; 2083 2084 if (topdown) 2085 tmp = LEFT_ENTRY(prev); 2086 else 2087 tmp = RIGHT_ENTRY(prev); 2088 for (;;) { 2089 KASSERT(tmp && tmp->maxgap >= length); 2090 if (topdown) 2091 child = RIGHT_ENTRY(tmp); 2092 else 2093 child = LEFT_ENTRY(tmp); 2094 if (child && child->maxgap >= length) { 2095 tmp = child; 2096 continue; 2097 } 2098 if (tmp->gap >= length) 2099 break; 2100 if (topdown) 2101 tmp = LEFT_ENTRY(tmp); 2102 else 2103 tmp = RIGHT_ENTRY(tmp); 2104 } 2105 2106 if (topdown) { 2107 KASSERT(orig_hint >= tmp->next->start - length || 2108 tmp->next->start - length > tmp->next->start); 2109 hint = tmp->next->start - length; 2110 } else { 2111 KASSERT(orig_hint <= tmp->end); 2112 hint = tmp->end; 2113 } 2114 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2115 flags, topdown, tmp)) { 2116 case 1: 2117 entry = tmp; 2118 goto found; 2119 case -1: 2120 goto wraparound; 2121 } 2122 2123 /* 2124 * The tree fails to find an entry because of offset or alignment 2125 * restrictions. Search the list instead. 2126 */ 2127 listsearch: 2128 /* 2129 * Look through the rest of the map, trying to fit a new region in 2130 * the gap between existing regions, or after the very last region. 2131 * note: entry->end = base VA of current gap, 2132 * entry->next->start = VA of end of current gap 2133 */ 2134 2135 for (;;) { 2136 /* Update hint for current gap. */ 2137 hint = topdown ? entry->next->start - length : entry->end; 2138 2139 /* See if it fits. */ 2140 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2141 flags, topdown, entry)) { 2142 case 1: 2143 goto found; 2144 case -1: 2145 goto wraparound; 2146 } 2147 2148 /* Advance to next/previous gap */ 2149 if (topdown) { 2150 if (entry == &map->header) { 2151 UVMHIST_LOG(maphist, "<- failed (off start)", 2152 0,0,0,0); 2153 goto notfound; 2154 } 2155 entry = entry->prev; 2156 } else { 2157 entry = entry->next; 2158 if (entry == &map->header) { 2159 UVMHIST_LOG(maphist, "<- failed (off end)", 2160 0,0,0,0); 2161 goto notfound; 2162 } 2163 } 2164 } 2165 2166 found: 2167 SAVE_HINT(map, map->hint, entry); 2168 *result = hint; 2169 UVMHIST_LOG(maphist,"<- got it! (result=%#jx)", hint, 0,0,0); 2170 KASSERTMSG( topdown || hint >= orig_hint, "hint: %jx, orig_hint: %jx", 2171 (uintmax_t)hint, (uintmax_t)orig_hint); 2172 KASSERTMSG(!topdown || hint <= orig_hint, "hint: %jx, orig_hint: %jx", 2173 (uintmax_t)hint, (uintmax_t)orig_hint); 2174 KASSERT(entry->end <= hint); 2175 KASSERT(hint + length <= entry->next->start); 2176 return (entry); 2177 2178 wraparound: 2179 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0); 2180 2181 return (NULL); 2182 2183 notfound: 2184 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0); 2185 2186 return (NULL); 2187 } 2188 2189 /* 2190 * U N M A P - m a i n h e l p e r f u n c t i o n s 2191 */ 2192 2193 /* 2194 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop") 2195 * 2196 * => caller must check alignment and size 2197 * => map must be locked by caller 2198 * => we return a list of map entries that we've remove from the map 2199 * in "entry_list" 2200 */ 2201 2202 void 2203 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end, 2204 struct vm_map_entry **entry_list /* OUT */, int flags) 2205 { 2206 struct vm_map_entry *entry, *first_entry, *next; 2207 vaddr_t len; 2208 UVMHIST_FUNC("uvm_unmap_remove"); UVMHIST_CALLED(maphist); 2209 2210 UVMHIST_LOG(maphist,"(map=%#jx, start=%#jx, end=%#jx)", 2211 (uintptr_t)map, start, end, 0); 2212 VM_MAP_RANGE_CHECK(map, start, end); 2213 2214 uvm_map_check(map, "unmap_remove entry"); 2215 2216 /* 2217 * find first entry 2218 */ 2219 2220 if (uvm_map_lookup_entry(map, start, &first_entry) == true) { 2221 /* clip and go... */ 2222 entry = first_entry; 2223 UVM_MAP_CLIP_START(map, entry, start); 2224 /* critical! prevents stale hint */ 2225 SAVE_HINT(map, entry, entry->prev); 2226 } else { 2227 entry = first_entry->next; 2228 } 2229 2230 /* 2231 * Save the free space hint 2232 */ 2233 2234 if (map->first_free != &map->header && map->first_free->start >= start) 2235 map->first_free = entry->prev; 2236 2237 /* 2238 * note: we now re-use first_entry for a different task. we remove 2239 * a number of map entries from the map and save them in a linked 2240 * list headed by "first_entry". once we remove them from the map 2241 * the caller should unlock the map and drop the references to the 2242 * backing objects [c.f. uvm_unmap_detach]. the object is to 2243 * separate unmapping from reference dropping. why? 2244 * [1] the map has to be locked for unmapping 2245 * [2] the map need not be locked for reference dropping 2246 * [3] dropping references may trigger pager I/O, and if we hit 2247 * a pager that does synchronous I/O we may have to wait for it. 2248 * [4] we would like all waiting for I/O to occur with maps unlocked 2249 * so that we don't block other threads. 2250 */ 2251 2252 first_entry = NULL; 2253 *entry_list = NULL; 2254 2255 /* 2256 * break up the area into map entry sized regions and unmap. note 2257 * that all mappings have to be removed before we can even consider 2258 * dropping references to amaps or VM objects (otherwise we could end 2259 * up with a mapping to a page on the free list which would be very bad) 2260 */ 2261 2262 while ((entry != &map->header) && (entry->start < end)) { 2263 KASSERT((entry->flags & UVM_MAP_STATIC) == 0); 2264 2265 UVM_MAP_CLIP_END(map, entry, end); 2266 next = entry->next; 2267 len = entry->end - entry->start; 2268 2269 /* 2270 * unwire before removing addresses from the pmap; otherwise 2271 * unwiring will put the entries back into the pmap (XXX). 2272 */ 2273 2274 if (VM_MAPENT_ISWIRED(entry)) { 2275 uvm_map_entry_unwire(map, entry); 2276 } 2277 if (flags & UVM_FLAG_VAONLY) { 2278 2279 /* nothing */ 2280 2281 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) { 2282 2283 /* 2284 * if the map is non-pageable, any pages mapped there 2285 * must be wired and entered with pmap_kenter_pa(), 2286 * and we should free any such pages immediately. 2287 * this is mostly used for kmem_map. 2288 */ 2289 KASSERT(vm_map_pmap(map) == pmap_kernel()); 2290 2291 uvm_km_pgremove_intrsafe(map, entry->start, entry->end); 2292 } else if (UVM_ET_ISOBJ(entry) && 2293 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) { 2294 panic("%s: kernel object %p %p\n", 2295 __func__, map, entry); 2296 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) { 2297 /* 2298 * remove mappings the standard way. lock object 2299 * and/or amap to ensure vm_page state does not 2300 * change while in pmap_remove(). 2301 */ 2302 2303 uvm_map_lock_entry(entry); 2304 pmap_remove(map->pmap, entry->start, entry->end); 2305 uvm_map_unlock_entry(entry); 2306 } 2307 2308 #if defined(UVMDEBUG) 2309 /* 2310 * check if there's remaining mapping, 2311 * which is a bug in caller. 2312 */ 2313 2314 vaddr_t va; 2315 for (va = entry->start; va < entry->end; 2316 va += PAGE_SIZE) { 2317 if (pmap_extract(vm_map_pmap(map), va, NULL)) { 2318 panic("%s: %#"PRIxVADDR" has mapping", 2319 __func__, va); 2320 } 2321 } 2322 2323 if (VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) { 2324 uvm_km_check_empty(map, entry->start, 2325 entry->end); 2326 } 2327 #endif /* defined(UVMDEBUG) */ 2328 2329 /* 2330 * remove entry from map and put it on our list of entries 2331 * that we've nuked. then go to next entry. 2332 */ 2333 2334 UVMHIST_LOG(maphist, " removed map entry %#jx", 2335 (uintptr_t)entry, 0, 0, 0); 2336 2337 /* critical! prevents stale hint */ 2338 SAVE_HINT(map, entry, entry->prev); 2339 2340 uvm_map_entry_unlink(map, entry); 2341 KASSERT(map->size >= len); 2342 map->size -= len; 2343 entry->prev = NULL; 2344 entry->next = first_entry; 2345 first_entry = entry; 2346 entry = next; 2347 } 2348 2349 /* 2350 * Note: if map is dying, leave pmap_update() for pmap_destroy(), 2351 * which will be called later. 2352 */ 2353 if ((map->flags & VM_MAP_DYING) == 0) { 2354 pmap_update(vm_map_pmap(map)); 2355 } else { 2356 KASSERT(vm_map_pmap(map) != pmap_kernel()); 2357 } 2358 2359 uvm_map_check(map, "unmap_remove leave"); 2360 2361 /* 2362 * now we've cleaned up the map and are ready for the caller to drop 2363 * references to the mapped objects. 2364 */ 2365 2366 *entry_list = first_entry; 2367 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 2368 2369 if (map->flags & VM_MAP_WANTVA) { 2370 mutex_enter(&map->misc_lock); 2371 map->flags &= ~VM_MAP_WANTVA; 2372 cv_broadcast(&map->cv); 2373 mutex_exit(&map->misc_lock); 2374 } 2375 } 2376 2377 /* 2378 * uvm_unmap_detach: drop references in a chain of map entries 2379 * 2380 * => we will free the map entries as we traverse the list. 2381 */ 2382 2383 void 2384 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags) 2385 { 2386 struct vm_map_entry *next_entry; 2387 UVMHIST_FUNC("uvm_unmap_detach"); UVMHIST_CALLED(maphist); 2388 2389 while (first_entry) { 2390 KASSERT(!VM_MAPENT_ISWIRED(first_entry)); 2391 UVMHIST_LOG(maphist, 2392 " detach %#jx: amap=%#jx, obj=%#jx, submap?=%jd", 2393 (uintptr_t)first_entry, 2394 (uintptr_t)first_entry->aref.ar_amap, 2395 (uintptr_t)first_entry->object.uvm_obj, 2396 UVM_ET_ISSUBMAP(first_entry)); 2397 2398 /* 2399 * drop reference to amap, if we've got one 2400 */ 2401 2402 if (first_entry->aref.ar_amap) 2403 uvm_map_unreference_amap(first_entry, flags); 2404 2405 /* 2406 * drop reference to our backing object, if we've got one 2407 */ 2408 2409 KASSERT(!UVM_ET_ISSUBMAP(first_entry)); 2410 if (UVM_ET_ISOBJ(first_entry) && 2411 first_entry->object.uvm_obj->pgops->pgo_detach) { 2412 (*first_entry->object.uvm_obj->pgops->pgo_detach) 2413 (first_entry->object.uvm_obj); 2414 } 2415 next_entry = first_entry->next; 2416 uvm_mapent_free(first_entry); 2417 first_entry = next_entry; 2418 } 2419 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 2420 } 2421 2422 /* 2423 * E X T R A C T I O N F U N C T I O N S 2424 */ 2425 2426 /* 2427 * uvm_map_reserve: reserve space in a vm_map for future use. 2428 * 2429 * => we reserve space in a map by putting a dummy map entry in the 2430 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE) 2431 * => map should be unlocked (we will write lock it) 2432 * => we return true if we were able to reserve space 2433 * => XXXCDC: should be inline? 2434 */ 2435 2436 int 2437 uvm_map_reserve(struct vm_map *map, vsize_t size, 2438 vaddr_t offset /* hint for pmap_prefer */, 2439 vsize_t align /* alignment */, 2440 vaddr_t *raddr /* IN:hint, OUT: reserved VA */, 2441 uvm_flag_t flags /* UVM_FLAG_FIXED or UVM_FLAG_COLORMATCH or 0 */) 2442 { 2443 UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist); 2444 2445 UVMHIST_LOG(maphist, "(map=%#jx, size=%#jx, offset=%#jx, addr=%#jx)", 2446 (uintptr_t)map, size, offset, (uintptr_t)raddr); 2447 2448 size = round_page(size); 2449 2450 /* 2451 * reserve some virtual space. 2452 */ 2453 2454 if (uvm_map(map, raddr, size, NULL, offset, align, 2455 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE, 2456 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) { 2457 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 2458 return (false); 2459 } 2460 2461 UVMHIST_LOG(maphist, "<- done (*raddr=%#jx)", *raddr,0,0,0); 2462 return (true); 2463 } 2464 2465 /* 2466 * uvm_map_replace: replace a reserved (blank) area of memory with 2467 * real mappings. 2468 * 2469 * => caller must WRITE-LOCK the map 2470 * => we return true if replacement was a success 2471 * => we expect the newents chain to have nnewents entrys on it and 2472 * we expect newents->prev to point to the last entry on the list 2473 * => note newents is allowed to be NULL 2474 */ 2475 2476 static int 2477 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end, 2478 struct vm_map_entry *newents, int nnewents, vsize_t nsize, 2479 struct vm_map_entry **oldentryp) 2480 { 2481 struct vm_map_entry *oldent, *last; 2482 2483 uvm_map_check(map, "map_replace entry"); 2484 2485 /* 2486 * first find the blank map entry at the specified address 2487 */ 2488 2489 if (!uvm_map_lookup_entry(map, start, &oldent)) { 2490 return (false); 2491 } 2492 2493 /* 2494 * check to make sure we have a proper blank entry 2495 */ 2496 2497 if (end < oldent->end) { 2498 UVM_MAP_CLIP_END(map, oldent, end); 2499 } 2500 if (oldent->start != start || oldent->end != end || 2501 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) { 2502 return (false); 2503 } 2504 2505 #ifdef DIAGNOSTIC 2506 2507 /* 2508 * sanity check the newents chain 2509 */ 2510 2511 { 2512 struct vm_map_entry *tmpent = newents; 2513 int nent = 0; 2514 vsize_t sz = 0; 2515 vaddr_t cur = start; 2516 2517 while (tmpent) { 2518 nent++; 2519 sz += tmpent->end - tmpent->start; 2520 if (tmpent->start < cur) 2521 panic("uvm_map_replace1"); 2522 if (tmpent->start >= tmpent->end || tmpent->end > end) { 2523 panic("uvm_map_replace2: " 2524 "tmpent->start=%#"PRIxVADDR 2525 ", tmpent->end=%#"PRIxVADDR 2526 ", end=%#"PRIxVADDR, 2527 tmpent->start, tmpent->end, end); 2528 } 2529 cur = tmpent->end; 2530 if (tmpent->next) { 2531 if (tmpent->next->prev != tmpent) 2532 panic("uvm_map_replace3"); 2533 } else { 2534 if (newents->prev != tmpent) 2535 panic("uvm_map_replace4"); 2536 } 2537 tmpent = tmpent->next; 2538 } 2539 if (nent != nnewents) 2540 panic("uvm_map_replace5"); 2541 if (sz != nsize) 2542 panic("uvm_map_replace6"); 2543 } 2544 #endif 2545 2546 /* 2547 * map entry is a valid blank! replace it. (this does all the 2548 * work of map entry link/unlink...). 2549 */ 2550 2551 if (newents) { 2552 last = newents->prev; 2553 2554 /* critical: flush stale hints out of map */ 2555 SAVE_HINT(map, map->hint, newents); 2556 if (map->first_free == oldent) 2557 map->first_free = last; 2558 2559 last->next = oldent->next; 2560 last->next->prev = last; 2561 2562 /* Fix RB tree */ 2563 uvm_rb_remove(map, oldent); 2564 2565 newents->prev = oldent->prev; 2566 newents->prev->next = newents; 2567 map->nentries = map->nentries + (nnewents - 1); 2568 2569 /* Fixup the RB tree */ 2570 { 2571 int i; 2572 struct vm_map_entry *tmp; 2573 2574 tmp = newents; 2575 for (i = 0; i < nnewents && tmp; i++) { 2576 uvm_rb_insert(map, tmp); 2577 tmp = tmp->next; 2578 } 2579 } 2580 } else { 2581 /* NULL list of new entries: just remove the old one */ 2582 clear_hints(map, oldent); 2583 uvm_map_entry_unlink(map, oldent); 2584 } 2585 map->size -= end - start - nsize; 2586 2587 uvm_map_check(map, "map_replace leave"); 2588 2589 /* 2590 * now we can free the old blank entry and return. 2591 */ 2592 2593 *oldentryp = oldent; 2594 return (true); 2595 } 2596 2597 /* 2598 * uvm_map_extract: extract a mapping from a map and put it somewhere 2599 * (maybe removing the old mapping) 2600 * 2601 * => maps should be unlocked (we will write lock them) 2602 * => returns 0 on success, error code otherwise 2603 * => start must be page aligned 2604 * => len must be page sized 2605 * => flags: 2606 * UVM_EXTRACT_REMOVE: remove mappings from srcmap 2607 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only) 2608 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs 2609 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go 2610 * UVM_EXTRACT_PROT_ALL: set prot to UVM_PROT_ALL as we go 2611 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<< 2612 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only 2613 * be used from within the kernel in a kernel level map <<< 2614 */ 2615 2616 int 2617 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len, 2618 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags) 2619 { 2620 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge; 2621 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry, 2622 *deadentry, *oldentry; 2623 struct vm_map_entry *resentry = NULL; /* a dummy reservation entry */ 2624 vsize_t elen __unused; 2625 int nchain, error, copy_ok; 2626 vsize_t nsize; 2627 UVMHIST_FUNC("uvm_map_extract"); UVMHIST_CALLED(maphist); 2628 2629 UVMHIST_LOG(maphist,"(srcmap=%#jx,start=%#jx, len=%#jx", 2630 (uintptr_t)srcmap, start, len, 0); 2631 UVMHIST_LOG(maphist," ...,dstmap=%#jx, flags=%#jx)", 2632 (uintptr_t)dstmap, flags, 0, 0); 2633 2634 /* 2635 * step 0: sanity check: start must be on a page boundary, length 2636 * must be page sized. can't ask for CONTIG/QREF if you asked for 2637 * REMOVE. 2638 */ 2639 2640 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0); 2641 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 || 2642 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0); 2643 2644 /* 2645 * step 1: reserve space in the target map for the extracted area 2646 */ 2647 2648 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2649 dstaddr = vm_map_min(dstmap); 2650 if (!uvm_map_reserve(dstmap, len, start, 2651 atop(start) & uvmexp.colormask, &dstaddr, 2652 UVM_FLAG_COLORMATCH)) 2653 return (ENOMEM); 2654 KASSERT((atop(start ^ dstaddr) & uvmexp.colormask) == 0); 2655 *dstaddrp = dstaddr; /* pass address back to caller */ 2656 UVMHIST_LOG(maphist, " dstaddr=%#jx", dstaddr,0,0,0); 2657 } else { 2658 dstaddr = *dstaddrp; 2659 } 2660 2661 /* 2662 * step 2: setup for the extraction process loop by init'ing the 2663 * map entry chain, locking src map, and looking up the first useful 2664 * entry in the map. 2665 */ 2666 2667 end = start + len; 2668 newend = dstaddr + len; 2669 chain = endchain = NULL; 2670 nchain = 0; 2671 nsize = 0; 2672 vm_map_lock(srcmap); 2673 2674 if (uvm_map_lookup_entry(srcmap, start, &entry)) { 2675 2676 /* "start" is within an entry */ 2677 if (flags & UVM_EXTRACT_QREF) { 2678 2679 /* 2680 * for quick references we don't clip the entry, so 2681 * the entry may map space "before" the starting 2682 * virtual address... this is the "fudge" factor 2683 * (which can be non-zero only the first time 2684 * through the "while" loop in step 3). 2685 */ 2686 2687 fudge = start - entry->start; 2688 } else { 2689 2690 /* 2691 * normal reference: we clip the map to fit (thus 2692 * fudge is zero) 2693 */ 2694 2695 UVM_MAP_CLIP_START(srcmap, entry, start); 2696 SAVE_HINT(srcmap, srcmap->hint, entry->prev); 2697 fudge = 0; 2698 } 2699 } else { 2700 2701 /* "start" is not within an entry ... skip to next entry */ 2702 if (flags & UVM_EXTRACT_CONTIG) { 2703 error = EINVAL; 2704 goto bad; /* definite hole here ... */ 2705 } 2706 2707 entry = entry->next; 2708 fudge = 0; 2709 } 2710 2711 /* save values from srcmap for step 6 */ 2712 orig_entry = entry; 2713 orig_fudge = fudge; 2714 2715 /* 2716 * step 3: now start looping through the map entries, extracting 2717 * as we go. 2718 */ 2719 2720 while (entry->start < end && entry != &srcmap->header) { 2721 2722 /* if we are not doing a quick reference, clip it */ 2723 if ((flags & UVM_EXTRACT_QREF) == 0) 2724 UVM_MAP_CLIP_END(srcmap, entry, end); 2725 2726 /* clear needs_copy (allow chunking) */ 2727 if (UVM_ET_ISNEEDSCOPY(entry)) { 2728 amap_copy(srcmap, entry, 2729 AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end); 2730 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */ 2731 error = ENOMEM; 2732 goto bad; 2733 } 2734 2735 /* amap_copy could clip (during chunk)! update fudge */ 2736 if (fudge) { 2737 fudge = start - entry->start; 2738 orig_fudge = fudge; 2739 } 2740 } 2741 2742 /* calculate the offset of this from "start" */ 2743 oldoffset = (entry->start + fudge) - start; 2744 2745 /* allocate a new map entry */ 2746 newentry = uvm_mapent_alloc(dstmap, 0); 2747 if (newentry == NULL) { 2748 error = ENOMEM; 2749 goto bad; 2750 } 2751 2752 /* set up new map entry */ 2753 newentry->next = NULL; 2754 newentry->prev = endchain; 2755 newentry->start = dstaddr + oldoffset; 2756 newentry->end = 2757 newentry->start + (entry->end - (entry->start + fudge)); 2758 if (newentry->end > newend || newentry->end < newentry->start) 2759 newentry->end = newend; 2760 newentry->object.uvm_obj = entry->object.uvm_obj; 2761 if (newentry->object.uvm_obj) { 2762 if (newentry->object.uvm_obj->pgops->pgo_reference) 2763 newentry->object.uvm_obj->pgops-> 2764 pgo_reference(newentry->object.uvm_obj); 2765 newentry->offset = entry->offset + fudge; 2766 } else { 2767 newentry->offset = 0; 2768 } 2769 newentry->etype = entry->etype; 2770 if (flags & UVM_EXTRACT_PROT_ALL) { 2771 newentry->protection = newentry->max_protection = 2772 UVM_PROT_ALL; 2773 } else { 2774 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ? 2775 entry->max_protection : entry->protection; 2776 newentry->max_protection = entry->max_protection; 2777 } 2778 newentry->inheritance = entry->inheritance; 2779 newentry->wired_count = 0; 2780 newentry->aref.ar_amap = entry->aref.ar_amap; 2781 if (newentry->aref.ar_amap) { 2782 newentry->aref.ar_pageoff = 2783 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT); 2784 uvm_map_reference_amap(newentry, AMAP_SHARED | 2785 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0)); 2786 } else { 2787 newentry->aref.ar_pageoff = 0; 2788 } 2789 newentry->advice = entry->advice; 2790 if ((flags & UVM_EXTRACT_QREF) != 0) { 2791 newentry->flags |= UVM_MAP_NOMERGE; 2792 } 2793 2794 /* now link it on the chain */ 2795 nchain++; 2796 nsize += newentry->end - newentry->start; 2797 if (endchain == NULL) { 2798 chain = endchain = newentry; 2799 } else { 2800 endchain->next = newentry; 2801 endchain = newentry; 2802 } 2803 2804 /* end of 'while' loop! */ 2805 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end && 2806 (entry->next == &srcmap->header || 2807 entry->next->start != entry->end)) { 2808 error = EINVAL; 2809 goto bad; 2810 } 2811 entry = entry->next; 2812 fudge = 0; 2813 } 2814 2815 /* 2816 * step 4: close off chain (in format expected by uvm_map_replace) 2817 */ 2818 2819 if (chain) 2820 chain->prev = endchain; 2821 2822 /* 2823 * step 5: attempt to lock the dest map so we can pmap_copy. 2824 * note usage of copy_ok: 2825 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5) 2826 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7 2827 */ 2828 2829 if (srcmap == dstmap || vm_map_lock_try(dstmap) == true) { 2830 copy_ok = 1; 2831 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2832 nchain, nsize, &resentry)) { 2833 if (srcmap != dstmap) 2834 vm_map_unlock(dstmap); 2835 error = EIO; 2836 goto bad; 2837 } 2838 } else { 2839 copy_ok = 0; 2840 /* replace defered until step 7 */ 2841 } 2842 2843 /* 2844 * step 6: traverse the srcmap a second time to do the following: 2845 * - if we got a lock on the dstmap do pmap_copy 2846 * - if UVM_EXTRACT_REMOVE remove the entries 2847 * we make use of orig_entry and orig_fudge (saved in step 2) 2848 */ 2849 2850 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) { 2851 2852 /* purge possible stale hints from srcmap */ 2853 if (flags & UVM_EXTRACT_REMOVE) { 2854 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev); 2855 if (srcmap->first_free != &srcmap->header && 2856 srcmap->first_free->start >= start) 2857 srcmap->first_free = orig_entry->prev; 2858 } 2859 2860 entry = orig_entry; 2861 fudge = orig_fudge; 2862 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */ 2863 2864 while (entry->start < end && entry != &srcmap->header) { 2865 if (copy_ok) { 2866 oldoffset = (entry->start + fudge) - start; 2867 elen = MIN(end, entry->end) - 2868 (entry->start + fudge); 2869 pmap_copy(dstmap->pmap, srcmap->pmap, 2870 dstaddr + oldoffset, elen, 2871 entry->start + fudge); 2872 } 2873 2874 /* we advance "entry" in the following if statement */ 2875 if (flags & UVM_EXTRACT_REMOVE) { 2876 uvm_map_lock_entry(entry); 2877 pmap_remove(srcmap->pmap, entry->start, 2878 entry->end); 2879 uvm_map_unlock_entry(entry); 2880 oldentry = entry; /* save entry */ 2881 entry = entry->next; /* advance */ 2882 uvm_map_entry_unlink(srcmap, oldentry); 2883 /* add to dead list */ 2884 oldentry->next = deadentry; 2885 deadentry = oldentry; 2886 } else { 2887 entry = entry->next; /* advance */ 2888 } 2889 2890 /* end of 'while' loop */ 2891 fudge = 0; 2892 } 2893 pmap_update(srcmap->pmap); 2894 2895 /* 2896 * unlock dstmap. we will dispose of deadentry in 2897 * step 7 if needed 2898 */ 2899 2900 if (copy_ok && srcmap != dstmap) 2901 vm_map_unlock(dstmap); 2902 2903 } else { 2904 deadentry = NULL; 2905 } 2906 2907 /* 2908 * step 7: we are done with the source map, unlock. if copy_ok 2909 * is 0 then we have not replaced the dummy mapping in dstmap yet 2910 * and we need to do so now. 2911 */ 2912 2913 vm_map_unlock(srcmap); 2914 if ((flags & UVM_EXTRACT_REMOVE) && deadentry) 2915 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */ 2916 2917 /* now do the replacement if we didn't do it in step 5 */ 2918 if (copy_ok == 0) { 2919 vm_map_lock(dstmap); 2920 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2921 nchain, nsize, &resentry); 2922 vm_map_unlock(dstmap); 2923 2924 if (error == false) { 2925 error = EIO; 2926 goto bad2; 2927 } 2928 } 2929 2930 if (resentry != NULL) 2931 uvm_mapent_free(resentry); 2932 2933 return (0); 2934 2935 /* 2936 * bad: failure recovery 2937 */ 2938 bad: 2939 vm_map_unlock(srcmap); 2940 bad2: /* src already unlocked */ 2941 if (chain) 2942 uvm_unmap_detach(chain, 2943 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0); 2944 2945 if (resentry != NULL) 2946 uvm_mapent_free(resentry); 2947 2948 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2949 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */ 2950 } 2951 return (error); 2952 } 2953 2954 /* end of extraction functions */ 2955 2956 /* 2957 * uvm_map_submap: punch down part of a map into a submap 2958 * 2959 * => only the kernel_map is allowed to be submapped 2960 * => the purpose of submapping is to break up the locking granularity 2961 * of a larger map 2962 * => the range specified must have been mapped previously with a uvm_map() 2963 * call [with uobj==NULL] to create a blank map entry in the main map. 2964 * [And it had better still be blank!] 2965 * => maps which contain submaps should never be copied or forked. 2966 * => to remove a submap, use uvm_unmap() on the main map 2967 * and then uvm_map_deallocate() the submap. 2968 * => main map must be unlocked. 2969 * => submap must have been init'd and have a zero reference count. 2970 * [need not be locked as we don't actually reference it] 2971 */ 2972 2973 int 2974 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end, 2975 struct vm_map *submap) 2976 { 2977 struct vm_map_entry *entry; 2978 int error; 2979 2980 vm_map_lock(map); 2981 VM_MAP_RANGE_CHECK(map, start, end); 2982 2983 if (uvm_map_lookup_entry(map, start, &entry)) { 2984 UVM_MAP_CLIP_START(map, entry, start); 2985 UVM_MAP_CLIP_END(map, entry, end); /* to be safe */ 2986 } else { 2987 entry = NULL; 2988 } 2989 2990 if (entry != NULL && 2991 entry->start == start && entry->end == end && 2992 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL && 2993 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) { 2994 entry->etype |= UVM_ET_SUBMAP; 2995 entry->object.sub_map = submap; 2996 entry->offset = 0; 2997 uvm_map_reference(submap); 2998 error = 0; 2999 } else { 3000 error = EINVAL; 3001 } 3002 vm_map_unlock(map); 3003 3004 return error; 3005 } 3006 3007 /* 3008 * uvm_map_protect_user: change map protection on behalf of the user. 3009 * Enforces PAX settings as necessary. 3010 */ 3011 int 3012 uvm_map_protect_user(struct lwp *l, vaddr_t start, vaddr_t end, 3013 vm_prot_t new_prot) 3014 { 3015 int error; 3016 3017 if ((error = PAX_MPROTECT_VALIDATE(l, new_prot))) 3018 return error; 3019 3020 return uvm_map_protect(&l->l_proc->p_vmspace->vm_map, start, end, 3021 new_prot, false); 3022 } 3023 3024 3025 /* 3026 * uvm_map_protect: change map protection 3027 * 3028 * => set_max means set max_protection. 3029 * => map must be unlocked. 3030 */ 3031 3032 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \ 3033 ~VM_PROT_WRITE : VM_PROT_ALL) 3034 3035 int 3036 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end, 3037 vm_prot_t new_prot, bool set_max) 3038 { 3039 struct vm_map_entry *current, *entry; 3040 int error = 0; 3041 UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist); 3042 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_prot=%#jx)", 3043 (uintptr_t)map, start, end, new_prot); 3044 3045 vm_map_lock(map); 3046 VM_MAP_RANGE_CHECK(map, start, end); 3047 if (uvm_map_lookup_entry(map, start, &entry)) { 3048 UVM_MAP_CLIP_START(map, entry, start); 3049 } else { 3050 entry = entry->next; 3051 } 3052 3053 /* 3054 * make a first pass to check for protection violations. 3055 */ 3056 3057 current = entry; 3058 while ((current != &map->header) && (current->start < end)) { 3059 if (UVM_ET_ISSUBMAP(current)) { 3060 error = EINVAL; 3061 goto out; 3062 } 3063 if ((new_prot & current->max_protection) != new_prot) { 3064 error = EACCES; 3065 goto out; 3066 } 3067 /* 3068 * Don't allow VM_PROT_EXECUTE to be set on entries that 3069 * point to vnodes that are associated with a NOEXEC file 3070 * system. 3071 */ 3072 if (UVM_ET_ISOBJ(current) && 3073 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) { 3074 struct vnode *vp = 3075 (struct vnode *) current->object.uvm_obj; 3076 3077 if ((new_prot & VM_PROT_EXECUTE) != 0 && 3078 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { 3079 error = EACCES; 3080 goto out; 3081 } 3082 } 3083 3084 current = current->next; 3085 } 3086 3087 /* go back and fix up protections (no need to clip this time). */ 3088 3089 current = entry; 3090 while ((current != &map->header) && (current->start < end)) { 3091 vm_prot_t old_prot; 3092 3093 UVM_MAP_CLIP_END(map, current, end); 3094 old_prot = current->protection; 3095 if (set_max) 3096 current->protection = 3097 (current->max_protection = new_prot) & old_prot; 3098 else 3099 current->protection = new_prot; 3100 3101 /* 3102 * update physical map if necessary. worry about copy-on-write 3103 * here -- CHECK THIS XXX 3104 */ 3105 3106 if (current->protection != old_prot) { 3107 /* update pmap! */ 3108 uvm_map_lock_entry(current); 3109 pmap_protect(map->pmap, current->start, current->end, 3110 current->protection & MASK(entry)); 3111 uvm_map_unlock_entry(current); 3112 3113 /* 3114 * If this entry points at a vnode, and the 3115 * protection includes VM_PROT_EXECUTE, mark 3116 * the vnode as VEXECMAP. 3117 */ 3118 if (UVM_ET_ISOBJ(current)) { 3119 struct uvm_object *uobj = 3120 current->object.uvm_obj; 3121 3122 if (UVM_OBJ_IS_VNODE(uobj) && 3123 (current->protection & VM_PROT_EXECUTE)) { 3124 vn_markexec((struct vnode *) uobj); 3125 } 3126 } 3127 } 3128 3129 /* 3130 * If the map is configured to lock any future mappings, 3131 * wire this entry now if the old protection was VM_PROT_NONE 3132 * and the new protection is not VM_PROT_NONE. 3133 */ 3134 3135 if ((map->flags & VM_MAP_WIREFUTURE) != 0 && 3136 VM_MAPENT_ISWIRED(entry) == 0 && 3137 old_prot == VM_PROT_NONE && 3138 new_prot != VM_PROT_NONE) { 3139 if (uvm_map_pageable(map, entry->start, 3140 entry->end, false, 3141 UVM_LK_ENTER|UVM_LK_EXIT) != 0) { 3142 3143 /* 3144 * If locking the entry fails, remember the 3145 * error if it's the first one. Note we 3146 * still continue setting the protection in 3147 * the map, but will return the error 3148 * condition regardless. 3149 * 3150 * XXX Ignore what the actual error is, 3151 * XXX just call it a resource shortage 3152 * XXX so that it doesn't get confused 3153 * XXX what uvm_map_protect() itself would 3154 * XXX normally return. 3155 */ 3156 3157 error = ENOMEM; 3158 } 3159 } 3160 current = current->next; 3161 } 3162 pmap_update(map->pmap); 3163 3164 out: 3165 vm_map_unlock(map); 3166 3167 UVMHIST_LOG(maphist, "<- done, error=%jd",error,0,0,0); 3168 return error; 3169 } 3170 3171 #undef MASK 3172 3173 /* 3174 * uvm_map_inherit: set inheritance code for range of addrs in map. 3175 * 3176 * => map must be unlocked 3177 * => note that the inherit code is used during a "fork". see fork 3178 * code for details. 3179 */ 3180 3181 int 3182 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end, 3183 vm_inherit_t new_inheritance) 3184 { 3185 struct vm_map_entry *entry, *temp_entry; 3186 UVMHIST_FUNC("uvm_map_inherit"); UVMHIST_CALLED(maphist); 3187 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_inh=%#jx)", 3188 (uintptr_t)map, start, end, new_inheritance); 3189 3190 switch (new_inheritance) { 3191 case MAP_INHERIT_NONE: 3192 case MAP_INHERIT_COPY: 3193 case MAP_INHERIT_SHARE: 3194 case MAP_INHERIT_ZERO: 3195 break; 3196 default: 3197 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3198 return EINVAL; 3199 } 3200 3201 vm_map_lock(map); 3202 VM_MAP_RANGE_CHECK(map, start, end); 3203 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3204 entry = temp_entry; 3205 UVM_MAP_CLIP_START(map, entry, start); 3206 } else { 3207 entry = temp_entry->next; 3208 } 3209 while ((entry != &map->header) && (entry->start < end)) { 3210 UVM_MAP_CLIP_END(map, entry, end); 3211 entry->inheritance = new_inheritance; 3212 entry = entry->next; 3213 } 3214 vm_map_unlock(map); 3215 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3216 return 0; 3217 } 3218 3219 /* 3220 * uvm_map_advice: set advice code for range of addrs in map. 3221 * 3222 * => map must be unlocked 3223 */ 3224 3225 int 3226 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice) 3227 { 3228 struct vm_map_entry *entry, *temp_entry; 3229 UVMHIST_FUNC("uvm_map_advice"); UVMHIST_CALLED(maphist); 3230 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_adv=%#jx)", 3231 (uintptr_t)map, start, end, new_advice); 3232 3233 vm_map_lock(map); 3234 VM_MAP_RANGE_CHECK(map, start, end); 3235 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3236 entry = temp_entry; 3237 UVM_MAP_CLIP_START(map, entry, start); 3238 } else { 3239 entry = temp_entry->next; 3240 } 3241 3242 /* 3243 * XXXJRT: disallow holes? 3244 */ 3245 3246 while ((entry != &map->header) && (entry->start < end)) { 3247 UVM_MAP_CLIP_END(map, entry, end); 3248 3249 switch (new_advice) { 3250 case MADV_NORMAL: 3251 case MADV_RANDOM: 3252 case MADV_SEQUENTIAL: 3253 /* nothing special here */ 3254 break; 3255 3256 default: 3257 vm_map_unlock(map); 3258 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3259 return EINVAL; 3260 } 3261 entry->advice = new_advice; 3262 entry = entry->next; 3263 } 3264 3265 vm_map_unlock(map); 3266 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3267 return 0; 3268 } 3269 3270 /* 3271 * uvm_map_willneed: apply MADV_WILLNEED 3272 */ 3273 3274 int 3275 uvm_map_willneed(struct vm_map *map, vaddr_t start, vaddr_t end) 3276 { 3277 struct vm_map_entry *entry; 3278 UVMHIST_FUNC("uvm_map_willneed"); UVMHIST_CALLED(maphist); 3279 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx)", 3280 (uintptr_t)map, start, end, 0); 3281 3282 vm_map_lock_read(map); 3283 VM_MAP_RANGE_CHECK(map, start, end); 3284 if (!uvm_map_lookup_entry(map, start, &entry)) { 3285 entry = entry->next; 3286 } 3287 while (entry->start < end) { 3288 struct vm_amap * const amap = entry->aref.ar_amap; 3289 struct uvm_object * const uobj = entry->object.uvm_obj; 3290 3291 KASSERT(entry != &map->header); 3292 KASSERT(start < entry->end); 3293 /* 3294 * For now, we handle only the easy but commonly-requested case. 3295 * ie. start prefetching of backing uobj pages. 3296 * 3297 * XXX It might be useful to pmap_enter() the already-in-core 3298 * pages by inventing a "weak" mode for uvm_fault() which would 3299 * only do the PGO_LOCKED pgo_get(). 3300 */ 3301 if (UVM_ET_ISOBJ(entry) && amap == NULL && uobj != NULL) { 3302 off_t offset; 3303 off_t size; 3304 3305 offset = entry->offset; 3306 if (start < entry->start) { 3307 offset += entry->start - start; 3308 } 3309 size = entry->offset + (entry->end - entry->start); 3310 if (entry->end < end) { 3311 size -= end - entry->end; 3312 } 3313 uvm_readahead(uobj, offset, size); 3314 } 3315 entry = entry->next; 3316 } 3317 vm_map_unlock_read(map); 3318 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3319 return 0; 3320 } 3321 3322 /* 3323 * uvm_map_pageable: sets the pageability of a range in a map. 3324 * 3325 * => wires map entries. should not be used for transient page locking. 3326 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). 3327 * => regions specified as not pageable require lock-down (wired) memory 3328 * and page tables. 3329 * => map must never be read-locked 3330 * => if islocked is true, map is already write-locked 3331 * => we always unlock the map, since we must downgrade to a read-lock 3332 * to call uvm_fault_wire() 3333 * => XXXCDC: check this and try and clean it up. 3334 */ 3335 3336 int 3337 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end, 3338 bool new_pageable, int lockflags) 3339 { 3340 struct vm_map_entry *entry, *start_entry, *failed_entry; 3341 int rv; 3342 #ifdef DIAGNOSTIC 3343 u_int timestamp_save; 3344 #endif 3345 UVMHIST_FUNC("uvm_map_pageable"); UVMHIST_CALLED(maphist); 3346 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_pageable=%ju)", 3347 (uintptr_t)map, start, end, new_pageable); 3348 KASSERT(map->flags & VM_MAP_PAGEABLE); 3349 3350 if ((lockflags & UVM_LK_ENTER) == 0) 3351 vm_map_lock(map); 3352 VM_MAP_RANGE_CHECK(map, start, end); 3353 3354 /* 3355 * only one pageability change may take place at one time, since 3356 * uvm_fault_wire assumes it will be called only once for each 3357 * wiring/unwiring. therefore, we have to make sure we're actually 3358 * changing the pageability for the entire region. we do so before 3359 * making any changes. 3360 */ 3361 3362 if (uvm_map_lookup_entry(map, start, &start_entry) == false) { 3363 if ((lockflags & UVM_LK_EXIT) == 0) 3364 vm_map_unlock(map); 3365 3366 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0); 3367 return EFAULT; 3368 } 3369 entry = start_entry; 3370 3371 /* 3372 * handle wiring and unwiring separately. 3373 */ 3374 3375 if (new_pageable) { /* unwire */ 3376 UVM_MAP_CLIP_START(map, entry, start); 3377 3378 /* 3379 * unwiring. first ensure that the range to be unwired is 3380 * really wired down and that there are no holes. 3381 */ 3382 3383 while ((entry != &map->header) && (entry->start < end)) { 3384 if (entry->wired_count == 0 || 3385 (entry->end < end && 3386 (entry->next == &map->header || 3387 entry->next->start > entry->end))) { 3388 if ((lockflags & UVM_LK_EXIT) == 0) 3389 vm_map_unlock(map); 3390 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0); 3391 return EINVAL; 3392 } 3393 entry = entry->next; 3394 } 3395 3396 /* 3397 * POSIX 1003.1b - a single munlock call unlocks a region, 3398 * regardless of the number of mlock calls made on that 3399 * region. 3400 */ 3401 3402 entry = start_entry; 3403 while ((entry != &map->header) && (entry->start < end)) { 3404 UVM_MAP_CLIP_END(map, entry, end); 3405 if (VM_MAPENT_ISWIRED(entry)) 3406 uvm_map_entry_unwire(map, entry); 3407 entry = entry->next; 3408 } 3409 if ((lockflags & UVM_LK_EXIT) == 0) 3410 vm_map_unlock(map); 3411 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3412 return 0; 3413 } 3414 3415 /* 3416 * wire case: in two passes [XXXCDC: ugly block of code here] 3417 * 3418 * 1: holding the write lock, we create any anonymous maps that need 3419 * to be created. then we clip each map entry to the region to 3420 * be wired and increment its wiring count. 3421 * 3422 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 3423 * in the pages for any newly wired area (wired_count == 1). 3424 * 3425 * downgrading to a read lock for uvm_fault_wire avoids a possible 3426 * deadlock with another thread that may have faulted on one of 3427 * the pages to be wired (it would mark the page busy, blocking 3428 * us, then in turn block on the map lock that we hold). because 3429 * of problems in the recursive lock package, we cannot upgrade 3430 * to a write lock in vm_map_lookup. thus, any actions that 3431 * require the write lock must be done beforehand. because we 3432 * keep the read lock on the map, the copy-on-write status of the 3433 * entries we modify here cannot change. 3434 */ 3435 3436 while ((entry != &map->header) && (entry->start < end)) { 3437 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3438 3439 /* 3440 * perform actions of vm_map_lookup that need the 3441 * write lock on the map: create an anonymous map 3442 * for a copy-on-write region, or an anonymous map 3443 * for a zero-fill region. (XXXCDC: submap case 3444 * ok?) 3445 */ 3446 3447 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3448 if (UVM_ET_ISNEEDSCOPY(entry) && 3449 ((entry->max_protection & VM_PROT_WRITE) || 3450 (entry->object.uvm_obj == NULL))) { 3451 amap_copy(map, entry, 0, start, end); 3452 /* XXXCDC: wait OK? */ 3453 } 3454 } 3455 } 3456 UVM_MAP_CLIP_START(map, entry, start); 3457 UVM_MAP_CLIP_END(map, entry, end); 3458 entry->wired_count++; 3459 3460 /* 3461 * Check for holes 3462 */ 3463 3464 if (entry->protection == VM_PROT_NONE || 3465 (entry->end < end && 3466 (entry->next == &map->header || 3467 entry->next->start > entry->end))) { 3468 3469 /* 3470 * found one. amap creation actions do not need to 3471 * be undone, but the wired counts need to be restored. 3472 */ 3473 3474 while (entry != &map->header && entry->end > start) { 3475 entry->wired_count--; 3476 entry = entry->prev; 3477 } 3478 if ((lockflags & UVM_LK_EXIT) == 0) 3479 vm_map_unlock(map); 3480 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0); 3481 return EINVAL; 3482 } 3483 entry = entry->next; 3484 } 3485 3486 /* 3487 * Pass 2. 3488 */ 3489 3490 #ifdef DIAGNOSTIC 3491 timestamp_save = map->timestamp; 3492 #endif 3493 vm_map_busy(map); 3494 vm_map_unlock(map); 3495 3496 rv = 0; 3497 entry = start_entry; 3498 while (entry != &map->header && entry->start < end) { 3499 if (entry->wired_count == 1) { 3500 rv = uvm_fault_wire(map, entry->start, entry->end, 3501 entry->max_protection, 1); 3502 if (rv) { 3503 3504 /* 3505 * wiring failed. break out of the loop. 3506 * we'll clean up the map below, once we 3507 * have a write lock again. 3508 */ 3509 3510 break; 3511 } 3512 } 3513 entry = entry->next; 3514 } 3515 3516 if (rv) { /* failed? */ 3517 3518 /* 3519 * Get back to an exclusive (write) lock. 3520 */ 3521 3522 vm_map_lock(map); 3523 vm_map_unbusy(map); 3524 3525 #ifdef DIAGNOSTIC 3526 if (timestamp_save + 1 != map->timestamp) 3527 panic("uvm_map_pageable: stale map"); 3528 #endif 3529 3530 /* 3531 * first drop the wiring count on all the entries 3532 * which haven't actually been wired yet. 3533 */ 3534 3535 failed_entry = entry; 3536 while (entry != &map->header && entry->start < end) { 3537 entry->wired_count--; 3538 entry = entry->next; 3539 } 3540 3541 /* 3542 * now, unwire all the entries that were successfully 3543 * wired above. 3544 */ 3545 3546 entry = start_entry; 3547 while (entry != failed_entry) { 3548 entry->wired_count--; 3549 if (VM_MAPENT_ISWIRED(entry) == 0) 3550 uvm_map_entry_unwire(map, entry); 3551 entry = entry->next; 3552 } 3553 if ((lockflags & UVM_LK_EXIT) == 0) 3554 vm_map_unlock(map); 3555 UVMHIST_LOG(maphist, "<- done (RV=%jd)", rv,0,0,0); 3556 return (rv); 3557 } 3558 3559 if ((lockflags & UVM_LK_EXIT) == 0) { 3560 vm_map_unbusy(map); 3561 } else { 3562 3563 /* 3564 * Get back to an exclusive (write) lock. 3565 */ 3566 3567 vm_map_lock(map); 3568 vm_map_unbusy(map); 3569 } 3570 3571 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3572 return 0; 3573 } 3574 3575 /* 3576 * uvm_map_pageable_all: special case of uvm_map_pageable - affects 3577 * all mapped regions. 3578 * 3579 * => map must not be locked. 3580 * => if no flags are specified, all regions are unwired. 3581 * => XXXJRT: has some of the same problems as uvm_map_pageable() above. 3582 */ 3583 3584 int 3585 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit) 3586 { 3587 struct vm_map_entry *entry, *failed_entry; 3588 vsize_t size; 3589 int rv; 3590 #ifdef DIAGNOSTIC 3591 u_int timestamp_save; 3592 #endif 3593 UVMHIST_FUNC("uvm_map_pageable_all"); UVMHIST_CALLED(maphist); 3594 UVMHIST_LOG(maphist,"(map=%#jx,flags=%#jx)", (uintptr_t)map, flags, 3595 0, 0); 3596 3597 KASSERT(map->flags & VM_MAP_PAGEABLE); 3598 3599 vm_map_lock(map); 3600 3601 /* 3602 * handle wiring and unwiring separately. 3603 */ 3604 3605 if (flags == 0) { /* unwire */ 3606 3607 /* 3608 * POSIX 1003.1b -- munlockall unlocks all regions, 3609 * regardless of how many times mlockall has been called. 3610 */ 3611 3612 for (entry = map->header.next; entry != &map->header; 3613 entry = entry->next) { 3614 if (VM_MAPENT_ISWIRED(entry)) 3615 uvm_map_entry_unwire(map, entry); 3616 } 3617 map->flags &= ~VM_MAP_WIREFUTURE; 3618 vm_map_unlock(map); 3619 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3620 return 0; 3621 } 3622 3623 if (flags & MCL_FUTURE) { 3624 3625 /* 3626 * must wire all future mappings; remember this. 3627 */ 3628 3629 map->flags |= VM_MAP_WIREFUTURE; 3630 } 3631 3632 if ((flags & MCL_CURRENT) == 0) { 3633 3634 /* 3635 * no more work to do! 3636 */ 3637 3638 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0); 3639 vm_map_unlock(map); 3640 return 0; 3641 } 3642 3643 /* 3644 * wire case: in three passes [XXXCDC: ugly block of code here] 3645 * 3646 * 1: holding the write lock, count all pages mapped by non-wired 3647 * entries. if this would cause us to go over our limit, we fail. 3648 * 3649 * 2: still holding the write lock, we create any anonymous maps that 3650 * need to be created. then we increment its wiring count. 3651 * 3652 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault 3653 * in the pages for any newly wired area (wired_count == 1). 3654 * 3655 * downgrading to a read lock for uvm_fault_wire avoids a possible 3656 * deadlock with another thread that may have faulted on one of 3657 * the pages to be wired (it would mark the page busy, blocking 3658 * us, then in turn block on the map lock that we hold). because 3659 * of problems in the recursive lock package, we cannot upgrade 3660 * to a write lock in vm_map_lookup. thus, any actions that 3661 * require the write lock must be done beforehand. because we 3662 * keep the read lock on the map, the copy-on-write status of the 3663 * entries we modify here cannot change. 3664 */ 3665 3666 for (size = 0, entry = map->header.next; entry != &map->header; 3667 entry = entry->next) { 3668 if (entry->protection != VM_PROT_NONE && 3669 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3670 size += entry->end - entry->start; 3671 } 3672 } 3673 3674 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) { 3675 vm_map_unlock(map); 3676 return ENOMEM; 3677 } 3678 3679 if (limit != 0 && 3680 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) { 3681 vm_map_unlock(map); 3682 return ENOMEM; 3683 } 3684 3685 /* 3686 * Pass 2. 3687 */ 3688 3689 for (entry = map->header.next; entry != &map->header; 3690 entry = entry->next) { 3691 if (entry->protection == VM_PROT_NONE) 3692 continue; 3693 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3694 3695 /* 3696 * perform actions of vm_map_lookup that need the 3697 * write lock on the map: create an anonymous map 3698 * for a copy-on-write region, or an anonymous map 3699 * for a zero-fill region. (XXXCDC: submap case 3700 * ok?) 3701 */ 3702 3703 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3704 if (UVM_ET_ISNEEDSCOPY(entry) && 3705 ((entry->max_protection & VM_PROT_WRITE) || 3706 (entry->object.uvm_obj == NULL))) { 3707 amap_copy(map, entry, 0, entry->start, 3708 entry->end); 3709 /* XXXCDC: wait OK? */ 3710 } 3711 } 3712 } 3713 entry->wired_count++; 3714 } 3715 3716 /* 3717 * Pass 3. 3718 */ 3719 3720 #ifdef DIAGNOSTIC 3721 timestamp_save = map->timestamp; 3722 #endif 3723 vm_map_busy(map); 3724 vm_map_unlock(map); 3725 3726 rv = 0; 3727 for (entry = map->header.next; entry != &map->header; 3728 entry = entry->next) { 3729 if (entry->wired_count == 1) { 3730 rv = uvm_fault_wire(map, entry->start, entry->end, 3731 entry->max_protection, 1); 3732 if (rv) { 3733 3734 /* 3735 * wiring failed. break out of the loop. 3736 * we'll clean up the map below, once we 3737 * have a write lock again. 3738 */ 3739 3740 break; 3741 } 3742 } 3743 } 3744 3745 if (rv) { 3746 3747 /* 3748 * Get back an exclusive (write) lock. 3749 */ 3750 3751 vm_map_lock(map); 3752 vm_map_unbusy(map); 3753 3754 #ifdef DIAGNOSTIC 3755 if (timestamp_save + 1 != map->timestamp) 3756 panic("uvm_map_pageable_all: stale map"); 3757 #endif 3758 3759 /* 3760 * first drop the wiring count on all the entries 3761 * which haven't actually been wired yet. 3762 * 3763 * Skip VM_PROT_NONE entries like we did above. 3764 */ 3765 3766 failed_entry = entry; 3767 for (/* nothing */; entry != &map->header; 3768 entry = entry->next) { 3769 if (entry->protection == VM_PROT_NONE) 3770 continue; 3771 entry->wired_count--; 3772 } 3773 3774 /* 3775 * now, unwire all the entries that were successfully 3776 * wired above. 3777 * 3778 * Skip VM_PROT_NONE entries like we did above. 3779 */ 3780 3781 for (entry = map->header.next; entry != failed_entry; 3782 entry = entry->next) { 3783 if (entry->protection == VM_PROT_NONE) 3784 continue; 3785 entry->wired_count--; 3786 if (VM_MAPENT_ISWIRED(entry)) 3787 uvm_map_entry_unwire(map, entry); 3788 } 3789 vm_map_unlock(map); 3790 UVMHIST_LOG(maphist,"<- done (RV=%jd)", rv,0,0,0); 3791 return (rv); 3792 } 3793 3794 vm_map_unbusy(map); 3795 3796 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3797 return 0; 3798 } 3799 3800 /* 3801 * uvm_map_clean: clean out a map range 3802 * 3803 * => valid flags: 3804 * if (flags & PGO_CLEANIT): dirty pages are cleaned first 3805 * if (flags & PGO_SYNCIO): dirty pages are written synchronously 3806 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean 3807 * if (flags & PGO_FREE): any cached pages are freed after clean 3808 * => returns an error if any part of the specified range isn't mapped 3809 * => never a need to flush amap layer since the anonymous memory has 3810 * no permanent home, but may deactivate pages there 3811 * => called from sys_msync() and sys_madvise() 3812 * => caller must not write-lock map (read OK). 3813 * => we may sleep while cleaning if SYNCIO [with map read-locked] 3814 */ 3815 3816 int 3817 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 3818 { 3819 struct vm_map_entry *current, *entry; 3820 struct uvm_object *uobj; 3821 struct vm_amap *amap; 3822 struct vm_anon *anon, *anon_tofree; 3823 struct vm_page *pg; 3824 vaddr_t offset; 3825 vsize_t size; 3826 voff_t uoff; 3827 int error, refs; 3828 UVMHIST_FUNC("uvm_map_clean"); UVMHIST_CALLED(maphist); 3829 3830 UVMHIST_LOG(maphist,"(map=%#jx,start=%#jx,end=%#jx,flags=%#jx)", 3831 (uintptr_t)map, start, end, flags); 3832 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) != 3833 (PGO_FREE|PGO_DEACTIVATE)); 3834 3835 vm_map_lock_read(map); 3836 VM_MAP_RANGE_CHECK(map, start, end); 3837 if (uvm_map_lookup_entry(map, start, &entry) == false) { 3838 vm_map_unlock_read(map); 3839 return EFAULT; 3840 } 3841 3842 /* 3843 * Make a first pass to check for holes and wiring problems. 3844 */ 3845 3846 for (current = entry; current->start < end; current = current->next) { 3847 if (UVM_ET_ISSUBMAP(current)) { 3848 vm_map_unlock_read(map); 3849 return EINVAL; 3850 } 3851 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) { 3852 vm_map_unlock_read(map); 3853 return EBUSY; 3854 } 3855 if (end <= current->end) { 3856 break; 3857 } 3858 if (current->end != current->next->start) { 3859 vm_map_unlock_read(map); 3860 return EFAULT; 3861 } 3862 } 3863 3864 error = 0; 3865 for (current = entry; start < end; current = current->next) { 3866 amap = current->aref.ar_amap; /* upper layer */ 3867 uobj = current->object.uvm_obj; /* lower layer */ 3868 KASSERT(start >= current->start); 3869 3870 /* 3871 * No amap cleaning necessary if: 3872 * 3873 * (1) There's no amap. 3874 * 3875 * (2) We're not deactivating or freeing pages. 3876 */ 3877 3878 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) 3879 goto flush_object; 3880 3881 offset = start - current->start; 3882 size = MIN(end, current->end) - start; 3883 anon_tofree = NULL; 3884 3885 amap_lock(amap); 3886 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) { 3887 anon = amap_lookup(¤t->aref, offset); 3888 if (anon == NULL) 3889 continue; 3890 3891 KASSERT(anon->an_lock == amap->am_lock); 3892 pg = anon->an_page; 3893 if (pg == NULL) { 3894 continue; 3895 } 3896 if (pg->flags & PG_BUSY) { 3897 continue; 3898 } 3899 3900 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) { 3901 3902 /* 3903 * In these first 3 cases, we just deactivate the page. 3904 */ 3905 3906 case PGO_CLEANIT|PGO_FREE: 3907 case PGO_CLEANIT|PGO_DEACTIVATE: 3908 case PGO_DEACTIVATE: 3909 deactivate_it: 3910 /* 3911 * skip the page if it's loaned or wired, 3912 * since it shouldn't be on a paging queue 3913 * at all in these cases. 3914 */ 3915 3916 mutex_enter(&uvm_pageqlock); 3917 if (pg->loan_count != 0 || 3918 pg->wire_count != 0) { 3919 mutex_exit(&uvm_pageqlock); 3920 continue; 3921 } 3922 KASSERT(pg->uanon == anon); 3923 uvm_pagedeactivate(pg); 3924 mutex_exit(&uvm_pageqlock); 3925 continue; 3926 3927 case PGO_FREE: 3928 3929 /* 3930 * If there are multiple references to 3931 * the amap, just deactivate the page. 3932 */ 3933 3934 if (amap_refs(amap) > 1) 3935 goto deactivate_it; 3936 3937 /* skip the page if it's wired */ 3938 if (pg->wire_count != 0) { 3939 continue; 3940 } 3941 amap_unadd(¤t->aref, offset); 3942 refs = --anon->an_ref; 3943 if (refs == 0) { 3944 anon->an_link = anon_tofree; 3945 anon_tofree = anon; 3946 } 3947 continue; 3948 } 3949 } 3950 uvm_anon_freelst(amap, anon_tofree); 3951 3952 flush_object: 3953 /* 3954 * flush pages if we've got a valid backing object. 3955 * note that we must always clean object pages before 3956 * freeing them since otherwise we could reveal stale 3957 * data from files. 3958 */ 3959 3960 uoff = current->offset + (start - current->start); 3961 size = MIN(end, current->end) - start; 3962 if (uobj != NULL) { 3963 mutex_enter(uobj->vmobjlock); 3964 if (uobj->pgops->pgo_put != NULL) 3965 error = (uobj->pgops->pgo_put)(uobj, uoff, 3966 uoff + size, flags | PGO_CLEANIT); 3967 else 3968 error = 0; 3969 } 3970 start += size; 3971 } 3972 vm_map_unlock_read(map); 3973 return (error); 3974 } 3975 3976 3977 /* 3978 * uvm_map_checkprot: check protection in map 3979 * 3980 * => must allow specified protection in a fully allocated region. 3981 * => map must be read or write locked by caller. 3982 */ 3983 3984 bool 3985 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end, 3986 vm_prot_t protection) 3987 { 3988 struct vm_map_entry *entry; 3989 struct vm_map_entry *tmp_entry; 3990 3991 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) { 3992 return (false); 3993 } 3994 entry = tmp_entry; 3995 while (start < end) { 3996 if (entry == &map->header) { 3997 return (false); 3998 } 3999 4000 /* 4001 * no holes allowed 4002 */ 4003 4004 if (start < entry->start) { 4005 return (false); 4006 } 4007 4008 /* 4009 * check protection associated with entry 4010 */ 4011 4012 if ((entry->protection & protection) != protection) { 4013 return (false); 4014 } 4015 start = entry->end; 4016 entry = entry->next; 4017 } 4018 return (true); 4019 } 4020 4021 /* 4022 * uvmspace_alloc: allocate a vmspace structure. 4023 * 4024 * - structure includes vm_map and pmap 4025 * - XXX: no locking on this structure 4026 * - refcnt set to 1, rest must be init'd by caller 4027 */ 4028 struct vmspace * 4029 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax, bool topdown) 4030 { 4031 struct vmspace *vm; 4032 UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist); 4033 4034 vm = pool_cache_get(&uvm_vmspace_cache, PR_WAITOK); 4035 uvmspace_init(vm, NULL, vmin, vmax, topdown); 4036 UVMHIST_LOG(maphist,"<- done (vm=%#jx)", (uintptr_t)vm, 0, 0, 0); 4037 return (vm); 4038 } 4039 4040 /* 4041 * uvmspace_init: initialize a vmspace structure. 4042 * 4043 * - XXX: no locking on this structure 4044 * - refcnt set to 1, rest must be init'd by caller 4045 */ 4046 void 4047 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, 4048 vaddr_t vmax, bool topdown) 4049 { 4050 UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist); 4051 4052 UVMHIST_LOG(maphist, "(vm=%#jx, pmap=%#jx, vmin=%#jx, vmax=%#jx", 4053 (uintptr_t)vm, (uintptr_t)pmap, vmin, vmax); 4054 UVMHIST_LOG(maphist, " topdown=%ju)", topdown, 0, 0, 0); 4055 4056 memset(vm, 0, sizeof(*vm)); 4057 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE 4058 | (topdown ? VM_MAP_TOPDOWN : 0) 4059 ); 4060 if (pmap) 4061 pmap_reference(pmap); 4062 else 4063 pmap = pmap_create(); 4064 vm->vm_map.pmap = pmap; 4065 vm->vm_refcnt = 1; 4066 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4067 } 4068 4069 /* 4070 * uvmspace_share: share a vmspace between two processes 4071 * 4072 * - used for vfork, threads(?) 4073 */ 4074 4075 void 4076 uvmspace_share(struct proc *p1, struct proc *p2) 4077 { 4078 4079 uvmspace_addref(p1->p_vmspace); 4080 p2->p_vmspace = p1->p_vmspace; 4081 } 4082 4083 #if 0 4084 4085 /* 4086 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace 4087 * 4088 * - XXX: no locking on vmspace 4089 */ 4090 4091 void 4092 uvmspace_unshare(struct lwp *l) 4093 { 4094 struct proc *p = l->l_proc; 4095 struct vmspace *nvm, *ovm = p->p_vmspace; 4096 4097 if (ovm->vm_refcnt == 1) 4098 /* nothing to do: vmspace isn't shared in the first place */ 4099 return; 4100 4101 /* make a new vmspace, still holding old one */ 4102 nvm = uvmspace_fork(ovm); 4103 4104 kpreempt_disable(); 4105 pmap_deactivate(l); /* unbind old vmspace */ 4106 p->p_vmspace = nvm; 4107 pmap_activate(l); /* switch to new vmspace */ 4108 kpreempt_enable(); 4109 4110 uvmspace_free(ovm); /* drop reference to old vmspace */ 4111 } 4112 4113 #endif 4114 4115 4116 /* 4117 * uvmspace_spawn: a new process has been spawned and needs a vmspace 4118 */ 4119 4120 void 4121 uvmspace_spawn(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown) 4122 { 4123 struct proc *p = l->l_proc; 4124 struct vmspace *nvm; 4125 4126 #ifdef __HAVE_CPU_VMSPACE_EXEC 4127 cpu_vmspace_exec(l, start, end); 4128 #endif 4129 4130 nvm = uvmspace_alloc(start, end, topdown); 4131 kpreempt_disable(); 4132 p->p_vmspace = nvm; 4133 pmap_activate(l); 4134 kpreempt_enable(); 4135 } 4136 4137 /* 4138 * uvmspace_exec: the process wants to exec a new program 4139 */ 4140 4141 void 4142 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown) 4143 { 4144 struct proc *p = l->l_proc; 4145 struct vmspace *nvm, *ovm = p->p_vmspace; 4146 struct vm_map *map; 4147 4148 KASSERT(ovm != NULL); 4149 #ifdef __HAVE_CPU_VMSPACE_EXEC 4150 cpu_vmspace_exec(l, start, end); 4151 #endif 4152 4153 map = &ovm->vm_map; 4154 /* 4155 * see if more than one process is using this vmspace... 4156 */ 4157 4158 if (ovm->vm_refcnt == 1 4159 && topdown == ((ovm->vm_map.flags & VM_MAP_TOPDOWN) != 0)) { 4160 4161 /* 4162 * if p is the only process using its vmspace then we can safely 4163 * recycle that vmspace for the program that is being exec'd. 4164 * But only if TOPDOWN matches the requested value for the new 4165 * vm space! 4166 */ 4167 4168 /* 4169 * SYSV SHM semantics require us to kill all segments on an exec 4170 */ 4171 if (uvm_shmexit && ovm->vm_shm) 4172 (*uvm_shmexit)(ovm); 4173 4174 /* 4175 * POSIX 1003.1b -- "lock future mappings" is revoked 4176 * when a process execs another program image. 4177 */ 4178 4179 map->flags &= ~VM_MAP_WIREFUTURE; 4180 4181 /* 4182 * now unmap the old program 4183 */ 4184 4185 pmap_remove_all(map->pmap); 4186 uvm_unmap(map, vm_map_min(map), vm_map_max(map)); 4187 KASSERT(map->header.prev == &map->header); 4188 KASSERT(map->nentries == 0); 4189 4190 /* 4191 * resize the map 4192 */ 4193 4194 vm_map_setmin(map, start); 4195 vm_map_setmax(map, end); 4196 } else { 4197 4198 /* 4199 * p's vmspace is being shared, so we can't reuse it for p since 4200 * it is still being used for others. allocate a new vmspace 4201 * for p 4202 */ 4203 4204 nvm = uvmspace_alloc(start, end, topdown); 4205 4206 /* 4207 * install new vmspace and drop our ref to the old one. 4208 */ 4209 4210 kpreempt_disable(); 4211 pmap_deactivate(l); 4212 p->p_vmspace = nvm; 4213 pmap_activate(l); 4214 kpreempt_enable(); 4215 4216 uvmspace_free(ovm); 4217 } 4218 } 4219 4220 /* 4221 * uvmspace_addref: add a referece to a vmspace. 4222 */ 4223 4224 void 4225 uvmspace_addref(struct vmspace *vm) 4226 { 4227 struct vm_map *map = &vm->vm_map; 4228 4229 KASSERT((map->flags & VM_MAP_DYING) == 0); 4230 4231 mutex_enter(&map->misc_lock); 4232 KASSERT(vm->vm_refcnt > 0); 4233 vm->vm_refcnt++; 4234 mutex_exit(&map->misc_lock); 4235 } 4236 4237 /* 4238 * uvmspace_free: free a vmspace data structure 4239 */ 4240 4241 void 4242 uvmspace_free(struct vmspace *vm) 4243 { 4244 struct vm_map_entry *dead_entries; 4245 struct vm_map *map = &vm->vm_map; 4246 int n; 4247 4248 UVMHIST_FUNC("uvmspace_free"); UVMHIST_CALLED(maphist); 4249 4250 UVMHIST_LOG(maphist,"(vm=%#jx) ref=%jd", (uintptr_t)vm, vm->vm_refcnt, 4251 0, 0); 4252 mutex_enter(&map->misc_lock); 4253 n = --vm->vm_refcnt; 4254 mutex_exit(&map->misc_lock); 4255 if (n > 0) 4256 return; 4257 4258 /* 4259 * at this point, there should be no other references to the map. 4260 * delete all of the mappings, then destroy the pmap. 4261 */ 4262 4263 map->flags |= VM_MAP_DYING; 4264 pmap_remove_all(map->pmap); 4265 4266 /* Get rid of any SYSV shared memory segments. */ 4267 if (uvm_shmexit && vm->vm_shm != NULL) 4268 (*uvm_shmexit)(vm); 4269 4270 if (map->nentries) { 4271 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map), 4272 &dead_entries, 0); 4273 if (dead_entries != NULL) 4274 uvm_unmap_detach(dead_entries, 0); 4275 } 4276 KASSERT(map->nentries == 0); 4277 KASSERT(map->size == 0); 4278 4279 mutex_destroy(&map->misc_lock); 4280 rw_destroy(&map->lock); 4281 cv_destroy(&map->cv); 4282 pmap_destroy(map->pmap); 4283 pool_cache_put(&uvm_vmspace_cache, vm); 4284 } 4285 4286 static struct vm_map_entry * 4287 uvm_mapent_clone(struct vm_map *new_map, struct vm_map_entry *old_entry, 4288 int flags) 4289 { 4290 struct vm_map_entry *new_entry; 4291 4292 new_entry = uvm_mapent_alloc(new_map, 0); 4293 /* old_entry -> new_entry */ 4294 uvm_mapent_copy(old_entry, new_entry); 4295 4296 /* new pmap has nothing wired in it */ 4297 new_entry->wired_count = 0; 4298 4299 /* 4300 * gain reference to object backing the map (can't 4301 * be a submap, already checked this case). 4302 */ 4303 4304 if (new_entry->aref.ar_amap) 4305 uvm_map_reference_amap(new_entry, flags); 4306 4307 if (new_entry->object.uvm_obj && 4308 new_entry->object.uvm_obj->pgops->pgo_reference) 4309 new_entry->object.uvm_obj->pgops->pgo_reference( 4310 new_entry->object.uvm_obj); 4311 4312 /* insert entry at end of new_map's entry list */ 4313 uvm_map_entry_link(new_map, new_map->header.prev, 4314 new_entry); 4315 4316 return new_entry; 4317 } 4318 4319 /* 4320 * share the mapping: this means we want the old and 4321 * new entries to share amaps and backing objects. 4322 */ 4323 static void 4324 uvm_mapent_forkshared(struct vm_map *new_map, struct vm_map *old_map, 4325 struct vm_map_entry *old_entry) 4326 { 4327 /* 4328 * if the old_entry needs a new amap (due to prev fork) 4329 * then we need to allocate it now so that we have 4330 * something we own to share with the new_entry. [in 4331 * other words, we need to clear needs_copy] 4332 */ 4333 4334 if (UVM_ET_ISNEEDSCOPY(old_entry)) { 4335 /* get our own amap, clears needs_copy */ 4336 amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK, 4337 0, 0); 4338 /* XXXCDC: WAITOK??? */ 4339 } 4340 4341 uvm_mapent_clone(new_map, old_entry, AMAP_SHARED); 4342 } 4343 4344 4345 static void 4346 uvm_mapent_forkcopy(struct vm_map *new_map, struct vm_map *old_map, 4347 struct vm_map_entry *old_entry) 4348 { 4349 struct vm_map_entry *new_entry; 4350 4351 /* 4352 * copy-on-write the mapping (using mmap's 4353 * MAP_PRIVATE semantics) 4354 * 4355 * allocate new_entry, adjust reference counts. 4356 * (note that new references are read-only). 4357 */ 4358 4359 new_entry = uvm_mapent_clone(new_map, old_entry, 0); 4360 4361 new_entry->etype |= 4362 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4363 4364 /* 4365 * the new entry will need an amap. it will either 4366 * need to be copied from the old entry or created 4367 * from scratch (if the old entry does not have an 4368 * amap). can we defer this process until later 4369 * (by setting "needs_copy") or do we need to copy 4370 * the amap now? 4371 * 4372 * we must copy the amap now if any of the following 4373 * conditions hold: 4374 * 1. the old entry has an amap and that amap is 4375 * being shared. this means that the old (parent) 4376 * process is sharing the amap with another 4377 * process. if we do not clear needs_copy here 4378 * we will end up in a situation where both the 4379 * parent and child process are refering to the 4380 * same amap with "needs_copy" set. if the 4381 * parent write-faults, the fault routine will 4382 * clear "needs_copy" in the parent by allocating 4383 * a new amap. this is wrong because the 4384 * parent is supposed to be sharing the old amap 4385 * and the new amap will break that. 4386 * 4387 * 2. if the old entry has an amap and a non-zero 4388 * wire count then we are going to have to call 4389 * amap_cow_now to avoid page faults in the 4390 * parent process. since amap_cow_now requires 4391 * "needs_copy" to be clear we might as well 4392 * clear it here as well. 4393 * 4394 */ 4395 4396 if (old_entry->aref.ar_amap != NULL) { 4397 if ((amap_flags(old_entry->aref.ar_amap) & AMAP_SHARED) != 0 || 4398 VM_MAPENT_ISWIRED(old_entry)) { 4399 4400 amap_copy(new_map, new_entry, 4401 AMAP_COPY_NOCHUNK, 0, 0); 4402 /* XXXCDC: M_WAITOK ... ok? */ 4403 } 4404 } 4405 4406 /* 4407 * if the parent's entry is wired down, then the 4408 * parent process does not want page faults on 4409 * access to that memory. this means that we 4410 * cannot do copy-on-write because we can't write 4411 * protect the old entry. in this case we 4412 * resolve all copy-on-write faults now, using 4413 * amap_cow_now. note that we have already 4414 * allocated any needed amap (above). 4415 */ 4416 4417 if (VM_MAPENT_ISWIRED(old_entry)) { 4418 4419 /* 4420 * resolve all copy-on-write faults now 4421 * (note that there is nothing to do if 4422 * the old mapping does not have an amap). 4423 */ 4424 if (old_entry->aref.ar_amap) 4425 amap_cow_now(new_map, new_entry); 4426 4427 } else { 4428 /* 4429 * setup mappings to trigger copy-on-write faults 4430 * we must write-protect the parent if it has 4431 * an amap and it is not already "needs_copy"... 4432 * if it is already "needs_copy" then the parent 4433 * has already been write-protected by a previous 4434 * fork operation. 4435 */ 4436 if (old_entry->aref.ar_amap && 4437 !UVM_ET_ISNEEDSCOPY(old_entry)) { 4438 if (old_entry->max_protection & VM_PROT_WRITE) { 4439 pmap_protect(old_map->pmap, 4440 old_entry->start, old_entry->end, 4441 old_entry->protection & ~VM_PROT_WRITE); 4442 } 4443 old_entry->etype |= UVM_ET_NEEDSCOPY; 4444 } 4445 } 4446 } 4447 4448 /* 4449 * zero the mapping: the new entry will be zero initialized 4450 */ 4451 static void 4452 uvm_mapent_forkzero(struct vm_map *new_map, struct vm_map *old_map, 4453 struct vm_map_entry *old_entry) 4454 { 4455 struct vm_map_entry *new_entry; 4456 4457 new_entry = uvm_mapent_clone(new_map, old_entry, 0); 4458 4459 new_entry->etype |= 4460 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4461 4462 if (new_entry->aref.ar_amap) { 4463 uvm_map_unreference_amap(new_entry, 0); 4464 new_entry->aref.ar_pageoff = 0; 4465 new_entry->aref.ar_amap = NULL; 4466 } 4467 4468 if (UVM_ET_ISOBJ(new_entry)) { 4469 if (new_entry->object.uvm_obj->pgops->pgo_detach) 4470 new_entry->object.uvm_obj->pgops->pgo_detach( 4471 new_entry->object.uvm_obj); 4472 new_entry->object.uvm_obj = NULL; 4473 new_entry->etype &= ~UVM_ET_OBJ; 4474 } 4475 } 4476 4477 /* 4478 * F O R K - m a i n e n t r y p o i n t 4479 */ 4480 /* 4481 * uvmspace_fork: fork a process' main map 4482 * 4483 * => create a new vmspace for child process from parent. 4484 * => parent's map must not be locked. 4485 */ 4486 4487 struct vmspace * 4488 uvmspace_fork(struct vmspace *vm1) 4489 { 4490 struct vmspace *vm2; 4491 struct vm_map *old_map = &vm1->vm_map; 4492 struct vm_map *new_map; 4493 struct vm_map_entry *old_entry; 4494 UVMHIST_FUNC("uvmspace_fork"); UVMHIST_CALLED(maphist); 4495 4496 vm_map_lock(old_map); 4497 4498 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map), 4499 vm1->vm_map.flags & VM_MAP_TOPDOWN); 4500 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy, 4501 (char *) (vm1 + 1) - (char *) &vm1->vm_startcopy); 4502 new_map = &vm2->vm_map; /* XXX */ 4503 4504 old_entry = old_map->header.next; 4505 new_map->size = old_map->size; 4506 4507 /* 4508 * go entry-by-entry 4509 */ 4510 4511 while (old_entry != &old_map->header) { 4512 4513 /* 4514 * first, some sanity checks on the old entry 4515 */ 4516 4517 KASSERT(!UVM_ET_ISSUBMAP(old_entry)); 4518 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) || 4519 !UVM_ET_ISNEEDSCOPY(old_entry)); 4520 4521 switch (old_entry->inheritance) { 4522 case MAP_INHERIT_NONE: 4523 /* 4524 * drop the mapping, modify size 4525 */ 4526 new_map->size -= old_entry->end - old_entry->start; 4527 break; 4528 4529 case MAP_INHERIT_SHARE: 4530 uvm_mapent_forkshared(new_map, old_map, old_entry); 4531 break; 4532 4533 case MAP_INHERIT_COPY: 4534 uvm_mapent_forkcopy(new_map, old_map, old_entry); 4535 break; 4536 4537 case MAP_INHERIT_ZERO: 4538 uvm_mapent_forkzero(new_map, old_map, old_entry); 4539 break; 4540 default: 4541 KASSERT(0); 4542 break; 4543 } 4544 old_entry = old_entry->next; 4545 } 4546 4547 pmap_update(old_map->pmap); 4548 vm_map_unlock(old_map); 4549 4550 if (uvm_shmfork && vm1->vm_shm) 4551 (*uvm_shmfork)(vm1, vm2); 4552 4553 #ifdef PMAP_FORK 4554 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap); 4555 #endif 4556 4557 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4558 return (vm2); 4559 } 4560 4561 4562 /* 4563 * uvm_mapent_trymerge: try to merge an entry with its neighbors. 4564 * 4565 * => called with map locked. 4566 * => return non zero if successfully merged. 4567 */ 4568 4569 int 4570 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags) 4571 { 4572 struct uvm_object *uobj; 4573 struct vm_map_entry *next; 4574 struct vm_map_entry *prev; 4575 vsize_t size; 4576 int merged = 0; 4577 bool copying; 4578 int newetype; 4579 4580 if (entry->aref.ar_amap != NULL) { 4581 return 0; 4582 } 4583 if ((entry->flags & UVM_MAP_NOMERGE) != 0) { 4584 return 0; 4585 } 4586 4587 uobj = entry->object.uvm_obj; 4588 size = entry->end - entry->start; 4589 copying = (flags & UVM_MERGE_COPYING) != 0; 4590 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype; 4591 4592 next = entry->next; 4593 if (next != &map->header && 4594 next->start == entry->end && 4595 ((copying && next->aref.ar_amap != NULL && 4596 amap_refs(next->aref.ar_amap) == 1) || 4597 (!copying && next->aref.ar_amap == NULL)) && 4598 UVM_ET_ISCOMPATIBLE(next, newetype, 4599 uobj, entry->flags, entry->protection, 4600 entry->max_protection, entry->inheritance, entry->advice, 4601 entry->wired_count) && 4602 (uobj == NULL || entry->offset + size == next->offset)) { 4603 int error; 4604 4605 if (copying) { 4606 error = amap_extend(next, size, 4607 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS); 4608 } else { 4609 error = 0; 4610 } 4611 if (error == 0) { 4612 if (uobj) { 4613 if (uobj->pgops->pgo_detach) { 4614 uobj->pgops->pgo_detach(uobj); 4615 } 4616 } 4617 4618 entry->end = next->end; 4619 clear_hints(map, next); 4620 uvm_map_entry_unlink(map, next); 4621 if (copying) { 4622 entry->aref = next->aref; 4623 entry->etype &= ~UVM_ET_NEEDSCOPY; 4624 } 4625 uvm_map_check(map, "trymerge forwardmerge"); 4626 uvm_mapent_free(next); 4627 merged++; 4628 } 4629 } 4630 4631 prev = entry->prev; 4632 if (prev != &map->header && 4633 prev->end == entry->start && 4634 ((copying && !merged && prev->aref.ar_amap != NULL && 4635 amap_refs(prev->aref.ar_amap) == 1) || 4636 (!copying && prev->aref.ar_amap == NULL)) && 4637 UVM_ET_ISCOMPATIBLE(prev, newetype, 4638 uobj, entry->flags, entry->protection, 4639 entry->max_protection, entry->inheritance, entry->advice, 4640 entry->wired_count) && 4641 (uobj == NULL || 4642 prev->offset + prev->end - prev->start == entry->offset)) { 4643 int error; 4644 4645 if (copying) { 4646 error = amap_extend(prev, size, 4647 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS); 4648 } else { 4649 error = 0; 4650 } 4651 if (error == 0) { 4652 if (uobj) { 4653 if (uobj->pgops->pgo_detach) { 4654 uobj->pgops->pgo_detach(uobj); 4655 } 4656 entry->offset = prev->offset; 4657 } 4658 4659 entry->start = prev->start; 4660 clear_hints(map, prev); 4661 uvm_map_entry_unlink(map, prev); 4662 if (copying) { 4663 entry->aref = prev->aref; 4664 entry->etype &= ~UVM_ET_NEEDSCOPY; 4665 } 4666 uvm_map_check(map, "trymerge backmerge"); 4667 uvm_mapent_free(prev); 4668 merged++; 4669 } 4670 } 4671 4672 return merged; 4673 } 4674 4675 /* 4676 * uvm_map_setup: init map 4677 * 4678 * => map must not be in service yet. 4679 */ 4680 4681 void 4682 uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags) 4683 { 4684 4685 rb_tree_init(&map->rb_tree, &uvm_map_tree_ops); 4686 map->header.next = map->header.prev = &map->header; 4687 map->nentries = 0; 4688 map->size = 0; 4689 map->ref_count = 1; 4690 vm_map_setmin(map, vmin); 4691 vm_map_setmax(map, vmax); 4692 map->flags = flags; 4693 map->first_free = &map->header; 4694 map->hint = &map->header; 4695 map->timestamp = 0; 4696 map->busy = NULL; 4697 4698 rw_init(&map->lock); 4699 cv_init(&map->cv, "vm_map"); 4700 mutex_init(&map->misc_lock, MUTEX_DRIVER, IPL_NONE); 4701 } 4702 4703 /* 4704 * U N M A P - m a i n e n t r y p o i n t 4705 */ 4706 4707 /* 4708 * uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop") 4709 * 4710 * => caller must check alignment and size 4711 * => map must be unlocked (we will lock it) 4712 * => flags is UVM_FLAG_QUANTUM or 0. 4713 */ 4714 4715 void 4716 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 4717 { 4718 struct vm_map_entry *dead_entries; 4719 UVMHIST_FUNC("uvm_unmap"); UVMHIST_CALLED(maphist); 4720 4721 KASSERT(start < end); 4722 UVMHIST_LOG(maphist, " (map=%#jx, start=%#jx, end=%#jx)", 4723 (uintptr_t)map, start, end, 0); 4724 if (map == kernel_map) { 4725 LOCKDEBUG_MEM_CHECK((void *)start, end - start); 4726 } 4727 4728 /* 4729 * work now done by helper functions. wipe the pmap's and then 4730 * detach from the dead entries... 4731 */ 4732 vm_map_lock(map); 4733 uvm_unmap_remove(map, start, end, &dead_entries, flags); 4734 vm_map_unlock(map); 4735 4736 if (dead_entries != NULL) 4737 uvm_unmap_detach(dead_entries, 0); 4738 4739 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 4740 } 4741 4742 4743 /* 4744 * uvm_map_reference: add reference to a map 4745 * 4746 * => map need not be locked (we use misc_lock). 4747 */ 4748 4749 void 4750 uvm_map_reference(struct vm_map *map) 4751 { 4752 mutex_enter(&map->misc_lock); 4753 map->ref_count++; 4754 mutex_exit(&map->misc_lock); 4755 } 4756 4757 bool 4758 vm_map_starved_p(struct vm_map *map) 4759 { 4760 4761 if ((map->flags & VM_MAP_WANTVA) != 0) { 4762 return true; 4763 } 4764 /* XXX */ 4765 if ((vm_map_max(map) - vm_map_min(map)) / 16 * 15 < map->size) { 4766 return true; 4767 } 4768 return false; 4769 } 4770 4771 void 4772 uvm_map_lock_entry(struct vm_map_entry *entry) 4773 { 4774 4775 if (entry->aref.ar_amap != NULL) { 4776 amap_lock(entry->aref.ar_amap); 4777 } 4778 if (UVM_ET_ISOBJ(entry)) { 4779 mutex_enter(entry->object.uvm_obj->vmobjlock); 4780 } 4781 } 4782 4783 void 4784 uvm_map_unlock_entry(struct vm_map_entry *entry) 4785 { 4786 4787 if (UVM_ET_ISOBJ(entry)) { 4788 mutex_exit(entry->object.uvm_obj->vmobjlock); 4789 } 4790 if (entry->aref.ar_amap != NULL) { 4791 amap_unlock(entry->aref.ar_amap); 4792 } 4793 } 4794 4795 #if defined(DDB) || defined(DEBUGPRINT) 4796 4797 /* 4798 * uvm_map_printit: actually prints the map 4799 */ 4800 4801 void 4802 uvm_map_printit(struct vm_map *map, bool full, 4803 void (*pr)(const char *, ...)) 4804 { 4805 struct vm_map_entry *entry; 4806 4807 (*pr)("MAP %p: [%#lx->%#lx]\n", map, vm_map_min(map), 4808 vm_map_max(map)); 4809 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=%#x\n", 4810 map->nentries, map->size, map->ref_count, map->timestamp, 4811 map->flags); 4812 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap, 4813 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap)); 4814 if (!full) 4815 return; 4816 for (entry = map->header.next; entry != &map->header; 4817 entry = entry->next) { 4818 (*pr)(" - %p: %#lx->%#lx: obj=%p/%#llx, amap=%p/%d\n", 4819 entry, entry->start, entry->end, entry->object.uvm_obj, 4820 (long long)entry->offset, entry->aref.ar_amap, 4821 entry->aref.ar_pageoff); 4822 (*pr)( 4823 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, " 4824 "wc=%d, adv=%d\n", 4825 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F', 4826 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F', 4827 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F', 4828 entry->protection, entry->max_protection, 4829 entry->inheritance, entry->wired_count, entry->advice); 4830 } 4831 } 4832 4833 void 4834 uvm_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 4835 { 4836 struct vm_map *map; 4837 4838 for (map = kernel_map;;) { 4839 struct vm_map_entry *entry; 4840 4841 if (!uvm_map_lookup_entry_bytree(map, (vaddr_t)addr, &entry)) { 4842 break; 4843 } 4844 (*pr)("%p is %p+%zu from VMMAP %p\n", 4845 (void *)addr, (void *)entry->start, 4846 (size_t)(addr - (uintptr_t)entry->start), map); 4847 if (!UVM_ET_ISSUBMAP(entry)) { 4848 break; 4849 } 4850 map = entry->object.sub_map; 4851 } 4852 } 4853 4854 #endif /* DDB || DEBUGPRINT */ 4855 4856 #ifndef __USER_VA0_IS_SAFE 4857 static int 4858 sysctl_user_va0_disable(SYSCTLFN_ARGS) 4859 { 4860 struct sysctlnode node; 4861 int t, error; 4862 4863 node = *rnode; 4864 node.sysctl_data = &t; 4865 t = user_va0_disable; 4866 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 4867 if (error || newp == NULL) 4868 return (error); 4869 4870 if (!t && user_va0_disable && 4871 kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MAP_VA_ZERO, 0, 4872 NULL, NULL, NULL)) 4873 return EPERM; 4874 4875 user_va0_disable = !!t; 4876 return 0; 4877 } 4878 #endif 4879 4880 static int 4881 fill_vmentry(struct lwp *l, struct proc *p, struct kinfo_vmentry *kve, 4882 struct vm_map *m, struct vm_map_entry *e) 4883 { 4884 #ifndef _RUMPKERNEL 4885 int error; 4886 4887 memset(kve, 0, sizeof(*kve)); 4888 KASSERT(e != NULL); 4889 if (UVM_ET_ISOBJ(e)) { 4890 struct uvm_object *uobj = e->object.uvm_obj; 4891 KASSERT(uobj != NULL); 4892 kve->kve_ref_count = uobj->uo_refs; 4893 kve->kve_count = uobj->uo_npages; 4894 if (UVM_OBJ_IS_VNODE(uobj)) { 4895 struct vattr va; 4896 struct vnode *vp = (struct vnode *)uobj; 4897 vn_lock(vp, LK_SHARED | LK_RETRY); 4898 error = VOP_GETATTR(vp, &va, l->l_cred); 4899 VOP_UNLOCK(vp); 4900 kve->kve_type = KVME_TYPE_VNODE; 4901 if (error == 0) { 4902 kve->kve_vn_size = vp->v_size; 4903 kve->kve_vn_type = (int)vp->v_type; 4904 kve->kve_vn_mode = va.va_mode; 4905 kve->kve_vn_rdev = va.va_rdev; 4906 kve->kve_vn_fileid = va.va_fileid; 4907 kve->kve_vn_fsid = va.va_fsid; 4908 error = vnode_to_path(kve->kve_path, 4909 sizeof(kve->kve_path) / 2, vp, l, p); 4910 #ifdef DIAGNOSTIC 4911 if (error) 4912 printf("%s: vp %p error %d\n", __func__, 4913 vp, error); 4914 #endif 4915 } 4916 } else if (UVM_OBJ_IS_KERN_OBJECT(uobj)) { 4917 kve->kve_type = KVME_TYPE_KERN; 4918 } else if (UVM_OBJ_IS_DEVICE(uobj)) { 4919 kve->kve_type = KVME_TYPE_DEVICE; 4920 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 4921 kve->kve_type = KVME_TYPE_ANON; 4922 } else { 4923 kve->kve_type = KVME_TYPE_OBJECT; 4924 } 4925 } else if (UVM_ET_ISSUBMAP(e)) { 4926 struct vm_map *map = e->object.sub_map; 4927 KASSERT(map != NULL); 4928 kve->kve_ref_count = map->ref_count; 4929 kve->kve_count = map->nentries; 4930 kve->kve_type = KVME_TYPE_SUBMAP; 4931 } else 4932 kve->kve_type = KVME_TYPE_UNKNOWN; 4933 4934 kve->kve_start = e->start; 4935 kve->kve_end = e->end; 4936 kve->kve_offset = e->offset; 4937 kve->kve_wired_count = e->wired_count; 4938 kve->kve_inheritance = e->inheritance; 4939 kve->kve_attributes = e->map_attrib; 4940 kve->kve_advice = e->advice; 4941 #define PROT(p) (((p) & VM_PROT_READ) ? KVME_PROT_READ : 0) | \ 4942 (((p) & VM_PROT_WRITE) ? KVME_PROT_WRITE : 0) | \ 4943 (((p) & VM_PROT_EXECUTE) ? KVME_PROT_EXEC : 0) 4944 kve->kve_protection = PROT(e->protection); 4945 kve->kve_max_protection = PROT(e->max_protection); 4946 kve->kve_flags |= (e->etype & UVM_ET_COPYONWRITE) 4947 ? KVME_FLAG_COW : 0; 4948 kve->kve_flags |= (e->etype & UVM_ET_NEEDSCOPY) 4949 ? KVME_FLAG_NEEDS_COPY : 0; 4950 kve->kve_flags |= (m->flags & VM_MAP_TOPDOWN) 4951 ? KVME_FLAG_GROWS_DOWN : KVME_FLAG_GROWS_UP; 4952 kve->kve_flags |= (m->flags & VM_MAP_PAGEABLE) 4953 ? KVME_FLAG_PAGEABLE : 0; 4954 #endif 4955 return 0; 4956 } 4957 4958 static int 4959 fill_vmentries(struct lwp *l, pid_t pid, u_int elem_size, void *oldp, 4960 size_t *oldlenp) 4961 { 4962 int error; 4963 struct proc *p; 4964 struct kinfo_vmentry *vme; 4965 struct vmspace *vm; 4966 struct vm_map *map; 4967 struct vm_map_entry *entry; 4968 char *dp; 4969 size_t count, vmesize; 4970 4971 if (elem_size == 0 || elem_size > 2 * sizeof(*vme)) 4972 return EINVAL; 4973 4974 if (oldp) { 4975 if (*oldlenp > 1024 * 1024) 4976 return E2BIG; 4977 count = *oldlenp / elem_size; 4978 if (count == 0) 4979 return ENOMEM; 4980 vmesize = count * sizeof(*vme); 4981 } else 4982 vmesize = 0; 4983 4984 if ((error = proc_find_locked(l, &p, pid)) != 0) 4985 return error; 4986 4987 vme = NULL; 4988 count = 0; 4989 4990 if ((error = proc_vmspace_getref(p, &vm)) != 0) 4991 goto out; 4992 4993 map = &vm->vm_map; 4994 vm_map_lock_read(map); 4995 4996 dp = oldp; 4997 if (oldp) 4998 vme = kmem_alloc(vmesize, KM_SLEEP); 4999 for (entry = map->header.next; entry != &map->header; 5000 entry = entry->next) { 5001 if (oldp && (dp - (char *)oldp) < vmesize) { 5002 error = fill_vmentry(l, p, &vme[count], map, entry); 5003 if (error) 5004 goto out; 5005 dp += elem_size; 5006 } 5007 count++; 5008 } 5009 vm_map_unlock_read(map); 5010 uvmspace_free(vm); 5011 5012 out: 5013 if (pid != -1) 5014 mutex_exit(p->p_lock); 5015 if (error == 0) { 5016 const u_int esize = min(sizeof(*vme), elem_size); 5017 dp = oldp; 5018 for (size_t i = 0; i < count; i++) { 5019 if (oldp && (dp - (char *)oldp) < vmesize) { 5020 error = sysctl_copyout(l, &vme[i], dp, esize); 5021 if (error) 5022 break; 5023 dp += elem_size; 5024 } else 5025 break; 5026 } 5027 count *= elem_size; 5028 if (oldp != NULL && *oldlenp < count) 5029 error = ENOSPC; 5030 *oldlenp = count; 5031 } 5032 if (vme) 5033 kmem_free(vme, vmesize); 5034 return error; 5035 } 5036 5037 static int 5038 sysctl_vmproc(SYSCTLFN_ARGS) 5039 { 5040 int error; 5041 5042 if (namelen == 1 && name[0] == CTL_QUERY) 5043 return (sysctl_query(SYSCTLFN_CALL(rnode))); 5044 5045 if (namelen == 0) 5046 return EINVAL; 5047 5048 switch (name[0]) { 5049 case VM_PROC_MAP: 5050 if (namelen != 3) 5051 return EINVAL; 5052 sysctl_unlock(); 5053 error = fill_vmentries(l, name[1], name[2], oldp, oldlenp); 5054 sysctl_relock(); 5055 return error; 5056 default: 5057 return EINVAL; 5058 } 5059 } 5060 5061 SYSCTL_SETUP(sysctl_uvmmap_setup, "sysctl uvmmap setup") 5062 { 5063 5064 sysctl_createv(clog, 0, NULL, NULL, 5065 CTLFLAG_PERMANENT, 5066 CTLTYPE_STRUCT, "proc", 5067 SYSCTL_DESCR("Process vm information"), 5068 sysctl_vmproc, 0, NULL, 0, 5069 CTL_VM, VM_PROC, CTL_EOL); 5070 #ifndef __USER_VA0_IS_SAFE 5071 sysctl_createv(clog, 0, NULL, NULL, 5072 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 5073 CTLTYPE_INT, "user_va0_disable", 5074 SYSCTL_DESCR("Disable VA 0"), 5075 sysctl_user_va0_disable, 0, &user_va0_disable, 0, 5076 CTL_VM, CTL_CREATE, CTL_EOL); 5077 #endif 5078 } 5079