| 1 | /* |
| 2 | * Copyright (c) 1991, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * Copyright (c) 2003-2022 The DragonFly Project. All rights reserved. |
| 5 | * |
| 6 | * This code is derived from software contributed to Berkeley by |
| 7 | * The Mach Operating System project at Carnegie-Mellon University. |
| 8 | * |
| 9 | * This code is derived from software contributed to The DragonFly Project |
| 10 | * by Matthew Dillon <dillon@backplane.com> |
| 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 | * from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94 |
| 37 | * |
| 38 | * Copyright (c) 1987, 1990 Carnegie-Mellon University. |
| 39 | * All rights reserved. |
| 40 | * |
| 41 | * Authors: Avadis Tevanian, Jr., Michael Wayne Young |
| 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 | #include <sys/param.h> |
| 64 | #include <sys/systm.h> |
| 65 | #include <sys/kernel.h> |
| 66 | #include <sys/proc.h> |
| 67 | #include <sys/serialize.h> |
| 68 | #include <sys/lock.h> |
| 69 | #include <sys/vmmeter.h> |
| 70 | #include <sys/mman.h> |
| 71 | #include <sys/vnode.h> |
| 72 | #include <sys/resourcevar.h> |
| 73 | #include <sys/shm.h> |
| 74 | #include <sys/tree.h> |
| 75 | #include <sys/malloc.h> |
| 76 | #include <sys/objcache.h> |
| 77 | #include <sys/kern_syscall.h> |
| 78 | |
| 79 | #include <vm/vm.h> |
| 80 | #include <vm/vm_param.h> |
| 81 | #include <vm/pmap.h> |
| 82 | #include <vm/vm_map.h> |
| 83 | #include <vm/vm_page.h> |
| 84 | #include <vm/vm_object.h> |
| 85 | #include <vm/vm_pager.h> |
| 86 | #include <vm/vm_kern.h> |
| 87 | #include <vm/vm_extern.h> |
| 88 | #include <vm/swap_pager.h> |
| 89 | #include <vm/vm_zone.h> |
| 90 | |
| 91 | #include <sys/random.h> |
| 92 | #include <sys/sysctl.h> |
| 93 | #include <sys/spinlock.h> |
| 94 | |
| 95 | #include <sys/thread2.h> |
| 96 | #include <sys/spinlock2.h> |
| 97 | |
| 98 | /* |
| 99 | * Virtual memory maps provide for the mapping, protection, and sharing |
| 100 | * of virtual memory objects. In addition, this module provides for an |
| 101 | * efficient virtual copy of memory from one map to another. |
| 102 | * |
| 103 | * Synchronization is required prior to most operations. |
| 104 | * |
| 105 | * Maps consist of an ordered doubly-linked list of simple entries. |
| 106 | * A hint and a RB tree is used to speed-up lookups. |
| 107 | * |
| 108 | * Callers looking to modify maps specify start/end addresses which cause |
| 109 | * the related map entry to be clipped if necessary, and then later |
| 110 | * recombined if the pieces remained compatible. |
| 111 | * |
| 112 | * Virtual copy operations are performed by copying VM object references |
| 113 | * from one map to another, and then marking both regions as copy-on-write. |
| 114 | */ |
| 115 | static boolean_t vmspace_ctor(void *obj, void *privdata, int ocflags); |
| 116 | static void vmspace_dtor(void *obj, void *privdata); |
| 117 | static void vmspace_terminate(struct vmspace *vm, int final); |
| 118 | |
| 119 | MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore"); |
| 120 | MALLOC_DEFINE(M_MAP_BACKING, "map_backing", "vm_map_backing to entry"); |
| 121 | static struct objcache *vmspace_cache; |
| 122 | |
| 123 | /* |
| 124 | * per-cpu page table cross mappings are initialized in early boot |
| 125 | * and might require a considerable number of vm_map_entry structures. |
| 126 | */ |
| 127 | #define MAPENTRYBSP_CACHE (MAXCPU+1) |
| 128 | #define MAPENTRYAP_CACHE 8 |
| 129 | |
| 130 | /* |
| 131 | * Partioning threaded programs with large anonymous memory areas can |
| 132 | * improve concurrent fault performance. |
| 133 | */ |
| 134 | #define MAP_ENTRY_PARTITION_SIZE ((vm_offset_t)(32 * 1024 * 1024)) |
| 135 | #define MAP_ENTRY_PARTITION_MASK (MAP_ENTRY_PARTITION_SIZE - 1) |
| 136 | |
| 137 | #define VM_MAP_ENTRY_WITHIN_PARTITION(entry) \ |
| 138 | ((((entry)->ba.start ^ (entry)->ba.end) & ~MAP_ENTRY_PARTITION_MASK) == 0) |
| 139 | |
| 140 | static struct vm_zone mapentzone_store; |
| 141 | __read_mostly static vm_zone_t mapentzone; |
| 142 | |
| 143 | static struct vm_map_entry map_entry_init[MAX_MAPENT]; |
| 144 | static struct vm_map_entry cpu_map_entry_init_bsp[MAPENTRYBSP_CACHE]; |
| 145 | static struct vm_map_entry cpu_map_entry_init_ap[MAXCPU][MAPENTRYAP_CACHE]; |
| 146 | |
| 147 | __read_mostly static int randomize_mmap; |
| 148 | SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0, |
| 149 | "Randomize mmap offsets"); |
| 150 | __read_mostly static int vm_map_relock_enable = 1; |
| 151 | SYSCTL_INT(_vm, OID_AUTO, map_relock_enable, CTLFLAG_RW, |
| 152 | &vm_map_relock_enable, 0, "insert pop pgtable optimization"); |
| 153 | __read_mostly static int vm_map_partition_enable = 1; |
| 154 | SYSCTL_INT(_vm, OID_AUTO, map_partition_enable, CTLFLAG_RW, |
| 155 | &vm_map_partition_enable, 0, "Break up larger vm_map_entry's"); |
| 156 | __read_mostly static int vm_map_backing_limit = 5; |
| 157 | SYSCTL_INT(_vm, OID_AUTO, map_backing_limit, CTLFLAG_RW, |
| 158 | &vm_map_backing_limit, 0, "ba.backing_ba link depth"); |
| 159 | __read_mostly static int vm_map_backing_shadow_test = 1; |
| 160 | SYSCTL_INT(_vm, OID_AUTO, map_backing_shadow_test, CTLFLAG_RW, |
| 161 | &vm_map_backing_shadow_test, 0, "ba.object shadow test"); |
| 162 | |
| 163 | static void vmspace_drop_notoken(struct vmspace *vm); |
| 164 | static void vm_map_entry_shadow(vm_map_entry_t entry); |
| 165 | static vm_map_entry_t vm_map_entry_create(int *); |
| 166 | static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *); |
| 167 | static void vm_map_entry_dispose_ba (vm_map_entry_t entry, vm_map_backing_t ba); |
| 168 | static void vm_map_backing_replicated(vm_map_t map, |
| 169 | vm_map_entry_t entry, int flags); |
| 170 | static void vm_map_backing_adjust_start(vm_map_entry_t entry, |
| 171 | vm_ooffset_t start); |
| 172 | static void vm_map_backing_adjust_end(vm_map_entry_t entry, |
| 173 | vm_ooffset_t end); |
| 174 | static void vm_map_backing_attach (vm_map_entry_t entry, vm_map_backing_t ba); |
| 175 | static void vm_map_backing_detach (vm_map_entry_t entry, vm_map_backing_t ba); |
| 176 | static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *); |
| 177 | static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *); |
| 178 | static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *); |
| 179 | static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t); |
| 180 | static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t, |
| 181 | vm_map_entry_t); |
| 182 | static void vm_map_unclip_range (vm_map_t map, vm_map_entry_t start_entry, |
| 183 | vm_offset_t start, vm_offset_t end, int *countp, int flags); |
| 184 | static void vm_map_entry_partition(vm_map_t map, vm_map_entry_t entry, |
| 185 | vm_offset_t vaddr, int *countp); |
| 186 | |
| 187 | #define MAP_BACK_CLIPPED 0x0001 |
| 188 | #define MAP_BACK_BASEOBJREFD 0x0002 |
| 189 | |
| 190 | /* |
| 191 | * Initialize the vm_map module. Must be called before any other vm_map |
| 192 | * routines. |
| 193 | * |
| 194 | * Map and entry structures are allocated from the general purpose |
| 195 | * memory pool with some exceptions: |
| 196 | * |
| 197 | * - The kernel map is allocated statically. |
| 198 | * - Initial kernel map entries are allocated out of a static pool. |
| 199 | * - We must set ZONE_SPECIAL here or the early boot code can get |
| 200 | * stuck if there are >63 cores. |
| 201 | * |
| 202 | * These restrictions are necessary since malloc() uses the |
| 203 | * maps and requires map entries. |
| 204 | * |
| 205 | * Called from the low level boot code only. |
| 206 | */ |
| 207 | void |
| 208 | vm_map_startup(void) |
| 209 | { |
| 210 | mapentzone = &mapentzone_store; |
| 211 | zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry), |
| 212 | map_entry_init, MAX_MAPENT); |
| 213 | mapentzone_store.zflags |= ZONE_SPECIAL; |
| 214 | } |
| 215 | |
| 216 | /* |
| 217 | * Called prior to any vmspace allocations. |
| 218 | * |
| 219 | * Called from the low level boot code only. |
| 220 | */ |
| 221 | void |
| 222 | vm_init2(void) |
| 223 | { |
| 224 | vmspace_cache = objcache_create_mbacked(M_VMSPACE, |
| 225 | sizeof(struct vmspace), |
| 226 | 0, ncpus * 4, |
| 227 | vmspace_ctor, vmspace_dtor, |
| 228 | NULL); |
| 229 | zinitna(mapentzone, NULL, 0, 0, ZONE_USE_RESERVE | ZONE_SPECIAL); |
| 230 | pmap_init2(); |
| 231 | vm_object_init2(); |
| 232 | } |
| 233 | |
| 234 | /* |
| 235 | * objcache support. We leave the pmap root cached as long as possible |
| 236 | * for performance reasons. |
| 237 | */ |
| 238 | static |
| 239 | boolean_t |
| 240 | vmspace_ctor(void *obj, void *privdata, int ocflags) |
| 241 | { |
| 242 | struct vmspace *vm = obj; |
| 243 | |
| 244 | bzero(vm, sizeof(*vm)); |
| 245 | vm->vm_refcnt = VM_REF_DELETED; |
| 246 | |
| 247 | return 1; |
| 248 | } |
| 249 | |
| 250 | static |
| 251 | void |
| 252 | vmspace_dtor(void *obj, void *privdata) |
| 253 | { |
| 254 | struct vmspace *vm = obj; |
| 255 | |
| 256 | KKASSERT(vm->vm_refcnt == VM_REF_DELETED); |
| 257 | pmap_puninit(vmspace_pmap(vm)); |
| 258 | } |
| 259 | |
| 260 | /* |
| 261 | * Red black tree functions |
| 262 | * |
| 263 | * The caller must hold the related map lock. |
| 264 | */ |
| 265 | static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b); |
| 266 | RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare); |
| 267 | |
| 268 | /* a->ba.start is address, and the only field which must be initialized */ |
| 269 | static int |
| 270 | rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b) |
| 271 | { |
| 272 | if (a->ba.start < b->ba.start) |
| 273 | return(-1); |
| 274 | else if (a->ba.start > b->ba.start) |
| 275 | return(1); |
| 276 | return(0); |
| 277 | } |
| 278 | |
| 279 | /* |
| 280 | * Initialize vmspace ref/hold counts vmspace0. There is a holdcnt for |
| 281 | * every refcnt. |
| 282 | */ |
| 283 | void |
| 284 | vmspace_initrefs(struct vmspace *vm) |
| 285 | { |
| 286 | vm->vm_refcnt = 1; |
| 287 | vm->vm_holdcnt = 1; |
| 288 | } |
| 289 | |
| 290 | /* |
| 291 | * Allocate a vmspace structure, including a vm_map and pmap. |
| 292 | * Initialize numerous fields. While the initial allocation is zerod, |
| 293 | * subsequence reuse from the objcache leaves elements of the structure |
| 294 | * intact (particularly the pmap), so portions must be zerod. |
| 295 | * |
| 296 | * Returns a referenced vmspace. |
| 297 | * |
| 298 | * No requirements. |
| 299 | */ |
| 300 | struct vmspace * |
| 301 | vmspace_alloc(vm_offset_t min, vm_offset_t max) |
| 302 | { |
| 303 | struct vmspace *vm; |
| 304 | |
| 305 | vm = objcache_get(vmspace_cache, M_WAITOK); |
| 306 | |
| 307 | bzero(&vm->vm_startcopy, |
| 308 | (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy); |
| 309 | vm_map_init(&vm->vm_map, min, max, NULL); /* initializes token */ |
| 310 | |
| 311 | /* |
| 312 | * NOTE: hold to acquires token for safety. |
| 313 | * |
| 314 | * On return vmspace is referenced (refs=1, hold=1). That is, |
| 315 | * each refcnt also has a holdcnt. There can be additional holds |
| 316 | * (holdcnt) above and beyond the refcnt. Finalization is handled in |
| 317 | * two stages, one on refs 1->0, and the the second on hold 1->0. |
| 318 | */ |
| 319 | KKASSERT(vm->vm_holdcnt == 0); |
| 320 | KKASSERT(vm->vm_refcnt == VM_REF_DELETED); |
| 321 | vmspace_initrefs(vm); |
| 322 | vmspace_hold(vm); |
| 323 | pmap_pinit(vmspace_pmap(vm)); /* (some fields reused) */ |
| 324 | vm->vm_map.pmap = vmspace_pmap(vm); /* XXX */ |
| 325 | vm->vm_shm = NULL; |
| 326 | vm->vm_flags = 0; |
| 327 | cpu_vmspace_alloc(vm); |
| 328 | vmspace_drop(vm); |
| 329 | |
| 330 | return (vm); |
| 331 | } |
| 332 | |
| 333 | /* |
| 334 | * NOTE: Can return 0 if the vmspace is exiting. |
| 335 | */ |
| 336 | int |
| 337 | vmspace_getrefs(struct vmspace *vm) |
| 338 | { |
| 339 | int32_t n; |
| 340 | |
| 341 | n = vm->vm_refcnt; |
| 342 | cpu_ccfence(); |
| 343 | if (n & VM_REF_DELETED) |
| 344 | n = -1; |
| 345 | return n; |
| 346 | } |
| 347 | |
| 348 | void |
| 349 | vmspace_hold(struct vmspace *vm) |
| 350 | { |
| 351 | atomic_add_int(&vm->vm_holdcnt, 1); |
| 352 | lwkt_gettoken(&vm->vm_map.token); |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * Drop with final termination interlock. |
| 357 | */ |
| 358 | void |
| 359 | vmspace_drop(struct vmspace *vm) |
| 360 | { |
| 361 | lwkt_reltoken(&vm->vm_map.token); |
| 362 | vmspace_drop_notoken(vm); |
| 363 | } |
| 364 | |
| 365 | static void |
| 366 | vmspace_drop_notoken(struct vmspace *vm) |
| 367 | { |
| 368 | if (atomic_fetchadd_int(&vm->vm_holdcnt, -1) == 1) { |
| 369 | if (vm->vm_refcnt & VM_REF_DELETED) |
| 370 | vmspace_terminate(vm, 1); |
| 371 | } |
| 372 | } |
| 373 | |
| 374 | /* |
| 375 | * A vmspace object must not be in a terminated state to be able to obtain |
| 376 | * additional refs on it. |
| 377 | * |
| 378 | * These are official references to the vmspace, the count is used to check |
| 379 | * for vmspace sharing. Foreign accessors should use 'hold' and not 'ref'. |
| 380 | * |
| 381 | * XXX we need to combine hold & ref together into one 64-bit field to allow |
| 382 | * holds to prevent stage-1 termination. |
| 383 | */ |
| 384 | void |
| 385 | vmspace_ref(struct vmspace *vm) |
| 386 | { |
| 387 | uint32_t n; |
| 388 | |
| 389 | atomic_add_int(&vm->vm_holdcnt, 1); |
| 390 | n = atomic_fetchadd_int(&vm->vm_refcnt, 1); |
| 391 | KKASSERT((n & VM_REF_DELETED) == 0); |
| 392 | } |
| 393 | |
| 394 | /* |
| 395 | * Release a ref on the vmspace. On the 1->0 transition we do stage-1 |
| 396 | * termination of the vmspace. Then, on the final drop of the hold we |
| 397 | * will do stage-2 final termination. |
| 398 | */ |
| 399 | void |
| 400 | vmspace_rel(struct vmspace *vm) |
| 401 | { |
| 402 | uint32_t n; |
| 403 | |
| 404 | /* |
| 405 | * Drop refs. Each ref also has a hold which is also dropped. |
| 406 | * |
| 407 | * When refs hits 0 compete to get the VM_REF_DELETED flag (hold |
| 408 | * prevent finalization) to start termination processing. |
| 409 | * Finalization occurs when the last hold count drops to 0. |
| 410 | */ |
| 411 | n = atomic_fetchadd_int(&vm->vm_refcnt, -1) - 1; |
| 412 | while (n == 0) { |
| 413 | if (atomic_cmpset_int(&vm->vm_refcnt, 0, VM_REF_DELETED)) { |
| 414 | vmspace_terminate(vm, 0); |
| 415 | break; |
| 416 | } |
| 417 | n = vm->vm_refcnt; |
| 418 | cpu_ccfence(); |
| 419 | } |
| 420 | vmspace_drop_notoken(vm); |
| 421 | } |
| 422 | |
| 423 | /* |
| 424 | * This is called during exit indicating that the vmspace is no |
| 425 | * longer in used by an exiting process, but the process has not yet |
| 426 | * been reaped. |
| 427 | * |
| 428 | * We drop refs, allowing for stage-1 termination, but maintain a holdcnt |
| 429 | * to prevent stage-2 until the process is reaped. Note hte order of |
| 430 | * operation, we must hold first. |
| 431 | * |
| 432 | * No requirements. |
| 433 | */ |
| 434 | void |
| 435 | vmspace_relexit(struct vmspace *vm) |
| 436 | { |
| 437 | atomic_add_int(&vm->vm_holdcnt, 1); |
| 438 | vmspace_rel(vm); |
| 439 | } |
| 440 | |
| 441 | /* |
| 442 | * Called during reap to disconnect the remainder of the vmspace from |
| 443 | * the process. On the hold drop the vmspace termination is finalized. |
| 444 | * |
| 445 | * No requirements. |
| 446 | */ |
| 447 | void |
| 448 | vmspace_exitfree(struct proc *p) |
| 449 | { |
| 450 | struct vmspace *vm; |
| 451 | |
| 452 | vm = p->p_vmspace; |
| 453 | p->p_vmspace = NULL; |
| 454 | vmspace_drop_notoken(vm); |
| 455 | } |
| 456 | |
| 457 | /* |
| 458 | * Called in two cases: |
| 459 | * |
| 460 | * (1) When the last refcnt is dropped and the vmspace becomes inactive, |
| 461 | * called with final == 0. refcnt will be (u_int)-1 at this point, |
| 462 | * and holdcnt will still be non-zero. |
| 463 | * |
| 464 | * (2) When holdcnt becomes 0, called with final == 1. There should no |
| 465 | * longer be anyone with access to the vmspace. |
| 466 | * |
| 467 | * VMSPACE_EXIT1 flags the primary deactivation |
| 468 | * VMSPACE_EXIT2 flags the last reap |
| 469 | */ |
| 470 | static void |
| 471 | vmspace_terminate(struct vmspace *vm, int final) |
| 472 | { |
| 473 | int count; |
| 474 | |
| 475 | lwkt_gettoken(&vm->vm_map.token); |
| 476 | if (final == 0) { |
| 477 | KKASSERT((vm->vm_flags & VMSPACE_EXIT1) == 0); |
| 478 | vm->vm_flags |= VMSPACE_EXIT1; |
| 479 | |
| 480 | /* |
| 481 | * Get rid of most of the resources. Leave the kernel pmap |
| 482 | * intact. |
| 483 | * |
| 484 | * If the pmap does not contain wired pages we can bulk-delete |
| 485 | * the pmap as a performance optimization before removing the |
| 486 | * related mappings. |
| 487 | * |
| 488 | * If the pmap contains wired pages we cannot do this |
| 489 | * pre-optimization because currently vm_fault_unwire() |
| 490 | * expects the pmap pages to exist and will not decrement |
| 491 | * p->wire_count if they do not. |
| 492 | */ |
| 493 | shmexit(vm); |
| 494 | if (vmspace_pmap(vm)->pm_stats.wired_count) { |
| 495 | vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS, |
| 496 | VM_MAX_USER_ADDRESS); |
| 497 | pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS, |
| 498 | VM_MAX_USER_ADDRESS); |
| 499 | } else { |
| 500 | pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS, |
| 501 | VM_MAX_USER_ADDRESS); |
| 502 | vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS, |
| 503 | VM_MAX_USER_ADDRESS); |
| 504 | } |
| 505 | lwkt_reltoken(&vm->vm_map.token); |
| 506 | } else { |
| 507 | KKASSERT((vm->vm_flags & VMSPACE_EXIT1) != 0); |
| 508 | KKASSERT((vm->vm_flags & VMSPACE_EXIT2) == 0); |
| 509 | |
| 510 | /* |
| 511 | * Get rid of remaining basic resources. |
| 512 | */ |
| 513 | vm->vm_flags |= VMSPACE_EXIT2; |
| 514 | shmexit(vm); |
| 515 | |
| 516 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 517 | vm_map_lock(&vm->vm_map); |
| 518 | cpu_vmspace_free(vm); |
| 519 | |
| 520 | /* |
| 521 | * Lock the map, to wait out all other references to it. |
| 522 | * Delete all of the mappings and pages they hold, then call |
| 523 | * the pmap module to reclaim anything left. |
| 524 | */ |
| 525 | vm_map_delete(&vm->vm_map, |
| 526 | vm_map_min(&vm->vm_map), |
| 527 | vm_map_max(&vm->vm_map), |
| 528 | &count); |
| 529 | vm_map_unlock(&vm->vm_map); |
| 530 | vm_map_entry_release(count); |
| 531 | |
| 532 | pmap_release(vmspace_pmap(vm)); |
| 533 | lwkt_reltoken(&vm->vm_map.token); |
| 534 | objcache_put(vmspace_cache, vm); |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | /* |
| 539 | * Swap useage is determined by taking the proportional swap used by |
| 540 | * VM objects backing the VM map. To make up for fractional losses, |
| 541 | * if the VM object has any swap use at all the associated map entries |
| 542 | * count for at least 1 swap page. |
| 543 | * |
| 544 | * No requirements. |
| 545 | */ |
| 546 | vm_offset_t |
| 547 | vmspace_swap_count(struct vmspace *vm) |
| 548 | { |
| 549 | vm_map_t map = &vm->vm_map; |
| 550 | vm_map_entry_t cur; |
| 551 | vm_object_t object; |
| 552 | vm_offset_t count = 0; |
| 553 | vm_offset_t n; |
| 554 | |
| 555 | vmspace_hold(vm); |
| 556 | |
| 557 | RB_FOREACH(cur, vm_map_rb_tree, &map->rb_root) { |
| 558 | switch(cur->maptype) { |
| 559 | case VM_MAPTYPE_NORMAL: |
| 560 | if ((object = cur->ba.object) == NULL) |
| 561 | break; |
| 562 | if (object->swblock_count) { |
| 563 | n = (cur->ba.end - cur->ba.start) / PAGE_SIZE; |
| 564 | count += object->swblock_count * |
| 565 | SWAP_META_PAGES * n / object->size + 1; |
| 566 | } |
| 567 | break; |
| 568 | default: |
| 569 | break; |
| 570 | } |
| 571 | } |
| 572 | vmspace_drop(vm); |
| 573 | |
| 574 | return(count); |
| 575 | } |
| 576 | |
| 577 | /* |
| 578 | * Calculate the approximate number of anonymous pages in use by |
| 579 | * this vmspace. To make up for fractional losses, we count each |
| 580 | * VM object as having at least 1 anonymous page. |
| 581 | * |
| 582 | * No requirements. |
| 583 | */ |
| 584 | vm_offset_t |
| 585 | vmspace_anonymous_count(struct vmspace *vm) |
| 586 | { |
| 587 | vm_map_t map = &vm->vm_map; |
| 588 | vm_map_entry_t cur; |
| 589 | vm_object_t object; |
| 590 | vm_offset_t count = 0; |
| 591 | |
| 592 | vmspace_hold(vm); |
| 593 | RB_FOREACH(cur, vm_map_rb_tree, &map->rb_root) { |
| 594 | switch(cur->maptype) { |
| 595 | case VM_MAPTYPE_NORMAL: |
| 596 | if ((object = cur->ba.object) == NULL) |
| 597 | break; |
| 598 | if (object->type != OBJT_DEFAULT && |
| 599 | object->type != OBJT_SWAP) { |
| 600 | break; |
| 601 | } |
| 602 | count += object->resident_page_count; |
| 603 | break; |
| 604 | default: |
| 605 | break; |
| 606 | } |
| 607 | } |
| 608 | vmspace_drop(vm); |
| 609 | |
| 610 | return(count); |
| 611 | } |
| 612 | |
| 613 | /* |
| 614 | * Initialize an existing vm_map structure such as that in the vmspace |
| 615 | * structure. The pmap is initialized elsewhere. |
| 616 | * |
| 617 | * No requirements. |
| 618 | */ |
| 619 | void |
| 620 | vm_map_init(struct vm_map *map, vm_offset_t min_addr, vm_offset_t max_addr, |
| 621 | pmap_t pmap) |
| 622 | { |
| 623 | RB_INIT(&map->rb_root); |
| 624 | spin_init(&map->ilock_spin, "ilock"); |
| 625 | map->ilock_base = NULL; |
| 626 | map->nentries = 0; |
| 627 | map->size = 0; |
| 628 | map->system_map = 0; |
| 629 | vm_map_min(map) = min_addr; |
| 630 | vm_map_max(map) = max_addr; |
| 631 | map->pmap = pmap; |
| 632 | map->timestamp = 0; |
| 633 | map->flags = 0; |
| 634 | bzero(&map->freehint, sizeof(map->freehint)); |
| 635 | lwkt_token_init(&map->token, "vm_map"); |
| 636 | lockinit(&map->lock, "vm_maplk", (hz + 9) / 10, 0); |
| 637 | } |
| 638 | |
| 639 | /* |
| 640 | * Find the first possible free address for the specified request length. |
| 641 | * Returns 0 if we don't have one cached. |
| 642 | */ |
| 643 | static |
| 644 | vm_offset_t |
| 645 | vm_map_freehint_find(vm_map_t map, vm_size_t length, vm_size_t align) |
| 646 | { |
| 647 | vm_map_freehint_t *scan; |
| 648 | |
| 649 | scan = &map->freehint[0]; |
| 650 | while (scan < &map->freehint[VM_MAP_FFCOUNT]) { |
| 651 | if (scan->length == length && scan->align == align) |
| 652 | return(scan->start); |
| 653 | ++scan; |
| 654 | } |
| 655 | return 0; |
| 656 | } |
| 657 | |
| 658 | /* |
| 659 | * Unconditionally set the freehint. Called by vm_map_findspace() after |
| 660 | * it finds an address. This will help us iterate optimally on the next |
| 661 | * similar findspace. |
| 662 | */ |
| 663 | static |
| 664 | void |
| 665 | vm_map_freehint_update(vm_map_t map, vm_offset_t start, |
| 666 | vm_size_t length, vm_size_t align) |
| 667 | { |
| 668 | vm_map_freehint_t *scan; |
| 669 | |
| 670 | scan = &map->freehint[0]; |
| 671 | while (scan < &map->freehint[VM_MAP_FFCOUNT]) { |
| 672 | if (scan->length == length && scan->align == align) { |
| 673 | scan->start = start; |
| 674 | return; |
| 675 | } |
| 676 | ++scan; |
| 677 | } |
| 678 | scan = &map->freehint[map->freehint_newindex & VM_MAP_FFMASK]; |
| 679 | scan->start = start; |
| 680 | scan->align = align; |
| 681 | scan->length = length; |
| 682 | ++map->freehint_newindex; |
| 683 | } |
| 684 | |
| 685 | /* |
| 686 | * Update any existing freehints (for any alignment), for the hole we just |
| 687 | * added. |
| 688 | */ |
| 689 | static |
| 690 | void |
| 691 | vm_map_freehint_hole(vm_map_t map, vm_offset_t start, vm_size_t length) |
| 692 | { |
| 693 | vm_map_freehint_t *scan; |
| 694 | |
| 695 | scan = &map->freehint[0]; |
| 696 | while (scan < &map->freehint[VM_MAP_FFCOUNT]) { |
| 697 | if (scan->length <= length && scan->start > start) |
| 698 | scan->start = start; |
| 699 | ++scan; |
| 700 | } |
| 701 | } |
| 702 | |
| 703 | /* |
| 704 | * This function handles MAP_ENTRY_NEEDS_COPY by inserting a fronting |
| 705 | * object in the entry for COW faults. |
| 706 | * |
| 707 | * The entire chain including entry->ba (prior to inserting the fronting |
| 708 | * object) essentially becomes set in stone... elements of it can be paged |
| 709 | * in or out, but cannot be further modified. |
| 710 | * |
| 711 | * NOTE: If we do not optimize the backing chain then a unique copy is not |
| 712 | * needed. Note, however, that because portions of the chain are |
| 713 | * shared across pmaps we cannot make any changes to the vm_map_backing |
| 714 | * elements themselves. |
| 715 | * |
| 716 | * If the map segment is governed by a virtual page table then it is |
| 717 | * possible to address offsets beyond the mapped area. Just allocate |
| 718 | * a maximally sized object for this case. |
| 719 | * |
| 720 | * If addref is non-zero an additional reference is added to the returned |
| 721 | * entry. This mechanic exists because the additional reference might have |
| 722 | * to be added atomically and not after return to prevent a premature |
| 723 | * collapse. XXX currently there is no collapse code. |
| 724 | * |
| 725 | * The vm_map must be exclusively locked. |
| 726 | * No other requirements. |
| 727 | */ |
| 728 | static |
| 729 | void |
| 730 | vm_map_entry_shadow(vm_map_entry_t entry) |
| 731 | { |
| 732 | vm_map_backing_t ba; |
| 733 | vm_size_t length; |
| 734 | vm_object_t source; |
| 735 | vm_object_t result; |
| 736 | |
| 737 | /* |
| 738 | * Number of bytes we have to shadow |
| 739 | */ |
| 740 | length = atop(entry->ba.end - entry->ba.start); |
| 741 | |
| 742 | /* |
| 743 | * Don't create the new object if the old object isn't shared. |
| 744 | * This case occurs quite often when programs fork/exec/wait. |
| 745 | * |
| 746 | * Caller ensures source exists (all backing_ba's must have objects), |
| 747 | * typically indirectly by virtue of the NEEDS_COPY flag being set. |
| 748 | * We have a ref on source by virtue of the entry and do not need |
| 749 | * to lock it to do this test. |
| 750 | */ |
| 751 | source = entry->ba.object; |
| 752 | KKASSERT(source); |
| 753 | |
| 754 | if (source->type != OBJT_VNODE) { |
| 755 | if (source->ref_count == 1 && |
| 756 | source->handle == NULL && |
| 757 | (source->type == OBJT_DEFAULT || |
| 758 | source->type == OBJT_SWAP)) { |
| 759 | goto done; |
| 760 | } |
| 761 | } |
| 762 | ba = kmalloc(sizeof(*ba), M_MAP_BACKING, M_INTWAIT); /* copied later */ |
| 763 | vm_object_hold_shared(source); |
| 764 | |
| 765 | /* |
| 766 | * Once it becomes part of a backing_ba chain it can wind up anywhere, |
| 767 | * drop the ONEMAPPING flag now. |
| 768 | */ |
| 769 | vm_object_clear_flag(source, OBJ_ONEMAPPING); |
| 770 | |
| 771 | /* |
| 772 | * Allocate a new object with the given length. The new object |
| 773 | * is returned referenced but we may have to add another one. |
| 774 | * If we are adding a second reference we must clear OBJ_ONEMAPPING. |
| 775 | * (typically because the caller is about to clone a vm_map_entry). |
| 776 | * |
| 777 | * The source object currently has an extra reference to prevent |
| 778 | * collapses into it while we mess with its shadow list, which |
| 779 | * we will remove later in this routine. |
| 780 | * |
| 781 | * The target object may require a second reference if asked for one |
| 782 | * by the caller. |
| 783 | */ |
| 784 | result = vm_object_allocate_hold(OBJT_DEFAULT, length); |
| 785 | if (result == NULL) |
| 786 | panic("vm_object_shadow: no object for shadowing"); |
| 787 | |
| 788 | /* |
| 789 | * The new object shadows the source object. |
| 790 | * |
| 791 | * Try to optimize the result object's page color when shadowing |
| 792 | * in order to maintain page coloring consistency in the combined |
| 793 | * shadowed object. |
| 794 | * |
| 795 | * The source object is moved to ba, retaining its existing ref-count. |
| 796 | * No additional ref is needed. |
| 797 | * |
| 798 | * SHADOWING IS NOT APPLICABLE TO OBJT_VNODE OBJECTS |
| 799 | */ |
| 800 | vm_map_backing_detach(entry, &entry->ba); |
| 801 | *ba = entry->ba; /* previous ba */ |
| 802 | entry->ba.object = result; /* new ba (at head of entry) */ |
| 803 | entry->ba.backing_ba = ba; |
| 804 | entry->ba.backing_count = ba->backing_count + 1; |
| 805 | entry->ba.offset = 0; |
| 806 | |
| 807 | /* cpu localization twist */ |
| 808 | result->pg_color = vm_quickcolor(); |
| 809 | |
| 810 | vm_map_backing_attach(entry, &entry->ba); |
| 811 | vm_map_backing_attach(entry, ba); |
| 812 | |
| 813 | /* |
| 814 | * Adjust the return storage. Drop the ref on source before |
| 815 | * returning. |
| 816 | */ |
| 817 | vm_object_drop(result); |
| 818 | vm_object_drop(source); |
| 819 | done: |
| 820 | entry->eflags &= ~MAP_ENTRY_NEEDS_COPY; |
| 821 | } |
| 822 | |
| 823 | /* |
| 824 | * Allocate an object for a vm_map_entry. |
| 825 | * |
| 826 | * Object allocation for anonymous mappings is defered as long as possible. |
| 827 | * This function is called when we can defer no longer, generally when a map |
| 828 | * entry might be split or forked or takes a page fault. |
| 829 | * |
| 830 | * If the map segment is governed by a virtual page table then it is |
| 831 | * possible to address offsets beyond the mapped area. Just allocate |
| 832 | * a maximally sized object for this case. |
| 833 | * |
| 834 | * The vm_map must be exclusively locked. |
| 835 | * No other requirements. |
| 836 | */ |
| 837 | void |
| 838 | vm_map_entry_allocate_object(vm_map_entry_t entry) |
| 839 | { |
| 840 | vm_object_t obj; |
| 841 | |
| 842 | /* |
| 843 | * ba.offset is NOT cumulatively added in the backing_ba scan like |
| 844 | * it was in the old object chain, so we can assign whatever offset |
| 845 | * we like to the new object. |
| 846 | * |
| 847 | * For now assign a value of 0 to make debugging object sizes |
| 848 | * easier. |
| 849 | */ |
| 850 | entry->ba.offset = 0; |
| 851 | |
| 852 | obj = vm_object_allocate(OBJT_DEFAULT, |
| 853 | atop(entry->ba.end - entry->ba.start) + |
| 854 | entry->ba.offset); |
| 855 | entry->ba.object = obj; |
| 856 | vm_map_backing_attach(entry, &entry->ba); |
| 857 | } |
| 858 | |
| 859 | /* |
| 860 | * Set an initial negative count so the first attempt to reserve |
| 861 | * space preloads a bunch of vm_map_entry's for this cpu. Also |
| 862 | * pre-allocate 2 vm_map_entries which will be needed by zalloc() to |
| 863 | * map a new page for vm_map_entry structures. SMP systems are |
| 864 | * particularly sensitive. |
| 865 | * |
| 866 | * This routine is called in early boot so we cannot just call |
| 867 | * vm_map_entry_reserve(). |
| 868 | * |
| 869 | * Called from the low level boot code only (for each cpu) |
| 870 | * |
| 871 | * WARNING! Take care not to have too-big a static/BSS structure here |
| 872 | * as MAXCPU can be 256+, otherwise the loader's 64MB heap |
| 873 | * can get blown out by the kernel plus the initrd image. |
| 874 | */ |
| 875 | void |
| 876 | vm_map_entry_reserve_cpu_init(globaldata_t gd) |
| 877 | { |
| 878 | vm_map_entry_t entry; |
| 879 | int count; |
| 880 | int i; |
| 881 | |
| 882 | atomic_add_int(&gd->gd_vme_avail, -MAP_RESERVE_COUNT * 2); |
| 883 | if (gd->gd_cpuid == 0) { |
| 884 | entry = &cpu_map_entry_init_bsp[0]; |
| 885 | count = MAPENTRYBSP_CACHE; |
| 886 | } else { |
| 887 | entry = &cpu_map_entry_init_ap[gd->gd_cpuid][0]; |
| 888 | count = MAPENTRYAP_CACHE; |
| 889 | } |
| 890 | for (i = 0; i < count; ++i, ++entry) { |
| 891 | MAPENT_FREELIST(entry) = gd->gd_vme_base; |
| 892 | gd->gd_vme_base = entry; |
| 893 | } |
| 894 | } |
| 895 | |
| 896 | /* |
| 897 | * Reserves vm_map_entry structures so code later-on can manipulate |
| 898 | * map_entry structures within a locked map without blocking trying |
| 899 | * to allocate a new vm_map_entry. |
| 900 | * |
| 901 | * No requirements. |
| 902 | * |
| 903 | * WARNING! We must not decrement gd_vme_avail until after we have |
| 904 | * ensured that sufficient entries exist, otherwise we can |
| 905 | * get into an endless call recursion in the zalloc code |
| 906 | * itself. |
| 907 | */ |
| 908 | int |
| 909 | vm_map_entry_reserve(int count) |
| 910 | { |
| 911 | struct globaldata *gd = mycpu; |
| 912 | vm_map_entry_t entry; |
| 913 | |
| 914 | /* |
| 915 | * Make sure we have enough structures in gd_vme_base to handle |
| 916 | * the reservation request. |
| 917 | * |
| 918 | * Use a critical section to protect against VM faults. It might |
| 919 | * not be needed, but we have to be careful here. |
| 920 | */ |
| 921 | if (gd->gd_vme_avail < count) { |
| 922 | crit_enter(); |
| 923 | while (gd->gd_vme_avail < count) { |
| 924 | entry = zalloc(mapentzone); |
| 925 | MAPENT_FREELIST(entry) = gd->gd_vme_base; |
| 926 | gd->gd_vme_base = entry; |
| 927 | atomic_add_int(&gd->gd_vme_avail, 1); |
| 928 | } |
| 929 | crit_exit(); |
| 930 | } |
| 931 | atomic_add_int(&gd->gd_vme_avail, -count); |
| 932 | |
| 933 | return(count); |
| 934 | } |
| 935 | |
| 936 | /* |
| 937 | * Releases previously reserved vm_map_entry structures that were not |
| 938 | * used. If we have too much junk in our per-cpu cache clean some of |
| 939 | * it out. |
| 940 | * |
| 941 | * No requirements. |
| 942 | */ |
| 943 | void |
| 944 | vm_map_entry_release(int count) |
| 945 | { |
| 946 | struct globaldata *gd = mycpu; |
| 947 | vm_map_entry_t entry; |
| 948 | vm_map_entry_t efree; |
| 949 | |
| 950 | count = atomic_fetchadd_int(&gd->gd_vme_avail, count) + count; |
| 951 | if (gd->gd_vme_avail > MAP_RESERVE_SLOP) { |
| 952 | efree = NULL; |
| 953 | crit_enter(); |
| 954 | while (gd->gd_vme_avail > MAP_RESERVE_HYST) { |
| 955 | entry = gd->gd_vme_base; |
| 956 | KKASSERT(entry != NULL); |
| 957 | gd->gd_vme_base = MAPENT_FREELIST(entry); |
| 958 | atomic_add_int(&gd->gd_vme_avail, -1); |
| 959 | MAPENT_FREELIST(entry) = efree; |
| 960 | efree = entry; |
| 961 | } |
| 962 | crit_exit(); |
| 963 | while ((entry = efree) != NULL) { |
| 964 | efree = MAPENT_FREELIST(efree); |
| 965 | zfree(mapentzone, entry); |
| 966 | } |
| 967 | } |
| 968 | } |
| 969 | |
| 970 | /* |
| 971 | * Reserve map entry structures for use in kernel_map itself. These |
| 972 | * entries have *ALREADY* been reserved on a per-cpu basis when the map |
| 973 | * was inited. This function is used by zalloc() to avoid a recursion |
| 974 | * when zalloc() itself needs to allocate additional kernel memory. |
| 975 | * |
| 976 | * This function works like the normal reserve but does not load the |
| 977 | * vm_map_entry cache (because that would result in an infinite |
| 978 | * recursion). Note that gd_vme_avail may go negative. This is expected. |
| 979 | * |
| 980 | * Any caller of this function must be sure to renormalize after |
| 981 | * potentially eating entries to ensure that the reserve supply |
| 982 | * remains intact. |
| 983 | * |
| 984 | * No requirements. |
| 985 | */ |
| 986 | int |
| 987 | vm_map_entry_kreserve(int count) |
| 988 | { |
| 989 | struct globaldata *gd = mycpu; |
| 990 | |
| 991 | atomic_add_int(&gd->gd_vme_avail, -count); |
| 992 | KASSERT(gd->gd_vme_base != NULL, |
| 993 | ("no reserved entries left, gd_vme_avail = %d", |
| 994 | gd->gd_vme_avail)); |
| 995 | return(count); |
| 996 | } |
| 997 | |
| 998 | /* |
| 999 | * Release previously reserved map entries for kernel_map. We do not |
| 1000 | * attempt to clean up like the normal release function as this would |
| 1001 | * cause an unnecessary (but probably not fatal) deep procedure call. |
| 1002 | * |
| 1003 | * No requirements. |
| 1004 | */ |
| 1005 | void |
| 1006 | vm_map_entry_krelease(int count) |
| 1007 | { |
| 1008 | struct globaldata *gd = mycpu; |
| 1009 | |
| 1010 | atomic_add_int(&gd->gd_vme_avail, count); |
| 1011 | } |
| 1012 | |
| 1013 | /* |
| 1014 | * Allocates a VM map entry for insertion. No entry fields are filled in. |
| 1015 | * |
| 1016 | * The entries should have previously been reserved. The reservation count |
| 1017 | * is tracked in (*countp). |
| 1018 | * |
| 1019 | * No requirements. |
| 1020 | */ |
| 1021 | static vm_map_entry_t |
| 1022 | vm_map_entry_create(int *countp) |
| 1023 | { |
| 1024 | struct globaldata *gd = mycpu; |
| 1025 | vm_map_entry_t entry; |
| 1026 | |
| 1027 | KKASSERT(*countp > 0); |
| 1028 | --*countp; |
| 1029 | crit_enter(); |
| 1030 | entry = gd->gd_vme_base; |
| 1031 | KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp)); |
| 1032 | gd->gd_vme_base = MAPENT_FREELIST(entry); |
| 1033 | crit_exit(); |
| 1034 | |
| 1035 | return(entry); |
| 1036 | } |
| 1037 | |
| 1038 | /* |
| 1039 | * Attach and detach backing store elements |
| 1040 | */ |
| 1041 | static void |
| 1042 | vm_map_backing_attach(vm_map_entry_t entry, vm_map_backing_t ba) |
| 1043 | { |
| 1044 | vm_object_t obj; |
| 1045 | |
| 1046 | switch(entry->maptype) { |
| 1047 | case VM_MAPTYPE_NORMAL: |
| 1048 | obj = ba->object; |
| 1049 | lockmgr(&obj->backing_lk, LK_EXCLUSIVE); |
| 1050 | TAILQ_INSERT_TAIL(&obj->backing_list, ba, entry); |
| 1051 | lockmgr(&obj->backing_lk, LK_RELEASE); |
| 1052 | break; |
| 1053 | case VM_MAPTYPE_UKSMAP: |
| 1054 | ba->uksmap(ba, UKSMAPOP_ADD, entry->aux.dev, NULL); |
| 1055 | break; |
| 1056 | } |
| 1057 | } |
| 1058 | |
| 1059 | static void |
| 1060 | vm_map_backing_detach(vm_map_entry_t entry, vm_map_backing_t ba) |
| 1061 | { |
| 1062 | vm_object_t obj; |
| 1063 | |
| 1064 | switch(entry->maptype) { |
| 1065 | case VM_MAPTYPE_NORMAL: |
| 1066 | obj = ba->object; |
| 1067 | lockmgr(&obj->backing_lk, LK_EXCLUSIVE); |
| 1068 | TAILQ_REMOVE(&obj->backing_list, ba, entry); |
| 1069 | lockmgr(&obj->backing_lk, LK_RELEASE); |
| 1070 | break; |
| 1071 | case VM_MAPTYPE_UKSMAP: |
| 1072 | ba->uksmap(ba, UKSMAPOP_REM, entry->aux.dev, NULL); |
| 1073 | break; |
| 1074 | } |
| 1075 | } |
| 1076 | |
| 1077 | /* |
| 1078 | * Dispose of the dynamically allocated backing_ba chain associated |
| 1079 | * with a vm_map_entry. |
| 1080 | * |
| 1081 | * We decrement the (possibly shared) element and kfree() on the |
| 1082 | * 1->0 transition. We only iterate to the next backing_ba when |
| 1083 | * the previous one went through a 1->0 transition. |
| 1084 | * |
| 1085 | * These can only be normal vm_object based backings. |
| 1086 | */ |
| 1087 | static void |
| 1088 | vm_map_entry_dispose_ba(vm_map_entry_t entry, vm_map_backing_t ba) |
| 1089 | { |
| 1090 | vm_map_backing_t next; |
| 1091 | |
| 1092 | while (ba) { |
| 1093 | if (ba->map_object) { |
| 1094 | vm_map_backing_detach(entry, ba); |
| 1095 | vm_object_deallocate(ba->object); |
| 1096 | } |
| 1097 | next = ba->backing_ba; |
| 1098 | kfree(ba, M_MAP_BACKING); |
| 1099 | ba = next; |
| 1100 | } |
| 1101 | } |
| 1102 | |
| 1103 | /* |
| 1104 | * Dispose of a vm_map_entry that is no longer being referenced. |
| 1105 | * |
| 1106 | * No requirements. |
| 1107 | */ |
| 1108 | static void |
| 1109 | vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp) |
| 1110 | { |
| 1111 | struct globaldata *gd = mycpu; |
| 1112 | |
| 1113 | /* |
| 1114 | * Dispose of the base object and the backing link. |
| 1115 | */ |
| 1116 | switch(entry->maptype) { |
| 1117 | case VM_MAPTYPE_NORMAL: |
| 1118 | if (entry->ba.map_object) { |
| 1119 | vm_map_backing_detach(entry, &entry->ba); |
| 1120 | vm_object_deallocate(entry->ba.object); |
| 1121 | } |
| 1122 | break; |
| 1123 | case VM_MAPTYPE_SUBMAP: |
| 1124 | break; |
| 1125 | case VM_MAPTYPE_UKSMAP: |
| 1126 | vm_map_backing_detach(entry, &entry->ba); |
| 1127 | break; |
| 1128 | default: |
| 1129 | break; |
| 1130 | } |
| 1131 | vm_map_entry_dispose_ba(entry, entry->ba.backing_ba); |
| 1132 | |
| 1133 | /* |
| 1134 | * Cleanup for safety. |
| 1135 | */ |
| 1136 | entry->ba.backing_ba = NULL; |
| 1137 | entry->ba.object = NULL; |
| 1138 | entry->ba.offset = 0; |
| 1139 | |
| 1140 | ++*countp; |
| 1141 | crit_enter(); |
| 1142 | MAPENT_FREELIST(entry) = gd->gd_vme_base; |
| 1143 | gd->gd_vme_base = entry; |
| 1144 | crit_exit(); |
| 1145 | } |
| 1146 | |
| 1147 | |
| 1148 | /* |
| 1149 | * Insert/remove entries from maps. |
| 1150 | * |
| 1151 | * The related map must be exclusively locked. |
| 1152 | * The caller must hold map->token |
| 1153 | * No other requirements. |
| 1154 | */ |
| 1155 | static __inline void |
| 1156 | vm_map_entry_link(vm_map_t map, vm_map_entry_t entry) |
| 1157 | { |
| 1158 | ASSERT_VM_MAP_LOCKED(map); |
| 1159 | |
| 1160 | map->nentries++; |
| 1161 | if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry)) |
| 1162 | panic("vm_map_entry_link: dup addr map %p ent %p", map, entry); |
| 1163 | } |
| 1164 | |
| 1165 | static __inline void |
| 1166 | vm_map_entry_unlink(vm_map_t map, |
| 1167 | vm_map_entry_t entry) |
| 1168 | { |
| 1169 | ASSERT_VM_MAP_LOCKED(map); |
| 1170 | |
| 1171 | if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { |
| 1172 | panic("vm_map_entry_unlink: attempt to mess with " |
| 1173 | "locked entry! %p", entry); |
| 1174 | } |
| 1175 | vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry); |
| 1176 | map->nentries--; |
| 1177 | } |
| 1178 | |
| 1179 | /* |
| 1180 | * Finds the map entry containing (or immediately preceding) the specified |
| 1181 | * address in the given map. The entry is returned in (*entry). |
| 1182 | * |
| 1183 | * The boolean result indicates whether the address is actually contained |
| 1184 | * in the map. |
| 1185 | * |
| 1186 | * The related map must be locked. |
| 1187 | * No other requirements. |
| 1188 | */ |
| 1189 | boolean_t |
| 1190 | vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry) |
| 1191 | { |
| 1192 | vm_map_entry_t tmp; |
| 1193 | vm_map_entry_t last; |
| 1194 | |
| 1195 | ASSERT_VM_MAP_LOCKED(map); |
| 1196 | |
| 1197 | /* |
| 1198 | * Locate the record from the top of the tree. 'last' tracks the |
| 1199 | * closest prior record and is returned if no match is found, which |
| 1200 | * in binary tree terms means tracking the most recent right-branch |
| 1201 | * taken. If there is no prior record, *entry is set to NULL. |
| 1202 | */ |
| 1203 | last = NULL; |
| 1204 | tmp = RB_ROOT(&map->rb_root); |
| 1205 | |
| 1206 | while (tmp) { |
| 1207 | if (address >= tmp->ba.start) { |
| 1208 | if (address < tmp->ba.end) { |
| 1209 | *entry = tmp; |
| 1210 | return(TRUE); |
| 1211 | } |
| 1212 | last = tmp; |
| 1213 | tmp = RB_RIGHT(tmp, rb_entry); |
| 1214 | } else { |
| 1215 | tmp = RB_LEFT(tmp, rb_entry); |
| 1216 | } |
| 1217 | } |
| 1218 | *entry = last; |
| 1219 | return (FALSE); |
| 1220 | } |
| 1221 | |
| 1222 | /* |
| 1223 | * Inserts the given whole VM object into the target map at the specified |
| 1224 | * address range. The object's size should match that of the address range. |
| 1225 | * |
| 1226 | * The map must be exclusively locked. |
| 1227 | * The object must be held. |
| 1228 | * The caller must have reserved sufficient vm_map_entry structures. |
| 1229 | * |
| 1230 | * If object is non-NULL, ref count must be bumped by caller prior to |
| 1231 | * making call to account for the new entry. XXX API is a bit messy. |
| 1232 | */ |
| 1233 | int |
| 1234 | vm_map_insert(vm_map_t map, int *countp, |
| 1235 | void *map_object, void *map_aux, |
| 1236 | vm_ooffset_t offset, void *aux_info, |
| 1237 | vm_offset_t start, vm_offset_t end, |
| 1238 | vm_maptype_t maptype, vm_subsys_t id, |
| 1239 | vm_prot_t prot, vm_prot_t max, int cow) |
| 1240 | { |
| 1241 | vm_map_entry_t new_entry; |
| 1242 | vm_map_entry_t prev_entry; |
| 1243 | vm_map_entry_t next; |
| 1244 | vm_map_entry_t temp_entry; |
| 1245 | vm_eflags_t protoeflags; |
| 1246 | vm_object_t object; |
| 1247 | int must_drop = 0; |
| 1248 | |
| 1249 | if (maptype == VM_MAPTYPE_UKSMAP) |
| 1250 | object = NULL; |
| 1251 | else |
| 1252 | object = map_object; |
| 1253 | |
| 1254 | ASSERT_VM_MAP_LOCKED(map); |
| 1255 | if (object) |
| 1256 | ASSERT_LWKT_TOKEN_HELD(vm_object_token(object)); |
| 1257 | |
| 1258 | /* |
| 1259 | * Check that the start and end points are not bogus. |
| 1260 | */ |
| 1261 | if ((start < vm_map_min(map)) || (end > vm_map_max(map)) || |
| 1262 | (start >= end)) { |
| 1263 | return (KERN_INVALID_ADDRESS); |
| 1264 | } |
| 1265 | |
| 1266 | /* |
| 1267 | * Find the entry prior to the proposed starting address; if it's part |
| 1268 | * of an existing entry, this range is bogus. |
| 1269 | */ |
| 1270 | if (vm_map_lookup_entry(map, start, &temp_entry)) |
| 1271 | return (KERN_NO_SPACE); |
| 1272 | prev_entry = temp_entry; |
| 1273 | |
| 1274 | /* |
| 1275 | * Assert that the next entry doesn't overlap the end point. |
| 1276 | */ |
| 1277 | if (prev_entry) |
| 1278 | next = vm_map_rb_tree_RB_NEXT(prev_entry); |
| 1279 | else |
| 1280 | next = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 1281 | if (next && next->ba.start < end) |
| 1282 | return (KERN_NO_SPACE); |
| 1283 | |
| 1284 | protoeflags = 0; |
| 1285 | |
| 1286 | if (cow & MAP_COPY_ON_WRITE) |
| 1287 | protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY; |
| 1288 | |
| 1289 | if (cow & MAP_NOFAULT) { |
| 1290 | protoeflags |= MAP_ENTRY_NOFAULT; |
| 1291 | |
| 1292 | KASSERT(object == NULL, |
| 1293 | ("vm_map_insert: paradoxical MAP_NOFAULT request")); |
| 1294 | } |
| 1295 | if (cow & MAP_DISABLE_SYNCER) |
| 1296 | protoeflags |= MAP_ENTRY_NOSYNC; |
| 1297 | if (cow & MAP_DISABLE_COREDUMP) |
| 1298 | protoeflags |= MAP_ENTRY_NOCOREDUMP; |
| 1299 | if (cow & MAP_IS_STACK) |
| 1300 | protoeflags |= MAP_ENTRY_STACK; |
| 1301 | if (cow & MAP_IS_KSTACK) |
| 1302 | protoeflags |= MAP_ENTRY_KSTACK; |
| 1303 | |
| 1304 | lwkt_gettoken(&map->token); |
| 1305 | |
| 1306 | if (object) { |
| 1307 | ; |
| 1308 | } else if (prev_entry && |
| 1309 | (prev_entry->eflags == protoeflags) && |
| 1310 | (prev_entry->ba.end == start) && |
| 1311 | (prev_entry->wired_count == 0) && |
| 1312 | (prev_entry->id == id) && |
| 1313 | prev_entry->maptype == maptype && |
| 1314 | maptype == VM_MAPTYPE_NORMAL && |
| 1315 | prev_entry->ba.backing_ba == NULL && /* not backed */ |
| 1316 | ((prev_entry->ba.object == NULL) || |
| 1317 | vm_object_coalesce(prev_entry->ba.object, |
| 1318 | OFF_TO_IDX(prev_entry->ba.offset), |
| 1319 | (vm_size_t)(prev_entry->ba.end - prev_entry->ba.start), |
| 1320 | (vm_size_t)(end - prev_entry->ba.end)))) { |
| 1321 | /* |
| 1322 | * We were able to extend the object. Determine if we |
| 1323 | * can extend the previous map entry to include the |
| 1324 | * new range as well. |
| 1325 | */ |
| 1326 | if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) && |
| 1327 | (prev_entry->protection == prot) && |
| 1328 | (prev_entry->max_protection == max)) { |
| 1329 | map->size += (end - prev_entry->ba.end); |
| 1330 | vm_map_backing_adjust_end(prev_entry, end); |
| 1331 | vm_map_simplify_entry(map, prev_entry, countp); |
| 1332 | lwkt_reltoken(&map->token); |
| 1333 | return (KERN_SUCCESS); |
| 1334 | } |
| 1335 | |
| 1336 | /* |
| 1337 | * If we can extend the object but cannot extend the |
| 1338 | * map entry, we have to create a new map entry. We |
| 1339 | * must bump the ref count on the extended object to |
| 1340 | * account for it. object may be NULL. |
| 1341 | */ |
| 1342 | object = prev_entry->ba.object; |
| 1343 | offset = prev_entry->ba.offset + |
| 1344 | (prev_entry->ba.end - prev_entry->ba.start); |
| 1345 | if (object) { |
| 1346 | vm_object_hold(object); |
| 1347 | vm_object_lock_swap(); /* map->token order */ |
| 1348 | vm_object_reference_locked(object); |
| 1349 | map_object = object; |
| 1350 | must_drop = 1; |
| 1351 | } |
| 1352 | } |
| 1353 | |
| 1354 | /* |
| 1355 | * NOTE: if conditionals fail, object can be NULL here. This occurs |
| 1356 | * in things like the buffer map where we manage kva but do not manage |
| 1357 | * backing objects. |
| 1358 | */ |
| 1359 | |
| 1360 | /* |
| 1361 | * Create a new entry |
| 1362 | */ |
| 1363 | new_entry = vm_map_entry_create(countp); |
| 1364 | new_entry->ba.pmap = map->pmap; |
| 1365 | new_entry->ba.start = start; |
| 1366 | new_entry->ba.end = end; |
| 1367 | new_entry->id = id; |
| 1368 | |
| 1369 | new_entry->maptype = maptype; |
| 1370 | new_entry->eflags = protoeflags; |
| 1371 | new_entry->aux.master_pde = 0; /* in case size is different */ |
| 1372 | new_entry->aux.map_aux = map_aux; |
| 1373 | new_entry->ba.map_object = map_object; |
| 1374 | new_entry->ba.backing_ba = NULL; |
| 1375 | new_entry->ba.backing_count = 0; |
| 1376 | new_entry->ba.offset = offset; |
| 1377 | new_entry->ba.aux_info = aux_info; |
| 1378 | new_entry->ba.flags = 0; |
| 1379 | new_entry->ba.pmap = map->pmap; |
| 1380 | |
| 1381 | new_entry->inheritance = VM_INHERIT_DEFAULT; |
| 1382 | new_entry->protection = prot; |
| 1383 | new_entry->max_protection = max; |
| 1384 | new_entry->wired_count = 0; |
| 1385 | |
| 1386 | /* |
| 1387 | * Insert the new entry into the list |
| 1388 | */ |
| 1389 | vm_map_backing_replicated(map, new_entry, MAP_BACK_BASEOBJREFD); |
| 1390 | vm_map_entry_link(map, new_entry); |
| 1391 | map->size += new_entry->ba.end - new_entry->ba.start; |
| 1392 | |
| 1393 | /* |
| 1394 | * Don't worry about updating freehint[] when inserting, allow |
| 1395 | * addresses to be lower than the actual first free spot. |
| 1396 | */ |
| 1397 | #if 0 |
| 1398 | /* |
| 1399 | * Temporarily removed to avoid MAP_STACK panic, due to |
| 1400 | * MAP_STACK being a huge hack. Will be added back in |
| 1401 | * when MAP_STACK (and the user stack mapping) is fixed. |
| 1402 | */ |
| 1403 | /* |
| 1404 | * It may be possible to simplify the entry |
| 1405 | */ |
| 1406 | vm_map_simplify_entry(map, new_entry, countp); |
| 1407 | #endif |
| 1408 | |
| 1409 | /* |
| 1410 | * Try to pre-populate the page table. Mappings governed by virtual |
| 1411 | * page tables cannot be prepopulated without a lot of work, so |
| 1412 | * don't try. |
| 1413 | */ |
| 1414 | if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) && |
| 1415 | maptype != VM_MAPTYPE_UKSMAP) { |
| 1416 | int dorelock = 0; |
| 1417 | if (vm_map_relock_enable && (cow & MAP_PREFAULT_RELOCK)) { |
| 1418 | dorelock = 1; |
| 1419 | vm_object_lock_swap(); |
| 1420 | vm_object_drop(object); |
| 1421 | } |
| 1422 | pmap_object_init_pt(map->pmap, new_entry, |
| 1423 | new_entry->ba.start, |
| 1424 | new_entry->ba.end - new_entry->ba.start, |
| 1425 | cow & MAP_PREFAULT_PARTIAL); |
| 1426 | if (dorelock) { |
| 1427 | vm_object_hold(object); |
| 1428 | vm_object_lock_swap(); |
| 1429 | } |
| 1430 | } |
| 1431 | lwkt_reltoken(&map->token); |
| 1432 | if (must_drop) |
| 1433 | vm_object_drop(object); |
| 1434 | |
| 1435 | return (KERN_SUCCESS); |
| 1436 | } |
| 1437 | |
| 1438 | /* |
| 1439 | * Find sufficient space for `length' bytes in the given map, starting at |
| 1440 | * `start'. Returns 0 on success, 1 on no space. |
| 1441 | * |
| 1442 | * This function will returned an arbitrarily aligned pointer. If no |
| 1443 | * particular alignment is required you should pass align as 1. Note that |
| 1444 | * the map may return PAGE_SIZE aligned pointers if all the lengths used in |
| 1445 | * the map are a multiple of PAGE_SIZE, even if you pass a smaller align |
| 1446 | * argument. |
| 1447 | * |
| 1448 | * 'align' should be a power of 2 but is not required to be. |
| 1449 | * |
| 1450 | * The map must be exclusively locked. |
| 1451 | * No other requirements. |
| 1452 | */ |
| 1453 | int |
| 1454 | vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length, |
| 1455 | vm_size_t align, int flags, vm_offset_t *addr) |
| 1456 | { |
| 1457 | vm_map_entry_t entry; |
| 1458 | vm_map_entry_t tmp; |
| 1459 | vm_offset_t hole_start; |
| 1460 | vm_offset_t end; |
| 1461 | vm_offset_t align_mask; |
| 1462 | |
| 1463 | if (start < vm_map_min(map)) |
| 1464 | start = vm_map_min(map); |
| 1465 | if (start > vm_map_max(map)) |
| 1466 | return (1); |
| 1467 | |
| 1468 | /* |
| 1469 | * If the alignment is not a power of 2 we will have to use |
| 1470 | * a mod/division, set align_mask to a special value. |
| 1471 | */ |
| 1472 | if ((align | (align - 1)) + 1 != (align << 1)) |
| 1473 | align_mask = (vm_offset_t)-1; |
| 1474 | else |
| 1475 | align_mask = align - 1; |
| 1476 | |
| 1477 | /* |
| 1478 | * Use freehint to adjust the start point, hopefully reducing |
| 1479 | * the iteration to O(1). |
| 1480 | */ |
| 1481 | hole_start = vm_map_freehint_find(map, length, align); |
| 1482 | if (start < hole_start) |
| 1483 | start = hole_start; |
| 1484 | if (vm_map_lookup_entry(map, start, &tmp)) |
| 1485 | start = tmp->ba.end; |
| 1486 | entry = tmp; /* may be NULL */ |
| 1487 | |
| 1488 | /* |
| 1489 | * Look through the rest of the map, trying to fit a new region in the |
| 1490 | * gap between existing regions, or after the very last region. |
| 1491 | */ |
| 1492 | for (;;) { |
| 1493 | /* |
| 1494 | * Adjust the proposed start by the requested alignment, |
| 1495 | * be sure that we didn't wrap the address. |
| 1496 | */ |
| 1497 | if (align_mask == (vm_offset_t)-1) |
| 1498 | end = roundup(start, align); |
| 1499 | else |
| 1500 | end = (start + align_mask) & ~align_mask; |
| 1501 | if (end < start) |
| 1502 | return (1); |
| 1503 | start = end; |
| 1504 | |
| 1505 | /* |
| 1506 | * Find the end of the proposed new region. Be sure we didn't |
| 1507 | * go beyond the end of the map, or wrap around the address. |
| 1508 | * Then check to see if this is the last entry or if the |
| 1509 | * proposed end fits in the gap between this and the next |
| 1510 | * entry. |
| 1511 | */ |
| 1512 | end = start + length; |
| 1513 | if (end > vm_map_max(map) || end < start) |
| 1514 | return (1); |
| 1515 | |
| 1516 | /* |
| 1517 | * Locate the next entry, we can stop if this is the |
| 1518 | * last entry (we know we are in-bounds so that would |
| 1519 | * be a sucess). |
| 1520 | */ |
| 1521 | if (entry) |
| 1522 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 1523 | else |
| 1524 | entry = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 1525 | if (entry == NULL) |
| 1526 | break; |
| 1527 | |
| 1528 | /* |
| 1529 | * Determine if the proposed area would overlap the |
| 1530 | * next entry. |
| 1531 | * |
| 1532 | * When matching against a STACK entry, only allow the |
| 1533 | * memory map to intrude on the ungrown portion of the |
| 1534 | * STACK entry when MAP_TRYFIXED is set. |
| 1535 | */ |
| 1536 | if (entry->ba.start >= end) { |
| 1537 | if ((entry->eflags & MAP_ENTRY_STACK) == 0) |
| 1538 | break; |
| 1539 | if (flags & MAP_TRYFIXED) |
| 1540 | break; |
| 1541 | if (entry->ba.start - entry->aux.avail_ssize >= end) |
| 1542 | break; |
| 1543 | } |
| 1544 | start = entry->ba.end; |
| 1545 | } |
| 1546 | |
| 1547 | /* |
| 1548 | * Update the freehint |
| 1549 | */ |
| 1550 | vm_map_freehint_update(map, start, length, align); |
| 1551 | |
| 1552 | /* |
| 1553 | * Grow the kernel_map if necessary. pmap_growkernel() will panic |
| 1554 | * if it fails. The kernel_map is locked and nothing can steal |
| 1555 | * our address space if pmap_growkernel() blocks. |
| 1556 | * |
| 1557 | * NOTE: This may be unconditionally called for kldload areas on |
| 1558 | * x86_64 because these do not bump kernel_vm_end (which would |
| 1559 | * fill 128G worth of page tables!). Therefore we must not |
| 1560 | * retry. |
| 1561 | */ |
| 1562 | if (map == kernel_map) { |
| 1563 | vm_offset_t kstop; |
| 1564 | |
| 1565 | kstop = round_page(start + length); |
| 1566 | if (kstop > kernel_vm_end) |
| 1567 | pmap_growkernel(start, kstop); |
| 1568 | } |
| 1569 | *addr = start; |
| 1570 | return (0); |
| 1571 | } |
| 1572 | |
| 1573 | /* |
| 1574 | * vm_map_find finds an unallocated region in the target address map with |
| 1575 | * the given length and allocates it. The search is defined to be first-fit |
| 1576 | * from the specified address; the region found is returned in the same |
| 1577 | * parameter. |
| 1578 | * |
| 1579 | * If object is non-NULL, ref count must be bumped by caller |
| 1580 | * prior to making call to account for the new entry. |
| 1581 | * |
| 1582 | * No requirements. This function will lock the map temporarily. |
| 1583 | */ |
| 1584 | int |
| 1585 | vm_map_find(vm_map_t map, void *map_object, void *map_aux, |
| 1586 | vm_ooffset_t offset, vm_offset_t *addr, |
| 1587 | vm_size_t length, vm_size_t align, boolean_t fitit, |
| 1588 | vm_maptype_t maptype, vm_subsys_t id, |
| 1589 | vm_prot_t prot, vm_prot_t max, int cow) |
| 1590 | { |
| 1591 | vm_offset_t start; |
| 1592 | vm_object_t object; |
| 1593 | void *aux_info; |
| 1594 | int result; |
| 1595 | int count; |
| 1596 | |
| 1597 | /* |
| 1598 | * Certain UKSMAPs may need aux_info. |
| 1599 | * |
| 1600 | * (map_object is the callback function, aux_info is the process |
| 1601 | * or thread, if necessary). |
| 1602 | */ |
| 1603 | aux_info = NULL; |
| 1604 | if (maptype == VM_MAPTYPE_UKSMAP) { |
| 1605 | KKASSERT(map_aux != NULL && map_object != NULL); |
| 1606 | |
| 1607 | switch(minor(((struct cdev *)map_aux))) { |
| 1608 | case 5: |
| 1609 | /* |
| 1610 | * /dev/upmap |
| 1611 | */ |
| 1612 | aux_info = curproc; |
| 1613 | break; |
| 1614 | case 6: |
| 1615 | /* |
| 1616 | * /dev/kpmap |
| 1617 | */ |
| 1618 | break; |
| 1619 | case 7: |
| 1620 | /* |
| 1621 | * /dev/lpmap |
| 1622 | */ |
| 1623 | aux_info = curthread->td_lwp; |
| 1624 | break; |
| 1625 | } |
| 1626 | object = NULL; |
| 1627 | } else { |
| 1628 | object = map_object; |
| 1629 | } |
| 1630 | |
| 1631 | start = *addr; |
| 1632 | |
| 1633 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 1634 | vm_map_lock(map); |
| 1635 | if (object) |
| 1636 | vm_object_hold_shared(object); |
| 1637 | if (fitit) { |
| 1638 | if (vm_map_findspace(map, start, length, align, 0, addr)) { |
| 1639 | if (object) |
| 1640 | vm_object_drop(object); |
| 1641 | vm_map_unlock(map); |
| 1642 | vm_map_entry_release(count); |
| 1643 | return (KERN_NO_SPACE); |
| 1644 | } |
| 1645 | start = *addr; |
| 1646 | } |
| 1647 | result = vm_map_insert(map, &count, |
| 1648 | map_object, map_aux, |
| 1649 | offset, aux_info, |
| 1650 | start, start + length, |
| 1651 | maptype, id, prot, max, cow); |
| 1652 | if (object) |
| 1653 | vm_object_drop(object); |
| 1654 | vm_map_unlock(map); |
| 1655 | vm_map_entry_release(count); |
| 1656 | |
| 1657 | return (result); |
| 1658 | } |
| 1659 | |
| 1660 | /* |
| 1661 | * Simplify the given map entry by merging with either neighbor. This |
| 1662 | * routine also has the ability to merge with both neighbors. |
| 1663 | * |
| 1664 | * This routine guarentees that the passed entry remains valid (though |
| 1665 | * possibly extended). When merging, this routine may delete one or |
| 1666 | * both neighbors. No action is taken on entries which have their |
| 1667 | * in-transition flag set. |
| 1668 | * |
| 1669 | * The map must be exclusively locked. |
| 1670 | */ |
| 1671 | void |
| 1672 | vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp) |
| 1673 | { |
| 1674 | vm_map_entry_t next, prev; |
| 1675 | vm_size_t prevsize, esize; |
| 1676 | |
| 1677 | if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { |
| 1678 | ++mycpu->gd_cnt.v_intrans_coll; |
| 1679 | return; |
| 1680 | } |
| 1681 | |
| 1682 | if (entry->maptype == VM_MAPTYPE_SUBMAP) |
| 1683 | return; |
| 1684 | if (entry->maptype == VM_MAPTYPE_UKSMAP) |
| 1685 | return; |
| 1686 | |
| 1687 | prev = vm_map_rb_tree_RB_PREV(entry); |
| 1688 | if (prev) { |
| 1689 | prevsize = prev->ba.end - prev->ba.start; |
| 1690 | if ( (prev->ba.end == entry->ba.start) && |
| 1691 | (prev->maptype == entry->maptype) && |
| 1692 | (prev->ba.object == entry->ba.object) && |
| 1693 | (prev->ba.backing_ba == entry->ba.backing_ba) && |
| 1694 | (!prev->ba.object || |
| 1695 | (prev->ba.offset + prevsize == entry->ba.offset)) && |
| 1696 | (prev->eflags == entry->eflags) && |
| 1697 | (prev->protection == entry->protection) && |
| 1698 | (prev->max_protection == entry->max_protection) && |
| 1699 | (prev->inheritance == entry->inheritance) && |
| 1700 | (prev->id == entry->id) && |
| 1701 | (prev->wired_count == entry->wired_count)) { |
| 1702 | /* |
| 1703 | * NOTE: order important. Unlink before gumming up |
| 1704 | * the RBTREE w/adjust, adjust before disposal |
| 1705 | * of prior entry, to avoid pmap snafus. |
| 1706 | */ |
| 1707 | vm_map_entry_unlink(map, prev); |
| 1708 | vm_map_backing_adjust_start(entry, prev->ba.start); |
| 1709 | if (entry->ba.object == NULL) |
| 1710 | entry->ba.offset = 0; |
| 1711 | vm_map_entry_dispose(map, prev, countp); |
| 1712 | } |
| 1713 | } |
| 1714 | |
| 1715 | next = vm_map_rb_tree_RB_NEXT(entry); |
| 1716 | if (next) { |
| 1717 | esize = entry->ba.end - entry->ba.start; |
| 1718 | if ((entry->ba.end == next->ba.start) && |
| 1719 | (next->maptype == entry->maptype) && |
| 1720 | (next->ba.object == entry->ba.object) && |
| 1721 | (prev->ba.backing_ba == entry->ba.backing_ba) && |
| 1722 | (!entry->ba.object || |
| 1723 | (entry->ba.offset + esize == next->ba.offset)) && |
| 1724 | (next->eflags == entry->eflags) && |
| 1725 | (next->protection == entry->protection) && |
| 1726 | (next->max_protection == entry->max_protection) && |
| 1727 | (next->inheritance == entry->inheritance) && |
| 1728 | (next->id == entry->id) && |
| 1729 | (next->wired_count == entry->wired_count)) { |
| 1730 | /* |
| 1731 | * NOTE: order important. Unlink before gumming up |
| 1732 | * the RBTREE w/adjust, adjust before disposal |
| 1733 | * of prior entry, to avoid pmap snafus. |
| 1734 | */ |
| 1735 | vm_map_entry_unlink(map, next); |
| 1736 | vm_map_backing_adjust_end(entry, next->ba.end); |
| 1737 | vm_map_entry_dispose(map, next, countp); |
| 1738 | } |
| 1739 | } |
| 1740 | } |
| 1741 | |
| 1742 | /* |
| 1743 | * Asserts that the given entry begins at or after the specified address. |
| 1744 | * If necessary, it splits the entry into two. |
| 1745 | */ |
| 1746 | #define vm_map_clip_start(map, entry, startaddr, countp) \ |
| 1747 | { \ |
| 1748 | if (startaddr > entry->ba.start) \ |
| 1749 | _vm_map_clip_start(map, entry, startaddr, countp); \ |
| 1750 | } |
| 1751 | |
| 1752 | /* |
| 1753 | * This routine is called only when it is known that the entry must be split. |
| 1754 | * |
| 1755 | * The map must be exclusively locked. |
| 1756 | */ |
| 1757 | static void |
| 1758 | _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start, |
| 1759 | int *countp) |
| 1760 | { |
| 1761 | vm_map_entry_t new_entry; |
| 1762 | |
| 1763 | /* |
| 1764 | * Split off the front portion -- note that we must insert the new |
| 1765 | * entry BEFORE this one, so that this entry has the specified |
| 1766 | * starting address. |
| 1767 | */ |
| 1768 | |
| 1769 | vm_map_simplify_entry(map, entry, countp); |
| 1770 | |
| 1771 | /* |
| 1772 | * If there is no object backing this entry, we might as well create |
| 1773 | * one now. If we defer it, an object can get created after the map |
| 1774 | * is clipped, and individual objects will be created for the split-up |
| 1775 | * map. This is a bit of a hack, but is also about the best place to |
| 1776 | * put this improvement. |
| 1777 | */ |
| 1778 | if (entry->ba.object == NULL && !map->system_map && |
| 1779 | VM_MAP_ENTRY_WITHIN_PARTITION(entry)) { |
| 1780 | vm_map_entry_allocate_object(entry); |
| 1781 | } |
| 1782 | |
| 1783 | /* |
| 1784 | * NOTE: The replicated function will adjust start, end, and offset |
| 1785 | * for the remainder of the backing_ba linkages. We must fixup |
| 1786 | * the embedded ba. |
| 1787 | */ |
| 1788 | new_entry = vm_map_entry_create(countp); |
| 1789 | *new_entry = *entry; |
| 1790 | new_entry->ba.end = start; |
| 1791 | |
| 1792 | /* |
| 1793 | * Ordering is important, make sure the new entry is replicated |
| 1794 | * before we cut the exiting entry. |
| 1795 | */ |
| 1796 | vm_map_backing_replicated(map, new_entry, MAP_BACK_CLIPPED); |
| 1797 | vm_map_backing_adjust_start(entry, start); |
| 1798 | vm_map_entry_link(map, new_entry); |
| 1799 | } |
| 1800 | |
| 1801 | /* |
| 1802 | * Asserts that the given entry ends at or before the specified address. |
| 1803 | * If necessary, it splits the entry into two. |
| 1804 | * |
| 1805 | * The map must be exclusively locked. |
| 1806 | */ |
| 1807 | #define vm_map_clip_end(map, entry, endaddr, countp) \ |
| 1808 | { \ |
| 1809 | if (endaddr < entry->ba.end) \ |
| 1810 | _vm_map_clip_end(map, entry, endaddr, countp); \ |
| 1811 | } |
| 1812 | |
| 1813 | /* |
| 1814 | * This routine is called only when it is known that the entry must be split. |
| 1815 | * |
| 1816 | * The map must be exclusively locked. |
| 1817 | */ |
| 1818 | static void |
| 1819 | _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end, |
| 1820 | int *countp) |
| 1821 | { |
| 1822 | vm_map_entry_t new_entry; |
| 1823 | |
| 1824 | /* |
| 1825 | * If there is no object backing this entry, we might as well create |
| 1826 | * one now. If we defer it, an object can get created after the map |
| 1827 | * is clipped, and individual objects will be created for the split-up |
| 1828 | * map. This is a bit of a hack, but is also about the best place to |
| 1829 | * put this improvement. |
| 1830 | */ |
| 1831 | |
| 1832 | if (entry->ba.object == NULL && !map->system_map && |
| 1833 | VM_MAP_ENTRY_WITHIN_PARTITION(entry)) { |
| 1834 | vm_map_entry_allocate_object(entry); |
| 1835 | } |
| 1836 | |
| 1837 | /* |
| 1838 | * Create a new entry and insert it AFTER the specified entry |
| 1839 | * |
| 1840 | * NOTE: The replicated function will adjust start, end, and offset |
| 1841 | * for the remainder of the backing_ba linkages. We must fixup |
| 1842 | * the embedded ba. |
| 1843 | */ |
| 1844 | new_entry = vm_map_entry_create(countp); |
| 1845 | *new_entry = *entry; |
| 1846 | new_entry->ba.start = end; |
| 1847 | new_entry->ba.offset += (new_entry->ba.start - entry->ba.start); |
| 1848 | |
| 1849 | /* |
| 1850 | * Ordering is important, make sure the new entry is replicated |
| 1851 | * before we cut the exiting entry. |
| 1852 | */ |
| 1853 | vm_map_backing_replicated(map, new_entry, MAP_BACK_CLIPPED); |
| 1854 | vm_map_backing_adjust_end(entry, end); |
| 1855 | vm_map_entry_link(map, new_entry); |
| 1856 | } |
| 1857 | |
| 1858 | /* |
| 1859 | * Asserts that the starting and ending region addresses fall within the |
| 1860 | * valid range for the map. |
| 1861 | */ |
| 1862 | #define VM_MAP_RANGE_CHECK(map, start, end) \ |
| 1863 | { \ |
| 1864 | if (start < vm_map_min(map)) \ |
| 1865 | start = vm_map_min(map); \ |
| 1866 | if (end > vm_map_max(map)) \ |
| 1867 | end = vm_map_max(map); \ |
| 1868 | if (start > end) \ |
| 1869 | start = end; \ |
| 1870 | } |
| 1871 | |
| 1872 | /* |
| 1873 | * Used to block when an in-transition collison occurs. The map |
| 1874 | * is unlocked for the sleep and relocked before the return. |
| 1875 | */ |
| 1876 | void |
| 1877 | vm_map_transition_wait(vm_map_t map, int relock) |
| 1878 | { |
| 1879 | tsleep_interlock(map, 0); |
| 1880 | vm_map_unlock(map); |
| 1881 | tsleep(map, PINTERLOCKED, "vment", 0); |
| 1882 | if (relock) |
| 1883 | vm_map_lock(map); |
| 1884 | } |
| 1885 | |
| 1886 | /* |
| 1887 | * When we do blocking operations with the map lock held it is |
| 1888 | * possible that a clip might have occured on our in-transit entry, |
| 1889 | * requiring an adjustment to the entry in our loop. These macros |
| 1890 | * help the pageable and clip_range code deal with the case. The |
| 1891 | * conditional costs virtually nothing if no clipping has occured. |
| 1892 | */ |
| 1893 | |
| 1894 | #define CLIP_CHECK_BACK(entry, save_start) \ |
| 1895 | do { \ |
| 1896 | while (entry->ba.start != save_start) { \ |
| 1897 | entry = vm_map_rb_tree_RB_PREV(entry); \ |
| 1898 | KASSERT(entry, ("bad entry clip")); \ |
| 1899 | } \ |
| 1900 | } while(0) |
| 1901 | |
| 1902 | #define CLIP_CHECK_FWD(entry, save_end) \ |
| 1903 | do { \ |
| 1904 | while (entry->ba.end != save_end) { \ |
| 1905 | entry = vm_map_rb_tree_RB_NEXT(entry); \ |
| 1906 | KASSERT(entry, ("bad entry clip")); \ |
| 1907 | } \ |
| 1908 | } while(0) |
| 1909 | |
| 1910 | |
| 1911 | /* |
| 1912 | * Clip the specified range and return the base entry. The |
| 1913 | * range may cover several entries starting at the returned base |
| 1914 | * and the first and last entry in the covering sequence will be |
| 1915 | * properly clipped to the requested start and end address. |
| 1916 | * |
| 1917 | * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES |
| 1918 | * flag. |
| 1919 | * |
| 1920 | * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries |
| 1921 | * covered by the requested range. |
| 1922 | * |
| 1923 | * The map must be exclusively locked on entry and will remain locked |
| 1924 | * on return. If no range exists or the range contains holes and you |
| 1925 | * specified that no holes were allowed, NULL will be returned. This |
| 1926 | * routine may temporarily unlock the map in order avoid a deadlock when |
| 1927 | * sleeping. |
| 1928 | */ |
| 1929 | static |
| 1930 | vm_map_entry_t |
| 1931 | vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, |
| 1932 | int *countp, int flags) |
| 1933 | { |
| 1934 | vm_map_entry_t start_entry; |
| 1935 | vm_map_entry_t entry; |
| 1936 | vm_map_entry_t next; |
| 1937 | |
| 1938 | /* |
| 1939 | * Locate the entry and effect initial clipping. The in-transition |
| 1940 | * case does not occur very often so do not try to optimize it. |
| 1941 | */ |
| 1942 | again: |
| 1943 | if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) |
| 1944 | return (NULL); |
| 1945 | entry = start_entry; |
| 1946 | if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { |
| 1947 | entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; |
| 1948 | ++mycpu->gd_cnt.v_intrans_coll; |
| 1949 | ++mycpu->gd_cnt.v_intrans_wait; |
| 1950 | vm_map_transition_wait(map, 1); |
| 1951 | /* |
| 1952 | * entry and/or start_entry may have been clipped while |
| 1953 | * we slept, or may have gone away entirely. We have |
| 1954 | * to restart from the lookup. |
| 1955 | */ |
| 1956 | goto again; |
| 1957 | } |
| 1958 | |
| 1959 | /* |
| 1960 | * Since we hold an exclusive map lock we do not have to restart |
| 1961 | * after clipping, even though clipping may block in zalloc. |
| 1962 | */ |
| 1963 | vm_map_clip_start(map, entry, start, countp); |
| 1964 | vm_map_clip_end(map, entry, end, countp); |
| 1965 | entry->eflags |= MAP_ENTRY_IN_TRANSITION; |
| 1966 | |
| 1967 | /* |
| 1968 | * Scan entries covered by the range. When working on the next |
| 1969 | * entry a restart need only re-loop on the current entry which |
| 1970 | * we have already locked, since 'next' may have changed. Also, |
| 1971 | * even though entry is safe, it may have been clipped so we |
| 1972 | * have to iterate forwards through the clip after sleeping. |
| 1973 | */ |
| 1974 | for (;;) { |
| 1975 | next = vm_map_rb_tree_RB_NEXT(entry); |
| 1976 | if (next == NULL || next->ba.start >= end) |
| 1977 | break; |
| 1978 | if (flags & MAP_CLIP_NO_HOLES) { |
| 1979 | if (next->ba.start > entry->ba.end) { |
| 1980 | vm_map_unclip_range(map, start_entry, |
| 1981 | start, entry->ba.end, countp, flags); |
| 1982 | return(NULL); |
| 1983 | } |
| 1984 | } |
| 1985 | |
| 1986 | if (next->eflags & MAP_ENTRY_IN_TRANSITION) { |
| 1987 | vm_offset_t save_end = entry->ba.end; |
| 1988 | next->eflags |= MAP_ENTRY_NEEDS_WAKEUP; |
| 1989 | ++mycpu->gd_cnt.v_intrans_coll; |
| 1990 | ++mycpu->gd_cnt.v_intrans_wait; |
| 1991 | vm_map_transition_wait(map, 1); |
| 1992 | |
| 1993 | /* |
| 1994 | * clips might have occured while we blocked. |
| 1995 | */ |
| 1996 | CLIP_CHECK_FWD(entry, save_end); |
| 1997 | CLIP_CHECK_BACK(start_entry, start); |
| 1998 | continue; |
| 1999 | } |
| 2000 | |
| 2001 | /* |
| 2002 | * No restart necessary even though clip_end may block, we |
| 2003 | * are holding the map lock. |
| 2004 | */ |
| 2005 | vm_map_clip_end(map, next, end, countp); |
| 2006 | next->eflags |= MAP_ENTRY_IN_TRANSITION; |
| 2007 | entry = next; |
| 2008 | } |
| 2009 | if (flags & MAP_CLIP_NO_HOLES) { |
| 2010 | if (entry->ba.end != end) { |
| 2011 | vm_map_unclip_range(map, start_entry, |
| 2012 | start, entry->ba.end, countp, flags); |
| 2013 | return(NULL); |
| 2014 | } |
| 2015 | } |
| 2016 | return(start_entry); |
| 2017 | } |
| 2018 | |
| 2019 | /* |
| 2020 | * Undo the effect of vm_map_clip_range(). You should pass the same |
| 2021 | * flags and the same range that you passed to vm_map_clip_range(). |
| 2022 | * This code will clear the in-transition flag on the entries and |
| 2023 | * wake up anyone waiting. This code will also simplify the sequence |
| 2024 | * and attempt to merge it with entries before and after the sequence. |
| 2025 | * |
| 2026 | * The map must be locked on entry and will remain locked on return. |
| 2027 | * |
| 2028 | * Note that you should also pass the start_entry returned by |
| 2029 | * vm_map_clip_range(). However, if you block between the two calls |
| 2030 | * with the map unlocked please be aware that the start_entry may |
| 2031 | * have been clipped and you may need to scan it backwards to find |
| 2032 | * the entry corresponding with the original start address. You are |
| 2033 | * responsible for this, vm_map_unclip_range() expects the correct |
| 2034 | * start_entry to be passed to it and will KASSERT otherwise. |
| 2035 | */ |
| 2036 | static |
| 2037 | void |
| 2038 | vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry, |
| 2039 | vm_offset_t start, vm_offset_t end, |
| 2040 | int *countp, int flags) |
| 2041 | { |
| 2042 | vm_map_entry_t entry; |
| 2043 | |
| 2044 | entry = start_entry; |
| 2045 | |
| 2046 | KASSERT(entry->ba.start == start, ("unclip_range: illegal base entry")); |
| 2047 | while (entry && entry->ba.start < end) { |
| 2048 | KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION, |
| 2049 | ("in-transition flag not set during unclip on: %p", |
| 2050 | entry)); |
| 2051 | KASSERT(entry->ba.end <= end, |
| 2052 | ("unclip_range: tail wasn't clipped")); |
| 2053 | entry->eflags &= ~MAP_ENTRY_IN_TRANSITION; |
| 2054 | if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) { |
| 2055 | entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP; |
| 2056 | wakeup(map); |
| 2057 | } |
| 2058 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2059 | } |
| 2060 | |
| 2061 | /* |
| 2062 | * Simplification does not block so there is no restart case. |
| 2063 | */ |
| 2064 | entry = start_entry; |
| 2065 | while (entry && entry->ba.start < end) { |
| 2066 | vm_map_simplify_entry(map, entry, countp); |
| 2067 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2068 | } |
| 2069 | } |
| 2070 | |
| 2071 | /* |
| 2072 | * Mark the given range as handled by a subordinate map. |
| 2073 | * |
| 2074 | * This range must have been created with vm_map_find(), and no other |
| 2075 | * operations may have been performed on this range prior to calling |
| 2076 | * vm_map_submap(). |
| 2077 | * |
| 2078 | * Submappings cannot be removed. |
| 2079 | * |
| 2080 | * No requirements. |
| 2081 | */ |
| 2082 | int |
| 2083 | vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap) |
| 2084 | { |
| 2085 | vm_map_entry_t entry; |
| 2086 | int result = KERN_INVALID_ARGUMENT; |
| 2087 | int count; |
| 2088 | |
| 2089 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 2090 | vm_map_lock(map); |
| 2091 | |
| 2092 | VM_MAP_RANGE_CHECK(map, start, end); |
| 2093 | |
| 2094 | if (vm_map_lookup_entry(map, start, &entry)) { |
| 2095 | vm_map_clip_start(map, entry, start, &count); |
| 2096 | } else if (entry) { |
| 2097 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2098 | } else { |
| 2099 | entry = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 2100 | } |
| 2101 | |
| 2102 | vm_map_clip_end(map, entry, end, &count); |
| 2103 | |
| 2104 | if ((entry->ba.start == start) && (entry->ba.end == end) && |
| 2105 | ((entry->eflags & MAP_ENTRY_COW) == 0) && |
| 2106 | (entry->ba.object == NULL)) { |
| 2107 | entry->ba.sub_map = submap; |
| 2108 | entry->maptype = VM_MAPTYPE_SUBMAP; |
| 2109 | result = KERN_SUCCESS; |
| 2110 | } |
| 2111 | vm_map_unlock(map); |
| 2112 | vm_map_entry_release(count); |
| 2113 | |
| 2114 | return (result); |
| 2115 | } |
| 2116 | |
| 2117 | /* |
| 2118 | * Sets the protection of the specified address region in the target map. |
| 2119 | * If "set_max" is specified, the maximum protection is to be set; |
| 2120 | * otherwise, only the current protection is affected. |
| 2121 | * |
| 2122 | * The protection is not applicable to submaps, but is applicable to normal |
| 2123 | * maps and maps governed by virtual page tables. For example, when operating |
| 2124 | * on a virtual page table our protection basically controls how COW occurs |
| 2125 | * on the backing object, whereas the virtual page table abstraction itself |
| 2126 | * is an abstraction for userland. |
| 2127 | * |
| 2128 | * No requirements. |
| 2129 | */ |
| 2130 | int |
| 2131 | vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end, |
| 2132 | vm_prot_t new_prot, boolean_t set_max) |
| 2133 | { |
| 2134 | vm_map_entry_t current; |
| 2135 | vm_map_entry_t entry; |
| 2136 | int count; |
| 2137 | |
| 2138 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 2139 | vm_map_lock(map); |
| 2140 | |
| 2141 | VM_MAP_RANGE_CHECK(map, start, end); |
| 2142 | |
| 2143 | if (vm_map_lookup_entry(map, start, &entry)) { |
| 2144 | vm_map_clip_start(map, entry, start, &count); |
| 2145 | } else if (entry) { |
| 2146 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2147 | } else { |
| 2148 | entry = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 2149 | } |
| 2150 | |
| 2151 | /* |
| 2152 | * Make a first pass to check for protection violations. |
| 2153 | */ |
| 2154 | current = entry; |
| 2155 | while (current && current->ba.start < end) { |
| 2156 | if (current->maptype == VM_MAPTYPE_SUBMAP) { |
| 2157 | vm_map_unlock(map); |
| 2158 | vm_map_entry_release(count); |
| 2159 | return (KERN_INVALID_ARGUMENT); |
| 2160 | } |
| 2161 | if ((new_prot & current->max_protection) != new_prot) { |
| 2162 | vm_map_unlock(map); |
| 2163 | vm_map_entry_release(count); |
| 2164 | return (KERN_PROTECTION_FAILURE); |
| 2165 | } |
| 2166 | |
| 2167 | /* |
| 2168 | * When making a SHARED+RW file mmap writable, update |
| 2169 | * v_lastwrite_ts. |
| 2170 | */ |
| 2171 | if (new_prot & PROT_WRITE && |
| 2172 | (current->eflags & MAP_ENTRY_NEEDS_COPY) == 0 && |
| 2173 | current->maptype == VM_MAPTYPE_NORMAL && |
| 2174 | current->ba.object && |
| 2175 | current->ba.object->type == OBJT_VNODE) { |
| 2176 | struct vnode *vp; |
| 2177 | |
| 2178 | vp = current->ba.object->handle; |
| 2179 | if (vp && vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_NOWAIT) == 0) { |
| 2180 | vfs_timestamp(&vp->v_lastwrite_ts); |
| 2181 | vsetflags(vp, VLASTWRITETS); |
| 2182 | vn_unlock(vp); |
| 2183 | } |
| 2184 | } |
| 2185 | current = vm_map_rb_tree_RB_NEXT(current); |
| 2186 | } |
| 2187 | |
| 2188 | /* |
| 2189 | * Go back and fix up protections. [Note that clipping is not |
| 2190 | * necessary the second time.] |
| 2191 | */ |
| 2192 | current = entry; |
| 2193 | |
| 2194 | while (current && current->ba.start < end) { |
| 2195 | vm_prot_t old_prot; |
| 2196 | |
| 2197 | vm_map_clip_end(map, current, end, &count); |
| 2198 | |
| 2199 | old_prot = current->protection; |
| 2200 | if (set_max) { |
| 2201 | current->max_protection = new_prot; |
| 2202 | current->protection = new_prot & old_prot; |
| 2203 | } else { |
| 2204 | current->protection = new_prot; |
| 2205 | } |
| 2206 | |
| 2207 | /* |
| 2208 | * Update physical map if necessary. Worry about copy-on-write |
| 2209 | * here -- CHECK THIS XXX |
| 2210 | */ |
| 2211 | if (current->protection != old_prot) { |
| 2212 | #define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \ |
| 2213 | VM_PROT_ALL) |
| 2214 | |
| 2215 | pmap_protect(map->pmap, current->ba.start, |
| 2216 | current->ba.end, |
| 2217 | current->protection & MASK(current)); |
| 2218 | #undef MASK |
| 2219 | } |
| 2220 | |
| 2221 | vm_map_simplify_entry(map, current, &count); |
| 2222 | |
| 2223 | current = vm_map_rb_tree_RB_NEXT(current); |
| 2224 | } |
| 2225 | vm_map_unlock(map); |
| 2226 | vm_map_entry_release(count); |
| 2227 | return (KERN_SUCCESS); |
| 2228 | } |
| 2229 | |
| 2230 | /* |
| 2231 | * This routine traverses a processes map handling the madvise |
| 2232 | * system call. Advisories are classified as either those effecting |
| 2233 | * the vm_map_entry structure, or those effecting the underlying |
| 2234 | * objects. |
| 2235 | * |
| 2236 | * The <value> argument is used for extended madvise calls. |
| 2237 | * |
| 2238 | * No requirements. |
| 2239 | */ |
| 2240 | int |
| 2241 | vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end, |
| 2242 | int behav, off_t value) |
| 2243 | { |
| 2244 | vm_map_entry_t current, entry; |
| 2245 | int modify_map = 0; |
| 2246 | int error = 0; |
| 2247 | int count; |
| 2248 | |
| 2249 | /* |
| 2250 | * Some madvise calls directly modify the vm_map_entry, in which case |
| 2251 | * we need to use an exclusive lock on the map and we need to perform |
| 2252 | * various clipping operations. Otherwise we only need a read-lock |
| 2253 | * on the map. |
| 2254 | */ |
| 2255 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 2256 | |
| 2257 | switch(behav) { |
| 2258 | case MADV_NORMAL: |
| 2259 | case MADV_SEQUENTIAL: |
| 2260 | case MADV_RANDOM: |
| 2261 | case MADV_NOSYNC: |
| 2262 | case MADV_AUTOSYNC: |
| 2263 | case MADV_NOCORE: |
| 2264 | case MADV_CORE: |
| 2265 | case MADV_SETMAP: |
| 2266 | modify_map = 1; |
| 2267 | vm_map_lock(map); |
| 2268 | break; |
| 2269 | case MADV_INVAL: |
| 2270 | case MADV_WILLNEED: |
| 2271 | case MADV_DONTNEED: |
| 2272 | case MADV_FREE: |
| 2273 | vm_map_lock_read(map); |
| 2274 | break; |
| 2275 | default: |
| 2276 | vm_map_entry_release(count); |
| 2277 | return (EINVAL); |
| 2278 | } |
| 2279 | |
| 2280 | /* |
| 2281 | * Locate starting entry and clip if necessary. |
| 2282 | */ |
| 2283 | |
| 2284 | VM_MAP_RANGE_CHECK(map, start, end); |
| 2285 | |
| 2286 | if (vm_map_lookup_entry(map, start, &entry)) { |
| 2287 | if (modify_map) |
| 2288 | vm_map_clip_start(map, entry, start, &count); |
| 2289 | } else if (entry) { |
| 2290 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2291 | } else { |
| 2292 | entry = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 2293 | } |
| 2294 | |
| 2295 | if (modify_map) { |
| 2296 | /* |
| 2297 | * madvise behaviors that are implemented in the vm_map_entry. |
| 2298 | * |
| 2299 | * We clip the vm_map_entry so that behavioral changes are |
| 2300 | * limited to the specified address range. |
| 2301 | */ |
| 2302 | for (current = entry; |
| 2303 | current && current->ba.start < end; |
| 2304 | current = vm_map_rb_tree_RB_NEXT(current)) { |
| 2305 | /* |
| 2306 | * Ignore submaps |
| 2307 | */ |
| 2308 | if (current->maptype == VM_MAPTYPE_SUBMAP) |
| 2309 | continue; |
| 2310 | |
| 2311 | vm_map_clip_end(map, current, end, &count); |
| 2312 | |
| 2313 | switch (behav) { |
| 2314 | case MADV_NORMAL: |
| 2315 | vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL); |
| 2316 | break; |
| 2317 | case MADV_SEQUENTIAL: |
| 2318 | vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL); |
| 2319 | break; |
| 2320 | case MADV_RANDOM: |
| 2321 | vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM); |
| 2322 | break; |
| 2323 | case MADV_NOSYNC: |
| 2324 | current->eflags |= MAP_ENTRY_NOSYNC; |
| 2325 | break; |
| 2326 | case MADV_AUTOSYNC: |
| 2327 | current->eflags &= ~MAP_ENTRY_NOSYNC; |
| 2328 | break; |
| 2329 | case MADV_NOCORE: |
| 2330 | current->eflags |= MAP_ENTRY_NOCOREDUMP; |
| 2331 | break; |
| 2332 | case MADV_CORE: |
| 2333 | current->eflags &= ~MAP_ENTRY_NOCOREDUMP; |
| 2334 | break; |
| 2335 | case MADV_SETMAP: |
| 2336 | /* |
| 2337 | * Set the page directory page for a map |
| 2338 | * governed by a virtual page table. |
| 2339 | * |
| 2340 | * Software virtual page table support has |
| 2341 | * been removed, this MADV is no longer |
| 2342 | * supported. |
| 2343 | */ |
| 2344 | error = EINVAL; |
| 2345 | break; |
| 2346 | case MADV_INVAL: |
| 2347 | /* |
| 2348 | * Invalidate the related pmap entries, used |
| 2349 | * to flush portions of the real kernel's |
| 2350 | * pmap when the caller has removed or |
| 2351 | * modified existing mappings in a virtual |
| 2352 | * page table. |
| 2353 | * |
| 2354 | * (exclusive locked map version does not |
| 2355 | * need the range interlock). |
| 2356 | */ |
| 2357 | pmap_remove(map->pmap, |
| 2358 | current->ba.start, current->ba.end); |
| 2359 | break; |
| 2360 | default: |
| 2361 | error = EINVAL; |
| 2362 | break; |
| 2363 | } |
| 2364 | vm_map_simplify_entry(map, current, &count); |
| 2365 | } |
| 2366 | vm_map_unlock(map); |
| 2367 | } else { |
| 2368 | vm_pindex_t pindex; |
| 2369 | vm_pindex_t delta; |
| 2370 | |
| 2371 | /* |
| 2372 | * madvise behaviors that are implemented in the underlying |
| 2373 | * vm_object. |
| 2374 | * |
| 2375 | * Since we don't clip the vm_map_entry, we have to clip |
| 2376 | * the vm_object pindex and count. |
| 2377 | * |
| 2378 | * NOTE! These functions are only supported on normal maps. |
| 2379 | * |
| 2380 | * NOTE! These functions only apply to the top-most object. |
| 2381 | * It is not applicable to backing objects. |
| 2382 | */ |
| 2383 | for (current = entry; |
| 2384 | current && current->ba.start < end; |
| 2385 | current = vm_map_rb_tree_RB_NEXT(current)) { |
| 2386 | vm_offset_t useStart; |
| 2387 | |
| 2388 | if (current->maptype != VM_MAPTYPE_NORMAL) |
| 2389 | continue; |
| 2390 | |
| 2391 | pindex = OFF_TO_IDX(current->ba.offset); |
| 2392 | delta = atop(current->ba.end - current->ba.start); |
| 2393 | useStart = current->ba.start; |
| 2394 | |
| 2395 | if (current->ba.start < start) { |
| 2396 | pindex += atop(start - current->ba.start); |
| 2397 | delta -= atop(start - current->ba.start); |
| 2398 | useStart = start; |
| 2399 | } |
| 2400 | if (current->ba.end > end) |
| 2401 | delta -= atop(current->ba.end - end); |
| 2402 | |
| 2403 | if ((vm_spindex_t)delta <= 0) |
| 2404 | continue; |
| 2405 | |
| 2406 | if (behav == MADV_INVAL) { |
| 2407 | /* |
| 2408 | * Invalidate the related pmap entries, used |
| 2409 | * to flush portions of the real kernel's |
| 2410 | * pmap when the caller has removed or |
| 2411 | * modified existing mappings in a virtual |
| 2412 | * page table. |
| 2413 | * |
| 2414 | * (shared locked map version needs the |
| 2415 | * interlock, see vm_fault()). |
| 2416 | */ |
| 2417 | struct vm_map_ilock ilock; |
| 2418 | |
| 2419 | KASSERT(useStart >= VM_MIN_USER_ADDRESS && |
| 2420 | useStart + ptoa(delta) <= |
| 2421 | VM_MAX_USER_ADDRESS, |
| 2422 | ("Bad range %016jx-%016jx (%016jx)", |
| 2423 | useStart, useStart + ptoa(delta), |
| 2424 | delta)); |
| 2425 | vm_map_interlock(map, &ilock, |
| 2426 | useStart, |
| 2427 | useStart + ptoa(delta)); |
| 2428 | pmap_remove(map->pmap, |
| 2429 | useStart, |
| 2430 | useStart + ptoa(delta)); |
| 2431 | vm_map_deinterlock(map, &ilock); |
| 2432 | } else { |
| 2433 | vm_object_madvise(current->ba.object, |
| 2434 | pindex, delta, behav); |
| 2435 | } |
| 2436 | |
| 2437 | /* |
| 2438 | * Try to pre-populate the page table. |
| 2439 | */ |
| 2440 | if (behav == MADV_WILLNEED) { |
| 2441 | pmap_object_init_pt( |
| 2442 | map->pmap, current, |
| 2443 | useStart, |
| 2444 | (delta << PAGE_SHIFT), |
| 2445 | MAP_PREFAULT_MADVISE |
| 2446 | ); |
| 2447 | } |
| 2448 | } |
| 2449 | vm_map_unlock_read(map); |
| 2450 | } |
| 2451 | vm_map_entry_release(count); |
| 2452 | return(error); |
| 2453 | } |
| 2454 | |
| 2455 | |
| 2456 | /* |
| 2457 | * Sets the inheritance of the specified address range in the target map. |
| 2458 | * Inheritance affects how the map will be shared with child maps at the |
| 2459 | * time of vm_map_fork. |
| 2460 | */ |
| 2461 | int |
| 2462 | vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end, |
| 2463 | vm_inherit_t new_inheritance) |
| 2464 | { |
| 2465 | vm_map_entry_t entry; |
| 2466 | vm_map_entry_t temp_entry; |
| 2467 | int count; |
| 2468 | |
| 2469 | switch (new_inheritance) { |
| 2470 | case VM_INHERIT_NONE: |
| 2471 | case VM_INHERIT_COPY: |
| 2472 | case VM_INHERIT_SHARE: |
| 2473 | break; |
| 2474 | default: |
| 2475 | return (KERN_INVALID_ARGUMENT); |
| 2476 | } |
| 2477 | |
| 2478 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 2479 | vm_map_lock(map); |
| 2480 | |
| 2481 | VM_MAP_RANGE_CHECK(map, start, end); |
| 2482 | |
| 2483 | if (vm_map_lookup_entry(map, start, &temp_entry)) { |
| 2484 | entry = temp_entry; |
| 2485 | vm_map_clip_start(map, entry, start, &count); |
| 2486 | } else if (temp_entry) { |
| 2487 | entry = vm_map_rb_tree_RB_NEXT(temp_entry); |
| 2488 | } else { |
| 2489 | entry = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 2490 | } |
| 2491 | |
| 2492 | while (entry && entry->ba.start < end) { |
| 2493 | vm_map_clip_end(map, entry, end, &count); |
| 2494 | |
| 2495 | entry->inheritance = new_inheritance; |
| 2496 | |
| 2497 | vm_map_simplify_entry(map, entry, &count); |
| 2498 | |
| 2499 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2500 | } |
| 2501 | vm_map_unlock(map); |
| 2502 | vm_map_entry_release(count); |
| 2503 | return (KERN_SUCCESS); |
| 2504 | } |
| 2505 | |
| 2506 | /* |
| 2507 | * Wiring/Unwiring of memory for user-related operation. |
| 2508 | * |
| 2509 | * Implement the semantics of mlock |
| 2510 | */ |
| 2511 | int |
| 2512 | vm_map_user_wiring(vm_map_t map, vm_offset_t start, vm_offset_t real_end, |
| 2513 | boolean_t new_pageable) |
| 2514 | { |
| 2515 | vm_map_entry_t entry; |
| 2516 | vm_map_entry_t start_entry; |
| 2517 | vm_offset_t end; |
| 2518 | int rv = KERN_SUCCESS; |
| 2519 | int count; |
| 2520 | |
| 2521 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 2522 | vm_map_lock(map); |
| 2523 | VM_MAP_RANGE_CHECK(map, start, real_end); |
| 2524 | end = real_end; |
| 2525 | |
| 2526 | start_entry = vm_map_clip_range(map, start, end, &count, |
| 2527 | MAP_CLIP_NO_HOLES); |
| 2528 | if (start_entry == NULL) { |
| 2529 | vm_map_unlock(map); |
| 2530 | vm_map_entry_release(count); |
| 2531 | return (KERN_INVALID_ADDRESS); |
| 2532 | } |
| 2533 | |
| 2534 | if (new_pageable == 0) { |
| 2535 | entry = start_entry; |
| 2536 | while (entry && entry->ba.start < end) { |
| 2537 | vm_offset_t save_start; |
| 2538 | vm_offset_t save_end; |
| 2539 | |
| 2540 | /* |
| 2541 | * Already user wired or hard wired (trivial cases) |
| 2542 | */ |
| 2543 | if (entry->eflags & MAP_ENTRY_USER_WIRED) { |
| 2544 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2545 | continue; |
| 2546 | } |
| 2547 | if (entry->wired_count != 0) { |
| 2548 | entry->wired_count++; |
| 2549 | entry->eflags |= MAP_ENTRY_USER_WIRED; |
| 2550 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2551 | continue; |
| 2552 | } |
| 2553 | |
| 2554 | /* |
| 2555 | * A new wiring requires instantiation of appropriate |
| 2556 | * management structures and the faulting in of the |
| 2557 | * page. |
| 2558 | */ |
| 2559 | if (entry->maptype == VM_MAPTYPE_NORMAL) { |
| 2560 | int copyflag = entry->eflags & |
| 2561 | MAP_ENTRY_NEEDS_COPY; |
| 2562 | if (copyflag && ((entry->protection & |
| 2563 | VM_PROT_WRITE) != 0)) { |
| 2564 | vm_map_entry_shadow(entry); |
| 2565 | } else if (entry->ba.object == NULL && |
| 2566 | !map->system_map) { |
| 2567 | vm_map_entry_allocate_object(entry); |
| 2568 | } |
| 2569 | } |
| 2570 | entry->wired_count++; |
| 2571 | entry->eflags |= MAP_ENTRY_USER_WIRED; |
| 2572 | |
| 2573 | /* |
| 2574 | * Now fault in the area. Note that vm_fault_wire() |
| 2575 | * may release the map lock temporarily, it will be |
| 2576 | * relocked on return. The in-transition |
| 2577 | * flag protects the entries. |
| 2578 | */ |
| 2579 | save_start = entry->ba.start; |
| 2580 | save_end = entry->ba.end; |
| 2581 | rv = vm_fault_wire(map, entry, TRUE, 0); |
| 2582 | if (rv) { |
| 2583 | CLIP_CHECK_BACK(entry, save_start); |
| 2584 | for (;;) { |
| 2585 | KASSERT(entry->wired_count == 1, ("bad wired_count on entry")); |
| 2586 | entry->eflags &= ~MAP_ENTRY_USER_WIRED; |
| 2587 | entry->wired_count = 0; |
| 2588 | if (entry->ba.end == save_end) |
| 2589 | break; |
| 2590 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2591 | KASSERT(entry, |
| 2592 | ("bad entry clip during backout")); |
| 2593 | } |
| 2594 | end = save_start; /* unwire the rest */ |
| 2595 | break; |
| 2596 | } |
| 2597 | /* |
| 2598 | * note that even though the entry might have been |
| 2599 | * clipped, the USER_WIRED flag we set prevents |
| 2600 | * duplication so we do not have to do a |
| 2601 | * clip check. |
| 2602 | */ |
| 2603 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2604 | } |
| 2605 | |
| 2606 | /* |
| 2607 | * If we failed fall through to the unwiring section to |
| 2608 | * unwire what we had wired so far. 'end' has already |
| 2609 | * been adjusted. |
| 2610 | */ |
| 2611 | if (rv) |
| 2612 | new_pageable = 1; |
| 2613 | |
| 2614 | /* |
| 2615 | * start_entry might have been clipped if we unlocked the |
| 2616 | * map and blocked. No matter how clipped it has gotten |
| 2617 | * there should be a fragment that is on our start boundary. |
| 2618 | */ |
| 2619 | CLIP_CHECK_BACK(start_entry, start); |
| 2620 | } |
| 2621 | |
| 2622 | /* |
| 2623 | * Deal with the unwiring case. |
| 2624 | */ |
| 2625 | if (new_pageable) { |
| 2626 | /* |
| 2627 | * This is the unwiring case. We must first ensure that the |
| 2628 | * range to be unwired is really wired down. We know there |
| 2629 | * are no holes. |
| 2630 | */ |
| 2631 | entry = start_entry; |
| 2632 | while (entry && entry->ba.start < end) { |
| 2633 | if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) { |
| 2634 | rv = KERN_INVALID_ARGUMENT; |
| 2635 | goto done; |
| 2636 | } |
| 2637 | KASSERT(entry->wired_count != 0, |
| 2638 | ("wired count was 0 with USER_WIRED set! %p", |
| 2639 | entry)); |
| 2640 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2641 | } |
| 2642 | |
| 2643 | /* |
| 2644 | * Now decrement the wiring count for each region. If a region |
| 2645 | * becomes completely unwired, unwire its physical pages and |
| 2646 | * mappings. |
| 2647 | */ |
| 2648 | /* |
| 2649 | * The map entries are processed in a loop, checking to |
| 2650 | * make sure the entry is wired and asserting it has a wired |
| 2651 | * count. However, another loop was inserted more-or-less in |
| 2652 | * the middle of the unwiring path. This loop picks up the |
| 2653 | * "entry" loop variable from the first loop without first |
| 2654 | * setting it to start_entry. Naturally, the secound loop |
| 2655 | * is never entered and the pages backing the entries are |
| 2656 | * never unwired. This can lead to a leak of wired pages. |
| 2657 | */ |
| 2658 | entry = start_entry; |
| 2659 | while (entry && entry->ba.start < end) { |
| 2660 | KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED, |
| 2661 | ("expected USER_WIRED on entry %p", entry)); |
| 2662 | entry->eflags &= ~MAP_ENTRY_USER_WIRED; |
| 2663 | entry->wired_count--; |
| 2664 | if (entry->wired_count == 0) |
| 2665 | vm_fault_unwire(map, entry); |
| 2666 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2667 | } |
| 2668 | } |
| 2669 | done: |
| 2670 | vm_map_unclip_range(map, start_entry, start, real_end, &count, |
| 2671 | MAP_CLIP_NO_HOLES); |
| 2672 | vm_map_unlock(map); |
| 2673 | vm_map_entry_release(count); |
| 2674 | |
| 2675 | return (rv); |
| 2676 | } |
| 2677 | |
| 2678 | /* |
| 2679 | * Wiring/Unwiring of memory for kernel-related operation. |
| 2680 | * |
| 2681 | * Sets the pageability of the specified address range in the target map. |
| 2682 | * Regions specified as not pageable require locked-down physical |
| 2683 | * memory and physical page maps. |
| 2684 | * |
| 2685 | * The map must not be locked, but a reference must remain to the map |
| 2686 | * throughout the call. |
| 2687 | * |
| 2688 | * This function may be called via the zalloc path and must properly |
| 2689 | * reserve map entries for kernel_map. |
| 2690 | * |
| 2691 | * No requirements. |
| 2692 | */ |
| 2693 | int |
| 2694 | vm_map_kernel_wiring(vm_map_t map, vm_offset_t start, |
| 2695 | vm_offset_t real_end, int kmflags) |
| 2696 | { |
| 2697 | vm_map_entry_t entry; |
| 2698 | vm_map_entry_t start_entry; |
| 2699 | vm_offset_t end; |
| 2700 | int rv = KERN_SUCCESS; |
| 2701 | int count; |
| 2702 | |
| 2703 | if (kmflags & KM_KRESERVE) |
| 2704 | count = vm_map_entry_kreserve(MAP_RESERVE_COUNT); |
| 2705 | else |
| 2706 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 2707 | vm_map_lock(map); |
| 2708 | VM_MAP_RANGE_CHECK(map, start, real_end); |
| 2709 | end = real_end; |
| 2710 | |
| 2711 | start_entry = vm_map_clip_range(map, start, end, &count, |
| 2712 | MAP_CLIP_NO_HOLES); |
| 2713 | if (start_entry == NULL) { |
| 2714 | vm_map_unlock(map); |
| 2715 | rv = KERN_INVALID_ADDRESS; |
| 2716 | goto failure; |
| 2717 | } |
| 2718 | if ((kmflags & KM_PAGEABLE) == 0) { |
| 2719 | /* |
| 2720 | * Wiring. |
| 2721 | * |
| 2722 | * 1. Holding the write lock, we create any shadow or zero-fill |
| 2723 | * objects that need to be created. Then we clip each map |
| 2724 | * entry to the region to be wired and increment its wiring |
| 2725 | * count. We create objects before clipping the map entries |
| 2726 | * to avoid object proliferation. |
| 2727 | * |
| 2728 | * 2. We downgrade to a read lock, and call vm_fault_wire to |
| 2729 | * fault in the pages for any newly wired area (wired_count is |
| 2730 | * 1). |
| 2731 | * |
| 2732 | * Downgrading to a read lock for vm_fault_wire avoids a |
| 2733 | * possible deadlock with another process that may have faulted |
| 2734 | * on one of the pages to be wired (it would mark the page busy, |
| 2735 | * blocking us, then in turn block on the map lock that we |
| 2736 | * hold). Because of problems in the recursive lock package, |
| 2737 | * we cannot upgrade to a write lock in vm_map_lookup. Thus, |
| 2738 | * any actions that require the write lock must be done |
| 2739 | * beforehand. Because we keep the read lock on the map, the |
| 2740 | * copy-on-write status of the entries we modify here cannot |
| 2741 | * change. |
| 2742 | */ |
| 2743 | entry = start_entry; |
| 2744 | while (entry && entry->ba.start < end) { |
| 2745 | /* |
| 2746 | * Trivial case if the entry is already wired |
| 2747 | */ |
| 2748 | if (entry->wired_count) { |
| 2749 | entry->wired_count++; |
| 2750 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2751 | continue; |
| 2752 | } |
| 2753 | |
| 2754 | /* |
| 2755 | * The entry is being newly wired, we have to setup |
| 2756 | * appropriate management structures. A shadow |
| 2757 | * object is required for a copy-on-write region, |
| 2758 | * or a normal object for a zero-fill region. We |
| 2759 | * do not have to do this for entries that point to sub |
| 2760 | * maps because we won't hold the lock on the sub map. |
| 2761 | */ |
| 2762 | if (entry->maptype == VM_MAPTYPE_NORMAL) { |
| 2763 | int copyflag = entry->eflags & |
| 2764 | MAP_ENTRY_NEEDS_COPY; |
| 2765 | if (copyflag && ((entry->protection & |
| 2766 | VM_PROT_WRITE) != 0)) { |
| 2767 | vm_map_entry_shadow(entry); |
| 2768 | } else if (entry->ba.object == NULL && |
| 2769 | !map->system_map) { |
| 2770 | vm_map_entry_allocate_object(entry); |
| 2771 | } |
| 2772 | } |
| 2773 | entry->wired_count++; |
| 2774 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2775 | } |
| 2776 | |
| 2777 | /* |
| 2778 | * Pass 2. |
| 2779 | */ |
| 2780 | |
| 2781 | /* |
| 2782 | * HACK HACK HACK HACK |
| 2783 | * |
| 2784 | * vm_fault_wire() temporarily unlocks the map to avoid |
| 2785 | * deadlocks. The in-transition flag from vm_map_clip_range |
| 2786 | * call should protect us from changes while the map is |
| 2787 | * unlocked. T |
| 2788 | * |
| 2789 | * NOTE: Previously this comment stated that clipping might |
| 2790 | * still occur while the entry is unlocked, but from |
| 2791 | * what I can tell it actually cannot. |
| 2792 | * |
| 2793 | * It is unclear whether the CLIP_CHECK_*() calls |
| 2794 | * are still needed but we keep them in anyway. |
| 2795 | * |
| 2796 | * HACK HACK HACK HACK |
| 2797 | */ |
| 2798 | |
| 2799 | entry = start_entry; |
| 2800 | while (entry && entry->ba.start < end) { |
| 2801 | /* |
| 2802 | * If vm_fault_wire fails for any page we need to undo |
| 2803 | * what has been done. We decrement the wiring count |
| 2804 | * for those pages which have not yet been wired (now) |
| 2805 | * and unwire those that have (later). |
| 2806 | */ |
| 2807 | vm_offset_t save_start = entry->ba.start; |
| 2808 | vm_offset_t save_end = entry->ba.end; |
| 2809 | |
| 2810 | if (entry->wired_count == 1) |
| 2811 | rv = vm_fault_wire(map, entry, FALSE, kmflags); |
| 2812 | if (rv) { |
| 2813 | CLIP_CHECK_BACK(entry, save_start); |
| 2814 | for (;;) { |
| 2815 | KASSERT(entry->wired_count == 1, |
| 2816 | ("wired_count changed unexpectedly")); |
| 2817 | entry->wired_count = 0; |
| 2818 | if (entry->ba.end == save_end) |
| 2819 | break; |
| 2820 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2821 | KASSERT(entry, |
| 2822 | ("bad entry clip during backout")); |
| 2823 | } |
| 2824 | end = save_start; |
| 2825 | break; |
| 2826 | } |
| 2827 | CLIP_CHECK_FWD(entry, save_end); |
| 2828 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2829 | } |
| 2830 | |
| 2831 | /* |
| 2832 | * If a failure occured undo everything by falling through |
| 2833 | * to the unwiring code. 'end' has already been adjusted |
| 2834 | * appropriately. |
| 2835 | */ |
| 2836 | if (rv) |
| 2837 | kmflags |= KM_PAGEABLE; |
| 2838 | |
| 2839 | /* |
| 2840 | * start_entry is still IN_TRANSITION but may have been |
| 2841 | * clipped since vm_fault_wire() unlocks and relocks the |
| 2842 | * map. No matter how clipped it has gotten there should |
| 2843 | * be a fragment that is on our start boundary. |
| 2844 | */ |
| 2845 | CLIP_CHECK_BACK(start_entry, start); |
| 2846 | } |
| 2847 | |
| 2848 | if (kmflags & KM_PAGEABLE) { |
| 2849 | /* |
| 2850 | * This is the unwiring case. We must first ensure that the |
| 2851 | * range to be unwired is really wired down. We know there |
| 2852 | * are no holes. |
| 2853 | */ |
| 2854 | entry = start_entry; |
| 2855 | while (entry && entry->ba.start < end) { |
| 2856 | if (entry->wired_count == 0) { |
| 2857 | rv = KERN_INVALID_ARGUMENT; |
| 2858 | goto done; |
| 2859 | } |
| 2860 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2861 | } |
| 2862 | |
| 2863 | /* |
| 2864 | * Now decrement the wiring count for each region. If a region |
| 2865 | * becomes completely unwired, unwire its physical pages and |
| 2866 | * mappings. |
| 2867 | */ |
| 2868 | entry = start_entry; |
| 2869 | while (entry && entry->ba.start < end) { |
| 2870 | entry->wired_count--; |
| 2871 | if (entry->wired_count == 0) |
| 2872 | vm_fault_unwire(map, entry); |
| 2873 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 2874 | } |
| 2875 | } |
| 2876 | done: |
| 2877 | vm_map_unclip_range(map, start_entry, start, real_end, |
| 2878 | &count, MAP_CLIP_NO_HOLES); |
| 2879 | vm_map_unlock(map); |
| 2880 | failure: |
| 2881 | if (kmflags & KM_KRESERVE) |
| 2882 | vm_map_entry_krelease(count); |
| 2883 | else |
| 2884 | vm_map_entry_release(count); |
| 2885 | return (rv); |
| 2886 | } |
| 2887 | |
| 2888 | /* |
| 2889 | * Mark a newly allocated address range as wired but do not fault in |
| 2890 | * the pages. The caller is expected to load the pages into the object. |
| 2891 | * |
| 2892 | * The map must be locked on entry and will remain locked on return. |
| 2893 | * No other requirements. |
| 2894 | */ |
| 2895 | void |
| 2896 | vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size, |
| 2897 | int *countp) |
| 2898 | { |
| 2899 | vm_map_entry_t scan; |
| 2900 | vm_map_entry_t entry; |
| 2901 | |
| 2902 | entry = vm_map_clip_range(map, addr, addr + size, |
| 2903 | countp, MAP_CLIP_NO_HOLES); |
| 2904 | scan = entry; |
| 2905 | while (scan && scan->ba.start < addr + size) { |
| 2906 | KKASSERT(scan->wired_count == 0); |
| 2907 | scan->wired_count = 1; |
| 2908 | scan = vm_map_rb_tree_RB_NEXT(scan); |
| 2909 | } |
| 2910 | vm_map_unclip_range(map, entry, addr, addr + size, |
| 2911 | countp, MAP_CLIP_NO_HOLES); |
| 2912 | } |
| 2913 | |
| 2914 | /* |
| 2915 | * Push any dirty cached pages in the address range to their pager. |
| 2916 | * If syncio is TRUE, dirty pages are written synchronously. |
| 2917 | * If invalidate is TRUE, any cached pages are freed as well. |
| 2918 | * |
| 2919 | * This routine is called by sys_msync() |
| 2920 | * |
| 2921 | * Returns an error if any part of the specified range is not mapped. |
| 2922 | * |
| 2923 | * No requirements. |
| 2924 | */ |
| 2925 | int |
| 2926 | vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end, |
| 2927 | boolean_t syncio, boolean_t invalidate) |
| 2928 | { |
| 2929 | vm_map_entry_t current; |
| 2930 | vm_map_entry_t next; |
| 2931 | vm_map_entry_t entry; |
| 2932 | vm_map_backing_t ba; |
| 2933 | vm_size_t size; |
| 2934 | vm_object_t object; |
| 2935 | vm_ooffset_t offset; |
| 2936 | |
| 2937 | vm_map_lock_read(map); |
| 2938 | VM_MAP_RANGE_CHECK(map, start, end); |
| 2939 | if (!vm_map_lookup_entry(map, start, &entry)) { |
| 2940 | vm_map_unlock_read(map); |
| 2941 | return (KERN_INVALID_ADDRESS); |
| 2942 | } |
| 2943 | lwkt_gettoken(&map->token); |
| 2944 | |
| 2945 | /* |
| 2946 | * Make a first pass to check for holes. |
| 2947 | */ |
| 2948 | current = entry; |
| 2949 | while (current && current->ba.start < end) { |
| 2950 | if (current->maptype == VM_MAPTYPE_SUBMAP) { |
| 2951 | lwkt_reltoken(&map->token); |
| 2952 | vm_map_unlock_read(map); |
| 2953 | return (KERN_INVALID_ARGUMENT); |
| 2954 | } |
| 2955 | next = vm_map_rb_tree_RB_NEXT(current); |
| 2956 | if (end > current->ba.end && |
| 2957 | (next == NULL || |
| 2958 | current->ba.end != next->ba.start)) { |
| 2959 | lwkt_reltoken(&map->token); |
| 2960 | vm_map_unlock_read(map); |
| 2961 | return (KERN_INVALID_ADDRESS); |
| 2962 | } |
| 2963 | current = next; |
| 2964 | } |
| 2965 | |
| 2966 | if (invalidate) |
| 2967 | pmap_remove(vm_map_pmap(map), start, end); |
| 2968 | |
| 2969 | /* |
| 2970 | * Make a second pass, cleaning/uncaching pages from the indicated |
| 2971 | * objects as we go. |
| 2972 | */ |
| 2973 | current = entry; |
| 2974 | while (current && current->ba.start < end) { |
| 2975 | offset = current->ba.offset + (start - current->ba.start); |
| 2976 | size = (end <= current->ba.end ? end : current->ba.end) - start; |
| 2977 | |
| 2978 | switch(current->maptype) { |
| 2979 | case VM_MAPTYPE_SUBMAP: |
| 2980 | { |
| 2981 | vm_map_t smap; |
| 2982 | vm_map_entry_t tentry; |
| 2983 | vm_size_t tsize; |
| 2984 | |
| 2985 | smap = current->ba.sub_map; |
| 2986 | vm_map_lock_read(smap); |
| 2987 | vm_map_lookup_entry(smap, offset, &tentry); |
| 2988 | if (tentry == NULL) { |
| 2989 | tsize = vm_map_max(smap) - offset; |
| 2990 | ba = NULL; |
| 2991 | offset = 0 + (offset - vm_map_min(smap)); |
| 2992 | } else { |
| 2993 | tsize = tentry->ba.end - offset; |
| 2994 | ba = &tentry->ba; |
| 2995 | offset = tentry->ba.offset + |
| 2996 | (offset - tentry->ba.start); |
| 2997 | } |
| 2998 | vm_map_unlock_read(smap); |
| 2999 | if (tsize < size) |
| 3000 | size = tsize; |
| 3001 | break; |
| 3002 | } |
| 3003 | case VM_MAPTYPE_NORMAL: |
| 3004 | ba = ¤t->ba; |
| 3005 | break; |
| 3006 | default: |
| 3007 | ba = NULL; |
| 3008 | break; |
| 3009 | } |
| 3010 | if (ba) { |
| 3011 | object = ba->object; |
| 3012 | if (object) |
| 3013 | vm_object_hold(object); |
| 3014 | } else { |
| 3015 | object = NULL; |
| 3016 | } |
| 3017 | |
| 3018 | /* |
| 3019 | * Note that there is absolutely no sense in writing out |
| 3020 | * anonymous objects, so we track down the vnode object |
| 3021 | * to write out. |
| 3022 | * We invalidate (remove) all pages from the address space |
| 3023 | * anyway, for semantic correctness. |
| 3024 | * |
| 3025 | * note: certain anonymous maps, such as MAP_NOSYNC maps, |
| 3026 | * may start out with a NULL object. |
| 3027 | * |
| 3028 | * XXX do we really want to stop at the first backing store |
| 3029 | * here if there are more? XXX |
| 3030 | */ |
| 3031 | if (ba) { |
| 3032 | vm_object_t tobj; |
| 3033 | |
| 3034 | tobj = object; |
| 3035 | while (ba->backing_ba != NULL) { |
| 3036 | offset -= ba->offset; |
| 3037 | ba = ba->backing_ba; |
| 3038 | offset += ba->offset; |
| 3039 | tobj = ba->object; |
| 3040 | if (tobj->size < OFF_TO_IDX(offset + size)) |
| 3041 | size = IDX_TO_OFF(tobj->size) - offset; |
| 3042 | break; /* XXX this break is not correct */ |
| 3043 | } |
| 3044 | if (object != tobj) { |
| 3045 | if (object) |
| 3046 | vm_object_drop(object); |
| 3047 | object = tobj; |
| 3048 | vm_object_hold(object); |
| 3049 | } |
| 3050 | } |
| 3051 | |
| 3052 | if (object && (object->type == OBJT_VNODE) && |
| 3053 | (current->protection & VM_PROT_WRITE) && |
| 3054 | (object->flags & OBJ_NOMSYNC) == 0) { |
| 3055 | /* |
| 3056 | * Flush pages if writing is allowed, invalidate them |
| 3057 | * if invalidation requested. Pages undergoing I/O |
| 3058 | * will be ignored by vm_object_page_remove(). |
| 3059 | * |
| 3060 | * We cannot lock the vnode and then wait for paging |
| 3061 | * to complete without deadlocking against vm_fault. |
| 3062 | * Instead we simply call vm_object_page_remove() and |
| 3063 | * allow it to block internally on a page-by-page |
| 3064 | * basis when it encounters pages undergoing async |
| 3065 | * I/O. |
| 3066 | */ |
| 3067 | int flags; |
| 3068 | |
| 3069 | /* no chain wait needed for vnode objects */ |
| 3070 | vm_object_reference_locked(object); |
| 3071 | vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY); |
| 3072 | flags = (syncio || invalidate) ? OBJPC_SYNC : 0; |
| 3073 | flags |= invalidate ? OBJPC_INVAL : 0; |
| 3074 | |
| 3075 | if (current->maptype == VM_MAPTYPE_NORMAL) { |
| 3076 | vm_object_page_clean(object, |
| 3077 | OFF_TO_IDX(offset), |
| 3078 | OFF_TO_IDX(offset + size + PAGE_MASK), |
| 3079 | flags); |
| 3080 | } |
| 3081 | vn_unlock(((struct vnode *)object->handle)); |
| 3082 | vm_object_deallocate_locked(object); |
| 3083 | } |
| 3084 | if (object && invalidate && |
| 3085 | ((object->type == OBJT_VNODE) || |
| 3086 | (object->type == OBJT_DEVICE) || |
| 3087 | (object->type == OBJT_MGTDEVICE))) { |
| 3088 | int clean_only = |
| 3089 | ((object->type == OBJT_DEVICE) || |
| 3090 | (object->type == OBJT_MGTDEVICE)) ? FALSE : TRUE; |
| 3091 | /* no chain wait needed for vnode/device objects */ |
| 3092 | vm_object_reference_locked(object); |
| 3093 | if (current->maptype == VM_MAPTYPE_NORMAL) { |
| 3094 | vm_object_page_remove(object, |
| 3095 | OFF_TO_IDX(offset), |
| 3096 | OFF_TO_IDX(offset + size + PAGE_MASK), |
| 3097 | clean_only); |
| 3098 | } |
| 3099 | vm_object_deallocate_locked(object); |
| 3100 | } |
| 3101 | start += size; |
| 3102 | if (object) |
| 3103 | vm_object_drop(object); |
| 3104 | current = vm_map_rb_tree_RB_NEXT(current); |
| 3105 | } |
| 3106 | |
| 3107 | lwkt_reltoken(&map->token); |
| 3108 | vm_map_unlock_read(map); |
| 3109 | |
| 3110 | return (KERN_SUCCESS); |
| 3111 | } |
| 3112 | |
| 3113 | /* |
| 3114 | * Make the region specified by this entry pageable. |
| 3115 | * |
| 3116 | * The vm_map must be exclusively locked. |
| 3117 | */ |
| 3118 | static void |
| 3119 | vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry) |
| 3120 | { |
| 3121 | entry->eflags &= ~MAP_ENTRY_USER_WIRED; |
| 3122 | entry->wired_count = 0; |
| 3123 | vm_fault_unwire(map, entry); |
| 3124 | } |
| 3125 | |
| 3126 | /* |
| 3127 | * Deallocate the given entry from the target map. |
| 3128 | * |
| 3129 | * The vm_map must be exclusively locked. |
| 3130 | */ |
| 3131 | static void |
| 3132 | vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp) |
| 3133 | { |
| 3134 | vm_map_entry_unlink(map, entry); |
| 3135 | map->size -= entry->ba.end - entry->ba.start; |
| 3136 | vm_map_entry_dispose(map, entry, countp); |
| 3137 | } |
| 3138 | |
| 3139 | /* |
| 3140 | * Deallocates the given address range from the target map. |
| 3141 | * |
| 3142 | * The vm_map must be exclusively locked. |
| 3143 | */ |
| 3144 | int |
| 3145 | vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp) |
| 3146 | { |
| 3147 | vm_object_t object; |
| 3148 | vm_map_entry_t entry; |
| 3149 | vm_map_entry_t first_entry; |
| 3150 | vm_offset_t hole_start; |
| 3151 | |
| 3152 | ASSERT_VM_MAP_LOCKED(map); |
| 3153 | lwkt_gettoken(&map->token); |
| 3154 | again: |
| 3155 | /* |
| 3156 | * Find the start of the region, and clip it. Set entry to point |
| 3157 | * at the first record containing the requested address or, if no |
| 3158 | * such record exists, the next record with a greater address. The |
| 3159 | * loop will run from this point until a record beyond the termination |
| 3160 | * address is encountered. |
| 3161 | * |
| 3162 | * Adjust freehint[] for either the clip case or the extension case. |
| 3163 | * |
| 3164 | * GGG see other GGG comment. |
| 3165 | */ |
| 3166 | if (vm_map_lookup_entry(map, start, &first_entry)) { |
| 3167 | entry = first_entry; |
| 3168 | vm_map_clip_start(map, entry, start, countp); |
| 3169 | hole_start = start; |
| 3170 | } else { |
| 3171 | if (first_entry) { |
| 3172 | entry = vm_map_rb_tree_RB_NEXT(first_entry); |
| 3173 | if (entry == NULL) |
| 3174 | hole_start = first_entry->ba.start; |
| 3175 | else |
| 3176 | hole_start = first_entry->ba.end; |
| 3177 | } else { |
| 3178 | entry = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 3179 | if (entry == NULL) |
| 3180 | hole_start = vm_map_min(map); |
| 3181 | else |
| 3182 | hole_start = vm_map_max(map); |
| 3183 | } |
| 3184 | } |
| 3185 | |
| 3186 | /* |
| 3187 | * Step through all entries in this region |
| 3188 | */ |
| 3189 | while (entry && entry->ba.start < end) { |
| 3190 | vm_map_entry_t next; |
| 3191 | vm_offset_t s, e; |
| 3192 | vm_pindex_t offidxstart, offidxend, count; |
| 3193 | |
| 3194 | /* |
| 3195 | * If we hit an in-transition entry we have to sleep and |
| 3196 | * retry. It's easier (and not really slower) to just retry |
| 3197 | * since this case occurs so rarely and the hint is already |
| 3198 | * pointing at the right place. We have to reset the |
| 3199 | * start offset so as not to accidently delete an entry |
| 3200 | * another process just created in vacated space. |
| 3201 | */ |
| 3202 | if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { |
| 3203 | entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; |
| 3204 | start = entry->ba.start; |
| 3205 | ++mycpu->gd_cnt.v_intrans_coll; |
| 3206 | ++mycpu->gd_cnt.v_intrans_wait; |
| 3207 | vm_map_transition_wait(map, 1); |
| 3208 | goto again; |
| 3209 | } |
| 3210 | vm_map_clip_end(map, entry, end, countp); |
| 3211 | |
| 3212 | s = entry->ba.start; |
| 3213 | e = entry->ba.end; |
| 3214 | next = vm_map_rb_tree_RB_NEXT(entry); |
| 3215 | |
| 3216 | offidxstart = OFF_TO_IDX(entry->ba.offset); |
| 3217 | count = OFF_TO_IDX(e - s); |
| 3218 | |
| 3219 | switch(entry->maptype) { |
| 3220 | case VM_MAPTYPE_NORMAL: |
| 3221 | case VM_MAPTYPE_SUBMAP: |
| 3222 | object = entry->ba.object; |
| 3223 | break; |
| 3224 | default: |
| 3225 | object = NULL; |
| 3226 | break; |
| 3227 | } |
| 3228 | |
| 3229 | /* |
| 3230 | * Unwire before removing addresses from the pmap; otherwise, |
| 3231 | * unwiring will put the entries back in the pmap. |
| 3232 | * |
| 3233 | * Generally speaking, doing a bulk pmap_remove() before |
| 3234 | * removing the pages from the VM object is better at |
| 3235 | * reducing unnecessary IPIs. The pmap code is now optimized |
| 3236 | * to not blindly iterate the range when pt and pd pages |
| 3237 | * are missing. |
| 3238 | */ |
| 3239 | if (entry->wired_count != 0) |
| 3240 | vm_map_entry_unwire(map, entry); |
| 3241 | |
| 3242 | offidxend = offidxstart + count; |
| 3243 | |
| 3244 | if (object == kernel_object) { |
| 3245 | pmap_remove(map->pmap, s, e); |
| 3246 | vm_object_hold(object); |
| 3247 | vm_object_page_remove(object, offidxstart, |
| 3248 | offidxend, FALSE); |
| 3249 | vm_object_drop(object); |
| 3250 | } else if (object && object->type != OBJT_DEFAULT && |
| 3251 | object->type != OBJT_SWAP) { |
| 3252 | /* |
| 3253 | * vnode object routines cannot be chain-locked, |
| 3254 | * but since we aren't removing pages from the |
| 3255 | * object here we can use a shared hold. |
| 3256 | */ |
| 3257 | vm_object_hold_shared(object); |
| 3258 | pmap_remove(map->pmap, s, e); |
| 3259 | vm_object_drop(object); |
| 3260 | } else if (object) { |
| 3261 | vm_object_hold(object); |
| 3262 | pmap_remove(map->pmap, s, e); |
| 3263 | |
| 3264 | if (object != NULL && |
| 3265 | object->ref_count != 1 && |
| 3266 | (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == |
| 3267 | OBJ_ONEMAPPING && |
| 3268 | (object->type == OBJT_DEFAULT || |
| 3269 | object->type == OBJT_SWAP)) { |
| 3270 | /* |
| 3271 | * When ONEMAPPING is set we can destroy the |
| 3272 | * pages underlying the entry's range. |
| 3273 | */ |
| 3274 | vm_object_page_remove(object, offidxstart, |
| 3275 | offidxend, FALSE); |
| 3276 | if (object->type == OBJT_SWAP) { |
| 3277 | swap_pager_freespace(object, |
| 3278 | offidxstart, |
| 3279 | count); |
| 3280 | } |
| 3281 | if (offidxend >= object->size && |
| 3282 | offidxstart < object->size) { |
| 3283 | object->size = offidxstart; |
| 3284 | } |
| 3285 | } |
| 3286 | vm_object_drop(object); |
| 3287 | } else if (entry->maptype == VM_MAPTYPE_UKSMAP) { |
| 3288 | pmap_remove(map->pmap, s, e); |
| 3289 | } |
| 3290 | |
| 3291 | /* |
| 3292 | * Delete the entry (which may delete the object) only after |
| 3293 | * removing all pmap entries pointing to its pages. |
| 3294 | * (Otherwise, its page frames may be reallocated, and any |
| 3295 | * modify bits will be set in the wrong object!) |
| 3296 | */ |
| 3297 | vm_map_entry_delete(map, entry, countp); |
| 3298 | entry = next; |
| 3299 | } |
| 3300 | |
| 3301 | /* |
| 3302 | * We either reached the end and use vm_map_max as the end |
| 3303 | * address, or we didn't and we use the next entry as the |
| 3304 | * end address. |
| 3305 | */ |
| 3306 | if (entry == NULL) { |
| 3307 | vm_map_freehint_hole(map, hole_start, |
| 3308 | vm_map_max(map) - hole_start); |
| 3309 | } else { |
| 3310 | vm_map_freehint_hole(map, hole_start, |
| 3311 | entry->ba.start - hole_start); |
| 3312 | } |
| 3313 | |
| 3314 | lwkt_reltoken(&map->token); |
| 3315 | |
| 3316 | return (KERN_SUCCESS); |
| 3317 | } |
| 3318 | |
| 3319 | /* |
| 3320 | * Remove the given address range from the target map. |
| 3321 | * This is the exported form of vm_map_delete. |
| 3322 | * |
| 3323 | * No requirements. |
| 3324 | */ |
| 3325 | int |
| 3326 | vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end) |
| 3327 | { |
| 3328 | int result; |
| 3329 | int count; |
| 3330 | |
| 3331 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 3332 | vm_map_lock(map); |
| 3333 | VM_MAP_RANGE_CHECK(map, start, end); |
| 3334 | result = vm_map_delete(map, start, end, &count); |
| 3335 | vm_map_unlock(map); |
| 3336 | vm_map_entry_release(count); |
| 3337 | |
| 3338 | return (result); |
| 3339 | } |
| 3340 | |
| 3341 | /* |
| 3342 | * Assert that the target map allows the specified privilege on the |
| 3343 | * entire address region given. The entire region must be allocated. |
| 3344 | * |
| 3345 | * The caller must specify whether the vm_map is already locked or not. |
| 3346 | */ |
| 3347 | boolean_t |
| 3348 | vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end, |
| 3349 | vm_prot_t protection, boolean_t have_lock) |
| 3350 | { |
| 3351 | vm_map_entry_t entry; |
| 3352 | vm_map_entry_t tmp_entry; |
| 3353 | boolean_t result; |
| 3354 | |
| 3355 | if (have_lock == FALSE) |
| 3356 | vm_map_lock_read(map); |
| 3357 | |
| 3358 | if (!vm_map_lookup_entry(map, start, &tmp_entry)) { |
| 3359 | if (have_lock == FALSE) |
| 3360 | vm_map_unlock_read(map); |
| 3361 | return (FALSE); |
| 3362 | } |
| 3363 | entry = tmp_entry; |
| 3364 | |
| 3365 | result = TRUE; |
| 3366 | while (start < end) { |
| 3367 | if (entry == NULL) { |
| 3368 | result = FALSE; |
| 3369 | break; |
| 3370 | } |
| 3371 | |
| 3372 | /* |
| 3373 | * No holes allowed! |
| 3374 | */ |
| 3375 | |
| 3376 | if (start < entry->ba.start) { |
| 3377 | result = FALSE; |
| 3378 | break; |
| 3379 | } |
| 3380 | /* |
| 3381 | * Check protection associated with entry. |
| 3382 | */ |
| 3383 | |
| 3384 | if ((entry->protection & protection) != protection) { |
| 3385 | result = FALSE; |
| 3386 | break; |
| 3387 | } |
| 3388 | /* go to next entry */ |
| 3389 | start = entry->ba.end; |
| 3390 | entry = vm_map_rb_tree_RB_NEXT(entry); |
| 3391 | } |
| 3392 | if (have_lock == FALSE) |
| 3393 | vm_map_unlock_read(map); |
| 3394 | return (result); |
| 3395 | } |
| 3396 | |
| 3397 | /* |
| 3398 | * vm_map_backing structures are not shared across forks and must be |
| 3399 | * replicated. |
| 3400 | * |
| 3401 | * Generally speaking we must reallocate the backing_ba sequence and |
| 3402 | * also adjust it for any changes made to the base entry->ba.start and |
| 3403 | * entry->ba.end. The first ba in the chain is of course &entry->ba, |
| 3404 | * so we only need to adjust subsequent ba's start, end, and offset. |
| 3405 | * |
| 3406 | * MAP_BACK_CLIPPED - Called as part of a clipping replication. |
| 3407 | * Do not clear OBJ_ONEMAPPING. |
| 3408 | * |
| 3409 | * MAP_BACK_BASEOBJREFD - Called from vm_map_insert(). The base object |
| 3410 | * has already been referenced. |
| 3411 | */ |
| 3412 | static |
| 3413 | void |
| 3414 | vm_map_backing_replicated(vm_map_t map, vm_map_entry_t entry, int flags) |
| 3415 | { |
| 3416 | vm_map_backing_t ba; |
| 3417 | vm_map_backing_t nba; |
| 3418 | vm_object_t object; |
| 3419 | |
| 3420 | ba = &entry->ba; |
| 3421 | for (;;) { |
| 3422 | ba->pmap = map->pmap; |
| 3423 | |
| 3424 | if (ba->map_object) { |
| 3425 | switch(entry->maptype) { |
| 3426 | case VM_MAPTYPE_NORMAL: |
| 3427 | object = ba->object; |
| 3428 | if (ba != &entry->ba || |
| 3429 | (flags & MAP_BACK_BASEOBJREFD) == 0) { |
| 3430 | vm_object_reference_quick(object); |
| 3431 | } |
| 3432 | vm_map_backing_attach(entry, ba); |
| 3433 | if ((flags & MAP_BACK_CLIPPED) == 0 && |
| 3434 | object->ref_count > 1) { |
| 3435 | vm_object_clear_flag(object, |
| 3436 | OBJ_ONEMAPPING); |
| 3437 | } |
| 3438 | break; |
| 3439 | case VM_MAPTYPE_UKSMAP: |
| 3440 | vm_map_backing_attach(entry, ba); |
| 3441 | break; |
| 3442 | default: |
| 3443 | break; |
| 3444 | } |
| 3445 | } |
| 3446 | if (ba->backing_ba == NULL) |
| 3447 | break; |
| 3448 | |
| 3449 | /* |
| 3450 | * NOTE: The aux_info field is retained. |
| 3451 | */ |
| 3452 | nba = kmalloc(sizeof(*nba), M_MAP_BACKING, M_INTWAIT); |
| 3453 | *nba = *ba->backing_ba; |
| 3454 | nba->offset += (ba->start - nba->start); /* += (new - old) */ |
| 3455 | nba->start = ba->start; |
| 3456 | nba->end = ba->end; |
| 3457 | ba->backing_ba = nba; |
| 3458 | ba = nba; |
| 3459 | /* pmap is replaced at the top of the loop */ |
| 3460 | } |
| 3461 | } |
| 3462 | |
| 3463 | static |
| 3464 | void |
| 3465 | vm_map_backing_adjust_start(vm_map_entry_t entry, vm_ooffset_t start) |
| 3466 | { |
| 3467 | vm_map_backing_t ba; |
| 3468 | |
| 3469 | if (entry->maptype == VM_MAPTYPE_NORMAL) { |
| 3470 | for (ba = &entry->ba; ba; ba = ba->backing_ba) { |
| 3471 | if (ba->object) { |
| 3472 | lockmgr(&ba->object->backing_lk, LK_EXCLUSIVE); |
| 3473 | ba->offset += (start - ba->start); |
| 3474 | ba->start = start; |
| 3475 | lockmgr(&ba->object->backing_lk, LK_RELEASE); |
| 3476 | } else { |
| 3477 | ba->offset += (start - ba->start); |
| 3478 | ba->start = start; |
| 3479 | } |
| 3480 | } |
| 3481 | } else { |
| 3482 | /* not an object and can't be shadowed */ |
| 3483 | } |
| 3484 | } |
| 3485 | |
| 3486 | static |
| 3487 | void |
| 3488 | vm_map_backing_adjust_end(vm_map_entry_t entry, vm_ooffset_t end) |
| 3489 | { |
| 3490 | vm_map_backing_t ba; |
| 3491 | |
| 3492 | if (entry->maptype == VM_MAPTYPE_NORMAL) { |
| 3493 | for (ba = &entry->ba; ba; ba = ba->backing_ba) { |
| 3494 | if (ba->object) { |
| 3495 | lockmgr(&ba->object->backing_lk, LK_EXCLUSIVE); |
| 3496 | ba->end = end; |
| 3497 | lockmgr(&ba->object->backing_lk, LK_RELEASE); |
| 3498 | } else { |
| 3499 | ba->end = end; |
| 3500 | } |
| 3501 | } |
| 3502 | } /* else not an object and/or can't be shadowed */ |
| 3503 | } |
| 3504 | |
| 3505 | /* |
| 3506 | * Handles the dirty work of making src_entry and dst_entry copy-on-write |
| 3507 | * after src_entry has been cloned to dst_entry. For normal entries only. |
| 3508 | * |
| 3509 | * The vm_maps must be exclusively locked. |
| 3510 | * The vm_map's token must be held. |
| 3511 | * |
| 3512 | * Because the maps are locked no faults can be in progress during the |
| 3513 | * operation. |
| 3514 | */ |
| 3515 | static void |
| 3516 | vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map, |
| 3517 | vm_map_entry_t src_entry, vm_map_entry_t dst_entry) |
| 3518 | { |
| 3519 | vm_object_t obj; |
| 3520 | |
| 3521 | KKASSERT(dst_entry->maptype == VM_MAPTYPE_NORMAL); |
| 3522 | |
| 3523 | if (src_entry->wired_count) { |
| 3524 | /* |
| 3525 | * Of course, wired down pages can't be set copy-on-write. |
| 3526 | * Cause wired pages to be copied into the new map by |
| 3527 | * simulating faults (the new pages are pageable) |
| 3528 | * |
| 3529 | * Scrap ba.object (its ref-count has not yet been adjusted |
| 3530 | * so we can just NULL out the field). Remove the backing |
| 3531 | * store. |
| 3532 | * |
| 3533 | * Then call vm_fault_copy_entry() to create a new object |
| 3534 | * in dst_entry and copy the wired pages from src to dst. |
| 3535 | * |
| 3536 | * The fault-copy code doesn't work with virtual page |
| 3537 | * tables. |
| 3538 | * |
| 3539 | * NOTE: obj is not actually an object for all MAPTYPEs, |
| 3540 | * just test against NULL. |
| 3541 | */ |
| 3542 | if (dst_entry->ba.map_object != NULL) { |
| 3543 | vm_map_backing_detach(dst_entry, &dst_entry->ba); |
| 3544 | dst_entry->ba.map_object = NULL; |
| 3545 | vm_map_entry_dispose_ba(dst_entry, |
| 3546 | dst_entry->ba.backing_ba); |
| 3547 | dst_entry->ba.backing_ba = NULL; |
| 3548 | dst_entry->ba.backing_count = 0; |
| 3549 | } |
| 3550 | vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); |
| 3551 | } else { |
| 3552 | if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) { |
| 3553 | /* |
| 3554 | * If the source entry is not already marked NEEDS_COPY |
| 3555 | * we need to write-protect the PTEs. |
| 3556 | */ |
| 3557 | pmap_protect(src_map->pmap, |
| 3558 | src_entry->ba.start, |
| 3559 | src_entry->ba.end, |
| 3560 | src_entry->protection & ~VM_PROT_WRITE); |
| 3561 | } |
| 3562 | |
| 3563 | /* |
| 3564 | * dst_entry.ba_object might be stale. Update it (its |
| 3565 | * ref-count has not yet been updated so just overwrite |
| 3566 | * the field). |
| 3567 | * |
| 3568 | * If there is no object then we are golden. Also, in |
| 3569 | * this situation if there are no backing_ba linkages then |
| 3570 | * we can set ba.offset to whatever we want. For now we |
| 3571 | * set the offset for 0 for make debugging object sizes |
| 3572 | * easier. |
| 3573 | */ |
| 3574 | obj = src_entry->ba.object; |
| 3575 | |
| 3576 | if (obj) { |
| 3577 | src_entry->eflags |= (MAP_ENTRY_COW | |
| 3578 | MAP_ENTRY_NEEDS_COPY); |
| 3579 | dst_entry->eflags |= (MAP_ENTRY_COW | |
| 3580 | MAP_ENTRY_NEEDS_COPY); |
| 3581 | KKASSERT(dst_entry->ba.offset == src_entry->ba.offset); |
| 3582 | } else { |
| 3583 | dst_entry->ba.offset = 0; |
| 3584 | } |
| 3585 | |
| 3586 | /* |
| 3587 | * Normal, allow the backing_ba link depth to |
| 3588 | * increase. |
| 3589 | */ |
| 3590 | pmap_copy(dst_map->pmap, src_map->pmap, |
| 3591 | dst_entry->ba.start, |
| 3592 | dst_entry->ba.end - dst_entry->ba.start, |
| 3593 | src_entry->ba.start); |
| 3594 | } |
| 3595 | } |
| 3596 | |
| 3597 | /* |
| 3598 | * Create a vmspace for a new process and its related vm_map based on an |
| 3599 | * existing vmspace. The new map inherits information from the old map |
| 3600 | * according to inheritance settings. |
| 3601 | * |
| 3602 | * The source map must not be locked. |
| 3603 | * No requirements. |
| 3604 | */ |
| 3605 | static void vmspace_fork_normal_entry(vm_map_t old_map, vm_map_t new_map, |
| 3606 | vm_map_entry_t old_entry, int *countp); |
| 3607 | static void vmspace_fork_uksmap_entry(struct proc *p2, struct lwp *lp2, |
| 3608 | vm_map_t old_map, vm_map_t new_map, |
| 3609 | vm_map_entry_t old_entry, int *countp); |
| 3610 | |
| 3611 | struct vmspace * |
| 3612 | vmspace_fork(struct vmspace *vm1, struct proc *p2, struct lwp *lp2) |
| 3613 | { |
| 3614 | struct vmspace *vm2; |
| 3615 | vm_map_t old_map = &vm1->vm_map; |
| 3616 | vm_map_t new_map; |
| 3617 | vm_map_entry_t old_entry; |
| 3618 | int count; |
| 3619 | |
| 3620 | lwkt_gettoken(&vm1->vm_map.token); |
| 3621 | vm_map_lock(old_map); |
| 3622 | |
| 3623 | vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map)); |
| 3624 | lwkt_gettoken(&vm2->vm_map.token); |
| 3625 | |
| 3626 | /* |
| 3627 | * We must bump the timestamp to force any concurrent fault |
| 3628 | * to retry. |
| 3629 | */ |
| 3630 | bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy, |
| 3631 | (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy); |
| 3632 | new_map = &vm2->vm_map; /* XXX */ |
| 3633 | new_map->timestamp = 1; |
| 3634 | |
| 3635 | vm_map_lock(new_map); |
| 3636 | |
| 3637 | count = old_map->nentries; |
| 3638 | count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT); |
| 3639 | |
| 3640 | RB_FOREACH(old_entry, vm_map_rb_tree, &old_map->rb_root) { |
| 3641 | switch(old_entry->maptype) { |
| 3642 | case VM_MAPTYPE_SUBMAP: |
| 3643 | panic("vm_map_fork: encountered a submap"); |
| 3644 | break; |
| 3645 | case VM_MAPTYPE_UKSMAP: |
| 3646 | vmspace_fork_uksmap_entry(p2, lp2, |
| 3647 | old_map, new_map, |
| 3648 | old_entry, &count); |
| 3649 | break; |
| 3650 | case VM_MAPTYPE_NORMAL: |
| 3651 | vmspace_fork_normal_entry(old_map, new_map, |
| 3652 | old_entry, &count); |
| 3653 | break; |
| 3654 | default: |
| 3655 | /* nothing to do */ |
| 3656 | break; |
| 3657 | } |
| 3658 | } |
| 3659 | |
| 3660 | new_map->size = old_map->size; |
| 3661 | vm_map_unlock(new_map); |
| 3662 | vm_map_unlock(old_map); |
| 3663 | vm_map_entry_release(count); |
| 3664 | |
| 3665 | lwkt_reltoken(&vm2->vm_map.token); |
| 3666 | lwkt_reltoken(&vm1->vm_map.token); |
| 3667 | |
| 3668 | return (vm2); |
| 3669 | } |
| 3670 | |
| 3671 | static |
| 3672 | void |
| 3673 | vmspace_fork_normal_entry(vm_map_t old_map, vm_map_t new_map, |
| 3674 | vm_map_entry_t old_entry, int *countp) |
| 3675 | { |
| 3676 | vm_map_entry_t new_entry; |
| 3677 | vm_map_backing_t ba; |
| 3678 | vm_object_t object; |
| 3679 | |
| 3680 | /* |
| 3681 | * If the backing_ba link list gets too long then fault it |
| 3682 | * all into the head object and dispose of the list. We do |
| 3683 | * this in old_entry prior to cloning in order to benefit both |
| 3684 | * parent and child. |
| 3685 | * |
| 3686 | * We can test our fronting object's size against its |
| 3687 | * resident_page_count for a really cheap (but probably not perfect) |
| 3688 | * all-shadowed test, allowing us to disconnect the backing_ba |
| 3689 | * link list early. |
| 3690 | */ |
| 3691 | object = old_entry->ba.object; |
| 3692 | if (old_entry->ba.backing_ba && |
| 3693 | (old_entry->ba.backing_count >= vm_map_backing_limit || |
| 3694 | (vm_map_backing_shadow_test && object && |
| 3695 | object->size == object->resident_page_count))) { |
| 3696 | /* |
| 3697 | * If there are too many backing_ba linkages we |
| 3698 | * collapse everything into the head |
| 3699 | * |
| 3700 | * This will also remove all the pte's. |
| 3701 | */ |
| 3702 | if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) |
| 3703 | vm_map_entry_shadow(old_entry); |
| 3704 | if (object == NULL) |
| 3705 | vm_map_entry_allocate_object(old_entry); |
| 3706 | if (vm_fault_collapse(old_map, old_entry) == KERN_SUCCESS) { |
| 3707 | ba = old_entry->ba.backing_ba; |
| 3708 | old_entry->ba.backing_ba = NULL; |
| 3709 | old_entry->ba.backing_count = 0; |
| 3710 | vm_map_entry_dispose_ba(old_entry, ba); |
| 3711 | } |
| 3712 | } |
| 3713 | object = NULL; /* object variable is now invalid */ |
| 3714 | |
| 3715 | /* |
| 3716 | * Fork the entry |
| 3717 | */ |
| 3718 | switch (old_entry->inheritance) { |
| 3719 | case VM_INHERIT_NONE: |
| 3720 | break; |
| 3721 | case VM_INHERIT_SHARE: |
| 3722 | /* |
| 3723 | * Clone the entry as a shared entry. This will look like |
| 3724 | * shared memory across the old and the new process. We must |
| 3725 | * ensure that the object is allocated. |
| 3726 | */ |
| 3727 | if (old_entry->ba.object == NULL) |
| 3728 | vm_map_entry_allocate_object(old_entry); |
| 3729 | |
| 3730 | if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) { |
| 3731 | /* |
| 3732 | * Create the fronting vm_map_backing for |
| 3733 | * an entry which needs a copy, plus an extra |
| 3734 | * ref because we are going to duplicate it |
| 3735 | * in the fork. |
| 3736 | * |
| 3737 | * The call to vm_map_entry_shadow() will also clear |
| 3738 | * OBJ_ONEMAPPING. |
| 3739 | * |
| 3740 | * XXX no more collapse. Still need extra ref |
| 3741 | * for the fork. |
| 3742 | */ |
| 3743 | vm_map_entry_shadow(old_entry); |
| 3744 | } else if (old_entry->ba.object) { |
| 3745 | object = old_entry->ba.object; |
| 3746 | } |
| 3747 | |
| 3748 | /* |
| 3749 | * Clone the entry. We've already bumped the ref on |
| 3750 | * the vm_object for our new entry. |
| 3751 | */ |
| 3752 | new_entry = vm_map_entry_create(countp); |
| 3753 | *new_entry = *old_entry; |
| 3754 | |
| 3755 | new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; |
| 3756 | new_entry->wired_count = 0; |
| 3757 | |
| 3758 | /* |
| 3759 | * Replicate and index the vm_map_backing. Don't share |
| 3760 | * the vm_map_backing across vm_map's (only across clips). |
| 3761 | * |
| 3762 | * Insert the entry into the new map -- we know we're |
| 3763 | * inserting at the end of the new map. |
| 3764 | */ |
| 3765 | vm_map_backing_replicated(new_map, new_entry, 0); |
| 3766 | vm_map_entry_link(new_map, new_entry); |
| 3767 | |
| 3768 | /* |
| 3769 | * Update the physical map |
| 3770 | */ |
| 3771 | pmap_copy(new_map->pmap, old_map->pmap, |
| 3772 | new_entry->ba.start, |
| 3773 | (old_entry->ba.end - old_entry->ba.start), |
| 3774 | old_entry->ba.start); |
| 3775 | break; |
| 3776 | case VM_INHERIT_COPY: |
| 3777 | /* |
| 3778 | * Clone the entry and link the copy into the new map. |
| 3779 | * |
| 3780 | * Note that ref-counting adjustment for old_entry->ba.object |
| 3781 | * (if it isn't a special map that is) is handled by |
| 3782 | * vm_map_copy_entry(). |
| 3783 | */ |
| 3784 | new_entry = vm_map_entry_create(countp); |
| 3785 | *new_entry = *old_entry; |
| 3786 | |
| 3787 | new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; |
| 3788 | new_entry->wired_count = 0; |
| 3789 | |
| 3790 | vm_map_backing_replicated(new_map, new_entry, 0); |
| 3791 | vm_map_entry_link(new_map, new_entry); |
| 3792 | |
| 3793 | /* |
| 3794 | * This does the actual dirty work of making both entries |
| 3795 | * copy-on-write, and will also handle the fronting object. |
| 3796 | */ |
| 3797 | vm_map_copy_entry(old_map, new_map, old_entry, new_entry); |
| 3798 | break; |
| 3799 | } |
| 3800 | } |
| 3801 | |
| 3802 | /* |
| 3803 | * When forking user-kernel shared maps, the map might change in the |
| 3804 | * child so do not try to copy the underlying pmap entries. |
| 3805 | */ |
| 3806 | static |
| 3807 | void |
| 3808 | vmspace_fork_uksmap_entry(struct proc *p2, struct lwp *lp2, |
| 3809 | vm_map_t old_map, vm_map_t new_map, |
| 3810 | vm_map_entry_t old_entry, int *countp) |
| 3811 | { |
| 3812 | vm_map_entry_t new_entry; |
| 3813 | |
| 3814 | /* |
| 3815 | * Do not fork lpmap entries whos TIDs do not match lp2's tid. |
| 3816 | * |
| 3817 | * XXX if p2 is NULL and lp2 is non-NULL, we retain the lpmap entry |
| 3818 | * (this is for e.g. resident'ing vmspace's) but set the field |
| 3819 | * to NULL. Upon restore it should be restored. XXX NOT IMPL YET |
| 3820 | */ |
| 3821 | if (old_entry->aux.dev) { |
| 3822 | switch(minor(old_entry->aux.dev)) { |
| 3823 | case 5: |
| 3824 | break; |
| 3825 | case 6: |
| 3826 | break; |
| 3827 | case 7: |
| 3828 | if (lp2 == NULL) |
| 3829 | return; |
| 3830 | if (old_entry->ba.aux_info == NULL) |
| 3831 | return; |
| 3832 | if (((struct lwp *)old_entry->ba.aux_info)->lwp_tid != |
| 3833 | lp2->lwp_tid) |
| 3834 | return; |
| 3835 | break; |
| 3836 | } |
| 3837 | } |
| 3838 | |
| 3839 | new_entry = vm_map_entry_create(countp); |
| 3840 | *new_entry = *old_entry; |
| 3841 | |
| 3842 | new_entry->eflags &= ~MAP_ENTRY_USER_WIRED; |
| 3843 | new_entry->wired_count = 0; |
| 3844 | KKASSERT(new_entry->ba.backing_ba == NULL); |
| 3845 | |
| 3846 | if (new_entry->aux.dev) { |
| 3847 | switch(minor(new_entry->aux.dev)) { |
| 3848 | case 5: |
| 3849 | /* |
| 3850 | * upmap |
| 3851 | */ |
| 3852 | new_entry->ba.aux_info = p2; |
| 3853 | break; |
| 3854 | case 6: |
| 3855 | /* |
| 3856 | * kpmap |
| 3857 | */ |
| 3858 | new_entry->ba.aux_info = NULL; |
| 3859 | break; |
| 3860 | case 7: |
| 3861 | /* |
| 3862 | * lpmap |
| 3863 | */ |
| 3864 | new_entry->ba.aux_info = lp2; |
| 3865 | break; |
| 3866 | } |
| 3867 | } else { |
| 3868 | new_entry->ba.aux_info = NULL; |
| 3869 | } |
| 3870 | |
| 3871 | vm_map_backing_replicated(new_map, new_entry, 0); |
| 3872 | |
| 3873 | vm_map_entry_link(new_map, new_entry); |
| 3874 | } |
| 3875 | |
| 3876 | /* |
| 3877 | * Create an auto-grow stack entry |
| 3878 | * |
| 3879 | * No requirements. |
| 3880 | */ |
| 3881 | int |
| 3882 | vm_map_stack (vm_map_t map, vm_offset_t *addrbos, vm_size_t max_ssize, |
| 3883 | int flags, vm_prot_t prot, vm_prot_t max, int cow) |
| 3884 | { |
| 3885 | vm_map_entry_t prev_entry; |
| 3886 | vm_map_entry_t next; |
| 3887 | vm_size_t init_ssize; |
| 3888 | int rv; |
| 3889 | int count; |
| 3890 | vm_offset_t tmpaddr; |
| 3891 | |
| 3892 | cow |= MAP_IS_STACK; |
| 3893 | |
| 3894 | if (max_ssize < sgrowsiz) |
| 3895 | init_ssize = max_ssize; |
| 3896 | else |
| 3897 | init_ssize = sgrowsiz; |
| 3898 | |
| 3899 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 3900 | vm_map_lock(map); |
| 3901 | |
| 3902 | /* |
| 3903 | * Find space for the mapping |
| 3904 | */ |
| 3905 | if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) { |
| 3906 | if (vm_map_findspace(map, *addrbos, max_ssize, 1, |
| 3907 | flags, &tmpaddr)) { |
| 3908 | vm_map_unlock(map); |
| 3909 | vm_map_entry_release(count); |
| 3910 | return (KERN_NO_SPACE); |
| 3911 | } |
| 3912 | *addrbos = tmpaddr; |
| 3913 | } |
| 3914 | |
| 3915 | /* If addr is already mapped, no go */ |
| 3916 | if (vm_map_lookup_entry(map, *addrbos, &prev_entry)) { |
| 3917 | vm_map_unlock(map); |
| 3918 | vm_map_entry_release(count); |
| 3919 | return (KERN_NO_SPACE); |
| 3920 | } |
| 3921 | |
| 3922 | #if 0 |
| 3923 | /* XXX already handled by kern_mmap() */ |
| 3924 | /* If we would blow our VMEM resource limit, no go */ |
| 3925 | if (map->size + init_ssize > |
| 3926 | curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) { |
| 3927 | vm_map_unlock(map); |
| 3928 | vm_map_entry_release(count); |
| 3929 | return (KERN_NO_SPACE); |
| 3930 | } |
| 3931 | #endif |
| 3932 | |
| 3933 | /* |
| 3934 | * If we can't accomodate max_ssize in the current mapping, |
| 3935 | * no go. However, we need to be aware that subsequent user |
| 3936 | * mappings might map into the space we have reserved for |
| 3937 | * stack, and currently this space is not protected. |
| 3938 | * |
| 3939 | * Hopefully we will at least detect this condition |
| 3940 | * when we try to grow the stack. |
| 3941 | */ |
| 3942 | if (prev_entry) |
| 3943 | next = vm_map_rb_tree_RB_NEXT(prev_entry); |
| 3944 | else |
| 3945 | next = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 3946 | |
| 3947 | if (next && next->ba.start < *addrbos + max_ssize) { |
| 3948 | vm_map_unlock(map); |
| 3949 | vm_map_entry_release(count); |
| 3950 | return (KERN_NO_SPACE); |
| 3951 | } |
| 3952 | |
| 3953 | /* |
| 3954 | * We initially map a stack of only init_ssize. We will |
| 3955 | * grow as needed later. Since this is to be a grow |
| 3956 | * down stack, we map at the top of the range. |
| 3957 | * |
| 3958 | * Note: we would normally expect prot and max to be |
| 3959 | * VM_PROT_ALL, and cow to be 0. Possibly we should |
| 3960 | * eliminate these as input parameters, and just |
| 3961 | * pass these values here in the insert call. |
| 3962 | */ |
| 3963 | rv = vm_map_insert(map, &count, |
| 3964 | NULL, NULL, |
| 3965 | 0, NULL, |
| 3966 | *addrbos + max_ssize - init_ssize, |
| 3967 | *addrbos + max_ssize, |
| 3968 | VM_MAPTYPE_NORMAL, |
| 3969 | VM_SUBSYS_STACK, prot, max, cow); |
| 3970 | |
| 3971 | /* Now set the avail_ssize amount */ |
| 3972 | if (rv == KERN_SUCCESS) { |
| 3973 | if (prev_entry) |
| 3974 | next = vm_map_rb_tree_RB_NEXT(prev_entry); |
| 3975 | else |
| 3976 | next = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 3977 | if (prev_entry != NULL) { |
| 3978 | vm_map_clip_end(map, |
| 3979 | prev_entry, |
| 3980 | *addrbos + max_ssize - init_ssize, |
| 3981 | &count); |
| 3982 | } |
| 3983 | if (next->ba.end != *addrbos + max_ssize || |
| 3984 | next->ba.start != *addrbos + max_ssize - init_ssize){ |
| 3985 | panic ("Bad entry start/end for new stack entry"); |
| 3986 | } else { |
| 3987 | next->aux.avail_ssize = max_ssize - init_ssize; |
| 3988 | } |
| 3989 | } |
| 3990 | |
| 3991 | vm_map_unlock(map); |
| 3992 | vm_map_entry_release(count); |
| 3993 | return (rv); |
| 3994 | } |
| 3995 | |
| 3996 | /* |
| 3997 | * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the |
| 3998 | * desired address is already mapped, or if we successfully grow |
| 3999 | * the stack. Also returns KERN_SUCCESS if addr is outside the |
| 4000 | * stack range (this is strange, but preserves compatibility with |
| 4001 | * the grow function in vm_machdep.c). |
| 4002 | * |
| 4003 | * No requirements. |
| 4004 | */ |
| 4005 | int |
| 4006 | vm_map_growstack (vm_map_t map, vm_offset_t addr) |
| 4007 | { |
| 4008 | vm_map_entry_t prev_entry; |
| 4009 | vm_map_entry_t stack_entry; |
| 4010 | vm_map_entry_t next; |
| 4011 | struct vmspace *vm; |
| 4012 | struct lwp *lp; |
| 4013 | struct proc *p; |
| 4014 | vm_offset_t end; |
| 4015 | int grow_amount; |
| 4016 | int rv = KERN_SUCCESS; |
| 4017 | int is_procstack; |
| 4018 | int use_read_lock = 1; |
| 4019 | int count; |
| 4020 | |
| 4021 | /* |
| 4022 | * Find the vm |
| 4023 | */ |
| 4024 | lp = curthread->td_lwp; |
| 4025 | p = curthread->td_proc; |
| 4026 | KKASSERT(lp != NULL); |
| 4027 | vm = lp->lwp_vmspace; |
| 4028 | |
| 4029 | /* |
| 4030 | * Growstack is only allowed on the current process. We disallow |
| 4031 | * other use cases, e.g. trying to access memory via procfs that |
| 4032 | * the stack hasn't grown into. |
| 4033 | */ |
| 4034 | if (map != &vm->vm_map) { |
| 4035 | return KERN_FAILURE; |
| 4036 | } |
| 4037 | |
| 4038 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 4039 | Retry: |
| 4040 | if (use_read_lock) |
| 4041 | vm_map_lock_read(map); |
| 4042 | else |
| 4043 | vm_map_lock(map); |
| 4044 | |
| 4045 | /* |
| 4046 | * If addr is already in the entry range, no need to grow. |
| 4047 | * prev_entry returns NULL if addr is at the head. |
| 4048 | */ |
| 4049 | if (vm_map_lookup_entry(map, addr, &prev_entry)) |
| 4050 | goto done; |
| 4051 | if (prev_entry) |
| 4052 | stack_entry = vm_map_rb_tree_RB_NEXT(prev_entry); |
| 4053 | else |
| 4054 | stack_entry = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 4055 | |
| 4056 | if (stack_entry == NULL) |
| 4057 | goto done; |
| 4058 | if (prev_entry == NULL) |
| 4059 | end = stack_entry->ba.start - stack_entry->aux.avail_ssize; |
| 4060 | else |
| 4061 | end = prev_entry->ba.end; |
| 4062 | |
| 4063 | /* |
| 4064 | * This next test mimics the old grow function in vm_machdep.c. |
| 4065 | * It really doesn't quite make sense, but we do it anyway |
| 4066 | * for compatibility. |
| 4067 | * |
| 4068 | * If not growable stack, return success. This signals the |
| 4069 | * caller to proceed as he would normally with normal vm. |
| 4070 | */ |
| 4071 | if (stack_entry->aux.avail_ssize < 1 || |
| 4072 | addr >= stack_entry->ba.start || |
| 4073 | addr < stack_entry->ba.start - stack_entry->aux.avail_ssize) { |
| 4074 | goto done; |
| 4075 | } |
| 4076 | |
| 4077 | /* Find the minimum grow amount */ |
| 4078 | grow_amount = roundup (stack_entry->ba.start - addr, PAGE_SIZE); |
| 4079 | if (grow_amount > stack_entry->aux.avail_ssize) { |
| 4080 | rv = KERN_NO_SPACE; |
| 4081 | goto done; |
| 4082 | } |
| 4083 | |
| 4084 | /* |
| 4085 | * If there is no longer enough space between the entries |
| 4086 | * nogo, and adjust the available space. Note: this |
| 4087 | * should only happen if the user has mapped into the |
| 4088 | * stack area after the stack was created, and is |
| 4089 | * probably an error. |
| 4090 | * |
| 4091 | * This also effectively destroys any guard page the user |
| 4092 | * might have intended by limiting the stack size. |
| 4093 | */ |
| 4094 | if (grow_amount > stack_entry->ba.start - end) { |
| 4095 | if (use_read_lock && vm_map_lock_upgrade(map)) { |
| 4096 | /* lost lock */ |
| 4097 | use_read_lock = 0; |
| 4098 | goto Retry; |
| 4099 | } |
| 4100 | use_read_lock = 0; |
| 4101 | stack_entry->aux.avail_ssize = stack_entry->ba.start - end; |
| 4102 | rv = KERN_NO_SPACE; |
| 4103 | goto done; |
| 4104 | } |
| 4105 | |
| 4106 | is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr; |
| 4107 | |
| 4108 | /* If this is the main process stack, see if we're over the |
| 4109 | * stack limit. |
| 4110 | */ |
| 4111 | if (is_procstack && (vm->vm_ssize + grow_amount > |
| 4112 | p->p_rlimit[RLIMIT_STACK].rlim_cur)) { |
| 4113 | rv = KERN_NO_SPACE; |
| 4114 | goto done; |
| 4115 | } |
| 4116 | |
| 4117 | /* Round up the grow amount modulo SGROWSIZ */ |
| 4118 | grow_amount = roundup (grow_amount, sgrowsiz); |
| 4119 | if (grow_amount > stack_entry->aux.avail_ssize) { |
| 4120 | grow_amount = stack_entry->aux.avail_ssize; |
| 4121 | } |
| 4122 | if (is_procstack && (vm->vm_ssize + grow_amount > |
| 4123 | p->p_rlimit[RLIMIT_STACK].rlim_cur)) { |
| 4124 | grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur - vm->vm_ssize; |
| 4125 | } |
| 4126 | |
| 4127 | /* If we would blow our VMEM resource limit, no go */ |
| 4128 | if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) { |
| 4129 | rv = KERN_NO_SPACE; |
| 4130 | goto done; |
| 4131 | } |
| 4132 | |
| 4133 | if (use_read_lock && vm_map_lock_upgrade(map)) { |
| 4134 | /* lost lock */ |
| 4135 | use_read_lock = 0; |
| 4136 | goto Retry; |
| 4137 | } |
| 4138 | use_read_lock = 0; |
| 4139 | |
| 4140 | /* Get the preliminary new entry start value */ |
| 4141 | addr = stack_entry->ba.start - grow_amount; |
| 4142 | |
| 4143 | /* If this puts us into the previous entry, cut back our growth |
| 4144 | * to the available space. Also, see the note above. |
| 4145 | */ |
| 4146 | if (addr < end) { |
| 4147 | stack_entry->aux.avail_ssize = stack_entry->ba.start - end; |
| 4148 | addr = end; |
| 4149 | } |
| 4150 | |
| 4151 | rv = vm_map_insert(map, &count, |
| 4152 | NULL, NULL, |
| 4153 | 0, NULL, |
| 4154 | addr, stack_entry->ba.start, |
| 4155 | VM_MAPTYPE_NORMAL, |
| 4156 | VM_SUBSYS_STACK, VM_PROT_ALL, VM_PROT_ALL, 0); |
| 4157 | |
| 4158 | /* Adjust the available stack space by the amount we grew. */ |
| 4159 | if (rv == KERN_SUCCESS) { |
| 4160 | if (prev_entry) { |
| 4161 | vm_map_clip_end(map, prev_entry, addr, &count); |
| 4162 | next = vm_map_rb_tree_RB_NEXT(prev_entry); |
| 4163 | } else { |
| 4164 | next = RB_MIN(vm_map_rb_tree, &map->rb_root); |
| 4165 | } |
| 4166 | if (next->ba.end != stack_entry->ba.start || |
| 4167 | next->ba.start != addr) { |
| 4168 | panic ("Bad stack grow start/end in new stack entry"); |
| 4169 | } else { |
| 4170 | next->aux.avail_ssize = |
| 4171 | stack_entry->aux.avail_ssize - |
| 4172 | (next->ba.end - next->ba.start); |
| 4173 | if (is_procstack) { |
| 4174 | vm->vm_ssize += next->ba.end - |
| 4175 | next->ba.start; |
| 4176 | } |
| 4177 | } |
| 4178 | |
| 4179 | if (map->flags & MAP_WIREFUTURE) { |
| 4180 | vm_map_user_wiring(map, |
| 4181 | next->ba.start, |
| 4182 | next->ba.end, |
| 4183 | FALSE); |
| 4184 | } |
| 4185 | } |
| 4186 | |
| 4187 | done: |
| 4188 | if (use_read_lock) |
| 4189 | vm_map_unlock_read(map); |
| 4190 | else |
| 4191 | vm_map_unlock(map); |
| 4192 | vm_map_entry_release(count); |
| 4193 | return (rv); |
| 4194 | } |
| 4195 | |
| 4196 | /* |
| 4197 | * Unshare the specified VM space for exec. If other processes are |
| 4198 | * mapped to it, then create a new one. The new vmspace is null. |
| 4199 | * |
| 4200 | * No requirements. |
| 4201 | */ |
| 4202 | void |
| 4203 | vmspace_exec(struct proc *p, struct vmspace *vmcopy) |
| 4204 | { |
| 4205 | struct vmspace *oldvmspace = p->p_vmspace; |
| 4206 | struct vmspace *newvmspace; |
| 4207 | vm_map_t map = &p->p_vmspace->vm_map; |
| 4208 | |
| 4209 | /* |
| 4210 | * If we are execing a resident vmspace we fork it, otherwise |
| 4211 | * we create a new vmspace. Note that exitingcnt is not |
| 4212 | * copied to the new vmspace. |
| 4213 | */ |
| 4214 | lwkt_gettoken(&oldvmspace->vm_map.token); |
| 4215 | if (vmcopy) { |
| 4216 | newvmspace = vmspace_fork(vmcopy, NULL, NULL); |
| 4217 | lwkt_gettoken(&newvmspace->vm_map.token); |
| 4218 | } else { |
| 4219 | newvmspace = vmspace_alloc(vm_map_min(map), vm_map_max(map)); |
| 4220 | lwkt_gettoken(&newvmspace->vm_map.token); |
| 4221 | bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy, |
| 4222 | (caddr_t)&oldvmspace->vm_endcopy - |
| 4223 | (caddr_t)&oldvmspace->vm_startcopy); |
| 4224 | } |
| 4225 | |
| 4226 | /* |
| 4227 | * Finish initializing the vmspace before assigning it |
| 4228 | * to the process. The vmspace will become the current vmspace |
| 4229 | * if p == curproc. |
| 4230 | */ |
| 4231 | pmap_pinit2(vmspace_pmap(newvmspace)); |
| 4232 | pmap_replacevm(p, newvmspace, 0); |
| 4233 | lwkt_reltoken(&newvmspace->vm_map.token); |
| 4234 | lwkt_reltoken(&oldvmspace->vm_map.token); |
| 4235 | vmspace_rel(oldvmspace); |
| 4236 | } |
| 4237 | |
| 4238 | /* |
| 4239 | * Unshare the specified VM space for forcing COW. This |
| 4240 | * is called by rfork, for the (RFMEM|RFPROC) == 0 case. |
| 4241 | */ |
| 4242 | void |
| 4243 | vmspace_unshare(struct proc *p) |
| 4244 | { |
| 4245 | struct vmspace *oldvmspace = p->p_vmspace; |
| 4246 | struct vmspace *newvmspace; |
| 4247 | |
| 4248 | lwkt_gettoken(&oldvmspace->vm_map.token); |
| 4249 | if (vmspace_getrefs(oldvmspace) == 1) { |
| 4250 | lwkt_reltoken(&oldvmspace->vm_map.token); |
| 4251 | return; |
| 4252 | } |
| 4253 | newvmspace = vmspace_fork(oldvmspace, NULL, NULL); |
| 4254 | lwkt_gettoken(&newvmspace->vm_map.token); |
| 4255 | pmap_pinit2(vmspace_pmap(newvmspace)); |
| 4256 | pmap_replacevm(p, newvmspace, 0); |
| 4257 | lwkt_reltoken(&newvmspace->vm_map.token); |
| 4258 | lwkt_reltoken(&oldvmspace->vm_map.token); |
| 4259 | vmspace_rel(oldvmspace); |
| 4260 | } |
| 4261 | |
| 4262 | /* |
| 4263 | * vm_map_hint: return the beginning of the best area suitable for |
| 4264 | * creating a new mapping with "prot" protection. |
| 4265 | * |
| 4266 | * No requirements. |
| 4267 | */ |
| 4268 | vm_offset_t |
| 4269 | vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot) |
| 4270 | { |
| 4271 | struct vmspace *vms = p->p_vmspace; |
| 4272 | struct rlimit limit; |
| 4273 | rlim_t dsiz; |
| 4274 | |
| 4275 | /* |
| 4276 | * Acquire datasize limit for mmap() operation, |
| 4277 | * calculate nearest power of 2. |
| 4278 | */ |
| 4279 | if (kern_getrlimit(RLIMIT_DATA, &limit)) |
| 4280 | limit.rlim_cur = maxdsiz; |
| 4281 | dsiz = limit.rlim_cur; |
| 4282 | |
| 4283 | if (!randomize_mmap || addr != 0) { |
| 4284 | /* |
| 4285 | * Set a reasonable start point for the hint if it was |
| 4286 | * not specified or if it falls within the heap space. |
| 4287 | * Hinted mmap()s do not allocate out of the heap space. |
| 4288 | */ |
| 4289 | if (addr == 0 || |
| 4290 | (addr >= round_page((vm_offset_t)vms->vm_taddr) && |
| 4291 | addr < round_page((vm_offset_t)vms->vm_daddr + dsiz))) { |
| 4292 | addr = round_page((vm_offset_t)vms->vm_daddr + dsiz); |
| 4293 | } |
| 4294 | |
| 4295 | return addr; |
| 4296 | } |
| 4297 | |
| 4298 | /* |
| 4299 | * randomize_mmap && addr == 0. For now randomize the |
| 4300 | * address within a dsiz range beyond the data limit. |
| 4301 | */ |
| 4302 | addr = (vm_offset_t)vms->vm_daddr + dsiz; |
| 4303 | if (dsiz) |
| 4304 | addr += (karc4random64() & 0x7FFFFFFFFFFFFFFFLU) % dsiz; |
| 4305 | return (round_page(addr)); |
| 4306 | } |
| 4307 | |
| 4308 | /* |
| 4309 | * Finds the VM object, offset, and protection for a given virtual address |
| 4310 | * in the specified map, assuming a page fault of the type specified. |
| 4311 | * |
| 4312 | * Leaves the map in question locked for read; return values are guaranteed |
| 4313 | * until a vm_map_lookup_done call is performed. Note that the map argument |
| 4314 | * is in/out; the returned map must be used in the call to vm_map_lookup_done. |
| 4315 | * |
| 4316 | * A handle (out_entry) is returned for use in vm_map_lookup_done, to make |
| 4317 | * that fast. |
| 4318 | * |
| 4319 | * If a lookup is requested with "write protection" specified, the map may |
| 4320 | * be changed to perform virtual copying operations, although the data |
| 4321 | * referenced will remain the same. |
| 4322 | * |
| 4323 | * No requirements. |
| 4324 | */ |
| 4325 | int |
| 4326 | vm_map_lookup(vm_map_t *var_map, /* IN/OUT */ |
| 4327 | vm_offset_t vaddr, |
| 4328 | vm_prot_t fault_typea, |
| 4329 | vm_map_entry_t *out_entry, /* OUT */ |
| 4330 | struct vm_map_backing **bap, /* OUT */ |
| 4331 | vm_pindex_t *pindex, /* OUT */ |
| 4332 | vm_pindex_t *pcount, /* OUT */ |
| 4333 | vm_prot_t *out_prot, /* OUT */ |
| 4334 | int *wflags) /* OUT */ |
| 4335 | { |
| 4336 | vm_map_entry_t entry; |
| 4337 | vm_map_t map = *var_map; |
| 4338 | vm_prot_t prot; |
| 4339 | vm_prot_t fault_type = fault_typea; |
| 4340 | int use_read_lock = 1; |
| 4341 | int rv = KERN_SUCCESS; |
| 4342 | int count; |
| 4343 | thread_t td = curthread; |
| 4344 | |
| 4345 | /* |
| 4346 | * vm_map_entry_reserve() implements an important mitigation |
| 4347 | * against mmap() span running the kernel out of vm_map_entry |
| 4348 | * structures, but it can also cause an infinite call recursion. |
| 4349 | * Use td_nest_count to prevent an infinite recursion (allows |
| 4350 | * the vm_map code to dig into the pcpu vm_map_entry reserve). |
| 4351 | */ |
| 4352 | count = 0; |
| 4353 | if (td->td_nest_count == 0) { |
| 4354 | ++td->td_nest_count; |
| 4355 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 4356 | --td->td_nest_count; |
| 4357 | } |
| 4358 | RetryLookup: |
| 4359 | if (use_read_lock) |
| 4360 | vm_map_lock_read(map); |
| 4361 | else |
| 4362 | vm_map_lock(map); |
| 4363 | |
| 4364 | /* |
| 4365 | * Always do a full lookup. The hint doesn't get us much anymore |
| 4366 | * now that the map is RB'd. |
| 4367 | */ |
| 4368 | cpu_ccfence(); |
| 4369 | *out_entry = NULL; |
| 4370 | *bap = NULL; |
| 4371 | |
| 4372 | { |
| 4373 | vm_map_entry_t tmp_entry; |
| 4374 | |
| 4375 | if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) { |
| 4376 | rv = KERN_INVALID_ADDRESS; |
| 4377 | goto done; |
| 4378 | } |
| 4379 | entry = tmp_entry; |
| 4380 | *out_entry = entry; |
| 4381 | } |
| 4382 | |
| 4383 | /* |
| 4384 | * Handle submaps. |
| 4385 | */ |
| 4386 | if (entry->maptype == VM_MAPTYPE_SUBMAP) { |
| 4387 | vm_map_t old_map = map; |
| 4388 | |
| 4389 | *var_map = map = entry->ba.sub_map; |
| 4390 | if (use_read_lock) |
| 4391 | vm_map_unlock_read(old_map); |
| 4392 | else |
| 4393 | vm_map_unlock(old_map); |
| 4394 | use_read_lock = 1; |
| 4395 | goto RetryLookup; |
| 4396 | } |
| 4397 | |
| 4398 | /* |
| 4399 | * Check whether this task is allowed to have this page. |
| 4400 | * Note the special case for MAP_ENTRY_COW pages with an override. |
| 4401 | * This is to implement a forced COW for debuggers. |
| 4402 | */ |
| 4403 | if (fault_type & VM_PROT_OVERRIDE_WRITE) |
| 4404 | prot = entry->max_protection; |
| 4405 | else |
| 4406 | prot = entry->protection; |
| 4407 | |
| 4408 | fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); |
| 4409 | if ((fault_type & prot) != fault_type) { |
| 4410 | rv = KERN_PROTECTION_FAILURE; |
| 4411 | goto done; |
| 4412 | } |
| 4413 | |
| 4414 | if ((entry->eflags & MAP_ENTRY_USER_WIRED) && |
| 4415 | (entry->eflags & MAP_ENTRY_COW) && |
| 4416 | (fault_type & VM_PROT_WRITE) && |
| 4417 | (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) { |
| 4418 | rv = KERN_PROTECTION_FAILURE; |
| 4419 | goto done; |
| 4420 | } |
| 4421 | |
| 4422 | /* |
| 4423 | * Flag regular pages that are supposed to be wired. Remove prior |
| 4424 | * semantics that disallowed protection changes for such pages. |
| 4425 | * |
| 4426 | * The prior semantics are not used by modern systems. Applications |
| 4427 | * do not assume an inability to change protection modes and may |
| 4428 | * operate incorrectly if we try to prevent protection changes. |
| 4429 | * |
| 4430 | * Modern applications are aware that even for locked memory, |
| 4431 | * changing protection modes, modifying MAP_PRIVATE mappings, |
| 4432 | * or fork() may still cause page faults on the locked memory. |
| 4433 | */ |
| 4434 | *wflags = 0; |
| 4435 | if (entry->wired_count) { |
| 4436 | *wflags |= FW_WIRED; |
| 4437 | #if 0 |
| 4438 | prot = fault_type = entry->protection; |
| 4439 | #endif |
| 4440 | } |
| 4441 | |
| 4442 | if (curthread->td_lwp && curthread->td_lwp->lwp_vmspace && |
| 4443 | pmap_emulate_ad_bits(&curthread->td_lwp->lwp_vmspace->vm_pmap)) { |
| 4444 | if ((prot & VM_PROT_WRITE) == 0) |
| 4445 | fault_type |= VM_PROT_WRITE; |
| 4446 | } |
| 4447 | |
| 4448 | /* |
| 4449 | * Only NORMAL maps are object-based. UKSMAPs are not. |
| 4450 | */ |
| 4451 | if (entry->maptype != VM_MAPTYPE_NORMAL) { |
| 4452 | *bap = NULL; |
| 4453 | goto skip; |
| 4454 | } |
| 4455 | |
| 4456 | /* |
| 4457 | * If the entry was copy-on-write, we either ... |
| 4458 | */ |
| 4459 | if (entry->eflags & MAP_ENTRY_NEEDS_COPY) { |
| 4460 | /* |
| 4461 | * If we want to write the page, we may as well handle that |
| 4462 | * now since we've got the map locked. |
| 4463 | * |
| 4464 | * If we don't need to write the page, we just demote the |
| 4465 | * permissions allowed. |
| 4466 | */ |
| 4467 | if (fault_type & VM_PROT_WRITE) { |
| 4468 | /* |
| 4469 | * Not allowed if TDF_NOFAULT is set as the shadowing |
| 4470 | * operation can deadlock against the faulting |
| 4471 | * function due to the copy-on-write. |
| 4472 | */ |
| 4473 | if (curthread->td_flags & TDF_NOFAULT) { |
| 4474 | rv = KERN_FAILURE_NOFAULT; |
| 4475 | goto done; |
| 4476 | } |
| 4477 | |
| 4478 | /* |
| 4479 | * Make a new vm_map_backing + object, and place it |
| 4480 | * in the object chain. Note that no new references |
| 4481 | * have appeared -- one just moved from the map to |
| 4482 | * the new object. |
| 4483 | */ |
| 4484 | if (use_read_lock && vm_map_lock_upgrade(map)) { |
| 4485 | /* lost lock */ |
| 4486 | use_read_lock = 0; |
| 4487 | goto RetryLookup; |
| 4488 | } |
| 4489 | use_read_lock = 0; |
| 4490 | vm_map_entry_shadow(entry); |
| 4491 | *wflags |= FW_DIDCOW; |
| 4492 | } else { |
| 4493 | /* |
| 4494 | * We're attempting to read a copy-on-write page -- |
| 4495 | * don't allow writes. |
| 4496 | */ |
| 4497 | prot &= ~VM_PROT_WRITE; |
| 4498 | } |
| 4499 | } |
| 4500 | |
| 4501 | /* |
| 4502 | * Create an object if necessary. This code also handles |
| 4503 | * partitioning large entries to improve vm_fault performance. |
| 4504 | */ |
| 4505 | if (entry->ba.object == NULL && !map->system_map) { |
| 4506 | if (use_read_lock && vm_map_lock_upgrade(map)) { |
| 4507 | /* lost lock */ |
| 4508 | use_read_lock = 0; |
| 4509 | goto RetryLookup; |
| 4510 | } |
| 4511 | use_read_lock = 0; |
| 4512 | |
| 4513 | /* |
| 4514 | * Partition large entries, giving each its own VM object, |
| 4515 | * to improve concurrent fault performance. This is only |
| 4516 | * applicable to userspace. |
| 4517 | */ |
| 4518 | if (map != kernel_map && |
| 4519 | entry->maptype == VM_MAPTYPE_NORMAL && |
| 4520 | ((entry->ba.start ^ entry->ba.end) & |
| 4521 | ~MAP_ENTRY_PARTITION_MASK) && |
| 4522 | vm_map_partition_enable) { |
| 4523 | if (entry->eflags & MAP_ENTRY_IN_TRANSITION) { |
| 4524 | entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP; |
| 4525 | ++mycpu->gd_cnt.v_intrans_coll; |
| 4526 | ++mycpu->gd_cnt.v_intrans_wait; |
| 4527 | vm_map_transition_wait(map, 0); |
| 4528 | goto RetryLookup; |
| 4529 | } |
| 4530 | vm_map_entry_partition(map, entry, vaddr, &count); |
| 4531 | } |
| 4532 | vm_map_entry_allocate_object(entry); |
| 4533 | } |
| 4534 | |
| 4535 | /* |
| 4536 | * Return the object/offset from this entry. If the entry was |
| 4537 | * copy-on-write or empty, it has been fixed up. |
| 4538 | */ |
| 4539 | *bap = &entry->ba; |
| 4540 | |
| 4541 | skip: |
| 4542 | *pindex = OFF_TO_IDX((vaddr - entry->ba.start) + entry->ba.offset); |
| 4543 | *pcount = OFF_TO_IDX(entry->ba.end - trunc_page(vaddr)); |
| 4544 | |
| 4545 | /* |
| 4546 | * Return whether this is the only map sharing this data. On |
| 4547 | * success we return with a read lock held on the map. On failure |
| 4548 | * we return with the map unlocked. |
| 4549 | */ |
| 4550 | *out_prot = prot; |
| 4551 | done: |
| 4552 | if (rv == KERN_SUCCESS) { |
| 4553 | if (use_read_lock == 0) |
| 4554 | vm_map_lock_downgrade(map); |
| 4555 | } else if (use_read_lock) { |
| 4556 | vm_map_unlock_read(map); |
| 4557 | } else { |
| 4558 | vm_map_unlock(map); |
| 4559 | } |
| 4560 | if (count > 0) |
| 4561 | vm_map_entry_release(count); |
| 4562 | |
| 4563 | return (rv); |
| 4564 | } |
| 4565 | |
| 4566 | /* |
| 4567 | * Releases locks acquired by a vm_map_lookup() |
| 4568 | * (according to the handle returned by that lookup). |
| 4569 | * |
| 4570 | * No other requirements. |
| 4571 | */ |
| 4572 | void |
| 4573 | vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count) |
| 4574 | { |
| 4575 | /* |
| 4576 | * Unlock the main-level map |
| 4577 | */ |
| 4578 | vm_map_unlock_read(map); |
| 4579 | if (count) |
| 4580 | vm_map_entry_release(count); |
| 4581 | } |
| 4582 | |
| 4583 | static void |
| 4584 | vm_map_entry_partition(vm_map_t map, vm_map_entry_t entry, |
| 4585 | vm_offset_t vaddr, int *countp) |
| 4586 | { |
| 4587 | vaddr &= ~MAP_ENTRY_PARTITION_MASK; |
| 4588 | vm_map_clip_start(map, entry, vaddr, countp); |
| 4589 | vaddr += MAP_ENTRY_PARTITION_SIZE; |
| 4590 | vm_map_clip_end(map, entry, vaddr, countp); |
| 4591 | } |
| 4592 | |
| 4593 | /* |
| 4594 | * Quick hack, needs some help to make it more SMP friendly. |
| 4595 | */ |
| 4596 | void |
| 4597 | vm_map_interlock(vm_map_t map, struct vm_map_ilock *ilock, |
| 4598 | vm_offset_t ran_beg, vm_offset_t ran_end) |
| 4599 | { |
| 4600 | struct vm_map_ilock *scan; |
| 4601 | |
| 4602 | ilock->ran_beg = ran_beg; |
| 4603 | ilock->ran_end = ran_end; |
| 4604 | ilock->flags = 0; |
| 4605 | |
| 4606 | spin_lock(&map->ilock_spin); |
| 4607 | restart: |
| 4608 | for (scan = map->ilock_base; scan; scan = scan->next) { |
| 4609 | if (ran_end > scan->ran_beg && ran_beg < scan->ran_end) { |
| 4610 | scan->flags |= ILOCK_WAITING; |
| 4611 | ssleep(scan, &map->ilock_spin, 0, "ilock", 0); |
| 4612 | goto restart; |
| 4613 | } |
| 4614 | } |
| 4615 | ilock->next = map->ilock_base; |
| 4616 | map->ilock_base = ilock; |
| 4617 | spin_unlock(&map->ilock_spin); |
| 4618 | } |
| 4619 | |
| 4620 | void |
| 4621 | vm_map_deinterlock(vm_map_t map, struct vm_map_ilock *ilock) |
| 4622 | { |
| 4623 | struct vm_map_ilock *scan; |
| 4624 | struct vm_map_ilock **scanp; |
| 4625 | |
| 4626 | spin_lock(&map->ilock_spin); |
| 4627 | scanp = &map->ilock_base; |
| 4628 | while ((scan = *scanp) != NULL) { |
| 4629 | if (scan == ilock) { |
| 4630 | *scanp = ilock->next; |
| 4631 | spin_unlock(&map->ilock_spin); |
| 4632 | if (ilock->flags & ILOCK_WAITING) |
| 4633 | wakeup(ilock); |
| 4634 | return; |
| 4635 | } |
| 4636 | scanp = &scan->next; |
| 4637 | } |
| 4638 | spin_unlock(&map->ilock_spin); |
| 4639 | panic("vm_map_deinterlock: missing ilock!"); |
| 4640 | } |
| 4641 | |
| 4642 | #include "opt_ddb.h" |
| 4643 | #ifdef DDB |
| 4644 | #include <ddb/ddb.h> |
| 4645 | |
| 4646 | /* |
| 4647 | * Debugging only |
| 4648 | */ |
| 4649 | DB_SHOW_COMMAND(map, vm_map_print) |
| 4650 | { |
| 4651 | static int nlines; |
| 4652 | /* XXX convert args. */ |
| 4653 | vm_map_t map = (vm_map_t)addr; |
| 4654 | boolean_t full = have_addr; |
| 4655 | |
| 4656 | vm_map_entry_t entry; |
| 4657 | |
| 4658 | db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n", |
| 4659 | (void *)map, |
| 4660 | (void *)map->pmap, map->nentries, map->timestamp); |
| 4661 | nlines++; |
| 4662 | |
| 4663 | if (!full && db_indent) |
| 4664 | return; |
| 4665 | |
| 4666 | db_indent += 2; |
| 4667 | RB_FOREACH(entry, vm_map_rb_tree, &map->rb_root) { |
| 4668 | db_iprintf("map entry %p: start=%p, end=%p\n", |
| 4669 | (void *)entry, |
| 4670 | (void *)entry->ba.start, (void *)entry->ba.end); |
| 4671 | nlines++; |
| 4672 | { |
| 4673 | static char *inheritance_name[4] = |
| 4674 | {"share", "copy", "none", "donate_copy"}; |
| 4675 | |
| 4676 | db_iprintf(" prot=%x/%x/%s", |
| 4677 | entry->protection, |
| 4678 | entry->max_protection, |
| 4679 | inheritance_name[(int)(unsigned char) |
| 4680 | entry->inheritance]); |
| 4681 | if (entry->wired_count != 0) |
| 4682 | db_printf(", wired"); |
| 4683 | } |
| 4684 | switch(entry->maptype) { |
| 4685 | case VM_MAPTYPE_SUBMAP: |
| 4686 | /* XXX no %qd in kernel. Truncate entry->ba.offset. */ |
| 4687 | db_printf(", share=%p, offset=0x%lx\n", |
| 4688 | (void *)entry->ba.sub_map, |
| 4689 | (long)entry->ba.offset); |
| 4690 | nlines++; |
| 4691 | |
| 4692 | db_indent += 2; |
| 4693 | vm_map_print((db_expr_t)(intptr_t)entry->ba.sub_map, |
| 4694 | full, 0, NULL); |
| 4695 | db_indent -= 2; |
| 4696 | break; |
| 4697 | case VM_MAPTYPE_NORMAL: |
| 4698 | /* XXX no %qd in kernel. Truncate entry->ba.offset. */ |
| 4699 | db_printf(", object=%p, offset=0x%lx", |
| 4700 | (void *)entry->ba.object, |
| 4701 | (long)entry->ba.offset); |
| 4702 | if (entry->eflags & MAP_ENTRY_COW) |
| 4703 | db_printf(", copy (%s)", |
| 4704 | ((entry->eflags & MAP_ENTRY_NEEDS_COPY) ? |
| 4705 | "needed" : "done")); |
| 4706 | db_printf("\n"); |
| 4707 | nlines++; |
| 4708 | |
| 4709 | if (entry->ba.object) { |
| 4710 | db_indent += 2; |
| 4711 | vm_object_print((db_expr_t)(intptr_t) |
| 4712 | entry->ba.object, |
| 4713 | full, 0, NULL); |
| 4714 | nlines += 4; |
| 4715 | db_indent -= 2; |
| 4716 | } |
| 4717 | break; |
| 4718 | case VM_MAPTYPE_UKSMAP: |
| 4719 | db_printf(", uksmap=%p, offset=0x%lx", |
| 4720 | (void *)entry->ba.uksmap, |
| 4721 | (long)entry->ba.offset); |
| 4722 | if (entry->eflags & MAP_ENTRY_COW) |
| 4723 | db_printf(", copy (%s)", |
| 4724 | (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done"); |
| 4725 | db_printf("\n"); |
| 4726 | nlines++; |
| 4727 | break; |
| 4728 | default: |
| 4729 | break; |
| 4730 | } |
| 4731 | } |
| 4732 | db_indent -= 2; |
| 4733 | if (db_indent == 0) |
| 4734 | nlines = 0; |
| 4735 | } |
| 4736 | |
| 4737 | /* |
| 4738 | * Debugging only |
| 4739 | */ |
| 4740 | DB_SHOW_COMMAND(procvm, procvm) |
| 4741 | { |
| 4742 | struct proc *p; |
| 4743 | |
| 4744 | if (have_addr) { |
| 4745 | p = (struct proc *) addr; |
| 4746 | } else { |
| 4747 | p = curproc; |
| 4748 | } |
| 4749 | |
| 4750 | db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n", |
| 4751 | (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map, |
| 4752 | (void *)vmspace_pmap(p->p_vmspace)); |
| 4753 | |
| 4754 | vm_map_print((db_expr_t)(intptr_t)&p->p_vmspace->vm_map, 1, 0, NULL); |
| 4755 | } |
| 4756 | |
| 4757 | #endif /* DDB */ |