1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Permission to use, copy, modify and distribute this software and 39 * its documentation is hereby granted, provided that both the copyright 40 * notice and this permission notice appear in all copies of the 41 * software, derivative works or modified versions, and any portions 42 * thereof, and that both notices appear in supporting documentation. 43 * 44 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 45 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 46 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 47 * 48 * Carnegie Mellon requests users of this software to return to 49 * 50 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 51 * School of Computer Science 52 * Carnegie Mellon University 53 * Pittsburgh PA 15213-3890 54 * 55 * any improvements or extensions that they make and grant Carnegie the 56 * rights to redistribute these changes. 57 */ 58 59 #include "opt_vm.h" 60 #include "opt_kstack_pages.h" 61 #include "opt_kstack_max_pages.h" 62 #include "opt_kstack_usage_prof.h" 63 64 #include <sys/param.h> 65 #include <sys/systm.h> 66 #include <sys/asan.h> 67 #include <sys/domainset.h> 68 #include <sys/limits.h> 69 #include <sys/lock.h> 70 #include <sys/malloc.h> 71 #include <sys/msan.h> 72 #include <sys/mutex.h> 73 #include <sys/proc.h> 74 #include <sys/racct.h> 75 #include <sys/refcount.h> 76 #include <sys/resourcevar.h> 77 #include <sys/rwlock.h> 78 #include <sys/sched.h> 79 #include <sys/sf_buf.h> 80 #include <sys/shm.h> 81 #include <sys/smp.h> 82 #include <sys/vmmeter.h> 83 #include <sys/vmem.h> 84 #include <sys/sx.h> 85 #include <sys/sysctl.h> 86 #include <sys/kernel.h> 87 #include <sys/ktr.h> 88 #include <sys/unistd.h> 89 90 #include <vm/uma.h> 91 #include <vm/vm.h> 92 #include <vm/vm_param.h> 93 #include <vm/pmap.h> 94 #include <vm/vm_domainset.h> 95 #include <vm/vm_map.h> 96 #include <vm/vm_page.h> 97 #include <vm/vm_pageout.h> 98 #include <vm/vm_pagequeue.h> 99 #include <vm/vm_object.h> 100 #include <vm/vm_kern.h> 101 #include <vm/vm_extern.h> 102 #include <vm/vm_pager.h> 103 #include <vm/vm_phys.h> 104 105 #include <machine/cpu.h> 106 107 #if VM_NRESERVLEVEL > 1 108 #define KVA_KSTACK_QUANTUM_SHIFT (VM_LEVEL_1_ORDER + VM_LEVEL_0_ORDER + \ 109 PAGE_SHIFT) 110 #elif VM_NRESERVLEVEL > 0 111 #define KVA_KSTACK_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) 112 #else 113 #define KVA_KSTACK_QUANTUM_SHIFT (8 + PAGE_SHIFT) 114 #endif 115 #define KVA_KSTACK_QUANTUM (1ul << KVA_KSTACK_QUANTUM_SHIFT) 116 117 /* 118 * MPSAFE 119 * 120 * WARNING! This code calls vm_map_check_protection() which only checks 121 * the associated vm_map_entry range. It does not determine whether the 122 * contents of the memory is actually readable or writable. In most cases 123 * just checking the vm_map_entry is sufficient within the kernel's address 124 * space. 125 */ 126 bool 127 kernacc(void *addr, int len, int rw) 128 { 129 boolean_t rv; 130 vm_offset_t saddr, eaddr; 131 vm_prot_t prot; 132 133 KASSERT((rw & ~VM_PROT_ALL) == 0, 134 ("illegal ``rw'' argument to kernacc (%x)\n", rw)); 135 136 if ((vm_offset_t)addr + len > vm_map_max(kernel_map) || 137 (vm_offset_t)addr + len < (vm_offset_t)addr) 138 return (false); 139 140 prot = rw; 141 saddr = trunc_page((vm_offset_t)addr); 142 eaddr = round_page((vm_offset_t)addr + len); 143 vm_map_lock_read(kernel_map); 144 rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot); 145 vm_map_unlock_read(kernel_map); 146 return (rv == TRUE); 147 } 148 149 /* 150 * MPSAFE 151 * 152 * WARNING! This code calls vm_map_check_protection() which only checks 153 * the associated vm_map_entry range. It does not determine whether the 154 * contents of the memory is actually readable or writable. vmapbuf(), 155 * vm_fault_quick(), or copyin()/copout()/su*()/fu*() functions should be 156 * used in conjunction with this call. 157 */ 158 bool 159 useracc(void *addr, int len, int rw) 160 { 161 boolean_t rv; 162 vm_prot_t prot; 163 vm_map_t map; 164 165 KASSERT((rw & ~VM_PROT_ALL) == 0, 166 ("illegal ``rw'' argument to useracc (%x)\n", rw)); 167 prot = rw; 168 map = &curproc->p_vmspace->vm_map; 169 if ((vm_offset_t)addr + len > vm_map_max(map) || 170 (vm_offset_t)addr + len < (vm_offset_t)addr) { 171 return (false); 172 } 173 vm_map_lock_read(map); 174 rv = vm_map_check_protection(map, trunc_page((vm_offset_t)addr), 175 round_page((vm_offset_t)addr + len), prot); 176 vm_map_unlock_read(map); 177 return (rv == TRUE); 178 } 179 180 int 181 vslock(void *addr, size_t len) 182 { 183 vm_offset_t end, last, start; 184 vm_size_t npages; 185 int error; 186 187 last = (vm_offset_t)addr + len; 188 start = trunc_page((vm_offset_t)addr); 189 end = round_page(last); 190 if (last < (vm_offset_t)addr || end < (vm_offset_t)addr) 191 return (EINVAL); 192 npages = atop(end - start); 193 if (npages > vm_page_max_user_wired) 194 return (ENOMEM); 195 error = vm_map_wire(&curproc->p_vmspace->vm_map, start, end, 196 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 197 if (error == KERN_SUCCESS) { 198 curthread->td_vslock_sz += len; 199 return (0); 200 } 201 202 /* 203 * Return EFAULT on error to match copy{in,out}() behaviour 204 * rather than returning ENOMEM like mlock() would. 205 */ 206 return (EFAULT); 207 } 208 209 void 210 vsunlock(void *addr, size_t len) 211 { 212 213 /* Rely on the parameter sanity checks performed by vslock(). */ 214 MPASS(curthread->td_vslock_sz >= len); 215 curthread->td_vslock_sz -= len; 216 (void)vm_map_unwire(&curproc->p_vmspace->vm_map, 217 trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len), 218 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 219 } 220 221 /* 222 * Pin the page contained within the given object at the given offset. If the 223 * page is not resident, allocate and load it using the given object's pager. 224 * Return the pinned page if successful; otherwise, return NULL. 225 */ 226 static vm_page_t 227 vm_imgact_hold_page(vm_object_t object, vm_ooffset_t offset) 228 { 229 vm_page_t m; 230 vm_pindex_t pindex; 231 232 pindex = OFF_TO_IDX(offset); 233 (void)vm_page_grab_valid_unlocked(&m, object, pindex, 234 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 235 return (m); 236 } 237 238 /* 239 * Return a CPU private mapping to the page at the given offset within the 240 * given object. The page is pinned before it is mapped. 241 */ 242 struct sf_buf * 243 vm_imgact_map_page(vm_object_t object, vm_ooffset_t offset) 244 { 245 vm_page_t m; 246 247 m = vm_imgact_hold_page(object, offset); 248 if (m == NULL) 249 return (NULL); 250 sched_pin(); 251 return (sf_buf_alloc(m, SFB_CPUPRIVATE)); 252 } 253 254 /* 255 * Destroy the given CPU private mapping and unpin the page that it mapped. 256 */ 257 void 258 vm_imgact_unmap_page(struct sf_buf *sf) 259 { 260 vm_page_t m; 261 262 m = sf_buf_page(sf); 263 sf_buf_free(sf); 264 sched_unpin(); 265 vm_page_unwire(m, PQ_ACTIVE); 266 } 267 268 void 269 vm_sync_icache(vm_map_t map, vm_offset_t va, vm_offset_t sz) 270 { 271 272 pmap_sync_icache(map->pmap, va, sz); 273 } 274 275 static vm_object_t kstack_object; 276 static vm_object_t kstack_alt_object; 277 static uma_zone_t kstack_cache; 278 static int kstack_cache_size; 279 static vmem_t *vmd_kstack_arena[MAXMEMDOM]; 280 281 static vm_pindex_t vm_kstack_pindex(vm_offset_t ks, int npages); 282 static vm_object_t vm_thread_kstack_size_to_obj(int npages); 283 static int vm_thread_stack_back(vm_offset_t kaddr, vm_page_t ma[], int npages, 284 int req_class, int domain); 285 286 static int 287 sysctl_kstack_cache_size(SYSCTL_HANDLER_ARGS) 288 { 289 int error, oldsize; 290 291 oldsize = kstack_cache_size; 292 error = sysctl_handle_int(oidp, arg1, arg2, req); 293 if (error == 0 && req->newptr && oldsize != kstack_cache_size) 294 uma_zone_set_maxcache(kstack_cache, kstack_cache_size); 295 return (error); 296 } 297 SYSCTL_PROC(_vm, OID_AUTO, kstack_cache_size, 298 CTLTYPE_INT|CTLFLAG_MPSAFE|CTLFLAG_RW, &kstack_cache_size, 0, 299 sysctl_kstack_cache_size, "IU", "Maximum number of cached kernel stacks"); 300 301 /* 302 * Allocate a virtual address range from a domain kstack arena, following 303 * the specified NUMA policy. 304 */ 305 static vm_offset_t 306 vm_thread_alloc_kstack_kva(vm_size_t size, int domain) 307 { 308 #ifndef __ILP32__ 309 int rv; 310 vmem_t *arena; 311 vm_offset_t addr = 0; 312 313 size = round_page(size); 314 /* Allocate from the kernel arena for non-standard kstack sizes. */ 315 if (size != ptoa(kstack_pages + KSTACK_GUARD_PAGES)) { 316 arena = vm_dom[domain].vmd_kernel_arena; 317 } else { 318 arena = vmd_kstack_arena[domain]; 319 } 320 rv = vmem_alloc(arena, size, M_BESTFIT | M_NOWAIT, &addr); 321 if (rv == ENOMEM) 322 return (0); 323 KASSERT(atop(addr - VM_MIN_KERNEL_ADDRESS) % 324 (kstack_pages + KSTACK_GUARD_PAGES) == 0, 325 ("%s: allocated kstack KVA not aligned to multiple of kstack size", 326 __func__)); 327 328 return (addr); 329 #else 330 return (kva_alloc(size)); 331 #endif 332 } 333 334 /* 335 * Release a region of kernel virtual memory 336 * allocated from the kstack arena. 337 */ 338 static __noinline void 339 vm_thread_free_kstack_kva(vm_offset_t addr, vm_size_t size, int domain) 340 { 341 vmem_t *arena; 342 343 size = round_page(size); 344 #ifdef __ILP32__ 345 arena = kernel_arena; 346 #else 347 arena = vmd_kstack_arena[domain]; 348 if (size != ptoa(kstack_pages + KSTACK_GUARD_PAGES)) { 349 arena = vm_dom[domain].vmd_kernel_arena; 350 } 351 #endif 352 vmem_free(arena, addr, size); 353 } 354 355 static vmem_size_t 356 vm_thread_kstack_import_quantum(void) 357 { 358 #ifndef __ILP32__ 359 /* 360 * The kstack_quantum is larger than KVA_QUANTUM to account 361 * for holes induced by guard pages. 362 */ 363 return (KVA_KSTACK_QUANTUM * (kstack_pages + KSTACK_GUARD_PAGES)); 364 #else 365 return (KVA_KSTACK_QUANTUM); 366 #endif 367 } 368 369 /* 370 * Import KVA from a parent arena into the kstack arena. Imports must be 371 * a multiple of kernel stack pages + guard pages in size. 372 * 373 * Kstack VA allocations need to be aligned so that the linear KVA pindex 374 * is divisible by the total number of kstack VA pages. This is necessary to 375 * make vm_kstack_pindex work properly. 376 * 377 * We import a multiple of KVA_KSTACK_QUANTUM-sized region from the parent 378 * arena. The actual size used by the kstack arena is one kstack smaller to 379 * allow for the necessary alignment adjustments to be made. 380 */ 381 static int 382 vm_thread_kstack_arena_import(void *arena, vmem_size_t size, int flags, 383 vmem_addr_t *addrp) 384 { 385 int error, rem; 386 size_t kpages = kstack_pages + KSTACK_GUARD_PAGES; 387 388 KASSERT(atop(size) % kpages == 0, 389 ("%s: Size %jd is not a multiple of kstack pages (%d)", __func__, 390 (intmax_t)size, (int)kpages)); 391 392 error = vmem_xalloc(arena, vm_thread_kstack_import_quantum(), 393 KVA_KSTACK_QUANTUM, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, flags, 394 addrp); 395 if (error) { 396 return (error); 397 } 398 399 rem = atop(*addrp - VM_MIN_KERNEL_ADDRESS) % kpages; 400 if (rem != 0) { 401 /* Bump addr to next aligned address */ 402 *addrp = *addrp + (kpages - rem) * PAGE_SIZE; 403 } 404 405 return (0); 406 } 407 408 /* 409 * Release KVA from a parent arena into the kstack arena. Released imports must 410 * be a multiple of kernel stack pages + guard pages in size. 411 */ 412 static void 413 vm_thread_kstack_arena_release(void *arena, vmem_addr_t addr, vmem_size_t size) 414 { 415 int rem; 416 size_t kpages __diagused = kstack_pages + KSTACK_GUARD_PAGES; 417 418 KASSERT(size % kpages == 0, 419 ("%s: Size %jd is not a multiple of kstack pages (%d)", __func__, 420 (intmax_t)size, (int)kpages)); 421 422 KASSERT((addr - VM_MIN_KERNEL_ADDRESS) % kpages == 0, 423 ("%s: Address %p is not properly aligned (%p)", __func__, 424 (void *)addr, (void *)VM_MIN_KERNEL_ADDRESS)); 425 /* 426 * If the address is not KVA_KSTACK_QUANTUM-aligned we have to decrement 427 * it to account for the shift in kva_import_kstack. 428 */ 429 rem = addr % KVA_KSTACK_QUANTUM; 430 if (rem) { 431 KASSERT(rem <= ptoa(kpages), 432 ("%s: rem > kpages (%d), (%d)", __func__, rem, 433 (int)kpages)); 434 addr -= rem; 435 } 436 vmem_xfree(arena, addr, vm_thread_kstack_import_quantum()); 437 } 438 439 /* 440 * Create the kernel stack for a new thread. 441 */ 442 static vm_offset_t 443 vm_thread_stack_create(struct domainset *ds, int pages) 444 { 445 vm_page_t ma[KSTACK_MAX_PAGES]; 446 struct vm_domainset_iter di; 447 int req = VM_ALLOC_NORMAL; 448 vm_object_t obj; 449 vm_offset_t ks; 450 int domain, i; 451 452 obj = vm_thread_kstack_size_to_obj(pages); 453 if (vm_ndomains > 1) 454 obj->domain.dr_policy = ds; 455 vm_domainset_iter_page_init(&di, obj, 0, &domain, &req); 456 do { 457 /* 458 * Get a kernel virtual address for this thread's kstack. 459 */ 460 ks = vm_thread_alloc_kstack_kva(ptoa(pages + KSTACK_GUARD_PAGES), 461 domain); 462 if (ks == 0) 463 continue; 464 ks += ptoa(KSTACK_GUARD_PAGES); 465 466 /* 467 * Allocate physical pages to back the stack. 468 */ 469 if (vm_thread_stack_back(ks, ma, pages, req, domain) != 0) { 470 vm_thread_free_kstack_kva(ks - ptoa(KSTACK_GUARD_PAGES), 471 ptoa(pages + KSTACK_GUARD_PAGES), domain); 472 continue; 473 } 474 if (KSTACK_GUARD_PAGES != 0) { 475 pmap_qremove(ks - ptoa(KSTACK_GUARD_PAGES), 476 KSTACK_GUARD_PAGES); 477 } 478 for (i = 0; i < pages; i++) 479 vm_page_valid(ma[i]); 480 pmap_qenter(ks, ma, pages); 481 return (ks); 482 } while (vm_domainset_iter_page(&di, obj, &domain) == 0); 483 484 return (0); 485 } 486 487 static __noinline void 488 vm_thread_stack_dispose(vm_offset_t ks, int pages) 489 { 490 vm_page_t m; 491 vm_pindex_t pindex; 492 int i, domain; 493 vm_object_t obj = vm_thread_kstack_size_to_obj(pages); 494 495 pindex = vm_kstack_pindex(ks, pages); 496 domain = vm_phys_domain(vtophys(ks)); 497 pmap_qremove(ks, pages); 498 VM_OBJECT_WLOCK(obj); 499 for (i = 0; i < pages; i++) { 500 m = vm_page_lookup(obj, pindex + i); 501 if (m == NULL) 502 panic("%s: kstack already missing?", __func__); 503 KASSERT(vm_page_domain(m) == domain, 504 ("%s: page %p domain mismatch, expected %d got %d", 505 __func__, m, domain, vm_page_domain(m))); 506 vm_page_xbusy_claim(m); 507 vm_page_unwire_noq(m); 508 vm_page_free(m); 509 } 510 VM_OBJECT_WUNLOCK(obj); 511 kasan_mark((void *)ks, ptoa(pages), ptoa(pages), 0); 512 vm_thread_free_kstack_kva(ks - (KSTACK_GUARD_PAGES * PAGE_SIZE), 513 ptoa(pages + KSTACK_GUARD_PAGES), domain); 514 } 515 516 /* 517 * Allocate the kernel stack for a new thread. 518 */ 519 int 520 vm_thread_new(struct thread *td, int pages) 521 { 522 vm_offset_t ks; 523 u_short ks_domain; 524 525 /* Bounds check */ 526 if (pages <= 1) 527 pages = kstack_pages; 528 else if (pages > KSTACK_MAX_PAGES) 529 pages = KSTACK_MAX_PAGES; 530 531 ks = 0; 532 if (pages == kstack_pages && kstack_cache != NULL) 533 ks = (vm_offset_t)uma_zalloc(kstack_cache, M_NOWAIT); 534 535 /* 536 * Ensure that kstack objects can draw pages from any memory 537 * domain. Otherwise a local memory shortage can block a process 538 * swap-in. 539 */ 540 if (ks == 0) 541 ks = vm_thread_stack_create(DOMAINSET_PREF(PCPU_GET(domain)), 542 pages); 543 if (ks == 0) 544 return (0); 545 546 ks_domain = vm_phys_domain(vtophys(ks)); 547 KASSERT(ks_domain >= 0 && ks_domain < vm_ndomains, 548 ("%s: invalid domain for kstack %p", __func__, (void *)ks)); 549 td->td_kstack = ks; 550 td->td_kstack_pages = pages; 551 td->td_kstack_domain = ks_domain; 552 return (1); 553 } 554 555 /* 556 * Dispose of a thread's kernel stack. 557 */ 558 void 559 vm_thread_dispose(struct thread *td) 560 { 561 vm_offset_t ks; 562 int pages; 563 564 pages = td->td_kstack_pages; 565 ks = td->td_kstack; 566 td->td_kstack = 0; 567 td->td_kstack_pages = 0; 568 td->td_kstack_domain = MAXMEMDOM; 569 if (pages == kstack_pages) { 570 kasan_mark((void *)ks, 0, ptoa(pages), KASAN_KSTACK_FREED); 571 uma_zfree(kstack_cache, (void *)ks); 572 } else { 573 vm_thread_stack_dispose(ks, pages); 574 } 575 } 576 577 /* 578 * Calculate kstack pindex. 579 * 580 * Uses a non-identity mapping if guard pages are 581 * active to avoid pindex holes in the kstack object. 582 */ 583 static vm_pindex_t 584 vm_kstack_pindex(vm_offset_t ks, int kpages) 585 { 586 vm_pindex_t pindex = atop(ks - VM_MIN_KERNEL_ADDRESS); 587 588 #ifdef __ILP32__ 589 return (pindex); 590 #else 591 /* 592 * Return the linear pindex if guard pages aren't active or if we are 593 * allocating a non-standard kstack size. 594 */ 595 if (KSTACK_GUARD_PAGES == 0 || kpages != kstack_pages) { 596 return (pindex); 597 } 598 KASSERT(pindex % (kpages + KSTACK_GUARD_PAGES) >= KSTACK_GUARD_PAGES, 599 ("%s: Attempting to calculate kstack guard page pindex", __func__)); 600 601 return (pindex - 602 (pindex / (kpages + KSTACK_GUARD_PAGES) + 1) * KSTACK_GUARD_PAGES); 603 #endif 604 } 605 606 /* 607 * Allocate physical pages, following the specified NUMA policy, to back a 608 * kernel stack. 609 */ 610 static int 611 vm_thread_stack_back(vm_offset_t ks, vm_page_t ma[], int npages, int req_class, 612 int domain) 613 { 614 vm_object_t obj = vm_thread_kstack_size_to_obj(npages); 615 vm_pindex_t pindex; 616 vm_page_t m; 617 int n; 618 619 pindex = vm_kstack_pindex(ks, npages); 620 621 VM_OBJECT_WLOCK(obj); 622 for (n = 0; n < npages;) { 623 m = vm_page_grab(obj, pindex + n, 624 VM_ALLOC_NOCREAT | VM_ALLOC_WIRED); 625 if (m == NULL) { 626 m = n > 0 ? ma[n - 1] : vm_page_mpred(obj, pindex); 627 m = vm_page_alloc_domain_after(obj, pindex + n, domain, 628 req_class | VM_ALLOC_WIRED, m); 629 } 630 if (m == NULL) 631 break; 632 ma[n++] = m; 633 } 634 if (n < npages) 635 goto cleanup; 636 VM_OBJECT_WUNLOCK(obj); 637 638 return (0); 639 cleanup: 640 for (int i = 0; i < n; i++) { 641 m = ma[i]; 642 (void)vm_page_unwire_noq(m); 643 vm_page_free(m); 644 } 645 VM_OBJECT_WUNLOCK(obj); 646 647 return (ENOMEM); 648 } 649 650 static vm_object_t 651 vm_thread_kstack_size_to_obj(int npages) 652 { 653 return (npages == kstack_pages ? kstack_object : kstack_alt_object); 654 } 655 656 static int 657 kstack_import(void *arg, void **store, int cnt, int domain, int flags) 658 { 659 struct domainset *ds; 660 int i; 661 662 if (domain == UMA_ANYDOMAIN) 663 ds = DOMAINSET_RR(); 664 else 665 ds = DOMAINSET_PREF(domain); 666 667 for (i = 0; i < cnt; i++) { 668 store[i] = (void *)vm_thread_stack_create(ds, kstack_pages); 669 if (store[i] == NULL) 670 break; 671 } 672 return (i); 673 } 674 675 static void 676 kstack_release(void *arg, void **store, int cnt) 677 { 678 vm_offset_t ks; 679 int i; 680 681 for (i = 0; i < cnt; i++) { 682 ks = (vm_offset_t)store[i]; 683 vm_thread_stack_dispose(ks, kstack_pages); 684 } 685 } 686 687 static void 688 kstack_cache_init(void *null) 689 { 690 vm_size_t kstack_quantum; 691 int domain; 692 693 kstack_object = vm_object_allocate(OBJT_PHYS, 694 atop(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS)); 695 kstack_cache = uma_zcache_create("kstack_cache", 696 kstack_pages * PAGE_SIZE, NULL, NULL, NULL, NULL, 697 kstack_import, kstack_release, NULL, 698 UMA_ZONE_FIRSTTOUCH); 699 kstack_cache_size = imax(128, mp_ncpus * 4); 700 uma_zone_set_maxcache(kstack_cache, kstack_cache_size); 701 702 kstack_alt_object = vm_object_allocate(OBJT_PHYS, 703 atop(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS)); 704 705 kstack_quantum = vm_thread_kstack_import_quantum(); 706 /* 707 * Reduce size used by the kstack arena to allow for 708 * alignment adjustments in vm_thread_kstack_arena_import. 709 */ 710 kstack_quantum -= (kstack_pages + KSTACK_GUARD_PAGES) * PAGE_SIZE; 711 /* 712 * Create the kstack_arena for each domain and set kernel_arena as 713 * parent. 714 */ 715 for (domain = 0; domain < vm_ndomains; domain++) { 716 vmd_kstack_arena[domain] = vmem_create("kstack arena", 0, 0, 717 PAGE_SIZE, 0, M_WAITOK); 718 KASSERT(vmd_kstack_arena[domain] != NULL, 719 ("%s: failed to create domain %d kstack_arena", __func__, 720 domain)); 721 vmem_set_import(vmd_kstack_arena[domain], 722 vm_thread_kstack_arena_import, 723 vm_thread_kstack_arena_release, 724 vm_dom[domain].vmd_kernel_arena, kstack_quantum); 725 } 726 } 727 SYSINIT(vm_kstacks, SI_SUB_KMEM, SI_ORDER_ANY, kstack_cache_init, NULL); 728 729 #ifdef KSTACK_USAGE_PROF 730 /* 731 * Track maximum stack used by a thread in kernel. 732 */ 733 static int max_kstack_used; 734 735 SYSCTL_INT(_debug, OID_AUTO, max_kstack_used, CTLFLAG_RD, 736 &max_kstack_used, 0, 737 "Maximum stack depth used by a thread in kernel"); 738 739 void 740 intr_prof_stack_use(struct thread *td, struct trapframe *frame) 741 { 742 vm_offset_t stack_top; 743 vm_offset_t current; 744 int used, prev_used; 745 746 /* 747 * Testing for interrupted kernel mode isn't strictly 748 * needed. It optimizes the execution, since interrupts from 749 * usermode will have only the trap frame on the stack. 750 */ 751 if (TRAPF_USERMODE(frame)) 752 return; 753 754 stack_top = td->td_kstack + td->td_kstack_pages * PAGE_SIZE; 755 current = (vm_offset_t)(uintptr_t)&stack_top; 756 757 /* 758 * Try to detect if interrupt is using kernel thread stack. 759 * Hardware could use a dedicated stack for interrupt handling. 760 */ 761 if (stack_top <= current || current < td->td_kstack) 762 return; 763 764 used = stack_top - current; 765 for (;;) { 766 prev_used = max_kstack_used; 767 if (prev_used >= used) 768 break; 769 if (atomic_cmpset_int(&max_kstack_used, prev_used, used)) 770 break; 771 } 772 } 773 #endif /* KSTACK_USAGE_PROF */ 774 775 /* 776 * Implement fork's actions on an address space. 777 * Here we arrange for the address space to be copied or referenced, 778 * allocate a user struct (pcb and kernel stack), then call the 779 * machine-dependent layer to fill those in and make the new process 780 * ready to run. The new process is set up so that it returns directly 781 * to user mode to avoid stack copying and relocation problems. 782 */ 783 int 784 vm_forkproc(struct thread *td, struct proc *p2, struct thread *td2, 785 struct vmspace *vm2, int flags) 786 { 787 struct proc *p1 = td->td_proc; 788 struct domainset *dset; 789 int error; 790 791 if ((flags & RFPROC) == 0) { 792 /* 793 * Divorce the memory, if it is shared, essentially 794 * this changes shared memory amongst threads, into 795 * COW locally. 796 */ 797 if ((flags & RFMEM) == 0) { 798 error = vmspace_unshare(p1); 799 if (error) 800 return (error); 801 } 802 cpu_fork(td, p2, td2, flags); 803 return (0); 804 } 805 806 if (flags & RFMEM) { 807 p2->p_vmspace = p1->p_vmspace; 808 refcount_acquire(&p1->p_vmspace->vm_refcnt); 809 } 810 dset = td2->td_domain.dr_policy; 811 while (vm_page_count_severe_set(&dset->ds_mask)) { 812 vm_wait_doms(&dset->ds_mask, 0); 813 } 814 815 if ((flags & RFMEM) == 0) { 816 p2->p_vmspace = vm2; 817 if (p1->p_vmspace->vm_shm) 818 shmfork(p1, p2); 819 } 820 821 /* 822 * cpu_fork will copy and update the pcb, set up the kernel stack, 823 * and make the child ready to run. 824 */ 825 cpu_fork(td, p2, td2, flags); 826 return (0); 827 } 828 829 /* 830 * Called after process has been wait(2)'ed upon and is being reaped. 831 * The idea is to reclaim resources that we could not reclaim while 832 * the process was still executing. 833 */ 834 void 835 vm_waitproc(struct proc *p) 836 { 837 838 vmspace_exitfree(p); /* and clean-out the vmspace */ 839 } 840