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 <sys/cdefs.h> 60#include "opt_vm.h" 61#include "opt_kstack_pages.h" 62#include "opt_kstack_max_pages.h" 63#include "opt_kstack_usage_prof.h" 64 65#include <sys/param.h> 66#include <sys/systm.h> 67#include <sys/asan.h> 68#include <sys/domainset.h> 69#include <sys/limits.h> 70#include <sys/lock.h> 71#include <sys/malloc.h> 72#include <sys/msan.h> 73#include <sys/mutex.h> 74#include <sys/proc.h> 75#include <sys/racct.h> 76#include <sys/refcount.h> 77#include <sys/resourcevar.h> 78#include <sys/rwlock.h> 79#include <sys/sched.h> 80#include <sys/sf_buf.h> 81#include <sys/shm.h> 82#include <sys/smp.h> 83#include <sys/vmmeter.h> 84#include <sys/vmem.h> 85#include <sys/sx.h> 86#include <sys/sysctl.h> 87#include <sys/kernel.h> 88#include <sys/ktr.h> 89#include <sys/unistd.h> 90 91#include <vm/uma.h> 92#include <vm/vm.h> 93#include <vm/vm_param.h> 94#include <vm/pmap.h> 95#include <vm/vm_domainset.h> 96#include <vm/vm_map.h> 97#include <vm/vm_page.h> 98#include <vm/vm_pageout.h> 99#include <vm/vm_pagequeue.h> 100#include <vm/vm_object.h> 101#include <vm/vm_kern.h> 102#include <vm/vm_extern.h> 103#include <vm/vm_pager.h> 104#include <vm/swap_pager.h> 105#include <vm/vm_phys.h> 106 107#include <machine/cpu.h> 108 109#if VM_NRESERVLEVEL > 0 110#define KVA_KSTACK_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) 111#else 112#define KVA_KSTACK_QUANTUM_SHIFT (8 + PAGE_SHIFT) 113#endif 114#define KVA_KSTACK_QUANTUM (1ul << KVA_KSTACK_QUANTUM_SHIFT) 115 116/* 117 * MPSAFE 118 * 119 * WARNING! This code calls vm_map_check_protection() which only checks 120 * the associated vm_map_entry range. It does not determine whether the 121 * contents of the memory is actually readable or writable. In most cases 122 * just checking the vm_map_entry is sufficient within the kernel's address 123 * space. 124 */ 125bool 126kernacc(void *addr, int len, int rw) 127{ 128 boolean_t rv; 129 vm_offset_t saddr, eaddr; 130 vm_prot_t prot; 131 132 KASSERT((rw & ~VM_PROT_ALL) == 0, 133 ("illegal ``rw'' argument to kernacc (%x)\n", rw)); 134 135 if ((vm_offset_t)addr + len > vm_map_max(kernel_map) || 136 (vm_offset_t)addr + len < (vm_offset_t)addr) 137 return (false); 138 139 prot = rw; 140 saddr = trunc_page((vm_offset_t)addr); 141 eaddr = round_page((vm_offset_t)addr + len); 142 vm_map_lock_read(kernel_map); 143 rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot); 144 vm_map_unlock_read(kernel_map); 145 return (rv == TRUE); 146} 147 148/* 149 * MPSAFE 150 * 151 * WARNING! This code calls vm_map_check_protection() which only checks 152 * the associated vm_map_entry range. It does not determine whether the 153 * contents of the memory is actually readable or writable. vmapbuf(), 154 * vm_fault_quick(), or copyin()/copout()/su*()/fu*() functions should be 155 * used in conjunction with this call. 156 */ 157bool 158useracc(void *addr, int len, int rw) 159{ 160 boolean_t rv; 161 vm_prot_t prot; 162 vm_map_t map; 163 164 KASSERT((rw & ~VM_PROT_ALL) == 0, 165 ("illegal ``rw'' argument to useracc (%x)\n", rw)); 166 prot = rw; 167 map = &curproc->p_vmspace->vm_map; 168 if ((vm_offset_t)addr + len > vm_map_max(map) || 169 (vm_offset_t)addr + len < (vm_offset_t)addr) { 170 return (false); 171 } 172 vm_map_lock_read(map); 173 rv = vm_map_check_protection(map, trunc_page((vm_offset_t)addr), 174 round_page((vm_offset_t)addr + len), prot); 175 vm_map_unlock_read(map); 176 return (rv == TRUE); 177} 178 179int 180vslock(void *addr, size_t len) 181{ 182 vm_offset_t end, last, start; 183 vm_size_t npages; 184 int error; 185 186 last = (vm_offset_t)addr + len; 187 start = trunc_page((vm_offset_t)addr); 188 end = round_page(last); 189 if (last < (vm_offset_t)addr || end < (vm_offset_t)addr) 190 return (EINVAL); 191 npages = atop(end - start); 192 if (npages > vm_page_max_user_wired) 193 return (ENOMEM); 194 error = vm_map_wire(&curproc->p_vmspace->vm_map, start, end, 195 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 196 if (error == KERN_SUCCESS) { 197 curthread->td_vslock_sz += len; 198 return (0); 199 } 200 201 /* 202 * Return EFAULT on error to match copy{in,out}() behaviour 203 * rather than returning ENOMEM like mlock() would. 204 */ 205 return (EFAULT); 206} 207 208void 209vsunlock(void *addr, size_t len) 210{ 211 212 /* Rely on the parameter sanity checks performed by vslock(). */ 213 MPASS(curthread->td_vslock_sz >= len); 214 curthread->td_vslock_sz -= len; 215 (void)vm_map_unwire(&curproc->p_vmspace->vm_map, 216 trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len), 217 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 218} 219 220/* 221 * Pin the page contained within the given object at the given offset. If the 222 * page is not resident, allocate and load it using the given object's pager. 223 * Return the pinned page if successful; otherwise, return NULL. 224 */ 225static vm_page_t 226vm_imgact_hold_page(vm_object_t object, vm_ooffset_t offset) 227{ 228 vm_page_t m; 229 vm_pindex_t pindex; 230 231 pindex = OFF_TO_IDX(offset); 232 (void)vm_page_grab_valid_unlocked(&m, object, pindex, 233 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED); 234 return (m); 235} 236 237/* 238 * Return a CPU private mapping to the page at the given offset within the 239 * given object. The page is pinned before it is mapped. 240 */ 241struct sf_buf * 242vm_imgact_map_page(vm_object_t object, vm_ooffset_t offset) 243{ 244 vm_page_t m; 245 246 m = vm_imgact_hold_page(object, offset); 247 if (m == NULL) 248 return (NULL); 249 sched_pin(); 250 return (sf_buf_alloc(m, SFB_CPUPRIVATE)); 251} 252 253/* 254 * Destroy the given CPU private mapping and unpin the page that it mapped. 255 */ 256void 257vm_imgact_unmap_page(struct sf_buf *sf) 258{ 259 vm_page_t m; 260 261 m = sf_buf_page(sf); 262 sf_buf_free(sf); 263 sched_unpin(); 264 vm_page_unwire(m, PQ_ACTIVE); 265} 266 267void 268vm_sync_icache(vm_map_t map, vm_offset_t va, vm_offset_t sz) 269{ 270 271 pmap_sync_icache(map->pmap, va, sz); 272} 273 274static vm_object_t kstack_object; 275static vm_object_t kstack_alt_object; 276static uma_zone_t kstack_cache; 277static int kstack_cache_size; 278static vmem_t *vmd_kstack_arena[MAXMEMDOM]; 279 280static int 281sysctl_kstack_cache_size(SYSCTL_HANDLER_ARGS) 282{ 283 int error, oldsize; 284 285 oldsize = kstack_cache_size; 286 error = sysctl_handle_int(oidp, arg1, arg2, req); 287 if (error == 0 && req->newptr && oldsize != kstack_cache_size) 288 uma_zone_set_maxcache(kstack_cache, kstack_cache_size); 289 return (error); 290} 291SYSCTL_PROC(_vm, OID_AUTO, kstack_cache_size, 292 CTLTYPE_INT|CTLFLAG_MPSAFE|CTLFLAG_RW, &kstack_cache_size, 0, 293 sysctl_kstack_cache_size, "IU", "Maximum number of cached kernel stacks"); 294 295/* 296 * Allocate a virtual address range from a domain kstack arena, following 297 * the specified NUMA policy. 298 */ 299static vm_offset_t 300vm_thread_alloc_kstack_kva(vm_size_t size, int domain) 301{ 302#ifndef __ILP32__ 303 int rv; 304 vmem_t *arena; 305 vm_offset_t addr = 0; 306 307 size = round_page(size); 308 /* Allocate from the kernel arena for non-standard kstack sizes. */ 309 if (size != ptoa(kstack_pages + KSTACK_GUARD_PAGES)) { 310 arena = vm_dom[domain].vmd_kernel_arena; 311 } else { 312 arena = vmd_kstack_arena[domain]; 313 } 314 rv = vmem_alloc(arena, size, M_BESTFIT | M_NOWAIT, &addr); 315 if (rv == ENOMEM) 316 return (0); 317 KASSERT(atop(addr - VM_MIN_KERNEL_ADDRESS) % 318 (kstack_pages + KSTACK_GUARD_PAGES) == 0, 319 ("%s: allocated kstack KVA not aligned to multiple of kstack size", 320 __func__)); 321 322 return (addr); 323#else 324 return (kva_alloc(size)); 325#endif 326} 327 328/* 329 * Release a region of kernel virtual memory 330 * allocated from the kstack arena. 331 */ 332static __noinline void 333vm_thread_free_kstack_kva(vm_offset_t addr, vm_size_t size, int domain) 334{ 335 vmem_t *arena; 336 337 size = round_page(size); 338#ifdef __ILP32__ 339 arena = kernel_arena; 340#else 341 arena = vmd_kstack_arena[domain]; 342 if (size != ptoa(kstack_pages + KSTACK_GUARD_PAGES)) { 343 arena = vm_dom[domain].vmd_kernel_arena; 344 } 345#endif 346 vmem_free(arena, addr, size); 347} 348 349static vmem_size_t 350vm_thread_kstack_import_quantum(void) 351{ 352#ifndef __ILP32__ 353 /* 354 * The kstack_quantum is larger than KVA_QUANTUM to account 355 * for holes induced by guard pages. 356 */ 357 return (KVA_KSTACK_QUANTUM * (kstack_pages + KSTACK_GUARD_PAGES)); 358#else 359 return (KVA_KSTACK_QUANTUM); 360#endif 361} 362 363/* 364 * Import KVA from a parent arena into the kstack arena. Imports must be 365 * a multiple of kernel stack pages + guard pages in size. 366 * 367 * Kstack VA allocations need to be aligned so that the linear KVA pindex 368 * is divisible by the total number of kstack VA pages. This is necessary to 369 * make vm_kstack_pindex work properly. 370 * 371 * We import a multiple of KVA_KSTACK_QUANTUM-sized region from the parent 372 * arena. The actual size used by the kstack arena is one kstack smaller to 373 * allow for the necessary alignment adjustments to be made. 374 */ 375static int 376vm_thread_kstack_arena_import(void *arena, vmem_size_t size, int flags, 377 vmem_addr_t *addrp) 378{ 379 int error, rem; 380 size_t kpages = kstack_pages + KSTACK_GUARD_PAGES; 381 382 KASSERT(atop(size) % kpages == 0, 383 ("%s: Size %jd is not a multiple of kstack pages (%d)", __func__, 384 (intmax_t)size, (int)kpages)); 385 386 error = vmem_xalloc(arena, vm_thread_kstack_import_quantum(), 387 KVA_KSTACK_QUANTUM, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, flags, 388 addrp); 389 if (error) { 390 return (error); 391 } 392 393 rem = atop(*addrp - VM_MIN_KERNEL_ADDRESS) % kpages; 394 if (rem != 0) { 395 /* Bump addr to next aligned address */ 396 *addrp = *addrp + (kpages - rem) * PAGE_SIZE; 397 } 398 399 return (0); 400} 401 402/* 403 * Release KVA from a parent arena into the kstack arena. Released imports must 404 * be a multiple of kernel stack pages + guard pages in size. 405 */ 406static void 407vm_thread_kstack_arena_release(void *arena, vmem_addr_t addr, vmem_size_t size) 408{ 409 int rem; 410 size_t kpages __diagused = kstack_pages + KSTACK_GUARD_PAGES; 411 412 KASSERT(size % kpages == 0, 413 ("%s: Size %jd is not a multiple of kstack pages (%d)", __func__, 414 (intmax_t)size, (int)kpages)); 415 416 KASSERT((addr - VM_MIN_KERNEL_ADDRESS) % kpages == 0, 417 ("%s: Address %p is not properly aligned (%p)", __func__, 418 (void *)addr, (void *)VM_MIN_KERNEL_ADDRESS)); 419 /* 420 * If the address is not KVA_KSTACK_QUANTUM-aligned we have to decrement 421 * it to account for the shift in kva_import_kstack. 422 */ 423 rem = addr % KVA_KSTACK_QUANTUM; 424 if (rem) { 425 KASSERT(rem <= ptoa(kpages), 426 ("%s: rem > kpages (%d), (%d)", __func__, rem, 427 (int)kpages)); 428 addr -= rem; 429 } 430 vmem_xfree(arena, addr, vm_thread_kstack_import_quantum()); 431} 432 433/* 434 * Create the kernel stack for a new thread. 435 */ 436static vm_offset_t 437vm_thread_stack_create(struct domainset *ds, int pages) 438{ 439 vm_page_t ma[KSTACK_MAX_PAGES]; 440 struct vm_domainset_iter di; 441 int req = VM_ALLOC_NORMAL; 442 vm_object_t obj; 443 vm_offset_t ks; 444 int domain, i; 445 446 obj = vm_thread_kstack_size_to_obj(pages); 447 if (vm_ndomains > 1) 448 obj->domain.dr_policy = ds; 449 vm_domainset_iter_page_init(&di, obj, 0, &domain, &req); 450 do { 451 /* 452 * Get a kernel virtual address for this thread's kstack. 453 */ 454 ks = vm_thread_alloc_kstack_kva(ptoa(pages + KSTACK_GUARD_PAGES), 455 domain); 456 if (ks == 0) 457 continue; 458 ks += ptoa(KSTACK_GUARD_PAGES); 459 460 /* 461 * Allocate physical pages to back the stack. 462 */ 463 if (vm_thread_stack_back(ks, ma, pages, req, domain) != 0) { 464 vm_thread_free_kstack_kva(ks - ptoa(KSTACK_GUARD_PAGES), 465 ptoa(pages + KSTACK_GUARD_PAGES), domain); 466 continue; 467 } 468 if (KSTACK_GUARD_PAGES != 0) { 469 pmap_qremove(ks - ptoa(KSTACK_GUARD_PAGES), 470 KSTACK_GUARD_PAGES); 471 } 472 for (i = 0; i < pages; i++) 473 vm_page_valid(ma[i]); 474 pmap_qenter(ks, ma, pages); 475 return (ks); 476 } while (vm_domainset_iter_page(&di, obj, &domain) == 0); 477 478 return (0); 479} 480 481static __noinline void 482vm_thread_stack_dispose(vm_offset_t ks, int pages) 483{ 484 vm_page_t m; 485 vm_pindex_t pindex; 486 int i, domain; 487 vm_object_t obj = vm_thread_kstack_size_to_obj(pages); 488 489 pindex = vm_kstack_pindex(ks, pages); 490 domain = vm_phys_domain(vtophys(ks)); 491 pmap_qremove(ks, pages); 492 VM_OBJECT_WLOCK(obj); 493 for (i = 0; i < pages; i++) { 494 m = vm_page_lookup(obj, pindex + i); 495 if (m == NULL) 496 panic("%s: kstack already missing?", __func__); 497 KASSERT(vm_page_domain(m) == domain, 498 ("%s: page %p domain mismatch, expected %d got %d", 499 __func__, m, domain, vm_page_domain(m))); 500 vm_page_xbusy_claim(m); 501 vm_page_unwire_noq(m); 502 vm_page_free(m); 503 } 504 VM_OBJECT_WUNLOCK(obj); 505 kasan_mark((void *)ks, ptoa(pages), ptoa(pages), 0); 506 vm_thread_free_kstack_kva(ks - (KSTACK_GUARD_PAGES * PAGE_SIZE), 507 ptoa(pages + KSTACK_GUARD_PAGES), domain); 508} 509 510/* 511 * Allocate the kernel stack for a new thread. 512 */ 513int 514vm_thread_new(struct thread *td, int pages) 515{ 516 vm_offset_t ks; 517 u_short ks_domain; 518 519 /* Bounds check */ 520 if (pages <= 1) 521 pages = kstack_pages; 522 else if (pages > KSTACK_MAX_PAGES) 523 pages = KSTACK_MAX_PAGES; 524 525 ks = 0; 526 if (pages == kstack_pages && kstack_cache != NULL) 527 ks = (vm_offset_t)uma_zalloc(kstack_cache, M_NOWAIT); 528 529 /* 530 * Ensure that kstack objects can draw pages from any memory 531 * domain. Otherwise a local memory shortage can block a process 532 * swap-in. 533 */ 534 if (ks == 0) 535 ks = vm_thread_stack_create(DOMAINSET_PREF(PCPU_GET(domain)), 536 pages); 537 if (ks == 0) 538 return (0); 539 540 ks_domain = vm_phys_domain(vtophys(ks)); 541 KASSERT(ks_domain >= 0 && ks_domain < vm_ndomains, 542 ("%s: invalid domain for kstack %p", __func__, (void *)ks)); 543 td->td_kstack = ks; 544 td->td_kstack_pages = pages; 545 td->td_kstack_domain = ks_domain; 546 return (1); 547} 548 549/* 550 * Dispose of a thread's kernel stack. 551 */ 552void 553vm_thread_dispose(struct thread *td) 554{ 555 vm_offset_t ks; 556 int pages; 557 558 pages = td->td_kstack_pages; 559 ks = td->td_kstack; 560 td->td_kstack = 0; 561 td->td_kstack_pages = 0; 562 td->td_kstack_domain = MAXMEMDOM; 563 if (pages == kstack_pages) { 564 kasan_mark((void *)ks, 0, ptoa(pages), KASAN_KSTACK_FREED); 565 uma_zfree(kstack_cache, (void *)ks); 566 } else { 567 vm_thread_stack_dispose(ks, pages); 568 } 569} 570 571/* 572 * Calculate kstack pindex. 573 * 574 * Uses a non-identity mapping if guard pages are 575 * active to avoid pindex holes in the kstack object. 576 */ 577vm_pindex_t 578vm_kstack_pindex(vm_offset_t ks, int kpages) 579{ 580 vm_pindex_t pindex = atop(ks - VM_MIN_KERNEL_ADDRESS); 581 582#ifdef __ILP32__ 583 return (pindex); 584#else 585 /* 586 * Return the linear pindex if guard pages aren't active or if we are 587 * allocating a non-standard kstack size. 588 */ 589 if (KSTACK_GUARD_PAGES == 0 || kpages != kstack_pages) { 590 return (pindex); 591 } 592 KASSERT(pindex % (kpages + KSTACK_GUARD_PAGES) >= KSTACK_GUARD_PAGES, 593 ("%s: Attempting to calculate kstack guard page pindex", __func__)); 594 595 return (pindex - 596 (pindex / (kpages + KSTACK_GUARD_PAGES) + 1) * KSTACK_GUARD_PAGES); 597#endif 598} 599 600/* 601 * Allocate physical pages, following the specified NUMA policy, to back a 602 * kernel stack. 603 */ 604int 605vm_thread_stack_back(vm_offset_t ks, vm_page_t ma[], int npages, int req_class, 606 int domain) 607{ 608 vm_object_t obj = vm_thread_kstack_size_to_obj(npages); 609 vm_pindex_t pindex; 610 vm_page_t m; 611 int n; 612 613 pindex = vm_kstack_pindex(ks, npages); 614 615 VM_OBJECT_WLOCK(obj); 616 for (n = 0; n < npages;) { 617 m = vm_page_grab(obj, pindex + n, 618 VM_ALLOC_NOCREAT | VM_ALLOC_WIRED); 619 if (m == NULL) { 620 m = vm_page_alloc_domain(obj, pindex + n, domain, 621 req_class | VM_ALLOC_WIRED); 622 } 623 if (m == NULL) 624 break; 625 ma[n++] = m; 626 } 627 if (n < npages) 628 goto cleanup; 629 VM_OBJECT_WUNLOCK(obj); 630 631 return (0); 632cleanup: 633 for (int i = 0; i < n; i++) { 634 m = ma[i]; 635 (void)vm_page_unwire_noq(m); 636 vm_page_free(m); 637 } 638 VM_OBJECT_WUNLOCK(obj); 639 640 return (ENOMEM); 641} 642 643vm_object_t 644vm_thread_kstack_size_to_obj(int npages) 645{ 646 return (npages == kstack_pages ? kstack_object : kstack_alt_object); 647} 648 649static int 650kstack_import(void *arg, void **store, int cnt, int domain, int flags) 651{ 652 struct domainset *ds; 653 int i; 654 655 if (domain == UMA_ANYDOMAIN) 656 ds = DOMAINSET_RR(); 657 else 658 ds = DOMAINSET_PREF(domain); 659 660 for (i = 0; i < cnt; i++) { 661 store[i] = (void *)vm_thread_stack_create(ds, kstack_pages); 662 if (store[i] == NULL) 663 break; 664 } 665 return (i); 666} 667 668static void 669kstack_release(void *arg, void **store, int cnt) 670{ 671 vm_offset_t ks; 672 int i; 673 674 for (i = 0; i < cnt; i++) { 675 ks = (vm_offset_t)store[i]; 676 vm_thread_stack_dispose(ks, kstack_pages); 677 } 678} 679 680static void 681kstack_cache_init(void *null) 682{ 683 vm_size_t kstack_quantum; 684 int domain; 685 686 kstack_object = vm_object_allocate(OBJT_SWAP, 687 atop(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS)); 688 kstack_cache = uma_zcache_create("kstack_cache", 689 kstack_pages * PAGE_SIZE, NULL, NULL, NULL, NULL, 690 kstack_import, kstack_release, NULL, 691 UMA_ZONE_FIRSTTOUCH); 692 kstack_cache_size = imax(128, mp_ncpus * 4); 693 uma_zone_set_maxcache(kstack_cache, kstack_cache_size); 694 695 kstack_alt_object = vm_object_allocate(OBJT_SWAP, 696 atop(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS)); 697 698 kstack_quantum = vm_thread_kstack_import_quantum(); 699 /* 700 * Reduce size used by the kstack arena to allow for 701 * alignment adjustments in vm_thread_kstack_arena_import. 702 */ 703 kstack_quantum -= (kstack_pages + KSTACK_GUARD_PAGES) * PAGE_SIZE; 704 /* 705 * Create the kstack_arena for each domain and set kernel_arena as 706 * parent. 707 */ 708 for (domain = 0; domain < vm_ndomains; domain++) { 709 vmd_kstack_arena[domain] = vmem_create("kstack arena", 0, 0, 710 PAGE_SIZE, 0, M_WAITOK); 711 KASSERT(vmd_kstack_arena[domain] != NULL, 712 ("%s: failed to create domain %d kstack_arena", __func__, 713 domain)); 714 vmem_set_import(vmd_kstack_arena[domain], 715 vm_thread_kstack_arena_import, 716 vm_thread_kstack_arena_release, 717 vm_dom[domain].vmd_kernel_arena, kstack_quantum); 718 } 719} 720SYSINIT(vm_kstacks, SI_SUB_KMEM, SI_ORDER_ANY, kstack_cache_init, NULL); 721 722#ifdef KSTACK_USAGE_PROF 723/* 724 * Track maximum stack used by a thread in kernel. 725 */ 726static int max_kstack_used; 727 728SYSCTL_INT(_debug, OID_AUTO, max_kstack_used, CTLFLAG_RD, 729 &max_kstack_used, 0, 730 "Maximum stack depth used by a thread in kernel"); 731 732void 733intr_prof_stack_use(struct thread *td, struct trapframe *frame) 734{ 735 vm_offset_t stack_top; 736 vm_offset_t current; 737 int used, prev_used; 738 739 /* 740 * Testing for interrupted kernel mode isn't strictly 741 * needed. It optimizes the execution, since interrupts from 742 * usermode will have only the trap frame on the stack. 743 */ 744 if (TRAPF_USERMODE(frame)) 745 return; 746 747 stack_top = td->td_kstack + td->td_kstack_pages * PAGE_SIZE; 748 current = (vm_offset_t)(uintptr_t)&stack_top; 749 750 /* 751 * Try to detect if interrupt is using kernel thread stack. 752 * Hardware could use a dedicated stack for interrupt handling. 753 */ 754 if (stack_top <= current || current < td->td_kstack) 755 return; 756 757 used = stack_top - current; 758 for (;;) { 759 prev_used = max_kstack_used; 760 if (prev_used >= used) 761 break; 762 if (atomic_cmpset_int(&max_kstack_used, prev_used, used)) 763 break; 764 } 765} 766#endif /* KSTACK_USAGE_PROF */ 767 768/* 769 * Implement fork's actions on an address space. 770 * Here we arrange for the address space to be copied or referenced, 771 * allocate a user struct (pcb and kernel stack), then call the 772 * machine-dependent layer to fill those in and make the new process 773 * ready to run. The new process is set up so that it returns directly 774 * to user mode to avoid stack copying and relocation problems. 775 */ 776int 777vm_forkproc(struct thread *td, struct proc *p2, struct thread *td2, 778 struct vmspace *vm2, int flags) 779{ 780 struct proc *p1 = td->td_proc; 781 struct domainset *dset; 782 int error; 783 784 if ((flags & RFPROC) == 0) { 785 /* 786 * Divorce the memory, if it is shared, essentially 787 * this changes shared memory amongst threads, into 788 * COW locally. 789 */ 790 if ((flags & RFMEM) == 0) { 791 error = vmspace_unshare(p1); 792 if (error) 793 return (error); 794 } 795 cpu_fork(td, p2, td2, flags); 796 return (0); 797 } 798 799 if (flags & RFMEM) { 800 p2->p_vmspace = p1->p_vmspace; 801 refcount_acquire(&p1->p_vmspace->vm_refcnt); 802 } 803 dset = td2->td_domain.dr_policy; 804 while (vm_page_count_severe_set(&dset->ds_mask)) { 805 vm_wait_doms(&dset->ds_mask, 0); 806 } 807 808 if ((flags & RFMEM) == 0) { 809 p2->p_vmspace = vm2; 810 if (p1->p_vmspace->vm_shm) 811 shmfork(p1, p2); 812 } 813 814 /* 815 * cpu_fork will copy and update the pcb, set up the kernel stack, 816 * and make the child ready to run. 817 */ 818 cpu_fork(td, p2, td2, flags); 819 return (0); 820} 821 822/* 823 * Called after process has been wait(2)'ed upon and is being reaped. 824 * The idea is to reclaim resources that we could not reclaim while 825 * the process was still executing. 826 */ 827void 828vm_waitproc(struct proc *p) 829{ 830 831 vmspace_exitfree(p); /* and clean-out the vmspace */ 832} 833 834void 835kick_proc0(void) 836{ 837 838 wakeup(&proc0); 839} 840