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 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
39 *
40 * Permission to use, copy, modify and distribute this software and
41 * its documentation is hereby granted, provided that both the copyright
42 * notice and this permission notice appear in all copies of the
43 * software, derivative works or modified versions, and any portions
44 * thereof, and that both notices appear in supporting documentation.
45 *
46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
49 *
50 * Carnegie Mellon requests users of this software to return to
51 *
52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
53 * School of Computer Science
54 * Carnegie Mellon University
55 * Pittsburgh PA 15213-3890
56 *
57 * any improvements or extensions that they make and grant Carnegie the
58 * rights to redistribute these changes.
59 */
60
61 /*
62 * Kernel memory management.
63 */
64
65 #include <sys/cdefs.h>
66 #include "opt_vm.h"
67
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/asan.h>
71 #include <sys/domainset.h>
72 #include <sys/eventhandler.h>
73 #include <sys/kernel.h>
74 #include <sys/lock.h>
75 #include <sys/malloc.h>
76 #include <sys/msan.h>
77 #include <sys/proc.h>
78 #include <sys/rwlock.h>
79 #include <sys/smp.h>
80 #include <sys/sysctl.h>
81 #include <sys/vmem.h>
82 #include <sys/vmmeter.h>
83
84 #include <vm/vm.h>
85 #include <vm/vm_param.h>
86 #include <vm/vm_domainset.h>
87 #include <vm/vm_kern.h>
88 #include <vm/pmap.h>
89 #include <vm/vm_map.h>
90 #include <vm/vm_object.h>
91 #include <vm/vm_page.h>
92 #include <vm/vm_pageout.h>
93 #include <vm/vm_pagequeue.h>
94 #include <vm/vm_phys.h>
95 #include <vm/vm_radix.h>
96 #include <vm/vm_extern.h>
97 #include <vm/uma.h>
98
99 struct vm_map kernel_map_store;
100 struct vm_map exec_map_store;
101 struct vm_map pipe_map_store;
102
103 const void *zero_region;
104 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0);
105
106 /* NB: Used by kernel debuggers. */
107 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS;
108
109 u_int exec_map_entry_size;
110 u_int exec_map_entries;
111
112 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD,
113 SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address");
114
115 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD,
116 #if defined(__arm__)
117 &vm_max_kernel_address, 0,
118 #else
119 SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS,
120 #endif
121 "Max kernel address");
122
123 #if VM_NRESERVLEVEL > 1
124 #define KVA_QUANTUM_SHIFT (VM_LEVEL_1_ORDER + VM_LEVEL_0_ORDER + \
125 PAGE_SHIFT)
126 #elif VM_NRESERVLEVEL > 0
127 #define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT)
128 #else
129 /* On non-superpage architectures we want large import sizes. */
130 #define KVA_QUANTUM_SHIFT (8 + PAGE_SHIFT)
131 #endif
132 #define KVA_QUANTUM (1ul << KVA_QUANTUM_SHIFT)
133 #define KVA_NUMA_IMPORT_QUANTUM (KVA_QUANTUM * 128)
134
135 extern void uma_startup2(void);
136
137 /*
138 * kva_alloc:
139 *
140 * Allocate a virtual address range with no underlying object and
141 * no initial mapping to physical memory. Any mapping from this
142 * range to physical memory must be explicitly created prior to
143 * its use, typically with pmap_qenter(). Any attempt to create
144 * a mapping on demand through vm_fault() will result in a panic.
145 */
146 vm_offset_t
kva_alloc(vm_size_t size)147 kva_alloc(vm_size_t size)
148 {
149 vm_offset_t addr;
150
151 TSENTER();
152 size = round_page(size);
153 if (vmem_xalloc(kernel_arena, size, 0, 0, 0, VMEM_ADDR_MIN,
154 VMEM_ADDR_MAX, M_BESTFIT | M_NOWAIT, &addr))
155 return (0);
156 TSEXIT();
157
158 return (addr);
159 }
160
161 /*
162 * kva_alloc_aligned:
163 *
164 * Allocate a virtual address range as in kva_alloc where the base
165 * address is aligned to align.
166 */
167 vm_offset_t
kva_alloc_aligned(vm_size_t size,vm_size_t align)168 kva_alloc_aligned(vm_size_t size, vm_size_t align)
169 {
170 vm_offset_t addr;
171
172 TSENTER();
173 size = round_page(size);
174 if (vmem_xalloc(kernel_arena, size, align, 0, 0, VMEM_ADDR_MIN,
175 VMEM_ADDR_MAX, M_BESTFIT | M_NOWAIT, &addr))
176 return (0);
177 TSEXIT();
178
179 return (addr);
180 }
181
182 /*
183 * kva_free:
184 *
185 * Release a region of kernel virtual memory allocated
186 * with kva_alloc, and return the physical pages
187 * associated with that region.
188 *
189 * This routine may not block on kernel maps.
190 */
191 void
kva_free(vm_offset_t addr,vm_size_t size)192 kva_free(vm_offset_t addr, vm_size_t size)
193 {
194
195 size = round_page(size);
196 vmem_xfree(kernel_arena, addr, size);
197 }
198
199 /*
200 * Update sanitizer shadow state to reflect a new allocation. Force inlining to
201 * help make KMSAN origin tracking more precise.
202 */
203 static __always_inline void
kmem_alloc_san(vm_offset_t addr,vm_size_t size,vm_size_t asize,int flags)204 kmem_alloc_san(vm_offset_t addr, vm_size_t size, vm_size_t asize, int flags)
205 {
206 if ((flags & M_ZERO) == 0) {
207 kmsan_mark((void *)addr, asize, KMSAN_STATE_UNINIT);
208 kmsan_orig((void *)addr, asize, KMSAN_TYPE_KMEM,
209 KMSAN_RET_ADDR);
210 } else {
211 kmsan_mark((void *)addr, asize, KMSAN_STATE_INITED);
212 }
213 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE);
214 }
215
216 static vm_page_t
kmem_alloc_contig_pages(vm_object_t object,vm_pindex_t pindex,int domain,int pflags,u_long npages,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,vm_memattr_t memattr)217 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain,
218 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high,
219 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
220 {
221 vm_page_t m;
222 int tries;
223 bool wait, reclaim;
224
225 VM_OBJECT_ASSERT_WLOCKED(object);
226
227 wait = (pflags & VM_ALLOC_WAITOK) != 0;
228 reclaim = (pflags & VM_ALLOC_NORECLAIM) == 0;
229 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
230 pflags |= VM_ALLOC_NOWAIT;
231 for (tries = wait ? 3 : 1;; tries--) {
232 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags,
233 npages, low, high, alignment, boundary, memattr);
234 if (m != NULL || tries == 0 || !reclaim)
235 break;
236
237 VM_OBJECT_WUNLOCK(object);
238 if (vm_page_reclaim_contig_domain(domain, pflags, npages,
239 low, high, alignment, boundary) == ENOMEM && wait)
240 vm_wait_domain(domain);
241 VM_OBJECT_WLOCK(object);
242 }
243 return (m);
244 }
245
246 /*
247 * Allocates a region from the kernel address map and physical pages
248 * within the specified address range to the kernel object. Creates a
249 * wired mapping from this region to these pages, and returns the
250 * region's starting virtual address. The allocated pages are not
251 * necessarily physically contiguous. If M_ZERO is specified through the
252 * given flags, then the pages are zeroed before they are mapped.
253 */
254 static void *
kmem_alloc_attr_domain(int domain,vm_size_t size,int flags,vm_paddr_t low,vm_paddr_t high,vm_memattr_t memattr)255 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
256 vm_paddr_t high, vm_memattr_t memattr)
257 {
258 vmem_t *vmem;
259 vm_object_t object;
260 vm_offset_t addr, i, offset;
261 vm_page_t m;
262 vm_size_t asize;
263 int pflags;
264 vm_prot_t prot;
265
266 object = kernel_object;
267 asize = round_page(size);
268 vmem = vm_dom[domain].vmd_kernel_arena;
269 if (vmem_alloc(vmem, asize, M_BESTFIT | flags, &addr))
270 return (0);
271 offset = addr - VM_MIN_KERNEL_ADDRESS;
272 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
273 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
274 VM_OBJECT_WLOCK(object);
275 for (i = 0; i < asize; i += PAGE_SIZE) {
276 m = kmem_alloc_contig_pages(object, atop(offset + i),
277 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr);
278 if (m == NULL) {
279 VM_OBJECT_WUNLOCK(object);
280 kmem_unback(object, addr, i);
281 vmem_free(vmem, addr, asize);
282 return (0);
283 }
284 KASSERT(vm_page_domain(m) == domain,
285 ("kmem_alloc_attr_domain: Domain mismatch %d != %d",
286 vm_page_domain(m), domain));
287 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
288 pmap_zero_page(m);
289 vm_page_valid(m);
290 pmap_enter(kernel_pmap, addr + i, m, prot,
291 prot | PMAP_ENTER_WIRED, 0);
292 }
293 VM_OBJECT_WUNLOCK(object);
294 kmem_alloc_san(addr, size, asize, flags);
295 return ((void *)addr);
296 }
297
298 void *
kmem_alloc_attr(vm_size_t size,int flags,vm_paddr_t low,vm_paddr_t high,vm_memattr_t memattr)299 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
300 vm_memattr_t memattr)
301 {
302
303 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low,
304 high, memattr));
305 }
306
307 void *
kmem_alloc_attr_domainset(struct domainset * ds,vm_size_t size,int flags,vm_paddr_t low,vm_paddr_t high,vm_memattr_t memattr)308 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags,
309 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr)
310 {
311 struct vm_domainset_iter di;
312 vm_page_t bounds[2];
313 void *addr;
314 int domain;
315 int start_segind;
316
317 start_segind = -1;
318
319 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
320 do {
321 addr = kmem_alloc_attr_domain(domain, size, flags, low, high,
322 memattr);
323 if (addr != NULL)
324 break;
325 if (start_segind == -1)
326 start_segind = vm_phys_lookup_segind(low);
327 if (vm_phys_find_range(bounds, start_segind, domain,
328 atop(round_page(size)), low, high) == -1) {
329 vm_domainset_iter_ignore(&di, domain);
330 }
331 } while (vm_domainset_iter_policy(&di, &domain) == 0);
332
333 return (addr);
334 }
335
336 /*
337 * Allocates a region from the kernel address map and physically
338 * contiguous pages within the specified address range to the kernel
339 * object. Creates a wired mapping from this region to these pages, and
340 * returns the region's starting virtual address. If M_ZERO is specified
341 * through the given flags, then the pages are zeroed before they are
342 * mapped.
343 */
344 static void *
kmem_alloc_contig_domain(int domain,vm_size_t size,int flags,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,vm_memattr_t memattr)345 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
346 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
347 vm_memattr_t memattr)
348 {
349 vmem_t *vmem;
350 vm_object_t object;
351 vm_offset_t addr, offset, tmp;
352 vm_page_t end_m, m;
353 vm_size_t asize;
354 u_long npages;
355 int pflags;
356
357 object = kernel_object;
358 asize = round_page(size);
359 vmem = vm_dom[domain].vmd_kernel_arena;
360 if (vmem_alloc(vmem, asize, flags | M_BESTFIT, &addr))
361 return (NULL);
362 offset = addr - VM_MIN_KERNEL_ADDRESS;
363 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
364 npages = atop(asize);
365 VM_OBJECT_WLOCK(object);
366 m = kmem_alloc_contig_pages(object, atop(offset), domain,
367 pflags, npages, low, high, alignment, boundary, memattr);
368 if (m == NULL) {
369 VM_OBJECT_WUNLOCK(object);
370 vmem_free(vmem, addr, asize);
371 return (NULL);
372 }
373 KASSERT(vm_page_domain(m) == domain,
374 ("kmem_alloc_contig_domain: Domain mismatch %d != %d",
375 vm_page_domain(m), domain));
376 end_m = m + npages;
377 tmp = addr;
378 for (; m < end_m; m++) {
379 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
380 pmap_zero_page(m);
381 vm_page_valid(m);
382 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW,
383 VM_PROT_RW | PMAP_ENTER_WIRED, 0);
384 tmp += PAGE_SIZE;
385 }
386 VM_OBJECT_WUNLOCK(object);
387 kmem_alloc_san(addr, size, asize, flags);
388 return ((void *)addr);
389 }
390
391 void *
kmem_alloc_contig(vm_size_t size,int flags,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,vm_memattr_t memattr)392 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
393 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
394 {
395
396 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low,
397 high, alignment, boundary, memattr));
398 }
399
400 void *
kmem_alloc_contig_domainset(struct domainset * ds,vm_size_t size,int flags,vm_paddr_t low,vm_paddr_t high,u_long alignment,vm_paddr_t boundary,vm_memattr_t memattr)401 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags,
402 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
403 vm_memattr_t memattr)
404 {
405 struct vm_domainset_iter di;
406 vm_page_t bounds[2];
407 void *addr;
408 int domain;
409 int start_segind;
410
411 start_segind = -1;
412
413 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
414 do {
415 addr = kmem_alloc_contig_domain(domain, size, flags, low, high,
416 alignment, boundary, memattr);
417 if (addr != NULL)
418 break;
419 if (start_segind == -1)
420 start_segind = vm_phys_lookup_segind(low);
421 if (vm_phys_find_range(bounds, start_segind, domain,
422 atop(round_page(size)), low, high) == -1) {
423 vm_domainset_iter_ignore(&di, domain);
424 }
425 } while (vm_domainset_iter_policy(&di, &domain) == 0);
426
427 return (addr);
428 }
429
430 /*
431 * kmem_subinit:
432 *
433 * Initializes a map to manage a subrange
434 * of the kernel virtual address space.
435 *
436 * Arguments are as follows:
437 *
438 * parent Map to take range from
439 * min, max Returned endpoints of map
440 * size Size of range to find
441 * superpage_align Request that min is superpage aligned
442 */
443 void
kmem_subinit(vm_map_t map,vm_map_t parent,vm_offset_t * min,vm_offset_t * max,vm_size_t size,bool superpage_align)444 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
445 vm_size_t size, bool superpage_align)
446 {
447 int ret;
448
449 size = round_page(size);
450
451 *min = vm_map_min(parent);
452 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ?
453 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL,
454 MAP_ACC_NO_CHARGE);
455 if (ret != KERN_SUCCESS)
456 panic("kmem_subinit: bad status return of %d", ret);
457 *max = *min + size;
458 vm_map_init(map, vm_map_pmap(parent), *min, *max);
459 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS)
460 panic("kmem_subinit: unable to change range to submap");
461 }
462
463 /*
464 * kmem_malloc_domain:
465 *
466 * Allocate wired-down pages in the kernel's address space.
467 */
468 static void *
kmem_malloc_domain(int domain,vm_size_t size,int flags)469 kmem_malloc_domain(int domain, vm_size_t size, int flags)
470 {
471 vmem_t *arena;
472 vm_offset_t addr;
473 vm_size_t asize;
474 int rv;
475
476 if (__predict_true((flags & (M_EXEC | M_NEVERFREED)) == 0))
477 arena = vm_dom[domain].vmd_kernel_arena;
478 else if ((flags & M_EXEC) != 0)
479 arena = vm_dom[domain].vmd_kernel_rwx_arena;
480 else
481 arena = vm_dom[domain].vmd_kernel_nofree_arena;
482 asize = round_page(size);
483 if (vmem_alloc(arena, asize, flags | M_BESTFIT, &addr))
484 return (0);
485
486 rv = kmem_back_domain(domain, kernel_object, addr, asize, flags);
487 if (rv != KERN_SUCCESS) {
488 vmem_free(arena, addr, asize);
489 return (0);
490 }
491 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE);
492 return ((void *)addr);
493 }
494
495 void *
kmem_malloc(vm_size_t size,int flags)496 kmem_malloc(vm_size_t size, int flags)
497 {
498 void * p;
499
500 TSENTER();
501 p = kmem_malloc_domainset(DOMAINSET_RR(), size, flags);
502 TSEXIT();
503 return (p);
504 }
505
506 void *
kmem_malloc_domainset(struct domainset * ds,vm_size_t size,int flags)507 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags)
508 {
509 struct vm_domainset_iter di;
510 void *addr;
511 int domain;
512
513 vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
514 do {
515 addr = kmem_malloc_domain(domain, size, flags);
516 if (addr != NULL)
517 break;
518 } while (vm_domainset_iter_policy(&di, &domain) == 0);
519
520 return (addr);
521 }
522
523 /*
524 * kmem_back_domain:
525 *
526 * Allocate physical pages from the specified domain for the specified
527 * virtual address range.
528 */
529 int
kmem_back_domain(int domain,vm_object_t object,vm_offset_t addr,vm_size_t size,int flags)530 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr,
531 vm_size_t size, int flags)
532 {
533 struct pctrie_iter pages;
534 vm_offset_t offset, i;
535 vm_page_t m, mpred;
536 vm_prot_t prot;
537 int pflags;
538
539 KASSERT(object == kernel_object,
540 ("kmem_back_domain: only supports kernel object."));
541
542 offset = addr - VM_MIN_KERNEL_ADDRESS;
543 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
544 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
545 if (flags & M_WAITOK)
546 pflags |= VM_ALLOC_WAITFAIL;
547 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
548
549 i = 0;
550 vm_page_iter_init(&pages, object);
551 VM_OBJECT_WLOCK(object);
552 retry:
553 mpred = vm_radix_iter_lookup_lt(&pages, atop(offset + i));
554 for (; i < size; i += PAGE_SIZE, mpred = m) {
555 m = vm_page_alloc_domain_after(object, &pages, atop(offset + i),
556 domain, pflags, mpred);
557
558 /*
559 * Ran out of space, free everything up and return. Don't need
560 * to lock page queues here as we know that the pages we got
561 * aren't on any queues.
562 */
563 if (m == NULL) {
564 if ((flags & M_NOWAIT) == 0)
565 goto retry;
566 VM_OBJECT_WUNLOCK(object);
567 kmem_unback(object, addr, i);
568 return (KERN_NO_SPACE);
569 }
570 KASSERT(vm_page_domain(m) == domain,
571 ("kmem_back_domain: Domain mismatch %d != %d",
572 vm_page_domain(m), domain));
573 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
574 pmap_zero_page(m);
575 KASSERT((m->oflags & VPO_UNMANAGED) != 0,
576 ("kmem_malloc: page %p is managed", m));
577 vm_page_valid(m);
578 pmap_enter(kernel_pmap, addr + i, m, prot,
579 prot | PMAP_ENTER_WIRED, 0);
580 if (__predict_false((prot & VM_PROT_EXECUTE) != 0))
581 m->oflags |= VPO_KMEM_EXEC;
582 }
583 VM_OBJECT_WUNLOCK(object);
584 kmem_alloc_san(addr, size, size, flags);
585 return (KERN_SUCCESS);
586 }
587
588 /*
589 * kmem_back:
590 *
591 * Allocate physical pages for the specified virtual address range.
592 */
593 int
kmem_back(vm_object_t object,vm_offset_t addr,vm_size_t size,int flags)594 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags)
595 {
596 vm_offset_t end, next, start;
597 int domain, rv;
598
599 KASSERT(object == kernel_object,
600 ("kmem_back: only supports kernel object."));
601
602 for (start = addr, end = addr + size; addr < end; addr = next) {
603 /*
604 * We must ensure that pages backing a given large virtual page
605 * all come from the same physical domain.
606 */
607 if (vm_ndomains > 1) {
608 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains;
609 while (VM_DOMAIN_EMPTY(domain))
610 domain++;
611 next = roundup2(addr + 1, KVA_QUANTUM);
612 if (next > end || next < start)
613 next = end;
614 } else {
615 domain = 0;
616 next = end;
617 }
618 rv = kmem_back_domain(domain, object, addr, next - addr, flags);
619 if (rv != KERN_SUCCESS) {
620 kmem_unback(object, start, addr - start);
621 break;
622 }
623 }
624 return (rv);
625 }
626
627 /*
628 * kmem_unback:
629 *
630 * Unmap and free the physical pages underlying the specified virtual
631 * address range.
632 *
633 * A physical page must exist within the specified object at each index
634 * that is being unmapped.
635 */
636 static struct vmem *
_kmem_unback(vm_object_t object,vm_offset_t addr,vm_size_t size)637 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
638 {
639 struct pctrie_iter pages;
640 struct vmem *arena;
641 vm_page_t m;
642 vm_offset_t end, offset;
643 int domain;
644
645 KASSERT(object == kernel_object,
646 ("kmem_unback: only supports kernel object."));
647
648 if (size == 0)
649 return (NULL);
650 pmap_remove(kernel_pmap, addr, addr + size);
651 offset = addr - VM_MIN_KERNEL_ADDRESS;
652 end = offset + size;
653 vm_page_iter_init(&pages, object);
654 VM_OBJECT_WLOCK(object);
655 m = vm_radix_iter_lookup(&pages, atop(offset));
656 domain = vm_page_domain(m);
657 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0))
658 arena = vm_dom[domain].vmd_kernel_arena;
659 else
660 arena = vm_dom[domain].vmd_kernel_rwx_arena;
661 for (; offset < end; offset += PAGE_SIZE,
662 m = vm_radix_iter_lookup(&pages, atop(offset))) {
663 vm_page_xbusy_claim(m);
664 vm_page_unwire_noq(m);
665 vm_page_iter_free(&pages, m);
666 }
667 VM_OBJECT_WUNLOCK(object);
668
669 return (arena);
670 }
671
672 void
kmem_unback(vm_object_t object,vm_offset_t addr,vm_size_t size)673 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
674 {
675
676 (void)_kmem_unback(object, addr, size);
677 }
678
679 /*
680 * kmem_free:
681 *
682 * Free memory allocated with kmem_malloc. The size must match the
683 * original allocation.
684 */
685 void
kmem_free(void * addr,vm_size_t size)686 kmem_free(void *addr, vm_size_t size)
687 {
688 struct vmem *arena;
689
690 size = round_page(size);
691 kasan_mark(addr, size, size, 0);
692 arena = _kmem_unback(kernel_object, (uintptr_t)addr, size);
693 if (arena != NULL)
694 vmem_free(arena, (uintptr_t)addr, size);
695 }
696
697 /*
698 * kmap_alloc_wait:
699 *
700 * Allocates pageable memory from a sub-map of the kernel. If the submap
701 * has no room, the caller sleeps waiting for more memory in the submap.
702 *
703 * This routine may block.
704 */
705 vm_offset_t
kmap_alloc_wait(vm_map_t map,vm_size_t size)706 kmap_alloc_wait(vm_map_t map, vm_size_t size)
707 {
708 vm_offset_t addr;
709
710 size = round_page(size);
711 if (!swap_reserve(size))
712 return (0);
713
714 for (;;) {
715 /*
716 * To make this work for more than one map, use the map's lock
717 * to lock out sleepers/wakers.
718 */
719 vm_map_lock(map);
720 addr = vm_map_findspace(map, vm_map_min(map), size);
721 if (addr + size <= vm_map_max(map))
722 break;
723 /* no space now; see if we can ever get space */
724 if (vm_map_max(map) - vm_map_min(map) < size) {
725 vm_map_unlock(map);
726 swap_release(size);
727 return (0);
728 }
729 vm_map_modflags(map, MAP_NEEDS_WAKEUP, 0);
730 vm_map_unlock_and_wait(map, 0);
731 }
732 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW,
733 MAP_ACC_CHARGED);
734 vm_map_unlock(map);
735 return (addr);
736 }
737
738 /*
739 * kmap_free_wakeup:
740 *
741 * Returns memory to a submap of the kernel, and wakes up any processes
742 * waiting for memory in that map.
743 */
744 void
kmap_free_wakeup(vm_map_t map,vm_offset_t addr,vm_size_t size)745 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size)
746 {
747
748 vm_map_lock(map);
749 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
750 if ((map->flags & MAP_NEEDS_WAKEUP) != 0) {
751 vm_map_modflags(map, 0, MAP_NEEDS_WAKEUP);
752 vm_map_wakeup(map);
753 }
754 vm_map_unlock(map);
755 }
756
757 void
kmem_init_zero_region(void)758 kmem_init_zero_region(void)
759 {
760 vm_offset_t addr, i;
761 vm_page_t m;
762
763 /*
764 * Map a single physical page of zeros to a larger virtual range.
765 * This requires less looping in places that want large amounts of
766 * zeros, while not using much more physical resources.
767 */
768 addr = kva_alloc(ZERO_REGION_SIZE);
769 m = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_ZERO |
770 VM_ALLOC_NOFREE);
771 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE)
772 pmap_qenter(addr + i, &m, 1);
773 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ);
774
775 zero_region = (const void *)addr;
776 }
777
778 /*
779 * Import KVA from the kernel map into the kernel arena.
780 */
781 static int
kva_import(void * unused,vmem_size_t size,int flags,vmem_addr_t * addrp)782 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp)
783 {
784 vm_offset_t addr;
785 int result;
786
787 TSENTER();
788 KASSERT((size % KVA_QUANTUM) == 0,
789 ("kva_import: Size %jd is not a multiple of %d",
790 (intmax_t)size, (int)KVA_QUANTUM));
791 addr = vm_map_min(kernel_map);
792 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0,
793 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
794 if (result != KERN_SUCCESS) {
795 TSEXIT();
796 return (ENOMEM);
797 }
798
799 *addrp = addr;
800
801 TSEXIT();
802 return (0);
803 }
804
805 /*
806 * Import KVA from a parent arena into a per-domain arena. Imports must be
807 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size.
808 */
809 static int
kva_import_domain(void * arena,vmem_size_t size,int flags,vmem_addr_t * addrp)810 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp)
811 {
812
813 KASSERT((size % KVA_QUANTUM) == 0,
814 ("kva_import_domain: Size %jd is not a multiple of %d",
815 (intmax_t)size, (int)KVA_QUANTUM));
816 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN,
817 VMEM_ADDR_MAX, flags, addrp));
818 }
819
820 /*
821 * kmem_init:
822 *
823 * Create the kernel map; insert a mapping covering kernel text,
824 * data, bss, and all space allocated thus far (`boostrap' data). The
825 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and
826 * `start' as allocated, and the range between `start' and `end' as free.
827 * Create the kernel vmem arena and its per-domain children.
828 */
829 void
kmem_init(vm_offset_t start,vm_offset_t end)830 kmem_init(vm_offset_t start, vm_offset_t end)
831 {
832 vm_size_t quantum;
833 int domain;
834
835 vm_map_init_system(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
836 vm_map_lock(kernel_map);
837 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */
838 (void)vm_map_insert(kernel_map, NULL, 0,
839 #ifdef __amd64__
840 KERNBASE,
841 #else
842 VM_MIN_KERNEL_ADDRESS,
843 #endif
844 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
845 /* ... and ending with the completion of the above `insert' */
846
847 #ifdef __amd64__
848 /*
849 * Mark KVA used for the page array as allocated. Other platforms
850 * that handle vm_page_array allocation can simply adjust virtual_avail
851 * instead.
852 */
853 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array,
854 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size *
855 sizeof(struct vm_page)),
856 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
857 #endif
858 vm_map_unlock(kernel_map);
859
860 /*
861 * Use a large import quantum on NUMA systems. This helps minimize
862 * interleaving of superpages, reducing internal fragmentation within
863 * the per-domain arenas.
864 */
865 if (vm_ndomains > 1 && PMAP_HAS_DMAP)
866 quantum = KVA_NUMA_IMPORT_QUANTUM;
867 else
868 quantum = KVA_QUANTUM;
869
870 /*
871 * Initialize the kernel_arena. This can grow on demand.
872 */
873 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0);
874 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum);
875
876 for (domain = 0; domain < vm_ndomains; domain++) {
877 /*
878 * Initialize the per-domain arenas. These are used to color
879 * the KVA space in a way that ensures that virtual large pages
880 * are backed by memory from the same physical domain,
881 * maximizing the potential for superpage promotion.
882 */
883 vm_dom[domain].vmd_kernel_arena = vmem_create(
884 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
885 vmem_set_import(vm_dom[domain].vmd_kernel_arena,
886 kva_import_domain, NULL, kernel_arena, quantum);
887
888 /*
889 * In architectures with superpages, maintain separate arenas
890 * for allocations with permissions that differ from the
891 * "standard" read/write permissions used for kernel memory
892 * and pages that are never released, so as not to inhibit
893 * superpage promotion.
894 *
895 * Use the base import quantum since these arenas are rarely
896 * used.
897 */
898 #if VM_NRESERVLEVEL > 0
899 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create(
900 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
901 vm_dom[domain].vmd_kernel_nofree_arena = vmem_create(
902 "kernel NOFREE arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
903 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena,
904 kva_import_domain, (vmem_release_t *)vmem_xfree,
905 kernel_arena, KVA_QUANTUM);
906 vmem_set_import(vm_dom[domain].vmd_kernel_nofree_arena,
907 kva_import_domain, (vmem_release_t *)vmem_xfree,
908 kernel_arena, KVA_QUANTUM);
909 #else
910 vm_dom[domain].vmd_kernel_rwx_arena =
911 vm_dom[domain].vmd_kernel_arena;
912 vm_dom[domain].vmd_kernel_nofree_arena =
913 vm_dom[domain].vmd_kernel_arena;
914 #endif
915 }
916
917 /*
918 * This must be the very first call so that the virtual address
919 * space used for early allocations is properly marked used in
920 * the map.
921 */
922 uma_startup2();
923 }
924
925 /*
926 * kmem_bootstrap_free:
927 *
928 * Free pages backing preloaded data (e.g., kernel modules) to the
929 * system. Currently only supported on platforms that create a
930 * vm_phys segment for preloaded data.
931 */
932 void
kmem_bootstrap_free(vm_offset_t start,vm_size_t size)933 kmem_bootstrap_free(vm_offset_t start, vm_size_t size)
934 {
935 #if defined(__i386__) || defined(__amd64__)
936 struct vm_domain *vmd;
937 vm_offset_t end, va;
938 vm_paddr_t pa;
939 vm_page_t m;
940
941 end = trunc_page(start + size);
942 start = round_page(start);
943
944 #ifdef __amd64__
945 /*
946 * Preloaded files do not have execute permissions by default on amd64.
947 * Restore the default permissions to ensure that the direct map alias
948 * is updated.
949 */
950 pmap_change_prot(start, end - start, VM_PROT_RW);
951 #endif
952 for (va = start; va < end; va += PAGE_SIZE) {
953 pa = pmap_kextract(va);
954 m = PHYS_TO_VM_PAGE(pa);
955
956 vmd = vm_pagequeue_domain(m);
957 vm_domain_free_lock(vmd);
958 vm_phys_free_pages(m, m->pool, 0);
959 vm_domain_free_unlock(vmd);
960
961 vm_domain_freecnt_inc(vmd, 1);
962 vm_cnt.v_page_count++;
963 }
964 pmap_remove(kernel_pmap, start, end);
965 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK);
966 #endif
967 }
968
969 #ifdef PMAP_WANT_ACTIVE_CPUS_NAIVE
970 void
pmap_active_cpus(pmap_t pmap,cpuset_t * res)971 pmap_active_cpus(pmap_t pmap, cpuset_t *res)
972 {
973 struct thread *td;
974 struct proc *p;
975 struct vmspace *vm;
976 int c;
977
978 CPU_ZERO(res);
979 CPU_FOREACH(c) {
980 td = cpuid_to_pcpu[c]->pc_curthread;
981 p = td->td_proc;
982 if (p == NULL)
983 continue;
984 vm = vmspace_acquire_ref(p);
985 if (vm == NULL)
986 continue;
987 if (pmap == vmspace_pmap(vm))
988 CPU_SET(c, res);
989 vmspace_free(vm);
990 }
991 }
992 #endif
993
994 /*
995 * Allow userspace to directly trigger the VM drain routine for testing
996 * purposes.
997 */
998 static int
debug_vm_lowmem(SYSCTL_HANDLER_ARGS)999 debug_vm_lowmem(SYSCTL_HANDLER_ARGS)
1000 {
1001 int error, i;
1002
1003 i = 0;
1004 error = sysctl_handle_int(oidp, &i, 0, req);
1005 if (error != 0)
1006 return (error);
1007 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0)
1008 return (EINVAL);
1009 if (i != 0)
1010 EVENTHANDLER_INVOKE(vm_lowmem, i);
1011 return (0);
1012 }
1013 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem,
1014 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_vm_lowmem, "I",
1015 "set to trigger vm_lowmem event with given flags");
1016
1017 static int
debug_uma_reclaim(SYSCTL_HANDLER_ARGS)1018 debug_uma_reclaim(SYSCTL_HANDLER_ARGS)
1019 {
1020 int error, i;
1021
1022 i = 0;
1023 error = sysctl_handle_int(oidp, &i, 0, req);
1024 if (error != 0 || req->newptr == NULL)
1025 return (error);
1026 if (i != UMA_RECLAIM_TRIM && i != UMA_RECLAIM_DRAIN &&
1027 i != UMA_RECLAIM_DRAIN_CPU)
1028 return (EINVAL);
1029 uma_reclaim(i);
1030 return (0);
1031 }
1032 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim,
1033 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_uma_reclaim, "I",
1034 "set to generate request to reclaim uma caches");
1035
1036 static int
debug_uma_reclaim_domain(SYSCTL_HANDLER_ARGS)1037 debug_uma_reclaim_domain(SYSCTL_HANDLER_ARGS)
1038 {
1039 int domain, error, request;
1040
1041 request = 0;
1042 error = sysctl_handle_int(oidp, &request, 0, req);
1043 if (error != 0 || req->newptr == NULL)
1044 return (error);
1045
1046 domain = request >> 4;
1047 request &= 0xf;
1048 if (request != UMA_RECLAIM_TRIM && request != UMA_RECLAIM_DRAIN &&
1049 request != UMA_RECLAIM_DRAIN_CPU)
1050 return (EINVAL);
1051 if (domain < 0 || domain >= vm_ndomains)
1052 return (EINVAL);
1053 uma_reclaim_domain(request, domain);
1054 return (0);
1055 }
1056 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim_domain,
1057 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0,
1058 debug_uma_reclaim_domain, "I",
1059 "");
1060