2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
34 * from: @(#)vm_glue.c 8.6 (Berkeley) 1/5/94
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
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.
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.
50 * Carnegie Mellon requests users of this software to return to
52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
53 * School of Computer Science
54 * Carnegie Mellon University
55 * Pittsburgh PA 15213-3890
57 * any improvements or extensions that they make and grant Carnegie the
58 * rights to redistribute these changes.
61 #include <sys/cdefs.h>
62 __FBSDID("$FreeBSD$");
65 #include "opt_kstack_pages.h"
66 #include "opt_kstack_max_pages.h"
67 #include "opt_kstack_usage_prof.h"
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/domainset.h>
72 #include <sys/limits.h>
74 #include <sys/malloc.h>
75 #include <sys/mutex.h>
77 #include <sys/racct.h>
78 #include <sys/resourcevar.h>
79 #include <sys/rwlock.h>
80 #include <sys/sched.h>
81 #include <sys/sf_buf.h>
84 #include <sys/vmmeter.h>
87 #include <sys/sysctl.h>
88 #include <sys/eventhandler.h>
89 #include <sys/kernel.h>
91 #include <sys/unistd.h>
95 #include <vm/vm_param.h>
97 #include <vm/vm_domainset.h>
98 #include <vm/vm_map.h>
99 #include <vm/vm_page.h>
100 #include <vm/vm_pageout.h>
101 #include <vm/vm_object.h>
102 #include <vm/vm_kern.h>
103 #include <vm/vm_extern.h>
104 #include <vm/vm_pager.h>
105 #include <vm/swap_pager.h>
107 #include <machine/cpu.h>
112 * WARNING! This code calls vm_map_check_protection() which only checks
113 * the associated vm_map_entry range. It does not determine whether the
114 * contents of the memory is actually readable or writable. In most cases
115 * just checking the vm_map_entry is sufficient within the kernel's address
119 kernacc(void *addr, int len, int rw)
122 vm_offset_t saddr, eaddr;
125 KASSERT((rw & ~VM_PROT_ALL) == 0,
126 ("illegal ``rw'' argument to kernacc (%x)\n", rw));
128 if ((vm_offset_t)addr + len > vm_map_max(kernel_map) ||
129 (vm_offset_t)addr + len < (vm_offset_t)addr)
133 saddr = trunc_page((vm_offset_t)addr);
134 eaddr = round_page((vm_offset_t)addr + len);
135 vm_map_lock_read(kernel_map);
136 rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot);
137 vm_map_unlock_read(kernel_map);
144 * WARNING! This code calls vm_map_check_protection() which only checks
145 * the associated vm_map_entry range. It does not determine whether the
146 * contents of the memory is actually readable or writable. vmapbuf(),
147 * vm_fault_quick(), or copyin()/copout()/su*()/fu*() functions should be
148 * used in conjunction with this call.
151 useracc(void *addr, int len, int rw)
157 KASSERT((rw & ~VM_PROT_ALL) == 0,
158 ("illegal ``rw'' argument to useracc (%x)\n", rw));
160 map = &curproc->p_vmspace->vm_map;
161 if ((vm_offset_t)addr + len > vm_map_max(map) ||
162 (vm_offset_t)addr + len < (vm_offset_t)addr) {
165 vm_map_lock_read(map);
166 rv = vm_map_check_protection(map, trunc_page((vm_offset_t)addr),
167 round_page((vm_offset_t)addr + len), prot);
168 vm_map_unlock_read(map);
173 vslock(void *addr, size_t len)
175 vm_offset_t end, last, start;
179 last = (vm_offset_t)addr + len;
180 start = trunc_page((vm_offset_t)addr);
181 end = round_page(last);
182 if (last < (vm_offset_t)addr || end < (vm_offset_t)addr)
184 npages = atop(end - start);
185 if (npages > vm_page_max_user_wired)
187 error = vm_map_wire(&curproc->p_vmspace->vm_map, start, end,
188 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
189 if (error == KERN_SUCCESS) {
190 curthread->td_vslock_sz += len;
195 * Return EFAULT on error to match copy{in,out}() behaviour
196 * rather than returning ENOMEM like mlock() would.
202 vsunlock(void *addr, size_t len)
205 /* Rely on the parameter sanity checks performed by vslock(). */
206 MPASS(curthread->td_vslock_sz >= len);
207 curthread->td_vslock_sz -= len;
208 (void)vm_map_unwire(&curproc->p_vmspace->vm_map,
209 trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len),
210 VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
214 * Pin the page contained within the given object at the given offset. If the
215 * page is not resident, allocate and load it using the given object's pager.
216 * Return the pinned page if successful; otherwise, return NULL.
219 vm_imgact_hold_page(vm_object_t object, vm_ooffset_t offset)
224 pindex = OFF_TO_IDX(offset);
225 VM_OBJECT_WLOCK(object);
226 (void)vm_page_grab_valid(&m, object, pindex,
227 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED);
228 VM_OBJECT_WUNLOCK(object);
233 * Return a CPU private mapping to the page at the given offset within the
234 * given object. The page is pinned before it is mapped.
237 vm_imgact_map_page(vm_object_t object, vm_ooffset_t offset)
241 m = vm_imgact_hold_page(object, offset);
245 return (sf_buf_alloc(m, SFB_CPUPRIVATE));
249 * Destroy the given CPU private mapping and unpin the page that it mapped.
252 vm_imgact_unmap_page(struct sf_buf *sf)
259 vm_page_unwire(m, PQ_ACTIVE);
263 vm_sync_icache(vm_map_t map, vm_offset_t va, vm_offset_t sz)
266 pmap_sync_icache(map->pmap, va, sz);
269 static uma_zone_t kstack_cache;
270 static int kstack_cache_size;
271 static int kstack_domain_iter;
274 sysctl_kstack_cache_size(SYSCTL_HANDLER_ARGS)
278 oldsize = kstack_cache_size;
279 error = sysctl_handle_int(oidp, arg1, arg2, req);
280 if (error == 0 && req->newptr && oldsize != kstack_cache_size)
281 uma_zone_set_maxcache(kstack_cache, kstack_cache_size);
284 SYSCTL_PROC(_vm, OID_AUTO, kstack_cache_size, CTLTYPE_INT|CTLFLAG_RW,
285 &kstack_cache_size, 0, sysctl_kstack_cache_size, "IU",
286 "Maximum number of cached kernel stacks");
289 * Create the kernel stack (including pcb for i386) for a new thread.
290 * This routine directly affects the fork perf for a process and
291 * create performance for a thread.
294 vm_thread_stack_create(struct domainset *ds, vm_object_t *ksobjp, int pages)
296 vm_page_t ma[KSTACK_MAX_PAGES];
302 * Allocate an object for the kstack.
304 ksobj = vm_object_allocate(OBJT_DEFAULT, pages);
307 * Get a kernel virtual address for this thread's kstack.
309 #if defined(__mips__)
311 * We need to align the kstack's mapped address to fit within
312 * a single TLB entry.
314 if (vmem_xalloc(kernel_arena, (pages + KSTACK_GUARD_PAGES) * PAGE_SIZE,
315 PAGE_SIZE * 2, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
316 M_BESTFIT | M_NOWAIT, &ks)) {
320 ks = kva_alloc((pages + KSTACK_GUARD_PAGES) * PAGE_SIZE);
323 printf("%s: kstack allocation failed\n", __func__);
324 vm_object_deallocate(ksobj);
327 if (vm_ndomains > 1) {
328 ksobj->domain.dr_policy = ds;
329 ksobj->domain.dr_iter =
330 atomic_fetchadd_int(&kstack_domain_iter, 1);
333 if (KSTACK_GUARD_PAGES != 0) {
334 pmap_qremove(ks, KSTACK_GUARD_PAGES);
335 ks += KSTACK_GUARD_PAGES * PAGE_SIZE;
339 * For the length of the stack, link in a real page of ram for each
342 VM_OBJECT_WLOCK(ksobj);
343 (void)vm_page_grab_pages(ksobj, 0, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY |
344 VM_ALLOC_WIRED, ma, pages);
345 for (i = 0; i < pages; i++)
346 ma[i]->valid = VM_PAGE_BITS_ALL;
347 VM_OBJECT_WUNLOCK(ksobj);
348 pmap_qenter(ks, ma, pages);
355 vm_thread_stack_dispose(vm_object_t ksobj, vm_offset_t ks, int pages)
360 pmap_qremove(ks, pages);
361 VM_OBJECT_WLOCK(ksobj);
362 for (i = 0; i < pages; i++) {
363 m = vm_page_lookup(ksobj, i);
365 panic("%s: kstack already missing?", __func__);
366 vm_page_busy_acquire(m, 0);
367 vm_page_unwire_noq(m);
370 VM_OBJECT_WUNLOCK(ksobj);
371 vm_object_deallocate(ksobj);
372 kva_free(ks - (KSTACK_GUARD_PAGES * PAGE_SIZE),
373 (pages + KSTACK_GUARD_PAGES) * PAGE_SIZE);
377 * Allocate the kernel stack for a new thread.
380 vm_thread_new(struct thread *td, int pages)
387 pages = kstack_pages;
388 else if (pages > KSTACK_MAX_PAGES)
389 pages = KSTACK_MAX_PAGES;
393 if (pages == kstack_pages && kstack_cache != NULL) {
394 ks = (vm_offset_t)uma_zalloc(kstack_cache, M_NOWAIT);
396 ksobj = PHYS_TO_VM_PAGE(pmap_kextract(ks))->object;
400 * Ensure that kstack objects can draw pages from any memory
401 * domain. Otherwise a local memory shortage can block a process
405 ks = vm_thread_stack_create(DOMAINSET_PREF(PCPU_GET(domain)),
409 td->td_kstack_obj = ksobj;
411 td->td_kstack_pages = pages;
416 * Dispose of a thread's kernel stack.
419 vm_thread_dispose(struct thread *td)
425 pages = td->td_kstack_pages;
426 ksobj = td->td_kstack_obj;
429 td->td_kstack_pages = 0;
430 if (pages == kstack_pages)
431 uma_zfree(kstack_cache, (void *)ks);
433 vm_thread_stack_dispose(ksobj, ks, pages);
437 kstack_import(void *arg, void **store, int cnt, int domain, int flags)
439 struct domainset *ds;
443 if (domain == UMA_ANYDOMAIN)
446 ds = DOMAINSET_PREF(domain);
448 for (i = 0; i < cnt; i++) {
449 store[i] = (void *)vm_thread_stack_create(ds, &ksobj,
451 if (store[i] == NULL)
458 kstack_release(void *arg, void **store, int cnt)
463 for (i = 0; i < cnt; i++) {
464 ks = (vm_offset_t)store[i];
465 vm_thread_stack_dispose(
466 PHYS_TO_VM_PAGE(pmap_kextract(ks))->object,
472 kstack_cache_init(void *null)
474 kstack_cache = uma_zcache_create("kstack_cache",
475 kstack_pages * PAGE_SIZE, NULL, NULL, NULL, NULL,
476 kstack_import, kstack_release, NULL,
478 kstack_cache_size = imax(128, mp_ncpus * 4);
479 uma_zone_set_maxcache(kstack_cache, kstack_cache_size);
482 SYSINIT(vm_kstacks, SI_SUB_KTHREAD_INIT, SI_ORDER_ANY, kstack_cache_init, NULL);
484 #ifdef KSTACK_USAGE_PROF
486 * Track maximum stack used by a thread in kernel.
488 static int max_kstack_used;
490 SYSCTL_INT(_debug, OID_AUTO, max_kstack_used, CTLFLAG_RD,
492 "Maxiumum stack depth used by a thread in kernel");
495 intr_prof_stack_use(struct thread *td, struct trapframe *frame)
497 vm_offset_t stack_top;
502 * Testing for interrupted kernel mode isn't strictly
503 * needed. It optimizes the execution, since interrupts from
504 * usermode will have only the trap frame on the stack.
506 if (TRAPF_USERMODE(frame))
509 stack_top = td->td_kstack + td->td_kstack_pages * PAGE_SIZE;
510 current = (vm_offset_t)(uintptr_t)&stack_top;
513 * Try to detect if interrupt is using kernel thread stack.
514 * Hardware could use a dedicated stack for interrupt handling.
516 if (stack_top <= current || current < td->td_kstack)
519 used = stack_top - current;
521 prev_used = max_kstack_used;
522 if (prev_used >= used)
524 if (atomic_cmpset_int(&max_kstack_used, prev_used, used))
528 #endif /* KSTACK_USAGE_PROF */
531 * Implement fork's actions on an address space.
532 * Here we arrange for the address space to be copied or referenced,
533 * allocate a user struct (pcb and kernel stack), then call the
534 * machine-dependent layer to fill those in and make the new process
535 * ready to run. The new process is set up so that it returns directly
536 * to user mode to avoid stack copying and relocation problems.
539 vm_forkproc(struct thread *td, struct proc *p2, struct thread *td2,
540 struct vmspace *vm2, int flags)
542 struct proc *p1 = td->td_proc;
543 struct domainset *dset;
546 if ((flags & RFPROC) == 0) {
548 * Divorce the memory, if it is shared, essentially
549 * this changes shared memory amongst threads, into
552 if ((flags & RFMEM) == 0) {
553 if (p1->p_vmspace->vm_refcnt > 1) {
554 error = vmspace_unshare(p1);
559 cpu_fork(td, p2, td2, flags);
564 p2->p_vmspace = p1->p_vmspace;
565 atomic_add_int(&p1->p_vmspace->vm_refcnt, 1);
567 dset = td2->td_domain.dr_policy;
568 while (vm_page_count_severe_set(&dset->ds_mask)) {
569 vm_wait_doms(&dset->ds_mask);
572 if ((flags & RFMEM) == 0) {
574 if (p1->p_vmspace->vm_shm)
579 * cpu_fork will copy and update the pcb, set up the kernel stack,
580 * and make the child ready to run.
582 cpu_fork(td, p2, td2, flags);
587 * Called after process has been wait(2)'ed upon and is being reaped.
588 * The idea is to reclaim resources that we could not reclaim while
589 * the process was still executing.
596 vmspace_exitfree(p); /* and clean-out the vmspace */