We allocate kernel stacks using a UMA cache zone. Cache zones have KASAN disabled by default, but in this case it makes sense to enable it. Reviewed by: andrew MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D29457
608 lines
16 KiB
C
608 lines
16 KiB
C
/*-
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* SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
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*
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* The Mach Operating System project at Carnegie-Mellon University.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)vm_glue.c 8.6 (Berkeley) 1/5/94
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*
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*
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* Copyright (c) 1987, 1990 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_vm.h"
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#include "opt_kstack_pages.h"
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#include "opt_kstack_max_pages.h"
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#include "opt_kstack_usage_prof.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/asan.h>
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#include <sys/domainset.h>
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#include <sys/limits.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/racct.h>
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#include <sys/refcount.h>
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#include <sys/resourcevar.h>
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#include <sys/rwlock.h>
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#include <sys/sched.h>
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#include <sys/sf_buf.h>
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#include <sys/shm.h>
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#include <sys/smp.h>
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#include <sys/vmmeter.h>
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#include <sys/vmem.h>
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#include <sys/sx.h>
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#include <sys/sysctl.h>
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#include <sys/kernel.h>
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#include <sys/ktr.h>
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#include <sys/unistd.h>
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#include <vm/uma.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/pmap.h>
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#include <vm/vm_domainset.h>
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#include <vm/vm_map.h>
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#include <vm/vm_page.h>
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#include <vm/vm_pageout.h>
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#include <vm/vm_object.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#include <vm/vm_pager.h>
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#include <vm/swap_pager.h>
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#include <machine/cpu.h>
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/*
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* MPSAFE
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*
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* WARNING! This code calls vm_map_check_protection() which only checks
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* the associated vm_map_entry range. It does not determine whether the
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* contents of the memory is actually readable or writable. In most cases
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* just checking the vm_map_entry is sufficient within the kernel's address
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* space.
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*/
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int
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kernacc(void *addr, int len, int rw)
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{
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boolean_t rv;
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vm_offset_t saddr, eaddr;
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vm_prot_t prot;
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KASSERT((rw & ~VM_PROT_ALL) == 0,
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("illegal ``rw'' argument to kernacc (%x)\n", rw));
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if ((vm_offset_t)addr + len > vm_map_max(kernel_map) ||
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(vm_offset_t)addr + len < (vm_offset_t)addr)
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return (FALSE);
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prot = rw;
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saddr = trunc_page((vm_offset_t)addr);
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eaddr = round_page((vm_offset_t)addr + len);
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vm_map_lock_read(kernel_map);
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rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot);
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vm_map_unlock_read(kernel_map);
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return (rv == TRUE);
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}
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/*
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* MPSAFE
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*
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* WARNING! This code calls vm_map_check_protection() which only checks
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* the associated vm_map_entry range. It does not determine whether the
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* contents of the memory is actually readable or writable. vmapbuf(),
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* vm_fault_quick(), or copyin()/copout()/su*()/fu*() functions should be
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* used in conjunction with this call.
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*/
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int
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useracc(void *addr, int len, int rw)
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{
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boolean_t rv;
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vm_prot_t prot;
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vm_map_t map;
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KASSERT((rw & ~VM_PROT_ALL) == 0,
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("illegal ``rw'' argument to useracc (%x)\n", rw));
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prot = rw;
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map = &curproc->p_vmspace->vm_map;
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if ((vm_offset_t)addr + len > vm_map_max(map) ||
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(vm_offset_t)addr + len < (vm_offset_t)addr) {
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return (FALSE);
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}
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vm_map_lock_read(map);
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rv = vm_map_check_protection(map, trunc_page((vm_offset_t)addr),
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round_page((vm_offset_t)addr + len), prot);
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vm_map_unlock_read(map);
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return (rv == TRUE);
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}
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int
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vslock(void *addr, size_t len)
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{
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vm_offset_t end, last, start;
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vm_size_t npages;
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int error;
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last = (vm_offset_t)addr + len;
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start = trunc_page((vm_offset_t)addr);
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end = round_page(last);
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if (last < (vm_offset_t)addr || end < (vm_offset_t)addr)
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return (EINVAL);
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npages = atop(end - start);
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if (npages > vm_page_max_user_wired)
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return (ENOMEM);
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error = vm_map_wire(&curproc->p_vmspace->vm_map, start, end,
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VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
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if (error == KERN_SUCCESS) {
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curthread->td_vslock_sz += len;
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return (0);
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}
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/*
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* Return EFAULT on error to match copy{in,out}() behaviour
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* rather than returning ENOMEM like mlock() would.
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*/
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return (EFAULT);
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}
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void
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vsunlock(void *addr, size_t len)
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{
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/* Rely on the parameter sanity checks performed by vslock(). */
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MPASS(curthread->td_vslock_sz >= len);
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curthread->td_vslock_sz -= len;
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(void)vm_map_unwire(&curproc->p_vmspace->vm_map,
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trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len),
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VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
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}
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/*
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* Pin the page contained within the given object at the given offset. If the
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* page is not resident, allocate and load it using the given object's pager.
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* Return the pinned page if successful; otherwise, return NULL.
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*/
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static vm_page_t
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vm_imgact_hold_page(vm_object_t object, vm_ooffset_t offset)
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{
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vm_page_t m;
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vm_pindex_t pindex;
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pindex = OFF_TO_IDX(offset);
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(void)vm_page_grab_valid_unlocked(&m, object, pindex,
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VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED);
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return (m);
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}
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/*
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* Return a CPU private mapping to the page at the given offset within the
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* given object. The page is pinned before it is mapped.
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*/
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struct sf_buf *
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vm_imgact_map_page(vm_object_t object, vm_ooffset_t offset)
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{
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vm_page_t m;
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m = vm_imgact_hold_page(object, offset);
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if (m == NULL)
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return (NULL);
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sched_pin();
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return (sf_buf_alloc(m, SFB_CPUPRIVATE));
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}
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/*
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* Destroy the given CPU private mapping and unpin the page that it mapped.
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*/
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void
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vm_imgact_unmap_page(struct sf_buf *sf)
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{
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vm_page_t m;
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m = sf_buf_page(sf);
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sf_buf_free(sf);
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sched_unpin();
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vm_page_unwire(m, PQ_ACTIVE);
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}
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void
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vm_sync_icache(vm_map_t map, vm_offset_t va, vm_offset_t sz)
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{
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pmap_sync_icache(map->pmap, va, sz);
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}
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vm_object_t kstack_object;
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static uma_zone_t kstack_cache;
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static int kstack_cache_size;
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static int
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sysctl_kstack_cache_size(SYSCTL_HANDLER_ARGS)
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{
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int error, oldsize;
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oldsize = kstack_cache_size;
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error = sysctl_handle_int(oidp, arg1, arg2, req);
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if (error == 0 && req->newptr && oldsize != kstack_cache_size)
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uma_zone_set_maxcache(kstack_cache, kstack_cache_size);
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return (error);
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}
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SYSCTL_PROC(_vm, OID_AUTO, kstack_cache_size,
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CTLTYPE_INT|CTLFLAG_MPSAFE|CTLFLAG_RW, &kstack_cache_size, 0,
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sysctl_kstack_cache_size, "IU", "Maximum number of cached kernel stacks");
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/*
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* Create the kernel stack (including pcb for i386) for a new thread.
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*/
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static vm_offset_t
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vm_thread_stack_create(struct domainset *ds, int pages)
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{
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vm_page_t ma[KSTACK_MAX_PAGES];
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vm_offset_t ks;
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int i;
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/*
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* Get a kernel virtual address for this thread's kstack.
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*/
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#if defined(__mips__)
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/*
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* We need to align the kstack's mapped address to fit within
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* a single TLB entry.
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*/
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if (vmem_xalloc(kernel_arena, (pages + KSTACK_GUARD_PAGES) * PAGE_SIZE,
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PAGE_SIZE * 2, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
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M_BESTFIT | M_NOWAIT, &ks)) {
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ks = 0;
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}
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#else
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ks = kva_alloc((pages + KSTACK_GUARD_PAGES) * PAGE_SIZE);
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#endif
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if (ks == 0) {
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printf("%s: kstack allocation failed\n", __func__);
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return (0);
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}
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if (KSTACK_GUARD_PAGES != 0) {
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pmap_qremove(ks, KSTACK_GUARD_PAGES);
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ks += KSTACK_GUARD_PAGES * PAGE_SIZE;
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}
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/*
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* Allocate physical pages to back the stack.
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*/
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vm_thread_stack_back(ds, ks, ma, pages, VM_ALLOC_NORMAL);
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for (i = 0; i < pages; i++)
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vm_page_valid(ma[i]);
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pmap_qenter(ks, ma, pages);
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return (ks);
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}
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static void
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vm_thread_stack_dispose(vm_offset_t ks, int pages)
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{
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vm_page_t m;
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vm_pindex_t pindex;
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int i;
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pindex = atop(ks - VM_MIN_KERNEL_ADDRESS);
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pmap_qremove(ks, pages);
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VM_OBJECT_WLOCK(kstack_object);
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for (i = 0; i < pages; i++) {
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m = vm_page_lookup(kstack_object, pindex + i);
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if (m == NULL)
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panic("%s: kstack already missing?", __func__);
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vm_page_xbusy_claim(m);
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vm_page_unwire_noq(m);
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vm_page_free(m);
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}
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VM_OBJECT_WUNLOCK(kstack_object);
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kasan_mark((void *)ks, ptoa(pages), ptoa(pages), 0);
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kva_free(ks - (KSTACK_GUARD_PAGES * PAGE_SIZE),
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(pages + KSTACK_GUARD_PAGES) * PAGE_SIZE);
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}
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/*
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* Allocate the kernel stack for a new thread.
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*/
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int
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vm_thread_new(struct thread *td, int pages)
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{
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vm_offset_t ks;
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/* Bounds check */
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if (pages <= 1)
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pages = kstack_pages;
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else if (pages > KSTACK_MAX_PAGES)
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pages = KSTACK_MAX_PAGES;
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ks = 0;
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if (pages == kstack_pages && kstack_cache != NULL)
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ks = (vm_offset_t)uma_zalloc(kstack_cache, M_NOWAIT);
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/*
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* Ensure that kstack objects can draw pages from any memory
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* domain. Otherwise a local memory shortage can block a process
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* swap-in.
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*/
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if (ks == 0)
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ks = vm_thread_stack_create(DOMAINSET_PREF(PCPU_GET(domain)),
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pages);
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if (ks == 0)
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return (0);
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td->td_kstack = ks;
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td->td_kstack_pages = pages;
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kasan_mark((void *)ks, ptoa(pages), ptoa(pages), 0);
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return (1);
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}
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/*
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* Dispose of a thread's kernel stack.
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*/
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void
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vm_thread_dispose(struct thread *td)
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{
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vm_offset_t ks;
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int pages;
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pages = td->td_kstack_pages;
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ks = td->td_kstack;
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td->td_kstack = 0;
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td->td_kstack_pages = 0;
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kasan_mark((void *)ks, 0, ptoa(pages), KASAN_KSTACK_FREED);
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if (pages == kstack_pages)
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uma_zfree(kstack_cache, (void *)ks);
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else
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vm_thread_stack_dispose(ks, pages);
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}
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/*
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* Allocate physical pages, following the specified NUMA policy, to back a
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* kernel stack.
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*/
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void
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vm_thread_stack_back(struct domainset *ds, vm_offset_t ks, vm_page_t ma[],
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int npages, int req_class)
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{
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vm_pindex_t pindex;
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int n;
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pindex = atop(ks - VM_MIN_KERNEL_ADDRESS);
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VM_OBJECT_WLOCK(kstack_object);
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for (n = 0; n < npages;) {
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if (vm_ndomains > 1)
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kstack_object->domain.dr_policy = ds;
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/*
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* Use WAITFAIL to force a reset of the domain selection policy
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* if we had to sleep for pages.
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*/
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n += vm_page_grab_pages(kstack_object, pindex + n,
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req_class | VM_ALLOC_WIRED | VM_ALLOC_WAITFAIL,
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&ma[n], npages - n);
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}
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VM_OBJECT_WUNLOCK(kstack_object);
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}
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static int
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kstack_import(void *arg, void **store, int cnt, int domain, int flags)
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{
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struct domainset *ds;
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int i;
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if (domain == UMA_ANYDOMAIN)
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ds = DOMAINSET_RR();
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else
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ds = DOMAINSET_PREF(domain);
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for (i = 0; i < cnt; i++) {
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store[i] = (void *)vm_thread_stack_create(ds, kstack_pages);
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if (store[i] == NULL)
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break;
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}
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return (i);
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}
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static void
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kstack_release(void *arg, void **store, int cnt)
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{
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vm_offset_t ks;
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int i;
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for (i = 0; i < cnt; i++) {
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ks = (vm_offset_t)store[i];
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vm_thread_stack_dispose(ks, kstack_pages);
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}
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}
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static void
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kstack_cache_init(void *null)
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{
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kstack_object = vm_object_allocate(OBJT_SWAP,
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atop(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS));
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kstack_cache = uma_zcache_create("kstack_cache",
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kstack_pages * PAGE_SIZE, NULL, NULL, NULL, NULL,
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kstack_import, kstack_release, NULL,
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UMA_ZONE_FIRSTTOUCH);
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kstack_cache_size = imax(128, mp_ncpus * 4);
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uma_zone_set_maxcache(kstack_cache, kstack_cache_size);
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}
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SYSINIT(vm_kstacks, SI_SUB_KMEM, SI_ORDER_ANY, kstack_cache_init, NULL);
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#ifdef KSTACK_USAGE_PROF
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/*
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* Track maximum stack used by a thread in kernel.
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*/
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static int max_kstack_used;
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|
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SYSCTL_INT(_debug, OID_AUTO, max_kstack_used, CTLFLAG_RD,
|
|
&max_kstack_used, 0,
|
|
"Maxiumum stack depth used by a thread in kernel");
|
|
|
|
void
|
|
intr_prof_stack_use(struct thread *td, struct trapframe *frame)
|
|
{
|
|
vm_offset_t stack_top;
|
|
vm_offset_t current;
|
|
int used, prev_used;
|
|
|
|
/*
|
|
* Testing for interrupted kernel mode isn't strictly
|
|
* needed. It optimizes the execution, since interrupts from
|
|
* usermode will have only the trap frame on the stack.
|
|
*/
|
|
if (TRAPF_USERMODE(frame))
|
|
return;
|
|
|
|
stack_top = td->td_kstack + td->td_kstack_pages * PAGE_SIZE;
|
|
current = (vm_offset_t)(uintptr_t)&stack_top;
|
|
|
|
/*
|
|
* Try to detect if interrupt is using kernel thread stack.
|
|
* Hardware could use a dedicated stack for interrupt handling.
|
|
*/
|
|
if (stack_top <= current || current < td->td_kstack)
|
|
return;
|
|
|
|
used = stack_top - current;
|
|
for (;;) {
|
|
prev_used = max_kstack_used;
|
|
if (prev_used >= used)
|
|
break;
|
|
if (atomic_cmpset_int(&max_kstack_used, prev_used, used))
|
|
break;
|
|
}
|
|
}
|
|
#endif /* KSTACK_USAGE_PROF */
|
|
|
|
/*
|
|
* Implement fork's actions on an address space.
|
|
* Here we arrange for the address space to be copied or referenced,
|
|
* allocate a user struct (pcb and kernel stack), then call the
|
|
* machine-dependent layer to fill those in and make the new process
|
|
* ready to run. The new process is set up so that it returns directly
|
|
* to user mode to avoid stack copying and relocation problems.
|
|
*/
|
|
int
|
|
vm_forkproc(struct thread *td, struct proc *p2, struct thread *td2,
|
|
struct vmspace *vm2, int flags)
|
|
{
|
|
struct proc *p1 = td->td_proc;
|
|
struct domainset *dset;
|
|
int error;
|
|
|
|
if ((flags & RFPROC) == 0) {
|
|
/*
|
|
* Divorce the memory, if it is shared, essentially
|
|
* this changes shared memory amongst threads, into
|
|
* COW locally.
|
|
*/
|
|
if ((flags & RFMEM) == 0) {
|
|
if (refcount_load(&p1->p_vmspace->vm_refcnt) > 1) {
|
|
error = vmspace_unshare(p1);
|
|
if (error)
|
|
return (error);
|
|
}
|
|
}
|
|
cpu_fork(td, p2, td2, flags);
|
|
return (0);
|
|
}
|
|
|
|
if (flags & RFMEM) {
|
|
p2->p_vmspace = p1->p_vmspace;
|
|
refcount_acquire(&p1->p_vmspace->vm_refcnt);
|
|
}
|
|
dset = td2->td_domain.dr_policy;
|
|
while (vm_page_count_severe_set(&dset->ds_mask)) {
|
|
vm_wait_doms(&dset->ds_mask, 0);
|
|
}
|
|
|
|
if ((flags & RFMEM) == 0) {
|
|
p2->p_vmspace = vm2;
|
|
if (p1->p_vmspace->vm_shm)
|
|
shmfork(p1, p2);
|
|
}
|
|
|
|
/*
|
|
* cpu_fork will copy and update the pcb, set up the kernel stack,
|
|
* and make the child ready to run.
|
|
*/
|
|
cpu_fork(td, p2, td2, flags);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Called after process has been wait(2)'ed upon and is being reaped.
|
|
* The idea is to reclaim resources that we could not reclaim while
|
|
* the process was still executing.
|
|
*/
|
|
void
|
|
vm_waitproc(p)
|
|
struct proc *p;
|
|
{
|
|
|
|
vmspace_exitfree(p); /* and clean-out the vmspace */
|
|
}
|
|
|
|
void
|
|
kick_proc0(void)
|
|
{
|
|
|
|
wakeup(&proc0);
|
|
}
|