3364c323e6
rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
343 lines
8.6 KiB
C
343 lines
8.6 KiB
C
/*-
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* Copyright (c) 1990 University of Utah.
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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 Systems Programming Group of the University of Utah Computer
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* Science Department.
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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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* 4. 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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* @(#)device_pager.c 8.1 (Berkeley) 6/11/93
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include <sys/lock.h>
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#include <sys/proc.h>
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#include <sys/mutex.h>
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#include <sys/mman.h>
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#include <sys/sx.h>
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#include <vm/vm.h>
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#include <vm/vm_object.h>
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#include <vm/vm_page.h>
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#include <vm/vm_pager.h>
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#include <vm/uma.h>
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static void dev_pager_init(void);
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static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
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vm_ooffset_t, struct ucred *);
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static void dev_pager_dealloc(vm_object_t);
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static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int);
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static void dev_pager_putpages(vm_object_t, vm_page_t *, int,
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boolean_t, int *);
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static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *,
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int *);
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/* list of device pager objects */
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static struct pagerlst dev_pager_object_list;
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/* protect list manipulation */
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static struct mtx dev_pager_mtx;
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static uma_zone_t fakepg_zone;
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static vm_page_t dev_pager_getfake(vm_paddr_t);
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static void dev_pager_putfake(vm_page_t);
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static void dev_pager_updatefake(vm_page_t, vm_paddr_t);
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struct pagerops devicepagerops = {
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.pgo_init = dev_pager_init,
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.pgo_alloc = dev_pager_alloc,
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.pgo_dealloc = dev_pager_dealloc,
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.pgo_getpages = dev_pager_getpages,
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.pgo_putpages = dev_pager_putpages,
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.pgo_haspage = dev_pager_haspage,
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};
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static void
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dev_pager_init()
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{
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TAILQ_INIT(&dev_pager_object_list);
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mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
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fakepg_zone = uma_zcreate("DP fakepg", sizeof(struct vm_page),
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NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
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UMA_ZONE_NOFREE|UMA_ZONE_VM);
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}
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/*
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* MPSAFE
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*/
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static vm_object_t
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dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
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vm_ooffset_t foff, struct ucred *cred)
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{
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struct cdev *dev;
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vm_object_t object, object1;
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vm_pindex_t pindex;
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unsigned int npages;
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vm_paddr_t paddr;
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vm_offset_t off;
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struct cdevsw *csw;
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/*
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* Offset should be page aligned.
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*/
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if (foff & PAGE_MASK)
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return (NULL);
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size = round_page(size);
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pindex = OFF_TO_IDX(foff + size);
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/*
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* Make sure this device can be mapped.
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*/
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dev = handle;
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csw = dev_refthread(dev);
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if (csw == NULL)
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return (NULL);
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/*
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* Check that the specified range of the device allows the desired
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* protection.
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*
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* XXX assumes VM_PROT_* == PROT_*
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*/
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npages = OFF_TO_IDX(size);
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for (off = foff; npages--; off += PAGE_SIZE)
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if ((*csw->d_mmap)(dev, off, &paddr, (int)prot) != 0) {
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dev_relthread(dev);
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return (NULL);
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}
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mtx_lock(&dev_pager_mtx);
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/*
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* Look up pager, creating as necessary.
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*/
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object1 = NULL;
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object = vm_pager_object_lookup(&dev_pager_object_list, handle);
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if (object == NULL) {
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/*
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* Allocate object and associate it with the pager. Initialize
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* the object's pg_color based upon the physical address of the
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* device's memory.
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*/
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mtx_unlock(&dev_pager_mtx);
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object1 = vm_object_allocate(OBJT_DEVICE, pindex);
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object1->flags |= OBJ_COLORED;
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object1->pg_color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
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mtx_lock(&dev_pager_mtx);
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object = vm_pager_object_lookup(&dev_pager_object_list, handle);
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if (object != NULL) {
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/*
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* We raced with other thread while allocating object.
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*/
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if (pindex > object->size)
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object->size = pindex;
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} else {
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object = object1;
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object1 = NULL;
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object->handle = handle;
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TAILQ_INIT(&object->un_pager.devp.devp_pglist);
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TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
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pager_object_list);
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}
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} else {
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if (pindex > object->size)
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object->size = pindex;
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}
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mtx_unlock(&dev_pager_mtx);
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dev_relthread(dev);
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vm_object_deallocate(object1);
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return (object);
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}
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static void
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dev_pager_dealloc(object)
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vm_object_t object;
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{
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vm_page_t m;
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VM_OBJECT_UNLOCK(object);
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mtx_lock(&dev_pager_mtx);
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TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
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mtx_unlock(&dev_pager_mtx);
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VM_OBJECT_LOCK(object);
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/*
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* Free up our fake pages.
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*/
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while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != NULL) {
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TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq);
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dev_pager_putfake(m);
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}
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}
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static int
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dev_pager_getpages(object, m, count, reqpage)
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vm_object_t object;
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vm_page_t *m;
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int count;
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int reqpage;
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{
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vm_pindex_t offset;
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vm_paddr_t paddr;
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vm_page_t page;
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struct cdev *dev;
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int i, ret;
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int prot;
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struct cdevsw *csw;
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struct thread *td;
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struct file *fpop;
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VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
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dev = object->handle;
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page = m[reqpage];
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offset = page->pindex;
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VM_OBJECT_UNLOCK(object);
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csw = dev_refthread(dev);
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if (csw == NULL)
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panic("dev_pager_getpage: no cdevsw");
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prot = PROT_READ; /* XXX should pass in? */
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td = curthread;
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fpop = td->td_fpop;
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td->td_fpop = NULL;
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ret = (*csw->d_mmap)(dev, (vm_offset_t)offset << PAGE_SHIFT, &paddr, prot);
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KASSERT(ret == 0, ("dev_pager_getpage: map function returns error"));
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td->td_fpop = fpop;
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dev_relthread(dev);
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if ((page->flags & PG_FICTITIOUS) != 0) {
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/*
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* If the passed in reqpage page is a fake page, update it with
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* the new physical address.
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*/
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VM_OBJECT_LOCK(object);
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dev_pager_updatefake(page, paddr);
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if (count > 1) {
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vm_page_lock_queues();
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for (i = 0; i < count; i++) {
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if (i != reqpage)
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vm_page_free(m[i]);
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}
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vm_page_unlock_queues();
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}
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} else {
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/*
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* Replace the passed in reqpage page with our own fake page and
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* free up the all of the original pages.
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*/
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page = dev_pager_getfake(paddr);
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VM_OBJECT_LOCK(object);
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TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
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vm_page_lock_queues();
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for (i = 0; i < count; i++)
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vm_page_free(m[i]);
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vm_page_unlock_queues();
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vm_page_insert(page, object, offset);
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m[reqpage] = page;
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}
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page->valid = VM_PAGE_BITS_ALL;
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return (VM_PAGER_OK);
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}
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static void
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dev_pager_putpages(object, m, count, sync, rtvals)
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vm_object_t object;
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vm_page_t *m;
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int count;
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boolean_t sync;
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int *rtvals;
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{
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panic("dev_pager_putpage called");
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}
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static boolean_t
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dev_pager_haspage(object, pindex, before, after)
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vm_object_t object;
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vm_pindex_t pindex;
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int *before;
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int *after;
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{
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if (before != NULL)
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*before = 0;
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if (after != NULL)
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*after = 0;
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return (TRUE);
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}
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/*
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* Instantiate a fictitious page. Unlike physical memory pages, only
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* the machine-independent fields must be initialized.
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*/
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static vm_page_t
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dev_pager_getfake(paddr)
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vm_paddr_t paddr;
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{
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vm_page_t m;
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m = uma_zalloc(fakepg_zone, M_WAITOK);
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m->flags = PG_FICTITIOUS;
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m->oflags = VPO_BUSY;
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/* Fictitious pages don't use "act_count". */
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m->dirty = 0;
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m->busy = 0;
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m->queue = PQ_NONE;
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m->object = NULL;
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m->wire_count = 1;
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m->hold_count = 0;
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m->phys_addr = paddr;
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return (m);
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}
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static void
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dev_pager_putfake(m)
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vm_page_t m;
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{
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if (!(m->flags & PG_FICTITIOUS))
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panic("dev_pager_putfake: bad page");
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uma_zfree(fakepg_zone, m);
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}
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static void
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dev_pager_updatefake(m, paddr)
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vm_page_t m;
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vm_paddr_t paddr;
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{
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if (!(m->flags & PG_FICTITIOUS))
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panic("dev_pager_updatefake: bad page");
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m->phys_addr = paddr;
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}
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