3cad40e517
system's machine-dependent and machine-independent layers. Once pmap_clear_write() is implemented on all of our supported architectures, I intend to replace all calls to pmap_page_protect() by calls to pmap_clear_write(). Why? Both the use and implementation of pmap_page_protect() in our virtual memory system has subtle errors, specifically, the management of execute permission is broken on some architectures. The "prot" argument to pmap_page_protect() should behave differently from the "prot" argument to other pmap functions. Instead of meaning, "give the specified access rights to all of the physical page's mappings," it means "don't take away the specified access rights from all of the physical page's mappings, but do take away the ones that aren't specified." However, owing to our i386 legacy, i.e., no support for no-execute rights, all but one invocation of pmap_page_protect() specifies VM_PROT_READ only, when the intent is, in fact, to remove only write permission. Consequently, a faithful implementation of pmap_page_protect(), e.g., ia64, would remove execute permission as well as write permission. On the other hand, some architectures that support execute permission have basically ignored whether or not VM_PROT_EXECUTE is passed to pmap_page_protect(), e.g., amd64 and sparc64. This change represents the first step in replacing pmap_page_protect() by the less subtle pmap_clear_write() that is already implemented on amd64, i386, and sparc64. Discussed with: grehan@ and marcel@
140 lines
5.5 KiB
C
140 lines
5.5 KiB
C
/*-
|
|
* Copyright (c) 1991, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* The Mach Operating System project at Carnegie-Mellon University.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* from: @(#)pmap.h 8.1 (Berkeley) 6/11/93
|
|
*
|
|
*
|
|
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
|
|
* All rights reserved.
|
|
*
|
|
* Author: Avadis Tevanian, Jr.
|
|
*
|
|
* Permission to use, copy, modify and distribute this software and
|
|
* its documentation is hereby granted, provided that both the copyright
|
|
* notice and this permission notice appear in all copies of the
|
|
* software, derivative works or modified versions, and any portions
|
|
* thereof, and that both notices appear in supporting documentation.
|
|
*
|
|
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
|
|
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
|
|
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
|
|
*
|
|
* Carnegie Mellon requests users of this software to return to
|
|
*
|
|
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
|
|
* School of Computer Science
|
|
* Carnegie Mellon University
|
|
* Pittsburgh PA 15213-3890
|
|
*
|
|
* any improvements or extensions that they make and grant Carnegie the
|
|
* rights to redistribute these changes.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* Machine address mapping definitions -- machine-independent
|
|
* section. [For machine-dependent section, see "machine/pmap.h".]
|
|
*/
|
|
|
|
#ifndef _PMAP_VM_
|
|
#define _PMAP_VM_
|
|
/*
|
|
* Each machine dependent implementation is expected to
|
|
* keep certain statistics. They may do this anyway they
|
|
* so choose, but are expected to return the statistics
|
|
* in the following structure.
|
|
*/
|
|
struct pmap_statistics {
|
|
long resident_count; /* # of pages mapped (total) */
|
|
long wired_count; /* # of pages wired */
|
|
};
|
|
typedef struct pmap_statistics *pmap_statistics_t;
|
|
|
|
#include <machine/pmap.h>
|
|
|
|
#ifdef _KERNEL
|
|
struct proc;
|
|
struct thread;
|
|
|
|
/*
|
|
* Updates to kernel_vm_end are synchronized by the kernel_map's system mutex.
|
|
*/
|
|
extern vm_offset_t kernel_vm_end;
|
|
|
|
void pmap_change_wiring(pmap_t, vm_offset_t, boolean_t);
|
|
void pmap_clear_modify(vm_page_t m);
|
|
void pmap_clear_reference(vm_page_t m);
|
|
void pmap_clear_write(vm_page_t m);
|
|
void pmap_copy(pmap_t, pmap_t, vm_offset_t, vm_size_t, vm_offset_t);
|
|
void pmap_copy_page(vm_page_t, vm_page_t);
|
|
void pmap_enter(pmap_t, vm_offset_t, vm_page_t, vm_prot_t,
|
|
boolean_t);
|
|
void pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m,
|
|
vm_prot_t prot);
|
|
void pmap_enter_object(pmap_t pmap, vm_offset_t start,
|
|
vm_offset_t end, vm_page_t m_start, vm_prot_t prot);
|
|
vm_paddr_t pmap_extract(pmap_t pmap, vm_offset_t va);
|
|
vm_page_t pmap_extract_and_hold(pmap_t pmap, vm_offset_t va,
|
|
vm_prot_t prot);
|
|
void pmap_growkernel(vm_offset_t);
|
|
void pmap_init(void);
|
|
boolean_t pmap_is_modified(vm_page_t m);
|
|
boolean_t pmap_is_prefaultable(pmap_t pmap, vm_offset_t va);
|
|
boolean_t pmap_ts_referenced(vm_page_t m);
|
|
vm_offset_t pmap_map(vm_offset_t *, vm_paddr_t, vm_paddr_t, int);
|
|
void pmap_object_init_pt(pmap_t pmap, vm_offset_t addr,
|
|
vm_object_t object, vm_pindex_t pindex, vm_size_t size);
|
|
boolean_t pmap_page_exists_quick(pmap_t pmap, vm_page_t m);
|
|
void pmap_page_init(vm_page_t m);
|
|
void pmap_page_protect(vm_page_t m, vm_prot_t prot);
|
|
void pmap_pinit(pmap_t);
|
|
void pmap_pinit0(pmap_t);
|
|
void pmap_protect(pmap_t, vm_offset_t, vm_offset_t, vm_prot_t);
|
|
void pmap_qenter(vm_offset_t, vm_page_t *, int);
|
|
void pmap_qremove(vm_offset_t, int);
|
|
void pmap_release(pmap_t);
|
|
void pmap_remove(pmap_t, vm_offset_t, vm_offset_t);
|
|
void pmap_remove_all(vm_page_t m);
|
|
void pmap_remove_pages(pmap_t);
|
|
void pmap_zero_page(vm_page_t);
|
|
void pmap_zero_page_area(vm_page_t, int off, int size);
|
|
void pmap_zero_page_idle(vm_page_t);
|
|
int pmap_mincore(pmap_t pmap, vm_offset_t addr);
|
|
void pmap_activate(struct thread *td);
|
|
vm_offset_t pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size);
|
|
|
|
#define pmap_resident_count(pm) ((pm)->pm_stats.resident_count)
|
|
#define pmap_wired_count(pm) ((pm)->pm_stats.wired_count)
|
|
|
|
#endif /* _KERNEL */
|
|
#endif /* _PMAP_VM_ */
|