projects / unix-history / blob
? search:
summary | tags | clone url | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
BSD 4_4_Lite2 release
[unix-history] / usr / src / sys / miscfs / procfs / procfs_mem.c
/*
* Copyright (c) 1993 Jan-Simon Pendry
* Copyright (c) 1993 Sean Eric Fagan
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry and Sean Eric Fagan.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
* @(#)procfs_mem.c 8.5 (Berkeley) 6/15/94
*
* From:
* $Id: procfs_mem.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
*/
/*
* This is a lightly hacked and merged version
* of sef's pread/pwrite functions
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <miscfs/procfs/procfs.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
static int
procfs_rwmem(p, uio)
struct proc *p;
struct uio *uio;
{
int error;
int writing;
writing = uio->uio_rw == UIO_WRITE;
/*
* Only map in one page at a time. We don't have to, but it
* makes things easier. This way is trivial - right?
*/
do {
vm_map_t map, tmap;
vm_object_t object;
vm_offset_t kva;
vm_offset_t uva;
int page_offset; /* offset into page */
vm_offset_t pageno; /* page number */
vm_map_entry_t out_entry;
vm_prot_t out_prot;
vm_page_t m;
boolean_t wired, single_use;
vm_offset_t off;
u_int len;
int fix_prot;
uva = (vm_offset_t) uio->uio_offset;
if (uva > VM_MAXUSER_ADDRESS) {
error = 0;
break;
}
/*
* Get the page number of this segment.
*/
pageno = trunc_page(uva);
page_offset = uva - pageno;
/*
* How many bytes to copy
*/
len = min(PAGE_SIZE - page_offset, uio->uio_resid);
/*
* The map we want...
*/
map = &p->p_vmspace->vm_map;
/*
* Check the permissions for the area we're interested
* in.
*/
fix_prot = 0;
if (writing)
fix_prot = !vm_map_check_protection(map, pageno,
pageno + PAGE_SIZE, VM_PROT_WRITE);
if (fix_prot) {
/*
* If the page is not writable, we make it so.
* XXX It is possible that a page may *not* be
* read/executable, if a process changes that!
* We will assume, for now, that a page is either
* VM_PROT_ALL, or VM_PROT_READ|VM_PROT_EXECUTE.
*/
error = vm_map_protect(map, pageno,
pageno + PAGE_SIZE, VM_PROT_ALL, 0);
if (error)
break;
}
/*
* Now we need to get the page. out_entry, out_prot, wired,
* and single_use aren't used. One would think the vm code
* would be a *bit* nicer... We use tmap because
* vm_map_lookup() can change the map argument.
*/
tmap = map;
error = vm_map_lookup(&tmap, pageno,
writing ? VM_PROT_WRITE : VM_PROT_READ,
&out_entry, &object, &off, &out_prot,
&wired, &single_use);
/*
* We're done with tmap now.
*/
if (!error)
vm_map_lookup_done(tmap, out_entry);
/*
* Fault the page in...
*/
if (!error && writing && object->shadow) {
m = vm_page_lookup(object, off);
if (m == 0 || (m->flags & PG_COPYONWRITE))
error = vm_fault(map, pageno,
VM_PROT_WRITE, FALSE);
}
/* Find space in kernel_map for the page we're interested in */
if (!error)
error = vm_map_find(kernel_map, object, off, &kva,
PAGE_SIZE, 1);
if (!error) {
/*
* Neither vm_map_lookup() nor vm_map_find() appear
* to add a reference count to the object, so we do
* that here and now.
*/
vm_object_reference(object);
/*
* Mark the page we just found as pageable.
*/
error = vm_map_pageable(kernel_map, kva,
kva + PAGE_SIZE, 0);
/*
* Now do the i/o move.
*/
if (!error)
error = uiomove(kva + page_offset, len, uio);
vm_map_remove(kernel_map, kva, kva + PAGE_SIZE);
}
if (fix_prot)
vm_map_protect(map, pageno, pageno + PAGE_SIZE,
VM_PROT_READ|VM_PROT_EXECUTE, 0);
} while (error == 0 && uio->uio_resid > 0);
return (error);
}
/*
* Copy data in and out of the target process.
* We do this by mapping the process's page into
* the kernel and then doing a uiomove direct
* from the kernel address space.
*/
int
procfs_domem(curp, p, pfs, uio)
struct proc *curp;
struct proc *p;
struct pfsnode *pfs;
struct uio *uio;
{
if (uio->uio_resid == 0)
return (0);
return (procfs_rwmem(p, uio));
}
/*
* Given process (p), find the vnode from which
* it's text segment is being executed.
*
* It would be nice to grab this information from
* the VM system, however, there is no sure-fire
* way of doing that. Instead, fork(), exec() and
* wait() all maintain the p_textvp field in the
* process proc structure which contains a held
* reference to the exec'ed vnode.
*/
struct vnode *
procfs_findtextvp(p)
struct proc *p;
{
return (p->p_textvp);
}
#ifdef probably_never
/*
* Given process (p), find the vnode from which
* it's text segment is being mapped.
*
* (This is here, rather than in procfs_subr in order
* to keep all the VM related code in one place.)
*/
struct vnode *
procfs_findtextvp(p)
struct proc *p;
{
int error;
vm_object_t object;
vm_offset_t pageno; /* page number */
/* find a vnode pager for the user address space */
for (pageno = VM_MIN_ADDRESS;
pageno < VM_MAXUSER_ADDRESS;
pageno += PAGE_SIZE) {
vm_map_t map;
vm_map_entry_t out_entry;
vm_prot_t out_prot;
boolean_t wired, single_use;
vm_offset_t off;
map = &p->p_vmspace->vm_map;
error = vm_map_lookup(&map, pageno,
VM_PROT_READ,
&out_entry, &object, &off, &out_prot,
&wired, &single_use);
if (!error) {
vm_pager_t pager;
printf("procfs: found vm object\n");
vm_map_lookup_done(map, out_entry);
printf("procfs: vm object = %x\n", object);
/*
* At this point, assuming no errors, object
* is the VM object mapping UVA (pageno).
* Ensure it has a vnode pager, then grab
* the vnode from that pager's handle.
*/
pager = object->pager;
printf("procfs: pager = %x\n", pager);
if (pager)
printf("procfs: found pager, type = %d\n", pager->pg_type);
if (pager && pager->pg_type == PG_VNODE) {
struct vnode *vp;
vp = (struct vnode *) pager->pg_handle;
printf("procfs: vp = 0x%x\n", vp);
return (vp);
}
}
}
printf("procfs: text object not found\n");
return (0);
}
#endif /* probably_never */
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.