7ce7970731
Implement a "variable" directory structure. Files that do not make sense for the given process do not "appear" and cannot be opened. For example, "system" processes do not have "file", "regs" or "fpregs", because they do not have a user area. "attempt" to fill in the user area of a given process when it is being accessed via /proc/pid/mem (the user struct is just after VM_MAXUSER_ADDRESS in the process address space.) Dont do IO to the U area while it's swapped, hold it in place if possible. Lock off access to the "ctl" file if it's done a setuid like the other pseudo-files in there.
257 lines
6.9 KiB
C
257 lines
6.9 KiB
C
/*
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* Copyright (c) 1993 Jan-Simon Pendry
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* Copyright (c) 1993 Sean Eric Fagan
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* Copyright (c) 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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* Jan-Simon Pendry and Sean Eric Fagan.
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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. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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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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* @(#)procfs_mem.c 8.4 (Berkeley) 1/21/94
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*
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* $Id: procfs_mem.c,v 1.15 1996/01/19 03:58:32 dyson Exp $
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*/
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/*
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* This is a lightly hacked and merged version
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* of sef's pread/pwrite functions
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/time.h>
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#include <sys/kernel.h>
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#include <sys/proc.h>
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#include <sys/vnode.h>
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#include <miscfs/procfs/procfs.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_prot.h>
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#include <vm/lock.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <vm/vm_kern.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_extern.h>
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#include <sys/user.h>
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static int procfs_rwmem __P((struct proc *p, struct uio *uio));
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static int
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procfs_rwmem(p, uio)
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struct proc *p;
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struct uio *uio;
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{
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int error;
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int writing;
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writing = uio->uio_rw == UIO_WRITE;
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/*
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* Only map in one page at a time. We don't have to, but it
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* makes things easier. This way is trivial - right?
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*/
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do {
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vm_map_t map, tmap;
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vm_object_t object;
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vm_offset_t kva = 0;
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vm_offset_t uva;
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int page_offset; /* offset into page */
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vm_offset_t pageno; /* page number */
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vm_map_entry_t out_entry;
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vm_prot_t out_prot;
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vm_page_t m;
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boolean_t wired, single_use;
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vm_pindex_t pindex;
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u_int len;
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int fix_prot;
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uva = (vm_offset_t) uio->uio_offset;
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if (uva >= VM_MAXUSER_ADDRESS) {
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if (writing || (uva >= (VM_MAXUSER_ADDRESS + UPAGES * PAGE_SIZE))) {
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error = 0;
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break;
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}
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/* we are reading the "U area", fill it in */
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PHOLD(p);
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if (p->p_flag & P_INMEM) {
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p->p_addr->u_kproc.kp_proc = *p;
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fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
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}
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PRELE(p);
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}
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/*
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* Get the page number of this segment.
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*/
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pageno = trunc_page(uva);
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page_offset = uva - pageno;
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/*
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* How many bytes to copy
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*/
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len = min(PAGE_SIZE - page_offset, uio->uio_resid);
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/*
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* The map we want...
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*/
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map = &p->p_vmspace->vm_map;
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/*
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* Check the permissions for the area we're interested
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* in.
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*/
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fix_prot = 0;
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if (writing)
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fix_prot = !vm_map_check_protection(map, pageno,
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pageno + PAGE_SIZE, VM_PROT_WRITE);
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if (fix_prot) {
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/*
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* If the page is not writable, we make it so.
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* XXX It is possible that a page may *not* be
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* read/executable, if a process changes that!
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* We will assume, for now, that a page is either
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* VM_PROT_ALL, or VM_PROT_READ|VM_PROT_EXECUTE.
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*/
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error = vm_map_protect(map, pageno,
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pageno + PAGE_SIZE, VM_PROT_ALL, 0);
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if (error)
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break;
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}
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/*
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* Now we need to get the page. out_entry, out_prot, wired,
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* and single_use aren't used. One would think the vm code
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* would be a *bit* nicer... We use tmap because
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* vm_map_lookup() can change the map argument.
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*/
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tmap = map;
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error = vm_map_lookup(&tmap, pageno,
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writing ? VM_PROT_WRITE : VM_PROT_READ,
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&out_entry, &object, &pindex, &out_prot,
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&wired, &single_use);
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/*
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* We're done with tmap now.
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*/
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if (!error)
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vm_map_lookup_done(tmap, out_entry);
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/*
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* Fault the page in...
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*/
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if (!error && writing && object->backing_object) {
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m = vm_page_lookup(object, pindex);
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if (m == 0)
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error = vm_fault(map, pageno,
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VM_PROT_WRITE, FALSE);
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}
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/* Find space in kernel_map for the page we're interested in */
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if (!error)
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error = vm_map_find(kernel_map, object,
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IDX_TO_OFF(pindex), &kva, PAGE_SIZE, 1,
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VM_PROT_ALL, VM_PROT_ALL, 0);
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if (!error) {
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/*
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* Neither vm_map_lookup() nor vm_map_find() appear
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* to add a reference count to the object, so we do
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* that here and now.
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*/
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vm_object_reference(object);
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/*
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* Mark the page we just found as pageable.
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*/
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error = vm_map_pageable(kernel_map, kva,
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kva + PAGE_SIZE, 0);
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/*
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* Now do the i/o move.
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*/
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if (!error)
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error = uiomove((caddr_t)(kva + page_offset),
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len, uio);
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vm_map_remove(kernel_map, kva, kva + PAGE_SIZE);
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}
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if (fix_prot)
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vm_map_protect(map, pageno, pageno + PAGE_SIZE,
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VM_PROT_READ|VM_PROT_EXECUTE, 0);
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} while (error == 0 && uio->uio_resid > 0);
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return (error);
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}
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/*
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* Copy data in and out of the target process.
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* We do this by mapping the process's page into
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* the kernel and then doing a uiomove direct
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* from the kernel address space.
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*/
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int
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procfs_domem(curp, p, pfs, uio)
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struct proc *curp;
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struct proc *p;
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struct pfsnode *pfs;
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struct uio *uio;
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{
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int error;
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if (uio->uio_resid == 0)
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return (0);
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error = procfs_rwmem(p, uio);
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return (error);
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}
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/*
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* Given process (p), find the vnode from which
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* it's text segment is being executed.
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*
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* It would be nice to grab this information from
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* the VM system, however, there is no sure-fire
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* way of doing that. Instead, fork(), exec() and
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* wait() all maintain the p_textvp field in the
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* process proc structure which contains a held
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* reference to the exec'ed vnode.
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*/
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struct vnode *
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procfs_findtextvp(p)
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struct proc *p;
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{
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return (p->p_textvp);
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}
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