NetBSD/sys/miscfs/procfs/procfs_mem.c

236 lines
6.3 KiB
C

/* $NetBSD: procfs_mem.c,v 1.23 1999/03/25 04:45:57 sommerfe Exp $ */
/*
* 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
*/
/*
* 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>
#include <uvm/uvm_extern.h>
#define ISSET(t, f) ((t) & (f))
/*
* 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; /* tracer */
struct proc *p; /* traced */
struct pfsnode *pfs;
struct uio *uio;
{
int error;
size_t len;
vaddr_t addr;
len = uio->uio_resid;
if (len == 0)
return (0);
addr = uio->uio_offset;
if ((error = procfs_checkioperm(curp, p)) != 0)
return (error);
/* XXXCDC: how should locking work here? */
if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1))
return(EFAULT);
PHOLD(p);
p->p_vmspace->vm_refcnt++; /* XXX */
error = uvm_io(&p->p_vmspace->vm_map, uio);
PRELE(p);
uvmspace_free(p->p_vmspace);
#ifdef PMAP_NEED_PROCWR
if (uio->uio_rw == UIO_WRITE)
pmap_procwr(p, addr, len);
#endif
return (error);
}
/*
* 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);
}
/*
* Ensure that a process has permission to perform I/O on another.
* Arguments:
* p The process wishing to do the I/O (the tracer).
* t The process who's memory/registers will be read/written.
*/
int
procfs_checkioperm(p, t)
struct proc *p, *t;
{
int error;
/*
* You cannot attach to a processes mem/regs if:
*
* (1) it's not owned by you, or is set-id on exec
* (unless you're root), or...
*/
if ((t->p_cred->p_ruid != p->p_cred->p_ruid ||
ISSET(t->p_flag, P_SUGID)) &&
(error = suser(p->p_ucred, &p->p_acflag)) != 0)
return (error);
/*
* (2) ...it's init, which controls the security level
* of the entire system, and the system was not
* compiled with permanetly insecure mode turned on.
*/
if (t == initproc && securelevel > -1)
return (EPERM);
/*
* (3) the tracer is chrooted, and its root directory is
* not at or above the root directory of the tracee
*/
if (!proc_isunder(t, p))
return EPERM;
return (0);
}
#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;
vaddr_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;
vaddr_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 = %p\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 = %p\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 = %p\n", vp);
return (vp);
}
}
}
printf("procfs: text object not found\n");
return (0);
}
#endif /* probably_never */