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procfs_mem.c revision 1.23.8.1
      1  1.23.8.1    bouyer /*	$NetBSD: procfs_mem.c,v 1.23.8.1 2000/11/20 18:09:49 bouyer Exp $	*/
      2       1.6       cgd 
      3       1.1       cgd /*
      4       1.1       cgd  * Copyright (c) 1993 Jan-Simon Pendry
      5       1.4   mycroft  * Copyright (c) 1993 Sean Eric Fagan
      6       1.4   mycroft  * Copyright (c) 1993
      7       1.4   mycroft  *	The Regents of the University of California.  All rights reserved.
      8       1.1       cgd  *
      9       1.1       cgd  * This code is derived from software contributed to Berkeley by
     10       1.4   mycroft  * Jan-Simon Pendry and Sean Eric Fagan.
     11       1.1       cgd  *
     12       1.1       cgd  * Redistribution and use in source and binary forms, with or without
     13       1.1       cgd  * modification, are permitted provided that the following conditions
     14       1.1       cgd  * are met:
     15       1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     16       1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     17       1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     18       1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     19       1.1       cgd  *    documentation and/or other materials provided with the distribution.
     20       1.1       cgd  * 3. All advertising materials mentioning features or use of this software
     21       1.1       cgd  *    must display the following acknowledgement:
     22       1.1       cgd  *	This product includes software developed by the University of
     23       1.1       cgd  *	California, Berkeley and its contributors.
     24       1.1       cgd  * 4. Neither the name of the University nor the names of its contributors
     25       1.1       cgd  *    may be used to endorse or promote products derived from this software
     26       1.1       cgd  *    without specific prior written permission.
     27       1.1       cgd  *
     28       1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29       1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30       1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31       1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32       1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33       1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34       1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35       1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36       1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37       1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38       1.1       cgd  * SUCH DAMAGE.
     39       1.1       cgd  *
     40       1.6       cgd  *	@(#)procfs_mem.c	8.5 (Berkeley) 6/15/94
     41       1.1       cgd  */
     42       1.1       cgd 
     43       1.1       cgd /*
     44       1.1       cgd  * This is a lightly hacked and merged version
     45       1.1       cgd  * of sef's pread/pwrite functions
     46       1.1       cgd  */
     47      1.18       mrg 
     48       1.1       cgd #include <sys/param.h>
     49       1.1       cgd #include <sys/systm.h>
     50       1.1       cgd #include <sys/time.h>
     51       1.1       cgd #include <sys/kernel.h>
     52       1.1       cgd #include <sys/proc.h>
     53       1.1       cgd #include <sys/vnode.h>
     54      1.22       mrg 
     55       1.1       cgd #include <miscfs/procfs/procfs.h>
     56      1.22       mrg 
     57      1.17       mrg #include <uvm/uvm_extern.h>
     58      1.17       mrg 
     59      1.13  explorer #define	ISSET(t, f)	((t) & (f))
     60      1.13  explorer 
     61       1.1       cgd /*
     62       1.1       cgd  * Copy data in and out of the target process.
     63       1.1       cgd  * We do this by mapping the process's page into
     64       1.1       cgd  * the kernel and then doing a uiomove direct
     65       1.1       cgd  * from the kernel address space.
     66       1.1       cgd  */
     67       1.4   mycroft int
     68       1.4   mycroft procfs_domem(curp, p, pfs, uio)
     69      1.14   thorpej 	struct proc *curp;		/* tracer */
     70      1.14   thorpej 	struct proc *p;			/* traced */
     71       1.1       cgd 	struct pfsnode *pfs;
     72       1.1       cgd 	struct uio *uio;
     73       1.1       cgd {
     74       1.9   mycroft 	int error;
     75       1.1       cgd 
     76      1.20        is 	size_t len;
     77      1.20        is 	vaddr_t	addr;
     78      1.20        is 
     79      1.20        is 	len = uio->uio_resid;
     80      1.20        is 
     81      1.20        is 	if (len == 0)
     82       1.1       cgd 		return (0);
     83      1.12   thorpej 
     84      1.20        is 	addr = uio->uio_offset;
     85      1.20        is 
     86      1.12   thorpej 	if ((error = procfs_checkioperm(curp, p)) != 0)
     87      1.12   thorpej 		return (error);
     88       1.1       cgd 
     89      1.17       mrg 	/* XXXCDC: how should locking work here? */
     90      1.17       mrg 	if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1))
     91      1.17       mrg 		return(EFAULT);
     92      1.17       mrg 	p->p_vmspace->vm_refcnt++;  /* XXX */
     93      1.17       mrg 	error = uvm_io(&p->p_vmspace->vm_map, uio);
     94      1.17       mrg 	uvmspace_free(p->p_vmspace);
     95      1.20        is 
     96      1.20        is #ifdef PMAP_NEED_PROCWR
     97      1.20        is 	if (uio->uio_rw == UIO_WRITE)
     98      1.20        is 		pmap_procwr(p, addr, len);
     99      1.17       mrg #endif
    100       1.9   mycroft 	return (error);
    101       1.1       cgd }
    102       1.1       cgd 
    103       1.1       cgd /*
    104       1.1       cgd  * Given process (p), find the vnode from which
    105       1.1       cgd  * it's text segment is being executed.
    106       1.1       cgd  *
    107       1.1       cgd  * It would be nice to grab this information from
    108       1.1       cgd  * the VM system, however, there is no sure-fire
    109       1.1       cgd  * way of doing that.  Instead, fork(), exec() and
    110       1.1       cgd  * wait() all maintain the p_textvp field in the
    111       1.1       cgd  * process proc structure which contains a held
    112       1.1       cgd  * reference to the exec'ed vnode.
    113       1.1       cgd  */
    114       1.1       cgd struct vnode *
    115       1.1       cgd procfs_findtextvp(p)
    116       1.1       cgd 	struct proc *p;
    117       1.1       cgd {
    118       1.4   mycroft 
    119       1.1       cgd 	return (p->p_textvp);
    120       1.1       cgd }
    121       1.1       cgd 
    122      1.14   thorpej /*
    123      1.14   thorpej  * Ensure that a process has permission to perform I/O on another.
    124      1.14   thorpej  * Arguments:
    125      1.14   thorpej  *	p	The process wishing to do the I/O (the tracer).
    126      1.14   thorpej  *	t	The process who's memory/registers will be read/written.
    127      1.14   thorpej  */
    128      1.13  explorer int
    129      1.14   thorpej procfs_checkioperm(p, t)
    130      1.14   thorpej 	struct proc *p, *t;
    131      1.13  explorer {
    132      1.13  explorer 	int error;
    133      1.13  explorer 
    134      1.13  explorer 	/*
    135      1.13  explorer 	 * You cannot attach to a processes mem/regs if:
    136      1.13  explorer 	 *
    137      1.13  explorer 	 *	(1) it's not owned by you, or is set-id on exec
    138      1.13  explorer 	 *	    (unless you're root), or...
    139      1.13  explorer 	 */
    140      1.13  explorer 	if ((t->p_cred->p_ruid != p->p_cred->p_ruid ||
    141      1.16     enami 		ISSET(t->p_flag, P_SUGID)) &&
    142      1.13  explorer 	    (error = suser(p->p_ucred, &p->p_acflag)) != 0)
    143      1.13  explorer 		return (error);
    144      1.13  explorer 
    145      1.13  explorer 	/*
    146      1.13  explorer 	 *	(2) ...it's init, which controls the security level
    147      1.13  explorer 	 *	    of the entire system, and the system was not
    148      1.13  explorer 	 *	    compiled with permanetly insecure mode turned on.
    149      1.13  explorer 	 */
    150      1.13  explorer 	if (t == initproc && securelevel > -1)
    151      1.13  explorer 		return (EPERM);
    152      1.13  explorer 
    153      1.23  sommerfe 	/*
    154      1.23  sommerfe 	 * (3) the tracer is chrooted, and its root directory is
    155      1.23  sommerfe 	 * not at or above the root directory of the tracee
    156      1.23  sommerfe 	 */
    157      1.23  sommerfe 
    158      1.23  sommerfe 	if (!proc_isunder(t, p))
    159      1.23  sommerfe 		return EPERM;
    160      1.23  sommerfe 
    161      1.13  explorer 	return (0);
    162      1.13  explorer }
    163       1.1       cgd 
    164       1.1       cgd #ifdef probably_never
    165       1.1       cgd /*
    166       1.1       cgd  * Given process (p), find the vnode from which
    167       1.1       cgd  * it's text segment is being mapped.
    168       1.1       cgd  *
    169       1.1       cgd  * (This is here, rather than in procfs_subr in order
    170       1.1       cgd  * to keep all the VM related code in one place.)
    171       1.1       cgd  */
    172       1.1       cgd struct vnode *
    173       1.1       cgd procfs_findtextvp(p)
    174       1.1       cgd 	struct proc *p;
    175       1.1       cgd {
    176       1.1       cgd 	int error;
    177       1.1       cgd 	vm_object_t object;
    178      1.19       eeh 	vaddr_t pageno;		/* page number */
    179       1.1       cgd 
    180       1.1       cgd 	/* find a vnode pager for the user address space */
    181       1.1       cgd 
    182       1.1       cgd 	for (pageno = VM_MIN_ADDRESS;
    183       1.1       cgd 			pageno < VM_MAXUSER_ADDRESS;
    184       1.1       cgd 			pageno += PAGE_SIZE) {
    185       1.1       cgd 		vm_map_t map;
    186       1.1       cgd 		vm_map_entry_t out_entry;
    187       1.1       cgd 		vm_prot_t out_prot;
    188       1.1       cgd 		boolean_t wired, single_use;
    189      1.19       eeh 		vaddr_t off;
    190       1.1       cgd 
    191       1.1       cgd 		map = &p->p_vmspace->vm_map;
    192       1.1       cgd 		error = vm_map_lookup(&map, pageno,
    193       1.1       cgd 			      VM_PROT_READ,
    194       1.1       cgd 			      &out_entry, &object, &off, &out_prot,
    195       1.1       cgd 			      &wired, &single_use);
    196       1.1       cgd 
    197       1.1       cgd 		if (!error) {
    198       1.1       cgd 			vm_pager_t pager;
    199       1.1       cgd 
    200      1.11  christos 			printf("procfs: found vm object\n");
    201       1.1       cgd 			vm_map_lookup_done(map, out_entry);
    202      1.15  christos 			printf("procfs: vm object = %p\n", object);
    203       1.1       cgd 
    204       1.1       cgd 			/*
    205       1.1       cgd 			 * At this point, assuming no errors, object
    206       1.1       cgd 			 * is the VM object mapping UVA (pageno).
    207       1.1       cgd 			 * Ensure it has a vnode pager, then grab
    208       1.1       cgd 			 * the vnode from that pager's handle.
    209       1.1       cgd 			 */
    210       1.1       cgd 
    211       1.1       cgd 			pager = object->pager;
    212      1.15  christos 			printf("procfs: pager = %p\n", pager);
    213       1.1       cgd 			if (pager)
    214      1.11  christos 				printf("procfs: found pager, type = %d\n",
    215      1.10  christos 				    pager->pg_type);
    216       1.1       cgd 			if (pager && pager->pg_type == PG_VNODE) {
    217       1.1       cgd 				struct vnode *vp;
    218       1.1       cgd 
    219       1.1       cgd 				vp = (struct vnode *) pager->pg_handle;
    220      1.15  christos 				printf("procfs: vp = %p\n", vp);
    221       1.1       cgd 				return (vp);
    222       1.1       cgd 			}
    223       1.1       cgd 		}
    224       1.1       cgd 	}
    225       1.1       cgd 
    226      1.11  christos 	printf("procfs: text object not found\n");
    227       1.1       cgd 	return (0);
    228       1.1       cgd }
    229       1.4   mycroft #endif /* probably_never */
    230