[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 */
Commit	Line	Data
66375577	1	/*
66375577	2	* Copyright (c) 1993 Jan-Simon Pendry
e14d91e9	3	* Copyright (c) 1993 Sean Eric Fagan
1611db1e KB	4	* Copyright (c) 1993
1611db1e KB	5	* The Regents of the University of California. All rights reserved.
66375577 JSP	6	*
66375577 JSP	7	* This code is derived from software contributed to Berkeley by
ad7740d9	8	* Jan-Simon Pendry and Sean Eric Fagan.
66375577	9	*
ed554bc5 C	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	* 3. All advertising materials mentioning features or use of this software
	19	* must display the following acknowledgement:
	20	* This product includes software developed by the University of
	21	* California, Berkeley and its contributors.
	22	* 4. Neither the name of the University nor the names of its contributors
	23	* may be used to endorse or promote products derived from this software
	24	* without specific prior written permission.
66375577	25	*
ed554bc5 C	26	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	27	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	28	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	29	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	30	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	31	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	32	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	33	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	34	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	35	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	36	* SUCH DAMAGE.
	37	*
fd88f5c5	38	* @(#)procfs_mem.c 8.5 (Berkeley) 6/15/94
66375577 JSP	39	*
	40	* From:
	41	* $Id: procfs_mem.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
	42	*/
	43
	44	/*
	45	* This is a lightly hacked and merged version
	46	* of sef's pread/pwrite functions
	47	*/
	48
	49	#include <sys/param.h>
	50	#include <sys/systm.h>
	51	#include <sys/time.h>
	52	#include <sys/kernel.h>
	53	#include <sys/proc.h>
	54	#include <sys/vnode.h>
	55	#include <miscfs/procfs/procfs.h>
	56	#include <vm/vm.h>
	57	#include <vm/vm_kern.h>
	58	#include <vm/vm_page.h>
	59
	60	static int
	61	procfs_rwmem(p, uio)
	62	struct proc *p;
	63	struct uio *uio;
	64	{
	65	int error;
	66	int writing;
	67
	68	writing = uio->uio_rw == UIO_WRITE;
	69
	70	/*
	71	* Only map in one page at a time. We don't have to, but it
	72	* makes things easier. This way is trivial - right?
	73	*/
	74	do {
	75	vm_map_t map, tmap;
	76	vm_object_t object;
	77	vm_offset_t kva;
	78	vm_offset_t uva;
	79	int page_offset; /* offset into page */
	80	vm_offset_t pageno; /* page number */
	81	vm_map_entry_t out_entry;
	82	vm_prot_t out_prot;
	83	vm_page_t m;
	84	boolean_t wired, single_use;
	85	vm_offset_t off;
	86	u_int len;
	87	int fix_prot;
	88
	89	uva = (vm_offset_t) uio->uio_offset;
	90	if (uva > VM_MAXUSER_ADDRESS) {
	91	error = 0;
	92	break;
	93	}
	94
	95	/*
	96	* Get the page number of this segment.
	97	*/
	98	pageno = trunc_page(uva);
	99	page_offset = uva - pageno;
	100
	101	/*
	102	* How many bytes to copy
103	*/
104	len = min(PAGE_SIZE - page_offset, uio->uio_resid);
105
106	/*
107	* The map we want...
108	*/
109	map = &p->p_vmspace->vm_map;
110
111	/*
112	* Check the permissions for the area we're interested
113	* in.
114	*/
115	fix_prot = 0;
116	if (writing)
117	fix_prot = !vm_map_check_protection(map, pageno,
118	pageno + PAGE_SIZE, VM_PROT_WRITE);
119
120	if (fix_prot) {
121	/*
122	* If the page is not writable, we make it so.
123	* XXX It is possible that a page may not be
124	* read/executable, if a process changes that!
125	* We will assume, for now, that a page is either
126	* VM_PROT_ALL, or VM_PROT_READ\|VM_PROT_EXECUTE.
127	*/
128	error = vm_map_protect(map, pageno,
129	pageno + PAGE_SIZE, VM_PROT_ALL, 0);
130	if (error)
131	break;
132	}
133
134	/*
135	* Now we need to get the page. out_entry, out_prot, wired,
136	* and single_use aren't used. One would think the vm code
137	* would be a bit nicer... We use tmap because
138	* vm_map_lookup() can change the map argument.
139	*/
140	tmap = map;
141	error = vm_map_lookup(&tmap, pageno,
142	writing ? VM_PROT_WRITE : VM_PROT_READ,
143	&out_entry, &object, &off, &out_prot,
144	&wired, &single_use);
145	/*
146	* We're done with tmap now.
147	*/
148	if (!error)
149	vm_map_lookup_done(tmap, out_entry);
150
151	/*
152	* Fault the page in...
153	*/
154	if (!error && writing && object->shadow) {
155	m = vm_page_lookup(object, off);
156	if (m == 0 \|\| (m->flags & PG_COPYONWRITE))
157	error = vm_fault(map, pageno,
158	VM_PROT_WRITE, FALSE);
159	}
160
161	/* Find space in kernel_map for the page we're interested in */
162	if (!error)
163	error = vm_map_find(kernel_map, object, off, &kva,
164	PAGE_SIZE, 1);
165
166	if (!error) {
167	/*
168	* Neither vm_map_lookup() nor vm_map_find() appear
169	* to add a reference count to the object, so we do
170	* that here and now.
171	*/
172	vm_object_reference(object);
173
174	/*
175	* Mark the page we just found as pageable.
176	*/
177	error = vm_map_pageable(kernel_map, kva,
178	kva + PAGE_SIZE, 0);
179
180	/*
181	* Now do the i/o move.
182	*/
183	if (!error)
184	error = uiomove(kva + page_offset, len, uio);
185
186	vm_map_remove(kernel_map, kva, kva + PAGE_SIZE);
187	}
188	if (fix_prot)
189	vm_map_protect(map, pageno, pageno + PAGE_SIZE,
190	VM_PROT_READ\|VM_PROT_EXECUTE, 0);
191	} while (error == 0 && uio->uio_resid > 0);
192
193	return (error);
194	}
195
196	/*
197	* Copy data in and out of the target process.
198	* We do this by mapping the process's page into
199	* the kernel and then doing a uiomove direct
200	* from the kernel address space.
201	*/
202	int
203	procfs_domem(curp, p, pfs, uio)
204	struct proc *curp;
205	struct proc *p;
206	struct pfsnode *pfs;
207	struct uio *uio;
208	{
66375577 JSP	209
	210	if (uio->uio_resid == 0)
	211	return (0);
	212
679a7c6b	213	return (procfs_rwmem(p, uio));
66375577 JSP	214	}
	215
	216	/*
	217	* Given process (p), find the vnode from which
	218	* it's text segment is being executed.
	219	*
	220	* It would be nice to grab this information from
	221	* the VM system, however, there is no sure-fire
	222	* way of doing that. Instead, fork(), exec() and
	223	* wait() all maintain the p_textvp field in the
	224	* process proc structure which contains a held
	225	* reference to the exec'ed vnode.
	226	*/
	227	struct vnode *
	228	procfs_findtextvp(p)
	229	struct proc *p;
	230	{
679a7c6b	231
66375577 JSP	232	return (p->p_textvp);
	233	}
	234
	235
	236	#ifdef probably_never
	237	/*
	238	* Given process (p), find the vnode from which
	239	* it's text segment is being mapped.
	240	*
	241	* (This is here, rather than in procfs_subr in order
	242	* to keep all the VM related code in one place.)
	243	*/
	244	struct vnode *
	245	procfs_findtextvp(p)
	246	struct proc *p;
	247	{
	248	int error;
	249	vm_object_t object;
	250	vm_offset_t pageno; /* page number */
	251
	252	/* find a vnode pager for the user address space */
	253
	254	for (pageno = VM_MIN_ADDRESS;
	255	pageno < VM_MAXUSER_ADDRESS;
	256	pageno += PAGE_SIZE) {
	257	vm_map_t map;
	258	vm_map_entry_t out_entry;
	259	vm_prot_t out_prot;
	260	boolean_t wired, single_use;
	261	vm_offset_t off;
	262
	263	map = &p->p_vmspace->vm_map;
	264	error = vm_map_lookup(&map, pageno,
	265	VM_PROT_READ,
	266	&out_entry, &object, &off, &out_prot,
	267	&wired, &single_use);
	268
	269	if (!error) {
	270	vm_pager_t pager;
	271
	272	printf("procfs: found vm object\n");
	273	vm_map_lookup_done(map, out_entry);
	274	printf("procfs: vm object = %x\n", object);
	275
	276	/*
	277	* At this point, assuming no errors, object
	278	* is the VM object mapping UVA (pageno).
	279	* Ensure it has a vnode pager, then grab
	280	* the vnode from that pager's handle.
	281	*/
	282
	283	pager = object->pager;
	284	printf("procfs: pager = %x\n", pager);
	285	if (pager)
	286	printf("procfs: found pager, type = %d\n", pager->pg_type);
	287	if (pager && pager->pg_type == PG_VNODE) {
	288	struct vnode *vp;
	289
	290	vp = (struct vnode *) pager->pg_handle;
	291	printf("procfs: vp = 0x%x\n", vp);
	292	return (vp);
	293	}
	294	}
	295	}
296
297	printf("procfs: text object not found\n");
298	return (0);
299	}
300	#endif /* probably_never */