xref: /netbsd-src/sys/miscfs/procfs/procfs_map.c (revision a7761fd2c552f671585576eeb03d56c875a0b1c1)
1 /*	$NetBSD: procfs_map.c,v 1.31 2007/04/01 03:18:57 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Jan-Simon Pendry.
9  *
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. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)procfs_status.c	8.3 (Berkeley) 2/17/94
35  *
36  *	$FreeBSD: procfs_map.c,v 1.18 1998/12/04 22:54:51 archie Exp $
37  */
38 
39 /*
40  * Copyright (c) 1993 Jan-Simon Pendry
41  *
42  * This code is derived from software contributed to Berkeley by
43  * Jan-Simon Pendry.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. All advertising materials mentioning features or use of this software
54  *    must display the following acknowledgement:
55  *	This product includes software developed by the University of
56  *	California, Berkeley and its contributors.
57  * 4. Neither the name of the University nor the names of its contributors
58  *    may be used to endorse or promote products derived from this software
59  *    without specific prior written permission.
60  *
61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71  * SUCH DAMAGE.
72  *
73  *	@(#)procfs_status.c	8.3 (Berkeley) 2/17/94
74  *
75  *	$FreeBSD: procfs_map.c,v 1.18 1998/12/04 22:54:51 archie Exp $
76  */
77 
78 #include <sys/cdefs.h>
79 __KERNEL_RCSID(0, "$NetBSD: procfs_map.c,v 1.31 2007/04/01 03:18:57 christos Exp $");
80 
81 #include <sys/param.h>
82 #include <sys/systm.h>
83 #include <sys/proc.h>
84 #include <sys/vnode.h>
85 #include <sys/malloc.h>
86 #include <sys/namei.h>
87 #include <miscfs/procfs/procfs.h>
88 
89 #include <sys/lock.h>
90 
91 #include <uvm/uvm.h>
92 
93 #define BUFFERSIZE (64 * 1024)
94 
95 extern int getcwd_common(struct vnode *, struct vnode *,
96 			      char **, char *, int, int, struct lwp *);
97 
98 static int procfs_vnode_to_path(struct vnode *vp, char *path, int len,
99 				struct lwp *curl, struct proc *p);
100 
101 /*
102  * The map entries can *almost* be read with programs like cat.  However,
103  * large maps need special programs to read.  It is not easy to implement
104  * a program that can sense the required size of the buffer, and then
105  * subsequently do a read with the appropriate size.  This operation cannot
106  * be atomic.  The best that we can do is to allow the program to do a read
107  * with an arbitrarily large buffer, and return as much as we can.  We can
108  * return an error code if the buffer is too small (EFBIG), then the program
109  * can try a bigger buffer.
110  */
111 int
112 procfs_domap(struct lwp *curl, struct proc *p, struct pfsnode *pfs,
113 	     struct uio *uio, int linuxmode)
114 {
115 	int error;
116 	struct vmspace *vm;
117 	struct vm_map *map;
118 	struct vm_map_entry *entry;
119 	char *buffer;
120 	char *path;
121 	struct vnode *vp;
122 	struct vattr va;
123 	dev_t dev;
124 	long fileid;
125 	size_t pos;
126 
127 	if (uio->uio_rw != UIO_READ)
128 		return EOPNOTSUPP;
129 
130 	if (uio->uio_offset != 0) {
131 		/*
132 		 * we return 0 here, so that the second read returns EOF
133 		 * we don't support reading from an offset because the
134 		 * map could have changed between the two reads.
135 		 */
136 		return 0;
137 	}
138 
139 	error = 0;
140 
141 	buffer = malloc(BUFFERSIZE, M_TEMP, M_WAITOK);
142 	if (linuxmode != 0)
143 		path = malloc(MAXPATHLEN * 4, M_TEMP, M_WAITOK);
144 	else
145 		path = NULL;
146 
147 	if ((error = proc_vmspace_getref(p, &vm)) != 0)
148 		goto out;
149 
150 	map = &vm->vm_map;
151 	vm_map_lock_read(map);
152 
153 	pos = 0;
154 	for (entry = map->header.next; entry != &map->header;
155 	    entry = entry->next) {
156 
157 		if (UVM_ET_ISSUBMAP(entry))
158 			continue;
159 
160 		if (linuxmode != 0) {
161 			*path = 0;
162 			dev = (dev_t)0;
163 			fileid = 0;
164 			if (UVM_ET_ISOBJ(entry) &&
165 			    UVM_OBJ_IS_VNODE(entry->object.uvm_obj)) {
166 				vp = (struct vnode *)entry->object.uvm_obj;
167 				error = VOP_GETATTR(vp, &va, curl->l_cred,
168 				    curl);
169 				if (error == 0 && vp != pfs->pfs_vnode) {
170 					fileid = va.va_fileid;
171 					dev = va.va_fsid;
172 					error = procfs_vnode_to_path(vp, path,
173 					    MAXPATHLEN * 4, curl, p);
174 				}
175 			}
176 			pos += snprintf(buffer + pos, BUFFERSIZE - pos,
177 			    "%0*lx-%0*lx %c%c%c%c %0*lx %02x:%02x %ld     %s\n",
178 			    (int)sizeof(void *) * 2,(unsigned long)entry->start,
179 			    (int)sizeof(void *) * 2,(unsigned long)entry->end,
180 			    (entry->protection & VM_PROT_READ) ? 'r' : '-',
181 			    (entry->protection & VM_PROT_WRITE) ? 'w' : '-',
182 			    (entry->protection & VM_PROT_EXECUTE) ? 'x' : '-',
183 			    (entry->etype & UVM_ET_COPYONWRITE) ? 'p' : 's',
184 			    (int)sizeof(void *) * 2,
185 			    (unsigned long)entry->offset,
186 			    major(dev), minor(dev), fileid, path);
187 		} else {
188 			pos += snprintf(buffer + pos, BUFFERSIZE - pos,
189 			    "0x%lx 0x%lx %c%c%c %c%c%c %s %s %d %d %d\n",
190 			    entry->start, entry->end,
191 			    (entry->protection & VM_PROT_READ) ? 'r' : '-',
192 			    (entry->protection & VM_PROT_WRITE) ? 'w' : '-',
193 			    (entry->protection & VM_PROT_EXECUTE) ? 'x' : '-',
194 			    (entry->max_protection & VM_PROT_READ) ? 'r' : '-',
195 			    (entry->max_protection & VM_PROT_WRITE) ? 'w' : '-',
196 			    (entry->max_protection & VM_PROT_EXECUTE) ?
197 				'x' : '-',
198 			    (entry->etype & UVM_ET_COPYONWRITE) ?
199 				"COW" : "NCOW",
200 			    (entry->etype & UVM_ET_NEEDSCOPY) ? "NC" : "NNC",
201 			    entry->inheritance, entry->wired_count,
202 			    entry->advice);
203 		}
204 	}
205 
206 	vm_map_unlock_read(map);
207 	uvmspace_free(vm);
208 
209 	error = uiomove(buffer, pos, uio);
210 out:
211 	if (path != NULL)
212 		free(path, M_TEMP);
213 	if (buffer != NULL)
214 		free(buffer, M_TEMP);
215 
216 	return error;
217 }
218 
219 int
220 procfs_validmap(struct lwp *l, struct mount *mp)
221 {
222 	return ((l->l_flag & LW_SYSTEM) == 0);
223 }
224 
225 /*
226  * Try to find a pathname for a vnode. Since there is no mapping
227  * vnode -> parent directory, this needs the NAMECACHE_ENTER_REVERSE
228  * option to work (to make cache_revlookup succeed).
229  */
230 static int procfs_vnode_to_path(struct vnode *vp, char *path, int len,
231 				struct lwp *curl, struct proc *p)
232 {
233 	struct proc *curp = curl->l_proc;
234 	int error, lenused, elen;
235 	char *bp, *bend;
236 	struct vnode *dvp;
237 
238 	bp = bend = &path[len];
239 	*(--bp) = '\0';
240 
241 	error = vget(vp, LK_EXCLUSIVE | LK_RETRY);
242 	if (error != 0)
243 		return error;
244 	error = cache_revlookup(vp, &dvp, &bp, path);
245 	vput(vp);
246 	if (error != 0)
247 		return (error == -1 ? ENOENT : error);
248 
249 	error = vget(dvp, 0);
250 	if (error != 0)
251 		return error;
252 	*(--bp) = '/';
253 	/* XXX GETCWD_CHECK_ACCESS == 0x0001 */
254 	error = getcwd_common(dvp, NULL, &bp, path, len / 2, 1, curl);
255 
256 	/*
257 	 * Strip off emulation path for emulated processes looking at
258 	 * the maps file of a process of the same emulation. (Won't
259 	 * work if /emul/xxx is a symlink..)
260 	 */
261 	if (curp->p_emul == p->p_emul && curp->p_emul->e_path != NULL) {
262 		elen = strlen(curp->p_emul->e_path);
263 		if (!strncmp(bp, curp->p_emul->e_path, elen))
264 			bp = &bp[elen];
265 	}
266 
267 	lenused = bend - bp;
268 
269 	memcpy(path, bp, lenused);
270 	path[lenused] = 0;
271 
272 	return 0;
273 }
274