xref: /freebsd/sys/fs/procfs/procfs_map.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1993 Jan-Simon Pendry
5  * Copyright (c) 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Jan-Simon Pendry.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)procfs_status.c	8.3 (Berkeley) 2/17/94
36  *
37  * $FreeBSD$
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/lock.h>
43 #include <sys/filedesc.h>
44 #include <sys/malloc.h>
45 #include <sys/mount.h>
46 #include <sys/proc.h>
47 #include <sys/resourcevar.h>
48 #include <sys/rwlock.h>
49 #include <sys/sbuf.h>
50 #ifdef COMPAT_FREEBSD32
51 #include <sys/sysent.h>
52 #endif
53 #include <sys/uio.h>
54 #include <sys/user.h>
55 #include <sys/vnode.h>
56 
57 #include <fs/pseudofs/pseudofs.h>
58 #include <fs/procfs/procfs.h>
59 
60 #include <vm/vm.h>
61 #include <vm/vm_extern.h>
62 #include <vm/pmap.h>
63 #include <vm/vm_map.h>
64 #include <vm/vm_page.h>
65 #include <vm/vm_object.h>
66 
67 #define MEBUFFERSIZE 256
68 
69 /*
70  * The map entries can *almost* be read with programs like cat.  However,
71  * large maps need special programs to read.  It is not easy to implement
72  * a program that can sense the required size of the buffer, and then
73  * subsequently do a read with the appropriate size.  This operation cannot
74  * be atomic.  The best that we can do is to allow the program to do a read
75  * with an arbitrarily large buffer, and return as much as we can.  We can
76  * return an error code if the buffer is too small (EFBIG), then the program
77  * can try a bigger buffer.
78  */
79 int
80 procfs_doprocmap(PFS_FILL_ARGS)
81 {
82 	struct vmspace *vm;
83 	vm_map_t map;
84 	vm_map_entry_t entry, tmp_entry;
85 	struct vnode *vp;
86 	char *fullpath, *freepath, *type;
87 	struct ucred *cred;
88 	vm_object_t lobj, nobj, obj, tobj;
89 	int error, flags, kvme, privateresident, ref_count, resident;
90 	int shadow_count;
91 	vm_offset_t e_start, e_end;
92 	vm_eflags_t e_eflags;
93 	vm_prot_t e_prot;
94 	unsigned int last_timestamp;
95 	bool super;
96 #ifdef COMPAT_FREEBSD32
97 	bool wrap32;
98 #endif
99 
100 	PROC_LOCK(p);
101 	error = p_candebug(td, p);
102 	PROC_UNLOCK(p);
103 	if (error)
104 		return (error);
105 
106 	if (uio->uio_rw != UIO_READ)
107 		return (EOPNOTSUPP);
108 
109 #ifdef COMPAT_FREEBSD32
110 	wrap32 = false;
111 	if (SV_CURPROC_FLAG(SV_ILP32)) {
112 		if (!(SV_PROC_FLAG(p, SV_ILP32)))
113 			return (EOPNOTSUPP);
114 		wrap32 = true;
115 	}
116 #endif
117 
118 	vm = vmspace_acquire_ref(p);
119 	if (vm == NULL)
120 		return (ESRCH);
121 	map = &vm->vm_map;
122 	vm_map_lock_read(map);
123 	VM_MAP_ENTRY_FOREACH(entry, map) {
124 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
125 			continue;
126 
127 		e_eflags = entry->eflags;
128 		e_prot = entry->protection;
129 		e_start = entry->start;
130 		e_end = entry->end;
131 		privateresident = 0;
132 		resident = 0;
133 		obj = entry->object.vm_object;
134 		if (obj != NULL) {
135 			VM_OBJECT_RLOCK(obj);
136 			if (obj->shadow_count == 1)
137 				privateresident = obj->resident_page_count;
138 		}
139 		cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
140 
141 		for (lobj = tobj = obj; tobj != NULL;
142 		    tobj = tobj->backing_object) {
143 			if (tobj != obj)
144 				VM_OBJECT_RLOCK(tobj);
145 			lobj = tobj;
146 		}
147 		if (obj != NULL)
148 			kern_proc_vmmap_resident(map, entry, &resident, &super);
149 		for (tobj = obj; tobj != NULL; tobj = nobj) {
150 			nobj = tobj->backing_object;
151 			if (tobj != obj && tobj != lobj)
152 				VM_OBJECT_RUNLOCK(tobj);
153 		}
154 		last_timestamp = map->timestamp;
155 		vm_map_unlock_read(map);
156 
157 		freepath = NULL;
158 		fullpath = "-";
159 		if (lobj) {
160 			kvme = vm_object_kvme_type(lobj, &vp);
161 			if (vp != NULL)
162 				vref(vp);
163 			switch (kvme) {
164 			default:
165 				type = "unknown";
166 				break;
167 			case KVME_TYPE_PHYS:
168 				type = "phys";
169 				break;
170 			case KVME_TYPE_SWAP:
171 				type = "swap";
172 				break;
173 			case KVME_TYPE_DEAD:
174 				type = "dead";
175 				break;
176 			case KVME_TYPE_VNODE:
177 				type = "vnode";
178 				break;
179 			case KVME_TYPE_SG:
180 			case KVME_TYPE_DEVICE:
181 			case KVME_TYPE_MGTDEVICE:
182 				type = "device";
183 				break;
184 			}
185 			if (lobj != obj)
186 				VM_OBJECT_RUNLOCK(lobj);
187 
188 			flags = obj->flags;
189 			ref_count = obj->ref_count;
190 			shadow_count = obj->shadow_count;
191 			VM_OBJECT_RUNLOCK(obj);
192 			if (vp != NULL) {
193 				vn_fullpath(vp, &fullpath, &freepath);
194 				vrele(vp);
195 			}
196 		} else {
197 			type = "none";
198 			flags = 0;
199 			ref_count = 0;
200 			shadow_count = 0;
201 		}
202 
203 		/*
204 		 * format:
205 		 *  start, end, resident, private resident, cow, access, type,
206 		 *         charged, charged uid.
207 		 */
208 		error = sbuf_printf(sb,
209 		    "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
210 			(u_long)e_start, (u_long)e_end,
211 			resident, privateresident,
212 #ifdef COMPAT_FREEBSD32
213 			wrap32 ? NULL : obj,	/* Hide 64 bit value */
214 #else
215 			obj,
216 #endif
217 			(e_prot & VM_PROT_READ)?"r":"-",
218 			(e_prot & VM_PROT_WRITE)?"w":"-",
219 			(e_prot & VM_PROT_EXECUTE)?"x":"-",
220 			ref_count, shadow_count, flags,
221 			(e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
222 			(e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
223 			type, fullpath,
224 			cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
225 
226 		if (freepath != NULL)
227 			free(freepath, M_TEMP);
228 		vm_map_lock_read(map);
229 		if (error == -1) {
230 			error = 0;
231 			break;
232 		}
233 		if (last_timestamp != map->timestamp) {
234 			/*
235 			 * Look again for the entry because the map was
236 			 * modified while it was unlocked.  Specifically,
237 			 * the entry may have been clipped, merged, or deleted.
238 			 */
239 			vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
240 			entry = tmp_entry;
241 		}
242 	}
243 	vm_map_unlock_read(map);
244 	vmspace_free(vm);
245 	return (error);
246 }
247