xref: /freebsd/sys/fs/procfs/procfs_map.c (revision 29363fb446372cb3f10bc98664e9767c53fbb457)
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 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/lock.h>
39 #include <sys/filedesc.h>
40 #include <sys/malloc.h>
41 #include <sys/mount.h>
42 #include <sys/proc.h>
43 #include <sys/resourcevar.h>
44 #include <sys/rwlock.h>
45 #include <sys/sbuf.h>
46 #ifdef COMPAT_FREEBSD32
47 #include <sys/sysent.h>
48 #endif
49 #include <sys/uio.h>
50 #include <sys/user.h>
51 #include <sys/vnode.h>
52 
53 #include <fs/pseudofs/pseudofs.h>
54 #include <fs/procfs/procfs.h>
55 
56 #include <vm/vm.h>
57 #include <vm/vm_extern.h>
58 #include <vm/pmap.h>
59 #include <vm/vm_map.h>
60 #include <vm/vm_page.h>
61 #include <vm/vm_object.h>
62 
63 #define MEBUFFERSIZE 256
64 
65 /*
66  * The map entries can *almost* be read with programs like cat.  However,
67  * large maps need special programs to read.  It is not easy to implement
68  * a program that can sense the required size of the buffer, and then
69  * subsequently do a read with the appropriate size.  This operation cannot
70  * be atomic.  The best that we can do is to allow the program to do a read
71  * with an arbitrarily large buffer, and return as much as we can.  We can
72  * return an error code if the buffer is too small (EFBIG), then the program
73  * can try a bigger buffer.
74  */
75 int
procfs_doprocmap(PFS_FILL_ARGS)76 procfs_doprocmap(PFS_FILL_ARGS)
77 {
78 	struct vmspace *vm;
79 	vm_map_t map;
80 	vm_map_entry_t entry, tmp_entry;
81 	struct vnode *vp;
82 	char *fullpath, *freepath, *type;
83 	struct ucred *cred;
84 	vm_object_t lobj, nobj, obj, tobj;
85 	int error, flags, kvme, privateresident, ref_count, resident;
86 	int shadow_count;
87 	vm_offset_t e_start, e_end;
88 	vm_eflags_t e_eflags;
89 	vm_prot_t e_prot;
90 	unsigned int last_timestamp;
91 	bool super;
92 #ifdef COMPAT_FREEBSD32
93 	bool wrap32;
94 #endif
95 
96 	PROC_LOCK(p);
97 	error = p_candebug(td, p);
98 	PROC_UNLOCK(p);
99 	if (error)
100 		return (error);
101 
102 	if (uio->uio_rw != UIO_READ)
103 		return (EOPNOTSUPP);
104 
105 #ifdef COMPAT_FREEBSD32
106 	wrap32 = false;
107 	if (SV_CURPROC_FLAG(SV_ILP32)) {
108 		if (!(SV_PROC_FLAG(p, SV_ILP32)))
109 			return (EOPNOTSUPP);
110 		wrap32 = true;
111 	}
112 #endif
113 
114 	vm = vmspace_acquire_ref(p);
115 	if (vm == NULL)
116 		return (ESRCH);
117 	map = &vm->vm_map;
118 	vm_map_lock_read(map);
119 	VM_MAP_ENTRY_FOREACH(entry, map) {
120 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
121 			continue;
122 
123 		e_eflags = entry->eflags;
124 		e_prot = entry->protection;
125 		e_start = entry->start;
126 		e_end = entry->end;
127 		privateresident = 0;
128 		resident = 0;
129 		obj = entry->object.vm_object;
130 		if (obj != NULL) {
131 			VM_OBJECT_RLOCK(obj);
132 			if (obj->shadow_count == 1)
133 				privateresident = obj->resident_page_count;
134 		}
135 		cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
136 
137 		for (lobj = tobj = obj; tobj != NULL;
138 		    tobj = tobj->backing_object) {
139 			if (tobj != obj)
140 				VM_OBJECT_RLOCK(tobj);
141 			lobj = tobj;
142 		}
143 		if (obj != NULL)
144 			kern_proc_vmmap_resident(map, entry, &resident, &super);
145 		for (tobj = obj; tobj != NULL; tobj = nobj) {
146 			nobj = tobj->backing_object;
147 			if (tobj != obj && tobj != lobj)
148 				VM_OBJECT_RUNLOCK(tobj);
149 		}
150 		last_timestamp = map->timestamp;
151 		vm_map_unlock_read(map);
152 
153 		freepath = NULL;
154 		fullpath = "-";
155 		if (lobj) {
156 			kvme = vm_object_kvme_type(lobj, &vp);
157 			if (vp != NULL)
158 				vref(vp);
159 			switch (kvme) {
160 			default:
161 				type = "unknown";
162 				break;
163 			case KVME_TYPE_PHYS:
164 				type = "phys";
165 				break;
166 			case KVME_TYPE_SWAP:
167 				type = "swap";
168 				break;
169 			case KVME_TYPE_DEAD:
170 				type = "dead";
171 				break;
172 			case KVME_TYPE_VNODE:
173 				type = "vnode";
174 				break;
175 			case KVME_TYPE_SG:
176 			case KVME_TYPE_DEVICE:
177 			case KVME_TYPE_MGTDEVICE:
178 				type = "device";
179 				break;
180 			}
181 			if (lobj != obj)
182 				VM_OBJECT_RUNLOCK(lobj);
183 
184 			flags = obj->flags;
185 			ref_count = obj->ref_count;
186 			shadow_count = obj->shadow_count;
187 			VM_OBJECT_RUNLOCK(obj);
188 			if (vp != NULL) {
189 				vn_fullpath(vp, &fullpath, &freepath);
190 				vrele(vp);
191 			}
192 		} else {
193 			type = "none";
194 			flags = 0;
195 			ref_count = 0;
196 			shadow_count = 0;
197 		}
198 
199 		/*
200 		 * format:
201 		 *  start, end, resident, private-resident, obj, access,
202 		 *  ref_count, shadow_count, flags, cow, needs_copy, type,
203 		 *  fullpath, charged, charged uid.
204 		 */
205 		error = sbuf_printf(sb,
206 		    "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
207 			(u_long)e_start, (u_long)e_end,
208 			resident, privateresident,
209 #ifdef COMPAT_FREEBSD32
210 			wrap32 ? NULL : obj,	/* Hide 64 bit value */
211 #else
212 			obj,
213 #endif
214 			(e_prot & VM_PROT_READ)?"r":"-",
215 			(e_prot & VM_PROT_WRITE)?"w":"-",
216 			(e_prot & VM_PROT_EXECUTE)?"x":"-",
217 			ref_count, shadow_count, flags,
218 			(e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
219 			(e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
220 			type, fullpath,
221 			cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
222 
223 		if (freepath != NULL)
224 			free(freepath, M_TEMP);
225 		vm_map_lock_read(map);
226 		if (error == -1) {
227 			error = 0;
228 			break;
229 		}
230 		if (last_timestamp != map->timestamp) {
231 			/*
232 			 * Look again for the entry because the map was
233 			 * modified while it was unlocked.  Specifically,
234 			 * the entry may have been clipped, merged, or deleted.
235 			 */
236 			vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
237 			entry = tmp_entry;
238 		}
239 	}
240 	vm_map_unlock_read(map);
241 	vmspace_free(vm);
242 	return (error);
243 }
244