xref: /freebsd/sys/fs/procfs/procfs_map.c (revision 64038db825d64fb4827fc8ee264ea0fa1a046d82)
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/ptrace.h>
44 #include <sys/resourcevar.h>
45 #include <sys/rwlock.h>
46 #include <sys/sbuf.h>
47 #ifdef COMPAT_FREEBSD32
48 #include <sys/sysent.h>
49 #endif
50 #include <sys/uio.h>
51 #include <sys/user.h>
52 #include <sys/vnode.h>
53 
54 #include <fs/pseudofs/pseudofs.h>
55 #include <fs/procfs/procfs.h>
56 
57 #include <vm/vm.h>
58 #include <vm/vm_extern.h>
59 #include <vm/pmap.h>
60 #include <vm/vm_map.h>
61 #include <vm/vm_page.h>
62 #include <vm/vm_object.h>
63 
64 #define MEBUFFERSIZE 256
65 
66 /*
67  * The map entries can *almost* be read with programs like cat.  However,
68  * large maps need special programs to read.  It is not easy to implement
69  * a program that can sense the required size of the buffer, and then
70  * subsequently do a read with the appropriate size.  This operation cannot
71  * be atomic.  The best that we can do is to allow the program to do a read
72  * with an arbitrarily large buffer, and return as much as we can.  We can
73  * return an error code if the buffer is too small (EFBIG), then the program
74  * can try a bigger buffer.
75  */
76 int
77 procfs_doprocmap(PFS_FILL_ARGS)
78 {
79 	struct vmspace *vm;
80 	vm_map_t map;
81 	vm_map_entry_t entry, tmp_entry;
82 	struct vnode *vp;
83 	char *fullpath, *freepath, *type;
84 	struct ucred *cred;
85 	vm_object_t lobj, nobj, obj, tobj;
86 	int error, flags, kvme, privateresident, ref_count, resident;
87 	int shadow_count;
88 	vm_offset_t e_start, e_end;
89 	vm_eflags_t e_eflags;
90 	vm_prot_t e_prot;
91 	unsigned int last_timestamp;
92 	bool super;
93 #ifdef COMPAT_FREEBSD32
94 	bool wrap32;
95 #endif
96 
97 	if (uio->uio_rw != UIO_READ)
98 		return (EOPNOTSUPP);
99 
100 	error = proc_vmspace_ref(td, p, PRVM_BLOCK_EXEC | PRVM_CHECK_DEBUG,
101 	    &vm);
102 	if (error != 0)
103 		return (error);
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 	map = &vm->vm_map;
115 	vm_map_lock_read(map);
116 	VM_MAP_ENTRY_FOREACH(entry, map) {
117 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
118 			continue;
119 
120 		e_eflags = entry->eflags;
121 		e_prot = entry->protection;
122 		e_start = entry->start;
123 		e_end = entry->end;
124 		privateresident = 0;
125 		resident = 0;
126 		obj = entry->object.vm_object;
127 		if (obj != NULL) {
128 			VM_OBJECT_RLOCK(obj);
129 			if (obj->shadow_count == 1)
130 				privateresident = obj->resident_page_count;
131 		}
132 		cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
133 
134 		for (lobj = tobj = obj; tobj != NULL;
135 		    tobj = tobj->backing_object) {
136 			if (tobj != obj)
137 				VM_OBJECT_RLOCK(tobj);
138 			lobj = tobj;
139 		}
140 		if (obj != NULL)
141 			kern_proc_vmmap_resident(map, entry, &resident, &super);
142 		for (tobj = obj; tobj != NULL; tobj = nobj) {
143 			nobj = tobj->backing_object;
144 			if (tobj != obj && tobj != lobj)
145 				VM_OBJECT_RUNLOCK(tobj);
146 		}
147 		last_timestamp = map->timestamp;
148 		vm_map_unlock_read(map);
149 
150 		freepath = NULL;
151 		fullpath = "-";
152 		if (lobj) {
153 			kvme = vm_object_kvme_type(lobj, &vp);
154 			if (vp != NULL)
155 				vref(vp);
156 			switch (kvme) {
157 			default:
158 				type = "unknown";
159 				break;
160 			case KVME_TYPE_PHYS:
161 				type = "phys";
162 				break;
163 			case KVME_TYPE_SWAP:
164 				type = "swap";
165 				break;
166 			case KVME_TYPE_DEAD:
167 				type = "dead";
168 				break;
169 			case KVME_TYPE_VNODE:
170 				type = "vnode";
171 				break;
172 			case KVME_TYPE_SG:
173 			case KVME_TYPE_DEVICE:
174 			case KVME_TYPE_MGTDEVICE:
175 				type = "device";
176 				break;
177 			}
178 			if (lobj != obj)
179 				VM_OBJECT_RUNLOCK(lobj);
180 
181 			flags = obj->flags;
182 			ref_count = obj->ref_count;
183 			shadow_count = obj->shadow_count;
184 			VM_OBJECT_RUNLOCK(obj);
185 			if (vp != NULL) {
186 				vn_fullpath(vp, &fullpath, &freepath);
187 				vrele(vp);
188 			}
189 		} else {
190 			type = "none";
191 			flags = 0;
192 			ref_count = 0;
193 			shadow_count = 0;
194 		}
195 
196 		/*
197 		 * format:
198 		 *  start, end, resident, private-resident, obj, access,
199 		 *  ref_count, shadow_count, flags, cow, needs_copy, type,
200 		 *  fullpath, charged, charged uid.
201 		 */
202 		error = sbuf_printf(sb,
203 		    "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
204 			(u_long)e_start, (u_long)e_end,
205 			resident, privateresident,
206 #ifdef COMPAT_FREEBSD32
207 			wrap32 ? NULL : obj,	/* Hide 64 bit value */
208 #else
209 			obj,
210 #endif
211 			(e_prot & VM_PROT_READ)?"r":"-",
212 			(e_prot & VM_PROT_WRITE)?"w":"-",
213 			(e_prot & VM_PROT_EXECUTE)?"x":"-",
214 			ref_count, shadow_count, flags,
215 			(e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
216 			(e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
217 			type, fullpath,
218 			cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
219 
220 		if (freepath != NULL)
221 			free(freepath, M_TEMP);
222 		vm_map_lock_read(map);
223 		if (error == -1) {
224 			error = 0;
225 			break;
226 		}
227 		if (last_timestamp != map->timestamp) {
228 			/*
229 			 * Look again for the entry because the map was
230 			 * modified while it was unlocked.  Specifically,
231 			 * the entry may have been clipped, merged, or deleted.
232 			 */
233 			vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
234 			entry = tmp_entry;
235 		}
236 	}
237 	vm_map_unlock_read(map);
238 	proc_vmspace_unref(td, p, PRVM_BLOCK_EXEC | PRVM_CHECK_DEBUG, vm);
239 	return (error);
240 }
241