xref: /freebsd/sys/fs/procfs/procfs_map.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
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 "opt_compat.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/lock.h>
45 #include <sys/filedesc.h>
46 #include <sys/malloc.h>
47 #include <sys/mount.h>
48 #include <sys/proc.h>
49 #include <sys/resourcevar.h>
50 #include <sys/rwlock.h>
51 #include <sys/sbuf.h>
52 #ifdef COMPAT_FREEBSD32
53 #include <sys/sysent.h>
54 #endif
55 #include <sys/uio.h>
56 #include <sys/vnode.h>
57 
58 #include <fs/pseudofs/pseudofs.h>
59 #include <fs/procfs/procfs.h>
60 
61 #include <vm/vm.h>
62 #include <vm/vm_extern.h>
63 #include <vm/pmap.h>
64 #include <vm/vm_map.h>
65 #include <vm/vm_page.h>
66 #include <vm/vm_object.h>
67 
68 #define MEBUFFERSIZE 256
69 
70 /*
71  * The map entries can *almost* be read with programs like cat.  However,
72  * large maps need special programs to read.  It is not easy to implement
73  * a program that can sense the required size of the buffer, and then
74  * subsequently do a read with the appropriate size.  This operation cannot
75  * be atomic.  The best that we can do is to allow the program to do a read
76  * with an arbitrarily large buffer, and return as much as we can.  We can
77  * return an error code if the buffer is too small (EFBIG), then the program
78  * can try a bigger buffer.
79  */
80 int
81 procfs_doprocmap(PFS_FILL_ARGS)
82 {
83 	struct vmspace *vm;
84 	vm_map_t map;
85 	vm_map_entry_t entry, tmp_entry;
86 	struct vnode *vp;
87 	char *fullpath, *freepath, *type;
88 	struct ucred *cred;
89 	vm_object_t obj, tobj, lobj;
90 	int error, privateresident, ref_count, resident, shadow_count, flags;
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 	for (entry = map->header.next; entry != &map->header;
124 	     entry = entry->next) {
125 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
126 			continue;
127 
128 		e_eflags = entry->eflags;
129 		e_prot = entry->protection;
130 		e_start = entry->start;
131 		e_end = entry->end;
132 		privateresident = 0;
133 		resident = 0;
134 		obj = entry->object.vm_object;
135 		if (obj != NULL) {
136 			VM_OBJECT_RLOCK(obj);
137 			if (obj->shadow_count == 1)
138 				privateresident = obj->resident_page_count;
139 		}
140 		cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
141 
142 		for (lobj = tobj = obj; tobj != NULL;
143 		    tobj = tobj->backing_object) {
144 			if (tobj != obj)
145 				VM_OBJECT_RLOCK(tobj);
146 			lobj = tobj;
147 		}
148 		if (obj != NULL)
149 			kern_proc_vmmap_resident(map, entry, &resident, &super);
150 		for (tobj = obj; tobj != NULL; tobj = 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 			vp = NULL;
161 			switch (lobj->type) {
162 			default:
163 			case OBJT_DEFAULT:
164 				type = "default";
165 				break;
166 			case OBJT_VNODE:
167 				type = "vnode";
168 				vp = lobj->handle;
169 				vref(vp);
170 				break;
171 			case OBJT_SWAP:
172 				if ((lobj->flags & OBJ_TMPFS_NODE) != 0) {
173 					type = "vnode";
174 					if ((lobj->flags & OBJ_TMPFS) != 0) {
175 						vp = lobj->un_pager.swp.swp_tmpfs;
176 						vref(vp);
177 					}
178 				} else {
179 					type = "swap";
180 				}
181 				break;
182 			case OBJT_SG:
183 			case OBJT_DEVICE:
184 				type = "device";
185 				break;
186 			}
187 			if (lobj != obj)
188 				VM_OBJECT_RUNLOCK(lobj);
189 
190 			flags = obj->flags;
191 			ref_count = obj->ref_count;
192 			shadow_count = obj->shadow_count;
193 			VM_OBJECT_RUNLOCK(obj);
194 			if (vp != NULL) {
195 				vn_fullpath(td, vp, &fullpath, &freepath);
196 				vrele(vp);
197 			}
198 		} else {
199 			type = "none";
200 			flags = 0;
201 			ref_count = 0;
202 			shadow_count = 0;
203 		}
204 
205 		/*
206 		 * format:
207 		 *  start, end, resident, private resident, cow, access, type,
208 		 *         charged, charged uid.
209 		 */
210 		error = sbuf_printf(sb,
211 		    "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
212 			(u_long)e_start, (u_long)e_end,
213 			resident, privateresident,
214 #ifdef COMPAT_FREEBSD32
215 			wrap32 ? NULL : obj,	/* Hide 64 bit value */
216 #else
217 			obj,
218 #endif
219 			(e_prot & VM_PROT_READ)?"r":"-",
220 			(e_prot & VM_PROT_WRITE)?"w":"-",
221 			(e_prot & VM_PROT_EXECUTE)?"x":"-",
222 			ref_count, shadow_count, flags,
223 			(e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
224 			(e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
225 			type, fullpath,
226 			cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
227 
228 		if (freepath != NULL)
229 			free(freepath, M_TEMP);
230 		vm_map_lock_read(map);
231 		if (error == -1) {
232 			error = 0;
233 			break;
234 		}
235 		if (last_timestamp != map->timestamp) {
236 			/*
237 			 * Look again for the entry because the map was
238 			 * modified while it was unlocked.  Specifically,
239 			 * the entry may have been clipped, merged, or deleted.
240 			 */
241 			vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
242 			entry = tmp_entry;
243 		}
244 	}
245 	vm_map_unlock_read(map);
246 	vmspace_free(vm);
247 	return (error);
248 }
249