xref: /freebsd/sys/fs/procfs/procfs_map.c (revision f0cfa1b168014f56c02b83e5f28412cc5f78d117)
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;
88 	struct ucred *cred;
89 	int error;
90 	unsigned int last_timestamp;
91 #ifdef COMPAT_FREEBSD32
92 	int wrap32 = 0;
93 #endif
94 
95 	PROC_LOCK(p);
96 	error = p_candebug(td, p);
97 	PROC_UNLOCK(p);
98 	if (error)
99 		return (error);
100 
101 	if (uio->uio_rw != UIO_READ)
102 		return (EOPNOTSUPP);
103 
104 #ifdef COMPAT_FREEBSD32
105         if (SV_CURPROC_FLAG(SV_ILP32)) {
106                 if (!(SV_PROC_FLAG(p, SV_ILP32)))
107                         return (EOPNOTSUPP);
108                 wrap32 = 1;
109         }
110 #endif
111 
112 	vm = vmspace_acquire_ref(p);
113 	if (vm == NULL)
114 		return (ESRCH);
115 	map = &vm->vm_map;
116 	vm_map_lock_read(map);
117 	for (entry = map->header.next; entry != &map->header;
118 	     entry = entry->next) {
119 		vm_object_t obj, tobj, lobj;
120 		int ref_count, shadow_count, flags;
121 		vm_offset_t e_start, e_end, addr;
122 		int resident, privateresident;
123 		char *type;
124 		vm_eflags_t e_eflags;
125 		vm_prot_t e_prot;
126 
127 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
128 			continue;
129 
130 		e_eflags = entry->eflags;
131 		e_prot = entry->protection;
132 		e_start = entry->start;
133 		e_end = entry->end;
134 		privateresident = 0;
135 		obj = entry->object.vm_object;
136 		if (obj != NULL) {
137 			VM_OBJECT_RLOCK(obj);
138 			if (obj->shadow_count == 1)
139 				privateresident = obj->resident_page_count;
140 		}
141 		cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
142 
143 		resident = 0;
144 		addr = entry->start;
145 		while (addr < entry->end) {
146 			if (pmap_extract(map->pmap, addr))
147 				resident++;
148 			addr += PAGE_SIZE;
149 		}
150 
151 		for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
152 			if (tobj != obj)
153 				VM_OBJECT_RLOCK(tobj);
154 			if (lobj != obj)
155 				VM_OBJECT_RUNLOCK(lobj);
156 			lobj = tobj;
157 		}
158 		last_timestamp = map->timestamp;
159 		vm_map_unlock_read(map);
160 
161 		freepath = NULL;
162 		fullpath = "-";
163 		if (lobj) {
164 			vp = NULL;
165 			switch (lobj->type) {
166 			default:
167 			case OBJT_DEFAULT:
168 				type = "default";
169 				break;
170 			case OBJT_VNODE:
171 				type = "vnode";
172 				vp = lobj->handle;
173 				vref(vp);
174 				break;
175 			case OBJT_SWAP:
176 				if ((lobj->flags & OBJ_TMPFS_NODE) != 0) {
177 					type = "vnode";
178 					if ((lobj->flags & OBJ_TMPFS) != 0) {
179 						vp = lobj->un_pager.swp.swp_tmpfs;
180 						vref(vp);
181 					}
182 				} else {
183 					type = "swap";
184 				}
185 				break;
186 			case OBJT_SG:
187 			case OBJT_DEVICE:
188 				type = "device";
189 				break;
190 			}
191 			if (lobj != obj)
192 				VM_OBJECT_RUNLOCK(lobj);
193 
194 			flags = obj->flags;
195 			ref_count = obj->ref_count;
196 			shadow_count = obj->shadow_count;
197 			VM_OBJECT_RUNLOCK(obj);
198 			if (vp != NULL) {
199 				vn_fullpath(td, vp, &fullpath, &freepath);
200 				vrele(vp);
201 			}
202 		} else {
203 			type = "none";
204 			flags = 0;
205 			ref_count = 0;
206 			shadow_count = 0;
207 		}
208 
209 		/*
210 		 * format:
211 		 *  start, end, resident, private resident, cow, access, type,
212 		 *         charged, charged uid.
213 		 */
214 		error = sbuf_printf(sb,
215 		    "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
216 			(u_long)e_start, (u_long)e_end,
217 			resident, privateresident,
218 #ifdef COMPAT_FREEBSD32
219 			wrap32 ? NULL : obj,	/* Hide 64 bit value */
220 #else
221 			obj,
222 #endif
223 			(e_prot & VM_PROT_READ)?"r":"-",
224 			(e_prot & VM_PROT_WRITE)?"w":"-",
225 			(e_prot & VM_PROT_EXECUTE)?"x":"-",
226 			ref_count, shadow_count, flags,
227 			(e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
228 			(e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
229 			type, fullpath,
230 			cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
231 
232 		if (freepath != NULL)
233 			free(freepath, M_TEMP);
234 		vm_map_lock_read(map);
235 		if (error == -1) {
236 			error = 0;
237 			break;
238 		}
239 		if (last_timestamp != map->timestamp) {
240 			/*
241 			 * Look again for the entry because the map was
242 			 * modified while it was unlocked.  Specifically,
243 			 * the entry may have been clipped, merged, or deleted.
244 			 */
245 			vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
246 			entry = tmp_entry;
247 		}
248 	}
249 	vm_map_unlock_read(map);
250 	vmspace_free(vm);
251 	return (error);
252 }
253