xref: /freebsd/sys/fs/procfs/procfs_map.c (revision 8655c70597b0e0918c82114b1186df5669b83eb6)
1 /*-
2  * Copyright (c) 1993 Jan-Simon Pendry
3  * Copyright (c) 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Jan-Simon Pendry.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)procfs_status.c	8.3 (Berkeley) 2/17/94
34  *
35  * $FreeBSD$
36  */
37 
38 #include "opt_compat.h"
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/mutex.h>
47 #include <sys/proc.h>
48 #include <sys/sbuf.h>
49 #ifdef COMPAT_IA32
50 #include <sys/sysent.h>
51 #endif
52 #include <sys/uio.h>
53 #include <sys/vnode.h>
54 
55 #include <fs/pseudofs/pseudofs.h>
56 #include <fs/procfs/procfs.h>
57 
58 #include <vm/vm.h>
59 #include <vm/vm_extern.h>
60 #include <vm/pmap.h>
61 #include <vm/vm_map.h>
62 #include <vm/vm_page.h>
63 #include <vm/vm_object.h>
64 
65 #define MEBUFFERSIZE 256
66 
67 /*
68  * The map entries can *almost* be read with programs like cat.  However,
69  * large maps need special programs to read.  It is not easy to implement
70  * a program that can sense the required size of the buffer, and then
71  * subsequently do a read with the appropriate size.  This operation cannot
72  * be atomic.  The best that we can do is to allow the program to do a read
73  * with an arbitrarily large buffer, and return as much as we can.  We can
74  * return an error code if the buffer is too small (EFBIG), then the program
75  * can try a bigger buffer.
76  */
77 int
78 procfs_doprocmap(PFS_FILL_ARGS)
79 {
80 	struct vmspace *vm;
81 	vm_map_t map;
82 	vm_map_entry_t entry, tmp_entry;
83 	struct vnode *vp;
84 	char *fullpath, *freepath;
85 	int error, vfslocked;
86 	unsigned int last_timestamp;
87 #ifdef COMPAT_IA32
88 	int wrap32 = 0;
89 #endif
90 
91 	PROC_LOCK(p);
92 	error = p_candebug(td, p);
93 	PROC_UNLOCK(p);
94 	if (error)
95 		return (error);
96 
97 	if (uio->uio_rw != UIO_READ)
98 		return (EOPNOTSUPP);
99 
100 #ifdef COMPAT_IA32
101         if (curproc->p_sysent->sv_flags & SV_ILP32) {
102                 if (!(p->p_sysent->sv_flags & SV_ILP32))
103                         return (EOPNOTSUPP);
104                 wrap32 = 1;
105         }
106 #endif
107 
108 	vm = vmspace_acquire_ref(p);
109 	if (vm == NULL)
110 		return (ESRCH);
111 	map = &vm->vm_map;
112 	vm_map_lock_read(map);
113 	for (entry = map->header.next; entry != &map->header;
114 	     entry = entry->next) {
115 		vm_object_t obj, tobj, lobj;
116 		int ref_count, shadow_count, flags;
117 		vm_offset_t e_start, e_end, addr;
118 		int resident, privateresident;
119 		char *type;
120 		vm_eflags_t e_eflags;
121 		vm_prot_t e_prot;
122 
123 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
124 			continue;
125 
126 		e_eflags = entry->eflags;
127 		e_prot = entry->protection;
128 		e_start = entry->start;
129 		e_end = entry->end;
130 		privateresident = 0;
131 		obj = entry->object.vm_object;
132 		if (obj != NULL) {
133 			VM_OBJECT_LOCK(obj);
134 			if (obj->shadow_count == 1)
135 				privateresident = obj->resident_page_count;
136 		}
137 
138 		resident = 0;
139 		addr = entry->start;
140 		while (addr < entry->end) {
141 			if (pmap_extract(map->pmap, addr))
142 				resident++;
143 			addr += PAGE_SIZE;
144 		}
145 
146 		for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
147 			if (tobj != obj)
148 				VM_OBJECT_LOCK(tobj);
149 			if (lobj != obj)
150 				VM_OBJECT_UNLOCK(lobj);
151 			lobj = tobj;
152 		}
153 		last_timestamp = map->timestamp;
154 		vm_map_unlock_read(map);
155 
156 		freepath = NULL;
157 		fullpath = "-";
158 		if (lobj) {
159 			switch (lobj->type) {
160 			default:
161 			case OBJT_DEFAULT:
162 				type = "default";
163 				vp = NULL;
164 				break;
165 			case OBJT_VNODE:
166 				type = "vnode";
167 				vp = lobj->handle;
168 				vref(vp);
169 				break;
170 			case OBJT_SWAP:
171 				type = "swap";
172 				vp = NULL;
173 				break;
174 			case OBJT_DEVICE:
175 				type = "device";
176 				vp = NULL;
177 				break;
178 			}
179 			if (lobj != obj)
180 				VM_OBJECT_UNLOCK(lobj);
181 
182 			flags = obj->flags;
183 			ref_count = obj->ref_count;
184 			shadow_count = obj->shadow_count;
185 			VM_OBJECT_UNLOCK(obj);
186 			if (vp != NULL) {
187 				vn_fullpath(td, vp, &fullpath, &freepath);
188 				vfslocked = VFS_LOCK_GIANT(vp->v_mount);
189 				vrele(vp);
190 				VFS_UNLOCK_GIANT(vfslocked);
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, cow, access, type.
202 		 */
203 		error = sbuf_printf(sb,
204 		    "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s\n",
205 			(u_long)e_start, (u_long)e_end,
206 			resident, privateresident,
207 #ifdef COMPAT_IA32
208 			wrap32 ? NULL : obj,	/* Hide 64 bit value */
209 #else
210 			obj,
211 #endif
212 			(e_prot & VM_PROT_READ)?"r":"-",
213 			(e_prot & VM_PROT_WRITE)?"w":"-",
214 			(e_prot & VM_PROT_EXECUTE)?"x":"-",
215 			ref_count, shadow_count, flags,
216 			(e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
217 			(e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
218 			type, fullpath);
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 	vmspace_free(vm);
239 	return (error);
240 }
241