xref: /freebsd/sys/fs/procfs/procfs_map.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
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/resourcevar.h>
49 #include <sys/sbuf.h>
50 #ifdef COMPAT_FREEBSD32
51 #include <sys/sysent.h>
52 #endif
53 #include <sys/uio.h>
54 #include <sys/vnode.h>
55 
56 #include <fs/pseudofs/pseudofs.h>
57 #include <fs/procfs/procfs.h>
58 
59 #include <vm/vm.h>
60 #include <vm/vm_extern.h>
61 #include <vm/pmap.h>
62 #include <vm/vm_map.h>
63 #include <vm/vm_page.h>
64 #include <vm/vm_object.h>
65 
66 #define MEBUFFERSIZE 256
67 
68 /*
69  * The map entries can *almost* be read with programs like cat.  However,
70  * large maps need special programs to read.  It is not easy to implement
71  * a program that can sense the required size of the buffer, and then
72  * subsequently do a read with the appropriate size.  This operation cannot
73  * be atomic.  The best that we can do is to allow the program to do a read
74  * with an arbitrarily large buffer, and return as much as we can.  We can
75  * return an error code if the buffer is too small (EFBIG), then the program
76  * can try a bigger buffer.
77  */
78 int
79 procfs_doprocmap(PFS_FILL_ARGS)
80 {
81 	struct vmspace *vm;
82 	vm_map_t map;
83 	vm_map_entry_t entry, tmp_entry;
84 	struct vnode *vp;
85 	char *fullpath, *freepath;
86 	struct ucred *cred;
87 	int error, vfslocked;
88 	unsigned int last_timestamp;
89 #ifdef COMPAT_FREEBSD32
90 	int wrap32 = 0;
91 #endif
92 
93 	PROC_LOCK(p);
94 	error = p_candebug(td, p);
95 	PROC_UNLOCK(p);
96 	if (error)
97 		return (error);
98 
99 	if (uio->uio_rw != UIO_READ)
100 		return (EOPNOTSUPP);
101 
102 #ifdef COMPAT_FREEBSD32
103         if (SV_CURPROC_FLAG(SV_ILP32)) {
104                 if (!(SV_PROC_FLAG(p, SV_ILP32)))
105                         return (EOPNOTSUPP);
106                 wrap32 = 1;
107         }
108 #endif
109 
110 	vm = vmspace_acquire_ref(p);
111 	if (vm == NULL)
112 		return (ESRCH);
113 	map = &vm->vm_map;
114 	vm_map_lock_read(map);
115 	for (entry = map->header.next; entry != &map->header;
116 	     entry = entry->next) {
117 		vm_object_t obj, tobj, lobj;
118 		int ref_count, shadow_count, flags;
119 		vm_offset_t e_start, e_end, addr;
120 		int resident, privateresident;
121 		char *type;
122 		vm_eflags_t e_eflags;
123 		vm_prot_t e_prot;
124 
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 		obj = entry->object.vm_object;
134 		if (obj != NULL) {
135 			VM_OBJECT_LOCK(obj);
136 			if (obj->shadow_count == 1)
137 				privateresident = obj->resident_page_count;
138 		}
139 		cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
140 
141 		resident = 0;
142 		addr = entry->start;
143 		while (addr < entry->end) {
144 			if (pmap_extract(map->pmap, addr))
145 				resident++;
146 			addr += PAGE_SIZE;
147 		}
148 
149 		for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
150 			if (tobj != obj)
151 				VM_OBJECT_LOCK(tobj);
152 			if (lobj != obj)
153 				VM_OBJECT_UNLOCK(lobj);
154 			lobj = tobj;
155 		}
156 		last_timestamp = map->timestamp;
157 		vm_map_unlock_read(map);
158 
159 		freepath = NULL;
160 		fullpath = "-";
161 		if (lobj) {
162 			switch (lobj->type) {
163 			default:
164 			case OBJT_DEFAULT:
165 				type = "default";
166 				vp = NULL;
167 				break;
168 			case OBJT_VNODE:
169 				type = "vnode";
170 				vp = lobj->handle;
171 				vref(vp);
172 				break;
173 			case OBJT_SWAP:
174 				type = "swap";
175 				vp = NULL;
176 				break;
177 			case OBJT_SG:
178 			case OBJT_DEVICE:
179 				type = "device";
180 				vp = NULL;
181 				break;
182 			}
183 			if (lobj != obj)
184 				VM_OBJECT_UNLOCK(lobj);
185 
186 			flags = obj->flags;
187 			ref_count = obj->ref_count;
188 			shadow_count = obj->shadow_count;
189 			VM_OBJECT_UNLOCK(obj);
190 			if (vp != NULL) {
191 				vn_fullpath(td, vp, &fullpath, &freepath);
192 				vfslocked = VFS_LOCK_GIANT(vp->v_mount);
193 				vrele(vp);
194 				VFS_UNLOCK_GIANT(vfslocked);
195 			}
196 		} else {
197 			type = "none";
198 			flags = 0;
199 			ref_count = 0;
200 			shadow_count = 0;
201 		}
202 
203 		/*
204 		 * format:
205 		 *  start, end, resident, private resident, cow, access, type,
206 		 *         charged, charged uid.
207 		 */
208 		error = sbuf_printf(sb,
209 		    "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
210 			(u_long)e_start, (u_long)e_end,
211 			resident, privateresident,
212 #ifdef COMPAT_FREEBSD32
213 			wrap32 ? NULL : obj,	/* Hide 64 bit value */
214 #else
215 			obj,
216 #endif
217 			(e_prot & VM_PROT_READ)?"r":"-",
218 			(e_prot & VM_PROT_WRITE)?"w":"-",
219 			(e_prot & VM_PROT_EXECUTE)?"x":"-",
220 			ref_count, shadow_count, flags,
221 			(e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
222 			(e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
223 			type, fullpath,
224 			cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
225 
226 		if (freepath != NULL)
227 			free(freepath, M_TEMP);
228 		vm_map_lock_read(map);
229 		if (error == -1) {
230 			error = 0;
231 			break;
232 		}
233 		if (last_timestamp != map->timestamp) {
234 			/*
235 			 * Look again for the entry because the map was
236 			 * modified while it was unlocked.  Specifically,
237 			 * the entry may have been clipped, merged, or deleted.
238 			 */
239 			vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
240 			entry = tmp_entry;
241 		}
242 	}
243 	vm_map_unlock_read(map);
244 	vmspace_free(vm);
245 	return (error);
246 }
247