1 /* $OpenBSD: monitor_mm.c,v 1.21 2015/02/06 23:21:59 millert Exp $ */
2 /*
3 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include "includes.h"
28
29 #include <sys/types.h>
30 #ifdef HAVE_SYS_MMAN_H
31 #include <sys/mman.h>
32 #endif
33 #include "openbsd-compat/sys-tree.h"
34
35 #include <errno.h>
36 #include <stdarg.h>
37 #include <stddef.h>
38 #ifdef HAVE_STDINT_H
39 #include <stdint.h>
40 #endif
41 #include <stdlib.h>
42 #include <string.h>
43
44 #include "xmalloc.h"
45 #include "ssh.h"
46 #include "log.h"
47 #include "monitor_mm.h"
48
49 static int
mm_compare(struct mm_share * a,struct mm_share * b)50 mm_compare(struct mm_share *a, struct mm_share *b)
51 {
52 ptrdiff_t diff = (char *)a->address - (char *)b->address;
53
54 if (diff == 0)
55 return (0);
56 else if (diff < 0)
57 return (-1);
58 else
59 return (1);
60 }
61
RB_GENERATE(mmtree,mm_share,next,mm_compare)62 RB_GENERATE(mmtree, mm_share, next, mm_compare)
63
64 static struct mm_share *
65 mm_make_entry(struct mm_master *mm, struct mmtree *head,
66 void *address, size_t size)
67 {
68 struct mm_share *tmp, *tmp2;
69
70 if (mm->mmalloc == NULL)
71 tmp = xcalloc(1, sizeof(struct mm_share));
72 else
73 tmp = mm_xmalloc(mm->mmalloc, sizeof(struct mm_share));
74 tmp->address = address;
75 tmp->size = size;
76
77 tmp2 = RB_INSERT(mmtree, head, tmp);
78 if (tmp2 != NULL)
79 fatal("mm_make_entry(%p): double address %p->%p(%zu)",
80 mm, tmp2, address, size);
81
82 return (tmp);
83 }
84
85 /* Creates a shared memory area of a certain size */
86
87 struct mm_master *
mm_create(struct mm_master * mmalloc,size_t size)88 mm_create(struct mm_master *mmalloc, size_t size)
89 {
90 void *address;
91 struct mm_master *mm;
92
93 if (mmalloc == NULL)
94 mm = xcalloc(1, sizeof(struct mm_master));
95 else
96 mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
97
98 /*
99 * If the memory map has a mm_master it can be completely
100 * shared including authentication between the child
101 * and the client.
102 */
103 mm->mmalloc = mmalloc;
104
105 address = xmmap(size);
106 if (address == (void *)MAP_FAILED)
107 fatal("mmap(%zu): %s", size, strerror(errno));
108
109 mm->address = address;
110 mm->size = size;
111
112 RB_INIT(&mm->rb_free);
113 RB_INIT(&mm->rb_allocated);
114
115 mm_make_entry(mm, &mm->rb_free, address, size);
116
117 return (mm);
118 }
119
120 /* Frees either the allocated or the free list */
121
122 static void
mm_freelist(struct mm_master * mmalloc,struct mmtree * head)123 mm_freelist(struct mm_master *mmalloc, struct mmtree *head)
124 {
125 struct mm_share *mms, *next;
126
127 for (mms = RB_ROOT(head); mms; mms = next) {
128 next = RB_NEXT(mmtree, head, mms);
129 RB_REMOVE(mmtree, head, mms);
130 if (mmalloc == NULL)
131 free(mms);
132 else
133 mm_free(mmalloc, mms);
134 }
135 }
136
137 /* Destroys a memory mapped area */
138
139 void
mm_destroy(struct mm_master * mm)140 mm_destroy(struct mm_master *mm)
141 {
142 mm_freelist(mm->mmalloc, &mm->rb_free);
143 mm_freelist(mm->mmalloc, &mm->rb_allocated);
144
145 #ifdef HAVE_MMAP
146 if (munmap(mm->address, mm->size) == -1)
147 fatal("munmap(%p, %zu): %s", mm->address, mm->size,
148 strerror(errno));
149 #else
150 fatal("%s: UsePrivilegeSeparation=yes and Compression=yes not supported",
151 __func__);
152 #endif
153 if (mm->mmalloc == NULL)
154 free(mm);
155 else
156 mm_free(mm->mmalloc, mm);
157 }
158
159 void *
mm_xmalloc(struct mm_master * mm,size_t size)160 mm_xmalloc(struct mm_master *mm, size_t size)
161 {
162 void *address;
163
164 address = mm_malloc(mm, size);
165 if (address == NULL)
166 fatal("%s: mm_malloc(%zu)", __func__, size);
167 memset(address, 0, size);
168 return (address);
169 }
170
171
172 /* Allocates data from a memory mapped area */
173
174 void *
mm_malloc(struct mm_master * mm,size_t size)175 mm_malloc(struct mm_master *mm, size_t size)
176 {
177 struct mm_share *mms, *tmp;
178
179 if (size == 0)
180 fatal("mm_malloc: try to allocate 0 space");
181 if (size > SIZE_MAX - MM_MINSIZE + 1)
182 fatal("mm_malloc: size too big");
183
184 size = ((size + (MM_MINSIZE - 1)) / MM_MINSIZE) * MM_MINSIZE;
185
186 RB_FOREACH(mms, mmtree, &mm->rb_free) {
187 if (mms->size >= size)
188 break;
189 }
190
191 if (mms == NULL)
192 return (NULL);
193
194 /* Debug */
195 memset(mms->address, 0xd0, size);
196
197 tmp = mm_make_entry(mm, &mm->rb_allocated, mms->address, size);
198
199 /* Does not change order in RB tree */
200 mms->size -= size;
201 mms->address = (char *)mms->address + size;
202
203 if (mms->size == 0) {
204 RB_REMOVE(mmtree, &mm->rb_free, mms);
205 if (mm->mmalloc == NULL)
206 free(mms);
207 else
208 mm_free(mm->mmalloc, mms);
209 }
210
211 return (tmp->address);
212 }
213
214 /* Frees memory in a memory mapped area */
215
216 void
mm_free(struct mm_master * mm,void * address)217 mm_free(struct mm_master *mm, void *address)
218 {
219 struct mm_share *mms, *prev, tmp;
220
221 tmp.address = address;
222 mms = RB_FIND(mmtree, &mm->rb_allocated, &tmp);
223 if (mms == NULL)
224 fatal("mm_free(%p): can not find %p", mm, address);
225
226 /* Debug */
227 memset(mms->address, 0xd0, mms->size);
228
229 /* Remove from allocated list and insert in free list */
230 RB_REMOVE(mmtree, &mm->rb_allocated, mms);
231 if (RB_INSERT(mmtree, &mm->rb_free, mms) != NULL)
232 fatal("mm_free(%p): double address %p", mm, address);
233
234 /* Find previous entry */
235 prev = mms;
236 if (RB_LEFT(prev, next)) {
237 prev = RB_LEFT(prev, next);
238 while (RB_RIGHT(prev, next))
239 prev = RB_RIGHT(prev, next);
240 } else {
241 if (RB_PARENT(prev, next) &&
242 (prev == RB_RIGHT(RB_PARENT(prev, next), next)))
243 prev = RB_PARENT(prev, next);
244 else {
245 while (RB_PARENT(prev, next) &&
246 (prev == RB_LEFT(RB_PARENT(prev, next), next)))
247 prev = RB_PARENT(prev, next);
248 prev = RB_PARENT(prev, next);
249 }
250 }
251
252 /* Check if range does not overlap */
253 if (prev != NULL && MM_ADDRESS_END(prev) > address)
254 fatal("mm_free: memory corruption: %p(%zu) > %p",
255 prev->address, prev->size, address);
256
257 /* See if we can merge backwards */
258 if (prev != NULL && MM_ADDRESS_END(prev) == address) {
259 prev->size += mms->size;
260 RB_REMOVE(mmtree, &mm->rb_free, mms);
261 if (mm->mmalloc == NULL)
262 free(mms);
263 else
264 mm_free(mm->mmalloc, mms);
265 } else
266 prev = mms;
267
268 if (prev == NULL)
269 return;
270
271 /* Check if we can merge forwards */
272 mms = RB_NEXT(mmtree, &mm->rb_free, prev);
273 if (mms == NULL)
274 return;
275
276 if (MM_ADDRESS_END(prev) > mms->address)
277 fatal("mm_free: memory corruption: %p < %p(%zu)",
278 mms->address, prev->address, prev->size);
279 if (MM_ADDRESS_END(prev) != mms->address)
280 return;
281
282 prev->size += mms->size;
283 RB_REMOVE(mmtree, &mm->rb_free, mms);
284
285 if (mm->mmalloc == NULL)
286 free(mms);
287 else
288 mm_free(mm->mmalloc, mms);
289 }
290
291 static void
mm_sync_list(struct mmtree * oldtree,struct mmtree * newtree,struct mm_master * mm,struct mm_master * mmold)292 mm_sync_list(struct mmtree *oldtree, struct mmtree *newtree,
293 struct mm_master *mm, struct mm_master *mmold)
294 {
295 struct mm_master *mmalloc = mm->mmalloc;
296 struct mm_share *mms, *new;
297
298 /* Sync free list */
299 RB_FOREACH(mms, mmtree, oldtree) {
300 /* Check the values */
301 mm_memvalid(mmold, mms, sizeof(struct mm_share));
302 mm_memvalid(mm, mms->address, mms->size);
303
304 new = mm_xmalloc(mmalloc, sizeof(struct mm_share));
305 memcpy(new, mms, sizeof(struct mm_share));
306 RB_INSERT(mmtree, newtree, new);
307 }
308 }
309
310 void
mm_share_sync(struct mm_master ** pmm,struct mm_master ** pmmalloc)311 mm_share_sync(struct mm_master **pmm, struct mm_master **pmmalloc)
312 {
313 struct mm_master *mm;
314 struct mm_master *mmalloc;
315 struct mm_master *mmold;
316 struct mmtree rb_free, rb_allocated;
317
318 debug3("%s: Share sync", __func__);
319
320 mm = *pmm;
321 mmold = mm->mmalloc;
322 mm_memvalid(mmold, mm, sizeof(*mm));
323
324 mmalloc = mm_create(NULL, mm->size);
325 mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
326 memcpy(mm, *pmm, sizeof(struct mm_master));
327 mm->mmalloc = mmalloc;
328
329 rb_free = mm->rb_free;
330 rb_allocated = mm->rb_allocated;
331
332 RB_INIT(&mm->rb_free);
333 RB_INIT(&mm->rb_allocated);
334
335 mm_sync_list(&rb_free, &mm->rb_free, mm, mmold);
336 mm_sync_list(&rb_allocated, &mm->rb_allocated, mm, mmold);
337
338 mm_destroy(mmold);
339
340 *pmm = mm;
341 *pmmalloc = mmalloc;
342
343 debug3("%s: Share sync end", __func__);
344 }
345
346 void
mm_memvalid(struct mm_master * mm,void * address,size_t size)347 mm_memvalid(struct mm_master *mm, void *address, size_t size)
348 {
349 void *end = (char *)address + size;
350
351 if (address < mm->address)
352 fatal("mm_memvalid: address too small: %p", address);
353 if (end < address)
354 fatal("mm_memvalid: end < address: %p < %p", end, address);
355 if (end > MM_ADDRESS_END(mm))
356 fatal("mm_memvalid: address too large: %p", address);
357 }
358