monitor_mm.c revision 106121 
1/*
2 * Copyright 2002 Niels Provos <provos@citi.umich.edu>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "includes.h"
27RCSID("$OpenBSD: monitor_mm.c,v 1.8 2002/08/02 14:43:15 millert Exp $");
28
29#ifdef HAVE_SYS_MMAN_H
30#include <sys/mman.h>
31#endif
32
33#include "openbsd-compat/xmmap.h"
34#include "ssh.h"
35#include "xmalloc.h"
36#include "log.h"
37#include "monitor_mm.h"
38
39static int
40mm_compare(struct mm_share *a, struct mm_share *b)
41{
42	long diff = (char *)a->address - (char *)b->address;
43
44	if (diff == 0)
45		return (0);
46	else if (diff < 0)
47		return (-1);
48	else
49		return (1);
50}
51
52RB_GENERATE(mmtree, mm_share, next, mm_compare)
53
54static struct mm_share *
55mm_make_entry(struct mm_master *mm, struct mmtree *head,
56    void *address, size_t size)
57{
58	struct mm_share *tmp, *tmp2;
59
60	if (mm->mmalloc == NULL)
61		tmp = xmalloc(sizeof(struct mm_share));
62	else
63		tmp = mm_xmalloc(mm->mmalloc, sizeof(struct mm_share));
64	tmp->address = address;
65	tmp->size = size;
66
67	tmp2 = RB_INSERT(mmtree, head, tmp);
68	if (tmp2 != NULL)
69		fatal("mm_make_entry(%p): double address %p->%p(%lu)",
70		    mm, tmp2, address, (u_long)size);
71
72	return (tmp);
73}
74
75/* Creates a shared memory area of a certain size */
76
77struct mm_master *
78mm_create(struct mm_master *mmalloc, size_t size)
79{
80	void *address;
81	struct mm_master *mm;
82
83	if (mmalloc == NULL)
84		mm = xmalloc(sizeof(struct mm_master));
85	else
86		mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
87
88	/*
89	 * If the memory map has a mm_master it can be completely
90	 * shared including authentication between the child
91	 * and the client.
92	 */
93	mm->mmalloc = mmalloc;
94
95	address = xmmap(size);
96	if (address == MAP_FAILED)
97		fatal("mmap(%lu): %s", (u_long)size, strerror(errno));
98
99	mm->address = address;
100	mm->size = size;
101
102	RB_INIT(&mm->rb_free);
103	RB_INIT(&mm->rb_allocated);
104
105	mm_make_entry(mm, &mm->rb_free, address, size);
106
107	return (mm);
108}
109
110/* Frees either the allocated or the free list */
111
112static void
113mm_freelist(struct mm_master *mmalloc, struct mmtree *head)
114{
115	struct mm_share *mms, *next;
116
117	for (mms = RB_ROOT(head); mms; mms = next) {
118		next = RB_NEXT(mmtree, head, mms);
119		RB_REMOVE(mmtree, head, mms);
120		if (mmalloc == NULL)
121			xfree(mms);
122		else
123			mm_free(mmalloc, mms);
124	}
125}
126
127/* Destroys a memory mapped area */
128
129void
130mm_destroy(struct mm_master *mm)
131{
132	mm_freelist(mm->mmalloc, &mm->rb_free);
133	mm_freelist(mm->mmalloc, &mm->rb_allocated);
134
135#ifdef HAVE_MMAP
136	if (munmap(mm->address, mm->size) == -1)
137		fatal("munmap(%p, %lu): %s", mm->address, (u_long)mm->size,
138		    strerror(errno));
139#else
140	fatal("%s: UsePrivilegeSeparation=yes and Compression=yes not supported",
141	    __func__);
142#endif
143	if (mm->mmalloc == NULL)
144		xfree(mm);
145	else
146		mm_free(mm->mmalloc, mm);
147}
148
149void *
150mm_xmalloc(struct mm_master *mm, size_t size)
151{
152	void *address;
153
154	address = mm_malloc(mm, size);
155	if (address == NULL)
156		fatal("%s: mm_malloc(%lu)", __func__, (u_long)size);
157	return (address);
158}
159
160
161/* Allocates data from a memory mapped area */
162
163void *
164mm_malloc(struct mm_master *mm, size_t size)
165{
166	struct mm_share *mms, *tmp;
167
168	if (size == 0)
169		fatal("mm_malloc: try to allocate 0 space");
170	if (size > SIZE_T_MAX - MM_MINSIZE + 1)
171		fatal("mm_malloc: size too big");
172
173	size = ((size + (MM_MINSIZE - 1)) / MM_MINSIZE) * MM_MINSIZE;
174
175	RB_FOREACH(mms, mmtree, &mm->rb_free) {
176		if (mms->size >= size)
177			break;
178	}
179
180	if (mms == NULL)
181		return (NULL);
182
183	/* Debug */
184	memset(mms->address, 0xd0, size);
185
186	tmp = mm_make_entry(mm, &mm->rb_allocated, mms->address, size);
187
188	/* Does not change order in RB tree */
189	mms->size -= size;
190	mms->address = (u_char *)mms->address + size;
191
192	if (mms->size == 0) {
193		RB_REMOVE(mmtree, &mm->rb_free, mms);
194		if (mm->mmalloc == NULL)
195			xfree(mms);
196		else
197			mm_free(mm->mmalloc, mms);
198	}
199
200	return (tmp->address);
201}
202
203/* Frees memory in a memory mapped area */
204
205void
206mm_free(struct mm_master *mm, void *address)
207{
208	struct mm_share *mms, *prev, tmp;
209
210	tmp.address = address;
211	mms = RB_FIND(mmtree, &mm->rb_allocated, &tmp);
212	if (mms == NULL)
213		fatal("mm_free(%p): can not find %p", mm, address);
214
215	/* Debug */
216	memset(mms->address, 0xd0, mms->size);
217
218	/* Remove from allocated list and insert in free list */
219	RB_REMOVE(mmtree, &mm->rb_allocated, mms);
220	if (RB_INSERT(mmtree, &mm->rb_free, mms) != NULL)
221		fatal("mm_free(%p): double address %p", mm, address);
222
223	/* Find previous entry */
224	prev = mms;
225	if (RB_LEFT(prev, next)) {
226		prev = RB_LEFT(prev, next);
227		while (RB_RIGHT(prev, next))
228			prev = RB_RIGHT(prev, next);
229	} else {
230		if (RB_PARENT(prev, next) &&
231		    (prev == RB_RIGHT(RB_PARENT(prev, next), next)))
232			prev = RB_PARENT(prev, next);
233		else {
234			while (RB_PARENT(prev, next) &&
235			    (prev == RB_LEFT(RB_PARENT(prev, next), next)))
236				prev = RB_PARENT(prev, next);
237			prev = RB_PARENT(prev, next);
238		}
239	}
240
241	/* Check if range does not overlap */
242	if (prev != NULL && MM_ADDRESS_END(prev) > address)
243		fatal("mm_free: memory corruption: %p(%lu) > %p",
244		    prev->address, (u_long)prev->size, address);
245
246	/* See if we can merge backwards */
247	if (prev != NULL && MM_ADDRESS_END(prev) == address) {
248		prev->size += mms->size;
249		RB_REMOVE(mmtree, &mm->rb_free, mms);
250		if (mm->mmalloc == NULL)
251			xfree(mms);
252		else
253			mm_free(mm->mmalloc, mms);
254	} else
255		prev = mms;
256
257	if (prev == NULL)
258		return;
259
260	/* Check if we can merge forwards */
261	mms = RB_NEXT(mmtree, &mm->rb_free, prev);
262	if (mms == NULL)
263		return;
264
265	if (MM_ADDRESS_END(prev) > mms->address)
266		fatal("mm_free: memory corruption: %p < %p(%lu)",
267		    mms->address, prev->address, (u_long)prev->size);
268	if (MM_ADDRESS_END(prev) != mms->address)
269		return;
270
271	prev->size += mms->size;
272	RB_REMOVE(mmtree, &mm->rb_free, mms);
273
274	if (mm->mmalloc == NULL)
275		xfree(mms);
276	else
277		mm_free(mm->mmalloc, mms);
278}
279
280static void
281mm_sync_list(struct mmtree *oldtree, struct mmtree *newtree,
282    struct mm_master *mm, struct mm_master *mmold)
283{
284	struct mm_master *mmalloc = mm->mmalloc;
285	struct mm_share *mms, *new;
286
287	/* Sync free list */
288	RB_FOREACH(mms, mmtree, oldtree) {
289		/* Check the values */
290		mm_memvalid(mmold, mms, sizeof(struct mm_share));
291		mm_memvalid(mm, mms->address, mms->size);
292
293		new = mm_xmalloc(mmalloc, sizeof(struct mm_share));
294		memcpy(new, mms, sizeof(struct mm_share));
295		RB_INSERT(mmtree, newtree, new);
296	}
297}
298
299void
300mm_share_sync(struct mm_master **pmm, struct mm_master **pmmalloc)
301{
302	struct mm_master *mm;
303	struct mm_master *mmalloc;
304	struct mm_master *mmold;
305	struct mmtree rb_free, rb_allocated;
306
307	debug3("%s: Share sync", __func__);
308
309	mm = *pmm;
310	mmold = mm->mmalloc;
311	mm_memvalid(mmold, mm, sizeof(*mm));
312
313	mmalloc = mm_create(NULL, mm->size);
314	mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
315	memcpy(mm, *pmm, sizeof(struct mm_master));
316	mm->mmalloc = mmalloc;
317
318	rb_free = mm->rb_free;
319	rb_allocated = mm->rb_allocated;
320
321	RB_INIT(&mm->rb_free);
322	RB_INIT(&mm->rb_allocated);
323
324	mm_sync_list(&rb_free, &mm->rb_free, mm, mmold);
325	mm_sync_list(&rb_allocated, &mm->rb_allocated, mm, mmold);
326
327	mm_destroy(mmold);
328
329	*pmm = mm;
330	*pmmalloc = mmalloc;
331
332	debug3("%s: Share sync end", __func__);
333}
334
335void
336mm_memvalid(struct mm_master *mm, void *address, size_t size)
337{
338	void *end = (u_char *)address + size;
339
340	if (address < mm->address)
341		fatal("mm_memvalid: address too small: %p", address);
342	if (end < address)
343		fatal("mm_memvalid: end < address: %p < %p", end, address);
344	if (end > (void *)((u_char *)mm->address + mm->size))
345		fatal("mm_memvalid: address too large: %p", address);
346}
347