monitor_mm.c revision 99060 
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 1.6 2002/06/04 23:05:49 markus Exp $");
28
29#ifdef HAVE_SYS_MMAN_H
30#include <sys/mman.h>
31#endif
32
33#include "ssh.h"
34#include "xmalloc.h"
35#include "log.h"
36#include "monitor_mm.h"
37
38static int
39mm_compare(struct mm_share *a, struct mm_share *b)
40{
41	return ((char *)a->address - (char *)b->address);
42}
43
44RB_GENERATE(mmtree, mm_share, next, mm_compare)
45
46static struct mm_share *
47mm_make_entry(struct mm_master *mm, struct mmtree *head,
48    void *address, size_t size)
49{
50	struct mm_share *tmp, *tmp2;
51
52	if (mm->mmalloc == NULL)
53		tmp = xmalloc(sizeof(struct mm_share));
54	else
55		tmp = mm_xmalloc(mm->mmalloc, sizeof(struct mm_share));
56	tmp->address = address;
57	tmp->size = size;
58
59	tmp2 = RB_INSERT(mmtree, head, tmp);
60	if (tmp2 != NULL)
61		fatal("mm_make_entry(%p): double address %p->%p(%lu)",
62		    mm, tmp2, address, (u_long)size);
63
64	return (tmp);
65}
66
67/* Creates a shared memory area of a certain size */
68
69struct mm_master *
70mm_create(struct mm_master *mmalloc, size_t size)
71{
72	void *address;
73	struct mm_master *mm;
74
75	if (mmalloc == NULL)
76		mm = xmalloc(sizeof(struct mm_master));
77	else
78		mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
79
80	/*
81	 * If the memory map has a mm_master it can be completely
82	 * shared including authentication between the child
83	 * and the client.
84	 */
85	mm->mmalloc = mmalloc;
86
87#ifdef HAVE_MMAP_ANON_SHARED
88	address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_ANON|MAP_SHARED,
89	    -1, 0);
90	if (address == MAP_FAILED)
91		fatal("mmap(%lu): %s", (u_long)size, strerror(errno));
92#else
93	fatal("%s: UsePrivilegeSeparation=yes and Compression=yes not supported",
94	    __func__);
95#endif
96
97	mm->address = address;
98	mm->size = size;
99
100	RB_INIT(&mm->rb_free);
101	RB_INIT(&mm->rb_allocated);
102
103	mm_make_entry(mm, &mm->rb_free, address, size);
104
105	return (mm);
106}
107
108/* Frees either the allocated or the free list */
109
110static void
111mm_freelist(struct mm_master *mmalloc, struct mmtree *head)
112{
113	struct mm_share *mms, *next;
114
115	for (mms = RB_ROOT(head); mms; mms = next) {
116		next = RB_NEXT(mmtree, head, mms);
117		RB_REMOVE(mmtree, head, mms);
118		if (mmalloc == NULL)
119			xfree(mms);
120		else
121			mm_free(mmalloc, mms);
122	}
123}
124
125/* Destroys a memory mapped area */
126
127void
128mm_destroy(struct mm_master *mm)
129{
130	mm_freelist(mm->mmalloc, &mm->rb_free);
131	mm_freelist(mm->mmalloc, &mm->rb_allocated);
132
133#ifdef HAVE_MMAP_ANON_SHARED
134	if (munmap(mm->address, mm->size) == -1)
135		fatal("munmap(%p, %lu): %s", mm->address, (u_long)mm->size,
136		    strerror(errno));
137#else
138	fatal("%s: UsePrivilegeSeparation=yes and Compression=yes not supported",
139	    __func__);
140#endif
141	if (mm->mmalloc == NULL)
142		xfree(mm);
143	else
144		mm_free(mm->mmalloc, mm);
145}
146
147void *
148mm_xmalloc(struct mm_master *mm, size_t size)
149{
150	void *address;
151
152	address = mm_malloc(mm, size);
153	if (address == NULL)
154		fatal("%s: mm_malloc(%lu)", __func__, (u_long)size);
155	return (address);
156}
157
158
159/* Allocates data from a memory mapped area */
160
161void *
162mm_malloc(struct mm_master *mm, size_t size)
163{
164	struct mm_share *mms, *tmp;
165
166	if (size == 0)
167		fatal("mm_malloc: try to allocate 0 space");
168
169	size = ((size + MM_MINSIZE - 1) / MM_MINSIZE) * MM_MINSIZE;
170
171	RB_FOREACH(mms, mmtree, &mm->rb_free) {
172		if (mms->size >= size)
173			break;
174	}
175
176	if (mms == NULL)
177		return (NULL);
178
179	/* Debug */
180	memset(mms->address, 0xd0, size);
181
182	tmp = mm_make_entry(mm, &mm->rb_allocated, mms->address, size);
183
184	/* Does not change order in RB tree */
185	mms->size -= size;
186	mms->address = (u_char *)mms->address + size;
187
188	if (mms->size == 0) {
189		RB_REMOVE(mmtree, &mm->rb_free, mms);
190		if (mm->mmalloc == NULL)
191			xfree(mms);
192		else
193			mm_free(mm->mmalloc, mms);
194	}
195
196	return (tmp->address);
197}
198
199/* Frees memory in a memory mapped area */
200
201void
202mm_free(struct mm_master *mm, void *address)
203{
204	struct mm_share *mms, *prev, tmp;
205
206	tmp.address = address;
207	mms = RB_FIND(mmtree, &mm->rb_allocated, &tmp);
208	if (mms == NULL)
209		fatal("mm_free(%p): can not find %p", mm, address);
210
211	/* Debug */
212	memset(mms->address, 0xd0, mms->size);
213
214	/* Remove from allocated list and insert in free list */
215	RB_REMOVE(mmtree, &mm->rb_allocated, mms);
216	if (RB_INSERT(mmtree, &mm->rb_free, mms) != NULL)
217		fatal("mm_free(%p): double address %p", mm, address);
218
219	/* Find previous entry */
220	prev = mms;
221	if (RB_LEFT(prev, next)) {
222		prev = RB_LEFT(prev, next);
223		while (RB_RIGHT(prev, next))
224			prev = RB_RIGHT(prev, next);
225	} else {
226		if (RB_PARENT(prev, next) &&
227		    (prev == RB_RIGHT(RB_PARENT(prev, next), next)))
228			prev = RB_PARENT(prev, next);
229		else {
230			while (RB_PARENT(prev, next) &&
231			    (prev == RB_LEFT(RB_PARENT(prev, next), next)))
232				prev = RB_PARENT(prev, next);
233			prev = RB_PARENT(prev, next);
234		}
235	}
236
237	/* Check if range does not overlap */
238	if (prev != NULL && MM_ADDRESS_END(prev) > address)
239		fatal("mm_free: memory corruption: %p(%lu) > %p",
240		    prev->address, (u_long)prev->size, address);
241
242	/* See if we can merge backwards */
243	if (prev != NULL && MM_ADDRESS_END(prev) == address) {
244		prev->size += mms->size;
245		RB_REMOVE(mmtree, &mm->rb_free, mms);
246		if (mm->mmalloc == NULL)
247			xfree(mms);
248		else
249			mm_free(mm->mmalloc, mms);
250	} else
251		prev = mms;
252
253	if (prev == NULL)
254		return;
255
256	/* Check if we can merge forwards */
257	mms = RB_NEXT(mmtree, &mm->rb_free, prev);
258	if (mms == NULL)
259		return;
260
261	if (MM_ADDRESS_END(prev) > mms->address)
262		fatal("mm_free: memory corruption: %p < %p(%lu)",
263		    mms->address, prev->address, (u_long)prev->size);
264	if (MM_ADDRESS_END(prev) != mms->address)
265		return;
266
267	prev->size += mms->size;
268	RB_REMOVE(mmtree, &mm->rb_free, mms);
269
270	if (mm->mmalloc == NULL)
271		xfree(mms);
272	else
273		mm_free(mm->mmalloc, mms);
274}
275
276static void
277mm_sync_list(struct mmtree *oldtree, struct mmtree *newtree,
278    struct mm_master *mm, struct mm_master *mmold)
279{
280	struct mm_master *mmalloc = mm->mmalloc;
281	struct mm_share *mms, *new;
282
283	/* Sync free list */
284	RB_FOREACH(mms, mmtree, oldtree) {
285		/* Check the values */
286		mm_memvalid(mmold, mms, sizeof(struct mm_share));
287		mm_memvalid(mm, mms->address, mms->size);
288
289		new = mm_xmalloc(mmalloc, sizeof(struct mm_share));
290		memcpy(new, mms, sizeof(struct mm_share));
291		RB_INSERT(mmtree, newtree, new);
292	}
293}
294
295void
296mm_share_sync(struct mm_master **pmm, struct mm_master **pmmalloc)
297{
298	struct mm_master *mm;
299	struct mm_master *mmalloc;
300	struct mm_master *mmold;
301	struct mmtree rb_free, rb_allocated;
302
303	debug3("%s: Share sync", __func__);
304
305	mm = *pmm;
306	mmold = mm->mmalloc;
307	mm_memvalid(mmold, mm, sizeof(*mm));
308
309	mmalloc = mm_create(NULL, mm->size);
310	mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
311	memcpy(mm, *pmm, sizeof(struct mm_master));
312	mm->mmalloc = mmalloc;
313
314	rb_free = mm->rb_free;
315	rb_allocated = mm->rb_allocated;
316
317	RB_INIT(&mm->rb_free);
318	RB_INIT(&mm->rb_allocated);
319
320	mm_sync_list(&rb_free, &mm->rb_free, mm, mmold);
321	mm_sync_list(&rb_allocated, &mm->rb_allocated, mm, mmold);
322
323	mm_destroy(mmold);
324
325	*pmm = mm;
326	*pmmalloc = mmalloc;
327
328	debug3("%s: Share sync end", __func__);
329}
330
331void
332mm_memvalid(struct mm_master *mm, void *address, size_t size)
333{
334	void *end = (u_char *)address + size;
335
336	if (address < mm->address)
337		fatal("mm_memvalid: address too small: %p", address);
338	if (end < address)
339		fatal("mm_memvalid: end < address: %p < %p", end, address);
340	if (end > (void *)((u_char *)mm->address + mm->size))
341		fatal("mm_memvalid: address too large: %p", address);
342}
343