monitor_mm.c revision 98675 
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#include <sys/mman.h>
30
31#include "ssh.h"
32#include "xmalloc.h"
33#include "log.h"
34#include "monitor_mm.h"
35
36static int
37mm_compare(struct mm_share *a, struct mm_share *b)
38{
39	return ((char *)a->address - (char *)b->address);
40}
41
42RB_GENERATE(mmtree, mm_share, next, mm_compare)
43
44static struct mm_share *
45mm_make_entry(struct mm_master *mm, struct mmtree *head,
46    void *address, size_t size)
47{
48	struct mm_share *tmp, *tmp2;
49
50	if (mm->mmalloc == NULL)
51		tmp = xmalloc(sizeof(struct mm_share));
52	else
53		tmp = mm_xmalloc(mm->mmalloc, sizeof(struct mm_share));
54	tmp->address = address;
55	tmp->size = size;
56
57	tmp2 = RB_INSERT(mmtree, head, tmp);
58	if (tmp2 != NULL)
59		fatal("mm_make_entry(%p): double address %p->%p(%lu)",
60		    mm, tmp2, address, (u_long)size);
61
62	return (tmp);
63}
64
65/* Creates a shared memory area of a certain size */
66
67struct mm_master *
68mm_create(struct mm_master *mmalloc, size_t size)
69{
70	void *address;
71	struct mm_master *mm;
72
73	if (mmalloc == NULL)
74		mm = xmalloc(sizeof(struct mm_master));
75	else
76		mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
77
78	/*
79	 * If the memory map has a mm_master it can be completely
80	 * shared including authentication between the child
81	 * and the client.
82	 */
83	mm->mmalloc = mmalloc;
84
85	address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_ANON|MAP_SHARED,
86	    -1, 0);
87	if (address == MAP_FAILED)
88		fatal("mmap(%lu): %s", (u_long)size, strerror(errno));
89
90	mm->address = address;
91	mm->size = size;
92
93	RB_INIT(&mm->rb_free);
94	RB_INIT(&mm->rb_allocated);
95
96	mm_make_entry(mm, &mm->rb_free, address, size);
97
98	return (mm);
99}
100
101/* Frees either the allocated or the free list */
102
103static void
104mm_freelist(struct mm_master *mmalloc, struct mmtree *head)
105{
106	struct mm_share *mms, *next;
107
108	for (mms = RB_ROOT(head); mms; mms = next) {
109		next = RB_NEXT(mmtree, head, mms);
110		RB_REMOVE(mmtree, head, mms);
111		if (mmalloc == NULL)
112			xfree(mms);
113		else
114			mm_free(mmalloc, mms);
115	}
116}
117
118/* Destroys a memory mapped area */
119
120void
121mm_destroy(struct mm_master *mm)
122{
123	mm_freelist(mm->mmalloc, &mm->rb_free);
124	mm_freelist(mm->mmalloc, &mm->rb_allocated);
125
126	if (munmap(mm->address, mm->size) == -1)
127		fatal("munmap(%p, %lu): %s", mm->address, (u_long)mm->size,
128		    strerror(errno));
129	if (mm->mmalloc == NULL)
130		xfree(mm);
131	else
132		mm_free(mm->mmalloc, mm);
133}
134
135void *
136mm_xmalloc(struct mm_master *mm, size_t size)
137{
138	void *address;
139
140	address = mm_malloc(mm, size);
141	if (address == NULL)
142		fatal("%s: mm_malloc(%lu)", __func__, (u_long)size);
143	return (address);
144}
145
146
147/* Allocates data from a memory mapped area */
148
149void *
150mm_malloc(struct mm_master *mm, size_t size)
151{
152	struct mm_share *mms, *tmp;
153
154	if (size == 0)
155		fatal("mm_malloc: try to allocate 0 space");
156
157	size = ((size + MM_MINSIZE - 1) / MM_MINSIZE) * MM_MINSIZE;
158
159	RB_FOREACH(mms, mmtree, &mm->rb_free) {
160		if (mms->size >= size)
161			break;
162	}
163
164	if (mms == NULL)
165		return (NULL);
166
167	/* Debug */
168	memset(mms->address, 0xd0, size);
169
170	tmp = mm_make_entry(mm, &mm->rb_allocated, mms->address, size);
171
172	/* Does not change order in RB tree */
173	mms->size -= size;
174	mms->address = (u_char *)mms->address + size;
175
176	if (mms->size == 0) {
177		RB_REMOVE(mmtree, &mm->rb_free, mms);
178		if (mm->mmalloc == NULL)
179			xfree(mms);
180		else
181			mm_free(mm->mmalloc, mms);
182	}
183
184	return (tmp->address);
185}
186
187/* Frees memory in a memory mapped area */
188
189void
190mm_free(struct mm_master *mm, void *address)
191{
192	struct mm_share *mms, *prev, tmp;
193
194	tmp.address = address;
195	mms = RB_FIND(mmtree, &mm->rb_allocated, &tmp);
196	if (mms == NULL)
197		fatal("mm_free(%p): can not find %p", mm, address);
198
199	/* Debug */
200	memset(mms->address, 0xd0, mms->size);
201
202	/* Remove from allocated list and insert in free list */
203	RB_REMOVE(mmtree, &mm->rb_allocated, mms);
204	if (RB_INSERT(mmtree, &mm->rb_free, mms) != NULL)
205		fatal("mm_free(%p): double address %p", mm, address);
206
207	/* Find previous entry */
208	prev = mms;
209	if (RB_LEFT(prev, next)) {
210		prev = RB_LEFT(prev, next);
211		while (RB_RIGHT(prev, next))
212			prev = RB_RIGHT(prev, next);
213	} else {
214		if (RB_PARENT(prev, next) &&
215		    (prev == RB_RIGHT(RB_PARENT(prev, next), next)))
216			prev = RB_PARENT(prev, next);
217		else {
218			while (RB_PARENT(prev, next) &&
219			    (prev == RB_LEFT(RB_PARENT(prev, next), next)))
220				prev = RB_PARENT(prev, next);
221			prev = RB_PARENT(prev, next);
222		}
223	}
224
225	/* Check if range does not overlap */
226	if (prev != NULL && MM_ADDRESS_END(prev) > address)
227		fatal("mm_free: memory corruption: %p(%lu) > %p",
228		    prev->address, (u_long)prev->size, address);
229
230	/* See if we can merge backwards */
231	if (prev != NULL && MM_ADDRESS_END(prev) == address) {
232		prev->size += mms->size;
233		RB_REMOVE(mmtree, &mm->rb_free, mms);
234		if (mm->mmalloc == NULL)
235			xfree(mms);
236		else
237			mm_free(mm->mmalloc, mms);
238	} else
239		prev = mms;
240
241	if (prev == NULL)
242		return;
243
244	/* Check if we can merge forwards */
245	mms = RB_NEXT(mmtree, &mm->rb_free, prev);
246	if (mms == NULL)
247		return;
248
249	if (MM_ADDRESS_END(prev) > mms->address)
250		fatal("mm_free: memory corruption: %p < %p(%lu)",
251		    mms->address, prev->address, (u_long)prev->size);
252	if (MM_ADDRESS_END(prev) != mms->address)
253		return;
254
255	prev->size += mms->size;
256	RB_REMOVE(mmtree, &mm->rb_free, mms);
257
258	if (mm->mmalloc == NULL)
259		xfree(mms);
260	else
261		mm_free(mm->mmalloc, mms);
262}
263
264static void
265mm_sync_list(struct mmtree *oldtree, struct mmtree *newtree,
266    struct mm_master *mm, struct mm_master *mmold)
267{
268	struct mm_master *mmalloc = mm->mmalloc;
269	struct mm_share *mms, *new;
270
271	/* Sync free list */
272	RB_FOREACH(mms, mmtree, oldtree) {
273		/* Check the values */
274		mm_memvalid(mmold, mms, sizeof(struct mm_share));
275		mm_memvalid(mm, mms->address, mms->size);
276
277		new = mm_xmalloc(mmalloc, sizeof(struct mm_share));
278		memcpy(new, mms, sizeof(struct mm_share));
279		RB_INSERT(mmtree, newtree, new);
280	}
281}
282
283void
284mm_share_sync(struct mm_master **pmm, struct mm_master **pmmalloc)
285{
286	struct mm_master *mm;
287	struct mm_master *mmalloc;
288	struct mm_master *mmold;
289	struct mmtree rb_free, rb_allocated;
290
291	debug3("%s: Share sync", __func__);
292
293	mm = *pmm;
294	mmold = mm->mmalloc;
295	mm_memvalid(mmold, mm, sizeof(*mm));
296
297	mmalloc = mm_create(NULL, mm->size);
298	mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
299	memcpy(mm, *pmm, sizeof(struct mm_master));
300	mm->mmalloc = mmalloc;
301
302	rb_free = mm->rb_free;
303	rb_allocated = mm->rb_allocated;
304
305	RB_INIT(&mm->rb_free);
306	RB_INIT(&mm->rb_allocated);
307
308	mm_sync_list(&rb_free, &mm->rb_free, mm, mmold);
309	mm_sync_list(&rb_allocated, &mm->rb_allocated, mm, mmold);
310
311	mm_destroy(mmold);
312
313	*pmm = mm;
314	*pmmalloc = mmalloc;
315
316	debug3("%s: Share sync end", __func__);
317}
318
319void
320mm_memvalid(struct mm_master *mm, void *address, size_t size)
321{
322	void *end = (u_char *)address + size;
323
324	if (address < mm->address)
325		fatal("mm_memvalid: address too small: %p", address);
326	if (end < address)
327		fatal("mm_memvalid: end < address: %p < %p", end, address);
328	if (end > (void *)((u_char *)mm->address + mm->size))
329		fatal("mm_memvalid: address too large: %p", address);
330}
331