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source: vbox/trunk/src/libs/openssl-3.1.5/crypto/mem_sec.c@ 104078

Last change on this file since 104078 was 104078, checked in by vboxsync, 8 months ago

openssl-3.1.5: Applied and adjusted our OpenSSL changes to 3.1.4. bugref:10638

File size: 19.9 KB
Line 
1/*
2 * Copyright 2015-2023 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright 2004-2014, Akamai Technologies. All Rights Reserved.
4 *
5 * Licensed under the Apache License 2.0 (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
9 */
10
11/*
12 * This file is in two halves. The first half implements the public API
13 * to be used by external consumers, and to be used by OpenSSL to store
14 * data in a "secure arena." The second half implements the secure arena.
15 * For details on that implementation, see below (look for uppercase
16 * "SECURE HEAP IMPLEMENTATION").
17 */
18#include "internal/e_os.h"
19#include <openssl/crypto.h>
20
21#include <string.h>
22
23#if defined(VBOX)
24# include <iprt/memsafer.h>
25#else
26#ifndef OPENSSL_NO_SECURE_MEMORY
27# if defined(_WIN32)
28# include <windows.h>
29# if defined(WINAPI_FAMILY_PARTITION)
30# if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP | WINAPI_PARTITION_SYSTEM)
31/*
32 * While VirtualLock is available under the app partition (e.g. UWP),
33 * the headers do not define the API. Define it ourselves instead.
34 */
35WINBASEAPI
36BOOL
37WINAPI
38VirtualLock(
39 _In_ LPVOID lpAddress,
40 _In_ SIZE_T dwSize
41 );
42# endif
43# endif
44# endif
45# include <stdlib.h>
46# include <assert.h>
47# if defined(OPENSSL_SYS_UNIX)
48# include <unistd.h>
49# endif
50# include <sys/types.h>
51# if defined(OPENSSL_SYS_UNIX)
52# include <sys/mman.h>
53# if defined(__FreeBSD__)
54# define MADV_DONTDUMP MADV_NOCORE
55# endif
56# if !defined(MAP_CONCEAL)
57# define MAP_CONCEAL 0
58# endif
59# endif
60# if defined(OPENSSL_SYS_LINUX)
61# include <sys/syscall.h>
62# if defined(SYS_mlock2)
63# include <linux/mman.h>
64# include <errno.h>
65# endif
66# include <sys/param.h>
67# endif
68# include <sys/stat.h>
69# include <fcntl.h>
70#endif
71#endif /* !VBOX */
72
73#define CLEAR(p, s) OPENSSL_cleanse(p, s)
74#ifndef PAGE_SIZE
75# define PAGE_SIZE 4096
76#endif
77#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
78# define MAP_ANON MAP_ANONYMOUS
79#endif
80
81#ifndef OPENSSL_NO_SECURE_MEMORY
82static size_t secure_mem_used;
83
84static int secure_mem_initialized;
85
86static CRYPTO_RWLOCK *sec_malloc_lock = NULL;
87
88/*
89 * These are the functions that must be implemented by a secure heap (sh).
90 */
91static int sh_init(size_t size, size_t minsize);
92static void *sh_malloc(size_t size);
93static void sh_free(void *ptr);
94static void sh_done(void);
95static size_t sh_actual_size(char *ptr);
96static int sh_allocated(const char *ptr);
97#endif
98
99int CRYPTO_secure_malloc_init(size_t size, size_t minsize)
100{
101#ifndef VBOX
102#ifndef OPENSSL_NO_SECURE_MEMORY
103 int ret = 0;
104
105 if (!secure_mem_initialized) {
106 sec_malloc_lock = CRYPTO_THREAD_lock_new();
107 if (sec_malloc_lock == NULL)
108 return 0;
109 if ((ret = sh_init(size, minsize)) != 0) {
110 secure_mem_initialized = 1;
111 } else {
112 CRYPTO_THREAD_lock_free(sec_malloc_lock);
113 sec_malloc_lock = NULL;
114 }
115 }
116
117 return ret;
118#else
119 return 0;
120#endif /* OPENSSL_NO_SECURE_MEMORY */
121#else
122 return 0;
123#endif /* VBOX */
124}
125
126int CRYPTO_secure_malloc_done(void)
127{
128#ifndef VBOX
129#ifndef OPENSSL_NO_SECURE_MEMORY
130 if (secure_mem_used == 0) {
131 sh_done();
132 secure_mem_initialized = 0;
133 CRYPTO_THREAD_lock_free(sec_malloc_lock);
134 sec_malloc_lock = NULL;
135 return 1;
136 }
137#endif /* OPENSSL_NO_SECURE_MEMORY */
138#endif /* VBOX */
139 return 0;
140}
141
142int CRYPTO_secure_malloc_initialized(void)
143{
144#ifndef VBOX
145#ifndef OPENSSL_NO_SECURE_MEMORY
146 return secure_mem_initialized;
147#else
148 return 0;
149#endif /* OPENSSL_NO_SECURE_MEMORY */
150#else
151 return 0;
152#endif /* VBOX */
153}
154
155void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
156{
157#ifndef VBOX
158#ifndef OPENSSL_NO_SECURE_MEMORY
159 void *ret;
160 size_t actual_size;
161
162 if (!secure_mem_initialized) {
163 return CRYPTO_malloc(num, file, line);
164 }
165 if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
166 return NULL;
167 ret = sh_malloc(num);
168 actual_size = ret ? sh_actual_size(ret) : 0;
169 secure_mem_used += actual_size;
170 CRYPTO_THREAD_unlock(sec_malloc_lock);
171 return ret;
172#else
173 return CRYPTO_malloc(num, file, line);
174#endif /* OPENSSL_NO_SECURE_MEMORY */
175#else
176 RT_NOREF(line);
177 return RTMemSaferAllocZTag(num, file);
178#endif /* VBOX */
179}
180
181void *CRYPTO_secure_zalloc(size_t num, const char *file, int line)
182{
183#ifndef VBOX
184#ifndef OPENSSL_NO_SECURE_MEMORY
185 if (secure_mem_initialized)
186 /* CRYPTO_secure_malloc() zeroes allocations when it is implemented */
187 return CRYPTO_secure_malloc(num, file, line);
188#endif
189 return CRYPTO_zalloc(num, file, line);
190#else
191 RT_NOREF(line);
192 return RTMemSaferAllocZTag(num, file);
193#endif
194}
195
196void CRYPTO_secure_free(void *ptr, const char *file, int line)
197{
198#ifndef VBOX
199#ifndef OPENSSL_NO_SECURE_MEMORY
200 size_t actual_size;
201
202 if (ptr == NULL)
203 return;
204 if (!CRYPTO_secure_allocated(ptr)) {
205 CRYPTO_free(ptr, file, line);
206 return;
207 }
208 if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
209 return;
210 actual_size = sh_actual_size(ptr);
211 CLEAR(ptr, actual_size);
212 secure_mem_used -= actual_size;
213 sh_free(ptr);
214 CRYPTO_THREAD_unlock(sec_malloc_lock);
215#else
216 CRYPTO_free(ptr, file, line);
217#endif /* OPENSSL_NO_SECURE_MEMORY */
218#else
219 RT_NOREF(line);
220 RTMemSaferFree(ptr, 0);
221#endif /* VBOX */
222}
223
224void CRYPTO_secure_clear_free(void *ptr, size_t num,
225 const char *file, int line)
226{
227#ifndef VBOX
228#ifndef OPENSSL_NO_SECURE_MEMORY
229 size_t actual_size;
230
231 if (ptr == NULL)
232 return;
233 if (!CRYPTO_secure_allocated(ptr)) {
234 OPENSSL_cleanse(ptr, num);
235 CRYPTO_free(ptr, file, line);
236 return;
237 }
238 if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
239 return;
240 actual_size = sh_actual_size(ptr);
241 CLEAR(ptr, actual_size);
242 secure_mem_used -= actual_size;
243 sh_free(ptr);
244 CRYPTO_THREAD_unlock(sec_malloc_lock);
245#else
246 if (ptr == NULL)
247 return;
248 OPENSSL_cleanse(ptr, num);
249 CRYPTO_free(ptr, file, line);
250#endif /* OPENSSL_NO_SECURE_MEMORY */
251#else
252 RT_NOREF(line);
253 RTMemSaferFree(ptr, 0);
254#endif /* VBOX */
255}
256
257int CRYPTO_secure_allocated(const void *ptr)
258{
259#ifndef VBOX
260#ifndef OPENSSL_NO_SECURE_MEMORY
261 if (!secure_mem_initialized)
262 return 0;
263 /*
264 * Only read accesses to the arena take place in sh_allocated() and this
265 * is only changed by the sh_init() and sh_done() calls which are not
266 * locked. Hence, it is safe to make this check without a lock too.
267 */
268 return sh_allocated(ptr);
269#else
270 return 0;
271#endif /* OPENSSL_NO_SECURE_MEMORY */
272#else
273 return RTMemSaferGetSize((void *)ptr) > 0;
274#endif /* VBOX */
275}
276
277size_t CRYPTO_secure_used(void)
278{
279#ifndef VBOX
280#ifndef OPENSSL_NO_SECURE_MEMORY
281 if (!CRYPTO_THREAD_read_lock(sec_malloc_lock))
282 return 0;
283
284 ret = secure_mem_used;
285
286 CRYPTO_THREAD_unlock(sec_malloc_lock);
287#endif /* OPENSSL_NO_SECURE_MEMORY */
288#else
289 return 0;
290#endif /* VBOX */
291}
292
293size_t CRYPTO_secure_actual_size(void *ptr)
294{
295#ifndef VBOX
296#ifndef OPENSSL_NO_SECURE_MEMORY
297 size_t actual_size;
298
299 if (!CRYPTO_THREAD_write_lock(sec_malloc_lock))
300 return 0;
301 actual_size = sh_actual_size(ptr);
302 CRYPTO_THREAD_unlock(sec_malloc_lock);
303 return actual_size;
304#else
305 return 0;
306#endif
307#else
308 return RTMemSaferGetSize(ptr);
309#endif /* VBOX */
310}
311
312#ifndef VBOX
313/*
314 * SECURE HEAP IMPLEMENTATION
315 */
316#ifndef OPENSSL_NO_SECURE_MEMORY
317
318
319/*
320 * The implementation provided here uses a fixed-sized mmap() heap,
321 * which is locked into memory, not written to core files, and protected
322 * on either side by an unmapped page, which will catch pointer overruns
323 * (or underruns) and an attempt to read data out of the secure heap.
324 * Free'd memory is zero'd or otherwise cleansed.
325 *
326 * This is a pretty standard buddy allocator. We keep areas in a multiple
327 * of "sh.minsize" units. The freelist and bitmaps are kept separately,
328 * so all (and only) data is kept in the mmap'd heap.
329 *
330 * This code assumes eight-bit bytes. The numbers 3 and 7 are all over the
331 * place.
332 */
333
334#define ONE ((size_t)1)
335
336# define TESTBIT(t, b) (t[(b) >> 3] & (ONE << ((b) & 7)))
337# define SETBIT(t, b) (t[(b) >> 3] |= (ONE << ((b) & 7)))
338# define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(ONE << ((b) & 7))))
339
340#define WITHIN_ARENA(p) \
341 ((char*)(p) >= sh.arena && (char*)(p) < &sh.arena[sh.arena_size])
342#define WITHIN_FREELIST(p) \
343 ((char*)(p) >= (char*)sh.freelist && (char*)(p) < (char*)&sh.freelist[sh.freelist_size])
344
345
346typedef struct sh_list_st
347{
348 struct sh_list_st *next;
349 struct sh_list_st **p_next;
350} SH_LIST;
351
352typedef struct sh_st
353{
354 char* map_result;
355 size_t map_size;
356 char *arena;
357 size_t arena_size;
358 char **freelist;
359 ossl_ssize_t freelist_size;
360 size_t minsize;
361 unsigned char *bittable;
362 unsigned char *bitmalloc;
363 size_t bittable_size; /* size in bits */
364} SH;
365
366static SH sh;
367
368static size_t sh_getlist(char *ptr)
369{
370 ossl_ssize_t list = sh.freelist_size - 1;
371 size_t bit = (sh.arena_size + ptr - sh.arena) / sh.minsize;
372
373 for (; bit; bit >>= 1, list--) {
374 if (TESTBIT(sh.bittable, bit))
375 break;
376 OPENSSL_assert((bit & 1) == 0);
377 }
378
379 return list;
380}
381
382
383static int sh_testbit(char *ptr, int list, unsigned char *table)
384{
385 size_t bit;
386
387 OPENSSL_assert(list >= 0 && list < sh.freelist_size);
388 OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
389 bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
390 OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
391 return TESTBIT(table, bit);
392}
393
394static void sh_clearbit(char *ptr, int list, unsigned char *table)
395{
396 size_t bit;
397
398 OPENSSL_assert(list >= 0 && list < sh.freelist_size);
399 OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
400 bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
401 OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
402 OPENSSL_assert(TESTBIT(table, bit));
403 CLEARBIT(table, bit);
404}
405
406static void sh_setbit(char *ptr, int list, unsigned char *table)
407{
408 size_t bit;
409
410 OPENSSL_assert(list >= 0 && list < sh.freelist_size);
411 OPENSSL_assert(((ptr - sh.arena) & ((sh.arena_size >> list) - 1)) == 0);
412 bit = (ONE << list) + ((ptr - sh.arena) / (sh.arena_size >> list));
413 OPENSSL_assert(bit > 0 && bit < sh.bittable_size);
414 OPENSSL_assert(!TESTBIT(table, bit));
415 SETBIT(table, bit);
416}
417
418static void sh_add_to_list(char **list, char *ptr)
419{
420 SH_LIST *temp;
421
422 OPENSSL_assert(WITHIN_FREELIST(list));
423 OPENSSL_assert(WITHIN_ARENA(ptr));
424
425 temp = (SH_LIST *)ptr;
426 temp->next = *(SH_LIST **)list;
427 OPENSSL_assert(temp->next == NULL || WITHIN_ARENA(temp->next));
428 temp->p_next = (SH_LIST **)list;
429
430 if (temp->next != NULL) {
431 OPENSSL_assert((char **)temp->next->p_next == list);
432 temp->next->p_next = &(temp->next);
433 }
434
435 *list = ptr;
436}
437
438static void sh_remove_from_list(char *ptr)
439{
440 SH_LIST *temp, *temp2;
441
442 temp = (SH_LIST *)ptr;
443 if (temp->next != NULL)
444 temp->next->p_next = temp->p_next;
445 *temp->p_next = temp->next;
446 if (temp->next == NULL)
447 return;
448
449 temp2 = temp->next;
450 OPENSSL_assert(WITHIN_FREELIST(temp2->p_next) || WITHIN_ARENA(temp2->p_next));
451}
452
453
454static int sh_init(size_t size, size_t minsize)
455{
456 int ret;
457 size_t i;
458 size_t pgsize;
459 size_t aligned;
460#if defined(_WIN32)
461 DWORD flOldProtect;
462 SYSTEM_INFO systemInfo;
463#endif
464
465 memset(&sh, 0, sizeof(sh));
466
467 /* make sure size is a powers of 2 */
468 OPENSSL_assert(size > 0);
469 OPENSSL_assert((size & (size - 1)) == 0);
470 if (size == 0 || (size & (size - 1)) != 0)
471 goto err;
472
473 if (minsize <= sizeof(SH_LIST)) {
474 OPENSSL_assert(sizeof(SH_LIST) <= 65536);
475 /*
476 * Compute the minimum possible allocation size.
477 * This must be a power of 2 and at least as large as the SH_LIST
478 * structure.
479 */
480 minsize = sizeof(SH_LIST) - 1;
481 minsize |= minsize >> 1;
482 minsize |= minsize >> 2;
483 if (sizeof(SH_LIST) > 16)
484 minsize |= minsize >> 4;
485 if (sizeof(SH_LIST) > 256)
486 minsize |= minsize >> 8;
487 minsize++;
488 } else {
489 /* make sure minsize is a powers of 2 */
490 OPENSSL_assert((minsize & (minsize - 1)) == 0);
491 if ((minsize & (minsize - 1)) != 0)
492 goto err;
493 }
494
495 sh.arena_size = size;
496 sh.minsize = minsize;
497 sh.bittable_size = (sh.arena_size / sh.minsize) * 2;
498
499 /* Prevent allocations of size 0 later on */
500 if (sh.bittable_size >> 3 == 0)
501 goto err;
502
503 sh.freelist_size = -1;
504 for (i = sh.bittable_size; i; i >>= 1)
505 sh.freelist_size++;
506
507 sh.freelist = OPENSSL_zalloc(sh.freelist_size * sizeof(char *));
508 OPENSSL_assert(sh.freelist != NULL);
509 if (sh.freelist == NULL)
510 goto err;
511
512 sh.bittable = OPENSSL_zalloc(sh.bittable_size >> 3);
513 OPENSSL_assert(sh.bittable != NULL);
514 if (sh.bittable == NULL)
515 goto err;
516
517 sh.bitmalloc = OPENSSL_zalloc(sh.bittable_size >> 3);
518 OPENSSL_assert(sh.bitmalloc != NULL);
519 if (sh.bitmalloc == NULL)
520 goto err;
521
522 /* Allocate space for heap, and two extra pages as guards */
523#if defined(_SC_PAGE_SIZE) || defined (_SC_PAGESIZE)
524 {
525# if defined(_SC_PAGE_SIZE)
526 long tmppgsize = sysconf(_SC_PAGE_SIZE);
527# else
528 long tmppgsize = sysconf(_SC_PAGESIZE);
529# endif
530 if (tmppgsize < 1)
531 pgsize = PAGE_SIZE;
532 else
533 pgsize = (size_t)tmppgsize;
534 }
535#elif defined(_WIN32)
536 GetSystemInfo(&systemInfo);
537 pgsize = (size_t)systemInfo.dwPageSize;
538#else
539 pgsize = PAGE_SIZE;
540#endif
541 sh.map_size = pgsize + sh.arena_size + pgsize;
542
543#if !defined(_WIN32)
544# ifdef MAP_ANON
545 sh.map_result = mmap(NULL, sh.map_size,
546 PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE|MAP_CONCEAL, -1, 0);
547# else
548 {
549 int fd;
550
551 sh.map_result = MAP_FAILED;
552 if ((fd = open("/dev/zero", O_RDWR)) >= 0) {
553 sh.map_result = mmap(NULL, sh.map_size,
554 PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
555 close(fd);
556 }
557 }
558# endif
559 if (sh.map_result == MAP_FAILED)
560 goto err;
561#else
562 sh.map_result = VirtualAlloc(NULL, sh.map_size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
563
564 if (sh.map_result == NULL)
565 goto err;
566#endif
567
568 sh.arena = (char *)(sh.map_result + pgsize);
569 sh_setbit(sh.arena, 0, sh.bittable);
570 sh_add_to_list(&sh.freelist[0], sh.arena);
571
572 /* Now try to add guard pages and lock into memory. */
573 ret = 1;
574
575#if !defined(_WIN32)
576 /* Starting guard is already aligned from mmap. */
577 if (mprotect(sh.map_result, pgsize, PROT_NONE) < 0)
578 ret = 2;
579#else
580 if (VirtualProtect(sh.map_result, pgsize, PAGE_NOACCESS, &flOldProtect) == FALSE)
581 ret = 2;
582#endif
583
584 /* Ending guard page - need to round up to page boundary */
585 aligned = (pgsize + sh.arena_size + (pgsize - 1)) & ~(pgsize - 1);
586#if !defined(_WIN32)
587 if (mprotect(sh.map_result + aligned, pgsize, PROT_NONE) < 0)
588 ret = 2;
589#else
590 if (VirtualProtect(sh.map_result + aligned, pgsize, PAGE_NOACCESS, &flOldProtect) == FALSE)
591 ret = 2;
592#endif
593
594#if defined(OPENSSL_SYS_LINUX) && defined(MLOCK_ONFAULT) && defined(SYS_mlock2)
595 if (syscall(SYS_mlock2, sh.arena, sh.arena_size, MLOCK_ONFAULT) < 0) {
596 if (errno == ENOSYS) {
597 if (mlock(sh.arena, sh.arena_size) < 0)
598 ret = 2;
599 } else {
600 ret = 2;
601 }
602 }
603#elif defined(_WIN32)
604 if (VirtualLock(sh.arena, sh.arena_size) == FALSE)
605 ret = 2;
606#else
607 if (mlock(sh.arena, sh.arena_size) < 0)
608 ret = 2;
609#endif
610#ifdef MADV_DONTDUMP
611 if (madvise(sh.arena, sh.arena_size, MADV_DONTDUMP) < 0)
612 ret = 2;
613#endif
614
615 return ret;
616
617 err:
618 sh_done();
619 return 0;
620}
621
622static void sh_done(void)
623{
624 OPENSSL_free(sh.freelist);
625 OPENSSL_free(sh.bittable);
626 OPENSSL_free(sh.bitmalloc);
627#if !defined(_WIN32)
628 if (sh.map_result != MAP_FAILED && sh.map_size)
629 munmap(sh.map_result, sh.map_size);
630#else
631 if (sh.map_result != NULL && sh.map_size)
632 VirtualFree(sh.map_result, 0, MEM_RELEASE);
633#endif
634 memset(&sh, 0, sizeof(sh));
635}
636
637static int sh_allocated(const char *ptr)
638{
639 return WITHIN_ARENA(ptr) ? 1 : 0;
640}
641
642static char *sh_find_my_buddy(char *ptr, int list)
643{
644 size_t bit;
645 char *chunk = NULL;
646
647 bit = (ONE << list) + (ptr - sh.arena) / (sh.arena_size >> list);
648 bit ^= 1;
649
650 if (TESTBIT(sh.bittable, bit) && !TESTBIT(sh.bitmalloc, bit))
651 chunk = sh.arena + ((bit & ((ONE << list) - 1)) * (sh.arena_size >> list));
652
653 return chunk;
654}
655
656static void *sh_malloc(size_t size)
657{
658 ossl_ssize_t list, slist;
659 size_t i;
660 char *chunk;
661
662 if (size > sh.arena_size)
663 return NULL;
664
665 list = sh.freelist_size - 1;
666 for (i = sh.minsize; i < size; i <<= 1)
667 list--;
668 if (list < 0)
669 return NULL;
670
671 /* try to find a larger entry to split */
672 for (slist = list; slist >= 0; slist--)
673 if (sh.freelist[slist] != NULL)
674 break;
675 if (slist < 0)
676 return NULL;
677
678 /* split larger entry */
679 while (slist != list) {
680 char *temp = sh.freelist[slist];
681
682 /* remove from bigger list */
683 OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
684 sh_clearbit(temp, slist, sh.bittable);
685 sh_remove_from_list(temp);
686 OPENSSL_assert(temp != sh.freelist[slist]);
687
688 /* done with bigger list */
689 slist++;
690
691 /* add to smaller list */
692 OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
693 sh_setbit(temp, slist, sh.bittable);
694 sh_add_to_list(&sh.freelist[slist], temp);
695 OPENSSL_assert(sh.freelist[slist] == temp);
696
697 /* split in 2 */
698 temp += sh.arena_size >> slist;
699 OPENSSL_assert(!sh_testbit(temp, slist, sh.bitmalloc));
700 sh_setbit(temp, slist, sh.bittable);
701 sh_add_to_list(&sh.freelist[slist], temp);
702 OPENSSL_assert(sh.freelist[slist] == temp);
703
704 OPENSSL_assert(temp-(sh.arena_size >> slist) == sh_find_my_buddy(temp, slist));
705 }
706
707 /* peel off memory to hand back */
708 chunk = sh.freelist[list];
709 OPENSSL_assert(sh_testbit(chunk, list, sh.bittable));
710 sh_setbit(chunk, list, sh.bitmalloc);
711 sh_remove_from_list(chunk);
712
713 OPENSSL_assert(WITHIN_ARENA(chunk));
714
715 /* zero the free list header as a precaution against information leakage */
716 memset(chunk, 0, sizeof(SH_LIST));
717
718 return chunk;
719}
720
721static void sh_free(void *ptr)
722{
723 size_t list;
724 void *buddy;
725
726 if (ptr == NULL)
727 return;
728 OPENSSL_assert(WITHIN_ARENA(ptr));
729 if (!WITHIN_ARENA(ptr))
730 return;
731
732 list = sh_getlist(ptr);
733 OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
734 sh_clearbit(ptr, list, sh.bitmalloc);
735 sh_add_to_list(&sh.freelist[list], ptr);
736
737 /* Try to coalesce two adjacent free areas. */
738 while ((buddy = sh_find_my_buddy(ptr, list)) != NULL) {
739 OPENSSL_assert(ptr == sh_find_my_buddy(buddy, list));
740 OPENSSL_assert(ptr != NULL);
741 OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
742 sh_clearbit(ptr, list, sh.bittable);
743 sh_remove_from_list(ptr);
744 OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
745 sh_clearbit(buddy, list, sh.bittable);
746 sh_remove_from_list(buddy);
747
748 list--;
749
750 /* Zero the higher addressed block's free list pointers */
751 memset(ptr > buddy ? ptr : buddy, 0, sizeof(SH_LIST));
752 if (ptr > buddy)
753 ptr = buddy;
754
755 OPENSSL_assert(!sh_testbit(ptr, list, sh.bitmalloc));
756 sh_setbit(ptr, list, sh.bittable);
757 sh_add_to_list(&sh.freelist[list], ptr);
758 OPENSSL_assert(sh.freelist[list] == ptr);
759 }
760}
761
762static size_t sh_actual_size(char *ptr)
763{
764 int list;
765
766 OPENSSL_assert(WITHIN_ARENA(ptr));
767 if (!WITHIN_ARENA(ptr))
768 return 0;
769 list = sh_getlist(ptr);
770 OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
771 return sh.arena_size / (ONE << list);
772}
773#endif /* OPENSSL_NO_SECURE_MEMORY */
774#endif /* VBOX */
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