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godot/thirdparty/mbedtls/library/memory_buffer_alloc.c

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/*
* Buffer-based memory allocator
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
#include "common.h"
#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
#include "mbedtls/memory_buffer_alloc.h"
/* No need for the header guard as MBEDTLS_MEMORY_BUFFER_ALLOC_C
is dependent upon MBEDTLS_PLATFORM_C */
#include "mbedtls/platform.h"
#include "mbedtls/platform_util.h"
#include <string.h>
#if defined(MBEDTLS_MEMORY_BACKTRACE)
#include <execinfo.h>
#endif
#if defined(MBEDTLS_THREADING_C)
#include "mbedtls/threading.h"
#endif
#define MAGIC1 0xFF00AA55
#define MAGIC2 0xEE119966
#define MAX_BT 20
typedef struct _memory_header memory_header;
struct _memory_header {
size_t magic1;
size_t size;
size_t alloc;
memory_header *prev;
memory_header *next;
memory_header *prev_free;
memory_header *next_free;
#if defined(MBEDTLS_MEMORY_BACKTRACE)
char **trace;
size_t trace_count;
#endif
size_t magic2;
};
typedef struct {
unsigned char *buf;
size_t len;
memory_header *first;
memory_header *first_free;
int verify;
#if defined(MBEDTLS_MEMORY_DEBUG)
size_t alloc_count;
size_t free_count;
size_t total_used;
size_t maximum_used;
size_t header_count;
size_t maximum_header_count;
#endif
#if defined(MBEDTLS_THREADING_C)
mbedtls_threading_mutex_t mutex;
#endif
}
buffer_alloc_ctx;
static buffer_alloc_ctx heap;
#if defined(MBEDTLS_MEMORY_DEBUG)
static void debug_header(memory_header *hdr)
{
#if defined(MBEDTLS_MEMORY_BACKTRACE)
size_t i;
#endif
mbedtls_fprintf(stderr, "HDR: PTR(%10zu), PREV(%10zu), NEXT(%10zu), "
"ALLOC(%zu), SIZE(%10zu)\n",
(size_t) hdr, (size_t) hdr->prev, (size_t) hdr->next,
hdr->alloc, hdr->size);
mbedtls_fprintf(stderr, " FPREV(%10zu), FNEXT(%10zu)\n",
(size_t) hdr->prev_free, (size_t) hdr->next_free);
#if defined(MBEDTLS_MEMORY_BACKTRACE)
mbedtls_fprintf(stderr, "TRACE: \n");
for (i = 0; i < hdr->trace_count; i++) {
mbedtls_fprintf(stderr, "%s\n", hdr->trace[i]);
}
mbedtls_fprintf(stderr, "\n");
#endif
}
static void debug_chain(void)
{
memory_header *cur = heap.first;
mbedtls_fprintf(stderr, "\nBlock list\n");
while (cur != NULL) {
debug_header(cur);
cur = cur->next;
}
mbedtls_fprintf(stderr, "Free list\n");
cur = heap.first_free;
while (cur != NULL) {
debug_header(cur);
cur = cur->next_free;
}
}
#endif /* MBEDTLS_MEMORY_DEBUG */
static int verify_header(memory_header *hdr)
{
if (hdr->magic1 != MAGIC1) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: MAGIC1 mismatch\n");
#endif
return 1;
}
if (hdr->magic2 != MAGIC2) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: MAGIC2 mismatch\n");
#endif
return 1;
}
if (hdr->alloc > 1) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: alloc has illegal value\n");
#endif
return 1;
}
if (hdr->prev != NULL && hdr->prev == hdr->next) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: prev == next\n");
#endif
return 1;
}
if (hdr->prev_free != NULL && hdr->prev_free == hdr->next_free) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: prev_free == next_free\n");
#endif
return 1;
}
return 0;
}
static int verify_chain(void)
{
memory_header *prv = heap.first, *cur;
if (prv == NULL || verify_header(prv) != 0) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: verification of first header "
"failed\n");
#endif
return 1;
}
if (heap.first->prev != NULL) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: verification failed: "
"first->prev != NULL\n");
#endif
return 1;
}
cur = heap.first->next;
while (cur != NULL) {
if (verify_header(cur) != 0) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: verification of header "
"failed\n");
#endif
return 1;
}
if (cur->prev != prv) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: verification failed: "
"cur->prev != prv\n");
#endif
return 1;
}
prv = cur;
cur = cur->next;
}
return 0;
}
static void *buffer_alloc_calloc(size_t n, size_t size)
{
memory_header *new, *cur = heap.first_free;
unsigned char *p;
void *ret;
size_t original_len, len;
#if defined(MBEDTLS_MEMORY_BACKTRACE)
void *trace_buffer[MAX_BT];
size_t trace_cnt;
#endif
if (heap.buf == NULL || heap.first == NULL) {
return NULL;
}
original_len = len = n * size;
if (n == 0 || size == 0 || len / n != size) {
return NULL;
} else if (len > (size_t) -MBEDTLS_MEMORY_ALIGN_MULTIPLE) {
return NULL;
}
if (len % MBEDTLS_MEMORY_ALIGN_MULTIPLE) {
len -= len % MBEDTLS_MEMORY_ALIGN_MULTIPLE;
len += MBEDTLS_MEMORY_ALIGN_MULTIPLE;
}
// Find block that fits
//
while (cur != NULL) {
if (cur->size >= len) {
break;
}
cur = cur->next_free;
}
if (cur == NULL) {
return NULL;
}
if (cur->alloc != 0) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: block in free_list but allocated "
"data\n");
#endif
mbedtls_exit(1);
}
#if defined(MBEDTLS_MEMORY_DEBUG)
heap.alloc_count++;
#endif
// Found location, split block if > memory_header + 4 room left
//
if (cur->size - len < sizeof(memory_header) +
MBEDTLS_MEMORY_ALIGN_MULTIPLE) {
cur->alloc = 1;
// Remove from free_list
//
if (cur->prev_free != NULL) {
cur->prev_free->next_free = cur->next_free;
} else {
heap.first_free = cur->next_free;
}
if (cur->next_free != NULL) {
cur->next_free->prev_free = cur->prev_free;
}
cur->prev_free = NULL;
cur->next_free = NULL;
#if defined(MBEDTLS_MEMORY_DEBUG)
heap.total_used += cur->size;
if (heap.total_used > heap.maximum_used) {
heap.maximum_used = heap.total_used;
}
#endif
#if defined(MBEDTLS_MEMORY_BACKTRACE)
trace_cnt = backtrace(trace_buffer, MAX_BT);
cur->trace = backtrace_symbols(trace_buffer, trace_cnt);
cur->trace_count = trace_cnt;
#endif
if ((heap.verify & MBEDTLS_MEMORY_VERIFY_ALLOC) && verify_chain() != 0) {
mbedtls_exit(1);
}
ret = (unsigned char *) cur + sizeof(memory_header);
memset(ret, 0, original_len);
return ret;
}
p = ((unsigned char *) cur) + sizeof(memory_header) + len;
new = (memory_header *) p;
new->size = cur->size - len - sizeof(memory_header);
new->alloc = 0;
new->prev = cur;
new->next = cur->next;
#if defined(MBEDTLS_MEMORY_BACKTRACE)
new->trace = NULL;
new->trace_count = 0;
#endif
new->magic1 = MAGIC1;
new->magic2 = MAGIC2;
if (new->next != NULL) {
new->next->prev = new;
}
// Replace cur with new in free_list
//
new->prev_free = cur->prev_free;
new->next_free = cur->next_free;
if (new->prev_free != NULL) {
new->prev_free->next_free = new;
} else {
heap.first_free = new;
}
if (new->next_free != NULL) {
new->next_free->prev_free = new;
}
cur->alloc = 1;
cur->size = len;
cur->next = new;
cur->prev_free = NULL;
cur->next_free = NULL;
#if defined(MBEDTLS_MEMORY_DEBUG)
heap.header_count++;
if (heap.header_count > heap.maximum_header_count) {
heap.maximum_header_count = heap.header_count;
}
heap.total_used += cur->size;
if (heap.total_used > heap.maximum_used) {
heap.maximum_used = heap.total_used;
}
#endif
#if defined(MBEDTLS_MEMORY_BACKTRACE)
trace_cnt = backtrace(trace_buffer, MAX_BT);
cur->trace = backtrace_symbols(trace_buffer, trace_cnt);
cur->trace_count = trace_cnt;
#endif
if ((heap.verify & MBEDTLS_MEMORY_VERIFY_ALLOC) && verify_chain() != 0) {
mbedtls_exit(1);
}
ret = (unsigned char *) cur + sizeof(memory_header);
memset(ret, 0, original_len);
return ret;
}
static void buffer_alloc_free(void *ptr)
{
memory_header *hdr, *old = NULL;
unsigned char *p = (unsigned char *) ptr;
if (ptr == NULL || heap.buf == NULL || heap.first == NULL) {
return;
}
if (p < heap.buf || p >= heap.buf + heap.len) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: mbedtls_free() outside of managed "
"space\n");
#endif
mbedtls_exit(1);
}
p -= sizeof(memory_header);
hdr = (memory_header *) p;
if (verify_header(hdr) != 0) {
mbedtls_exit(1);
}
if (hdr->alloc != 1) {
#if defined(MBEDTLS_MEMORY_DEBUG)
mbedtls_fprintf(stderr, "FATAL: mbedtls_free() on unallocated "
"data\n");
#endif
mbedtls_exit(1);
}
hdr->alloc = 0;
#if defined(MBEDTLS_MEMORY_DEBUG)
heap.free_count++;
heap.total_used -= hdr->size;
#endif
#if defined(MBEDTLS_MEMORY_BACKTRACE)
free(hdr->trace);
hdr->trace = NULL;
hdr->trace_count = 0;
#endif
// Regroup with block before
//
if (hdr->prev != NULL && hdr->prev->alloc == 0) {
#if defined(MBEDTLS_MEMORY_DEBUG)
heap.header_count--;
#endif
hdr->prev->size += sizeof(memory_header) + hdr->size;
hdr->prev->next = hdr->next;
old = hdr;
hdr = hdr->prev;
if (hdr->next != NULL) {
hdr->next->prev = hdr;
}
memset(old, 0, sizeof(memory_header));
}
// Regroup with block after
//
if (hdr->next != NULL && hdr->next->alloc == 0) {
#if defined(MBEDTLS_MEMORY_DEBUG)
heap.header_count--;
#endif
hdr->size += sizeof(memory_header) + hdr->next->size;
old = hdr->next;
hdr->next = hdr->next->next;
if (hdr->prev_free != NULL || hdr->next_free != NULL) {
if (hdr->prev_free != NULL) {
hdr->prev_free->next_free = hdr->next_free;
} else {
heap.first_free = hdr->next_free;
}
if (hdr->next_free != NULL) {
hdr->next_free->prev_free = hdr->prev_free;
}
}
hdr->prev_free = old->prev_free;
hdr->next_free = old->next_free;
if (hdr->prev_free != NULL) {
hdr->prev_free->next_free = hdr;
} else {
heap.first_free = hdr;
}
if (hdr->next_free != NULL) {
hdr->next_free->prev_free = hdr;
}
if (hdr->next != NULL) {
hdr->next->prev = hdr;
}
memset(old, 0, sizeof(memory_header));
}
// Prepend to free_list if we have not merged
// (Does not have to stay in same order as prev / next list)
//
if (old == NULL) {
hdr->next_free = heap.first_free;
if (heap.first_free != NULL) {
heap.first_free->prev_free = hdr;
}
heap.first_free = hdr;
}
if ((heap.verify & MBEDTLS_MEMORY_VERIFY_FREE) && verify_chain() != 0) {
mbedtls_exit(1);
}
}
void mbedtls_memory_buffer_set_verify(int verify)
{
heap.verify = verify;
}
int mbedtls_memory_buffer_alloc_verify(void)
{
return verify_chain();
}
#if defined(MBEDTLS_MEMORY_DEBUG)
void mbedtls_memory_buffer_alloc_status(void)
{
mbedtls_fprintf(stderr,
"Current use: %zu blocks / %zu bytes, max: %zu blocks / "
"%zu bytes (total %zu bytes), alloc / free: %zu / %zu\n",
heap.header_count, heap.total_used,
heap.maximum_header_count, heap.maximum_used,
heap.maximum_header_count * sizeof(memory_header)
+ heap.maximum_used,
heap.alloc_count, heap.free_count);
if (heap.first->next == NULL) {
mbedtls_fprintf(stderr, "All memory de-allocated in stack buffer\n");
} else {
mbedtls_fprintf(stderr, "Memory currently allocated:\n");
debug_chain();
}
}
void mbedtls_memory_buffer_alloc_count_get(size_t *alloc_count, size_t *free_count)
{
*alloc_count = heap.alloc_count;
*free_count = heap.free_count;
}
void mbedtls_memory_buffer_alloc_max_get(size_t *max_used, size_t *max_blocks)
{
*max_used = heap.maximum_used;
*max_blocks = heap.maximum_header_count;
}
void mbedtls_memory_buffer_alloc_max_reset(void)
{
heap.maximum_used = 0;
heap.maximum_header_count = 0;
}
void mbedtls_memory_buffer_alloc_cur_get(size_t *cur_used, size_t *cur_blocks)
{
*cur_used = heap.total_used;
*cur_blocks = heap.header_count;
}
#endif /* MBEDTLS_MEMORY_DEBUG */
#if defined(MBEDTLS_THREADING_C)
static void *buffer_alloc_calloc_mutexed(size_t n, size_t size)
{
void *buf;
if (mbedtls_mutex_lock(&heap.mutex) != 0) {
return NULL;
}
buf = buffer_alloc_calloc(n, size);
if (mbedtls_mutex_unlock(&heap.mutex)) {
return NULL;
}
return buf;
}
static void buffer_alloc_free_mutexed(void *ptr)
{
/* We have no good option here, but corrupting the heap seems
* worse than losing memory. */
if (mbedtls_mutex_lock(&heap.mutex)) {
return;
}
buffer_alloc_free(ptr);
(void) mbedtls_mutex_unlock(&heap.mutex);
}
#endif /* MBEDTLS_THREADING_C */
void mbedtls_memory_buffer_alloc_init(unsigned char *buf, size_t len)
{
memset(&heap, 0, sizeof(buffer_alloc_ctx));
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init(&heap.mutex);
mbedtls_platform_set_calloc_free(buffer_alloc_calloc_mutexed,
buffer_alloc_free_mutexed);
#else
mbedtls_platform_set_calloc_free(buffer_alloc_calloc, buffer_alloc_free);
#endif
if (len < sizeof(memory_header) + MBEDTLS_MEMORY_ALIGN_MULTIPLE) {
return;
} else if ((size_t) buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE) {
/* Adjust len first since buf is used in the computation */
len -= MBEDTLS_MEMORY_ALIGN_MULTIPLE
- (size_t) buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE;
buf += MBEDTLS_MEMORY_ALIGN_MULTIPLE
- (size_t) buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE;
}
memset(buf, 0, len);
heap.buf = buf;
heap.len = len;
heap.first = (memory_header *) buf;
heap.first->size = len - sizeof(memory_header);
heap.first->magic1 = MAGIC1;
heap.first->magic2 = MAGIC2;
heap.first_free = heap.first;
}
void mbedtls_memory_buffer_alloc_free(void)
{
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_free(&heap.mutex);
#endif
mbedtls_platform_zeroize(&heap, sizeof(buffer_alloc_ctx));
}
#if defined(MBEDTLS_SELF_TEST)
static int check_pointer(void *p)
{
if (p == NULL) {
return -1;
}
if ((size_t) p % MBEDTLS_MEMORY_ALIGN_MULTIPLE != 0) {
return -1;
}
return 0;
}
static int check_all_free(void)
{
if (
#if defined(MBEDTLS_MEMORY_DEBUG)
heap.total_used != 0 ||
#endif
heap.first != heap.first_free ||
(void *) heap.first != (void *) heap.buf) {
return -1;
}
return 0;
}
#define TEST_ASSERT(condition) \
if (!(condition)) \
{ \
if (verbose != 0) \
mbedtls_printf("failed\n"); \
\
ret = 1; \
goto cleanup; \
}
int mbedtls_memory_buffer_alloc_self_test(int verbose)
{
unsigned char buf[1024];
unsigned char *p, *q, *r, *end;
int ret = 0;
if (verbose != 0) {
mbedtls_printf(" MBA test #1 (basic alloc-free cycle): ");
}
mbedtls_memory_buffer_alloc_init(buf, sizeof(buf));
p = mbedtls_calloc(1, 1);
q = mbedtls_calloc(1, 128);
r = mbedtls_calloc(1, 16);
TEST_ASSERT(check_pointer(p) == 0 &&
check_pointer(q) == 0 &&
check_pointer(r) == 0);
mbedtls_free(r);
mbedtls_free(q);
mbedtls_free(p);
TEST_ASSERT(check_all_free() == 0);
/* Memorize end to compare with the next test */
end = heap.buf + heap.len;
mbedtls_memory_buffer_alloc_free();
if (verbose != 0) {
mbedtls_printf("passed\n");
}
if (verbose != 0) {
mbedtls_printf(" MBA test #2 (buf not aligned): ");
}
mbedtls_memory_buffer_alloc_init(buf + 1, sizeof(buf) - 1);
TEST_ASSERT(heap.buf + heap.len == end);
p = mbedtls_calloc(1, 1);
q = mbedtls_calloc(1, 128);
r = mbedtls_calloc(1, 16);
TEST_ASSERT(check_pointer(p) == 0 &&
check_pointer(q) == 0 &&
check_pointer(r) == 0);
mbedtls_free(r);
mbedtls_free(q);
mbedtls_free(p);
TEST_ASSERT(check_all_free() == 0);
mbedtls_memory_buffer_alloc_free();
if (verbose != 0) {
mbedtls_printf("passed\n");
}
if (verbose != 0) {
mbedtls_printf(" MBA test #3 (full): ");
}
mbedtls_memory_buffer_alloc_init(buf, sizeof(buf));
p = mbedtls_calloc(1, sizeof(buf) - sizeof(memory_header));
TEST_ASSERT(check_pointer(p) == 0);
TEST_ASSERT(mbedtls_calloc(1, 1) == NULL);
mbedtls_free(p);
p = mbedtls_calloc(1, sizeof(buf) - 2 * sizeof(memory_header) - 16);
q = mbedtls_calloc(1, 16);
TEST_ASSERT(check_pointer(p) == 0 && check_pointer(q) == 0);
TEST_ASSERT(mbedtls_calloc(1, 1) == NULL);
mbedtls_free(q);
TEST_ASSERT(mbedtls_calloc(1, 17) == NULL);
mbedtls_free(p);
TEST_ASSERT(check_all_free() == 0);
mbedtls_memory_buffer_alloc_free();
if (verbose != 0) {
mbedtls_printf("passed\n");
}
cleanup:
mbedtls_memory_buffer_alloc_free();
return ret;
}
#endif /* MBEDTLS_SELF_TEST */
#endif /* MBEDTLS_MEMORY_BUFFER_ALLOC_C */
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