mbedtls/library/memory_buffer_alloc.c
Manuel Pégourié-Gonnard 6ced002a69 Count allocs without side-effects
At the end of the benchmark program, heap stats are printed, and these
stats will be wrong if we reset counters in the middle.

Also remove the function to reset counters, in order to encourage other
programs to behave correctly as well.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2022-01-05 10:08:59 +01:00

751 lines
19 KiB
C

/*
* Buffer-based memory allocator
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#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 to good option here, but corrupting the heap seems
* worse than loosing 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 */