Doug Anson
mbed TLS library
Dependents: HTTPClient-SSL WS_SERVER
Diff: polarssl/memory_buffer_alloc.c
- Revision:
- 0:137634ff4186
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/polarssl/memory_buffer_alloc.c Thu Jun 11 03:27:03 2015 +0000
@@ -0,0 +1,735 @@
+/*
+ * Buffer-based memory allocator
+ *
+ * Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#if !defined(POLARSSL_CONFIG_FILE)
+#include "polarssl/config.h"
+#else
+#include POLARSSL_CONFIG_FILE
+#endif
+
+#if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C)
+#include "polarssl/memory_buffer_alloc.h"
+
+/* No need for the header guard as POLARSSL_MEMORY_BUFFER_ALLOC_C
+ is dependent upon POLARSSL_PLATFORM_C */
+#include "polarssl/platform.h"
+
+#include <string.h>
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+#include <execinfo.h>
+#endif
+
+#if defined(POLARSSL_THREADING_C)
+#include "polarssl/threading.h"
+#endif
+
+/* Implementation that should never be optimized out by the compiler */
+static void polarssl_zeroize( void *v, size_t n ) {
+ volatile unsigned char *p = v; while( n-- ) *p++ = 0;
+}
+
+#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(POLARSSL_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(POLARSSL_MEMORY_DEBUG)
+ size_t malloc_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(POLARSSL_THREADING_C)
+ threading_mutex_t mutex;
+#endif
+}
+buffer_alloc_ctx;
+
+static buffer_alloc_ctx heap;
+
+#if defined(POLARSSL_MEMORY_DEBUG)
+static void debug_header( memory_header *hdr )
+{
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ size_t i;
+#endif
+
+ polarssl_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 );
+ polarssl_fprintf( stderr, " FPREV(%10zu), FNEXT(%10zu)\n",
+ (size_t) hdr->prev_free, (size_t) hdr->next_free );
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ polarssl_fprintf( stderr, "TRACE: \n" );
+ for( i = 0; i < hdr->trace_count; i++ )
+ polarssl_fprintf( stderr, "%s\n", hdr->trace[i] );
+ polarssl_fprintf( stderr, "\n" );
+#endif
+}
+
+static void debug_chain()
+{
+ memory_header *cur = heap.first;
+
+ polarssl_fprintf( stderr, "\nBlock list\n" );
+ while( cur != NULL )
+ {
+ debug_header( cur );
+ cur = cur->next;
+ }
+
+ polarssl_fprintf( stderr, "Free list\n" );
+ cur = heap.first_free;
+
+ while( cur != NULL )
+ {
+ debug_header( cur );
+ cur = cur->next_free;
+ }
+}
+#endif /* POLARSSL_MEMORY_DEBUG */
+
+static int verify_header( memory_header *hdr )
+{
+ if( hdr->magic1 != MAGIC1 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: MAGIC1 mismatch\n" );
+#endif
+ return( 1 );
+ }
+
+ if( hdr->magic2 != MAGIC2 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: MAGIC2 mismatch\n" );
+#endif
+ return( 1 );
+ }
+
+ if( hdr->alloc > 1 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: alloc has illegal value\n" );
+#endif
+ return( 1 );
+ }
+
+ if( hdr->prev != NULL && hdr->prev == hdr->next )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: prev == next\n" );
+#endif
+ return( 1 );
+ }
+
+ if( hdr->prev_free != NULL && hdr->prev_free == hdr->next_free )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: prev_free == next_free\n" );
+#endif
+ return( 1 );
+ }
+
+ return( 0 );
+}
+
+static int verify_chain()
+{
+ memory_header *prv = heap.first, *cur = heap.first->next;
+
+ if( verify_header( heap.first ) != 0 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: verification of first header "
+ "failed\n" );
+#endif
+ return( 1 );
+ }
+
+ if( heap.first->prev != NULL )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: verification failed: "
+ "first->prev != NULL\n" );
+#endif
+ return( 1 );
+ }
+
+ while( cur != NULL )
+ {
+ if( verify_header( cur ) != 0 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: verification of header "
+ "failed\n" );
+#endif
+ return( 1 );
+ }
+
+ if( cur->prev != prv )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: verification failed: "
+ "cur->prev != prv\n" );
+#endif
+ return( 1 );
+ }
+
+ prv = cur;
+ cur = cur->next;
+ }
+
+ return( 0 );
+}
+
+static void *buffer_alloc_malloc( size_t len )
+{
+ memory_header *new, *cur = heap.first_free;
+ unsigned char *p;
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ void *trace_buffer[MAX_BT];
+ size_t trace_cnt;
+#endif
+
+ if( heap.buf == NULL || heap.first == NULL )
+ return( NULL );
+
+ if( len % POLARSSL_MEMORY_ALIGN_MULTIPLE )
+ {
+ len -= len % POLARSSL_MEMORY_ALIGN_MULTIPLE;
+ len += POLARSSL_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(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: block in free_list but allocated "
+ "data\n" );
+#endif
+ polarssl_exit( 1 );
+ }
+
+#if defined(POLARSSL_MEMORY_DEBUG)
+ heap.malloc_count++;
+#endif
+
+ // Found location, split block if > memory_header + 4 room left
+ //
+ if( cur->size - len < sizeof(memory_header) +
+ POLARSSL_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(POLARSSL_MEMORY_DEBUG)
+ heap.total_used += cur->size;
+ if( heap.total_used > heap.maximum_used )
+ heap.maximum_used = heap.total_used;
+#endif
+#if defined(POLARSSL_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 & MEMORY_VERIFY_ALLOC ) && verify_chain() != 0 )
+ polarssl_exit( 1 );
+
+ return( ( (unsigned char *) cur ) + sizeof(memory_header) );
+ }
+
+ 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(POLARSSL_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(POLARSSL_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(POLARSSL_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 & MEMORY_VERIFY_ALLOC ) && verify_chain() != 0 )
+ polarssl_exit( 1 );
+
+ return( ( (unsigned char *) cur ) + sizeof(memory_header) );
+}
+
+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(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: polarssl_free() outside of managed "
+ "space\n" );
+#endif
+ polarssl_exit( 1 );
+ }
+
+ p -= sizeof(memory_header);
+ hdr = (memory_header *) p;
+
+ if( verify_header( hdr ) != 0 )
+ polarssl_exit( 1 );
+
+ if( hdr->alloc != 1 )
+ {
+#if defined(POLARSSL_MEMORY_DEBUG)
+ polarssl_fprintf( stderr, "FATAL: polarssl_free() on unallocated "
+ "data\n" );
+#endif
+ polarssl_exit( 1 );
+ }
+
+ hdr->alloc = 0;
+
+#if defined(POLARSSL_MEMORY_DEBUG)
+ heap.free_count++;
+ heap.total_used -= hdr->size;
+#endif
+
+ // Regroup with block before
+ //
+ if( hdr->prev != NULL && hdr->prev->alloc == 0 )
+ {
+#if defined(POLARSSL_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;
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ free( old->trace );
+#endif
+ memset( old, 0, sizeof(memory_header) );
+ }
+
+ // Regroup with block after
+ //
+ if( hdr->next != NULL && hdr->next->alloc == 0 )
+ {
+#if defined(POLARSSL_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;
+
+#if defined(POLARSSL_MEMORY_BACKTRACE)
+ free( old->trace );
+#endif
+ 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 defined(POLARSSL_MEMORY_BACKTRACE)
+ hdr->trace = NULL;
+ hdr->trace_count = 0;
+#endif
+
+ if( ( heap.verify & MEMORY_VERIFY_FREE ) && verify_chain() != 0 )
+ polarssl_exit( 1 );
+}
+
+void memory_buffer_set_verify( int verify )
+{
+ heap.verify = verify;
+}
+
+int memory_buffer_alloc_verify()
+{
+ return verify_chain();
+}
+
+#if defined(POLARSSL_MEMORY_DEBUG)
+void memory_buffer_alloc_status()
+{
+ polarssl_fprintf( stderr,
+ "Current use: %zu blocks / %zu bytes, max: %zu blocks / "
+ "%zu bytes (total %zu bytes), malloc / 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.malloc_count, heap.free_count );
+
+ if( heap.first->next == NULL )
+ polarssl_fprintf( stderr, "All memory de-allocated in stack buffer\n" );
+ else
+ {
+ polarssl_fprintf( stderr, "Memory currently allocated:\n" );
+ debug_chain();
+ }
+}
+
+void 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 memory_buffer_alloc_max_reset( void )
+{
+ heap.maximum_used = 0;
+ heap.maximum_header_count = 0;
+}
+
+void memory_buffer_alloc_cur_get( size_t *cur_used, size_t *cur_blocks )
+{
+ *cur_used = heap.total_used;
+ *cur_blocks = heap.header_count;
+}
+#endif /* POLARSSL_MEMORY_DEBUG */
+
+#if defined(POLARSSL_THREADING_C)
+static void *buffer_alloc_malloc_mutexed( size_t len )
+{
+ void *buf;
+ polarssl_mutex_lock( &heap.mutex );
+ buf = buffer_alloc_malloc( len );
+ polarssl_mutex_unlock( &heap.mutex );
+ return( buf );
+}
+
+static void buffer_alloc_free_mutexed( void *ptr )
+{
+ polarssl_mutex_lock( &heap.mutex );
+ buffer_alloc_free( ptr );
+ polarssl_mutex_unlock( &heap.mutex );
+}
+#endif /* POLARSSL_THREADING_C */
+
+int memory_buffer_alloc_init( unsigned char *buf, size_t len )
+{
+ memset( &heap, 0, sizeof(buffer_alloc_ctx) );
+ memset( buf, 0, len );
+
+#if defined(POLARSSL_THREADING_C)
+ polarssl_mutex_init( &heap.mutex );
+ platform_set_malloc_free( buffer_alloc_malloc_mutexed,
+ buffer_alloc_free_mutexed );
+#else
+ platform_set_malloc_free( buffer_alloc_malloc, buffer_alloc_free );
+#endif
+
+ if( (size_t) buf % POLARSSL_MEMORY_ALIGN_MULTIPLE )
+ {
+ /* Adjust len first since buf is used in the computation */
+ len -= POLARSSL_MEMORY_ALIGN_MULTIPLE
+ - (size_t) buf % POLARSSL_MEMORY_ALIGN_MULTIPLE;
+ buf += POLARSSL_MEMORY_ALIGN_MULTIPLE
+ - (size_t) buf % POLARSSL_MEMORY_ALIGN_MULTIPLE;
+ }
+
+ 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;
+ return( 0 );
+}
+
+void memory_buffer_alloc_free()
+{
+#if defined(POLARSSL_THREADING_C)
+ polarssl_mutex_free( &heap.mutex );
+#endif
+ polarssl_zeroize( &heap, sizeof(buffer_alloc_ctx) );
+}
+
+#if defined(POLARSSL_SELF_TEST)
+static int check_pointer( void *p )
+{
+ if( p == NULL )
+ return( -1 );
+
+ if( (size_t) p % POLARSSL_MEMORY_ALIGN_MULTIPLE != 0 )
+ return( -1 );
+
+ return( 0 );
+}
+
+static int check_all_free( )
+{
+ if(
+#if defined(POLARSSL_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 ) \
+ polarssl_printf( "failed\n" ); \
+ \
+ ret = 1; \
+ goto cleanup; \
+ }
+
+int memory_buffer_alloc_self_test( int verbose )
+{
+ unsigned char buf[1024];
+ unsigned char *p, *q, *r, *end;
+ int ret = 0;
+
+ if( verbose != 0 )
+ polarssl_printf( " MBA test #1 (basic alloc-free cycle): " );
+
+ memory_buffer_alloc_init( buf, sizeof( buf ) );
+
+ p = polarssl_malloc( 1 );
+ q = polarssl_malloc( 128 );
+ r = polarssl_malloc( 16 );
+
+ TEST_ASSERT( check_pointer( p ) == 0 &&
+ check_pointer( q ) == 0 &&
+ check_pointer( r ) == 0 );
+
+ polarssl_free( r );
+ polarssl_free( q );
+ polarssl_free( p );
+
+ TEST_ASSERT( check_all_free( ) == 0 );
+
+ /* Memorize end to compare with the next test */
+ end = heap.buf + heap.len;
+
+ memory_buffer_alloc_free( );
+
+ if( verbose != 0 )
+ polarssl_printf( "passed\n" );
+
+ if( verbose != 0 )
+ polarssl_printf( " MBA test #2 (buf not aligned): " );
+
+ memory_buffer_alloc_init( buf + 1, sizeof( buf ) - 1 );
+
+ TEST_ASSERT( heap.buf + heap.len == end );
+
+ p = polarssl_malloc( 1 );
+ q = polarssl_malloc( 128 );
+ r = polarssl_malloc( 16 );
+
+ TEST_ASSERT( check_pointer( p ) == 0 &&
+ check_pointer( q ) == 0 &&
+ check_pointer( r ) == 0 );
+
+ polarssl_free( r );
+ polarssl_free( q );
+ polarssl_free( p );
+
+ TEST_ASSERT( check_all_free( ) == 0 );
+
+ memory_buffer_alloc_free( );
+
+ if( verbose != 0 )
+ polarssl_printf( "passed\n" );
+
+ if( verbose != 0 )
+ polarssl_printf( " MBA test #3 (full): " );
+
+ memory_buffer_alloc_init( buf, sizeof( buf ) );
+
+ p = polarssl_malloc( sizeof( buf ) - sizeof( memory_header ) );
+
+ TEST_ASSERT( check_pointer( p ) == 0 );
+ TEST_ASSERT( polarssl_malloc( 1 ) == NULL );
+
+ polarssl_free( p );
+
+ p = polarssl_malloc( sizeof( buf ) - 2 * sizeof( memory_header ) - 16 );
+ q = polarssl_malloc( 16 );
+
+ TEST_ASSERT( check_pointer( p ) == 0 && check_pointer( q ) == 0 );
+ TEST_ASSERT( polarssl_malloc( 1 ) == NULL );
+
+ polarssl_free( q );
+
+ TEST_ASSERT( polarssl_malloc( 17 ) == NULL );
+
+ polarssl_free( p );
+
+ TEST_ASSERT( check_all_free( ) == 0 );
+
+ memory_buffer_alloc_free( );
+
+ if( verbose != 0 )
+ polarssl_printf( "passed\n" );
+
+cleanup:
+ memory_buffer_alloc_free( );
+
+ return( ret );
+}
+#endif /* POLARSSL_SELF_TEST */
+
+#endif /* POLARSSL_MEMORY_BUFFER_ALLOC_C */
+