mbedtls/library/threading.c
Janos Follath 0be2b01a6b Add safety check to sample mutex implementation
Due to inconsistent freeing strategy in pkparse.c the sample mutex
implementation in threading.c could lead to undefined behaviour by
destroying the same mutex several times.

This fix prevents mutexes from being destroyed several times in the
sample threading implementation.
2016-10-13 13:51:07 +01:00

138 lines
4.2 KiB
C

/*
* Threading abstraction layer
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* 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.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_THREADING_C)
#include "mbedtls/threading.h"
#if defined(MBEDTLS_THREADING_PTHREAD)
static void threading_mutex_init_pthread( mbedtls_threading_mutex_t *mutex )
{
if( mutex == NULL || mutex->is_valid )
return;
mutex->is_valid = pthread_mutex_init( &mutex->mutex, NULL ) == 0;
}
static void threading_mutex_free_pthread( mbedtls_threading_mutex_t *mutex )
{
if( mutex == NULL || !mutex->is_valid )
return;
(void) pthread_mutex_destroy( &mutex->mutex );
mutex->is_valid = 0;
}
static int threading_mutex_lock_pthread( mbedtls_threading_mutex_t *mutex )
{
if( mutex == NULL || ! mutex->is_valid )
return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
if( pthread_mutex_lock( &mutex->mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
return( 0 );
}
static int threading_mutex_unlock_pthread( mbedtls_threading_mutex_t *mutex )
{
if( mutex == NULL || ! mutex->is_valid )
return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
if( pthread_mutex_unlock( &mutex->mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
return( 0 );
}
void (*mbedtls_mutex_init)( mbedtls_threading_mutex_t * ) = threading_mutex_init_pthread;
void (*mbedtls_mutex_free)( mbedtls_threading_mutex_t * ) = threading_mutex_free_pthread;
int (*mbedtls_mutex_lock)( mbedtls_threading_mutex_t * ) = threading_mutex_lock_pthread;
int (*mbedtls_mutex_unlock)( mbedtls_threading_mutex_t * ) = threading_mutex_unlock_pthread;
/*
* With phtreads we can statically initialize mutexes
*/
#define MUTEX_INIT = { PTHREAD_MUTEX_INITIALIZER, 1 }
#endif /* MBEDTLS_THREADING_PTHREAD */
#if defined(MBEDTLS_THREADING_ALT)
static int threading_mutex_fail( mbedtls_threading_mutex_t *mutex )
{
((void) mutex );
return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
}
static void threading_mutex_dummy( mbedtls_threading_mutex_t *mutex )
{
((void) mutex );
return;
}
void (*mbedtls_mutex_init)( mbedtls_threading_mutex_t * ) = threading_mutex_dummy;
void (*mbedtls_mutex_free)( mbedtls_threading_mutex_t * ) = threading_mutex_dummy;
int (*mbedtls_mutex_lock)( mbedtls_threading_mutex_t * ) = threading_mutex_fail;
int (*mbedtls_mutex_unlock)( mbedtls_threading_mutex_t * ) = threading_mutex_fail;
/*
* Set functions pointers and initialize global mutexes
*/
void mbedtls_threading_set_alt( void (*mutex_init)( mbedtls_threading_mutex_t * ),
void (*mutex_free)( mbedtls_threading_mutex_t * ),
int (*mutex_lock)( mbedtls_threading_mutex_t * ),
int (*mutex_unlock)( mbedtls_threading_mutex_t * ) )
{
mbedtls_mutex_init = mutex_init;
mbedtls_mutex_free = mutex_free;
mbedtls_mutex_lock = mutex_lock;
mbedtls_mutex_unlock = mutex_unlock;
mbedtls_mutex_init( &mbedtls_threading_readdir_mutex );
mbedtls_mutex_init( &mbedtls_threading_gmtime_mutex );
}
/*
* Free global mutexes
*/
void mbedtls_threading_free_alt( void )
{
mbedtls_mutex_free( &mbedtls_threading_readdir_mutex );
mbedtls_mutex_free( &mbedtls_threading_gmtime_mutex );
}
#endif /* MBEDTLS_THREADING_ALT */
/*
* Define global mutexes
*/
#ifndef MUTEX_INIT
#define MUTEX_INIT
#endif
mbedtls_threading_mutex_t mbedtls_threading_readdir_mutex MUTEX_INIT;
mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex MUTEX_INIT;
#endif /* MBEDTLS_THREADING_C */