@ -104,6 +104,9 @@
/* Check if adding a and b will result in overflow. */
# define heapADD_WILL_OVERFLOW( a, b ) ( ( a ) > ( heapSIZE_MAX - ( b ) ) )
/* Check if the subtraction operation ( a - b ) will result in underflow. */
# define heapSUBTRACT_WILL_UNDERFLOW( a, b ) ( ( a ) < ( b ) )
/* MSB of the xBlockSize member of an BlockLink_t structure is used to track
* the allocation status of a block . When MSB of the xBlockSize member of
* an BlockLink_t structure is set then the block belongs to the application .
@ -124,6 +127,46 @@ typedef struct A_BLOCK_LINK
size_t xBlockSize ; /**< The size of the free block. */
} BlockLink_t ;
/* Setting configENABLE_HEAP_PROTECTOR to 1 enables heap block pointers
* protection using an application supplied canary value to catch heap
* corruption should a heap buffer overflow occur .
*/
# if ( configENABLE_HEAP_PROTECTOR == 1 )
/**
* @ brief Application provided function to get a random value to be used as canary .
*
* @ param pxHeapCanary [ out ] Output parameter to return the canary value .
*/
extern void vApplicationGetRandomHeapCanary ( portPOINTER_SIZE_TYPE * pxHeapCanary ) ;
/* Canary value for protecting internal heap pointers. */
PRIVILEGED_DATA static portPOINTER_SIZE_TYPE xHeapCanary ;
/* Macro to load/store BlockLink_t pointers to memory. By XORing the
* pointers with a random canary value , heap overflows will result
* in randomly unpredictable pointer values which will be caught by
* heapVALIDATE_BLOCK_POINTER assert . */
# define heapPROTECT_BLOCK_POINTER( pxBlock ) ( ( BlockLink_t * ) ( ( ( portPOINTER_SIZE_TYPE ) ( pxBlock ) ) ^ xHeapCanary ) )
# else /* if ( configENABLE_HEAP_PROTECTOR == 1 ) */
# define heapPROTECT_BLOCK_POINTER( pxBlock ) ( pxBlock )
# endif /* configENABLE_HEAP_PROTECTOR */
/* Highest and lowest heap addresses used for heap block bounds checking. */
PRIVILEGED_DATA static uint8_t * pucHeapHighAddress = NULL ;
PRIVILEGED_DATA static uint8_t * pucHeapLowAddress = NULL ;
/* Assert that a heap block pointer is within the heap bounds. */
# define heapVALIDATE_BLOCK_POINTER( pxBlock ) \
configASSERT ( ( pucHeapHighAddress ! = NULL ) & & \
( pucHeapLowAddress ! = NULL ) & & \
( ( uint8_t * ) ( pxBlock ) > = pucHeapLowAddress ) & & \
( ( uint8_t * ) ( pxBlock ) < pucHeapHighAddress ) )
/*-----------------------------------------------------------*/
/*
@ -132,8 +175,8 @@ typedef struct A_BLOCK_LINK
* the block in front it and / or the block behind it if the memory blocks are
* adjacent to each other .
*/
static void prvInsertBlockIntoFreeList ( BlockLink_t * pxBlockToInsert ) ;
static void prvInsertBlockIntoFreeList ( BlockLink_t * pxBlockToInsert ) PRIVILEGED_FUNCTION ;
void vPortDefineHeapRegions ( const HeapRegion_t * const pxHeapRegions ) PRIVILEGED_FUNCTION ;
/*-----------------------------------------------------------*/
/* The size of the structure placed at the beginning of each allocated memory
@ -141,15 +184,15 @@ static void prvInsertBlockIntoFreeList( BlockLink_t * pxBlockToInsert );
static const size_t xHeapStructSize = ( sizeof ( BlockLink_t ) + ( ( size_t ) ( portBYTE_ALIGNMENT - 1 ) ) ) & ~ ( ( size_t ) portBYTE_ALIGNMENT_MASK ) ;
/* Create a couple of list links to mark the start and end of the list. */
static BlockLink_t xStart ;
static BlockLink_t * pxEnd = NULL ;
PRIVILEGED_DATA static BlockLink_t xStart ;
PRIVILEGED_DATA static BlockLink_t * pxEnd = NULL ;
/* Keeps track of the number of calls to allocate and free memory as well as the
* number of free bytes remaining , but says nothing about fragmentation . */
static size_t xFreeBytesRemaining = 0U ;
static size_t xMinimumEverFreeBytesRemaining = 0U ;
static size_t xNumberOfSuccessfulAllocations = 0 ;
static size_t xNumberOfSuccessfulFrees = 0 ;
PRIVILEGED_DATA static size_t xFreeBytesRemaining = 0U ;
PRIVILEGED_DATA static size_t xMinimumEverFreeBytesRemaining = 0U ;
PRIVILEGED_DATA static size_t xNumberOfSuccessfulAllocations = 0 ;
PRIVILEGED_DATA static size_t xNumberOfSuccessfulFrees = 0 ;
/*-----------------------------------------------------------*/
@ -217,12 +260,14 @@ void * pvPortMalloc( size_t xWantedSize )
/* Traverse the list from the start (lowest address) block until
* one of adequate size is found . */
pxPreviousBlock = & xStart ;
pxBlock = xStart . pxNextFreeBlock ;
pxBlock = heapPROTECT_BLOCK_POINTER ( xStart . pxNextFreeBlock ) ;
heapVALIDATE_BLOCK_POINTER ( pxBlock ) ;
while ( ( pxBlock - > xBlockSize < xWantedSize ) & & ( pxBlock - > pxNextFreeBlock ! = NULL ) )
while ( ( pxBlock - > xBlockSize < xWantedSize ) & & ( pxBlock - > pxNextFreeBlock ! = heapPROTECT_BLOCK_POINTER ( NULL ) ) )
{
pxPreviousBlock = pxBlock ;
pxBlock = pxBlock - > pxNextFreeBlock ;
pxBlock = heapPROTECT_BLOCK_POINTER ( pxBlock - > pxNextFreeBlock ) ;
heapVALIDATE_BLOCK_POINTER ( pxBlock ) ;
}
/* If the end marker was reached then a block of adequate size
@ -231,7 +276,8 @@ void * pvPortMalloc( size_t xWantedSize )
{
/* Return the memory space pointed to - jumping over the
* BlockLink_t structure at its start . */
pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock - > pxNextFreeBlock ) + xHeapStructSize ) ;
pvReturn = ( void * ) ( ( ( uint8_t * ) heapPROTECT_BLOCK_POINTER ( pxPreviousBlock - > pxNextFreeBlock ) ) + xHeapStructSize ) ;
heapVALIDATE_BLOCK_POINTER ( pvReturn ) ;
/* This block is being returned for use so must be taken out
* of the list of free blocks . */
@ -239,6 +285,8 @@ void * pvPortMalloc( size_t xWantedSize )
/* If the block is larger than required it can be split into
* two . */
configASSERT ( heapSUBTRACT_WILL_UNDERFLOW ( pxBlock - > xBlockSize , xWantedSize ) = = 0 ) ;
if ( ( pxBlock - > xBlockSize - xWantedSize ) > heapMINIMUM_BLOCK_SIZE )
{
/* This block is to be split into two. Create a new
@ -246,6 +294,7 @@ void * pvPortMalloc( size_t xWantedSize )
* cast is used to prevent byte alignment warnings from the
* compiler . */
pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize ) ;
configASSERT ( ( ( ( size_t ) pxNewBlockLink ) & portBYTE_ALIGNMENT_MASK ) = = 0 ) ;
/* Calculate the sizes of two blocks split from the
* single block . */
@ -254,7 +303,7 @@ void * pvPortMalloc( size_t xWantedSize )
/* Insert the new block into the list of free blocks. */
pxNewBlockLink - > pxNextFreeBlock = pxPreviousBlock - > pxNextFreeBlock ;
pxPreviousBlock - > pxNextFreeBlock = pxNewBlockLink ;
pxPreviousBlock - > pxNextFreeBlock = heapPROTECT_BLOCK_POINTER ( pxNewBlockLink ) ;
}
else
{
@ -310,6 +359,7 @@ void * pvPortMalloc( size_t xWantedSize )
}
# endif /* if ( configUSE_MALLOC_FAILED_HOOK == 1 ) */
configASSERT ( ( ( ( size_t ) pvReturn ) & ( size_t ) portBYTE_ALIGNMENT_MASK ) = = 0 ) ;
return pvReturn ;
}
/*-----------------------------------------------------------*/
@ -328,6 +378,7 @@ void vPortFree( void * pv )
/* This casting is to keep the compiler from issuing warnings. */
pxLink = ( void * ) puc ;
heapVALIDATE_BLOCK_POINTER ( pxLink ) ;
configASSERT ( heapBLOCK_IS_ALLOCATED ( pxLink ) ! = 0 ) ;
configASSERT ( pxLink - > pxNextFreeBlock = = NULL ) ;
@ -339,9 +390,14 @@ void vPortFree( void * pv )
* allocated . */
heapFREE_BLOCK ( pxLink ) ;
# if ( configHEAP_CLEAR_MEMORY_ON_FREE == 1 )
{
/* Check for underflow as this can occur if xBlockSize is
* overwritten in a heap block . */
if ( heapSUBTRACT_WILL_UNDERFLOW ( pxLink - > xBlockSize , xHeapStructSize ) = = 0 )
{
( void ) memset ( puc + xHeapStructSize , 0 , pxLink - > xBlockSize - xHeapStructSize ) ;
}
}
# endif
vTaskSuspendAll ( ) ;
@ -398,18 +454,23 @@ void * pvPortCalloc( size_t xNum,
}
/*-----------------------------------------------------------*/
static void prvInsertBlockIntoFreeList ( BlockLink_t * pxBlockToInsert )
static void prvInsertBlockIntoFreeList ( BlockLink_t * pxBlockToInsert ) /* PRIVILEGED_FUNCTION */
{
BlockLink_t * pxIterator ;
uint8_t * puc ;
/* Iterate through the list until a block is found that has a higher address
* than the block being inserted . */
for ( pxIterator = & xStart ; pxIterator - > pxNextFreeBlock < pxBlockToInsert ; pxIterator = pxIterator - > pxNextFreeBlock )
for ( pxIterator = & xStart ; heapPROTECT_BLOCK_POINTER ( pxIterator - > pxNextFreeBlock ) < pxBlockToInsert ; pxIterator = heapPROTECT_BLOCK_POINTER ( pxIterator - > pxNextFreeBlock ) )
{
/* Nothing to do here, just iterate to the right position. */
}
if ( pxIterator ! = & xStart )
{
heapVALIDATE_BLOCK_POINTER ( pxIterator ) ;
}
/* Do the block being inserted, and the block it is being inserted after
* make a contiguous block of memory ? */
puc = ( uint8_t * ) pxIterator ;
@ -428,17 +489,17 @@ static void prvInsertBlockIntoFreeList( BlockLink_t * pxBlockToInsert )
* make a contiguous block of memory ? */
puc = ( uint8_t * ) pxBlockToInsert ;
if ( ( puc + pxBlockToInsert - > xBlockSize ) = = ( uint8_t * ) pxIterator - > pxNextFreeBlock )
if ( ( puc + pxBlockToInsert - > xBlockSize ) = = ( uint8_t * ) heapPROTECT_BLOCK_POINTER ( pxIterator - > pxNextFreeBlock ) )
{
if ( pxIterator - > pxNextFreeBlock ! = pxEnd )
if ( heapPROTECT_BLOCK_POINTER ( pxIterator - > pxNextFreeBlock ) ! = pxEnd )
{
/* Form one big block from the two blocks. */
pxBlockToInsert - > xBlockSize + = pxIterator - > pxNextFreeBlock - > xBlockSize ;
pxBlockToInsert - > pxNextFreeBlock = pxIterator - > pxNextFreeBlock - > pxNextFreeBlock ;
pxBlockToInsert - > xBlockSize + = heapPROTECT_BLOCK_POINTER ( pxIterator - > pxNextFreeBlock ) - > xBlockSize ;
pxBlockToInsert - > pxNextFreeBlock = heapPROTECT_BLOCK_POINTER ( pxIterator - > pxNextFreeBlock ) - > pxNextFreeBlock ;
}
else
{
pxBlockToInsert - > pxNextFreeBlock = pxEnd ;
pxBlockToInsert - > pxNextFreeBlock = heapPROTECT_BLOCK_POINTER ( pxEnd ) ;
}
}
else
@ -446,13 +507,13 @@ static void prvInsertBlockIntoFreeList( BlockLink_t * pxBlockToInsert )
pxBlockToInsert - > pxNextFreeBlock = pxIterator - > pxNextFreeBlock ;
}
/* If the block being inserted plugged a ga b , so was merged with the block
/* If the block being inserted plugged a ga p , so was merged with the block
* before and the block after , then it ' s pxNextFreeBlock pointer will have
* already been set , and should not be set here as that would make it point
* to itself . */
if ( pxIterator ! = pxBlockToInsert )
{
pxIterator - > pxNextFreeBlock = pxBlockToInsert ;
pxIterator - > pxNextFreeBlock = heapPROTECT_BLOCK_POINTER ( pxBlockToInsert ) ;
}
else
{
@ -461,7 +522,7 @@ static void prvInsertBlockIntoFreeList( BlockLink_t * pxBlockToInsert )
}
/*-----------------------------------------------------------*/
void vPortDefineHeapRegions ( const HeapRegion_t * const pxHeapRegions )
void vPortDefineHeapRegions ( const HeapRegion_t * const pxHeapRegions ) /* PRIVILEGED_FUNCTION */
{
BlockLink_t * pxFirstFreeBlockInRegion = NULL ;
BlockLink_t * pxPreviousFreeBlock ;
@ -474,6 +535,12 @@ void vPortDefineHeapRegions( const HeapRegion_t * const pxHeapRegions )
/* Can only call once! */
configASSERT ( pxEnd = = NULL ) ;
# if ( configENABLE_HEAP_PROTECTOR == 1 )
{
vApplicationGetRandomHeapCanary ( & ( xHeapCanary ) ) ;
}
# endif
pxHeapRegion = & ( pxHeapRegions [ xDefinedRegions ] ) ;
while ( pxHeapRegion - > xSizeInBytes > 0 )
@ -499,19 +566,29 @@ void vPortDefineHeapRegions( const HeapRegion_t * const pxHeapRegions )
{
/* xStart is used to hold a pointer to the first item in the list of
* free blocks . The void cast is used to prevent compiler warnings . */
xStart . pxNextFreeBlock = ( BlockLink_t * ) xAlignedHeap ;
xStart . pxNextFreeBlock = ( BlockLink_t * ) heapPROTECT_BLOCK_POINTER ( xAlignedHeap ) ;
xStart . xBlockSize = ( size_t ) 0 ;
}
else
{
/* Should only get here if one region has already been added to the
* heap . */
configASSERT ( pxEnd ! = NULL ) ;
configASSERT ( pxEnd ! = heapPROTECT_BLOCK_POINTER ( NULL ) ) ;
/* Check blocks are passed in with increasing start addresses. */
configASSERT ( ( size_t ) xAddress > ( size_t ) pxEnd ) ;
}
# if ( configENABLE_HEAP_PROTECTOR == 1 )
{
if ( ( pucHeapLowAddress = = NULL ) | |
( ( uint8_t * ) xAlignedHeap < pucHeapLowAddress ) )
{
pucHeapLowAddress = ( uint8_t * ) xAlignedHeap ;
}
}
# endif /* configENABLE_HEAP_PROTECTOR */
/* Remember the location of the end marker in the previous region, if
* any . */
pxPreviousFreeBlock = pxEnd ;
@ -523,24 +600,34 @@ void vPortDefineHeapRegions( const HeapRegion_t * const pxHeapRegions )
xAddress & = ~ ( ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) ;
pxEnd = ( BlockLink_t * ) xAddress ;
pxEnd - > xBlockSize = 0 ;
pxEnd - > pxNextFreeBlock = NULL ;
pxEnd - > pxNextFreeBlock = heapPROTECT_BLOCK_POINTER ( NULL ) ;
/* To start with there is a single free block in this region that is
* sized to take up the entire heap region minus the space taken by the
* free block structure . */
pxFirstFreeBlockInRegion = ( BlockLink_t * ) xAlignedHeap ;
pxFirstFreeBlockInRegion - > xBlockSize = ( size_t ) ( xAddress - ( portPOINTER_SIZE_TYPE ) pxFirstFreeBlockInRegion ) ;
pxFirstFreeBlockInRegion - > pxNextFreeBlock = pxEnd ;
pxFirstFreeBlockInRegion - > pxNextFreeBlock = heapPROTECT_BLOCK_POINTER ( pxEnd ) ;
/* If this is not the first region that makes up the entire heap space
* then link the previous region to this region . */
if ( pxPreviousFreeBlock ! = NULL )
{
pxPreviousFreeBlock - > pxNextFreeBlock = pxFirstFreeBlockInRegion ;
pxPreviousFreeBlock - > pxNextFreeBlock = heapPROTECT_BLOCK_POINTER ( pxFirstFreeBlockInRegion ) ;
}
xTotalHeapSize + = pxFirstFreeBlockInRegion - > xBlockSize ;
# if ( configENABLE_HEAP_PROTECTOR == 1 )
{
if ( ( pucHeapHighAddress = = NULL ) | |
( ( ( ( uint8_t * ) pxFirstFreeBlockInRegion ) + pxFirstFreeBlockInRegion - > xBlockSize ) > pucHeapHighAddress ) )
{
pucHeapHighAddress = ( ( uint8_t * ) pxFirstFreeBlockInRegion ) + pxFirstFreeBlockInRegion - > xBlockSize ;
}
}
# endif
/* Move onto the next HeapRegion_t structure. */
xDefinedRegions + + ;
pxHeapRegion = & ( pxHeapRegions [ xDefinedRegions ] ) ;
@ -561,7 +648,7 @@ void vPortGetHeapStats( HeapStats_t * pxHeapStats )
vTaskSuspendAll ( ) ;
{
pxBlock = xStart . pxNextFreeBlock ;
pxBlock = heapPROTECT_BLOCK_POINTER ( xStart . pxNextFreeBlock ) ;
/* pxBlock will be NULL if the heap has not been initialised. The heap
* is initialised automatically when the first allocation is made . */
@ -591,7 +678,7 @@ void vPortGetHeapStats( HeapStats_t * pxHeapStats )
/* Move to the next block in the chain until the last block is
* reached . */
pxBlock = pxBlock - > pxNextFreeBlock ;
pxBlock = heapPROTECT_BLOCK_POINTER ( pxBlock - > pxNextFreeBlock ) ;
}
}
}