Move MSB check after final size calculation (#463)
We use the MSB of the size member of a BlockLink_t to track whether not
a block is allocated. Consequently, the size must not be so large that
the MSB is set. The check to see if the MSB in the size is set needs to
be done after the final size (metadata + alignment) is calculated.
Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
diff --git a/portable/MemMang/heap_2.c b/portable/MemMang/heap_2.c
index 85ebdf2..f50965e 100644
--- a/portable/MemMang/heap_2.c
+++ b/portable/MemMang/heap_2.c
@@ -160,36 +160,36 @@
xHeapHasBeenInitialised = pdTRUE;
}
- /* Check the requested block size is not so large that the top bit is
- * set. The top bit of the block size member of the BlockLink_t structure
- * is used to determine who owns the block - the application or the
- * kernel, so it must be free. */
- if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) )
+ /* The wanted size must be increased so it can contain a BlockLink_t
+ * structure in addition to the requested amount of bytes. */
+ if( ( xWantedSize > 0 ) &&
+ ( ( xWantedSize + heapSTRUCT_SIZE ) > xWantedSize ) ) /* Overflow check. */
{
- /* The wanted size must be increased so it can contain a BlockLink_t
- * structure in addition to the requested amount of bytes. */
- if( ( xWantedSize > 0 ) &&
- ( ( xWantedSize + heapSTRUCT_SIZE ) > xWantedSize ) ) /* Overflow check */
- {
- xWantedSize += heapSTRUCT_SIZE;
+ xWantedSize += heapSTRUCT_SIZE;
- /* Byte alignment required. Check for overflow. */
- if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) )
- > xWantedSize )
- {
- xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
- configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
- }
- else
- {
- xWantedSize = 0;
- }
+ /* Byte alignment required. Check for overflow. */
+ if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) )
+ > xWantedSize )
+ {
+ xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
+ configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
}
else
{
xWantedSize = 0;
}
+ }
+ else
+ {
+ xWantedSize = 0;
+ }
+ /* Check the block size we are trying to allocate is not so large that the
+ * top bit is set. The top bit of the block size member of the BlockLink_t
+ * structure is used to determine who owns the block - the application or
+ * the kernel, so it must be free. */
+ if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) != 0 )
+ {
if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
{
/* Blocks are stored in byte order - traverse the list from the start
@@ -274,10 +274,10 @@
* byte alignment warnings. */
pxLink = ( void * ) puc;
- configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) );
+ configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) != 0 );
configASSERT( pxLink->pxNextFreeBlock == NULL );
- if( heapBLOCK_IS_ALLOCATED( pxLink ) )
+ if( heapBLOCK_IS_ALLOCATED( pxLink ) != 0 )
{
if( pxLink->pxNextFreeBlock == NULL )
{
diff --git a/portable/MemMang/heap_4.c b/portable/MemMang/heap_4.c
index 2ef5381..28efcbb 100644
--- a/portable/MemMang/heap_4.c
+++ b/portable/MemMang/heap_4.c
@@ -146,44 +146,43 @@
mtCOVERAGE_TEST_MARKER();
}
- /* Check the requested block size is not so large that the top bit is
- * set. The top bit of the block size member of the BlockLink_t structure
- * is used to determine who owns the block - the application or the
- * kernel, so it must be free. */
- if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) )
+ /* The wanted size must be increased so it can contain a BlockLink_t
+ * structure in addition to the requested amount of bytes. */
+ if( ( xWantedSize > 0 ) &&
+ ( ( xWantedSize + xHeapStructSize ) > xWantedSize ) ) /* Overflow check. */
{
- /* The wanted size must be increased so it can contain a BlockLink_t
- * structure in addition to the requested amount of bytes. */
- if( ( xWantedSize > 0 ) &&
- ( ( xWantedSize + xHeapStructSize ) > xWantedSize ) ) /* Overflow check */
- {
- xWantedSize += xHeapStructSize;
+ xWantedSize += xHeapStructSize;
- /* Ensure that blocks are always aligned. */
- if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
+ /* Ensure that blocks are always aligned. */
+ if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
+ {
+ /* Byte alignment required. Check for overflow. */
+ if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) ) > xWantedSize )
{
- /* Byte alignment required. Check for overflow. */
- if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) )
- > xWantedSize )
- {
- xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
- configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
- }
- else
- {
- xWantedSize = 0;
- }
+ xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
+ configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
}
else
{
- mtCOVERAGE_TEST_MARKER();
+ xWantedSize = 0;
}
}
else
{
- xWantedSize = 0;
+ mtCOVERAGE_TEST_MARKER();
}
+ }
+ else
+ {
+ xWantedSize = 0;
+ }
+ /* Check the block size we are trying to allocate is not so large that the
+ * top bit is set. The top bit of the block size member of the BlockLink_t
+ * structure is used to determine who owns the block - the application or
+ * the kernel, so it must be free. */
+ if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) != 0 )
+ {
if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
{
/* Traverse the list from the start (lowest address) block until
@@ -302,10 +301,10 @@
/* This casting is to keep the compiler from issuing warnings. */
pxLink = ( void * ) puc;
- configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) );
+ configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) != 0 );
configASSERT( pxLink->pxNextFreeBlock == NULL );
- if( heapBLOCK_IS_ALLOCATED( pxLink ) )
+ if( heapBLOCK_IS_ALLOCATED( pxLink ) != 0 )
{
if( pxLink->pxNextFreeBlock == NULL )
{
diff --git a/portable/MemMang/heap_5.c b/portable/MemMang/heap_5.c
index c12c956..c0c4ea4 100644
--- a/portable/MemMang/heap_5.c
+++ b/portable/MemMang/heap_5.c
@@ -157,43 +157,43 @@
vTaskSuspendAll();
{
- /* Check the requested block size is not so large that the top bit is
- * set. The top bit of the block size member of the BlockLink_t structure
- * is used to determine who owns the block - the application or the
- * kernel, so it must be free. */
- if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) )
+ /* The wanted size is increased so it can contain a BlockLink_t
+ * structure in addition to the requested amount of bytes. */
+ if( ( xWantedSize > 0 ) &&
+ ( ( xWantedSize + xHeapStructSize ) > xWantedSize ) ) /* Overflow check. */
{
- /* The wanted size is increased so it can contain a BlockLink_t
- * structure in addition to the requested amount of bytes. */
- if( ( xWantedSize > 0 ) &&
- ( ( xWantedSize + xHeapStructSize ) > xWantedSize ) ) /* Overflow check */
- {
- xWantedSize += xHeapStructSize;
+ xWantedSize += xHeapStructSize;
- /* Ensure that blocks are always aligned */
- if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
+ /* Ensure that blocks are always aligned */
+ if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
+ {
+ /* Byte alignment required. Check for overflow */
+ if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) ) >
+ xWantedSize )
{
- /* Byte alignment required. Check for overflow */
- if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) ) >
- xWantedSize )
- {
- xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
- }
- else
- {
- xWantedSize = 0;
- }
+ xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
}
else
{
- mtCOVERAGE_TEST_MARKER();
+ xWantedSize = 0;
}
}
else
{
- xWantedSize = 0;
+ mtCOVERAGE_TEST_MARKER();
}
+ }
+ else
+ {
+ xWantedSize = 0;
+ }
+ /* Check the block size we are trying to allocate is not so large that the
+ * top bit is set. The top bit of the block size member of the BlockLink_t
+ * structure is used to determine who owns the block - the application or
+ * the kernel, so it must be free. */
+ if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) != 0 )
+ {
if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
{
/* Traverse the list from the start (lowest address) block until
@@ -310,10 +310,10 @@
/* This casting is to keep the compiler from issuing warnings. */
pxLink = ( void * ) puc;
- configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) );
+ configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) != 0 );
configASSERT( pxLink->pxNextFreeBlock == NULL );
- if( heapBLOCK_IS_ALLOCATED( pxLink ) )
+ if( heapBLOCK_IS_ALLOCATED( pxLink ) != 0 )
{
if( pxLink->pxNextFreeBlock == NULL )
{
