drivers/amd/agesa: Fix AGESA heap deallocator

Ported from commit e6033ce1
soc/amd/common/block/pi: Fix AGESA heap deallocator

The deallocation was always subtracting the header, even when it
shouldn't. This caused problems for the allocator where buffer
sizes were incorrect and freed and used buffers could collide.
Fix the deallocation size.

Clear deallocated concatinated buffer header memory.

Fix the initial calculation of the total buffer size
available to be allocated.

Original-Change-Id: I2789ddf72d662f24709dc5d9873741169cc4ef36

Change-Id: Ibac916fcd964adca97a72617428e3d53012e13a1
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: https://review.coreboot.org/23309
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

1 files changed, 22 insertions, 15 deletions

diff --git a/src/drivers/amd/agesa/heapmanager.c b/src/drivers/amd/agesa/heapmanager.c
index 04775cd36e..07ac315ab7 100644
--- a/src/drivers/amd/agesa/heapmanager.c
+++ b/src/drivers/amd/agesa/heapmanager.c
@@ -121,7 +121,9 @@ static AGESA_STATUS agesa_AllocateBuffer(BIOS_HEAP_MANAGER *BiosHeapBasePtr,
 		/* Update the remaining free space */
 		FreedNodeOffset = CurrNodeOffset + CurrNodePtr->BufferSize + sizeof(BIOS_BUFFER_NODE);
 		FreedNodePtr = (BIOS_BUFFER_NODE *) (BiosHeapBaseAddr + FreedNodeOffset);
-		FreedNodePtr->BufferSize = AvailableHeapSize - sizeof(BIOS_BUFFER_NODE) - CurrNodePtr->BufferSize;
+		FreedNodePtr->BufferSize = AvailableHeapSize
+					- (FreedNodeOffset - CurrNodeOffset)
+					- sizeof(BIOS_BUFFER_NODE);
 		FreedNodePtr->NextNodeOffset = 0;
 
 		/* Update the offsets for Allocated and Freed nodes */
@@ -250,25 +252,25 @@ static AGESA_STATUS agesa_DeallocateBuffer(BIOS_HEAP_MANAGER *BiosHeapBasePtr,
 	/* Zero out the buffer, and clear the BufferHandle */
 	LibAmdMemFill ((UINT8 *)AllocNodePtr + sizeof(BIOS_BUFFER_NODE), 0, AllocNodePtr->BufferSize, &(AllocParams->StdHeader));
 	AllocNodePtr->BufferHandle = 0;
-	AllocNodePtr->BufferSize += sizeof(BIOS_BUFFER_NODE);
 
 	/* Add deallocated node in order to the list of freed nodes */
 	FreedNodeOffset = BiosHeapBasePtr->StartOfFreedNodes;
 	FreedNodePtr = (BIOS_BUFFER_NODE *) (BiosHeapBaseAddr + FreedNodeOffset);
 
-	EndNodeOffset = AllocNodeOffset + AllocNodePtr->BufferSize;
+	EndNodeOffset = AllocNodeOffset + AllocNodePtr->BufferSize +
+						sizeof(BIOS_BUFFER_NODE);
 
 	if (AllocNodeOffset < FreedNodeOffset) {
 		/* Add to the start of the freed list */
 		if (EndNodeOffset == FreedNodeOffset) {
 			/* If the freed node is adjacent to the first node in the list, concatenate both nodes */
-			AllocNodePtr->BufferSize += FreedNodePtr->BufferSize;
+			AllocNodePtr->BufferSize += FreedNodePtr->BufferSize +
+						sizeof(BIOS_BUFFER_NODE);
 			AllocNodePtr->NextNodeOffset = FreedNodePtr->NextNodeOffset;
 
-			/* Clear the BufferSize and NextNodeOffset of the previous first node */
-			FreedNodePtr->BufferSize = 0;
-			FreedNodePtr->NextNodeOffset = 0;
-
+			/* Zero out the FreedNode header */
+			memset((UINT8 *)FreedNodePtr, 0,
+						sizeof(BIOS_BUFFER_NODE));
 		} else {
 			/* Otherwise, add freed node to the start of the list
 			 * Update NextNodeOffset and BufferSize to include the
@@ -298,11 +300,13 @@ static AGESA_STATUS agesa_DeallocateBuffer(BIOS_HEAP_MANAGER *BiosHeapBasePtr,
 		 */
 		if (NextNodeOffset == EndNodeOffset) {
 			NextNodePtr = (BIOS_BUFFER_NODE *) (BiosHeapBaseAddr + NextNodeOffset);
-			AllocNodePtr->BufferSize += NextNodePtr->BufferSize;
+			AllocNodePtr->BufferSize += NextNodePtr->BufferSize +
+						sizeof(BIOS_BUFFER_NODE);
 			AllocNodePtr->NextNodeOffset = NextNodePtr->NextNodeOffset;
 
-			NextNodePtr->BufferSize = 0;
-			NextNodePtr->NextNodeOffset = 0;
+			/* Zero out the NextNode header */
+			memset((UINT8 *)NextNodePtr, 0,
+						sizeof(BIOS_BUFFER_NODE));
 		} else {
 			/*AllocNodePtr->NextNodeOffset = FreedNodePtr->NextNodeOffset; */
 			AllocNodePtr->NextNodeOffset = NextNodeOffset;
@@ -311,13 +315,16 @@ static AGESA_STATUS agesa_DeallocateBuffer(BIOS_HEAP_MANAGER *BiosHeapBasePtr,
 		 * concatenate both nodes.
 		 */
 		PrevNodePtr = (BIOS_BUFFER_NODE *) (BiosHeapBaseAddr + PrevNodeOffset);
-		EndNodeOffset = PrevNodeOffset + PrevNodePtr->BufferSize;
+		EndNodeOffset = PrevNodeOffset + PrevNodePtr->BufferSize +
+						sizeof(BIOS_BUFFER_NODE);
 		if (AllocNodeOffset == EndNodeOffset) {
 			PrevNodePtr->NextNodeOffset = AllocNodePtr->NextNodeOffset;
-			PrevNodePtr->BufferSize += AllocNodePtr->BufferSize;
+			PrevNodePtr->BufferSize += AllocNodePtr->BufferSize +
+						sizeof(BIOS_BUFFER_NODE);
 
-			AllocNodePtr->BufferSize = 0;
-			AllocNodePtr->NextNodeOffset = 0;
+			/* Zero out the AllocNode header */
+			memset((UINT8 *)AllocNodePtr, 0,
+						sizeof(BIOS_BUFFER_NODE));
 		} else {
 			PrevNodePtr->NextNodeOffset = AllocNodeOffset;
 		}