DynamicTablesPkg: Fix Proc node length assignment

The length field for the Processor Hierarchy node structure is
8-bit wide while the number of private resource field is 32-bit
wide. Therefore, the GetProcHierarchyNodeSize() returns the size
as a 32-bit value.

The VS2017 compiler reports 'warning C4244: '=': conversion from
'UINT32' to 'UINT8', possible loss of data' while assigning the
length field of the Processor Hierarchy node structure.

To fix this, a type cast is added. In addition, there is a check
to ensure that the Processor Hierarchy node size does not exceed
MAX_UINT8.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/DynamicTablesPkg/Library/Acpi/Arm/AcpiPpttLibArm/PpttGenerator.c b/DynamicTablesPkg/Library/Acpi/Arm/AcpiPpttLibArm/PpttGenerator.c
index 9e42eee9b7..40699ce113 100644
--- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiPpttLibArm/PpttGenerator.c
+++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiPpttLibArm/PpttGenerator.c
@@ -504,6 +504,7 @@ AddProcHierarchyNodes (
 

   PPTT_NODE_INDEXER                     * ProcNodeIterator;

   UINT32                                  NodeCount;

+  UINT32                                  Length;

 

   ASSERT (

     (Generator != NULL) &&

@@ -539,8 +540,8 @@ AddProcHierarchyNodes (
     // imposed on the Processor Hierarchy node by the specification.

     // Note: The length field is 8 bit wide while the number of private

     // resource field is 32 bit wide.

-    if ((sizeof (EFI_ACPI_6_3_PPTT_STRUCTURE_PROCESSOR) +

-        (ProcInfoNode->NoOfPrivateResources * sizeof (UINT32))) > MAX_UINT8) {

+    Length = GetProcHierarchyNodeSize (ProcInfoNode);

+    if (Length > MAX_UINT8) {

       Status = EFI_INVALID_PARAMETER;

       DEBUG ((

         DEBUG_ERROR,

@@ -556,7 +557,7 @@ AddProcHierarchyNodes (
 

     // Populate the node header

     ProcStruct->Type = EFI_ACPI_6_3_PPTT_TYPE_PROCESSOR;

-    ProcStruct->Length = GetProcHierarchyNodeSize (ProcInfoNode);

+    ProcStruct->Length = (UINT8)Length;

     ProcStruct->Reserved[0] = EFI_ACPI_RESERVED_BYTE;

     ProcStruct->Reserved[1] = EFI_ACPI_RESERVED_BYTE;