From: Sami Mujawar <sami.mujawar@arm.com>
Date: Tue, 9 Jul 2019 12:35:02 +0000 (+0100)
Subject: DynamicTablesPkg: Fix Proc node length assignment
X-Git-Tag: edk2-stable202005~275
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=96bb6704e036a2fb66d41d4ab95e976bcaab7a82;p=mirror_edk2.git

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>
---

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;