[edk2-devel] [edk2-platforms][PATCH v1 1/1] MinPlatformPkg/TestPointCheckLib: Fix DMAR structure length calculation

[Michael Kubacki]

From: Michael Kubacki <michael.kubacki at microsoft.com>

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3768

When processing DMAR structures of type
EFI_ACPI_DMAR_STRUCTURE_HEADER within the ACPI DMAR table, the code
determines the structure length by subtracting the DMAR structure
headers present from the overall DMAR ACPI table size.

The terminating condition is that the remaining total DMAR length
is greater than zero. However, the current DMAR structure length
is subtracted after the DMAR structure pointer has already been
assigned to the next structure.

This change subtracts the current DMAR structure length before
transitioning to the next structure.

Cc: Chasel Chiu <chasel.chiu at intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone at intel.com>
Cc: Liming Gao <gaoliming at byosoft.com.cn>
Cc: Eric Dong <eric.dong at intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki at microsoft.com>
---
 Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckAcpiDmar.c      | 4 ++--
 Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckDmaProtection.c | 2 +-
 Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/PeiCheckDmaProtection.c | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckAcpiDmar.c b/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckAcpiDmar.c
index b2279966d8ed..c20ef58dbacf 100644
--- a/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckAcpiDmar.c
+++ b/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckAcpiDmar.c
@@ -204,8 +204,8 @@ DumpAcpiDmar (
       DEBUG ((DEBUG_INFO, "\n"));
       break;
     }
-    DmarStructHeader = (EFI_ACPI_DMAR_STRUCTURE_HEADER *)((UINT8 *)DmarStructHeader + DmarStructHeader->Length);
     DmarLen         -= DmarStructHeader->Length;
+    DmarStructHeader = (EFI_ACPI_DMAR_STRUCTURE_HEADER *)((UINT8 *)DmarStructHeader + DmarStructHeader->Length);
   }
 }
 
@@ -232,8 +232,8 @@ CheckAcpiDmar (
     default:
       break;
     }
-    DmarStructHeader = (EFI_ACPI_DMAR_STRUCTURE_HEADER *)((UINT8 *)DmarStructHeader + DmarStructHeader->Length);
     DmarLen         -= DmarStructHeader->Length;
+    DmarStructHeader = (EFI_ACPI_DMAR_STRUCTURE_HEADER *)((UINT8 *)DmarStructHeader + DmarStructHeader->Length);
   }
   return EFI_SUCCESS;
 }
\ No newline at end of file
diff --git a/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckDmaProtection.c b/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckDmaProtection.c
index 10b44fe8b9b8..105c8f23e3bd 100644
--- a/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckDmaProtection.c
+++ b/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/DxeCheckDmaProtection.c
@@ -56,8 +56,8 @@ CheckDrhd (
     default:
       break;
     }
-    DmarStructHeader = (EFI_ACPI_DMAR_STRUCTURE_HEADER *)((UINT8 *)DmarStructHeader + DmarStructHeader->Length);
     DmarLen         -= DmarStructHeader->Length;
+    DmarStructHeader = (EFI_ACPI_DMAR_STRUCTURE_HEADER *)((UINT8 *)DmarStructHeader + DmarStructHeader->Length);
   }
 
   return EFI_SUCCESS;
diff --git a/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/PeiCheckDmaProtection.c b/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/PeiCheckDmaProtection.c
index cb764b3633ef..9054b9944e0c 100644
--- a/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/PeiCheckDmaProtection.c
+++ b/Platform/Intel/MinPlatformPkg/Test/Library/TestPointCheckLib/PeiCheckDmaProtection.c
@@ -61,8 +61,8 @@ CheckDrhd (
     default:
       break;
     }
-    DmarStructHeader = (EFI_ACPI_DMAR_STRUCTURE_HEADER *)((UINT8 *)DmarStructHeader + DmarStructHeader->Length);
     DmarLen         -= DmarStructHeader->Length;
+    DmarStructHeader = (EFI_ACPI_DMAR_STRUCTURE_HEADER *)((UINT8 *)DmarStructHeader + DmarStructHeader->Length);
   }
 
   return EFI_SUCCESS;
-- 
2.28.0.windows.1



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