IntelSiliconPkg/IntelVTdDxe: Add explicit NULL pointer checks

[mirror_edk2.git] / IntelSiliconPkg / IntelVTdDxe / TranslationTable.c

diff --git a/IntelSiliconPkg/IntelVTdDxe/TranslationTable.c b/IntelSiliconPkg/IntelVTdDxe/TranslationTable.c
index 0cff2cc939a37ae98719448fa4ad6d1153541e09..5af4a4627b69cbd25640003ad16df8567da73283 100644 (file)
--- a/IntelSiliconPkg/IntelVTdDxe/TranslationTable.c
+++ b/IntelSiliconPkg/IntelVTdDxe/TranslationTable.c
@@ -862,6 +862,8 @@ SetAccessAttribute (
   VTD_SECOND_LEVEL_PAGING_ENTRY *SecondLevelPagingEntry;\r
   UINT64                        Pt;\r
 \r
+  SecondLevelPagingEntry = NULL;\r
+\r
   DEBUG ((DEBUG_INFO,"SetAccessAttribute (S%04x B%02x D%02x F%02x) (0x%016lx - 0x%08x, %x)\n", Segment, SourceId.Bits.Bus, SourceId.Bits.Device, SourceId.Bits.Function, BaseAddress, (UINTN)Length, IoMmuAccess));\r
 \r
   VtdIndex = FindVtdIndexByPciDevice (Segment, SourceId, &ExtContextEntry, &ContextEntry);\r
@@ -884,7 +886,7 @@ SetAccessAttribute (
       SecondLevelPagingEntry = (VOID *)(UINTN)LShiftU64 (ExtContextEntry->Bits.SecondLevelPageTranslationPointer, 12);\r
       DEBUG ((DEBUG_VERBOSE,"SecondLevelPagingEntry - 0x%x (S%04x B%02x D%02x F%02x)\n", SecondLevelPagingEntry, Segment, SourceId.Bits.Bus, SourceId.Bits.Device, SourceId.Bits.Function));\r
     }\r
-  } else {\r
+  } else if (ContextEntry != NULL) {\r
     if (ContextEntry->Bits.Present == 0) {\r
       SecondLevelPagingEntry = CreateSecondLevelPagingEntry (VtdIndex, 0);\r
       DEBUG ((DEBUG_VERBOSE,"SecondLevelPagingEntry - 0x%x (S%04x B%02x D%02x F%02x) New\n", SecondLevelPagingEntry, Segment, SourceId.Bits.Bus, SourceId.Bits.Device, SourceId.Bits.Function));\r
@@ -959,7 +961,7 @@ AlwaysEnablePageAttribute (
     ExtContextEntry->Bits.SecondLevelPageTranslationPointer = Pt;\r
     ExtContextEntry->Bits.DomainIdentifier = ((1 << (UINT8)((UINTN)mVtdUnitInformation[VtdIndex].CapReg.Bits.ND * 2 + 4)) - 1);\r
     ExtContextEntry->Bits.Present = 1;\r
-  } else {\r
+  } else if (ContextEntry != NULL) {\r
     ContextEntry->Bits.SecondLevelPageTranslationPointer = Pt;\r
     ContextEntry->Bits.DomainIdentifier = ((1 << (UINT8)((UINTN)mVtdUnitInformation[VtdIndex].CapReg.Bits.ND * 2 + 4)) - 1);\r
     ContextEntry->Bits.Present = 1;\r