OvmfPkg: Sec: force reinit of BaseExtractGuidedSectionLib handler table

[mirror_edk2.git] / OvmfPkg / Sec / SecMain.c

diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c
index 4f87059e1755f463b805be924cca732c5180bd8b..0cf127af8486cd5077164846e137ee8a9854c742 100644 (file)
--- a/OvmfPkg/Sec/SecMain.c
+++ b/OvmfPkg/Sec/SecMain.c
@@ -698,6 +698,19 @@ SecCoreStartupWithStack (
   SEC_IDT_TABLE               IdtTableInStack;\r
   IA32_DESCRIPTOR             IdtDescriptor;\r
   UINT32                      Index;\r
+  volatile UINT8              *Table;\r
+\r
+  //\r
+  // To ensure SMM can't be compromised on S3 resume, we must force re-init of\r
+  // the BaseExtractGuidedSectionLib. Since this is before library contructors\r
+  // are called, we must use a loop rather than SetMem.\r
+  //\r
+  Table = (UINT8*)(UINTN)FixedPcdGet64 (PcdGuidedExtractHandlerTableAddress);\r
+  for (Index = 0;\r
+       Index < FixedPcdGet32 (PcdGuidedExtractHandlerTableSize);\r
+       ++Index) {\r
+    Table[Index] = 0;\r
+  }\r
 \r
   ProcessLibraryConstructorList (NULL, NULL);\r
 \r