UefiCpuPkg/CpuDxe: Enable protection for newly added page table

[mirror_edk2.git] / UefiCpuPkg / CpuDxe / CpuDxe.c

diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.c b/UefiCpuPkg/CpuDxe/CpuDxe.c
index 8ddebabd02eaa2b3a02833717679ee69858f42e5..6ae2dcd1c71136bd6fa364ba906dd80a6befcde6 100644 (file)
--- a/UefiCpuPkg/CpuDxe/CpuDxe.c
+++ b/UefiCpuPkg/CpuDxe/CpuDxe.c
@@ -25,6 +25,7 @@
 BOOLEAN                   InterruptState = FALSE;\r
 EFI_HANDLE                mCpuHandle = NULL;\r
 BOOLEAN                   mIsFlushingGCD;\r
+BOOLEAN                   mIsAllocatingPageTable = FALSE;\r
 UINT64                    mValidMtrrAddressMask;\r
 UINT64                    mValidMtrrBitsMask;\r
 UINT64                    mTimerPeriod = 0;\r
@@ -407,6 +408,20 @@ CpuSetMemoryAttributes (
     return EFI_SUCCESS;\r
   }\r
 \r
+  //\r
+  // During memory attributes updating, new pages may be allocated to setup\r
+  // smaller granularity of page table. Page allocation action might then cause\r
+  // another calling of CpuSetMemoryAttributes() recursively, due to memory\r
+  // protection policy configured (such as PcdDxeNxMemoryProtectionPolicy).\r
+  // Since this driver will always protect memory used as page table by itself,\r
+  // there's no need to apply protection policy requested from memory service.\r
+  // So it's safe to just return EFI_SUCCESS if this time of calling is caused\r
+  // by page table memory allocation.\r
+  //\r
+  if (mIsAllocatingPageTable) {\r
+    DEBUG((DEBUG_VERBOSE, "  Allocating page table memory\n"));\r
+    return EFI_SUCCESS;\r
+  }\r
 \r
   CacheAttributes = Attributes & CACHE_ATTRIBUTE_MASK;\r
   MemoryAttributes = Attributes & MEMORY_ATTRIBUTE_MASK;\r
@@ -487,7 +502,7 @@ CpuSetMemoryAttributes (
   //\r
   // Set memory attribute by page table\r
   //\r
-  return AssignMemoryPageAttributes (NULL, BaseAddress, Length, MemoryAttributes, AllocatePages);\r
+  return AssignMemoryPageAttributes (NULL, BaseAddress, Length, MemoryAttributes, NULL);\r
 }\r
 \r
 /**\r