MdeModulePkg/PiSmmCore: fix bits operation error on a boundary condition

[mirror_edk2.git] / MdeModulePkg / Core / PiSmmCore / HeapGuard.c

diff --git a/MdeModulePkg/Core/PiSmmCore/HeapGuard.c b/MdeModulePkg/Core/PiSmmCore/HeapGuard.c
index c5ffb263420e0a3d37e1de9d9825c96ce87f1a17..f9657f9baa529c5b03c29106546dfdc66db2d6df 100644 (file)
--- a/MdeModulePkg/Core/PiSmmCore/HeapGuard.c
+++ b/MdeModulePkg/Core/PiSmmCore/HeapGuard.c
@@ -1,7 +1,7 @@
 /** @file\r
   UEFI Heap Guard functions.\r
 \r
-Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>\r
+Copyright (c) 2017-2018, Intel Corporation. All rights reserved.<BR>\r
 This program and the accompanying materials\r
 are licensed and made available under the terms and conditions of the BSD License\r
 which accompanies this distribution.  The full text of the license may be found at\r
@@ -73,7 +73,7 @@ SetBits (
   StartBit  = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address);\r
   EndBit    = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS;\r
 \r
-  if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) {\r
+  if ((StartBit + BitNumber) >= GUARDED_HEAP_MAP_ENTRY_BITS) {\r
     Msbs    = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) %\r
               GUARDED_HEAP_MAP_ENTRY_BITS;\r
     Lsbs    = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS;\r
@@ -126,7 +126,7 @@ ClearBits (
   StartBit  = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address);\r
   EndBit    = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS;\r
 \r
-  if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) {\r
+  if ((StartBit + BitNumber) >= GUARDED_HEAP_MAP_ENTRY_BITS) {\r
     Msbs    = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) %\r
               GUARDED_HEAP_MAP_ENTRY_BITS;\r
     Lsbs    = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS;\r
@@ -191,10 +191,14 @@ GetBits (
     Lsbs = 0;\r
   }\r
 \r
-  Result    = RShiftU64 ((*BitMap), StartBit) & (LShiftU64 (1, Msbs) - 1);\r
-  if (Lsbs > 0) {\r
-    BitMap  += 1;\r
-    Result  |= LShiftU64 ((*BitMap) & (LShiftU64 (1, Lsbs) - 1), Msbs);\r
+  if (StartBit == 0 && BitNumber == GUARDED_HEAP_MAP_ENTRY_BITS) {\r
+    Result = *BitMap;\r
+  } else {\r
+    Result    = RShiftU64((*BitMap), StartBit) & (LShiftU64(1, Msbs) - 1);\r
+    if (Lsbs > 0) {\r
+      BitMap  += 1;\r
+      Result  |= LShiftU64 ((*BitMap) & (LShiftU64 (1, Lsbs) - 1), Msbs);\r
+    }\r
   }\r
 \r
   return Result;\r
@@ -251,8 +255,8 @@ FindGuardedMemoryMap (
   //\r
   // Adjust current map table depth according to the address to access\r
   //\r
-  while (mMapLevel < GUARDED_HEAP_MAP_TABLE_DEPTH\r
-         &&\r
+  while (AllocMapUnit &&\r
+         mMapLevel < GUARDED_HEAP_MAP_TABLE_DEPTH &&\r
          RShiftU64 (\r
            Address,\r
            mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1]\r
@@ -887,11 +891,8 @@ AdjustMemoryS (
   }\r
 \r
   Target = Start + Size - SizeRequested;\r
-\r
-  //\r
-  // At least one more page needed for Guard page.\r
-  //\r
-  if (Size < (SizeRequested + EFI_PAGES_TO_SIZE (1))) {\r
+  ASSERT (Target >= Start);\r
+  if (Target == 0) {\r
     return 0;\r
   }\r
 \r