[PATCH] MdePkg PeiHobLib: Check FV alignment when building FV HOB

[PATCH] MdePkg PeiHobLib: Check FV alignment when building FV HOB

[Star Zeng]

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=205

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
---
 MdePkg/Library/PeiHobLib/HobLib.c | 66 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 65 insertions(+), 1 deletion(-)

diff --git a/MdePkg/Library/PeiHobLib/HobLib.c b/MdePkg/Library/PeiHobLib/HobLib.c
index f3ce93afc63e..f2e44016e71c 100644
--- a/MdePkg/Library/PeiHobLib/HobLib.c
+++ b/MdePkg/Library/PeiHobLib/HobLib.c
@@ -1,7 +1,7 @@
 /** @file
   Provide Hob Library functions for Pei phase.
 
-Copyright (c) 2007 - 2014, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2007 - 2016, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -474,6 +474,62 @@ BuildGuidDataHob (
 }
 
 /**
+  Check FV alignment.
+
+  @param  BaseAddress   The base address of the Firmware Volume.
+  @param  Length        The size of the Firmware Volume in bytes.
+
+  @retval TRUE          FvImage buffer is at its required alignment.
+  @retval FALSE         FvImage buffer is not at its required alignment.
+
+**/
+BOOLEAN
+InternalCheckFvAlignment (
+  IN EFI_PHYSICAL_ADDRESS       BaseAddress,
+  IN UINT64                     Length
+  )
+{
+  EFI_FIRMWARE_VOLUME_HEADER    *FwVolHeader;
+  UINT32                        FvAlignment;
+
+  FvAlignment = 0;
+  FwVolHeader = (EFI_FIRMWARE_VOLUME_HEADER *) (UINTN) BaseAddress;
+
+  //
+  // If EFI_FVB2_WEAK_ALIGNMENT is set in the volume header then the first byte of the volume
+  // can be aligned on any power-of-two boundary. A weakly aligned volume can not be moved from
+  // its initial linked location and maintain its alignment.
+  //
+  if ((FwVolHeader->Attributes & EFI_FVB2_WEAK_ALIGNMENT) != EFI_FVB2_WEAK_ALIGNMENT) {
+    //
+    // Get FvHeader alignment
+    //
+    FvAlignment = 1 << ((FwVolHeader->Attributes & EFI_FVB2_ALIGNMENT) >> 16);
+    //
+    // FvAlignment must be greater than or equal to 8 bytes of the minimum FFS alignment value.
+    //
+    if (FvAlignment < 8) {
+      FvAlignment = 8;
+    }
+    if ((UINTN)BaseAddress % FvAlignment != 0) {
+      //
+      // FvImage buffer is not at its required alignment.
+      //
+      DEBUG ((
+        DEBUG_ERROR,
+        "Unaligned FvImage found at 0x%lx:0x%lx, the required alignment is 0x%x\n",
+        BaseAddress,
+        Length,
+        FvAlignment
+        ));
+      return FALSE;
+    }
+  }
+
+  return TRUE;
+}
+
+/**
   Builds a Firmware Volume HOB.
 
   This function builds a Firmware Volume HOB.
@@ -495,6 +551,10 @@ BuildFvHob (
 {
   EFI_HOB_FIRMWARE_VOLUME  *Hob;
 
+  if (!InternalCheckFvAlignment (BaseAddress, Length)) {
+    return;
+  }
+
   Hob = InternalPeiCreateHob (EFI_HOB_TYPE_FV, (UINT16) sizeof (EFI_HOB_FIRMWARE_VOLUME));
   if (Hob == NULL) {
     return;
@@ -530,6 +590,10 @@ BuildFv2Hob (
 {
   EFI_HOB_FIRMWARE_VOLUME2  *Hob;
 
+  if (!InternalCheckFvAlignment (BaseAddress, Length)) {
+    return;
+  }
+
   Hob = InternalPeiCreateHob (EFI_HOB_TYPE_FV2, (UINT16) sizeof (EFI_HOB_FIRMWARE_VOLUME2));
   if (Hob == NULL) {
     return;
-- 
2.7.0.windows.1