From 35dde2452d03227a02434e5fad70cd424ab1a274 Mon Sep 17 00:00:00 2001
From: Sean Rhodes <sean@starlabs.systems>
Date: Thu, 31 Mar 2022 16:53:51 +0100
Subject: [PATCH] MdeModulePkg/FaultTolerantWriteDxe: Don't check for address
 alignment

WorkSpaceAddress and SpareAreaAddress point into MMIO, which isn't
always aligned. Remove the check for block alignment to avoid
false assertions.

Signed-off-by: Sean Rhodes <sean@starlabs.systems>
Change-Id: Ia1c1f44b6a0e7f32cac0d7806e74d729e5d83a6d
---
 .../Universal/FaultTolerantWriteDxe/FtwMisc.c | 20 ++++++++-----------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FtwMisc.c b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FtwMisc.c
index f1335870e7..b342b353af 100644
--- a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FtwMisc.c
+++ b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FtwMisc.c
@@ -1119,8 +1119,8 @@ FindFvbForFtw (
       // To get the LBA of work space
       //
       for (LbaIndex = 1; LbaIndex <= NumberOfBlocks; LbaIndex += 1) {
-        if (  (FtwDevice->WorkSpaceAddress >= (FvbBaseAddress + BlockSize * (LbaIndex - 1)))
-           && (FtwDevice->WorkSpaceAddress < (FvbBaseAddress + BlockSize * LbaIndex)))
+        if (FtwDevice->WorkSpaceAddress - FvbBaseAddress >= BlockSize * (LbaIndex - 1) &&
+            (FtwDevice->WorkSpaceAddress - FvbBaseAddress) / BlockSize >= LbaIndex - 1)
         {
           FtwDevice->FtwWorkSpaceLba = LbaIndex - 1;
           //
@@ -1132,12 +1132,10 @@ FindFvbForFtw (
           FtwDevice->NumberOfWorkSpaceBlock = FTW_BLOCKS (FtwDevice->FtwWorkSpaceBase + FtwDevice->FtwWorkSpaceSize, FtwDevice->WorkBlockSize);
           if (FtwDevice->FtwWorkSpaceSize >= FtwDevice->WorkBlockSize) {
             //
-            // Check the alignment of work space address and length, they should be block size aligned when work space size is larger than one block size.
+            // Check the alignment of work space length, it should be block size aligned when work space size is larger than one block size.
             //
-            if (((FtwDevice->WorkSpaceAddress & (FtwDevice->WorkBlockSize - 1)) != 0) ||
-                ((FtwDevice->WorkSpaceLength & (FtwDevice->WorkBlockSize - 1)) != 0))
-            {
-              DEBUG ((DEBUG_ERROR, "Ftw: Work space address or length is not block size aligned when work space size is larger than one block size\n"));
+            if ((FtwDevice->WorkSpaceLength & (FtwDevice->WorkBlockSize - 1)) != 0) {
+              DEBUG ((EFI_D_ERROR, "Ftw: Work space length is not block size aligned when work space size is larger than one block size\n"));
               FreePool (HandleBuffer);
               ASSERT (FALSE);
               return EFI_ABORTED;
@@ -1182,12 +1180,10 @@ FindFvbForFtw (
           }
 
           //
-          // Check the alignment of spare area address and length, they should be block size aligned
+          // Check the alignment of spare area length, it should be block size aligned
           //
-          if (((FtwDevice->SpareAreaAddress & (FtwDevice->SpareBlockSize - 1)) != 0) ||
-              ((FtwDevice->SpareAreaLength & (FtwDevice->SpareBlockSize - 1)) != 0))
-          {
-            DEBUG ((DEBUG_ERROR, "Ftw: Spare area address or length is not block size aligned\n"));
+          if ((FtwDevice->SpareAreaLength & (FtwDevice->SpareBlockSize - 1)) != 0) {
+            DEBUG ((EFI_D_ERROR, "Ftw: Spare area address or length is not block size aligned\n"));
             FreePool (HandleBuffer);
             //
             // Report Status Code EFI_SW_EC_ABORTED.