MdeModulePkg: Fix MAT Descriptor Count Calculation

|4K PAGE|DATA|CODE|DATA|CODE|DATA|4K PAGE|
Say the above memory region is currently one memory map descriptor.
The above image memory layout example contains two code sections
oriented in a way that maximizes the number of descriptors which
would be required to describe each section.

NOTE: It's unlikely that a data section would ever be between
two code sections, but it's still handled by the below formula
for correctness.

There are two code sections (let's say CodeSegmentMax == 2),
three data sections, and two unrelated memory regions flanking the
image. The number of required descriptors to describe this layout
will be 2 * 2 + 3 == 7. This patch updates the calculations to account
for the worst-case scenario.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Dandan Bi <dandan.bi@intel.com>
Signed-off-by: Taylor Beebe <taylor.d.beebe@gmail.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

2 files changed, 2 insertions, 2 deletions

diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c b/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c
index 51630f504e..af6c26244c 100644
--- a/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c
+++ b/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c
@@ -517,7 +517,7 @@ CoreGetMemoryMapWithSeparatedImageSection (
 

   CoreAcquiremMemoryAttributesTableLock ();

 

-  AdditionalRecordCount = (2 * mImagePropertiesPrivateData.CodeSegmentCountMax + 1) * mImagePropertiesPrivateData.ImageRecordCount;

+  AdditionalRecordCount = (2 * mImagePropertiesPrivateData.CodeSegmentCountMax + 3) * mImagePropertiesPrivateData.ImageRecordCount;

 

   OldMemoryMapSize = *MemoryMapSize;

   Status           = CoreGetMemoryMap (MemoryMapSize, MemoryMap, MapKey, DescriptorSize, DescriptorVersion);

diff --git a/MdeModulePkg/Library/ImagePropertiesRecordLib/ImagePropertiesRecordLib.c b/MdeModulePkg/Library/ImagePropertiesRecordLib/ImagePropertiesRecordLib.c
index 9fb3b92203..7c0ecd07c1 100644
--- a/MdeModulePkg/Library/ImagePropertiesRecordLib/ImagePropertiesRecordLib.c
+++ b/MdeModulePkg/Library/ImagePropertiesRecordLib/ImagePropertiesRecordLib.c
@@ -277,7 +277,7 @@ GetMaxSplitRecordCount (
       break;

     }

 

-    SplitRecordCount += (2 * ImageRecord->CodeSegmentCount + 1);

+    SplitRecordCount += (2 * ImageRecord->CodeSegmentCount + 3);

     PhysicalStart     = ImageRecord->ImageBase + ImageRecord->ImageSize;

   } while ((ImageRecord != NULL) && (PhysicalStart < PhysicalEnd));