ArmPkg/BdsLib: Fixed manipulation of the Memory Map returned by GetMemoryMap()

The UEFI specification mandates that software uses the DescriptorSize returned
by the GetMemoryMap() function to find the start of each EFI_MEMORY_DESCRIPTOR
in the MemoryMap array. This allows for future expansion of the EFI_MEMORY_DESCRIPTOR.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14447 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 15 insertions, 6 deletions

diff --git a/ArmPkg/Library/BdsLib/BdsLinuxFdt.c b/ArmPkg/Library/BdsLib/BdsLinuxFdt.c
index 821774020..1927de726 100644
--- a/ArmPkg/Library/BdsLib/BdsLinuxFdt.c
+++ b/ArmPkg/Library/BdsLib/BdsLinuxFdt.c
@@ -354,6 +354,7 @@ PrepareFdt (
   UINT64                CpuReleaseAddr;

   UINTN                 MemoryMapSize;

   EFI_MEMORY_DESCRIPTOR *MemoryMap;

+  EFI_MEMORY_DESCRIPTOR *MemoryMapPtr;

   UINTN                 MapKey;

   UINTN                 DescriptorSize;

   UINT32                DescriptorVersion;

@@ -483,24 +484,32 @@ PrepareFdt (
   MemoryMapSize = 0;

   Status = gBS->GetMemoryMap (&MemoryMapSize, MemoryMap, &MapKey, &DescriptorSize, &DescriptorVersion);

   if (Status == EFI_BUFFER_TOO_SMALL) {

+    // The UEFI specification advises to allocate more memory for the MemoryMap buffer between successive

+    // calls to GetMemoryMap(), since allocation of the new buffer may potentially increase memory map size.

     Pages = EFI_SIZE_TO_PAGES (MemoryMapSize) + 1;

     MemoryMap = AllocatePages (Pages);

+    if (MemoryMap == NULL) {

+      Status = EFI_OUT_OF_RESOURCES;

+      goto FAIL_COMPLETE_FDT;

+    }

     Status = gBS->GetMemoryMap (&MemoryMapSize, MemoryMap, &MapKey, &DescriptorSize, &DescriptorVersion);

   }

 

   // Go through the list and add the reserved region to the Device Tree

   if (!EFI_ERROR(Status)) {

-    for (Index = 0; Index < (MemoryMapSize / sizeof(EFI_MEMORY_DESCRIPTOR)); Index++) {

-      if (IsLinuxReservedRegion ((EFI_MEMORY_TYPE)MemoryMap[Index].Type)) {

+    MemoryMapPtr = MemoryMap;

+    for (Index = 0; Index < (MemoryMapSize / DescriptorSize); Index++) {

+      if (IsLinuxReservedRegion ((EFI_MEMORY_TYPE)MemoryMapPtr->Type)) {

         DEBUG((DEBUG_VERBOSE, "Reserved region of type %d [0x%X, 0x%X]\n",

-            MemoryMap[Index].Type,

-            (UINTN)MemoryMap[Index].PhysicalStart,

-            (UINTN)(MemoryMap[Index].PhysicalStart + MemoryMap[Index].NumberOfPages * EFI_PAGE_SIZE)));

-        err = fdt_add_mem_rsv(fdt, MemoryMap[Index].PhysicalStart, MemoryMap[Index].NumberOfPages * EFI_PAGE_SIZE);

+            MemoryMapPtr->Type,

+            (UINTN)MemoryMapPtr->PhysicalStart,

+            (UINTN)(MemoryMapPtr->PhysicalStart + MemoryMapPtr->NumberOfPages * EFI_PAGE_SIZE)));

+        err = fdt_add_mem_rsv(fdt, MemoryMapPtr->PhysicalStart, MemoryMapPtr->NumberOfPages * EFI_PAGE_SIZE);

         if (err != 0) {

           Print(L"Warning: Fail to add 'memreserve' (err:%d)\n", err);

         }

       }

+      MemoryMapPtr = (EFI_MEMORY_DESCRIPTOR*)((UINTN)MemoryMapPtr + DescriptorSize);

     }

   }