X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=ArmVirtPkg%2FHighMemDxe%2FHighMemDxe.c;h=aa3f5f6d8956c4d8ca28ef1b6dcc9cb9973a9d65;hp=f70978f6414fc80c0325feb7afa42339ae4699f6;hb=76c09700edc67686b29662e81a3ca7d947594ce5;hpb=413edd470932d8e542325fa205b1e4f5e163a85c

diff --git a/ArmVirtPkg/HighMemDxe/HighMemDxe.c b/ArmVirtPkg/HighMemDxe/HighMemDxe.c
index f70978f641..aa3f5f6d89 100644
--- a/ArmVirtPkg/HighMemDxe/HighMemDxe.c
+++ b/ArmVirtPkg/HighMemDxe/HighMemDxe.c
@@ -20,6 +20,7 @@
 #include <Library/PcdLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 
+#include <Protocol/Cpu.h>
 #include <Protocol/FdtClient.h>
 
 EFI_STATUS
@@ -29,20 +30,26 @@ InitializeHighMemDxe (
   IN EFI_SYSTEM_TABLE     *SystemTable
   )
 {
-  FDT_CLIENT_PROTOCOL   *FdtClient;
-  EFI_STATUS            Status, FindNodeStatus;
-  INT32                 Node;
-  CONST UINT32          *Reg;
-  UINT32                RegSize;
-  UINTN                 AddressCells, SizeCells;
-  UINT64                CurBase;
-  UINT64                CurSize;
-  UINT64                Attributes;
+  FDT_CLIENT_PROTOCOL               *FdtClient;
+  EFI_CPU_ARCH_PROTOCOL             *Cpu;
+  EFI_STATUS                        Status, FindNodeStatus;
+  INT32                             Node;
+  CONST UINT32                      *Reg;
+  UINT32                            RegSize;
+  UINTN                             AddressCells, SizeCells;
+  UINT64                            CurBase;
+  UINT64                            CurSize;
+  UINT64                            Attributes;
+  EFI_GCD_MEMORY_SPACE_DESCRIPTOR   GcdDescriptor;
 
   Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
                   (VOID **)&FdtClient);
   ASSERT_EFI_ERROR (Status);
 
+  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL,
+                  (VOID **)&Cpu);
+  ASSERT_EFI_ERROR (Status);
+
   //
   // Check for memory node and add the memory spaces except the lowest one
   //
@@ -67,7 +74,14 @@ InitializeHighMemDxe (
       }
       RegSize -= (AddressCells + SizeCells) * sizeof (UINT32);
 
-      if (PcdGet64 (PcdSystemMemoryBase) != CurBase) {
+      Status = gDS->GetMemorySpaceDescriptor (CurBase, &GcdDescriptor);
+      if (EFI_ERROR (Status)) {
+        DEBUG ((DEBUG_WARN,
+          "%a: Region 0x%lx - 0x%lx not found in the GCD memory space map\n",
+          __FUNCTION__, CurBase, CurBase + CurSize - 1));
+          continue;
+      }
+      if (GcdDescriptor.GcdMemoryType == EfiGcdMemoryTypeNonExistent) {
         Status = gDS->AddMemorySpace (EfiGcdMemoryTypeSystemMemory, CurBase,
                         CurSize, EFI_MEMORY_WB);
 
@@ -78,13 +92,24 @@ InitializeHighMemDxe (
           continue;
         }
 
+        Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize,
+                        EFI_MEMORY_WB);
+        if (EFI_ERROR (Status)) {
+          DEBUG ((DEBUG_WARN,
+            "%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n",
+            __FUNCTION__, CurBase, CurBase + CurSize - 1, Status));
+        }
+
+        //
+        // Due to the ambiguous nature of the RO/XP GCD memory space attributes,
+        // it is impossible to add a memory space with the XP attribute in a way
+        // that does not result in the XP attribute being set on *all* UEFI
+        // memory map entries that are carved from it, including code regions
+        // that require executable permissions.
         //
-        // Take care not to strip any permission attributes that will have been
-        // set by DxeCore on the region we just added if a strict permission
-        // policy is in effect for EfiConventionalMemory regions.
-        // Unfortunately, we cannot interrogate the GCD memory space map for
-        // those permissions, since they are not recorded there (for historical
-        // reasons), so check the policy directly.
+        // So instead, we never set the RO/XP attributes in the GCD memory space
+        // capabilities or attribute fields, and apply any protections directly
+        // on the page table mappings by going through the cpu arch protocol.
         //
         Attributes = EFI_MEMORY_WB;
         if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) &
@@ -92,7 +117,7 @@ InitializeHighMemDxe (
           Attributes |= EFI_MEMORY_XP;
         }
 
-        Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize, Attributes);
+        Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes);
 
         if (EFI_ERROR (Status)) {
           DEBUG ((EFI_D_ERROR,