audk/ArmPkg/Drivers/CpuDxe
Michael Kubacki 38ba4a64c5 ArmPkg/Drivers/CpuDxe: Use lower and upper attributes
GetNextEntryAttribute() is currently applying a 64-bit mask
(TT_ATTRIBUTES_MASK) to a 32-bit descriptor value (EntryType).
The original descriptor was 64 bits containing the upper and
lower attributes which are included in TT_ATTRIBUTES_MASK.

The PrevEntryAttribute parameter is also a UINT32, but passed to
PageAttributeToGcdAttribute() for a UINT64 parameter where the
function checks masks in the upper 32 bits of the integer value:

  PageAttributeToGcdAttribute (*PrevEntryAttribute)
  ...
  STATIC
  UINT64
  PageAttributeToGcdAttribute (
    IN UINT64  PageAttributes
    )
  ...
  if ((PageAttributes & (TT_PXN_MASK | TT_UXN_MASK)) != 0) {
    GcdAttributes |= EFI_MEMORY_XP;
  }
  ...
  #define TT_PXN_MASK  BIT53
  #define TT_UXN_MASK  BIT54  // EL1&0

This change removes UINT32 intermediary values. For EntryType,
eliminating an unncessary cast. For EntryAttribute, preserving the
upper and lower attributes for evaluation in
PageAttributeToGcdAttribute().

This also resolves the following compiler warning previously present
on Visual Studio for the assignment to the previously 32-bit local
variables.

  '=': conversion from 'UINT64' to 'UINT32', possible loss of data

Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2023-11-28 19:10:19 +00:00
..
AArch64 ArmPkg/Drivers/CpuDxe: Use lower and upper attributes 2023-11-28 19:10:19 +00:00
Arm ArmPkg: Add Function Headers to MMU Logic 2023-07-03 14:29:32 +00:00
CpuDxe.c ArmPkg: Drop individual memory permission helpers 2023-06-27 16:40:07 +00:00
CpuDxe.h ArmPkg/CpuDxe: Implement EFI memory attributes protocol 2023-03-16 21:14:49 +00:00
CpuDxe.inf ArmPkg/CpuDxe: Perform preliminary NX remap of free memory 2023-05-29 16:51:01 +00:00
CpuMmuCommon.c ArmPkg/ArmMmuLib: Extend API to manage memory permissions better 2023-06-26 09:11:53 +00:00
Exception.c ArmPkg: Apply uncrustify changes 2021-12-07 17:24:28 +00:00
MemoryAttribute.c ArmPkg/CpuDxe: Simplify memory attributes protocol implementation 2023-06-26 09:11:53 +00:00