diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2023-02-07 16:09:56 +0100 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2023-03-16 21:14:49 +0000 |
| commit | 6b821be1407c46950a2d334e5a240ea5ba47d416 (patch) | |
| tree | 17126792336bf1a0702719d614a6d0f030720075 /ArmPkg/Drivers | |
| parent | 041c7a31c2213844a7a30dd57205bae2f754a5bb (diff) | |
| download | edk2-6b821be1407c46950a2d334e5a240ea5ba47d416.tar.gz | |
ArmPkg/ArmMmuLib: Implement EFI_MEMORY_RP using access flag
Implement support for read-protected memory by wiring it up to the
access flag in the page table descriptor. The resulting mapping is
implicitly non-writable and non-executable as well, but this is good
enough for implementing this attribute, as we never rely on write or
execute permissions without read permissions.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>
Diffstat (limited to 'ArmPkg/Drivers')
| -rw-r--r-- | ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c b/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c index 8bb33046e7..8bda11f08a 100644 --- a/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c +++ b/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c @@ -64,6 +64,10 @@ PageAttributeToGcdAttribute ( }
// Determine protection attributes
+ if ((PageAttributes & TT_AF) == 0) {
+ GcdAttributes |= EFI_MEMORY_RP;
+ }
+
if (((PageAttributes & TT_AP_MASK) == TT_AP_NO_RO) ||
((PageAttributes & TT_AP_MASK) == TT_AP_RO_RO))
{
@@ -301,7 +305,9 @@ EfiAttributeToArmAttribute ( }
// Set the access flag to match the block attributes
- ArmAttributes |= TT_AF;
+ if ((EfiAttributes & EFI_MEMORY_RP) == 0) {
+ ArmAttributes |= TT_AF;
+ }
// Determine protection attributes
if ((EfiAttributes & EFI_MEMORY_RO) != 0) {
|