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| 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/Library/ArmMmuLib/Arm | |
| parent | 041c7a31c2213844a7a30dd57205bae2f754a5bb (diff) | |
| download | edk2-6b821be1407c46950a2d334e5a240ea5ba47d416.tar.gz edk2-6b821be1407c46950a2d334e5a240ea5ba47d416.tar.bz2 edk2-6b821be1407c46950a2d334e5a240ea5ba47d416.zip | |
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/Library/ArmMmuLib/Arm')
| -rw-r--r-- | ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c index 23f613f5db..247cf87bf3 100644 --- a/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c +++ b/ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c @@ -523,3 +523,51 @@ ArmClearMemoryRegionReadOnly ( TT_DESCRIPTOR_SECTION_AP_MASK
);
}
+
+/**
+ Convert a region of memory to read-protected, by clearing the access flag.
+
+ @param BaseAddress The start of the region.
+ @param Length The size of the region.
+
+ @retval EFI_SUCCESS The attributes were set successfully.
+ @retval EFI_OUT_OF_RESOURCES The operation failed due to insufficient memory.
+
+**/
+EFI_STATUS
+ArmSetMemoryRegionNoAccess (
+ IN EFI_PHYSICAL_ADDRESS BaseAddress,
+ IN UINT64 Length
+ )
+{
+ return SetMemoryAttributes (
+ BaseAddress,
+ Length,
+ EFI_MEMORY_RP,
+ TT_DESCRIPTOR_SECTION_AF
+ );
+}
+
+/**
+ Convert a region of memory to read-enabled, by setting the access flag.
+
+ @param BaseAddress The start of the region.
+ @param Length The size of the region.
+
+ @retval EFI_SUCCESS The attributes were set successfully.
+ @retval EFI_OUT_OF_RESOURCES The operation failed due to insufficient memory.
+
+**/
+EFI_STATUS
+ArmClearMemoryRegionNoAccess (
+ IN EFI_PHYSICAL_ADDRESS BaseAddress,
+ IN UINT64 Length
+ )
+{
+ return SetMemoryAttributes (
+ BaseAddress,
+ Length,
+ 0,
+ TT_DESCRIPTOR_SECTION_AF
+ );
+}
|