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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 | |
| 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')
| -rw-r--r-- | ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c | 8 | ||||
| -rw-r--r-- | ArmPkg/Include/Library/ArmMmuLib.h | 34 | ||||
| -rw-r--r-- | ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c | 58 | ||||
| -rw-r--r-- | ArmPkg/Library/ArmMmuLib/Arm/ArmMmuLibUpdate.c | 48 |
4 files changed, 144 insertions, 4 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) {
diff --git a/ArmPkg/Include/Library/ArmMmuLib.h b/ArmPkg/Include/Library/ArmMmuLib.h index b745e2230e..4cf59a1e37 100644 --- a/ArmPkg/Include/Library/ArmMmuLib.h +++ b/ArmPkg/Include/Library/ArmMmuLib.h @@ -21,6 +21,40 @@ ArmConfigureMmu ( OUT UINTN *TranslationTableSize OPTIONAL
);
+/**
+ 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
+EFIAPI
+ArmSetMemoryRegionNoAccess (
+ IN EFI_PHYSICAL_ADDRESS BaseAddress,
+ IN UINT64 Length
+ );
+
+/**
+ 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
+EFIAPI
+ArmClearMemoryRegionNoAccess (
+ IN EFI_PHYSICAL_ADDRESS BaseAddress,
+ IN UINT64 Length
+ );
+
EFI_STATUS
EFIAPI
ArmSetMemoryRegionNoExec (
diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c index 764c7d362e..6d21a2e41d 100644 --- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c +++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c @@ -438,7 +438,11 @@ GcdAttributeToPageAttribute ( PageAttributes |= TT_AP_NO_RO;
}
- return PageAttributes | TT_AF;
+ if ((GcdAttributes & EFI_MEMORY_RP) == 0) {
+ PageAttributes |= TT_AF;
+ }
+
+ return PageAttributes;
}
EFI_STATUS
@@ -459,9 +463,9 @@ ArmSetMemoryAttributes ( // No memory type was set in Attributes, so we are going to update the
// permissions only.
//
- PageAttributes &= TT_AP_MASK | TT_UXN_MASK | TT_PXN_MASK;
+ PageAttributes &= TT_AP_MASK | TT_UXN_MASK | TT_PXN_MASK | TT_AF;
PageAttributeMask = ~(TT_ADDRESS_MASK_BLOCK_ENTRY | TT_AP_MASK |
- TT_PXN_MASK | TT_XN_MASK);
+ TT_PXN_MASK | TT_XN_MASK | TT_AF);
}
return UpdateRegionMapping (
@@ -534,6 +538,54 @@ ArmClearMemoryRegionNoExec ( );
}
+/**
+ 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 SetMemoryRegionAttribute (
+ BaseAddress,
+ Length,
+ 0,
+ ~(TT_ADDRESS_MASK_BLOCK_ENTRY | TT_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 SetMemoryRegionAttribute (
+ BaseAddress,
+ Length,
+ TT_AF,
+ ~TT_ADDRESS_MASK_BLOCK_ENTRY
+ );
+}
+
EFI_STATUS
ArmSetMemoryRegionReadOnly (
IN EFI_PHYSICAL_ADDRESS BaseAddress,
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
+ );
+}
|