[CI CHECK]ArmPkg: CpuDxe: Report AARCH64 Memory Protections Attributes To GCD #4423
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When the AARCH64 CpuDxe attempts to SyncCacheConfig() with the GCD, it collects the page attributes as: EntryAttribute = Entry & TT_ATTR_INDX_MASK However, TT_ATTR_INDX_MASK only masks the cacheability attributes and drops the memory protections attributes. Importantly, it also drops the TT_AF (access flag) which is now wired up in EDK2 to represent EFI_MEMORY_RP, so by default all SystemMem pages will report as EFI_MEMORY_RP to the GCD. The GCD currently drops that silently, because the Capabilities field in the GCD does not support EFI_MEMORY_RP by default. However, some ranges may support EFI_MEMORY_RP and incorrectly mark those ranges as read protected. In conjunction with another change on the mailing list (see: https://edk2.groups.io/g/devel/topic/98505340#:~:text=This%20patch%20follows%20the%20UefiCpuPkg%20pattern%20and%20adds%3D0D,between%20the%20GCD%20and%20the%20page%20table.%3D0D%20%3D0D), this causes an access flag fault incorrectly. See the linked BZ below for full details. This patch exposes all memory protections attributes to the GCD layer so it can correctly set pages as EFI_MEMORY[RP|XP|RO] when it initially syncs. BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4463 Personal GitHub PR: tianocore#4423 Github branch: https://github.com/os-d/edk2/tree/aarch64_report_af_v1 Cc: Leif Lindholm <quic_llindhol@quicinc.com> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org> Cc: Sami Mujawar <sami.mujawar@arm.com> Cc: Taylor Beebe <t@taylorbeebe.com> Cc: Michael Kubacki <mikuback@linux.microsoft.com> Cc: Sean Brogan <sean.brogan@microsoft.com> Signed-off-by: Oliver Smith-Denny <osde@linux.microsoft.com>
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Closing as it was merged as: 647cd40. |
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When the AARCH64 CpuDxe attempts to SyncCacheConfig() with the GCD, it collects the page attributes as:
EntryAttribute = Entry & TT_ATTR_INDX_MASK
However, TT_ATTR_INDX_MASK only masks the cacheability attributes and drops the memory protections attributes. Importantly, it also drops the TT_AF (access flag) which is now wired up in EDK2 to represent EFI_MEMORY_RP, so by default all SystemMem pages will report as EFI_MEMORY_RP to the GCD. The GCD currently drops that silently, because the Capabilities field in the GCD does not support EFI_MEMORY_RP by default.
However, some ranges may support EFI_MEMORY_RP and incorrectly mark those ranges as read protected. In conjunction with another change on the mailing list (see:
https://edk2.groups.io/g/devel/topic/98505340#:~:text=This%20patch%20follows%20the%20UefiCpuPkg%20pattern%20and%20adds%3D0D,between%20the%20GCD%20and%20the%20page%20table.%3D0D%20%3D0D), this causes an access flag fault incorrectly. See the linked BZ below for full details.
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4463 Personal GitHub PR:
Github branch:
Cc: Leif Lindholm quic_llindhol@quicinc.com
Cc: Ard Biesheuvel ardb+tianocore@kernel.org
Cc: Sami Mujawar sami.mujawar@arm.com
Cc: Michael Kubacki mikuback@linux.microsoft.com
Cc: Sean Brogan sean.brogan@microsoft.com