On Fri, Mar 06, 2020 at 17:12:46 +0100, Ard Biesheuvel wrote:
> As it turns out, ARMv8 also permits accesses made with the MMU and
> caches off to hit in the caches, so to ensure that any modifications
> we make before enabling the MMU are visible afterwards as well, we
> should invalidate page tables right after allocation like we do now on
> ARM, if the MMU is still disabled at that point.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
Urgh.
Reviewed-by: Leif Lindholm <l...@nuviainc.com>
> ---
> ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> index e36594fea3ad..10ca8bac6a3f 100644
> --- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> +++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> @@ -217,6 +217,14 @@ UpdateRegionMappingRec (
> return EFI_OUT_OF_RESOURCES;
> }
>
> + if (!ArmMmuEnabled ()) {
> + //
> + // Make sure we are not inadvertently hitting in the caches
> + // when populating the page tables.
> + //
> + InvalidateDataCacheRange (TranslationTable, EFI_PAGE_SIZE);
> + }
> +
> if ((*Entry & TT_TYPE_MASK) == TT_TYPE_BLOCK_ENTRY) {
> //
> // We are splitting an existing block entry, so we have to populate
> @@ -581,6 +589,12 @@ ArmConfigureMmu (
> *TranslationTableSize = RootTableEntryCount * sizeof(UINT64);
> }
>
> + //
> + // Make sure we are not inadvertently hitting in the caches
> + // when populating the page tables.
> + //
> + InvalidateDataCacheRange (TranslationTable,
> + RootTableEntryCount * sizeof(UINT64));
> ZeroMem (TranslationTable, RootTableEntryCount * sizeof(UINT64));
>
> TranslationTableAttribute = TT_ATTR_INDX_INVALID;
> --
> 2.17.1
>
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#55613): https://edk2.groups.io/g/devel/message/55613
Mute This Topic: https://groups.io/mt/71776545/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
