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ArmPkg/Mmu: set required XN attributes for device mappings

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To prevent speculative intruction fetches from MMIO ranges that may
have side effects on reads, the architecture requires device mappings
to be created with the XN or UXN/PXN bits set (for the ARM/EL2 and
EL1&0 translation regimes, respectively.)

Note that, in the ARM case, this involves moving all accesses to a
client domain since permission attributes like XN are ignored from
a manager domain. The use of a client domain is actually mandated
explicitly by the UEFI spec.

Reported-by: Heyi Guo <heyi.guo@linaro.org>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18891 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Ard Biesheuvel
2015-11-18 11:51:06 +00:00
committed by abiesheuvel
parent 19bb46c411
commit 6bc35cbaca
3 changed files with 7 additions and 2 deletions
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2
ArmPkg/Include/Chipset/ArmV7Mmu.h
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@@ -192,6 +192,7 @@
TT_DESCRIPTOR_SECTION_S_NOT_SHARED | \
TT_DESCRIPTOR_SECTION_DOMAIN(0) | \
TT_DESCRIPTOR_SECTION_AP_RW_RW | \
TT_DESCRIPTOR_SECTION_XN_MASK | \
TT_DESCRIPTOR_SECTION_CACHE_POLICY_SHAREABLE_DEVICE)
#define TT_DESCRIPTOR_SECTION_UNCACHED(NonSecure) (TT_DESCRIPTOR_SECTION_TYPE_SECTION | \
((NonSecure) ? TT_DESCRIPTOR_SECTION_NS : 0) | \
@@ -215,6 +216,7 @@
TT_DESCRIPTOR_PAGE_NG_GLOBAL | \
TT_DESCRIPTOR_PAGE_S_NOT_SHARED | \
TT_DESCRIPTOR_PAGE_AP_RW_RW | \
TT_DESCRIPTOR_PAGE_XN_MASK | \
TT_DESCRIPTOR_PAGE_CACHE_POLICY_SHAREABLE_DEVICE)
#define TT_DESCRIPTOR_PAGE_UNCACHED (TT_DESCRIPTOR_PAGE_TYPE_PAGE | \
TT_DESCRIPTOR_PAGE_NG_GLOBAL | \