path: root/docs/firmware-design.rst
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authorJeenu Viswambharan <jeenu.viswambharan@arm.com>2018-08-15 14:29:29 +0100
committerJeenu Viswambharan <jeenu.viswambharan@arm.com>2018-10-16 08:31:13 +0100
commit3ff4aaaca44b75504aec5ab5b72cd587a6fcd432 (patch)
tree44b97dc48ba347fb1056d075f0ea9e549ee61cf7 /docs/firmware-design.rst
parent0a09313ec780d2f66efcda3eb2a5d1632719bd81 (diff)
AArch64: Enable lower ELs to use pointer authentication
Pointer authentication is an Armv8.3 feature that introduces instructions that can be used to authenticate and verify pointers. Pointer authentication instructions are allowed to be accessed from all ELs but only when EL3 explicitly allows for it; otherwise, their usage will trap to EL3. Since EL3 doesn't have trap handling in place, this patch unconditionally disables all related traps to EL3 to avoid potential misconfiguration leading to an unhandled EL3 exception. Fixes ARM-software/tf-issues#629 Change-Id: I9bd2efe0dc714196f503713b721ffbf05672c14d Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
Diffstat (limited to 'docs/firmware-design.rst')
1 files changed, 6 insertions, 0 deletions
diff --git a/docs/firmware-design.rst b/docs/firmware-design.rst
index 7cc74855de..051b92bbab 100644
--- a/docs/firmware-design.rst
+++ b/docs/firmware-design.rst
@@ -2532,6 +2532,12 @@ This Architecture Extension is targeted when ``ARM_ARCH_MAJOR`` == 8 and
translation table entries for a given stage of translation for a particular
translation regime.
+- Pointer Authentication features of Armv8.3-A are unconditionally enabled so
+ that lower ELs are allowed to use them without causing a trap to EL3.