[PATCH v5 10/17] arm64: enable pointer authentication

From: Kristina Martsenko
Date: Fri Oct 05 2018 - 04:50:27 EST


From: Mark Rutland <mark.rutland@xxxxxxx>

Now that all the necessary bits are in place for userspace, add the
necessary Kconfig logic to allow this to be enabled.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Kristina Martsenko <kristina.martsenko@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
---
arch/arm64/Kconfig | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1b1a0e95c751..8a6d44160fa8 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1134,6 +1134,29 @@ config ARM64_RAS_EXTN

endmenu

+menu "ARMv8.3 architectural features"
+
+config ARM64_PTR_AUTH
+ bool "Enable support for pointer authentication"
+ default y
+ help
+ Pointer authentication (part of the ARMv8.3 Extensions) provides
+ instructions for signing and authenticating pointers against secret
+ keys, which can be used to mitigate Return Oriented Programming (ROP)
+ and other attacks.
+
+ This option enables these instructions at EL0 (i.e. for userspace).
+
+ Choosing this option will cause the kernel to initialise secret keys
+ for each process at exec() time, with these keys being
+ context-switched along with the process.
+
+ The feature is detected at runtime. If the feature is not present in
+ hardware it will not be advertised to userspace nor will it be
+ enabled.
+
+endmenu
+
config ARM64_SVE
bool "ARM Scalable Vector Extension support"
default y
--
2.11.0