[PATCH v3 22/23] arm64: mte: Kconfig entry

Catalin Marinas
2020-04-21T14:33:29Z

From: Vincenzo Frascino <vincenzo.frascino@arm.com>

Add Memory Tagging Extension support to the arm64 kbuild.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/Kconfig | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 40fb05d96c60..af2e6e5dae1b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1606,6 +1606,38 @@ config ARCH_RANDOM

endmenu

+menu "ARMv8.5 architectural features"
+
+config ARM64_AS_HAS_MTE
+ def_bool $(as-instr,.arch armv8.5-a+memtag)
+
+config ARM64_MTE
+ bool "Memory Tagging Extension support"
+ depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
+ select ARCH_USES_HIGH_VMA_FLAGS
+ select ARCH_NO_SWAP
+ help
+ Memory Tagging (part of the ARMv8.5 Extensions) provides
+ architectural support for run-time, always-on detection of
+ various classes of memory error to aid with software debugging
+ to eliminate vulnerabilities arising from memory-unsafe
+ languages.
+
+ This option enables the support for the Memory Tagging
+ Extension at EL0 (i.e. for userspace).
+
+ Selecting this option allows the feature to be detected at
+ runtime. Any secondary CPU not implementing this feature will
+ not be allowed a late bring-up.
+
+ Userspace binaries that want to use this feature must
+ explicitly opt in. The mechanism for the userspace is
+ described in:
+
+ Documentation/arm64/memory-tagging-extension.rst.
+
+endmenu
+
config ARM64_SVE
bool "ARM Scalable Vector Extension support"
default y