[PATCH v5 24/25] arm64: mte: Kconfig entry

Catalin Marinas
2020-06-24T17:53:45Z

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>
---

Notes:
v5:
- Remove duplicate ARMv8.5 menu entry.

v4:
- select ARCH_USES_PG_ARCH_2.
- remove ARCH_NO_SWAP.
- default y.

arch/arm64/Kconfig | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a4a094bedcb2..66f9b0805403 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1664,6 +1664,35 @@ config ARCH_RANDOM
provides a high bandwidth, cryptographically secure
hardware random number generator.

+config ARM64_AS_HAS_MTE
+ def_bool $(as-instr,.arch armv8.5-a+memtag)
+
+config ARM64_MTE
+ bool "Memory Tagging Extension support"
+ default y
+ depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
+ select ARCH_USES_HIGH_VMA_FLAGS
+ select ARCH_USES_PG_ARCH_2
+ 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