[PATCH v8 27/28] arm64: mte: Kconfig entry
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STALE2225d
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2020-08-24 18:29:08
Also in:
linux-mm
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Revision v8 of 3 in this series.
Revisions (3)
- v7 [diff vs current]
- v8 current
- v9 [diff vs current]
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:
v7:
- Binutils gained initial support for MTE in 2.32.0. However, a late
architecture addition (LDGM/STGM) is only supported in the newer
2.32.x and 2.33 versions. Change the AS_HAS_MTE option to also check
for stgm in addition to .arch armv8.5-a+memtag.
v6:
- Remove select ARCH_USES_PG_ARCH_2, no longer defined.
v5:
- Remove duplicate ARMv8.5 menu entry.
v4:
- select ARCH_USES_PG_ARCH_2.
- remove ARCH_NO_SWAP.
- default y.
arch/arm64/Kconfig | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6d232837cbee..10cf81d70657 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -1664,6 +1664,37 @@ config ARCH_RANDOM provides a high bandwidth, cryptographically secure hardware random number generator. +config ARM64_AS_HAS_MTE + # Binutils gained initial support for MTE in 2.32.0. However, a + # late architecture addition (LDGM/STGM) is only supported in + # the newer 2.32.x and 2.33 versions. + def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) + +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 + 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