The patch titled
Subject: arm64: mte: ensure CONFIG_ARM64_PAN is enabled with MTE
has been added to the -mm tree. Its filename is
arm64-mte-add-in-kernel-tag-fault-handler-fix.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/arm64-mte-add-in-kernel-tag-fault-handler-fix.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/arm64-mte-add-in-kernel-tag-fault-handler-fix.patch
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------------------------------------------------------
From: Catalin Marinas <catalin.marinas@xxxxxxx>
Subject: arm64: mte: ensure CONFIG_ARM64_PAN is enabled with MTE
The uaccess routines like get/put_user() rely on the user TCF0 mode
setting for tag checking. However, if CONFIG_ARM64_PAN is disabled, these
routines would use the standard LDR/STR instructions and therefore the
kernel TCF mode. In 5.10, the kernel TCF==0, so no tag checking, but this
will change with the in-kernel MTE support.
Make ARM64_MTE depend on ARM64_PAN.
Link: https://lkml.kernel.org/r/20201203102628.GB2224@gaia
Fixes: 89b94df9dfb1 ("arm64: mte: Kconfig entry")
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm64/Kconfig | 2 ++
1 file changed, 2 insertions(+)
--- a/arch/arm64/Kconfig~arm64-mte-add-in-kernel-tag-fault-handler-fix
+++ a/arch/arm64/Kconfig
@@ -1650,6 +1650,8 @@ config ARM64_MTE
default y
depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI
depends on AS_HAS_ARMV8_5
+ # Required for tag checking in the uaccess routines
+ depends on ARM64_PAN
select ARCH_USES_HIGH_VMA_FLAGS
help
Memory Tagging (part of the ARMv8.5 Extensions) provides
_
Patches currently in -mm which might be from catalin.marinas@xxxxxxx are
arm64-mte-add-in-kernel-tag-fault-handler-fix.patch
