[PATCH] arm64: mte: Ensure CONFIG_ARM64_PAN is enabled with MTE

[Catalin Marinas]

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.

Fixes: 89b94df9dfb1 ("arm64: mte: Kconfig entry")
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
---
 arch/arm64/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 844d62df776c..f9eed3a5917e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1673,6 +1673,8 @@ 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