[PATCH] arm64: Make ARMV8_DEPRECATED depend on SYSCTL

[Punit Agrawal]

Dave Martin <Dave.Martin at arm.com> writes:

> If CONFIG_SYSCTL=n and CONFIG_ARMV8_DEPRECATED=y, the deprecated
> instruction emulation code currently leaks some memory at boot
> time, and won't have any runtime control interface.  This does
> not feel like useful or intended behaviour...
>
> This patch adds a dependency on CONFIG_SYSCTL, so that such a
> kernel can't be built in the first place.
>
> It's probably not worth adding the error-handling / cleanup code
> that would be needed to deal with this otherwise: people who
> desperately need the emulation can still enable SYSCTL.
>
> Signed-off-by: Dave Martin <Dave.Martin at arm.com>
> ---
>  arch/arm64/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 1046074..df296b7 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -807,6 +807,7 @@ config FORCE_MAX_ZONEORDER
>  menuconfig ARMV8_DEPRECATED
>  	bool "Emulate deprecated/obsolete ARMv8 instructions"
>  	depends on COMPAT
> +	depends on SYSCTL
>  	help
>  	  Legacy software support may require certain instructions
>  	  that have been deprecated or obsoleted in the architecture.

Adding the dependency makes sense.

Acked-by: Punit Agrawal <punit.agrawal at arm.com>

Thanks!