Re: [RFC] MIPS: Enable ARCH_HAS_DEBUG_VIRTUAL for 64-bit

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

On Thu, Jul 07, 2022 at 03:04:27PM -0700, Florian Fainelli wrote:
> Update __debug_virt_addr_valid() to check for a virtual address'
> validity below CKSSEG and remove the !64BIT dependency on
> ARCH_HAS_DEBUG_VIRTUAL to make DEBUG_VIRTUAL selectable.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
> This requires the previous patch to be applied for this to work cleanly.
> 
>  arch/mips/Kconfig       | 2 +-
>  arch/mips/mm/physaddr.c | 4 ++++
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index db09d45d59ec..ddb6bde8fa1f 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -5,7 +5,7 @@ config MIPS
>  	select ARCH_32BIT_OFF_T if !64BIT
>  	select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
>  	select ARCH_HAS_CURRENT_STACK_POINTER if !CC_IS_CLANG || CLANG_VERSION >= 140000
> -	select ARCH_HAS_DEBUG_VIRTUAL if !64BIT
> +	select ARCH_HAS_DEBUG_VIRTUAL
>  	select ARCH_HAS_FORTIFY_SOURCE
>  	select ARCH_HAS_KCOV
>  	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if !EVA
> diff --git a/arch/mips/mm/physaddr.c b/arch/mips/mm/physaddr.c
> index a82f8f57a652..3076238943d3 100644
> --- a/arch/mips/mm/physaddr.c
> +++ b/arch/mips/mm/physaddr.c
> @@ -31,7 +31,11 @@ static inline bool __debug_virt_addr_valid(unsigned long x)
>  	if (x == MAX_DMA_ADDRESS)
>  		return true;
>  
> +#ifdef CONFIG_64BIT
> +	return KSEGX(x) < CKSSEG;

as KSEGX does 32bit casts, I have some doubts that this is correct.
What do I miss ?

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
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