Re: [PATCH 11/17] MIPS: Makefile: sign-extend TEXT_BASE value on CONFIG_64BIT

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 05.06.23 22:10, Denis Orlov wrote:
> The code that uses TEXT_BASE will fail on reading truncated 32-bit
> address if running with 64BIT enabled. As we only support running from
> compatibility segments (i.e. no 'proper' 64-bit base addresses), simply
> make sure the value is sign-extended when passing it as a define.

Below is not really a sign extension. e.g. 0x0000_0000 would be turned
into 0xffff_ffff_0000_0000. Is that ok? 

> 
> Signed-off-by: Denis Orlov <denorl2009@gmail.com>
> ---
>  arch/mips/Makefile | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/mips/Makefile b/arch/mips/Makefile
> index bad6e574c4..65a00379ab 100644
> --- a/arch/mips/Makefile
> +++ b/arch/mips/Makefile
> @@ -57,7 +57,13 @@ cflags-$(CONFIG_CPU_MIPS64_R1) += $(call cc-option,-march=mips64,-mips64 -U_MIPS
>  cflags-$(CONFIG_CPU_MIPS64_R2) += $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) -Wa,-mips64r2 -Wa,--trap
>  cflags-$(CONFIG_CPU_GS232)     += $(call cc-option,-march=mips32r2,-mips32r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS32) -Wa,-mips32r2 -Wa,--trap
>  
> -KBUILD_CPPFLAGS += -DTEXT_BASE=$(CONFIG_TEXT_BASE)
> +ifdef CONFIG_64BIT
> +MIPS_TEXT_BASE = $(subst 0x,0xffffffff,$(CONFIG_TEXT_BASE))
> +else
> +MIPS_TEXT_BASE = $(CONFIG_TEXT_BASE)
> +endif
> +
> +KBUILD_CPPFLAGS += -DTEXT_BASE=$(MIPS_TEXT_BASE)
>  
>  ifndef CONFIG_MODULES
>  # Add cleanup flags

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