Re: [PATCH 15/15] riscv: add binfmt_flat support

[Vladimir Murzin <vladimir.murzin@arm.com>]

On 6/10/19 10:20 PM, Christoph Hellwig wrote:
> Use the generic support with arguments are on the stack.  Same as arm
> and m68k.

Out of curiosity, what is reason for keeping arguments on the stack?

ARM port of uClibc has following comment around manipulating of argv/argc:

        /*
         * uClinux/arm stacks look a little different from normal
         * MMU-full Linux/arm stacks (for no good reason)
         */

So I though it is kind of legacy.

Thanks
Vladimir

> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/riscv/Kconfig            | 2 ++
>  arch/riscv/include/asm/Kbuild | 1 +
>  2 files changed, 3 insertions(+)
> 
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 0c4b12205632..2e3b60cdeef4 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -17,7 +17,9 @@ config RISCV
>  	select OF
>  	select OF_EARLY_FLATTREE
>  	select OF_IRQ
> +	select ARCH_HAS_BINFMT_FLAT
>  	select ARCH_WANT_FRAME_POINTERS
> +	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
>  	select CLONE_BACKWARDS
>  	select COMMON_CLK
>  	select GENERIC_CLOCKEVENTS
> diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
> index 5ee646619cc3..1efaeddf1e4b 100644
> --- a/arch/riscv/include/asm/Kbuild
> +++ b/arch/riscv/include/asm/Kbuild
> @@ -5,6 +5,7 @@ generic-y += compat.h
>  generic-y += device.h
>  generic-y += div64.h
>  generic-y += extable.h
> +generic-y += flat.h
>  generic-y += dma.h
>  generic-y += dma-contiguous.h
>  generic-y += dma-mapping.h
>