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Date:   Tue, 27 Aug 2019 17:07:38 +0800
From:   Nick Hu <nickhu@andestech.com>
To:     Andrey Ryabinin <aryabinin@virtuozzo.com>
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Subject: Re: [PATCH 1/2] riscv: Add memmove string operation.
Message-ID: <20190827090738.GA22972@andestech.com>
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Hi Andrey

On Thu, Aug 22, 2019 at 11:59:02PM +0800, Andrey Ryabinin wrote:
> On 8/7/19 10:19 AM, Nick Hu wrote:
> > There are some features which need this string operation for compilation,
> > like KASAN. So the purpose of this porting is for the features like KASAN
> > which cannot be compiled without it.
> > 
> 
> Compilation error can be fixed by diff bellow (I didn't test it).
> If you don't need memmove very early (before kasan_early_init()) than arch-specific not-instrumented memmove()
> isn't necessary to have.
> 
> ---
>  mm/kasan/common.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 6814d6d6a023..897f9520bab3 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -107,6 +107,7 @@ void *memset(void *addr, int c, size_t len)
>  	return __memset(addr, c, len);
>  }
>  
> +#ifdef __HAVE_ARCH_MEMMOVE
>  #undef memmove
>  void *memmove(void *dest, const void *src, size_t len)
>  {
> @@ -115,6 +116,7 @@ void *memmove(void *dest, const void *src, size_t len)
>  
>  	return __memmove(dest, src, len);
>  }
> +#endif
>  
>  #undef memcpy
>  void *memcpy(void *dest, const void *src, size_t len)
> -- 
> 2.21.0
> 
> 
> 
I have confirmed that the string operations are not used before kasan_early_init().
But I can't make sure whether other ARCHs would need it before kasan_early_init().
Do you have any idea to check that? Should I cc all other ARCH maintainers?

Nick