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Date:   Thu, 05 Nov 2020 23:45:03 -0800 (PST)
Subject:     Re: [PATCH] riscv: uaccess: fix __put_kernel_nofault()
In-Reply-To: <20201102073052.199638-1-changbin.du@gmail.com>
CC:     Paul Walmsley <paul.walmsley@sifive.com>, aou@eecs.berkeley.edu,
        akpm@linux-foundation.org, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, changbin.du@gmail.com,
        Christoph Hellwig <hch@lst.de>
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     changbin.du@gmail.com
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On Sun, 01 Nov 2020 23:30:52 PST (-0800), changbin.du@gmail.com wrote:
> The copy_from_kernel_nofault() is broken on riscv because the 'dst' and
> 'src' are mistakenly reversed in __put_kernel_nofault() macro.
>
> copy_to_kernel_nofault:
> ...
> 0xffffffe0003159b8 <+30>:    sd      a4,0(a1) # a1 aka 'src'
>
> Fixes: d464118cdc ("riscv: implement __get_kernel_nofault and __put_user_nofault")
> Signed-off-by: Changbin Du <changbin.du@gmail.com>
> Cc: Christoph Hellwig <hch@lst.de>
> ---
>  arch/riscv/include/asm/uaccess.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
> index c47e6b35c551..824b2c9da75b 100644
> --- a/arch/riscv/include/asm/uaccess.h
> +++ b/arch/riscv/include/asm/uaccess.h
> @@ -476,7 +476,7 @@ do {									\
>  do {									\
>  	long __kr_err;							\
>  									\
> -	__put_user_nocheck(*((type *)(dst)), (type *)(src), __kr_err);	\
> +	__put_user_nocheck(*((type *)(src)), (type *)(dst), __kr_err);	\
>  	if (unlikely(__kr_err))						\
>  		goto err_label;						\
>  } while (0)

Thanks, this is on fixes.