Subject: Re: [PATCH v1 02/27] powerpc/mm: don't BUG in add_huge_page_size()

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Thu, 11 Apr 2019 11:11:13 +0530

Christophe Leroy <[email-masked]> writes:

> No reason to BUG() in add_huge_page_size(). Just WARN and
> reject the add.
>
> Signed-off-by: Christophe Leroy <[email-masked]>
> ---
>  arch/powerpc/mm/hugetlbpage.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index 9e732bb2c84a..cf2978e235f3 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -634,7 +634,8 @@ static int __init add_huge_page_size(unsigned long long size)
>  	}
>  #endif
>  
> -	BUG_ON(mmu_psize_defs[mmu_psize].shift != shift);
> +	if (WARN_ON(mmu_psize_defs[mmu_psize].shift != shift))
> +		return -EINVAL;

Same here. There are not catching runtime errors. We should never find
that true. This is to catch mistakes during development changes. Switch
to VM_BUG_ON?

>  
>  	/* Return if huge page size has already been setup */
>  	if (size_to_hstate(size))
> -- 
> 2.13.3