Subject: Re: [PATCH linux-next] power:pkeys: fix bugon.cocci warnings

From: Daniel Axtens <[email-masked]>
Date: Tue, 31 Aug 2021 16:01:29 +1000

Hi Jing,

Thanks for your patch.

The patch looks good, but looking at the output of `make coccicheck
M=arch/powerpc MODE=report`, it looks like there might be a few other
things that we might want to fix. Would it be worth trying to make the
arch/powerpc directory free from coccinelle warnings in one big patch
series, and then we could add coccicheck to our automatic patch testing?
(see
e.g. https://patchwork.ozlabs.org/project/linuxppc-dev/patch/[email-masked]/ )

For this patch, I think we should try to fix all of arch/powerpc at the
same time. The check points out the following other possible uses of
BUG_ON:

arch/powerpc/include/asm/book3s/64/pgtable-64k.h:68:2-5: WARNING: Use BUG_ON instead of if condition followed by BUG.
Please make sure the condition has no side effects (see conditional BUG_ON definition in include/asm-generic/bug.h)
arch/powerpc/platforms/cell/spufs/sched.c:908:2-5: WARNING: Use BUG_ON instead of if condition followed by BUG.
Please make sure the condition has no side effects (see conditional BUG_ON definition in include/asm-generic/bug.h)
arch/powerpc/platforms/powernv/idle.c:968:3-6: WARNING: Use BUG_ON instead of if condition followed by BUG.
Please make sure the condition has no side effects (see conditional BUG_ON definition in include/asm-generic/bug.h)
arch/powerpc/platforms/powernv/idle.c:456:2-5: WARNING: Use BUG_ON instead of if condition followed by BUG.
Please make sure the condition has no side effects (see conditional BUG_ON definition in include/asm-generic/bug.h)

Kind regards,
Daniel

> Use BUG_ON instead of a if condition followed by BUG.
>
> ./arch/powerpc/include/asm/book3s/64/pkeys.h:21:2-5:WARNING
> Use BUG_ON instead of if condition followed by BUG.
> ./arch/powerpc/include/asm/book3s/64/pkeys.h:14:2-5:WARNING
> Use BUG_ON instead of if condition followed by BUG.
>
> Generated by: scripts/coccinelle/misc/bugon.cocci
>
> Reported-by: Zeal Robot <[email-masked]>
> Signed-off-by: Jing Yangyang <[email-masked]>
> ---
>  arch/powerpc/include/asm/book3s/64/pkeys.h | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/pkeys.h b/arch/powerpc/include/asm/book3s/64/pkeys.h
> index 5b17813..5f74f0c 100644
> --- a/arch/powerpc/include/asm/book3s/64/pkeys.h
> +++ b/arch/powerpc/include/asm/book3s/64/pkeys.h
> @@ -10,15 +10,13 @@ static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags)
>  	if (!mmu_has_feature(MMU_FTR_PKEY))
>  		return 0x0UL;
>  
> -	if (radix_enabled())
> -		BUG();
> +	BUG_ON(radix_enabled());
>  	return hash__vmflag_to_pte_pkey_bits(vm_flags);
>  }
>  
>  static inline u16 pte_to_pkey_bits(u64 pteflags)
>  {
> -	if (radix_enabled())
> -		BUG();
> +	BUG_ON(radix_enabled());
>  	return hash__pte_to_pkey_bits(pteflags);
>  }
>  
> -- 
> 1.8.3.1