linux-kernel - Re: [PATCH] s390/nmi: Simplify return statement in nmi_registers

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Message-ID: <20250909062501.8968Abb-hca@linux.ibm.com>
Date: Tue, 9 Sep 2025 08:25:01 +0200
From: Heiko Carstens <hca@...ux.ibm.com>
To: Alexander Gordeev <agordeev@...ux.ibm.com>
Cc: Thorsten Blum <thorsten.blum@...ux.dev>, Vasily Gorbik <gor@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>,
        Sven Schnelle <svens@...ux.ibm.com>, linux-s390@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] s390/nmi: Simplify return statement in
 nmi_registers_valid()

On Mon, Sep 08, 2025 at 06:52:11PM +0200, Alexander Gordeev wrote:
> On Mon, Sep 08, 2025 at 05:32:20PM +0200, Thorsten Blum wrote:
> ...
> > @@ -321,9 +321,7 @@ static bool notrace nmi_registers_valid(union mci mci)
> >  	cr2.reg = get_lowcore()->cregs_save_area[2];
> >  	if (cr2.gse && !mci.gs && !test_cpu_flag(CIF_MCCK_GUEST))
> >  		return false;
> > -	if (!mci.ms || !mci.pm || !mci.ia)
> > -		return false;
> > -	return true;
> > +	return mci.ms && mci.pm && mci.ia;
> >  }
> >  NOKPROBE_SYMBOL(nmi_registers_valid);
> 
> This change does not make the whole function readability better.

It actually would decrease readability since every if-statement tells
you one condition when registers are not valid. Negating the last one
makes this harder to understand.

But in general please do not send patches like this, which do not come
with a significant improvement.