linux-kernel - Re: [PATCH v5 03/11] mm/mempolicy: refactor sanitize_mpol

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Date: Tue, 26 Dec 2023 06:48:34 -0500
From: Gregory Price <gregory.price@...verge.com>
To: "Huang, Ying" <ying.huang@...el.com>
Cc: Gregory Price <gourry.memverge@...il.com>, linux-mm@...ck.org,
	linux-doc@...r.kernel.org, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-api@...r.kernel.org,
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	sthanneeru@...ron.com, emirakhur@...ron.com, Hasan.Maruf@....com,
	seungjun.ha@...sung.com
Subject: Re: [PATCH v5 03/11] mm/mempolicy: refactor sanitize_mpol_flags for
 reuse

On Tue, Dec 26, 2023 at 02:05:35AM -0500, Gregory Price wrote:
> On Wed, Dec 27, 2023 at 04:39:29PM +0800, Huang, Ying wrote:
> > Gregory Price <gourry.memverge@...il.com> writes:
> > 
> > > +	unsigned short mode = (*mode_arg & ~MPOL_MODE_FLAGS);
> > > +
> > > +	*flags = *mode_arg & MPOL_MODE_FLAGS;
> > > +	*mode_arg = mode;
> > 
> > It appears that it's unnecessary to introduce a local variable to split
> > mode/flags.  Just reuse the original code?
> > 

Revisiting during fixes: Note the change from int to short.

I chose to make this explicit because validate_mpol_flags takes a short.

I'm fairly sure changing it back throws a truncation warning.

~Gregroy