linux-kernel - Re: [PATCH v3 2/3] overflow: Introduce add_wrap(), sub_wrap(), and mul

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Message-ID: <20240205231712.GC2220@sol.localdomain>
Date: Mon, 5 Feb 2024 15:17:12 -0800
From: Eric Biggers <ebiggers@...nel.org>
To: Kees Cook <keescook@...omium.org>
Cc: linux-hardening@...r.kernel.org,
	Rasmus Villemoes <rasmus.villemoes@...vas.dk>,
	Mark Rutland <mark.rutland@....com>,
	"Gustavo A. R. Silva" <gustavoars@...nel.org>,
	Marco Elver <elver@...gle.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/3] overflow: Introduce add_wrap(), sub_wrap(), and
 mul_wrap()

On Mon, Feb 05, 2024 at 02:44:14PM -0800, Kees Cook wrote:
> On Mon, Feb 05, 2024 at 12:21:45PM -0800, Eric Biggers wrote:
> > On Mon, Feb 05, 2024 at 01:12:30AM -0800, Kees Cook wrote:
> > > Subject: Re: [PATCH v3 2/3] overflow: Introduce add_wrap(), sub_wrap(), and mul_wrap()
> > 
> > Maybe these should be called wrapping_add, wrapping_sub, and wrapping_mul?
> > Those names are more grammatically correct, and Rust chose those names too.
> 
> Sure, that works for me. What bout the inc_wrap() and dec_wrap() names?
> I assume wrapping_inc() and wrapping_dec() ?
> 

Yes, though I'm not sure those should exist at all.  Maybe a += b should just
become a = wrapping_add(a, b), instead of wrapping_inc(a, b)?
wrapping_inc(a, b) isn't as self-explanatory.  Likewise for wrapping_dec.

- Eric