linux-kernel - Re: [PATCH] docs: deprecated.rst: Clarify open-coded arithmetic with literals

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Message-ID: <bd7487c725e15b0c20612a44ecf301637a60c157.camel@perches.com>
Date:   Fri, 27 Aug 2021 12:06:18 -0700
From:   Joe Perches <joe@...ches.com>
To:     Len Baker <len.baker@....com>, Jonathan Corbet <corbet@....net>,
        Kees Cook <keescook@...omium.org>
Cc:     "Gustavo A. R. Silva" <gustavoars@...nel.org>,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-hardening@...r.kernel.org
Subject: Re: [PATCH] docs: deprecated.rst: Clarify open-coded arithmetic
 with literals

On Fri, 2021-08-27 at 19:12 +0200, Len Baker wrote:
> Although using literals for size calculation in allocator arguments may
> be harmless due to compiler warnings in case of overflows, it is better
> to refactor the code to avoid the use of open-coded math idiom.
> 
> So, clarify the preferred way in these cases.
[]
> diff --git a/Documentation/process/deprecated.rst b/Documentation/process/deprecated.rst
[]
> @@ -60,7 +60,8 @@ smaller allocation being made than the caller was expecting. Using those
>  allocations could lead to linear overflows of heap memory and other
>  misbehaviors. (One exception to this is literal values where the compiler
>  can warn if they might overflow. Though using literals for arguments as
> -suggested below is also harmless.)
> +suggested below is also harmless. So, the preferred way in these cases is
> +to refactor the code to keep the open-coded math idiom out.)

wordsmithing trivia:

'keep <foo> out' is difficult to parse as 'keep' is generally a positive
word but its meaning is later reversed with out.

'avoid <foo>' maybe be better phrasing.