lkml.org 
[lkml]   [2018]   [Jan]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] tcp_lp: use 64-bit arithmetic instead of 32-bit

Hi Alan,

Quoting Alan Cox <gnomes@lxorguk.ukuu.org.uk>:

> On Wed, 31 Jan 2018 18:24:07 -0600
> "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>
>> Cast to s64 some variables and a macro in order to give the
>> compiler complete information about the proper arithmetic to
>> use. Notice that these elements are used in contexts that
>> expect expressions of type s64 (64 bits, signed).
>>
>> Currently such expression are being evaluated using 32-bit
>> arithmetic.
>
> The question you need to ask is 'can it overflow 32bit maths', otherwise
> you are potentially making the system do extra work for no reason.
>

Yeah, I get your point and it seems that in this particular case there
is no risk of a 32bit overflow, but in general and IMHO as the code
evolves, the use of incorrect arithmetic may have security
implications in the future, so I advocate for code correctness in this
case.

Thanks
--
Gustavo





\
 
 \ /
  Last update: 2018-02-01 02:08    [W:0.056 / U:0.728 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site