netdev - Re: [TCP] IPV6 : Change a divide into a right shift in tcp_v6_send

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20071221.014620.91361895.davem@davemloft.net>
Date:	Fri, 21 Dec 2007 01:46:20 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	dada1@...mosbay.com
Cc:	yoshfuji@...ux-ipv6.org, netdev@...r.kernel.org
Subject: Re: [TCP] IPV6 : Change a divide into a right shift in
 tcp_v6_send_ack()

From: Eric Dumazet <dada1@...mosbay.com>
Date: Fri, 21 Dec 2007 08:39:24 +0100

> I didnt chose this path, because David was against changing some
> fields from 'int' to 'unsigned'. If you look in other parts of
> networking, we have many >> 1 or >> 2 already there.

I don't remember making this statement, where did I say this?
I'm genuinely curious :-)

But I am indeed against it in cases where the variable is compared
against signed quantities.

I think the shifts are more pretty and more closely match what the
programmer wants to come out of the compiler.  Getting all of these
divides is an awful surprise for me.

I've learned over the years to never explicitly code divides
or multiplies by powers of two and to always use shifts.  As
a result I am never surprised.  In fact I've been burnt every
time I mistakedly didn't use a shift.

Nevertheless, this tcplen arg is always assigned to and used
with unsigned quantities so I'll apply Yoshifuji's version of
the fix.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html