netdev - Re: [PATCH v2 net-next] net: poll/select low latency socket support

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

Message-ID: <51C02478.7020708@linux.intel.com>
Date:	Tue, 18 Jun 2013 12:12:24 +0300
From:	Eliezer Tamir <eliezer.tamir@...ux.intel.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
CC:	David Miller <davem@...emloft.net>, linux-kernel@...r.kernel.org,
	netdev@...r.kernel.org,
	Jesse Brandeburg <jesse.brandeburg@...el.com>,
	Don Skidmore <donald.c.skidmore@...el.com>,
	e1000-devel@...ts.sourceforge.net,
	Willem de Bruijn <willemb@...gle.com>,
	Ben Hutchings <bhutchings@...arflare.com>,
	Andi Kleen <andi@...stfloor.org>, HPA <hpa@...or.com>,
	Eilon Greenstien <eilong@...adcom.com>,
	Or Gerlitz <or.gerlitz@...il.com>,
	Amir Vadai <amirv@...lanox.com>,
	Alex Rosenbaum <alexr@...lanox.com>,
	Avner Ben Hanoch <avnerb@...lanox.com>,
	Or Kehati <ork@...lanox.com>, sockperf-dev@...glegroups.com,
	Eliezer Tamir <eliezer@...ir.org.il>
Subject: Re: [PATCH v2 net-next] net: poll/select low latency socket support

On 18/06/2013 12:08, Eric Dumazet wrote:
> On Tue, 2013-06-18 at 11:58 +0300, Eliezer Tamir wrote:
>> select/poll busy-poll support.
>>
>
>
>>    */
>> -static inline u64 ll_end_time(struct sock *sk)
>> +static inline u64 ll_sk_end_time(struct sock *sk)
>>   {
>> -	u64 end_time = ACCESS_ONCE(sk->sk_ll_usec);
>> -
>> -	/* we don't mind a ~2.5% imprecision
>> -	 * sk->sk_ll_usec is a u_int so this can't overflow
>> -	 */
>> -	end_time = (end_time << 10) + sched_clock();
>> +	return (ACCESS_ONCE(sk->sk_ll_usec) << 10) + sched_clock();
>> +}
>>
>
> This is the fourth time you try to introduce an overflow in this code.
>
> (same for ll_end_time())

sorry,
Please review the rest of the patch to see if you have any other comments.
--
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