From: "H. Peter Anvin" <hpa@zytor.com>
To: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Pavel Emelyanov <xemul@parallels.com>,
KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
david@lang.hm, Alexey Dobriyan <adobriyan@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Andrey Vagin <avagin@openvz.org>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
Glauber Costa <glommer@parallels.com>,
Andi Kleen <andi@firstfloor.org>, Tejun Heo <tj@kernel.org>,
Matt Helsley <matthltc@us.ibm.com>,
Pekka Enberg <penberg@kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
Vasiliy Kulikov <segoon@openwall.com>,
Andrew Morton <akpm@linux-foundation.org>,
Valdis.Kletnieks@vt.edu
Subject: Re: [RFC] syscalls, x86: Add __NR_kcmp syscall
Date: Fri, 20 Jan 2012 08:57:11 -0800 [thread overview]
Message-ID: <4F199CE7.3020900@zytor.com> (raw)
In-Reply-To: <20120120162900.GP1954@moon>
On 01/20/2012 08:29 AM, Cyrill Gorcunov wrote:
>
> We've had kind of emergency pool before which were used in such cases.
> These legitime cases can happen not that frequently, so I guess -- can
> we use it again?
>
> if (cookies[i][j])
> continue;
> else
> cookies[i][j] = some-value;
>
> One wont know which exactly values we were using.
>
I would not worry about get_random_bytes() returning nothing... if so, a
lot of other places in the kernel would be broken.
>> The other thing is that for the multiplicative cookie you should OR in
>> the value (~(~0UL>> 1) | 1) in order to make sure that the value is (a)
>> large and (b) odd.
>>
>
> I see, i'll update (at first, I occasionally translated odd as 'even' which
> made me really scratching the head, until I realized it's 'odd'! :)
>
> Cyrill
next prev parent reply other threads:[~2012-01-20 16:58 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-17 14:27 [RFC] syscalls, x86: Add __NR_kcmp syscall Cyrill Gorcunov
2012-01-17 14:38 ` Alexey Dobriyan
2012-01-17 14:44 ` Cyrill Gorcunov
2012-01-17 18:47 ` H. Peter Anvin
2012-01-17 21:15 ` Cyrill Gorcunov
2012-01-17 21:40 ` Eric W. Biederman
2012-01-18 5:07 ` Pavel Emelyanov
2012-01-17 21:35 ` Eric W. Biederman
2012-01-18 8:01 ` Cyrill Gorcunov
2012-01-18 9:12 ` KOSAKI Motohiro
2012-01-18 9:19 ` Pavel Emelyanov
2012-01-18 9:23 ` KOSAKI Motohiro
2012-01-18 11:57 ` Cyrill Gorcunov
2012-01-18 16:46 ` KOSAKI Motohiro
2012-01-18 17:20 ` Cyrill Gorcunov
2012-01-18 22:05 ` david
2012-01-18 22:49 ` Cyrill Gorcunov
2012-01-18 23:29 ` Eric W. Biederman
2012-01-19 6:55 ` Cyrill Gorcunov
2012-01-20 3:16 ` Eric W. Biederman
2012-01-20 8:40 ` Cyrill Gorcunov
2012-01-20 9:02 ` Cyrill Gorcunov
2012-01-20 14:51 ` H. Peter Anvin
2012-01-20 16:29 ` Cyrill Gorcunov
2012-01-20 16:57 ` H. Peter Anvin [this message]
2012-01-20 18:19 ` Cyrill Gorcunov
2012-01-20 18:22 ` Cyrill Gorcunov
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