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From: David Miller <davem@davemloft.net>
To: bhutchings@solarflare.com
Cc: penguin-kernel@I-love.SAKURA.ne.jp, eric.dumazet@gmail.com,
	netdev@vger.kernel.org
Subject: Re: [PATCH] Prevent reading uninitialized memory with socketfilters
Date: Wed, 10 Nov 2010 12:59:29 -0800 (PST)	[thread overview]
Message-ID: <20101110.125929.245406622.davem@davemloft.net> (raw)
In-Reply-To: <1289422664.2249.1.camel@achroite.uk.solarflarecom.com>

From: Ben Hutchings <bhutchings@solarflare.com>
Date: Wed, 10 Nov 2010 20:57:44 +0000

> On Wed, 2010-11-10 at 10:39 -0800, David Miller wrote:
> [...]
>> In this patch, I use a bitmap (a single long var) so that only filters
>> using mem[] loads/stores pay the price of added security checks.
>> 
>> For other filters, additional cost is a single instruction.
>> 
>> [ Since we access fentry->k a lot now, cache it in a local variable
>>   and mark filter entry pointer as const. -DaveM ]
> [...]
> 
> I don't see the justification for combining these changes.  One patch,
> one fix, right?

I'm minimizing the performance impact of the new bitmap checks.

  reply	other threads:[~2010-11-10 20:59 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-09 22:28 [PATCH] Prevent reading uninitialized memory with socket filters Dan Rosenberg
2010-11-09 23:03 ` Joe Perches
2010-11-10  5:28 ` David Miller
2010-11-10  5:53   ` Eric Dumazet
2010-11-10  7:22     ` Eric Dumazet
2010-11-10 14:25       ` [PATCH] Prevent reading uninitialized memory with socketfilters Tetsuo Handa
2010-11-10 18:32         ` David Miller
2010-11-10 18:39         ` David Miller
2010-11-10 20:57           ` Ben Hutchings
2010-11-10 20:59             ` David Miller [this message]
2010-11-10 21:25               ` Ben Hutchings
2010-11-10 11:12   ` [PATCH] Prevent reading uninitialized memory with socket filters Dan Rosenberg
2010-11-10 13:19     ` Dan Rosenberg
2010-11-10 18:07     ` David Miller
  -- strict thread matches above, loose matches on Subject: below --
2010-11-10 18:18 [PATCH] Prevent reading uninitialized memory with socketfilters Dan Rosenberg
2010-11-10 18:21 ` David Miller
2010-11-10 18:33   ` Eric Dumazet
2010-11-10 18:38     ` David Miller
2010-11-10 18:25 Dan Rosenberg

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