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From: Hamza Mahfooz <someguy@effective-light.com>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	WireGuard mailing list <wireguard@lists.zx2c4.com>,
	Netdev <netdev@vger.kernel.org>, Thomas Graf <tgraf@suug.ch>,
	Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: [PATCH] wireguard: convert index_hashtable and pubkey_hashtable into rhashtables
Date: Wed, 08 Sep 2021 21:56:12 -0400	[thread overview]
Message-ID: <OD95ZQ.FW5WHNPSV04F@effective-light.com> (raw)
In-Reply-To: <CAHmME9oSo=4BtfO+=327n=gsor5gWcvhzAMS_BpqQ-6=6yxVRA@mail.gmail.com>

Hey Jason,
On Wed, Sep 8 2021 at 01:27:12 PM +0200, Jason A. Donenfeld 
<Jason@zx2c4.com> wrote:
> - What's performance like? Does the abstraction of rhashtable
> introduce overhead? These are used in fast paths -- for every packet
> -- so being quick is important.

Are you familiar with any (micro)benchmarks (for WireGuard) that, you
believe would be particularly informative in assessing the outlined
performance characteristics?

> - How does this interact with the timing side channel concerns in the
> comment of the file? Will the time required to find an unused index
> leak the number of items in the hash table? Do we need stochastic
> masking? Or is the construction of rhashtable such that we always get
> ball-park same time?

I think the maintainers of rhashtable are best positioned to answer 
these
questions (I have cc'd them).



  reply	other threads:[~2021-09-09  1:56 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-06  4:43 [PATCH] wireguard: convert index_hashtable and pubkey_hashtable into rhashtables Hamza Mahfooz
2021-09-08 10:27 ` Hamza Mahfooz
2021-09-08 11:27   ` Jason A. Donenfeld
2021-09-09  1:56     ` Hamza Mahfooz [this message]
2021-09-09  7:59       ` Issues with latest Windows build Peter Whisker
2021-09-09  8:05         ` Jason A. Donenfeld
     [not found]           ` <044be90d-1caf-08a2-3389-d60010986b16@gmail.com>
     [not found]             ` <CAHmME9pJQ8cgOhHPZU+3o9nMgoMe_OrWg+gkY34iOMAd-AZHCQ@mail.gmail.com>
     [not found]               ` <3329757c-b2b9-113d-b6e4-fc28f86cd704@gmail.com>
     [not found]                 ` <CAHmME9osjYgu-0CbEvpNK-Vj6CWg8njraAdegefeG1NrJUETfA@mail.gmail.com>
     [not found]                   ` <eaef596b-c75d-3f42-f43a-fa80cc98d732@gmail.com>
2021-09-09  9:21                     ` Jason A. Donenfeld

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