From: Heiko Carstens <heiko.carstens@de.ibm.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>,
netdev@vger.kernel.org, dborkman@redhat.com,
darkjames-ws@darkjames.pl, Mircea Gherzan <mgherzan@gmail.com>,
Russell King <rmk+kernel@arm.linux.org.uk>,
Matt Evans <matt@ozlabs.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH net] bpf: do not use reciprocal divide
Date: Wed, 15 Jan 2014 16:10:08 +0100 [thread overview]
Message-ID: <20140115151008.GD6638@osiris> (raw)
In-Reply-To: <1389795398.31367.329.camel@edumazet-glaptop2.roam.corp.google.com>
On Wed, Jan 15, 2014 at 06:16:38AM -0800, Eric Dumazet wrote:
> On Wed, 2014-01-15 at 09:00 +0100, Heiko Carstens wrote:
> > Are you sure you want to remove the k == 0 check? Is there something
> > else that would prevent a division by zero?
>
> This is done by factoring the two cases, modulo and divide :
>
> vi +553 net/core/filter.c
>
> /* Some instructions need special checks */
> switch (code) {
> case BPF_S_ALU_DIV_K:
> case BPF_S_ALU_MOD_K:
> /* check for division by zero */
> if (ftest->k == 0)
> return -EINVAL;
> break;
Oh, sorry. I missed the fallthrough.
prev parent reply other threads:[~2014-01-15 15:10 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-13 21:42 [PATCH RFC] reciprocal_divide: correction/update of the algorithm Hannes Frederic Sowa
2014-01-14 18:02 ` Randy Dunlap
2014-01-15 15:02 ` Hannes Frederic Sowa
2014-01-14 18:07 ` Eric Dumazet
2014-01-14 19:22 ` Austin S Hemmelgarn
2014-01-14 19:50 ` Eric Dumazet
2014-01-14 20:10 ` Hannes Frederic Sowa
2014-01-14 20:53 ` Austin S Hemmelgarn
2014-01-14 22:45 ` Eric Dumazet
2014-01-14 23:25 ` Borislav Petkov
2014-01-15 2:51 ` Austin S. Hemmelgarn
2014-01-14 22:39 ` Hannes Frederic Sowa
2014-01-15 7:02 ` [PATCH net] bpf: do not use reciprocal divide Eric Dumazet
2014-01-15 7:28 ` David Miller
2014-01-15 7:39 ` Eric Dumazet
2014-01-15 8:00 ` Heiko Carstens
2014-01-15 8:13 ` Martin Schwidefsky
2014-01-15 10:51 ` Heiko Carstens
2014-01-15 14:21 ` Eric Dumazet
2014-01-15 14:25 ` Eric Dumazet
2014-01-15 14:50 ` [PATCH v2 " Eric Dumazet
2014-01-15 15:10 ` Matt Evans
2014-01-15 16:09 ` Eric Dumazet
2014-01-16 1:02 ` David Miller
2014-01-17 8:59 ` Heiko Carstens
2014-01-18 2:56 ` David Miller
2014-01-18 10:12 ` Heiko Carstens
2014-01-15 15:35 ` [PATCH " Martin Schwidefsky
2014-01-15 15:26 ` Martin Schwidefsky
2014-01-15 16:07 ` Eric Dumazet
2014-01-15 14:16 ` Eric Dumazet
2014-01-15 15:10 ` Heiko Carstens [this message]
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