From: Florian Westphal <fw@strlen.de>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Florian Westphal <fw@strlen.de>,
Pablo Neira Ayuso <pablo@netfilter.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Arnd Bergmann <arnd@arndb.de>
Subject: Re: Division by zero on UP (was: Re: netfilter: nat: use keyed locks)
Date: Sun, 10 Sep 2017 13:21:26 +0200 [thread overview]
Message-ID: <20170910112126.GB25977@breakpoint.cc> (raw)
In-Reply-To: <CAMuHMdVwp1njkMYo-y8FZHWNWW6wtN2LYVC=9-mbcF-omDaztw@mail.gmail.com>
Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > srchash = hash_by_src(net,
> > &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
> > - spin_lock_bh(&nf_nat_lock);
> > + lock = &nf_nat_locks[srchash % ARRAY_SIZE(nf_nat_locks)];
> > + spin_lock_bh(lock);
>
> If no spinlock debugging options (CONFIG_GENERIC_LOCKBREAK,
> CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_LOCK_ALLOC) are enabled on a UP platform
> (e.g. m68k defconfig), arch_spinlock_t is an empty struct, and thus
> ARRAY_SIZE(nf_nat_locks)] is zero, leading to:
>
> net/netfilter/nf_nat_core.c: In function ‘nf_nat_setup_info’:
> net/netfilter/nf_nat_core.c:432: warning: division by zero
Gah. Sorry. This is the 2nd time I add such a bug :(
Can you send a patch? It should be enough to use CONNTRACK_LOCKS
instead of ARRAY_SIZE(nf_nat_locks) to avoid this problem.
Otherwise I will take care of this next thing monday morning.
next prev parent reply other threads:[~2017-09-10 11:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-10 11:08 Division by zero on UP (was: Re: netfilter: nat: use keyed locks) Geert Uytterhoeven
2017-09-10 11:21 ` Florian Westphal [this message]
2017-09-10 11:34 ` Geert Uytterhoeven
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