From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [dpdk-stable] [PATCH] enic: check for nb_free > 0
Date: Thu, 03 Aug 2017 22:58:31 +0200
Message-ID: <7771250.dkQc2fQUgz@xps>
References: <20170802180213.28736-1-aconole@redhat.com>
 <1a29ffbed0e442798d0e29b5af90f1fc@XCH-RCD-007.cisco.com>
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Cc: stable@dpdk.org, "John Daley (johndale)" <johndale@cisco.com>, dev@dpdk.org,
 Bruce Richardson <bruce.richardson@intel.com>
To: Aaron Conole <aconole@redhat.com>
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> > Occasionally, the amount of packets to free from the work queue ends
> > perfectly on a boundary to have nb_free = 0 and pool = 0.  This causes a
> > segfault as follows:
> > 
> >   (gdb) bt
> >   #0  rte_mempool_default_cache (mp=<optimized out>, mp=<optimized
> > out>,
> >       lcore_id=<optimized out>)
> >       at /usr/src/debug/openvswitch-2.6.1/dpdk-16.11/x86_64-native-
> > linuxapp-gcc/include/rte_mempool.h:1017
> >   #1  rte_mempool_put_bulk (n=0, obj_table=0x7f10deff2530, mp=0x0)
> >       at /usr/src/debug/openvswitch-2.6.1/dpdk-16.11/x86_64-native-
> > linuxapp-gcc/include/rte_mempool.h:1174
> >   #2  enic_free_wq_bufs (wq=wq@entry=0x7efabffcd5b0,
> >       completed_index=completed_index@entry=33)
> >       at /usr/src/debug/openvswitch-2.6.1/dpdk-
> > 16.11/drivers/net/enic/enic_rxtx.c:429
> >   #3  0x00007f11e9c86e17 in enic_cleanup_wq (enic=<optimized out>,
> >       wq=wq@entry=0x7efabffcd5b0)
> >       at /usr/src/debug/openvswitch-2.6.1/dpdk-
> > 16.11/drivers/net/enic/enic_rxtx.c:442
> >   #4  0x00007f11e9c86e5f in enic_xmit_pkts (tx_queue=0x7efabffcd5b0,
> >       tx_pkts=0x7f10deffb1a8, nb_pkts=<optimized out>)
> >       at /usr/src/debug/openvswitch-2.6.1/dpdk-
> > 16.11/drivers/net/enic/enic_rxtx.c:470
> >   #5  0x00007f11e9e147ad in rte_eth_tx_burst (nb_pkts=<optimized out>,
> >       tx_pkts=0x7f10deffb1a8, queue_id=0, port_id=<optimized out>)
> > 
> > This commit makes the enic wq driver match other drivers who call the bulk
> > free, by checking that there are actual packets to free.
> > 
> > Fixes: 36935afbc53c ("net/enic: refactor Tx mbuf recycling")
> > CC: stable@dpdk.org
> > Reported-by: Vincent S. Cojot <vcojot@redhat.com>
> > Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1468631
> > Signed-off-by: Aaron Conole <aconole@redhat.com>
> 
> Reviewed-by: John Daley <johndale@cisco.com>

Applied, thanks

With more context in the title:
	net/enic: fix crash when freeing 0 packet to mempool