From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [PATCH 03/10] net/virtio: fix compilation with -Og Date: Fri, 6 Oct 2017 00:28:54 +0100 Message-ID: References: <20170911151333.5727-1-olivier.matz@6wind.com> <20170911151333.5727-4-olivier.matz@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit To: Olivier Matz , dev@dpdk.org, Yuanhan Liu , Maxime Coquelin Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 247E21B19E for ; Fri, 6 Oct 2017 01:28:56 +0200 (CEST) In-Reply-To: Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 10/6/2017 12:17 AM, Ferruh Yigit wrote: > On 9/11/2017 4:13 PM, Olivier Matz wrote: >> The compilation with gcc-6.3.0 and EXTRA_CFLAGS=-Og gives the following >> error: >> >> CC virtio_rxtx.o >> virtio_rxtx.c: In function ‘virtio_rx_offload’: >> virtio_rxtx.c:680:10: error: ‘csum’ may be used uninitialized in >> this function [-Werror=maybe-uninitialized] >> csum = ~csum; >> ~~~~~^~~~~~~ >> >> The function rte_raw_cksum_mbuf() may indeed return an error, and >> in this case, csum won't be initialized. Fix it by initializing csum >> to 0. > > After this fix if rte_raw_cksum_mbuf() returns error csum still will be > wrong and since compiler warning suppressed it may be harder to find the > root cause. > > For this case checking rte_raw_cksum_mbuf() return value seems better > idea but I will cc the maintainer for decision. Trying harder to add maintainer! > >> >> Fixes: 96cb6711939e ("net/virtio: support Rx checksum offload") >> Signed-off-by: Olivier Matz >> --- >> drivers/net/virtio/virtio_rxtx.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c >> index 45a9c919a..cab3a1675 100644 >> --- a/drivers/net/virtio/virtio_rxtx.c >> +++ b/drivers/net/virtio/virtio_rxtx.c >> @@ -671,7 +671,7 @@ virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr) >> * In case of SCTP, this will be wrong since it's a CRC >> * but there's nothing we can do. >> */ >> - uint16_t csum, off; >> + uint16_t csum = 0, off; >> >> rte_raw_cksum_mbuf(m, hdr->csum_start, >> rte_pktmbuf_pkt_len(m) - hdr->csum_start, >> >