From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 0C285A0544 for ; Wed, 5 Oct 2022 17:36:56 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 0835F42685; Wed, 5 Oct 2022 17:36:56 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id CD5B940143 for ; Wed, 5 Oct 2022 17:36:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664984213; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yIx2nGeqyX/MeEnSPcJsXQnB0lmmxDvFCCakid2zaRc=; b=Jj3kQZKzGsYXZfi880OPytrdcRF4Yy3l3i8QZzGQmN1T9gRZaiyHP6sjrqHn3v9ZZHblGG 2a+RtgKl4qEa5Dy+y4xt8siQDw7kC91PtlKaxZ9qHORHY2rp/0wFQ7+fEBCxNnelju8KWl iPaULcRZ+Zz1MvHY7RIcPrT+gXAWQzY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-562-QTnj7sGlOuSQFt0PvKOxTQ-1; Wed, 05 Oct 2022 11:36:49 -0400 X-MC-Unique: QTnj7sGlOuSQFt0PvKOxTQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2BC84185A78B; Wed, 5 Oct 2022 15:36:49 +0000 (UTC) Received: from [10.39.208.19] (unknown [10.39.208.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1E6CC40C6F75; Wed, 5 Oct 2022 15:36:46 +0000 (UTC) Message-ID: Date: Wed, 5 Oct 2022 17:36:45 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 Subject: Re: [PATCH v2] vhost: fix compilation issue in async path To: dev@dpdk.org, cheng1.jiang@intel.com, chenbo.xia@intel.com, zhoumin@loongson.cn, david.marchand@redhat.com, thomas@monjalon.net Cc: stable@dpdk.org References: <20221005151159.72366-1-maxime.coquelin@redhat.com> From: Maxime Coquelin In-Reply-To: <20221005151159.72366-1-maxime.coquelin@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org On 10/5/22 17:11, Maxime Coquelin wrote: > This patch fixes a compilation issue met with GCC 12 on > LoongArch64: > > In function ‘mbuf_to_desc’, > inlined from ‘vhost_enqueue_async_packed’ at ../../../dpdk/lib/vhost/virtio_net.c:1822:6, > inlined from ‘virtio_dev_rx_async_packed’ at ../../../dpdk/lib/vhost/virtio_net.c:1836:6, > inlined from ‘virtio_dev_rx_async_submit_packed’ at ../../../dpdk/lib/vhost/virtio_net.c:1895:7: > ../../../dpdk/lib/vhost/virtio_net.c:1159:18: error: ‘buf_vec[0].buf_addr’ may be used uninitialized [-Werror=maybe-uninitialized] > 1159 | buf_addr = buf_vec[vec_idx].buf_addr; > | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ > ../../../dpdk/lib/vhost/virtio_net.c: In function ‘virtio_dev_rx_async_submit_packed’: > ../../../dpdk/lib/vhost/virtio_net.c:1834:27: note: ‘buf_vec’ declared here > 1834 | struct buf_vector buf_vec[BUF_VECTOR_MAX]; > | ^~~~~~~ > > It happens because the compiler assumes that 'size' > variable in vhost_enqueue_async_packed could wrap to 0 since > 'size' is uint32_t and pkt->pkt_len too. > > In practice, it would never happen since 'pkt->pkt_len' is > unlikely to be close to UINT32_MAX, but let's just change > 'size' to uint64_t to make the compiler happy without > having to add runtime checks. > > Fixes: 873e8dad6f49 ("vhost: support packed ring in async datapath") > Cc: stable@dpdk.org > > Signed-off-by: Maxime Coquelin Forgot to report the R-by from David on v1: Reviewed-by: David Marchand > --- > lib/vhost/virtio_net.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c > index 8f4d0f0502..b86fb26040 100644 > --- a/lib/vhost/virtio_net.c > +++ b/lib/vhost/virtio_net.c > @@ -1780,7 +1780,7 @@ vhost_enqueue_async_packed(struct virtio_net *dev, > uint16_t buf_id = 0; > uint32_t len = 0; > uint16_t desc_count = 0; > - uint32_t size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf); > + uint64_t size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf); > uint32_t buffer_len[vq->size]; > uint16_t buffer_buf_id[vq->size]; > uint16_t buffer_desc_count[vq->size];