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 5203BA0543 for ; Wed, 5 Oct 2022 17:09:28 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 4723E427EE; Wed, 5 Oct 2022 17:09:28 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mails.dpdk.org (Postfix) with ESMTP id 39F2840143 for ; Wed, 5 Oct 2022 17:09:27 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664982566; 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=s1TD9msWAooEemHsO55d91R74+XL0Yd4UQ913fcYpnM=; b=PhybWfx4NdH13vT1nABzcSdCkz8QHu/DYXtEisuhebgjQrTF0U71Q/JzRFnB+EU3z7W/nM 6x+J4mDeQQUjVOYgMkfXdpVZI5/R/1T3f9nX/l2bV9D9+8JCEtSIabWb+JBIRirBjTTWGj k0eLVX3tEGOoBiW7I8TdUM3v3Ija8dU= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-457-NleEpe0YNNKmVbz3kom0Mg-1; Wed, 05 Oct 2022 11:09:22 -0400 X-MC-Unique: NleEpe0YNNKmVbz3kom0Mg-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 3852C3C1487C; Wed, 5 Oct 2022 15:09:22 +0000 (UTC) Received: from [10.39.208.19] (unknown [10.39.208.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 33DFB40C958D; Wed, 5 Oct 2022 15:09:20 +0000 (UTC) Message-ID: <61f1cd33-e5ee-382c-1b8b-814c84b22c6b@redhat.com> Date: Wed, 5 Oct 2022 17:09:18 +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] vhost: fix compilation issue in async path To: David Marchand Cc: dev@dpdk.org, cheng1.jiang@intel.com, chenbo.xia@intel.com, zhoumin@loongson.cn, stable@dpdk.org, Thomas Monjalon References: <20221005144859.70717-1-maxime.coquelin@redhat.com> From: Maxime Coquelin In-Reply-To: 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 16:56, David Marchand wrote: > On Wed, Oct 5, 2022 at 4:49 PM Maxime Coquelin > wrote: >> >> This patch fixes a compilation issue met with GCC on > > GCC 12 (it is worth detailing, since I and Thomas hit the same issue > on some other cross compiling toolchains using GCC 12). > >> Loongarch64: > > LoongArch64 > Oops, I did the changes you asked me off-list, but forgot to format the patch again! Posting v2. >> >> 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 > Reviewed-by: David Marchand > >