From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id DAA8EA058A; Fri, 17 Apr 2020 11:34:08 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 6CBEE1DEEE; Fri, 17 Apr 2020 11:34:08 +0200 (CEST) Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by dpdk.org (Postfix) with ESMTP id 12B7A1D67B for ; Fri, 17 Apr 2020 11:34:05 +0200 (CEST) IronPort-SDR: iOk5u+iJu3vHK3cBDWQvDgFCLZ+cf3oP2ExjWGp/jppoBs6i1eIEBpjBu6r6h/oulm6xEMc+kY gFR4PtfzIHSw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Apr 2020 02:34:05 -0700 IronPort-SDR: FsuVMbyW5lzA1a9dmHJVnwhbqhymYe/6qe3j852YzrAt1KpezGdjKKg0NPU90626/shsWTYOWm 0x2L/8X/5QJA== X-IronPort-AV: E=Sophos;i="5.72,394,1580803200"; d="scan'208";a="289212200" Received: from bricha3-mobl.ger.corp.intel.com ([10.212.38.175]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-SHA; 17 Apr 2020 02:34:01 -0700 Date: Fri, 17 Apr 2020 10:33:58 +0100 From: Bruce Richardson To: Kevin Traynor Cc: dev@dpdk.org, thomas@monjalon.net, Gavin.Hu@arm.com, ravi1.kumar@amd.com, g.singh@nxp.com, hemant.agrawal@nxp.com, akhil.goyal@nxp.com, johndale@cisco.com, hyonkim@cisco.com, jingjing.wu@intel.com, wenzhuo.lu@intel.com, rmody@marvell.com, shshaikh@marvell.com, matan@mellanox.com, shahafs@mellanox.com, declan.doherty@intel.com, cristian.dumitrescu@intel.com Message-ID: <20200417093358.GB1701@bricha3-MOBL.ger.corp.intel.com> References: <20200407162755.6802-1-ktraynor@redhat.com> <20200416184549.10747-1-ktraynor@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200416184549.10747-1-ktraynor@redhat.com> Subject: Re: [dpdk-dev] [PATCH v2] x86/eal: gcc 10 ignore stringop-overflow warnings X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list 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 Thu, Apr 16, 2020 at 07:45:49PM +0100, Kevin Traynor wrote: > stringop-overflow warns when it sees a possible overflow > in a string operation. > > In the rte_memcpy functions different branches are taken > depending on the size. stringop-overflow is raised for the > branches in the function where it sees the static size of the > src could be overflowed. > > However, in reality a correct size argument and in some cases > dynamic allocation would ensure that this does not happen. > > For example, in the case below for key, the correct path will be > chosen in rte_memcpy_generic at runtime based on the size argument > but as some paths in the function could lead to a cast to 32 bytes > a warning is raised. > > In function ‘_mm256_storeu_si256’, > inlined from ‘rte_memcpy_generic’ > at ../lib/librte_eal/common/include/arch/x86/rte_memcpy.h:315:2, > inlined from ‘iavf_configure_rss_key’ > at ../lib/librte_eal/common/include/arch/x86/rte_memcpy.h:869:10: > > /usr/lib/gcc/x86_64-redhat-linux/10/include/avxintrin.h:928:8: > warning: writing 32 bytes into a region of size 1 [-Wstringop-overflow=] > 928 | *__P = __A; > | ~~~~~^~~~~ > In file included > from ../drivers/net/iavf/../../common/iavf/iavf_prototype.h:10, > from ../drivers/net/iavf/iavf.h:9, > from ../drivers/net/iavf/iavf_vchnl.c:22: > > ../drivers/net/iavf/iavf_vchnl.c: > In function ‘iavf_configure_rss_key’: > > ../drivers/net/iavf/../../common/iavf/virtchnl.h:508:5: > note: at offset 0 to object ‘key’ with size 1 declared here > 508 | u8 key[1]; /* RSS hash key, packed bytes */ > | ^~~ > > Ignore the stringop-overflow warnings for rte_memcpy.h functions. > > Bugzilla ID: 394 > Bugzilla ID: 421 > > Signed-off-by: Kevin Traynor > > --- > > v2: Change from a global disable to just disabling for x86/rte_memcpy.h > --- > lib/librte_eal/x86/include/rte_memcpy.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/lib/librte_eal/x86/include/rte_memcpy.h b/lib/librte_eal/x86/include/rte_memcpy.h > index ba44c4a32..283fb79ba 100644 > --- a/lib/librte_eal/x86/include/rte_memcpy.h > +++ b/lib/librte_eal/x86/include/rte_memcpy.h > @@ -23,4 +23,8 @@ extern "C" { > #endif > > +#if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 100000) > +#pragma GCC diagnostic ignored "-Wstringop-overflow" > +#endif > + > /** > * Copy bytes from one location to another. The locations must not overlap. Does this permanently need to be disabled for all compilation units including rte_memcpy.h, or can it be used with a push/pop set of pragmas to only disable for the required functions?