From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:50996) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hLlnT-00083v-1U for qemu-devel@nongnu.org; Wed, 01 May 2019 05:45:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hLlnP-0000on-Vd for qemu-devel@nongnu.org; Wed, 01 May 2019 05:45:03 -0400 Date: Wed, 1 May 2019 10:44:53 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20190501094452.GQ29808@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <14aab381eaa678eca875d0b8bd456feb22a21bd8.1556666645.git.alistair.francis@wdc.com> <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v2 4/5] linux-user/uname: Fix GCC 9 build warnings List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laurent Vivier Cc: Alistair Francis , "qemu-devel@nongnu.org" , "alistair23@gmail.com" , "kraxel@redhat.com" , "riku.voipio@iki.fi" , "qemu-trivial@nongnu.org" On Wed, May 01, 2019 at 11:40:13AM +0200, Laurent Vivier wrote: > On 01/05/2019 01:28, Alistair Francis wrote: > > Fix this warning when building with GCC9 on Fedora 30: > > In function =E2=80=98strncpy=E2=80=99, > > inlined from =E2=80=98sys_uname=E2=80=99 at /home/alistair/qemu/l= inux-user/uname.c:94:3: > > /usr/include/bits/string_fortified.h:106:10: error: =E2=80=98__builti= n_strncpy=E2=80=99 output may be truncated copying 64 bytes from a string= of length 64 [-Werror=3Dstringop-truncation] > > 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos= (__dest)); > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~~ > >=20 > > Signed-off-by: Alistair Francis > > --- > > linux-user/uname.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > >=20 > > diff --git a/linux-user/uname.c b/linux-user/uname.c > > index 313b79dbad..2fc6096a5b 100644 > > --- a/linux-user/uname.c > > +++ b/linux-user/uname.c > > @@ -73,7 +73,7 @@ const char *cpu_to_uname_machine(void *cpu_env) > > #define COPY_UTSNAME_FIELD(dest, src) \ > > do { \ > > /* __NEW_UTS_LEN doesn't include terminating null */ \ > > - (void) strncpy((dest), (src), __NEW_UTS_LEN); \ > > + (void) memcpy((dest), (src), MIN(strlen(src), __NEW_UTS_LEN));= \ >=20 > You should use MIN(strlen(src) + 1, __NEW_UTS_LEN) to copy the NUL > character if it is present and fit in __NEW_UTS_LEN. IMHO we shouldn't use strlen at all. I proposed fixing it using sizeof() instead here: https://lists.gnu.org/archive/html/qemu-devel/2019-04/msg02154.html >=20 > > (dest)[__NEW_UTS_LEN] =3D '\0'; \ > > } while (0) Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :| From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 234F8C43219 for ; Wed, 1 May 2019 09:49:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E296721670 for ; 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Wed, 01 May 2019 05:44:59 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 13924C057F32; Wed, 1 May 2019 09:44:59 +0000 (UTC) Received: from redhat.com (ovpn-112-28.ams2.redhat.com [10.36.112.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5273653; Wed, 1 May 2019 09:44:56 +0000 (UTC) Date: Wed, 1 May 2019 10:44:53 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Laurent Vivier Message-ID: <20190501094452.GQ29808@redhat.com> References: <14aab381eaa678eca875d0b8bd456feb22a21bd8.1556666645.git.alistair.francis@wdc.com> <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 01 May 2019 09:44:59 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v2 4/5] linux-user/uname: Fix GCC 9 build warnings X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: "qemu-trivial@nongnu.org" , "riku.voipio@iki.fi" , "qemu-devel@nongnu.org" , Alistair Francis , "kraxel@redhat.com" , "alistair23@gmail.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20190501094453.Ci0in6NQtgMfEqRCqviLHudXVP1hxtReRR8UTmqQ8JM@z> On Wed, May 01, 2019 at 11:40:13AM +0200, Laurent Vivier wrote: > On 01/05/2019 01:28, Alistair Francis wrote: > > Fix this warning when building with GCC9 on Fedora 30: > > In function =E2=80=98strncpy=E2=80=99, > > inlined from =E2=80=98sys_uname=E2=80=99 at /home/alistair/qemu/l= inux-user/uname.c:94:3: > > /usr/include/bits/string_fortified.h:106:10: error: =E2=80=98__builti= n_strncpy=E2=80=99 output may be truncated copying 64 bytes from a string= of length 64 [-Werror=3Dstringop-truncation] > > 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos= (__dest)); > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~~ > >=20 > > Signed-off-by: Alistair Francis > > --- > > linux-user/uname.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > >=20 > > diff --git a/linux-user/uname.c b/linux-user/uname.c > > index 313b79dbad..2fc6096a5b 100644 > > --- a/linux-user/uname.c > > +++ b/linux-user/uname.c > > @@ -73,7 +73,7 @@ const char *cpu_to_uname_machine(void *cpu_env) > > #define COPY_UTSNAME_FIELD(dest, src) \ > > do { \ > > /* __NEW_UTS_LEN doesn't include terminating null */ \ > > - (void) strncpy((dest), (src), __NEW_UTS_LEN); \ > > + (void) memcpy((dest), (src), MIN(strlen(src), __NEW_UTS_LEN));= \ >=20 > You should use MIN(strlen(src) + 1, __NEW_UTS_LEN) to copy the NUL > character if it is present and fit in __NEW_UTS_LEN. IMHO we shouldn't use strlen at all. I proposed fixing it using sizeof() instead here: https://lists.gnu.org/archive/html/qemu-devel/2019-04/msg02154.html >=20 > > (dest)[__NEW_UTS_LEN] =3D '\0'; \ > > } while (0) Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|