From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:55971) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hLnuz-0002AA-IS for qemu-devel@nongnu.org; Wed, 01 May 2019 08:01:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hLnuw-00031u-GD for qemu-devel@nongnu.org; Wed, 01 May 2019 08:00:57 -0400 References: <14aab381eaa678eca875d0b8bd456feb22a21bd8.1556666645.git.alistair.francis@wdc.com> <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> From: Eric Blake Message-ID: Date: Wed, 1 May 2019 07:00:03 -0500 MIME-Version: 1.0 In-Reply-To: <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="cWuKhQNXUyPcCDWb7oTARORvy0k7wUsDw" 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 , Alistair Francis , "qemu-devel@nongnu.org" Cc: "qemu-trivial@nongnu.org" , "alistair23@gmail.com" , "riku.voipio@iki.fi" , "kraxel@redhat.com" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --cWuKhQNXUyPcCDWb7oTARORvy0k7wUsDw From: Eric Blake To: Laurent Vivier , Alistair Francis , "qemu-devel@nongnu.org" Cc: "qemu-trivial@nongnu.org" , "alistair23@gmail.com" , "riku.voipio@iki.fi" , "kraxel@redhat.com" Message-ID: Subject: Re: [Qemu-devel] [PATCH v2 4/5] linux-user/uname: Fix GCC 9 build warnings References: <14aab381eaa678eca875d0b8bd456feb22a21bd8.1556666645.git.alistair.francis@wdc.com> <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> In-Reply-To: <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 5/1/19 4:40 AM, 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/li= nux-user/uname.c:94:3: >> /usr/include/bits/string_fortified.h:106:10: error: =E2=80=98__builtin= _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)); >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~ >> >> Signed-off-by: Alistair Francis >> --- >> linux-user/uname.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> 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. No, the NUL character is already present, due to the memset() prior to any use of COPY_UTSNAME_FIELD(). However, the commit message should call that out, as it is not part of the default 3-line diff. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org --cWuKhQNXUyPcCDWb7oTARORvy0k7wUsDw Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlzJikQACgkQp6FrSiUn Q2qfuAgApDJvUYWkMmk2kJMcz8AzL8zkLXtT1lbru3HnonwcauRyRUmLeUHgn7hq I0lNxoR1/rxZmOr3cuiRxuO2N2Y6bLMNgYlRXeW7cgGnkEYVsjwuSD3dVkJ53ggh pfIfVmiY2V1+WgoTj/9OL+RVDK5iu18GT3/D3FCqbjJTuDX4UlrCM0usd9kt616j C0A5THCh7JhfY0GuqgkzrZmMUofBwR6CJTriAFPfEWQhNQRoTSCGS8kRjYNwGeW4 QZkOfRwZIX/3Mc1RsAf1Zba40mwtNAIKDfJNahYqidK4GulptiGIK2Mi33xKIocW W0OqU6jTHk6ocLw7NjSwgC5wp0jwnw== =74z3 -----END PGP SIGNATURE----- --cWuKhQNXUyPcCDWb7oTARORvy0k7wUsDw-- 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=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 78E68C43219 for ; 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Wed, 01 May 2019 08:00:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52546) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hLnuw-00031U-6o; Wed, 01 May 2019 08:00:54 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 12CE1308212A; Wed, 1 May 2019 12:00:53 +0000 (UTC) Received: from [10.3.116.15] (ovpn-116-15.phx2.redhat.com [10.3.116.15]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 90FEE71D4C; Wed, 1 May 2019 12:00:04 +0000 (UTC) To: Laurent Vivier , Alistair Francis , "qemu-devel@nongnu.org" References: <14aab381eaa678eca875d0b8bd456feb22a21bd8.1556666645.git.alistair.francis@wdc.com> <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> From: Eric Blake Openpgp: preference=signencrypt Autocrypt: addr=eblake@redhat.com; keydata= xsBNBEvHyWwBCACw7DwsQIh0kAbUXyqhfiKAKOTVu6OiMGffw2w90Ggrp4bdVKmCaEXlrVLU xphBM8mb+wsFkU+pq9YR621WXo9REYVIl0FxKeQo9dyQBZ/XvmUMka4NOmHtFg74nvkpJFCD TUNzmqfcjdKhfFV0d7P/ixKQeZr2WP1xMcjmAQY5YvQ2lUoHP43m8TtpB1LkjyYBCodd+LkV GmCx2Bop1LSblbvbrOm2bKpZdBPjncRNob73eTpIXEutvEaHH72LzpzksfcKM+M18cyRH+nP sAd98xIbVjm3Jm4k4d5oQyE2HwOur+trk2EcxTgdp17QapuWPwMfhaNq3runaX7x34zhABEB AAHNHkVyaWMgQmxha2UgPGVibGFrZUByZWRoYXQuY29tPsLAegQTAQgAJAIbAwULCQgHAwUV CgkICwUWAgMBAAIeAQIXgAUCS8fL9QIZAQAKCRCnoWtKJSdDahBHCACbl/5FGkUqJ89GAjeX RjpAeJtdKhujir0iS4CMSIng7fCiGZ0fNJCpL5RpViSo03Q7l37ss+No+dJI8KtAp6ID+PMz wTJe5Egtv/KGUKSDvOLYJ9WIIbftEObekP+GBpWP2+KbpADsc7EsNd70sYxExD3liwVJYqLc Rw7so1PEIFp+Ni9A1DrBR5NaJBnno2PHzHPTS9nmZVYm/4I32qkLXOcdX0XElO8VPDoVobG6 gELf4v/vIImdmxLh/w5WctUpBhWWIfQDvSOW2VZDOihm7pzhQodr3QP/GDLfpK6wI7exeu3P pfPtqwa06s1pae3ad13mZGzkBdNKs1HEm8x6zsBNBEvHyWwBCADGkMFzFjmmyqAEn5D+Mt4P zPdO8NatsDw8Qit3Rmzu+kUygxyYbz52ZO40WUu7EgQ5kDTOeRPnTOd7awWDQcl1gGBXgrkR pAlQ0l0ReO57Q0eglFydLMi5bkwYhfY+TwDPMh3aOP5qBXkm4qIYSsxb8A+i00P72AqFb9Q7 3weG/flxSPApLYQE5qWGSXjOkXJv42NGS6o6gd4RmD6Ap5e8ACo1lSMPfTpGzXlt4aRkBfvb NCfNsQikLZzFYDLbQgKBA33BDeV6vNJ9Cj0SgEGOkYyed4I6AbU0kIy1hHAm1r6+sAnEdIKj cHi3xWH/UPrZW5flM8Kqo14OTDkI9EtlABEBAAHCwF8EGAEIAAkFAkvHyWwCGwwACgkQp6Fr SiUnQ2q03wgAmRFGDeXzc58NX0NrDijUu0zx3Lns/qZ9VrkSWbNZBFjpWKaeL1fdVeE4TDGm I5mRRIsStjQzc2R9b+2VBUhlAqY1nAiBDv0Qnt+9cLiuEICeUwlyl42YdwpmY0ELcy5+u6wz mK/jxrYOpzXKDwLq5k4X+hmGuSNWWAN3gHiJqmJZPkhFPUIozZUCeEc76pS/IUN72NfprZmF Dp6/QDjDFtfS39bHSWXKVZUbqaMPqlj/z6Ugk027/3GUjHHr8WkeL1ezWepYDY7WSoXwfoAL 2UXYsMAr/uUncSKlfjvArhsej0S4zbqim2ZY6S8aRWw94J3bSvJR+Nwbs34GPTD4Pg== Organization: Red Hat, Inc. Message-ID: Date: Wed, 1 May 2019 07:00:03 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="cWuKhQNXUyPcCDWb7oTARORvy0k7wUsDw" X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Wed, 01 May 2019 12:00:53 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 X-Content-Filtered-By: Mailman/MimeDel 2.1.21 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: , Cc: "qemu-trivial@nongnu.org" , "alistair23@gmail.com" , "riku.voipio@iki.fi" , "kraxel@redhat.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20190501120003.7d6BYurOrtXdL64YS0S1KIKaWTtXr8LwPAuzOy-G3w4@z> This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --cWuKhQNXUyPcCDWb7oTARORvy0k7wUsDw From: Eric Blake To: Laurent Vivier , Alistair Francis , "qemu-devel@nongnu.org" Cc: "qemu-trivial@nongnu.org" , "alistair23@gmail.com" , "riku.voipio@iki.fi" , "kraxel@redhat.com" Message-ID: Subject: Re: [Qemu-devel] [PATCH v2 4/5] linux-user/uname: Fix GCC 9 build warnings References: <14aab381eaa678eca875d0b8bd456feb22a21bd8.1556666645.git.alistair.francis@wdc.com> <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> In-Reply-To: <503a1f5f-7dad-1e4e-e1b1-aaeeeac9739f@vivier.eu> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 5/1/19 4:40 AM, 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/li= nux-user/uname.c:94:3: >> /usr/include/bits/string_fortified.h:106:10: error: =E2=80=98__builtin= _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)); >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~ >> >> Signed-off-by: Alistair Francis >> --- >> linux-user/uname.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> 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. No, the NUL character is already present, due to the memset() prior to any use of COPY_UTSNAME_FIELD(). However, the commit message should call that out, as it is not part of the default 3-line diff. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org --cWuKhQNXUyPcCDWb7oTARORvy0k7wUsDw Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlzJikQACgkQp6FrSiUn Q2qfuAgApDJvUYWkMmk2kJMcz8AzL8zkLXtT1lbru3HnonwcauRyRUmLeUHgn7hq I0lNxoR1/rxZmOr3cuiRxuO2N2Y6bLMNgYlRXeW7cgGnkEYVsjwuSD3dVkJ53ggh pfIfVmiY2V1+WgoTj/9OL+RVDK5iu18GT3/D3FCqbjJTuDX4UlrCM0usd9kt616j C0A5THCh7JhfY0GuqgkzrZmMUofBwR6CJTriAFPfEWQhNQRoTSCGS8kRjYNwGeW4 QZkOfRwZIX/3Mc1RsAf1Zba40mwtNAIKDfJNahYqidK4GulptiGIK2Mi33xKIocW W0OqU6jTHk6ocLw7NjSwgC5wp0jwnw== =74z3 -----END PGP SIGNATURE----- --cWuKhQNXUyPcCDWb7oTARORvy0k7wUsDw--