From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34955) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZLF9-00059q-LJ for qemu-devel@nongnu.org; Tue, 18 Dec 2018 14:41:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gZL9f-000343-WB for qemu-devel@nongnu.org; Tue, 18 Dec 2018 14:35:52 -0500 Received: from indium.canonical.com ([91.189.90.7]:49700) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gZL9f-0002u8-P1 for qemu-devel@nongnu.org; Tue, 18 Dec 2018 14:35:47 -0500 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1gZL9e-0003XF-7a for ; Tue, 18 Dec 2018 19:35:46 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 2B63A2E80CC for ; Tue, 18 Dec 2018 19:35:46 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Tue, 18 Dec 2018 19:29:51 -0000 From: Eric Blake <1803872@bugs.launchpad.net> Reply-To: Bug 1803872 <1803872@bugs.launchpad.net> Sender: bounces@canonical.com References: <154254872666.7803.12367996737502527787.malonedeb@wampee.canonical.com> Message-Id: <79a10131-a596-33ff-d58c-1e01bb98beb2@redhat.com> Errors-To: bounces@canonical.com Subject: [Qemu-devel] [Bug 1803872] Re: [PATCH v3 4/5] migration: Use QEMU_NONSTRING for non NUL-terminated arrays List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On 12/18/18 11:51 AM, Philippe Mathieu-Daud=C3=A9 wrote: > GCC 8 added a -Wstringop-truncation warning: > = > The -Wstringop-truncation warning added in GCC 8.0 via r254630 for > bug 81117 is specifically intended to highlight likely unintended > uses of the strncpy function that truncate the terminating NUL > character from the source string. > = > This new warning leads to compilation failures: > = > CC migration/global_state.o > qemu/migration/global_state.c: In function 'global_state_store_running= ': > qemu/migration/global_state.c:45:5: error: 'strncpy' specified bound 1= 00 equals destination size [-Werror=3Dstringop-truncation] > strncpy((char *)global_state.runstate, state, sizeof(global_state= .runstate)); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~~~ > make: *** [qemu/rules.mak:69: migration/global_state.o] Error 1 > = > Use the QEMU_NONSTRING attribute, since this array is intended to store > character arrays that do not necessarily contain a terminating NUL. > = > Suggested-by: Michael S. Tsirkin > Signed-off-by: Philippe Mathieu-Daud=C3=A9 > --- > migration/global_state.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Should this be squashed with 5/5? -- = Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1803872 Title: gcc 8.2 reports stringop-truncation when building qemu Status in QEMU: New Bug description: QEMU 3.0 block/sheepdog.c: In function 'find_vdi_name': block/sheepdog.c:1239:5: error: 'strncpy' specified bound 256 equals dest= ination size [-Werror=3Dstringop-truncation] =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_V= DI_TAG_LEN); =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~~~ If this is the intended behavior, please suppress the warning. For example: #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wstringop-truncation" =C2=A0=C2=A0=C2=A0=C2=A0strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG= _LEN); #pragma GCC diagnostic pop This also happens on other sources, for example hw/acpi/core.c, so another option is to suppress it globally on CFLAGS (-Wno-stringop- truncation) To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1803872/+subscriptions