From nobody Wed Oct 1 02:38:25 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1545162574805203.4696458422693; Tue, 18 Dec 2018 11:49:34 -0800 (PST) Received: from localhost ([::1]:55606 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZJZg-0006W8-Mr for importer@patchew.org; Tue, 18 Dec 2018 12:54:32 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33431) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZJXt-00059X-LA for qemu-devel@nongnu.org; Tue, 18 Dec 2018 12:52:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gZJXs-0003JB-Ix for qemu-devel@nongnu.org; Tue, 18 Dec 2018 12:52:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35950) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gZJXl-00035J-Qp; Tue, 18 Dec 2018 12:52:34 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B1D15C0587E5; Tue, 18 Dec 2018 17:52:32 +0000 (UTC) Received: from x1w.redhat.com (ovpn-204-92.brq.redhat.com [10.40.204.92]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 493C01059581; Tue, 18 Dec 2018 17:52:10 +0000 (UTC) From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org Date: Tue, 18 Dec 2018 18:51:19 +0100 Message-Id: <20181218175122.3229-3-philmd@redhat.com> In-Reply-To: <20181218175122.3229-1-philmd@redhat.com> References: <20181218175122.3229-1-philmd@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 18 Dec 2018 17:52:32 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 2/5] block/sheepdog: Use QEMU_NONSTRING for non NUL-terminated arrays 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: "Michael S. Tsirkin" , Jeff Cody , Ben Pye , qemu-block@nongnu.org, Juan Quintela , David Hildenbrand , Markus Armbruster , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Liu Yuan , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Thomas Huth , Stefan Weil , Howard Spoelstra , "Dr. David Alan Gilbert" , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , Paolo Bonzini , David Gibson , Kevin Wolf , Max Reitz , 1803872@bugs.launchpad.net, Igor Mammedov Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" 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 block/sheepdog.o qemu/block/sheepdog.c: In function 'find_vdi_name': qemu/block/sheepdog.c:1239:5: error: 'strncpy' specified bound 256 equals= destination size [-Werror=3Dstringop-truncation] strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ make: *** [qemu/rules.mak:69: block/sheepdog.o] Error 1 As described previous to the strncpy() calls, the use of strncpy() is correct here: /* This pair of strncpy calls ensures that the buffer is zero-filled, * which is desirable since we'll soon be sending those bytes, and * don't want the send_req to read uninitialized data. */ strncpy(buf, filename, SD_MAX_VDI_LEN); strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN); 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 Reviewed-by: Eric Blake --- block/sheepdog.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/sheepdog.c b/block/sheepdog.c index 0125df9d49..d4ad6b119d 100644 --- a/block/sheepdog.c +++ b/block/sheepdog.c @@ -1224,7 +1224,7 @@ static int find_vdi_name(BDRVSheepdogState *s, const = char *filename, SheepdogVdiReq hdr; SheepdogVdiRsp *rsp =3D (SheepdogVdiRsp *)&hdr; unsigned int wlen, rlen =3D 0; - char buf[SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN]; + QEMU_NONSTRING char buf[SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN]; =20 fd =3D connect_to_sdog(s, errp); if (fd < 0) { --=20 2.17.2