From patchwork Mon Jul 31 10:21:28 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 9871505 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EFED8603B4 for ; Mon, 31 Jul 2017 10:24:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E000028576 for ; Mon, 31 Jul 2017 10:24:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D4E4F285A3; Mon, 31 Jul 2017 10:24:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3AF4D285A7 for ; Mon, 31 Jul 2017 10:24:26 +0000 (UTC) Received: from localhost ([::1]:58554 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dc7rN-0004hG-6I for patchwork-qemu-devel@patchwork.kernel.org; Mon, 31 Jul 2017 06:23:37 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50905) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dc7pd-00046s-VM for qemu-devel@nongnu.org; Mon, 31 Jul 2017 06:21:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dc7pb-00069F-9s for qemu-devel@nongnu.org; Mon, 31 Jul 2017 06:21:49 -0400 Received: from isrv.corpit.ru ([86.62.121.231]:58391) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dc7pb-00068S-1j; Mon, 31 Jul 2017 06:21:47 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 148BB42ABE; Mon, 31 Jul 2017 13:21:46 +0300 (MSK) Received: from tls.msk.ru (mjt.vpn.tls.msk.ru [192.168.177.99]) by tsrv.corpit.ru (Postfix) with SMTP id F2AB6B77; Mon, 31 Jul 2017 13:21:43 +0300 (MSK) Received: (nullmailer pid 5556 invoked by uid 1000); Mon, 31 Jul 2017 10:21:45 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Date: Mon, 31 Jul 2017 13:21:28 +0300 Message-Id: X-Mailer: git-send-email 2.11.0 In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 86.62.121.231 Subject: [Qemu-devel] [PULL 09/25] ivshmem: fix incorrect error handling in ivshmem_recv_msg() 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, Michael Tokarev , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Philippe Mathieu-Daudé Screwed up in commit 3a55fc0f, v2.6.0. If qemu_chr_fe_read_all() returns -EINTR the do {} statement continues and the n accumulator used to complete reads upto sizeof(msg) is decremented by 4 (the value of EINTR on Linux). To avoid that, use simpler if() statements and continue if EINTR occured. hw/misc/ivshmem.c:650:14: warning: Loss of sign in implicit conversion } while (n < sizeof(msg)); ^ Reported-by: Clang Static Analyzer Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Markus Armbruster Signed-off-by: Michael Tokarev --- hw/misc/ivshmem.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index a58f9ee579..47a015f072 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -642,7 +642,10 @@ static int64_t ivshmem_recv_msg(IVShmemState *s, int *pfd, Error **errp) do { ret = qemu_chr_fe_read_all(&s->server_chr, (uint8_t *)&msg + n, sizeof(msg) - n); - if (ret < 0 && ret != -EINTR) { + if (ret < 0) { + if (ret == -EINTR) { + continue; + } error_setg_errno(errp, -ret, "read from server failed"); return INT64_MIN; }