From nobody Sat Nov 1 09:48:48 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 (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 152704559085378.8946707266374; Tue, 22 May 2018 20:19:50 -0700 (PDT) Received: from localhost ([::1]:58998 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fLKJS-0001J2-Mj for importer@patchew.org; Tue, 22 May 2018 23:19:42 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44355) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fLKI1-0000fT-9Y for qemu-devel@nongnu.org; Tue, 22 May 2018 23:18:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fLKI0-00088S-Fs for qemu-devel@nongnu.org; Tue, 22 May 2018 23:18:13 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60378 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fLKI0-00088D-Az for qemu-devel@nongnu.org; Tue, 22 May 2018 23:18:12 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 00DFD77060; Wed, 23 May 2018 03:18:12 +0000 (UTC) Received: from xz-mi.nay.redhat.com (dhcp-14-151.nay.redhat.com [10.66.14.151]) by smtp.corp.redhat.com (Postfix) with ESMTP id A1B622024CD8; Wed, 23 May 2018 03:18:09 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Wed, 23 May 2018 11:18:04 +0800 Message-Id: <20180523031805.27101-2-peterx@redhat.com> In-Reply-To: <20180523031805.27101-1-peterx@redhat.com> References: <20180523031805.27101-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 23 May 2018 03:18:12 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 23 May 2018 03:18:12 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'peterx@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v3 1/2] qemu-error: introduce {error|warn}_report_once 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: Jason Wang , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Markus Armbruster , peterx@redhat.com, "Michael S . Tsirkin" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" I stole the printk_once() macro. I always wanted to be able to print some error directly if there is a buffer to dump, however we can't use error_report() where the code path can be triggered by DDOS attack. To avoid that, we can introduce a print-once-like function for it. Meanwhile, we also introduce the corresponding helper for warn_report(). CC: Markus Armbruster Signed-off-by: Peter Xu --- include/qemu/error-report.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/include/qemu/error-report.h b/include/qemu/error-report.h index e1c8ae1a52..3e6e84801f 100644 --- a/include/qemu/error-report.h +++ b/include/qemu/error-report.h @@ -44,6 +44,32 @@ void error_report(const char *fmt, ...) GCC_FMT_ATTR(1, = 2); void warn_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2); void info_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2); =20 +/* Similar to error_report(), but it only prints the message once. */ +#define error_report_once(fmt, ...) \ + ({ \ + static bool __print_once; \ + bool __ret_print_once =3D !__print_once; \ + \ + if (!__print_once) { \ + __print_once =3D true; \ + error_report(fmt, ##__VA_ARGS__); \ + } \ + unlikely(__ret_print_once); \ + }) + +/* Similar to warn_report(), but it only prints the message once. */ +#define warn_report_once(fmt, ...) \ + ({ \ + static bool __print_once; \ + bool __ret_print_once =3D !__print_once; \ + \ + if (!__print_once) { \ + __print_once =3D true; \ + warn_report(fmt, ##__VA_ARGS__); \ + } \ + unlikely(__ret_print_once); \ + }) + const char *error_get_progname(void); extern bool enable_timestamp_msg; =20 --=20 2.17.0