From patchwork Wed Oct 19 15:16:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 13011994 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AB571C43219 for ; Wed, 19 Oct 2022 15:22:06 +0000 (UTC) Received: from localhost ([::1]:44160 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1olAtR-0006Rf-Pr for qemu-devel@archiver.kernel.org; Wed, 19 Oct 2022 11:22:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45244) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1olAog-000455-Eh for qemu-devel@nongnu.org; Wed, 19 Oct 2022 11:17:11 -0400 Received: from us-smtp-delivery-44.mimecast.com ([207.211.30.44]:33367) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1olAof-00022G-43 for qemu-devel@nongnu.org; Wed, 19 Oct 2022 11:17:10 -0400 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-633-4jUr-gS8Nkqo3GCG-EpnJg-1; Wed, 19 Oct 2022 11:16:54 -0400 X-MC-Unique: 4jUr-gS8Nkqo3GCG-EpnJg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D8BFB101A56C; Wed, 19 Oct 2022 15:16:53 +0000 (UTC) Received: from bahia.redhat.com (unknown [10.39.192.144]) by smtp.corp.redhat.com (Postfix) with ESMTP id CB75553AA; Wed, 19 Oct 2022 15:16:52 +0000 (UTC) From: Greg Kurz To: qemu-devel@nongnu.org Cc: =?utf-8?q?Alex_Benn=C3=A9e?= , =?utf-8?q?Daniel_?= =?utf-8?q?P_=2E_Berrang=C3=A9?= , Richard Henderson , Paolo Bonzini , Greg Kurz Subject: [PATCH v2 0/2] util/log: Always send errors to logfile when daemonized Date: Wed, 19 Oct 2022 17:16:49 +0200 Message-Id: <20221019151651.334334-1-groug@kaod.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: softfail client-ip=207.211.30.44; envelope-from=groug@kaod.org; helo=us-smtp-delivery-44.mimecast.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" When QEMU is started with `--daemonize -D ${logfile} -d ${some_log_item}`, error logs from error_report() and friends go to ${logfile}, but if QEMU is started with `-daemonize -D ${logfile}` and no `-d`, the file isn't even created and all logs go to /dev/null. This inconsistency is quite confusing for users and gives the impression that QEMU doesn't log errors at all. It seems much saner to always create the log file when `-D` was passed and to be able to report errors. It was spotted by the kata-containers project, which happens to do just that `--daemonize -D` without `-d` trick. It is possible that they will stop doing so and catch errors through QEMU's stderr at some point, but I'm posting the patches anyway. v2: - new log_thread_id() implementation for hosts without gettid() syscall - avoid conflict between global log file and per-thread logfile - style improvements Greg Kurz (2): util/log: Derive thread id from getpid() on hosts w/o gettid() syscall util/log: Always send errors to logfile when daemonized util/log.c | 56 ++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 42 insertions(+), 14 deletions(-)