From nobody Sat Oct 25 19:45:43 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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 15180059800091010.8851357358776; Wed, 7 Feb 2018 04:19:40 -0800 (PST) Received: from localhost ([::1]:57089 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOhP-0005Ig-6D for importer@patchew.org; Wed, 07 Feb 2018 07:19:39 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50485) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOTe-00019J-Ni for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:05:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ejOTa-0004Tf-2x for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:05:26 -0500 Received: from mail.ispras.ru ([83.149.199.45]:47640) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOTZ-0004TM-Qu for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:05:22 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id D51A154008B; Wed, 7 Feb 2018 15:05:20 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 07 Feb 2018 15:05:23 +0300 Message-ID: <20180207120523.5389.91342.stgit@pasha-VirtualBox> In-Reply-To: <20180207120353.5389.54531.stgit@pasha-VirtualBox> References: <20180207120353.5389.54531.stgit@pasha-VirtualBox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 83.149.199.45 Subject: [Qemu-devel] [RFC PATCH v6 16/20] replay: avoid recursive call of checkpoints 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: kwolf@redhat.com, peter.maydell@linaro.org, war2jordan@live.com, pavel.dovgaluk@ispras.ru, quintela@redhat.com, ciro.santilli@gmail.com, jasowang@redhat.com, mst@redhat.com, zuban32s@gmail.com, maria.klimushenkova@ispras.ru, dovgaluk@ispras.ru, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 This patch adds a flag which denies recursive call of replay_checkpoint function. Checkpoints may be accompanied by the hardware events. When event is processed, virtual device may invoke timer modification functions that also invoke the checkpoint function. This leads to infinite loop. Signed-off-by: Pavel Dovgalyuk --- replay/replay.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/replay/replay.c b/replay/replay.c index 585c5de..c676dd4 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -176,13 +176,24 @@ void replay_shutdown_request(ShutdownCause cause) bool replay_checkpoint(ReplayCheckpoint checkpoint) { bool res =3D false; + static bool in_checkpoint; assert(EVENT_CHECKPOINT + checkpoint <=3D EVENT_CHECKPOINT_LAST); - replay_save_instructions(); =20 if (!replay_file) { return true; } =20 + if (in_checkpoint) { + /* If we are already in checkpoint, then there is no need + for additional synchronization. + Recursion occurs when HW event modifies timers. + Timer modification may invoke the checkpoint and + proceed to recursion. */ + return true; + } + in_checkpoint =3D true; + + replay_save_instructions(); =20 if (replay_mode =3D=3D REPLAY_MODE_PLAY) { g_assert(replay_mutex_locked()); @@ -204,6 +215,7 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint) res =3D true; } out: + in_checkpoint =3D false; return res; } =20