From nobody Sun Oct 26 00:02:46 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 (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1516352944358522.6094165121135; Fri, 19 Jan 2018 01:09:04 -0800 (PST) Received: from localhost ([::1]:36446 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecSfS-0004if-J6 for importer@patchew.org; Fri, 19 Jan 2018 04:08:58 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54635) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecSIK-00024k-JH for qemu-devel@nongnu.org; Fri, 19 Jan 2018 03:45:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ecSIJ-00063y-Qg for qemu-devel@nongnu.org; Fri, 19 Jan 2018 03:45:04 -0500 Received: from mail.ispras.ru ([83.149.199.45]:53892) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecSIJ-00062u-JA for qemu-devel@nongnu.org; Fri, 19 Jan 2018 03:45:03 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id EE92D54006A; Fri, 19 Jan 2018 11:45:01 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Fri, 19 Jan 2018 11:45:06 +0300 Message-ID: <20180119084506.7100.20031.stgit@pasha-VirtualBox> In-Reply-To: <20180119084235.7100.98318.stgit@pasha-VirtualBox> References: <20180119084235.7100.98318.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 v4 20/23] 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, pavel.dovgaluk@ispras.ru, mst@redhat.com, jasowang@redhat.com, quintela@redhat.com, zuban32s@gmail.com, maria.klimushenkova@ispras.ru, dovgaluk@ispras.ru, kraxel@redhat.com, boost.lists@gmail.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