From patchwork Wed Jan 23 12:00:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 10777167 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6A6CE91E for ; Wed, 23 Jan 2019 12:25:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 587442BF26 for ; Wed, 23 Jan 2019 12:25:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4C83C2BF32; Wed, 23 Jan 2019 12:25:20 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id DDF9B2BF26 for ; Wed, 23 Jan 2019 12:25:19 +0000 (UTC) Received: from localhost ([127.0.0.1]:33531 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gmHao-0003QS-Rp for patchwork-qemu-devel@patchwork.kernel.org; Wed, 23 Jan 2019 07:25:18 -0500 Received: from eggs.gnu.org ([209.51.188.92]:38795) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gmHOq-0002im-Ds for qemu-devel@nongnu.org; Wed, 23 Jan 2019 07:12:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gmHCv-0003ql-2P for qemu-devel@nongnu.org; Wed, 23 Jan 2019 07:00:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52476) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gmHCu-0003pN-QF for qemu-devel@nongnu.org; Wed, 23 Jan 2019 07:00:37 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 84741C070154 for ; Wed, 23 Jan 2019 12:00:34 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-112-66.ams2.redhat.com [10.36.112.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id DC42D2635C; Wed, 23 Jan 2019 12:00:31 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Date: Wed, 23 Jan 2019 12:00:15 +0000 Message-Id: <20190123120016.4538-4-berrange@redhat.com> In-Reply-To: <20190123120016.4538-1-berrange@redhat.com> References: <20190123120016.4538-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 23 Jan 2019 12:00:34 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v4 3/4] trace: forbid use of %m in trace event format strings 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: Alex Williamson , Gerd Hoffmann , Stefan Hajnoczi Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP The '%m' format instructs glibc's printf()/syslog() implementation to insert the contents of strerror(errno). Since this is a glibc extension it should generally be avoided in QEMU due to need for portability to a variety of platforms. Even though vfio is Linux-only code that could otherwise use "%m", it must still be avoided in trace-events files because several of the backends do not use the format string and so this error information is invisible to them. The errno string value should be given as an explicit trace argument instead, making it accessible to all backends. This also allows it to work correctly with future patches that use the format string with systemtap's simple printf code. Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrangé --- hw/vfio/pci.c | 2 +- hw/vfio/trace-events | 2 +- scripts/tracetool/__init__.py | 4 ++++ 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index c0cb1ec289..dd12f36391 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -2581,7 +2581,7 @@ static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp) ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info); if (ret) { /* This can fail for an old kernel or legacy PCI dev */ - trace_vfio_populate_device_get_irq_info_failure(); + trace_vfio_populate_device_get_irq_info_failure(strerror(errno)); } else if (irq_info.count == 1) { vdev->pci_aer = true; } else { diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index a85e8662ea..f41ca96160 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -37,7 +37,7 @@ vfio_pci_hot_reset_has_dep_devices(const char *name) "%s: hot reset dependent de vfio_pci_hot_reset_dep_devices(int domain, int bus, int slot, int function, int group_id) "\t%04x:%02x:%02x.%x group %d" vfio_pci_hot_reset_result(const char *name, const char *result) "%s hot reset: %s" vfio_populate_device_config(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device %s config:\n size: 0x%lx, offset: 0x%lx, flags: 0x%lx" -vfio_populate_device_get_irq_info_failure(void) "VFIO_DEVICE_GET_IRQ_INFO failure: %m" +vfio_populate_device_get_irq_info_failure(const char *errstr) "VFIO_DEVICE_GET_IRQ_INFO failure: %s" vfio_realize(const char *name, int group_id) " (%s) group %d" vfio_mdev(const char *name, bool is_mdev) " (%s) is_mdev %d" vfio_add_ext_cap_dropped(const char *name, uint16_t cap, uint16_t offset) "%s 0x%x@0x%x" diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py index 3478ac93ab..6fca674936 100644 --- a/scripts/tracetool/__init__.py +++ b/scripts/tracetool/__init__.py @@ -274,6 +274,10 @@ class Event(object): props = groups["props"].split() fmt = groups["fmt"] fmt_trans = groups["fmt_trans"] + if fmt.find("%m") != -1 or fmt_trans.find("%m") != -1: + raise ValueError("Event format '%m' is forbidden, pass the error " + "as an explicit trace argument") + if len(fmt_trans) > 0: fmt = [fmt_trans, fmt] args = Arguments.build(groups["args"])