From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86EC2C432C0 for ; Fri, 29 Nov 2019 08:02:08 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 51F9621721 for ; Fri, 29 Nov 2019 08:02:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Hn/W+rJK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 51F9621721 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55736 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iabE5-0002it-D7 for qemu-devel@archiver.kernel.org; Fri, 29 Nov 2019 03:02:05 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:37852) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iab8w-0000QJ-UE for qemu-devel@nongnu.org; Fri, 29 Nov 2019 02:56:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iab8o-0000Xj-Tb for qemu-devel@nongnu.org; Fri, 29 Nov 2019 02:56:40 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:59145 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iab8n-0008WK-NQ for qemu-devel@nongnu.org; Fri, 29 Nov 2019 02:56:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575014191; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0yY8LoFUfQZeQENdfkF9j+qRSJ3HGQ9ejMRlDygOXz0=; b=Hn/W+rJKSaPfNJNVcMdx9KPezRRZypwUNm7v4JTGAPRBUejt3S/O5ezxNn7qpZqt6k4vq1 1XUGUOdpkZUFBiggqa+pIoE7CA7ruGKSsvkXexhgny2nz8VU7xbdr4PEATQgiy4mPuaeVT nGi8vJPb6AbMISV6lyGimpVuJ+1Wk9o= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-69-B4jAes0kMRyVEUbV1pv4AA-1; Fri, 29 Nov 2019 02:56:28 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 24EB2DB61; Fri, 29 Nov 2019 07:56:27 +0000 (UTC) Received: from gondolin (ovpn-116-140.ams2.redhat.com [10.36.116.140]) by smtp.corp.redhat.com (Postfix) with ESMTP id EE5C5608C9; Fri, 29 Nov 2019 07:56:25 +0000 (UTC) Date: Fri, 29 Nov 2019 08:56:23 +0100 From: Cornelia Huck To: Laszlo Ersek Subject: Re: [PATCH v2] qga: fence guest-set-time if hwclock not available Message-ID: <20191129085623.498e76b2.cohuck@redhat.com> In-Reply-To: References: <20191128181100.23187-1-cohuck@redhat.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: B4jAes0kMRyVEUbV1pv4AA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Daniel P . =?UTF-8?B?QmVycmFuZ8Op?=" , Michael Roth , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 28 Nov 2019 19:38:00 +0100 Laszlo Ersek wrote: > Hi Cornelia, > > On 11/28/19 19:11, Cornelia Huck wrote: > > The Posix implementation of guest-set-time invokes hwclock to > > set/retrieve the time to/from the hardware clock. If hwclock > > is not available, the user is currently informed that "hwclock > > failed to set hardware clock to system time", which is quite > > misleading. This may happen e.g. on s390x, which has a different > > timekeeping concept anyway. > > > > Let's check for the availability of the hwclock command and > > return QERR_UNSUPPORTED for guest-set-time if it is not available. > > > > Signed-off-by: Cornelia Huck > > --- > > > > v1 (RFC) -> v2: > > - use hwclock_path[] > > - use access() instead of stat() > > > > --- > > qga/commands-posix.c | 13 ++++++++++++- > > 1 file changed, 12 insertions(+), 1 deletion(-) > > > > diff --git a/qga/commands-posix.c b/qga/commands-posix.c > > index 1c1a165daed8..ffb6420fa9cd 100644 > > --- a/qga/commands-posix.c > > +++ b/qga/commands-posix.c > > @@ -156,6 +156,17 @@ void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp) > > pid_t pid; > > Error *local_err = NULL; > > struct timeval tv; > > + const char hwclock_path[] = "/sbin/hwclock"; > > Did you drop the "static" storage-class specifier on purpose? No, I just need to do patches when I'm less tired :/ > > > + static int hwclock_available = -1; > > + > > + if (hwclock_available < 0) { > > + hwclock_available = (access(hwclock_path, X_OK) == 0); > > + } > > + > > + if (!hwclock_available) { > > + error_setg(errp, QERR_UNSUPPORTED); > > + return; > > + } > > > > /* If user has passed a time, validate and set it. */ > > if (has_time) { > > @@ -195,7 +206,7 @@ void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp) > > > > /* Use '/sbin/hwclock -w' to set RTC from the system time, > > * or '/sbin/hwclock -s' to set the system time from RTC. */ > > - execle("/sbin/hwclock", "hwclock", has_time ? "-w" : "-s", > > + execle(hwclock_path, "hwclock", has_time ? "-w" : "-s", > > I think it's somewhat obscure now that arg="hwclock" is supposed to > match the last pathname component in hwclock_path="/sbin/hwclock". > > There are multiple ways to compute "arg" like that, of course. But I > think they all look uglier than the above. So I'm fine if we just keep this. Yes, I was not able to come up with something elegant, either. [Side note: does really everyone put hwclock under /sbin (i.e., nobody doing something creative?)] > > > If you purposely dropped the "static", then: > > Reviewed-by: Laszlo Ersek > > If you just missed the "static" and now intend to add it back, then for v3: > > Reviewed-by: Laszlo Ersek > > Thanks > Laszlo Thanks for looking! There'll be a v3. > > > > > NULL, environ); > > _exit(EXIT_FAILURE); > > } else if (pid < 0) { > > >