From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35125) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cMyFD-0004SF-CY for qemu-devel@nongnu.org; Fri, 30 Dec 2016 09:33:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cMyFA-0002zO-9u for qemu-devel@nongnu.org; Fri, 30 Dec 2016 09:33:19 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60102) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cMyFA-0002z4-3r for qemu-devel@nongnu.org; Fri, 30 Dec 2016 09:33:16 -0500 From: Igor Mammedov Date: Fri, 30 Dec 2016 15:33:11 +0100 Message-Id: <1483108391-199542-1-git-send-email-imammedo@redhat.com> Subject: [Qemu-devel] [PATCH] pc: fix crash in rtc_set_memory() if initial cpu is marked as hotplugged List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, mst@redhat.com, armbru@redhat.com, afaerber@suse.de, ehabkost@redhat.com 'hotplugged' propperty is meant to be used on migration side when migrating source with hotplugged devices. However though it not exacly correct usage of 'hotplugged' property it's possible to set generic hotplugged property for CPU using -cpu foo,hotplugged=on or -global foo.hotplugged=on in this case qemu crashes with following backtrace: ... because pc_cpu_plug() assumes that hotplugged CPU could appear only after rtc/fw_cfg are initialized. Fix crash by replacing assumption with explicit checks of rtc/fw_cfg and updating them only if they were initialized. Signed-off-by: Igor Mammedov Reported-by: Eduardo Habkost --- hw/i386/pc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index f3d7ad4..7b7e126 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1810,8 +1810,10 @@ static void pc_cpu_plug(HotplugHandler *hotplug_dev, /* increment the number of CPUs */ pcms->boot_cpus++; - if (dev->hotplugged) { + if (pcms->rtc) { rtc_set_cpus_count(pcms->rtc, pcms->boot_cpus); + } + if (pcms->fw_cfg) { fw_cfg_modify_i16(pcms->fw_cfg, FW_CFG_NB_CPUS, pcms->boot_cpus); } -- 2.7.4