From patchwork Wed Jan 11 20:40:50 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Huth X-Patchwork-Id: 9511375 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8D46760710 for ; Wed, 11 Jan 2017 21:06:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7F88E2865F for ; Wed, 11 Jan 2017 21:06:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7299E28696; Wed, 11 Jan 2017 21:06:32 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0467428692 for ; Wed, 11 Jan 2017 21:06:32 +0000 (UTC) Received: from localhost ([::1]:57100 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cRQ6J-00039a-3l for patchwork-qemu-devel@patchwork.kernel.org; Wed, 11 Jan 2017 16:06:31 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59484) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cRPhY-0002ZO-VJ for qemu-devel@nongnu.org; Wed, 11 Jan 2017 15:40:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cRPhV-0008PS-S7 for qemu-devel@nongnu.org; Wed, 11 Jan 2017 15:40:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44352) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cRPhV-0008P1-KE; Wed, 11 Jan 2017 15:40:53 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1696CC04B92C; Wed, 11 Jan 2017 20:40:53 +0000 (UTC) Received: from thh440s.redhat.com (ovpn-116-105.ams2.redhat.com [10.36.116.105]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v0BKepdt028170; Wed, 11 Jan 2017 15:40:51 -0500 From: Thomas Huth To: qemu-devel@nongnu.org, "Dr. David Alan Gilbert" Date: Wed, 11 Jan 2017 21:40:50 +0100 Message-Id: <1484167250-16089-1-git-send-email-thuth@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 11 Jan 2017 20:40:53 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] monitor: Fix crashes when using HMP commands without CPU 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: qemu-trivial@nongnu.org, Markus Armbruster Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP When running certain HMP commands ("info registers", "info cpustats" or dumping virtual memory) with the "none" machine, QEMU crashes with a segmentation fault. This happens because the "none" machine does not have any CPUs by default, but these HMP commands did not check for a valid CPU pointer yet. Add such a check now and print a message about the missing CPU instead. Signed-off-by: Thomas Huth --- monitor.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/monitor.c b/monitor.c index 0841d43..0103979 100644 --- a/monitor.c +++ b/monitor.c @@ -1025,6 +1025,9 @@ int monitor_set_cpu(int cpu_index) CPUState *mon_get_cpu(void) { if (!cur_mon->mon_cpu) { + if (!first_cpu) { + return NULL; + } monitor_set_cpu(first_cpu->cpu_index); } cpu_synchronize_state(cur_mon->mon_cpu); @@ -1043,7 +1046,13 @@ int monitor_get_cpu_index(void) static void hmp_info_registers(Monitor *mon, const QDict *qdict) { - cpu_dump_state(mon_get_cpu(), (FILE *)mon, monitor_fprintf, CPU_DUMP_FPU); + CPUState *cs = mon_get_cpu(); + + if (!cs) { + monitor_printf(mon, "No CPU available\n"); + return; + } + cpu_dump_state(cs, (FILE *)mon, monitor_fprintf, CPU_DUMP_FPU); } static void hmp_info_jit(Monitor *mon, const QDict *qdict) @@ -1076,7 +1085,13 @@ static void hmp_info_history(Monitor *mon, const QDict *qdict) static void hmp_info_cpustats(Monitor *mon, const QDict *qdict) { - cpu_dump_statistics(mon_get_cpu(), (FILE *)mon, &monitor_fprintf, 0); + CPUState *cs = mon_get_cpu(); + + if (!cs) { + monitor_printf(mon, "No CPU available\n"); + return; + } + cpu_dump_statistics(cs, (FILE *)mon, &monitor_fprintf, 0); } static void hmp_info_trace_events(Monitor *mon, const QDict *qdict) @@ -1235,6 +1250,12 @@ static void memory_dump(Monitor *mon, int count, int format, int wsize, int l, line_size, i, max_digits, len; uint8_t buf[16]; uint64_t v; + CPUState *cs = mon_get_cpu(); + + if (!cs && (format == 'i' || !is_physical)) { + monitor_printf(mon, "Can not dump without CPU\n"); + return; + } if (format == 'i') { int flags = 0; @@ -1264,7 +1285,7 @@ static void memory_dump(Monitor *mon, int count, int format, int wsize, flags = msr_le << 16; flags |= env->bfd_mach; #endif - monitor_disas(mon, mon_get_cpu(), addr, count, is_physical, flags); + monitor_disas(mon, cs, addr, count, is_physical, flags); return; } @@ -1303,7 +1324,7 @@ static void memory_dump(Monitor *mon, int count, int format, int wsize, if (is_physical) { cpu_physical_memory_read(addr, buf, l); } else { - if (cpu_memory_rw_debug(mon_get_cpu(), addr, buf, l, 0) < 0) { + if (cpu_memory_rw_debug(cs, addr, buf, l, 0) < 0) { monitor_printf(mon, " Cannot access memory\n"); break; }