From: Greg Kurz <groug@kaod.org>
Date: Thu, 24 Oct 2019 14:27:33 +0000 (+0200)
Subject: ppc: Skip partially initialized vCPUs in 'info pic'
X-Git-Tag: v4.2.0-rc2~9^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0a83b47055246d3942084f03fc54731c4fb9b731;p=thirdparty%2Fqemu.git

ppc: Skip partially initialized vCPUs in 'info pic'

CPU_FOREACH() can race with vCPU hotplug/unplug on sPAPR machines, ie.
we may try to print out info about a vCPU with a NULL presenter pointer.

Check that in order to prevent QEMU from crashing.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <157192725327.3146912.12047076483178652551.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---

diff --git a/hw/intc/xics.c b/hw/intc/xics.c
index 5f746079be4..e7ac9ba618f 100644
--- a/hw/intc/xics.c
+++ b/hw/intc/xics.c
@@ -44,7 +44,16 @@
 
 void icp_pic_print_info(ICPState *icp, Monitor *mon)
 {
-    int cpu_index = icp->cs ? icp->cs->cpu_index : -1;
+    int cpu_index;
+
+    /* Skip partially initialized vCPUs. This can happen on sPAPR when vCPUs
+     * are hot plugged or unplugged.
+     */
+    if (!icp) {
+        return;
+    }
+
+    cpu_index = icp->cs ? icp->cs->cpu_index : -1;
 
     if (!icp->output) {
         return;
diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index 952a461d532..75dce82fb20 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -523,9 +523,18 @@ static const char * const xive_tctx_ring_names[] = {
 
 void xive_tctx_pic_print_info(XiveTCTX *tctx, Monitor *mon)
 {
-    int cpu_index = tctx->cs ? tctx->cs->cpu_index : -1;
+    int cpu_index;
     int i;
 
+    /* Skip partially initialized vCPUs. This can happen on sPAPR when vCPUs
+     * are hot plugged or unplugged.
+     */
+    if (!tctx) {
+        return;
+    }
+
+    cpu_index = tctx->cs ? tctx->cs->cpu_index : -1;
+
     if (kvm_irqchip_in_kernel()) {
         Error *local_err = NULL;