[PULL,v2,3/6] ppc: Skip partially initialized vCPUs in 'info pic'

Commit Message

Laurent Vivier Nov. 18, 2019, 10:53 a.m. UTC

From: Greg Kurz <[e-mail]>

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 <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: David Gibson <[e-mail]>
Signed-off-by: Laurent Vivier <[e-mail]>
---
 hw/intc/xics.c | 11 ++++++++++-
 hw/intc/xive.c | 11 ++++++++++-
 2 files changed, 20 insertions(+), 2 deletions(-)

Patch

diff --git a/hw/intc/xics.c b/hw/intc/xics.c
index 5f746079be46..e7ac9ba618fa 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 952a461d5329..75dce82fb205 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;