monitor: Fix crashes when using HMP commands without CPU
When running certain HMP commands ("info registers", "info cpustats",
"info tlb", "nmi", "memsave" 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 checks now, so we get
an error message about the missing CPU instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1484309555-1935-1-git-send-email-thuth@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
diff --git a/target/sh4/monitor.c b/target/sh4/monitor.c
index 426e5d4..4c7f36c 100644
--- a/target/sh4/monitor.c
+++ b/target/sh4/monitor.c
@@ -44,6 +44,11 @@
CPUArchState *env = mon_get_cpu_env();
int i;
+ if (!env) {
+ monitor_printf(mon, "No CPU available\n");
+ return;
+ }
+
monitor_printf (mon, "ITLB:\n");
for (i = 0 ; i < ITLB_SIZE ; i++)
print_tlb (mon, i, &env->itlb[i]);
