From: Dunrong Huang <riegamaths@gmail.com>
Date: Mon, 23 Jul 2012 16:42:20 +0000 (+0800)
Subject: vl.c: Exit QEMU early if no machine is found
X-Git-Tag: v1.2.0-rc0~34^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fb7c269ed694c103397c5fffbfcccd3e90aed23c;p=thirdparty%2Fqemu.git

vl.c: Exit QEMU early if no machine is found

We check whether the variable machine is NULL or not before accessing
it. If machine is NULL, exit QEMU with an error, this can avoids a
segfault error.

Markus Armbruster <armbru@redhat.com> adds that the segfault can be
reproduced as follows:

  $ qemu-system-xtensa -cpu help

Signed-off-by: Dunrong Huang <riegamaths@gmail.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---

diff --git a/vl.c b/vl.c
index a4a520fb7e6..48714288646 100644
--- a/vl.c
+++ b/vl.c
@@ -3204,6 +3204,11 @@ int main(int argc, char **argv, char **envp)
     }
     loc_set_none();
 
+    if (machine == NULL) {
+        fprintf(stderr, "No machine found.\n");
+        exit(1);
+    }
+
     if (machine->hw_version) {
         qemu_set_version(machine->hw_version);
     }
@@ -3246,11 +3251,6 @@ int main(int argc, char **argv, char **envp)
         data_dir = CONFIG_QEMU_DATADIR;
     }
 
-    if (machine == NULL) {
-        fprintf(stderr, "No machine found.\n");
-        exit(1);
-    }
-
     /*
      * Default to max_cpus = smp_cpus, in case the user doesn't
      * specify a max_cpus value.