fuzz: Expect the cmdline in a freeable GString

In the initial FuzzTarget, get_init_cmdline returned a char *. With this
API, we had no guarantee about where the string came from. For example,
i440fx-qtest-reboot-fuzz simply returned a pointer to a string literal,
while the QOS-based targets build the arguments out in a GString an
return the gchar *str pointer. Since we did not try to free the cmdline,
we have a leak for any targets that do not simply return string
literals. Clean up this mess by forcing fuzz-targets to return
a GString, that we can free.

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20200714174616.20709-1-alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/tests/qtest/fuzz/fuzz.h b/tests/qtest/fuzz/fuzz.h
index 72d5710f6c..9ca3d107c5 100644
--- a/tests/qtest/fuzz/fuzz.h
+++ b/tests/qtest/fuzz/fuzz.h
@@ -50,10 +50,10 @@ typedef struct FuzzTarget {
 
 
     /*
-     * returns the arg-list that is passed to qemu/softmmu init()
-     * Cannot be NULL
+     * Returns the arguments that are passed to qemu/softmmu init(). Freed by
+     * the caller.
      */
-    const char* (*get_init_cmdline)(struct FuzzTarget *);
+    GString *(*get_init_cmdline)(struct FuzzTarget *);
 
     /*
      * will run once, prior to running qemu/softmmu init.