target/arm: Free name string in ARMCPRegInfo hashtable entries

When we add a new entry to the ARMCPRegInfo hash table in
add_cpreg_to_hashtable(), we allocate memory for tehe
ARMCPRegInfo struct itself, and we also g_strdup() the
name string. So the hashtable's value destructor function
must free the name string as well as the struct.

Spotted by clang's leak sanitizer. The leak here is a
small one-off leak at startup, because we don't support
CPU hotplug, and so the only time when we destroy
hash table entries is for the case where ARM_CP_OVERRIDE
means we register a wildcard entry and then override it later.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181204132952.2601-2-peter.maydell@linaro.org

target/arm/cpu.c

@@ -642,6 +642,20 @@ uint64_t arm_cpu_mp_affinity(int idx, uint8_t clustersz)
     return (Aff1 << ARM_AFF1_SHIFT) | Aff0;
 }
 
+static void cpreg_hashtable_data_destroy(gpointer data)
+{
+    /*
+     * Destroy function for cpu->cp_regs hashtable data entries.
+     * We must free the name string because it was g_strdup()ed in
+     * add_cpreg_to_hashtable(). It's OK to cast away the 'const'
+     * from r->name because we know we definitely allocated it.
+     */
+    ARMCPRegInfo *r = data;
+
+    g_free((void *)r->name);
+    g_free(r);
+}
+
 static void arm_cpu_initfn(Object *obj)
 {
     CPUState *cs = CPU(obj);
@@ -649,7 +663,7 @@ static void arm_cpu_initfn(Object *obj)
 
     cs->env_ptr = &cpu->env;
     cpu->cp_regs = g_hash_table_new_full(g_int_hash, g_int_equal,
-                                         g_free, g_free);
+                                         g_free, cpreg_hashtable_data_destroy);
 
     QLIST_INIT(&cpu->pre_el_change_hooks);
     QLIST_INIT(&cpu->el_change_hooks);