modules: don't fail to load on unknown parameters.

Although parameters are supposed to be part of the kernel API, experimental
parameters are often removed.  In addition, downgrading a kernel might cause
previously-working modules to fail to load.

On balance, it's probably better to warn, and load the module anyway.
This may let through a typo, but at least the logs will show it.
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

kernel/module.c

@@ -3212,6 +3212,17 @@ static int complete_formation(struct module *mod, struct load_info *info)
 	return err;
 }
 
+static int unknown_module_param_cb(char *param, char *val, const char *modname)
+{
+	/* Check for magic 'dyndbg' arg */ 
+	int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
+	if (ret != 0) {
+		printk(KERN_WARNING "%s: unknown parameter '%s' ignored\n",
+		       modname, param);
+	}
+	return 0;
+}
+
 /* Allocate and load the module: note that size of section 0 is always
    zero, and we rely on this for optional sections. */
 static int load_module(struct load_info *info, const char __user *uargs,
@@ -3298,7 +3309,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
 
 	/* Module is ready to execute: parsing args may do that. */
 	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
-			 -32768, 32767, &ddebug_dyndbg_module_param_cb);
+			 -32768, 32767, unknown_module_param_cb);
 	if (err < 0)
 		goto bug_cleanup;