module: Enable dynamic debugging regardless of taint

Dynamic debugging is currently disabled for tainted modules, except
for TAINT_CRAP.  This prevents use of dynamic debugging for
out-of-tree modules once the next patch is applied.

This condition was apparently intended to avoid a crash if a force-
loaded module has an incompatible definition of dynamic debug
structures.  However, a administrator that forces us to load a module
is claiming that it *is* compatible even though it fails our version
checks.  If they are mistaken, there are any number of ways the module
could crash the system.

As a side-effect, proprietary and other tainted modules can now use
dynamic_debug.

Signed-off-by: Ben Hutchings <[email protected]>
Acked-by: Mathieu Desnoyers <[email protected]>
Signed-off-by: Rusty Russell <[email protected]>

kernel/module.c

@@ -2878,8 +2878,7 @@ static struct module *load_module(void __user *umod,
 	}
 
 	/* This has to be done once we're sure module name is unique. */
-	if (!mod->taints || mod->taints == (1U<<TAINT_CRAP))
-		dynamic_debug_setup(info.debug, info.num_debug);
+	dynamic_debug_setup(info.debug, info.num_debug);
 
 	/* Find duplicate symbols */
 	err = verify_export_symbols(mod);
@@ -2915,8 +2914,7 @@ static struct module *load_module(void __user *umod,
 	module_bug_cleanup(mod);
 
  ddebug:
-	if (!mod->taints || mod->taints == (1U<<TAINT_CRAP))
-		dynamic_debug_remove(info.debug);
+	dynamic_debug_remove(info.debug);
  unlock:
 	mutex_unlock(&module_mutex);
 	synchronize_sched();