module: panic: Taint the kernel when selftest modules load

Taint the kernel with TAINT_TEST whenever a test module loads, by adding
a new "TEST" module property, and setting it for all modules in the
tools/testing directory. This property can also be set manually, for
tests which live outside the tools/testing directory with:
MODULE_INFO(test, "Y");

Reviewed-by: Luis Chamberlain <[e-mail]>
Reviewed-by: Aaron Tomlin <[e-mail]>
Acked-by: Brendan Higgins <[e-mail]>
Signed-off-by: David Gow <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

kernel/module/main.c

···
 	/* Set up license info based on the info section */
 	set_license(mod, get_modinfo(info, "license"));
 
+	if (get_modinfo(info, "test")) {
+		if (!test_taint(TAINT_TEST))
+			pr_warn("%s: loading test module taints kernel.\n",
+				mod->name);
+		add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
+	}
+
 	return 0;
 }
 

scripts/mod/modpost.c

···
 
 	if (strstarts(mod->name, "drivers/staging"))
 		buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
+
+	if (strstarts(mod->name, "tools/testing"))
+		buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
 }
 
 static void add_exported_symbols(struct buffer *buf, struct module *mod)