module: export module signature enforcement status

A static variable sig_enforce is used as status var to indicate the real value of CONFIG_MODULE_SIG_FORCE, once this one is set the var will hold true, but if the CONFIG is not set the status var will hold whatever value is present in the module.sig_enforce kernel cmdline param: true when =1 and false when =0 or not present. Considering this cmdline param take place over the CONFIG value when it's not set, other places in the kernel could misbehave since they would have only the CONFIG_MODULE_SIG_FORCE value to rely on. Exporting this status var allows the kernel to rely in the effective value of module signature enforcement, being it from CONFIG value or cmdline param.

Bruno E. O. Meneguele committed 9 years ago

Commit fda784e1 parent ebe7c0a2 files · +17 −0Browse files

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kernel/module.c+10−0

@@ -278,6 +278,16 @@ static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); · 277 unmodified lines
278	278	module_param(sig_enforce, bool_enable_only, 0644);
279	279	#endif /* !CONFIG_MODULE_SIG_FORCE */
280	280
	281	+/*
	282	+ * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
	283	+ * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
	284	+ */
	285	+bool is_module_sig_enforced(void)
	286	+{
	287	+ return sig_enforce;
	288	+}
	289	+EXPORT_SYMBOL(is_module_sig_enforced);
	290	+
281	291	/* Block module loading/unloading? */
282	292	int modules_disabled = 0;
283	293	core_param(nomodule, modules_disabled, bint, 0);