1 files changed, 69 insertions, 0 deletions
diff --git a/backport-include/linux/module.h b/backport-include/linux/module.h
new file mode 100644
index 0000000..675d8d7
--- /dev/null
+++ b/backport-include/linux/module.h
@@ -0,0 +1,69 @@
+#ifndef __BACKPORT_LINUX_MODULE_H
+#define __BACKPORT_LINUX_MODULE_H
+#include_next <linux/module.h>
+#include <linux/rcupdate.h>
+
+/*
+ * The define overwriting module_init is based on the original module_init
+ * which looks like this:
+ * #define module_init(initfn)					\
+ *	static inline initcall_t __inittest(void)		\
+ *	{ return initfn; }					\
+ *	int init_module(void) __attribute__((alias(#initfn)));
+ *
+ * To the call to the initfn we added the symbol dependency on compat
+ * to make sure that compat.ko gets loaded for any compat modules.
+ */
+extern void backport_dependency_symbol(void);
+
+#ifdef BACKPORTS_GIT_TRACKED
+#define BACKPORT_MOD_VERSIONS MODULE_VERSION(BACKPORTS_GIT_TRACKED);
+#else
+#define BACKPORT_MOD_VERSIONS						\
+	MODULE_VERSION("backported from " CPTCFG_KERNEL_NAME	\
+		       " (" CPTCFG_KERNEL_VERSION ")"		\
+		       " using backports " CPTCFG_VERSION);
+#endif
+
+#ifdef MODULE
+#undef module_init
+#define module_init(initfn)						\
+	static int __init __init_backport(void)				\
+	{								\
+		backport_dependency_symbol();				\
+		return initfn();					\
+	}								\
+	int init_module(void) __attribute__((cold,alias("__init_backport")));\
+	BACKPORT_MOD_VERSIONS
+
+/*
+ * The define overwriting module_exit is based on the original module_exit
+ * which looks like this:
+ * #define module_exit(exitfn)                                    \
+ *         static inline exitcall_t __exittest(void)               \
+ *         { return exitfn; }                                      \
+ *         void cleanup_module(void) __attribute__((alias(#exitfn)));
+ *
+ * We replaced the call to the actual function exitfn() with a call to our
+ * function which calls the original exitfn() and then rcu_barrier()
+ *
+ * As a module will not be unloaded that ofter it should not have a big
+ * performance impact when rcu_barrier() is called on every module exit,
+ * also when no kfree_rcu() backport is used in that module.
+ */
+#undef module_exit
+#define module_exit(exitfn)						\
+	static void __exit __exit_compat(void)				\
+	{								\
+		exitfn();						\
+		rcu_barrier();						\
+	}								\
+	void cleanup_module(void) __attribute__((cold,alias("__exit_compat")));
+#endif
+
+#if LINUX_VERSION_IS_LESS(3,3,0)
+#undef param_check_bool
+#define param_check_bool(name, p) __param_check(name, p, bool)
+#endif
+
+#endif /* __BACKPORT_LINUX_MODULE_H */