[PATCH] Add EXPORT_UNUSED_SYMBOL and EXPORT_UNUSED_SYMBOL_GPL
Temporarily add EXPORT_UNUSED_SYMBOL and EXPORT_UNUSED_SYMBOL_GPL. These
will be used as a transition measure for symbols that aren't used in the
kernel and are on the way out. When a module uses such a symbol, a warning
is printk'd at modprobe time.
The main reason for removing unused exports is size: eacho export takes
roughly between 100 and 150 bytes of kernel space in the binary. This
patch gives users the option to immediately get this size gain via a config
option.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/module.h b/include/linux/module.h
index 9ebbb74..9e9dc7c 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -203,6 +203,15 @@
#define EXPORT_SYMBOL_GPL_FUTURE(sym) \
__EXPORT_SYMBOL(sym, "_gpl_future")
+
+#ifdef CONFIG_UNUSED_SYMBOLS
+#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
+#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
+#else
+#define EXPORT_UNUSED_SYMBOL(sym)
+#define EXPORT_UNUSED_SYMBOL_GPL(sym)
+#endif
+
#endif
struct module_ref
@@ -261,6 +270,15 @@
unsigned int num_gpl_syms;
const unsigned long *gpl_crcs;
+ /* unused exported symbols. */
+ const struct kernel_symbol *unused_syms;
+ unsigned int num_unused_syms;
+ const unsigned long *unused_crcs;
+ /* GPL-only, unused exported symbols. */
+ const struct kernel_symbol *unused_gpl_syms;
+ unsigned int num_unused_gpl_syms;
+ const unsigned long *unused_gpl_crcs;
+
/* symbols that will be GPL-only in the near future. */
const struct kernel_symbol *gpl_future_syms;
unsigned int num_gpl_future_syms;
@@ -456,6 +474,8 @@
#define EXPORT_SYMBOL(sym)
#define EXPORT_SYMBOL_GPL(sym)
#define EXPORT_SYMBOL_GPL_FUTURE(sym)
+#define EXPORT_UNUSED_SYMBOL(sym)
+#define EXPORT_UNUSED_SYMBOL_GPL(sym)
/* Given an address, look for it in the exception tables. */
static inline const struct exception_table_entry *