[PATCH v4 8/8] kconfig option for TRIM_UNUSED_KSYMS

Nicolas Pitre
2016-02-29T03:48:30Z

The config option to enable it all.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
---
init/Kconfig | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/init/Kconfig b/init/Kconfig
index 22320804fb..e6f666331b 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1990,6 +1990,22 @@ config MODULE_COMPRESS_XZ

endchoice

+config TRIM_UNUSED_KSYMS
+ bool "Trim unused exported kernel symbols"
+ depends on MODULES && !UNUSED_SYMBOLS
+ help
+ The kernel and some modules make many symbols available for
+ other modules to use via EXPORT_SYMBOL() and variants. Depending
+ on the set of modules being selected in your kernel configuration,
+ many of those exported symbols might never be used.
+
+ This option allows for unused exported symbols to be dropped from
+ the build. In turn, this provides the compiler more opportunities
+ (especially when using LTO) for optimizing the code and reducing
+ binary size. This might have some security advantages as well.
+
+ If unsure say N.
+
endif # MODULES

config MODULES_TREE_LOOKUP
--
2.5.0