It doesn't trim just symbols that are totally unused in-tree - it trims the symbols unused by any in-tree modules actually built. If you've done a 'make localmodconfig' and only build a hundred or so modules, it's pretty likely that your out-of-tree module will come up lacking something...
Hopefully this will save the next guy from a Homer Simpson "D'oh!" moment. Signed-off-by: Valdis Kletnieks <[email protected]> --- diff --git a/init/Kconfig b/init/Kconfig index 55c07b855e90..b4c9eb8119c0 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2083,7 +2083,7 @@ config TRIM_UNUSED_KSYMS (especially when using LTO) for optimizing the code and reducing binary size. This might have some security advantages as well. - If unsure say N. + If unsure, or if you need to build out-of-tree modules, say N. endif # MODULES
