From 74ee585b7eecd98be3650e677625a0ee588d08e0 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 2 Jun 2021 23:02:13 +0900 Subject: kbuild: remove trailing slashes from $(KBUILD_EXTMOD) M= (or KBUILD_EXTMOD) generally expects a directory path without any trailing slashes, like M=a/b/c. If you add a trailing slash, like M=a/b/c/, you will get ugly build logs (two slashes in a series), but it still works fine as long as it is consistent between 'make modules' and 'make modules_install'. The following commands correctly build and install the modules. $ make M=a/b/c/ modules $ sudo make M=a/b/c/ modules_install Since commit ccae4cfa7bfb ("kbuild: refactor scripts/Makefile.modinst"), a problem happens if you add a trailing slash only for modules_install. $ make M=a/b/c modules $ sudo make M=a/b/c/ modules_install No module is installed in this case, Johannes Berg reported. [1] Trim any trailing slashes from $(KBUILD_EXTMOD). I used the 'dirname' command to remove all the trailing slashes in case someone adds more slashes like M=a/b/c/////. The Make's built-in function, $(dir ...) cannot take care of such a case. [1]: https://lore.kernel.org/lkml/10cc8522b27a051e6a9c3e158a4c4b6414fd04a0.camel@sipsolutions.net/ Fixes: ccae4cfa7bfb ("kbuild: refactor scripts/Makefile.modinst") Reported-by: Johannes Berg Signed-off-by: Masahiro Yamada --- Makefile | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 504327207d66..cbab0dc53065 100644 --- a/Makefile +++ b/Makefile @@ -129,6 +129,11 @@ endif $(if $(word 2, $(KBUILD_EXTMOD)), \ $(error building multiple external modules is not supported)) +# Remove trailing slashes +ifneq ($(filter %/, $(KBUILD_EXTMOD)),) +KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).) +endif + export KBUILD_EXTMOD # Kbuild will save output files in the current working directory. -- cgit v1.2.3-59-g8ed1b