From: Masahiro Yamada masahiroy@kernel.org
[ Upstream commit 74ee585b7eecd98be3650e677625a0ee588d08e0 ]
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@...
Fixes: ccae4cfa7bfb ("kbuild: refactor scripts/Makefile.modinst") Reported-by: Johannes Berg johannes@sipsolutions.net Signed-off-by: Masahiro Yamada masahiroy@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- Makefile | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/Makefile b/Makefile index 83f4212e004f..4258a60f6119 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.