Hello, with these patches it is possible to install kernel modules in an arbitrary directory - eg. moving the /lib/modules to /usr/lib/modules or /opt/linux. While the modprobe.d and depmod.d search which already includes multiple paths is expanded to also include $(prefix) the module directory still supports only one location, only a different one under $(module_directory). Having kmod search multiple module locations while only one is supported now might break some assumption about relative module path corresponding to a specific file, would require more invasive changes to implement, and is not supportive of the goal of moving the modules away from /lib. Both kmod and the kernel need to be patched to make use of this feature. Patched kernel is backwards compatible with older kmod. Patched kmod with $(module_directory) set to /lib/modules is equivalent to unpatched kmod. With this patch the kmod tool can spit out a JSON with the tool build-time configuration, and jq is used for getting a single value out of that. I opted for this because crating .pc files requires putting the logic into the autohell files which is very clumsy. Also pkg-config insists on hiding the actual .pc file data and only allowing clumsy queries through its commandline interface. jq has its downsides, too. So far it is not used by kernel build, only by other tools shipped with the kernel. This adds another dependency for kernel builds. It turns out that the kernel already does use pkg-config. There are two alternate spellings: pkg-config and pkgconfig. Searching for the latter gives a few matches in the kernel giving off the impression that it's a thing but not really used. Thanks Michal Link: https://lore.kernel.org/linux-modules/20210112160211.5614-1-msuchanek@xxxxxxx/ Michal Suchanek (4): man/depmod.d: Fix incorrect /usr/lib search path libkmod, depmod: Load modprobe.d, depmod.d from $prefix/lib. kmod: Add config command to show compile time configuration as JSON libkmod, depmod, modprobe: Make directory for kernel modules configurable Makefile.am | 4 +- configure.ac | 7 ++ libkmod/libkmod.c | 11 +-- man/Makefile.am | 10 ++- man/depmod.d.xml | 9 ++- man/depmod.xml | 4 +- man/kmod.xml | 6 ++ man/modinfo.xml | 2 +- man/modprobe.d.xml | 1 + man/modprobe.xml | 2 +- man/modules.dep.xml | 6 +- testsuite/module-playground/Makefile | 2 +- testsuite/setup-rootfs.sh | 109 +++++++++++++++------------ testsuite/test-depmod.c | 16 ++-- testsuite/test-testsuite.c | 8 +- tools/depmod.c | 7 +- tools/kmod.c | 41 ++++++++++ tools/modinfo.c | 4 +- tools/modprobe.c | 4 +- tools/static-nodes.c | 6 +- 20 files changed, 169 insertions(+), 90 deletions(-) -- 2.41.0
