On Fri, Aug 18, 2023 at 12:15 PM Michal Suchánek <msuchanek@xxxxxxx> wrote:
>
> Hello,
>
> On Tue, Jul 18, 2023 at 02:01:51PM +0200, Michal Suchanek wrote:
> > 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 $(module_directory) set to /lib/modules is equivalent to unpatched kmod.
>
> The patch to kernel to support autodetection of module directory is
> rejected. However, a workaround like
>
> make MODLIB='$(INSTALL_MOD_PATH)/usr/lib/modules/$(KERNELRELEASE)'
>
> is suggested.
>
> Can you consider inluding the kmod changes?
Hi.
I have a question about your original patch
for the Kbuild change.
In your patch, Kbuild runs 'kmod config' or
'pkg-config --variable=module_directory kmod',
then sets the returned string to MODLIB.
If kmod is configured to use /usr/lib/modules,
/opt/modules, or whatever,
should we change the installation path of the debug
vdso accordingly?
Currently, the debug vdso is always installed
to /lib/modules/$(KERNELRELEASE)/vdso/.
However, modules and vdso are unrelated to each other.
kmod does not care about vdso.
The following commits started to install debug vdso.
Commit 8150caad0226 ("[POWERPC] powerpc vDSO: install unstripped
copies on disk")
Commit f79eb83b3af4 ("x86: Install unstripped copy of 64bit vdso to disk")
I do not know why they chose $(MODLIB)/vdso as the install destination.
I am thinking of split the variable into two:
MODLIB - installation path for modules
VDSOLIB - installation path for debug vdso (not affected by kmod config)
I think that is the way to do this correctly.
>
> Thanks
>
> Michal
>
> >
> > Thanks
> >
> > Michal
> >
> > Link: https://lore.kernel.org/linux-modules/20210112160211.5614-1-msuchanek@xxxxxxx/
> >
> > v4: set whole path to module directory instead of adding prefix
> > v5: use pkg-config instead of jq, fix build on openssl without sm3 support
> >
> >
> > Michal Suchanek (5):
> > configure: Detect openssl sm3 support
> > man/depmod.d: Fix incorrect /usr/lib search path
> > libkmod, depmod: Load modprobe.d, depmod.d from ${prefix}/lib.
> > kmod: Add pkgconfig file with kmod compile time configuration
> > libkmod, depmod, modprobe: Make directory for kernel modules
> > configurable
> >
> > Makefile.am | 6 +-
> > configure.ac | 30 ++++++++
> > libkmod/libkmod.c | 11 +--
> > man/Makefile.am | 10 ++-
> > man/depmod.d.xml | 9 ++-
> > man/depmod.xml | 4 +-
> > 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.pc.in | 10 +++
> > tools/modinfo.c | 4 +-
> > tools/modprobe.c | 4 +-
> > tools/static-nodes.c | 6 +-
> > 19 files changed, 156 insertions(+), 91 deletions(-)
> > create mode 100644 tools/kmod.pc.in
> >
> > --
> > 2.41.0
> >
--
Best Regards
Masahiro Yamada
