Re: [PATCH v6] modules: introduce the MODULE_SCMVERSION config

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



+++ Will McVicker [21/01/21 21:36 +0000]:
Config MODULE_SCMVERSION introduces a new module attribute --
`scmversion` -- which can be used to identify a given module's SCM
version.  This is very useful for developers that update their kernel
independently from their kernel modules or vice-versa since the SCM
version provided by UTS_RELEASE (`uname -r`) will now differ from the
module's vermagic attribute.

For example, we have a CI setup that tests new kernel changes on the
hikey960 and db845c devices without updating their kernel modules. When
these tests fail, we need to be able to identify the exact device
configuration the test was using. By including MODULE_SCMVERSION, we can
identify the exact kernel and modules' SCM versions for debugging the
failures.

Additionally, by exposing the SCM version via the sysfs node
/sys/module/MODULENAME/scmversion, one can also verify the SCM versions
of the modules loaded from the initramfs. Currently, modinfo can only
retrieve module attributes from the module's ko on disk and not from the
actual module that is loaded in RAM.

You can retrieve the SCM version in two ways,

1) By using modinfo:
   > modinfo -F scmversion MODULENAME
2) By module sysfs node:
   > cat /sys/module/MODULENAME/scmversion

Hi Will,

First off, thanks for being patient and being responsive throughout the patch
review process.

Personally, I am rather neutral towards this feature. We already provide
CONFIG_MODULE_SRCVERSION to provide a checksum of a module's source files and I
think the SCMVERSION is a nicer alternative. I can see how an optional
scmversion field might be helpful information for distro developers in testing
environments and in situations where it is possible for the kernel and modules
to be updated/packaged separately (for instance, the kernel selftest modules
under lib/ are in-tree modules that are provided as a separate kernel module
package in SLE).

Generally, out of principle, I do not want to merge a patch that's been NAK'd
repeatedly; even if I take the patch it'd likely be contested all the way up to
the merge window. So this boils down to whether Christoph (and maybe Greg) are
fine with this being a debug option that's not enabled by default.

Thanks,

Jessica



[Index of Archives]     [Linux&nblp;USB Development]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite Secrets]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux