A small kernel module (or, rather module template) that can help you change DMI variables in the kernel and in sysfs. This can be helpful if your vendor forgot to set them, or set them incorrectly.
This is experimental, and uses kretprobes to hook the dmi_get_system_info kernel function. It then replaces the values returned from the function with the internal values of the module.
This is the same approach as this not accepted patch https://lore.kernel.org/lkml/20220206214345.31214-1-sp1rit@national.shitposting.agency/T/, but done with runtime code injection, and on a lower level function.
This module uses a debug interface to hook and modify a low-level kernel function. This can obviously lead to instability and other things. It also hooks a function that is used ina lot of internal things in the kernel (mainly to apply hardware-specific hacks), and thus can have unintended side effects. On the other hand, it can be easily used to alter the behavior of kernel internals, which can be desirable.
In general, use with care, and understand that this is experimental.
Clone this repo.
Modify the overrides.h file so that it contains overrides
for the values you want to change. Their names correspond
to the variable names in DMI, field names in the kernel,
and file names in /sys/class/dmi/id. When a value in
overrides.h is set to "", the module does not change
the real value.
Compile the module with make. Make sure that you have
the headers for your kernel installed.
Load the dmi_override.ko module with insmod.
Check that you can see the overrides in /sys/class/dmi/id
- DKMS Support
- Take overrides as arguments