Hi François,

On 7/15/24 6:10 PM, François Belias via lttng-dev wrote:
Hello,

I'm currently running Linux kernel version 6.5.0-41-generic and attempting to install LTTng from source. Here are the steps I followed:

 - I cloned the LTTng git repository to my computer from [https://github.com/lttng/lttng-modules.git](https://github.com/lttng/lttng-modules.git) <https://github.com/lttng/lttng-modules.git](https://github.com/lttng/lttng-modules.git)>. - Downloaded the kernel source tree corresponding to my kernel version to enable compilation. - Executed `make KERNELDIR=/path/to/my/linux/source`, which was completed successfully. - Ran `make KERNELDIR=/path/to/my/linux/source modules_install`, also without any issues.
- Finally, I executed `sudo depmod -a`, which was completed successfully.

However, when I attempt to load a module with commands like `sudo modprobe lttng-ketprobes` or "sudo modprobe lttng-tracer", I encounter the following errors:

- For `lttng-ketprobes`: `modprobe: FATAL: Module lttng-ketprobes not found in directory /lib/modules/6.5.0-41-generic`. - For `lttng-tracer`: `modprobe: ERROR: could not insert 'lttng_tracer': Exec format error`.

If you rebuilt modules on the master branch as of yesterday you may need to clean the LTTng modules install directory, rebuild, and reinstall.

This is due to kprobes, kretprobes, and uprobes modules being included in the tracer core module. C.f. https://github.com/lttng/lttng-modules/commit/0c2c6606eb66cb5222ab7a2a4f8329fd5dfdef70

You may want to stick with running lttng-modules 2.13.x which will not have breaking changes merged in.

The exec format error also could be due to modules that are installed but built against a different version of the Linux kernel.

A few things to check

- If your kernel has been upgraded recently, ensure the new kernel is the one actually running - If the modules haven't been rebuilt since the upgrade, they should be rebuilt and reinstalled - As I recall, you are playing around with some addon modules - do any of those modules define dependencies on the kprobes, kretprobes, or uprobes modules which now are no longer produced by builds of the master branch

Is there further information in dmesg or journalctl regarding the module loading?

hope this helps.

thanks,
kienan


I've confirmed that the modules exist but can't load them. I'm unsure how to resolve these issues. Could someone please assist me?

Thank you.

_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

Reply via email to