Hello Kienan, When I proceed with the following steps:
``` # Warning: this removes all untracked content from the lttng-modules directory cd /path/to/lttng-modules-source git clean -dxf make sudo make modules_install sudo depmod -a ``` I encounter a warning in `/home/philippe/lttng-modules/src/probes/Kbuild:79` stating "File ./arch/x86/kvm/lapic.h not found. Probe 'kvm' x86-specific is disabled. Use full kernel source tree to enable it." Although everything compiles fine and I'm able to load modules, when I execute `sudo lttng list -k`, I don't see the tracepoints `kvm_entry` and `kvm_exit`, which I believe should be available. Could this be due to not using my full kernel tree during compilation? Here are the answers to your questions: - *Where did `/usr/src/linux-source-6.5.0` come from?* I initially attempted `sudo apt-get update && sudo apt-get install linux-source`, but it gave me this answer *linux-source is already the newest version (5.15.0.116.116)*`, which doesn't match my current kernel version. So, I downloaded it directly from kernel.org using this command: `wget https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.5.tar.xz`. - *Which Linux distribution and version are you using?* Running `lsb_release -a` gives me: ``` No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 22.04.4 LTS Release: 22.04 Codename: jammy ``` - *Assuming your distribution has kernel packages, which do you have installed, and do you have the corresponding kernel headers package installed?* Running `dpkg -l | grep linux-image` shows these installed packages: ``` ii linux-image-5.15.0-116-generic 5.15.0-116.126 amd64 Signed kernel image generic ii linux-image-6.5.0-28-generic 6.5.0-28.29~22.04.1 amd64 Signed kernel image generic ii linux-image-6.5.0-41-generic 6.5.0-41.41~22.04.2 amd64 Signed kernel image generic ii linux-image-6.5.0-44-generic 6.5.0-44.44~22.04.1 amd64 Signed kernel image generic ii linux-image-generic 5.15.0.116.116 amd64 Generic Linux kernel image ii linux-image-generic-hwe-22.04 6.5.0.44.44~22.04.1 amd64 Generic Linux kernel image ``` And `dpkg -l | grep linux-headers` shows these installed header packages: ``` ii linux-headers-5.15.0-116 5.15.0-116.126 all Header files related to Linux kernel version 5.15.0 ii linux-headers-5.15.0-116-generic 5.15.0-116.126 amd64 Linux kernel headers for version 5.15.0 on 64 bit x86 SMP ii linux-headers-6.5.0-28-generic 6.5.0-28.29~22.04.1 amd64 Linux kernel headers for version 6.5.0 on 64 bit x86 SMP ii linux-headers-6.5.0-41-generic 6.5.0-41.41~22.04.2 amd64 Linux kernel headers for version 6.5.0 on 64 bit x86 SMP ii linux-headers-6.5.0-44-generic 6.5.0-44.44~22.04.1 amd64 Linux kernel headers for version 6.5.0 on 64 bit x86 SMP ii linux-headers-generic 5.15.0.116.116 amd64 Generic Linux kernel headers ii linux-headers-generic-hwe-22.04 6.5.0.44.44~22.04.1 amd64 Generic Linux kernel headers ``` Thanks. Le mar. 16 juill. 2024, à 15 h 41, Kienan Stewart <kstew...@efficios.com> a écrit : > Hi François, > > On 7/16/24 3:01 PM, François Belias wrote: > > Hello Kienan, > > > > I've continued investigating my issue and discovered something new that > > might shed some light. Here's the rundown: > > > > 1. To ensure my add-ons weren't causing problems, deleted all old > > modules and I followed the documentation on the LTTng website > > (https://lttng.org/docs/v2.13/#doc-building-from-source > > <https://lttng.org/docs/v2.13/#doc-building-from-source>) and > downloaded > > `lttng-modules-2.13.13`. > > > > 2. Inside the downloaded folder, I successfully executed `make > > KERNELDIR=/usr/src/linux-source-6.5.0` without any issues. > > > > 3. Subsequently, I ran `make KERNELDIR=/usr/src/linux-source-6.5.0 > > modules_install`, which also completed successfully. > > > > 4. After that, I updated the module dependencies using `sudo depmod -a`, > > which went fine. > > > > However, when I tried to load a module, such as `sudo modprobe > > lttng-probe-kvm`, it reported that the module couldn't be found at > > `/lib/modules/6.5.0-41-generic/`. Upon checking the logs, I confirmed > > that step 3 had installed the modules in `/lib/modules/6.5.0/`. > > > > To address this, I modified step 3 to simply `make modules_install`, > > which then installed the modules correctly at > > `/lib/modules/6.5.0-41-generic/` and ran again step 4. But now, when > > attempting to load a module, I'm encountering the error `modprobe: > > ERROR: could not insert 'lttng_probe_kvm': Exec format error`. > > > > Do you have any insights or ideas on what might be causing this issue? > > > > It sounds like /usr/src/linux-source-6.5.0 is not correct source for the > kernel that you are currently running. > > When running `make modules_install` in your modified step 3 (without > KERNELDIR set), the modules were installed for your current kernel > directory as auto-detected by the build script. > > What happens if you do the following > > ``` > unset KERNELDIR > > # Warning: this removes all untracked content from the lttng-modules > directory > cd /path/to/lttng-modules-source > git clean -dxf > > make > sudo make modules_install > sudo depmod -a > ``` > > KERNELDIR is set based on the current running kernel: `uname -r`. C.f. > > https://github.com/lttng/lttng-modules/blob/434e86eea846b33cad57f1d8105089905f541853/Makefile#L16C1-L16C50 > > A couple of questions for you: > > - Where did /usr/src/linux-source-6.5.0 come from? > - Which linux distribution + version are you using? > - Assuming your distribution has kernel packages, which do you have > installed, and do you have the corresponding kernel headers package > installed? > > thanks, > kienan > > > Thanks again for your assistance. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Le mar. 16 juill. 2024, à 09 h 05, Kienan Stewart <kstew...@efficios.com > > <mailto:kstew...@efficios.com>> a écrit : > > > > 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%5D(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%5D(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 > < > 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 <mailto:lttng-dev@lists.lttng.org> > > > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > > <https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev> > > >
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