Bug #1184: can't report find any system calls with lttng list --kernel --syscall - LTTng-tools - LTTng bugs repository

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Bug #1184

open

can't report find any system calls with lttng list --kernel --syscall

Added by Colin King over 5 years ago. Updated over 5 years ago.

Status:

New

Priority:

Normal

Assignee:

Target version:

Start date:

05/21/2019

Due date:

% Done:

Estimated time:

Description

Steps to reproduce:

sudo lttng create test
sudo lttng list --kernel --syscall

Output:

System calls:
-------------

.. and no system calls reported(!?). Tested against Ubuntu Bionic with mainline kernels from 5.1 down to 4.8 on amd64 and i386 from https://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D - interestingly pre-4.8 kernels this works fine. Was unsuccessful in bisecting this because 4.7-rcX kernels break in the lttng module build.

Using lttng-modules-dkms 2.10.5-1ubuntu1.2

Files

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config-4.15.0-50-generic (214 KB) config-4.15.0-50-generic		Colin King, 05/22/2019 12:38 PM
0001-Fix-initialize-syscall-table-when-kernel-tracer-is-l.patch (1.54 KB) 0001-Fix-initialize-syscall-table-when-kernel-tracer-is-l.patch	Fix: initialize syscall table when kernel tracer is lazily initialized	Mathieu Desnoyers, 05/23/2019 12:09 PM

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Updated by Mathieu Desnoyers over 5 years ago

What is the version of your lttng-tools ?

You can check with lttng-sessiond --version

Thanks,

Mathieu

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Updated by Colin King over 5 years ago

$ lttng-sessiond --version
2.10.2

dpkg -l | grep lttng
ii liblttng-ctl0:amd64 2.10.2-1 amd64 LTTng control and utility library
ii liblttng-ust-ctl4:amd64 2.10.1-1 amd64 LTTng 2.0 Userspace Tracer (trace control library)
ii lttng-modules-dkms 2.10.5-1ubuntu1.2 all Linux Trace Toolkit (LTTng) kernel modules (DKMS)
ii lttng-tools 2.10.2-1 amd64 LTTng control and utility programs

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Updated by Mathieu Desnoyers over 5 years ago

Can you provide an example kernel config for the 5.1 kernel which triggers the issue ?

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Updated by Mathieu Desnoyers over 5 years ago

It appears to work fine here on a Ubuntu Bionic running the following kernel:

5.0.0-15-generic #16~18.04.1-Ubuntu SMP Tue May 7 14:17:37 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Package: linux-image-5.0.0-15-generic
Architecture: amd64
Version: 5.0.0-15.16~18.04.1+signed1
Built-Using: linux (= 5.0.0-15.16~18.04.1)
Filename: pool/main/l/linux-signed-hwe-edge/linux-image-5.0.0-15-generic_5.0.0-15.16~18.04.1+signed1_amd64.deb

This seems to point towards an issue with the kernel configuration you are using on the ppa.

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