LTTng » LTTng-modules

Hi,

lttng-modules must follow kernel changes hence you need to use at least the latest patch level release of a stable version if you want maximum compatibility in regards to supported kernels.

From a quick git history search I suppose that the patch that address this problem is:

ommit 21ed5ea7e16fcce1cf1169b8e953e6d02ad531c9
Author: Michael Jeanson <mjeanson@efficios.com>
Date:   Tue Aug 25 10:56:29 2020 -0400

    fix: removal of [smp_]read_barrier_depends (v5.9)

    See upstream commits:

      commit 76ebbe78f7390aee075a7f3768af197ded1bdfbb
      Author: Will Deacon <will@kernel.org>
      Date:   Tue Oct 24 11:22:47 2017 +0100

        locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()

        In preparation for the removal of lockless_dereference(), which is the
        same as READ_ONCE() on all architectures other than Alpha, add an
        implicit smp_read_barrier_depends() to READ_ONCE() so that it can be
        used to head dependency chains on all architectures.

      commit 76ebbe78f7390aee075a7f3768af197ded1bdfbb
      Author: Will Deacon <will.deacon@arm.com>
      Date:   Tue Oct 24 11:22:47 2017 +0100

        locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()

        In preparation for the removal of lockless_dereference(), which is the
        same as READ_ONCE() on all architectures other than Alpha, add an
        implicit smp_read_barrier_depends() to READ_ONCE() so that it can be
        used to head dependency chains on all architectures.

    Change-Id: Ife8880bd9378dca2972da8838f40fc35ccdfaaac
    Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Note that this patch is available (for the stable 2.11 branch) in:

joraj@~/lttng/master/lttng-modules [(45fe4e1a...)][]$ git tag --contains 21ed5ea7e16fcce1cf1169b8e953e6d02ad531c9
v2.11.6
v2.11.7
v2.11.8
v2.11.9

On 2.12.x it is available since:

joraj@~/lttng/stable-2.12/lttng-modules [master][]$ git tag --contains 57ccbfa6a8a79c7b84394c2097efaf7935607aa5
v2.12.3
v2.12.4
v2.12.5
v2.12.6
v2.12.7

Please upgrade lttng-modules to the latest available patch level release for the stable branch off your desire.

I'm no buildroot expert but it should be quite straight forward to change lttng-modules.mk and lttng-modules.hash

lttng-modules.mk:

LTTNG_MODULES_VERSION = 2.11.9

lttng-modules.hash

0c5fe9f8d8dbd1411a3c1c643dcbd0a55577bd15845758b73948e00bc7c387a6  lttng-modules-2.11.9.tar.bz2

Based on this update commit: https://github.com/buildroot/buildroot/commit/67ffe1f2a55140c1171b1afd596fb7b86595c82b to 2.11.0.

If this does not work, I suppose that reaching out to the package maintainers of the lttng-modules builroot package would be the next step to get some guidance.

Cheers