[RELEASE] LTTng-modules 2.15.3 and 2.14.7 (Linux kernel tracer)

[Mathieu Desnoyers via lttng-dev <lttng-dev@lists.lttng.org>]

Hi,

This is a stable release announcement for the LTTng kernel tracer,
an out-of-tree kernel tracer for the Linux kernel.

* Highlights

LTTng-modules 2.15.3 adds support for the Linux kernel v7.2.
The 2.14.x releases of LTTng-modules now have an upper bound:
they support kernels up to v7.1. Considering that we expect
LTTng-modules 2.16.0 final to be released around next week,
we can expect this 2.14.7 release to be the last one for the
stable-2.14 branch.

A fix appears in those releases: since we introduced the
"flush or populate packet ioctl", a kernel trace could contain
zeroed UUID in the very last packet of the streams within snapshots,
thus causing Babeltrace 2 to fail with e.g.:

         Invalid metadata stream UUID:
         uuid=00000000-0000-0000-0000-000000000000,
         expected-uuid=8962f7e1-f875-8f47-a112-43868a4b000b

The commit "Fix: ring buffer: zeroed UUID in populated empty packet headers"
fixes this issue.

* New in these releases:

2026-08-17 LTTng modules 2.15.3
         * fix: backport: hrtimer: Reduce trace noise in hrtimer_start() (Ubuntu-6.8.0-136)
         * fix: string: Remove strncpy() from the kernel (v7.2)
         * fix: btrfs: tracepoints: trace transaction states during commit phase (v7.2)
         * fix: btrfs: tracepoints: add in_fsync field to transaction commit event (v7.2)
         * fix: btrfs: tracepoints: pass a transaction handle to transaction commit event (v7.2)
         * fix: net: constify sk_skb_reason_drop() sock parameter (v7.2)
         * fix: KVM: x86: Rename kvm_cache_regs.h => regs.h (v7.2)
         * fix: x86/msr: Remove rdmsrl() / wrmsrl() (v7.2)
         * fix: warning -Wordered-compare-function-pointers with LLVM
         * fix: warning -Wcast-function-type-strict with LLVM
         * Fix: ring buffer: zeroed UUID in populated empty packet headers

2026-08-17 LTTng modules 2.14.7
         * Document last supported kernel version for stable-2.14 branch
         * fix: backport: hrtimer: Reduce trace noise in hrtimer_start() (Ubuntu-6.8.0-136)
         * fix: warning -Wordered-compare-function-pointers with LLVM
         * fix: warning -Wcast-function-type-strict with LLVM
         * Fix: ring buffer: zeroed UUID in populated empty packet headers

Project website: https://lttng.org
Documentation: https://lttng.org/docs
Download link: https://lttng.org/download

Thanks,

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com