lttng-modules-dkms FTBS in Noble with the linux-6.17 kernel

[John Cabaj]

[ Impact ]

DKMS make.log for lttng-modules-2.13.11 for kernel 6.17.0-7-generic (x86_64)
Thu Dec 4 18:20:31 UTC 2025
make: Entering directory '/usr/src/linux-headers-6.17.0-7-generic'
make[1]: Entering directory '/var/lib/dkms/lttng-modules/2.13.11/build'
warning: the compiler differs from the one used to build the kernel
  The kernel was built by: x86_64-linux-gnu-gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0
  You are using: gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0
  CC [M] src/lttng-ring-buffer-client-discard.o
src/probes/Kbuild:27: File /usr/src/linux-headers-6.17.0-7-generic/mm/slab.h not found. Probe "kmem" is disabled. Use full kernel source tree to enable it.
src/probes/Kbuild:81: File /usr/src/linux-headers-6.17.0-7-generic/arch/x86/kvm/lapic.h not found. Probe "kvm" x86-specific is disabled. Use full kernel source tree to enable it.
  CC [M] src/tests/probes/lttng-test.o
  CC [M] src/lib/ringbuffer/ring_buffer_backend.o
src/probes/Kbuild:188: Files /usr/src/linux-headers-6.17.0-7-generic/fs/btrfs/*.h not found. Probe "btrfs" is disabled. Use full kernel source tree to enable it.
src/probes/Kbuild:207: Files /usr/src/linux-headers-6.17.0-7-generic/mm/internal.h not found. Probe "compaction" is disabled. Use full kernel source tree to enable it.
src/probes/Kbuild:216: Files /usr/src/linux-headers-6.17.0-7-generic/fs/ext4/*.h not found. Probe "ext4" is disabled. Use full kernel source tree to enable it.
src/probes/Kbuild:245: File /usr/src/linux-headers-6.17.0-7-generic/drivers/base/regmap/trace.h not found. Probe "regmap" is disabled. Need Linux 4.1+ kernel source tree to enable it.
  CC [M] src/probes/lttng-probe-sched.o
In file included from <command-line>:
/usr/src/linux-headers-6.17.0-7-generic/include/linux/static_call_types.h:15:41: error: ‘__SCT__tp_func_lttng_test_filter_event’ undeclared here (not in a function); did you mean ‘__SCK__tp_func_lttng_test_filter_event’?
   15 | #define STATIC_CALL_TRAMP_PREFIX __SCT__
      | ^~~~~~~
/usr/src/linux-headers-6.17.0-7-generic/include/linux/compiler_types.h:83:23: note: in definition of macro ‘___PASTE’
   83 | #define ___PASTE(a,b) a##b
      | ^
/usr/src/linux-headers-6.17.0-7-generic/include/linux/static_call_types.h:18:41: note: in expansion of macro ‘__PASTE’
   18 | #define STATIC_CALL_TRAMP(name) __PASTE(STATIC_CALL_TRAMP_PREFIX, name)
      | ^~~~~~~
/usr/src/linux-headers-6.17.0-7-generic/include/linux/static_call_types.h:18:49: note: in expansion of macro ‘STATIC_CALL_TRAMP_PREFIX’
   18 | #define STATIC_CALL_TRAMP(name) __PASTE(STATIC_CALL_TRAMP_PREFIX, name)
      | ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/src/linux-headers-6.17.0-7-generic/include/linux/static_call.h:146:39: note: in expansion of macro ‘STATIC_CALL_TRAMP’
  146 | #define STATIC_CALL_TRAMP_ADDR(name) &STATIC_CALL_TRAMP(name)
      | ^~~~~~~~~~~~~~~~~
/usr/src/linux-headers-6.17.0-7-generic/include/linux/tracepoint.h:325:38: note: in expansion of macro ‘STATIC_CALL_TRAMP_ADDR’
  325 | .static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \
      | ^~~~~~~~~~~~~~~~~~~~~~
/usr/src/linux-headers-6.17.0-7-generic/include/linux/tracepoint.h:371:9: note: in expansion of macro ‘__DEFINE_TRACE_EXT’
  371 | __DEFINE_TRACE_EXT(_name, NULL, PARAMS(_proto), PARAMS(_args));
      | ^~~~~~~~~~~~~~~~~~
src/tests/../../include/wrapper/tracepoint.h:19:9: note: in expansion of macro ‘DEFINE_TRACE’
   19 | DEFINE_TRACE(name, PARAMS(proto), PARAMS(args))
      | ^~~~~~~~~~~~
src/tests/probes/lttng-test.c:28:1: note: in expansion of macro ‘LTTNG_DEFINE_TRACE’
   28 | LTTNG_DEFINE_TRACE(lttng_test_filter_event,
      | ^~~~~~~~~~~~~~~~~~
In file included from src/probes/../../include/lttng/define_trace.h:87,
                 from src/probes/../../include/instrumentation/events/sched.h:730,
                 from src/probes/lttng-probe-sched.c:28:
src/probes/../../include/lttng/tracepoint-event-impl.h:133:6: error: conflicting types for ‘trace_sched_process_exit’; have ‘void(struct task_struct *)’
  133 | void trace_##_name(_proto);
      | ^~~~~~
src/probes/../../include/lttng/tracepoint-event-impl.h:98:9: note: in expansion of macro ‘LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP’
   98 | LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(template, name, name, PARAMS(proto), PARAMS(args))
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/probes/../../include/instrumentation/events/sched.h:474:1: note: in expansion of macro ‘LTTNG_TRACEPOINT_EVENT_INSTANCE’
  474 | LTTNG_TRACEPOINT_EVENT_INSTANCE(sched_process_template, sched_process_exit,
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/src/linux-headers-6.17.0-7-generic/include/trace/events/sched.h:10,
                 from src/probes/lttng-probe-sched.c:17:
/usr/src/linux-headers-6.17.0-7-generic/include/linux/tracepoint.h:278:28: note: previous definition of ‘trace_sched_process_exit’ with type ‘void(struct task_struct *, bool)’ {aka ‘void(struct task_struct *, _Bool)’}
  278 | static inline void trace_##name(proto) \
      | ^~~~~~
/usr/src/linux-headers-6.17.0-7-generic/include/linux/tracepoint.h:481:9: note: in expansion of macro ‘__DECLARE_TRACE’
  481 | __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
      | ^~~~~~~~~~~~~~~
/usr/src/linux-headers-6.17.0-7-generic/include/linux/tracepoint.h:619:9: note: in expansion of macro ‘DECLARE_TRACE_EVENT’
  619 | DECLARE_TRACE_EVENT(name, PARAMS(proto), PARAMS(args))
      | ^~~~~~~~~~~~~~~~~~~
/usr/src/linux-headers-6.17.0-7-generic/include/trace/events/sched.h:335:1: note: in expansion of macro ‘TRACE_EVENT’
  335 | TRACE_EVENT(sched_process_exit,
      | ^~~~~~~~~~~
make[5]: *** [/usr/src/linux-headers-6.17.0-7-generic/scripts/Makefile.build:287: src/tests/probes/lttng-test.o] Error 1
make[4]: *** [/usr/src/linux-headers-6.17.0-7-generic/scripts/Makefile.build:556: src/tests] Error 2
make[4]: *** Waiting for unfinished jobs....
  CC [M] src/probes/lttng-probe-irq.o
make[5]: *** [/usr/src/linux-headers-6.17.0-7-generic/scripts/Makefile.build:287: src/probes/lttng-probe-sched.o] Error 1
make[5]: *** Waiting for unfinished jobs....
  CC [M] src/lib/ringbuffer/ring_buffer_frontend.o
  CC [M] src/lib/ringbuffer/ring_buffer_iterator.o
  CC [M] src/lib/ringbuffer/ring_buffer_vfs.o
In file included from src/lib/ringbuffer/ring_buffer_frontend.c:54:
src/lib/ringbuffer/ring_buffer_frontend.c: In function ‘switch_buffer_timer’:
src/lib/../../include/wrapper/timer.h:38:9: error: implicit declaration of function ‘from_timer’; did you mean ‘mod_timer’? [-Werror=implicit-function-declaration]
   38 | from_timer(var, callback_timer, timer_fieldname)
      | ^~~~~~~~~~
src/lib/ringbuffer/ring_buffer_frontend.c:337:48: note: in expansion of macro ‘lttng_from_timer’
  337 | struct lttng_kernel_ring_buffer *buf = lttng_from_timer(buf, t, switch_timer);
      | ^~~~~~~~~~~~~~~~
src/lib/ringbuffer/ring_buffer_frontend.c:337:73: error: ‘switch_timer’ undeclared (first use in this function); did you mean ‘switch_mode’?
  337 | struct lttng_kernel_ring_buffer *buf = lttng_from_timer(buf, t, switch_timer);
      | ^~~~~~~~~~~~
src/lib/../../include/wrapper/timer.h:38:41: note: in definition of macro ‘lttng_from_timer’
   38 | from_timer(var, callback_timer, timer_fieldname)
      | ^~~~~~~~~~~~~~~
src/lib/ringbuffer/ring_buffer_frontend.c:337:73: note: each undeclared identifier is reported only once for each function it appears in
  337 | struct lttng_kernel_ring_buffer *buf = lttng_from_timer(buf, t, switch_timer);
      | ^~~~~~~~~~~~
src/lib/../../include/wrapper/timer.h:38:41: note: in definition of macro ‘lttng_from_timer’
   38 | from_timer(var, callback_timer, timer_fieldname)
      | ^~~~~~~~~~~~~~~
src/lib/ringbuffer/ring_buffer_frontend.c: In function ‘lib_ring_buffer_stop_switch_timer’:
src/lib/ringbuffer/ring_buffer_frontend.c:391:9: error: implicit declaration of function ‘del_timer_sync’ [-Werror=implicit-function-declaration]
  391 | del_timer_sync(&buf->switch_timer);
      | ^~~~~~~~~~~~~~
src/lib/ringbuffer/ring_buffer_frontend.c: In function ‘read_buffer_timer’:
src/lib/ringbuffer/ring_buffer_frontend.c:400:73: error: ‘read_timer’ undeclared (first use in this function); did you mean ‘vread_iter’?
  400 | struct lttng_kernel_ring_buffer *buf = lttng_from_timer(buf, t, read_timer);
      | ^~~~~~~~~~
src/lib/../../include/wrapper/timer.h:38:41: note: in definition of macro ‘lttng_from_timer’
   38 | from_timer(var, callback_timer, timer_fieldname)
      | ^~~~~~~~~~~~~~~
make[4]: *** [/usr/src/linux-headers-6.17.0-7-generic/scripts/Makefile.build:556: src/probes] Error 2
  CC [M] src/lib/ringbuffer/ring_buffer_splice.o
src/lib/ringbuffer/ring_buffer_frontend.c: At top level:
src/lib/ringbuffer/ring_buffer_frontend.c:2409:12: warning: no previous prototype for ‘init_lib_ring_buffer_frontend’ [-Wmissing-prototypes]
 2409 | int __init init_lib_ring_buffer_frontend(void)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/lib/ringbuffer/ring_buffer_frontend.c:2420:13: warning: no previous prototype for ‘exit_lib_ring_buffer_frontend’ [-Wmissing-prototypes]
 2420 | void __exit exit_lib_ring_buffer_frontend(void)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
make[5]: *** [/usr/src/linux-headers-6.17.0-7-generic/scripts/Makefile.build:287: src/lib/ringbuffer/ring_buffer_frontend.o] Error 1
make[5]: *** Waiting for unfinished jobs....
make[4]: *** [/usr/src/linux-headers-6.17.0-7-generic/scripts/Makefile.build:556: src/lib] Error 2
make[3]: *** [/usr/src/linux-headers-6.17.0-7-generic/scripts/Makefile.build:556: src] Error 2
make[2]: *** [/usr/src/linux-headers-6.17.0-7-generic/Makefile:2016: .] Error 2
make[1]: *** [/usr/src/linux-headers-6.17.0-7-generic/Makefile:248: __sub-make] Error 2
make[1]: Leaving directory '/var/lib/dkms/lttng-modules/2.13.11/build'
make: *** [Makefile:248: __sub-make] Error 2
make: Leaving directory '/usr/src/linux-headers-6.17.0-7-generic'

[ Test case ]

Install the latest linux-6.17 kernel on Noble:

$ sudo add-apt-repository ppa:canonical-kernel-team/ppa3
$ sudo apt install linux-generic-hwe-24.04-edge

Install lttng-modules-dkms:

$ sudo apt install lttng-modules-dkms

Module built and installed successfully.

Load the module:

$ sudo modprobe lttng-test

Module loaded successfully.

The same procedure can be repeated on linux-6.8 to test for possible regressions.

Install the latest kernel on Questing and Resolute:

Install lttng-modules-dkms:

$ sudo apt install lttng-modules-dkms

Module built and installed successfully.

Load the module:

$ sudo modprobe lttng-test

Module loaded successfully.

The same test must be repeated on Noble linux-6.8 and linux-6.14 kernels.
The same test should be repeated for Questing.

[ Fix ]

Backport upstream patches from lttng-modules (https://git.lttng.org/?p=lttng-modules.git):

    - debian/patches/writeback-instrumentation-Add-missing-provider-name-.patch
    - debian/patches/Add-missing-prototype-for-wrapper_get_pfnblock_flags.patch
    - debian/patches/Fix-Add-wrapper-for-get_pfnblock_migatetype.patch
    - debian/patches/fix-get_pfnblock_flags_mask-get_pfnblock_migratetype.patch
    - debian/patches/fix-btrfs-use-refcount_t-type-for-the-extent-buffer-.patch
    - debian/patches/fix-always-print-to-kernel-log-on-module-load-failur.patch

This is required because lttng-test has been failing to load for some time, and required more patches to pull in that had been previously missed. Backporting was the safer route rather than cherry-picking prospective patches.

[ Regression potential ]

We may experience regressions in systems that are using the lttng-modules drivers, especially with kernels >= 6.8 kernel.

[John Cabaj (john-cabaj)]

2.14.0-1ubuntu1 -> 2.14.0-1ubuntu1.1 debdiff

[John Cabaj (john-cabaj)]

Packages built and available here - https://launchpad.net/~john-cabaj/+archive/ubuntu/lttng-modules-dkms/. Leaving out Noble debdiff as it wouldn't make much sense with a backport.

[Massimiliano Pellizzer (mpellizzer)]

Questing uploaded, thanks

[Massimiliano Pellizzer (mpellizzer)]

Noble uploaded, thanks

[Timo Aaltonen (tjaalton)]

Hello John, or anyone else affected,

Accepted lttng-modules into questing-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/lttng-modules/2.14.0-1ubuntu1.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-questing to verification-done-questing. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-questing. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Timo Aaltonen (tjaalton)]

for noble it's a full version backport though, it should be mentioned on the description as to why

[Timo Aaltonen (tjaalton)]

Hello John, or anyone else affected,

Accepted lttng-modules into noble-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/lttng-modules/2.14.0-1ubuntu1.1~24.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-noble to verification-done-noble. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-noble. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[John Cabaj (john-cabaj)]

Modules built and installed successfully. Modules loaded successfully:

Noble 6.8 kernel:

root@noble-lts-vm:~# uname -r
6.8.0-90-generic
root@noble-lts-vm:~# modprobe lttng-test
root@noble-lts-vm:~#

Noble 6.14 kernel:

root@noble-614-vm:~# uname -r
6.14.0-37-generic
root@noble-614-vm:~# modprobe lttng-test
root@noble-614-vm:~#

Noble 6.17 kernel:

root@noble-hwe-vm:~# uname -r
6.17.0-7-generic
root@noble-hwe-vm:~# modprobe lttng-test
root@noble-hwe-vm:~#

Questing 6.17 kernel:

root@questing-vm:~# uname -r
6.17.0-8-generic
root@questing-vm:~# modprobe lttng-test
root@questing-vm:~#