Re: [OE-core] [PATCH 1/4] lttng-modules: update from 2.15.2 to 2.16.0-rc2

[Mikko Rapeli <mikko.rapeli@linaro.org>]

Hi,

On Fri, Aug 14, 2026 at 08:50:20AM -0400, Bruce Ashfield wrote:
> On Fri, Aug 14, 2026 at 7:27 AM Mikko Rapeli <mikko.rapeli@linaro.org> wrote:
> > On Fri, Aug 14, 2026 at 11:48:32AM +0100, Richard Purdie wrote:
> > > On Fri, 2026-08-14 at 09:48 +0300, Mikko Rapeli via lists.openembedded.org wrote:
> > > > To support kernel version 7.2. Fixes build error:
> > > >
> > > > > lttng-syscalls.c: In function 'lttng_syscall_event_enabler_create_event':
> > > > > lttng-syscalls.c:612:17: error: implicit declaration of function 'strncpy' [-Wimplicit-function-declaration]
> > > > >   612 |                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
> > > > >       |                 ^~~~~~~
> > > > > lttng-syscalls.c:101:1: note: include '<string.h>' or provide a declaration of 'strncpy'
> > > > >   100 | #include <instrumentation/syscalls/syscalls_unknown.h>
> > > > >   +++ |+#include <string.h>
> > > > >   101 | #undef TRACE_SYSTEM
> > > > > lttng-syscalls.c:612:17: warning: incompatible implicit declaration of built-in function 'strncpy' [-Wbuiltin-declaration-mismatch]
> > > > >   612 |                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
> > > > >       |                 ^~~~~~~
> > > > > lttng-syscalls.c:612:17: note: include '<string.h>' or provide a declaration of 'strncpy'
> > > > > lttng-syscalls.c:704:17: warning: incompatible implicit declaration of built-in function 'strncpy' [-Wbuiltin-declaration-mismatch]
> > > > >   704 |                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
> > > > >       |                 ^~~~~~~
> > > > > lttng-syscalls.c:704:17: note: include '<string.h>' or provide a declaration of 'strncpy'
> > > >
> > > > Signed-off-by: Mikko Rapeli <mikko.rapeli@linaro.org>
> > > > ---
> > > >  .../{lttng-modules_2.15.2.bb => lttng-modules_2.16.0-rc2.bb} | 5 +++--
> > > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > > >  rename meta/recipes-kernel/lttng/{lttng-modules_2.15.2.bb => lttng-modules_2.16.0-rc2.bb} (94%)
> > >
> > > This probably needs to have a PV of 2.16.0~rc2 else the version sorting
> > > when we upgrade to the release won't work...
> >
> > Then the version is different compared to upstream tags. For CVEs I can set
> > CVE_VERSION.
> >
> > > Do we know how far off the final release is?
> >
> > Honestly I don't know. Past releases seem to have around six weeks between
> > last release candidate and actual release. v2.16.0-rc1 was tagged 7 weeks ago,
> > v2.16.0-rc2 just two weeks ago so feels like it is quite close now.
> 
> That's why I've always avoided the lttng-modules -rc releases and have opted
> to just cherry-pick the patches supporting the newer kernels when I go through
> an uprev cycle.
> 
> That being said, the -rc isn't any riskier than that approach, I just don't like
> timing their release.

Digging a bit more into this I found that the needed patches are also in upstream 2.15 stable
branch pending release. I will pick those separately to current 2.15 recipe and they can be
dropped when new point release update is done.

Cheers,

-Mikko