Re: [yocto-patches] [meta-rockchip][PATCH] add kprobes for 32-bit kernels

[Trevor Woerner <twoerner@gmail.com>]

On Thu 2026-03-26 @ 04:08:16 PM, Bruce Ashfield via lists.yoctoproject.org wrote:
> On Thu, Mar 26, 2026 at 10:08 AM Quentin Schulz via lists.yoctoproject.org
> <quentin.schulz=cherry.de@lists.yoctoproject.org> wrote:
> 
> > Hi Trevor,
> >
> > On 3/26/26 2:06 PM, Trevor Woerner via lists.yoctoproject.org wrote:
> > > While building the modules for linux-yocto for 32-bit machines, the
> > > following error occurs:
> > >
> > >       | probes/Kbuild:236: CONFIG_KALLSYMS_ALL is disabled, therefore
> > probe "writeback" is disabled. Rebuild your kernel with this configuration
> > option enabled in order to trace this subsystem.
> > >       | wrapper/kallsyms.c:20:3: error: #error "LTTng-modules requires
> > CONFIG_KPROBES on kernels >= 5.7.0"
> > >       |    20 | # error "LTTng-modules requires CONFIG_KPROBES on
> > kernels >= 5.7.0"
> > >
> > > Signed-off-by: Trevor Woerner <twoerner@gmail.com>
> > > ---
> > >   recipes-kernel/linux/linux-rockchip.inc | 5 ++++-
> > >   1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/recipes-kernel/linux/linux-rockchip.inc
> > b/recipes-kernel/linux/linux-rockchip.inc
> > > index 6c62e849834c..4e67ff14f6e6 100644
> > > --- a/recipes-kernel/linux/linux-rockchip.inc
> > > +++ b/recipes-kernel/linux/linux-rockchip.inc
> > > @@ -34,5 +34,8 @@ COMPATIBLE_MACHINE:soquartz = "soquartz"
> > >   SRC_URI:append:rockchip = "
> > file://rockchip-kmeta;type=kmeta;name=rockchip-kmeta;destsuffix=rockchip-kmeta"
> > >   SRC_URI:append:nanopi-r4s = " file://realtek-r8169.cfg"
> > >
> > > -KERNEL_FEATURES:append:rockchip:arm = "
> > bsp/rockchip/remove-non-rockchip-arch-arm.scc"
> > > +KERNEL_FEATURES:append:rockchip:arm = " \
> > > +    bsp/rockchip/remove-non-rockchip-arch-arm.scc \
> > > +    features/kprobes/kprobes.scc \
> >
> > This is coming from the yocto-kernel-cache as far as I could tell. It's
> > only available if the recipe actually points to it and only linux-yocto
> > recipes do that. linux-mainline and linux-stable from
> > meta-linux-mainline which you've said in the past you're using sometimes
> > do not support that from a cursory look.
> >
> > What happens if there's a KERNEL_FEATURES that isn't found?
> >
> > Maybe we should have this in some linux-yocto bbappend instead? Or
> > import this fragment into meta-rockchip (the downside being we need to
> > maintain this on our own then, but it's been updated only once, 8.5y ago
> > so not too much risk for this one I guess.
> >
> 
> or just do what meta-virtualization does. See the yocto-cfg-fragments
> recipe.
> It makes the fragments available to anything using linux-yocto
> infrastructure,
> but for whatever reason doesn't have meta on it's SRC_URI

I get the feeling this isn't a rockchip-specific issue necessarily. Are
linux-yocto kernel builds for other 32-bit (probably Arm) machines
seeing the same thing? Is this something I should be looking to solve
more broadly?

> 
> Bruce
> 
> 
> 
> >
> > Cheers,
> > Quentin
> >
> >
> > 
> >
> >
> >
> 
> -- 
> - Thou shalt not follow the NULL pointer, for chaos and madness await thee
> at its end
> - "Use the force Harry" - Gandalf, Star Trek II
> 
> 
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