[meta-rockchip][PATCH] add kprobes for 32-bit kernels

[meta-rockchip][PATCH] add kprobes for 32-bit kernels

[Trevor Woerner]

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 \
+    "
 KERNEL_FEATURES:append:rockchip:aarch64 = " bsp/rockchip/remove-non-rockchip-arch-arm64.scc"
-- 
2.51.0

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

[Quentin Schulz]

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.

Cheers,
Quentin

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

[Bruce Ashfield]

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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

Bruce



>
> Cheers,
> Quentin
>
>
> -=-=-=-=-=-=-=-=-=-=-=-
> Links: You receive all messages sent to this group.
> View/Reply Online (#3556):
> https://lists.yoctoproject.org/g/yocto-patches/message/3556
> Mute This Topic: https://lists.yoctoproject.org/mt/118517725/1050810
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> [bruce.ashfield@gmail.com]
> -=-=-=-=-=-=-=-=-=-=-=-
>
>
>

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

[Trevor Woerner]

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
> 
> 
> -=-=-=-=-=-=-=-=-=-=-=-
> Links: You receive all messages sent to this group.
> View/Reply Online (#3560): https://lists.yoctoproject.org/g/yocto-patches/message/3560
> Mute This Topic: https://lists.yoctoproject.org/mt/118517725/900817
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> Unsubscribe: https://lists.yoctoproject.org/g/yocto-patches/leave/13168745/900817/63955952/xyzzy [twoerner@gmail.com]
> -=-=-=-=-=-=-=-=-=-=-=-
> 
> 

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

[Bruce Ashfield]

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On Thu, Mar 26, 2026 at 7:35 PM Trevor Woerner via lists.yoctoproject.org
<twoerner=gmail.com@lists.yoctoproject.org> wrote:

> 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?
>
>
The standard kernel type always includes kprobes, so they don't have
this issue.

Bruce



> >
> > 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
> >
> >
> >
> >
> >
>
>
> -=-=-=-=-=-=-=-=-=-=-=-
> Links: You receive all messages sent to this group.
> View/Reply Online (#3561):
> https://lists.yoctoproject.org/g/yocto-patches/message/3561
> Mute This Topic: https://lists.yoctoproject.org/mt/118517725/1050810
> Group Owner: yocto-patches+owner@lists.yoctoproject.org
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> [bruce.ashfield@gmail.com]
> -=-=-=-=-=-=-=-=-=-=-=-
>
>
>

-- 
- 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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