diff mbox series

linux-yocto: fix missing pahole and elfutils when CONFIG_DEBUG_INFO_BTF enabled in devshell

Message ID 20230508013317.3937457-1-xiangyu.chen@eng.windriver.com
State New
Headers show
Series linux-yocto: fix missing pahole and elfutils when CONFIG_DEBUG_INFO_BTF enabled in devshell | expand

Commit Message

Xiangyu Chen May 8, 2023, 1:33 a.m. UTC
From: Xiangyu Chen <xiangyu.chen@windriver.com>

after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
and elfutils dependency.

Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
---
 meta/recipes-kernel/linux/linux-yocto.inc | 2 ++
 1 file changed, 2 insertions(+)

Comments

Richard Purdie May 10, 2023, 4:16 p.m. UTC | #1
On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> 
> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
> and elfutils dependency.

Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
option documented somewhere?

I also think the mention of devshell in the commit message is
misleading, this issue happens regardless of how you enable the option.
There are also other ways of enabling this than local.conf, you'd
likely not want people doing that at the end of development.

I'm curious on Bruce's opinion but to me this at the very least needs a
commit message rewrite and I'd question whether the docs elsewhere
would allow someone to discover this workflow anyway.

Cheers,

Richard
Bruce Ashfield May 10, 2023, 4:25 p.m. UTC | #2
On Wed, May 10, 2023 at 12:16 PM Richard Purdie
<richard.purdie@linuxfoundation.org> wrote:
>
> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> > From: Xiangyu Chen <xiangyu.chen@windriver.com>
> >
> > after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
> > errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
> > add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
> > option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
> > and elfutils dependency.
>
> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
> option documented somewhere?
>
> I also think the mention of devshell in the commit message is
> misleading, this issue happens regardless of how you enable the option.
> There are also other ways of enabling this than local.conf, you'd
> likely not want people doing that at the end of development.
>
> I'm curious on Bruce's opinion but to me this at the very least needs a
> commit message rewrite and I'd question whether the docs elsewhere
> would allow someone to discover this workflow anyway.

I missed this entirely, thanks for replying to it, or I never would
have noticed.

This mechanism isn't appropriate for these dependencies. I only added
it to work around pkgconfig issues (which we can more cleanly solve in
newer kernels  (see what I've been doing with make-mod-scripts) .. so
it can eventually be dropped).

We are already enabling elfutils-native conditionally on a
per-architecture basis (currently only x86-64).

If we need it on more arches now, we should enable it in the version
specific recipes, or actually, we have moved far enough into newer
kernel's that it could be in the .inc now.

Similarly, we should enable the pahole-native dependency on a per-arch basis.

As Richard mentioned, what's the reproducer to see the errors ? it
must be more than devshell.

If you can follow up with the steps to reproduce, I can take on the
refactoring and broader dependency cleanup question, since I can test
the wider matrix at the same time.

Bruce

>
> Cheers,
>
> Richard
>
Xiangyu Chen May 11, 2023, 2:22 a.m. UTC | #3
Hi Richard and Bruce,


Thanks for your suggestion,


On 5/11/23 00:25, Bruce Ashfield wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> <richard.purdie@linuxfoundation.org> wrote:
>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
>>>
>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
>>> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
>>> and elfutils dependency.
>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
>> option documented somewhere?
>>
>> I also think the mention of devshell in the commit message is
>> misleading, this issue happens regardless of how you enable the option.
>> There are also other ways of enabling this than local.conf, you'd
>> likely not want people doing that at the end of development.
>>
>> I'm curious on Bruce's opinion but to me this at the very least needs a
>> commit message rewrite and I'd question whether the docs elsewhere
>> would allow someone to discover this workflow anyway.
> I missed this entirely, thanks for replying to it, or I never would
> have noticed.
>
> This mechanism isn't appropriate for these dependencies. I only added
> it to work around pkgconfig issues (which we can more cleanly solve in
> newer kernels  (see what I've been doing with make-mod-scripts) .. so
> it can eventually be dropped).
>
> We are already enabling elfutils-native conditionally on a
> per-architecture basis (currently only x86-64).
>
> If we need it on more arches now, we should enable it in the version
> specific recipes, or actually, we have moved far enough into newer
> kernel's that it could be in the .inc now.
This commit's background was some kernel debug options needs elfutils 
and pahole native package, since the issue happens on enabling kernel 
debug options and not all people needs it, so I conditionally add the 
dependency in KERNEL_DEBUG_OPTION.

If possible we can enable it in .inc because newer kernel tools like btf 
are support using pkg-config to locate the libelf instead of finding it 
from /usr/ folder, so we can use elfutils-natvie instead of installing 
elfutils package on host PC.

>
> Similarly, we should enable the pahole-native dependency on a per-arch basis.
>
> As Richard mentioned, what's the reproducer to see the errors ? it
> must be more than devshell.

Yes, this happens on devshell and normal world if some kernel debug 
options are enabled. We can reproduce this issue with following steps(I 
have found the issue with kernel 5.15):

1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and 
CONFIG_DEBUG_INFO_BTF

2. build the kernel image, the compiler would report missing libelf.h 
and gelf.h which contains in elfutils-native(this step not happens on 
x86-64 due to it has been enabled).

3. enable elfutils-native by manual, the kernel source code can be 
compiled successfully but failed in final step due to missing pahole.


>
> If you can follow up with the steps to reproduce, I can take on the
> refactoring and broader dependency cleanup question, since I can test
> the wider matrix at the same time.

Thanks, my local setup might missing some corner case, this is another 
reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).


Xiangyu

> Bruce
>
>> Cheers,
>>
>> Richard
>>
>
> --
> - Thou shalt not follow the NULL pointer, for chaos and madness await
> thee at its end
> - "Use the force Harry" - Gandalf, Star Trek II
Bruce Ashfield May 12, 2023, 2:47 p.m. UTC | #4
On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
<xiangyu.chen@eng.windriver.com> wrote:
>
> Hi Richard and Bruce,
>
>
> Thanks for your suggestion,
>
>
> On 5/11/23 00:25, Bruce Ashfield wrote:
> > CAUTION: This email comes from a non Wind River email account!
> > Do not click links or open attachments unless you recognize the sender and know the content is safe.
> >
> > On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> > <richard.purdie@linuxfoundation.org> wrote:
> >> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> >>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> >>>
> >>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
> >>> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
> >>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
> >>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
> >>> and elfutils dependency.
> >> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
> >> option documented somewhere?
> >>
> >> I also think the mention of devshell in the commit message is
> >> misleading, this issue happens regardless of how you enable the option.
> >> There are also other ways of enabling this than local.conf, you'd
> >> likely not want people doing that at the end of development.
> >>
> >> I'm curious on Bruce's opinion but to me this at the very least needs a
> >> commit message rewrite and I'd question whether the docs elsewhere
> >> would allow someone to discover this workflow anyway.
> > I missed this entirely, thanks for replying to it, or I never would
> > have noticed.
> >
> > This mechanism isn't appropriate for these dependencies. I only added
> > it to work around pkgconfig issues (which we can more cleanly solve in
> > newer kernels  (see what I've been doing with make-mod-scripts) .. so
> > it can eventually be dropped).
> >
> > We are already enabling elfutils-native conditionally on a
> > per-architecture basis (currently only x86-64).
> >
> > If we need it on more arches now, we should enable it in the version
> > specific recipes, or actually, we have moved far enough into newer
> > kernel's that it could be in the .inc now.
> This commit's background was some kernel debug options needs elfutils
> and pahole native package, since the issue happens on enabling kernel
> debug options and not all people needs it, so I conditionally add the
> dependency in KERNEL_DEBUG_OPTION.
>
> If possible we can enable it in .inc because newer kernel tools like btf
> are support using pkg-config to locate the libelf instead of finding it
> from /usr/ folder, so we can use elfutils-natvie instead of installing
> elfutils package on host PC.
>
> >
> > Similarly, we should enable the pahole-native dependency on a per-arch basis.
> >
> > As Richard mentioned, what's the reproducer to see the errors ? it
> > must be more than devshell.
>
> Yes, this happens on devshell and normal world if some kernel debug
> options are enabled. We can reproduce this issue with following steps(I
> have found the issue with kernel 5.15):
>
> 1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> CONFIG_DEBUG_INFO_BTF
>
> 2. build the kernel image, the compiler would report missing libelf.h
> and gelf.h which contains in elfutils-native(this step not happens on
> x86-64 due to it has been enabled).
>
> 3. enable elfutils-native by manual, the kernel source code can be
> compiled successfully but failed in final step due to missing pahole.
>
>
> >
> > If you can follow up with the steps to reproduce, I can take on the
> > refactoring and broader dependency cleanup question, since I can test
> > the wider matrix at the same time.
>
> Thanks, my local setup might missing some corner case, this is another
> reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).
>

I've been thinking about this, and I've come to the following suggestion:

I plan on moving the elfutils-native to linux-yocto.inc, out of the
version specific
recipes.  I'll also drop the architecture specific nature of the
current DEPENDS.
The need for this is much more common now, and all of the reference kernels
in master are new enough. The elfutils-native build dependency is not
significant
enough to worry about adding it for all architectures. If it does
become a problem,
there are options to make it conditional again.

I can drop the HOST_LIBELF_LIBS work around in the linux-yocto.inc, as
we can now properly detect libelf via pkg-config. I didn't need it in any of
my testing. Again, if this proves to be wrong, I'd enable it in a
different way now
(using what I've learned from fixing make-mod-scripts).

As for the pahole-native dependency, there's been a "developer" kernel-type
for quite some time. The design intention behind it was to enable options like
this, and not make the "standard" or "production" kernel's too large by default.
So the dependency could be conditional on that kernel type ... but we don't
want to break other kernels just because they've enabled that option. We also
don't (and won't) get into the game of looking for individual options in the
.config to enable something, since a) it is too late b) it is a moving target.

So that leaves the following options: a) enable pahole-native unconditionally
on the arches that support it (x86-64, aarch64) (and also move the pahole
recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
and simply call it KERNEL_DEBUG, when enabled, we could conditionally
add pahole-native (I'd also submit documentation for the functionality
c) something I haven't thought about ...

I'm moving on the implementation now, but will adjust course if
there's something
I've missed.

Bruce


>
> Xiangyu
>
> > Bruce
> >
> >> Cheers,
> >>
> >> Richard
> >>
> >
> > --
> > - Thou shalt not follow the NULL pointer, for chaos and madness await
> > thee at its end
> > - "Use the force Harry" - Gandalf, Star Trek II
Bruce Ashfield May 13, 2023, 1:16 a.m. UTC | #5
On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
lists.openembedded.org
<bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>
> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
> <xiangyu.chen@eng.windriver.com> wrote:
> >
> > Hi Richard and Bruce,
> >
> >
> > Thanks for your suggestion,
> >
> >
> > On 5/11/23 00:25, Bruce Ashfield wrote:
> > > CAUTION: This email comes from a non Wind River email account!
> > > Do not click links or open attachments unless you recognize the sender and know the content is safe.
> > >
> > > On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> > > <richard.purdie@linuxfoundation.org> wrote:
> > >> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> > >>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> > >>>
> > >>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
> > >>> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
> > >>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
> > >>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
> > >>> and elfutils dependency.
> > >> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
> > >> option documented somewhere?
> > >>
> > >> I also think the mention of devshell in the commit message is
> > >> misleading, this issue happens regardless of how you enable the option.
> > >> There are also other ways of enabling this than local.conf, you'd
> > >> likely not want people doing that at the end of development.
> > >>
> > >> I'm curious on Bruce's opinion but to me this at the very least needs a
> > >> commit message rewrite and I'd question whether the docs elsewhere
> > >> would allow someone to discover this workflow anyway.
> > > I missed this entirely, thanks for replying to it, or I never would
> > > have noticed.
> > >
> > > This mechanism isn't appropriate for these dependencies. I only added
> > > it to work around pkgconfig issues (which we can more cleanly solve in
> > > newer kernels  (see what I've been doing with make-mod-scripts) .. so
> > > it can eventually be dropped).
> > >
> > > We are already enabling elfutils-native conditionally on a
> > > per-architecture basis (currently only x86-64).
> > >
> > > If we need it on more arches now, we should enable it in the version
> > > specific recipes, or actually, we have moved far enough into newer
> > > kernel's that it could be in the .inc now.
> > This commit's background was some kernel debug options needs elfutils
> > and pahole native package, since the issue happens on enabling kernel
> > debug options and not all people needs it, so I conditionally add the
> > dependency in KERNEL_DEBUG_OPTION.
> >
> > If possible we can enable it in .inc because newer kernel tools like btf
> > are support using pkg-config to locate the libelf instead of finding it
> > from /usr/ folder, so we can use elfutils-natvie instead of installing
> > elfutils package on host PC.
> >
> > >
> > > Similarly, we should enable the pahole-native dependency on a per-arch basis.
> > >
> > > As Richard mentioned, what's the reproducer to see the errors ? it
> > > must be more than devshell.
> >
> > Yes, this happens on devshell and normal world if some kernel debug
> > options are enabled. We can reproduce this issue with following steps(I
> > have found the issue with kernel 5.15):
> >
> > 1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> > CONFIG_DEBUG_INFO_BTF
> >
> > 2. build the kernel image, the compiler would report missing libelf.h
> > and gelf.h which contains in elfutils-native(this step not happens on
> > x86-64 due to it has been enabled).
> >
> > 3. enable elfutils-native by manual, the kernel source code can be
> > compiled successfully but failed in final step due to missing pahole.
> >
> >
> > >
> > > If you can follow up with the steps to reproduce, I can take on the
> > > refactoring and broader dependency cleanup question, since I can test
> > > the wider matrix at the same time.
> >
> > Thanks, my local setup might missing some corner case, this is another
> > reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).
> >
>
> I've been thinking about this, and I've come to the following suggestion:
>
> I plan on moving the elfutils-native to linux-yocto.inc, out of the
> version specific
> recipes.  I'll also drop the architecture specific nature of the
> current DEPENDS.
> The need for this is much more common now, and all of the reference kernels
> in master are new enough. The elfutils-native build dependency is not
> significant
> enough to worry about adding it for all architectures. If it does
> become a problem,
> there are options to make it conditional again.
>
> I can drop the HOST_LIBELF_LIBS work around in the linux-yocto.inc, as
> we can now properly detect libelf via pkg-config. I didn't need it in any of
> my testing. Again, if this proves to be wrong, I'd enable it in a
> different way now
> (using what I've learned from fixing make-mod-scripts).
>
> As for the pahole-native dependency, there's been a "developer" kernel-type
> for quite some time. The design intention behind it was to enable options like
> this, and not make the "standard" or "production" kernel's too large by default.
> So the dependency could be conditional on that kernel type ... but we don't
> want to break other kernels just because they've enabled that option. We also
> don't (and won't) get into the game of looking for individual options in the
> .config to enable something, since a) it is too late b) it is a moving target.
>
> So that leaves the following options: a) enable pahole-native unconditionally
> on the arches that support it (x86-64, aarch64) (and also move the pahole
> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
> and simply call it KERNEL_DEBUG, when enabled, we could conditionally
> add pahole-native (I'd also submit documentation for the functionality
> c) something I haven't thought about ...
>
> I'm moving on the implementation now, but will adjust course if
> there's something
> I've missed.

I have my implementation done, but I'm wondering what your configuration
was for testing pahole ?

I'm seeing the following in qemux86-64 at the end of the build:

| Unsupported DW_TAG_unspecified_type(0x3b)
| Encountered error while encoding BTF.
|   LD      .tmp_vmlinux.kallsyms1
|   NM      .tmp_vmlinux.kallsyms1.syms
|   KSYMS   .tmp_vmlinux.kallsyms1.S
|   AS      .tmp_vmlinux.kallsyms1.S
|   LD      .tmp_vmlinux.kallsyms2
|   NM      .tmp_vmlinux.kallsyms2.syms
|   KSYMS   .tmp_vmlinux.kallsyms2.S
|   AS      .tmp_vmlinux.kallsyms2.S
|   LD      vmlinux
|   BTFIDS  vmlinux
| FAILED: load BTF from vmlinux: No such file or directory
| make[1]: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
vmlinux] Error 255
| make[1]: *** Deleting file 'vmlinux'
| make: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
vmlinux] Error 2

I haven't looked into it at all yet (but will do so over the weekend)
.. but I thought
I should check with you first to get the details on how you were testing pahole
functionality.

Bruce


>
> Bruce
>
>
> >
> > Xiangyu
> >
> > > Bruce
> > >
> > >> Cheers,
> > >>
> > >> Richard
> > >>
> > >
> > > --
> > > - Thou shalt not follow the NULL pointer, for chaos and madness await
> > > thee at its end
> > > - "Use the force Harry" - Gandalf, Star Trek II
>
>
>
> --
> - 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 (#181185): https://lists.openembedded.org/g/openembedded-core/message/181185
> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
> Group Owner: openembedded-core+owner@lists.openembedded.org
> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [bruce.ashfield@gmail.com]
> -=-=-=-=-=-=-=-=-=-=-=-
>
Xiangyu Chen May 15, 2023, 10:04 a.m. UTC | #6
Hi Bruce,


Sorry for being late..


On 5/13/23 09:16, Bruce Ashfield wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
> lists.openembedded.org
> <bruce.ashfield=gmail.com@lists.openembedded.org>  wrote:
>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
>> <xiangyu.chen@eng.windriver.com>  wrote:
>>> Hi Richard and Bruce,
>>>
>>>
>>> Thanks for your suggestion,
>>>
>>>
>>> On 5/11/23 00:25, Bruce Ashfield wrote:
>>>> CAUTION: This email comes from a non Wind River email account!
>>>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>>>>
>>>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
>>>> <richard.purdie@linuxfoundation.org>  wrote:
>>>>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
>>>>>> From: Xiangyu Chen<xiangyu.chen@windriver.com>
>>>>>>
>>>>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
>>>>>> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
>>>>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
>>>>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
>>>>>> and elfutils dependency.
>>>>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
>>>>> option documented somewhere?
>>>>>
>>>>> I also think the mention of devshell in the commit message is
>>>>> misleading, this issue happens regardless of how you enable the option.
>>>>> There are also other ways of enabling this than local.conf, you'd
>>>>> likely not want people doing that at the end of development.
>>>>>
>>>>> I'm curious on Bruce's opinion but to me this at the very least needs a
>>>>> commit message rewrite and I'd question whether the docs elsewhere
>>>>> would allow someone to discover this workflow anyway.
>>>> I missed this entirely, thanks for replying to it, or I never would
>>>> have noticed.
>>>>
>>>> This mechanism isn't appropriate for these dependencies. I only added
>>>> it to work around pkgconfig issues (which we can more cleanly solve in
>>>> newer kernels  (see what I've been doing with make-mod-scripts) .. so
>>>> it can eventually be dropped).
>>>>
>>>> We are already enabling elfutils-native conditionally on a
>>>> per-architecture basis (currently only x86-64).
>>>>
>>>> If we need it on more arches now, we should enable it in the version
>>>> specific recipes, or actually, we have moved far enough into newer
>>>> kernel's that it could be in the .inc now.
>>> This commit's background was some kernel debug options needs elfutils
>>> and pahole native package, since the issue happens on enabling kernel
>>> debug options and not all people needs it, so I conditionally add the
>>> dependency in KERNEL_DEBUG_OPTION.
>>>
>>> If possible we can enable it in .inc because newer kernel tools like btf
>>> are support using pkg-config to locate the libelf instead of finding it
>>> from /usr/ folder, so we can use elfutils-natvie instead of installing
>>> elfutils package on host PC.
>>>
>>>> Similarly, we should enable the pahole-native dependency on a per-arch basis.
>>>>
>>>> As Richard mentioned, what's the reproducer to see the errors ? it
>>>> must be more than devshell.
>>> Yes, this happens on devshell and normal world if some kernel debug
>>> options are enabled. We can reproduce this issue with following steps(I
>>> have found the issue with kernel 5.15):
>>>
>>> 1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
>>> CONFIG_DEBUG_INFO_BTF
>>>
>>> 2. build the kernel image, the compiler would report missing libelf.h
>>> and gelf.h which contains in elfutils-native(this step not happens on
>>> x86-64 due to it has been enabled).
>>>
>>> 3. enable elfutils-native by manual, the kernel source code can be
>>> compiled successfully but failed in final step due to missing pahole.
>>>
>>>
>>>> If you can follow up with the steps to reproduce, I can take on the
>>>> refactoring and broader dependency cleanup question, since I can test
>>>> the wider matrix at the same time.
>>> Thanks, my local setup might missing some corner case, this is another
>>> reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).
>>>
>> I've been thinking about this, and I've come to the following suggestion:
>>
>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
>> version specific
>> recipes.  I'll also drop the architecture specific nature of the
>> current DEPENDS.
>> The need for this is much more common now, and all of the reference kernels
>> in master are new enough. The elfutils-native build dependency is not
>> significant
>> enough to worry about adding it for all architectures. If it does
>> become a problem,
>> there are options to make it conditional again.
>>
>> I can drop the HOST_LIBELF_LIBS work around in the linux-yocto.inc, as
>> we can now properly detect libelf via pkg-config. I didn't need it in any of
>> my testing. Again, if this proves to be wrong, I'd enable it in a
>> different way now
>> (using what I've learned from fixing make-mod-scripts).
>>
>> As for the pahole-native dependency, there's been a "developer" kernel-type
>> for quite some time. The design intention behind it was to enable options like
>> this, and not make the "standard" or "production" kernel's too large by default.
>> So the dependency could be conditional on that kernel type ... but we don't
>> want to break other kernels just because they've enabled that option. We also
>> don't (and won't) get into the game of looking for individual options in the
>> .config to enable something, since a) it is too late b) it is a moving target.
>>
>> So that leaves the following options: a) enable pahole-native unconditionally
>> on the arches that support it (x86-64, aarch64) (and also move the pahole
>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
>> and simply call it KERNEL_DEBUG, when enabled, we could conditionally
>> add pahole-native (I'd also submit documentation for the functionality
>> c) something I haven't thought about ...
>>
>> I'm moving on the implementation now, but will adjust course if
>> there's something
>> I've missed.
> I have my implementation done, but I'm wondering what your configuration
> was for testing pahole ?

I have tested on a devshell, with oe-master branch, the kernel version 
using 5.15

1. enable pahole-native and elfutils-native in linux-yocto.inc as a 
dependency.

2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
CONFIG_DEBUG_INFO_BTF under menuconfig

3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning 
PKG_CONFIG_SYSROOT_DIR

4, make


If the test environment using bitbake, then we need to remove 
PAHOLE=false flag in kernel EXTRA_OEMAKE in 
classes-recipe/kernel.bbclass, otherwise, bitbake would report missing 
pahole error.


> I'm seeing the following in qemux86-64 at the end of the build:
>
> | Unsupported DW_TAG_unspecified_type(0x3b)
> | Encountered error while encoding BTF.
> |   LD      .tmp_vmlinux.kallsyms1
> |   NM      .tmp_vmlinux.kallsyms1.syms
> |   KSYMS   .tmp_vmlinux.kallsyms1.S
> |   AS      .tmp_vmlinux.kallsyms1.S
> |   LD      .tmp_vmlinux.kallsyms2
> |   NM      .tmp_vmlinux.kallsyms2.syms
> |   KSYMS   .tmp_vmlinux.kallsyms2.S
> |   AS      .tmp_vmlinux.kallsyms2.S
> |   LD      vmlinux
> |   BTFIDS  vmlinux
> | FAILED: load BTF from vmlinux: No such file or directory
> | make[1]: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
> vmlinux] Error 255
> | make[1]: *** Deleting file 'vmlinux'
> | make: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
> vmlinux] Error 2
>
> I haven't looked into it at all yet (but will do so over the weekend)
> .. but I thought

I haven't seen this problem yet(i'll pull the latest oe-core and meta-oe 
code and try again), if possible, could you share a patch with me so 
that we can test it together? thanks.

> I should check with you first to get the details on how you were testing pahole
> functionality.
>
> Bruce


Br,

Xiangyu

>
>> Bruce
>>
>>
>>> Xiangyu
>>>
>>>> Bruce
>>>>
>>>>> Cheers,
>>>>>
>>>>> Richard
>>>>>
>>>> --
>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>>> thee at its end
>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>
>>
>> --
>> - 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 (#181185):https://lists.openembedded.org/g/openembedded-core/message/181185
>> Mute This Topic:https://lists.openembedded.org/mt/98753313/1050810
>> Group Owner:openembedded-core+owner@lists.openembedded.org
>> Unsubscribe:https://lists.openembedded.org/g/openembedded-core/unsub  [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
Bruce Ashfield May 15, 2023, 12:34 p.m. UTC | #7
On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
<xiangyu.chen@eng.windriver.com> wrote:
>
> Hi Bruce,
>
>
> Sorry for being late..
>
>
> On 5/13/23 09:16, Bruce Ashfield wrote:
>
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
> lists.openembedded.org
> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>
> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
> <xiangyu.chen@eng.windriver.com> wrote:
>
> Hi Richard and Bruce,
>
>
> Thanks for your suggestion,
>
>
> On 5/11/23 00:25, Bruce Ashfield wrote:
>
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> <richard.purdie@linuxfoundation.org> wrote:
>
> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
>
> From: Xiangyu Chen <xiangyu.chen@windriver.com>
>
> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
> and elfutils dependency.
>
> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
> option documented somewhere?
>
> I also think the mention of devshell in the commit message is
> misleading, this issue happens regardless of how you enable the option.
> There are also other ways of enabling this than local.conf, you'd
> likely not want people doing that at the end of development.
>
> I'm curious on Bruce's opinion but to me this at the very least needs a
> commit message rewrite and I'd question whether the docs elsewhere
> would allow someone to discover this workflow anyway.
>
> I missed this entirely, thanks for replying to it, or I never would
> have noticed.
>
> This mechanism isn't appropriate for these dependencies. I only added
> it to work around pkgconfig issues (which we can more cleanly solve in
> newer kernels  (see what I've been doing with make-mod-scripts) .. so
> it can eventually be dropped).
>
> We are already enabling elfutils-native conditionally on a
> per-architecture basis (currently only x86-64).
>
> If we need it on more arches now, we should enable it in the version
> specific recipes, or actually, we have moved far enough into newer
> kernel's that it could be in the .inc now.
>
> This commit's background was some kernel debug options needs elfutils
> and pahole native package, since the issue happens on enabling kernel
> debug options and not all people needs it, so I conditionally add the
> dependency in KERNEL_DEBUG_OPTION.
>
> If possible we can enable it in .inc because newer kernel tools like btf
> are support using pkg-config to locate the libelf instead of finding it
> from /usr/ folder, so we can use elfutils-natvie instead of installing
> elfutils package on host PC.
>
> Similarly, we should enable the pahole-native dependency on a per-arch basis.
>
> As Richard mentioned, what's the reproducer to see the errors ? it
> must be more than devshell.
>
> Yes, this happens on devshell and normal world if some kernel debug
> options are enabled. We can reproduce this issue with following steps(I
> have found the issue with kernel 5.15):
>
> 1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> CONFIG_DEBUG_INFO_BTF
>
> 2. build the kernel image, the compiler would report missing libelf.h
> and gelf.h which contains in elfutils-native(this step not happens on
> x86-64 due to it has been enabled).
>
> 3. enable elfutils-native by manual, the kernel source code can be
> compiled successfully but failed in final step due to missing pahole.
>
>
> If you can follow up with the steps to reproduce, I can take on the
> refactoring and broader dependency cleanup question, since I can test
> the wider matrix at the same time.
>
> Thanks, my local setup might missing some corner case, this is another
> reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).
>
> I've been thinking about this, and I've come to the following suggestion:
>
> I plan on moving the elfutils-native to linux-yocto.inc, out of the
> version specific
> recipes.  I'll also drop the architecture specific nature of the
> current DEPENDS.
> The need for this is much more common now, and all of the reference kernels
> in master are new enough. The elfutils-native build dependency is not
> significant
> enough to worry about adding it for all architectures. If it does
> become a problem,
> there are options to make it conditional again.
>
> I can drop the HOST_LIBELF_LIBS work around in the linux-yocto.inc, as
> we can now properly detect libelf via pkg-config. I didn't need it in any of
> my testing. Again, if this proves to be wrong, I'd enable it in a
> different way now
> (using what I've learned from fixing make-mod-scripts).
>
> As for the pahole-native dependency, there's been a "developer" kernel-type
> for quite some time. The design intention behind it was to enable options like
> this, and not make the "standard" or "production" kernel's too large by default.
> So the dependency could be conditional on that kernel type ... but we don't
> want to break other kernels just because they've enabled that option. We also
> don't (and won't) get into the game of looking for individual options in the
> .config to enable something, since a) it is too late b) it is a moving target.
>
> So that leaves the following options: a) enable pahole-native unconditionally
> on the arches that support it (x86-64, aarch64) (and also move the pahole
> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
> and simply call it KERNEL_DEBUG, when enabled, we could conditionally
> add pahole-native (I'd also submit documentation for the functionality
> c) something I haven't thought about ...
>
> I'm moving on the implementation now, but will adjust course if
> there's something
> I've missed.
>
> I have my implementation done, but I'm wondering what your configuration
> was for testing pahole ?
>

My reply will be hard to read, as plain text reply to the html doesn't
give us proper
context indenting.

> I have tested on a devshell, with oe-master branch, the kernel version using 5.15
>
> 1. enable pahole-native and elfutils-native in linux-yocto.inc as a dependency.
>
> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> CONFIG_DEBUG_INFO_BTF under menuconfig
>
> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning PKG_CONFIG_SYSROOT_DIR
>
> 4, make
>
>
> If the test environment using bitbake, then we need to remove PAHOLE=false flag in kernel EXTRA_OEMAKE in classes-recipe/kernel.bbclass, otherwise, bitbake would report missing pahole error.
>

That's the same as my patch series (I've also changed PAHOLE=false to
a conditional in my series).

>
> I'm seeing the following in qemux86-64 at the end of the build:
>
> | Unsupported DW_TAG_unspecified_type(0x3b)
> | Encountered error while encoding BTF.
> |   LD      .tmp_vmlinux.kallsyms1
> |   NM      .tmp_vmlinux.kallsyms1.syms
> |   KSYMS   .tmp_vmlinux.kallsyms1.S
> |   AS      .tmp_vmlinux.kallsyms1.S
> |   LD      .tmp_vmlinux.kallsyms2
> |   NM      .tmp_vmlinux.kallsyms2.syms
> |   KSYMS   .tmp_vmlinux.kallsyms2.S
> |   AS      .tmp_vmlinux.kallsyms2.S
> |   LD      vmlinux
> |   BTFIDS  vmlinux
> | FAILED: load BTF from vmlinux: No such file or directory
> | make[1]: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
> vmlinux] Error 255
> | make[1]: *** Deleting file 'vmlinux'
> | make: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
> vmlinux] Error 2
>
> I haven't looked into it at all yet (but will do so over the weekend)
> .. but I thought
>
> I haven't seen this problem yet(i'll pull the latest oe-core and meta-oe code and try again), if possible, could you share a patch with me so that we can test it together? thanks.
>

I'm on oe-core master, with qemux86-64.

I'll do a bit more work on the patch today, and can share it if I
can't figure out where that unsupported tag is coming from.

Bruce

> I should check with you first to get the details on how you were testing pahole
> functionality.
>
> Bruce
>
>
> Br,
>
> Xiangyu
>
> Bruce
>
>
> Xiangyu
>
> Bruce
>
> Cheers,
>
> Richard
>
> --
> - Thou shalt not follow the NULL pointer, for chaos and madness await
> thee at its end
> - "Use the force Harry" - Gandalf, Star Trek II
>
> --
> - 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 (#181185): https://lists.openembedded.org/g/openembedded-core/message/181185
> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
> Group Owner: openembedded-core+owner@lists.openembedded.org
> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [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
Bruce Ashfield May 15, 2023, 1:11 p.m. UTC | #8
On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
lists.openembedded.org
<bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>
> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
> <xiangyu.chen@eng.windriver.com> wrote:
> >
> > Hi Bruce,
> >
> >
> > Sorry for being late..
> >
> >
> > On 5/13/23 09:16, Bruce Ashfield wrote:
> >
> > CAUTION: This email comes from a non Wind River email account!
> > Do not click links or open attachments unless you recognize the sender and know the content is safe.
> >
> > On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
> > lists.openembedded.org
> > <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> >
> > On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
> > <xiangyu.chen@eng.windriver.com> wrote:
> >
> > Hi Richard and Bruce,
> >
> >
> > Thanks for your suggestion,
> >
> >
> > On 5/11/23 00:25, Bruce Ashfield wrote:
> >
> > CAUTION: This email comes from a non Wind River email account!
> > Do not click links or open attachments unless you recognize the sender and know the content is safe.
> >
> > On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> > <richard.purdie@linuxfoundation.org> wrote:
> >
> > On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> >
> > From: Xiangyu Chen <xiangyu.chen@windriver.com>
> >
> > after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
> > errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
> > add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
> > option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
> > and elfutils dependency.
> >
> > Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
> > option documented somewhere?
> >
> > I also think the mention of devshell in the commit message is
> > misleading, this issue happens regardless of how you enable the option.
> > There are also other ways of enabling this than local.conf, you'd
> > likely not want people doing that at the end of development.
> >
> > I'm curious on Bruce's opinion but to me this at the very least needs a
> > commit message rewrite and I'd question whether the docs elsewhere
> > would allow someone to discover this workflow anyway.
> >
> > I missed this entirely, thanks for replying to it, or I never would
> > have noticed.
> >
> > This mechanism isn't appropriate for these dependencies. I only added
> > it to work around pkgconfig issues (which we can more cleanly solve in
> > newer kernels  (see what I've been doing with make-mod-scripts) .. so
> > it can eventually be dropped).
> >
> > We are already enabling elfutils-native conditionally on a
> > per-architecture basis (currently only x86-64).
> >
> > If we need it on more arches now, we should enable it in the version
> > specific recipes, or actually, we have moved far enough into newer
> > kernel's that it could be in the .inc now.
> >
> > This commit's background was some kernel debug options needs elfutils
> > and pahole native package, since the issue happens on enabling kernel
> > debug options and not all people needs it, so I conditionally add the
> > dependency in KERNEL_DEBUG_OPTION.
> >
> > If possible we can enable it in .inc because newer kernel tools like btf
> > are support using pkg-config to locate the libelf instead of finding it
> > from /usr/ folder, so we can use elfutils-natvie instead of installing
> > elfutils package on host PC.
> >
> > Similarly, we should enable the pahole-native dependency on a per-arch basis.
> >
> > As Richard mentioned, what's the reproducer to see the errors ? it
> > must be more than devshell.
> >
> > Yes, this happens on devshell and normal world if some kernel debug
> > options are enabled. We can reproduce this issue with following steps(I
> > have found the issue with kernel 5.15):
> >
> > 1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> > CONFIG_DEBUG_INFO_BTF
> >
> > 2. build the kernel image, the compiler would report missing libelf.h
> > and gelf.h which contains in elfutils-native(this step not happens on
> > x86-64 due to it has been enabled).
> >
> > 3. enable elfutils-native by manual, the kernel source code can be
> > compiled successfully but failed in final step due to missing pahole.
> >
> >
> > If you can follow up with the steps to reproduce, I can take on the
> > refactoring and broader dependency cleanup question, since I can test
> > the wider matrix at the same time.
> >
> > Thanks, my local setup might missing some corner case, this is another
> > reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).
> >
> > I've been thinking about this, and I've come to the following suggestion:
> >
> > I plan on moving the elfutils-native to linux-yocto.inc, out of the
> > version specific
> > recipes.  I'll also drop the architecture specific nature of the
> > current DEPENDS.
> > The need for this is much more common now, and all of the reference kernels
> > in master are new enough. The elfutils-native build dependency is not
> > significant
> > enough to worry about adding it for all architectures. If it does
> > become a problem,
> > there are options to make it conditional again.
> >
> > I can drop the HOST_LIBELF_LIBS work around in the linux-yocto.inc, as
> > we can now properly detect libelf via pkg-config. I didn't need it in any of
> > my testing. Again, if this proves to be wrong, I'd enable it in a
> > different way now
> > (using what I've learned from fixing make-mod-scripts).
> >
> > As for the pahole-native dependency, there's been a "developer" kernel-type
> > for quite some time. The design intention behind it was to enable options like
> > this, and not make the "standard" or "production" kernel's too large by default.
> > So the dependency could be conditional on that kernel type ... but we don't
> > want to break other kernels just because they've enabled that option. We also
> > don't (and won't) get into the game of looking for individual options in the
> > .config to enable something, since a) it is too late b) it is a moving target.
> >
> > So that leaves the following options: a) enable pahole-native unconditionally
> > on the arches that support it (x86-64, aarch64) (and also move the pahole
> > recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
> > and simply call it KERNEL_DEBUG, when enabled, we could conditionally
> > add pahole-native (I'd also submit documentation for the functionality
> > c) something I haven't thought about ...
> >
> > I'm moving on the implementation now, but will adjust course if
> > there's something
> > I've missed.
> >
> > I have my implementation done, but I'm wondering what your configuration
> > was for testing pahole ?
> >
>
> My reply will be hard to read, as plain text reply to the html doesn't
> give us proper
> context indenting.
>
> > I have tested on a devshell, with oe-master branch, the kernel version using 5.15
> >
> > 1. enable pahole-native and elfutils-native in linux-yocto.inc as a dependency.
> >
> > 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> > CONFIG_DEBUG_INFO_BTF under menuconfig
> >
> > 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning PKG_CONFIG_SYSROOT_DIR
> >
> > 4, make
> >
> >
> > If the test environment using bitbake, then we need to remove PAHOLE=false flag in kernel EXTRA_OEMAKE in classes-recipe/kernel.bbclass, otherwise, bitbake would report missing pahole error.
> >
>
> That's the same as my patch series (I've also changed PAHOLE=false to
> a conditional in my series).
>
> >
> > I'm seeing the following in qemux86-64 at the end of the build:
> >
> > | Unsupported DW_TAG_unspecified_type(0x3b)
> > | Encountered error while encoding BTF.
> > |   LD      .tmp_vmlinux.kallsyms1
> > |   NM      .tmp_vmlinux.kallsyms1.syms
> > |   KSYMS   .tmp_vmlinux.kallsyms1.S
> > |   AS      .tmp_vmlinux.kallsyms1.S
> > |   LD      .tmp_vmlinux.kallsyms2
> > |   NM      .tmp_vmlinux.kallsyms2.syms
> > |   KSYMS   .tmp_vmlinux.kallsyms2.S
> > |   AS      .tmp_vmlinux.kallsyms2.S
> > |   LD      vmlinux
> > |   BTFIDS  vmlinux
> > | FAILED: load BTF from vmlinux: No such file or directory
> > | make[1]: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
> > vmlinux] Error 255
> > | make[1]: *** Deleting file 'vmlinux'
> > | make: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
> > vmlinux] Error 2
> >
> > I haven't looked into it at all yet (but will do so over the weekend)
> > .. but I thought
> >
> > I haven't seen this problem yet(i'll pull the latest oe-core and meta-oe code and try again), if possible, could you share a patch with me so that we can test it together? thanks.
> >
>
> I'm on oe-core master, with qemux86-64.
>
> I'll do a bit more work on the patch today, and can share it if I
> can't figure out where that unsupported tag is coming from.

It seems like it is a known issue, I found both a lkml thread and
debian bug from October 2022.

Your 5.15 kernel wouldn't show the issue.

You can find a link to the lkml thread from the debian bug:
https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1873553.html

I'll clean up my patch, since this isn't something I can fix immediately.

If you do track down patches in the latest kernel that haven't been
sent to -stable, we can backport them to fix the linux-yocto builds
with pahole.

Bruce

>
> Bruce
>
> > I should check with you first to get the details on how you were testing pahole
> > functionality.
> >
> > Bruce
> >
> >
> > Br,
> >
> > Xiangyu
> >
> > Bruce
> >
> >
> > Xiangyu
> >
> > Bruce
> >
> > Cheers,
> >
> > Richard
> >
> > --
> > - Thou shalt not follow the NULL pointer, for chaos and madness await
> > thee at its end
> > - "Use the force Harry" - Gandalf, Star Trek II
> >
> > --
> > - Thou shalt not follow the NULL pointer, for chaos and madness await
> > thee at its end
> > - "Use the force Harry" - Gandalf, Star Trek II
> >
> >
> >
> > --
> > - Thou shalt not follow the NULL pointer, for chaos and madness await
> > thee at its end
> > - "Use the force Harry" - Gandalf, Star Trek II
>
>
>
> --
> - 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 (#181248): https://lists.openembedded.org/g/openembedded-core/message/181248
> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
> Group Owner: openembedded-core+owner@lists.openembedded.org
> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [bruce.ashfield@gmail.com]
> -=-=-=-=-=-=-=-=-=-=-=-
>
Xiangyu Chen May 16, 2023, 8:55 a.m. UTC | #9
Hi Bruce,


On 5/15/23 21:11, Bruce Ashfield wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
> lists.openembedded.org
> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
>> <xiangyu.chen@eng.windriver.com> wrote:
>>> Hi Bruce,
>>>
>>>
>>> Sorry for being late..
>>>
>>>
>>> On 5/13/23 09:16, Bruce Ashfield wrote:
>>>
>>> CAUTION: This email comes from a non Wind River email account!
>>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>>>
>>> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
>>> lists.openembedded.org
>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>>>
>>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
>>> <xiangyu.chen@eng.windriver.com> wrote:
>>>
>>> Hi Richard and Bruce,
>>>
>>>
>>> Thanks for your suggestion,
>>>
>>>
>>> On 5/11/23 00:25, Bruce Ashfield wrote:
>>>
>>> CAUTION: This email comes from a non Wind River email account!
>>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>>>
>>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
>>> <richard.purdie@linuxfoundation.org> wrote:
>>>
>>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
>>>
>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
>>>
>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
>>> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
>>> and elfutils dependency.
>>>
>>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
>>> option documented somewhere?
>>>
>>> I also think the mention of devshell in the commit message is
>>> misleading, this issue happens regardless of how you enable the option.
>>> There are also other ways of enabling this than local.conf, you'd
>>> likely not want people doing that at the end of development.
>>>
>>> I'm curious on Bruce's opinion but to me this at the very least needs a
>>> commit message rewrite and I'd question whether the docs elsewhere
>>> would allow someone to discover this workflow anyway.
>>>
>>> I missed this entirely, thanks for replying to it, or I never would
>>> have noticed.
>>>
>>> This mechanism isn't appropriate for these dependencies. I only added
>>> it to work around pkgconfig issues (which we can more cleanly solve in
>>> newer kernels  (see what I've been doing with make-mod-scripts) .. so
>>> it can eventually be dropped).
>>>
>>> We are already enabling elfutils-native conditionally on a
>>> per-architecture basis (currently only x86-64).
>>>
>>> If we need it on more arches now, we should enable it in the version
>>> specific recipes, or actually, we have moved far enough into newer
>>> kernel's that it could be in the .inc now.
>>>
>>> This commit's background was some kernel debug options needs elfutils
>>> and pahole native package, since the issue happens on enabling kernel
>>> debug options and not all people needs it, so I conditionally add the
>>> dependency in KERNEL_DEBUG_OPTION.
>>>
>>> If possible we can enable it in .inc because newer kernel tools like btf
>>> are support using pkg-config to locate the libelf instead of finding it
>>> from /usr/ folder, so we can use elfutils-natvie instead of installing
>>> elfutils package on host PC.
>>>
>>> Similarly, we should enable the pahole-native dependency on a per-arch basis.
>>>
>>> As Richard mentioned, what's the reproducer to see the errors ? it
>>> must be more than devshell.
>>>
>>> Yes, this happens on devshell and normal world if some kernel debug
>>> options are enabled. We can reproduce this issue with following steps(I
>>> have found the issue with kernel 5.15):
>>>
>>> 1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
>>> CONFIG_DEBUG_INFO_BTF
>>>
>>> 2. build the kernel image, the compiler would report missing libelf.h
>>> and gelf.h which contains in elfutils-native(this step not happens on
>>> x86-64 due to it has been enabled).
>>>
>>> 3. enable elfutils-native by manual, the kernel source code can be
>>> compiled successfully but failed in final step due to missing pahole.
>>>
>>>
>>> If you can follow up with the steps to reproduce, I can take on the
>>> refactoring and broader dependency cleanup question, since I can test
>>> the wider matrix at the same time.
>>>
>>> Thanks, my local setup might missing some corner case, this is another
>>> reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).
>>>
>>> I've been thinking about this, and I've come to the following suggestion:
>>>
>>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
>>> version specific
>>> recipes.  I'll also drop the architecture specific nature of the
>>> current DEPENDS.
>>> The need for this is much more common now, and all of the reference kernels
>>> in master are new enough. The elfutils-native build dependency is not
>>> significant
>>> enough to worry about adding it for all architectures. If it does
>>> become a problem,
>>> there are options to make it conditional again.
>>>
>>> I can drop the HOST_LIBELF_LIBS work around in the linux-yocto.inc, as
>>> we can now properly detect libelf via pkg-config. I didn't need it in any of
>>> my testing. Again, if this proves to be wrong, I'd enable it in a
>>> different way now
>>> (using what I've learned from fixing make-mod-scripts).
>>>
>>> As for the pahole-native dependency, there's been a "developer" kernel-type
>>> for quite some time. The design intention behind it was to enable options like
>>> this, and not make the "standard" or "production" kernel's too large by default.
>>> So the dependency could be conditional on that kernel type ... but we don't
>>> want to break other kernels just because they've enabled that option. We also
>>> don't (and won't) get into the game of looking for individual options in the
>>> .config to enable something, since a) it is too late b) it is a moving target.
>>>
>>> So that leaves the following options: a) enable pahole-native unconditionally
>>> on the arches that support it (x86-64, aarch64) (and also move the pahole
>>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
>>> and simply call it KERNEL_DEBUG, when enabled, we could conditionally
>>> add pahole-native (I'd also submit documentation for the functionality
>>> c) something I haven't thought about ...
>>>
>>> I'm moving on the implementation now, but will adjust course if
>>> there's something
>>> I've missed.
>>>
>>> I have my implementation done, but I'm wondering what your configuration
>>> was for testing pahole ?
>>>
>> My reply will be hard to read, as plain text reply to the html doesn't
>> give us proper
>> context indenting.
>>
>>> I have tested on a devshell, with oe-master branch, the kernel version using 5.15
>>>
>>> 1. enable pahole-native and elfutils-native in linux-yocto.inc as a dependency.
>>>
>>> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
>>> CONFIG_DEBUG_INFO_BTF under menuconfig
>>>
>>> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning PKG_CONFIG_SYSROOT_DIR
>>>
>>> 4, make
>>>
>>>
>>> If the test environment using bitbake, then we need to remove PAHOLE=false flag in kernel EXTRA_OEMAKE in classes-recipe/kernel.bbclass, otherwise, bitbake would report missing pahole error.
>>>
>> That's the same as my patch series (I've also changed PAHOLE=false to
>> a conditional in my series).
>>
>>> I'm seeing the following in qemux86-64 at the end of the build:
>>>
>>> | Unsupported DW_TAG_unspecified_type(0x3b)
>>> | Encountered error while encoding BTF.
>>> |   LD      .tmp_vmlinux.kallsyms1
>>> |   NM      .tmp_vmlinux.kallsyms1.syms
>>> |   KSYMS   .tmp_vmlinux.kallsyms1.S
>>> |   AS      .tmp_vmlinux.kallsyms1.S
>>> |   LD      .tmp_vmlinux.kallsyms2
>>> |   NM      .tmp_vmlinux.kallsyms2.syms
>>> |   KSYMS   .tmp_vmlinux.kallsyms2.S
>>> |   AS      .tmp_vmlinux.kallsyms2.S
>>> |   LD      vmlinux
>>> |   BTFIDS  vmlinux
>>> | FAILED: load BTF from vmlinux: No such file or directory
>>> | make[1]: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
>>> vmlinux] Error 255
>>> | make[1]: *** Deleting file 'vmlinux'
>>> | make: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
>>> vmlinux] Error 2
>>>
>>> I haven't looked into it at all yet (but will do so over the weekend)
>>> .. but I thought
>>>
>>> I haven't seen this problem yet(i'll pull the latest oe-core and meta-oe code and try again), if possible, could you share a patch with me so that we can test it together? thanks.
>>>
>> I'm on oe-core master, with qemux86-64.
>>
>> I'll do a bit more work on the patch today, and can share it if I
>> can't figure out where that unsupported tag is coming from.
> It seems like it is a known issue, I found both a lkml thread and
> debian bug from October 2022.
>
> Your 5.15 kernel wouldn't show the issue.

Yes, this should not happens on 5.15 kernel.


Today I synced the oe-core/poky to latest master version, removed the 
build dir and run oe-init-build-env again and switched to use default 
linux 6.1.25 instead of 5.15.

Some kernel config has been updated, there is no CONFIG_DEBUG_INFO, I 
used CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT.

So, currently my local setup kernel config is enabled 
CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and 
CONFIG_DEBUG_INFO_BTF, in order to make a easy test, I enabled 
elfutils-native and pahole-native as DEPEND directly in linux-yocto.in, 
and remove the PAHOLE=false in EXTRA_OEMAKE.

my oe-core rev: 35e5d29a7d654fc79bdb898d0f1fb277270dbfd5

my meta-oe rev:b7aa66d734b911737b61610c1c47778e14b15c55


When I ran bitbake linux-yocto -v -D, I have met the same issue,

| Unsupported DW_TAG_unspecified_type(0x3b)
| Encountered error while encoding BTF.

It's bit strange that the I removed my local OS(ubuntu)'s pahole and the 
code can be compiled without error:


   CC      init/version-timestamp.o
   LD      .tmp_vmlinux.btf
   BTF     .btf.vmlinux.bin.o
   LD      .tmp_vmlinux.kallsyms1
   NM      .tmp_vmlinux.kallsyms1.syms
   KSYMS   .tmp_vmlinux.kallsyms1.S
   AS      .tmp_vmlinux.kallsyms1.S
   LD      .tmp_vmlinux.kallsyms2
   NM      .tmp_vmlinux.kallsyms2.syms
   KSYMS   .tmp_vmlinux.kallsyms2.S
   AS      .tmp_vmlinux.kallsyms2.S
   LD      vmlinux
   BTFIDS  vmlinux
   NM      System.map
   SORTTAB vmlinux



>
> You can find a link to the lkml thread from the debian bug:
> https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1873553.html

>
> I'll clean up my patch, since this isn't something I can fix immediately.
>
> If you do track down patches in the latest kernel that haven't been
> sent to -stable, we can backport them to fix the linux-yocto builds
> with pahole.
>
> Bruce
>

Br,

Xiangyu

>> Bruce
>>
>>> I should check with you first to get the details on how you were testing pahole
>>> functionality.
>>>
>>> Bruce
>>>
>>>
>>> Br,
>>>
>>> Xiangyu
>>>
>>> Bruce
>>>
>>>
>>> Xiangyu
>>>
>>> Bruce
>>>
>>> Cheers,
>>>
>>> Richard
>>>
>>> --
>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>> thee at its end
>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>
>>> --
>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>> thee at its end
>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>
>>>
>>>
>>> --
>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>> thee at its end
>>> - "Use the force Harry" - Gandalf, Star Trek II
>>
>>
>> --
>> - 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 (#181248): https://lists.openembedded.org/g/openembedded-core/message/181248
>> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
>> Group Owner: openembedded-core+owner@lists.openembedded.org
>> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [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
Bruce Ashfield May 16, 2023, 12:55 p.m. UTC | #10
On Tue, May 16, 2023 at 4:56 AM Xiangyu Chen
<xiangyu.chen@eng.windriver.com> wrote:
>
> Hi Bruce,
>
>
> On 5/15/23 21:11, Bruce Ashfield wrote:
> > CAUTION: This email comes from a non Wind River email account!
> > Do not click links or open attachments unless you recognize the sender and know the content is safe.
> >
> > On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
> > lists.openembedded.org
> > <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> >> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
> >> <xiangyu.chen@eng.windriver.com> wrote:
> >>> Hi Bruce,
> >>>
> >>>
> >>> Sorry for being late..
> >>>
> >>>
> >>> On 5/13/23 09:16, Bruce Ashfield wrote:
> >>>
> >>> CAUTION: This email comes from a non Wind River email account!
> >>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
> >>>
> >>> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
> >>> lists.openembedded.org
> >>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> >>>
> >>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
> >>> <xiangyu.chen@eng.windriver.com> wrote:
> >>>
> >>> Hi Richard and Bruce,
> >>>
> >>>
> >>> Thanks for your suggestion,
> >>>
> >>>
> >>> On 5/11/23 00:25, Bruce Ashfield wrote:
> >>>
> >>> CAUTION: This email comes from a non Wind River email account!
> >>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
> >>>
> >>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> >>> <richard.purdie@linuxfoundation.org> wrote:
> >>>
> >>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> >>>
> >>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> >>>
> >>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
> >>> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
> >>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
> >>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
> >>> and elfutils dependency.
> >>>
> >>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
> >>> option documented somewhere?
> >>>
> >>> I also think the mention of devshell in the commit message is
> >>> misleading, this issue happens regardless of how you enable the option.
> >>> There are also other ways of enabling this than local.conf, you'd
> >>> likely not want people doing that at the end of development.
> >>>
> >>> I'm curious on Bruce's opinion but to me this at the very least needs a
> >>> commit message rewrite and I'd question whether the docs elsewhere
> >>> would allow someone to discover this workflow anyway.
> >>>
> >>> I missed this entirely, thanks for replying to it, or I never would
> >>> have noticed.
> >>>
> >>> This mechanism isn't appropriate for these dependencies. I only added
> >>> it to work around pkgconfig issues (which we can more cleanly solve in
> >>> newer kernels  (see what I've been doing with make-mod-scripts) .. so
> >>> it can eventually be dropped).
> >>>
> >>> We are already enabling elfutils-native conditionally on a
> >>> per-architecture basis (currently only x86-64).
> >>>
> >>> If we need it on more arches now, we should enable it in the version
> >>> specific recipes, or actually, we have moved far enough into newer
> >>> kernel's that it could be in the .inc now.
> >>>
> >>> This commit's background was some kernel debug options needs elfutils
> >>> and pahole native package, since the issue happens on enabling kernel
> >>> debug options and not all people needs it, so I conditionally add the
> >>> dependency in KERNEL_DEBUG_OPTION.
> >>>
> >>> If possible we can enable it in .inc because newer kernel tools like btf
> >>> are support using pkg-config to locate the libelf instead of finding it
> >>> from /usr/ folder, so we can use elfutils-natvie instead of installing
> >>> elfutils package on host PC.
> >>>
> >>> Similarly, we should enable the pahole-native dependency on a per-arch basis.
> >>>
> >>> As Richard mentioned, what's the reproducer to see the errors ? it
> >>> must be more than devshell.
> >>>
> >>> Yes, this happens on devshell and normal world if some kernel debug
> >>> options are enabled. We can reproduce this issue with following steps(I
> >>> have found the issue with kernel 5.15):
> >>>
> >>> 1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> >>> CONFIG_DEBUG_INFO_BTF
> >>>
> >>> 2. build the kernel image, the compiler would report missing libelf.h
> >>> and gelf.h which contains in elfutils-native(this step not happens on
> >>> x86-64 due to it has been enabled).
> >>>
> >>> 3. enable elfutils-native by manual, the kernel source code can be
> >>> compiled successfully but failed in final step due to missing pahole.
> >>>
> >>>
> >>> If you can follow up with the steps to reproduce, I can take on the
> >>> refactoring and broader dependency cleanup question, since I can test
> >>> the wider matrix at the same time.
> >>>
> >>> Thanks, my local setup might missing some corner case, this is another
> >>> reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).
> >>>
> >>> I've been thinking about this, and I've come to the following suggestion:
> >>>
> >>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
> >>> version specific
> >>> recipes.  I'll also drop the architecture specific nature of the
> >>> current DEPENDS.
> >>> The need for this is much more common now, and all of the reference kernels
> >>> in master are new enough. The elfutils-native build dependency is not
> >>> significant
> >>> enough to worry about adding it for all architectures. If it does
> >>> become a problem,
> >>> there are options to make it conditional again.
> >>>
> >>> I can drop the HOST_LIBELF_LIBS work around in the linux-yocto.inc, as
> >>> we can now properly detect libelf via pkg-config. I didn't need it in any of
> >>> my testing. Again, if this proves to be wrong, I'd enable it in a
> >>> different way now
> >>> (using what I've learned from fixing make-mod-scripts).
> >>>
> >>> As for the pahole-native dependency, there's been a "developer" kernel-type
> >>> for quite some time. The design intention behind it was to enable options like
> >>> this, and not make the "standard" or "production" kernel's too large by default.
> >>> So the dependency could be conditional on that kernel type ... but we don't
> >>> want to break other kernels just because they've enabled that option. We also
> >>> don't (and won't) get into the game of looking for individual options in the
> >>> .config to enable something, since a) it is too late b) it is a moving target.
> >>>
> >>> So that leaves the following options: a) enable pahole-native unconditionally
> >>> on the arches that support it (x86-64, aarch64) (and also move the pahole
> >>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
> >>> and simply call it KERNEL_DEBUG, when enabled, we could conditionally
> >>> add pahole-native (I'd also submit documentation for the functionality
> >>> c) something I haven't thought about ...
> >>>
> >>> I'm moving on the implementation now, but will adjust course if
> >>> there's something
> >>> I've missed.
> >>>
> >>> I have my implementation done, but I'm wondering what your configuration
> >>> was for testing pahole ?
> >>>
> >> My reply will be hard to read, as plain text reply to the html doesn't
> >> give us proper
> >> context indenting.
> >>
> >>> I have tested on a devshell, with oe-master branch, the kernel version using 5.15
> >>>
> >>> 1. enable pahole-native and elfutils-native in linux-yocto.inc as a dependency.
> >>>
> >>> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> >>> CONFIG_DEBUG_INFO_BTF under menuconfig
> >>>
> >>> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning PKG_CONFIG_SYSROOT_DIR
> >>>
> >>> 4, make
> >>>
> >>>
> >>> If the test environment using bitbake, then we need to remove PAHOLE=false flag in kernel EXTRA_OEMAKE in classes-recipe/kernel.bbclass, otherwise, bitbake would report missing pahole error.
> >>>
> >> That's the same as my patch series (I've also changed PAHOLE=false to
> >> a conditional in my series).
> >>
> >>> I'm seeing the following in qemux86-64 at the end of the build:
> >>>
> >>> | Unsupported DW_TAG_unspecified_type(0x3b)
> >>> | Encountered error while encoding BTF.
> >>> |   LD      .tmp_vmlinux.kallsyms1
> >>> |   NM      .tmp_vmlinux.kallsyms1.syms
> >>> |   KSYMS   .tmp_vmlinux.kallsyms1.S
> >>> |   AS      .tmp_vmlinux.kallsyms1.S
> >>> |   LD      .tmp_vmlinux.kallsyms2
> >>> |   NM      .tmp_vmlinux.kallsyms2.syms
> >>> |   KSYMS   .tmp_vmlinux.kallsyms2.S
> >>> |   AS      .tmp_vmlinux.kallsyms2.S
> >>> |   LD      vmlinux
> >>> |   BTFIDS  vmlinux
> >>> | FAILED: load BTF from vmlinux: No such file or directory
> >>> | make[1]: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
> >>> vmlinux] Error 255
> >>> | make[1]: *** Deleting file 'vmlinux'
> >>> | make: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
> >>> vmlinux] Error 2
> >>>
> >>> I haven't looked into it at all yet (but will do so over the weekend)
> >>> .. but I thought
> >>>
> >>> I haven't seen this problem yet(i'll pull the latest oe-core and meta-oe code and try again), if possible, could you share a patch with me so that we can test it together? thanks.
> >>>
> >> I'm on oe-core master, with qemux86-64.
> >>
> >> I'll do a bit more work on the patch today, and can share it if I
> >> can't figure out where that unsupported tag is coming from.
> > It seems like it is a known issue, I found both a lkml thread and
> > debian bug from October 2022.
> >
> > Your 5.15 kernel wouldn't show the issue.
>
> Yes, this should not happens on 5.15 kernel.
>
>
> Today I synced the oe-core/poky to latest master version, removed the
> build dir and run oe-init-build-env again and switched to use default
> linux 6.1.25 instead of 5.15.
>
> Some kernel config has been updated, there is no CONFIG_DEBUG_INFO, I
> used CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT.
>
> So, currently my local setup kernel config is enabled
> CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and
> CONFIG_DEBUG_INFO_BTF, in order to make a easy test, I enabled
> elfutils-native and pahole-native as DEPEND directly in linux-yocto.in,
> and remove the PAHOLE=false in EXTRA_OEMAKE.
>
> my oe-core rev: 35e5d29a7d654fc79bdb898d0f1fb277270dbfd5
>
> my meta-oe rev:b7aa66d734b911737b61610c1c47778e14b15c55
>
>
> When I ran bitbake linux-yocto -v -D, I have met the same issue,
>
> | Unsupported DW_TAG_unspecified_type(0x3b)
> | Encountered error while encoding BTF.
>
> It's bit strange that the I removed my local OS(ubuntu)'s pahole and the
> code can be compiled without error:
>
>
>    CC      init/version-timestamp.o
>    LD      .tmp_vmlinux.btf
>    BTF     .btf.vmlinux.bin.o
>    LD      .tmp_vmlinux.kallsyms1
>    NM      .tmp_vmlinux.kallsyms1.syms
>    KSYMS   .tmp_vmlinux.kallsyms1.S
>    AS      .tmp_vmlinux.kallsyms1.S
>    LD      .tmp_vmlinux.kallsyms2
>    NM      .tmp_vmlinux.kallsyms2.syms
>    KSYMS   .tmp_vmlinux.kallsyms2.S
>    AS      .tmp_vmlinux.kallsyms2.S
>    LD      vmlinux
>    BTFIDS  vmlinux
>    NM      System.map
>    SORTTAB vmlinux
>

Indeed!

What's the toolchain version on your ubuntu install ? It is likely
either our toolchain version or configuration in combination with the
kernel version that is adding the section that pahole can't
understand/decode.

If you want to work with my patches, you can find my branch here:

https://git.yoctoproject.org/poky-contrib/log/?h=zedd/kernel

(you also need the linux-yocto bumps on that branch as they'll contain
the kernel-cache SRCREV bumps to pick up the fragments for BTF, etc).

Bruce

>
>
> >
> > You can find a link to the lkml thread from the debian bug:
> > https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1873553.html
>
> >
> > I'll clean up my patch, since this isn't something I can fix immediately.
> >
> > If you do track down patches in the latest kernel that haven't been
> > sent to -stable, we can backport them to fix the linux-yocto builds
> > with pahole.
> >
> > Bruce
> >
>
> Br,
>
> Xiangyu
>
> >> Bruce
> >>
> >>> I should check with you first to get the details on how you were testing pahole
> >>> functionality.
> >>>
> >>> Bruce
> >>>
> >>>
> >>> Br,
> >>>
> >>> Xiangyu
> >>>
> >>> Bruce
> >>>
> >>>
> >>> Xiangyu
> >>>
> >>> Bruce
> >>>
> >>> Cheers,
> >>>
> >>> Richard
> >>>
> >>> --
> >>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> >>> thee at its end
> >>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>
> >>> --
> >>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> >>> thee at its end
> >>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>
> >>>
> >>>
> >>> --
> >>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> >>> thee at its end
> >>> - "Use the force Harry" - Gandalf, Star Trek II
> >>
> >>
> >> --
> >> - 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 (#181248): https://lists.openembedded.org/g/openembedded-core/message/181248
> >> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
> >> Group Owner: openembedded-core+owner@lists.openembedded.org
> >> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [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
Xiangyu Chen May 17, 2023, 1:35 a.m. UTC | #11
On 5/16/23 20:55, Bruce Ashfield wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Tue, May 16, 2023 at 4:56 AM Xiangyu Chen
> <xiangyu.chen@eng.windriver.com> wrote:
>> Hi Bruce,
>>
>>
>> On 5/15/23 21:11, Bruce Ashfield wrote:
>>> CAUTION: This email comes from a non Wind River email account!
>>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>>>
>>> On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
>>> lists.openembedded.org
>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>>>> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
>>>> <xiangyu.chen@eng.windriver.com> wrote:
>>>>> Hi Bruce,
>>>>>
>>>>>
>>>>> Sorry for being late..
>>>>>
>>>>>
>>>>> On 5/13/23 09:16, Bruce Ashfield wrote:
>>>>>
>>>>> CAUTION: This email comes from a non Wind River email account!
>>>>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>>>>>
>>>>> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
>>>>> lists.openembedded.org
>>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>>>>>
>>>>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
>>>>> <xiangyu.chen@eng.windriver.com> wrote:
>>>>>
>>>>> Hi Richard and Bruce,
>>>>>
>>>>>
>>>>> Thanks for your suggestion,
>>>>>
>>>>>
>>>>> On 5/11/23 00:25, Bruce Ashfield wrote:
>>>>>
>>>>> CAUTION: This email comes from a non Wind River email account!
>>>>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>>>>>
>>>>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
>>>>> <richard.purdie@linuxfoundation.org> wrote:
>>>>>
>>>>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
>>>>>
>>>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
>>>>>
>>>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the make would report some
>>>>> errors due to pahole and elfuitls is missing, since this is a debug option, so conditionally
>>>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone need enable CONFIG_DEBUG_INFO_BTF
>>>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in local.conf to solve the pahole
>>>>> and elfutils dependency.
>>>>>
>>>>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS with this
>>>>> option documented somewhere?
>>>>>
>>>>> I also think the mention of devshell in the commit message is
>>>>> misleading, this issue happens regardless of how you enable the option.
>>>>> There are also other ways of enabling this than local.conf, you'd
>>>>> likely not want people doing that at the end of development.
>>>>>
>>>>> I'm curious on Bruce's opinion but to me this at the very least needs a
>>>>> commit message rewrite and I'd question whether the docs elsewhere
>>>>> would allow someone to discover this workflow anyway.
>>>>>
>>>>> I missed this entirely, thanks for replying to it, or I never would
>>>>> have noticed.
>>>>>
>>>>> This mechanism isn't appropriate for these dependencies. I only added
>>>>> it to work around pkgconfig issues (which we can more cleanly solve in
>>>>> newer kernels  (see what I've been doing with make-mod-scripts) .. so
>>>>> it can eventually be dropped).
>>>>>
>>>>> We are already enabling elfutils-native conditionally on a
>>>>> per-architecture basis (currently only x86-64).
>>>>>
>>>>> If we need it on more arches now, we should enable it in the version
>>>>> specific recipes, or actually, we have moved far enough into newer
>>>>> kernel's that it could be in the .inc now.
>>>>>
>>>>> This commit's background was some kernel debug options needs elfutils
>>>>> and pahole native package, since the issue happens on enabling kernel
>>>>> debug options and not all people needs it, so I conditionally add the
>>>>> dependency in KERNEL_DEBUG_OPTION.
>>>>>
>>>>> If possible we can enable it in .inc because newer kernel tools like btf
>>>>> are support using pkg-config to locate the libelf instead of finding it
>>>>> from /usr/ folder, so we can use elfutils-natvie instead of installing
>>>>> elfutils package on host PC.
>>>>>
>>>>> Similarly, we should enable the pahole-native dependency on a per-arch basis.
>>>>>
>>>>> As Richard mentioned, what's the reproducer to see the errors ? it
>>>>> must be more than devshell.
>>>>>
>>>>> Yes, this happens on devshell and normal world if some kernel debug
>>>>> options are enabled. We can reproduce this issue with following steps(I
>>>>> have found the issue with kernel 5.15):
>>>>>
>>>>> 1. enable kernel option CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
>>>>> CONFIG_DEBUG_INFO_BTF
>>>>>
>>>>> 2. build the kernel image, the compiler would report missing libelf.h
>>>>> and gelf.h which contains in elfutils-native(this step not happens on
>>>>> x86-64 due to it has been enabled).
>>>>>
>>>>> 3. enable elfutils-native by manual, the kernel source code can be
>>>>> compiled successfully but failed in final step due to missing pahole.
>>>>>
>>>>>
>>>>> If you can follow up with the steps to reproduce, I can take on the
>>>>> refactoring and broader dependency cleanup question, since I can test
>>>>> the wider matrix at the same time.
>>>>>
>>>>> Thanks, my local setup might missing some corner case, this is another
>>>>> reason I enable those native packages limit in KERNEL_DEBUG_OPTION :).
>>>>>
>>>>> I've been thinking about this, and I've come to the following suggestion:
>>>>>
>>>>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
>>>>> version specific
>>>>> recipes.  I'll also drop the architecture specific nature of the
>>>>> current DEPENDS.
>>>>> The need for this is much more common now, and all of the reference kernels
>>>>> in master are new enough. The elfutils-native build dependency is not
>>>>> significant
>>>>> enough to worry about adding it for all architectures. If it does
>>>>> become a problem,
>>>>> there are options to make it conditional again.
>>>>>
>>>>> I can drop the HOST_LIBELF_LIBS work around in the linux-yocto.inc, as
>>>>> we can now properly detect libelf via pkg-config. I didn't need it in any of
>>>>> my testing. Again, if this proves to be wrong, I'd enable it in a
>>>>> different way now
>>>>> (using what I've learned from fixing make-mod-scripts).
>>>>>
>>>>> As for the pahole-native dependency, there's been a "developer" kernel-type
>>>>> for quite some time. The design intention behind it was to enable options like
>>>>> this, and not make the "standard" or "production" kernel's too large by default.
>>>>> So the dependency could be conditional on that kernel type ... but we don't
>>>>> want to break other kernels just because they've enabled that option. We also
>>>>> don't (and won't) get into the game of looking for individual options in the
>>>>> .config to enable something, since a) it is too late b) it is a moving target.
>>>>>
>>>>> So that leaves the following options: a) enable pahole-native unconditionally
>>>>> on the arches that support it (x86-64, aarch64) (and also move the pahole
>>>>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
>>>>> and simply call it KERNEL_DEBUG, when enabled, we could conditionally
>>>>> add pahole-native (I'd also submit documentation for the functionality
>>>>> c) something I haven't thought about ...
>>>>>
>>>>> I'm moving on the implementation now, but will adjust course if
>>>>> there's something
>>>>> I've missed.
>>>>>
>>>>> I have my implementation done, but I'm wondering what your configuration
>>>>> was for testing pahole ?
>>>>>
>>>> My reply will be hard to read, as plain text reply to the html doesn't
>>>> give us proper
>>>> context indenting.
>>>>
>>>>> I have tested on a devshell, with oe-master branch, the kernel version using 5.15
>>>>>
>>>>> 1. enable pahole-native and elfutils-native in linux-yocto.inc as a dependency.
>>>>>
>>>>> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
>>>>> CONFIG_DEBUG_INFO_BTF under menuconfig
>>>>>
>>>>> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning PKG_CONFIG_SYSROOT_DIR
>>>>>
>>>>> 4, make
>>>>>
>>>>>
>>>>> If the test environment using bitbake, then we need to remove PAHOLE=false flag in kernel EXTRA_OEMAKE in classes-recipe/kernel.bbclass, otherwise, bitbake would report missing pahole error.
>>>>>
>>>> That's the same as my patch series (I've also changed PAHOLE=false to
>>>> a conditional in my series).
>>>>
>>>>> I'm seeing the following in qemux86-64 at the end of the build:
>>>>>
>>>>> | Unsupported DW_TAG_unspecified_type(0x3b)
>>>>> | Encountered error while encoding BTF.
>>>>> |   LD      .tmp_vmlinux.kallsyms1
>>>>> |   NM      .tmp_vmlinux.kallsyms1.syms
>>>>> |   KSYMS   .tmp_vmlinux.kallsyms1.S
>>>>> |   AS      .tmp_vmlinux.kallsyms1.S
>>>>> |   LD      .tmp_vmlinux.kallsyms2
>>>>> |   NM      .tmp_vmlinux.kallsyms2.syms
>>>>> |   KSYMS   .tmp_vmlinux.kallsyms2.S
>>>>> |   AS      .tmp_vmlinux.kallsyms2.S
>>>>> |   LD      vmlinux
>>>>> |   BTFIDS  vmlinux
>>>>> | FAILED: load BTF from vmlinux: No such file or directory
>>>>> | make[1]: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
>>>>> vmlinux] Error 255
>>>>> | make[1]: *** Deleting file 'vmlinux'
>>>>> | make: *** [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
>>>>> vmlinux] Error 2
>>>>>
>>>>> I haven't looked into it at all yet (but will do so over the weekend)
>>>>> .. but I thought
>>>>>
>>>>> I haven't seen this problem yet(i'll pull the latest oe-core and meta-oe code and try again), if possible, could you share a patch with me so that we can test it together? thanks.
>>>>>
>>>> I'm on oe-core master, with qemux86-64.
>>>>
>>>> I'll do a bit more work on the patch today, and can share it if I
>>>> can't figure out where that unsupported tag is coming from.
>>> It seems like it is a known issue, I found both a lkml thread and
>>> debian bug from October 2022.
>>>
>>> Your 5.15 kernel wouldn't show the issue.
>> Yes, this should not happens on 5.15 kernel.
>>
>>
>> Today I synced the oe-core/poky to latest master version, removed the
>> build dir and run oe-init-build-env again and switched to use default
>> linux 6.1.25 instead of 5.15.
>>
>> Some kernel config has been updated, there is no CONFIG_DEBUG_INFO, I
>> used CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT.
>>
>> So, currently my local setup kernel config is enabled
>> CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and
>> CONFIG_DEBUG_INFO_BTF, in order to make a easy test, I enabled
>> elfutils-native and pahole-native as DEPEND directly in linux-yocto.in,
>> and remove the PAHOLE=false in EXTRA_OEMAKE.
>>
>> my oe-core rev: 35e5d29a7d654fc79bdb898d0f1fb277270dbfd5
>>
>> my meta-oe rev:b7aa66d734b911737b61610c1c47778e14b15c55
>>
>>
>> When I ran bitbake linux-yocto -v -D, I have met the same issue,
>>
>> | Unsupported DW_TAG_unspecified_type(0x3b)
>> | Encountered error while encoding BTF.
>>
>> It's bit strange that the I removed my local OS(ubuntu)'s pahole and the
>> code can be compiled without error:
>>
>>
>>     CC      init/version-timestamp.o
>>     LD      .tmp_vmlinux.btf
>>     BTF     .btf.vmlinux.bin.o
>>     LD      .tmp_vmlinux.kallsyms1
>>     NM      .tmp_vmlinux.kallsyms1.syms
>>     KSYMS   .tmp_vmlinux.kallsyms1.S
>>     AS      .tmp_vmlinux.kallsyms1.S
>>     LD      .tmp_vmlinux.kallsyms2
>>     NM      .tmp_vmlinux.kallsyms2.syms
>>     KSYMS   .tmp_vmlinux.kallsyms2.S
>>     AS      .tmp_vmlinux.kallsyms2.S
>>     LD      vmlinux
>>     BTFIDS  vmlinux
>>     NM      System.map
>>     SORTTAB vmlinux
>>
> Indeed!
>
> What's the toolchain version on your ubuntu install ?

My local ubuntu's default pahole version is 1.22,seems some data 
structure not line up with new kernel, the yocto pahole package is 1.24 
is working well.

$ pahole --version
v1.22


> It is likely
> either our toolchain version or configuration in combination with the
> kernel version that is adding the section that pahole can't
> understand/decode.
Yes, perhaps this is a limitation, we have to use PAHOLE in EXTRA_OEMAKE 
to tell the make using pahole from the yocto native-sdk instead of local 
host OS's /usr/bin/pahole when building the kernel.
> If you want to work with my patches, you can find my branch here:
>
> https://git.yoctoproject.org/poky-contrib/log/?h=zedd/kernel
>
> (you also need the linux-yocto bumps on that branch as they'll contain
> the kernel-cache SRCREV bumps to pick up the fragments for BTF, etc).

Thanks, I will sync the branch today and feedback later :)


Br,

Xiangyu

> Bruce
>
>>
>>> You can find a link to the lkml thread from the debian bug:
>>> https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1873553.html
>>> I'll clean up my patch, since this isn't something I can fix immediately.
>>>
>>> If you do track down patches in the latest kernel that haven't been
>>> sent to -stable, we can backport them to fix the linux-yocto builds
>>> with pahole.
>>>
>>> Bruce
>>>
>> Br,
>>
>> Xiangyu
>>
>>>> Bruce
>>>>
>>>>> I should check with you first to get the details on how you were testing pahole
>>>>> functionality.
>>>>>
>>>>> Bruce
>>>>>
>>>>>
>>>>> Br,
>>>>>
>>>>> Xiangyu
>>>>>
>>>>> Bruce
>>>>>
>>>>>
>>>>> Xiangyu
>>>>>
>>>>> Bruce
>>>>>
>>>>> Cheers,
>>>>>
>>>>> Richard
>>>>>
>>>>> --
>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>>>> thee at its end
>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>>
>>>>> --
>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>>>> thee at its end
>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>>>> thee at its end
>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>
>>>> --
>>>> - 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 (#181248): https://lists.openembedded.org/g/openembedded-core/message/181248
>>>> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
>>>> Group Owner: openembedded-core+owner@lists.openembedded.org
>>>> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [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
>
>
> --
> - Thou shalt not follow the NULL pointer, for chaos and madness await
> thee at its end
> - "Use the force Harry" - Gandalf, Star Trek II
Xiangyu Chen May 17, 2023, 5:24 a.m. UTC | #12
On 5/17/23 09:35, Xiangyu Chen wrote:
>
> On 5/16/23 20:55, Bruce Ashfield wrote:
>> CAUTION: This email comes from a non Wind River email account!
>> Do not click links or open attachments unless you recognize the 
>> sender and know the content is safe.
>>
>> On Tue, May 16, 2023 at 4:56 AM Xiangyu Chen
>> <xiangyu.chen@eng.windriver.com> wrote:
>>> Hi Bruce,
>>>
>>>
>>> On 5/15/23 21:11, Bruce Ashfield wrote:
>>>> CAUTION: This email comes from a non Wind River email account!
>>>> Do not click links or open attachments unless you recognize the 
>>>> sender and know the content is safe.
>>>>
>>>> On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
>>>> lists.openembedded.org
>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>>>>> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
>>>>> <xiangyu.chen@eng.windriver.com> wrote:
>>>>>> Hi Bruce,
>>>>>>
>>>>>>
>>>>>> Sorry for being late..
>>>>>>
>>>>>>
>>>>>> On 5/13/23 09:16, Bruce Ashfield wrote:
>>>>>>
>>>>>> CAUTION: This email comes from a non Wind River email account!
>>>>>> Do not click links or open attachments unless you recognize the 
>>>>>> sender and know the content is safe.
>>>>>>
>>>>>> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
>>>>>> lists.openembedded.org
>>>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>>>>>>
>>>>>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
>>>>>> <xiangyu.chen@eng.windriver.com> wrote:
>>>>>>
>>>>>> Hi Richard and Bruce,
>>>>>>
>>>>>>
>>>>>> Thanks for your suggestion,
>>>>>>
>>>>>>
>>>>>> On 5/11/23 00:25, Bruce Ashfield wrote:
>>>>>>
>>>>>> CAUTION: This email comes from a non Wind River email account!
>>>>>> Do not click links or open attachments unless you recognize the 
>>>>>> sender and know the content is safe.
>>>>>>
>>>>>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
>>>>>> <richard.purdie@linuxfoundation.org> wrote:
>>>>>>
>>>>>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
>>>>>>
>>>>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
>>>>>>
>>>>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the 
>>>>>> make would report some
>>>>>> errors due to pahole and elfuitls is missing, since this is a 
>>>>>> debug option, so conditionally
>>>>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone 
>>>>>> need enable CONFIG_DEBUG_INFO_BTF
>>>>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in 
>>>>>> local.conf to solve the pahole
>>>>>> and elfutils dependency.
>>>>>>
>>>>>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS 
>>>>>> with this
>>>>>> option documented somewhere?
>>>>>>
>>>>>> I also think the mention of devshell in the commit message is
>>>>>> misleading, this issue happens regardless of how you enable the 
>>>>>> option.
>>>>>> There are also other ways of enabling this than local.conf, you'd
>>>>>> likely not want people doing that at the end of development.
>>>>>>
>>>>>> I'm curious on Bruce's opinion but to me this at the very least 
>>>>>> needs a
>>>>>> commit message rewrite and I'd question whether the docs elsewhere
>>>>>> would allow someone to discover this workflow anyway.
>>>>>>
>>>>>> I missed this entirely, thanks for replying to it, or I never would
>>>>>> have noticed.
>>>>>>
>>>>>> This mechanism isn't appropriate for these dependencies. I only 
>>>>>> added
>>>>>> it to work around pkgconfig issues (which we can more cleanly 
>>>>>> solve in
>>>>>> newer kernels  (see what I've been doing with make-mod-scripts) 
>>>>>> .. so
>>>>>> it can eventually be dropped).
>>>>>>
>>>>>> We are already enabling elfutils-native conditionally on a
>>>>>> per-architecture basis (currently only x86-64).
>>>>>>
>>>>>> If we need it on more arches now, we should enable it in the version
>>>>>> specific recipes, or actually, we have moved far enough into newer
>>>>>> kernel's that it could be in the .inc now.
>>>>>>
>>>>>> This commit's background was some kernel debug options needs 
>>>>>> elfutils
>>>>>> and pahole native package, since the issue happens on enabling 
>>>>>> kernel
>>>>>> debug options and not all people needs it, so I conditionally add 
>>>>>> the
>>>>>> dependency in KERNEL_DEBUG_OPTION.
>>>>>>
>>>>>> If possible we can enable it in .inc because newer kernel tools 
>>>>>> like btf
>>>>>> are support using pkg-config to locate the libelf instead of 
>>>>>> finding it
>>>>>> from /usr/ folder, so we can use elfutils-natvie instead of 
>>>>>> installing
>>>>>> elfutils package on host PC.
>>>>>>
>>>>>> Similarly, we should enable the pahole-native dependency on a 
>>>>>> per-arch basis.
>>>>>>
>>>>>> As Richard mentioned, what's the reproducer to see the errors ? it
>>>>>> must be more than devshell.
>>>>>>
>>>>>> Yes, this happens on devshell and normal world if some kernel debug
>>>>>> options are enabled. We can reproduce this issue with following 
>>>>>> steps(I
>>>>>> have found the issue with kernel 5.15):
>>>>>>
>>>>>> 1. enable kernel option CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO and
>>>>>> CONFIG_DEBUG_INFO_BTF
>>>>>>
>>>>>> 2. build the kernel image, the compiler would report missing 
>>>>>> libelf.h
>>>>>> and gelf.h which contains in elfutils-native(this step not 
>>>>>> happens on
>>>>>> x86-64 due to it has been enabled).
>>>>>>
>>>>>> 3. enable elfutils-native by manual, the kernel source code can be
>>>>>> compiled successfully but failed in final step due to missing 
>>>>>> pahole.
>>>>>>
>>>>>>
>>>>>> If you can follow up with the steps to reproduce, I can take on the
>>>>>> refactoring and broader dependency cleanup question, since I can 
>>>>>> test
>>>>>> the wider matrix at the same time.
>>>>>>
>>>>>> Thanks, my local setup might missing some corner case, this is 
>>>>>> another
>>>>>> reason I enable those native packages limit in 
>>>>>> KERNEL_DEBUG_OPTION :).
>>>>>>
>>>>>> I've been thinking about this, and I've come to the following 
>>>>>> suggestion:
>>>>>>
>>>>>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
>>>>>> version specific
>>>>>> recipes.  I'll also drop the architecture specific nature of the
>>>>>> current DEPENDS.
>>>>>> The need for this is much more common now, and all of the 
>>>>>> reference kernels
>>>>>> in master are new enough. The elfutils-native build dependency is 
>>>>>> not
>>>>>> significant
>>>>>> enough to worry about adding it for all architectures. If it does
>>>>>> become a problem,
>>>>>> there are options to make it conditional again.
>>>>>>
>>>>>> I can drop the HOST_LIBELF_LIBS work around in the 
>>>>>> linux-yocto.inc, as
>>>>>> we can now properly detect libelf via pkg-config. I didn't need 
>>>>>> it in any of
>>>>>> my testing. Again, if this proves to be wrong, I'd enable it in a
>>>>>> different way now
>>>>>> (using what I've learned from fixing make-mod-scripts).
>>>>>>
>>>>>> As for the pahole-native dependency, there's been a "developer" 
>>>>>> kernel-type
>>>>>> for quite some time. The design intention behind it was to enable 
>>>>>> options like
>>>>>> this, and not make the "standard" or "production" kernel's too 
>>>>>> large by default.
>>>>>> So the dependency could be conditional on that kernel type ... 
>>>>>> but we don't
>>>>>> want to break other kernels just because they've enabled that 
>>>>>> option. We also
>>>>>> don't (and won't) get into the game of looking for individual 
>>>>>> options in the
>>>>>> .config to enable something, since a) it is too late b) it is a 
>>>>>> moving target.
>>>>>>
>>>>>> So that leaves the following options: a) enable pahole-native 
>>>>>> unconditionally
>>>>>> on the arches that support it (x86-64, aarch64) (and also move 
>>>>>> the pahole
>>>>>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
>>>>>> and simply call it KERNEL_DEBUG, when enabled, we could 
>>>>>> conditionally
>>>>>> add pahole-native (I'd also submit documentation for the 
>>>>>> functionality
>>>>>> c) something I haven't thought about ...
>>>>>>
>>>>>> I'm moving on the implementation now, but will adjust course if
>>>>>> there's something
>>>>>> I've missed.
>>>>>>
>>>>>> I have my implementation done, but I'm wondering what your 
>>>>>> configuration
>>>>>> was for testing pahole ?
>>>>>>
>>>>> My reply will be hard to read, as plain text reply to the html 
>>>>> doesn't
>>>>> give us proper
>>>>> context indenting.
>>>>>
>>>>>> I have tested on a devshell, with oe-master branch, the kernel 
>>>>>> version using 5.15
>>>>>>
>>>>>> 1. enable pahole-native and elfutils-native in linux-yocto.inc as 
>>>>>> a dependency.
>>>>>>
>>>>>> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
>>>>>> CONFIG_DEBUG_INFO_BTF under menuconfig
>>>>>>
>>>>>> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning 
>>>>>> PKG_CONFIG_SYSROOT_DIR
>>>>>>
>>>>>> 4, make
>>>>>>
>>>>>>
>>>>>> If the test environment using bitbake, then we need to remove 
>>>>>> PAHOLE=false flag in kernel EXTRA_OEMAKE in 
>>>>>> classes-recipe/kernel.bbclass, otherwise, bitbake would report 
>>>>>> missing pahole error.
>>>>>>
>>>>> That's the same as my patch series (I've also changed PAHOLE=false to
>>>>> a conditional in my series).
>>>>>
>>>>>> I'm seeing the following in qemux86-64 at the end of the build:
>>>>>>
>>>>>> | Unsupported DW_TAG_unspecified_type(0x3b)
>>>>>> | Encountered error while encoding BTF.
>>>>>> |   LD      .tmp_vmlinux.kallsyms1
>>>>>> |   NM      .tmp_vmlinux.kallsyms1.syms
>>>>>> |   KSYMS   .tmp_vmlinux.kallsyms1.S
>>>>>> |   AS      .tmp_vmlinux.kallsyms1.S
>>>>>> |   LD      .tmp_vmlinux.kallsyms2
>>>>>> |   NM      .tmp_vmlinux.kallsyms2.syms
>>>>>> |   KSYMS   .tmp_vmlinux.kallsyms2.S
>>>>>> |   AS      .tmp_vmlinux.kallsyms2.S
>>>>>> |   LD      vmlinux
>>>>>> |   BTFIDS  vmlinux
>>>>>> | FAILED: load BTF from vmlinux: No such file or directory
>>>>>> | make[1]: *** 
>>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
>>>>>> vmlinux] Error 255
>>>>>> | make[1]: *** Deleting file 'vmlinux'
>>>>>> | make: *** 
>>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255: 
>>>>>>
>>>>>> vmlinux] Error 2
>>>>>>
>>>>>> I haven't looked into it at all yet (but will do so over the 
>>>>>> weekend)
>>>>>> .. but I thought
>>>>>>
>>>>>> I haven't seen this problem yet(i'll pull the latest oe-core and 
>>>>>> meta-oe code and try again), if possible, could you share a patch 
>>>>>> with me so that we can test it together? thanks.
>>>>>>
>>>>> I'm on oe-core master, with qemux86-64.
>>>>>
>>>>> I'll do a bit more work on the patch today, and can share it if I
>>>>> can't figure out where that unsupported tag is coming from.
>>>> It seems like it is a known issue, I found both a lkml thread and
>>>> debian bug from October 2022.
>>>>
>>>> Your 5.15 kernel wouldn't show the issue.
>>> Yes, this should not happens on 5.15 kernel.
>>>
>>>
>>> Today I synced the oe-core/poky to latest master version, removed the
>>> build dir and run oe-init-build-env again and switched to use default
>>> linux 6.1.25 instead of 5.15.
>>>
>>> Some kernel config has been updated, there is no CONFIG_DEBUG_INFO, I
>>> used CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT.
>>>
>>> So, currently my local setup kernel config is enabled
>>> CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and
>>> CONFIG_DEBUG_INFO_BTF, in order to make a easy test, I enabled
>>> elfutils-native and pahole-native as DEPEND directly in linux-yocto.in,
>>> and remove the PAHOLE=false in EXTRA_OEMAKE.
>>>
>>> my oe-core rev: 35e5d29a7d654fc79bdb898d0f1fb277270dbfd5
>>>
>>> my meta-oe rev:b7aa66d734b911737b61610c1c47778e14b15c55
>>>
>>>
>>> When I ran bitbake linux-yocto -v -D, I have met the same issue,
>>>
>>> | Unsupported DW_TAG_unspecified_type(0x3b)
>>> | Encountered error while encoding BTF.
>>>
>>> It's bit strange that the I removed my local OS(ubuntu)'s pahole and 
>>> the
>>> code can be compiled without error:
>>>
>>>
>>>     CC      init/version-timestamp.o
>>>     LD      .tmp_vmlinux.btf
>>>     BTF     .btf.vmlinux.bin.o
>>>     LD      .tmp_vmlinux.kallsyms1
>>>     NM      .tmp_vmlinux.kallsyms1.syms
>>>     KSYMS   .tmp_vmlinux.kallsyms1.S
>>>     AS      .tmp_vmlinux.kallsyms1.S
>>>     LD      .tmp_vmlinux.kallsyms2
>>>     NM      .tmp_vmlinux.kallsyms2.syms
>>>     KSYMS   .tmp_vmlinux.kallsyms2.S
>>>     AS      .tmp_vmlinux.kallsyms2.S
>>>     LD      vmlinux
>>>     BTFIDS  vmlinux
>>>     NM      System.map
>>>     SORTTAB vmlinux
>>>
>> Indeed!
>>
>> What's the toolchain version on your ubuntu install ?
>
> My local ubuntu's default pahole version is 1.22,seems some data 
> structure not line up with new kernel, the yocto pahole package is 
> 1.24 is working well.
>
> $ pahole --version
> v1.22
>
>
>> It is likely
>> either our toolchain version or configuration in combination with the
>> kernel version that is adding the section that pahole can't
>> understand/decode.
> Yes, perhaps this is a limitation, we have to use PAHOLE in 
> EXTRA_OEMAKE to tell the make using pahole from the yocto native-sdk 
> instead of local host OS's /usr/bin/pahole when building the kernel.
>> If you want to work with my patches, you can find my branch here:
>>
>> https://git.yoctoproject.org/poky-contrib/log/?h=zedd/kernel
>>
>> (you also need the linux-yocto bumps on that branch as they'll contain
>> the kernel-cache SRCREV bumps to pick up the fragments for BTF, etc).
>
> Thanks, I will sync the branch today and feedback later :)
>
Hi Bruce,


I used the zedd/kernel branch build a qmemux86-64 kernel image, 
everything goes well.

Shall we set the PAHOLE to native-sdk in EXTRA_OEMAKE to make sure 
kernel make use pahole from yocto not from host pc?

I tried to attached a patch as below, it has been tested on my local 
setup, from log we can see the PAHOLE point to native-sdk:

-O2 -pipe 
PAHOLE=/local/upstream/poky-contrib/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+76f7fbdf33_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole 
-j 20 bzImage

and the image build without error:

   LD      .tmp_vmlinux.btf
   BTF     .btf.vmlinux.bin.o
   LD      .tmp_vmlinux.kallsyms1
   NM      .tmp_vmlinux.kallsyms1.syms
   KSYMS   .tmp_vmlinux.kallsyms1.S
   AS      .tmp_vmlinux.kallsyms1.S
   LD      .tmp_vmlinux.kallsyms2
   NM      .tmp_vmlinux.kallsyms2.syms
   KSYMS   .tmp_vmlinux.kallsyms2.S
   AS      .tmp_vmlinux.kallsyms2.S
   LD      vmlinux
   BTFIDS  vmlinux
   NM      System.map


 From da4cbdb517f28f1b4254376c4f1d091a5ebca76c Mon Sep 17 00:00:00 2001
From: Xiangyu Chen <xiangyu.chen@windriver.com>
Date: Wed, 17 May 2023 13:15:17 +0800
Subject: [PATCH] set the PAHOLE to native-sdk when KERNEL_DEBUG = True

Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
---
  meta/recipes-kernel/linux/linux-yocto.inc | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meta/recipes-kernel/linux/linux-yocto.inc 
b/meta/recipes-kernel/linux/linux-yocto.inc
index 04a8105e17..90be616363 100644
--- a/meta/recipes-kernel/linux/linux-yocto.inc
+++ b/meta/recipes-kernel/linux/linux-yocto.inc
@@ -66,7 +66,7 @@ DEPENDS += '${@bb.utils.contains_any("ARCH", [ "x86", 
"arm64" ], "elfutils-nativ
  DEPENDS += "openssl-native util-linux-native"
  DEPENDS += "gmp-native libmpc-native"
  DEPENDS += '${@bb.utils.contains("KERNEL_DEBUG", "True", 
"pahole-native", "", d)}'
-EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True", "", 
"PAHOLE=false", d)}'
+EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True", 
"PAHOLE=${STAGING_DIR_NATIVE}/usr/bin/pahole", "PAHOLE=false", d)}'

  do_devshell:prepend() {
      # setup native pkg-config variables (kconfig scripts call 
pkg-config directly, cannot generically be overriden to pkg-config-native)
Bruce Ashfield May 17, 2023, 12:32 p.m. UTC | #13
On Wed, May 17, 2023 at 1:24 AM Xiangyu Chen
<xiangyu.chen@eng.windriver.com> wrote:
>
>
> On 5/17/23 09:35, Xiangyu Chen wrote:
> >
> > On 5/16/23 20:55, Bruce Ashfield wrote:
> >> CAUTION: This email comes from a non Wind River email account!
> >> Do not click links or open attachments unless you recognize the
> >> sender and know the content is safe.
> >>
> >> On Tue, May 16, 2023 at 4:56 AM Xiangyu Chen
> >> <xiangyu.chen@eng.windriver.com> wrote:
> >>> Hi Bruce,
> >>>
> >>>
> >>> On 5/15/23 21:11, Bruce Ashfield wrote:
> >>>> CAUTION: This email comes from a non Wind River email account!
> >>>> Do not click links or open attachments unless you recognize the
> >>>> sender and know the content is safe.
> >>>>
> >>>> On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
> >>>> lists.openembedded.org
> >>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> >>>>> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
> >>>>> <xiangyu.chen@eng.windriver.com> wrote:
> >>>>>> Hi Bruce,
> >>>>>>
> >>>>>>
> >>>>>> Sorry for being late..
> >>>>>>
> >>>>>>
> >>>>>> On 5/13/23 09:16, Bruce Ashfield wrote:
> >>>>>>
> >>>>>> CAUTION: This email comes from a non Wind River email account!
> >>>>>> Do not click links or open attachments unless you recognize the
> >>>>>> sender and know the content is safe.
> >>>>>>
> >>>>>> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
> >>>>>> lists.openembedded.org
> >>>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> >>>>>>
> >>>>>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
> >>>>>> <xiangyu.chen@eng.windriver.com> wrote:
> >>>>>>
> >>>>>> Hi Richard and Bruce,
> >>>>>>
> >>>>>>
> >>>>>> Thanks for your suggestion,
> >>>>>>
> >>>>>>
> >>>>>> On 5/11/23 00:25, Bruce Ashfield wrote:
> >>>>>>
> >>>>>> CAUTION: This email comes from a non Wind River email account!
> >>>>>> Do not click links or open attachments unless you recognize the
> >>>>>> sender and know the content is safe.
> >>>>>>
> >>>>>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> >>>>>> <richard.purdie@linuxfoundation.org> wrote:
> >>>>>>
> >>>>>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> >>>>>>
> >>>>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> >>>>>>
> >>>>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the
> >>>>>> make would report some
> >>>>>> errors due to pahole and elfuitls is missing, since this is a
> >>>>>> debug option, so conditionally
> >>>>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone
> >>>>>> need enable CONFIG_DEBUG_INFO_BTF
> >>>>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in
> >>>>>> local.conf to solve the pahole
> >>>>>> and elfutils dependency.
> >>>>>>
> >>>>>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS
> >>>>>> with this
> >>>>>> option documented somewhere?
> >>>>>>
> >>>>>> I also think the mention of devshell in the commit message is
> >>>>>> misleading, this issue happens regardless of how you enable the
> >>>>>> option.
> >>>>>> There are also other ways of enabling this than local.conf, you'd
> >>>>>> likely not want people doing that at the end of development.
> >>>>>>
> >>>>>> I'm curious on Bruce's opinion but to me this at the very least
> >>>>>> needs a
> >>>>>> commit message rewrite and I'd question whether the docs elsewhere
> >>>>>> would allow someone to discover this workflow anyway.
> >>>>>>
> >>>>>> I missed this entirely, thanks for replying to it, or I never would
> >>>>>> have noticed.
> >>>>>>
> >>>>>> This mechanism isn't appropriate for these dependencies. I only
> >>>>>> added
> >>>>>> it to work around pkgconfig issues (which we can more cleanly
> >>>>>> solve in
> >>>>>> newer kernels  (see what I've been doing with make-mod-scripts)
> >>>>>> .. so
> >>>>>> it can eventually be dropped).
> >>>>>>
> >>>>>> We are already enabling elfutils-native conditionally on a
> >>>>>> per-architecture basis (currently only x86-64).
> >>>>>>
> >>>>>> If we need it on more arches now, we should enable it in the version
> >>>>>> specific recipes, or actually, we have moved far enough into newer
> >>>>>> kernel's that it could be in the .inc now.
> >>>>>>
> >>>>>> This commit's background was some kernel debug options needs
> >>>>>> elfutils
> >>>>>> and pahole native package, since the issue happens on enabling
> >>>>>> kernel
> >>>>>> debug options and not all people needs it, so I conditionally add
> >>>>>> the
> >>>>>> dependency in KERNEL_DEBUG_OPTION.
> >>>>>>
> >>>>>> If possible we can enable it in .inc because newer kernel tools
> >>>>>> like btf
> >>>>>> are support using pkg-config to locate the libelf instead of
> >>>>>> finding it
> >>>>>> from /usr/ folder, so we can use elfutils-natvie instead of
> >>>>>> installing
> >>>>>> elfutils package on host PC.
> >>>>>>
> >>>>>> Similarly, we should enable the pahole-native dependency on a
> >>>>>> per-arch basis.
> >>>>>>
> >>>>>> As Richard mentioned, what's the reproducer to see the errors ? it
> >>>>>> must be more than devshell.
> >>>>>>
> >>>>>> Yes, this happens on devshell and normal world if some kernel debug
> >>>>>> options are enabled. We can reproduce this issue with following
> >>>>>> steps(I
> >>>>>> have found the issue with kernel 5.15):
> >>>>>>
> >>>>>> 1. enable kernel option CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO and
> >>>>>> CONFIG_DEBUG_INFO_BTF
> >>>>>>
> >>>>>> 2. build the kernel image, the compiler would report missing
> >>>>>> libelf.h
> >>>>>> and gelf.h which contains in elfutils-native(this step not
> >>>>>> happens on
> >>>>>> x86-64 due to it has been enabled).
> >>>>>>
> >>>>>> 3. enable elfutils-native by manual, the kernel source code can be
> >>>>>> compiled successfully but failed in final step due to missing
> >>>>>> pahole.
> >>>>>>
> >>>>>>
> >>>>>> If you can follow up with the steps to reproduce, I can take on the
> >>>>>> refactoring and broader dependency cleanup question, since I can
> >>>>>> test
> >>>>>> the wider matrix at the same time.
> >>>>>>
> >>>>>> Thanks, my local setup might missing some corner case, this is
> >>>>>> another
> >>>>>> reason I enable those native packages limit in
> >>>>>> KERNEL_DEBUG_OPTION :).
> >>>>>>
> >>>>>> I've been thinking about this, and I've come to the following
> >>>>>> suggestion:
> >>>>>>
> >>>>>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
> >>>>>> version specific
> >>>>>> recipes.  I'll also drop the architecture specific nature of the
> >>>>>> current DEPENDS.
> >>>>>> The need for this is much more common now, and all of the
> >>>>>> reference kernels
> >>>>>> in master are new enough. The elfutils-native build dependency is
> >>>>>> not
> >>>>>> significant
> >>>>>> enough to worry about adding it for all architectures. If it does
> >>>>>> become a problem,
> >>>>>> there are options to make it conditional again.
> >>>>>>
> >>>>>> I can drop the HOST_LIBELF_LIBS work around in the
> >>>>>> linux-yocto.inc, as
> >>>>>> we can now properly detect libelf via pkg-config. I didn't need
> >>>>>> it in any of
> >>>>>> my testing. Again, if this proves to be wrong, I'd enable it in a
> >>>>>> different way now
> >>>>>> (using what I've learned from fixing make-mod-scripts).
> >>>>>>
> >>>>>> As for the pahole-native dependency, there's been a "developer"
> >>>>>> kernel-type
> >>>>>> for quite some time. The design intention behind it was to enable
> >>>>>> options like
> >>>>>> this, and not make the "standard" or "production" kernel's too
> >>>>>> large by default.
> >>>>>> So the dependency could be conditional on that kernel type ...
> >>>>>> but we don't
> >>>>>> want to break other kernels just because they've enabled that
> >>>>>> option. We also
> >>>>>> don't (and won't) get into the game of looking for individual
> >>>>>> options in the
> >>>>>> .config to enable something, since a) it is too late b) it is a
> >>>>>> moving target.
> >>>>>>
> >>>>>> So that leaves the following options: a) enable pahole-native
> >>>>>> unconditionally
> >>>>>> on the arches that support it (x86-64, aarch64) (and also move
> >>>>>> the pahole
> >>>>>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
> >>>>>> and simply call it KERNEL_DEBUG, when enabled, we could
> >>>>>> conditionally
> >>>>>> add pahole-native (I'd also submit documentation for the
> >>>>>> functionality
> >>>>>> c) something I haven't thought about ...
> >>>>>>
> >>>>>> I'm moving on the implementation now, but will adjust course if
> >>>>>> there's something
> >>>>>> I've missed.
> >>>>>>
> >>>>>> I have my implementation done, but I'm wondering what your
> >>>>>> configuration
> >>>>>> was for testing pahole ?
> >>>>>>
> >>>>> My reply will be hard to read, as plain text reply to the html
> >>>>> doesn't
> >>>>> give us proper
> >>>>> context indenting.
> >>>>>
> >>>>>> I have tested on a devshell, with oe-master branch, the kernel
> >>>>>> version using 5.15
> >>>>>>
> >>>>>> 1. enable pahole-native and elfutils-native in linux-yocto.inc as
> >>>>>> a dependency.
> >>>>>>
> >>>>>> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> >>>>>> CONFIG_DEBUG_INFO_BTF under menuconfig
> >>>>>>
> >>>>>> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning
> >>>>>> PKG_CONFIG_SYSROOT_DIR
> >>>>>>
> >>>>>> 4, make
> >>>>>>
> >>>>>>
> >>>>>> If the test environment using bitbake, then we need to remove
> >>>>>> PAHOLE=false flag in kernel EXTRA_OEMAKE in
> >>>>>> classes-recipe/kernel.bbclass, otherwise, bitbake would report
> >>>>>> missing pahole error.
> >>>>>>
> >>>>> That's the same as my patch series (I've also changed PAHOLE=false to
> >>>>> a conditional in my series).
> >>>>>
> >>>>>> I'm seeing the following in qemux86-64 at the end of the build:
> >>>>>>
> >>>>>> | Unsupported DW_TAG_unspecified_type(0x3b)
> >>>>>> | Encountered error while encoding BTF.
> >>>>>> |   LD      .tmp_vmlinux.kallsyms1
> >>>>>> |   NM      .tmp_vmlinux.kallsyms1.syms
> >>>>>> |   KSYMS   .tmp_vmlinux.kallsyms1.S
> >>>>>> |   AS      .tmp_vmlinux.kallsyms1.S
> >>>>>> |   LD      .tmp_vmlinux.kallsyms2
> >>>>>> |   NM      .tmp_vmlinux.kallsyms2.syms
> >>>>>> |   KSYMS   .tmp_vmlinux.kallsyms2.S
> >>>>>> |   AS      .tmp_vmlinux.kallsyms2.S
> >>>>>> |   LD      vmlinux
> >>>>>> |   BTFIDS  vmlinux
> >>>>>> | FAILED: load BTF from vmlinux: No such file or directory
> >>>>>> | make[1]: ***
> >>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
> >>>>>> vmlinux] Error 255
> >>>>>> | make[1]: *** Deleting file 'vmlinux'
> >>>>>> | make: ***
> >>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
> >>>>>>
> >>>>>> vmlinux] Error 2
> >>>>>>
> >>>>>> I haven't looked into it at all yet (but will do so over the
> >>>>>> weekend)
> >>>>>> .. but I thought
> >>>>>>
> >>>>>> I haven't seen this problem yet(i'll pull the latest oe-core and
> >>>>>> meta-oe code and try again), if possible, could you share a patch
> >>>>>> with me so that we can test it together? thanks.
> >>>>>>
> >>>>> I'm on oe-core master, with qemux86-64.
> >>>>>
> >>>>> I'll do a bit more work on the patch today, and can share it if I
> >>>>> can't figure out where that unsupported tag is coming from.
> >>>> It seems like it is a known issue, I found both a lkml thread and
> >>>> debian bug from October 2022.
> >>>>
> >>>> Your 5.15 kernel wouldn't show the issue.
> >>> Yes, this should not happens on 5.15 kernel.
> >>>
> >>>
> >>> Today I synced the oe-core/poky to latest master version, removed the
> >>> build dir and run oe-init-build-env again and switched to use default
> >>> linux 6.1.25 instead of 5.15.
> >>>
> >>> Some kernel config has been updated, there is no CONFIG_DEBUG_INFO, I
> >>> used CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT.
> >>>
> >>> So, currently my local setup kernel config is enabled
> >>> CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and
> >>> CONFIG_DEBUG_INFO_BTF, in order to make a easy test, I enabled
> >>> elfutils-native and pahole-native as DEPEND directly in linux-yocto.in,
> >>> and remove the PAHOLE=false in EXTRA_OEMAKE.
> >>>
> >>> my oe-core rev: 35e5d29a7d654fc79bdb898d0f1fb277270dbfd5
> >>>
> >>> my meta-oe rev:b7aa66d734b911737b61610c1c47778e14b15c55
> >>>
> >>>
> >>> When I ran bitbake linux-yocto -v -D, I have met the same issue,
> >>>
> >>> | Unsupported DW_TAG_unspecified_type(0x3b)
> >>> | Encountered error while encoding BTF.
> >>>
> >>> It's bit strange that the I removed my local OS(ubuntu)'s pahole and
> >>> the
> >>> code can be compiled without error:
> >>>
> >>>
> >>>     CC      init/version-timestamp.o
> >>>     LD      .tmp_vmlinux.btf
> >>>     BTF     .btf.vmlinux.bin.o
> >>>     LD      .tmp_vmlinux.kallsyms1
> >>>     NM      .tmp_vmlinux.kallsyms1.syms
> >>>     KSYMS   .tmp_vmlinux.kallsyms1.S
> >>>     AS      .tmp_vmlinux.kallsyms1.S
> >>>     LD      .tmp_vmlinux.kallsyms2
> >>>     NM      .tmp_vmlinux.kallsyms2.syms
> >>>     KSYMS   .tmp_vmlinux.kallsyms2.S
> >>>     AS      .tmp_vmlinux.kallsyms2.S
> >>>     LD      vmlinux
> >>>     BTFIDS  vmlinux
> >>>     NM      System.map
> >>>     SORTTAB vmlinux
> >>>
> >> Indeed!
> >>
> >> What's the toolchain version on your ubuntu install ?
> >
> > My local ubuntu's default pahole version is 1.22,seems some data
> > structure not line up with new kernel, the yocto pahole package is
> > 1.24 is working well.
> >
> > $ pahole --version
> > v1.22
> >
> >
> >> It is likely
> >> either our toolchain version or configuration in combination with the
> >> kernel version that is adding the section that pahole can't
> >> understand/decode.
> > Yes, perhaps this is a limitation, we have to use PAHOLE in
> > EXTRA_OEMAKE to tell the make using pahole from the yocto native-sdk
> > instead of local host OS's /usr/bin/pahole when building the kernel.
> >> If you want to work with my patches, you can find my branch here:
> >>
> >> https://git.yoctoproject.org/poky-contrib/log/?h=zedd/kernel
> >>
> >> (you also need the linux-yocto bumps on that branch as they'll contain
> >> the kernel-cache SRCREV bumps to pick up the fragments for BTF, etc).
> >
> > Thanks, I will sync the branch today and feedback later :)
> >
> Hi Bruce,
>
>
> I used the zedd/kernel branch build a qmemux86-64 kernel image,
> everything goes well.
>
> Shall we set the PAHOLE to native-sdk in EXTRA_OEMAKE to make sure
> kernel make use pahole from yocto not from host pc?

We shouldn't have to explicitly pass pahole like that, as our SDK and
native-sysroot paths
should be found first.

But if you were able to have it succeed and mine didn't ... that could
be the issue.

Thanks for the suggestion, I'll test it today and if so, I'll update
the patch accordingly
and add your sign-off.

Bruce

>
> I tried to attached a patch as below, it has been tested on my local
> setup, from log we can see the PAHOLE point to native-sdk:
>
> -O2 -pipe
> PAHOLE=/local/upstream/poky-contrib/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+76f7fbdf33_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> -j 20 bzImage
>
> and the image build without error:
>
>    LD      .tmp_vmlinux.btf
>    BTF     .btf.vmlinux.bin.o
>    LD      .tmp_vmlinux.kallsyms1
>    NM      .tmp_vmlinux.kallsyms1.syms
>    KSYMS   .tmp_vmlinux.kallsyms1.S
>    AS      .tmp_vmlinux.kallsyms1.S
>    LD      .tmp_vmlinux.kallsyms2
>    NM      .tmp_vmlinux.kallsyms2.syms
>    KSYMS   .tmp_vmlinux.kallsyms2.S
>    AS      .tmp_vmlinux.kallsyms2.S
>    LD      vmlinux
>    BTFIDS  vmlinux
>    NM      System.map
>
>
>  From da4cbdb517f28f1b4254376c4f1d091a5ebca76c Mon Sep 17 00:00:00 2001
> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> Date: Wed, 17 May 2023 13:15:17 +0800
> Subject: [PATCH] set the PAHOLE to native-sdk when KERNEL_DEBUG = True
>
> Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
> ---
>   meta/recipes-kernel/linux/linux-yocto.inc | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/meta/recipes-kernel/linux/linux-yocto.inc
> b/meta/recipes-kernel/linux/linux-yocto.inc
> index 04a8105e17..90be616363 100644
> --- a/meta/recipes-kernel/linux/linux-yocto.inc
> +++ b/meta/recipes-kernel/linux/linux-yocto.inc
> @@ -66,7 +66,7 @@ DEPENDS += '${@bb.utils.contains_any("ARCH", [ "x86",
> "arm64" ], "elfutils-nativ
>   DEPENDS += "openssl-native util-linux-native"
>   DEPENDS += "gmp-native libmpc-native"
>   DEPENDS += '${@bb.utils.contains("KERNEL_DEBUG", "True",
> "pahole-native", "", d)}'
> -EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True", "",
> "PAHOLE=false", d)}'
> +EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True",
> "PAHOLE=${STAGING_DIR_NATIVE}/usr/bin/pahole", "PAHOLE=false", d)}'
>
>   do_devshell:prepend() {
>       # setup native pkg-config variables (kconfig scripts call
> pkg-config directly, cannot generically be overriden to pkg-config-native)
> --
> 2.34.1
>
>
> Br,
>
> Xiangyu
>
> >
> > Br,
> >
> > Xiangyu
> >
> >> Bruce
> >>
> >>>
> >>>> You can find a link to the lkml thread from the debian bug:
> >>>> https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1873553.html
> >>>>
> >>>> I'll clean up my patch, since this isn't something I can fix
> >>>> immediately.
> >>>>
> >>>> If you do track down patches in the latest kernel that haven't been
> >>>> sent to -stable, we can backport them to fix the linux-yocto builds
> >>>> with pahole.
> >>>>
> >>>> Bruce
> >>>>
> >>> Br,
> >>>
> >>> Xiangyu
> >>>
> >>>>> Bruce
> >>>>>
> >>>>>> I should check with you first to get the details on how you were
> >>>>>> testing pahole
> >>>>>> functionality.
> >>>>>>
> >>>>>> Bruce
> >>>>>>
> >>>>>>
> >>>>>> Br,
> >>>>>>
> >>>>>> Xiangyu
> >>>>>>
> >>>>>> Bruce
> >>>>>>
> >>>>>>
> >>>>>> Xiangyu
> >>>>>>
> >>>>>> Bruce
> >>>>>>
> >>>>>> Cheers,
> >>>>>>
> >>>>>> Richard
> >>>>>>
> >>>>>> --
> >>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> >>>>>> await
> >>>>>> thee at its end
> >>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>>
> >>>>>> --
> >>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> >>>>>> await
> >>>>>> thee at its end
> >>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> --
> >>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> >>>>>> await
> >>>>>> thee at its end
> >>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>
> >>>>> --
> >>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> >>>>> thee at its end
> >>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>
> >>>>>
> >>>>>
> >>>> --
> >>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> >>>> thee at its end
> >>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>
> >>
> >> --
> >> - 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 (#181426): https://lists.openembedded.org/g/openembedded-core/message/181426
> > Mute This Topic: https://lists.openembedded.org/mt/98753313/7175143
> > Group Owner: openembedded-core+owner@lists.openembedded.org
> > Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [xiangyu.chen@eng.windriver.com]
> > -=-=-=-=-=-=-=-=-=-=-=-
> >
Bruce Ashfield May 17, 2023, 2:35 p.m. UTC | #14
On Wed, May 17, 2023 at 8:32 AM Bruce Ashfield via
lists.openembedded.org
<bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>
> On Wed, May 17, 2023 at 1:24 AM Xiangyu Chen
> <xiangyu.chen@eng.windriver.com> wrote:
> >
> >
> > On 5/17/23 09:35, Xiangyu Chen wrote:
> > >
> > > On 5/16/23 20:55, Bruce Ashfield wrote:
> > >> CAUTION: This email comes from a non Wind River email account!
> > >> Do not click links or open attachments unless you recognize the
> > >> sender and know the content is safe.
> > >>
> > >> On Tue, May 16, 2023 at 4:56 AM Xiangyu Chen
> > >> <xiangyu.chen@eng.windriver.com> wrote:
> > >>> Hi Bruce,
> > >>>
> > >>>
> > >>> On 5/15/23 21:11, Bruce Ashfield wrote:
> > >>>> CAUTION: This email comes from a non Wind River email account!
> > >>>> Do not click links or open attachments unless you recognize the
> > >>>> sender and know the content is safe.
> > >>>>
> > >>>> On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
> > >>>> lists.openembedded.org
> > >>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> > >>>>> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
> > >>>>> <xiangyu.chen@eng.windriver.com> wrote:
> > >>>>>> Hi Bruce,
> > >>>>>>
> > >>>>>>
> > >>>>>> Sorry for being late..
> > >>>>>>
> > >>>>>>
> > >>>>>> On 5/13/23 09:16, Bruce Ashfield wrote:
> > >>>>>>
> > >>>>>> CAUTION: This email comes from a non Wind River email account!
> > >>>>>> Do not click links or open attachments unless you recognize the
> > >>>>>> sender and know the content is safe.
> > >>>>>>
> > >>>>>> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
> > >>>>>> lists.openembedded.org
> > >>>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> > >>>>>>
> > >>>>>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
> > >>>>>> <xiangyu.chen@eng.windriver.com> wrote:
> > >>>>>>
> > >>>>>> Hi Richard and Bruce,
> > >>>>>>
> > >>>>>>
> > >>>>>> Thanks for your suggestion,
> > >>>>>>
> > >>>>>>
> > >>>>>> On 5/11/23 00:25, Bruce Ashfield wrote:
> > >>>>>>
> > >>>>>> CAUTION: This email comes from a non Wind River email account!
> > >>>>>> Do not click links or open attachments unless you recognize the
> > >>>>>> sender and know the content is safe.
> > >>>>>>
> > >>>>>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> > >>>>>> <richard.purdie@linuxfoundation.org> wrote:
> > >>>>>>
> > >>>>>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> > >>>>>>
> > >>>>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> > >>>>>>
> > >>>>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the
> > >>>>>> make would report some
> > >>>>>> errors due to pahole and elfuitls is missing, since this is a
> > >>>>>> debug option, so conditionally
> > >>>>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone
> > >>>>>> need enable CONFIG_DEBUG_INFO_BTF
> > >>>>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in
> > >>>>>> local.conf to solve the pahole
> > >>>>>> and elfutils dependency.
> > >>>>>>
> > >>>>>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS
> > >>>>>> with this
> > >>>>>> option documented somewhere?
> > >>>>>>
> > >>>>>> I also think the mention of devshell in the commit message is
> > >>>>>> misleading, this issue happens regardless of how you enable the
> > >>>>>> option.
> > >>>>>> There are also other ways of enabling this than local.conf, you'd
> > >>>>>> likely not want people doing that at the end of development.
> > >>>>>>
> > >>>>>> I'm curious on Bruce's opinion but to me this at the very least
> > >>>>>> needs a
> > >>>>>> commit message rewrite and I'd question whether the docs elsewhere
> > >>>>>> would allow someone to discover this workflow anyway.
> > >>>>>>
> > >>>>>> I missed this entirely, thanks for replying to it, or I never would
> > >>>>>> have noticed.
> > >>>>>>
> > >>>>>> This mechanism isn't appropriate for these dependencies. I only
> > >>>>>> added
> > >>>>>> it to work around pkgconfig issues (which we can more cleanly
> > >>>>>> solve in
> > >>>>>> newer kernels  (see what I've been doing with make-mod-scripts)
> > >>>>>> .. so
> > >>>>>> it can eventually be dropped).
> > >>>>>>
> > >>>>>> We are already enabling elfutils-native conditionally on a
> > >>>>>> per-architecture basis (currently only x86-64).
> > >>>>>>
> > >>>>>> If we need it on more arches now, we should enable it in the version
> > >>>>>> specific recipes, or actually, we have moved far enough into newer
> > >>>>>> kernel's that it could be in the .inc now.
> > >>>>>>
> > >>>>>> This commit's background was some kernel debug options needs
> > >>>>>> elfutils
> > >>>>>> and pahole native package, since the issue happens on enabling
> > >>>>>> kernel
> > >>>>>> debug options and not all people needs it, so I conditionally add
> > >>>>>> the
> > >>>>>> dependency in KERNEL_DEBUG_OPTION.
> > >>>>>>
> > >>>>>> If possible we can enable it in .inc because newer kernel tools
> > >>>>>> like btf
> > >>>>>> are support using pkg-config to locate the libelf instead of
> > >>>>>> finding it
> > >>>>>> from /usr/ folder, so we can use elfutils-natvie instead of
> > >>>>>> installing
> > >>>>>> elfutils package on host PC.
> > >>>>>>
> > >>>>>> Similarly, we should enable the pahole-native dependency on a
> > >>>>>> per-arch basis.
> > >>>>>>
> > >>>>>> As Richard mentioned, what's the reproducer to see the errors ? it
> > >>>>>> must be more than devshell.
> > >>>>>>
> > >>>>>> Yes, this happens on devshell and normal world if some kernel debug
> > >>>>>> options are enabled. We can reproduce this issue with following
> > >>>>>> steps(I
> > >>>>>> have found the issue with kernel 5.15):
> > >>>>>>
> > >>>>>> 1. enable kernel option CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO and
> > >>>>>> CONFIG_DEBUG_INFO_BTF
> > >>>>>>
> > >>>>>> 2. build the kernel image, the compiler would report missing
> > >>>>>> libelf.h
> > >>>>>> and gelf.h which contains in elfutils-native(this step not
> > >>>>>> happens on
> > >>>>>> x86-64 due to it has been enabled).
> > >>>>>>
> > >>>>>> 3. enable elfutils-native by manual, the kernel source code can be
> > >>>>>> compiled successfully but failed in final step due to missing
> > >>>>>> pahole.
> > >>>>>>
> > >>>>>>
> > >>>>>> If you can follow up with the steps to reproduce, I can take on the
> > >>>>>> refactoring and broader dependency cleanup question, since I can
> > >>>>>> test
> > >>>>>> the wider matrix at the same time.
> > >>>>>>
> > >>>>>> Thanks, my local setup might missing some corner case, this is
> > >>>>>> another
> > >>>>>> reason I enable those native packages limit in
> > >>>>>> KERNEL_DEBUG_OPTION :).
> > >>>>>>
> > >>>>>> I've been thinking about this, and I've come to the following
> > >>>>>> suggestion:
> > >>>>>>
> > >>>>>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
> > >>>>>> version specific
> > >>>>>> recipes.  I'll also drop the architecture specific nature of the
> > >>>>>> current DEPENDS.
> > >>>>>> The need for this is much more common now, and all of the
> > >>>>>> reference kernels
> > >>>>>> in master are new enough. The elfutils-native build dependency is
> > >>>>>> not
> > >>>>>> significant
> > >>>>>> enough to worry about adding it for all architectures. If it does
> > >>>>>> become a problem,
> > >>>>>> there are options to make it conditional again.
> > >>>>>>
> > >>>>>> I can drop the HOST_LIBELF_LIBS work around in the
> > >>>>>> linux-yocto.inc, as
> > >>>>>> we can now properly detect libelf via pkg-config. I didn't need
> > >>>>>> it in any of
> > >>>>>> my testing. Again, if this proves to be wrong, I'd enable it in a
> > >>>>>> different way now
> > >>>>>> (using what I've learned from fixing make-mod-scripts).
> > >>>>>>
> > >>>>>> As for the pahole-native dependency, there's been a "developer"
> > >>>>>> kernel-type
> > >>>>>> for quite some time. The design intention behind it was to enable
> > >>>>>> options like
> > >>>>>> this, and not make the "standard" or "production" kernel's too
> > >>>>>> large by default.
> > >>>>>> So the dependency could be conditional on that kernel type ...
> > >>>>>> but we don't
> > >>>>>> want to break other kernels just because they've enabled that
> > >>>>>> option. We also
> > >>>>>> don't (and won't) get into the game of looking for individual
> > >>>>>> options in the
> > >>>>>> .config to enable something, since a) it is too late b) it is a
> > >>>>>> moving target.
> > >>>>>>
> > >>>>>> So that leaves the following options: a) enable pahole-native
> > >>>>>> unconditionally
> > >>>>>> on the arches that support it (x86-64, aarch64) (and also move
> > >>>>>> the pahole
> > >>>>>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
> > >>>>>> and simply call it KERNEL_DEBUG, when enabled, we could
> > >>>>>> conditionally
> > >>>>>> add pahole-native (I'd also submit documentation for the
> > >>>>>> functionality
> > >>>>>> c) something I haven't thought about ...
> > >>>>>>
> > >>>>>> I'm moving on the implementation now, but will adjust course if
> > >>>>>> there's something
> > >>>>>> I've missed.
> > >>>>>>
> > >>>>>> I have my implementation done, but I'm wondering what your
> > >>>>>> configuration
> > >>>>>> was for testing pahole ?
> > >>>>>>
> > >>>>> My reply will be hard to read, as plain text reply to the html
> > >>>>> doesn't
> > >>>>> give us proper
> > >>>>> context indenting.
> > >>>>>
> > >>>>>> I have tested on a devshell, with oe-master branch, the kernel
> > >>>>>> version using 5.15
> > >>>>>>
> > >>>>>> 1. enable pahole-native and elfutils-native in linux-yocto.inc as
> > >>>>>> a dependency.
> > >>>>>>
> > >>>>>> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> > >>>>>> CONFIG_DEBUG_INFO_BTF under menuconfig
> > >>>>>>
> > >>>>>> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning
> > >>>>>> PKG_CONFIG_SYSROOT_DIR
> > >>>>>>
> > >>>>>> 4, make
> > >>>>>>
> > >>>>>>
> > >>>>>> If the test environment using bitbake, then we need to remove
> > >>>>>> PAHOLE=false flag in kernel EXTRA_OEMAKE in
> > >>>>>> classes-recipe/kernel.bbclass, otherwise, bitbake would report
> > >>>>>> missing pahole error.
> > >>>>>>
> > >>>>> That's the same as my patch series (I've also changed PAHOLE=false to
> > >>>>> a conditional in my series).
> > >>>>>
> > >>>>>> I'm seeing the following in qemux86-64 at the end of the build:
> > >>>>>>
> > >>>>>> | Unsupported DW_TAG_unspecified_type(0x3b)
> > >>>>>> | Encountered error while encoding BTF.
> > >>>>>> |   LD      .tmp_vmlinux.kallsyms1
> > >>>>>> |   NM      .tmp_vmlinux.kallsyms1.syms
> > >>>>>> |   KSYMS   .tmp_vmlinux.kallsyms1.S
> > >>>>>> |   AS      .tmp_vmlinux.kallsyms1.S
> > >>>>>> |   LD      .tmp_vmlinux.kallsyms2
> > >>>>>> |   NM      .tmp_vmlinux.kallsyms2.syms
> > >>>>>> |   KSYMS   .tmp_vmlinux.kallsyms2.S
> > >>>>>> |   AS      .tmp_vmlinux.kallsyms2.S
> > >>>>>> |   LD      vmlinux
> > >>>>>> |   BTFIDS  vmlinux
> > >>>>>> | FAILED: load BTF from vmlinux: No such file or directory
> > >>>>>> | make[1]: ***
> > >>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
> > >>>>>> vmlinux] Error 255
> > >>>>>> | make[1]: *** Deleting file 'vmlinux'
> > >>>>>> | make: ***
> > >>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
> > >>>>>>
> > >>>>>> vmlinux] Error 2
> > >>>>>>
> > >>>>>> I haven't looked into it at all yet (but will do so over the
> > >>>>>> weekend)
> > >>>>>> .. but I thought
> > >>>>>>
> > >>>>>> I haven't seen this problem yet(i'll pull the latest oe-core and
> > >>>>>> meta-oe code and try again), if possible, could you share a patch
> > >>>>>> with me so that we can test it together? thanks.
> > >>>>>>
> > >>>>> I'm on oe-core master, with qemux86-64.
> > >>>>>
> > >>>>> I'll do a bit more work on the patch today, and can share it if I
> > >>>>> can't figure out where that unsupported tag is coming from.
> > >>>> It seems like it is a known issue, I found both a lkml thread and
> > >>>> debian bug from October 2022.
> > >>>>
> > >>>> Your 5.15 kernel wouldn't show the issue.
> > >>> Yes, this should not happens on 5.15 kernel.
> > >>>
> > >>>
> > >>> Today I synced the oe-core/poky to latest master version, removed the
> > >>> build dir and run oe-init-build-env again and switched to use default
> > >>> linux 6.1.25 instead of 5.15.
> > >>>
> > >>> Some kernel config has been updated, there is no CONFIG_DEBUG_INFO, I
> > >>> used CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT.
> > >>>
> > >>> So, currently my local setup kernel config is enabled
> > >>> CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and
> > >>> CONFIG_DEBUG_INFO_BTF, in order to make a easy test, I enabled
> > >>> elfutils-native and pahole-native as DEPEND directly in linux-yocto.in,
> > >>> and remove the PAHOLE=false in EXTRA_OEMAKE.
> > >>>
> > >>> my oe-core rev: 35e5d29a7d654fc79bdb898d0f1fb277270dbfd5
> > >>>
> > >>> my meta-oe rev:b7aa66d734b911737b61610c1c47778e14b15c55
> > >>>
> > >>>
> > >>> When I ran bitbake linux-yocto -v -D, I have met the same issue,
> > >>>
> > >>> | Unsupported DW_TAG_unspecified_type(0x3b)
> > >>> | Encountered error while encoding BTF.
> > >>>
> > >>> It's bit strange that the I removed my local OS(ubuntu)'s pahole and
> > >>> the
> > >>> code can be compiled without error:
> > >>>
> > >>>
> > >>>     CC      init/version-timestamp.o
> > >>>     LD      .tmp_vmlinux.btf
> > >>>     BTF     .btf.vmlinux.bin.o
> > >>>     LD      .tmp_vmlinux.kallsyms1
> > >>>     NM      .tmp_vmlinux.kallsyms1.syms
> > >>>     KSYMS   .tmp_vmlinux.kallsyms1.S
> > >>>     AS      .tmp_vmlinux.kallsyms1.S
> > >>>     LD      .tmp_vmlinux.kallsyms2
> > >>>     NM      .tmp_vmlinux.kallsyms2.syms
> > >>>     KSYMS   .tmp_vmlinux.kallsyms2.S
> > >>>     AS      .tmp_vmlinux.kallsyms2.S
> > >>>     LD      vmlinux
> > >>>     BTFIDS  vmlinux
> > >>>     NM      System.map
> > >>>     SORTTAB vmlinux
> > >>>
> > >> Indeed!
> > >>
> > >> What's the toolchain version on your ubuntu install ?
> > >
> > > My local ubuntu's default pahole version is 1.22,seems some data
> > > structure not line up with new kernel, the yocto pahole package is
> > > 1.24 is working well.
> > >
> > > $ pahole --version
> > > v1.22
> > >
> > >
> > >> It is likely
> > >> either our toolchain version or configuration in combination with the
> > >> kernel version that is adding the section that pahole can't
> > >> understand/decode.
> > > Yes, perhaps this is a limitation, we have to use PAHOLE in
> > > EXTRA_OEMAKE to tell the make using pahole from the yocto native-sdk
> > > instead of local host OS's /usr/bin/pahole when building the kernel.
> > >> If you want to work with my patches, you can find my branch here:
> > >>
> > >> https://git.yoctoproject.org/poky-contrib/log/?h=zedd/kernel
> > >>
> > >> (you also need the linux-yocto bumps on that branch as they'll contain
> > >> the kernel-cache SRCREV bumps to pick up the fragments for BTF, etc).
> > >
> > > Thanks, I will sync the branch today and feedback later :)
> > >
> > Hi Bruce,
> >
> >
> > I used the zedd/kernel branch build a qmemux86-64 kernel image,
> > everything goes well.
> >
> > Shall we set the PAHOLE to native-sdk in EXTRA_OEMAKE to make sure
> > kernel make use pahole from yocto not from host pc?
>
> We shouldn't have to explicitly pass pahole like that, as our SDK and
> native-sysroot paths
> should be found first.
>
> But if you were able to have it succeed and mine didn't ... that could
> be the issue.
>
> Thanks for the suggestion, I'll test it today and if so, I'll update
> the patch accordingly
> and add your sign-off.

I instrumented the scripts to echo the pahole binary being used, and
as expected, the build environment is setup to prefer our sysroot
binaries (without that setup, we'd have all sorts of host
contamination).

|   GEN     Makefile
|   DESCEND objtool
|   DESCEND bpf/resolve_btfids
|   CALL    /opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/checksyscalls.sh
| /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
|   LD      .tmp_vmlinux.btf
|   BTF     .btf.vmlinux.bin.o
| Unsupported DW_TAG_unspecified_type(0x3b)
| Encountered error while encoding BTF.
| /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
|   LD      .tmp_vmlinux.kallsyms1
|   NM      .tmp_vmlinux.kallsyms1.syms
|   KSYMS   .tmp_vmlinux.kallsyms1.S
|   AS      .tmp_vmlinux.kallsyms1.S
| /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
|   LD      .tmp_vmlinux.kallsyms2
|   NM      .tmp_vmlinux.kallsyms2.syms
|   KSYMS   .tmp_vmlinux.kallsyms2.S
|   AS      .tmp_vmlinux.kallsyms2.S
| /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
|   LD      vmlinux
|   BTFIDS  vmlinux
| FAILED: load BTF from vmlinux: No such file or directory

But as you can see, I still get the DW_TAG issues.

My fragments are setting CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT,
and the required debug
options.  Those are enabled by the following in local.conf:

KERNEL_FEATURES:append = "ktypes/developer/developer.cfg
features/debug/debug-stack.scc features/debug/debug-btf.scc"

Can you confirm that your success run used both the yocto/bitbake
build and my fragments for configuration ?

There must still be something different that I'm missing.

Bruce

>
> Bruce
>
> >
> > I tried to attached a patch as below, it has been tested on my local
> > setup, from log we can see the PAHOLE point to native-sdk:
> >
> > -O2 -pipe
> > PAHOLE=/local/upstream/poky-contrib/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+76f7fbdf33_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> > -j 20 bzImage
> >
> > and the image build without error:
> >
> >    LD      .tmp_vmlinux.btf
> >    BTF     .btf.vmlinux.bin.o
> >    LD      .tmp_vmlinux.kallsyms1
> >    NM      .tmp_vmlinux.kallsyms1.syms
> >    KSYMS   .tmp_vmlinux.kallsyms1.S
> >    AS      .tmp_vmlinux.kallsyms1.S
> >    LD      .tmp_vmlinux.kallsyms2
> >    NM      .tmp_vmlinux.kallsyms2.syms
> >    KSYMS   .tmp_vmlinux.kallsyms2.S
> >    AS      .tmp_vmlinux.kallsyms2.S
> >    LD      vmlinux
> >    BTFIDS  vmlinux
> >    NM      System.map
> >
> >
> >  From da4cbdb517f28f1b4254376c4f1d091a5ebca76c Mon Sep 17 00:00:00 2001
> > From: Xiangyu Chen <xiangyu.chen@windriver.com>
> > Date: Wed, 17 May 2023 13:15:17 +0800
> > Subject: [PATCH] set the PAHOLE to native-sdk when KERNEL_DEBUG = True
> >
> > Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
> > ---
> >   meta/recipes-kernel/linux/linux-yocto.inc | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/meta/recipes-kernel/linux/linux-yocto.inc
> > b/meta/recipes-kernel/linux/linux-yocto.inc
> > index 04a8105e17..90be616363 100644
> > --- a/meta/recipes-kernel/linux/linux-yocto.inc
> > +++ b/meta/recipes-kernel/linux/linux-yocto.inc
> > @@ -66,7 +66,7 @@ DEPENDS += '${@bb.utils.contains_any("ARCH", [ "x86",
> > "arm64" ], "elfutils-nativ
> >   DEPENDS += "openssl-native util-linux-native"
> >   DEPENDS += "gmp-native libmpc-native"
> >   DEPENDS += '${@bb.utils.contains("KERNEL_DEBUG", "True",
> > "pahole-native", "", d)}'
> > -EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True", "",
> > "PAHOLE=false", d)}'
> > +EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True",
> > "PAHOLE=${STAGING_DIR_NATIVE}/usr/bin/pahole", "PAHOLE=false", d)}'
> >
> >   do_devshell:prepend() {
> >       # setup native pkg-config variables (kconfig scripts call
> > pkg-config directly, cannot generically be overriden to pkg-config-native)
> > --
> > 2.34.1
> >
> >
> > Br,
> >
> > Xiangyu
> >
> > >
> > > Br,
> > >
> > > Xiangyu
> > >
> > >> Bruce
> > >>
> > >>>
> > >>>> You can find a link to the lkml thread from the debian bug:
> > >>>> https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1873553.html
> > >>>>
> > >>>> I'll clean up my patch, since this isn't something I can fix
> > >>>> immediately.
> > >>>>
> > >>>> If you do track down patches in the latest kernel that haven't been
> > >>>> sent to -stable, we can backport them to fix the linux-yocto builds
> > >>>> with pahole.
> > >>>>
> > >>>> Bruce
> > >>>>
> > >>> Br,
> > >>>
> > >>> Xiangyu
> > >>>
> > >>>>> Bruce
> > >>>>>
> > >>>>>> I should check with you first to get the details on how you were
> > >>>>>> testing pahole
> > >>>>>> functionality.
> > >>>>>>
> > >>>>>> Bruce
> > >>>>>>
> > >>>>>>
> > >>>>>> Br,
> > >>>>>>
> > >>>>>> Xiangyu
> > >>>>>>
> > >>>>>> Bruce
> > >>>>>>
> > >>>>>>
> > >>>>>> Xiangyu
> > >>>>>>
> > >>>>>> Bruce
> > >>>>>>
> > >>>>>> Cheers,
> > >>>>>>
> > >>>>>> Richard
> > >>>>>>
> > >>>>>> --
> > >>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> > >>>>>> await
> > >>>>>> thee at its end
> > >>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> > >>>>>>
> > >>>>>> --
> > >>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> > >>>>>> await
> > >>>>>> thee at its end
> > >>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> > >>>>>>
> > >>>>>>
> > >>>>>>
> > >>>>>> --
> > >>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> > >>>>>> await
> > >>>>>> thee at its end
> > >>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> > >>>>>
> > >>>>> --
> > >>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> > >>>>> thee at its end
> > >>>>> - "Use the force Harry" - Gandalf, Star Trek II
> > >>>>>
> > >>>>>
> > >>>>>
> > >>>> --
> > >>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> > >>>> thee at its end
> > >>>> - "Use the force Harry" - Gandalf, Star Trek II
> > >>
> > >>
> > >> --
> > >> - Thou shalt not follow the NULL pointer, for chaos and madness await
> > >> thee at its end
> > >> - "Use the force Harry" - Gandalf, Star Trek II
> > >
> > >
> > >
>
>
>
> --
> - 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 (#181487): https://lists.openembedded.org/g/openembedded-core/message/181487
> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
> Group Owner: openembedded-core+owner@lists.openembedded.org
> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [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
Xiangyu Chen May 18, 2023, 2:08 a.m. UTC | #15
On 5/17/23 22:35, Bruce Ashfield wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Wed, May 17, 2023 at 8:32 AM Bruce Ashfield via
> lists.openembedded.org
> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>> On Wed, May 17, 2023 at 1:24 AM Xiangyu Chen
>> <xiangyu.chen@eng.windriver.com> wrote:
>>>
>>> On 5/17/23 09:35, Xiangyu Chen wrote:
>>>> On 5/16/23 20:55, Bruce Ashfield wrote:
>>>>> CAUTION: This email comes from a non Wind River email account!
>>>>> Do not click links or open attachments unless you recognize the
>>>>> sender and know the content is safe.
>>>>>
>>>>> On Tue, May 16, 2023 at 4:56 AM Xiangyu Chen
>>>>> <xiangyu.chen@eng.windriver.com> wrote:
>>>>>> Hi Bruce,
>>>>>>
>>>>>>
>>>>>> On 5/15/23 21:11, Bruce Ashfield wrote:
>>>>>>> CAUTION: This email comes from a non Wind River email account!
>>>>>>> Do not click links or open attachments unless you recognize the
>>>>>>> sender and know the content is safe.
>>>>>>>
>>>>>>> On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
>>>>>>> lists.openembedded.org
>>>>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>>>>>>>> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
>>>>>>>> <xiangyu.chen@eng.windriver.com> wrote:
>>>>>>>>> Hi Bruce,
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Sorry for being late..
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 5/13/23 09:16, Bruce Ashfield wrote:
>>>>>>>>>
>>>>>>>>> CAUTION: This email comes from a non Wind River email account!
>>>>>>>>> Do not click links or open attachments unless you recognize the
>>>>>>>>> sender and know the content is safe.
>>>>>>>>>
>>>>>>>>> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
>>>>>>>>> lists.openembedded.org
>>>>>>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
>>>>>>>>>
>>>>>>>>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
>>>>>>>>> <xiangyu.chen@eng.windriver.com> wrote:
>>>>>>>>>
>>>>>>>>> Hi Richard and Bruce,
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Thanks for your suggestion,
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 5/11/23 00:25, Bruce Ashfield wrote:
>>>>>>>>>
>>>>>>>>> CAUTION: This email comes from a non Wind River email account!
>>>>>>>>> Do not click links or open attachments unless you recognize the
>>>>>>>>> sender and know the content is safe.
>>>>>>>>>
>>>>>>>>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
>>>>>>>>> <richard.purdie@linuxfoundation.org> wrote:
>>>>>>>>>
>>>>>>>>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
>>>>>>>>>
>>>>>>>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
>>>>>>>>>
>>>>>>>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the
>>>>>>>>> make would report some
>>>>>>>>> errors due to pahole and elfuitls is missing, since this is a
>>>>>>>>> debug option, so conditionally
>>>>>>>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone
>>>>>>>>> need enable CONFIG_DEBUG_INFO_BTF
>>>>>>>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in
>>>>>>>>> local.conf to solve the pahole
>>>>>>>>> and elfutils dependency.
>>>>>>>>>
>>>>>>>>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS
>>>>>>>>> with this
>>>>>>>>> option documented somewhere?
>>>>>>>>>
>>>>>>>>> I also think the mention of devshell in the commit message is
>>>>>>>>> misleading, this issue happens regardless of how you enable the
>>>>>>>>> option.
>>>>>>>>> There are also other ways of enabling this than local.conf, you'd
>>>>>>>>> likely not want people doing that at the end of development.
>>>>>>>>>
>>>>>>>>> I'm curious on Bruce's opinion but to me this at the very least
>>>>>>>>> needs a
>>>>>>>>> commit message rewrite and I'd question whether the docs elsewhere
>>>>>>>>> would allow someone to discover this workflow anyway.
>>>>>>>>>
>>>>>>>>> I missed this entirely, thanks for replying to it, or I never would
>>>>>>>>> have noticed.
>>>>>>>>>
>>>>>>>>> This mechanism isn't appropriate for these dependencies. I only
>>>>>>>>> added
>>>>>>>>> it to work around pkgconfig issues (which we can more cleanly
>>>>>>>>> solve in
>>>>>>>>> newer kernels  (see what I've been doing with make-mod-scripts)
>>>>>>>>> .. so
>>>>>>>>> it can eventually be dropped).
>>>>>>>>>
>>>>>>>>> We are already enabling elfutils-native conditionally on a
>>>>>>>>> per-architecture basis (currently only x86-64).
>>>>>>>>>
>>>>>>>>> If we need it on more arches now, we should enable it in the version
>>>>>>>>> specific recipes, or actually, we have moved far enough into newer
>>>>>>>>> kernel's that it could be in the .inc now.
>>>>>>>>>
>>>>>>>>> This commit's background was some kernel debug options needs
>>>>>>>>> elfutils
>>>>>>>>> and pahole native package, since the issue happens on enabling
>>>>>>>>> kernel
>>>>>>>>> debug options and not all people needs it, so I conditionally add
>>>>>>>>> the
>>>>>>>>> dependency in KERNEL_DEBUG_OPTION.
>>>>>>>>>
>>>>>>>>> If possible we can enable it in .inc because newer kernel tools
>>>>>>>>> like btf
>>>>>>>>> are support using pkg-config to locate the libelf instead of
>>>>>>>>> finding it
>>>>>>>>> from /usr/ folder, so we can use elfutils-natvie instead of
>>>>>>>>> installing
>>>>>>>>> elfutils package on host PC.
>>>>>>>>>
>>>>>>>>> Similarly, we should enable the pahole-native dependency on a
>>>>>>>>> per-arch basis.
>>>>>>>>>
>>>>>>>>> As Richard mentioned, what's the reproducer to see the errors ? it
>>>>>>>>> must be more than devshell.
>>>>>>>>>
>>>>>>>>> Yes, this happens on devshell and normal world if some kernel debug
>>>>>>>>> options are enabled. We can reproduce this issue with following
>>>>>>>>> steps(I
>>>>>>>>> have found the issue with kernel 5.15):
>>>>>>>>>
>>>>>>>>> 1. enable kernel option CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO and
>>>>>>>>> CONFIG_DEBUG_INFO_BTF
>>>>>>>>>
>>>>>>>>> 2. build the kernel image, the compiler would report missing
>>>>>>>>> libelf.h
>>>>>>>>> and gelf.h which contains in elfutils-native(this step not
>>>>>>>>> happens on
>>>>>>>>> x86-64 due to it has been enabled).
>>>>>>>>>
>>>>>>>>> 3. enable elfutils-native by manual, the kernel source code can be
>>>>>>>>> compiled successfully but failed in final step due to missing
>>>>>>>>> pahole.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> If you can follow up with the steps to reproduce, I can take on the
>>>>>>>>> refactoring and broader dependency cleanup question, since I can
>>>>>>>>> test
>>>>>>>>> the wider matrix at the same time.
>>>>>>>>>
>>>>>>>>> Thanks, my local setup might missing some corner case, this is
>>>>>>>>> another
>>>>>>>>> reason I enable those native packages limit in
>>>>>>>>> KERNEL_DEBUG_OPTION :).
>>>>>>>>>
>>>>>>>>> I've been thinking about this, and I've come to the following
>>>>>>>>> suggestion:
>>>>>>>>>
>>>>>>>>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
>>>>>>>>> version specific
>>>>>>>>> recipes.  I'll also drop the architecture specific nature of the
>>>>>>>>> current DEPENDS.
>>>>>>>>> The need for this is much more common now, and all of the
>>>>>>>>> reference kernels
>>>>>>>>> in master are new enough. The elfutils-native build dependency is
>>>>>>>>> not
>>>>>>>>> significant
>>>>>>>>> enough to worry about adding it for all architectures. If it does
>>>>>>>>> become a problem,
>>>>>>>>> there are options to make it conditional again.
>>>>>>>>>
>>>>>>>>> I can drop the HOST_LIBELF_LIBS work around in the
>>>>>>>>> linux-yocto.inc, as
>>>>>>>>> we can now properly detect libelf via pkg-config. I didn't need
>>>>>>>>> it in any of
>>>>>>>>> my testing. Again, if this proves to be wrong, I'd enable it in a
>>>>>>>>> different way now
>>>>>>>>> (using what I've learned from fixing make-mod-scripts).
>>>>>>>>>
>>>>>>>>> As for the pahole-native dependency, there's been a "developer"
>>>>>>>>> kernel-type
>>>>>>>>> for quite some time. The design intention behind it was to enable
>>>>>>>>> options like
>>>>>>>>> this, and not make the "standard" or "production" kernel's too
>>>>>>>>> large by default.
>>>>>>>>> So the dependency could be conditional on that kernel type ...
>>>>>>>>> but we don't
>>>>>>>>> want to break other kernels just because they've enabled that
>>>>>>>>> option. We also
>>>>>>>>> don't (and won't) get into the game of looking for individual
>>>>>>>>> options in the
>>>>>>>>> .config to enable something, since a) it is too late b) it is a
>>>>>>>>> moving target.
>>>>>>>>>
>>>>>>>>> So that leaves the following options: a) enable pahole-native
>>>>>>>>> unconditionally
>>>>>>>>> on the arches that support it (x86-64, aarch64) (and also move
>>>>>>>>> the pahole
>>>>>>>>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
>>>>>>>>> and simply call it KERNEL_DEBUG, when enabled, we could
>>>>>>>>> conditionally
>>>>>>>>> add pahole-native (I'd also submit documentation for the
>>>>>>>>> functionality
>>>>>>>>> c) something I haven't thought about ...
>>>>>>>>>
>>>>>>>>> I'm moving on the implementation now, but will adjust course if
>>>>>>>>> there's something
>>>>>>>>> I've missed.
>>>>>>>>>
>>>>>>>>> I have my implementation done, but I'm wondering what your
>>>>>>>>> configuration
>>>>>>>>> was for testing pahole ?
>>>>>>>>>
>>>>>>>> My reply will be hard to read, as plain text reply to the html
>>>>>>>> doesn't
>>>>>>>> give us proper
>>>>>>>> context indenting.
>>>>>>>>
>>>>>>>>> I have tested on a devshell, with oe-master branch, the kernel
>>>>>>>>> version using 5.15
>>>>>>>>>
>>>>>>>>> 1. enable pahole-native and elfutils-native in linux-yocto.inc as
>>>>>>>>> a dependency.
>>>>>>>>>
>>>>>>>>> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
>>>>>>>>> CONFIG_DEBUG_INFO_BTF under menuconfig
>>>>>>>>>
>>>>>>>>> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning
>>>>>>>>> PKG_CONFIG_SYSROOT_DIR
>>>>>>>>>
>>>>>>>>> 4, make
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> If the test environment using bitbake, then we need to remove
>>>>>>>>> PAHOLE=false flag in kernel EXTRA_OEMAKE in
>>>>>>>>> classes-recipe/kernel.bbclass, otherwise, bitbake would report
>>>>>>>>> missing pahole error.
>>>>>>>>>
>>>>>>>> That's the same as my patch series (I've also changed PAHOLE=false to
>>>>>>>> a conditional in my series).
>>>>>>>>
>>>>>>>>> I'm seeing the following in qemux86-64 at the end of the build:
>>>>>>>>>
>>>>>>>>> | Unsupported DW_TAG_unspecified_type(0x3b)
>>>>>>>>> | Encountered error while encoding BTF.
>>>>>>>>> |   LD      .tmp_vmlinux.kallsyms1
>>>>>>>>> |   NM      .tmp_vmlinux.kallsyms1.syms
>>>>>>>>> |   KSYMS   .tmp_vmlinux.kallsyms1.S
>>>>>>>>> |   AS      .tmp_vmlinux.kallsyms1.S
>>>>>>>>> |   LD      .tmp_vmlinux.kallsyms2
>>>>>>>>> |   NM      .tmp_vmlinux.kallsyms2.syms
>>>>>>>>> |   KSYMS   .tmp_vmlinux.kallsyms2.S
>>>>>>>>> |   AS      .tmp_vmlinux.kallsyms2.S
>>>>>>>>> |   LD      vmlinux
>>>>>>>>> |   BTFIDS  vmlinux
>>>>>>>>> | FAILED: load BTF from vmlinux: No such file or directory
>>>>>>>>> | make[1]: ***
>>>>>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
>>>>>>>>> vmlinux] Error 255
>>>>>>>>> | make[1]: *** Deleting file 'vmlinux'
>>>>>>>>> | make: ***
>>>>>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
>>>>>>>>>
>>>>>>>>> vmlinux] Error 2
>>>>>>>>>
>>>>>>>>> I haven't looked into it at all yet (but will do so over the
>>>>>>>>> weekend)
>>>>>>>>> .. but I thought
>>>>>>>>>
>>>>>>>>> I haven't seen this problem yet(i'll pull the latest oe-core and
>>>>>>>>> meta-oe code and try again), if possible, could you share a patch
>>>>>>>>> with me so that we can test it together? thanks.
>>>>>>>>>
>>>>>>>> I'm on oe-core master, with qemux86-64.
>>>>>>>>
>>>>>>>> I'll do a bit more work on the patch today, and can share it if I
>>>>>>>> can't figure out where that unsupported tag is coming from.
>>>>>>> It seems like it is a known issue, I found both a lkml thread and
>>>>>>> debian bug from October 2022.
>>>>>>>
>>>>>>> Your 5.15 kernel wouldn't show the issue.
>>>>>> Yes, this should not happens on 5.15 kernel.
>>>>>>
>>>>>>
>>>>>> Today I synced the oe-core/poky to latest master version, removed the
>>>>>> build dir and run oe-init-build-env again and switched to use default
>>>>>> linux 6.1.25 instead of 5.15.
>>>>>>
>>>>>> Some kernel config has been updated, there is no CONFIG_DEBUG_INFO, I
>>>>>> used CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT.
>>>>>>
>>>>>> So, currently my local setup kernel config is enabled
>>>>>> CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and
>>>>>> CONFIG_DEBUG_INFO_BTF, in order to make a easy test, I enabled
>>>>>> elfutils-native and pahole-native as DEPEND directly in linux-yocto.in,
>>>>>> and remove the PAHOLE=false in EXTRA_OEMAKE.
>>>>>>
>>>>>> my oe-core rev: 35e5d29a7d654fc79bdb898d0f1fb277270dbfd5
>>>>>>
>>>>>> my meta-oe rev:b7aa66d734b911737b61610c1c47778e14b15c55
>>>>>>
>>>>>>
>>>>>> When I ran bitbake linux-yocto -v -D, I have met the same issue,
>>>>>>
>>>>>> | Unsupported DW_TAG_unspecified_type(0x3b)
>>>>>> | Encountered error while encoding BTF.
>>>>>>
>>>>>> It's bit strange that the I removed my local OS(ubuntu)'s pahole and
>>>>>> the
>>>>>> code can be compiled without error:
>>>>>>
>>>>>>
>>>>>>      CC      init/version-timestamp.o
>>>>>>      LD      .tmp_vmlinux.btf
>>>>>>      BTF     .btf.vmlinux.bin.o
>>>>>>      LD      .tmp_vmlinux.kallsyms1
>>>>>>      NM      .tmp_vmlinux.kallsyms1.syms
>>>>>>      KSYMS   .tmp_vmlinux.kallsyms1.S
>>>>>>      AS      .tmp_vmlinux.kallsyms1.S
>>>>>>      LD      .tmp_vmlinux.kallsyms2
>>>>>>      NM      .tmp_vmlinux.kallsyms2.syms
>>>>>>      KSYMS   .tmp_vmlinux.kallsyms2.S
>>>>>>      AS      .tmp_vmlinux.kallsyms2.S
>>>>>>      LD      vmlinux
>>>>>>      BTFIDS  vmlinux
>>>>>>      NM      System.map
>>>>>>      SORTTAB vmlinux
>>>>>>
>>>>> Indeed!
>>>>>
>>>>> What's the toolchain version on your ubuntu install ?
>>>> My local ubuntu's default pahole version is 1.22,seems some data
>>>> structure not line up with new kernel, the yocto pahole package is
>>>> 1.24 is working well.
>>>>
>>>> $ pahole --version
>>>> v1.22
>>>>
>>>>
>>>>> It is likely
>>>>> either our toolchain version or configuration in combination with the
>>>>> kernel version that is adding the section that pahole can't
>>>>> understand/decode.
>>>> Yes, perhaps this is a limitation, we have to use PAHOLE in
>>>> EXTRA_OEMAKE to tell the make using pahole from the yocto native-sdk
>>>> instead of local host OS's /usr/bin/pahole when building the kernel.
>>>>> If you want to work with my patches, you can find my branch here:
>>>>>
>>>>> https://git.yoctoproject.org/poky-contrib/log/?h=zedd/kernel
>>>>>
>>>>> (you also need the linux-yocto bumps on that branch as they'll contain
>>>>> the kernel-cache SRCREV bumps to pick up the fragments for BTF, etc).
>>>> Thanks, I will sync the branch today and feedback later :)
>>>>
>>> Hi Bruce,
>>>
>>>
>>> I used the zedd/kernel branch build a qmemux86-64 kernel image,
>>> everything goes well.
>>>
>>> Shall we set the PAHOLE to native-sdk in EXTRA_OEMAKE to make sure
>>> kernel make use pahole from yocto not from host pc?
>> We shouldn't have to explicitly pass pahole like that, as our SDK and
>> native-sysroot paths
>> should be found first.
>>
>> But if you were able to have it succeed and mine didn't ... that could
>> be the issue.
>>
>> Thanks for the suggestion, I'll test it today and if so, I'll update
>> the patch accordingly
>> and add your sign-off.
> I instrumented the scripts to echo the pahole binary being used, and
> as expected, the build environment is setup to prefer our sysroot
> binaries (without that setup, we'd have all sorts of host
> contamination).
>
> |   GEN     Makefile
> |   DESCEND objtool
> |   DESCEND bpf/resolve_btfids
> |   CALL    /opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/checksyscalls.sh
> | /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> |   LD      .tmp_vmlinux.btf
> |   BTF     .btf.vmlinux.bin.o
> | Unsupported DW_TAG_unspecified_type(0x3b)
> | Encountered error while encoding BTF.
> | /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> |   LD      .tmp_vmlinux.kallsyms1
> |   NM      .tmp_vmlinux.kallsyms1.syms
> |   KSYMS   .tmp_vmlinux.kallsyms1.S
> |   AS      .tmp_vmlinux.kallsyms1.S
> | /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> |   LD      .tmp_vmlinux.kallsyms2
> |   NM      .tmp_vmlinux.kallsyms2.syms
> |   KSYMS   .tmp_vmlinux.kallsyms2.S
> |   AS      .tmp_vmlinux.kallsyms2.S
> | /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> |   LD      vmlinux
> |   BTFIDS  vmlinux
> | FAILED: load BTF from vmlinux: No such file or directory
>
> But as you can see, I still get the DW_TAG issues.
>
> My fragments are setting CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT,
> and the required debug
> options.  Those are enabled by the following in local.conf:
>
> KERNEL_FEATURES:append = "ktypes/developer/developer.cfg
> features/debug/debug-stack.scc features/debug/debug-btf.scc"
>
> Can you confirm that your success run used both the yocto/bitbake
> build and my fragments for configuration ?
>
> There must still be something different that I'm missing.

Hi Bruce,


I have verified add "KERNEL_FEATURES:append = 
"ktypes/developer/developer.cfg features/debug/debug-stack.scc 
features/debug/debug-btf.scc" "

in local.conf today, I cleaned the source with bitbake linux-yocto -c 
cleanall and rebuilt, the result the same as before, BTF information was 
generated

without any error, in order to add more information, I uploaded the full 
log as following link:

https://raw.githubusercontent.com/chenxy1988/sync/main/oe-core-181487/1/linux-yocto-build.log


and my host pc os information:

PRETTY_NAME="Ubuntu 22.04.2 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.2 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy


If possible, could you share the local.conf with me so that I can test 
in my setup? And, there is another clue,

i am not sure this is a right way to locate the root cause, since this 
issue happens on pahole, can we exchange the

pahole native binary which was generated by yocto to replace 
linux-yocto/6.1.28+gitAUTOINC+76f7fbdf33_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole 


if something wrong with pahole-native, my setup should also report the 
DW_TAG_unspecified_type issue.


The following link is the pahole native binary that was generated by 
yocto in my local environment:

https://github.com/chenxy1988/sync/blob/main/oe-core-181487/1/pahole-native-yocto.tar.gz



Br,

Xiangyu


>
> Bruce
>
>> Bruce
>>
>>> I tried to attached a patch as below, it has been tested on my local
>>> setup, from log we can see the PAHOLE point to native-sdk:
>>>
>>> -O2 -pipe
>>> PAHOLE=/local/upstream/poky-contrib/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+76f7fbdf33_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
>>> -j 20 bzImage
>>>
>>> and the image build without error:
>>>
>>>     LD      .tmp_vmlinux.btf
>>>     BTF     .btf.vmlinux.bin.o
>>>     LD      .tmp_vmlinux.kallsyms1
>>>     NM      .tmp_vmlinux.kallsyms1.syms
>>>     KSYMS   .tmp_vmlinux.kallsyms1.S
>>>     AS      .tmp_vmlinux.kallsyms1.S
>>>     LD      .tmp_vmlinux.kallsyms2
>>>     NM      .tmp_vmlinux.kallsyms2.syms
>>>     KSYMS   .tmp_vmlinux.kallsyms2.S
>>>     AS      .tmp_vmlinux.kallsyms2.S
>>>     LD      vmlinux
>>>     BTFIDS  vmlinux
>>>     NM      System.map
>>>
>>>
>>>   From da4cbdb517f28f1b4254376c4f1d091a5ebca76c Mon Sep 17 00:00:00 2001
>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
>>> Date: Wed, 17 May 2023 13:15:17 +0800
>>> Subject: [PATCH] set the PAHOLE to native-sdk when KERNEL_DEBUG = True
>>>
>>> Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
>>> ---
>>>    meta/recipes-kernel/linux/linux-yocto.inc | 2 +-
>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/meta/recipes-kernel/linux/linux-yocto.inc
>>> b/meta/recipes-kernel/linux/linux-yocto.inc
>>> index 04a8105e17..90be616363 100644
>>> --- a/meta/recipes-kernel/linux/linux-yocto.inc
>>> +++ b/meta/recipes-kernel/linux/linux-yocto.inc
>>> @@ -66,7 +66,7 @@ DEPENDS += '${@bb.utils.contains_any("ARCH", [ "x86",
>>> "arm64" ], "elfutils-nativ
>>>    DEPENDS += "openssl-native util-linux-native"
>>>    DEPENDS += "gmp-native libmpc-native"
>>>    DEPENDS += '${@bb.utils.contains("KERNEL_DEBUG", "True",
>>> "pahole-native", "", d)}'
>>> -EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True", "",
>>> "PAHOLE=false", d)}'
>>> +EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True",
>>> "PAHOLE=${STAGING_DIR_NATIVE}/usr/bin/pahole", "PAHOLE=false", d)}'
>>>
>>>    do_devshell:prepend() {
>>>        # setup native pkg-config variables (kconfig scripts call
>>> pkg-config directly, cannot generically be overriden to pkg-config-native)
>>> --
>>> 2.34.1
>>>
>>>
>>> Br,
>>>
>>> Xiangyu
>>>
>>>> Br,
>>>>
>>>> Xiangyu
>>>>
>>>>> Bruce
>>>>>
>>>>>>> You can find a link to the lkml thread from the debian bug:
>>>>>>> https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1873553.html
>>>>>>>
>>>>>>> I'll clean up my patch, since this isn't something I can fix
>>>>>>> immediately.
>>>>>>>
>>>>>>> If you do track down patches in the latest kernel that haven't been
>>>>>>> sent to -stable, we can backport them to fix the linux-yocto builds
>>>>>>> with pahole.
>>>>>>>
>>>>>>> Bruce
>>>>>>>
>>>>>> Br,
>>>>>>
>>>>>> Xiangyu
>>>>>>
>>>>>>>> Bruce
>>>>>>>>
>>>>>>>>> I should check with you first to get the details on how you were
>>>>>>>>> testing pahole
>>>>>>>>> functionality.
>>>>>>>>>
>>>>>>>>> Bruce
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Br,
>>>>>>>>>
>>>>>>>>> Xiangyu
>>>>>>>>>
>>>>>>>>> Bruce
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Xiangyu
>>>>>>>>>
>>>>>>>>> Bruce
>>>>>>>>>
>>>>>>>>> Cheers,
>>>>>>>>>
>>>>>>>>> Richard
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
>>>>>>>>> await
>>>>>>>>> thee at its end
>>>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
>>>>>>>>> await
>>>>>>>>> thee at its end
>>>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
>>>>>>>>> await
>>>>>>>>> thee at its end
>>>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>>>>> --
>>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>>>>>>> thee at its end
>>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> --
>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>>>>>> thee at its end
>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>>
>>>>> --
>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
>>>>> thee at its end
>>>>> - "Use the force Harry" - Gandalf, Star Trek II
>>>>
>>>>
>>
>>
>> --
>> - 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 (#181487): https://lists.openembedded.org/g/openembedded-core/message/181487
>> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
>> Group Owner: openembedded-core+owner@lists.openembedded.org
>> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [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
Bruce Ashfield May 18, 2023, 12:25 p.m. UTC | #16
On Wed, May 17, 2023 at 10:08 PM Xiangyu Chen
<xiangyu.chen@eng.windriver.com> wrote:
>
>
> On 5/17/23 22:35, Bruce Ashfield wrote:
> > CAUTION: This email comes from a non Wind River email account!
> > Do not click links or open attachments unless you recognize the sender and know the content is safe.
> >
> > On Wed, May 17, 2023 at 8:32 AM Bruce Ashfield via
> > lists.openembedded.org
> > <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> >> On Wed, May 17, 2023 at 1:24 AM Xiangyu Chen
> >> <xiangyu.chen@eng.windriver.com> wrote:
> >>>
> >>> On 5/17/23 09:35, Xiangyu Chen wrote:
> >>>> On 5/16/23 20:55, Bruce Ashfield wrote:
> >>>>> CAUTION: This email comes from a non Wind River email account!
> >>>>> Do not click links or open attachments unless you recognize the
> >>>>> sender and know the content is safe.
> >>>>>
> >>>>> On Tue, May 16, 2023 at 4:56 AM Xiangyu Chen
> >>>>> <xiangyu.chen@eng.windriver.com> wrote:
> >>>>>> Hi Bruce,
> >>>>>>
> >>>>>>
> >>>>>> On 5/15/23 21:11, Bruce Ashfield wrote:
> >>>>>>> CAUTION: This email comes from a non Wind River email account!
> >>>>>>> Do not click links or open attachments unless you recognize the
> >>>>>>> sender and know the content is safe.
> >>>>>>>
> >>>>>>> On Mon, May 15, 2023 at 8:34 AM Bruce Ashfield via
> >>>>>>> lists.openembedded.org
> >>>>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> >>>>>>>> On Mon, May 15, 2023 at 6:04 AM Xiangyu Chen
> >>>>>>>> <xiangyu.chen@eng.windriver.com> wrote:
> >>>>>>>>> Hi Bruce,
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> Sorry for being late..
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> On 5/13/23 09:16, Bruce Ashfield wrote:
> >>>>>>>>>
> >>>>>>>>> CAUTION: This email comes from a non Wind River email account!
> >>>>>>>>> Do not click links or open attachments unless you recognize the
> >>>>>>>>> sender and know the content is safe.
> >>>>>>>>>
> >>>>>>>>> On Fri, May 12, 2023 at 10:47 AM Bruce Ashfield via
> >>>>>>>>> lists.openembedded.org
> >>>>>>>>> <bruce.ashfield=gmail.com@lists.openembedded.org> wrote:
> >>>>>>>>>
> >>>>>>>>> On Wed, May 10, 2023 at 10:23 PM Xiangyu Chen
> >>>>>>>>> <xiangyu.chen@eng.windriver.com> wrote:
> >>>>>>>>>
> >>>>>>>>> Hi Richard and Bruce,
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> Thanks for your suggestion,
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> On 5/11/23 00:25, Bruce Ashfield wrote:
> >>>>>>>>>
> >>>>>>>>> CAUTION: This email comes from a non Wind River email account!
> >>>>>>>>> Do not click links or open attachments unless you recognize the
> >>>>>>>>> sender and know the content is safe.
> >>>>>>>>>
> >>>>>>>>> On Wed, May 10, 2023 at 12:16 PM Richard Purdie
> >>>>>>>>> <richard.purdie@linuxfoundation.org> wrote:
> >>>>>>>>>
> >>>>>>>>> On Mon, 2023-05-08 at 09:33 +0800, Xiangyu Chen wrote:
> >>>>>>>>>
> >>>>>>>>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> >>>>>>>>>
> >>>>>>>>> after enable the kernel CONFIG_DEBUG_INFO_BTF in devshell, the
> >>>>>>>>> make would report some
> >>>>>>>>> errors due to pahole and elfuitls is missing, since this is a
> >>>>>>>>> debug option, so conditionally
> >>>>>>>>> add an option named "btf" in KERNEL_DEBUG_OPTIONS, if someone
> >>>>>>>>> need enable CONFIG_DEBUG_INFO_BTF
> >>>>>>>>> option in devshell, they can add KERNEL_DEBUG_OPTIONS += "btf" in
> >>>>>>>>> local.conf to solve the pahole
> >>>>>>>>> and elfutils dependency.
> >>>>>>>>>
> >>>>>>>>> Is this a defined workflow somewhere? Is KERNEL_DEBUG_OPTIONS
> >>>>>>>>> with this
> >>>>>>>>> option documented somewhere?
> >>>>>>>>>
> >>>>>>>>> I also think the mention of devshell in the commit message is
> >>>>>>>>> misleading, this issue happens regardless of how you enable the
> >>>>>>>>> option.
> >>>>>>>>> There are also other ways of enabling this than local.conf, you'd
> >>>>>>>>> likely not want people doing that at the end of development.
> >>>>>>>>>
> >>>>>>>>> I'm curious on Bruce's opinion but to me this at the very least
> >>>>>>>>> needs a
> >>>>>>>>> commit message rewrite and I'd question whether the docs elsewhere
> >>>>>>>>> would allow someone to discover this workflow anyway.
> >>>>>>>>>
> >>>>>>>>> I missed this entirely, thanks for replying to it, or I never would
> >>>>>>>>> have noticed.
> >>>>>>>>>
> >>>>>>>>> This mechanism isn't appropriate for these dependencies. I only
> >>>>>>>>> added
> >>>>>>>>> it to work around pkgconfig issues (which we can more cleanly
> >>>>>>>>> solve in
> >>>>>>>>> newer kernels  (see what I've been doing with make-mod-scripts)
> >>>>>>>>> .. so
> >>>>>>>>> it can eventually be dropped).
> >>>>>>>>>
> >>>>>>>>> We are already enabling elfutils-native conditionally on a
> >>>>>>>>> per-architecture basis (currently only x86-64).
> >>>>>>>>>
> >>>>>>>>> If we need it on more arches now, we should enable it in the version
> >>>>>>>>> specific recipes, or actually, we have moved far enough into newer
> >>>>>>>>> kernel's that it could be in the .inc now.
> >>>>>>>>>
> >>>>>>>>> This commit's background was some kernel debug options needs
> >>>>>>>>> elfutils
> >>>>>>>>> and pahole native package, since the issue happens on enabling
> >>>>>>>>> kernel
> >>>>>>>>> debug options and not all people needs it, so I conditionally add
> >>>>>>>>> the
> >>>>>>>>> dependency in KERNEL_DEBUG_OPTION.
> >>>>>>>>>
> >>>>>>>>> If possible we can enable it in .inc because newer kernel tools
> >>>>>>>>> like btf
> >>>>>>>>> are support using pkg-config to locate the libelf instead of
> >>>>>>>>> finding it
> >>>>>>>>> from /usr/ folder, so we can use elfutils-natvie instead of
> >>>>>>>>> installing
> >>>>>>>>> elfutils package on host PC.
> >>>>>>>>>
> >>>>>>>>> Similarly, we should enable the pahole-native dependency on a
> >>>>>>>>> per-arch basis.
> >>>>>>>>>
> >>>>>>>>> As Richard mentioned, what's the reproducer to see the errors ? it
> >>>>>>>>> must be more than devshell.
> >>>>>>>>>
> >>>>>>>>> Yes, this happens on devshell and normal world if some kernel debug
> >>>>>>>>> options are enabled. We can reproduce this issue with following
> >>>>>>>>> steps(I
> >>>>>>>>> have found the issue with kernel 5.15):
> >>>>>>>>>
> >>>>>>>>> 1. enable kernel option CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO and
> >>>>>>>>> CONFIG_DEBUG_INFO_BTF
> >>>>>>>>>
> >>>>>>>>> 2. build the kernel image, the compiler would report missing
> >>>>>>>>> libelf.h
> >>>>>>>>> and gelf.h which contains in elfutils-native(this step not
> >>>>>>>>> happens on
> >>>>>>>>> x86-64 due to it has been enabled).
> >>>>>>>>>
> >>>>>>>>> 3. enable elfutils-native by manual, the kernel source code can be
> >>>>>>>>> compiled successfully but failed in final step due to missing
> >>>>>>>>> pahole.
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> If you can follow up with the steps to reproduce, I can take on the
> >>>>>>>>> refactoring and broader dependency cleanup question, since I can
> >>>>>>>>> test
> >>>>>>>>> the wider matrix at the same time.
> >>>>>>>>>
> >>>>>>>>> Thanks, my local setup might missing some corner case, this is
> >>>>>>>>> another
> >>>>>>>>> reason I enable those native packages limit in
> >>>>>>>>> KERNEL_DEBUG_OPTION :).
> >>>>>>>>>
> >>>>>>>>> I've been thinking about this, and I've come to the following
> >>>>>>>>> suggestion:
> >>>>>>>>>
> >>>>>>>>> I plan on moving the elfutils-native to linux-yocto.inc, out of the
> >>>>>>>>> version specific
> >>>>>>>>> recipes.  I'll also drop the architecture specific nature of the
> >>>>>>>>> current DEPENDS.
> >>>>>>>>> The need for this is much more common now, and all of the
> >>>>>>>>> reference kernels
> >>>>>>>>> in master are new enough. The elfutils-native build dependency is
> >>>>>>>>> not
> >>>>>>>>> significant
> >>>>>>>>> enough to worry about adding it for all architectures. If it does
> >>>>>>>>> become a problem,
> >>>>>>>>> there are options to make it conditional again.
> >>>>>>>>>
> >>>>>>>>> I can drop the HOST_LIBELF_LIBS work around in the
> >>>>>>>>> linux-yocto.inc, as
> >>>>>>>>> we can now properly detect libelf via pkg-config. I didn't need
> >>>>>>>>> it in any of
> >>>>>>>>> my testing. Again, if this proves to be wrong, I'd enable it in a
> >>>>>>>>> different way now
> >>>>>>>>> (using what I've learned from fixing make-mod-scripts).
> >>>>>>>>>
> >>>>>>>>> As for the pahole-native dependency, there's been a "developer"
> >>>>>>>>> kernel-type
> >>>>>>>>> for quite some time. The design intention behind it was to enable
> >>>>>>>>> options like
> >>>>>>>>> this, and not make the "standard" or "production" kernel's too
> >>>>>>>>> large by default.
> >>>>>>>>> So the dependency could be conditional on that kernel type ...
> >>>>>>>>> but we don't
> >>>>>>>>> want to break other kernels just because they've enabled that
> >>>>>>>>> option. We also
> >>>>>>>>> don't (and won't) get into the game of looking for individual
> >>>>>>>>> options in the
> >>>>>>>>> .config to enable something, since a) it is too late b) it is a
> >>>>>>>>> moving target.
> >>>>>>>>>
> >>>>>>>>> So that leaves the following options: a) enable pahole-native
> >>>>>>>>> unconditionally
> >>>>>>>>> on the arches that support it (x86-64, aarch64) (and also move
> >>>>>>>>> the pahole
> >>>>>>>>> recipe into oe-core) b) make the KERNEL_DEBUG_OPTIONS less specific,
> >>>>>>>>> and simply call it KERNEL_DEBUG, when enabled, we could
> >>>>>>>>> conditionally
> >>>>>>>>> add pahole-native (I'd also submit documentation for the
> >>>>>>>>> functionality
> >>>>>>>>> c) something I haven't thought about ...
> >>>>>>>>>
> >>>>>>>>> I'm moving on the implementation now, but will adjust course if
> >>>>>>>>> there's something
> >>>>>>>>> I've missed.
> >>>>>>>>>
> >>>>>>>>> I have my implementation done, but I'm wondering what your
> >>>>>>>>> configuration
> >>>>>>>>> was for testing pahole ?
> >>>>>>>>>
> >>>>>>>> My reply will be hard to read, as plain text reply to the html
> >>>>>>>> doesn't
> >>>>>>>> give us proper
> >>>>>>>> context indenting.
> >>>>>>>>
> >>>>>>>>> I have tested on a devshell, with oe-master branch, the kernel
> >>>>>>>>> version using 5.15
> >>>>>>>>>
> >>>>>>>>> 1. enable pahole-native and elfutils-native in linux-yocto.inc as
> >>>>>>>>> a dependency.
> >>>>>>>>>
> >>>>>>>>> 2. enable CONFIG_DEBUG_KERNEL  CONFIG_DEBUG_INFO and
> >>>>>>>>> CONFIG_DEBUG_INFO_BTF under menuconfig
> >>>>>>>>>
> >>>>>>>>> 3. using "export PKG_CONFIG_SYSROOT_DIR=""" cleanning
> >>>>>>>>> PKG_CONFIG_SYSROOT_DIR
> >>>>>>>>>
> >>>>>>>>> 4, make
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> If the test environment using bitbake, then we need to remove
> >>>>>>>>> PAHOLE=false flag in kernel EXTRA_OEMAKE in
> >>>>>>>>> classes-recipe/kernel.bbclass, otherwise, bitbake would report
> >>>>>>>>> missing pahole error.
> >>>>>>>>>
> >>>>>>>> That's the same as my patch series (I've also changed PAHOLE=false to
> >>>>>>>> a conditional in my series).
> >>>>>>>>
> >>>>>>>>> I'm seeing the following in qemux86-64 at the end of the build:
> >>>>>>>>>
> >>>>>>>>> | Unsupported DW_TAG_unspecified_type(0x3b)
> >>>>>>>>> | Encountered error while encoding BTF.
> >>>>>>>>> |   LD      .tmp_vmlinux.kallsyms1
> >>>>>>>>> |   NM      .tmp_vmlinux.kallsyms1.syms
> >>>>>>>>> |   KSYMS   .tmp_vmlinux.kallsyms1.S
> >>>>>>>>> |   AS      .tmp_vmlinux.kallsyms1.S
> >>>>>>>>> |   LD      .tmp_vmlinux.kallsyms2
> >>>>>>>>> |   NM      .tmp_vmlinux.kallsyms2.syms
> >>>>>>>>> |   KSYMS   .tmp_vmlinux.kallsyms2.S
> >>>>>>>>> |   AS      .tmp_vmlinux.kallsyms2.S
> >>>>>>>>> |   LD      vmlinux
> >>>>>>>>> |   BTFIDS  vmlinux
> >>>>>>>>> | FAILED: load BTF from vmlinux: No such file or directory
> >>>>>>>>> | make[1]: ***
> >>>>>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/Makefile.vmlinux:34:
> >>>>>>>>> vmlinux] Error 255
> >>>>>>>>> | make[1]: *** Deleting file 'vmlinux'
> >>>>>>>>> | make: ***
> >>>>>>>>> [/opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/Makefile:1255:
> >>>>>>>>>
> >>>>>>>>> vmlinux] Error 2
> >>>>>>>>>
> >>>>>>>>> I haven't looked into it at all yet (but will do so over the
> >>>>>>>>> weekend)
> >>>>>>>>> .. but I thought
> >>>>>>>>>
> >>>>>>>>> I haven't seen this problem yet(i'll pull the latest oe-core and
> >>>>>>>>> meta-oe code and try again), if possible, could you share a patch
> >>>>>>>>> with me so that we can test it together? thanks.
> >>>>>>>>>
> >>>>>>>> I'm on oe-core master, with qemux86-64.
> >>>>>>>>
> >>>>>>>> I'll do a bit more work on the patch today, and can share it if I
> >>>>>>>> can't figure out where that unsupported tag is coming from.
> >>>>>>> It seems like it is a known issue, I found both a lkml thread and
> >>>>>>> debian bug from October 2022.
> >>>>>>>
> >>>>>>> Your 5.15 kernel wouldn't show the issue.
> >>>>>> Yes, this should not happens on 5.15 kernel.
> >>>>>>
> >>>>>>
> >>>>>> Today I synced the oe-core/poky to latest master version, removed the
> >>>>>> build dir and run oe-init-build-env again and switched to use default
> >>>>>> linux 6.1.25 instead of 5.15.
> >>>>>>
> >>>>>> Some kernel config has been updated, there is no CONFIG_DEBUG_INFO, I
> >>>>>> used CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT.
> >>>>>>
> >>>>>> So, currently my local setup kernel config is enabled
> >>>>>> CONFIG_DEBUG_KERNEL CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and
> >>>>>> CONFIG_DEBUG_INFO_BTF, in order to make a easy test, I enabled
> >>>>>> elfutils-native and pahole-native as DEPEND directly in linux-yocto.in,
> >>>>>> and remove the PAHOLE=false in EXTRA_OEMAKE.
> >>>>>>
> >>>>>> my oe-core rev: 35e5d29a7d654fc79bdb898d0f1fb277270dbfd5
> >>>>>>
> >>>>>> my meta-oe rev:b7aa66d734b911737b61610c1c47778e14b15c55
> >>>>>>
> >>>>>>
> >>>>>> When I ran bitbake linux-yocto -v -D, I have met the same issue,
> >>>>>>
> >>>>>> | Unsupported DW_TAG_unspecified_type(0x3b)
> >>>>>> | Encountered error while encoding BTF.
> >>>>>>
> >>>>>> It's bit strange that the I removed my local OS(ubuntu)'s pahole and
> >>>>>> the
> >>>>>> code can be compiled without error:
> >>>>>>
> >>>>>>
> >>>>>>      CC      init/version-timestamp.o
> >>>>>>      LD      .tmp_vmlinux.btf
> >>>>>>      BTF     .btf.vmlinux.bin.o
> >>>>>>      LD      .tmp_vmlinux.kallsyms1
> >>>>>>      NM      .tmp_vmlinux.kallsyms1.syms
> >>>>>>      KSYMS   .tmp_vmlinux.kallsyms1.S
> >>>>>>      AS      .tmp_vmlinux.kallsyms1.S
> >>>>>>      LD      .tmp_vmlinux.kallsyms2
> >>>>>>      NM      .tmp_vmlinux.kallsyms2.syms
> >>>>>>      KSYMS   .tmp_vmlinux.kallsyms2.S
> >>>>>>      AS      .tmp_vmlinux.kallsyms2.S
> >>>>>>      LD      vmlinux
> >>>>>>      BTFIDS  vmlinux
> >>>>>>      NM      System.map
> >>>>>>      SORTTAB vmlinux
> >>>>>>
> >>>>> Indeed!
> >>>>>
> >>>>> What's the toolchain version on your ubuntu install ?
> >>>> My local ubuntu's default pahole version is 1.22,seems some data
> >>>> structure not line up with new kernel, the yocto pahole package is
> >>>> 1.24 is working well.
> >>>>
> >>>> $ pahole --version
> >>>> v1.22
> >>>>
> >>>>
> >>>>> It is likely
> >>>>> either our toolchain version or configuration in combination with the
> >>>>> kernel version that is adding the section that pahole can't
> >>>>> understand/decode.
> >>>> Yes, perhaps this is a limitation, we have to use PAHOLE in
> >>>> EXTRA_OEMAKE to tell the make using pahole from the yocto native-sdk
> >>>> instead of local host OS's /usr/bin/pahole when building the kernel.
> >>>>> If you want to work with my patches, you can find my branch here:
> >>>>>
> >>>>> https://git.yoctoproject.org/poky-contrib/log/?h=zedd/kernel
> >>>>>
> >>>>> (you also need the linux-yocto bumps on that branch as they'll contain
> >>>>> the kernel-cache SRCREV bumps to pick up the fragments for BTF, etc).
> >>>> Thanks, I will sync the branch today and feedback later :)
> >>>>
> >>> Hi Bruce,
> >>>
> >>>
> >>> I used the zedd/kernel branch build a qmemux86-64 kernel image,
> >>> everything goes well.
> >>>
> >>> Shall we set the PAHOLE to native-sdk in EXTRA_OEMAKE to make sure
> >>> kernel make use pahole from yocto not from host pc?
> >> We shouldn't have to explicitly pass pahole like that, as our SDK and
> >> native-sysroot paths
> >> should be found first.
> >>
> >> But if you were able to have it succeed and mine didn't ... that could
> >> be the issue.
> >>
> >> Thanks for the suggestion, I'll test it today and if so, I'll update
> >> the patch accordingly
> >> and add your sign-off.
> > I instrumented the scripts to echo the pahole binary being used, and
> > as expected, the build environment is setup to prefer our sysroot
> > binaries (without that setup, we'd have all sorts of host
> > contamination).
> >
> > |   GEN     Makefile
> > |   DESCEND objtool
> > |   DESCEND bpf/resolve_btfids
> > |   CALL    /opt/poky/build/tmp/work-shared/qemux86-64/kernel-source/scripts/checksyscalls.sh
> > | /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> > |   LD      .tmp_vmlinux.btf
> > |   BTF     .btf.vmlinux.bin.o
> > | Unsupported DW_TAG_unspecified_type(0x3b)
> > | Encountered error while encoding BTF.
> > | /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> > |   LD      .tmp_vmlinux.kallsyms1
> > |   NM      .tmp_vmlinux.kallsyms1.syms
> > |   KSYMS   .tmp_vmlinux.kallsyms1.S
> > |   AS      .tmp_vmlinux.kallsyms1.S
> > | /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> > |   LD      .tmp_vmlinux.kallsyms2
> > |   NM      .tmp_vmlinux.kallsyms2.syms
> > |   KSYMS   .tmp_vmlinux.kallsyms2.S
> > |   AS      .tmp_vmlinux.kallsyms2.S
> > | /opt/poky/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+a18c55d2fc_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> > |   LD      vmlinux
> > |   BTFIDS  vmlinux
> > | FAILED: load BTF from vmlinux: No such file or directory
> >
> > But as you can see, I still get the DW_TAG issues.
> >
> > My fragments are setting CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT,
> > and the required debug
> > options.  Those are enabled by the following in local.conf:
> >
> > KERNEL_FEATURES:append = "ktypes/developer/developer.cfg
> > features/debug/debug-stack.scc features/debug/debug-btf.scc"
> >
> > Can you confirm that your success run used both the yocto/bitbake
> > build and my fragments for configuration ?
> >
> > There must still be something different that I'm missing.
>
> Hi Bruce,
>
>
> I have verified add "KERNEL_FEATURES:append =
> "ktypes/developer/developer.cfg features/debug/debug-stack.scc
> features/debug/debug-btf.scc" "
>
> in local.conf today, I cleaned the source with bitbake linux-yocto -c
> cleanall and rebuilt, the result the same as before, BTF information was
> generated
>
> without any error, in order to add more information, I uploaded the full
> log as following link:
>
> https://raw.githubusercontent.com/chenxy1988/sync/main/oe-core-181487/1/linux-yocto-build.log
>
>
> and my host pc os information:
>
> PRETTY_NAME="Ubuntu 22.04.2 LTS"
> NAME="Ubuntu"
> VERSION_ID="22.04"
> VERSION="22.04.2 LTS (Jammy Jellyfish)"
> VERSION_CODENAME=jammy
> ID=ubuntu
> ID_LIKE=debian
> HOME_URL="https://www.ubuntu.com/"
> SUPPORT_URL="https://help.ubuntu.com/"
> BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
> PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
> UBUNTU_CODENAME=jammy
>
>
> If possible, could you share the local.conf with me so that I can test
> in my setup? And, there is another clue,
>
> i am not sure this is a right way to locate the root cause, since this
> issue happens on pahole, can we exchange the
>
> pahole native binary which was generated by yocto to replace
> linux-yocto/6.1.28+gitAUTOINC+76f7fbdf33_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
>
>
> if something wrong with pahole-native, my setup should also report the
> DW_TAG_unspecified_type issue.
>
>
> The following link is the pahole native binary that was generated by
> yocto in my local environment:
>
> https://github.com/chenxy1988/sync/blob/main/oe-core-181487/1/pahole-native-yocto.tar.gz
>

I have it working on my builder.

I didn't realize, but I was on one of my machines with an older
meta-openembedded, so my
pahole native binary was just a bit too old!

Which is a reason to consider moving pahole to oe-core.

For now, I'll leave pahole where it is, and complete testing.

I'm away all of next week, so I won't submit my queue for merging
until I return. But I
will keep my zedd/kernel contrib branch up to date with the latest set
of patches.

Bruce

>
>
> Br,
>
> Xiangyu
>
>
> >
> > Bruce
> >
> >> Bruce
> >>
> >>> I tried to attached a patch as below, it has been tested on my local
> >>> setup, from log we can see the PAHOLE point to native-sdk:
> >>>
> >>> -O2 -pipe
> >>> PAHOLE=/local/upstream/poky-contrib/build/tmp/work/qemux86_64-poky-linux/linux-yocto/6.1.28+gitAUTOINC+76f7fbdf33_c5c0c7ccfe-r0/recipe-sysroot-native/usr/bin/pahole
> >>> -j 20 bzImage
> >>>
> >>> and the image build without error:
> >>>
> >>>     LD      .tmp_vmlinux.btf
> >>>     BTF     .btf.vmlinux.bin.o
> >>>     LD      .tmp_vmlinux.kallsyms1
> >>>     NM      .tmp_vmlinux.kallsyms1.syms
> >>>     KSYMS   .tmp_vmlinux.kallsyms1.S
> >>>     AS      .tmp_vmlinux.kallsyms1.S
> >>>     LD      .tmp_vmlinux.kallsyms2
> >>>     NM      .tmp_vmlinux.kallsyms2.syms
> >>>     KSYMS   .tmp_vmlinux.kallsyms2.S
> >>>     AS      .tmp_vmlinux.kallsyms2.S
> >>>     LD      vmlinux
> >>>     BTFIDS  vmlinux
> >>>     NM      System.map
> >>>
> >>>
> >>>   From da4cbdb517f28f1b4254376c4f1d091a5ebca76c Mon Sep 17 00:00:00 2001
> >>> From: Xiangyu Chen <xiangyu.chen@windriver.com>
> >>> Date: Wed, 17 May 2023 13:15:17 +0800
> >>> Subject: [PATCH] set the PAHOLE to native-sdk when KERNEL_DEBUG = True
> >>>
> >>> Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
> >>> ---
> >>>    meta/recipes-kernel/linux/linux-yocto.inc | 2 +-
> >>>    1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/meta/recipes-kernel/linux/linux-yocto.inc
> >>> b/meta/recipes-kernel/linux/linux-yocto.inc
> >>> index 04a8105e17..90be616363 100644
> >>> --- a/meta/recipes-kernel/linux/linux-yocto.inc
> >>> +++ b/meta/recipes-kernel/linux/linux-yocto.inc
> >>> @@ -66,7 +66,7 @@ DEPENDS += '${@bb.utils.contains_any("ARCH", [ "x86",
> >>> "arm64" ], "elfutils-nativ
> >>>    DEPENDS += "openssl-native util-linux-native"
> >>>    DEPENDS += "gmp-native libmpc-native"
> >>>    DEPENDS += '${@bb.utils.contains("KERNEL_DEBUG", "True",
> >>> "pahole-native", "", d)}'
> >>> -EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True", "",
> >>> "PAHOLE=false", d)}'
> >>> +EXTRA_OEMAKE += '${@bb.utils.contains("KERNEL_DEBUG", "True",
> >>> "PAHOLE=${STAGING_DIR_NATIVE}/usr/bin/pahole", "PAHOLE=false", d)}'
> >>>
> >>>    do_devshell:prepend() {
> >>>        # setup native pkg-config variables (kconfig scripts call
> >>> pkg-config directly, cannot generically be overriden to pkg-config-native)
> >>> --
> >>> 2.34.1
> >>>
> >>>
> >>> Br,
> >>>
> >>> Xiangyu
> >>>
> >>>> Br,
> >>>>
> >>>> Xiangyu
> >>>>
> >>>>> Bruce
> >>>>>
> >>>>>>> You can find a link to the lkml thread from the debian bug:
> >>>>>>> https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1873553.html
> >>>>>>>
> >>>>>>> I'll clean up my patch, since this isn't something I can fix
> >>>>>>> immediately.
> >>>>>>>
> >>>>>>> If you do track down patches in the latest kernel that haven't been
> >>>>>>> sent to -stable, we can backport them to fix the linux-yocto builds
> >>>>>>> with pahole.
> >>>>>>>
> >>>>>>> Bruce
> >>>>>>>
> >>>>>> Br,
> >>>>>>
> >>>>>> Xiangyu
> >>>>>>
> >>>>>>>> Bruce
> >>>>>>>>
> >>>>>>>>> I should check with you first to get the details on how you were
> >>>>>>>>> testing pahole
> >>>>>>>>> functionality.
> >>>>>>>>>
> >>>>>>>>> Bruce
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> Br,
> >>>>>>>>>
> >>>>>>>>> Xiangyu
> >>>>>>>>>
> >>>>>>>>> Bruce
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> Xiangyu
> >>>>>>>>>
> >>>>>>>>> Bruce
> >>>>>>>>>
> >>>>>>>>> Cheers,
> >>>>>>>>>
> >>>>>>>>> Richard
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> >>>>>>>>> await
> >>>>>>>>> thee at its end
> >>>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> >>>>>>>>> await
> >>>>>>>>> thee at its end
> >>>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness
> >>>>>>>>> await
> >>>>>>>>> thee at its end
> >>>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>>>> --
> >>>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> >>>>>>>> thee at its end
> >>>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>> --
> >>>>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> >>>>>>> thee at its end
> >>>>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>>
> >>>>> --
> >>>>> - Thou shalt not follow the NULL pointer, for chaos and madness await
> >>>>> thee at its end
> >>>>> - "Use the force Harry" - Gandalf, Star Trek II
> >>>>
> >>>>
> >>
> >>
> >> --
> >> - 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 (#181487): https://lists.openembedded.org/g/openembedded-core/message/181487
> >> Mute This Topic: https://lists.openembedded.org/mt/98753313/1050810
> >> Group Owner: openembedded-core+owner@lists.openembedded.org
> >> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [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
diff mbox series

Patch

diff --git a/meta/recipes-kernel/linux/linux-yocto.inc b/meta/recipes-kernel/linux/linux-yocto.inc
index 934591ff1c..67d72c8c21 100644
--- a/meta/recipes-kernel/linux/linux-yocto.inc
+++ b/meta/recipes-kernel/linux/linux-yocto.inc
@@ -61,6 +61,8 @@  KERNEL_FEATURES:append:qemuall=" features/kernel-sample/kernel-sample.scc"
 
 KERNEL_DEBUG_OPTIONS ?= "stack"
 KERNEL_EXTRA_ARGS:append:x86-64 = " ${@bb.utils.contains('KERNEL_DEBUG_OPTIONS', 'stack', 'HOST_LIBELF_LIBS="-L${RECIPE_SYSROOT_NATIVE}/usr/lib/pkgconfig/../../../usr/lib/ -lelf"', '', d)}"
+DEPENDS += "${@bb.utils.contains('KERNEL_DEBUG_OPTIONS', 'btf', 'pahole-native', '', d)}"
+DEPENDS += "${@bb.utils.contains('KERNEL_DEBUG_OPTIONS', 'btf', 'elfutils-native', '', d)}"
 
 do_devshell:prepend() {
     # setup native pkg-config variables (kconfig scripts call pkg-config directly, cannot generically be overriden to pkg-config-native)