79191f8590
The pkg-config workaround has been applied for kernel image building, but
not for module building. So pkg-config variables are different between
do_compile and do_compile_kernelmodules tasks. It may unnecessary trigger
rebuilding of a few host tools at the later task.
Especially when CONFIG_DEBUG_INFO_BTF is enabled in the kernel, it may even
trigger rebuilding vmlinux at do_compile_kernelmodules due to the rebuilt
host tools such as certs/extract-cert or objtool (on x86). This eventually
creates an inconsistent set of kernel binaries.
Here is the repro steps:
- Check out nanbield on x86
- The unexpected rebuild happens on kirkstone or possibly earlier
- Ensure that pahole is available (e.g. via meta-oe)
- Set KERNEL_DEBUG to "True" to properly set up PAHOLE
e.g.
$ export KERNEL_DEBUG="True"
$ export BB_ENV_PASSTHROUGH_ADDITIONS="${BB_ENV_PASSTHROUGH_ADDITIONS} KERNEL_DEBUG"
- Enable CONFIG_DEBUG_INFO_BTF=y
e.g.
$ bitbake -c menuconfig virtual/kernel
-> Kernel hacking
-> Compile-time checks and compiler options
-> Generate BTF typeinfo
- Build the kernel
e.g.
$ bitbake virtual/kernel
The BTF information in the resulting bzImage and kernel modules are
inconsistent, because the module's BTF information is generated using the
"second" vmlinux that doesn't have the identical BTF to the "first" vmlinux.
These modules can't be loaded at runtime due to the BTF mismatch.
This also leads to a build-id mismatch between the installed bzImage and
vmlinux since the bzImage is created from the first vmlinux, but the
installed vmlinux is the second one.
$ eu-readelf -n tmp/work/qemux86_64-poky-linux/linux-yocto/6.5.13+git/image/boot/{bzImage*,vmlinux*} | grep "Build ID"
Build ID: 4a0d62ee7fef0244950f0f604253729875bea493
Build ID: fb99b3d91399dbe42bf67ddee59e0f5a0c7f74d9
To avoid the unexpected rebuilding that results in such inconsistency, set
the same pkg-config variables when building kernel and modules. For kernel
5.19 and above, simply set the HOSTPKG_CONFIG in the make command line.
(From OE-Core rev: cd2072e5d953af981339427028e19083257e6a92)
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Poky
Poky is an integration of various components to form a pre-packaged build system and development environment which is used as a development and validation tool by the Yocto Project. It features support for building customised embedded style device images and custom containers. There are reference demo images ranging from X11/GTK+ to Weston, commandline and more. The system supports cross-architecture application development using QEMU emulation and a standalone toolchain and SDK suitable for IDE integration.
Additional information on the specifics of hardware that Poky supports is available in README.hardware. Further hardware support can easily be added in the form of BSP layers which extend the systems capabilities in a modular way. Many layers are available and can be found through the layer index.
As an integration layer Poky consists of several upstream projects such as BitBake, OpenEmbedded-Core, Yocto documentation, the 'meta-yocto' layer which has configuration and hardware support components. These components are all part of the Yocto Project and OpenEmbedded ecosystems.
The Yocto Project has extensive documentation about the system including a reference manual which can be found at https://docs.yoctoproject.org/
OpenEmbedded is the build architecture used by Poky and the Yocto project. For information about OpenEmbedded, see the OpenEmbedded website.
Contribution Guidelines
Please refer to our contributor guide here: https://docs.yoctoproject.org/dev/contributor-guide/ for full details on how to submit changes.
Where to Send Patches
As Poky is an integration repository (built using a tool called combo-layer), patches against the various components should be sent to their respective upstreams:
OpenEmbedded-Core (files in meta/, meta-selftest/, meta-skeleton/, scripts/):
- Git repository: https://git.openembedded.org/openembedded-core/
- Mailing list: openembedded-core@lists.openembedded.org
BitBake (files in bitbake/):
- Git repository: https://git.openembedded.org/bitbake/
- Mailing list: bitbake-devel@lists.openembedded.org
Documentation (files in documentation/):
- Git repository: https://git.yoctoproject.org/cgit/cgit.cgi/yocto-docs/
- Mailing list: docs@lists.yoctoproject.org
meta-yocto (files in meta-poky/, meta-yocto-bsp/):
- Git repository: https://git.yoctoproject.org/cgit/cgit.cgi/meta-yocto
- Mailing list: poky@lists.yoctoproject.org
If in doubt, check the openembedded-core git repository for the content you intend to modify as most files are from there unless clearly one of the above categories. Before sending, be sure the patches apply cleanly to the current git repository branch in question.