383 Commits

Author SHA1 Message Date
Inochi Amaoto
b5e3956535 kbuild: install-extmod-build: Fix build when specifying KBUILD_OUTPUT
Since commit 5f73e7d038 ("kbuild: refactor cross-compiling
linux-headers package"), the linux-headers pacman package fails
to build when "O=" is set. The build system complains:

/mnt/chroot/linux/scripts/Makefile.build:41: mnt/chroots/linux-mainline/pacman/linux-upstream/pkg/linux-upstream-headers/usr//lib/modules/6.14.0-rc3-00350-g771dba31fffc/build/scripts/Makefile: No such file or directory

This is because the "srcroot" variable is set to "." and the
"build" variable is set to the absolute path. This makes the
"src" variables point to wrong directory.

Change the "build" variable to a relative path to "." to
fix build.

Fixes: 5f73e7d038 ("kbuild: refactor cross-compiling linux-headers package")
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-06 20:32:30 +09:00
Masahiro Yamada
140332b6ed kbuild: fix linux-headers package build when $(CC) cannot link userspace
Since commit 5f73e7d038 ("kbuild: refactor cross-compiling
linux-headers package"), the linux-headers Debian package fails to
build when $(CC) cannot build userspace applications, for example,
when using toolchains installed by the 0day bot.

The host programs in the linux-headers package should be rebuilt using
the disto's cross-compiler, ${DEB_HOST_GNU_TYPE}-gcc instead of $(CC).
Hence, the variable 'CC' must be expanded in this shell script instead
of in the top-level Makefile.

Commit f354fc88a7 ("kbuild: install-extmod-build: add missing
quotation marks for CC variable") was not a correct fix because
CC="ccache gcc" should be unrelated when rebuilding userspace tools.

Fixes: 5f73e7d038 ("kbuild: refactor cross-compiling linux-headers package")
Reported-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Closes: https://lore.kernel.org/linux-kbuild/CAK7LNARb3xO3ptBWOMpwKcyf3=zkfhMey5H2KnB1dOmUwM79dA@mail.gmail.com/T/#t
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
2025-02-15 22:40:52 +09:00
WangYuli
f354fc88a7 kbuild: install-extmod-build: add missing quotation marks for CC variable
While attempting to build a Debian packages with CC="ccache gcc", I
saw the following error as builddeb builds linux-headers-$KERNELVERSION:

  make HOSTCC=ccache gcc VPATH= srcroot=. -f ./scripts/Makefile.build obj=debian/linux-headers-6.14.0-rc1/usr/src/linux-headers-6.14.0-rc1/scripts
  make[6]: *** No rule to make target 'gcc'.  Stop.

Upon investigation, it seems that one instance of $(CC) variable reference
in ./scripts/package/install-extmod-build was missing quotation marks,
causing the above error.

Add the missing quotation marks around $(CC) to fix build.

Fixes: 5f73e7d038 ("kbuild: refactor cross-compiling linux-headers package")
Co-developed-by: Mingcong Bai <jeffbai@aosc.io>
Signed-off-by: Mingcong Bai <jeffbai@aosc.io>
Tested-by: WangYuli <wangyuli@uniontech.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-02-08 03:37:57 +09:00
Masahiro Yamada
82a1978d0f kheaders: use 'tar' instead of 'cpio' for copying files
The 'cpio' command is used solely for copying header files to the
temporary directory. However, there is no strong reason to use 'cpio'
for this purpose. For example, scripts/package/install-extmod-build
uses the 'tar' command to copy files.

This commit replaces the use of 'cpio' with 'tar' because 'tar' is
already used in this script to generate kheaders_data.tar.xz anyway.

Performance-wide, there is no significant difference between 'cpio'
and 'tar'.

[Before]

  $ rm -fr kheaders; mkdir kheaders
  $ time sh -c '
  for f in include arch/x86/include
  do
          find "$f" -name "*.h"
  done | cpio --quiet -pd kheaders
  '
  real    0m0.148s
  user    0m0.021s
  sys     0m0.140s

[After]

  $ rm -fr kheaders; mkdir kheaders
  $ time sh -c '
  for f in include arch/x86/include
  do
          find "$f" -name "*.h"
  done | tar -c -f - -T - | tar -xf - -C kheaders
  '
  real    0m0.098s
  user    0m0.024s
  sys     0m0.131s

Revert commit 69ef0920bd ("Docs: Add cpio requirement to changes.rst")
because 'cpio' is not used anywhere else during the kernel build.
Please note that the built-in initramfs is created by the in-tree tool,
usr/gen_init_cpio, so it does not rely on the external 'cpio' command
at all.

Remove 'cpio' from the package build dependencies as well.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-10 23:01:22 +09:00
Masahiro Yamada
5f73e7d038 kbuild: refactor cross-compiling linux-headers package
Since commit 13b25489b6 ("kbuild: change working directory to external
module directory with M="), when cross-building host programs for the
linux-headers package, the "Entering directory" and "Leaving directory"
messages appear multiple times, and each object path shown is relative
to the working directory. This makes it difficult to track which objects
are being rebuilt.

In hindsight, using the external module build (M=) was not a good idea.

This commit simplifies the script by leveraging the run-command target,
resulting in a cleaner build log again.

[Before]

  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- bindeb-pkg
    [ snip ]
  Rebuilding host programs with aarch64-linux-gnu-gcc...
  make[5]: Entering directory '/home/masahiro/linux'
  make[6]: Entering directory '/home/masahiro/linux/debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+'
    HOSTCC  scripts/kallsyms
    HOSTCC  scripts/sorttable
    HOSTCC  scripts/asn1_compiler
  make[6]: Leaving directory '/home/masahiro/linux/debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+'
  make[5]: Leaving directory '/home/masahiro/linux'
  make[5]: Entering directory '/home/masahiro/linux'
  make[6]: Entering directory '/home/masahiro/linux/debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+'
    HOSTCC  scripts/basic/fixdep
    HOSTCC  scripts/mod/modpost.o
    HOSTCC  scripts/mod/file2alias.o
    HOSTCC  scripts/mod/sumversion.o
    HOSTCC  scripts/mod/symsearch.o
    HOSTLD  scripts/mod/modpost
  make[6]: Leaving directory '/home/masahiro/linux/debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+'
  make[5]: Leaving directory '/home/masahiro/linux'

[After]

  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- bindeb-pkg
    [ snip ]
    HOSTCC  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/basic/fixdep
    HOSTCC  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/kallsyms
    HOSTCC  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/sorttable
    HOSTCC  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/asn1_compiler
    HOSTCC  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/mod/modpost.o
    HOSTCC  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/mod/file2alias.o
    HOSTCC  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/mod/sumversion.o
    HOSTCC  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/mod/symsearch.o
    HOSTLD  debian/linux-headers-6.13.0-rc1+/usr/src/linux-headers-6.13.0-rc1+/scripts/mod/modpost

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-10 23:01:21 +09:00
Johannes Schauer Marin Rodrigues
ac2c30f98f kbuild: deb-pkg: allow hooks also in /usr/share/kernel
By passing an additional directory to run-parts, allow Debian and its
derivatives to ship maintainer scripts in /usr while at the same time
allowing the local admin to override or disable them by placing hooks of
the same name in /etc. This adds support for the mechanism described in
the UAPI Configuration Files Specification for kernel hooks. The same
idea is also used by udev, systemd or modprobe for their config files.
https://uapi-group.org/specifications/specs/configuration_files_specification/

This functionality relies on run-parts 5.21 or later.  It is the
responsibility of packages installing hooks into /usr/share/kernel to
also declare a Depends: debianutils (>= 5.21).

KDEB_HOOKDIR can be used to change the list of directories that is
searched. By default, /etc/kernel and /usr/share/kernel are hook
directories. Since the list of directories in KDEB_HOOKDIR is separated
by spaces, the paths must not contain the space character themselves.

Signed-off-by: Johannes Schauer Marin Rodrigues <josch@mister-muffin.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-10 23:01:21 +09:00
Masahiro Yamada
d9ecb92b4f kbuild: deb-pkg: do not include empty hook directories
The linux-image package currently includes empty hook directories
(/etc/kernel/{pre,post}{inst,rm}.d/ by default).

These directories were perhaps intended as a fail-safe in case no
hook scripts exist there.

However, they are really unnecessary because the run-parts command is
already guarded by the following check:

    test -d ${debhookdir}/${script}.d && run-parts ...

The only difference is that the run-parts command either runs for empty
directories (resulting in a no-op) or is skipped entirely.

The maintainer scripts will succeed without these dummy directories.

The linux-image packages from the Debian kernel do not contain
/etc/kernel/*.d/, either.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-10 23:01:21 +09:00
Thomas Weißschuh
385443057f kbuild: pacman-pkg: provide versioned linux-api-headers package
The Arch Linux glibc package contains a versioned dependency on
"linux-api-headers". If the linux-api-headers package provided by
pacman-pkg does not specify an explicit version this dependency is not
satisfied.
Fix the dependency by providing an explicit version.

Fixes: c8578539de ("kbuild: add script and target to generate pacman package")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-05 23:19:17 +09:00
Nicolas Schier
54956567a0 kbuild: deb-pkg: Do not install maint scripts for arch 'um'
Stop installing Debian maintainer scripts when building a
user-mode-linux Debian package.

Debian maintainer scripts are used for e.g. requesting rebuilds of
initrd, rebuilding DKMS modules and updating of grub configuration.  As
all of this is not relevant for UML but also may lead to failures while
processing the kernel hooks, do no more install maintainer scripts for
the UML package.

Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-12-21 12:42:10 +09:00
Masahiro Yamada
a34e92d2e8 kbuild: deb-pkg: add debarch for ARCH=um
'make ARCH=um bindeb-pkg' shows the following warning.

  $ make ARCH=um bindeb-pkg
     [snip]
    GEN     debian

  ** ** **  WARNING  ** ** **

  Your architecture doesn't have its equivalent
  Debian userspace architecture defined!
  Falling back to the current host architecture (amd64).
  Please add support for um to ./scripts/package/mkdebian ...

This commit hard-codes i386/amd64 because UML is only supported for x86.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-12-21 12:42:04 +09:00
Masahiro Yamada
d8d326d64f kbuild: deb-pkg: fix build error with O=
Since commit 13b25489b6 ("kbuild: change working directory to external
module directory with M="), the Debian package build fails if a relative
path is specified with the O= option.

  $ make O=build bindeb-pkg
    [ snip ]
  dpkg-deb: building package 'linux-image-6.13.0-rc1' in '../linux-image-6.13.0-rc1_6.13.0-rc1-6_amd64.deb'.
  Rebuilding host programs with x86_64-linux-gnu-gcc...
  make[6]: Entering directory '/home/masahiro/linux/build'
  /home/masahiro/linux/Makefile:190: *** specified kernel directory "build" does not exist.  Stop.

This occurs because the sub_make_done flag is cleared, even though the
working directory is already in the output directory.

Passing KBUILD_OUTPUT=. resolves the issue.

Fixes: 13b25489b6 ("kbuild: change working directory to external module directory with M=")
Reported-by: Charlie Jenkins <charlie@rivosinc.com>
Closes: https://lore.kernel.org/all/Z1DnP-GJcfseyrM3@ghost/
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-12-08 17:11:34 +09:00
Masahiro Yamada
6b1fabce73 kbuild: deb-pkg: add python3:native to build dependency
Python3 is necessary for running some scripts such as
drivers/gpu/drm/msm/registers/gen_header.py

Both scripts/package/kernel.spec and scripts/package/PKGBUILD already
list Python as the build dependency.

Do likewise for scripts/package/mkdebian.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-11-28 08:46:03 +09:00
Masahiro Yamada
13b25489b6 kbuild: change working directory to external module directory with M=
Currently, Kbuild always operates in the output directory of the kernel,
even when building external modules. This increases the risk of external
module Makefiles attempting to write to the kernel directory.

This commit switches the working directory to the external module
directory, allowing the removal of the $(KBUILD_EXTMOD)/ prefix from
some build artifacts.

The command for building external modules maintains backward
compatibility, but Makefiles that rely on working in the kernel
directory may break. In such cases, $(objtree) and $(srctree) should
be used to refer to the output and source directories of the kernel.

The appearance of the build log will change as follows:

[Before]

  $ make -C /path/to/my/linux M=/path/to/my/externel/module
  make: Entering directory '/path/to/my/linux'
    CC [M]  /path/to/my/externel/module/helloworld.o
    MODPOST /path/to/my/externel/module/Module.symvers
    CC [M]  /path/to/my/externel/module/helloworld.mod.o
    CC [M]  /path/to/my/externel/module/.module-common.o
    LD [M]  /path/to/my/externel/module/helloworld.ko
  make: Leaving directory '/path/to/my/linux'

[After]

  $ make -C /path/to/my/linux M=/path/to/my/externel/module
  make: Entering directory '/path/to/my/linux'
  make[1]: Entering directory '/path/to/my/externel/module'
    CC [M]  helloworld.o
    MODPOST Module.symvers
    CC [M]  helloworld.mod.o
    CC [M]  .module-common.o
    LD [M]  helloworld.ko
  make[1]: Leaving directory '/path/to/my/externel/module'
  make: Leaving directory '/path/to/my/linux'

Printing "Entering directory" twice is cumbersome. This will be
addressed later.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-11-28 08:10:23 +09:00
Matt Fleming
bcbbf493f2 kbuild: deb-pkg: Don't fail if modules.order is missing
Kernels built without CONFIG_MODULES might still want to create -dbg deb
packages but install_linux_image_dbg() assumes modules.order always
exists. This obviously isn't true if no modules were built, so we should
skip reading modules.order in that case.

Fixes: 16c36f8864 ("kbuild: deb-pkg: use build ID instead of debug link for dbg package")
Signed-off-by: Matt Fleming <mfleming@cloudflare.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Masahiro Yamada
2ad7126c51 kbuild: deb-pkg: add pkg.linux-upstream.nokerneldbg build profile
The Debian kernel supports the pkg.linux.nokerneldbg build profile.

The debug package tends to become huge, and you may not want to build
it even when CONFIG_DEBUG_INFO is enabled.

This commit introduces a similar profile for the upstream kernel.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-10-31 21:41:02 +09:00
Masahiro Yamada
e2c318225a kbuild: deb-pkg: add pkg.linux-upstream.nokernelheaders build profile
Since commit f1d87664b8 ("kbuild: cross-compile linux-headers package
when possible"), 'make bindeb-pkg' may attempt to cross-compile the
linux-headers package, but it fails under certain circumstances.

For example, when CONFIG_MODULE_SIG_FORMAT is enabled on Debian, the
following command fails:

  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- bindeb-pkg
      [ snip ]
  Rebuilding host programs with aarch64-linux-gnu-gcc...
    HOSTCC  debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/kallsyms
    HOSTCC  debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/sorttable
    HOSTCC  debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/asn1_compiler
    HOSTCC  debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/sign-file
  In file included from /usr/include/openssl/opensslv.h:109,
                   from debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/sign-file.c:25:
  /usr/include/openssl/macros.h:14:10: fatal error: openssl/opensslconf.h: No such file or directory
     14 | #include <openssl/opensslconf.h>
        |          ^~~~~~~~~~~~~~~~~~~~~~~
  compilation terminated.

This commit adds a new profile, pkg.linux-upstream.nokernelheaders, to
guard the linux-headers package.

There are two options to fix the above issue.

Option 1: Set the pkg.linux-upstream.nokernelheaders build profile

  $ DEB_BUILD_PROFILES=pkg.linux-upstream.nokernelheaders \
    make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- bindeb-pkg

This skips the building of the linux-headers package.

Option 2: Install the necessary build dependencies

If you want to cross-compile the linux-headers package, you need to
install additional packages.

For example, on Debian, the packages necessary for cross-compiling it
to arm64 can be installed with the following commands:

  # dpkg --add-architecture arm64
  # apt update
  # apt install gcc-aarch64-linux-gnu libssl-dev:arm64

Fixes: f1d87664b8 ("kbuild: cross-compile linux-headers package when possible")
Reported-by: Ron Economos <re@w6rz.net>
Closes: https://lore.kernel.org/all/b3d4f49e-7ddb-29ba-0967-689232329b53@w6rz.net/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Ron Economos <re@w6rz.net>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-10-31 21:41:02 +09:00
Aaron Thompson
82cb443089 kbuild: deb-pkg: Remove blank first line from maint scripts
The blank line causes execve() to fail:

  # strace ./postinst
  execve("./postinst", ...) = -1 ENOEXEC (Exec format error)
  strace: exec: Exec format error
  +++ exited with 1 +++

However running the scripts via shell does work (at least with bash)
because the shell attempts to execute the file as a shell script when
execve() fails.

Fixes: b611daae5e ("kbuild: deb-pkg: split image and debug objects staging out into functions")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-10-07 02:36:38 +09:00
Jose Fernandez
4929f5b95f kbuild: add debug package to pacman PKGBUILD
Add a new debug package to the PKGBUILD for the pacman-pkg target. The
debug package includes the non-stripped vmlinux file with debug symbols
for kernel debugging and profiling. The file is installed at
/usr/src/debug/${pkgbase}, with a symbolic link at
/usr/lib/modules/$(uname -r)/build/vmlinux. The debug package is built
by default.

Signed-off-by: Jose Fernandez <jose.fernandez@linux.dev>
Reviewed-by: Peter Jung <ptr1337@cachyos.org>
Acked-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-07 17:24:08 +09:00
Masahiro Yamada
5b000f3cbb kbuild: pacman-pkg: do not override objtree
objtree is defined and exported by the top-level Makefile. I prefer
not to override it.

There is no need to pass the absolute path of objtree. PKGBUILD can
detect it by itself.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by:  Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Christian Heusel <christian@heusel.eu>
2024-09-01 20:34:49 +09:00
Masahiro Yamada
b6223c2de6 kbuild: pacman-pkg: move common commands to a separate function
All build and package functions share the following commands:

  export MAKEFLAGS="${KBUILD_MAKEFLAGS}"
  cd "${objtree}"

Factor out the common code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by:  Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Christian Heusel <christian@heusel.eu>
2024-09-01 20:34:49 +09:00
Jose Fernandez
e6b65ee105 kbuild: control extra pacman packages with PACMAN_EXTRAPACKAGES
Introduce the PACMAN_EXTRAPACKAGES variable in PKGBUILD to allow users
to specify which additional packages are built by the pacman-pkg target.

Previously, the api-headers package was always included, and the headers
package was included only if CONFIG_MODULES=y. With this change, both
headers and api-headers packages are included by default. Users can now
control this behavior by setting PACMAN_EXTRAPACKAGES to a
space-separated list of desired extra packages or leaving it empty to
exclude all.

For example, to build only the base package without extras:

make pacman-pkg PACMAN_EXTRAPACKAGES=""

Signed-off-by: Jose Fernandez <jose.fernandez@linux.dev>
Reviewed-by: Peter Jung <ptr1337@cachyos.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Christian Heusel <christian@heusel.eu>
Tested-by: Christian Heusel <christian@heusel.eu>
Acked-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-01 20:34:49 +09:00
Masahiro Yamada
f1d87664b8 kbuild: cross-compile linux-headers package when possible
A long standing issue in the upstream kernel packaging is that the
linux-headers package is not cross-compiled.

For example, you can cross-build Debian packages for arm64 by running
the following command:

  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- bindeb-pkg

However, the generated linux-headers-*_arm64.deb is useless because the
host programs in it were built for your build machine architecture
(likely x86), not arm64.

The Debian kernel maintains its own Makefiles to cross-compile host
tools without relying on Kbuild. [1]

Instead of adding such full custom Makefiles, this commit adds a small
piece of code to cross-compile host programs located under the scripts/
directory.

A straightforward solution is to pass HOSTCC=${CROSS_COMPILE}gcc, but it
would also cross-compile scripts/basic/fixdep, which needs to be native
to process the if_changed_dep macro. (This approach may work under some
circumstances; you can execute foreign architecture programs with the
help of binfmt_misc because Debian systems enable CONFIG_BINFMT_MISC,
but it would require installing QEMU and libc for that architecture.)

A trick is to use the external module build (KBUILD_EXTMOD=), which
does not rebuild scripts/basic/fixdep. ${CC} needs to be able to link
userspace programs (CONFIG_CC_CAN_LINK=y).

There are known limitations:

 - GCC plugins

   It would possible to rebuild GCC plugins for the target architecture
   by passing HOSTCXX=${CROSS_COMPILE}g++ with necessary packages
   installed, but gcc on the installed system emits
   "cc1: error: incompatible gcc/plugin versions".

 - objtool and resolve_btfids

   These are built by the tools build system. They are not covered by
   the current solution. The resulting linux-headers package is broken
   if CONFIG_OBJTOOL or CONFIG_DEBUG_INFO_BTF is enabled.

I only tested this with Debian, but it should work for other package
systems as well.

[1]: https://salsa.debian.org/kernel-team/linux/-/blob/debian/6.9.9-1/debian/rules.real#L586

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-09-01 20:33:33 +09:00
Masahiro Yamada
aaed5c7739 kbuild: slim down package for building external modules
Exclude directories and files unnecessary for building external modules:

 - include/config/  (except include/config/{auto.conf,kernel.release})
 - scripts/atomic/
 - scripts/dtc/
 - scripts/kconfig/
 - scripts/mod/mk_elfconfig
 - scripts/package/
 - scripts/unifdef
 - .config
 - *.o
 - .*.cmd

Avoid copying files twice for the following directories:

 - include/generated/
 - arch/*/include/generated/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-09-01 20:33:33 +09:00
Jose Ignacio Tornos Martinez
d01c14074b kbuild: rpm-pkg: ghost modules.weakdep file
In the same way as for other similar files, mark as ghost the new file
generated by depmod for configured weak dependencies for modules,
modules.weakdep, so that although it is not included in the package,
claim the ownership on it.

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-28 17:07:03 +09:00
Petr Vorel
ba6c664081 kbuild: rpm-pkg: Fix C locale setup
semicolon separation in LC_ALL is wrong. Either variable needs to be
exported before as a separate commit or set as part of the commit in the
beginning. Used second variant.

This fixes broken build on user's locale setup which makes 'date' binary
to produce invalid characters in rpm changelog (e.g. cs_CZ.UTF-8 'čec'):

$ make binrpm-pkg
  GEN     rpmbuild/SPECS/kernel.spec
rpmbuild -bb rpmbuild/SPECS/kernel.spec --define='_topdirlinux/rpmbuild' \
    --target x86_64-linux --build-in-place --noprep --define='_smp_mflags \
    %{nil}' $(rpm -q rpm >/dev/null 2>&1 || echo --nodeps)
Building target platforms: x86_64-linux
Building for target x86_64-linux
error: bad date in %changelog: St čec 24 2024 user <user@somehost>
make[2]: *** [scripts/Makefile.package:71: binrpm-pkg] Error 1
make[1]: *** [linux/Makefile:1546: binrpm-pkg] Error 2
make: *** [Makefile:224: __sub-make] Error 2

Fixes: 301c10908e ("kbuild: rpm-pkg: introduce a simple changelog section for kernel.spec")
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-24 19:26:44 +09:00