Merge tag 'kbuild-7.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

Pull Kbuild / Kconfig updates from Nathan Chancellor:
"Kbuild:

- Suppress compiler flags in debug info for

Merge tag 'kbuild-7.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

Pull Kbuild / Kconfig updates from Nathan Chancellor:
"Kbuild:

- Suppress compiler flags in debug info for external module builds

- Use '-fmacro-prefix-map' in more places in the build

- Merge initial set of changes from Lorenzo's speed up series, along
with some fixes found through testing:

- Avoid allocating .modinfo in vmlinux

- Speed up kallsyms by indexing symbols by token and outputting
binary data to disk directly then including in assembly via
.incbin

- Don't sort $(NM) output when unnecessary

- Only emit relocations on the final vmlinx link

- Reimplement mksysmap in C

- Move many cc-option and ld-option calls into the Kconfig stage to
cache their results

- Use pigz for gzip compression when available

- Move gen_init_cpio and gen_initramfs.sh from usr/ to scripts/

- Add a TOML configuration to scripts/container and update
documentation accordingly

- Add a generic, opt-in mechanism for checking that headers can
compile standalone

- Update machine function splitting argument for LLVM 24 rename in
AutoFDO build

- Miscellaneous minor clean ups, fixes, and hardening, mostly
found/fixed via LLMs

Kconfig:

- Turn recursive ranges into an error

- Fix savedefconfig for defaults that were adjusted for being out of
range and revert a previously applied workaround

- Improvements and hardening around integer and hexadecimal values

- Emit a warning when selecting or implying a choice symbol, which
has no effect

- Emit a warning when KCONFIG_PROBABILITY is malformed

- Introduce def_string / def_int / def_hex to mirror the existing
def_bool / def_tristate to succinctly set a value and type at the
same time.

- Add cc-option-str and ld-option-str macros to act like Kbuild's
cc-option and ld-option, returning the string when the option is
supported, allowing many checks to be moved into Kconfig

- Minor usability improvements to Kconfig tests"

* tag 'kbuild-7.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (59 commits)
kbuild: AutoFDO: Update split machine function argument for upstream rename
kbuild: Mark the initcall ordering recipe as recursive
kbuild: Mark the gzip recipes as recursive
localmodconfig: Explicitly report boolean configs during integrity check
scripts/make_fit: Ignore schema checks when decomposing DTBs
clang-tools: Import os for broken pipe handling
kconfig: use the value argument in sym_get_near_range_bound()
kconfig: fix infinite loop in conf_choice() when no choice value is visible
kconfig: cleanup stale comment about 'keys' array
kconfig: Improve ergonomics around disabling warnings with cc-option
scripts/Kconfig.toolchain: Drop compiler symbols from dependencies
checkkconfigsymbols.py: Parse Git status output line by line
gen_init_cpio: stop parsing on lines with a missing argument list
.gitignore: drop Module.markers
.gitignore: ignore pacman package signatures
kbuild: add header check facility as a manually run static analyzer
Documentation: dev-tools: refer to user ID rather than id
Documentation: dev-tools: update container.rst with config file
scripts: add TOML config to container tool
kconfig: tests: {old,save}defconfig: Forward dynamic keyword arguments
...

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alpha: support the remaining kernel compression formats

Nothing about the boot stub is specific to gzip, so wire up bzip2, lz4,
lzma, lzo, xz and zstd as well: select the matching HAVE_KERNEL_*
symb

alpha: support the remaining kernel compression formats

Nothing about the boot stub is specific to gzip, so wire up bzip2, lz4,
lzma, lzo, xz and zstd as well: select the matching HAVE_KERNEL_*
symbol, add a suffix-y entry and a compression rule for the piggy-backed
image, and include the decompressor into the stub's misc.c.

Only gzip's trailer already carries the uncompressed size, so the other
formats use the _with_size variants; output_len, which vmlinux.scr takes
from the last 4 bytes of the payload, then works for all of them. The
stub passes it to __decompress(), which zstd requires.

Signed-off-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Magnus Lindholm <linmag7@gmail.com>
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Link: https://lore.kernel.org/r/20261017-alpha-kernel-compression-v2-3-c71e6b08dc63@gmail.com
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>

show more ...

alpha: add self-extracting compressed kernel boot stub

Alpha only ever supported gzip for the kernel image, and did so in a way
out of step with every other architecture: aboot, the disk boot loader

alpha: add self-extracting compressed kernel boot stub

Alpha only ever supported gzip for the kernel image, and did so in a way
out of step with every other architecture: aboot, the disk boot loader,
decompresses vmlinux.gz itself with its own bundled inflate code, so
adding a compression format meant writing a new decompressor inside
aboot as well as in the kernel.

Build a proper self-extracting arch/alpha/boot/compressed/vmlinux
instead, modeled on parisc: a small ELF stub with the real, compressed
vmlinux linked in, which decompresses the kernel, relocates it into
place and jumps to its entry point. aboot needs no changes.

The stub has no sanitizer or coverage runtime and must run on any Alpha,
so it builds private copies of the arch/alpha/lib/ memory and division
routines it needs instead of linking lib.a, whose objects carry the
kernel's instrumentation and -mcpu=.

The build now emits arch/alpha/boot/vmlinuz rather than vmlinux.gz,
which was never a name aboot cared about and would be a lie for an ELF
stub: the bootpz path in the same directory still produces real gzip
data as vmlinux.nh.gz. Existing aboot.conf files name the image as it
was installed in /boot, so only the command that copies it out of the
build tree changes.

Unlike parisc and mips, the stub is linked at START_ADDR rather than at
a separate low address; see compressed/vmlinux.lds.S. It has no console
output, since bringing up the HWRPB console callbacks needs more than
the CRB dispatch the kernel proper does much later, so error() just
halts.

The legacy SRM netboot path (bootpz.c) is left alone: it has its own
boot protocol (PALcode reinitialization, self-populated ZERO_PGE,
build-time-computed image sizes) that does not fit this design without a
separate rewrite, and keeps using plain gzip via vmlinux.nh.gz.

Co-developed-by: Magnus Lindholm <linmag7@gmail.com>
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Magnus Lindholm <linmag7@gmail.com>
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Link: https://lore.kernel.org/r/20261017-alpha-kernel-compression-v2-2-c71e6b08dc63@gmail.com
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>

show more ...