Fix bug where make nconfig doesn't initialize the default locale, which
causes ncurses menu borders to be displayed incorrectly (lqqqqk) in
UTF-8 terminals that don't support VT100 ACS by default, such as PuTTY.

Signed-off-by: Jakub Horký <jakub.git@horky.net>
Link: https://patch.msgid.link/20251014144405.3975275-2-jakub.git@horky.net
[nathan: Alphabetize locale.h include]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Fix bug where make menuconfig doesn't initialize the default locale, which
causes ncurses menu borders to be displayed incorrectly (lqqqqk) in
UTF-8 terminals that don't support VT100 ACS by default, such as PuTTY.

Signed-off-by: Jakub Horký <jakub.git@horky.net>
Link: https://patch.msgid.link/20251014154933.3990990-1-jakub.git@horky.net
[nathan: Alphabetize locale.h include]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Commit b5e395653546 ("kbuild: install-extmod-build: Fix build when
specifying KBUILD_OUTPUT") tried to address the "build" variable
expecting a relative path by using `realpath --relative-base=.`, but
this only works when the given directory is below the current directory.
`realpath --relative-to=.` will return a relative path in all cases.

Fixes: b5e395653546 ("kbuild: install-extmod-build: Fix build when specifying KBUILD_OUTPUT")
Signed-off-by: James Le Cuirot <chewi@gentoo.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20251016091417.9985-1-chewi@gentoo.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Pull Kbuild fixes from Nathan Chancellor:

 - Fix UAPI types check in headers_check.pl

 - Only enable -Werror for hostprogs with CONFIG_WERROR / W=e

 - Ignore fsync() error when output of gen_init_cpio is a pipe

 - Several little build fixes for recent modules.builtin.modinfo series

* tag 'kbuild-fixes-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
  kbuild: Use '--strip-unneeded-symbol' for removing module device table symbols
  s390/vmlinux.lds.S: Move .vmlinux.info to end of allocatable sections
  kbuild: Add '.rel.*' strip pattern for vmlinux
  kbuild: Restore pattern to avoid stripping .rela.dyn from vmlinux
  gen_init_cpio: Ignore fsync() returning EINVAL on pipes
  scripts/Makefile.extrawarn: Respect CONFIG_WERROR / W=e for hostprogs
  kbuild: uapi: Strip comments before size type check

Pull bpf fixes from Alexei Starovoitov:

 - Finish constification of 1st parameter of bpf_d_path() (Rong Tao)

 - Harden userspace-supplied xdp_desc validation (Alexander Lobakin)

 - Fix metadata_dst leak in __bpf_redirect_neigh_v{4,6}() (Daniel
   Borkmann)

 - Fix undefined behavior in {get,put}_unaligned_be32() (Eric Biggers)

 - Use correct context to unpin bpf hash map with special types (KaFai
   Wan)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Add test for unpinning htab with internal timer struct
  bpf: Avoid RCU context warning when unpinning htab with internal structs
  xsk: Harden userspace-supplied xdp_desc validation
  bpf: Fix metadata_dst leak __bpf_redirect_neigh_v{4,6}
  libbpf: Fix undefined behavior in {get,put}_unaligned_be32()
  bpf: Finish constification of 1st parameter of bpf_d_path()

After commit 5ab23c7923a1 ("modpost: Create modalias for builtin
modules"), relocatable RISC-V kernels with CONFIG_KASAN=y start failing
when attempting to strip the module device table symbols:

  riscv64-linux-objcopy: not stripping symbol `__mod_device_table__kmod_irq_starfive_jh8100_intc__of__starfive_intc_irqchip_match_table' because it is named in a relocation
  make[4]: *** [scripts/Makefile.vmlinux:97: vmlinux] Error 1

The relocation appears to come from .LASANLOC5 in .data.rel.local:

  $ llvm-objdump --disassemble-symbols=.LASANLOC5 --disassemble-all -r drivers/irqchip/irq-starfive-jh8100-intc.o

  drivers/irqchip/irq-starfive-jh8100-intc.o:   file format elf64-littleriscv

  Disassembly of section .data.rel.local:

  0000000000000180 <.LASANLOC5>:
  ...
       1d0: 0000          unimp
                  00000000000001d0:  R_RISCV_64   __mod_device_table__kmod_irq_starfive_jh8100_intc__of__starfive_intc_irqchip_match_table
  ...

This section appears to come from GCC for including additional
information about global variables that may be protected by KASAN.

There appears to be no way to opt out of the generation of these symbols
through either a flag or attribute. Attempting to remove '.LASANLOC*'
with '--strip-symbol' results in the same error as above because these
symbols may refer to (thus have relocation between) each other.

Avoid this build breakage by switching to '--strip-unneeded-symbol' for
removing __mod_device_table__ symbols, as it will only remove the symbol
when there is no relocation pointing to it. While this may result in a
little more bloat in the symbol table in certain configurations, it is
not as bad as outright build failures.

Fixes: 5ab23c7923a1 ("modpost: Create modalias for builtin modules")
Reported-by: Charles Mirabile <cmirabil@redhat.com>
Closes: https://lore.kernel.org/20251007011637.2512413-1-cmirabil@redhat.com/
Suggested-by: Alexey Gladkov <legion@kernel.org>
Tested-by: Nicolas Schier <nsc@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Prior to binutils commit c12d9fa2afe ("Support objcopy
--remove-section=.relaFOO") [1] in 2.32, stripping relocation sections
required the trailing period (i.e., '.rel.*') to work properly.

After commit 3e86e4d74c04 ("kbuild: keep .modinfo section in
vmlinux.unstripped"), there is an error with binutils 2.31.1 or earlier
because these sections are not properly removed:

  s390-linux-objcopy: st6tO8Ev: symbol `.modinfo' required but not present
  s390-linux-objcopy:st6tO8Ev: no symbols

Add the old pattern to resolve this issue (along with a comment to allow
cleaning this when binutils 2.32 or newer is the minimum supported
version). While the aforementioned kbuild change exposes this, the
pattern was originally changed by commit 71d815bf5dfd ("kbuild: Strip
runtime const RELA sections correctly"), where it would still be
incorrect with binutils older than 2.32.

Fixes: 71d815bf5dfd ("kbuild: Strip runtime const RELA sections correctly")
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c12d9fa2afe7abcbe407a00e15719e1a1350c2a7 [1]
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/CA+G9fYvVktRhFtZXdNgVOL8j+ArsJDpvMLgCitaQvQmCx=hwOQ@mail.gmail.com/
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20251008-kbuild-fix-modinfo-regressions-v1-2-9fc776c5887c@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Commit 0ce5139fd96e ("kbuild: always create intermediate
vmlinux.unstripped") removed the pattern to avoid stripping .rela.dyn
sections added by commit e9d86b8e17e7 ("scripts: Do not strip .rela.dyn
section"). Restore it so that .rela.dyn sections remain in the final
vmlinux.

Fixes: 0ce5139fd96e ("kbuild: always create intermediate vmlinux.unstripped")
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20251008-kbuild-fix-modinfo-regressions-v1-1-9fc776c5887c@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Commit 27758d8c2583 ("kbuild: enable -Werror for hostprogs")
unconditionally enabled -Werror for the compiler, assembler, and linker
when building the host programs, as the build footprint of the host
programs is small (thus risk of build failures from warnings are low)
and that stage of the build may not have Kconfig values (thus
CONFIG_WERROR could not be used as a precondition).

While turning warnings into errors unconditionally happens in a few
places within the kernel, it can be disruptive to people who may be
building with newer compilers, such as while doing a bisect. While it is
possible to avoid this behavior by passing HOSTCFLAGS=-w or
HOSTCFLAGS=-Wno-error, it may not be the most intuitive for regular
users not intimately familiar with Kbuild.

Avoid being disruptive to the entire build by depending on the explicit
opt-in of CONFIG_WERROR or W=e to enable -Werror and the like while
building the host programs. While this means there is a small portion of
the build that does not have -Werror enabled (namely scripts/kconfig/*
and scripts/basic/fixdep), it is better than not having it altogether.

Fixes: 27758d8c2583 ("kbuild: enable -Werror for hostprogs")
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reported-by: Askar Safin <safinaskar@gmail.com>
Closes: https://lore.kernel.org/20251005011100.1035272-1-safinaskar@gmail.com/
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Tested-by: Miguel Ojeda <ojeda@kernel.org> # Rust
Link: https://patch.msgid.link/20251006-kbuild-hostprogs-werror-fix-v1-1-23cf1ffced5c@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

The "transitional" symbol keyword, while working with the "olddefconfig"
target, was prompting during "oldconfig". This occurred because these
symbols were not being marked as user-defined when they received values
from transitional symbols that had user values. The "olddefconfig" target
explicitly doesn't prompt for anything, so this deficiency wasn't noticed.

The issue manifested when a symbol's value came from a transitional
symbol's user value but the receiving symbol wasn't marked with
SYMBOL_DEF_USER. Thus the "oldconfig" logic would then prompt for these
symbols unnecessarily.

Check after value calculation whether a symbol without a user value
gets its value from a single transitional symbol that does have a user
value. In such cases, mark the receiving symbol as user-defined to
prevent prompting.

Update regression tests to verify that symbols with transitional defaults
are not prompted in "oldconfig", except when conditional defaults evaluate
to 'no' and should legitimately be prompted.

Build tested with "make testconfig".

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Closes: https://lore.kernel.org/lkml/CAHk-=wgZjUk4Cy2XgNkTrQoO8XCmNUHrTe5D519Fij1POK+3qw@mail.gmail.com/
Fixes: f9afce4f32e9 ("kconfig: Add transitional symbol attribute for migration support")
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Link: https://lore.kernel.org/r/20250930154514.it.623-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>