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Fix kernel source build on GCC 15+ #377

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Merged
jserv merged 1 commit into from
May 18, 2026
Merged

Fix kernel source build on GCC 15+ #377

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22 changes: 20 additions & 2 deletions devtools/setup.sh
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Original file line number Diff line number Diff line change
Expand Up @@ -127,6 +127,8 @@ try_prebuilt() {

# The prebuilt build directory needs a "source" symlink pointing to the
# kernel source tree (kbuild follows it during out-of-tree module builds).
# The Makefile in the tarball already references source/Makefile (rewritten
# by pack-prebuilt.sh), so this symlink resolves it to the user's source.
ln -sfn "$KERNEL_SRC" "$KERNEL_BUILD/source"

echo " Prebuilt unpacked successfully"
Expand Down Expand Up @@ -229,8 +231,24 @@ build_kernel() {
# Copy vmlinux.symvers to Module.symvers so that out-of-tree module
# builds can resolve vmlinux symbols (printk, register_chrdev, etc.)
# without building all in-tree modules.
make -C "$KERNEL_SRC" O="$KERNEL_BUILD" -j"$NPROC" bzImage
make -C "$KERNEL_SRC" O="$KERNEL_BUILD" -j"$NPROC" modules_prepare
#
# Pin -std=gnu11: GCC 15+ defaults to C23 where bool/false/true are
# keywords, conflicting with the kernel's own typedefs. We pass it
# through three variables because several x86 sub-Makefiles (EFI stub,
# decompressor, real-mode setup) rebuild KBUILD_CFLAGS with := which
# discards the top-level -std=gnu11. KCPPFLAGS survives because those
# sub-Makefiles don't override KBUILD_CPPFLAGS.
#
# -Wno-error demotes all -Werror to warnings. Needed because CONFIG_WERROR
# (default y) enables -Werror, and newer GCC warns on kernel patterns that
# are intentional (non-NUL-terminated ACPI/PNP ID strings, etc.). KCFLAGS
# and KCPPFLAGS are appended after KBUILD_CFLAGS, so our -Wno-error
# overrides the kernel's -Werror.
local stdflag="-std=gnu11 -Wno-error"
make -C "$KERNEL_SRC" O="$KERNEL_BUILD" -j"$NPROC" \
KCFLAGS="$stdflag" KCPPFLAGS="$stdflag" HOSTCFLAGS="$stdflag" bzImage
make -C "$KERNEL_SRC" O="$KERNEL_BUILD" -j"$NPROC" \
KCFLAGS="$stdflag" KCPPFLAGS="$stdflag" HOSTCFLAGS="$stdflag" modules_prepare
cp "$KERNEL_BUILD/vmlinux.symvers" "$KERNEL_BUILD/Module.symvers"

echo "$expected" > "$stamp"
Expand Down