tools/headers: Pull in stddef.h to uapi to fix BPF selftests build in CI

2022-11-03T12:45:21Z

With recent sync of linux/in.h tools/include headers are now relying on __DECLARE_FLEX_ARRAY macro, which isn't itself defined inside tools/include headers anywhere and is instead assumed to be present in system-wide UAPI header. This breaks isolated environments that don't have kernel UAPI headers installed system-wide, like BPF CI ([0]). To fix this, bring in include/uapi/linux/stddef.h into tools/include. We can't just copy/paste it, though, it has to be processed with scripts/headers_install.sh, which has a dependency on scripts/unifdef. So the full command to (re-)generate stddef.h for inclusion into tools/include directory is: $ make scripts_unifdef && \ cp $KBUILD_OUTPUT/scripts/unifdef scripts/ && \ scripts/headers_install.sh include/uapi/linux/stddef.h tools/include/uapi/linux/stddef.h This assumes KBUILD_OUTPUT envvar is set and used for out-of-tree builds. [0] https://github.com/kernel-patches/bpf/actions/runs/3379432493/jobs/5610982609 Fixes: 036b8f5b8970 ("tools headers uapi: Update linux/in.h copy") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Cc: Jakub Kicinski Cc: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/bpf/20221102182517.2675301-2-andrii@kernel.org

user/sven/linux.git/tools/include/uapi/linux/stddef.h, branch v6.4.3

tools/headers: Pull in stddef.h to uapi to fix BPF selftests build in CI