(resending as my first email was sent without ml subscription) Hi, I have few questions about the linux/types.h file used to build bpf applications. This file gets included by both userspace applications using libbpf and by bpf programs. E.g., in a userspace application: foo.c foo.skel.h bpf/libbpf.h linux/bpf.h linux/types.h Or in a bpf program: foo.bpf.c linux/bpf.h linux/types.h libbpf provides its own copy of this file in include/linux/types.h. As I could understand from the Git history, it was initially copied from linux include/linux/types.h, but it is now maintained separately. Both linux bpftool and bpf selftests however are built using another types.h from tools/include/uapi/linux/types.h. Is there a reason why bpftool and selftests aren't built using the same types.h distributed by libbpf? I also see that the license of the three files differs: - (libbpf) include/linux/types.h is "LGPL-2.1 OR BSD-2-Clause" - (linux) include/linux/types.h is "GPL-2.0" - (linux) tools/include/uapi/linux/types.h is "GPL-2.0" Is there a reason why tools/include/uapi/linux/types.h isn't licensed as "GPL-2.0 WITH Linux-syscall-note"? Finally, would it make sense to also have libbpf use tools/include/uapi/linux/types.h instead of its own copy? The advantages would be: - consistency with linux use - the only architecture specific header included is "asm/bitsperlong.h", instead of all the ones currently included. Thanks, Marco
