On Mon, Apr 04, 2022 at 12:41:54AM -0700, Christoph Hellwig wrote: > On Mon, Apr 04, 2022 at 03:19:42PM +0900, Masahiro Yamada wrote: > > If we can make kernel headers self-contained (that is, none of exported > > kernel headers includes system headers), we will be able to add the > > -nostdinc flag, but that is much far from where we stand now. This is something I'd like to see done. IMO, the kernel headers should be the independent variable of which the libc is the dependendent variable. Android's libc, Bionic, is making use of the UAPI headers. They are doing some rewriting of UAPI headers, but I'd like to see what needs to be upstreamed from there. I just noticed include/uapi/linux/libc-compat.h, which seems like a good place for such compat related issues. In particular, having UAPI_HEADER_TESTS depend on CC_CAN_LINK is something I think we can works towards removing. The header tests themselves don't link; they force a dependency on a prebuilt libc sysroot, and they only need the headers from the sysroot because of this existing circular dependency between kernel headers and libc headers. I'd be happy to be explicitly cc'ed on changes like this series, going forward. Masahiro, if there's parts you'd like me to help with besides just code review, please let me know how I can help. > > What is still missing for that?