On Tue, Mar 29, 2022 at 02:21:30AM +0900, Masahiro Yamada wrote: > Some UAPI headers included <stdlib.h>, like this: > > #ifndef __KERNEL__ > #include <stdlib.h> > #endif > > As it turned out, they just included it for no good reason. > > After some fixes, now I can compile-test UAPI headers > (CONFIG_UAPI_HEADER_TEST=y) without <stdlib.h> included. > > To avoid somebody getting it back again, this commit adds the dummy > header, usr/dummy-include/stdlib.h > > I added $(srctree)/usr/dummy-include to the header search paths. > Because it is searched before the system directories, if someone > tries to include <stdlib.h>, they will see the error message. > > While I am here, I also replaced $(objtree)/usr/include with $(obj), but > it is just a small refactoring. > > If we achieve the situation where none of system headers is included > from exported kernel headers (i.e. kernel headers become self-contained), > we might be able to add -nostdinc, but that is much far from where we > stand now. (see many no-header-test lines in usr/include/Makefile) > > As a realistic solution, you can forbid header inclusion individually by > putting a dummy header into usr/dummy-include/. > > Currently, no header include <stdbool.h>. I put it as well before somebody > attempts to use it. > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> Nice work! Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
