On Fri, Mar 4, 2022 at 12:01 PM Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > On Mon, Feb 28, 2022 at 7:00 AM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: > > > > Hi James, > > > > On 2/27/22 3:25 PM, James Hilliard wrote: > > > This definition seems to be missing from some older toolchains. > > > > > > Note that the fcntl.h in libbpf_internal.h is not a kernel header > > > but rather a toolchain libc header. > > > > > > Fixes: > > > libbpf_internal.h:521:18: error: 'F_DUPFD_CLOEXEC' undeclared (first use in this function); did you mean 'FD_CLOEXEC'? > > > fd = fcntl(fd, F_DUPFD_CLOEXEC, 3); > > > ^~~~~~~~~~~~~~~ > > > FD_CLOEXEC > > > > > > Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx> > > > > Do you have some more info on your env (e.g. libc)? Looks like F_DUPFD_CLOEXEC > > was added back in 2.6.24 kernel. When did libc add it? > > It seems like it's guarded by __USE_XOPEN2K8 in glibc (from a quick > glance at glibc code). But it's been there since 2010 or so, at the > very least. The toolchain that hit this issue appears to be uclibc based which seems to have had some bugs with the F_DUPFD_CLOEXEC definition. > > > > > Should we instead just add an include for <linux/fcntl.h> to libbpf_internal.h > > (given it defines F_DUPFD_CLOEXEC as well)? > > yep, this is UAPI header so we can use it easily (we'll need to sync > it into Github repo, but that's not a problem) > > > > > > > --- > > > tools/lib/bpf/libbpf_internal.h | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h > > > index 4fda8bdf0a0d..d2a86b5a457a 100644 > > > --- a/tools/lib/bpf/libbpf_internal.h > > > +++ b/tools/lib/bpf/libbpf_internal.h > > > @@ -31,6 +31,10 @@ > > > #define EM_BPF 247 > > > #endif > > > > > > +#ifndef F_DUPFD_CLOEXEC > > > +#define F_DUPFD_CLOEXEC 1030 > > > +#endif > > > + > > > #ifndef R_BPF_64_64 > > > #define R_BPF_64_64 1 > > > #endif > > > > > > > Thanks, > > Daniel
