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. > > 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
