Hi, On 2021/10/30 12:59 PM, Andrii Nakryiko wrote: > cgroup.c in bpftool source code is defining _XOPEN_SOURCE 500, which, > apparently, makes syscall() unavailable. Which is a problem now that > libbpf exposes syscal()-usign bpf() API in bpf.h. > typo: syscal -> syscall usign -> using ? > Fix by defining _GNU_SOURCE instead, which enables syscall() wrapper. > > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > --- > tools/bpf/bpftool/cgroup.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c > index 3571a281c43f..4876364e753d 100644 > --- a/tools/bpf/bpftool/cgroup.c > +++ b/tools/bpf/bpftool/cgroup.c > @@ -2,7 +2,7 @@ > // Copyright (C) 2017 Facebook > // Author: Roman Gushchin <guro@xxxxxx> > > -#define _XOPEN_SOURCE 500 > +#define _GNU_SOURCE > #include <errno.h> > #include <fcntl.h> > #include <ftw.h> > According to the man page ([0]), defining _GNU_SOURCE also implicitly defines _XOPEN_SOURCE with the value 700 (600 in glibc versions before 2.10; 500 in glibc versions before 2.2), so this change should not break anything. [0]: https://man7.org/linux/man-pages/man7/feature_test_macros.7.html --Hengqi
