From: Paul Chaignon <paul@isovalent.com> stable inclusion from stable-v5.10.94 commit e668ac6506d3f45bf36b1f8463f62ce5e2776732 bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 1a1a0b0364ad291bd8e509da104ac8b5b1afec5d ] The output of bpftool prog tracelog is currently buffered, which is inconvenient when piping the output into other commands. A simple tracelog | grep will typically not display anything. This patch fixes it by enabling line buffering on stdout for the whole bpftool binary. Fixes: 30da46b5dc3a ("tools: bpftool: add a command to dump the trace pipe") Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Paul Chaignon <paul@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20211220214528.GA11706@Mem Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- tools/bpf/bpftool/main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index c58a135dc355..1854d6b97860 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -396,6 +396,8 @@ int main(int argc, char **argv) }; int opt, ret; + setlinebuf(stdout); + last_do_help = do_help; pretty_output = false; json_output = false; -- 2.20.1