From 00fa1d83a8b50351c830521d00135e823c46e7d0 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 18 Aug 2020 15:23:12 -0700 Subject: bpftool: Handle EAGAIN error code properly in pids collection When the error code is EAGAIN, the kernel signals the user space should retry the read() operation for bpf iterators. Let us do it. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200818222312.2181675-1-yhs@fb.com --- tools/bpf/bpftool/pids.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools') diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c index e3b116325403..df7d8ec76036 100644 --- a/tools/bpf/bpftool/pids.c +++ b/tools/bpf/bpftool/pids.c @@ -134,6 +134,8 @@ int build_obj_refs_table(struct obj_refs_table *table, enum bpf_obj_type type) while (true) { ret = read(fd, buf, sizeof(buf)); if (ret < 0) { + if (errno == EAGAIN) + continue; err = -errno; p_err("failed to read PID iterator output: %d", err); goto out; -- cgit v1.2.3-59-g8ed1b