From 97623ea23f6c9066e389fc60d7da517ba572c8d4 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 18 Aug 2020 15:23:12 -0700 Subject: [PATCH] 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(+) diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c index e3b116325403b..df7d8ec760361 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; -- 2.39.5