Commit 00fa1d83 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
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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: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200818222312.2181675-1-yhs@fb.com
parent e60572b8

tools/bpf/bpftool/pids.c

+2 −0
Original line number Diff line number Diff line
@@ -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;