mainline inclusion
from mainline-5.13-rc1
commit 56dda5a4
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=56dda5a48f4f610ac9a0487c6fb64d31950e4a3e

-------------------------------------------------

Adding the test to re-attach (detach/attach again) tracing
fentry programs, plus check that already linked program can't
be attached again.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210414195147.1624932-4-jolsa@kernel.org
(cherry picked from commit 56dda5a4)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>