mainline inclusion
from mainline-5.12-rc1
commit 406c557e
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=406c557edc5bb903db9f6cdd543cfc282c663ad8

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Add recursive non-sleepable fentry program as a test.
All attach points where sleepable progs can execute are non recursive so far.
The recursion protection mechanism for sleepable cannot be activated yet.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210210033634.62081-6-alexei.starovoitov@gmail.com
(cherry picked from commit 406c557e)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>