Martin KaFai Lau says:
====================
From: Martin KaFai Lau <martin.lau@kernel.org>
The commit
bc235cdb423a ("bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]")
added deadlock detection to avoid a tracing program from recurring
on the bpf_task_storage_{get,delete}() helpers. These helpers acquire
a spin lock and it will lead to deadlock.
It is unnecessary for the bpf_lsm and bpf_iter programs which do
not recur. The situation is the same as the existing
bpf_pid_task_storage_{lookup,delete}_elem() which are
used in the syscall and they also do not have deadlock detection.
This set is to add new bpf_task_storage_{get,delete}() helper proto
without the deadlock detection. The set also removes the prog->active
check from the bpf_lsm and bpf_iter program. Please see the individual
patch for details.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>