bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem()

[ Upstream commit d4965578 ]

bpf_map_lookup_percpu_elem() helper is also available for sleepable bpf
program. When BPF JIT is disabled or under 32-bit host,
bpf_map_lookup_percpu_elem() will not be inlined. Using it in a
sleepable bpf program will trigger the warning in
bpf_map_lookup_percpu_elem(), because the bpf program only holds
rcu_read_lock_trace lock. Therefore, add the missed check.

Reported-by:  <syzbot+dce5aae19ae4d6399986@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/bpf/000000000000176a130617420310@google.com/


Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250526062534.1105938-1-houtao@huaweicloud.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>