bpf, sockmap: fix deadlocks in the sockhash and sockmap
authorXin Liu <liuxin350@huawei.com>
Thu, 6 Apr 2023 12:26:22 +0000 (20:26 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 11 May 2023 14:03:21 +0000 (23:03 +0900)
commit1d4ac7b0ffc9dc683b8dafc78b8b93177071a02c
treeac2fb05a85f38715117d123f16850799e7c58a67
parentcfc7ee210f2f3c73b4981b7ab39fde90de43fbf5
bpf, sockmap: fix deadlocks in the sockhash and sockmap

[ Upstream commit ed17aa92dc56b6d8883e4b7a8f1c6fbf5ed6cd29 ]

When huang uses sched_switch tracepoint, the tracepoint
does only one thing in the mounted ebpf program, which
deletes the fixed elements in sockhash ([0])

It seems that elements in sockhash are rarely actively
deleted by users or ebpf program. Therefore, we do not
pay much attention to their deletion. Compared with hash
maps, sockhash only provides spin_lock_bh protection.
This causes it to appear to have self-locking behavior
in the interrupt context.

  [0]:https://lore.kernel.org/all/CABcoxUayum5oOqFMMqAeWuS8+EzojquSOSyDA3J_2omY=2EeAg@mail.gmail.com/

Reported-by: Hsin-Wei Hung <hsinweih@uci.edu>
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Xin Liu <liuxin350@huawei.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20230406122622.109978-1-liuxin350@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net/core/sock_map.c