Files
linux/tools/testing/selftests/bpf/prog_tests
Yonghong Song 14bb1e8c8d selftests/bpf: Fix flaky test btf_map_in_map/lookup_update
Recently, I frequently hit the following test failure:

  [root@arch-fb-vm1 bpf]# ./test_progs -n 33/1
  test_lookup_update:PASS:skel_open 0 nsec
  [...]
  test_lookup_update:PASS:sync_rcu 0 nsec
  test_lookup_update:FAIL:map1_leak inner_map1 leaked!
  #33/1    btf_map_in_map/lookup_update:FAIL
  #33      btf_map_in_map:FAIL

In the test, after map is closed and then after two rcu grace periods,
it is assumed that map_id is not available to user space.

But the above assumption cannot be guaranteed. After zero or one
or two rcu grace periods in different siturations, the actual
freeing-map-work is put into a workqueue. Later on, when the work
is dequeued, the map will be actually freed.
See bpf_map_put() in kernel/bpf/syscall.c.

By using workqueue, there is no ganrantee that map will be actually
freed after a couple of rcu grace periods. This patch removed
such map leak detection and then the test can pass consistently.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240322061353.632136-1-yonghong.song@linux.dev
2024-03-25 17:25:54 +01:00
..
2023-08-31 17:18:53 +02:00
2023-11-01 22:31:41 -07:00
2023-03-08 11:15:39 -08:00
2022-11-20 15:45:48 -08:00