Symbol: switch_userns
tools/testing/selftests/filesystems/overlayfs/set_layers_via_fds.c
358
if (!switch_userns(fd_userns2, 0, 0, false)) {
tools/testing/selftests/filesystems/overlayfs/set_layers_via_fds.c
382
ASSERT_EQ(switch_userns(fd_userns1, 0, 0, false), true);