Hi, all, With the latest 6.9-rc7 torvalds tree kernel, the "make kselftest" always hangs in the following ./pidfd_setns_test. Symptoms are that all ./pidfd_netne_test processes end up in pause() syscalls, with nothing to wake them up. Please find the config attached. All the options from the selftests/pidfdconfig are on (verified): CONFIG_UTS_NS=y CONFIG_IPC_NS=y CONFIG_USER_NS=y CONFIG_PID_NS=y CONFIG_NET_NS=y CONFIG_CGROUPS=y CONFIG_CHECKPOINT_RESTORE=y root 2090101 5211 0 21:53 pts/1 00:00:00 make OUTPUT=/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/pidfd -C pidfd run_tests SRC_PATH=/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests OB root 2090102 2090101 0 21:53 pts/1 00:00:00 /bin/sh -c BASE_DIR="/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests"; . /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/kselftest/runner.sh; if root 2133026 2090102 0 21:54 pts/1 00:00:00 /bin/sh -c BASE_DIR="/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests"; . /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/kselftest/runner.sh; if root 2133027 2133026 0 21:54 pts/1 00:00:00 /bin/sh -c BASE_DIR="/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests"; . /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/kselftest/runner.sh; if root 2133028 2133027 0 21:54 pts/1 00:00:00 /bin/sh -c BASE_DIR="/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests"; . /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/kselftest/runner.sh; if root 2133031 2133028 0 21:54 pts/1 00:00:00 /bin/sh -c BASE_DIR="/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests"; . /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/kselftest/runner.sh; if root 2133033 2133031 0 21:54 pts/1 00:00:00 perl /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/kselftest/prefix.pl root 2133050 2887 0 21:54 pts/1 00:00:00 ./pidfd_setns_test root 2133051 2887 0 21:54 pts/1 00:00:00 ./pidfd_setns_test root 2133056 2887 0 21:54 pts/1 00:00:00 ./pidfd_setns_test root 2133057 2887 0 21:54 pts/1 00:00:00 ./pidfd_setns_test root 2133062 2887 0 21:54 pts/1 00:00:00 ./pidfd_setns_test root 2133063 2887 0 21:54 pts/1 00:00:00 ./pidfd_setns_test root 2133068 2887 0 21:54 pts/1 00:00:00 ./pidfd_setns_test root 2133069 2887 0 21:54 pts/1 00:00:00 ./pidfd_setns_test . . . marvin@defiant:~/linux/kernel/linux_torvalds$ sudo bash [sudo] password for marvin: root@defiant:/home/marvin/linux/kernel/linux_torvalds# strace -p 2133050 strace: Process 2133050 attached pause(^Cstrace: Process 2133050 detached root@defiant:/home/marvin/linux/kernel/linux_torvalds# strace -p 2133051 strace: Process 2133051 attached pause(^Cstrace: Process 2133051 detached root@defiant:/home/marvin/linux/kernel/linux_torvalds# strace -p 2133056 strace: Process 2133056 attached pause(^Cstrace: Process 2133056 detached root@defiant:/home/marvin/linux/kernel/linux_torvalds# strace -p 2133057 strace: Process 2133057 attached pause(^Cstrace: Process 2133057 detached root@defiant:/home/marvin/linux/kernel/linux_torvalds# strace -p 2133062 strace: Process 2133062 attached pause(^Cstrace: Process 2133062 detached root@defiant:/home/marvin/linux/kernel/linux_torvalds# strace -p 2133063 strace: Process 2133063 attached pause(^Cstrace: Process 2133063 detached root@defiant:/home/marvin/linux/kernel/linux_torvalds# root@defiant:/home/marvin/linux/kernel/linux_torvalds# root@defiant:/home/marvin/linux/kernel/linux_torvalds# strace -p 2133068 strace: Process 2133068 attached pause(^Cstrace: Process 2133068 detached root@defiant:/home/marvin/linux/kernel/linux_torvalds# strace -p 2133069 strace: Process 2133069 attached pause(^Cstrace: Process 2133069 detached root@defiant:/home/marvin/linux/kernel/linux_torvalds# The output log is: # selftests: pidfd: pidfd_setns_test # TAP version 13 # 1..7 # # Starting 7 tests from 2 test cases. # # RUN global.setns_einval ... # # OK global.setns_einval # ok 1 global.setns_einval # # RUN current_nsset.invalid_flags ... # # pidfd_setns_test.c:161:invalid_flags:Expected self->child_pid_exited (0) > 0 (0) # # OK current_nsset.invalid_flags # ok 2 current_nsset.invalid_flags # # RUN current_nsset.pidfd_exited_child ... # # pidfd_setns_test.c:161:pidfd_exited_child:Expected self->child_pid_exited (0) > 0 (0) # # OK current_nsset.pidfd_exited_child # ok 3 current_nsset.pidfd_exited_child # # RUN current_nsset.pidfd_incremental_setns ... # # pidfd_setns_test.c:161:pidfd_incremental_setns:Expected self->child_pid_exited (0) > 0 (0) # # pidfd_setns_test.c:408:pidfd_incremental_setns:Managed to correctly setns to user namespace of 2133050 via pidfd 20 # # pidfd_setns_test.c:408:pidfd_incremental_setns:Managed to correctly setns to mnt namespace of 2133050 via pidfd 20 # # pidfd_setns_test.c:408:pidfd_incremental_setns:Managed to correctly setns to pid namespace of 2133050 via pidfd 20 # # pidfd_setns_test.c:408:pidfd_incremental_setns:Managed to correctly setns to uts namespace of 2133050 via pidfd 20 # # pidfd_setns_test.c:408:pidfd_incremental_setns:Managed to correctly setns to ipc namespace of 2133050 via pidfd 20 # # pidfd_setns_test.c:408:pidfd_incremental_setns:Managed to correctly setns to net namespace of 2133050 via pidfd 20 # # pidfd_setns_test.c:408:pidfd_incremental_setns:Managed to correctly setns to cgroup namespace of 2133050 via pidfd 20 # # pidfd_setns_test.c:408:pidfd_incremental_setns:Managed to correctly setns to pid_for_children namespace of 2133050 via pidfd 20 # # pidfd_setns_test.c:391:pidfd_incremental_setns:Expected setns(self->child_pidfd1, info->flag) (-1) == 0 (0) # # pidfd_setns_test.c:392:pidfd_incremental_setns:Too many users - Failed to setns to time namespace of 2133050 via pidfd 20 # # pidfd_incremental_setns: Test terminated by assertion # # FAIL current_nsset.pidfd_incremental_setns # not ok 4 current_nsset.pidfd_incremental_setns # # RUN current_nsset.nsfd_incremental_setns ... # # pidfd_setns_test.c:161:nsfd_incremental_setns:Expected self->child_pid_exited (0) > 0 (0) # # pidfd_setns_test.c:444:nsfd_incremental_setns:Managed to correctly setns to user namespace of 2133056 via nsfd 19 # # pidfd_setns_test.c:444:nsfd_incremental_setns:Managed to correctly setns to mnt namespace of 2133056 via nsfd 24 # # pidfd_setns_test.c:444:nsfd_incremental_setns:Managed to correctly setns to pid namespace of 2133056 via nsfd 27 # # pidfd_setns_test.c:444:nsfd_incremental_setns:Managed to correctly setns to uts namespace of 2133056 via nsfd 30 # # pidfd_setns_test.c:444:nsfd_incremental_setns:Managed to correctly setns to ipc namespace of 2133056 via nsfd 33 # # pidfd_setns_test.c:444:nsfd_incremental_setns:Managed to correctly setns to net namespace of 2133056 via nsfd 36 # # pidfd_setns_test.c:444:nsfd_incremental_setns:Managed to correctly setns to cgroup namespace of 2133056 via nsfd 39 # # pidfd_setns_test.c:444:nsfd_incremental_setns:Managed to correctly setns to pid_for_children namespace of 2133056 via nsfd 42 # # pidfd_setns_test.c:427:nsfd_incremental_setns:Expected setns(self->child_nsfds1[i], info->flag) (-1) == 0 (0) # # pidfd_setns_test.c:428:nsfd_incremental_setns:Too many users - Failed to setns to time namespace of 2133056 via nsfd 45 # # nsfd_incremental_setns: Test terminated by assertion # # FAIL current_nsset.nsfd_incremental_setns # not ok 5 current_nsset.nsfd_incremental_setns # # RUN current_nsset.pidfd_one_shot_setns ... # # pidfd_setns_test.c:161:pidfd_one_shot_setns:Expected self->child_pid_exited (0) > 0 (0) # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding user namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding mnt namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding pid namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding uts namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding ipc namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding net namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding cgroup namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding pid_for_children namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:462:pidfd_one_shot_setns:Adding time namespace of 2133062 to list of namespaces to attach to # # pidfd_setns_test.c:466:pidfd_one_shot_setns:Expected setns(self->child_pidfd1, flags) (-1) == 0 (0) # # pidfd_setns_test.c:467:pidfd_one_shot_setns:Too many users - Failed to setns to namespaces of 2133062 # # pidfd_one_shot_setns: Test terminated by assertion # # FAIL current_nsset.pidfd_one_shot_setns # not ok 6 current_nsset.pidfd_one_shot_setns # # RUN current_nsset.no_foul_play ... # # pidfd_setns_test.c:161:no_foul_play:Expected self->child_pid_exited (0) > 0 (0) # # pidfd_setns_test.c:506:no_foul_play:Adding user namespace of 2133068 to list of namespaces to attach to # # pidfd_setns_test.c:506:no_foul_play:Adding mnt namespace of 2133068 to list of namespaces to attach to # # pidfd_setns_test.c:506:no_foul_play:Adding pid namespace of 2133068 to list of namespaces to attach to # # pidfd_setns_test.c:506:no_foul_play:Adding uts namespace of 2133068 to list of namespaces to attach to # # pidfd_setns_test.c:506:no_foul_play:Adding ipc namespace of 2133068 to list of namespaces to attach to # # pidfd_setns_test.c:506:no_foul_play:Adding net namespace of 2133068 to list of namespaces to attach to # # pidfd_setns_test.c:506:no_foul_play:Adding cgroup namespace of 2133068 to list of namespaces to attach to # # pidfd_setns_test.c:506:no_foul_play:Adding time namespace of 2133068 to list of namespaces to attach to # # pidfd_setns_test.c:510:no_foul_play:Expected setns(self->child_pidfd1, flags) (-1) == 0 (0) # # pidfd_setns_test.c:511:no_foul_play:Too many users - Failed to setns to namespaces of 2133068 vid pidfd 20 # # no_foul_play: Test terminated by assertion # # FAIL current_nsset.no_foul_play # not ok 7 current_nsset.no_foul_play # # FAILED: 3 / 7 tests passed. # # Totals: pass:3 fail:4 xfail:0 xpass:0 skip:0 error:0 Thanks for your time and patience for reviewing this BUG report. Best regards, Mirsad Todorovac P.S. I have changed the email address because of the uncertainty whether the employer would continue to support my work on the Linux kernel testing as the part of my work research. Thank you.