Test 20 in fanotify10 from ubuntu_ltp_syscalls failed on 4.15 / 5.4

[Po-Hsu Lin]

Issue spotted with 4.15.0-1054.58~16.04.1-oracle

It looks like this is a new test case landed recently.

https://github.com/linux-test-project/ltp/commit/ad226e05faedc10c407b83811c420406fb687820#diff-0d924136c0f59211b55878ec1b863a24

The test failed with:
 fanotify10.c:452: INFO: Test #20: ignore mount events created inside a parent watching children
 fanotify10.c:413: PASS: group 0 (8) got event: mask 20 pid=21178 fd=30
 fanotify10.c:413: PASS: group 1 (8) got event: mask 20 pid=21178 fd=30
 fanotify10.c:413: PASS: group 2 (8) got event: mask 20 pid=21178 fd=30
 fanotify10.c:513: FAIL: group 0 (4) with FAN_MARK_MOUNT and FAN_MARK_INODE ignore mask got event
 fanotify10.c:513: FAIL: group 1 (4) with FAN_MARK_MOUNT and FAN_MARK_INODE ignore mask got event
 fanotify10.c:513: FAIL: group 2 (4) with FAN_MARK_MOUNT and FAN_MARK_INODE ignore mask got event
 fanotify10.c:513: FAIL: group 0 (0) with FAN_MARK_MOUNT and FAN_MARK_INODE ignore mask got event
 fanotify10.c:513: FAIL: group 1 (0) with FAN_MARK_MOUNT and FAN_MARK_INODE ignore mask got event
 fanotify10.c:513: FAIL: group 2 (0) with FAN_MARK_MOUNT and FAN_MARK_INODE ignore mask got event

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1895273

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Po-Hsu Lin (cypressyew)]

This issue can be found on Focal as well.

[Po-Hsu Lin (cypressyew)]

This test has an undefined behaviour < 5.9
It will be skipped now, test case modified upstream.
 fanotify10.c:452: TINFO: Test #20: ignore mount events created inside a parent watching children
 fanotify10.c:456: TCONF: ignored mask in combination with flag FAN_EVENT_ON_CHILD has undefined behavior on kernel < 5.9

https://github.com/linux-test-project/ltp/commit/e420134e50482e895655b40af2435095c6a8f991#diff-0d924136c0f59211b55878ec1b863a24