RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Created attachment 1065019 [details]
Simple little test file

Description of problem:

The documentation (https://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/libudev-udev-enumerate.html#udev-enumerate-add-match-parent) specifies that the parent argument should be included in the result. But, in some cases, it is not.

Version-Release number of selected component (if applicable):

systemd (216)

How reproducible:

Always reproducible for certain devices.

Steps to Reproduce:
1. Compile and execute the attached file on my machine.
2. Examine the output, and notice that "/sys/devices/system/memory" is not
included.

-- alternatively, run python-pyudev test suite and hope to see a few failures
in tests/test_enumerate.py:test_match_parent().


Actual results:

Parent is not included.

Expected results:

Parent is included.

Additional info:

This came to light while I was running the python-pyudev test-suite, but the
bug is in libudev.

Problem also occurs in systemd (219).

Perhaps this is a documentation bug? But, at some point, the statement in the documentation was true, and now it is false.

I believe that this bz is connected with bz#1297512, and is really just another expression of it. If a device has no subsystem, then it does not appear in the result of match_parent() on itself.

udev_enumerate_add_match_parent() did include the device, even if subsystem missing, in systemd version 175.

After evaluating this issue, there are no plans to address it further or fix it in an upcoming release.  Therefore, it is being closed.  If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.