Red Hat Bugzilla – Bug 973552
valgrind gives false positive 'definitely lost' reports
Last modified: 2015-02-17 10:32:45 EST
Once upon a time, I could run Evolution and its helper processes in valgrind, as long as I set G_SLICE=always-malloc, and any report of memory being 'definitely lost' was fairly certain to be true. I don't remember any false positives.
I last did this in late 2010; see https://bugzilla.gnome.org/showdependencytree.cgi?id=627707&hide_resolved=0
I had another go yesterday, and filed a few 'definitely lost' reports in GNOME bugzilla after doing very basic triage on them. And some of them look very much like they were false positives. There are some examples of basic structures like GString being used, which are clearly freed a few lines after they are created. Unless GLib has developed some egregious brokenness in its core data structures, valgrind seems to have got broken.
These appear to be false positives:
Valgrind also fails to track thread-local storage:
https://bugzilla.gnome.org/show_bug.cgi?id=702021 and probably also
It would be really useful to get back to the point where valgrind can sanely be used to track memory leaks in programs like Evolution again. It's bad enough that there's an unmanageable number of 'possibly lost' reports which are mostly false positives; for 'definitely lost' to start being untrustworthy too is really a PITA.
Deliberately filing this in distro bugzilla so it can be assigned to other components if appropriate. I think we have "real" maintainers here for all relevant parts.
> These appear to be false positives:
If you could provide the exact fedora package versions involved and the steps you did you trigger the leak that would help to reproduce the issues.
> Valgrind also fails to track thread-local storage
If you could provide a minimal example just using the pthread constructs without glibs own memory handling intertwined that would be really helpful.
There is an unanswered question from 2005 about valgrind's handling of pthread_key_create(): http://valgrind.10908.n7.nabble.com/pthread-key-create-question-td33955.html
This message is a notice that Fedora 19 is now at end of life. Fedora
has stopped maintaining and issuing updates for Fedora 19. It is
Fedora's policy to close all bug reports from releases that are no
longer maintained. Approximately 4 (four) weeks from now this bug will
be closed as EOL if it remains open with a Fedora 'version' of '19'.
Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version'
to a later Fedora version.
Thank you for reporting this issue and we are sorry that we were not
able to fix it before Fedora 19 is end of life. If you would still like
to see this bug fixed and are able to reproduce it against a later version
of Fedora, you are encouraged change the 'version' to a later Fedora
version prior this bug is closed as described in the policy above.
Although we aim to fix as many bugs as possible during every release's
lifetime, sometimes those efforts are overtaken by events. Often a
more recent Fedora release includes newer upstream software that fixes
bugs or makes them obsolete.
Fedora 19 changed to end-of-life (EOL) status on 2015-01-06. Fedora 19 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.
If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
are unable to reopen this bug, please file a new report against the
current release. If you experience problems, please add a comment to this
Thank you for reporting this bug and we are sorry it could not be fixed.