Date: Sun, 16 Oct 2005 21:50:12 GMT From: David Leppik <dleppik@vocalabs.com> To: freebsd-gnats-submit@FreeBSD.org Subject: docs/87548: LIST_*, TAILQ_* man pages include memory leak in sample code Message-ID: <200510162150.j9GLoCAt040327@www.freebsd.org> Resent-Message-ID: <200510162200.j9GM0RQK008697@freefall.freebsd.org>
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>Number: 87548
>Category: docs
>Synopsis: LIST_*, TAILQ_* man pages include memory leak in sample code
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-doc
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: doc-bug
>Submitter-Id: current-users
>Arrival-Date: Sun Oct 16 22:00:27 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator: David Leppik
>Release: None (old BSD code--see below)
>Organization:
Vocal Laboratories
>Environment:
>Description:
I've seen this on Mac OS X and Linux, so this probably affects FreeBSD as well.
The man page for TAILQ_INSERT, TAILQ_REMOVE, etc. have the following sample code:
while (head.tqh_first != NULL)
TAILQ_REMOVE(&head, head.tqh_first, entries);
I was so shocked that I checked queue.h and sure enough, TAILQ_REMOVE does not deallocate the queue entry (nor should it.) The same is true for the other structures mentioned in this man page.
>How-To-Repeat:
>Fix:
I'm just a lowly Java programmer, but I think the fix is:
while (head.tqh_first != NULL) {
np = head.tqh_first;
TAILQ_REMOVE(&head, np, entries);
free(np);
}
>Release-Note:
>Audit-Trail:
>Unformatted:
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