Ubuntu
plymouth package

Incorrect value passed for maxevents in call to epoll_wait() in ply-event-loop.c

Bug #518926 reported by Dave Martin on 2010-02-08

This bug affects 2 people

Affects		Status	Importance	Assigned to	Milestone
	plymouth (Ubuntu)	Fix Released	Low	Unassigned

Bug Description

Binary package hint: plymouth

Ubuntu lucid
plymouth 0.8.0~-9

In ply_event_loop_process_pending_events(), sizeof (events) is passed for the maxevents parameter to epoll_wait().

events is a pointer, to sizeof (events) is 4 or 8 on most architectures.

This seems unlikely to have been what was intended.

Is PLY_EVENT_LOOP_NUM_EVENT_HANDLERS supposed to be passed for maxevents instead? (This is the number if event structures allocated to events.) If so, the attached patch ought to fix it.

This bug was found while investigating the following issue, but is probably not directly related:
* https://bugs.launchpad.net/ubuntu/+source/plymouth/+bug/518937 (ply_event_loop_process_pending_events can block, causing mountall to deadlock)

See original description

Tags:

Related branches

lp:ubuntu/natty/plymouth

Revision history for this message

Dave Martin (dave-martin-arm) wrote on 2010-02-08:

possible fix Edit (524 bytes, text/plain)

Brian Murray (brian-murray) on 2010-02-08

tags:

added: patch

Dave Martin (dave-martin-arm) on 2010-02-08

description:	updated
description:	updated

Brian Murray (brian-murray) on 2010-02-08

Changed in plymouth (Ubuntu):
importance:	Undecided → Medium
status:	New → Triaged

Revision history for this message

Scott James Remnant (Canonical) (canonical-scott) wrote on 2010-03-13:

The patch looks correct - could you send that upstream yourself (if not, I'll do it)

There would only be a danger from this on platforms with larger than 64-byte pointers - but it's silly to not use the entire events array

Changed in plymouth (Ubuntu):
importance:	Medium → Low

Revision history for this message

Benjamin Drung (bdrung) wrote on 2010-05-16:

no debdiff for ubuntu-sponsors, subscribing ubuntu-reviewers for the patch instead

Colin Watson (cjwatson) on 2011-03-24

Changed in plymouth (Ubuntu):
status:	Triaged → Fix Committed

Revision history for this message

Launchpad Janitor (janitor) wrote on 2011-03-24:

This bug was fixed in the package plymouth - 0.8.2-2ubuntu20

---------------
plymouth (0.8.2-2ubuntu20) natty; urgency=low

  * Backport from upstream:
    - [event-loop] Add reference count to event sources (with any luck, this
      will fix LP: #553745).
    - [event-loop] Handle more than 8 events at once (LP: #518926).
    - [terminal] Force enter to output newline.
    - [terminal] Add OPOST to tty attributes (LP: #546251).
    - [terminal] Don't set ISTRIP in terminal attributes.
-- Colin Watson <email address hidden> Thu, 24 Mar 2011 14:17:20 +0000