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#2280 assigned defect

Object extend is broken on SMP

Reported by: Sebastian Huber Owned by: Needs Funding
Priority: normal Milestone: Indefinite
Component: score Version: 4.11
Severity: normal Keywords:
Cc: Blocked By:


The object identifier to control mapping is done like this:

the_object = information->local_table[ index ]

The object extension allocates a new local_table and frees the old one. Thus the sequence above may access freed memory under certain cases.

Possible solutions:

  1. Disable interrupts and make sure that the old table stays valid for a long enough time period after the registration of the new table. This timing depends on the particular hardware and may lead to very hard to find bugs.
  1. Use a generation count, e.g. update the generation count during local table updates and make sure the generation count didn't change during local table reads.

Change History (5)

comment:1 Changed on 05/20/16 at 06:00:48 by Sebastian Huber <sebastian.huber@…>

In [changeset:"b80156cf15a9e080e8608a30e3e2795211c03f3e/rtems"]:

score: Avoid Giant _Objects_Extend_information()

Avoid Giant lock for _Objects_Extend_information().

Update #2280.
Update #2555.

comment:2 Changed on 01/26/17 at 07:16:00 by Sebastian Huber


comment:3 Changed on 02/15/17 at 13:37:51 by Sebastian Huber

Milestone: 4.11.2Indefinite
Owner: set to Needs Funding
Status: newassigned

comment:4 Changed on 10/10/17 at 06:27:10 by Sebastian Huber

Component: SMPscore

comment:5 Changed on 10/10/17 at 06:29:01 by Sebastian Huber

Component: scorecpukit
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