[GHC] #11776: RTS segfaults when printing profiling information which refers to unloaded objects

[GHC]

#11776: RTS segfaults when printing profiling information which refers to unloaded
objects
-------------------------------------+-------------------------------------
        Reporter:  afarmer           |                Owner:  afarmer
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.0.2
       Component:  Runtime System    |              Version:  7.10.3
  (Linker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2067
       Wiki Page:                    |  Phab:D2068 Phab:D2069 Phab:D2071
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"36a0b6dc27ae0ee2022afbef5d3cd49dfde9e82b/ghc" 36a0b6d/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="36a0b6dc27ae0ee2022afbef5d3cd49dfde9e82b"
 Check CCS tree for pointers into shared object during checkUnload

 Prevent shared objects from being unloaded if cost centre stacks point
 at the object. This will prevent segfault in #11776, but also prevents
 objects from ever being unloaded when profiling. Pruning CCS tree will
 enable that in another diff.

 Test Plan: make TEST=linker_profiled, examine linker_profiled.run.stderr

 Reviewers: austin, simonmar, bgamari

 Reviewed By: simonmar, bgamari

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D2069

 GHC Trac Issues: #11776
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11776#comment:4>
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