[GHC] #8839: 64 bit windows executables compiled with ghc-7.8rc2 segfault when allocate more than 4G of memory

[GHC]

#8839: 64 bit windows executables compiled with ghc-7.8rc2 segfault when allocate
more than 4G of memory
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        Reporter:  awson           |            Owner:  simonmar
            Type:  bug             |           Status:  patch
        Priority:  highest         |        Milestone:  7.8.2
       Component:  Runtime System  |          Version:  7.8.1-rc2
      Resolution:                  |         Keywords:
Operating System:  Windows         |     Architecture:  x86_64 (amd64)
 Type of failure:  Runtime crash   |       Difficulty:  Unknown
       Test Case:                  |       Blocked By:
        Blocking:                  |  Related Tickets:
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Changes (by awson):

 * status:  new => patch


Comment:

 Oh, after another painful bug hunting I've found the
 [https://github.com/ghc/ghc/commit/36b042fbf60210ab6859d96e5b4b5e121085816d
 culprit]. `unsigned long` is 32 bit in Windows 64-bit ABI. I've attached
 the patch forcing block size to be `unsigned long long` on x86_64.
 Perhaps, it may be narrowed to 64-bit windows only, though.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8839#comment:4>
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