[GHC] #5188: Runtime error when allocating lots of memory

[GHC]

#5188: Runtime error when allocating lots of memory
---------------------------------+---------------------------
        Reporter:  knyblad       |            Owner:
            Type:  bug           |           Status:  new
        Priority:  low           |        Milestone:  7.6.2
       Component:  GHCi          |          Version:  6.12.1
      Resolution:                |         Keywords:
Operating System:  Linux         |     Architecture:  x86
 Type of failure:  None/Unknown  |       Difficulty:  Unknown
       Test Case:                |       Blocked By:
        Blocking:                |  Related Tickets:
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Comment (by rwbarton):

 The first attached patch checks for integer overflow in the computation of
 `size` in `osGetMBlocks`.  With the patch the example program now exits
 with this message:

 {{{
 pow: out of memory (requested 4096 MBlocks)
 }}}

 The second and third patches are extra checks for overflow when converting
 between integer types in `my_mmap` and `osGetMBlocks`.  AFAIK it *should*
 always be the case that `W_` >= `nat` and that `size_t` >= `W_` on
 platforms supported by GHC; but on any system where that is the case, the
 C compiler can eliminate the tests anyways, so I recommend including both
 tests.

 Oops, I see there is a missing `%` in the middle patch.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5188#comment:8>
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