ghc: segmentation fault under strange conditions

.gitignore

*.hi
stackoverflow_segv

README

$ # see http://stackoverflow.com/questions/10341943/ghc-segmentation-fault-under-strange-conditions
$ make
./stackoverflow_segv
entry point: 0x0a0e97e0
welcome back
$ # however, when executing the binary from shell...
$ ./stackoverflow_segv
entry point: 0x0916b7e0
Segmentation fault (core dumped)



# some information about the system
$ cat /etc/issue
Ubuntu 12.04 LTS \n \l
$ uname -a
Linux matevm-dev 3.2.0-23-generic #36-Ubuntu SMP Tue Apr 10 20:41:14 UTC 2012 i686 athlon i386 GNU/Linux
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.4.1
$ gcc --version
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ make --version
GNU Make 3.81
Copyright (C) 2006  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.

This program built for i686-pc-linux-gnu
$ ghc-pkg list
/var/lib/ghc/package.conf.d:
    Cabal-1.14.0
    array-0.4.0.0
    base-4.5.0.0
    bin-package-db-0.0.0.0
    binary-0.5.1.0
    bytestring-0.9.2.1
    containers-0.4.2.1
    deepseq-1.3.0.0
    directory-1.1.0.2
    extensible-exceptions-0.1.1.4
    filepath-1.3.0.0
    (ghc-7.4.1)
    ghc-prim-0.2.0.0
    (haskell2010-1.1.0.1)
    (haskell98-2.0.0.1)
    hoopl-3.8.7.3
    hpc-0.5.1.1
    integer-gmp-0.4.0.0
    old-locale-1.0.0.4
    old-time-1.1.0.0
    pretty-1.1.1.0
    process-1.1.0.1
    rts-1.0
    template-haskell-2.7.0.0
    time-1.4
    unix-2.5.1.0

/home/lewurm/.ghc/i386-linux-7.4.1/package.conf.d:
    HUnit-1.2.4.2
    MissingH-1.1.1.0
    QuickCheck-2.4.2
    binary-state-0.1.1
    control-monad-exception-0.10.2
    data-binary-ieee754-0.4.2.1
    disassembler-0.1.0.1
    failure-0.2.0.1
    ghc-paths-0.1.0.8
    harpy-0.4.3.0
    haskell-src-1.0.1.5
    heap-1.0.0
    hs-java-0.2
    hslogger-1.1.5
    monadloc-0.6
    mtl-1.1.1.1
    mtl-2.1.1
    network-2.3.0.13
    parsec-2.1.0.1
    plugins-1.5.2.1
    random-1.0.1.1
    regex-base-0.93.2
    regex-compat-0.95.1
    regex-posix-0.95.1
    syb-0.3.6.1
    transformers-0.3.0.0
    utf8-string-0.3.7

Main.hs

{-# LANGUAGE ForeignFunctionInterface #-}
module Main where

import Data.Word
import Text.Printf
import Foreign

foreign import ccall "dynamic"
   code_void :: FunPtr (IO ()) -> (IO ())

main :: IO ()
main = do
  entryPtr <- (mallocBytes 2)
  poke entryPtr (0xc390 :: Word16) -- nop (0x90); ret(0xc3) (little endian order)

  _ <- printf "entry point: 0x%08x\n" ((fromIntegral $ ptrToIntPtr entryPtr) :: Int)
  _ <- getLine -- for debugging
  code_void $ castPtrToFunPtr entryPtr
  putStrLn "welcome back"

Makefile

NAME := stackoverflow_segv

all: $(NAME)
	./$<

$(NAME): Main.hs
	ghc --make -Wall -O2 $^ -o $@

clean:
	rm -f *.hi *.o $(NAME)