[GHC] #10154: strange closure type 983040 (GHC version 7.8.3 for x86_64_unknown_linux)

[GHC]

#10154: strange closure type 983040 (GHC version 7.8.3 for x86_64_unknown_linux)
-------------------------------------+-------------------------------------
        Reporter:  masterdezign      |                   Owner:
            Type:  bug               |                  Status:  closed
        Priority:  high              |               Milestone:
       Component:  Compiler          |                 Version:  7.8.3
      Resolution:  invalid           |                Keywords:  strange
Operating System:  Linux             |  closure type
 Type of failure:  Runtime crash     |            Architecture:
      Blocked By:                    |  Unknown/Multiple
 Related Tickets:                    |               Test Case:
                                     |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------
Changes (by rwbarton):

 * status:  infoneeded => closed
 * resolution:   => invalid


Comment:

 I tried building with `-debug -rtsopts` and running with `+RTS -DS` under
 gdb and sure enough, many hours later, I got this:

 {{{
 ...
 Running epsilon=5.0e-3 delta=1.8e-2
 Running epsilon=5.0e-3 delta=1.9e-2
 Running epsilon=5.0e-3 delta=2.0e-2
 [New Thread 0x7fffa53ff700 (LWP 18847)]
 epsilon=2.0e-2 delta=1.0e-3     =>      0 head(s) (92.3%)
 Simul: internal error: ASSERTION FAILED: file rts/sm/Storage.c, line 789

     (GHC version 7.8.4 for x86_64_unknown_linux)
     Please report this as a GHC bug:
 http://www.haskell.org/ghc/reportabug

 Program received signal SIGABRT, Aborted.
 [Switching to Thread 0x7fffe5dfc700 (LWP 18737)]
 0x00007ffff6798077 in __GI_raise (sig=sig at entry=6) at
 ../nptl/sysdeps/unix/sysv/linux/raise.c:56
 56      ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or
 directory.
 (gdb) bt
 #0  0x00007ffff6798077 in __GI_raise (sig=sig at entry=6) at
 ../nptl/sysdeps/unix/sysv/linux/raise.c:56
 #1  0x00007ffff6799458 in __GI_abort () at abort.c:89
 #2  0x00000000007e5087 in rtsFatalInternalErrorFn (s=0x854810 "ASSERTION
 FAILED: file %s, line %u\n", ap=0x7fffe5df7cd8) at rts/RtsMessages.c:170
 #3  0x00000000007e4cbf in barf (s=0x854810 "ASSERTION FAILED: file %s,
 line %u\n") at rts/RtsMessages.c:42
 #4  0x00000000007e4d22 in _assertFail (filename=0x85a1c8
 "rts/sm/Storage.c", linenum=789) at rts/RtsMessages.c:57
 #5  0x0000000000804d69 in allocate (cap=0xacec60, n=8) at
 rts/sm/Storage.c:789
 #6  0x000000000080f522 in stg_newByteArrayzh ()
 #7  0x0000000000000000 in ?? ()
 }}}

 The failed assertion is at the end of `allocate`:

 {{{
     IF_DEBUG(sanity, ASSERT(*((StgWord8*)p) == 0xaa));
 }}}

 Inspecting the memory before `p` (the pointer that `allocate` has just
 allocated, and is about to return) I see

 {{{
 (gdb) x/ga p-8
 0x7ffff42ec9c0: 0x812e60 <stg_ARR_WORDS_info>
 (gdb)
 0x7ffff42ec9c8: 0x30
 (gdb)
 0x7ffff42ec9d0: 0x30002e0030002d
 (gdb)
 0x7ffff42ec9d8: 0x30003000300030
 (gdb)
 0x7ffff42ec9e0: 0x30003200300031
 (gdb)
 0x7ffff42ec9e8: 0x33003200340038
 (gdb)
 0x7ffff42ec9f0: 0x31003100340032
 (gdb)
 0x7ffff42ec9f8: 0x33003500380035
 (gdb)
 0x7ffff42eca00: 0xaaaaaaaaaaaa0032
 (gdb)
 }}}
 so, I strongly suspect that something in the C++ code in the `double-
 conversion` library is writing past the end of an allocated array.

 It's quite a lot of C++ code though, so I don't particularly want to
 investigate further. I'll file a bug with `double-conversion`.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10154#comment:8>
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