7.6.2 Segmentation Fault/Bus Error in large exponentation

mentioned in issue #4374

changed weight to 5

closed

This is fixed in GHC 7.6.1, according to http://www.reddit.com/r/haskell/comments/17jyw9/announce_ghc_version_762/c86g3ne

If you can reproduce the bug in 7.6, please reopen.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

reopened

changed title from 7.4.2 Segmentation Fault/Bus Error in large exponentation to 7.6.2 Segmentation Fault/Bus Error in large exponentation

Unfortunately, I am able to reproduce this partially in 7.6.2 for x86_64 using the available binary distribution: ghc-7.6.2-x86_64-apple-darwin.tar.bz2.

~/src/haskell/ghc/ghc-7.6.2$ ghci
GHCi, version 7.6.2: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude> 12345678901234567890 ^ 12345
Bus error: 10

However, my second example works:

~/src/haskell/ghc/ghc-7.6.2$ ghci
GHCi, version 7.6.2: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude> 2384729837498237 ^ 23455
6856427983194016568523 .... (goes on for hundreds of lines)

The full Bus Error crash report is:

Process:         ghc [27889]
Path:            /opt/ghc-7.6.2-x86_64/*/ghc
Identifier:      ghc
Version:         ???
Code Type:       X86-64 (Native)
Parent Process:  bash [24202]
User ID:         501

Date/Time:       2013-02-04 00:01:12.441 -0500
OS Version:      Mac OS X 10.8.2 (12C60)
Report Version:  10

Interval Since Last Report:          3611040 sec
Crashes Since Last Report:           696
Per-App Crashes Since Last Report:   7
Anonymous UUID:                      145798BC-982C-D5DB-8C3A-18EA16FAB47B

Crashed Thread:  1

Exception Type:  EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x000000011203c998

VM Regions Near 0x11203c998:
    MALLOC metadata        000000011203b000-000000011203c000 [    4K] r--/rwx SM=PRV  
--> Stack                  000000011203c000-000000011203d000 [    4K] ---/rwx SM=NUL  
    Stack                  000000011203d000-00000001120bf000 [  520K] rw-/rwx SM=COW  

Thread 0:: Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib        	0x00007fff8bbae0fa __psynch_cvwait + 10
1   libsystem_c.dylib             	0x00007fff93534f89 _pthread_cond_wait + 869
2   ghc                           	0x00000001100e16c9 waitCondition + 9
3   ghc                           	0x00000001100be8ab yieldCapability + 395
4   ghc                           	0x00000001100cd382 schedule + 386
5   ghc                           	0x00000001100cddf4 scheduleWaitThread + 164
6   ghc                           	0x00000001100c878e real_main + 68
7   ghc                           	0x00000001100c8896 hs_main + 93
8   ghc                           	0x000000010e0d44f9 main + 73
9   ghc                           	0x000000010e00dbb4 start + 52

Thread 1 Crashed:
0   ???                           	0x00000001129c3d3c 0 + 4607196476
1   ???                           	0x00000001129f44b3 0 + 4607394995
2   ???                           	0x00000001129dbbe4 0 + 4607294436
3   ???                           	0x00000001129f119c 0 + 4607381916
4   ???                           	0x00000001129cc8f2 0 + 4607232242
5   ???                           	0x00000001129c74fa 0 + 4607210746
6   ???                           	0x00000001129ab454 0 + 4607095892
7   ghc                           	0x00000001100f38c8 stg_marked_upd_frame_info_dsp + 16
8   ???                           	0x058d482177000000 0 + 400055250473451520

Thread 2:
0   libsystem_kernel.dylib        	0x00007fff8bbaed2a kevent64 + 10
1   ghc                           	0x000000011006c8f2 s52S_info + 170
2   ghc                           	0x000000011006ca48 s6qO_info_dsp + 24

Thread 3:
0   libsystem_kernel.dylib        	0x00007fff8bbae0fa __psynch_cvwait + 10
1   libsystem_c.dylib             	0x00007fff93534f89 _pthread_cond_wait + 869
2   ghc                           	0x00000001100e16c9 waitCondition + 9
3   ghc                           	0x00000001100be8ab yieldCapability + 395
4   ghc                           	0x00000001100cd382 schedule + 386
5   ghc                           	0x00000001100cdccb scheduleWorker + 27
6   libsystem_c.dylib             	0x00007fff93530742 _pthread_start + 327
7   libsystem_c.dylib             	0x00007fff9351d181 thread_start + 13

Thread 1 crashed with X86 Thread State (64-bit):
  rax: 0x00000000000a5771  rbx: 0x0000000000000560  rcx: 0x00000000ffffffeb  rdx: 0x00000000000000ac
  rdi: 0x000000011203c440  rsi: 0x0000000113b24680  rbp: 0x00000001120312c0  rsp: 0x0000000112031248
   r8: 0x000000000018192d   r9: 0x00000000000000a9  r10: 0xe7d24d796c78192d  r11: 0x41430d29ed17e85b
  r12: 0x0000000000000007  r13: 0x00000000000000a9  r14: 0x0000000000000003  r15: 0x00000000000000ac
  rip: 0x00000001129c3d3c  rfl: 0x0000000000010286  cr2: 0x000000011203c998
Logical CPU: 4

Binary Images:
       0x10e00d000 -        0x1101c0fe7 +ghc (???) <1010B9EB-C2AF-32E2-AD15-CEB7B26CA475> /opt/ghc-7.6.2-x86_64/*/ghc
    0x7fff6dc0d000 -     0x7fff6dc4193f  dyld (210.2.3) <A40597AA-5529-3337-8C09-D8A014EB1578> /usr/lib/dyld
    0x7fff8787a000 -     0x7fff87880fff  libmacho.dylib (829) <BF332AD9-E89F-387E-92A4-6E1AB74BD4D9> /usr/lib/system/libmacho.dylib
    0x7fff8797b000 -     0x7fff879c7ff7  libauto.dylib (185.1) <73CDC482-16E3-3FC7-9BB4-FBA2DA44DBC2> /usr/lib/libauto.dylib
    0x7fff87b21000 -     0x7fff87b29fff  liblaunch.dylib (442.26.2) <2F71CAF8-6524-329E-AC56-C506658B4C0C> /usr/lib/system/liblaunch.dylib
    0x7fff88aef000 -     0x7fff88af0ff7  libremovefile.dylib (23.1) <DBBFAF35-AC78-3856-92F6-6E4FD9DF14A2> /usr/lib/system/libremovefile.dylib
    0x7fff88db3000 -     0x7fff88dbbff7  libsystem_dnssd.dylib (379.32.1) <62AA0B84-188A-348B-8F9E-3E2DB08DB93C> /usr/lib/system/libsystem_dnssd.dylib
    0x7fff89272000 -     0x7fff8927dfff  libsystem_notify.dylib (98.5) <C49275CC-835A-3207-AFBA-8C01374927B6> /usr/lib/system/libsystem_notify.dylib
    0x7fff8b590000 -     0x7fff8b5dfff7  libcorecrypto.dylib (106.2) <CE0C29A3-C420-339B-ADAA-52F4683233CC> /usr/lib/system/libcorecrypto.dylib
    0x7fff8b9fb000 -     0x7fff8ba29ff7  libsystem_m.dylib (3022.6) <B434BE5C-25AB-3EBD-BAA7-5304B34E3441> /usr/lib/system/libsystem_m.dylib
    0x7fff8bb9a000 -     0x7fff8bb9bfff  libsystem_blocks.dylib (59) <D92DCBC3-541C-37BD-AADE-ACC75A0C59C8> /usr/lib/system/libsystem_blocks.dylib
    0x7fff8bb9c000 -     0x7fff8bbb7ff7  libsystem_kernel.dylib (2050.18.24) <C0535565-35D1-31A7-A744-63D9F10F12A4> /usr/lib/system/libsystem_kernel.dylib
    0x7fff8c182000 -     0x7fff8c185ff7  libdyld.dylib (210.2.3) <F59367C9-C110-382B-A695-9035A6DD387E> /usr/lib/system/libdyld.dylib
    0x7fff8d57f000 -     0x7fff8d580ff7  libSystem.B.dylib (169.3) <365477AB-D641-389D-B8F4-A1FAE9657EEE> /usr/lib/libSystem.B.dylib
    0x7fff8e231000 -     0x7fff8e236fff  libcache.dylib (57) <65187C6E-3FBF-3EB8-A1AA-389445E2984D> /usr/lib/system/libcache.dylib
    0x7fff8e237000 -     0x7fff8e26dfff  libsystem_info.dylib (406.17) <4FFCA242-7F04-365F-87A6-D4EFB89503C1> /usr/lib/system/libsystem_info.dylib
    0x7fff8e35d000 -     0x7fff8e452fff  libiconv.2.dylib (34) <FEE8B996-EB44-37FA-B96E-D379664DEFE1> /usr/lib/libiconv.2.dylib
    0x7fff8f2de000 -     0x7fff8f2e4ff7  libunwind.dylib (35.1) <21703D36-2DAB-3D8B-8442-EAAB23C060D3> /usr/lib/system/libunwind.dylib
    0x7fff8f8de000 -     0x7fff8f9f692f  libobjc.A.dylib (532.2) <90D31928-F48D-3E37-874F-220A51FD9E37> /usr/lib/libobjc.A.dylib
    0x7fff910e4000 -     0x7fff9114cff7  libc++.1.dylib (65.1) <20E31B90-19B9-3C2A-A9EB-474E08F9FE05> /usr/lib/libc++.1.dylib
    0x7fff9114d000 -     0x7fff9114fff7  libunc.dylib (25) <92805328-CD36-34FF-9436-571AB0485072> /usr/lib/system/libunc.dylib
    0x7fff91818000 -     0x7fff91819ff7  libdnsinfo.dylib (453.18) <E7595861-ECF9-336E-9901-BED2620FAA80> /usr/lib/system/libdnsinfo.dylib
    0x7fff91a6c000 -     0x7fff91a81ff7  libdispatch.dylib (228.23) <D26996BF-FC57-39EB-8829-F63585561E09> /usr/lib/system/libdispatch.dylib
    0x7fff91a84000 -     0x7fff91a8bfff  libcopyfile.dylib (89) <876573D0-E907-3566-A108-577EAD1B6182> /usr/lib/system/libcopyfile.dylib
    0x7fff92190000 -     0x7fff921b5ff7  libc++abi.dylib (24.4) <E7BD9363-1D25-3551-A68A-2E2FF6ABECD7> /usr/lib/libc++abi.dylib
    0x7fff92b1b000 -     0x7fff92b3dff7  libxpc.dylib (140.41) <FAC04D8B-680E-325F-8F0C-DD69859D0E01> /usr/lib/system/libxpc.dylib
    0x7fff92ce4000 -     0x7fff92ce4fff  libkeymgr.dylib (25) <CC9E3394-BE16-397F-926B-E579B60EE429> /usr/lib/system/libkeymgr.dylib
    0x7fff92ce6000 -     0x7fff92ce7ff7  libsystem_sandbox.dylib (220) <3C3B03CF-C525-3CB3-8557-62E91B93AC95> /usr/lib/system/libsystem_sandbox.dylib
    0x7fff92ce8000 -     0x7fff92cedfff  libcompiler_rt.dylib (30) <08F8731D-5961-39F1-AD00-4590321D24A9> /usr/lib/system/libcompiler_rt.dylib
    0x7fff933e2000 -     0x7fff933f0ff7  libsystem_network.dylib (77.10) <0D99F24E-56FE-380F-B81B-4A4C630EE587> /usr/lib/system/libsystem_network.dylib
    0x7fff934e3000 -     0x7fff9351bfff  libncurses.5.4.dylib (37.3) <68D5B5F5-8252-3F1E-AFF1-C6AFE145DBC1> /usr/lib/libncurses.5.4.dylib
    0x7fff9351c000 -     0x7fff935e8fe7  libsystem_c.dylib (825.25) <8CBCF9B9-EBB7-365E-A3FF-2F3850763C6B> /usr/lib/system/libsystem_c.dylib
    0x7fff93c5c000 -     0x7fff93c5efff  libquarantine.dylib (52) <4BE2E642-A14F-340A-B482-5BD2AEFD9C24> /usr/lib/system/libquarantine.dylib
    0x7fff93c61000 -     0x7fff93c6ffff  libcommonCrypto.dylib (60026) <2D6537F5-1B5E-305C-A1CF-D1FA80CA3939> /usr/lib/system/libcommonCrypto.dylib

External Modification Summary:
  Calls made by other processes targeting this process:
    task_for_pid: 0
    thread_create: 0
    thread_set_state: 0
  Calls made by this process:
    task_for_pid: 0
    thread_create: 0
    thread_set_state: 0
  Calls made by all processes on this machine:
    task_for_pid: 10900
    thread_create: 0
    thread_set_state: 0

VM Region Summary:
ReadOnly portion of Libraries: Total=120.4M resident=226.4M(188%) swapped_out_or_unallocated=16777216.0T(14611640221696%)
Writable regions: Total=70.3M written=22.0M(31%) resident=25.2M(36%) swapped_out=0K(0%) unallocated=45.2M(64%)
 
REGION TYPE                      VIRTUAL
===========                      =======
MALLOC                             36.4M
MALLOC guard page                    16K
STACK GUARD                        56.0M
Stack                              9756K
VM_ALLOCATE                        21.7M
__DATA                             3244K
__LINKEDIT                         81.0M
__TEXT                             39.4M
mapped file                        11.6M
shared memory                        12K
===========                      =======
TOTAL                             258.8M

Model: MacBookPro8,2, BootROM MBP81.0047.B27, 4 processors, Intel Core i7, 2.3 GHz, 16 GB, SMC 1.69f3
Graphics: Intel HD Graphics 3000, Intel HD Graphics 3000, Built-In, 512 MB
Graphics: AMD Radeon HD 6750M, AMD Radeon HD 6750M, PCIe, 1024 MB
Memory Module: BANK 0/DIMM0, 8 GB, DDR3, 1333 MHz, 0x0000, 0x000000000000000000000000000000000000
Memory Module: BANK 1/DIMM0, 8 GB, DDR3, 1333 MHz, 0x0000, 0x000000000000000000000000000000000000
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0xD6), Broadcom BCM43xx 1.0 (5.106.98.81.22)
Bluetooth: Version 4.0.9f33 10885, 2 service, 18 devices, 1 incoming serial ports
Network Service: AirPort, AirPort, en1
Network Service: Logitech Harmony USB (en2), Ethernet, en2
Serial ATA Device: OCZ-VERTEX3, 480.1 GB
Serial ATA Device: Hitachi HTS725050A9A362, 500.11 GB
USB Device: hub_device, 0x0424  (SMSC), 0x2513, 0xfa100000 / 3
USB Device: iPad, apple_vendor_id, 0x12ab, 0xfa130000 / 6
USB Device: Apple Internal Keyboard / Trackpad, apple_vendor_id, 0x0245, 0xfa120000 / 5
USB Device: BRCM2070 Hub, 0x0a5c  (Broadcom Corp.), 0x4500, 0xfa110000 / 4
USB Device: Bluetooth USB Host Controller, apple_vendor_id, 0x821a, 0xfa113000 / 8
USB Device: FaceTime HD Camera (Built-in), apple_vendor_id, 0x8509, 0xfa200000 / 2
USB Device: hub_device, 0x0424  (SMSC), 0x2513, 0xfd100000 / 2
USB Device: IR Receiver, apple_vendor_id, 0x8242, 0xfd110000 / 3

Trac metadata

Trac field	Value
Version	7.4.2 → 7.6.2
Resolution	ResolvedFixed → Unresolved

I downloaded the i386 Mac OS X binary of 7.6.2 and tested both these exponentiations, and one more (with another digit in the exponent just for good measure). They all worked fine.

changed milestone to %7.8.1

assigned to @trac-igloo

Thanks for the report. I'll see if I can reproduce the problem.

I can reproduce it with ghc-7.6.2-x86_64-apple-darwin.tar.bz2.

And also with a validated HEAD (with dynamic ghci).

Argh, now I can't reproduce it at all.

unassigned @trac-igloo

I can reproduce the first, 12345678901234567890 !^ 12345, the bus error, on 10.8.4 with ghc 7.6.3, i.e. the Haskell platform.

I can't reproduce the second, 2384729837498237!^23455, the second, the segmentation violation.

Trac metadata

Trac field	Value
CC	→ george.colpitts@gmail.com

same results in 7.8 RC1 on Mac OS 10.9.1 as my results above

Trac metadata

Trac field	Value
Version	7.6.2 → 7.8.1-rc1

GHCI in my 7.8 RC build has no errors with either example. (ie I get a very very large number printed out)

my ghc build is a bindist here https://github.com/cartazio/ghc/releases/tag/carters-build-7.8-preRC1 from commit 12853f4d

it may be related to that. heres my settings file

carter ~ » ghc --info
 [("Project name","The Glorious Glasgow Haskell Compilation System")
 ,("GCC extra via C opts"," -fwrapv")
 ,("C compiler command","gcc-4.8")
 ,("C compiler flags"," -m64 -fno-stack-protector")
 ,("C compiler link flags"," -m64")
 ,("ld command","/usr/bin/ld")
 ,("ld flags"," -arch x86_64")
 ,("ld supports compact unwind","YES")
 ,("ld supports build-id","NO")
 ,("ld supports filelist","YES")
 ,("ld is GNU ld","NO")
 ,("ar command","/usr/bin/ar")
 ,("ar flags","clqs")
 ,("ar supports at file","NO")
 ,("touch command","touch")
 ,("dllwrap command","/bin/false")
 ,("windres command","/bin/false")
 ,("libtool command","libtool")
 ,("perl command","/usr/bin/perl")
 ,("target os","OSDarwin")
 ,("target arch","ArchX86_64")
 ,("target word size","8")
 ,("target has GNU nonexec stack","False")
 ,("target has .ident directive","True")
 ,("target has subsections via symbols","True")
 ,("Unregisterised","NO")
 ,("LLVM llc command","/usr/local/bin/llc-3.4")
 ,("LLVM opt command","/usr/local/bin/opt-3.4")
 ,("Project version","7.8.20140130")
 ,("Booter version","7.6.3")
 ,("Stage","2")
 ,("Build platform","x86_64-apple-darwin")
 ,("Host platform","x86_64-apple-darwin")
 ,("Target platform","x86_64-apple-darwin")
 ,("Have interpreter","YES")
 ,("Object splitting supported","YES")
 ,("Have native code generator","YES")
 ,("Support SMP","YES")
 ,("Tables next to code","YES")
 ,("RTS ways","l debug thr thr_debug thr_l  dyn debug_dyn thr_dyn thr_debug_dyn l_dyn thr_l_dyn")
 ,("Support dynamic-too","YES")
 ,("Support parallel --make","YES")
 ,("Dynamic by default","NO")
 ,("GHC Dynamic","YES")
 ,("Leading underscore","YES")
 ,("Debug on","False")
 ,("LibDir","/usr/local/lib/ghc-7.8.20140130")
 ,("Global Package DB","/usr/local/lib/ghc-7.8.20140130/package.conf.d")
 ]

George, thanks for following up on this. Could you attach a crash report for the bus error like the one Doug310 posted above? (or Austin, if you can reproduce this also?)

Thanks for attempting to address this. It's nice to see some traction after a year. :) It would be great if the 64-bit GHC/GHCi would become as stable as the 32-bit on Mac OS X.

Also note that I just tried various random large numbers after I first noticed the problem. It crashed on some, but not all, which made the underlying reason for the issue mystifying.

btw, note that (^) for Integer is implemented via square-and-multiply, c.f. implementation in base. So it might be interesting if one could find out which one of the several Integer-primop calls involved causes the actual fault.

Attached file exp.txt (download).

crash report for bus error

output from ghc --info corresponding to crash report for bus error above

 ghc --info
 [("Project name","The Glorious Glasgow Haskell Compilation System")
 ,("GCC extra via C opts"," -fwrapv")
 ,("C compiler command","/usr/local/bin/gcc")
 ,("C compiler flags"," -m64 -fno-stack-protector")
 ,("C compiler link flags"," -m64")
 ,("ld command","/usr/bin/ld")
 ,("ld flags"," -arch x86_64")
 ,("ld supports compact unwind","YES")
 ,("ld supports build-id","NO")
 ,("ld supports filelist","YES")
 ,("ld is GNU ld","NO")
 ,("ar command","/usr/bin/ar")
 ,("ar flags","clqs")
 ,("ar supports at file","@ArSupportsAtFile@")
 ,("touch command","touch")
 ,("dllwrap command","/bin/false")
 ,("windres command","/bin/false")
 ,("libtool command","libtool")
 ,("perl command","/usr/bin/perl")
 ,("target os","OSDarwin")
 ,("target arch","ArchX86_64")
 ,("target word size","8")
 ,("target has GNU nonexec stack","False")
 ,("target has .ident directive","True")
 ,("target has subsections via symbols","True")
 ,("Unregisterised","NO")
 ,("LLVM llc command","llc")
 ,("LLVM opt command","opt")
 ,("Project version","7.8.20140130")
 ,("Booter version","7.6.3")
 ,("Stage","2")
 ,("Build platform","x86_64-apple-darwin")
 ,("Host platform","x86_64-apple-darwin")
 ,("Target platform","x86_64-apple-darwin")
 ,("Have interpreter","YES")
 ,("Object splitting supported","YES")
 ,("Have native code generator","YES")
 ,("Support SMP","YES")
 ,("Tables next to code","YES")
 ,("RTS ways","l debug thr thr_debug thr_l thr_p dyn debug_dyn thr_dyn thr_debug_dyn l_dyn thr_l_dyn")
 ,("Support dynamic-too","YES")
 ,("Support parallel --make","YES")
 ,("Dynamic by default","NO")
 ,("GHC Dynamic","YES")
 ,("Leading underscore","YES")
 ,("Debug on","False")
 ,("LibDir","/usr/local/lib/ghc-7.8.20140130")
 ,("Global Package DB","/usr/local/lib/ghc-7.8.20140130/package.conf.d")
 ]

hrm `` ("ar supports at file","@ArSupportsAtFile@")\

could that be problematic?

No idea but as we seem to have different versions of ar I assuming that we are on different versions of Mac OS or Xcode. I am on OS 10.9.1 and Xcode 5.0.2.

ls -l /usr/bin/ar
-rwxr-xr-x  1 root  wheel  14224 Oct 27 17:59 /usr/bin/ar

I'll add more of my system information shortly (just got off a plane. ). But the biggest difference is I'm using a real GCC. AND my build of ghc was built with it. Your GCC is actually clang.

I'm on a very up to date OS X 10.9 machine too. I'll confirm that shortly though.

The fact that you have something like @ArSupportsAtFile@ being passed to AR makes me think that the build of ghc went wrong. OR perhaps there's a problem with how clang works as an assembler on OS X?

ILL do a clang build of the RC myself to try to replicate this.

Crazy theory: what version of the gmp dylib do you have? I'm pretty sure I'm using s recent gmp built via brew. Could it be that you're using the apple libgmp dylib and you're tripping a bug there?

changed milestone to %7.8.2

I can no longer reproduce this using 7.8rc2. I believe I am using a real gcc and perhaps was before.

gcc --version gcc (GCC) 4.8.2 Copyright (C) 2013 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.

bash-3.2$

ghc --info [("Project name","The Glorious Glasgow Haskell Compilation System") ,("GCC extra via C opts"," -fwrapv") ,("C compiler command","/usr/local/bin/gcc") ,("C compiler flags"," -m64 -fno-stack-protector") ,("C compiler link flags"," -m64") ,("ld command","/usr/bin/ld") ,("ld flags"," -arch x86_64") ,("ld supports compact unwind","YES") ,("ld supports build-id","NO") ,("ld supports filelist","YES") ,("ld is GNU ld","NO") ,("ar command","/usr/bin/ar") ,("ar flags","clqs") ,("ar supports at file","NO") ,("touch command","touch") ,("dllwrap command","/bin/false") ,("windres command","/bin/false") ,("libtool command","libtool") ,("perl command","/usr/bin/perl") ,("target os","OSDarwin") ,("target arch","ArchX86_64") ,("target word size","8") ,("target has GNU nonexec stack","False") ,("target has .ident directive","True") ,("target has subsections via symbols","True") ,("Unregisterised","NO") ,("LLVM llc command","llc") ,("LLVM opt command","opt") ,("Project version","7.8.0.20140228") ,("Booter version","7.6.3") ,("Stage","2") ,("Build platform","x86_64-apple-darwin") ,("Host platform","x86_64-apple-darwin") ,("Target platform","x86_64-apple-darwin") ,("Have interpreter","YES") ,("Object splitting supported","YES") ,("Have native code generator","YES") ,("Support SMP","YES") ,("Tables next to code","YES") ,("RTS ways","l debug thr thr_debug thr_l thr_p dyn debug_dyn thr_dyn thr_debug_dyn l_dyn thr_l_dyn") ,("Support dynamic-too","YES") ,("Support parallel --make","YES") ,("Dynamic by default","NO") ,("GHC Dynamic","YES") ,("Leading underscore","YES") ,("Debug on","False") ,("LibDir","/usr/local/lib/ghc-7.8.0.20140228") ,("Global Package DB","/usr/local/lib/ghc-7.8.0.20140228/package.conf.d") ]

changed milestone to %7.8.3

changed milestone to %7.8.4

Moving to 7.8.4.

Hi, I think I ran in to this issue running the following code (fibonacci matrix exponentiation) in ghci. It seems to happen every single time I execute it inside ghci, but never when using the full compiler (ghc --make).

module Matrix where

data Matrix = Matrix Integer Integer Integer Integer deriving (Eq, Show)

instance Num Matrix where
        fromInteger n = Matrix n n n n
        negate = undefined
        (+) = plusMatrix
        (*) = mulMatrix
        abs (Matrix a00 a01 a10 a11) = Matrix a00' a01' a10' a11'
            where
                a00' = abs a00
                a01' = abs a01
                a10' = abs a10
                a11' = abs a11
        signum = undefined


plusMatrix :: Matrix -> Matrix -> Matrix
(Matrix a00 a01 a10 a11) `plusMatrix` (Matrix b00 b01 b10 b11) =
    Matrix (a00 + b00) (a01 + b01) (a10 + b10) (a11 + b11)

mulMatrix :: Matrix -> Matrix -> Matrix
(Matrix a00 a01 a10 a11) `mulMatrix` (Matrix b00 b01 b10 b11) =
    Matrix a00' a01' a10' a11'
           where
               a00' = a00 * b00 + a01 * b10
               a01' = a00 * b01 + a01 * b11
               a10' = a10 * b00 + a11 * b10
               a11' = a10 * b10 + a11 * b11

fib4 :: Integer -> Integer
fib4 0 = 0
fib4 n = case f ^ n of
             Matrix _ fn _ _ -> fn
    where
        f = Matrix 1 1
                   1 0


main = do
        print $ fib4 1000       -- ok
        putStrLn $ replicate 80 '-'
        print $ fib4 10000     -- ok
        putStrLn $ replicate 80 '-'
        print $ fib4 1000000 -- bus error: 10

crash report:

Process:         ghc [30070]
Path:            /usr/local/lib/ghc-7.8.3/bin/ghc
Identifier:      ghc
Version:         ???
Code Type:       X86-64 (Native)
Parent Process:  bash [97679]
User ID:         501

Date/Time:       2014-07-27 15:30:12.594 -0500
OS Version:      Mac OS X 10.8.4 (12E55)
Report Version:  10

Crashed Thread:  1

Exception Type:  EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000115341000

VM Regions Near 0x115341000:
    MALLOC metadata        000000011532c000-0000000115341000 [   84K] rw-/rwx SM=COW  
--> MALLOC guard page      0000000115341000-0000000115342000 [    4K] ---/rwx SM=NUL  
    Stack                  0000000115342000-0000000115343000 [    4K] ---/rwx SM=NUL  

Thread 0:: Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib        	0x00007fff8d3340fa __psynch_cvwait + 10
1   libsystem_c.dylib             	0x00007fff8d853fe9 _pthread_cond_wait + 869
2   libHSrts_thr-ghc7.8.3.dylib   	0x00000001152bde86 waitCondition + 6
3   libHSrts_thr-ghc7.8.3.dylib   	0x0000000115297752 yieldCapability + 354
4   libHSrts_thr-ghc7.8.3.dylib   	0x00000001152a7f26 schedule + 502
5   libHSrts_thr-ghc7.8.3.dylib   	0x00000001152a7d17 scheduleWaitThread + 167
6   libHSrts_thr-ghc7.8.3.dylib   	0x00000001152a3eea hs_main + 138
7   ghc                           	0x000000010e8c6d73 main + 115
8   ghc                           	0x000000010e7ddc34 start + 52

Thread 1 Crashed:
0   libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib	0x0000000115178811 __gmpn_addlsh2_n + 289
1   libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib	0x00000001151b87aa __gmpn_toom43_mul + 202
2   libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib	0x0000000115196c6b __gmpn_mul + 1835
3   libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib	0x000000011519d795 __gmpn_tdiv_qr + 3221
4   libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib	0x00000001151b4b88 __gmpz_tdiv_qr + 408
5   libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib	0x0000000115175b9f integer_cmm_quotRemIntegerzh + 207
6   libHSbase-4.7.0.1-ghc7.8.3.dylib	0x0000000114af08f0 c6Zm_info + 56

Thread 2:
0   libsystem_kernel.dylib        	0x00007fff8d334f96 poll + 10
1   libHSbase-4.7.0.1-ghc7.8.3.dylib	0x0000000114be1444 cbep_info + 660
2   ???                           	0x0000000115727e83 0 + 4654792323

Thread 3:
0   libsystem_kernel.dylib        	0x00007fff8d334d16 kevent + 10
1   libHSbase-4.7.0.1-ghc7.8.3.dylib	0x0000000114ba3de5 cbpC_info + 173
2   libHSbase-4.7.0.1-ghc7.8.3.dylib	0x0000000114ba4908 cbuZ_info + 56

Thread 4:
0   libsystem_kernel.dylib        	0x00007fff8d3340fa __psynch_cvwait + 10
1   libsystem_c.dylib             	0x00007fff8d853fe9 _pthread_cond_wait + 869
2   libHSrts_thr-ghc7.8.3.dylib   	0x00000001152bde86 waitCondition + 6
3   libHSrts_thr-ghc7.8.3.dylib   	0x0000000115297752 yieldCapability + 354
4   libHSrts_thr-ghc7.8.3.dylib   	0x00000001152a7f26 schedule + 502
5   libHSrts_thr-ghc7.8.3.dylib   	0x00000001152a88bd scheduleWorker + 13
6   libsystem_c.dylib             	0x00007fff8d84f7a2 _pthread_start + 327
7   libsystem_c.dylib             	0x00007fff8d83c1e1 thread_start + 13

Thread 1 crashed with X86 Thread State (64-bit):
  rax: 0x0000000000000000  rbx: 0x000000000000045b  rcx: 0xfffffffffffffe84  rdx: 0x00000001154a0b68
  rdi: 0x0000000115341bd0  rsi: 0x000000011549c5b8  rbp: 0x0000000115338f40  rsp: 0x0000000115338ec8
   r8: 0x0000000000000001   r9: 0x0000000000000003  r10: 0x0000000000000003  r11: 0x0000000000000003
  r12: 0xa37d223548939bc0  r13: 0x45cb5efb1fce45fd  r14: 0x1ad82f94a68b146b  r15: 0xaef755979088a4bb
  rip: 0x0000000115178811  rfl: 0x0000000000010286  cr2: 0x0000000115341000
Logical CPU: 2

Binary Images:
       0x10e7dc000 -        0x10e8cafff +ghc (???) <515FEFFC-8563-3E63-A019-2D36A4E5B376> /usr/local/lib/ghc-7.8.3/bin/ghc
       0x10e98f000 -        0x10ea80ff7 +libHShaskeline-0.7.1.2-ghc7.8.3.dylib (0) <77838A66-EC3D-3443-AA05-484564631E96> /usr/local/lib/ghc-7.8.3/haskeline-0.7.1.2/libHShaskeline-0.7.1.2-ghc7.8.3.dylib
       0x10eb8e000 -        0x10eba8fff +libHSterminfo-0.4.0.0-ghc7.8.3.dylib (0) <F7B1336A-D768-35FB-A956-611BED7E9B16> /usr/local/lib/ghc-7.8.3/terminfo-0.4.0.0/libHSterminfo-0.4.0.0-ghc7.8.3.dylib
       0x10ebd8000 -        0x111533ff7 +libHSghc-7.8.3-ghc7.8.3.dylib (0) <7496A043-6E06-3D38-9E0C-86B2F1443163> /usr/local/lib/ghc-7.8.3/ghc-7.8.3/libHSghc-7.8.3-ghc7.8.3.dylib
       0x112fe9000 -        0x113037ffe +libHStransformers-0.3.0.0-ghc7.8.3.dylib (0) <760D119E-6E9D-3958-8EBD-5FD0AE08F661> /usr/local/lib/ghc-7.8.3/transformers-0.3.0.0/libHStransformers-0.3.0.0-ghc7.8.3.dylib
       0x1130d0000 -        0x113217ffb +libHStemplate-haskell-2.9.0.0-ghc7.8.3.dylib (0) <07A381B5-881A-34E7-A336-ED1E94B69C3D> /usr/local/lib/ghc-7.8.3/template-haskell-2.9.0.0/libHStemplate-haskell-2.9.0.0-ghc7.8.3.dylib
       0x1133a2000 -        0x1133b9ff8 +libHShpc-0.6.0.1-ghc7.8.3.dylib (0) <90B745B0-63A3-3339-8D3C-1D0864FFB3ED> /usr/local/lib/ghc-7.8.3/hpc-0.6.0.1/libHShpc-0.6.0.1-ghc7.8.3.dylib
       0x1133e0000 -        0x113427fff +libHShoopl-3.10.0.1-ghc7.8.3.dylib (0) <40C41B4C-9A7B-3179-876C-648C08E50D0C> /usr/local/lib/ghc-7.8.3/hoopl-3.10.0.1/libHShoopl-3.10.0.1-ghc7.8.3.dylib
       0x11349a000 -        0x1134abffe +libHSbin-package-db-0.0.0.0-ghc7.8.3.dylib (0) <3C63EAE8-C8F7-3E49-845E-51BB912CAD10> /usr/local/lib/ghc-7.8.3/bin-package-db-0.0.0.0/libHSbin-package-db-0.0.0.0-ghc7.8.3.dylib
       0x1134be000 -        0x113510ff9 +libHSbinary-0.7.1.0-ghc7.8.3.dylib (0) <19FB0D1E-CADF-369D-AB5F-EFE63DB78B47> /usr/local/lib/ghc-7.8.3/binary-0.7.1.0/libHSbinary-0.7.1.0-ghc7.8.3.dylib
       0x11355d000 -        0x113b35ffe +libHSCabal-1.18.1.3-ghc7.8.3.dylib (0) <6E368272-1A7F-3C57-AAB0-4EBFC9AB09B2> /usr/local/lib/ghc-7.8.3/Cabal-1.18.1.3/libHSCabal-1.18.1.3-ghc7.8.3.dylib
       0x114104000 -        0x114113fff +libHSprocess-1.2.0.0-ghc7.8.3.dylib (0) <CE1B5F4C-46A2-320B-8CB6-2400EC97070F> /usr/local/lib/ghc-7.8.3/process-1.2.0.0/libHSprocess-1.2.0.0-ghc7.8.3.dylib
       0x11412a000 -        0x11413affe +libHSpretty-1.1.1.1-ghc7.8.3.dylib (0) <2CC28F0F-6F2F-3CEC-8A6F-DB9633147377> /usr/local/lib/ghc-7.8.3/pretty-1.1.1.1/libHSpretty-1.1.1.1-ghc7.8.3.dylib
       0x114151000 -        0x1142bcffe +libHScontainers-0.5.5.1-ghc7.8.3.dylib (0) <511470B1-0294-3F78-8BB7-CDC53E592EE1> /usr/local/lib/ghc-7.8.3/containers-0.5.5.1/libHScontainers-0.5.5.1-ghc7.8.3.dylib
       0x1143b1000 -        0x1143bffff +libHSdirectory-1.2.1.0-ghc7.8.3.dylib (0) <BBFAB672-10AD-326B-9080-09C1B8B04412> /usr/local/lib/ghc-7.8.3/directory-1.2.1.0/libHSdirectory-1.2.1.0-ghc7.8.3.dylib
       0x1143d7000 -        0x114431ff7 +libHSunix-2.7.0.1-ghc7.8.3.dylib (0) <82865E9A-9BBF-32B9-8A8A-31C61A1A87D7> /usr/local/lib/ghc-7.8.3/unix-2.7.0.1/libHSunix-2.7.0.1-ghc7.8.3.dylib
       0x1144c3000 -        0x11454cfff +libHStime-1.4.2-ghc7.8.3.dylib (0) <9F64C699-AEC9-372D-A926-A3D9114E5A40> /usr/local/lib/ghc-7.8.3/time-1.4.2/libHStime-1.4.2-ghc7.8.3.dylib
       0x1145fb000 -        0x114601ffb +libHSold-locale-1.0.0.6-ghc7.8.3.dylib (0) <1D324A30-3A30-3C2B-855B-BBE85CD3E46E> /usr/local/lib/ghc-7.8.3/old-locale-1.0.0.6/libHSold-locale-1.0.0.6-ghc7.8.3.dylib
       0x114611000 -        0x114621ffd +libHSfilepath-1.3.0.2-ghc7.8.3.dylib (0) <6A655401-5A48-3311-9F47-4913B98A1835> /usr/local/lib/ghc-7.8.3/filepath-1.3.0.2/libHSfilepath-1.3.0.2-ghc7.8.3.dylib
       0x11463e000 -        0x1146c9fff +libHSbytestring-0.10.4.0-ghc7.8.3.dylib (0) <37CA9ED5-C80A-3AEB-AE07-563EA9F8E0BC> /usr/local/lib/ghc-7.8.3/bytestring-0.10.4.0/libHSbytestring-0.10.4.0-ghc7.8.3.dylib
       0x11475a000 -        0x11475cff8 +libHSdeepseq-1.3.0.2-ghc7.8.3.dylib (0) <DC275F7A-BBCD-319A-A454-2720B46982FD> /usr/local/lib/ghc-7.8.3/deepseq-1.3.0.2/libHSdeepseq-1.3.0.2-ghc7.8.3.dylib
       0x114769000 -        0x1147d4ff9 +libHSarray-0.5.0.0-ghc7.8.3.dylib (0) <40F4C2AD-861A-3048-AE8D-970E3D6915D3> /usr/local/lib/ghc-7.8.3/array-0.5.0.0/libHSarray-0.5.0.0-ghc7.8.3.dylib
       0x11483f000 -        0x114c17ff7 +libHSbase-4.7.0.1-ghc7.8.3.dylib (0) <363FAE50-2090-3B3F-B9CC-BAF20493C5A9> /usr/local/lib/ghc-7.8.3/base-4.7.0.1/libHSbase-4.7.0.1-ghc7.8.3.dylib
       0x115167000 -        0x1151d8fc7 +libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib (0) <1904D998-1201-3691-BFA6-0B7E8C73D9E2> /usr/local/lib/ghc-7.8.3/integer-gmp-0.5.1.0/libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib
       0x1151f7000 -        0x115240ff7 +libHSghc-prim-0.3.1.0-ghc7.8.3.dylib (0) <7A005B4C-2B84-3FC4-8A8E-F4384C458F17> /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc-prim-0.3.1.0-ghc7.8.3.dylib
       0x115295000 -        0x1152e5fff +libHSrts_thr-ghc7.8.3.dylib (0) <C4F957DB-DCE5-34D4-B4F3-495B54AB59B1> /usr/local/lib/ghc-7.8.3/rts-1.0/libHSrts_thr-ghc7.8.3.dylib
       0x11530d000 -        0x115310fff +libffi.dylib (7) <F1F11422-6371-3183-9256-5B85867D7B05> /usr/local/lib/ghc-7.8.3/rts-1.0/libffi.dylib
    0x7fff6e3dc000 -     0x7fff6e41093f  dyld (210.2.3) <A40597AA-5529-3337-8C09-D8A014EB1578> /usr/lib/dyld
    0x7fff83549000 -     0x7fff8354cff7  libdyld.dylib (210.2.3) <F59367C9-C110-382B-A695-9035A6DD387E> /usr/lib/system/libdyld.dylib
    0x7fff839a7000 -     0x7fff839afff7  libsystem_dnssd.dylib (379.38.1) <BDCB8566-0189-34C0-9634-35ABD3EFE25B> /usr/lib/system/libsystem_dnssd.dylib
    0x7fff83e54000 -     0x7fff83ea0ff7  libauto.dylib (185.4) <AD5A4CE7-CB53-313C-9FAE-673303CC2D35> /usr/lib/libauto.dylib
    0x7fff848cc000 -     0x7fff848d1fff  libcache.dylib (57) <65187C6E-3FBF-3EB8-A1AA-389445E2984D> /usr/lib/system/libcache.dylib
    0x7fff8519c000 -     0x7fff851a7fff  libsystem_notify.dylib (98.5) <C49275CC-835A-3207-AFBA-8C01374927B6> /usr/lib/system/libsystem_notify.dylib
    0x7fff8750c000 -     0x7fff8750dfff  libsystem_blocks.dylib (59) <D92DCBC3-541C-37BD-AADE-ACC75A0C59C8> /usr/lib/system/libsystem_blocks.dylib
    0x7fff8787a000 -     0x7fff87888fff  libcommonCrypto.dylib (60027) <BAAFE0C9-BB86-3CA7-88C0-E3CBA98DA06F> /usr/lib/system/libcommonCrypto.dylib
    0x7fff8793e000 -     0x7fff8793fff7  libremovefile.dylib (23.2) <6763BC8E-18B8-3AD9-8FFA-B43713A7264F> /usr/lib/system/libremovefile.dylib
    0x7fff8798b000 -     0x7fff8798cff7  libSystem.B.dylib (169.3) <365477AB-D641-389D-B8F4-A1FAE9657EEE> /usr/lib/libSystem.B.dylib
    0x7fff87bd0000 -     0x7fff87bd2ff7  libunc.dylib (25) <92805328-CD36-34FF-9436-571AB0485072> /usr/lib/system/libunc.dylib
    0x7fff88180000 -     0x7fff8818eff7  libsystem_network.dylib (77.10) <0D99F24E-56FE-380F-B81B-4A4C630EE587> /usr/lib/system/libsystem_network.dylib
    0x7fff8822b000 -     0x7fff88233fff  liblaunch.dylib (442.26.2) <2F71CAF8-6524-329E-AC56-C506658B4C0C> /usr/lib/system/liblaunch.dylib
    0x7fff88395000 -     0x7fff8848afff  libiconv.2.dylib (34) <FEE8B996-EB44-37FA-B96E-D379664DEFE1> /usr/lib/libiconv.2.dylib
    0x7fff889a9000 -     0x7fff88ac192f  libobjc.A.dylib (532.2) <90D31928-F48D-3E37-874F-220A51FD9E37> /usr/lib/libobjc.A.dylib
    0x7fff89440000 -     0x7fff89442fff  libquarantine.dylib (52.1) <143B726E-DF47-37A8-90AA-F059CFD1A2E4> /usr/lib/system/libquarantine.dylib
    0x7fff89696000 -     0x7fff896c4ff7  libsystem_m.dylib (3022.6) <B434BE5C-25AB-3EBD-BAA7-5304B34E3441> /usr/lib/system/libsystem_m.dylib
    0x7fff896c5000 -     0x7fff896e7ff7  libxpc.dylib (140.43) <70BC645B-6952-3264-930C-C835010CCEF9> /usr/lib/system/libxpc.dylib
    0x7fff8ac55000 -     0x7fff8ac5afff  libcompiler_rt.dylib (30) <08F8731D-5961-39F1-AD00-4590321D24A9> /usr/lib/system/libcompiler_rt.dylib
    0x7fff8bb78000 -     0x7fff8bb8dff7  libdispatch.dylib (228.23) <D26996BF-FC57-39EB-8829-F63585561E09> /usr/lib/system/libdispatch.dylib
    0x7fff8d2d2000 -     0x7fff8d321ff7  libcorecrypto.dylib (106.2) <CE0C29A3-C420-339B-ADAA-52F4683233CC> /usr/lib/system/libcorecrypto.dylib
    0x7fff8d322000 -     0x7fff8d33dff7  libsystem_kernel.dylib (2050.24.15) <A9F97289-7985-31D6-AF89-151830684461> /usr/lib/system/libsystem_kernel.dylib
    0x7fff8d83b000 -     0x7fff8d907ff7  libsystem_c.dylib (825.26) <4C9EB006-FE1F-3F8F-8074-DFD94CF2CE7B> /usr/lib/system/libsystem_c.dylib
    0x7fff8d9d9000 -     0x7fff8d9d9fff  libkeymgr.dylib (25) <CC9E3394-BE16-397F-926B-E579B60EE429> /usr/lib/system/libkeymgr.dylib
    0x7fff8dce2000 -     0x7fff8dce3fff  libDiagnosticMessagesClient.dylib (8) <8548E0DC-0D2F-30B6-B045-FE8A038E76D8> /usr/lib/libDiagnosticMessagesClient.dylib
    0x7fff8dd40000 -     0x7fff8dd41ff7  libsystem_sandbox.dylib (220.3) <B739DA63-B675-387A-AD84-412A651143C0> /usr/lib/system/libsystem_sandbox.dylib
    0x7fff8eb49000 -     0x7fff8eb4aff7  libdnsinfo.dylib (453.19) <14202FFB-C3CA-3FCC-94B0-14611BF8692D> /usr/lib/system/libdnsinfo.dylib
    0x7fff8eb4b000 -     0x7fff8eb70ff7  libc++abi.dylib (26) <D86169F3-9F31-377A-9AF3-DB17142052E4> /usr/lib/libc++abi.dylib
    0x7fff8ebc5000 -     0x7fff8ec2dff7  libc++.1.dylib (65.1) <20E31B90-19B9-3C2A-A9EB-474E08F9FE05> /usr/lib/libc++.1.dylib
    0x7fff8f14c000 -     0x7fff8f152fff  libmacho.dylib (829) <BF332AD9-E89F-387E-92A4-6E1AB74BD4D9> /usr/lib/system/libmacho.dylib
    0x7fff8f26d000 -     0x7fff8f2a5fff  libncurses.5.4.dylib (37.3) <68D5B5F5-8252-3F1E-AFF1-C6AFE145DBC1> /usr/lib/libncurses.5.4.dylib
    0x7fff8f4ef000 -     0x7fff8f4f6fff  libcopyfile.dylib (89) <876573D0-E907-3566-A108-577EAD1B6182> /usr/lib/system/libcopyfile.dylib
    0x7fff8f746000 -     0x7fff8f77cfff  libsystem_info.dylib (406.17) <4FFCA242-7F04-365F-87A6-D4EFB89503C1> /usr/lib/system/libsystem_info.dylib
    0x7fff8f77d000 -     0x7fff8f783ff7  libunwind.dylib (35.1) <21703D36-2DAB-3D8B-8442-EAAB23C060D3> /usr/lib/system/libunwind.dylib

External Modification Summary:
  Calls made by other processes targeting this process:
    task_for_pid: 0
    thread_create: 0
    thread_set_state: 0
  Calls made by this process:
    task_for_pid: 0
    thread_create: 0
    thread_set_state: 0
  Calls made by all processes on this machine:
    task_for_pid: 11291
    thread_create: 1
    thread_set_state: 0

VM Region Summary:
ReadOnly portion of Libraries: Total=159.5M resident=138.3M(87%) swapped_out_or_unallocated=21.2M(13%)
Writable regions: Total=52.5M written=21.6M(41%) resident=23.9M(46%) swapped_out=0K(0%) unallocated=28.6M(54%)
 
REGION TYPE                      VIRTUAL
===========                      =======
MALLOC                             18.2M
MALLOC guard page                    16K
STACK GUARD                        56.0M
Stack                              10.0M
VM_ALLOCATE                        19.0M
__DATA                             5892K
__LINKEDIT                         93.8M
__TEXT                             65.7M
shared memory                        12K
===========                      =======
TOTAL                             268.5M

$ ghc --info

 [("Project name","The Glorious Glasgow Haskell Compilation System")
 ,("GCC extra via C opts"," -fwrapv")
 ,("C compiler command","/usr/local/bin/gcc")
 ,("C compiler flags"," -m64 -fno-stack-protector")
 ,("C compiler link flags"," -m64")
 ,("Haskell CPP command","/usr/local/bin/gcc")
 ,("Haskell CPP flags","-E -undef -traditional ")
 ,("ld command","/usr/bin/ld")
 ,("ld flags"," -arch x86_64")
 ,("ld supports compact unwind","YES")
 ,("ld supports build-id","NO")
 ,("ld supports filelist","YES")
 ,("ld is GNU ld","NO")
 ,("ar command","/usr/bin/ar")
 ,("ar flags","clqs")
 ,("ar supports at file","NO")
 ,("touch command","touch")
 ,("dllwrap command","/bin/false")
 ,("windres command","/bin/false")
 ,("libtool command","libtool")
 ,("perl command","/usr/bin/perl")
 ,("target os","OSDarwin")
 ,("target arch","ArchX86_64")
 ,("target word size","8")
 ,("target has GNU nonexec stack","False")
 ,("target has .ident directive","True")
 ,("target has subsections via symbols","True")
 ,("Unregisterised","NO")
 ,("LLVM llc command","llc")
 ,("LLVM opt command","opt")
 ,("Project version","7.8.3")
 ,("Booter version","7.6.3")
 ,("Stage","2")
 ,("Build platform","x86_64-apple-darwin")
 ,("Host platform","x86_64-apple-darwin")
 ,("Target platform","x86_64-apple-darwin")
 ,("Have interpreter","YES")
 ,("Object splitting supported","NO")
 ,("Have native code generator","YES")
 ,("Support SMP","YES")
 ,("Tables next to code","YES")
 ,("RTS ways","l debug thr thr_debug thr_l thr_p dyn debug_dyn thr_dyn thr_debug_dyn l_dyn thr_l_dyn")
 ,("Support dynamic-too","YES")
 ,("Support parallel --make","YES")
 ,("Dynamic by default","NO")
 ,("GHC Dynamic","YES")
 ,("Leading underscore","YES")
 ,("Debug on","False")
 ,("LibDir","/usr/local/lib/ghc-7.8.3")
 ,("Global Package DB","/usr/local/lib/ghc-7.8.3/package.conf.d")
 ]

$ gcc --version

gcc (GCC) 4.9.0 20140302 (experimental)
Copyright (C) 2014 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.

Please let me know if there's more I can do to help. I'd be willing to try and track down the issue myself, but I'm afraid I know next to nothing about ghc and it would probably take a lot more work helping me than it would to fix the issue otherwise.

Thanks, that was helpful.

GMP does large temporary allocations in, for example, mpn_mul. Somehow, we are configuring GMP to use alloca for temporary allocations. In the most recent report, we happened to alloca past the stack guard page and a malloc guard page, and then we crashed when we wrote into the "allocated" memory that was actually the malloc guard page. (Note that the "Stack" VM region is not actually the stack, it's a stack guard page.) In the original report, it's hard to tell what's going on with no symbols (due to the old ghci linker) but it looks like we may have allocaed directly into the stack guard page.

I imagine that we only saw this in ghci because non-threaded programs have larger stack areas (and maybe no guard pages).

GMP's temporary allocation method is controlled by the CPP symbols WANT_TMP_ALLOCA, WANT_TMP_REENTRANT etc. I don't understand how it is happening that we build with WANT_TMP_ALLOCA when (per configure.in) the default setting for --enable-alloca is reentrant. But I was able to confirm from examining libHSinteger-gmp-0.5.1.0-ghc7.8.3.dylib that it is using alloca, and mzero also provided the config.h file from his build of GHC which includes #define WANT_TMP_ALLOCA 1.

WANT_TMP_REENTRANT is the default, and what Debian's build of libgmp uses, so we should just use that.

Actually a few things were not quite right in that. --enable-alloca=reentrant is not the same as WANT_TMP_REENTRANT! It means "use WANT_TMP_ALLOCA if you have alloca, otherwise use WANT_TMP_REENTRANT". So that explains how WANT_TMP_ALLOCA is getting set.

Also, my examination of the Debian libgmp.so.10 was overly hasty. It is actually built with WANT_TMP_ALLOCA. There are several allocation paths in mpn_mul, and some call malloc when the amount to be allocated exceeds a certain threshold, while others unconditionally allocate on the stack.

Not sure what the best thing to do here is aside from resorting to WANT_TMP_REENTRANT, which I fear may carry a noticeable performance penalty.

So GMP 6 has (as I mentioned above) a macro to allocate small blocks with alloca and large blocks with malloc. The current release does not correctly use this macro in the code in question, but this backported patch fixes this. So if we wait for GMP 6.0.1 and then update the in-tree tarball, this should get fixed automatically.

Replying to [ticket:7655#comment:86422 rwbarton]:

So if we wait for GMP 6.0.1 and then update the in-tree tarball, this should get fixed automatically.

I'd rather get rid of the in-tree GMP tarball altogether than updating it, as it will increase the ghc.git history by a 2MiB blob everyone will have to download each time ghc.git gets cloned. Morever, the work I'm doing in #9281 (closed) is also somewhat motivated by finally getting rid of the in-tree GMP tarball for good.

OK, then I expect this bug will disappear if and only if the user's libgmp is (the as-yet unreleased) 6.0.1 or newer.

changed milestone to %7.10.1

Moving (in bulk) to 7.10.4

removed milestone

Moving to 7.12.1 milestone; if you feel this is an error and should be addressed sooner, please move it back to the 7.10.1 milestone.

I cannot reproduce this in 7.10.rc2 with the original test cases:

12345678901234567890 ^ 12345
2384729837498237 ^ 23455

The Matrix.hs program above also runs without crashing. Can others reproduce any of the above on 7.10.rc2?

hvr: So, what is the status of the in-tree GMP tarball now that 7.10.1 uses integer-gmp 1.*? Specifically where does the GMP library come from on OS X? Do we ship it as part of the binary distribution?

Trac field	Value
Version	7.4.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	GHCi
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

7.6.2 Segmentation Fault/Bus Error in large exponentation

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7.6.2 Segmentation Fault/Bus Error in large exponentation

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