[GHC] #11340: linker_unload test fails on ARM

[GHC]

#11340: linker_unload test fails on ARM
-------------------------------------+------------------------------
        Reporter:  bgamari           |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:  arm
 Type of failure:  Runtime crash     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+------------------------------

Comment (by bgamari):

 The crash is quite reproducible. It generally looks like this,
 {{{
 $ gdb --args linker_unload /mnt/ext/exp/ghc/inplace/lib +RTS
 GNU gdb (Debian 7.7.1+dfsg-5) 7.7.1
 ...
 Reading symbols from linker_unload...done.
 (gdb) run /mnt/ext/exp/ghc/inplace/lib +RTS -Dl 2> h
 Starting program: /mnt/ext/exp/ghc/testsuite/tests/rts/linker_unload
 /mnt/ext/exp/ghc/inplace/lib +RTS -Dl 2> h
 [Thread debugging using libthread_db enabled]
 Using host libthread_db library "/lib/arm-linux-
 gnueabihf/libthread_db.so.1".
 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52
 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77
 78 79 80 81 82 83 84 85
 Program received signal SIGSEGV, Segmentation fault.
 0xb8f6cf70 in ?? ()
 (gdb) info reg
 r0             0xb6ff7278       3070194296
 r1             0x4507d40        72383808
 r2             0xbefff578       3204445560
 r3             0xb6ff7214       3070194196
 r4             0xbefff3c0       3204445120
 r5             0xbefff3c4       3204445124
 r6             0xd8     216
 r7             0x0      0
 r8             0x0      0
 r9             0x0      0
 r10            0xb6fff000       3070226432
 r11            0xbefff31c       3204444956
 r12            0x45003f4        72352756
 sp             0xbefff318       0xbefff318
 lr             0xb6ff7228       -1224773080
 pc             0xb8f6cf70       0xb8f6cf70
 cpsr           0x800f0010       -2146500592
 (gdb) bt
 #0  0xb8f6cf70 in ?? ()
 #1  0xb6ff7228 in ?? ()
 Backtrace stopped: previous frame identical to this frame (corrupt stack?)
 (gdb) x/i $lr
    0xb6ff7228:  pop     {r11, pc}
 (gdb) x/32i $lr-64
    0xb6ff71e8:  ldr     r3, [r11, #-24]
    0xb6ff71ec:  mov     r0, r3
    0xb6ff71f0:  bl      0xb8f6cf50
    0xb6ff71f4:  str     r0, [r11, #-16]
    0xb6ff71f8:  ldr     r3, [r11, #-20]
    0xb6ff71fc:  mov     r0, r3
    0xb6ff7200:  bl      0xb8f6cf60
    0xb6ff7204:  ldr     r3, [r11, #-16]
    0xb6ff7208:  mov     r0, r3
    0xb6ff720c:  sub     sp, r11, #12
    0xb6ff7210:  pop     {r4, r5, r11, pc}
    0xb6ff7214:  push    {r11, lr}
    0xb6ff7218:  add     r11, sp, #4
    0xb6ff721c:  movw    r0, #29304      ; 0x7278
    0xb6ff7220:  movt    r0, #46847      ; 0xb6ff
    0xb6ff7224:  bl      0xb8f6cf70
    0xb6ff7228:  pop     {r11, pc}
    0xb6ff722c:  andeq   r0, r0, r0
    0xb6ff7230:                  ; <UNDEFINED> instruction: 0xb6fee838
 ...
 }}}
 Looks like reasonable code to me. Unfortunately it appears that the code
 at `*$pc` is total garbage. Moreover, looking at the linker output it
 seems that no code was ever mapped at this address.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11340#comment:1>
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