Re: [GHC] #10402: powerpc: unhandled ELF relocation(RelA) type 252

16 Jun 2015

      #10402: powerpc: unhandled ELF relocation(RelA) type 252
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        Reporter:  cjwatson        |                   Owner:  simonmar
            Type:  bug             |                  Status:  patch
        Priority:  normal          |               Milestone:  7.10.2
       Component:  Runtime System  |                 Version:  7.8.4
      Resolution:                  |                Keywords:
Operating System:  Linux           |            Architecture:  powerpc
 Type of failure:  Runtime crash   |               Test Case:
      Blocked By:                  |                Blocking:
 Related Tickets:                  |  Differential Revisions:
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Comment (by slyfox):

 Replying to [comment:8 nomeata]:
...
...
Does debian disable dynamic GHC by default as `DYNAMIC_GHC_PROGRAMS =
 NO`?
No (`ldd /usr/lib/ghc/bin/ghc` lists various `libHS...` libraries).
Do I do something incorrectly? (or the test was on non-powerpc?)
 {{{
 # debootstrap --arch=powerpc --include=ghc unstable .
 # chroot .
 # ghc --version
 The Glorious Glasgow Haskell Compilation System, version 7.8.4
 # ldd /usr/lib/ghc/bin/ghc
         linux-vdso32.so.1 (0x00100000)
         libtinfo.so.5 => /lib/powerpc-linux-gnu/libtinfo.so.5 (0x0ffaf000)
         librt.so.1 => /lib/powerpc-linux-gnu/librt.so.1 (0x0ff86000)
         libutil.so.1 => /lib/powerpc-linux-gnu/libutil.so.1 (0x0ff63000)
         libdl.so.2 => /lib/powerpc-linux-gnu/libdl.so.2 (0x0ff3f000)
         libpthread.so.0 => /lib/powerpc-linux-gnu/libpthread.so.0
 (0x0ff04000)
         libgmp.so.10 => /usr/lib/powerpc-linux-gnu/libgmp.so.10
 (0x0fe69000)
         libm.so.6 => /lib/powerpc-linux-gnu/libm.so.6 (0x0fd93000)
         libffi.so.6 => /usr/lib/powerpc-linux-gnu/libffi.so.6 (0x0fd6a000)
         libc.so.6 => /lib/powerpc-linux-gnu/libc.so.6 (0x0fbcb000)
         /lib/ld.so.1 (0x2052a000)
 # ghc --info | grep -i dyn
  ,("Support dynamic-too","YES")
  ,("Dynamic by default","NO")
  ,("GHC Dynamic","NO")
 }}}

 It's not able to handle PIC:
 {{{
 // cat a.c
 #include 

 void ffi_a_hello (int i) {
     fprintf (stderr, "WEEEEEEEE: i=%d\n", i);
 }

 -- cat A.hs
 {-# LANGUAGE ForeignFunctionInterface #-}
 module A where

 import Foreign.C

 foreign import ccall "ffi_a_hello" a :: CInt -> IO ()

 # ghc -fPIC -c a.c -fforce-recomp
 # ghc -fPIC -c A.hs -fforce-recomp
 # ghci --interactive ./a.o A
 GHCi, version 7.8.4: http://www.haskell.org/ghc/  :? for help
 Loading package ghc-prim ... linking ... done.
 Loading package integer-gmp ... linking ... done.
 Loading package base ... linking ... done.
 Loading object (static) a.o ... done
 final link ... done
 [1 of 1] Compiling A                ( A.hs, interpreted ) [flags changed]
 Ok, modules loaded: A.
 *A> a 42
 Segmentation fault
 }}}

 Non-PIC is fine, but it does not contain PLT-style relocations:
 {{{
 # ghc -c a.c -fforce-recomp
 # ghc -c A.hs -fforce-recomp
 # ghci --interactive ./a.o A
 GHCi, version 7.8.4: http://www.haskell.org/ghc/  :? for help
 Loading package ghc-prim ... linking ... done.
 Loading package integer-gmp ... linking ... done.
 Loading package base ... linking ... done.
 Loading object (static) a.o ... done
 final link ... done
 [1 of 1] Compiling A                ( A.hs, interpreted ) [flags changed]
 Ok, modules loaded: A.
 *A> a 42
 WEEEEEEEE: i=42
 *A>
 Leaving GHCi.

 # objdump -d -r a.o | grep PLT
 # objdump -d -r A.o | grep PLT
 }}}

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10402#comment:12
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