Re: Floating point exception dynamically loading a library

[Mark Davies <mark%mcs.vuw.ac.nz@localhost>]

On Tue, 27 May 2008, Andrew Doran wrote:
> Assuming that the backtrace is correct, then obj->nbuckets is
> probably zero on this line:
>
>       symnum = obj->buckets[hash % obj->nbuckets];

So what could cause this to happen when run on a xen domu system but 
not otherwise?

To get a bit more info I enabled debugging in ld.elf_so and this is 
what happened on the domu system

        [...]
 added path "/usr/pkg/lib"
  0xbb046000 .. 0xbb04afff: /usr/pkg/lib/libXdmcp.so.6
load by name libc.so.12 0xbbbea000
 Searching for "libc.so.12" (0xbbaca600)
  Trying "/usr/lib/libc.so.12"
load by name libz.so.1 0xbbbea000
 Searching for "libz.so.1" (0xbbaca800)
  Trying "/usr/lib/libz.so.1"
load by name libm.so.0 0xbbbea000
sysctl returns 1
entry 0
 Searching for "libm387.so.0" (0xbbaca800)
  Trying "/usr/lib/libm387.so.0"
 Searching for "libm.so.0" (0xbbaca800)
  Trying "/usr/lib/libm.so.0"
doing non-PLT relocations
Floating exception

vs a good system:

        [...]
 added path "/usr/pkg/lib"
  0xbb047000 .. 0xbb04bfff: /usr/pkg/lib/libXdmcp.so.6
load by name libz.so.1 0xbbbea000
 Searching for "libz.so.1" (0xbbaca800)
  Trying "/usr/lib/libz.so.1"
load by name libm.so.0 0xbbbea000
sysctl returns 1
entry 0
 Searching for "libm387.so.0" (0xbbaca800)
  Trying "/usr/lib/libm387.so.0"
 Searching for "libm.so.0" (0xbbaca800)
  Trying "/usr/lib/libm.so.0"
doing non-PLT relocations
doing lazy PLT binding
fixing up PLTGOT
doing non-PLT relocations
doing lazy PLT binding
fixing up PLTGOT
doing non-PLT relocations
doing lazy PLT binding
        [...]

Full debug traces available if useful.

cheers
mark