Trying to locate function using dlfunc with RLTD_NEXT from JNI

[Matthieu Volat]

Hi, a (maybe not) tricky question for people who know well the internals of the jdk on freebsd...

Trying to port a linux project that does quite a bit of introspection, begining by using malloc & co wrapper, with java binding, I found that strangely, you can use dlfunc(RTLD_NEXT, "malloc") in a non-java environment... But as soon as this code is loaded in the context of the jvm, the symbol won't be resolved.

This is maybe a bit suprising as this technique worked on Linux and I did not expect much difference here...

Small demonstration code:

  % git clone https://gist.github.com/f6993d7a48ecbab6c0c979b9a7a40912.git jni_dlfunc
  % cd jni_dlfunc
  % make
  [...]
  % ./testfoo 
  malloc function located at 0x800ade210
  % java -Djava.library.path=. testfoo
  could not locate function malloc: Undefined symbol "malloc"

Would anybody have an idea of why the jvm would cause the C symbols not to be found via RTLD_NEXT and if there would be a way to workaround it (that is not to load explicitely "/lib/libc.so.7")?

Thanks in advance

-- 
Matthieu Volat <mazhe at alkumuna.eu>

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 195 bytes
Desc: OpenPGP digital signature
URL: <http://lists.freebsd.org/pipermail/freebsd-java/attachments/20161130/0058fcef/attachment.sig>