Loading multiple shared libraries with different versions

Question

I have an executable on Linux that loads libfoo.so.1 (that\'s a SONAME) as one of its dependencies (via another shared library). It also links to a

Answer 1

I can only come up with a work-around. Which would be to statically link a version of the "system library" that you are using. For your static build, you could make it link against the same old version as the third-party library. Given that it does not rely on the newer version...

Perhaps it is also possible to avoid these problems with not linking to the third-party library the ordinary way. Instead, your program could load it at execution time. Perhaps then it could be shadowed against the rest. But I don't know much about that.

Answer 2

You may be able to do some version script tricks:

http://sunsite.ualberta.ca/Documentation/Gnu/binutils-2.9.1/html_node/ld_26.html

This may require that you write a wrapper around your lib that pulls in libfoo.so.1 that exports some symbols explicitly and masks all others as local. For example:

MYSYMS { global: foo1; foo2; local: *; };

and use this when you link that wrapper like:

gcc -shared -Wl,--version-script,mysyms.map -o mylib wrapper.o -lfoo -L/path/to/foo.so.1

This should make libfoo.so.1's symbols local to the wrapper and not available to the main exe.