dlopen question

[yuval at aduva dot com]

Hello,

I wrote a small shared library that has a global instance, named 'error', of a
certain dummy class.
When I try to dlopen this library, it works fine only on glibc 2.2, while on
glibc 2.3, it crashes when trying to construct the object.

What I managed to find out is that there's a symbol called 'error' in the 2
given libc's.  In glibc 2.2, ld binds the 'error' symbol to my shared object,
while the ld from glibc 2.3 binds that symbol to libc (and then my app segfaults).

I know that changing the name of my object solves the problem, but I'd like to
know what causes this behaviour ?

Here's the output from LD_DEBUG

glibc 2.2 (ld binds the 'error' symbol as expected to my shared object)
27472:  symbol=error;  lookup in file=./tt
27472:  symbol=error;  lookup in file=/lib/libdl.so.2
27472:  symbol=error;  lookup in file=/usr/lib/libstdc++-libc6.2-2.so.3
27472:  symbol=error;  lookup in file=/lib/i686/libm.so.6
27472:  symbol=error;  lookup in file=/lib/i686/libc.so.6
27472:  symbol=error;  lookup in file=/lib/ld-linux.so.2
27472:  symbol=error;  lookup in file=./t.so
27472:  binding file ./t.so to ./t.so: normal symbol `error'

glibc 2.3 (ld binds the 'error' symbol to the 'error' in libc)
10334: symbol=error;  lookup in file=./tt
10334: symbol=error;  lookup in file=/lib/tls/libdl.so.2
10334: symbol=error;  lookup in file=/usr/lib/libstdc++-libc6.2-2.so.3
10334: symbol=error;  lookup in file=/lib/tls/libm.so.6
10334: symbol=error;  lookup in file=/lib/tls/libc.so.6
10334: binding file ./t.so to /lib/tls/libc.so.6: normal symbol `error'

Same behaviour occurs when using the non-tls version of libc (2.3)
Any ideas ?

Thanks.

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