[CentOS] Static Linking, C++ Exceptions

Darrin Thompson darrinth at gmail.com
Thu Jul 31 13:59:25 UTC 2008


I'm having a problem statically linking a big c++ application on
Centos4. I can make it work on Centos5 and that's great. I just need
to figure out a way to reproduce the problem on a small test case.

The specific problem is that when I throw an exception, I get a
segfault. It only happens on Centos4, and only on ia-32 machines. In
an act of desparation I disassembled the bit of code that's
segfaulting and got this:

(gdb) disass
Dump of assembler code for function _ZN14__gnu_internal10get_globalEv:
0x08579614 <...get_globalEv+0>:	call   0x8577c3e <__i686.get_pc_thunk.cx>
0x08579619 <...get_globalEv+5>:	add    $0x3b31c7,%ecx
0x0857961f <...get_globalEv+11>:	push   %ebp
0x08579620 <...get_globalEv+12>:	mov    $0xfffffff8,%eax
0x08579626 <...get_globalEv+18>:	mov    %esp,%ebp
0x08579628 <...get_globalEv+20>:	pop    %ebp

0x08579629 <...get_globalEv+21>:	add    %gs:0x0,%eax <<<--- dies here! <<<

0x08579630 <...get_globalEv+28>:	ret
0x08579631 <...get_globalEv+29>:	nop
End of assembler dump.

When it dies, %gs is 0 which looks tls related.

Only problem is that when I write tiny test programs to reproduce
this, they work fine. %gs is nonzero and everybody is happy. But on my
big hulking app, I can throw and catch an exception immediately on
entry to main and it segfaults faithfully.

Relevant compiler flags are these:

g++ -c  -o whatever.o -O0 -ggdb -Wno-deprecated -Werror -fPIC
-Dmanything -Imanydirs whatever.cpp
g++ -o whatever -static -static-libgcc many.o -Lmanydirs -lpthread
-lanotherlib -lzlib -lesmtp -lnsl -lrpcsvc -lcrypt -lacl -ldl -lrt
-landmanymore

So I'm looking for some guidance on what things I could try to isolate
this in a smaller app.

--
Darrin



More information about the CentOS mailing list