GDB 6.0 and FreeBSD threads

Daniel Eischen eischen at
Sun Mar 28 06:47:37 PST 2004

On Sat, 27 Mar 2004, Niall Douglas wrote:

> Hash: SHA1
> Hi,
> I'm nearly finished porting my project to FreeBSD from Linux but I'm 
> getting a SIGSEGV at odd places in the code. Unfortunately my project 
> absolutely requires G++ v3.4 as the template support in v3.3 is not 
> up to par. Hence one has a problem debugging the executable with gdb 
> <6.0 (it works, but it's flaky).
> I tried compiling gdb 6.0 on FreeBSD and it compiles fine. 
> Unfortunately it appears to be missing thread support which is most 
> annoying. After searching around, I've discovered you guys patched 
> gdb 5.x with uthread.c.
> Here's my question - how much work would be required to getting the 
> 5.x uthread.c to work with gdb 6.0? Has somebody already done most of 
> the work (if so, can you supply me with a diff)? I don't need 
> fantastic support, just enough to help me find this bug (it's weird - 
> it's almost as though g++ is writing off the end of the stack ie; bad 
> code generation. Yet surely if that were the case, we'd have the same 
> SIGSEGV on Linux :( ).

Could be the threads have different stack sizes under FreeBSD.
Try using a larger stack.

No-one has touched uthread support for other GDB's as
far as I know.  Most work is going in to our other thread
libraries.  There is work trying to get GDB thread support
for libpthread, and that should be here by 5.3-release.

Dan Eischen

More information about the freebsd-threads mailing list