[OpenAFS-devel] segfault in process.c:savecontext() during lwp init -- how to debug?

[Marc Dionne]

On 06/29/2009 04:33 PM, Adam Megacz wrote:
> Can anybody advise me on how to proceed with debugging here?
>
> I'm getting a segfault in lwp/process.c's savecontext(), which appears
> to do some really scary stuff with the stack and setjmp()/longjmp().
> This happens during the lwp init.  Has anybody seen this before?
>
>    (gdb) bt
>    #0  0xb7df69eb in savecontext () from /lib/libnss_afs.so.2
>    #1  0xb7df6687 in LWP_CreateProcess () from /lib/libnss_afs.so.2

What architecture is this on, and which glibc?

In the past this has generally been a symptom of not dealing properly 
with setjmp/longjmp pointer mangling in glibc.  The solution has been to 
move to the ucontext interface (defining USE_UCONTEXT), or to implement 
a pointer demangling function (ptr_mangle()).

Marc