Interesting Segfault... Or not?

Matthew Turk m-turk at nwu.edu
Wed Aug 22 21:03:38 CEST 2001


Hi everybody.  Yeah, it's me posting again.

Anyway - I followed the instructions for debugging, which didn't work
precisely, but I ended up debugging on Linux anyway, since my boss
changed his mind about the backend.

Now, the point of all this is, I'm still getting segfaults, and I
wonder if there's another method I couldn't figure out to implement.

Here's a stack trace:

gdb python
import test

*Output*
Ctrl-d

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1024 (LWP 3226)]
__strtol_internal (nptr=0x80b6420 "", endptr=0x4018df00, base=0,
group=134723870) at eval.c:36
36	eval.c: No such file or directory.
	in eval.c
(gdb) bt
#0  __strtol_internal (nptr=0x80b6420 "", endptr=0x4018df00, base=0,
group=134723870) at eval.c:36
#1  0x08075725 in PyFunction_SetDefaults () at eval.c:41
#2  0x0807b977 in PyDict_Next () at eval.c:41
#3  0x0806dc22 in PyClass_New () at eval.c:41
#4  0x080806bd in PyTuple_SetItem () at eval.c:41
#5  0x0806dc09 in PyClass_New () at eval.c:41
#6  0x080806bd in PyTuple_SetItem () at eval.c:41
#7  0x0806dc09 in PyClass_New () at eval.c:41
#8  0x080806bd in PyTuple_SetItem () at eval.c:41
#9  0x0806dc09 in PyClass_New () at eval.c:41
#10 0x080844db in PyTuple_Fini () at eval.c:41
#11 0x08064469 in Py_Finalize () at eval.c:41
#12 0x0805033d in Py_Main () at eval.c:41
#13 0x0804fc73 in main () at eval.c:41
#14 0x40081177 in __libc_start_main (main=0x804fc54 <main>, argc=1,
ubp_av=0xbffffaac, init=0x804f1ec <_init>, fini=0x8096a1c <_fini>, 
    rtld_fini=0x4000e184 <_dl_fini>, stack_end=0xbffffa9c) at
../sysdeps/generic/libc-start.c:129

David Beazley's WAD corrected the problem - it didn't segfault after I
exited python once I had imported libwadpy.  I don't know what that
means.

Does this mean I'm not decrementing a reference I ought to?  Or am I
not increasing it appropriately?  What could this be the result of - I
assume it comes from garbage collection, but that could be *totally*
off.

Thanks - if anybody has any ideas, that is!




mjt
--------------------------------------------------
Matthew J. Turk <m-turk at nwu.edu>      ICQ: 3856787
"Music is the Best." - FZ       www.dailyvault.com



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