Stack Overflow error in HPUX11iv2

[sujeet joshi]

Hi All,

Getting following error in Application while doing the EOD Operation.
failure in writing the signal contec-possible stack overflow.
sendsig: useracc failed.

Can anybody help me in this issue? and how to increase the stack?

Thanks & regards,
Sujeet Joshi

[Taifur]

Hi Jishi,

you either have a main stack or a thread stack overflow.
You need to get a stack trace (use gdb) to determine which.

On the WDB page you can find this document:
Debugging core files using HP WDB
http://www.hp.com/go/wdb

Basically on the same system that caused the core dump:
$ file core
(Gives you the signal and up to 14 bytes of the basename of the executable.

$ gdb path-to/executable core
(gdb) bt
(gdb) q

If it is a main thread, you should see main at the bottom. If it is a thread, you should see some pthread on the bottom.

By taking the difference in the $sp register from the top and bottom frames, you can compute your current stack size.

There are two possibilities:
1) The user's shell (or a parent of that shell) has lowered the hard limit
using ulimit -h - at which point you have to find this and modify it.
Note, this is very rare -- you are much more likely to have to:

2) The system-wide hard limit is determined by the kernel tunable "maxssiz" and/or "maxssiz_64bit". maxssiz is the limit for 32-bit processes, maxssiz_64bit for 64-bit.
Note that maxssiz_64bit trumps maxssiz_32bit (i.e. a lower 64-bit limit will be used instead of the 32-bit limit.. this is a consequence of the parent bitness as the system comes up), so you'll want to consider both.

On 11.23, maxssiz / maxssiz_64bit are dynamic - changes to them take effect immediately for any new processes. So "kctune -u -s maxssiz=" and that should do it.

As a side note - if the user believes they need a very large stack, make sure that they understand why. Fortran and Java are both legitimate use cases -- for normal C programming, large stacks are usually a sign of poor recursion. Not saying there's a problem, but just worth a mention.


Cheers,
taifur

[Dennis Handly]

>Taifur: you either have a main stack or a thread stack overflow. You need to get a stack trace (use gdb) to determine which.

Exactly.

>So "kctune -u -s maxssiz=

-u and -s are obsolete kmtune(1m) options. You should leave both off.