Segmentation fault & Core-dump

[KapilRaj]

Guys,

Can anybody give me an explanation to segmentation fault and core dump ?. I hope this is an APPS issue. Still to convince the APPS guys !! ??

I think (though not sure) this is a program written in C.

Regds,

Kaps

[Mark Grant · Accepted solution]

This is probably an apps issue. If an application writes data across memory boundaries that it's not allowed to you will get a segmentation violation.

Usually this is the result of pointers waving in the breeze or writing 10k of data to a buffer that has only "malloc'ed" 1k.

[KapilRaj]

Thank you ..

These terms .... Malloc pointers ... ohmm .. can u explain little more in detail if u have time please...

Regds,

Kapil

[Nicolas Dumeige]

If there's a core dump, it can be analyzed with a debugger.
If the apps. is not home made, maybe you can contact the support team.

[Nicolas Dumeige]

A pointer is a reference to the begining of a memory area.
malloc() is the C standard fonction for memory allocation, the opposit function is free().
There is abondant littelrature on this subject on the web.

Good luck

[Mark Grant]

These are "C" type thingies.

A pointer is a variable that doesn't contain any data itself except the address of something else. For example I might have a chunk of memory, say 1k's worth that I have reserved for my application using the "malloc()" call. malloc() returns a "pointer" to that memory region. I can access this region by reference to this pointer. If I wrote 10k of data, using this pointer, I'd probably get a segmentation violation.

More fun is when you create a pointer to another variable, destroy the variable and then attempt to use the pointer again. This means you are using a pointer that points at nothing. It's rather hard to debug this because your code looks fine.

The fun of "C" eh :)

[KapilRaj]

Support admit to be stupids !. Is there any forum / help I can get to analise the coredumps ?

Regds,

Kaps

[Naveej.K.A]

hi kapil,

There is a command called adb(absolute debugger) in hpux which is used to analyse core dumps....Dont know how much it is usefull for analysing them.

Hi experts!!! Am i correct.

The man pages says:

The adb command executes a general-purpose debugging program that is sensitive to the underlying architecture of the processor and
operating system on which it runs. It can be used to examine files and provide a controlled environment for executing HP-UX programs.

With best wishes
Naveej

[Nicolas Dumeige]

For wich dumb firm does the dumb support works for ?

It would help to know what to look for.

For a segmentation violation, I guess the stack would be of interest since it contain run-time function ans procedure activation records.

Are you able to reproduce the error at will ?
That also the kind of information a support normaly ask for.