View Source: SIGSEGV - Waikato Linux Users Group

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!!! Signal: Segmentation Violation (SegmentationFault)

This is raised when the program attempts has a bad memory reference such as:

* The pointer is NULL.
* Address not mapped to object (eg, the memory is unallocated, and unmapped by the OS)
* Invalid Permission for mapped object (accessing memory that permissions deny).

This is almost invariably a programming fault.

The default action for this signal is to cause the program to terminate and dump core.

A classic example is to dereference a pointer in [C] that is either uninitialised, or has already been freed. Here is some [C] code:

<verbatim>
#include <stdio.h>
int main(void) {
    int *pointer;

    pointer = 0;

    printf("Value pointed to by pointer is %d\n",
        *pointer /* this will cause SEGV */
    );
}
</verbatim>

See CommonProgrammingBugs for hints on how to track down memory related bugs in the SourceCode.

10 pages link to SIGSEGV:

Last edited on Saturday, December 4, 2004 3:56:03 am by AristotlePagaltzis

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