core

Purpose

     Contains an image of memory at the time of an error.

Synopsis

     #include <core.h>
     #include <sys/param.h>
     #include <sys/reg.h>
     #include <sys/user.h>

Description

     The system writes a memory  image of a terminated process
     when various errors  occur in a core file  in the current
     directory.  See  the signal system  call for the  list of
     errors.  The  most common are memory  address violations,
     illegal instructions, bus errors, and user-generated quit
     signals.  The  memory image,  called core, is  written in
     the process working directory.   A process with an effec-
     tive user ID that is different from the real user ID does
     not produce a memory image.

     The first  section of the memory  image is a copy  of the
     system data  per user process, including  the contents of
     the registers  as they  exist at the  time of  the fault.
     The size of  this section depends on  the usize parameter
     defined in  /usr/include/sys/param.h.  The  first section
     contains two parts.  The first part is the user structure
     defined in  /usr/include/sys/user.h.  The second  part is
     the process  kernel stack.   Note that  RT PC  stores the
     user  process  registers at  the  beginning  of the  user
     stack, instead  of the  end of  the process  kernel stack
     where  they are  normally stored  on machines  with stack
     push  and pop  instructions.  The  /usr/include/sys/reg.h
     structure outlines the long word offsets of the registers
     from  the beginning  of the  user structure.   The second
     section represents  the actual contents of  the user area
     when the image was written.  If the text segment is sepa-
     rated from data space, it is not dumped.

File

     core

Related Information

     In this book:  "setuid, setgid" and "signal."

     The crash and  sdb commands in AIX  Operating System Com-
     mands Reference.