NAME
core — format of core image file
DESCRIPTION
The HP-UX
system writes out a file containing a core image
of a terminated process when certain signals are received
(see
signal(5)
for the list of reasons).
The most common causes are memory violations,
illegal instructions, floating point exceptions, bus errors,
and user-generated quit signals.
The core image file is called
core
and is written in the process's working directory
(provided it is allowed by normal access controls).
A process with an effective user ID
different from its real user ID
does not produce a core image.
The file contains sufficient information to determine
what the process was doing at the time of its termination.
Core file contents consist of objects that represent
different segments of a process.
Each object is preceded by a
corehead
data structure, and each
corehead
data structure describes the corresponding object following it.
The structure is defined in
<sys/core.h>,
and includes the following members:
int type;
space_t space;
caddr_t addr;
size_t len;
The
space
and
addr
members specify the virtual memory address
in the process where the described object began.
The
len
member is the length of the object in bytes.
The following possible values for
type
are defined in
<sys/core.h>:
- CORE_DATA
Process data as it existed at the time the core image was created.
This includes initialized data, uninitialized data,
and the heap at the time the core image is generated.
- CORE_EXEC
A compiler-dependent data structure containing the exec data structure,
the magic number of the executable file, and the command
(see the declaration of the
proc_exec
structure in
<sys/core.h>).
- CORE_FORMAT
The version number of the core format produced.
This number changes with each HP-UX
release where the core format itself has changed.
However, it does not necessarily change with every HP-UX release.
CORE_FORMAT
can thus be easily used by core-reading tools
to determine whether they are compatible with a given core image.
This type is expressed by a four-byte binary integer.
- CORE_KERNEL
The null-terminated version string associated with the kernel
at the time the core image was generated.
- CORE_PROC
An architecture-dependent data structure
containing per-process information
such as hardware register contents.
See the declaration of the
proc_info
structure in
<sys/core.h>.
- CORE_STACK
Process stack contents at the time the core image was created.
Objects dumped in a
core
image file are not arranged in any particular order.
Use
corehead
information to determine the type
of the object that immediately follows it.
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