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getaddressconf(2)
Contents
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getaddressconf - Get information about the system address
space configuration
#include <sys/types.h> #include <sys/addrconf.h>
int getaddressconf(
struct addressconf *buffer,
size_t length );
Points to an array of addressconf structures. Specifies
the size in bytes of the array pointed to by the buffer
parameter.
The getaddressconf() function fills in the array of structures
pointed to by the buffer parameter with information
describing the configuration of process address space on
the system. This information is intended to be used by
programs such as the program loader, which need to manage
the contents of a process' address space by using memory
management primitives such as the mmap() function.
The buffer parameter points to an array of addressconf
structures, occupying a total of length bytes. Each element
of the array describes a single area of the process
address space. The addressconf structure is defined in the
<sys/addrconf.h> header file, and it contains the following
member definitions: The base virtual address of the
area. For an upward-growing area, this is the lowest virtual
address in the area. For a downward-growing area,
this is the lowest virtual address above the area. Flags
that describe the area. Following are descriptions of
these flags, which are defined in the sys/addrconf.h
header file: The area grows towards higher addresses. The
base address specified is the lowest address in the area.
The area grows towards lower addresses. The base address
specified is the lowest address above the area. The area
always starts at the specified base address. For example,
on many machines the text area is a fixed area. The area
floats to the first available virtual address above the
specified base address. For example, on many machines, the
data area floats above the text area.
Each element in the array of addressconf structures
describes a separate area of the process' address space.
These areas have been defined in the <sys/addrconf.h>
header file; other areas may be defined in the future or
on other machine types. The array elements are indexed
with the following constants: The area that normally contains
the text region of an absolute executable program.
The area that normally contains the data region of an
absolute executable program. The area that normally contains
the bss region of an absolute executable program.
The area that normally contains the process' user-mode
stack. The area reserved for the text region of the
default program loader see the exec_with_loader() function.
The area reserved for the data region of the
default program loader. The area reserved for the bss
region of the default program loader. The area that
normally contains text regions of relocatable files loaded
by the program loader, or otherwise mapped using the
mmap() function. The area that normally contains data
regions of relocatable files loaded by the program loader,
or otherwise mapped using the mmap() function. The area
that normally contains the bss regions of relocatable
files loaded by the program loader, or anonymous regions
mapped using the mmap() function.
The <sys/addrconf.h> header file also defines the
AC_N_AREAS symbol to be the number of distinct areas that
are currently defined for this system. Normally, the
buffer parameter supplied to the getaddressconf() function
should be large enough to hold information for AC_N_AREAS
regions. If buffer is not large enough, the remaining
information is truncated. The getaddressconf() call fills
in the first AC_N_AREAS records in the user-supplied
buffer with the address configuration information for this
system, as described above.
Upon successful completion, the number of bytes actually
written to the user's buffer is returned. If an error
occurs, -1 is returned, and errno is set to indicate the
error.
If the getaddressconf() function fails, errno may be set
to the following value: The address specified for buffer
is not valid.
Functions: brk(2), exec(2), exec_with_loader(2), mmap(2)
getaddressconf(2)
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