2.11BSD#431 - /usr/man/cat2/fetchi.0

FETCHI(2)	    UNIX Programmer's Manual		FETCHI(2)


NAME
     fetchi - fetch from user instruction space (2BSD)

SYNOPSIS
     fetchi(addr)
     int *addr;

DESCRIPTION
     Fetchi fetches the word at addr from the caller's instruc-
     tion space.  This system call is required on PDP-11's with
     separate instruction and data spaces because the mfpi
     instruction reads from D-space if the current and previous
     modes in the program status word are both user.

RETURN VALUE
     Upon successful completion the contents of the caller's
     instruction space at addr are returned.  Otherwise, a value
     of -1 is returned.

ERRORS
     [EINVAL]	    The kernel has not been compiled for a pro-
		    cessor with separate I/D.

     [EFAULT]	    Addr points to an address not in the
		    process's allocated instruction space.

BUGS
     The error indication, -1, is a legitimate function value;
     errno, (see intro(2)), can be used to disambiguate.

     Fetchi is a kludge and exists only to circumvent an alleged
     security feature on some DEC PDP-11 processors.

     Fetchi is unique to the PDP-11 and 2BSD; its use is
     discouraged.


Printed 11/26/99	January 22, 1987			1