1: /* Copy memory to memory until the specified number of bytes
    2:    has been copied, return pointer to following byte, with error checking.
    3:    Overlap is NOT handled correctly.
    4:    Copyright (C) 1991, 1997, 1998, 2002, 2004 Free Software Foundation, Inc.
    5:    This file is part of the GNU C Library.
    6:    Contributed by Torbjorn Granlund (tege@sics.se).
    7: 
    8:    The GNU C Library is free software; you can redistribute it and/or
    9:    modify it under the terms of the GNU Lesser General Public
   10:    License as published by the Free Software Foundation; either
   11:    version 2.1 of the License, or (at your option) any later version.
   12: 
   13:    The GNU C Library is distributed in the hope that it will be useful,
   14:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   15:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   16:    Lesser General Public License for more details.
   17: 
   18:    You should have received a copy of the GNU Lesser General Public
   19:    License along with the GNU C Library; if not, write to the Free
   20:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   21:    02111-1307 USA.  */
   22: 
   23: #include <string.h>
   24: #include <memcopy.h>
   25: #include <pagecopy.h>
   26: 
   27: void *
   28: __mempcpy_chk (dstpp, srcpp, len, dstlen)
   29:      void *dstpp;
   30:      const void *srcpp;
   31:      size_t len;
   32:      size_t dstlen;
   33: {
   34:   if (__builtin_expect (dstlen < len, 0))
   35:     __chk_fail ();
   36: 
   37:   unsigned long int dstp = (long int) dstpp;
   38:   unsigned long int srcp = (long int) srcpp;
   39: 
   40:   /* Copy from the beginning to the end.  */
   41: 
   42:   /* If there not too few bytes to copy, use word copy.  */
   43:   if (len >= OP_T_THRES)
   44:     {
   45:       /* Copy just a few bytes to make DSTP aligned.  */
   46:       len -= (-dstp) % OPSIZ;
   47:       BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ);
   48: 
   49:       /* Copy whole pages from SRCP to DSTP by virtual address manipulation,
   50:          as much as possible.  */
   51: 
   52:       PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len);
   53: 
   54:       /* Copy from SRCP to DSTP taking advantage of the known alignment of
   55:          DSTP.  Number of bytes remaining is put in the third argument,
   56:          i.e. in LEN.  This number may vary from machine to machine.  */
   57: 
   58:       WORD_COPY_FWD (dstp, srcp, len, len);
   59: 
   60:       /* Fall out and copy the tail.  */
   61:     }
   62: 
   63:   /* There are just a few bytes to copy.  Use byte memory operations.  */
   64:   BYTE_COPY_FWD (dstp, srcp, len);
   65: 
   66:   return (void *) dstp;
   67: }