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-rw-r--r--sysdeps/generic/memcpy_chk.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/sysdeps/generic/memcpy_chk.c b/sysdeps/generic/memcpy_chk.c
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+++ b/sysdeps/generic/memcpy_chk.c
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+/* Copy memory to memory until the specified number of bytes
+   has been copied with error checking.  Overlap is NOT handled correctly.
+   Copyright (C) 1991, 1997, 2003, 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Torbjorn Granlund (tege@sics.se).
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <string.h>
+#include <memcopy.h>
+#include <pagecopy.h>
+
+void *
+__memcpy_chk (dstpp, srcpp, len, dstlen)
+     void *dstpp;
+     const void *srcpp;
+     size_t len;
+     size_t dstlen;
+{
+  if (__builtin_expect (dstlen < len, 0))
+    __chk_fail ();
+
+  unsigned long int dstp = (long int) dstpp;
+  unsigned long int srcp = (long int) srcpp;
+
+  /* Copy from the beginning to the end.  */
+
+  /* If there not too few bytes to copy, use word copy.  */
+  if (len >= OP_T_THRES)
+    {
+      /* Copy just a few bytes to make DSTP aligned.  */
+      len -= (-dstp) % OPSIZ;
+      BYTE_COPY_FWD (dstp, srcp, (-dstp) % OPSIZ);
+
+      /* Copy whole pages from SRCP to DSTP by virtual address manipulation,
+	 as much as possible.  */
+
+      PAGE_COPY_FWD_MAYBE (dstp, srcp, len, len);
+
+      /* Copy from SRCP to DSTP taking advantage of the known alignment of
+	 DSTP.  Number of bytes remaining is put in the third argument,
+	 i.e. in LEN.  This number may vary from machine to machine.  */
+
+      WORD_COPY_FWD (dstp, srcp, len, len);
+
+      /* Fall out and copy the tail.  */
+    }
+
+  /* There are just a few bytes to copy.  Use byte memory operations.  */
+  BYTE_COPY_FWD (dstp, srcp, len);
+
+  return dstpp;
+}