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708c687a6f
2004-10-18 Jakub Jelinek <jakub@redhat.com> * sysdeps/generic/strcpy_chk.c (__strcpy_chk): Speed up by checking destlen only every 4 bytes.
69 lines
1.7 KiB
C
69 lines
1.7 KiB
C
/* Copyright (C) 1991, 1997, 2000, 2003, 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <stddef.h>
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#include <string.h>
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#include <memcopy.h>
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#undef strcpy
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/* Copy SRC to DEST with checking of destination buffer overflow. */
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char *
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__strcpy_chk (dest, src, destlen)
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char *dest;
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const char *src;
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size_t destlen;
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{
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reg_char c;
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char *s = (char *) src;
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const ptrdiff_t off = dest - s;
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while (__builtin_expect (destlen >= 4, 0))
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{
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c = s[0];
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s[off] = c;
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if (c == '\0')
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return dest;
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c = s[1];
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s[off + 1] = c;
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if (c == '\0')
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return dest;
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c = s[2];
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s[off + 2] = c;
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if (c == '\0')
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return dest;
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c = s[3];
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s[off + 3] = c;
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if (c == '\0')
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return dest;
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destlen -= 4;
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s += 4;
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}
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do
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{
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if (__builtin_expect (destlen-- == 0, 0))
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__chk_fail ();
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c = *s;
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*(s++ + off) = c;
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}
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while (c != '\0');
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return dest;
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}
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