diff options
Diffstat (limited to 'sysdeps/generic/strncat_chk.c')
-rw-r--r-- | sysdeps/generic/strncat_chk.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/sysdeps/generic/strncat_chk.c b/sysdeps/generic/strncat_chk.c new file mode 100644 index 0000000..953b435 --- /dev/null +++ b/sysdeps/generic/strncat_chk.c @@ -0,0 +1,100 @@ +/* Copyright (C) 1991, 1997, 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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> + + +char * +__strncat_chk (s1, s2, n, s1len) + char *s1; + const char *s2; + size_t n; + size_t s1len; +{ + reg_char c; + char *s = s1; + + /* Find the end of S1. */ + do + { + if (__builtin_expect (s1len-- == 0, 0)) + __chk_fail (); + c = *s1++; + } + while (c != '\0'); + + /* Make S1 point before next character, so we can increment + it while memory is read (wins on pipelined cpus). */ + ++s1len; + s1 -= 2; + + if (n >= 4) + { + size_t n4 = n >> 2; + do + { + if (__builtin_expect (s1len-- == 0, 0)) + __chk_fail (); + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + if (__builtin_expect (s1len-- == 0, 0)) + __chk_fail (); + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + if (__builtin_expect (s1len-- == 0, 0)) + __chk_fail (); + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + if (__builtin_expect (s1len-- == 0, 0)) + __chk_fail (); + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + } while (--n4 > 0); + n &= 3; + } + + while (n > 0) + { + if (__builtin_expect (s1len-- == 0, 0)) + __chk_fail (); + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + n--; + } + + if (c != '\0') + { + if (__builtin_expect (s1len-- == 0, 0)) + __chk_fail (); + *++s1 = '\0'; + } + + return s; +} |