diff options
Diffstat (limited to 'debug/readlink_chk.c')
-rw-r--r-- | debug/readlink_chk.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/debug/readlink_chk.c b/debug/readlink_chk.c new file mode 100644 index 0000000000..662041957a --- /dev/null +++ b/debug/readlink_chk.c @@ -0,0 +1,41 @@ +/* Copyright (C) 2005 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 <unistd.h> +#include <sys/param.h> +#ifdef HAVE_INLINED_SYSCALLS +# include <errno.h> +# include <sysdep.h> +#endif + + +ssize_t +__readlink_chk (const char *path, void *buf, size_t len, size_t buflen) +{ + /* In case LEN is greater than BUFLEN, we read BUFLEN+1 bytes. + This might overflow the buffer but the damage is reduced to just + one byte. And the program will terminate right away. */ +#ifdef HAVE_INLINED_SYSCALLS + int n = INLINE_SYSCALL (readlink, 3, path, buf, MIN (len, buflen + 1)); +#else + int n = __readlink (path, buf, MIN (len, buflen + 1)); +#endif + if (n > 0 && (size_t) n > buflen) + __chk_fail (); + return n; +} |