1 files changed, 41 insertions, 0 deletions
diff --git a/debug/read_chk.c b/debug/read_chk.c
new file mode 100644
index 0000000000..88404ed205
--- /dev/null
+++ b/debug/read_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
+__read_chk (int fd, void *buf, size_t nbytes, size_t buflen)
+{
+  /* In case NBYTES 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
+  ssize_t n = INLINE_SYSCALL (read, 3, fd, buf, MIN (nbytes, buflen + 1));
+#else
+  ssize_t n = __read (fd, buf, MIN (nbytes, buflen + 1));
+#endif
+  if (n > 0 && (size_t) n > buflen)
+    __chk_fail ();
+  return n;
+}