aboutsummaryrefslogtreecommitdiff
path: root/debug/readlink_chk.c
blob: 662041957aad1fb5974a3bf11019b48c476d0b60 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
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;
}