sysdeps/unix/sysv/linux/fcntl.c

   1 /* Copyright (C) 2000-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <assert.h>
  19 #include <errno.h>
  20 #include <sysdep-cancel.h>      /* Must come before <fcntl.h>.  */
  21 #include <fcntl.h>
  22 #include <stdarg.h>
  23
  24 #include <sys/syscall.h>
  25
  26
  27 static int
  28 do_fcntl (int fd, int cmd, void *arg)
  29 {
  30   if (cmd != F_GETOWN)
  31     return INLINE_SYSCALL (fcntl, 3, fd, cmd, arg);
  32
  33   INTERNAL_SYSCALL_DECL (err);
  34   struct f_owner_ex fex;
  35   int res = INTERNAL_SYSCALL (fcntl, err, 3, fd, F_GETOWN_EX, &fex);
  36   if (!INTERNAL_SYSCALL_ERROR_P (res, err))
  37     return fex.type == F_OWNER_GID ? -fex.pid : fex.pid;
  38
  39   __set_errno (INTERNAL_SYSCALL_ERRNO (res, err));
  40   return -1;
  41 }
  42
  43
  44 #ifndef NO_CANCELLATION
  45 int
  46 __fcntl_nocancel (int fd, int cmd, ...)
  47 {
  48   va_list ap;
  49   void *arg;
  50
  51   va_start (ap, cmd);
  52   arg = va_arg (ap, void *);
  53   va_end (ap);
  54
  55   return do_fcntl (fd, cmd, arg);
  56 }
  57 #endif
  58
  59
  60 int
  61 __libc_fcntl (int fd, int cmd, ...)
  62 {
  63   va_list ap;
  64   void *arg;
  65
  66   va_start (ap, cmd);
  67   arg = va_arg (ap, void *);
  68   va_end (ap);
  69
  70   if (SINGLE_THREAD_P || cmd != F_SETLKW)
  71     return do_fcntl (fd, cmd, arg);
  72
  73   int oldtype = LIBC_CANCEL_ASYNC ();
  74
  75   int result = do_fcntl (fd, cmd, arg);
  76
  77   LIBC_CANCEL_RESET (oldtype);
  78
  79   return result;
  80 }
  81 libc_hidden_def (__libc_fcntl)
  82
  83 weak_alias (__libc_fcntl, __fcntl)
  84 libc_hidden_weak (__fcntl)
  85 weak_alias (__libc_fcntl, fcntl)