sysdeps/unix/sysv/linux/fcntl.c

   1 /* Copyright (C) 2000, 2002, 2003, 2004, 2009 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <assert.h>
  20 #include <errno.h>
  21 #include <sysdep-cancel.h>      /* Must come before <fcntl.h>.  */
  22 #include <fcntl.h>
  23 #include <stdarg.h>
  24
  25 #include <sys/syscall.h>
  26 #include <kernel-features.h>
  27
  28
  29 #ifdef __ASSUME_F_GETOWN_EX
  30 # define miss_F_GETOWN_EX 0
  31 #else
  32 static int miss_F_GETOWN_EX;
  33 #endif
  34
  35
  36 static int
  37 do_fcntl (int fd, int cmd, void *arg)
  38 {
  39   if (cmd != F_GETOWN || miss_F_GETOWN_EX)
  40     return INLINE_SYSCALL (fcntl, 3, fd, cmd, arg);
  41
  42   INTERNAL_SYSCALL_DECL (err);
  43   struct f_owner_ex fex;
  44   int res = INTERNAL_SYSCALL (fcntl, err, 3, fd, F_GETOWN_EX, &fex);
  45   if (!INTERNAL_SYSCALL_ERROR_P (res, err))
  46     return fex.type == F_OWNER_GID ? -fex.pid : fex.pid;
  47
  48 #ifndef __ASSUME_F_GETOWN_EX
  49   if (INTERNAL_SYSCALL_ERRNO (res, err) == EINVAL)
  50     {
  51       res = INLINE_SYSCALL (fcntl, 3, fd, F_GETOWN, arg);
  52       miss_F_GETOWN_EX = 1;
  53       return res;
  54     }
  55 #endif
  56
  57   __set_errno (INTERNAL_SYSCALL_ERRNO (res, err));
  58   return -1;
  59 }
  60
  61
  62 #ifndef NO_CANCELLATION
  63 int
  64 __fcntl_nocancel (int fd, int cmd, ...)
  65 {
  66   va_list ap;
  67   void *arg;
  68
  69   va_start (ap, cmd);
  70   arg = va_arg (ap, void *);
  71   va_end (ap);
  72
  73   return do_fcntl (fd, cmd, arg);
  74 }
  75 #endif
  76
  77
  78 int
  79 __libc_fcntl (int fd, int cmd, ...)
  80 {
  81   va_list ap;
  82   void *arg;
  83
  84   va_start (ap, cmd);
  85   arg = va_arg (ap, void *);
  86   va_end (ap);
  87
  88   if (SINGLE_THREAD_P || cmd != F_SETLKW)
  89     return do_fcntl (fd, cmd, arg);
  90
  91   int oldtype = LIBC_CANCEL_ASYNC ();
  92
  93   int result = do_fcntl (fd, cmd, arg);
  94
  95   LIBC_CANCEL_RESET (oldtype);
  96
  97   return result;
  98 }
  99 libc_hidden_def (__libc_fcntl)
 100
 101 weak_alias (__libc_fcntl, __fcntl)
 102 libc_hidden_weak (__fcntl)
 103 weak_alias (__libc_fcntl, fcntl)