sysdeps/unix/sysv/linux/fcntl.c

   1 /* Copyright (C) 2000-2017 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 <fcntl.h>
  19 #include <stdarg.h>
  20 #include <errno.h>
  21 #include <sysdep-cancel.h>
  22
  23 #ifndef __NR_fcntl64
  24 # define __NR_fcntl64 __NR_fcntl
  25 #endif
  26
  27 #ifndef FCNTL_ADJUST_CMD
  28 # define FCNTL_ADJUST_CMD(__cmd) __cmd
  29 #endif
  30
  31 static int
  32 fcntl_common (int fd, int cmd, void *arg)
  33 {
  34   if (cmd == F_GETOWN)
  35     {
  36       INTERNAL_SYSCALL_DECL (err);
  37       struct f_owner_ex fex;
  38       int res = INTERNAL_SYSCALL_CALL (fcntl64, err, fd, F_GETOWN_EX, &fex);
  39       if (!INTERNAL_SYSCALL_ERROR_P (res, err))
  40         return fex.type == F_OWNER_GID ? -fex.pid : fex.pid;
  41
  42       return INLINE_SYSCALL_ERROR_RETURN_VALUE (INTERNAL_SYSCALL_ERRNO (res,
  43                                                                     err));
  44     }
  45
  46   return INLINE_SYSCALL_CALL (fcntl64, fd, cmd, (void *) arg);
  47 }
  48
  49 #ifndef NO_CANCELLATION
  50 int
  51 __fcntl_nocancel (int fd, int cmd, ...)
  52 {
  53   va_list ap;
  54   void *arg;
  55
  56   va_start (ap, cmd);
  57   arg = va_arg (ap, void *);
  58   va_end (ap);
  59
  60   return fcntl_common (fd, cmd, arg);
  61 }
  62 #endif
  63
  64 int
  65 __libc_fcntl (int fd, int cmd, ...)
  66 {
  67   va_list ap;
  68   void *arg;
  69
  70   va_start (ap, cmd);
  71   arg = va_arg (ap, void *);
  72   va_end (ap);
  73
  74   cmd = FCNTL_ADJUST_CMD (cmd);
  75
  76   if (cmd == F_SETLKW || cmd == F_SETLKW64)
  77     return SYSCALL_CANCEL (fcntl64, fd, cmd, (void *) arg);
  78
  79   return fcntl_common (fd, cmd, arg);
  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)