sysdeps/unix/sysv/linux/shmat.c

   1 /* Copyright (C) 1995-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <sys/shm.h>
  21 #include <ipc_priv.h>
  22
  23 #include <sysdep.h>
  24 #include <unistd.h>
  25 #include <sys/syscall.h>
  26
  27 /* Attach the shared memory segment associated with SHMID to the data
  28    segment of the calling process.  SHMADDR and SHMFLG determine how
  29    and where the segment is attached.  */
  30
  31 void *
  32 shmat (shmid, shmaddr, shmflg)
  33      int shmid;
  34      const void *shmaddr;
  35      int shmflg;
  36 {
  37   INTERNAL_SYSCALL_DECL(err);
  38   unsigned long resultvar;
  39   void *raddr;
  40
  41   resultvar = INTERNAL_SYSCALL (ipc, err, 5, IPCOP_shmat,
  42                                 shmid, shmflg,
  43                                 (long int) &raddr,
  44                                 (void *) shmaddr);
  45   if (INTERNAL_SYSCALL_ERROR_P (resultvar, err))
  46     {
  47       __set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, err));
  48       return (void *) -1l;
  49     }
  50
  51   return raddr;
  52 }