sysdeps/unix/sysv/linux/shmat.c

   1 /* Copyright (C) 1995-2017 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 <sys/msg.h>
  20 #include <ipc_priv.h>
  21 #include <sysdep.h>
  22 #include <errno.h>
  23
  24 /* Attach the shared memory segment associated with SHMID to the data
  25    segment of the calling process.  SHMADDR and SHMFLG determine how
  26    and where the segment is attached.  */
  27
  28 void *
  29 shmat (int shmid, const void *shmaddr, int shmflg)
  30 {
  31 #ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
  32   return (void*) INLINE_SYSCALL_CALL (shmat, shmid, shmaddr, shmflg);
  33 #else
  34   INTERNAL_SYSCALL_DECL(err);
  35   unsigned long resultvar;
  36   void *raddr;
  37
  38   resultvar = INTERNAL_SYSCALL_CALL (ipc, err, IPCOP_shmat, shmid, shmflg,
  39                                      &raddr, shmaddr);
  40   if (INTERNAL_SYSCALL_ERROR_P (resultvar, err))
  41     return (void *) INLINE_SYSCALL_ERROR_RETURN_VALUE (INTERNAL_SYSCALL_ERRNO (resultvar,
  42                                                                                err));
  43
  44   return raddr;
  45 #endif
  46 }