sysdeps/unix/sysv/linux/shmat.c

   1 /* Copyright (C) 1995-2024 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <ipc_priv.h>
  19 #include <sysdep.h>
  20 #include <errno.h>
  21
  22 /* Attach the shared memory segment associated with SHMID to the data
  23    segment of the calling process.  SHMADDR and SHMFLG determine how
  24    and where the segment is attached.  */
  25
  26 void *
  27 shmat (int shmid, const void *shmaddr, int shmflg)
  28 {
  29 #ifdef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
  30   return (void*) INLINE_SYSCALL_CALL (shmat, shmid, shmaddr, shmflg);
  31 #else
  32   unsigned long resultvar;
  33   void *raddr;
  34
  35   resultvar = INTERNAL_SYSCALL_CALL (ipc, IPCOP_shmat, shmid, shmflg,
  36                                      &raddr, shmaddr);
  37   if (INTERNAL_SYSCALL_ERROR_P (resultvar))
  38     return (void *) INLINE_SYSCALL_ERROR_RETURN_VALUE (INTERNAL_SYSCALL_ERRNO (resultvar));
  39
  40   return raddr;
  41 #endif
  42 }