sysdeps/unix/sysv/linux/s390/s390-64/syscall.S

   1 /* Copyright (C) 2001-2020 Free Software Foundation, Inc.
   2    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   3    This file is part of the GNU C Library.
   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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20
  21 /* Please consult the file sysdeps/unix/sysv/linux/s390/sysdep.h for
  22    more information about the value -4095 used below.*/
  23
  24 ENTRY (syscall)
  25         stmg   %r6,%r7,48(%r15)    /* Save registers.  */
  26         cfi_offset (%r7,-104)
  27         cfi_offset (%r6,-112)
  28
  29         lgr    %r1,%r2             /* Move syscall number.  */
  30         lgr    %r2,%r3             /* First parameter.  */
  31         lgr    %r3,%r4             /* Second parameter.  */
  32         lgr    %r4,%r5             /* Third parameter.  */
  33         lgr    %r5,%r6             /* Fourth parameter.  */
  34         lmg    %r6,%r7,160(%r15)   /* Fifth / Sixth parameter.  */
  35         svc    0
  36
  37         lmg    %r6,%r7,48(%r15)    /* Load registers.  */
  38
  39         lghi   %r0,-4095
  40         clgr   %r2,%r0             /* Check R2 for error.  */
  41         jgnl   SYSCALL_ERROR_LABEL
  42         br     %r14                /* Return to caller.  */
  43 PSEUDO_END (syscall)