sysdeps/unix/sysv/linux/sparc/sparc64/makecontext.c

   1 /* Copyright (C) 2001-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>.
   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 <stdarg.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <ucontext.h>
  23
  24 extern void __start_context (struct ucontext *ucp);
  25
  26 void
  27 __makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
  28 {
  29   extern void __makecontext_ret (void);
  30   unsigned long *sp, *topsp;
  31   va_list ap;
  32   int i;
  33
  34   sp = (unsigned long *) ((long) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
  35   sp -= (argc > 6 ? argc : 6) + 32;
  36   sp = (unsigned long *) (((long) sp) & -16L);
  37   topsp = sp + (argc > 6 ? argc : 6) + 16;
  38
  39   ucp->uc_mcontext.mc_gregs[MC_PC] = (long) func;
  40   ucp->uc_mcontext.mc_gregs[MC_NPC] = ((long) func) + 4;
  41   ucp->uc_mcontext.mc_gregs[MC_O6] = ((long) sp) - 0x7ff;
  42   ucp->uc_mcontext.mc_gregs[MC_O7] = ((long) __start_context) - 8;
  43   ucp->uc_mcontext.mc_fp = ((long) topsp) - 0x7ff;
  44   ucp->uc_mcontext.mc_i7 = 0;
  45   topsp[14] = 0;
  46   topsp[15] = 0;
  47   sp[8] = (long) ucp->uc_link;
  48   va_start (ap, argc);
  49   for (i = 0; i < argc; ++i)
  50     if (i < 6)
  51       ucp->uc_mcontext.mc_gregs[MC_O0 + i] = va_arg (ap, long);
  52     else
  53       sp[16 + i] = va_arg (ap, long);
  54   va_end (ap);
  55 }
  56
  57 weak_alias (__makecontext, makecontext)