usr/src/lib/libc/sparc/gen/getctxt.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #pragma weak _getcontext = getcontext
  33
  34 #include "lint.h"
  35 #include "thr_uberdata.h"
  36 #include <ucontext.h>
  37 #include <sys/types.h>
  38
  39 int
  40 getcontext(ucontext_t *ucp)
  41 {
  42         greg_t *reg;
  43
  44         ucp->uc_flags = UC_ALL;
  45         if (__getcontext(ucp))
  46                 return (-1);
  47
  48         /*
  49          * Note that %o1 and %g1 are modified by the system call
  50          * routine. ABI calling conventions specify that the caller
  51          * cannot depend upon %o0 through %o5 nor %g1, so no effort is
  52          * made to maintain these registers. %o0 is forced to reflect
  53          * an affirmative return code.
  54          */
  55         reg = ucp->uc_mcontext.gregs;
  56         reg[REG_SP] = getfp();
  57         reg[REG_O7] = caller();
  58         reg[REG_PC] = reg[REG_O7] + 8;
  59         reg[REG_nPC] = reg[REG_PC] + 4;
  60         reg[REG_O0] = 0;
  61
  62         return (0);
  63 }