sparc/gen/siglongjmp.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1988 AT&T */
/*    All Rights Reserved   */

#pragma ident   "%Z%%M% %I% %E% SMI"

#pragma weak _siglongjmp = siglongjmp

#include "lint.h"
#include <sys/types.h>
#include <sys/stack.h>
#include <sys/frame.h>
#include <memory.h>
#include <ucontext.h>
#include <setjmp.h>
#include "sigjmp_struct.h"
#include "libc.h"

void
siglongjmp(sigjmp_buf env, int val)
{
    extern void _fetch_globals(greg_t *);
    ucontext_t uc;
    greg_t *reg = uc.uc_mcontext.gregs;
    volatile sigjmp_struct_t *bp = (sigjmp_struct_t *)env;
    greg_t fp = bp->sjs_fp;
    greg_t i7 = bp->sjs_i7;

    /*
     * Create a ucontext_t structure from scratch.
     * We only need to fetch the globals.
     * The outs are assumed to be trashed on return from sigsetjmp().
     * The ins and locals are restored from the resumed register window.
     * The floating point state is unmodified.
     * Everything else is in the sigjmp_struct_t buffer.
     */
    (void) memset(&uc, 0, sizeof (uc));
    uc.uc_flags = UC_STACK | UC_CPU;
    _fetch_globals(&reg[REG_G1]);
    uc.uc_stack = bp->sjs_stack;
    uc.uc_link = bp->sjs_uclink;
    reg[REG_PC] = bp->sjs_pc;
    reg[REG_nPC] = reg[REG_PC] + 0x4;
    reg[REG_SP] = bp->sjs_sp;

    if (bp->sjs_flags & JB_SAVEMASK) {
        uc.uc_flags |= UC_SIGMASK;
        uc.uc_sigmask = bp->sjs_sigmask;
    }

    if (val)
        reg[REG_O0] = (greg_t)val;
    else
        reg[REG_O0] = (greg_t)1;

    /*
     * Copy the fp and i7 values into the register window save area.
     * These may have been clobbered between calls to sigsetjmp
     * and siglongjmp.  For example, the save area could have been
     * relocated to lower addresses and the original save area
     * given to an alloca() call.  Notice that all reads from
     * the sigjmp_struct_t buffer should take place before the
     * following two writes.  It is possible that user code may
     * move/copy the sigjmpbuf around, and overlap the original
     * register window save area.
     */
    if (bp->sjs_sp != 0 && (bp->sjs_flags & JB_FRAMEPTR)) {
        struct frame *sp = (struct frame *)(bp->sjs_sp + STACK_BIAS);
        sp->fr_savfp = (struct frame *)fp;
        sp->fr_savpc = i7;
    }

    (void) setcontext(&uc);
}