6716785: implicit null checks not triggering with CompressedOops
Summary: allocate alignment-sized page(s) below java heap so that memory accesses at heap_base+1page give signal and cause an implicit null check
Reviewed-by: kvn, jmasa, phh, jcoomes
/*
* Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
#include "incls/_precompiled.incl"
#include "incls/_assembler_linux_sparc.cpp.incl"
#include <asm-sparc/traps.h>
void MacroAssembler::read_ccr_trap(Register ccr_save) {
// No implementation
breakpoint_trap();
}
void MacroAssembler::write_ccr_trap(Register ccr_save, Register scratch1, Register scratch2) {
// No implementation
breakpoint_trap();
}
void MacroAssembler::flush_windows_trap() { trap(SP_TRAP_FWIN); }
void MacroAssembler::clean_windows_trap() { trap(SP_TRAP_CWIN); }
// Use software breakpoint trap until we figure out how to do this on Linux
void MacroAssembler::get_psr_trap() { trap(SP_TRAP_SBPT); }
void MacroAssembler::set_psr_trap() { trap(SP_TRAP_SBPT); }