_stack_grow.s revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
.file "%M%"
/*
* void *
* _stack_grow(void *addr)
* {
* uintptr_t base = (uintptr_t)curthread->ul_ustack.ss_sp;
* size_t size = curthread->ul_ustack.ss_size;
*
* if (size > (uintptr_t)addr - base)
* return (addr);
*
* if (size == 0)
* return (addr);
*
* if (size > %sp - base)
* %sp = base - STACK_ALIGN;
*
* *((char *)(base - 1));
*
* _lwp_kill(_lwp_self(), SIGSEGV);
* }
*/
#include "SYS.h"
#include <../assym.h>
ENTRY(_stack_grow)
movq %rdi, %rax
movq %fs:UL_USTACK+SS_SP, %rcx
movq %fs:UL_USTACK+SS_SIZE, %rdx
movq %rax, %rbx
subq %rcx, %rbx
cmpq %rdx, %rbx
jae 1f
ret
1:
/
/ If the stack size is 0, stack checking is disabled.
/
cmpq $0, %rdx
jne 2f
ret
2:
/
/ Move the stack pointer outside the stack bounds if it isn't already.
/
movq %rsp, %rbx
subq %rcx, %rbx
cmpq %rdx, %rbx
jae 3f
pushq %rbp
movq %rsp, %rbp
movq %rcx, %rsp
subq $STACK_ALIGN, %rsp
3:
/
/ Dereference an address in the guard page.
/
movb -1(%rcx), %bl
/
/ If the above load doesn't raise a SIGSEGV then do it ourselves.
/
SYSTRAP_RVAL1(lwp_self)
movl $SIGSEGV, %esi
movl %eax, %edi
SYSTRAP_RVAL1(lwp_kill)
/
/ Try one last time to take out the process.
/
movq 0x0, %rax
SET_SIZE(_stack_grow)