/*

 * 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.

 */

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

#include "thr_uberdata.h"

#include <sys/stack.h>

/*

 * Initialization of the main stack is performed in libc_init().

 * Initialization of thread stacks is performed in _thrp_setup().

 */

#pragma weak _stack_getbounds = stack_getbounds

int

stack_getbounds(stack_t *sp)

{

	*sp = curthread->ul_ustack;

	return (0);

}

#pragma weak _stack_setbounds = stack_setbounds

int

stack_setbounds(const stack_t *sp)

{

	ulwp_t *self = curthread;

	if (sp == NULL || sp->ss_sp == NULL ||

	    (uintptr_t)sp->ss_sp != SA((uintptr_t)sp->ss_sp) ||

	    sp->ss_flags != 0 || sp->ss_size < MINSIGSTKSZ ||

	    (uintptr_t)sp->ss_size != SA((uintptr_t)sp->ss_size)) {

		errno = EINVAL;

		return (-1);

	}

	sigoff(self);

	self->ul_ustack = *sp;

	sigon(self);

	return (0);

}

/*

 * Returns a boolean value:

 *	1 addr is within the bounds of the current stack

 *	0 addr is outside of the bounds of the current stack

 * Note that addr is an unbiased value.

 */

#pragma weak _stack_inbounds = stack_inbounds

int

stack_inbounds(void *addr)

{

	stack_t *ustackp = &curthread->ul_ustack;

	uintptr_t base = (uintptr_t)ustackp->ss_sp;

	size_t size = ustackp->ss_size;

	return ((uintptr_t)addr >= base && (uintptr_t)addr < base + size);

}

#pragma weak _stack_violation = stack_violation

int

stack_violation(int sig, const siginfo_t *sip, const ucontext_t *ucp)

{

	uintptr_t addr;

	uintptr_t base;

	size_t size;

	if ((sig != SIGSEGV && sig != SIGBUS) ||

	    sip == NULL || ucp == NULL || SI_FROMUSER(sip))

		return (0);

	/*

	 * ucp has the correct view of the stack when the signal was raised.

	 */

	base = (uintptr_t)ucp->uc_stack.ss_sp;

	size = ucp->uc_stack.ss_size;

#if defined(__sparc)

	addr = ucp->uc_mcontext.gregs[REG_SP] + STACK_BIAS;

#elif defined(__amd64) || defined(__i386)

	addr = ucp->uc_mcontext.gregs[REG_SP];

	/*

	 * If the faulted address is just below the stack pointer we

	 * might be looking at a push instruction that caused the fault

	 * (the largest amount a push instruction can decrement the

	 * stack pointer by is 32).  In that case, use the faulted

	 * address in our computation rather than the stack pointer.

	 */

	if (addr - (uintptr_t)sip->si_addr < 32)

		addr = (uintptr_t)sip->si_addr;

#else

#error "none of __sparc, __amd64, __i386 is defined"

#endif

	return (!(addr >= base && addr < base + size));

}