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/*
* 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 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
.file "setjmp.s"
#include <sys/asm_linkage.h>
ANSI_PRAGMA_WEAK(setjmp,function)
ANSI_PRAGMA_WEAK(longjmp,function)
#include <../assym.h>
#include <sys/trap.h>
JB_FLAGS = (0*4) ! offsets in jmpbuf (see siglonglmp.c)
JB_SP = (1*4) ! words 5 through 11 are unused!
JB_PC = (2*4)
JB_FP = (3*4)
JB_I7 = (4*4)
/*
* Flag telling longjmp to set curthread->ul_siglink to NULL.
*/
JB_CLEARLINK = 0x10
/*
* setjmp(buf_ptr)
* buf_ptr points to a twelve word array (jmp_buf)
*/
ENTRY(setjmp)
clr %o2
ld [%g7 + UL_SIGLINK], %o1 ! are we in a signal context?
tst %o1
be,a,pt %icc, 1f
mov JB_CLEARLINK, %o2 ! no, tell longjmp to clear ul_siglink
1: st %o2, [%o0 + JB_FLAGS]
st %sp, [%o0 + JB_SP] ! save caller's sp
add %o7, 8, %o1 ! compute return pc
st %o1, [%o0 + JB_PC] ! save pc
st %fp, [%o0 + JB_FP] ! save fp
st %i7, [%o0 + JB_I7] ! save %i7
retl
clr %o0 ! return (0)
SET_SIZE(setjmp)
/*
* longjmp(buf_ptr, val)
* buf_ptr points to a jmpbuf which has been initialized by setjmp.
* val is the value we wish to return to setjmp's caller
*
* We flush the register file to the stack by doing a kernel call.
* This is necessary to ensure that the registers we want to
* pick up are stored on the stack, and that subsequent restores
* will function correctly.
*
* sp, fp, and %i7, the caller's return address, are all restored
* to the values they had at the time of the call to setjmp(). All
* other locals, ins and outs are set to potentially random values
* (as per the man page). This is sufficient to permit the correct
* operation of normal code.
*
* Actually, the above description is not quite correct. If the routine
* that called setjmp() has not altered the sp value of their frame we
* will restore the remaining locals and ins to the values these
* registers had in the this frame at the time of the call to longjmp()
* (not setjmp()!). This is intended to help compilers, typically not
* C compilers, that have some registers assigned to fixed purposes,
* and that only alter the values of these registers on function entry
* and exit.
*
* Since a C routine could call setjmp() followed by alloca() and thus
* alter the sp this feature will typically not be helpful for a C
* compiler.
*
* Note also that because the caller of a routine compiled "flat" (without
* register windows) assumes that their ins and locals are preserved,
* routines that call setjmp() must not be flat.
*/
ENTRY(longjmp)
ta ST_FLUSH_WINDOWS ! flush all reg windows to the stack.
ld [%o0 + JB_SP], %o2 ! sp in %o2 until safe to puke there
ldd [%o2 + (0*8)], %l0 ! restore locals and ins if we can
ldd [%o2 + (1*8)], %l2
ldd [%o2 + (2*8)], %l4
ldd [%o2 + (3*8)], %l6
ldd [%o2 + (4*8)], %i0
ldd [%o2 + (5*8)], %i2
ldd [%o2 + (6*8)], %i4
ld [%o0 + JB_FP], %fp ! restore fp
mov %o2, %sp ! restore sp
ld [%o0 + JB_FLAGS], %o2
btst JB_CLEARLINK, %o2 ! test JB_CLEARLINK flag
bne,a,pt %icc, 1f
clr [%g7 + UL_SIGLINK] ! if set, clear ul_siglink
1:
ld [%o0 + JB_I7], %i7 ! restore %i7
ld [%o0 + JB_PC], %o3 ! get new return pc
tst %o1 ! is return value 0?
bnz 1f ! no - leave it alone
sub %o3, 8, %o7 ! normalize return (for adb) (dly slot)
mov 1, %o1 ! yes - set it to one
1:
retl
mov %o1, %o0 ! return (val)
SET_SIZE(longjmp)
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