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/*
* 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"
#if defined(__lint)
#include <setjmp.h>
#endif
#include <sys/asm_linkage.h>
/*
* This is a copy of the setjmp (and longjmp) code used in libc. Note that
* we use sigsetjmp as an alias for setjmp, with a corresponding alias between
* siglongjmp and longjmp. We can do this because there aren't any signals
* in kmdb (with the possible exception of the smoke signals the machine will
* emit when we break something). We can also use a sigjmp_buf as a jmp_buf,
* since the latter is smaller than the former.
*/
#if !defined(__lint)
JB_FLAGS = (0*8) ! offsets in jmpbuf (see sigsetjmp.c)
JB_SP = (1*8) ! words 5 through 11 are unused!
JB_PC = (2*8)
JB_FP = (3*8)
JB_I7 = (4*8)
#endif
/*
* setjmp(buf_ptr)
* buf_ptr points to a twelve word array (jmp_buf)
*/
#if defined(__lint)
/* ARGSUSED */
int
setjmp(jmp_buf env)
{
return (0);
}
/* ARGSUSED */
int
sigsetjmp(sigjmp_buf env, int savemask)
{
return (0);
}
#else /* __lint */
ENTRY(setjmp)
ALTENTRY(sigsetjmp)
clr [%o0 + JB_FLAGS] ! clear flags (used by sigsetjmp)
stx %sp, [%o0 + JB_SP] ! save caller's sp
add %o7, 8, %o1 ! compute return pc
stx %o1, [%o0 + JB_PC] ! save pc
stx %fp, [%o0 + JB_FP] ! save fp
stx %i7, [%o0 + JB_I7] ! save %i7
flushw
retl
clr %o0 ! return (0)
SET_SIZE(setjmp)
#endif /* __lint */
/*
* 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.
*/
#if defined(__lint)
/* ARGSUSED */
void
longjmp(jmp_buf env, int val)
{
}
/* ARGSUSED */
void
siglongjmp(sigjmp_buf env, int val)
{
}
#else /* __lint */
ENTRY(longjmp)
ALTENTRY(siglongjmp)
/* flush all reg windows to the stack. */
save
flushw
restore
nop
ldx [%o0 + JB_SP], %o2 ! sp in %o2 until safe to puke there
ldx [%o2 + STACK_BIAS], %l0 ! restore locals and ins if we can
ldx [%o2 + (1*8) + STACK_BIAS], %l1
ldx [%o2 + (2*8) + STACK_BIAS], %l2
ldx [%o2 + (3*8) + STACK_BIAS], %l3
ldx [%o2 + (4*8) + STACK_BIAS], %l4
ldx [%o2 + (5*8) + STACK_BIAS], %l5
ldx [%o2 + (6*8) + STACK_BIAS], %l6
ldx [%o2 + (7*8) + STACK_BIAS], %l7
ldx [%o2 + (8*8) + STACK_BIAS], %i0
ldx [%o2 + (9*8) + STACK_BIAS], %i1
ldx [%o2 + (10*8) + STACK_BIAS], %i2
ldx [%o2 + (11*8) + STACK_BIAS], %i3
ldx [%o2 + (12*8) + STACK_BIAS], %i4
ldx [%o2 + (13*8) + STACK_BIAS], %i5
ldx [%o0 + JB_FP], %fp ! restore fp
mov %o2, %sp ! restore sp
ldx [%o0 + JB_I7], %i7 ! restore %i7
ldx [%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)
#endif /* __lint */
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