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1999-01-28 David S. Miller <davem@redhat.com> * sysdeps/sparc/sparc32/__longjmp.S: Rewrite without bogus sanity checks and aborts, to make longjmp based thread schemes work again.
81 lines
2.9 KiB
ArmAsm
81 lines
2.9 KiB
ArmAsm
/* Copyright (C) 1991, 93, 96, 97, 98, 99 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <sysdep.h>
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#define _ASM 1
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#include <jmp_buf.h>
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#define ENV(base,reg) [%base + (reg * 4)]
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#define ST_FLUSH_WINDOWS 3
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#define RW_FP [%fp + 0x38]
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ENTRY(__longjmp)
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/* Store our arguments in global registers so we can still
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use them while unwinding frames and their register windows. */
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ld ENV(o0,JB_FP), %g3 /* Cache target FP in register %g3. */
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mov %o0, %g1 /* ENV in %g1 */
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orcc %o1, %g0, %g2 /* VAL in %g2 */
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be,a 0f /* Branch if zero; else skip delay slot. */
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mov 1, %g2 /* Delay slot only hit if zero: VAL = 1. */
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0:
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xor %fp, %g3, %o0
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add %fp, 512, %o1
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andncc %o0, 4095, %o0
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bne LOC(thread)
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cmp %o1, %g3
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bl LOC(thread)
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/* Now we will loop, unwinding the register windows up the stack
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until the restored %fp value matches the target value in %g3. */
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LOC(loop):
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cmp %fp, %g3 /* Have we reached the target frame? */
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bl,a LOC(loop) /* Loop while current fp is below target. */
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restore /* Unwind register window in delay slot. */
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be,a LOC(found) /* Better have hit it exactly. */
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ld ENV(g1,JB_SP), %o0 /* Delay slot: extract target SP. */
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LOC(thread):
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/*
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* Do a "flush register windows trap". The trap handler in the
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* kernel writes all the register windows to their stack slots, and
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* marks them all as invalid (needing to be sucked up from the
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* stack when used). This ensures that all information needed to
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* unwind to these callers is in memory, not in the register
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* windows.
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*/
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ta ST_FLUSH_WINDOWS
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ld ENV(g1,JB_PC), %o7 /* Set return PC. */
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ld ENV(g1,JB_SP), %fp /* Set saved SP on restore below. */
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sub %fp, 64, %sp /* Allocate a register frame. */
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st %g3, RW_FP /* Set saved FP on restore below. */
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retl
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restore %g2, 0, %o0 /* Restore values from above register frame. */
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LOC(found):
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/* We have unwound register windows so %fp matches the target. */
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mov %o0, %sp /* OK, install new SP. */
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LOC(sp_ok):
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ld ENV(g1,JB_PC), %o0 /* Extract target return PC. */
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jmp %o0 + 8 /* Return there. */
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mov %g2, %o0 /* Delay slot: set return value. */
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END(__longjmp)
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