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/* Copyright (C) 1991-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <pointer_guard.h>
#include <jmpbuf-offsets.h>
#define ENV(base,reg) [%base + (reg * 4)]
#define ST_FLUSH_WINDOWS 3
ENTRY(__longjmp)
/* Store our arguments in global registers so we can still
use them while unwinding frames and their register windows. */
ld ENV(o0,JB_FP), %g3 /* Cache target FP in register %g3. */
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (%g3, %g3, %g4)
#endif
mov %o0, %g1 /* ENV in %g1 */
orcc %o1, %g0, %g2 /* VAL in %g2 */
be,a 0f /* Branch if zero; else skip delay slot. */
mov 1, %g2 /* Delay slot only hit if zero: VAL = 1. */
0:
xor %fp, %g3, %o0
add %fp, 512, %o1
andncc %o0, 4095, %o0
bne LOC(thread)
cmp %o1, %g3
bl LOC(thread)
/* Now we will loop, unwinding the register windows up the stack
until the restored %fp value matches the target value in %g3. */
LOC(loop):
cmp %fp, %g3 /* Have we reached the target frame? */
bl,a LOC(loop) /* Loop while current fp is below target. */
restore /* Unwind register window in delay slot. */
be,a LOC(found) /* Better have hit it exactly. */
ld ENV(g1,JB_SP), %o0 /* Delay slot: extract target SP. */
LOC(thread):
save %sp, -96, %sp
/*
* Do a "flush register windows trap". The trap handler in the
* kernel writes all the register windows to their stack slots, and
* marks them all as invalid (needing to be sucked up from the
* stack when used). This ensures that all information needed to
* unwind to these callers is in memory, not in the register
* windows.
*/
ta ST_FLUSH_WINDOWS
#ifdef PTR_DEMANGLE
ld ENV(g1,JB_PC), %g5 /* Set return PC. */
ld ENV(g1,JB_SP), %g1 /* Set saved SP on restore below. */
PTR_DEMANGLE2 (%i7, %g5, %g4)
PTR_DEMANGLE2 (%fp, %g1, %g4)
#else
ld ENV(g1,JB_PC), %i7 /* Set return PC. */
ld ENV(g1,JB_SP), %fp /* Set saved SP on restore below. */
#endif
jmp %i7 + 8
restore %g2, 0, %o0 /* Restore values from above register frame. */
LOC(found):
/* We have unwound register windows so %fp matches the target. */
#ifdef PTR_DEMANGLE
PTR_DEMANGLE2 (%sp, %o0, %g4)
#else
mov %o0, %sp /* OK, install new SP. */
#endif
LOC(sp_ok):
ld ENV(g1,JB_PC), %o0 /* Extract target return PC. */
#ifdef PTR_DEMANGLE
PTR_DEMANGLE2 (%o0, %o0, %g4)
#endif
jmp %o0 + 8 /* Return there. */
mov %g2, %o0 /* Delay slot: set return value. */
END(__longjmp)
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