glibc/ports/sysdeps/unix/sysv/linux/mips/makecontext.S

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/* Modify saved context.
Copyright (C) 2009 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Maciej W. Rozycki <macro@codesourcery.com>.
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
2012-03-09 23:56:38 +00:00
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <sys/asm.h>
#include <sys/fpregdef.h>
#include <sys/regdef.h>
#include "ucontext_i.h"
/* int makecontext (ucontext_t *ucp, (void *func) (), int argc, ...) */
.text
LOCALSZ = 0
ARGSZ = 0
MASK = 0x00000000
#ifdef __PIC__
LOCALSZ = 1 /* save gp */
#endif
#if _MIPS_SIM != _ABIO32
ARGSZ = 5 /* save a3-a7 */
# ifdef __PIC__
MASK = 0x10000000
# endif
#endif
FRAMESZ = (((ARGSZ + LOCALSZ) * SZREG) + ALSZ) & ALMASK
GPOFF = FRAMESZ - ((ARGSZ + 1) * SZREG)
#if _MIPS_SIM != _ABIO32
A3OFF = FRAMESZ - (5 * SZREG) /* callee-allocated */
A4OFF = FRAMESZ - (4 * SZREG)
A5OFF = FRAMESZ - (3 * SZREG)
A6OFF = FRAMESZ - (2 * SZREG)
A7OFF = FRAMESZ - (1 * SZREG)
NARGREGS = 8
#else
A3OFF = FRAMESZ + (3 * SZREG) /* caller-allocated */
NARGREGS = 4
#endif
NESTED (__makecontext, FRAMESZ, ra)
.mask MASK, -(ARGSZ * SZREG)
.fmask 0x00000000, 0
98:
#ifdef __PIC__
SETUP_GP
#endif
PTR_ADDIU sp, -FRAMESZ
#ifdef __PIC__
SETUP_GP64 (GPOFF, __makecontext)
SAVE_GP (GPOFF)
#endif
#ifdef PROF
.set noat
move AT, ra
jal _mcount
.set at
#endif
/* Store args to be passed. */
REG_S a3, A3OFF(sp)
#if _MIPS_SIM != _ABIO32
REG_S a4, A4OFF(sp)
REG_S a5, A5OFF(sp)
REG_S a6, A6OFF(sp)
REG_S a7, A7OFF(sp)
#endif
/* Store a magic flag. */
li v1, 1
REG_S v1, (0 * SZREG + MCONTEXT_GREGS)(a0) /* zero */
/* Set up the stack. */
PTR_L t0, STACK_SP(a0)
PTR_L t2, STACK_SIZE(a0)
PTR_ADDIU t1, sp, A3OFF
PTR_ADDU t0, t2
and t0, ALMASK
blez a2, 2f /* no arguments */
/* Store register arguments. */
PTR_ADDIU t2, a0, MCONTEXT_GREGS + 4 * SZREG
move t3, zero
0:
addiu t3, 1
REG_L v1, (t1)
PTR_ADDIU t1, SZREG
REG_S v1, (t2)
PTR_ADDIU t2, SZREG
bgeu t3, a2, 2f /* all done */
bltu t3, NARGREGS, 0b /* next */
/* Make room for stack arguments. */
PTR_SUBU t2, a2, t3
PTR_SLL t2, 3
PTR_SUBU t0, t2
and t0, ALMASK
/* Store stack arguments. */
move t2, t0
1:
addiu t3, 1
REG_L v1, (t1)
PTR_ADDIU t1, SZREG
REG_S v1, (t2)
PTR_ADDIU t2, SZREG
bltu t3, a2, 1b /* next */
2:
#if _MIPS_SIM == _ABIO32
/* Make room for a0-a3 storage. */
PTR_ADDIU t0, -(NARGSAVE * SZREG)
#endif
PTR_L v1, UCONTEXT_LINK(a0)
#ifdef __PIC__
PTR_ADDIU t9, 99f - 98b
#else
PTR_LA t9, 99f
#endif
REG_S t0, (29 * SZREG + MCONTEXT_GREGS)(a0) /* sp */
REG_S v1, (16 * SZREG + MCONTEXT_GREGS)(a0) /* s0 */
#ifdef __PIC__
REG_S gp, (17 * SZREG + MCONTEXT_GREGS)(a0) /* s1 */
#endif
REG_S t9, (31 * SZREG + MCONTEXT_GREGS)(a0) /* ra */
REG_S a1, MCONTEXT_PC(a0)
#ifdef __PIC__
RESTORE_GP64
PTR_ADDIU sp, FRAMESZ
#endif
jr ra
99:
#ifdef __PIC__
move gp, s1
#endif
move a0, zero
beqz s0, 0f
/* setcontext (ucp) */
move a0, s0
#ifdef __PIC__
PTR_LA t9, JUMPTARGET (__setcontext)
jalr t9
# if _MIPS_SIM == _ABIO32
move gp, s1
# endif
#else
jal JUMPTARGET (__setcontext)
#endif
move a0, v0
0:
/* exit (a0) */
#ifdef __PIC__
PTR_LA t9, HIDDEN_JUMPTARGET (exit)
jalr t9
#else
jal HIDDEN_JUMPTARGET (exit)
#endif
/* You don't exist, you won't feel anything. */
1:
lb zero, (zero)
b 1b
PSEUDO_END (__makecontext)
weak_alias (__makecontext, makecontext)