[thirdparty/glibc.git] / sysdeps / unix / sysv / linux / mips / makecontext.S

/* Modify saved context.
   Copyright (C) 2009-2019 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
   License along with the GNU C Library.  If not, see
   <https://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
	.set	nomips16
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
MCONTEXT_GREGSZ = 8
#if _MIPS_SIM == _ABIO32 && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
MCONTEXT_GREGOFF = 4
#else
MCONTEXT_GREGOFF = 0
#endif

NESTED (__makecontext, FRAMESZ, ra)
	.mask	MASK, -(ARGSZ * SZREG)
	.fmask	0x00000000, 0

98:
#ifdef __PIC__
	SETUP_GP
#endif

	PTR_ADDIU sp, -FRAMESZ
	cfi_adjust_cfa_offset (FRAMESZ)

#ifdef __PIC__
	SETUP_GP64_STACK (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

	/* 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 * MCONTEXT_GREGSZ + MCONTEXT_GREGOFF
	move	t3, zero
0:
	addiu	t3, 1
	REG_L	v1, (t1)
	PTR_ADDIU t1, SZREG
	REG_S	v1, (t2)
	PTR_ADDIU t2, MCONTEXT_GREGSZ
	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
	/* sp */
	REG_S	t0, (MCONTEXT_GREGOFF + 29 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
	/* s0 */
	REG_S	v1, (MCONTEXT_GREGOFF + 16 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
#ifdef __PIC__
	/* s1 */
	REG_S	gp, (MCONTEXT_GREGOFF + 17 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
#endif
	/* ra */
	REG_S	t9, (MCONTEXT_GREGOFF + 31 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
	REG_S	a1, (MCONTEXT_GREGOFF + MCONTEXT_PC)(a0)

#ifdef __PIC__
	RESTORE_GP64_STACK
	PTR_ADDIU sp, FRAMESZ
	cfi_adjust_cfa_offset (-FRAMESZ)
#endif
	jr	ra

	/* We need to terminate the FDE to stop unwinding if backtrace was
	   called within a context created by makecontext.  */
	cfi_endproc
	nop

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

	cfi_startproc
PSEUDO_END (__makecontext)

weak_alias (__makecontext, makecontext)
Commit	Line	Data
ff347533	1	/* Modify saved context.
04277e02	2	Copyright (C) 2009-2019 Free Software Foundation, Inc.
ff347533 JM	3	This file is part of the GNU C Library.
	4	Contributed by Maciej W. Rozycki <macro@codesourcery.com>.
	5
	6	The GNU C Library is free software; you can redistribute it and/or
	7	modify it under the terms of the GNU Lesser General Public
	8	License as published by the Free Software Foundation; either
	9	version 2.1 of the License, or (at your option) any later version.
	10
	11	The GNU C Library is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	Lesser General Public License for more details.
	15
	16	You should have received a copy of the GNU Lesser General Public
ab84e3ff	17	License along with the GNU C Library. If not, see
5a82c748	18	<https://www.gnu.org/licenses/>. */
ff347533 JM	19
	20	#include <sysdep.h>
	21	#include <sys/asm.h>
	22	#include <sys/fpregdef.h>
	23	#include <sys/regdef.h>
	24
	25	#include "ucontext_i.h"
	26
	27	/* int makecontext (ucontext_t ucp, (void func) (), int argc, ...) */
	28
	29	.text
43301bd3	30	.set nomips16
ff347533 JM	31	LOCALSZ = 0
	32	ARGSZ = 0
	33	MASK = 0x00000000
	34	#ifdef __PIC__
	35	LOCALSZ = 1 /* save gp */
	36	#endif
	37	#if _MIPS_SIM != _ABIO32
	38	ARGSZ = 5 /* save a3-a7 */
	39	# ifdef __PIC__
	40	MASK = 0x10000000
	41	# endif
	42	#endif
	43	FRAMESZ = (((ARGSZ + LOCALSZ) * SZREG) + ALSZ) & ALMASK
	44	GPOFF = FRAMESZ - ((ARGSZ + 1) * SZREG)
	45	#if _MIPS_SIM != _ABIO32
	46	A3OFF = FRAMESZ - (5 * SZREG) /* callee-allocated */
	47	A4OFF = FRAMESZ - (4 * SZREG)
	48	A5OFF = FRAMESZ - (3 * SZREG)
	49	A6OFF = FRAMESZ - (2 * SZREG)
	50	A7OFF = FRAMESZ - (1 * SZREG)
	51	NARGREGS = 8
	52	#else
	53	A3OFF = FRAMESZ + (3 * SZREG) /* caller-allocated */
	54	NARGREGS = 4
	55	#endif
b309f058 GC	56	MCONTEXT_GREGSZ = 8
	57	#if _MIPS_SIM == _ABIO32 && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
	58	MCONTEXT_GREGOFF = 4
	59	#else
	60	MCONTEXT_GREGOFF = 0
	61	#endif
ff347533 JM	62
	63	NESTED (__makecontext, FRAMESZ, ra)
	64	.mask MASK, -(ARGSZ * SZREG)
	65	.fmask 0x00000000, 0
	66
	67	98:
	68	#ifdef __PIC__
	69	SETUP_GP
	70	#endif
	71
	72	PTR_ADDIU sp, -FRAMESZ
aea7a9b9	73	cfi_adjust_cfa_offset (FRAMESZ)
ff347533 JM	74
ff347533 JM	75	#ifdef __PIC__
aea7a9b9	76	SETUP_GP64_STACK (GPOFF, __makecontext)
ff347533 JM	77	SAVE_GP (GPOFF)
	78	#endif
	79
	80	#ifdef PROF
	81	.set noat
	82	move AT, ra
	83	jal _mcount
	84	.set at
	85	#endif
	86
	87	/* Store args to be passed. */
	88	REG_S a3, A3OFF(sp)
	89	#if _MIPS_SIM != _ABIO32
	90	REG_S a4, A4OFF(sp)
	91	REG_S a5, A5OFF(sp)
	92	REG_S a6, A6OFF(sp)
	93	REG_S a7, A7OFF(sp)
	94	#endif
	95
ff347533 JM	96	/* Set up the stack. */
	97	PTR_L t0, STACK_SP(a0)
	98	PTR_L t2, STACK_SIZE(a0)
	99	PTR_ADDIU t1, sp, A3OFF
	100	PTR_ADDU t0, t2
	101	and t0, ALMASK
	102	blez a2, 2f /* no arguments */
	103
	104	/* Store register arguments. */
b309f058	105	PTR_ADDIU t2, a0, MCONTEXT_GREGS + 4 * MCONTEXT_GREGSZ + MCONTEXT_GREGOFF
ff347533 JM	106	move t3, zero
	107	0:
	108	addiu t3, 1
	109	REG_L v1, (t1)
	110	PTR_ADDIU t1, SZREG
	111	REG_S v1, (t2)
b309f058	112	PTR_ADDIU t2, MCONTEXT_GREGSZ
ff347533 JM	113	bgeu t3, a2, 2f /* all done */
	114	bltu t3, NARGREGS, 0b /* next */
	115
	116	/* Make room for stack arguments. */
	117	PTR_SUBU t2, a2, t3
	118	PTR_SLL t2, 3
	119	PTR_SUBU t0, t2
	120	and t0, ALMASK
	121
	122	/* Store stack arguments. */
	123	move t2, t0
	124	1:
	125	addiu t3, 1
	126	REG_L v1, (t1)
	127	PTR_ADDIU t1, SZREG
	128	REG_S v1, (t2)
	129	PTR_ADDIU t2, SZREG
	130	bltu t3, a2, 1b /* next */
	131
	132	2:
	133	#if _MIPS_SIM == _ABIO32
	134	/* Make room for a0-a3 storage. */
	135	PTR_ADDIU t0, -(NARGSAVE * SZREG)
	136	#endif
	137	PTR_L v1, UCONTEXT_LINK(a0)
	138	#ifdef __PIC__
	139	PTR_ADDIU t9, 99f - 98b
	140	#else
	141	PTR_LA t9, 99f
	142	#endif
b309f058 GC	143	/* sp */
	144	REG_S t0, (MCONTEXT_GREGOFF + 29 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
	145	/* s0 */
	146	REG_S v1, (MCONTEXT_GREGOFF + 16 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
ff347533	147	#ifdef __PIC__
b309f058 GC	148	/* s1 */
b309f058 GC	149	REG_S gp, (MCONTEXT_GREGOFF + 17 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
ff347533	150	#endif
b309f058 GC	151	/* ra */
	152	REG_S t9, (MCONTEXT_GREGOFF + 31 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
	153	REG_S a1, (MCONTEXT_GREGOFF + MCONTEXT_PC)(a0)
ff347533 JM	154
ff347533 JM	155	#ifdef __PIC__
aea7a9b9	156	RESTORE_GP64_STACK
ff347533	157	PTR_ADDIU sp, FRAMESZ
aea7a9b9	158	cfi_adjust_cfa_offset (-FRAMESZ)
ff347533 JM	159	#endif
	160	jr ra
	161
f8e9c4d3 AJ	162	/* We need to terminate the FDE to stop unwinding if backtrace was
	163	called within a context created by makecontext. */
	164	cfi_endproc
	165	nop
	166
ff347533 JM	167	99:
	168	#ifdef __PIC__
	169	move gp, s1
	170	#endif
	171	move a0, zero
	172	beqz s0, 0f
	173
	174	/* setcontext (ucp) */
	175	move a0, s0
	176	#ifdef __PIC__
	177	PTR_LA t9, JUMPTARGET (__setcontext)
	178	jalr t9
	179	# if _MIPS_SIM == _ABIO32
	180	move gp, s1
	181	# endif
	182	#else
	183	jal JUMPTARGET (__setcontext)
	184	#endif
	185	move a0, v0
	186
	187	0:
	188	/* exit (a0) */
	189	#ifdef __PIC__
	190	PTR_LA t9, HIDDEN_JUMPTARGET (exit)
	191	jalr t9
	192	#else
	193	jal HIDDEN_JUMPTARGET (exit)
	194	#endif
	195
	196	/* You don't exist, you won't feel anything. */
	197	1:
	198	lb zero, (zero)
	199	b 1b
f8e9c4d3 AJ	200
f8e9c4d3 AJ	201	cfi_startproc
ff347533 JM	202	PSEUDO_END (__makecontext)
	203
	204	weak_alias (__makecontext, makecontext)