[thirdparty/glibc.git] / sysdeps / unix / sysv / linux / powerpc / powerpc32 / makecontext.S

/* Set up a context to call a function.
   Copyright (C) 2002-2014 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
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <shlib-compat.h>

#define __ASSEMBLY__
#include <asm/ptrace.h>
#include "ucontext_i.h"

ENTRY(__makecontext)
	/* Set up the first 7 args to the function in its registers */
	lwz	r11,_UC_REGS_PTR(r3)
	stw	r6,_UC_GREGS+(PT_R3*4)(r11)
	stw	r7,_UC_GREGS+(PT_R4*4)(r11)
	stw	r8,_UC_GREGS+(PT_R5*4)(r11)
	stw	r9,_UC_GREGS+(PT_R6*4)(r11)
	stw	r10,_UC_GREGS+(PT_R7*4)(r11)
	lwz	r8,8(r1)
	lwz	r9,12(r1)
	stw	r8,_UC_GREGS+(PT_R8*4)(r11)
	stw	r9,_UC_GREGS+(PT_R9*4)(r11)

	/* Set the NIP to the start of the function */
	stw	r4,_UC_GREGS+(PT_NIP*4)(r11)

	/* Set the function's r31 to ucp->uc_link for the exitcode below. */
	lwz	r7,_UC_LINK(r3)
	stw	r7,_UC_GREGS+(PT_R31*4)(r11)

	/* Set the function's LR to point to the exitcode below. */
#ifdef PIC
	mflr	r0
	cfi_register(lr,r0)
	/* Use this conditional form of branch and link to avoid destroying
	   the cpu link stack used to predict blr return addresses.  */
	bcl	20,31,1f
1:	mflr	r6
	addi	r6,r6,L(exitcode)-1b
	mtlr	r0
	cfi_same_value (lr)
#else
	lis	r6,L(exitcode)@ha
	addi	r6,r6,L(exitcode)@l
#endif
	stw	r6,_UC_GREGS+(PT_LNK*4)(r11)

	/*
	 * Set up the stack frame for the function.
	 * If we have more than 5 args to the function (8 args to makecontext),
	 * there will be some arguments on the stack which have to end up
	 * in registers.  If there are more than 8 args to the function,
	 * we have to copy (argc - 8) args from our stack to the functions'
	 * stack (and allow space for them in the frame).
	 */
	lwz	r4,_UC_STACK_SP(r3)
	lwz	r8,_UC_STACK_SIZE(r3)
	add	r4,r4,r8
	rlwinm	r4,r4,0,0,27	/* round down to 16-byte boundary */
	addi	r7,r4,-16	/* stack frame for fn's caller */
	cmpwi	r5,8
	blt	2f		/* less than 8 args is easy */
	lwz	r10,16(r1)
	stw	r10,_UC_GREGS+(PT_R10*4)(r11)
	beq	2f		/* if exactly 8 args */
	subi	r9,r5,3
	subi	r5,r5,8
	rlwinm	r9,r9,2,0,27
	subf	r7,r9,r4
	mtctr	r5		/* copy the 9th and following args */
	addi	r6,r1,16
	addi	r8,r7,4
3:	lwzu	r10,4(r6)
	stwu	r10,4(r8)
	bdnz	3b
2:	stw	r7,_UC_GREGS+(PT_R1*4)(r11)
	li	r6,0
	stw	r6,0(r7)

	blr

/*
 * If the function returns, it comes here.  We put ucp->uc_link in
 * r31, which is a callee-saved register.  We have to continue with
 * the context that r31 points to, or exit if it is 0.
 */
L(exitcode):
	mr.	r3,r31
	beq	4f
	bl	__setcontext@local
4:	bl	HIDDEN_JUMPTARGET(exit)
	b	4b

END(__makecontext)

versioned_symbol (libc, __makecontext, makecontext, GLIBC_2_3_4)

#if SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)

	compat_text_section
ENTRY(__novec_makecontext)
	/* Set up the first 7 args to the function in its registers */
	addi	r11,r3,_UC_REG_SPACE
	stw	r11,_UC_REGS_PTR(r3)
	stw	r6,_UC_GREGS+(PT_R3*4)(r11)
	stw	r7,_UC_GREGS+(PT_R4*4)(r11)
	stw	r8,_UC_GREGS+(PT_R5*4)(r11)
	stw	r9,_UC_GREGS+(PT_R6*4)(r11)
	stw	r10,_UC_GREGS+(PT_R7*4)(r11)
	lwz	r8,8(r1)
	lwz	r9,12(r1)
	stw	r8,_UC_GREGS+(PT_R8*4)(r11)
	stw	r9,_UC_GREGS+(PT_R9*4)(r11)

	/* Set the NIP to the start of the function */
	stw	r4,_UC_GREGS+(PT_NIP*4)(r11)

	/* Set the function's r31 to ucp->uc_link for the exitcode below. */
	lwz	r7,_UC_LINK(r3)
	stw	r7,_UC_GREGS+(PT_R31*4)(r11)

	/* Set the function's LR to point to the exitcode below. */
#ifdef PIC
	mflr	r0
	cfi_register(lr,r0)
	/* Use this conditional form of branch and link to avoid destroying
	   the cpu link stack used to predict blr return addresses.  */
	bcl	20,31,1f
1:	mflr	r6
	addi	r6,r6,L(novec_exitcode)-1b
	mtlr	r0
	cfi_same_value (lr)
#else
	lis	r6,L(novec_exitcode)@ha
	addi	r6,r6,L(novec_exitcode)@l
#endif
	stw	r6,_UC_GREGS+(PT_LNK*4)(r11)

	/*
	 * Set up the stack frame for the function.
	 * If we have more than 5 args to the function (8 args to makecontext),
	 * there will be some arguments on the stack which have to end up
	 * in registers.  If there are more than 8 args to the function,
	 * we have to copy (argc - 8) args from our stack to the functions'
	 * stack (and allow space for them in the frame).
	 */
	lwz	r4,_UC_STACK_SP(r3)
	lwz	r8,_UC_STACK_SIZE(r3)
	add	r4,r4,r8
	rlwinm	r4,r4,0,0,27	/* round down to 16-byte boundary */
	addi	r7,r4,-16	/* stack frame for fn's caller */
	cmpwi	r5,8
	blt	2f		/* less than 8 args is easy */
	lwz	r10,16(r1)
	stw	r10,_UC_GREGS+(PT_R10*4)(r11)
	beq	2f		/* if exactly 8 args */
	subi	r9,r5,3
	subi	r5,r5,8
	rlwinm	r9,r9,2,0,27
	subf	r7,r9,r4
	mtctr	r5		/* copy the 9th and following args */
	addi	r6,r1,16
	addi	r8,r7,4
3:	lwzu	r10,4(r6)
	stwu	r10,4(r8)
	bdnz	3b
2:	stw	r7,_UC_GREGS+(PT_R1*4)(r11)
	li	r6,0
	stw	r6,0(r7)

	blr

/*
 * If the function returns, it comes here.  We put ucp->uc_link in
 * r31, which is a callee-saved register.  We have to continue with
 * the context that r31 points to, or exit if it is 0.
 */
L(novec_exitcode):
	mr.	r3,r31
	beq	4f
	bl	__novec_setcontext@local
4:	bl	HIDDEN_JUMPTARGET(exit)
	b	4b

END(__novec_makecontext)
	.previous

compat_symbol (libc, __novec_makecontext, makecontext, GLIBC_2_3_3)
#endif

#if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_3_3)

#define _ERRNO_H	1
#include <bits/errno.h>

	compat_text_section
ENTRY (__makecontext_stub)
	li	r3,ENOSYS
	b	__syscall_error@local
END (__makecontext_stub)
	.previous

compat_symbol (libc, __makecontext_stub, makecontext, GLIBC_2_1)

#endif
Commit	Line	Data
aebcf54c	1	/* Set up a context to call a function.
d4697bc9	2	Copyright (C) 2002-2014 Free Software Foundation, Inc.
aebcf54c UD	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
59ba27a6 PE	16	License along with the GNU C Library; if not, see
59ba27a6 PE	17	<http://www.gnu.org/licenses/>. */
aebcf54c UD	18
aebcf54c UD	19	#include <sysdep.h>
54ee14b3	20	#include <shlib-compat.h>
aebcf54c UD	21
	22	#define __ASSEMBLY__
	23	#include <asm/ptrace.h>
	24	#include "ucontext_i.h"
	25
	26	ENTRY(__makecontext)
	27	/* Set up the first 7 args to the function in its registers */
a12dcecc	28	lwz r11,_UC_REGS_PTR(r3)
54ee14b3 UD	29	stw r6,_UC_GREGS+(PT_R3*4)(r11)
	30	stw r7,_UC_GREGS+(PT_R4*4)(r11)
	31	stw r8,_UC_GREGS+(PT_R5*4)(r11)
	32	stw r9,_UC_GREGS+(PT_R6*4)(r11)
	33	stw r10,_UC_GREGS+(PT_R7*4)(r11)
aebcf54c UD	34	lwz r8,8(r1)
aebcf54c UD	35	lwz r9,12(r1)
54ee14b3 UD	36	stw r8,_UC_GREGS+(PT_R8*4)(r11)
54ee14b3 UD	37	stw r9,_UC_GREGS+(PT_R9*4)(r11)
aebcf54c UD	38
aebcf54c UD	39	/* Set the NIP to the start of the function */
54ee14b3	40	stw r4,_UC_GREGS+(PT_NIP*4)(r11)
aebcf54c UD	41
	42	/* Set the function's r31 to ucp->uc_link for the exitcode below. */
	43	lwz r7,_UC_LINK(r3)
54ee14b3	44	stw r7,_UC_GREGS+(PT_R31*4)(r11)
aebcf54c UD	45
	46	/* Set the function's LR to point to the exitcode below. */
	47	#ifdef PIC
	48	mflr r0
a7e91561	49	cfi_register(lr,r0)
0b2c2ace AM	50	/* Use this conditional form of branch and link to avoid destroying
	51	the cpu link stack used to predict blr return addresses. */
	52	bcl 20,31,1f
aebcf54c UD	53	1: mflr r6
	54	addi r6,r6,L(exitcode)-1b
	55	mtlr r0
a7e91561	56	cfi_same_value (lr)
aebcf54c UD	57	#else
	58	lis r6,L(exitcode)@ha
	59	addi r6,r6,L(exitcode)@l
	60	#endif
54ee14b3	61	stw r6,_UC_GREGS+(PT_LNK*4)(r11)
aebcf54c UD	62
	63	/*
	64	* Set up the stack frame for the function.
	65	* If we have more than 5 args to the function (8 args to makecontext),
	66	* there will be some arguments on the stack which have to end up
	67	* in registers. If there are more than 8 args to the function,
	68	* we have to copy (argc - 8) args from our stack to the functions'
	69	* stack (and allow space for them in the frame).
	70	*/
	71	lwz r4,_UC_STACK_SP(r3)
	72	lwz r8,_UC_STACK_SIZE(r3)
	73	add r4,r4,r8
	74	rlwinm r4,r4,0,0,27 /* round down to 16-byte boundary */
	75	addi r7,r4,-16 /* stack frame for fn's caller */
	76	cmpwi r5,8
	77	blt 2f /* less than 8 args is easy */
	78	lwz r10,16(r1)
54ee14b3	79	stw r10,_UC_GREGS+(PT_R10*4)(r11)
aebcf54c UD	80	beq 2f /* if exactly 8 args */
	81	subi r9,r5,3
	82	subi r5,r5,8
	83	rlwinm r9,r9,2,0,27
	84	subf r7,r9,r4
	85	mtctr r5 /* copy the 9th and following args */
	86	addi r6,r1,16
	87	addi r8,r7,4
	88	3: lwzu r10,4(r6)
	89	stwu r10,4(r8)
	90	bdnz 3b
54ee14b3	91	2: stw r7,_UC_GREGS+(PT_R1*4)(r11)
aebcf54c UD	92	li r6,0
	93	stw r6,0(r7)
	94
	95	blr
	96
	97	/*
	98	* If the function returns, it comes here. We put ucp->uc_link in
	99	* r31, which is a callee-saved register. We have to continue with
	100	* the context that r31 points to, or exit if it is 0.
	101	*/
	102	L(exitcode):
	103	mr. r3,r31
	104	beq 4f
b0e196a4	105	bl __setcontext@local
aebcf54c UD	106	4: bl HIDDEN_JUMPTARGET(exit)
	107	b 4b
	108
	109	END(__makecontext)
54ee14b3	110
5ef6ae4b UD	111	versioned_symbol (libc, __makecontext, makecontext, GLIBC_2_3_4)
	112
	113	#if SHLIB_COMPAT (libc, GLIBC_2_3_3, GLIBC_2_3_4)
	114
d3a4a571	115	compat_text_section
5ef6ae4b UD	116	ENTRY(__novec_makecontext)
	117	/* Set up the first 7 args to the function in its registers */
	118	addi r11,r3,_UC_REG_SPACE
	119	stw r11,_UC_REGS_PTR(r3)
	120	stw r6,_UC_GREGS+(PT_R3*4)(r11)
	121	stw r7,_UC_GREGS+(PT_R4*4)(r11)
	122	stw r8,_UC_GREGS+(PT_R5*4)(r11)
	123	stw r9,_UC_GREGS+(PT_R6*4)(r11)
	124	stw r10,_UC_GREGS+(PT_R7*4)(r11)
	125	lwz r8,8(r1)
	126	lwz r9,12(r1)
	127	stw r8,_UC_GREGS+(PT_R8*4)(r11)
	128	stw r9,_UC_GREGS+(PT_R9*4)(r11)
	129
	130	/* Set the NIP to the start of the function */
	131	stw r4,_UC_GREGS+(PT_NIP*4)(r11)
	132
	133	/* Set the function's r31 to ucp->uc_link for the exitcode below. */
	134	lwz r7,_UC_LINK(r3)
	135	stw r7,_UC_GREGS+(PT_R31*4)(r11)
	136
	137	/* Set the function's LR to point to the exitcode below. */
	138	#ifdef PIC
	139	mflr r0
a7e91561	140	cfi_register(lr,r0)
0b2c2ace AM	141	/* Use this conditional form of branch and link to avoid destroying
	142	the cpu link stack used to predict blr return addresses. */
	143	bcl 20,31,1f
5ef6ae4b UD	144	1: mflr r6
	145	addi r6,r6,L(novec_exitcode)-1b
	146	mtlr r0
a7e91561	147	cfi_same_value (lr)
5ef6ae4b UD	148	#else
	149	lis r6,L(novec_exitcode)@ha
	150	addi r6,r6,L(novec_exitcode)@l
	151	#endif
	152	stw r6,_UC_GREGS+(PT_LNK*4)(r11)
	153
	154	/*
	155	* Set up the stack frame for the function.
	156	* If we have more than 5 args to the function (8 args to makecontext),
	157	* there will be some arguments on the stack which have to end up
	158	* in registers. If there are more than 8 args to the function,
	159	* we have to copy (argc - 8) args from our stack to the functions'
	160	* stack (and allow space for them in the frame).
	161	*/
	162	lwz r4,_UC_STACK_SP(r3)
	163	lwz r8,_UC_STACK_SIZE(r3)
	164	add r4,r4,r8
	165	rlwinm r4,r4,0,0,27 /* round down to 16-byte boundary */
	166	addi r7,r4,-16 /* stack frame for fn's caller */
	167	cmpwi r5,8
	168	blt 2f /* less than 8 args is easy */
	169	lwz r10,16(r1)
	170	stw r10,_UC_GREGS+(PT_R10*4)(r11)
	171	beq 2f /* if exactly 8 args */
	172	subi r9,r5,3
	173	subi r5,r5,8
	174	rlwinm r9,r9,2,0,27
	175	subf r7,r9,r4
	176	mtctr r5 /* copy the 9th and following args */
	177	addi r6,r1,16
	178	addi r8,r7,4
	179	3: lwzu r10,4(r6)
	180	stwu r10,4(r8)
	181	bdnz 3b
	182	2: stw r7,_UC_GREGS+(PT_R1*4)(r11)
	183	li r6,0
	184	stw r6,0(r7)
	185
	186	blr
	187
	188	/*
	189	* If the function returns, it comes here. We put ucp->uc_link in
	190	* r31, which is a callee-saved register. We have to continue with
	191	* the context that r31 points to, or exit if it is 0.
	192	*/
	193	L(novec_exitcode):
	194	mr. r3,r31
	195	beq 4f
b0e196a4	196	bl __novec_setcontext@local
5ef6ae4b UD	197	4: bl HIDDEN_JUMPTARGET(exit)
	198	b 4b
	199
d3a4a571 UD	200	END(__novec_makecontext)
d3a4a571 UD	201	.previous
5ef6ae4b UD	202
	203	compat_symbol (libc, __novec_makecontext, makecontext, GLIBC_2_3_3)
	204	#endif
54ee14b3 UD	205
	206	#if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_3_3)
	207
	208	#define _ERRNO_H 1
	209	#include <bits/errno.h>
	210
d3a4a571	211	compat_text_section
54ee14b3 UD	212	ENTRY (__makecontext_stub)
54ee14b3 UD	213	li r3,ENOSYS
b0e196a4	214	b __syscall_error@local
d3a4a571 UD	215	END (__makecontext_stub)
d3a4a571 UD	216	.previous
54ee14b3 UD	217
	218	compat_symbol (libc, __makecontext_stub, makecontext, GLIBC_2_1)
	219
	220	#endif