[apple/libc.git] / i386 / sys / setjmp.s

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
 */
/*
 * NeXT 386 setjmp/longjmp
 *
 * Written by Bruce Martin, NeXT Inc. 4/9/92
 */

/*
 * C library -- setjmp, longjmp
 *
 *	longjmp(a,v)
 * will generate a "return(v)" from
 * the last call to
 *	setjmp(a)
 * by restoring registers from the stack,
 * The previous value of the signal mask is
 * restored.
 *
 */

#include <architecture/i386/asm_help.h>
#include "SYS.h"

#define JB_ONSTACK	0
#define JB_MASK		4
#define JB_EAX		8
#define JB_EBX		12
#define JB_ECX		16
#define JB_EDX		20
#define JB_EDI		24
#define JB_ESI		28
#define JB_EBP		32
#define JB_ESP		36
#define JB_SS		40
#define JB_EFLAGS	44
#define JB_EIP		48
#define JB_CS		52
#define JB_DS		56
#define JB_ES		60
#define JB_FS		64
#define JB_GS		68
#define JB_SAVEMASK	72	// sigsetjmp/siglongjmp only

LEAF(_sigsetjmp, 0)
	movl	4(%esp), %eax 		// sigjmp_buf * jmpbuf; 
	movl	8(%esp), %ecx		// int savemask;
	movl	%ecx, JB_SAVEMASK(%eax)	// jmpbuf[_JBLEN] = savemask;
	cmpl	$0, %ecx		// if savemask != 0
	jne	_setjmp			//     setjmp(jmpbuf); 
	BRANCH_EXTERN(__setjmp)		// else
					//     _setjmp(jmpbuf); 
	
LEAF(_setjmp, 0)
	movl	4(%esp), %ecx		// jmp_buf (struct sigcontext *)
	pushl	%ecx			// save ecx

	// call sigstack to get the current signal stack
	subl	$12, %esp		// space for return structure
	pushl	%esp
	pushl	$0
	CALL_EXTERN(_sigaltstack)
	movl	12(%esp), %eax		// save stack pointer
	movl	%eax, JB_ONSTACK(%ecx)
	addl	$20, %esp

	// call sigblock to get signal mask
	pushl	$0
	CALL_EXTERN(_sigblock)
	addl	$4, %esp
	popl	%ecx			// restore ecx
	movl	%eax, JB_MASK(%ecx)

	// now build sigcontext
	movl	%ebx, JB_EBX(%ecx)
	movl	%edi, JB_EDI(%ecx)
	movl	%esi, JB_ESI(%ecx)
	movl	%ebp, JB_EBP(%ecx)

	// EIP is set to the frame return address value
	movl	(%esp), %eax
	movl	%eax, JB_EIP(%ecx)
	// ESP is set to the frame return address plus 4
	movl	%esp, %eax
	addl	$4, %eax
	movl	%eax, JB_ESP(%ecx)

	// segment registers
	movl	$0,  JB_SS(%ecx)
	mov	%ss, JB_SS(%ecx)
	movl	$0,  JB_CS(%ecx)
	mov	%cs, JB_CS(%ecx)
	movl	$0,  JB_DS(%ecx)
	mov	%ds, JB_DS(%ecx)
	movl	$0,  JB_ES(%ecx)
	mov	%es, JB_ES(%ecx)
	movl	$0,  JB_FS(%ecx)
	mov	%fs, JB_FS(%ecx)
	movl	$0,  JB_GS(%ecx)
	mov	%gs, JB_GS(%ecx)

	// save eflags - you can't use movl
	pushf
	popl	%eax
	movl	%eax, JB_EFLAGS(%ecx)

	// return 0
	xorl	%eax, %eax
	ret

LEAF(_siglongjmp, 0)
	movl 4(%esp), %eax		// sigjmp_buf * jmpbuf; 
	cmpl $0, JB_SAVEMASK(%eax)	// if jmpbuf[_JBLEN] != 0
	jne 	_longjmp		//     longjmp(jmpbuf, var); 
	BRANCH_EXTERN(__longjmp)	// else
					//     _longjmp(jmpbuf, var); 
	
LEAF(_longjmp, 0)
	subl	$2,%esp
	fnstcw	(%esp)			// save FP control word
	fninit				// reset FP coprocessor
	fldcw	(%esp)			// restore FP control word
	addl	$2,%esp
	movl	4(%esp), %eax		// address of jmp_buf (saved context)
	movl	8(%esp), %edx		// return value
	movl	%edx, JB_EAX(%eax)	// return value into saved context
	movl	$ SYS_sigreturn, %eax	// sigreturn system call
	UNIX_SYSCALL_TRAP
	addl	$8, %esp
	CALL_EXTERN(_longjmperror)
	CALL_EXTERN(_abort)
END(_longjmp)
Commit	Line	Data
e9ce8d39 A	1	/*
	2	* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
734aad71	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
e9ce8d39	7	*
734aad71 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
e9ce8d39 A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
e9ce8d39 A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
734aad71 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
e9ce8d39 A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/*
	26	* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
	27	*/
	28	/*
	29	* NeXT 386 setjmp/longjmp
	30	*
	31	* Written by Bruce Martin, NeXT Inc. 4/9/92
	32	*/
	33
	34	/*
	35	* C library -- setjmp, longjmp
	36	*
	37	* longjmp(a,v)
	38	* will generate a "return(v)" from
	39	* the last call to
	40	* setjmp(a)
	41	* by restoring registers from the stack,
	42	* The previous value of the signal mask is
	43	* restored.
	44	*
	45	*/
	46
	47	#include <architecture/i386/asm_help.h>
	48	#include "SYS.h"
	49
	50	#define JB_ONSTACK 0
	51	#define JB_MASK 4
	52	#define JB_EAX 8
	53	#define JB_EBX 12
	54	#define JB_ECX 16
	55	#define JB_EDX 20
	56	#define JB_EDI 24
	57	#define JB_ESI 28
	58	#define JB_EBP 32
	59	#define JB_ESP 36
	60	#define JB_SS 40
	61	#define JB_EFLAGS 44
	62	#define JB_EIP 48
	63	#define JB_CS 52
	64	#define JB_DS 56
	65	#define JB_ES 60
	66	#define JB_FS 64
	67	#define JB_GS 68
	68	#define JB_SAVEMASK 72 // sigsetjmp/siglongjmp only
	69
	70	LEAF(_sigsetjmp, 0)
	71	movl 4(%esp), %eax // sigjmp_buf * jmpbuf;
	72	movl 8(%esp), %ecx // int savemask;
	73	movl %ecx, JB_SAVEMASK(%eax) // jmpbuf[_JBLEN] = savemask;
	74	cmpl $0, %ecx // if savemask != 0
	75	jne _setjmp // setjmp(jmpbuf);
	76	BRANCH_EXTERN(__setjmp) // else
	77	// _setjmp(jmpbuf);
	78
	79	LEAF(_setjmp, 0)
	80	movl 4(%esp), %ecx // jmp_buf (struct sigcontext *)
	81	pushl %ecx // save ecx
	82
	83	// call sigstack to get the current signal stack
	84	subl $12, %esp // space for return structure
	85	pushl %esp
86	pushl $0
87	CALL_EXTERN(_sigaltstack)
88	movl 12(%esp), %eax // save stack pointer
89	movl %eax, JB_ONSTACK(%ecx)
90	addl $20, %esp
91
92	// call sigblock to get signal mask
93	pushl $0
94	CALL_EXTERN(_sigblock)
95	addl $4, %esp
96	popl %ecx // restore ecx
97	movl %eax, JB_MASK(%ecx)
98
99	// now build sigcontext
100	movl %ebx, JB_EBX(%ecx)
101	movl %edi, JB_EDI(%ecx)
102	movl %esi, JB_ESI(%ecx)
103	movl %ebp, JB_EBP(%ecx)
104
105	// EIP is set to the frame return address value
106	movl (%esp), %eax
107	movl %eax, JB_EIP(%ecx)
108	// ESP is set to the frame return address plus 4
109	movl %esp, %eax
110	addl $4, %eax
111	movl %eax, JB_ESP(%ecx)
112
113	// segment registers
114	movl $0, JB_SS(%ecx)
115	mov %ss, JB_SS(%ecx)
116	movl $0, JB_CS(%ecx)
117	mov %cs, JB_CS(%ecx)
118	movl $0, JB_DS(%ecx)
119	mov %ds, JB_DS(%ecx)
120	movl $0, JB_ES(%ecx)
121	mov %es, JB_ES(%ecx)
122	movl $0, JB_FS(%ecx)
123	mov %fs, JB_FS(%ecx)
124	movl $0, JB_GS(%ecx)
125	mov %gs, JB_GS(%ecx)
126
127	// save eflags - you can't use movl
128	pushf
129	popl %eax
130	movl %eax, JB_EFLAGS(%ecx)
131
132	// return 0
133	xorl %eax, %eax
134	ret
135
136	LEAF(_siglongjmp, 0)
137	movl 4(%esp), %eax // sigjmp_buf * jmpbuf;
138	cmpl $0, JB_SAVEMASK(%eax) // if jmpbuf[_JBLEN] != 0
139	jne _longjmp // longjmp(jmpbuf, var);
140	BRANCH_EXTERN(__longjmp) // else
141	// _longjmp(jmpbuf, var);
142
143	LEAF(_longjmp, 0)
144	subl $2,%esp
145	fnstcw (%esp) // save FP control word
146	fninit // reset FP coprocessor
147	fldcw (%esp) // restore FP control word
148	addl $2,%esp
149	movl 4(%esp), %eax // address of jmp_buf (saved context)
150	movl 8(%esp), %edx // return value
151	movl %edx, JB_EAX(%eax) // return value into saved context
5b2abdfb	152	movl $ SYS_sigreturn, %eax // sigreturn system call
e9ce8d39 A	153	UNIX_SYSCALL_TRAP
	154	addl $8, %esp
	155	CALL_EXTERN(_longjmperror)
	156	CALL_EXTERN(_abort)
	157	END(_longjmp)