xref: /titanic_41/usr/src/lib/libc/i386/sys/door.s (revision dbed73cbda2229fd1aa6dc5743993cae7f0a7ee9)
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27	.file	"door.s"
28
29#include "SYS.h"
30#include <sys/door.h>
31
32	/*
33	 * weak aliases for public interfaces
34	 */
35	ANSI_PRAGMA_WEAK2(door_bind,__door_bind,function)
36	ANSI_PRAGMA_WEAK2(door_getparam,__door_getparam,function)
37	ANSI_PRAGMA_WEAK2(door_info,__door_info,function)
38	ANSI_PRAGMA_WEAK2(door_revoke,__door_revoke,function)
39	ANSI_PRAGMA_WEAK2(door_setparam,__door_setparam,function)
40	ANSI_PRAGMA_WEAK2(door_unbind,__door_unbind,function)
41
42/*
43 * Offsets within struct door_results
44 */
45#define	DOOR_COOKIE	_MUL(0, CLONGSIZE)
46#define	DOOR_DATA_PTR	_MUL(1, CLONGSIZE)
47#define	DOOR_DATA_SIZE	_MUL(2, CLONGSIZE)
48#define	DOOR_DESC_PTR	_MUL(3, CLONGSIZE)
49#define	DOOR_DESC_SIZE	_MUL(4, CLONGSIZE)
50#define	DOOR_PC		_MUL(5, CLONGSIZE)
51#define	DOOR_SERVERS	_MUL(6, CLONGSIZE)
52#define	DOOR_INFO_PTR	_MUL(7, CLONGSIZE)
53
54/*
55 * All of the syscalls except door_return() follow the same pattern.
56 * The subcode goes in argument 6, which means we have to copy our
57 * arguments into a new bit of stack, large enough to include the
58 * subcode.  We fill the unused positions with zeros.
59 */
60#define	DOOR_SYSCALL(name, code, copy_args)				\
61	ENTRY(name);							\
62	pushl	%ebp;							\
63	movl	%esp, %ebp;						\
64	pushl	$code;		/* syscall subcode, arg 6 */		\
65	pushl	$0;		/* dummy arg 5 */			\
66	pushl	$0;		/* dummy arg 4 */			\
67	copy_args;		/* args 1, 2, 3 */			\
68	pushl	$0;		/* dummy return PC */			\
69	SYSTRAP_RVAL1(door);						\
70	jae	1f;							\
71	addl	$28, %esp;						\
72	leave;								\
73	jmp	__cerror;						\
741:									\
75	addl	$28, %esp;						\
76	leave;								\
77	ret;								\
78	SET_SIZE(name)
79
80#define	COPY_0								\
81	pushl	$0;		/* dummy */				\
82	pushl	$0;		/* dummy */				\
83	pushl	$0		/* dummy */
84
85#define	COPY_1								\
86	pushl	$0;		/* dummy */				\
87	pushl	$0;		/* dummy */				\
88	pushl	8(%ebp)		/* 1 */
89
90#define	COPY_2								\
91	pushl	$0;		/* dummy */				\
92	pushl	12(%ebp);	/* 2 */					\
93	pushl	8(%ebp)		/* 1 */
94
95#define	COPY_3								\
96	pushl	16(%ebp);	/* 3 */					\
97	pushl	12(%ebp);	/* 2 */					\
98	pushl	8(%ebp)		/* 1 */
99
100	DOOR_SYSCALL(__door_bind,	DOOR_BIND,	COPY_1)
101	DOOR_SYSCALL(__door_call,	DOOR_CALL,	COPY_2)
102	DOOR_SYSCALL(__door_create,	DOOR_CREATE,	COPY_3)
103	DOOR_SYSCALL(__door_getparam,	DOOR_GETPARAM,	COPY_3)
104	DOOR_SYSCALL(__door_info,	DOOR_INFO,	COPY_2)
105	DOOR_SYSCALL(__door_revoke,	DOOR_REVOKE,	COPY_1)
106	DOOR_SYSCALL(__door_setparam,	DOOR_SETPARAM,	COPY_3)
107	DOOR_SYSCALL(__door_ucred,	DOOR_UCRED,	COPY_1)
108	DOOR_SYSCALL(__door_unbind,	DOOR_UNBIND,	COPY_0)
109	DOOR_SYSCALL(__door_unref,	DOOR_UNREFSYS,	COPY_0)
110
111/*
112 * int
113 * __door_return(
114 *	void 			*data_ptr,
115 *	size_t			data_size,	(in bytes)
116 *	door_return_desc_t	*door_ptr,	(holds returned desc info)
117 *	caddr_t			stack_base,
118 *	size_t			stack_size)
119 */
120	ENTRY(__door_return)
121	movl	%esp, %edx		/ Save pointer to args
122
123	pushl	%edi			/ save old %edi and %esi
124	pushl	%esi			/ and use them to hold the
125	movl	16(%edx), %esi		/ stack pointer and
126	movl	20(%edx), %edi		/ size.
127
128	pushl	$DOOR_RETURN		/ syscall subcode
129	pushl	%edi			/ size of user stack
130	pushl	%esi			/ base of user stack
131	pushl	12(%edx)		/ desc arguments ptr
132	pushl	8(%edx)			/ data size
133	pushl	4(%edx)			/ data ptr
134	pushl	0(%edx)			/ dummy return PC
135
136door_restart:
137	SYSTRAP_RVAL1(door)
138	jb	2f			/* errno is set */
139	/*
140	 * On return, we're serving a door_call.  Our stack looks like this:
141	 *
142	 *		descriptors (if any)
143	 *		data (if any)
144	 *	 sp->	struct door_results
145	 *
146	 * struct door_results has the arguments in place for the server proc,
147	 * so we just call it directly.
148	 */
149	movl	DOOR_SERVERS(%esp), %eax
150	andl	%eax, %eax	/* test nservers */
151	jg	1f
152	/*
153	 * this is the last server thread - call creation func for more
154	 */
155	movl	DOOR_INFO_PTR(%esp), %eax
156	_prologue_
157	pushl	%eax		/* door_info_t * */
158	movl	_daref_(door_server_func), %eax
159	movl	0(%eax), %eax
160	call	*%eax		/* call create function */
161	addl	$4, %esp
162	_epilogue_
1631:
164	/* Call the door server function now */
165	movl	DOOR_PC(%esp), %eax
166	call	*%eax
167	/* Exit the thread if we return here */
168	pushl	$0
169	call	_thrp_terminate
170	/* NOTREACHED */
1712:
172	/*
173	 * Error during door_return call.  Repark the thread in the kernel if
174	 * the error code is EINTR (or ERESTART) and this lwp is still part
175	 * of the same process.
176	 *
177	 * If the error code is EINTR or ERESTART, our stack may have been
178	 * corrupted by a partial door call, so we refresh the system call
179	 * arguments.
180	 */
181	cmpl	$ERESTART, %eax		/* ERESTART is same as EINTR */
182	jne	3f
183	movl	$EINTR, %eax
1843:
185	cmpl	$EINTR, %eax		/* interrupted while waiting? */
186	jne	4f			/* if not, return the error */
187	_prologue_
188	call	getpid
189	movl	_daref_(door_create_pid), %edx
190	movl	0(%edx), %edx
191	_epilogue_
192	cmpl	%eax, %edx		/* same process? */
193	movl	$EINTR, %eax	/* if no, return EINTR (child of forkall) */
194	jne	4f
195
196	movl	$0, 4(%esp)		/* clear arguments and restart */
197	movl	$0, 8(%esp)
198	movl	$0, 12(%esp)
199	movl	%esi, 16(%esp)		/* refresh sp */
200	movl	%edi, 20(%esp)		/* refresh ssize */
201	movl	$DOOR_RETURN, 24(%esp)	/* refresh syscall subcode */
202	jmp	door_restart
2034:
204	/* Something bad happened during the door_return */
205	addl	$28, %esp
206	popl	%esi
207	popl	%edi
208	jmp	__cerror
209	SET_SIZE(__door_return)
210