xref: /titanic_41/usr/src/lib/libc/i386/sys/door.s (revision 49b225e1cfa7bbf7738d4df0a03f18e3283426eb)
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 2009 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
41/*
42 * Offsets within struct door_results
43 */
44#define	DOOR_COOKIE	_MUL(0, CLONGSIZE)
45#define	DOOR_DATA_PTR	_MUL(1, CLONGSIZE)
46#define	DOOR_DATA_SIZE	_MUL(2, CLONGSIZE)
47#define	DOOR_DESC_PTR	_MUL(3, CLONGSIZE)
48#define	DOOR_DESC_SIZE	_MUL(4, CLONGSIZE)
49#define	DOOR_PC		_MUL(5, CLONGSIZE)
50#define	DOOR_SERVERS	_MUL(6, CLONGSIZE)
51#define	DOOR_INFO_PTR	_MUL(7, CLONGSIZE)
52
53/*
54 * All of the syscalls except door_return() follow the same pattern.
55 * The subcode goes in argument 6, which means we have to copy our
56 * arguments into a new bit of stack, large enough to include the
57 * subcode.  We fill the unused positions with zeros.
58 */
59#define	DOOR_SYSCALL(name, code, copy_args)				\
60	ENTRY(name);							\
61	pushl	%ebp;							\
62	movl	%esp, %ebp;						\
63	pushl	$code;		/* syscall subcode, arg 6 */		\
64	pushl	$0;		/* dummy arg 5 */			\
65	pushl	$0;		/* dummy arg 4 */			\
66	copy_args;		/* args 1, 2, 3 */			\
67	pushl	$0;		/* dummy return PC */			\
68	SYSTRAP_RVAL1(door);						\
69	jae	1f;							\
70	addl	$28, %esp;						\
71	leave;								\
72	jmp	__cerror;						\
731:									\
74	addl	$28, %esp;						\
75	leave;								\
76	ret;								\
77	SET_SIZE(name)
78
79#define	COPY_0								\
80	pushl	$0;		/* dummy */				\
81	pushl	$0;		/* dummy */				\
82	pushl	$0		/* dummy */
83
84#define	COPY_1								\
85	pushl	$0;		/* dummy */				\
86	pushl	$0;		/* dummy */				\
87	pushl	8(%ebp)		/* 1 */
88
89#define	COPY_2								\
90	pushl	$0;		/* dummy */				\
91	pushl	12(%ebp);	/* 2 */					\
92	pushl	8(%ebp)		/* 1 */
93
94#define	COPY_3								\
95	pushl	16(%ebp);	/* 3 */					\
96	pushl	12(%ebp);	/* 2 */					\
97	pushl	8(%ebp)		/* 1 */
98
99	DOOR_SYSCALL(__door_bind,	DOOR_BIND,	COPY_1)
100	DOOR_SYSCALL(__door_call,	DOOR_CALL,	COPY_2)
101	DOOR_SYSCALL(__door_create,	DOOR_CREATE,	COPY_3)
102	DOOR_SYSCALL(__door_getparam,	DOOR_GETPARAM,	COPY_3)
103	DOOR_SYSCALL(__door_info,	DOOR_INFO,	COPY_2)
104	DOOR_SYSCALL(__door_revoke,	DOOR_REVOKE,	COPY_1)
105	DOOR_SYSCALL(__door_setparam,	DOOR_SETPARAM,	COPY_3)
106	DOOR_SYSCALL(__door_ucred,	DOOR_UCRED,	COPY_1)
107	DOOR_SYSCALL(__door_unbind,	DOOR_UNBIND,	COPY_0)
108	DOOR_SYSCALL(__door_unref,	DOOR_UNREFSYS,	COPY_0)
109
110/*
111 * int
112 * __door_return(
113 *	void 			*data_ptr,
114 *	size_t			data_size,	(in bytes)
115 *	door_return_desc_t	*door_ptr,	(holds returned desc info)
116 *	caddr_t			stack_base,
117 *	size_t			stack_size)
118 */
119	ENTRY(__door_return)
120	movl	%esp, %edx		/ Save pointer to args
121
122	pushl	%edi			/ save old %edi and %esi
123	pushl	%esi			/ and use them to hold the
124	movl	16(%edx), %esi		/ stack pointer and
125	movl	20(%edx), %edi		/ size.
126
127	pushl	$DOOR_RETURN		/ syscall subcode
128	pushl	%edi			/ size of user stack
129	pushl	%esi			/ base of user stack
130	pushl	12(%edx)		/ desc arguments ptr
131	pushl	8(%edx)			/ data size
132	pushl	4(%edx)			/ data ptr
133	pushl	0(%edx)			/ dummy return PC
134
135door_restart:
136	SYSTRAP_RVAL1(door)
137	jb	2f			/* errno is set */
138	/*
139	 * On return, we're serving a door_call.  Our stack looks like this:
140	 *
141	 *		descriptors (if any)
142	 *		data (if any)
143	 *	 sp->	struct door_results
144	 *
145	 * struct door_results has the arguments in place for the server proc,
146	 * so we just call it directly.
147	 */
148	movl	DOOR_SERVERS(%esp), %eax
149	andl	%eax, %eax	/* test nservers */
150	jg	1f
151	/*
152	 * this is the last server thread - call creation func for more
153	 */
154	movl	DOOR_INFO_PTR(%esp), %eax
155	pushl	%eax		/* door_info_t * */
156	call	door_depletion_cb@PLT
157	addl	$4, %esp
1581:
159	/* Call the door server function now */
160	movl	DOOR_PC(%esp), %eax
161	call	*%eax
162	/* Exit the thread if we return here */
163	pushl	$0
164	call	_thrp_terminate
165	/* NOTREACHED */
1662:
167	/*
168	 * Error during door_return call.  Repark the thread in the kernel if
169	 * the error code is EINTR (or ERESTART) and this lwp is still part
170	 * of the same process.
171	 *
172	 * If the error code is EINTR or ERESTART, our stack may have been
173	 * corrupted by a partial door call, so we refresh the system call
174	 * arguments.
175	 */
176	cmpl	$ERESTART, %eax		/* ERESTART is same as EINTR */
177	jne	3f
178	movl	$EINTR, %eax
1793:
180	cmpl	$EINTR, %eax		/* interrupted while waiting? */
181	jne	4f			/* if not, return the error */
182	_prologue_
183	call	getpid
184	movl	_daref_(door_create_pid), %edx
185	movl	0(%edx), %edx
186	_epilogue_
187	cmpl	%eax, %edx		/* same process? */
188	movl	$EINTR, %eax	/* if no, return EINTR (child of forkall) */
189	jne	4f
190	movl	$0, 4(%esp)		/* clear arguments and restart */
191	movl	$0, 8(%esp)
192	movl	$0, 12(%esp)
193	movl	%esi, 16(%esp)		/* refresh sp */
194	movl	%edi, 20(%esp)		/* refresh ssize */
195	movl	$DOOR_RETURN, 24(%esp)	/* refresh syscall subcode */
196	jmp	door_restart
1974:
198	/* Something bad happened during the door_return */
199	addl	$28, %esp
200	popl	%esi
201	popl	%edi
202	jmp	__cerror
203	SET_SIZE(__door_return)
204