xref: /illumos-gate/usr/src/lib/libc/amd64/inc/SYS.h (revision 7257d1b4)
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 #ifndef	_LIBC_AMD64_INC_SYS_H
28 #define	_LIBC_AMD64_INC_SYS_H
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * This file defines common code sequences for system calls.
34  */
35 #include <sys/asm_linkage.h>
36 #include <sys/syscall.h>
37 #include <sys/errno.h>
38 
39 #define	_fref_(name)	name@PLT
40 #define	_daref_(name)	name@GOTPCREL(%rip)
41 #define	_sref_(name)	name(%rip)
42 
43 /*
44  * Define the external symbol __cerror for all files.
45  */
46 	.globl	__cerror
47 
48 /*
49  * __SYSCALL provides the basic trap sequence.  It assumes that
50  * an entry of the form SYS_name exists (from sys/syscall.h).
51  * Note that %rcx is smashed by the syscall instruction,
52  * so we move it to %r10 in order to pass it to the kernel.
53  */
54 #define	__SYSCALL(name)			\
55 	movq	%rcx, %r10;		\
56 	/* CSTYLED */			\
57 	movl	$SYS_/**/name, %eax;	\
58 	syscall
59 
60 #define	SYSTRAP_RVAL1(name)	__SYSCALL(name)
61 #define	SYSTRAP_RVAL2(name)	__SYSCALL(name)
62 #define	SYSTRAP_2RVALS(name)	__SYSCALL(name)
63 #define	SYSTRAP_64RVAL(name)	__SYSCALL(name)
64 
65 /*
66  * SYSFASTTRAP provides the fast system call trap sequence.  It assumes
67  * that an entry of the form T_name exists (probably from sys/trap.h).
68  */
69 #define	SYSFASTTRAP(name)		\
70 	/* CSTYLED */			\
71 	movl	$T_/**/name, %eax;	\
72 	int	$T_FASTTRAP
73 
74 /*
75  * SYSCERROR provides the sequence to branch to __cerror if an error is
76  * indicated by the carry-bit being set upon return from a trap.
77  */
78 #define	SYSCERROR		\
79 	jb	__cerror
80 
81 /*
82  * SYSLWPERR provides the sequence to return 0 on a successful trap
83  * and the error code if unsuccessful.
84  * Error is indicated by the carry-bit being set upon return from a trap.
85  */
86 #define	SYSLWPERR			\
87 	jae	1f;			\
88 	cmpl	$ERESTART, %eax;	\
89 	jne	2f;			\
90 	movl	$EINTR, %eax;		\
91 	jmp	2f;			\
92 1:					\
93 	xorq	%rax, %rax;		\
94 2:
95 
96 /*
97  * SYSREENTRY provides the entry sequence for restartable system calls.
98  */
99 #define	SYSREENTRY(name)	\
100 	ENTRY(name);		\
101 1:
102 
103 /*
104  * SYSRESTART provides the error handling sequence for restartable
105  * system calls.
106  * XX64 -- Are all of the argument registers restored to their
107  * original values on an ERESTART return (including %rcx)?
108  */
109 #define	SYSRESTART(name)		\
110 	jae	1f;			\
111 	cmpl	$ERESTART, %eax;	\
112 	je	1b;			\
113 	jmp	__cerror;		\
114 1:
115 
116 /*
117  * SYSINTR_RESTART provides the error handling sequence for restartable
118  * system calls in case of EINTR or ERESTART.
119  */
120 #define	SYSINTR_RESTART(name)		\
121 	jae	1f;			\
122 	cmpl	$ERESTART, %eax;	\
123 	je	1b;			\
124 	cmpl	$EINTR, %eax;		\
125 	je	1b;			\
126 	jmp	2f;			\
127 1:					\
128 	xorq	%rax, %rax;		\
129 2:
130 
131 /*
132  * SYSCALL provides the standard (i.e.: most common) system call sequence.
133  */
134 #define	SYSCALL(name)			\
135 	ENTRY(name);			\
136 	SYSTRAP_2RVALS(name);		\
137 	SYSCERROR
138 
139 #define	SYSCALL_RVAL1(name)		\
140 	ENTRY(name);			\
141 	SYSTRAP_RVAL1(name);		\
142 	SYSCERROR
143 
144 /*
145  * SYSCALL64 provides the standard (i.e.: most common) system call sequence
146  * for system calls that return 64-bit values.
147  */
148 #define	SYSCALL64(name)			\
149 	SYSCALL(name)
150 
151 /*
152  * SYSCALL_RESTART provides the most common restartable system call sequence.
153  */
154 #define	SYSCALL_RESTART(name)		\
155 	SYSREENTRY(name);		\
156 	SYSTRAP_2RVALS(name);		\
157 	SYSRESTART()
158 
159 #define	SYSCALL_RESTART_RVAL1(name)	\
160 	SYSREENTRY(name);		\
161 	SYSTRAP_RVAL1(name);		\
162 	SYSRESTART()
163 
164 /*
165  * SYSCALL2 provides a common system call sequence when the entry name
166  * is different than the trap name.
167  */
168 #define	SYSCALL2(entryname, trapname)	\
169 	ENTRY(entryname);		\
170 	SYSTRAP_2RVALS(trapname);	\
171 	SYSCERROR
172 
173 #define	SYSCALL2_RVAL1(entryname, trapname)	\
174 	ENTRY(entryname);			\
175 	SYSTRAP_RVAL1(trapname);		\
176 	SYSCERROR
177 
178 /*
179  * SYSCALL2_RESTART provides a common restartable system call sequence when the
180  * entry name is different than the trap name.
181  */
182 #define	SYSCALL2_RESTART(entryname, trapname)	\
183 	SYSREENTRY(entryname);			\
184 	SYSTRAP_2RVALS(trapname);		\
185 	SYSRESTART()
186 
187 #define	SYSCALL2_RESTART_RVAL1(entryname, trapname)	\
188 	SYSREENTRY(entryname);				\
189 	SYSTRAP_RVAL1(trapname);			\
190 	SYSRESTART()
191 
192 /*
193  * SYSCALL_NOERROR provides the most common system call sequence for those
194  * system calls which don't check the error reture (carry bit).
195  */
196 #define	SYSCALL_NOERROR(name)		\
197 	ENTRY(name);			\
198 	SYSTRAP_2RVALS(name)
199 
200 #define	SYSCALL_NOERROR_RVAL1(name)	\
201 	ENTRY(name);			\
202 	SYSTRAP_RVAL1(name)
203 
204 /*
205  * Standard syscall return sequence, return code equal to rval1.
206  */
207 #define	RET			\
208 	ret
209 
210 /*
211  * Syscall return sequence, return code equal to rval2.
212  */
213 #define	RET2			\
214 	movq	%rdx, %rax;	\
215 	ret
216 
217 /*
218  * Syscall return sequence with return code forced to zero.
219  */
220 #define	RETC			\
221 	xorq	%rax, %rax;	\
222 	ret
223 
224 #endif	/* _LIBC_AMD64_INC_SYS_H */
225