xref: /openbsd/libexec/ld.so/sh/SYS.h (revision 4bdff4be)
1 /*	$OpenBSD: SYS.h,v 1.4 2023/12/11 22:29:25 deraadt Exp $ */
2 
3 /*
4  * Copyright (c) 2006 Dale Rahn
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
19  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  */
28 
29 #include <machine/asm.h>
30 #include <sys/syscall.h>
31 
32 #define PINSYSCALL(sysno, label)				\
33 	.pushsection .openbsd.syscalls,"",@progbits		;\
34 	.p2align 2						;\
35 	.long label						;\
36 	.long sysno						;\
37 	.popsection
38 
39 #ifdef __ASSEMBLER__
40 /*
41  * If the system call number fits in a 8-bit signed value (i.e. fits in 7 bits),
42  * then we can use the #imm8 addressing mode.
43  */
44 
45 .macro systrap num
46 .iflt \num - 128
47 	mov	# \num, r0
48 99:	trapa	#0x80
49 	PINSYSCALL(\num, 99b)
50 .else
51 	mov.l	903f, r0
52 99:	trapa	#0x80
53 	PINSYSCALL(\num, 99b)
54 	bra	904f
55 	 nop
56 	.align	2
57  903:	.long	\num
58  904:
59 .endif
60 .endm
61 #endif
62 
63 #define SYSTRAP(x)						\
64 	systrap	SYS_ ## x
65 
66 #define DL_SYSCALL(n)						\
67 	.global		__CONCAT(_dl_,n)			;\
68 	.type		__CONCAT(_dl_,n)%function		;\
69 __CONCAT(_dl_,n):						;\
70 	SYSTRAP(n)						;\
71 	bf	.L_cerr						;\
72 	 nop							;\
73 	rts							;\
74 	 nop
75 
76 .L_cerr:
77 	neg	r0, r0
78 	rts
79 	 nop
80