1 /*	$NetBSD: syscallvar.h,v 1.11 2015/09/24 14:34:22 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software developed for The NetBSD Foundation
8  * by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_SYSCALLVAR_H_
33 #define	_SYS_SYSCALLVAR_H_
34 
35 #ifndef _KERNEL
36 #error nothing of interest to userspace here
37 #endif
38 
39 #if defined(_KERNEL) && defined(_KERNEL_OPT)
40 #include "opt_dtrace.h"
41 #endif
42 
43 #include <sys/systm.h>
44 #include <sys/proc.h>
45 
46 extern struct emul emul_netbsd;
47 
48 struct syscall_package {
49 	u_short		sp_code;
50 	u_short		sp_flags;
51 	sy_call_t	*sp_call;
52 };
53 
54 void	syscall_init(void);
55 int	syscall_establish(const struct emul *, const struct syscall_package *);
56 int	syscall_disestablish(const struct emul *, const struct syscall_package *);
57 
58 static inline int
sy_call(const struct sysent * sy,struct lwp * l,const void * uap,register_t * rval)59 sy_call(const struct sysent *sy, struct lwp *l, const void *uap,
60 	register_t *rval)
61 {
62 	int error;
63 
64 	l->l_sysent = sy;
65 	error = (*sy->sy_call)(l, uap, rval);
66 	l->l_sysent = NULL;
67 
68 	return error;
69 }
70 
71 static inline int
sy_invoke(const struct sysent * sy,struct lwp * l,const void * uap,register_t * rval,int code)72 sy_invoke(const struct sysent *sy, struct lwp *l, const void *uap,
73 	register_t *rval, int code)
74 {
75 	const bool do_trace = l->l_proc->p_trace_enabled &&
76 	    (sy->sy_flags & SYCALL_INDIRECT) == 0;
77 	int error;
78 
79 #ifdef KDTRACE_HOOKS
80 #define KDTRACE_ENTRY(a)	(a)
81 #else
82 #define KDTRACE_ENTRY(a)	(0)
83 #endif
84 	if (__predict_true(!(do_trace || KDTRACE_ENTRY(sy->sy_entry)))
85 	    || (error = trace_enter(code, sy, uap)) == 0) {
86 		rval[0] = 0;
87 #if !defined(__mips__) && !defined(__m68k__)
88 		/*
89 		 * Due to the mips userland code for SYS_break needing v1 to be
90 		 * preserved, we can't clear this on mips.
91 		 */
92 		rval[1] = 0;
93 #endif
94 		error = sy_call(sy, l, uap, rval);
95 	}
96 
97 	if (__predict_false(do_trace || KDTRACE_ENTRY(sy->sy_return))) {
98 		trace_exit(code, sy, uap, rval, error);
99 	}
100 	return error;
101 }
102 
103 /* inclusion in the kernel currently depends on SYSCALL_DEBUG */
104 extern const char * const syscallnames[];
105 extern const char * const altsyscallnames[];
106 
107 #endif	/* _SYS_SYSCALLVAR_H_ */
108