aboutsummaryrefslogtreecommitdiff
path: root/sys/sys/syscall_mi.h
blob: 76f34e0b0302d93e7c646f179256ce1081ab26a0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
/*	$OpenBSD: syscall_mi.h,v 1.25 2020/01/21 16:16:23 mpi Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)kern_xxx.c	8.2 (Berkeley) 11/14/93
 */

#include <sys/param.h>
#include <sys/pledge.h>
#include <sys/tracepoint.h>
#include <uvm/uvm_extern.h>

#ifdef KTRACE
#include <sys/ktrace.h>
#endif

#include "dt.h"
#if NDT > 0
#include <dev/dt/dtvar.h>
#endif


/*
 * The MD setup for a system call has been done; here's the MI part.
 */
static inline int
mi_syscall(struct proc *p, register_t code, const struct sysent *callp,
    register_t *argp, register_t retval[2])
{
	uint64_t tval;
	int lock = !(callp->sy_flags & SY_NOLOCK);
	int error, pledged;

	/* refresh the thread's cache of the process's creds */
	refreshcreds(p);

#ifdef SYSCALL_DEBUG
	KERNEL_LOCK();
	scdebug_call(p, code, argp);
	KERNEL_UNLOCK();
#endif
	TRACEPOINT(raw_syscalls, sys_enter, code, NULL);
#if NDT > 0
	DT_ENTER(syscall, code, callp->sy_argsize, argp);
#endif
#ifdef KTRACE
	if (KTRPOINT(p, KTR_SYSCALL)) {
		KERNEL_LOCK();
		ktrsyscall(p, code, callp->sy_argsize, argp);
		KERNEL_UNLOCK();
	}
#endif

	/* SP must be within MAP_STACK space */
	if (!uvm_map_inentry(p, &p->p_spinentry, PROC_STACK(p),
	    "[%s]%d/%d sp=%lx inside %lx-%lx: not MAP_STACK\n",
	    uvm_map_inentry_sp, p->p_vmspace->vm_map.sserial))
		return (EPERM);

	/* PC must be in un-writeable permitted text (sigtramp, libc, ld.so) */
	if (!uvm_map_inentry(p, &p->p_pcinentry, PROC_PC(p),
	    "[%s]%d/%d pc=%lx inside %lx-%lx: bogus syscall\n",
	    uvm_map_inentry_pc, p->p_vmspace->vm_map.wserial))
		return (EPERM);

	if (lock)
		KERNEL_LOCK();
	pledged = (p->p_p->ps_flags & PS_PLEDGE);
	if (pledged && (error = pledge_syscall(p, code, &tval))) {
		if (!lock)
			KERNEL_LOCK();
		error = pledge_fail(p, error, tval);
		KERNEL_UNLOCK();
		return (error);
	}
	error = (*callp->sy_call)(p, argp, retval);
	if (lock)
		KERNEL_UNLOCK();

	return (error);
}

/*
 * Finish MI stuff on return, after the registers have been set
 */
static inline void
mi_syscall_return(struct proc *p, register_t code, int error,
    const register_t retval[2])
{
#ifdef SYSCALL_DEBUG
	KERNEL_LOCK();
	scdebug_ret(p, code, error, retval);
	KERNEL_UNLOCK();
#endif
#if NDT > 0
	DT_LEAVE(syscall, code, error, retval[0], retval[1]);
#endif
	TRACEPOINT(raw_syscalls, sys_exit, code, NULL);

	userret(p);

#ifdef KTRACE
	if (KTRPOINT(p, KTR_SYSRET)) {
		KERNEL_LOCK();
		ktrsysret(p, code, error, retval);
		KERNEL_UNLOCK();
	}
#endif
}

/*
 * Finish MI stuff for a new process/thread to return
 */
static inline void
mi_child_return(struct proc *p)
{
#if defined(SYSCALL_DEBUG) || defined(KTRACE) || NDT > 0
	int code = (p->p_flag & P_THREAD) ? SYS___tfork :
	    (p->p_p->ps_flags & PS_PPWAIT) ? SYS_vfork : SYS_fork;
	const register_t child_retval[2] = { 0, 1 };
#endif

	TRACEPOINT(sched, on__cpu, NULL);

#ifdef SYSCALL_DEBUG
	KERNEL_LOCK();
	scdebug_ret(p, code, 0, child_retval);
	KERNEL_UNLOCK();
#endif
#if NDT > 0
	DT_LEAVE(syscall, code, 0, child_retval[0], child_retval[1]);
#endif
	TRACEPOINT(raw_syscalls, sys_exit, code, NULL);

	userret(p);

#ifdef KTRACE
	if (KTRPOINT(p, KTR_SYSRET)) {
		KERNEL_LOCK();
		ktrsysret(p, code, 0, child_retval);
		KERNEL_UNLOCK();
	}
#endif
}

/* 
 * Do the specific processing necessary for an AST
 */
static inline void
mi_ast(struct proc *p, int resched)
{
	if (p->p_flag & P_OWEUPC) {
		KERNEL_LOCK();
		ADDUPROF(p);
		KERNEL_UNLOCK();
	}
	if (resched)
		preempt();

	/*
	 * XXX could move call to userret() here, but
	 * hppa calls ast() in syscall return and sh calls
	 * it after userret()
	 */
}