xref: /netbsd-src/sys/arch/amd64/amd64/linux_syscall.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: linux_syscall.c,v 1.18 2007/11/03 12:58:04 dsl Exp $ */
2 
3 /*-
4  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: linux_syscall.c,v 1.18 2007/11/03 12:58:04 dsl Exp $");
41 
42 #if defined(_KERNEL_OPT)
43 #include "opt_compat_linux.h"
44 #endif
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/proc.h>
49 #include <sys/user.h>
50 #include <sys/signal.h>
51 #include <sys/syscall.h>
52 
53 #include <uvm/uvm_extern.h>
54 
55 #include <machine/cpu.h>
56 #include <machine/psl.h>
57 #include <machine/userret.h>
58 
59 #include <compat/linux/linux_syscall.h>
60 #include <compat/linux/common/linux_types.h>
61 #include <compat/linux/common/linux_errno.h>
62 #include <compat/linux/common/linux_signal.h>
63 #include <compat/linux/common/linux_siginfo.h>
64 #include <compat/linux/arch/amd64/linux_siginfo.h>
65 #include <compat/linux/arch/amd64/linux_syscall.h>
66 #include <compat/linux/arch/amd64/linux_machdep.h>
67 
68 void linux_syscall_intern(struct proc *);
69 static void linux_syscall(struct trapframe *);
70 
71 void
72 linux_syscall_intern(struct proc *p)
73 {
74 
75 	p->p_trace_enabled = trace_is_enabled(p);
76 	p->p_md.md_syscall = linux_syscall;
77 }
78 
79 /*
80  * syscall(frame):
81  *	System call request from POSIX system call gate interface to kernel.
82  * Like trap(), argument is call by reference.
83  */
84 static void
85 linux_syscall(struct trapframe *frame)
86 {
87 	const struct sysent *callp;
88 	struct proc *p;
89 	struct lwp *l;
90 	int error;
91 	register_t code, args[6], rval[2];
92 
93 	l = curlwp;
94 	p = l->l_proc;
95 
96 	code = frame->tf_rax;
97 	uvmexp.syscalls++;
98 
99 	LWP_CACHE_CREDS(l, p);
100 
101 	callp = p->p_emul->e_sysent;
102 
103 	code &= (SYS_NSYSENT - 1);
104 	callp += code;
105 
106 	/* Linux system calls have a maximum of 6 arguments, copy them all */
107 	args[0] = frame->tf_rdi;
108 	args[1] = frame->tf_rsi;
109 	args[2] = frame->tf_rdx;
110 	args[3] = frame->tf_r10;
111 	args[4] = frame->tf_r8;
112 	args[5] = frame->tf_r9;
113 
114 	KERNEL_LOCK(1, l);
115 	if (__predict_false(p->p_trace_enabled)
116 	    && (error = trace_enter(l, code, code, NULL, args)) != 0)
117 		goto out;
118 
119 	rval[0] = 0;
120 	rval[1] = 0;
121 	error = (*callp->sy_call)(l, args, rval);
122 out:
123 	KERNEL_UNLOCK_LAST(l);
124 	switch (error) {
125 	case 0:
126 		frame->tf_rax = rval[0];
127 		frame->tf_rflags &= ~PSL_C;	/* carry bit */
128 		break;
129 	case ERESTART:
130 		/*
131 		 * The offset to adjust the PC by depends on whether we entered
132 		 * the kernel through the trap or call gate.  We pushed the
133 		 * size of the instruction into tf_err on entry.
134 		 */
135 		frame->tf_rip -= frame->tf_err;
136 		break;
137 	case EJUSTRETURN:
138 		/* nothing to do */
139 		break;
140 	default:
141 		error = native_to_linux_errno[error];
142 		frame->tf_rax = error;
143 		frame->tf_rflags |= PSL_C;	/* carry bit */
144 		break;
145 	}
146 
147 	if (__predict_false(p->p_trace_enabled))
148 		trace_exit(l, code, args, rval, error);
149 
150 	userret(l);
151 }
152