xref: /netbsd-src/sys/compat/freebsd/freebsd_ptrace.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: freebsd_ptrace.c,v 1.16 2007/12/08 18:35:58 dsl Exp $	*/
2 
3 /*-
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
37  */
38 
39 /*-
40  * Copyright (c) 1994 Christopher G. Demetriou.  All rights reserved.
41  *
42  * Redistribution and use in source and binary forms, with or without
43  * modification, are permitted provided that the following conditions
44  * are met:
45  * 1. Redistributions of source code must retain the above copyright
46  *    notice, this list of conditions and the following disclaimer.
47  * 2. Redistributions in binary form must reproduce the above copyright
48  *    notice, this list of conditions and the following disclaimer in the
49  *    documentation and/or other materials provided with the distribution.
50  * 3. All advertising materials mentioning features or use of this software
51  *    must display the following acknowledgement:
52  *	This product includes software developed by the University of
53  *	California, Berkeley and its contributors.
54  * 4. Neither the name of the University nor the names of its contributors
55  *    may be used to endorse or promote products derived from this software
56  *    without specific prior written permission.
57  *
58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68  * SUCH DAMAGE.
69  *
70  *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
71  */
72 
73 #include <sys/cdefs.h>
74 __KERNEL_RCSID(0, "$NetBSD: freebsd_ptrace.c,v 1.16 2007/12/08 18:35:58 dsl Exp $");
75 
76 #if defined(_KERNEL_OPT)
77 #include "opt_ptrace.h"
78 #endif
79 
80 #include <sys/param.h>
81 #include <sys/systm.h>
82 #include <sys/proc.h>
83 #include <sys/errno.h>
84 #include <sys/ptrace.h>
85 #include <sys/uio.h>
86 #include <sys/user.h>
87 #include <sys/mount.h>
88 #include <sys/syscallargs.h>
89 
90 #include <compat/sys/signal.h>
91 #include <compat/sys/signalvar.h>
92 
93 #include <machine/reg.h>
94 #include <machine/freebsd_machdep.h>
95 
96 #include <compat/common/compat_util.h>
97 #include <compat/freebsd/freebsd_syscallargs.h>
98 #include <compat/freebsd/freebsd_ptrace.h>
99 
100 /*
101  * Process debugging system call.
102  */
103 int
104 freebsd_sys_ptrace(struct lwp *l, void *v, register_t *retval)
105 {
106 #if defined(PTRACE) || defined(_LKM)
107 	struct freebsd_sys_ptrace_args /* {
108 		syscallarg(int) req;
109 		syscallarg(pid_t) pid;
110 		syscallarg(void *) addr;
111 		syscallarg(int) data;
112 	} */ *uap = v;
113 	struct sys_ptrace_args npa;
114 #ifdef _LKM
115 	sy_call_t sys_ptrace = sysent[SYS_ptrace].sy_call;
116 #endif
117 
118 	switch (SCARG(uap, req)) {
119 #ifdef PT_STEP
120 	case FREEBSD_PT_STEP:
121 		SCARG(&npa, req) = PT_STEP;
122 		SCARG(&npa, pid) = SCARG(uap, pid);
123 		SCARG(&npa, addr) = SCARG(uap, addr);
124 		SCARG(&npa, data) = SCARG(uap, data);
125 		return sys_ptrace(l, &npa, retval);
126 #endif
127 	case FREEBSD_PT_TRACE_ME:
128 	case FREEBSD_PT_READ_I:
129 	case FREEBSD_PT_READ_D:
130 	case FREEBSD_PT_WRITE_I:
131 	case FREEBSD_PT_WRITE_D:
132 	case FREEBSD_PT_CONTINUE:
133 	case FREEBSD_PT_KILL:
134 		/* These requests are compatible with NetBSD */
135 		return sys_ptrace(l, uap, retval);
136 
137 #if 0
138 /*
139  * XXX: I've commented out this code, it is broken on too many fronts to fix.
140  *	1) It is doing an unlocked read-modify-write cycle on process that
141  *	   I assume might be running!
142  *	   and in code that might sleep (due to a pagefault), never mind
143  *	   what happens on an SMP system
144  *      2) It accesses data in userspace without using copyin/out.
145  *	3) It all looks like a nasty hack that isn't likely to work.
146  *	4) It uses the stackgap.
147  * dsl June 2007
148  */
149 	case FREEBSD_PT_READ_U:
150 	case FREEBSD_PT_WRITE_U:
151     {
152 	int error;
153 	struct {
154 		struct reg regs;
155 		struct fpreg fpregs;
156 	} *nrp;
157 	struct freebsd_ptrace_reg fr;
158 		sg = stackgap_init(p, 0);
159 		nrp = stackgap_alloc(p, &sg, sizeof(*nrp));
160 #ifdef PT_GETREGS
161 		SCARG(&npa, req) = PT_GETREGS;
162 		SCARG(&npa, pid) = SCARG(uap, pid);
163 		SCARG(&npa, addr) = (void *)&nrp->regs;
164 		if ((error = sys_ptrace(l, &npa, retval)) != 0)
165 			return error;
166 #endif
167 #ifdef PT_GETFPREGS
168 		SCARG(&npa, req) = PT_GETFPREGS;
169 		SCARG(&npa, pid) = SCARG(uap, pid);
170 		SCARG(&npa, addr) = (void *)&nrp->fpregs;
171 		if ((error = sys_ptrace(l, &npa, retval)) != 0)
172 			return error;
173 #endif
174 		netbsd_to_freebsd_ptrace_regs(&nrp->regs, &nrp->fpregs, &fr);
175 		switch (SCARG(uap, req)) {
176 		case FREEBSD_PT_READ_U:
177 			return freebsd_ptrace_getregs(&fr, SCARG(uap, addr),
178 						      retval);
179 
180 		case FREEBSD_PT_WRITE_U:
181 			error = freebsd_ptrace_setregs(&fr,
182 			    SCARG(uap, addr), SCARG(uap, data));
183 			if (error)
184 				return error;
185 			freebsd_to_netbsd_ptrace_regs(&fr,
186 						&nrp->regs, &nrp->fpregs);
187 #ifdef PT_SETREGS
188 			SCARG(&npa, req) = PT_SETREGS;
189 			SCARG(&npa, pid) = SCARG(uap, pid);
190 			SCARG(&npa, addr) = (void *)&nrp->regs;
191 			if ((error = sys_ptrace(l, &npa, retval)) != 0)
192 				return error;
193 #endif
194 #ifdef PT_SETFPREGS
195 			SCARG(&npa, req) = PT_SETFPREGS;
196 			SCARG(&npa, pid) = SCARG(uap, pid);
197 			SCARG(&npa, addr) = (void *)&nrp->fpregs;
198 			if ((error = sys_ptrace(l, &npa, retval)) != 0)
199 				return error;
200 #endif
201 			return 0;
202 		}
203     }
204 #endif
205 
206 	default:			/* It was not a legal request. */
207 		return (EINVAL);
208 	}
209 
210 #ifdef DIAGNOSTIC
211 	panic("freebsd_ptrace: impossible");
212 #endif
213 #else
214 	return (ENOSYS);
215 #endif /* PTRACE || _LKM */
216 }
217