xref: /netbsd-src/sys/compat/linux/arch/arm/linux_ptrace.c (revision 8ac07aec990b9d2e483062509d0a9fa5b4f57cf2)
1 /*	$NetBSD: linux_ptrace.c,v 1.12 2008/04/23 14:18:50 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matthias Scheler.
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 
40 #include <sys/cdefs.h>
41 __KERNEL_RCSID(0, "$NetBSD: linux_ptrace.c,v 1.12 2008/04/23 14:18:50 ad Exp $");
42 
43 #include <sys/param.h>
44 #include <sys/malloc.h>
45 #include <sys/mount.h>
46 #include <sys/proc.h>
47 #include <sys/ptrace.h>
48 #include <sys/systm.h>
49 #include <sys/syscallargs.h>
50 #include <uvm/uvm_extern.h>
51 
52 #include <machine/reg.h>
53 
54 #include <compat/linux/common/linux_types.h>
55 #include <compat/linux/common/linux_ptrace.h>
56 #include <compat/linux/common/linux_signal.h>
57 
58 #include <compat/linux/common/linux_util.h>
59 #include <compat/linux/common/linux_machdep.h>
60 #include <compat/linux/common/linux_emuldata.h>
61 #include <compat/linux/common/linux_exec.h>	/* for emul_linux */
62 
63 #include <compat/linux/linux_syscallargs.h>
64 
65 #include <lib/libkern/libkern.h>	/* for offsetof() */
66 
67 /*
68  * On ARMv2, uregs contains R0--R15, orig_R0.
69  * On ARMv3 and later, it's R0--R15, CPSR, orig_R0.
70  * As far as I can see, Linux doesn't initialise orig_R0 on ARMv2, so we
71  * just produce the ARMv3 version.
72  */
73 
74 struct linux_reg {
75 	long uregs[18];
76 };
77 
78 #define LINUX_REG_R0	0
79 #define LINUX_REG_R1	1
80 #define LINUX_REG_R2	2
81 #define LINUX_REG_R3	3
82 #define LINUX_REG_R4	4
83 #define LINUX_REG_R5	5
84 #define LINUX_REG_R6	6
85 #define LINUX_REG_R7	7
86 #define LINUX_REG_R8	8
87 #define LINUX_REG_R9	9
88 #define LINUX_REG_R10	10
89 #define LINUX_REG_FP	11
90 #define LINUX_REG_IP	12
91 #define LINUX_REG_SP	13
92 #define LINUX_REG_LR	14
93 #define LINUX_REG_PC	15
94 #define LINUX_REG_CPSR	16
95 #define LINUX_REG_ORIG_R0 17
96 
97 int linux_ptrace_disabled = 1;	/* bitrotted */
98 
99 int
100 linux_sys_ptrace_arch(struct lwp *l, const struct linux_sys_ptrace_args *uap, register_t *retval)
101 {
102 	/* {
103 		syscallarg(int) request;
104 		syscallarg(int) pid;
105 		syscallarg(int) addr;
106 		syscallarg(int) data;
107 	} */
108 	struct proc *p = l->l_proc;
109 	int request, error;
110 	struct proc *t;				/* target process */
111 	struct lwp *lt;
112 	struct reg *regs = NULL;
113 	struct fpreg *fpregs = NULL;
114 	struct linux_reg *linux_regs = NULL;
115 	struct linux_fpreg *linux_fpregs = NULL;
116 
117 	if (linux_ptrace_disabled)
118 		return ENOSYS;
119 
120 	request = SCARG(uap, request);
121 
122 	if ((request != LINUX_PTRACE_GETREGS) &&
123 	    (request != LINUX_PTRACE_SETREGS))
124 		return EIO;
125 
126 	/* Find the process we're supposed to be operating on. */
127 	if ((t = pfind(SCARG(uap, pid))) == NULL)
128 		return ESRCH;
129 
130 	/*
131 	 * You can't do what you want to the process if:
132 	 *	(1) It's not being traced at all,
133 	 */
134 	if (!ISSET(t->p_slflag, PSL_TRACED))
135 		return EPERM;
136 
137 	/*
138 	 *	(2) it's being traced by procfs (which has
139 	 *	    different signal delivery semantics),
140 	 */
141 	if (ISSET(t->p_slflag, PSL_FSTRACE))
142 		return EBUSY;
143 
144 	/*
145 	 *	(3) it's not being traced by _you_, or
146 	 */
147 	if (t->p_pptr != p)
148 		return EBUSY;
149 
150 	/*
151 	 *	(4) it's not currently stopped.
152 	 */
153 	if (t->p_stat != SSTOP || !t->p_waited)
154 		return EBUSY;
155 
156 	/* XXX NJWLWP
157 	 * The entire ptrace interface needs work to be useful to
158 	 * a process with multiple LWPs. For the moment, we'll
159 	 * just kluge this and fail on others.
160 	 */
161 
162 	if (p->p_nlwps > 1)
163 		return (ENOSYS);
164 
165 	lt = LIST_FIRST(&t->p_lwps);
166 
167 	*retval = 0;
168 
169 	switch (request) {
170 	case  LINUX_PTRACE_GETREGS:
171 		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
172 		MALLOC(linux_regs, struct linux_reg*, sizeof(struct linux_reg),
173 			M_TEMP, M_WAITOK);
174 
175 		error = process_read_regs(lt, regs);
176 		if (error != 0)
177 			goto out;
178 
179 		memcpy(linux_regs->uregs, regs->r, 13 * sizeof(register_t));
180 		linux_regs->uregs[LINUX_REG_SP] = regs->r_sp;
181 		linux_regs->uregs[LINUX_REG_LR] = regs->r_lr;
182 		linux_regs->uregs[LINUX_REG_PC] = regs->r_pc;
183 		linux_regs->uregs[LINUX_REG_CPSR] = regs->r_cpsr;
184 		linux_regs->uregs[LINUX_REG_ORIG_R0] = regs->r[0];
185 
186 		error = copyout(linux_regs, (void *)SCARG(uap, data),
187 		    sizeof(struct linux_reg));
188 		goto out;
189 
190 	case  LINUX_PTRACE_SETREGS:
191 		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
192 		MALLOC(linux_regs, struct linux_reg *, sizeof(struct linux_reg),
193 			M_TEMP, M_WAITOK);
194 
195 		error = copyin((void *)SCARG(uap, data), linux_regs,
196 		    sizeof(struct linux_reg));
197 		if (error != 0)
198 			goto out;
199 
200 		memcpy(regs->r, linux_regs->uregs, 13 * sizeof(register_t));
201 		regs->r_sp = linux_regs->uregs[LINUX_REG_SP];
202 		regs->r_lr = linux_regs->uregs[LINUX_REG_LR];
203 		regs->r_pc = linux_regs->uregs[LINUX_REG_PC];
204 		regs->r_cpsr = linux_regs->uregs[LINUX_REG_CPSR];
205 
206 		error = process_write_regs(lt, regs);
207 		goto out;
208 
209 	default:
210 		/* never reached */
211 		break;
212 	}
213 
214 	return EIO;
215 
216     out:
217 	if (regs)
218 		FREE(regs, M_TEMP);
219 	if (fpregs)
220 		FREE(fpregs, M_TEMP);
221 	if (linux_regs)
222 		FREE(linux_regs, M_TEMP);
223 	if (linux_fpregs)
224 		FREE(linux_fpregs, M_TEMP);
225 	return (error);
226 
227 }
228