xref: /netbsd-src/sys/compat/linux/arch/powerpc/linux_ptrace.c (revision 3cec974c61d7fac0a37c0377723a33214a458c8b)
1 /*	$NetBSD: linux_ptrace.c,v 1.3 2001/02/04 22:59:26 christos Exp $ */
2 
3 /*-
4  * Copyright (c) 1999, 2001 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 and Emmanuel Dreyfus.
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  * Function linux_sys_ptrace_arch() is taken from NetBSD/i386
41  * with some stuff deleted to get it compiling. It is not expected to
42  * work, and it should be checked with care or re-writen.
43  */
44 
45 #include <sys/types.h>
46 #include <sys/param.h>
47 #include <sys/malloc.h>
48 #include <sys/mount.h>
49 #include <sys/proc.h>
50 #include <sys/ptrace.h>
51 #include <sys/systm.h>
52 #include <sys/syscallargs.h>
53 #include <uvm/uvm_extern.h>
54 
55 #include <machine/reg.h>
56 
57 #include <compat/linux/common/linux_types.h>
58 #include <compat/linux/common/linux_ptrace.h>
59 #include <compat/linux/common/linux_signal.h>
60 
61 #include <compat/linux/common/linux_util.h>
62 #include <compat/linux/common/linux_machdep.h>
63 #include <compat/linux/common/linux_emuldata.h>
64 #include <compat/linux/common/linux_exec.h>	/* for emul_linux */
65 
66 #include <compat/linux/linux_syscallargs.h>
67 
68 #include <lib/libkern/libkern.h>	/* for offsetof() */
69 
70 /*
71  * From Linux's include/asm-ppc/ptrace.h.
72  * structure used for storing reg context:  defined in linux_machdep.h
73  * structure used for storing floating point context:
74  * Linux just uses a double fpr[32], no struct
75  */
76 
77 /*
78  * user struct for linux process - this is used for Linux ptrace emulation
79  * most of it is junk only used by gdb
80  *
81  * From Linux's include/asm-ppc/user.h
82  *
83  * XXX u_ar0 was a struct reg in Linux/powerpc
84  * Can't find out what a struct regs is for Linux/powerpc,
85  * so we use a struct pt_regs instead. don't know if this is right.
86  */
87 
88 struct linux_user {
89 	struct linux_pt_regs regs;
90 	size_t u_tsize;
91 	size_t u_dsize;
92 	size_t u_ssize;
93 	unsigned long start_code;
94 	unsigned long start_data;
95 	unsigned long start_stack;
96 	long int signal;
97 	struct linux_pt_regs *u_ar0;		/* help gdb find registers */
98 	unsigned long magic;
99 	char u_comm[32];
100 };
101 
102 #define lusr_startgdb regs
103 #define LUSR_OFF(member) offsetof(struct linux_user, member)
104 #define ISSET(t, f) ((t) & (f))
105 
106 int
107 linux_sys_ptrace_arch(p, v, retval)	/* XXX Check me! (From NetBSD/i386) */
108 	struct proc *p;
109 	void *v;
110 	register_t *retval;
111 {
112 	struct linux_sys_ptrace_args /* {
113 		syscallarg(int) request;
114 		syscallarg(int) pid;
115 		syscallarg(int) addr;
116 		syscallarg(int) data;
117 	} */ *uap = v;
118 	int request, error;
119 	struct proc *t;				/* target process */
120 	struct reg *regs = NULL;
121 	struct fpreg *fpregs = NULL;
122 	struct linux_pt_regs *linux_regs = NULL;
123 	double *linux_fpreg = NULL;  /* it's an array, not a struct */
124 	int addr;
125 	int i;
126 
127 
128 	switch (request = SCARG(uap, request)) {
129 	case LINUX_PTRACE_PEEKUSR:
130 	case LINUX_PTRACE_POKEUSR:
131 	case LINUX_PTRACE_GETREGS:
132 	case LINUX_PTRACE_SETREGS:
133 	case LINUX_PTRACE_GETFPREGS:
134 	case LINUX_PTRACE_SETFPREGS:
135 		break;
136 	default:
137 		return EIO;
138 	}
139 
140 	/* Find the process we're supposed to be operating on. */
141 	if ((t = pfind(SCARG(uap, pid))) == NULL)
142 		return ESRCH;
143 
144 	/*
145 	 * You can't do what you want to the process if:
146 	 *	(1) It's not being traced at all,
147 	 */
148 	if (!ISSET(t->p_flag, P_TRACED))
149 		return EPERM;
150 
151 	/*
152 	 *	(2) it's being traced by procfs (which has
153 	 *		 different signal delivery semantics),
154 	 */
155 	if (ISSET(t->p_flag, P_FSTRACE))
156 		return EBUSY;
157 
158 	/*
159 	 *	(3) it's not being traced by _you_, or
160 	 */
161 	if (t->p_pptr != p)
162 		return EBUSY;
163 
164 	/*
165 	 *	(4) it's not currently stopped.
166 	 */
167 	if (t->p_stat != SSTOP || !ISSET(t->p_flag, P_WAITED))
168 		return EBUSY;
169 
170 	*retval = 0;
171 
172 	switch (request) {
173 	case  LINUX_PTRACE_GETREGS:
174 		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
175 		MALLOC(linux_regs, struct linux_pt_regs*, sizeof(*linux_regs),
176 		    M_TEMP, M_WAITOK);
177 
178 		error = process_read_regs(t, regs);
179 		if (error != 0)
180 			goto out;
181 
182 		for (i=0; i<=31; i++)
183 			linux_regs->lgpr[i] = regs->fixreg[i];
184 		linux_regs->lnip = regs->pc;
185 		linux_regs->lmsr = 0;
186 		/* XXX Is that right? */
187 		linux_regs->lorig_gpr3 = regs->fixreg[3];
188 		linux_regs->lctr = regs->ctr;
189 		linux_regs->llink = regs->lr;
190 		linux_regs->lxer = regs->xer;
191 		linux_regs->lccr = regs->cr;
192 		linux_regs->lmq = 0;
193 		linux_regs->ltrap = 0;
194 		linux_regs->ldar = 0;
195 		linux_regs->ldsisr = 0;
196 		linux_regs->lresult = 0;
197 
198 		error = copyout(linux_regs, (caddr_t)SCARG(uap, data),
199 			 sizeof(struct linux_pt_regs));
200 		goto out;
201 
202 	case  LINUX_PTRACE_SETREGS:
203 		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
204 		MALLOC(linux_regs, struct linux_pt_regs*, sizeof(*linux_regs),
205 		    M_TEMP, M_WAITOK);
206 
207 		error = copyin((caddr_t)SCARG(uap, data), linux_regs,
208 			 sizeof(struct linux_pt_regs));
209 		if (error != 0)
210 			goto out;
211 
212 		for (i=0; i<=31; i++)
213 			regs->fixreg[i] = linux_regs->lgpr[i];
214 		regs->lr = linux_regs->llink;
215 		regs->cr = linux_regs->lccr;
216 		regs->xer = linux_regs->lxer;
217 		regs->ctr = linux_regs->lctr;
218 		regs->pc = linux_regs->lnip; /* XXX */
219 
220 		error = process_write_regs(t, regs);
221 		goto out;
222 
223 	case  LINUX_PTRACE_GETFPREGS:
224 		MALLOC(fpregs, struct fpreg *, sizeof(struct fpreg),
225 		    M_TEMP, M_WAITOK);
226 		MALLOC(linux_fpreg, double *,
227 		    32*sizeof(double), M_TEMP, M_WAITOK);
228 
229 		error = process_read_fpregs(t, fpregs);
230 		if (error != 0)
231 			goto out;
232 
233 		/* zero the contents if NetBSD fpreg structure is smaller */
234 		if (sizeof(struct fpreg) < (32*sizeof(double)))
235 			memset(linux_fpreg, '\0', (32*sizeof(double)));
236 
237 		memcpy(linux_fpreg, fpregs,
238 			min(32*sizeof(double), sizeof(struct fpreg)));
239 		error = copyout(linux_fpreg, (caddr_t)SCARG(uap, data),
240 			 32*sizeof(double));
241 		goto out;
242 
243 	case  LINUX_PTRACE_SETFPREGS:
244 		MALLOC(fpregs, struct fpreg *, sizeof(struct fpreg),
245 		    M_TEMP, M_WAITOK);
246 		MALLOC(linux_fpreg, double *,
247 		    32*sizeof(double), M_TEMP, M_WAITOK);
248 		error = copyin((caddr_t)SCARG(uap, data), linux_fpreg,
249 			 32*sizeof(double));
250 		if (error != 0)
251 			goto out;
252 
253 		memset(fpregs, '\0', sizeof(struct fpreg));
254 		memcpy(fpregs, linux_fpreg,
255 		    min(32*sizeof(double), sizeof(struct fpreg)));
256 
257 		error = process_write_regs(t, regs);
258 		goto out;
259 
260 	case  LINUX_PTRACE_PEEKUSR:
261 		addr = SCARG(uap, addr);
262 
263 		PHOLD(t);	/* need full process info */
264 		error = 0;
265 		 if (addr < LUSR_OFF(lusr_startgdb)) {
266 		 	error = 1;
267 		} else if (addr == LUSR_OFF(u_tsize))
268 			*retval = p->p_vmspace->vm_tsize;
269 		else if (addr == LUSR_OFF(u_dsize))
270 			*retval = p->p_vmspace->vm_dsize;
271 		else if (addr == LUSR_OFF(u_ssize))
272 			*retval = p->p_vmspace->vm_ssize;
273 		else if (addr == LUSR_OFF(start_code))
274 			*retval = (register_t) p->p_vmspace->vm_taddr;
275 		else if (addr == LUSR_OFF(start_stack))
276 			*retval = (register_t) p->p_vmspace->vm_minsaddr;
277 		else if (addr == LUSR_OFF(u_ar0))
278 			*retval = LUSR_OFF(regs);
279 		else if (addr == LUSR_OFF(signal)) {
280 			error = 1;
281 		} else if (addr == LUSR_OFF(signal)) {
282 			error = 1;
283 		} else if (addr == LUSR_OFF(magic)) {
284 			error = 1;
285 		} else if (addr == LUSR_OFF(u_comm)) {
286 			error = 1;
287 		} else {
288 #ifdef DEBUG_LINUX
289 			printf("linux_ptrace: unsupported address: %d\n", addr);
290 #endif
291 			error = 1;
292 		}
293 
294 		PRELE(t);
295 
296 		if (!error)
297 			return 0;
298 
299 	case  LINUX_PTRACE_POKEUSR:
300 		/*
301 		 * XXX NetBSD/i386 only handle debugregs here. It seems these
302 		 * debugregs are not availlable on powerpc. Hence we do nothing.
303 		 */
304 		break;
305 	default:
306 		/* never reached */
307 		break;
308 	}
309 
310 	return EIO;
311 
312 	 out:
313 	if (regs)
314 		FREE(regs, M_TEMP);
315 	if (fpregs)
316 		FREE(fpregs, M_TEMP);
317 	if (linux_regs)
318 		FREE(linux_regs, M_TEMP);
319 	if (linux_fpreg)
320 		FREE(linux_fpreg, M_TEMP);
321 	return (error);
322 }
323