1 /* $NetBSD: linux_ptrace.c,v 1.34 2022/09/05 14:14:42 tsutsui 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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: linux_ptrace.c,v 1.34 2022/09/05 14:14:42 tsutsui Exp $");
34
35 #include <sys/param.h>
36 #include <sys/mount.h>
37 #include <sys/proc.h>
38 #include <sys/ptrace.h>
39 #include <sys/systm.h>
40 #include <sys/syscallargs.h>
41 #include <uvm/uvm_extern.h>
42
43 #include <machine/reg.h>
44
45 #include <compat/linux/common/linux_types.h>
46 #include <compat/linux/common/linux_ptrace.h>
47 #include <compat/linux/common/linux_signal.h>
48
49 #include <compat/linux/common/linux_util.h>
50 #include <compat/linux/common/linux_machdep.h>
51 #include <compat/linux/common/linux_emuldata.h>
52 #include <compat/linux/common/linux_exec.h> /* for emul_linux */
53
54 #include <compat/linux/linux_syscallargs.h>
55
56 #include <lib/libkern/libkern.h> /* for offsetof() */
57
58 /*
59 * From Linux's include/asm-ppc/ptrace.h.
60 * structure used for storing reg context: defined in linux_machdep.h
61 * structure used for storing floating point context:
62 * Linux just uses a double fpr[32], no struct
63 */
64
65 /*
66 * user struct for linux process - this is used for Linux ptrace emulation
67 * most of it is junk only used by gdb
68 *
69 * From Linux's include/asm-ppc/user.h
70 *
71 * XXX u_ar0 was a struct reg in Linux/powerpc
72 * Can't find out what a struct regs is for Linux/powerpc,
73 * so we use a struct pt_regs instead. don't know if this is right.
74 */
75
76 struct linux_user {
77 struct linux_pt_regs regs;
78 #define lusr_startgdb regs
79 size_t u_tsize;
80 size_t u_dsize;
81 size_t u_ssize;
82 unsigned long start_code;
83 unsigned long start_data;
84 unsigned long start_stack;
85 long int signal;
86 struct linux_pt_regs *u_ar0; /* help gdb find registers */
87 unsigned long magic;
88 char u_comm[32];
89 #define lu_comm_end u_comm[31]
90 };
91
92 #define LUSR_OFF(member) offsetof(struct linux_user, member)
93 #define LUSR_REG_OFF(member) offsetof(struct linux_pt_regs, member)
94
95 int linux_ptrace_disabled = 1; /* bitrotted */
96
97 /* XXX Check me! (From NetBSD/i386) */
98 int
linux_sys_ptrace_arch(struct lwp * l,const struct linux_sys_ptrace_args * uap,register_t * retval)99 linux_sys_ptrace_arch(struct lwp *l, const struct linux_sys_ptrace_args *uap,
100 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, *t;
109 struct lwp *lt;
110 struct reg *regs = NULL;
111 struct fpreg *fpregs = NULL;
112 struct linux_pt_regs *linux_regs = NULL;
113 double *linux_fpreg = NULL; /* it's an array, not a struct */
114 int request, error, addr, i;
115
116 if (linux_ptrace_disabled)
117 return ENOSYS;
118
119 error = 0;
120 request = SCARG(uap, request);
121
122 switch (request) {
123 case LINUX_PTRACE_PEEKUSR:
124 case LINUX_PTRACE_POKEUSR:
125 regs = kmem_alloc(sizeof(struct reg), KM_SLEEP);
126 break;
127 case LINUX_PTRACE_GETREGS:
128 case LINUX_PTRACE_SETREGS:
129 regs = kmem_alloc(sizeof(struct reg), KM_SLEEP);
130 linux_regs = kmem_alloc(sizeof(*linux_regs), KM_SLEEP);
131 if (request == LINUX_PTRACE_SETREGS) {
132 error = copyin((void *)SCARG(uap, data), linux_regs,
133 sizeof(struct linux_pt_regs));
134 if (error) {
135 goto out;
136 }
137 }
138 break;
139 case LINUX_PTRACE_GETFPREGS:
140 case LINUX_PTRACE_SETFPREGS:
141 fpregs = kmem_alloc(sizeof(struct fpreg), KM_SLEEP);
142 linux_fpreg = kmem_alloc(32 * sizeof(double), KM_SLEEP);
143 if (request == LINUX_PTRACE_SETFPREGS) {
144 error = copyin((void *)SCARG(uap, data), linux_fpreg,
145 32 * sizeof(double));
146 if (error) {
147 goto out;
148 }
149 }
150 break;
151 default:
152 error = EIO;
153 goto out;
154 }
155
156 /* Find the process we are supposed to be operating on. */
157 mutex_enter(&proc_lock);
158 if ((t = proc_find(SCARG(uap, pid))) == NULL) {
159 mutex_exit(&proc_lock);
160 error = ESRCH;
161 goto out;
162 }
163 mutex_enter(t->p_lock);
164
165 /*
166 * You cannot do what you want to the process if:
167 * 1. It is not being traced at all,
168 */
169 if (!ISSET(t->p_slflag, PSL_TRACED)) {
170 mutex_exit(t->p_lock);
171 mutex_exit(&proc_lock);
172 error = EPERM;
173 goto out;
174 }
175 /*
176 * 2. It is not being traced by _you_, or
177 * 3. It is not currently stopped.
178 */
179 if (t->p_pptr != p || t->p_stat != SSTOP || !t->p_waited) {
180 mutex_exit(t->p_lock);
181 mutex_exit(&proc_lock);
182 error = EBUSY;
183 goto out;
184 }
185 mutex_exit(&proc_lock);
186 /* XXX: ptrace needs revamp for multi-threading support. */
187 if (t->p_nlwps > 1) {
188 mutex_exit(t->p_lock);
189 error = ENOSYS;
190 goto out;
191 }
192 lt = LIST_FIRST(&t->p_lwps);
193 *retval = 0;
194
195 switch (request) {
196 case LINUX_PTRACE_GETREGS:
197 error = process_read_regs(lt, regs);
198 mutex_exit(t->p_lock);
199 if (error) {
200 break;
201 }
202 memset(linux_regs, 0, sizeof(*linux_regs));
203 for (i = 0; i <= 31; i++) {
204 linux_regs->lgpr[i] = regs->fixreg[i];
205 }
206 linux_regs->lnip = regs->pc;
207 linux_regs->lmsr = 0;
208 /* XXX Is that right? */
209 linux_regs->lorig_gpr3 = regs->fixreg[3];
210 linux_regs->lctr = regs->ctr;
211 linux_regs->llink = regs->lr;
212 linux_regs->lxer = regs->xer;
213 linux_regs->lccr = regs->cr;
214 linux_regs->lmq = 0;
215 linux_regs->ltrap = 0;
216 linux_regs->ldar = 0;
217 linux_regs->ldsisr = 0;
218 linux_regs->lresult = 0;
219
220 error = copyout(linux_regs, (void *)SCARG(uap, data),
221 sizeof(struct linux_pt_regs));
222 break;
223
224 case LINUX_PTRACE_SETREGS:
225 for (i = 0; i <= 31; i++) {
226 regs->fixreg[i] = linux_regs->lgpr[i];
227 }
228 regs->lr = linux_regs->llink;
229 regs->cr = linux_regs->lccr;
230 regs->xer = linux_regs->lxer;
231 regs->ctr = linux_regs->lctr;
232 regs->pc = linux_regs->lnip; /* XXX */
233
234 error = process_write_regs(lt, regs);
235 mutex_exit(t->p_lock);
236 break;
237
238 case LINUX_PTRACE_GETFPREGS:
239 error = process_read_fpregs(lt, fpregs, NULL);
240 mutex_exit(t->p_lock);
241 if (error) {
242 break;
243 }
244 /* Zero the contents if NetBSD fpreg structure is smaller */
245 if (sizeof(struct fpreg) < (32 * sizeof(double))) {
246 memset(linux_fpreg, '\0', (32 * sizeof(double)));
247 }
248 memcpy(linux_fpreg, fpregs,
249 uimin(32 * sizeof(double), sizeof(struct fpreg)));
250 error = copyout(linux_fpreg, (void *)SCARG(uap, data),
251 32 * sizeof(double));
252 break;
253
254 case LINUX_PTRACE_SETFPREGS:
255 memset(fpregs, '\0', sizeof(struct fpreg));
256 memcpy(fpregs, linux_fpreg,
257 uimin(32 * sizeof(double), sizeof(struct fpreg)));
258 error = process_write_fpregs(lt, fpregs, sizeof fpregs);
259 mutex_exit(t->p_lock);
260 break;
261
262 case LINUX_PTRACE_PEEKUSR:
263 addr = SCARG(uap, addr);
264 error = process_read_regs(lt, regs);
265 mutex_exit(t->p_lock);
266 if (error) {
267 break;
268 }
269 error = 0;
270 if ((addr < LUSR_OFF(lusr_startgdb)) ||
271 (addr > LUSR_OFF(lu_comm_end)))
272 error = 1;
273 else if (addr == LUSR_OFF(u_tsize))
274 *retval = p->p_vmspace->vm_tsize;
275 else if (addr == LUSR_OFF(u_dsize))
276 *retval = p->p_vmspace->vm_dsize;
277 else if (addr == LUSR_OFF(u_ssize))
278 *retval = p->p_vmspace->vm_ssize;
279 else if (addr == LUSR_OFF(start_code))
280 *retval = (register_t) p->p_vmspace->vm_taddr;
281 else if (addr == LUSR_OFF(start_stack))
282 *retval = (register_t) p->p_vmspace->vm_minsaddr;
283 else if ((addr >= LUSR_REG_OFF(lpt_regs_fixreg_begin)) &&
284 (addr <= LUSR_REG_OFF(lpt_regs_fixreg_end)))
285 *retval = regs->fixreg[addr / sizeof (register_t)];
286 else if (addr == LUSR_REG_OFF(lnip))
287 *retval = regs->pc;
288 else if (addr == LUSR_REG_OFF(lctr))
289 *retval = regs->ctr;
290 else if (addr == LUSR_REG_OFF(llink))
291 *retval = regs->lr;
292 else if (addr == LUSR_REG_OFF(lxer))
293 *retval = regs->xer;
294 else if (addr == LUSR_REG_OFF(lccr))
295 *retval = regs->cr;
296 else if (addr == LUSR_OFF(signal))
297 error = 1;
298 else if (addr == LUSR_OFF(magic))
299 error = 1;
300 else if (addr == LUSR_OFF(u_comm))
301 error = 1;
302 else {
303 #ifdef DEBUG_LINUX
304 printf("linux_ptrace: unsupported address: %d\n", addr);
305 #endif
306 error = 1;
307 }
308 if (error) {
309 break;
310 }
311 error = copyout (retval, (void *)SCARG(uap, data),
312 sizeof(*retval));
313 *retval = SCARG(uap, data);
314 break;
315
316 case LINUX_PTRACE_POKEUSR: /* XXX Not tested */
317 addr = SCARG(uap, addr);
318 error = process_read_regs(lt, regs);
319 if (error) {
320 mutex_exit(t->p_lock);
321 break;
322 }
323 error = 0;
324 if ((addr < LUSR_OFF(lusr_startgdb)) ||
325 (addr > LUSR_OFF(lu_comm_end)))
326 error = 1;
327 else if (addr == LUSR_OFF(u_tsize))
328 error = 1;
329 else if (addr == LUSR_OFF(u_dsize))
330 error = 1;
331 else if (addr == LUSR_OFF(u_ssize))
332 error = 1;
333 else if (addr == LUSR_OFF(start_code))
334 error = 1;
335 else if (addr == LUSR_OFF(start_stack))
336 error = 1;
337 else if ((addr >= LUSR_REG_OFF(lpt_regs_fixreg_begin)) &&
338 (addr <= LUSR_REG_OFF(lpt_regs_fixreg_end)))
339 regs->fixreg[addr / sizeof (register_t)] =
340 (register_t)SCARG(uap, data);
341 else if (addr == LUSR_REG_OFF(lnip))
342 regs->pc = (register_t)SCARG(uap, data);
343 else if (addr == LUSR_REG_OFF(lctr))
344 regs->ctr = (register_t)SCARG(uap, data);
345 else if (addr == LUSR_REG_OFF(llink))
346 regs->lr = (register_t)SCARG(uap, data);
347 else if (addr == LUSR_REG_OFF(lxer))
348 regs->xer = (register_t)SCARG(uap, data);
349 else if (addr == LUSR_REG_OFF(lccr))
350 regs->cr = (register_t)SCARG(uap, data);
351 else if (addr == LUSR_OFF(signal))
352 error = 1;
353 else if (addr == LUSR_OFF(magic))
354 error = 1;
355 else if (addr == LUSR_OFF(u_comm))
356 error = 1;
357 else {
358 #ifdef DEBUG_LINUX
359 printf("linux_ptrace: unsupported address: %d\n", addr);
360 #endif
361 error = 1;
362 }
363 error = process_write_regs(lt,regs);
364 mutex_exit(t->p_lock);
365 break;
366 default:
367 mutex_exit(t->p_lock);
368 break;
369 }
370 out:
371 if (regs)
372 kmem_free(regs, sizeof(*regs));
373 if (fpregs)
374 kmem_free(fpregs, sizeof(*fpregs));
375 if (linux_regs)
376 kmem_free(linux_regs, sizeof(*linux_regs));
377 if (linux_fpreg)
378 kmem_free(linux_fpreg, sizeof(*linux_fpreg));
379 return error;
380 }
381