1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2001 Alexander Kabaev
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include "opt_cpu.h"
33
34 #include <sys/param.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/proc.h>
38 #include <sys/ptrace.h>
39 #include <sys/syscallsubr.h>
40 #include <sys/systm.h>
41
42 #include <machine/md_var.h>
43 #include <machine/pcb.h>
44 #include <machine/reg.h>
45
46 #include <i386/linux/linux.h>
47 #include <i386/linux/linux_proto.h>
48 #include <compat/linux/linux_signal.h>
49
50 /*
51 * Linux ptrace requests numbers. Mostly identical to FreeBSD,
52 * except for MD ones and PT_ATTACH/PT_DETACH.
53 */
54 #define PTRACE_TRACEME 0
55 #define PTRACE_PEEKTEXT 1
56 #define PTRACE_PEEKDATA 2
57 #define PTRACE_PEEKUSR 3
58 #define PTRACE_POKETEXT 4
59 #define PTRACE_POKEDATA 5
60 #define PTRACE_POKEUSR 6
61 #define PTRACE_CONT 7
62 #define PTRACE_KILL 8
63 #define PTRACE_SINGLESTEP 9
64
65 #define PTRACE_ATTACH 16
66 #define PTRACE_DETACH 17
67
68 #define LINUX_PTRACE_SYSCALL 24
69
70 #define PTRACE_GETREGS 12
71 #define PTRACE_SETREGS 13
72 #define PTRACE_GETFPREGS 14
73 #define PTRACE_SETFPREGS 15
74 #define PTRACE_GETFPXREGS 18
75 #define PTRACE_SETFPXREGS 19
76
77 #define PTRACE_SETOPTIONS 21
78
79 /*
80 * Linux keeps debug registers at the following
81 * offset in the user struct
82 */
83 #define LINUX_DBREG_OFFSET 252
84 #define LINUX_DBREG_SIZE (8*sizeof(l_int))
85
86 static __inline int
map_signum(int signum)87 map_signum(int signum)
88 {
89
90 signum = linux_to_bsd_signal(signum);
91 return ((signum == SIGSTOP)? 0 : signum);
92 }
93
94 struct linux_pt_reg {
95 l_long ebx;
96 l_long ecx;
97 l_long edx;
98 l_long esi;
99 l_long edi;
100 l_long ebp;
101 l_long eax;
102 l_int xds;
103 l_int xes;
104 l_int xfs;
105 l_int xgs;
106 l_long orig_eax;
107 l_long eip;
108 l_int xcs;
109 l_long eflags;
110 l_long esp;
111 l_int xss;
112 };
113
114 /*
115 * Translate i386 ptrace registers between Linux and FreeBSD formats.
116 * The translation is pretty straighforward, for all registers, but
117 * orig_eax on Linux side and r_trapno and r_err in FreeBSD
118 */
119 static void
map_regs_to_linux(struct reg * bsd_r,struct linux_pt_reg * linux_r)120 map_regs_to_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
121 {
122 linux_r->ebx = bsd_r->r_ebx;
123 linux_r->ecx = bsd_r->r_ecx;
124 linux_r->edx = bsd_r->r_edx;
125 linux_r->esi = bsd_r->r_esi;
126 linux_r->edi = bsd_r->r_edi;
127 linux_r->ebp = bsd_r->r_ebp;
128 linux_r->eax = bsd_r->r_eax;
129 linux_r->xds = bsd_r->r_ds;
130 linux_r->xes = bsd_r->r_es;
131 linux_r->xfs = bsd_r->r_fs;
132 linux_r->xgs = bsd_r->r_gs;
133 linux_r->orig_eax = bsd_r->r_eax;
134 linux_r->eip = bsd_r->r_eip;
135 linux_r->xcs = bsd_r->r_cs;
136 linux_r->eflags = bsd_r->r_eflags;
137 linux_r->esp = bsd_r->r_esp;
138 linux_r->xss = bsd_r->r_ss;
139 }
140
141 static void
map_regs_from_linux(struct reg * bsd_r,struct linux_pt_reg * linux_r)142 map_regs_from_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
143 {
144 bsd_r->r_ebx = linux_r->ebx;
145 bsd_r->r_ecx = linux_r->ecx;
146 bsd_r->r_edx = linux_r->edx;
147 bsd_r->r_esi = linux_r->esi;
148 bsd_r->r_edi = linux_r->edi;
149 bsd_r->r_ebp = linux_r->ebp;
150 bsd_r->r_eax = linux_r->eax;
151 bsd_r->r_ds = linux_r->xds;
152 bsd_r->r_es = linux_r->xes;
153 bsd_r->r_fs = linux_r->xfs;
154 bsd_r->r_gs = linux_r->xgs;
155 bsd_r->r_eip = linux_r->eip;
156 bsd_r->r_cs = linux_r->xcs;
157 bsd_r->r_eflags = linux_r->eflags;
158 bsd_r->r_esp = linux_r->esp;
159 bsd_r->r_ss = linux_r->xss;
160 }
161
162 struct linux_pt_fpreg {
163 l_long cwd;
164 l_long swd;
165 l_long twd;
166 l_long fip;
167 l_long fcs;
168 l_long foo;
169 l_long fos;
170 l_long st_space[2*10];
171 };
172
173 static void
map_fpregs_to_linux(struct fpreg * bsd_r,struct linux_pt_fpreg * linux_r)174 map_fpregs_to_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
175 {
176 linux_r->cwd = bsd_r->fpr_env[0];
177 linux_r->swd = bsd_r->fpr_env[1];
178 linux_r->twd = bsd_r->fpr_env[2];
179 linux_r->fip = bsd_r->fpr_env[3];
180 linux_r->fcs = bsd_r->fpr_env[4];
181 linux_r->foo = bsd_r->fpr_env[5];
182 linux_r->fos = bsd_r->fpr_env[6];
183 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(linux_r->st_space));
184 }
185
186 static void
map_fpregs_from_linux(struct fpreg * bsd_r,struct linux_pt_fpreg * linux_r)187 map_fpregs_from_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
188 {
189 bsd_r->fpr_env[0] = linux_r->cwd;
190 bsd_r->fpr_env[1] = linux_r->swd;
191 bsd_r->fpr_env[2] = linux_r->twd;
192 bsd_r->fpr_env[3] = linux_r->fip;
193 bsd_r->fpr_env[4] = linux_r->fcs;
194 bsd_r->fpr_env[5] = linux_r->foo;
195 bsd_r->fpr_env[6] = linux_r->fos;
196 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(bsd_r->fpr_acc));
197 }
198
199 struct linux_pt_fpxreg {
200 l_ushort cwd;
201 l_ushort swd;
202 l_ushort twd;
203 l_ushort fop;
204 l_long fip;
205 l_long fcs;
206 l_long foo;
207 l_long fos;
208 l_long mxcsr;
209 l_long reserved;
210 l_long st_space[32];
211 l_long xmm_space[32];
212 l_long padding[56];
213 };
214
215 static int
linux_proc_read_fpxregs(struct thread * td,struct linux_pt_fpxreg * fpxregs)216 linux_proc_read_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
217 {
218
219 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
220 if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
221 return (EIO);
222 bcopy(&get_pcb_user_save_td(td)->sv_xmm, fpxregs, sizeof(*fpxregs));
223 return (0);
224 }
225
226 static int
linux_proc_write_fpxregs(struct thread * td,struct linux_pt_fpxreg * fpxregs)227 linux_proc_write_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
228 {
229
230 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
231 if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
232 return (EIO);
233 bcopy(fpxregs, &get_pcb_user_save_td(td)->sv_xmm, sizeof(*fpxregs));
234 return (0);
235 }
236
237 int
linux_ptrace(struct thread * td,struct linux_ptrace_args * uap)238 linux_ptrace(struct thread *td, struct linux_ptrace_args *uap)
239 {
240 union {
241 struct linux_pt_reg reg;
242 struct linux_pt_fpreg fpreg;
243 struct linux_pt_fpxreg fpxreg;
244 } r;
245 union {
246 struct reg bsd_reg;
247 struct fpreg bsd_fpreg;
248 struct dbreg bsd_dbreg;
249 } u;
250 void *addr;
251 pid_t pid;
252 int error, req;
253
254 error = 0;
255
256 /* by default, just copy data intact */
257 req = uap->req;
258 pid = (pid_t)uap->pid;
259 addr = (void *)uap->addr;
260
261 switch (req) {
262 case PTRACE_TRACEME:
263 case PTRACE_POKETEXT:
264 case PTRACE_POKEDATA:
265 case PTRACE_KILL:
266 error = kern_ptrace(td, req, pid, addr, uap->data);
267 break;
268 case PTRACE_PEEKTEXT:
269 case PTRACE_PEEKDATA: {
270 /* need to preserve return value */
271 int rval = td->td_retval[0];
272 error = kern_ptrace(td, req, pid, addr, 0);
273 if (error == 0)
274 error = copyout(td->td_retval, (void *)uap->data,
275 sizeof(l_int));
276 td->td_retval[0] = rval;
277 break;
278 }
279 case PTRACE_DETACH:
280 error = kern_ptrace(td, PT_DETACH, pid, (void *)1,
281 map_signum(uap->data));
282 break;
283 case PTRACE_SINGLESTEP:
284 case PTRACE_CONT:
285 error = kern_ptrace(td, req, pid, (void *)1,
286 map_signum(uap->data));
287 break;
288 case PTRACE_ATTACH:
289 error = kern_ptrace(td, PT_ATTACH, pid, addr, uap->data);
290 break;
291 case PTRACE_GETREGS:
292 /* Linux is using data where FreeBSD is using addr */
293 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
294 if (error == 0) {
295 map_regs_to_linux(&u.bsd_reg, &r.reg);
296 error = copyout(&r.reg, (void *)uap->data,
297 sizeof(r.reg));
298 }
299 break;
300 case PTRACE_SETREGS:
301 /* Linux is using data where FreeBSD is using addr */
302 error = copyin((void *)uap->data, &r.reg, sizeof(r.reg));
303 if (error == 0) {
304 map_regs_from_linux(&u.bsd_reg, &r.reg);
305 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
306 }
307 break;
308 case PTRACE_GETFPREGS:
309 /* Linux is using data where FreeBSD is using addr */
310 error = kern_ptrace(td, PT_GETFPREGS, pid, &u.bsd_fpreg, 0);
311 if (error == 0) {
312 map_fpregs_to_linux(&u.bsd_fpreg, &r.fpreg);
313 error = copyout(&r.fpreg, (void *)uap->data,
314 sizeof(r.fpreg));
315 }
316 break;
317 case PTRACE_SETFPREGS:
318 /* Linux is using data where FreeBSD is using addr */
319 error = copyin((void *)uap->data, &r.fpreg, sizeof(r.fpreg));
320 if (error == 0) {
321 map_fpregs_from_linux(&u.bsd_fpreg, &r.fpreg);
322 error = kern_ptrace(td, PT_SETFPREGS, pid,
323 &u.bsd_fpreg, 0);
324 }
325 break;
326 case PTRACE_SETFPXREGS:
327 error = copyin((void *)uap->data, &r.fpxreg, sizeof(r.fpxreg));
328 if (error)
329 break;
330 /* FALL THROUGH */
331 case PTRACE_GETFPXREGS: {
332 struct proc *p;
333 struct thread *td2;
334
335 if (sizeof(struct linux_pt_fpxreg) != sizeof(struct savexmm)) {
336 static int once = 0;
337 if (!once) {
338 printf("linux: savexmm != linux_pt_fpxreg\n");
339 once = 1;
340 }
341 error = EIO;
342 break;
343 }
344
345 if ((p = pfind(uap->pid)) == NULL) {
346 error = ESRCH;
347 break;
348 }
349
350 /* Exiting processes can't be debugged. */
351 if ((p->p_flag & P_WEXIT) != 0) {
352 error = ESRCH;
353 goto fail;
354 }
355
356 if ((error = p_candebug(td, p)) != 0)
357 goto fail;
358
359 /* System processes can't be debugged. */
360 if ((p->p_flag & P_SYSTEM) != 0) {
361 error = EINVAL;
362 goto fail;
363 }
364
365 /* not being traced... */
366 if ((p->p_flag & P_TRACED) == 0) {
367 error = EPERM;
368 goto fail;
369 }
370
371 /* not being traced by YOU */
372 if (p->p_pptr != td->td_proc) {
373 error = EBUSY;
374 goto fail;
375 }
376
377 /* not currently stopped */
378 if (!P_SHOULDSTOP(p) || (p->p_flag & P_WAITED) == 0) {
379 error = EBUSY;
380 goto fail;
381 }
382
383 if (req == PTRACE_GETFPXREGS) {
384 _PHOLD(p); /* may block */
385 td2 = FIRST_THREAD_IN_PROC(p);
386 error = linux_proc_read_fpxregs(td2, &r.fpxreg);
387 _PRELE(p);
388 PROC_UNLOCK(p);
389 if (error == 0)
390 error = copyout(&r.fpxreg, (void *)uap->data,
391 sizeof(r.fpxreg));
392 } else {
393 /* clear dangerous bits exactly as Linux does*/
394 r.fpxreg.mxcsr &= 0xffbf;
395 _PHOLD(p); /* may block */
396 td2 = FIRST_THREAD_IN_PROC(p);
397 error = linux_proc_write_fpxregs(td2, &r.fpxreg);
398 _PRELE(p);
399 PROC_UNLOCK(p);
400 }
401 break;
402
403 fail:
404 PROC_UNLOCK(p);
405 break;
406 }
407 case PTRACE_PEEKUSR:
408 case PTRACE_POKEUSR: {
409 error = EIO;
410
411 /* check addr for alignment */
412 if (uap->addr < 0 || uap->addr & (sizeof(l_int) - 1))
413 break;
414 /*
415 * Allow Linux programs to access register values in
416 * user struct. We simulate this through PT_GET/SETREGS
417 * as necessary.
418 */
419 if (uap->addr < sizeof(struct linux_pt_reg)) {
420 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
421 if (error != 0)
422 break;
423
424 map_regs_to_linux(&u.bsd_reg, &r.reg);
425 if (req == PTRACE_PEEKUSR) {
426 error = copyout((char *)&r.reg + uap->addr,
427 (void *)uap->data, sizeof(l_int));
428 break;
429 }
430
431 *(l_int *)((char *)&r.reg + uap->addr) =
432 (l_int)uap->data;
433
434 map_regs_from_linux(&u.bsd_reg, &r.reg);
435 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
436 }
437
438 /*
439 * Simulate debug registers access
440 */
441 if (uap->addr >= LINUX_DBREG_OFFSET &&
442 uap->addr <= LINUX_DBREG_OFFSET + LINUX_DBREG_SIZE) {
443 error = kern_ptrace(td, PT_GETDBREGS, pid, &u.bsd_dbreg,
444 0);
445 if (error != 0)
446 break;
447
448 uap->addr -= LINUX_DBREG_OFFSET;
449 if (req == PTRACE_PEEKUSR) {
450 error = copyout((char *)&u.bsd_dbreg +
451 uap->addr, (void *)uap->data,
452 sizeof(l_int));
453 break;
454 }
455
456 *(l_int *)((char *)&u.bsd_dbreg + uap->addr) =
457 uap->data;
458 error = kern_ptrace(td, PT_SETDBREGS, pid,
459 &u.bsd_dbreg, 0);
460 }
461
462 break;
463 }
464 case LINUX_PTRACE_SYSCALL:
465 /* fall through */
466 default:
467 printf("linux: ptrace(%u, ...) not implemented\n",
468 (unsigned int)uap->req);
469 error = EINVAL;
470 break;
471 }
472
473 return (error);
474 }
475