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