1 /*-
2 * Copyright (c) 2001 Alexander Kabaev
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 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 #if !defined(CPU_DISABLE_SSE) && defined(I686_CPU)
51 #define CPU_ENABLE_SSE
52 #endif
53
54 /*
55 * Linux ptrace requests numbers. Mostly identical to FreeBSD,
56 * except for MD ones and PT_ATTACH/PT_DETACH.
57 */
58 #define PTRACE_TRACEME 0
59 #define PTRACE_PEEKTEXT 1
60 #define PTRACE_PEEKDATA 2
61 #define PTRACE_PEEKUSR 3
62 #define PTRACE_POKETEXT 4
63 #define PTRACE_POKEDATA 5
64 #define PTRACE_POKEUSR 6
65 #define PTRACE_CONT 7
66 #define PTRACE_KILL 8
67 #define PTRACE_SINGLESTEP 9
68
69 #define PTRACE_ATTACH 16
70 #define PTRACE_DETACH 17
71
72 #define PTRACE_SYSCALL 24
73
74 #define PTRACE_GETREGS 12
75 #define PTRACE_SETREGS 13
76 #define PTRACE_GETFPREGS 14
77 #define PTRACE_SETFPREGS 15
78 #define PTRACE_GETFPXREGS 18
79 #define PTRACE_SETFPXREGS 19
80
81 #define PTRACE_SETOPTIONS 21
82
83 /*
84 * Linux keeps debug registers at the following
85 * offset in the user struct
86 */
87 #define LINUX_DBREG_OFFSET 252
88 #define LINUX_DBREG_SIZE (8*sizeof(l_int))
89
90 static __inline int
map_signum(int signum)91 map_signum(int signum)
92 {
93
94 signum = linux_to_bsd_signal(signum);
95 return ((signum == SIGSTOP)? 0 : signum);
96 }
97
98 struct linux_pt_reg {
99 l_long ebx;
100 l_long ecx;
101 l_long edx;
102 l_long esi;
103 l_long edi;
104 l_long ebp;
105 l_long eax;
106 l_int xds;
107 l_int xes;
108 l_int xfs;
109 l_int xgs;
110 l_long orig_eax;
111 l_long eip;
112 l_int xcs;
113 l_long eflags;
114 l_long esp;
115 l_int xss;
116 };
117
118 /*
119 * Translate i386 ptrace registers between Linux and FreeBSD formats.
120 * The translation is pretty straighforward, for all registers, but
121 * orig_eax on Linux side and r_trapno and r_err in FreeBSD
122 */
123 static void
map_regs_to_linux(struct reg * bsd_r,struct linux_pt_reg * linux_r)124 map_regs_to_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
125 {
126 linux_r->ebx = bsd_r->r_ebx;
127 linux_r->ecx = bsd_r->r_ecx;
128 linux_r->edx = bsd_r->r_edx;
129 linux_r->esi = bsd_r->r_esi;
130 linux_r->edi = bsd_r->r_edi;
131 linux_r->ebp = bsd_r->r_ebp;
132 linux_r->eax = bsd_r->r_eax;
133 linux_r->xds = bsd_r->r_ds;
134 linux_r->xes = bsd_r->r_es;
135 linux_r->xfs = bsd_r->r_fs;
136 linux_r->xgs = bsd_r->r_gs;
137 linux_r->orig_eax = bsd_r->r_eax;
138 linux_r->eip = bsd_r->r_eip;
139 linux_r->xcs = bsd_r->r_cs;
140 linux_r->eflags = bsd_r->r_eflags;
141 linux_r->esp = bsd_r->r_esp;
142 linux_r->xss = bsd_r->r_ss;
143 }
144
145 static void
map_regs_from_linux(struct reg * bsd_r,struct linux_pt_reg * linux_r)146 map_regs_from_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
147 {
148 bsd_r->r_ebx = linux_r->ebx;
149 bsd_r->r_ecx = linux_r->ecx;
150 bsd_r->r_edx = linux_r->edx;
151 bsd_r->r_esi = linux_r->esi;
152 bsd_r->r_edi = linux_r->edi;
153 bsd_r->r_ebp = linux_r->ebp;
154 bsd_r->r_eax = linux_r->eax;
155 bsd_r->r_ds = linux_r->xds;
156 bsd_r->r_es = linux_r->xes;
157 bsd_r->r_fs = linux_r->xfs;
158 bsd_r->r_gs = linux_r->xgs;
159 bsd_r->r_eip = linux_r->eip;
160 bsd_r->r_cs = linux_r->xcs;
161 bsd_r->r_eflags = linux_r->eflags;
162 bsd_r->r_esp = linux_r->esp;
163 bsd_r->r_ss = linux_r->xss;
164 }
165
166 struct linux_pt_fpreg {
167 l_long cwd;
168 l_long swd;
169 l_long twd;
170 l_long fip;
171 l_long fcs;
172 l_long foo;
173 l_long fos;
174 l_long st_space[2*10];
175 };
176
177 static void
map_fpregs_to_linux(struct fpreg * bsd_r,struct linux_pt_fpreg * linux_r)178 map_fpregs_to_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
179 {
180 linux_r->cwd = bsd_r->fpr_env[0];
181 linux_r->swd = bsd_r->fpr_env[1];
182 linux_r->twd = bsd_r->fpr_env[2];
183 linux_r->fip = bsd_r->fpr_env[3];
184 linux_r->fcs = bsd_r->fpr_env[4];
185 linux_r->foo = bsd_r->fpr_env[5];
186 linux_r->fos = bsd_r->fpr_env[6];
187 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(linux_r->st_space));
188 }
189
190 static void
map_fpregs_from_linux(struct fpreg * bsd_r,struct linux_pt_fpreg * linux_r)191 map_fpregs_from_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
192 {
193 bsd_r->fpr_env[0] = linux_r->cwd;
194 bsd_r->fpr_env[1] = linux_r->swd;
195 bsd_r->fpr_env[2] = linux_r->twd;
196 bsd_r->fpr_env[3] = linux_r->fip;
197 bsd_r->fpr_env[4] = linux_r->fcs;
198 bsd_r->fpr_env[5] = linux_r->foo;
199 bsd_r->fpr_env[6] = linux_r->fos;
200 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(bsd_r->fpr_acc));
201 }
202
203 struct linux_pt_fpxreg {
204 l_ushort cwd;
205 l_ushort swd;
206 l_ushort twd;
207 l_ushort fop;
208 l_long fip;
209 l_long fcs;
210 l_long foo;
211 l_long fos;
212 l_long mxcsr;
213 l_long reserved;
214 l_long st_space[32];
215 l_long xmm_space[32];
216 l_long padding[56];
217 };
218
219 #ifdef CPU_ENABLE_SSE
220 static int
linux_proc_read_fpxregs(struct thread * td,struct linux_pt_fpxreg * fpxregs)221 linux_proc_read_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
222 {
223
224 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
225 if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
226 return (EIO);
227 bcopy(&get_pcb_user_save_td(td)->sv_xmm, fpxregs, sizeof(*fpxregs));
228 return (0);
229 }
230
231 static int
linux_proc_write_fpxregs(struct thread * td,struct linux_pt_fpxreg * fpxregs)232 linux_proc_write_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
233 {
234
235 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
236 if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
237 return (EIO);
238 bcopy(fpxregs, &get_pcb_user_save_td(td)->sv_xmm, sizeof(*fpxregs));
239 return (0);
240 }
241 #endif
242
243 int
linux_ptrace(struct thread * td,struct linux_ptrace_args * uap)244 linux_ptrace(struct thread *td, struct linux_ptrace_args *uap)
245 {
246 union {
247 struct linux_pt_reg reg;
248 struct linux_pt_fpreg fpreg;
249 struct linux_pt_fpxreg fpxreg;
250 } r;
251 union {
252 struct reg bsd_reg;
253 struct fpreg bsd_fpreg;
254 struct dbreg bsd_dbreg;
255 } u;
256 void *addr;
257 pid_t pid;
258 int error, req;
259
260 error = 0;
261
262 /* by default, just copy data intact */
263 req = uap->req;
264 pid = (pid_t)uap->pid;
265 addr = (void *)uap->addr;
266
267 switch (req) {
268 case PTRACE_TRACEME:
269 case PTRACE_POKETEXT:
270 case PTRACE_POKEDATA:
271 case PTRACE_KILL:
272 error = kern_ptrace(td, req, pid, addr, uap->data);
273 break;
274 case PTRACE_PEEKTEXT:
275 case PTRACE_PEEKDATA: {
276 /* need to preserve return value */
277 int rval = td->td_retval[0];
278 error = kern_ptrace(td, req, pid, addr, 0);
279 if (error == 0)
280 error = copyout(td->td_retval, (void *)uap->data,
281 sizeof(l_int));
282 td->td_retval[0] = rval;
283 break;
284 }
285 case PTRACE_DETACH:
286 error = kern_ptrace(td, PT_DETACH, pid, (void *)1,
287 map_signum(uap->data));
288 break;
289 case PTRACE_SINGLESTEP:
290 case PTRACE_CONT:
291 error = kern_ptrace(td, req, pid, (void *)1,
292 map_signum(uap->data));
293 break;
294 case PTRACE_ATTACH:
295 error = kern_ptrace(td, PT_ATTACH, pid, addr, uap->data);
296 break;
297 case PTRACE_GETREGS:
298 /* Linux is using data where FreeBSD is using addr */
299 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
300 if (error == 0) {
301 map_regs_to_linux(&u.bsd_reg, &r.reg);
302 error = copyout(&r.reg, (void *)uap->data,
303 sizeof(r.reg));
304 }
305 break;
306 case PTRACE_SETREGS:
307 /* Linux is using data where FreeBSD is using addr */
308 error = copyin((void *)uap->data, &r.reg, sizeof(r.reg));
309 if (error == 0) {
310 map_regs_from_linux(&u.bsd_reg, &r.reg);
311 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
312 }
313 break;
314 case PTRACE_GETFPREGS:
315 /* Linux is using data where FreeBSD is using addr */
316 error = kern_ptrace(td, PT_GETFPREGS, pid, &u.bsd_fpreg, 0);
317 if (error == 0) {
318 map_fpregs_to_linux(&u.bsd_fpreg, &r.fpreg);
319 error = copyout(&r.fpreg, (void *)uap->data,
320 sizeof(r.fpreg));
321 }
322 break;
323 case PTRACE_SETFPREGS:
324 /* Linux is using data where FreeBSD is using addr */
325 error = copyin((void *)uap->data, &r.fpreg, sizeof(r.fpreg));
326 if (error == 0) {
327 map_fpregs_from_linux(&u.bsd_fpreg, &r.fpreg);
328 error = kern_ptrace(td, PT_SETFPREGS, pid,
329 &u.bsd_fpreg, 0);
330 }
331 break;
332 case PTRACE_SETFPXREGS:
333 #ifdef CPU_ENABLE_SSE
334 error = copyin((void *)uap->data, &r.fpxreg, sizeof(r.fpxreg));
335 if (error)
336 break;
337 #endif
338 /* FALL THROUGH */
339 case PTRACE_GETFPXREGS: {
340 #ifdef CPU_ENABLE_SSE
341 struct proc *p;
342 struct thread *td2;
343
344 if (sizeof(struct linux_pt_fpxreg) != sizeof(struct savexmm)) {
345 static int once = 0;
346 if (!once) {
347 printf("linux: savexmm != linux_pt_fpxreg\n");
348 once = 1;
349 }
350 error = EIO;
351 break;
352 }
353
354 if ((p = pfind(uap->pid)) == NULL) {
355 error = ESRCH;
356 break;
357 }
358
359 /* Exiting processes can't be debugged. */
360 if ((p->p_flag & P_WEXIT) != 0) {
361 error = ESRCH;
362 goto fail;
363 }
364
365 if ((error = p_candebug(td, p)) != 0)
366 goto fail;
367
368 /* System processes can't be debugged. */
369 if ((p->p_flag & P_SYSTEM) != 0) {
370 error = EINVAL;
371 goto fail;
372 }
373
374 /* not being traced... */
375 if ((p->p_flag & P_TRACED) == 0) {
376 error = EPERM;
377 goto fail;
378 }
379
380 /* not being traced by YOU */
381 if (p->p_pptr != td->td_proc) {
382 error = EBUSY;
383 goto fail;
384 }
385
386 /* not currently stopped */
387 if (!P_SHOULDSTOP(p) || (p->p_flag & P_WAITED) == 0) {
388 error = EBUSY;
389 goto fail;
390 }
391
392 if (req == PTRACE_GETFPXREGS) {
393 _PHOLD(p); /* may block */
394 td2 = FIRST_THREAD_IN_PROC(p);
395 error = linux_proc_read_fpxregs(td2, &r.fpxreg);
396 _PRELE(p);
397 PROC_UNLOCK(p);
398 if (error == 0)
399 error = copyout(&r.fpxreg, (void *)uap->data,
400 sizeof(r.fpxreg));
401 } else {
402 /* clear dangerous bits exactly as Linux does*/
403 r.fpxreg.mxcsr &= 0xffbf;
404 _PHOLD(p); /* may block */
405 td2 = FIRST_THREAD_IN_PROC(p);
406 error = linux_proc_write_fpxregs(td2, &r.fpxreg);
407 _PRELE(p);
408 PROC_UNLOCK(p);
409 }
410 break;
411
412 fail:
413 PROC_UNLOCK(p);
414 #else
415 error = EIO;
416 #endif
417 break;
418 }
419 case PTRACE_PEEKUSR:
420 case PTRACE_POKEUSR: {
421 error = EIO;
422
423 /* check addr for alignment */
424 if (uap->addr < 0 || uap->addr & (sizeof(l_int) - 1))
425 break;
426 /*
427 * Allow linux programs to access register values in
428 * user struct. We simulate this through PT_GET/SETREGS
429 * as necessary.
430 */
431 if (uap->addr < sizeof(struct linux_pt_reg)) {
432 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
433 if (error != 0)
434 break;
435
436 map_regs_to_linux(&u.bsd_reg, &r.reg);
437 if (req == PTRACE_PEEKUSR) {
438 error = copyout((char *)&r.reg + uap->addr,
439 (void *)uap->data, sizeof(l_int));
440 break;
441 }
442
443 *(l_int *)((char *)&r.reg + uap->addr) =
444 (l_int)uap->data;
445
446 map_regs_from_linux(&u.bsd_reg, &r.reg);
447 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
448 }
449
450 /*
451 * Simulate debug registers access
452 */
453 if (uap->addr >= LINUX_DBREG_OFFSET &&
454 uap->addr <= LINUX_DBREG_OFFSET + LINUX_DBREG_SIZE) {
455 error = kern_ptrace(td, PT_GETDBREGS, pid, &u.bsd_dbreg,
456 0);
457 if (error != 0)
458 break;
459
460 uap->addr -= LINUX_DBREG_OFFSET;
461 if (req == PTRACE_PEEKUSR) {
462 error = copyout((char *)&u.bsd_dbreg +
463 uap->addr, (void *)uap->data,
464 sizeof(l_int));
465 break;
466 }
467
468 *(l_int *)((char *)&u.bsd_dbreg + uap->addr) =
469 uap->data;
470 error = kern_ptrace(td, PT_SETDBREGS, pid,
471 &u.bsd_dbreg, 0);
472 }
473
474 break;
475 }
476 case PTRACE_SYSCALL:
477 /* fall through */
478 default:
479 printf("linux: ptrace(%u, ...) not implemented\n",
480 (unsigned int)uap->req);
481 error = EINVAL;
482 break;
483 }
484
485 return (error);
486 }
487