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: releng/10.0/sys/i386/linux/linux_ptrace.c 246085 2013-01-29 18:41:30Z jhb $");
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
91 map_signum(int signum)
92 {
93
94 if (signum > 0 && signum <= LINUX_SIGTBLSZ)
95 signum = linux_to_bsd_signal[_SIG_IDX(signum)];
96 return ((signum == SIGSTOP)? 0 : signum);
97 }
98
99 struct linux_pt_reg {
100 l_long ebx;
101 l_long ecx;
102 l_long edx;
103 l_long esi;
104 l_long edi;
105 l_long ebp;
106 l_long eax;
107 l_int xds;
108 l_int xes;
109 l_int xfs;
110 l_int xgs;
111 l_long orig_eax;
112 l_long eip;
113 l_int xcs;
114 l_long eflags;
115 l_long esp;
116 l_int xss;
117 };
118
119 /*
120 * Translate i386 ptrace registers between Linux and FreeBSD formats.
121 * The translation is pretty straighforward, for all registers, but
122 * orig_eax on Linux side and r_trapno and r_err in FreeBSD
123 */
124 static void
125 map_regs_to_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
126 {
127 linux_r->ebx = bsd_r->r_ebx;
128 linux_r->ecx = bsd_r->r_ecx;
129 linux_r->edx = bsd_r->r_edx;
130 linux_r->esi = bsd_r->r_esi;
131 linux_r->edi = bsd_r->r_edi;
132 linux_r->ebp = bsd_r->r_ebp;
133 linux_r->eax = bsd_r->r_eax;
134 linux_r->xds = bsd_r->r_ds;
135 linux_r->xes = bsd_r->r_es;
136 linux_r->xfs = bsd_r->r_fs;
137 linux_r->xgs = bsd_r->r_gs;
138 linux_r->orig_eax = bsd_r->r_eax;
139 linux_r->eip = bsd_r->r_eip;
140 linux_r->xcs = bsd_r->r_cs;
141 linux_r->eflags = bsd_r->r_eflags;
142 linux_r->esp = bsd_r->r_esp;
143 linux_r->xss = bsd_r->r_ss;
144 }
145
146 static void
147 map_regs_from_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
148 {
149 bsd_r->r_ebx = linux_r->ebx;
150 bsd_r->r_ecx = linux_r->ecx;
151 bsd_r->r_edx = linux_r->edx;
152 bsd_r->r_esi = linux_r->esi;
153 bsd_r->r_edi = linux_r->edi;
154 bsd_r->r_ebp = linux_r->ebp;
155 bsd_r->r_eax = linux_r->eax;
156 bsd_r->r_ds = linux_r->xds;
157 bsd_r->r_es = linux_r->xes;
158 bsd_r->r_fs = linux_r->xfs;
159 bsd_r->r_gs = linux_r->xgs;
160 bsd_r->r_eip = linux_r->eip;
161 bsd_r->r_cs = linux_r->xcs;
162 bsd_r->r_eflags = linux_r->eflags;
163 bsd_r->r_esp = linux_r->esp;
164 bsd_r->r_ss = linux_r->xss;
165 }
166
167 struct linux_pt_fpreg {
168 l_long cwd;
169 l_long swd;
170 l_long twd;
171 l_long fip;
172 l_long fcs;
173 l_long foo;
174 l_long fos;
175 l_long st_space[2*10];
176 };
177
178 static void
179 map_fpregs_to_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
180 {
181 linux_r->cwd = bsd_r->fpr_env[0];
182 linux_r->swd = bsd_r->fpr_env[1];
183 linux_r->twd = bsd_r->fpr_env[2];
184 linux_r->fip = bsd_r->fpr_env[3];
185 linux_r->fcs = bsd_r->fpr_env[4];
186 linux_r->foo = bsd_r->fpr_env[5];
187 linux_r->fos = bsd_r->fpr_env[6];
188 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(linux_r->st_space));
189 }
190
191 static void
192 map_fpregs_from_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
193 {
194 bsd_r->fpr_env[0] = linux_r->cwd;
195 bsd_r->fpr_env[1] = linux_r->swd;
196 bsd_r->fpr_env[2] = linux_r->twd;
197 bsd_r->fpr_env[3] = linux_r->fip;
198 bsd_r->fpr_env[4] = linux_r->fcs;
199 bsd_r->fpr_env[5] = linux_r->foo;
200 bsd_r->fpr_env[6] = linux_r->fos;
201 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(bsd_r->fpr_acc));
202 }
203
204 struct linux_pt_fpxreg {
205 l_ushort cwd;
206 l_ushort swd;
207 l_ushort twd;
208 l_ushort fop;
209 l_long fip;
210 l_long fcs;
211 l_long foo;
212 l_long fos;
213 l_long mxcsr;
214 l_long reserved;
215 l_long st_space[32];
216 l_long xmm_space[32];
217 l_long padding[56];
218 };
219
220 #ifdef CPU_ENABLE_SSE
221 static int
222 linux_proc_read_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
223 {
224
225 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
226 if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
227 return (EIO);
228 bcopy(&td->td_pcb->pcb_user_save.sv_xmm, fpxregs, sizeof(*fpxregs));
229 return (0);
230 }
231
232 static int
233 linux_proc_write_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
234 {
235
236 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
237 if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
238 return (EIO);
239 bcopy(fpxregs, &td->td_pcb->pcb_user_save.sv_xmm, sizeof(*fpxregs));
240 return (0);
241 }
242 #endif
243
244 int
245 linux_ptrace(struct thread *td, struct linux_ptrace_args *uap)
246 {
247 union {
248 struct linux_pt_reg reg;
249 struct linux_pt_fpreg fpreg;
250 struct linux_pt_fpxreg fpxreg;
251 } r;
252 union {
253 struct reg bsd_reg;
254 struct fpreg bsd_fpreg;
255 struct dbreg bsd_dbreg;
256 } u;
257 void *addr;
258 pid_t pid;
259 int error, req;
260
261 error = 0;
262
263 /* by default, just copy data intact */
264 req = uap->req;
265 pid = (pid_t)uap->pid;
266 addr = (void *)uap->addr;
267
268 switch (req) {
269 case PTRACE_TRACEME:
270 case PTRACE_POKETEXT:
271 case PTRACE_POKEDATA:
272 case PTRACE_KILL:
273 error = kern_ptrace(td, req, pid, addr, uap->data);
274 break;
275 case PTRACE_PEEKTEXT:
276 case PTRACE_PEEKDATA: {
277 /* need to preserve return value */
278 int rval = td->td_retval[0];
279 error = kern_ptrace(td, req, pid, addr, 0);
280 if (error == 0)
281 error = copyout(td->td_retval, (void *)uap->data,
282 sizeof(l_int));
283 td->td_retval[0] = rval;
284 break;
285 }
286 case PTRACE_DETACH:
287 error = kern_ptrace(td, PT_DETACH, pid, (void *)1,
288 map_signum(uap->data));
289 break;
290 case PTRACE_SINGLESTEP:
291 case PTRACE_CONT:
292 error = kern_ptrace(td, req, pid, (void *)1,
293 map_signum(uap->data));
294 break;
295 case PTRACE_ATTACH:
296 error = kern_ptrace(td, PT_ATTACH, pid, addr, uap->data);
297 break;
298 case PTRACE_GETREGS:
299 /* Linux is using data where FreeBSD is using addr */
300 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
301 if (error == 0) {
302 map_regs_to_linux(&u.bsd_reg, &r.reg);
303 error = copyout(&r.reg, (void *)uap->data,
304 sizeof(r.reg));
305 }
306 break;
307 case PTRACE_SETREGS:
308 /* Linux is using data where FreeBSD is using addr */
309 error = copyin((void *)uap->data, &r.reg, sizeof(r.reg));
310 if (error == 0) {
311 map_regs_from_linux(&u.bsd_reg, &r.reg);
312 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
313 }
314 break;
315 case PTRACE_GETFPREGS:
316 /* Linux is using data where FreeBSD is using addr */
317 error = kern_ptrace(td, PT_GETFPREGS, pid, &u.bsd_fpreg, 0);
318 if (error == 0) {
319 map_fpregs_to_linux(&u.bsd_fpreg, &r.fpreg);
320 error = copyout(&r.fpreg, (void *)uap->data,
321 sizeof(r.fpreg));
322 }
323 break;
324 case PTRACE_SETFPREGS:
325 /* Linux is using data where FreeBSD is using addr */
326 error = copyin((void *)uap->data, &r.fpreg, sizeof(r.fpreg));
327 if (error == 0) {
328 map_fpregs_from_linux(&u.bsd_fpreg, &r.fpreg);
329 error = kern_ptrace(td, PT_SETFPREGS, pid,
330 &u.bsd_fpreg, 0);
331 }
332 break;
333 case PTRACE_SETFPXREGS:
334 #ifdef CPU_ENABLE_SSE
335 error = copyin((void *)uap->data, &r.fpxreg, sizeof(r.fpxreg));
336 if (error)
337 break;
338 #endif
339 /* FALL THROUGH */
340 case PTRACE_GETFPXREGS: {
341 #ifdef CPU_ENABLE_SSE
342 struct proc *p;
343 struct thread *td2;
344
345 if (sizeof(struct linux_pt_fpxreg) != sizeof(struct savexmm)) {
346 static int once = 0;
347 if (!once) {
348 printf("linux: savexmm != linux_pt_fpxreg\n");
349 once = 1;
350 }
351 error = EIO;
352 break;
353 }
354
355 if ((p = pfind(uap->pid)) == NULL) {
356 error = ESRCH;
357 break;
358 }
359
360 /* Exiting processes can't be debugged. */
361 if ((p->p_flag & P_WEXIT) != 0) {
362 error = ESRCH;
363 goto fail;
364 }
365
366 if ((error = p_candebug(td, p)) != 0)
367 goto fail;
368
369 /* System processes can't be debugged. */
370 if ((p->p_flag & P_SYSTEM) != 0) {
371 error = EINVAL;
372 goto fail;
373 }
374
375 /* not being traced... */
376 if ((p->p_flag & P_TRACED) == 0) {
377 error = EPERM;
378 goto fail;
379 }
380
381 /* not being traced by YOU */
382 if (p->p_pptr != td->td_proc) {
383 error = EBUSY;
384 goto fail;
385 }
386
387 /* not currently stopped */
388 if (!P_SHOULDSTOP(p) || (p->p_flag & P_WAITED) == 0) {
389 error = EBUSY;
390 goto fail;
391 }
392
393 if (req == PTRACE_GETFPXREGS) {
394 _PHOLD(p); /* may block */
395 td2 = FIRST_THREAD_IN_PROC(p);
396 error = linux_proc_read_fpxregs(td2, &r.fpxreg);
397 _PRELE(p);
398 PROC_UNLOCK(p);
399 if (error == 0)
400 error = copyout(&r.fpxreg, (void *)uap->data,
401 sizeof(r.fpxreg));
402 } else {
403 /* clear dangerous bits exactly as Linux does*/
404 r.fpxreg.mxcsr &= 0xffbf;
405 _PHOLD(p); /* may block */
406 td2 = FIRST_THREAD_IN_PROC(p);
407 error = linux_proc_write_fpxregs(td2, &r.fpxreg);
408 _PRELE(p);
409 PROC_UNLOCK(p);
410 }
411 break;
412
413 fail:
414 PROC_UNLOCK(p);
415 #else
416 error = EIO;
417 #endif
418 break;
419 }
420 case PTRACE_PEEKUSR:
421 case PTRACE_POKEUSR: {
422 error = EIO;
423
424 /* check addr for alignment */
425 if (uap->addr < 0 || uap->addr & (sizeof(l_int) - 1))
426 break;
427 /*
428 * Allow linux programs to access register values in
429 * user struct. We simulate this through PT_GET/SETREGS
430 * as necessary.
431 */
432 if (uap->addr < sizeof(struct linux_pt_reg)) {
433 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
434 if (error != 0)
435 break;
436
437 map_regs_to_linux(&u.bsd_reg, &r.reg);
438 if (req == PTRACE_PEEKUSR) {
439 error = copyout((char *)&r.reg + uap->addr,
440 (void *)uap->data, sizeof(l_int));
441 break;
442 }
443
444 *(l_int *)((char *)&r.reg + uap->addr) =
445 (l_int)uap->data;
446
447 map_regs_from_linux(&u.bsd_reg, &r.reg);
448 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
449 }
450
451 /*
452 * Simulate debug registers access
453 */
454 if (uap->addr >= LINUX_DBREG_OFFSET &&
455 uap->addr <= LINUX_DBREG_OFFSET + LINUX_DBREG_SIZE) {
456 error = kern_ptrace(td, PT_GETDBREGS, pid, &u.bsd_dbreg,
457 0);
458 if (error != 0)
459 break;
460
461 uap->addr -= LINUX_DBREG_OFFSET;
462 if (req == PTRACE_PEEKUSR) {
463 error = copyout((char *)&u.bsd_dbreg +
464 uap->addr, (void *)uap->data,
465 sizeof(l_int));
466 break;
467 }
468
469 *(l_int *)((char *)&u.bsd_dbreg + uap->addr) =
470 uap->data;
471 error = kern_ptrace(td, PT_SETDBREGS, pid,
472 &u.bsd_dbreg, 0);
473 }
474
475 break;
476 }
477 case PTRACE_SYSCALL:
478 /* fall through */
479 default:
480 printf("linux: ptrace(%u, ...) not implemented\n",
481 (unsigned int)uap->req);
482 error = EINVAL;
483 break;
484 }
485
486 return (error);
487 }
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