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 * $FreeBSD: releng/5.1/sys/i386/linux/linux_ptrace.c 113868 2003-04-22 20:01:56Z jhb $
29 */
30
31 #include "opt_cpu.h"
32
33 #include <sys/param.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/proc.h>
37 #include <sys/ptrace.h>
38 #include <sys/syscallsubr.h>
39 #include <sys/systm.h>
40
41 #include <machine/md_var.h>
42 #include <machine/pcb.h>
43 #include <machine/reg.h>
44
45 #include <i386/linux/linux.h>
46 #include <i386/linux/linux_proto.h>
47
48 #if !defined(CPU_ENABLE_SSE) && defined(I686_CPU)
49 #define CPU_ENABLE_SSE
50 #endif
51 #if defined(CPU_DISABLE_SSE)
52 #undef CPU_ENABLE_SSE
53 #endif
54
55 /*
56 * Linux ptrace requests numbers. Mostly identical to FreeBSD,
57 * except for MD ones and PT_ATTACH/PT_DETACH.
58 */
59 #define PTRACE_TRACEME 0
60 #define PTRACE_PEEKTEXT 1
61 #define PTRACE_PEEKDATA 2
62 #define PTRACE_PEEKUSR 3
63 #define PTRACE_POKETEXT 4
64 #define PTRACE_POKEDATA 5
65 #define PTRACE_POKEUSR 6
66 #define PTRACE_CONT 7
67 #define PTRACE_KILL 8
68 #define PTRACE_SINGLESTEP 9
69
70 #define PTRACE_ATTACH 16
71 #define PTRACE_DETACH 17
72
73 #define PTRACE_SYSCALL 24
74
75 #define PTRACE_GETREGS 12
76 #define PTRACE_SETREGS 13
77 #define PTRACE_GETFPREGS 14
78 #define PTRACE_SETFPREGS 15
79 #define PTRACE_GETFPXREGS 18
80 #define PTRACE_SETFPXREGS 19
81
82 #define PTRACE_SETOPTIONS 21
83
84 /*
85 * Linux keeps debug registers at the following
86 * offset in the user struct
87 */
88 #define LINUX_DBREG_OFFSET 252
89 #define LINUX_DBREG_SIZE (8*sizeof(l_int))
90
91 static __inline__ int
92 map_signum(int signum)
93 {
94
95 if (signum > 0 && signum <= LINUX_SIGTBLSZ)
96 signum = linux_to_bsd_signal[_SIG_IDX(signum)];
97 return ((signum == SIGSTOP)? 0 : signum);
98 }
99
100 struct linux_pt_reg {
101 l_long ebx;
102 l_long ecx;
103 l_long edx;
104 l_long esi;
105 l_long edi;
106 l_long ebp;
107 l_long eax;
108 l_int xds;
109 l_int xes;
110 l_int xfs;
111 l_int xgs;
112 l_long orig_eax;
113 l_long eip;
114 l_int xcs;
115 l_long eflags;
116 l_long esp;
117 l_int xss;
118 };
119
120 /*
121 * Translate i386 ptrace registers between Linux and FreeBSD formats.
122 * The translation is pretty straighforward, for all registers, but
123 * orig_eax on Linux side and r_trapno and r_err in FreeBSD
124 */
125 static void
126 map_regs_to_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
127 {
128 linux_r->ebx = bsd_r->r_ebx;
129 linux_r->ecx = bsd_r->r_ecx;
130 linux_r->edx = bsd_r->r_edx;
131 linux_r->esi = bsd_r->r_esi;
132 linux_r->edi = bsd_r->r_edi;
133 linux_r->ebp = bsd_r->r_ebp;
134 linux_r->eax = bsd_r->r_eax;
135 linux_r->xds = bsd_r->r_ds;
136 linux_r->xes = bsd_r->r_es;
137 linux_r->xfs = bsd_r->r_fs;
138 linux_r->xgs = bsd_r->r_gs;
139 linux_r->orig_eax = bsd_r->r_eax;
140 linux_r->eip = bsd_r->r_eip;
141 linux_r->xcs = bsd_r->r_cs;
142 linux_r->eflags = bsd_r->r_eflags;
143 linux_r->esp = bsd_r->r_esp;
144 linux_r->xss = bsd_r->r_ss;
145 }
146
147 static void
148 map_regs_from_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r)
149 {
150 bsd_r->r_ebx = linux_r->ebx;
151 bsd_r->r_ecx = linux_r->ecx;
152 bsd_r->r_edx = linux_r->edx;
153 bsd_r->r_esi = linux_r->esi;
154 bsd_r->r_edi = linux_r->edi;
155 bsd_r->r_ebp = linux_r->ebp;
156 bsd_r->r_eax = linux_r->eax;
157 bsd_r->r_ds = linux_r->xds;
158 bsd_r->r_es = linux_r->xes;
159 bsd_r->r_fs = linux_r->xfs;
160 bsd_r->r_gs = linux_r->xgs;
161 bsd_r->r_eip = linux_r->eip;
162 bsd_r->r_cs = linux_r->xcs;
163 bsd_r->r_eflags = linux_r->eflags;
164 bsd_r->r_esp = linux_r->esp;
165 bsd_r->r_ss = linux_r->xss;
166 }
167
168 struct linux_pt_fpreg {
169 l_long cwd;
170 l_long swd;
171 l_long twd;
172 l_long fip;
173 l_long fcs;
174 l_long foo;
175 l_long fos;
176 l_long st_space[2*10];
177 };
178
179 static void
180 map_fpregs_to_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
181 {
182 linux_r->cwd = bsd_r->fpr_env[0];
183 linux_r->swd = bsd_r->fpr_env[1];
184 linux_r->twd = bsd_r->fpr_env[2];
185 linux_r->fip = bsd_r->fpr_env[3];
186 linux_r->fcs = bsd_r->fpr_env[4];
187 linux_r->foo = bsd_r->fpr_env[5];
188 linux_r->fos = bsd_r->fpr_env[6];
189 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(linux_r->st_space));
190 }
191
192 static void
193 map_fpregs_from_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r)
194 {
195 bsd_r->fpr_env[0] = linux_r->cwd;
196 bsd_r->fpr_env[1] = linux_r->swd;
197 bsd_r->fpr_env[2] = linux_r->twd;
198 bsd_r->fpr_env[3] = linux_r->fip;
199 bsd_r->fpr_env[4] = linux_r->fcs;
200 bsd_r->fpr_env[5] = linux_r->foo;
201 bsd_r->fpr_env[6] = linux_r->fos;
202 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(bsd_r->fpr_acc));
203 }
204
205 struct linux_pt_fpxreg {
206 l_ushort cwd;
207 l_ushort swd;
208 l_ushort twd;
209 l_ushort fop;
210 l_long fip;
211 l_long fcs;
212 l_long foo;
213 l_long fos;
214 l_long mxcsr;
215 l_long reserved;
216 l_long st_space[32];
217 l_long xmm_space[32];
218 l_long padding[56];
219 };
220
221 #ifdef CPU_ENABLE_SSE
222 static int
223 linux_proc_read_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_sflag & PS_INMEM) == 0)
228 return (EIO);
229 bcopy(&td->td_pcb->pcb_save.sv_xmm, fpxregs, sizeof(*fpxregs));
230 return (0);
231 }
232
233 static int
234 linux_proc_write_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
235 {
236
237 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
238 if (cpu_fxsr == 0 || (td->td_proc->p_sflag & PS_INMEM) == 0)
239 return (EIO);
240 bcopy(fpxregs, &td->td_pcb->pcb_save.sv_xmm, sizeof(*fpxregs));
241 return (0);
242 }
243 #endif
244
245 int
246 linux_ptrace(struct thread *td, struct linux_ptrace_args *uap)
247 {
248 union {
249 struct linux_pt_reg reg;
250 struct linux_pt_fpreg fpreg;
251 struct linux_pt_fpxreg fpxreg;
252 } r;
253 union {
254 struct reg bsd_reg;
255 struct fpreg bsd_fpreg;
256 struct dbreg bsd_dbreg;
257 } u;
258 void *addr;
259 pid_t pid;
260 int error, req;
261
262 error = 0;
263
264 /* by default, just copy data intact */
265 req = uap->req;
266 pid = (pid_t)uap->pid;
267 addr = (void *)uap->addr;
268
269 switch (req) {
270 case PTRACE_TRACEME:
271 case PTRACE_POKETEXT:
272 case PTRACE_POKEDATA:
273 case PTRACE_KILL:
274 error = kern_ptrace(td, req, pid, addr, uap->data);
275 break;
276 case PTRACE_PEEKTEXT:
277 case PTRACE_PEEKDATA: {
278 /* need to preserve return value */
279 int rval = td->td_retval[0];
280 error = kern_ptrace(td, req, pid, addr, 0);
281 if (error == 0)
282 error = copyout(td->td_retval, (void *)uap->data,
283 sizeof(l_int));
284 td->td_retval[0] = rval;
285 break;
286 }
287 case PTRACE_DETACH:
288 error = kern_ptrace(td, PT_DETACH, pid, (void *)1,
289 map_signum(uap->data));
290 break;
291 case PTRACE_SINGLESTEP:
292 case PTRACE_CONT:
293 error = kern_ptrace(td, req, pid, (void *)1,
294 map_signum(uap->data));
295 break;
296 case PTRACE_ATTACH:
297 error = kern_ptrace(td, PT_ATTACH, pid, addr, uap->data);
298 break;
299 case PTRACE_GETREGS:
300 /* Linux is using data where FreeBSD is using addr */
301 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
302 if (error == 0) {
303 map_regs_to_linux(&u.bsd_reg, &r.reg);
304 error = copyout(&r.reg, (void *)uap->data,
305 sizeof(r.reg));
306 }
307 break;
308 case PTRACE_SETREGS:
309 /* Linux is using data where FreeBSD is using addr */
310 error = copyin((void *)uap->data, &r.reg, sizeof(r.reg));
311 if (error == 0) {
312 map_regs_from_linux(&u.bsd_reg, &r.reg);
313 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
314 }
315 break;
316 case PTRACE_GETFPREGS:
317 /* Linux is using data where FreeBSD is using addr */
318 error = kern_ptrace(td, PT_GETFPREGS, pid, &u.bsd_fpreg, 0);
319 if (error == 0) {
320 map_fpregs_to_linux(&u.bsd_fpreg, &r.fpreg);
321 error = copyout(&r.fpreg, (void *)uap->data,
322 sizeof(r.fpreg));
323 }
324 break;
325 case PTRACE_SETFPREGS:
326 /* Linux is using data where FreeBSD is using addr */
327 error = copyin((void *)uap->data, &r.fpreg, sizeof(r.fpreg));
328 if (error == 0) {
329 map_fpregs_from_linux(&u.bsd_fpreg, &r.fpreg);
330 error = kern_ptrace(td, PT_SETFPREGS, pid,
331 &u.bsd_fpreg, 0);
332 }
333 break;
334 case PTRACE_SETFPXREGS:
335 #ifdef CPU_ENABLE_SSE
336 error = copyin((void *)uap->data, &r.fpxreg, sizeof(r.fpxreg));
337 if (error)
338 break;
339 #endif
340 /* FALL THROUGH */
341 case PTRACE_GETFPXREGS: {
342 #ifdef CPU_ENABLE_SSE
343 struct proc *p;
344 struct thread *td2;
345
346 if (sizeof(struct linux_pt_fpxreg) != sizeof(struct savexmm)) {
347 static int once = 0;
348 if (!once) {
349 printf("linux: savexmm != linux_pt_fpxreg\n");
350 once = 1;
351 }
352 error = EIO;
353 break;
354 }
355
356 if ((p = pfind(uap->pid)) == NULL) {
357 error = ESRCH;
358 break;
359 }
360
361 if ((error = p_candebug(td, p)) != 0)
362 goto fail;
363
364 /* System processes can't be debugged. */
365 if ((p->p_flag & P_SYSTEM) != 0) {
366 error = EINVAL;
367 goto fail;
368 }
369
370 /* not being traced... */
371 if ((p->p_flag & P_TRACED) == 0) {
372 error = EPERM;
373 goto fail;
374 }
375
376 /* not being traced by YOU */
377 if (p->p_pptr != td->td_proc) {
378 error = EBUSY;
379 goto fail;
380 }
381
382 /* not currently stopped */
383 if (!P_SHOULDSTOP(p) || (p->p_flag & P_WAITED) == 0) {
384 error = EBUSY;
385 goto fail;
386 }
387
388 td2 = FIRST_THREAD_IN_PROC(p);
389 if (req == PTRACE_GETFPXREGS) {
390 _PHOLD(p);
391 error = linux_proc_read_fpxregs(td2, &r.fpxreg);
392 _PRELE(p);
393 PROC_UNLOCK(p);
394 if (error == 0)
395 error = copyout(&r.fpxreg, (void *)uap->data,
396 sizeof(r.fpxreg));
397 } else {
398 /* clear dangerous bits exactly as Linux does*/
399 r.fpxreg.mxcsr &= 0xffbf;
400 _PHOLD(p);
401 error = linux_proc_write_fpxregs(td2, &r.fpxreg);
402 _PRELE(p);
403 PROC_UNLOCK(p);
404 }
405 break;
406
407 fail:
408 PROC_UNLOCK(p);
409 #else
410 error = EIO;
411 #endif
412 break;
413 }
414 case PTRACE_PEEKUSR:
415 case PTRACE_POKEUSR: {
416 error = EIO;
417
418 /* check addr for alignment */
419 if (uap->addr < 0 || uap->addr & (sizeof(l_int) - 1))
420 break;
421 /*
422 * Allow linux programs to access register values in
423 * user struct. We simulate this through PT_GET/SETREGS
424 * as necessary.
425 */
426 if (uap->addr < sizeof(struct linux_pt_reg)) {
427 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0);
428 if (error != 0)
429 break;
430
431 map_regs_to_linux(&u.bsd_reg, &r.reg);
432 if (req == PTRACE_PEEKUSR) {
433 error = copyout((char *)&r.reg + uap->addr,
434 (void *)uap->data, sizeof(l_int));
435 break;
436 }
437
438 *(l_int *)((char *)&r.reg + uap->addr) =
439 (l_int)uap->data;
440
441 map_regs_from_linux(&u.bsd_reg, &r.reg);
442 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0);
443 }
444
445 /*
446 * Simulate debug registers access
447 */
448 if (uap->addr >= LINUX_DBREG_OFFSET &&
449 uap->addr <= LINUX_DBREG_OFFSET + LINUX_DBREG_SIZE) {
450 error = kern_ptrace(td, PT_GETDBREGS, pid, &u.bsd_dbreg,
451 0);
452 if (error != 0)
453 break;
454
455 uap->addr -= LINUX_DBREG_OFFSET;
456 if (req == PTRACE_PEEKUSR) {
457 error = copyout((char *)&u.bsd_dbreg +
458 uap->addr, (void *)uap->data,
459 sizeof(l_int));
460 break;
461 }
462
463 *(l_int *)((char *)&u.bsd_dbreg + uap->addr) =
464 uap->data;
465 error = kern_ptrace(td, PT_SETDBREGS, pid,
466 &u.bsd_dbreg, 0);
467 }
468
469 break;
470 }
471 case PTRACE_SYSCALL:
472 /* fall through */
473 default:
474 printf("linux: ptrace(%u, ...) not implemented\n",
475 (unsigned int)uap->req);
476 error = EINVAL;
477 break;
478 }
479
480 return (error);
481 }
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