1 /* ptrace.c: Sparc process tracing support.
2 *
3 * Copyright (C) 1996 David S. Miller (davem@caipfs.rutgers.edu)
4 *
5 * Based upon code written by Ross Biro, Linus Torvalds, Bob Manson,
6 * and David Mosberger.
7 *
8 * Added Linux support -miguel (weird, eh?, the orignal code was meant
9 * to emulate SunOS).
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/errno.h>
16 #include <linux/ptrace.h>
17 #include <linux/user.h>
18 #include <linux/smp.h>
19 #include <linux/smp_lock.h>
20 #include <linux/security.h>
21
22 #include <asm/pgtable.h>
23 #include <asm/system.h>
24 #include <asm/uaccess.h>
25
26 #define MAGIC_CONSTANT 0x80000000
27
28
29 /* Returning from ptrace is a bit tricky because the syscall return
30 * low level code assumes any value returned which is negative and
31 * is a valid errno will mean setting the condition codes to indicate
32 * an error return. This doesn't work, so we have this hook.
33 */
34 static inline void pt_error_return(struct pt_regs *regs, unsigned long error)
35 {
36 regs->u_regs[UREG_I0] = error;
37 regs->psr |= PSR_C;
38 regs->pc = regs->npc;
39 regs->npc += 4;
40 }
41
42 static inline void pt_succ_return(struct pt_regs *regs, unsigned long value)
43 {
44 regs->u_regs[UREG_I0] = value;
45 regs->psr &= ~PSR_C;
46 regs->pc = regs->npc;
47 regs->npc += 4;
48 }
49
50 static void
51 pt_succ_return_linux(struct pt_regs *regs, unsigned long value, long __user *addr)
52 {
53 if (put_user(value, addr)) {
54 pt_error_return(regs, EFAULT);
55 return;
56 }
57 regs->u_regs[UREG_I0] = 0;
58 regs->psr &= ~PSR_C;
59 regs->pc = regs->npc;
60 regs->npc += 4;
61 }
62
63 static void
64 pt_os_succ_return (struct pt_regs *regs, unsigned long val, long __user *addr)
65 {
66 if (current->personality == PER_SUNOS)
67 pt_succ_return (regs, val);
68 else
69 pt_succ_return_linux (regs, val, addr);
70 }
71
72 /* Fuck me gently with a chainsaw... */
73 static inline void read_sunos_user(struct pt_regs *regs, unsigned long offset,
74 struct task_struct *tsk, long __user *addr)
75 {
76 struct pt_regs *cregs = tsk->thread.kregs;
77 struct thread_info *t = tsk->thread_info;
78 int v;
79
80 if(offset >= 1024)
81 offset -= 1024; /* whee... */
82 if(offset & ((sizeof(unsigned long) - 1))) {
83 pt_error_return(regs, EIO);
84 return;
85 }
86 if(offset >= 16 && offset < 784) {
87 offset -= 16; offset >>= 2;
88 pt_os_succ_return(regs, *(((unsigned long *)(&t->reg_window[0]))+offset), addr);
89 return;
90 }
91 if(offset >= 784 && offset < 832) {
92 offset -= 784; offset >>= 2;
93 pt_os_succ_return(regs, *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset), addr);
94 return;
95 }
96 switch(offset) {
97 case 0:
98 v = t->ksp;
99 break;
100 case 4:
101 v = t->kpc;
102 break;
103 case 8:
104 v = t->kpsr;
105 break;
106 case 12:
107 v = t->uwinmask;
108 break;
109 case 832:
110 v = t->w_saved;
111 break;
112 case 896:
113 v = cregs->u_regs[UREG_I0];
114 break;
115 case 900:
116 v = cregs->u_regs[UREG_I1];
117 break;
118 case 904:
119 v = cregs->u_regs[UREG_I2];
120 break;
121 case 908:
122 v = cregs->u_regs[UREG_I3];
123 break;
124 case 912:
125 v = cregs->u_regs[UREG_I4];
126 break;
127 case 916:
128 v = cregs->u_regs[UREG_I5];
129 break;
130 case 920:
131 v = cregs->u_regs[UREG_I6];
132 break;
133 case 924:
134 if(tsk->thread.flags & MAGIC_CONSTANT)
135 v = cregs->u_regs[UREG_G1];
136 else
137 v = 0;
138 break;
139 case 940:
140 v = cregs->u_regs[UREG_I0];
141 break;
142 case 944:
143 v = cregs->u_regs[UREG_I1];
144 break;
145
146 case 948:
147 /* Isn't binary compatibility _fun_??? */
148 if(cregs->psr & PSR_C)
149 v = cregs->u_regs[UREG_I0] << 24;
150 else
151 v = 0;
152 break;
153
154 /* Rest of them are completely unsupported. */
155 default:
156 printk("%s [%d]: Wants to read user offset %ld\n",
157 current->comm, current->pid, offset);
158 pt_error_return(regs, EIO);
159 return;
160 }
161 if (current->personality == PER_SUNOS)
162 pt_succ_return (regs, v);
163 else
164 pt_succ_return_linux (regs, v, addr);
165 return;
166 }
167
168 static inline void write_sunos_user(struct pt_regs *regs, unsigned long offset,
169 struct task_struct *tsk)
170 {
171 struct pt_regs *cregs = tsk->thread.kregs;
172 struct thread_info *t = tsk->thread_info;
173 unsigned long value = regs->u_regs[UREG_I3];
174
175 if(offset >= 1024)
176 offset -= 1024; /* whee... */
177 if(offset & ((sizeof(unsigned long) - 1)))
178 goto failure;
179 if(offset >= 16 && offset < 784) {
180 offset -= 16; offset >>= 2;
181 *(((unsigned long *)(&t->reg_window[0]))+offset) = value;
182 goto success;
183 }
184 if(offset >= 784 && offset < 832) {
185 offset -= 784; offset >>= 2;
186 *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset) = value;
187 goto success;
188 }
189 switch(offset) {
190 case 896:
191 cregs->u_regs[UREG_I0] = value;
192 break;
193 case 900:
194 cregs->u_regs[UREG_I1] = value;
195 break;
196 case 904:
197 cregs->u_regs[UREG_I2] = value;
198 break;
199 case 908:
200 cregs->u_regs[UREG_I3] = value;
201 break;
202 case 912:
203 cregs->u_regs[UREG_I4] = value;
204 break;
205 case 916:
206 cregs->u_regs[UREG_I5] = value;
207 break;
208 case 920:
209 cregs->u_regs[UREG_I6] = value;
210 break;
211 case 924:
212 cregs->u_regs[UREG_I7] = value;
213 break;
214 case 940:
215 cregs->u_regs[UREG_I0] = value;
216 break;
217 case 944:
218 cregs->u_regs[UREG_I1] = value;
219 break;
220
221 /* Rest of them are completely unsupported or "no-touch". */
222 default:
223 printk("%s [%d]: Wants to write user offset %ld\n",
224 current->comm, current->pid, offset);
225 goto failure;
226 }
227 success:
228 pt_succ_return(regs, 0);
229 return;
230 failure:
231 pt_error_return(regs, EIO);
232 return;
233 }
234
235 /* #define ALLOW_INIT_TRACING */
236 /* #define DEBUG_PTRACE */
237
238 #ifdef DEBUG_PTRACE
239 char *pt_rq [] = {
240 /* 0 */ "TRACEME", "PEEKTEXT", "PEEKDATA", "PEEKUSR",
241 /* 4 */ "POKETEXT", "POKEDATA", "POKEUSR", "CONT",
242 /* 8 */ "KILL", "SINGLESTEP", "SUNATTACH", "SUNDETACH",
243 /* 12 */ "GETREGS", "SETREGS", "GETFPREGS", "SETFPREGS",
244 /* 16 */ "READDATA", "WRITEDATA", "READTEXT", "WRITETEXT",
245 /* 20 */ "GETFPAREGS", "SETFPAREGS", "unknown", "unknown",
246 /* 24 */ "SYSCALL", ""
247 };
248 #endif
249
250 /*
251 * Called by kernel/ptrace.c when detaching..
252 *
253 * Make sure single step bits etc are not set.
254 */
255 void ptrace_disable(struct task_struct *child)
256 {
257 /* nothing to do */
258 }
259
260 asmlinkage void do_ptrace(struct pt_regs *regs)
261 {
262 unsigned long request = regs->u_regs[UREG_I0];
263 unsigned long pid = regs->u_regs[UREG_I1];
264 unsigned long addr = regs->u_regs[UREG_I2];
265 unsigned long data = regs->u_regs[UREG_I3];
266 unsigned long addr2 = regs->u_regs[UREG_I4];
267 struct task_struct *child;
268 int ret;
269
270 lock_kernel();
271 #ifdef DEBUG_PTRACE
272 {
273 char *s;
274
275 if ((request >= 0) && (request <= 24))
276 s = pt_rq [request];
277 else
278 s = "unknown";
279
280 if (request == PTRACE_POKEDATA && data == 0x91d02001){
281 printk ("do_ptrace: breakpoint pid=%d, addr=%08lx addr2=%08lx\n",
282 pid, addr, addr2);
283 } else
284 printk("do_ptrace: rq=%s(%d) pid=%d addr=%08lx data=%08lx addr2=%08lx\n",
285 s, (int) request, (int) pid, addr, data, addr2);
286 }
287 #endif
288 if(request == PTRACE_TRACEME) {
289 int ret;
290
291 /* are we already being traced? */
292 if (current->ptrace & PT_PTRACED) {
293 pt_error_return(regs, EPERM);
294 goto out;
295 }
296 ret = security_ptrace(current->parent, current);
297 if (ret) {
298 pt_error_return(regs, -ret);
299 goto out;
300 }
301
302 /* set the ptrace bit in the process flags. */
303 current->ptrace |= PT_PTRACED;
304 pt_succ_return(regs, 0);
305 goto out;
306 }
307 #ifndef ALLOW_INIT_TRACING
308 if(pid == 1) {
309 /* Can't dork with init. */
310 pt_error_return(regs, EPERM);
311 goto out;
312 }
313 #endif
314 read_lock(&tasklist_lock);
315 child = find_task_by_pid(pid);
316 if (child)
317 get_task_struct(child);
318 read_unlock(&tasklist_lock);
319
320 if (!child) {
321 pt_error_return(regs, ESRCH);
322 goto out;
323 }
324
325 if ((current->personality == PER_SUNOS && request == PTRACE_SUNATTACH)
326 || (current->personality != PER_SUNOS && request == PTRACE_ATTACH)) {
327 if (ptrace_attach(child)) {
328 pt_error_return(regs, EPERM);
329 goto out_tsk;
330 }
331 pt_succ_return(regs, 0);
332 goto out_tsk;
333 }
334
335 ret = ptrace_check_attach(child, request == PTRACE_KILL);
336 if (ret < 0) {
337 pt_error_return(regs, -ret);
338 goto out_tsk;
339 }
340
341 switch(request) {
342 case PTRACE_PEEKTEXT: /* read word at location addr. */
343 case PTRACE_PEEKDATA: {
344 unsigned long tmp;
345
346 if (access_process_vm(child, addr,
347 &tmp, sizeof(tmp), 0) == sizeof(tmp))
348 pt_os_succ_return(regs, tmp, (long __user *)data);
349 else
350 pt_error_return(regs, EIO);
351 goto out_tsk;
352 }
353
354 case PTRACE_PEEKUSR:
355 read_sunos_user(regs, addr, child, (long __user *) data);
356 goto out_tsk;
357
358 case PTRACE_POKEUSR:
359 write_sunos_user(regs, addr, child);
360 goto out_tsk;
361
362 case PTRACE_POKETEXT: /* write the word at location addr. */
363 case PTRACE_POKEDATA: {
364 if (access_process_vm(child, addr,
365 &data, sizeof(data), 1) == sizeof(data))
366 pt_succ_return(regs, 0);
367 else
368 pt_error_return(regs, EIO);
369 goto out_tsk;
370 }
371
372 case PTRACE_GETREGS: {
373 struct pt_regs __user *pregs = (struct pt_regs __user *) addr;
374 struct pt_regs *cregs = child->thread.kregs;
375 int rval;
376
377 rval = verify_area(VERIFY_WRITE, pregs, sizeof(struct pt_regs));
378 if(rval) {
379 pt_error_return(regs, -rval);
380 goto out_tsk;
381 }
382 __put_user(cregs->psr, (&pregs->psr));
383 __put_user(cregs->pc, (&pregs->pc));
384 __put_user(cregs->npc, (&pregs->npc));
385 __put_user(cregs->y, (&pregs->y));
386 for(rval = 1; rval < 16; rval++)
387 __put_user(cregs->u_regs[rval], (&pregs->u_regs[rval - 1]));
388 pt_succ_return(regs, 0);
389 #ifdef DEBUG_PTRACE
390 printk ("PC=%x nPC=%x o7=%x\n", cregs->pc, cregs->npc, cregs->u_regs [15]);
391 #endif
392 goto out_tsk;
393 }
394
395 case PTRACE_SETREGS: {
396 struct pt_regs __user *pregs = (struct pt_regs __user *) addr;
397 struct pt_regs *cregs = child->thread.kregs;
398 unsigned long psr, pc, npc, y;
399 int i;
400
401 /* Must be careful, tracing process can only set certain
402 * bits in the psr.
403 */
404 i = verify_area(VERIFY_READ, pregs, sizeof(struct pt_regs));
405 if(i) {
406 pt_error_return(regs, -i);
407 goto out_tsk;
408 }
409 __get_user(psr, (&pregs->psr));
410 __get_user(pc, (&pregs->pc));
411 __get_user(npc, (&pregs->npc));
412 __get_user(y, (&pregs->y));
413 psr &= PSR_ICC;
414 cregs->psr &= ~PSR_ICC;
415 cregs->psr |= psr;
416 if(!((pc | npc) & 3)) {
417 cregs->pc = pc;
418 cregs->npc =npc;
419 }
420 cregs->y = y;
421 for(i = 1; i < 16; i++)
422 __get_user(cregs->u_regs[i], (&pregs->u_regs[i-1]));
423 pt_succ_return(regs, 0);
424 goto out_tsk;
425 }
426
427 case PTRACE_GETFPREGS: {
428 struct fps {
429 unsigned long regs[32];
430 unsigned long fsr;
431 unsigned long flags;
432 unsigned long extra;
433 unsigned long fpqd;
434 struct fq {
435 unsigned long *insnaddr;
436 unsigned long insn;
437 } fpq[16];
438 };
439 struct fps __user *fps = (struct fps __user *) addr;
440 int i;
441
442 i = verify_area(VERIFY_WRITE, fps, sizeof(struct fps));
443 if(i) {
444 pt_error_return(regs, -i);
445 goto out_tsk;
446 }
447 for(i = 0; i < 32; i++)
448 __put_user(child->thread.float_regs[i], (&fps->regs[i]));
449 __put_user(child->thread.fsr, (&fps->fsr));
450 __put_user(child->thread.fpqdepth, (&fps->fpqd));
451 __put_user(0, (&fps->flags));
452 __put_user(0, (&fps->extra));
453 for(i = 0; i < 16; i++) {
454 __put_user(child->thread.fpqueue[i].insn_addr,
455 (&fps->fpq[i].insnaddr));
456 __put_user(child->thread.fpqueue[i].insn, (&fps->fpq[i].insn));
457 }
458 pt_succ_return(regs, 0);
459 goto out_tsk;
460 }
461
462 case PTRACE_SETFPREGS: {
463 struct fps {
464 unsigned long regs[32];
465 unsigned long fsr;
466 unsigned long flags;
467 unsigned long extra;
468 unsigned long fpqd;
469 struct fq {
470 unsigned long *insnaddr;
471 unsigned long insn;
472 } fpq[16];
473 };
474 struct fps __user *fps = (struct fps __user *) addr;
475 int i;
476
477 i = verify_area(VERIFY_READ, fps, sizeof(struct fps));
478 if(i) {
479 pt_error_return(regs, -i);
480 goto out_tsk;
481 }
482 copy_from_user(&child->thread.float_regs[0], &fps->regs[0], (32 * sizeof(unsigned long)));
483 __get_user(child->thread.fsr, (&fps->fsr));
484 __get_user(child->thread.fpqdepth, (&fps->fpqd));
485 for(i = 0; i < 16; i++) {
486 __get_user(child->thread.fpqueue[i].insn_addr,
487 (&fps->fpq[i].insnaddr));
488 __get_user(child->thread.fpqueue[i].insn, (&fps->fpq[i].insn));
489 }
490 pt_succ_return(regs, 0);
491 goto out_tsk;
492 }
493
494 case PTRACE_READTEXT:
495 case PTRACE_READDATA: {
496 int res = ptrace_readdata(child, addr,
497 (void __user *) addr2, data);
498
499 if (res == data) {
500 pt_succ_return(regs, 0);
501 goto out_tsk;
502 }
503 /* Partial read is an IO failure */
504 if (res >= 0)
505 res = -EIO;
506 pt_error_return(regs, -res);
507 goto out_tsk;
508 }
509
510 case PTRACE_WRITETEXT:
511 case PTRACE_WRITEDATA: {
512 int res = ptrace_writedata(child, (void __user *) addr2,
513 addr, data);
514
515 if (res == data) {
516 pt_succ_return(regs, 0);
517 goto out_tsk;
518 }
519 /* Partial write is an IO failure */
520 if (res >= 0)
521 res = -EIO;
522 pt_error_return(regs, -res);
523 goto out_tsk;
524 }
525
526 case PTRACE_SYSCALL: /* continue and stop at (return from) syscall */
527 addr = 1;
528
529 case PTRACE_CONT: { /* restart after signal. */
530 if (data > _NSIG) {
531 pt_error_return(regs, EIO);
532 goto out_tsk;
533 }
534
535 if (request == PTRACE_SYSCALL)
536 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
537 else
538 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
539
540 child->exit_code = data;
541 #ifdef DEBUG_PTRACE
542 printk("CONT: %s [%d]: set exit_code = %x %lx %lx\n",
543 child->comm, child->pid, child->exit_code,
544 child->thread.kregs->pc,
545 child->thread.kregs->npc);
546 #endif
547 wake_up_process(child);
548 pt_succ_return(regs, 0);
549 goto out_tsk;
550 }
551
552 /*
553 * make the child exit. Best I can do is send it a sigkill.
554 * perhaps it should be put in the status that it wants to
555 * exit.
556 */
557 case PTRACE_KILL: {
558 if (child->exit_state == EXIT_ZOMBIE) { /* already dead */
559 pt_succ_return(regs, 0);
560 goto out_tsk;
561 }
562 wake_up_process(child);
563 child->exit_code = SIGKILL;
564 pt_succ_return(regs, 0);
565 goto out_tsk;
566 }
567
568 case PTRACE_SUNDETACH: { /* detach a process that was attached. */
569 int err = ptrace_detach(child, data);
570 if (err) {
571 pt_error_return(regs, EIO);
572 goto out_tsk;
573 }
574 pt_succ_return(regs, 0);
575 goto out_tsk;
576 }
577
578 /* PTRACE_DUMPCORE unsupported... */
579
580 default: {
581 int err = ptrace_request(child, request, addr, data);
582 if (err)
583 pt_error_return(regs, -err);
584 else
585 pt_succ_return(regs, 0);
586 goto out_tsk;
587 }
588 }
589 out_tsk:
590 if (child)
591 put_task_struct(child);
592 out:
593 unlock_kernel();
594 }
595
596 asmlinkage void syscall_trace(void)
597 {
598 #ifdef DEBUG_PTRACE
599 printk("%s [%d]: syscall_trace\n", current->comm, current->pid);
600 #endif
601 if (!test_thread_flag(TIF_SYSCALL_TRACE))
602 return;
603 if (!(current->ptrace & PT_PTRACED))
604 return;
605 current->thread.flags ^= MAGIC_CONSTANT;
606 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
607 ? 0x80 : 0));
608 /*
609 * this isn't the same as continuing with a signal, but it will do
610 * for normal use. strace only continues with a signal if the
611 * stopping signal is not SIGTRAP. -brl
612 */
613 #ifdef DEBUG_PTRACE
614 printk("%s [%d]: syscall_trace exit= %x\n", current->comm,
615 current->pid, current->exit_code);
616 #endif
617 if (current->exit_code) {
618 send_sig (current->exit_code, current, 1);
619 current->exit_code = 0;
620 }
621 }
622
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