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[PATCH] use ptrace_get_task_struct in various places
[linux-2.6-block.git] / arch / sparc / kernel / ptrace.c
CommitLineData
1da177e4
LT		 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>
7ed20e1a 21#include <linux/signal.h>
1da177e4
LT		 22
23#include <asm/pgtable.h>
24#include <asm/system.h>
25#include <asm/uaccess.h>
26
27#define MAGIC_CONSTANT 0x80000000
28
29
30/* Returning from ptrace is a bit tricky because the syscall return
31 * low level code assumes any value returned which is negative and
32 * is a valid errno will mean setting the condition codes to indicate
33 * an error return. This doesn't work, so we have this hook.
34 */
35static inline void pt_error_return(struct pt_regs *regs, unsigned long error)
36{
37 regs->u_regs[UREG_I0] = error;
38 regs->psr |= PSR_C;
39 regs->pc = regs->npc;
40 regs->npc += 4;
41}
42
43static inline void pt_succ_return(struct pt_regs *regs, unsigned long value)
44{
45 regs->u_regs[UREG_I0] = value;
46 regs->psr &= ~PSR_C;
47 regs->pc = regs->npc;
48 regs->npc += 4;
49}
50
51static void
52pt_succ_return_linux(struct pt_regs *regs, unsigned long value, long __user *addr)
53{
54 if (put_user(value, addr)) {
55 pt_error_return(regs, EFAULT);
56 return;
57 }
58 regs->u_regs[UREG_I0] = 0;
59 regs->psr &= ~PSR_C;
60 regs->pc = regs->npc;
61 regs->npc += 4;
62}
63
64static void
65pt_os_succ_return (struct pt_regs *regs, unsigned long val, long __user *addr)
66{
67 if (current->personality == PER_SUNOS)
68 pt_succ_return (regs, val);
69 else
70 pt_succ_return_linux (regs, val, addr);
71}
72
73/* Fuck me gently with a chainsaw... */
74static inline void read_sunos_user(struct pt_regs *regs, unsigned long offset,
75 struct task_struct *tsk, long __user *addr)
76{
77 struct pt_regs *cregs = tsk->thread.kregs;
78 struct thread_info *t = tsk->thread_info;
79 int v;
80
81 if(offset >= 1024)
82 offset -= 1024; /* whee... */
83 if(offset & ((sizeof(unsigned long) - 1))) {
84 pt_error_return(regs, EIO);
85 return;
86 }
87 if(offset >= 16 && offset < 784) {
88 offset -= 16; offset >>= 2;
89 pt_os_succ_return(regs, *(((unsigned long *)(&t->reg_window[0]))+offset), addr);
90 return;
91 }
92 if(offset >= 784 && offset < 832) {
93 offset -= 784; offset >>= 2;
94 pt_os_succ_return(regs, *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset), addr);
95 return;
96 }
97 switch(offset) {
98 case 0:
99 v = t->ksp;
100 break;
101 case 4:
102 v = t->kpc;
103 break;
104 case 8:
105 v = t->kpsr;
106 break;
107 case 12:
108 v = t->uwinmask;
109 break;
110 case 832:
111 v = t->w_saved;
112 break;
113 case 896:
114 v = cregs->u_regs[UREG_I0];
115 break;
116 case 900:
117 v = cregs->u_regs[UREG_I1];
118 break;
119 case 904:
120 v = cregs->u_regs[UREG_I2];
121 break;
122 case 908:
123 v = cregs->u_regs[UREG_I3];
124 break;
125 case 912:
126 v = cregs->u_regs[UREG_I4];
127 break;
128 case 916:
129 v = cregs->u_regs[UREG_I5];
130 break;
131 case 920:
132 v = cregs->u_regs[UREG_I6];
133 break;
134 case 924:
135 if(tsk->thread.flags & MAGIC_CONSTANT)
136 v = cregs->u_regs[UREG_G1];
137 else
138 v = 0;
139 break;
140 case 940:
141 v = cregs->u_regs[UREG_I0];
142 break;
143 case 944:
144 v = cregs->u_regs[UREG_I1];
145 break;
146
147 case 948:
148 /* Isn't binary compatibility _fun_??? */
149 if(cregs->psr & PSR_C)
150 v = cregs->u_regs[UREG_I0] << 24;
151 else
152 v = 0;
153 break;
154
155 /* Rest of them are completely unsupported. */
156 default:
157 printk("%s [%d]: Wants to read user offset %ld\n",
158 current->comm, current->pid, offset);
159 pt_error_return(regs, EIO);
160 return;
161 }
162 if (current->personality == PER_SUNOS)
163 pt_succ_return (regs, v);
164 else
165 pt_succ_return_linux (regs, v, addr);
166 return;
167}
168
169static inline void write_sunos_user(struct pt_regs *regs, unsigned long offset,
170 struct task_struct *tsk)
171{
172 struct pt_regs *cregs = tsk->thread.kregs;
173 struct thread_info *t = tsk->thread_info;
174 unsigned long value = regs->u_regs[UREG_I3];
175
176 if(offset >= 1024)
177 offset -= 1024; /* whee... */
178 if(offset & ((sizeof(unsigned long) - 1)))
179 goto failure;
180 if(offset >= 16 && offset < 784) {
181 offset -= 16; offset >>= 2;
182 *(((unsigned long *)(&t->reg_window[0]))+offset) = value;
183 goto success;
184 }
185 if(offset >= 784 && offset < 832) {
186 offset -= 784; offset >>= 2;
187 *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset) = value;
188 goto success;
189 }
190 switch(offset) {
191 case 896:
192 cregs->u_regs[UREG_I0] = value;
193 break;
194 case 900:
195 cregs->u_regs[UREG_I1] = value;
196 break;
197 case 904:
198 cregs->u_regs[UREG_I2] = value;
199 break;
200 case 908:
201 cregs->u_regs[UREG_I3] = value;
202 break;
203 case 912:
204 cregs->u_regs[UREG_I4] = value;
205 break;
206 case 916:
207 cregs->u_regs[UREG_I5] = value;
208 break;
209 case 920:
210 cregs->u_regs[UREG_I6] = value;
211 break;
212 case 924:
213 cregs->u_regs[UREG_I7] = value;
214 break;
215 case 940:
216 cregs->u_regs[UREG_I0] = value;
217 break;
218 case 944:
219 cregs->u_regs[UREG_I1] = value;
220 break;
221
222 /* Rest of them are completely unsupported or "no-touch". */
223 default:
224 printk("%s [%d]: Wants to write user offset %ld\n",
225 current->comm, current->pid, offset);
226 goto failure;
227 }
228success:
229 pt_succ_return(regs, 0);
230 return;
231failure:
232 pt_error_return(regs, EIO);
233 return;
234}
235
236/* #define ALLOW_INIT_TRACING */
237/* #define DEBUG_PTRACE */
238
239#ifdef DEBUG_PTRACE
240char *pt_rq [] = {
241 /* 0 */ "TRACEME", "PEEKTEXT", "PEEKDATA", "PEEKUSR",
242 /* 4 */ "POKETEXT", "POKEDATA", "POKEUSR", "CONT",
243 /* 8 */ "KILL", "SINGLESTEP", "SUNATTACH", "SUNDETACH",
244 /* 12 */ "GETREGS", "SETREGS", "GETFPREGS", "SETFPREGS",
245 /* 16 */ "READDATA", "WRITEDATA", "READTEXT", "WRITETEXT",
246 /* 20 */ "GETFPAREGS", "SETFPAREGS", "unknown", "unknown",
247 /* 24 */ "SYSCALL", ""
248};
249#endif
250
251/*
252 * Called by kernel/ptrace.c when detaching..
253 *
254 * Make sure single step bits etc are not set.
255 */
256void ptrace_disable(struct task_struct *child)
257{
258 /* nothing to do */
259}
260
261asmlinkage void do_ptrace(struct pt_regs *regs)
262{
263 unsigned long request = regs->u_regs[UREG_I0];
264 unsigned long pid = regs->u_regs[UREG_I1];
265 unsigned long addr = regs->u_regs[UREG_I2];
266 unsigned long data = regs->u_regs[UREG_I3];
267 unsigned long addr2 = regs->u_regs[UREG_I4];
268 struct task_struct *child;
269 int ret;
270
271 lock_kernel();
272#ifdef DEBUG_PTRACE
273 {
274 char *s;
275
276 if ((request >= 0) && (request <= 24))
277 s = pt_rq [request];
278 else
279 s = "unknown";
280
281 if (request == PTRACE_POKEDATA && data == 0x91d02001){
282 printk ("do_ptrace: breakpoint pid=%d, addr=%08lx addr2=%08lx\n",
283 pid, addr, addr2);
284 } else
285 printk("do_ptrace: rq=%s(%d) pid=%d addr=%08lx data=%08lx addr2=%08lx\n",
286 s, (int) request, (int) pid, addr, data, addr2);
287 }
288#endif
1da177e4 289
6b9c7ed8
CH		 290 if (request == PTRACE_TRACEME) {
291 ret = ptrace_traceme();
1da177e4
LT		 292 pt_succ_return(regs, 0);
293 goto out;
294 }
1da177e4 295
6b9c7ed8
CH		 296 child = ptrace_get_task_struct(pid);
297 if (IS_ERR(child)) {
298 ret = PTR_ERR(child);
299 pt_error_return(regs, -ret);
1da177e4
LT		 300 goto out;
301 }
302
303 if ((current->personality == PER_SUNOS && request == PTRACE_SUNATTACH)
304 || (current->personality != PER_SUNOS && request == PTRACE_ATTACH)) {
305 if (ptrace_attach(child)) {
306 pt_error_return(regs, EPERM);
307 goto out_tsk;
308 }
309 pt_succ_return(regs, 0);
310 goto out_tsk;
311 }
312
313 ret = ptrace_check_attach(child, request == PTRACE_KILL);
314 if (ret < 0) {
315 pt_error_return(regs, -ret);
316 goto out_tsk;
317 }
318
319 switch(request) {
320 case PTRACE_PEEKTEXT: /* read word at location addr. */
321 case PTRACE_PEEKDATA: {
322 unsigned long tmp;
323
324 if (access_process_vm(child, addr,
325 &tmp, sizeof(tmp), 0) == sizeof(tmp))
326 pt_os_succ_return(regs, tmp, (long __user *)data);
327 else
328 pt_error_return(regs, EIO);
329 goto out_tsk;
330 }
331
332 case PTRACE_PEEKUSR:
333 read_sunos_user(regs, addr, child, (long __user *) data);
334 goto out_tsk;
335
336 case PTRACE_POKEUSR:
337 write_sunos_user(regs, addr, child);
338 goto out_tsk;
339
340 case PTRACE_POKETEXT: /* write the word at location addr. */
341 case PTRACE_POKEDATA: {
342 if (access_process_vm(child, addr,
343 &data, sizeof(data), 1) == sizeof(data))
344 pt_succ_return(regs, 0);
345 else
346 pt_error_return(regs, EIO);
347 goto out_tsk;
348 }
349
350 case PTRACE_GETREGS: {
351 struct pt_regs __user *pregs = (struct pt_regs __user *) addr;
352 struct pt_regs *cregs = child->thread.kregs;
353 int rval;
354
355 if (!access_ok(VERIFY_WRITE, pregs, sizeof(struct pt_regs))) {
356 rval = -EFAULT;
357 pt_error_return(regs, -rval);
358 goto out_tsk;
359 }
360 __put_user(cregs->psr, (&pregs->psr));
361 __put_user(cregs->pc, (&pregs->pc));
362 __put_user(cregs->npc, (&pregs->npc));
363 __put_user(cregs->y, (&pregs->y));
364 for(rval = 1; rval < 16; rval++)
365 __put_user(cregs->u_regs[rval], (&pregs->u_regs[rval - 1]));
366 pt_succ_return(regs, 0);
367#ifdef DEBUG_PTRACE
368 printk ("PC=%x nPC=%x o7=%x\n", cregs->pc, cregs->npc, cregs->u_regs [15]);
369#endif
370 goto out_tsk;
371 }
372
373 case PTRACE_SETREGS: {
374 struct pt_regs __user *pregs = (struct pt_regs __user *) addr;
375 struct pt_regs *cregs = child->thread.kregs;
376 unsigned long psr, pc, npc, y;
377 int i;
378
379 /* Must be careful, tracing process can only set certain
380 * bits in the psr.
381 */
382 if (!access_ok(VERIFY_READ, pregs, sizeof(struct pt_regs))) {
383 pt_error_return(regs, EFAULT);
384 goto out_tsk;
385 }
386 __get_user(psr, (&pregs->psr));
387 __get_user(pc, (&pregs->pc));
388 __get_user(npc, (&pregs->npc));
389 __get_user(y, (&pregs->y));
390 psr &= PSR_ICC;
391 cregs->psr &= ~PSR_ICC;
392 cregs->psr |= psr;
393 if (!((pc | npc) & 3)) {
394 cregs->pc = pc;
395 cregs->npc =npc;
396 }
397 cregs->y = y;
398 for(i = 1; i < 16; i++)
399 __get_user(cregs->u_regs[i], (&pregs->u_regs[i-1]));
400 pt_succ_return(regs, 0);
401 goto out_tsk;
402 }
403
404 case PTRACE_GETFPREGS: {
405 struct fps {
406 unsigned long regs[32];
407 unsigned long fsr;
408 unsigned long flags;
409 unsigned long extra;
410 unsigned long fpqd;
411 struct fq {
412 unsigned long *insnaddr;
413 unsigned long insn;
414 } fpq[16];
415 };
416 struct fps __user *fps = (struct fps __user *) addr;
417 int i;
418
419 if (!access_ok(VERIFY_WRITE, fps, sizeof(struct fps))) {
420 i = -EFAULT;
421 pt_error_return(regs, -i);
422 goto out_tsk;
423 }
424 for(i = 0; i < 32; i++)
425 __put_user(child->thread.float_regs[i], (&fps->regs[i]));
426 __put_user(child->thread.fsr, (&fps->fsr));
427 __put_user(child->thread.fpqdepth, (&fps->fpqd));
428 __put_user(0, (&fps->flags));
429 __put_user(0, (&fps->extra));
430 for(i = 0; i < 16; i++) {
431 __put_user(child->thread.fpqueue[i].insn_addr,
432 (&fps->fpq[i].insnaddr));
433 __put_user(child->thread.fpqueue[i].insn, (&fps->fpq[i].insn));
434 }
435 pt_succ_return(regs, 0);
436 goto out_tsk;
437 }
438
439 case PTRACE_SETFPREGS: {
440 struct fps {
441 unsigned long regs[32];
442 unsigned long fsr;
443 unsigned long flags;
444 unsigned long extra;
445 unsigned long fpqd;
446 struct fq {
447 unsigned long *insnaddr;
448 unsigned long insn;
449 } fpq[16];
450 };
451 struct fps __user *fps = (struct fps __user *) addr;
452 int i;
453
454 if (!access_ok(VERIFY_READ, fps, sizeof(struct fps))) {
455 i = -EFAULT;
456 pt_error_return(regs, -i);
457 goto out_tsk;
458 }
459 copy_from_user(&child->thread.float_regs[0], &fps->regs[0], (32 * sizeof(unsigned long)));
460 __get_user(child->thread.fsr, (&fps->fsr));
461 __get_user(child->thread.fpqdepth, (&fps->fpqd));
462 for(i = 0; i < 16; i++) {
463 __get_user(child->thread.fpqueue[i].insn_addr,
464 (&fps->fpq[i].insnaddr));
465 __get_user(child->thread.fpqueue[i].insn, (&fps->fpq[i].insn));
466 }
467 pt_succ_return(regs, 0);
468 goto out_tsk;
469 }
470
471 case PTRACE_READTEXT:
472 case PTRACE_READDATA: {
473 int res = ptrace_readdata(child, addr,
474 (void __user *) addr2, data);
475
476 if (res == data) {
477 pt_succ_return(regs, 0);
478 goto out_tsk;
479 }
480 /* Partial read is an IO failure */
481 if (res >= 0)
482 res = -EIO;
483 pt_error_return(regs, -res);
484 goto out_tsk;
485 }
486
487 case PTRACE_WRITETEXT:
488 case PTRACE_WRITEDATA: {
489 int res = ptrace_writedata(child, (void __user *) addr2,
490 addr, data);
491
492 if (res == data) {
493 pt_succ_return(regs, 0);
494 goto out_tsk;
495 }
496 /* Partial write is an IO failure */
497 if (res >= 0)
498 res = -EIO;
499 pt_error_return(regs, -res);
500 goto out_tsk;
501 }
502
503 case PTRACE_SYSCALL: /* continue and stop at (return from) syscall */
504 addr = 1;
505
506 case PTRACE_CONT: { /* restart after signal. */
7ed20e1a 507 if (!valid_signal(data)) {
1da177e4
LT		 508 pt_error_return(regs, EIO);
509 goto out_tsk;
510 }
1da177e4
LT		 511
512 if (request == PTRACE_SYSCALL)
513 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
514 else
515 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
516
517 child->exit_code = data;
518#ifdef DEBUG_PTRACE
519 printk("CONT: %s [%d]: set exit_code = %x %lx %lx\n",
520 child->comm, child->pid, child->exit_code,
521 child->thread.kregs->pc,
522 child->thread.kregs->npc);
523#endif
524 wake_up_process(child);
525 pt_succ_return(regs, 0);
526 goto out_tsk;
527 }
528
529/*
530 * make the child exit. Best I can do is send it a sigkill.
531 * perhaps it should be put in the status that it wants to
532 * exit.
533 */
534 case PTRACE_KILL: {
535 if (child->exit_state == EXIT_ZOMBIE) { /* already dead */
536 pt_succ_return(regs, 0);
537 goto out_tsk;
538 }
539 wake_up_process(child);
540 child->exit_code = SIGKILL;
541 pt_succ_return(regs, 0);
542 goto out_tsk;
543 }
544
545 case PTRACE_SUNDETACH: { /* detach a process that was attached. */
546 int err = ptrace_detach(child, data);
547 if (err) {
548 pt_error_return(regs, EIO);
549 goto out_tsk;
550 }
551 pt_succ_return(regs, 0);
552 goto out_tsk;
553 }
554
555 /* PTRACE_DUMPCORE unsupported... */
556
557 default: {
558 int err = ptrace_request(child, request, addr, data);
559 if (err)
560 pt_error_return(regs, -err);
561 else
562 pt_succ_return(regs, 0);
563 goto out_tsk;
564 }
565 }
566out_tsk:
567 if (child)
568 put_task_struct(child);
569out:
570 unlock_kernel();
571}
572
573asmlinkage void syscall_trace(void)
574{
575#ifdef DEBUG_PTRACE
576 printk("%s [%d]: syscall_trace\n", current->comm, current->pid);
577#endif
578 if (!test_thread_flag(TIF_SYSCALL_TRACE))
579 return;
580 if (!(current->ptrace & PT_PTRACED))
581 return;
582 current->thread.flags ^= MAGIC_CONSTANT;
583 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
584 ? 0x80 : 0));
585 /*
586 * this isn't the same as continuing with a signal, but it will do
587 * for normal use. strace only continues with a signal if the
588 * stopping signal is not SIGTRAP. -brl
589 */
590#ifdef DEBUG_PTRACE
591 printk("%s [%d]: syscall_trace exit= %x\n", current->comm,
592 current->pid, current->exit_code);
593#endif
594 if (current->exit_code) {
595 send_sig (current->exit_code, current, 1);
596 current->exit_code = 0;
597 }
598}
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