[PATCH] remove superflous ctime/mtime updates in affs
[deliverable/linux.git] / arch / powerpc / kernel / ptrace.c
CommitLineData
1da177e4 1/*
1da177e4
LT
2 * PowerPC version
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
5 * Derived from "arch/m68k/kernel/ptrace.c"
6 * Copyright (C) 1994 by Hamish Macdonald
7 * Taken from linux/kernel/ptrace.c and modified for M680x0.
8 * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
9 *
10 * Modified by Cort Dougan (cort@hq.fsmlabs.com)
b123923d 11 * and Paul Mackerras (paulus@samba.org).
1da177e4
LT
12 *
13 * This file is subject to the terms and conditions of the GNU General
14 * Public License. See the file README.legal in the main directory of
15 * this archive for more details.
16 */
17
e8a30302 18#include <linux/config.h>
1da177e4
LT
19#include <linux/kernel.h>
20#include <linux/sched.h>
21#include <linux/mm.h>
22#include <linux/smp.h>
23#include <linux/smp_lock.h>
24#include <linux/errno.h>
25#include <linux/ptrace.h>
26#include <linux/user.h>
27#include <linux/security.h>
7ed20e1a 28#include <linux/signal.h>
ea9c102c
DW
29#include <linux/seccomp.h>
30#include <linux/audit.h>
e8a30302 31#ifdef CONFIG_PPC32
ea9c102c 32#include <linux/module.h>
e8a30302 33#endif
1da177e4
LT
34
35#include <asm/uaccess.h>
36#include <asm/page.h>
37#include <asm/pgtable.h>
38#include <asm/system.h>
e8a30302
SR
39#ifdef CONFIG_PPC64
40#include <asm/ptrace-common.h>
41#endif
1da177e4 42
e8a30302 43#ifdef CONFIG_PPC32
1da177e4
LT
44/*
45 * Set of msr bits that gdb can change on behalf of a process.
46 */
47#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
48#define MSR_DEBUGCHANGE 0
49#else
50#define MSR_DEBUGCHANGE (MSR_SE | MSR_BE)
51#endif
e8a30302 52#endif /* CONFIG_PPC32 */
1da177e4
LT
53
54/*
55 * does not yet catch signals sent when the child dies.
56 * in exit.c or in signal.c.
57 */
58
e8a30302 59#ifdef CONFIG_PPC32
1da177e4
LT
60/*
61 * Get contents of register REGNO in task TASK.
62 */
63static inline unsigned long get_reg(struct task_struct *task, int regno)
64{
65 if (regno < sizeof(struct pt_regs) / sizeof(unsigned long)
66 && task->thread.regs != NULL)
67 return ((unsigned long *)task->thread.regs)[regno];
68 return (0);
69}
70
71/*
72 * Write contents of register REGNO in task TASK.
73 */
74static inline int put_reg(struct task_struct *task, int regno,
75 unsigned long data)
76{
77 if (regno <= PT_MQ && task->thread.regs != NULL) {
78 if (regno == PT_MSR)
79 data = (data & MSR_DEBUGCHANGE)
80 | (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
81 ((unsigned long *)task->thread.regs)[regno] = data;
82 return 0;
83 }
84 return -EIO;
85}
86
87#ifdef CONFIG_ALTIVEC
88/*
89 * Get contents of AltiVec register state in task TASK
90 */
91static inline int get_vrregs(unsigned long __user *data, struct task_struct *task)
92{
93 int i, j;
94
95 if (!access_ok(VERIFY_WRITE, data, 133 * sizeof(unsigned long)))
96 return -EFAULT;
97
98 /* copy AltiVec registers VR[0] .. VR[31] */
99 for (i = 0; i < 32; i++)
100 for (j = 0; j < 4; j++, data++)
101 if (__put_user(task->thread.vr[i].u[j], data))
102 return -EFAULT;
103
104 /* copy VSCR */
105 for (i = 0; i < 4; i++, data++)
106 if (__put_user(task->thread.vscr.u[i], data))
107 return -EFAULT;
108
109 /* copy VRSAVE */
110 if (__put_user(task->thread.vrsave, data))
111 return -EFAULT;
112
113 return 0;
114}
115
116/*
117 * Write contents of AltiVec register state into task TASK.
118 */
119static inline int set_vrregs(struct task_struct *task, unsigned long __user *data)
120{
121 int i, j;
122
123 if (!access_ok(VERIFY_READ, data, 133 * sizeof(unsigned long)))
124 return -EFAULT;
125
126 /* copy AltiVec registers VR[0] .. VR[31] */
127 for (i = 0; i < 32; i++)
128 for (j = 0; j < 4; j++, data++)
129 if (__get_user(task->thread.vr[i].u[j], data))
130 return -EFAULT;
131
132 /* copy VSCR */
133 for (i = 0; i < 4; i++, data++)
134 if (__get_user(task->thread.vscr.u[i], data))
135 return -EFAULT;
136
137 /* copy VRSAVE */
138 if (__get_user(task->thread.vrsave, data))
139 return -EFAULT;
140
141 return 0;
142}
143#endif
144
145#ifdef CONFIG_SPE
146
147/*
148 * For get_evrregs/set_evrregs functions 'data' has the following layout:
149 *
150 * struct {
151 * u32 evr[32];
152 * u64 acc;
153 * u32 spefscr;
154 * }
155 */
156
157/*
158 * Get contents of SPE register state in task TASK.
159 */
160static inline int get_evrregs(unsigned long *data, struct task_struct *task)
161{
162 int i;
163
164 if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long)))
165 return -EFAULT;
166
167 /* copy SPEFSCR */
168 if (__put_user(task->thread.spefscr, &data[34]))
169 return -EFAULT;
170
171 /* copy SPE registers EVR[0] .. EVR[31] */
172 for (i = 0; i < 32; i++, data++)
173 if (__put_user(task->thread.evr[i], data))
174 return -EFAULT;
175
176 /* copy ACC */
177 if (__put_user64(task->thread.acc, (unsigned long long *)data))
178 return -EFAULT;
179
180 return 0;
181}
182
183/*
184 * Write contents of SPE register state into task TASK.
185 */
186static inline int set_evrregs(struct task_struct *task, unsigned long *data)
187{
188 int i;
189
190 if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long)))
191 return -EFAULT;
192
193 /* copy SPEFSCR */
194 if (__get_user(task->thread.spefscr, &data[34]))
195 return -EFAULT;
196
197 /* copy SPE registers EVR[0] .. EVR[31] */
198 for (i = 0; i < 32; i++, data++)
199 if (__get_user(task->thread.evr[i], data))
200 return -EFAULT;
201 /* copy ACC */
202 if (__get_user64(task->thread.acc, (unsigned long long*)data))
203 return -EFAULT;
204
205 return 0;
206}
207#endif /* CONFIG_SPE */
208
209static inline void
210set_single_step(struct task_struct *task)
211{
212 struct pt_regs *regs = task->thread.regs;
213
214 if (regs != NULL) {
215#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
216 task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC;
217 regs->msr |= MSR_DE;
218#else
219 regs->msr |= MSR_SE;
220#endif
221 }
222}
223
224static inline void
225clear_single_step(struct task_struct *task)
226{
227 struct pt_regs *regs = task->thread.regs;
228
229 if (regs != NULL) {
230#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
231 task->thread.dbcr0 = 0;
232 regs->msr &= ~MSR_DE;
233#else
234 regs->msr &= ~MSR_SE;
235#endif
236 }
237}
e8a30302 238#endif /* CONFIG_PPC32 */
1da177e4
LT
239
240/*
241 * Called by kernel/ptrace.c when detaching..
242 *
243 * Make sure single step bits etc are not set.
244 */
245void ptrace_disable(struct task_struct *child)
246{
247 /* make sure the single step bit is not set. */
248 clear_single_step(child);
249}
250
734d6524 251long sys_ptrace(long request, long pid, long addr, long data)
1da177e4
LT
252{
253 struct task_struct *child;
254 int ret = -EPERM;
255
256 lock_kernel();
257 if (request == PTRACE_TRACEME) {
258 /* are we already being traced? */
259 if (current->ptrace & PT_PTRACED)
260 goto out;
261 ret = security_ptrace(current->parent, current);
262 if (ret)
263 goto out;
264 /* set the ptrace bit in the process flags. */
265 current->ptrace |= PT_PTRACED;
266 ret = 0;
267 goto out;
268 }
269 ret = -ESRCH;
270 read_lock(&tasklist_lock);
271 child = find_task_by_pid(pid);
272 if (child)
273 get_task_struct(child);
274 read_unlock(&tasklist_lock);
275 if (!child)
276 goto out;
277
278 ret = -EPERM;
279 if (pid == 1) /* you may not mess with init */
280 goto out_tsk;
281
282 if (request == PTRACE_ATTACH) {
283 ret = ptrace_attach(child);
284 goto out_tsk;
285 }
286
287 ret = ptrace_check_attach(child, request == PTRACE_KILL);
288 if (ret < 0)
289 goto out_tsk;
290
291 switch (request) {
292 /* when I and D space are separate, these will need to be fixed. */
293 case PTRACE_PEEKTEXT: /* read word at location addr. */
294 case PTRACE_PEEKDATA: {
295 unsigned long tmp;
296 int copied;
297
298 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
299 ret = -EIO;
300 if (copied != sizeof(tmp))
301 break;
302 ret = put_user(tmp,(unsigned long __user *) data);
303 break;
304 }
305
306 /* read the word at location addr in the USER area. */
1da177e4
LT
307 case PTRACE_PEEKUSR: {
308 unsigned long index, tmp;
309
310 ret = -EIO;
311 /* convert to index and check */
e8a30302 312#ifdef CONFIG_PPC32
1da177e4 313 index = (unsigned long) addr >> 2;
e8a30302
SR
314 if ((addr & 3) || (index > PT_FPSCR)
315 || (child->thread.regs == NULL))
316#else
317 index = (unsigned long) addr >> 3;
318 if ((addr & 7) || (index > PT_FPSCR))
319#endif
1da177e4
LT
320 break;
321
e8a30302 322#ifdef CONFIG_PPC32
1da177e4 323 CHECK_FULL_REGS(child->thread.regs);
e8a30302 324#endif
1da177e4
LT
325 if (index < PT_FPR0) {
326 tmp = get_reg(child, (int) index);
327 } else {
e8a30302 328 flush_fp_to_thread(child);
1da177e4
LT
329 tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
330 }
331 ret = put_user(tmp,(unsigned long __user *) data);
332 break;
333 }
334
335 /* If I and D space are separate, this will have to be fixed. */
336 case PTRACE_POKETEXT: /* write the word at location addr. */
337 case PTRACE_POKEDATA:
338 ret = 0;
e8a30302
SR
339 if (access_process_vm(child, addr, &data, sizeof(data), 1)
340 == sizeof(data))
1da177e4
LT
341 break;
342 ret = -EIO;
343 break;
344
345 /* write the word at location addr in the USER area */
346 case PTRACE_POKEUSR: {
347 unsigned long index;
348
349 ret = -EIO;
350 /* convert to index and check */
e8a30302 351#ifdef CONFIG_PPC32
1da177e4 352 index = (unsigned long) addr >> 2;
e8a30302
SR
353 if ((addr & 3) || (index > PT_FPSCR)
354 || (child->thread.regs == NULL))
355#else
356 index = (unsigned long) addr >> 3;
357 if ((addr & 7) || (index > PT_FPSCR))
358#endif
1da177e4
LT
359 break;
360
e8a30302 361#ifdef CONFIG_PPC32
1da177e4 362 CHECK_FULL_REGS(child->thread.regs);
e8a30302 363#endif
1da177e4
LT
364 if (index == PT_ORIG_R3)
365 break;
366 if (index < PT_FPR0) {
367 ret = put_reg(child, index, data);
368 } else {
e8a30302 369 flush_fp_to_thread(child);
1da177e4
LT
370 ((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
371 ret = 0;
372 }
373 break;
374 }
375
376 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
377 case PTRACE_CONT: { /* restart after signal. */
378 ret = -EIO;
7ed20e1a 379 if (!valid_signal(data))
1da177e4 380 break;
e8a30302 381 if (request == PTRACE_SYSCALL)
1da177e4 382 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
e8a30302 383 else
1da177e4 384 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
1da177e4
LT
385 child->exit_code = data;
386 /* make sure the single step bit is not set. */
387 clear_single_step(child);
388 wake_up_process(child);
389 ret = 0;
390 break;
391 }
392
393/*
394 * make the child exit. Best I can do is send it a sigkill.
395 * perhaps it should be put in the status that it wants to
396 * exit.
397 */
398 case PTRACE_KILL: {
399 ret = 0;
400 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
401 break;
402 child->exit_code = SIGKILL;
403 /* make sure the single step bit is not set. */
404 clear_single_step(child);
405 wake_up_process(child);
406 break;
407 }
408
409 case PTRACE_SINGLESTEP: { /* set the trap flag. */
410 ret = -EIO;
7ed20e1a 411 if (!valid_signal(data))
1da177e4
LT
412 break;
413 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
414 set_single_step(child);
415 child->exit_code = data;
416 /* give it a chance to run. */
417 wake_up_process(child);
418 ret = 0;
419 break;
420 }
421
e8a30302
SR
422#ifdef CONFIG_PPC64
423 case PTRACE_GET_DEBUGREG: {
424 ret = -EINVAL;
425 /* We only support one DABR and no IABRS at the moment */
426 if (addr > 0)
427 break;
428 ret = put_user(child->thread.dabr,
429 (unsigned long __user *)data);
430 break;
431 }
432
433 case PTRACE_SET_DEBUGREG:
434 ret = ptrace_set_debugreg(child, addr, data);
435 break;
436#endif
437
1da177e4
LT
438 case PTRACE_DETACH:
439 ret = ptrace_detach(child, data);
440 break;
441
e8a30302
SR
442#ifdef CONFIG_PPC64
443 case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
444 int i;
445 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
446 unsigned long __user *tmp = (unsigned long __user *)addr;
447
448 for (i = 0; i < 32; i++) {
449 ret = put_user(*reg, tmp);
450 if (ret)
451 break;
452 reg++;
453 tmp++;
454 }
455 break;
456 }
457
458 case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
459 int i;
460 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
461 unsigned long __user *tmp = (unsigned long __user *)addr;
462
463 for (i = 0; i < 32; i++) {
464 ret = get_user(*reg, tmp);
465 if (ret)
466 break;
467 reg++;
468 tmp++;
469 }
470 break;
471 }
472
473 case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
474 int i;
475 unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
476 unsigned long __user *tmp = (unsigned long __user *)addr;
477
478 flush_fp_to_thread(child);
479
480 for (i = 0; i < 32; i++) {
481 ret = put_user(*reg, tmp);
482 if (ret)
483 break;
484 reg++;
485 tmp++;
486 }
487 break;
488 }
489
490 case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
491 int i;
492 unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
493 unsigned long __user *tmp = (unsigned long __user *)addr;
494
495 flush_fp_to_thread(child);
496
497 for (i = 0; i < 32; i++) {
498 ret = get_user(*reg, tmp);
499 if (ret)
500 break;
501 reg++;
502 tmp++;
503 }
504 break;
505 }
506#endif /* CONFIG_PPC64 */
507
1da177e4
LT
508#ifdef CONFIG_ALTIVEC
509 case PTRACE_GETVRREGS:
510 /* Get the child altivec register state. */
e8a30302 511 flush_altivec_to_thread(child);
1da177e4
LT
512 ret = get_vrregs((unsigned long __user *)data, child);
513 break;
514
515 case PTRACE_SETVRREGS:
516 /* Set the child altivec register state. */
e8a30302 517 flush_altivec_to_thread(child);
1da177e4
LT
518 ret = set_vrregs(child, (unsigned long __user *)data);
519 break;
520#endif
521#ifdef CONFIG_SPE
522 case PTRACE_GETEVRREGS:
523 /* Get the child spe register state. */
524 if (child->thread.regs->msr & MSR_SPE)
525 giveup_spe(child);
526 ret = get_evrregs((unsigned long __user *)data, child);
527 break;
528
529 case PTRACE_SETEVRREGS:
530 /* Set the child spe register state. */
531 /* this is to clear the MSR_SPE bit to force a reload
532 * of register state from memory */
533 if (child->thread.regs->msr & MSR_SPE)
534 giveup_spe(child);
535 ret = set_evrregs(child, (unsigned long __user *)data);
536 break;
537#endif
538
539 default:
540 ret = ptrace_request(child, request, addr, data);
541 break;
542 }
543out_tsk:
544 put_task_struct(child);
545out:
546 unlock_kernel();
547 return ret;
548}
549
ea9c102c 550static void do_syscall_trace(void)
1da177e4 551{
ea9c102c
DW
552 /* the 0x80 provides a way for the tracing parent to distinguish
553 between a syscall stop and SIGTRAP delivery */
1da177e4
LT
554 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
555 ? 0x80 : 0));
556
557 /*
558 * this isn't the same as continuing with a signal, but it will do
559 * for normal use. strace only continues with a signal if the
560 * stopping signal is not SIGTRAP. -brl
561 */
562 if (current->exit_code) {
563 send_sig(current->exit_code, current, 1);
564 current->exit_code = 0;
565 }
566}
ea9c102c
DW
567
568void do_syscall_trace_enter(struct pt_regs *regs)
569{
e8a30302
SR
570#ifdef CONFIG_PPC64
571 secure_computing(regs->gpr[0]);
572#endif
573
ea9c102c
DW
574 if (test_thread_flag(TIF_SYSCALL_TRACE)
575 && (current->ptrace & PT_PTRACED))
576 do_syscall_trace();
577
578 if (unlikely(current->audit_context))
e8a30302
SR
579 audit_syscall_entry(current,
580#ifdef CONFIG_PPC32
581 AUDIT_ARCH_PPC,
582#else
583 test_thread_flag(TIF_32BIT)?AUDIT_ARCH_PPC:AUDIT_ARCH_PPC64,
584#endif
ea9c102c
DW
585 regs->gpr[0],
586 regs->gpr[3], regs->gpr[4],
587 regs->gpr[5], regs->gpr[6]);
588}
589
590void do_syscall_trace_leave(struct pt_regs *regs)
591{
e8a30302 592#ifdef CONFIG_PPC32
ea9c102c 593 secure_computing(regs->gpr[0]);
e8a30302 594#endif
ea9c102c
DW
595
596 if (unlikely(current->audit_context))
597 audit_syscall_exit(current,
598 (regs->ccr&0x1000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
599 regs->result);
600
e8a30302
SR
601 if ((test_thread_flag(TIF_SYSCALL_TRACE)
602#ifdef CONFIG_PPC64
603 || test_thread_flag(TIF_SINGLESTEP)
604#endif
605 )
ea9c102c
DW
606 && (current->ptrace & PT_PTRACED))
607 do_syscall_trace();
608}
609
e8a30302 610#ifdef CONFIG_PPC32
ea9c102c
DW
611EXPORT_SYMBOL(do_syscall_trace_enter);
612EXPORT_SYMBOL(do_syscall_trace_leave);
e8a30302 613#endif
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