PTRACE_PEEKDATA consolidation
[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
18#include <linux/kernel.h>
19#include <linux/sched.h>
20#include <linux/mm.h>
21#include <linux/smp.h>
1da177e4
LT
22#include <linux/errno.h>
23#include <linux/ptrace.h>
24#include <linux/user.h>
25#include <linux/security.h>
7ed20e1a 26#include <linux/signal.h>
ea9c102c
DW
27#include <linux/seccomp.h>
28#include <linux/audit.h>
e8a30302 29#ifdef CONFIG_PPC32
ea9c102c 30#include <linux/module.h>
e8a30302 31#endif
1da177e4
LT
32
33#include <asm/uaccess.h>
34#include <asm/page.h>
35#include <asm/pgtable.h>
36#include <asm/system.h>
21a62902 37
abd06505
BH
38/*
39 * does not yet catch signals sent when the child dies.
40 * in exit.c or in signal.c.
41 */
42
43/*
44 * Set of msr bits that gdb can change on behalf of a process.
45 */
46#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
47#define MSR_DEBUGCHANGE 0
1da177e4 48#else
abd06505 49#define MSR_DEBUGCHANGE (MSR_SE | MSR_BE)
1da177e4 50#endif
acd89828 51
1da177e4 52/*
abd06505 53 * Max register writeable via put_reg
1da177e4 54 */
abd06505
BH
55#ifdef CONFIG_PPC32
56#define PT_MAX_PUT_REG PT_MQ
57#else
58#define PT_MAX_PUT_REG PT_CCR
59#endif
1da177e4 60
865418d8
BH
61/*
62 * Get contents of register REGNO in task TASK.
63 */
64unsigned long ptrace_get_reg(struct task_struct *task, int regno)
65{
66 unsigned long tmp = 0;
67
68 if (task->thread.regs == NULL)
69 return -EIO;
70
71 if (regno == PT_MSR) {
72 tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
abd06505 73 return tmp | task->thread.fpexc_mode;
865418d8
BH
74 }
75
76 if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
77 return ((unsigned long *)task->thread.regs)[regno];
78
79 return -EIO;
80}
81
82/*
83 * Write contents of register REGNO in task TASK.
84 */
85int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
86{
87 if (task->thread.regs == NULL)
88 return -EIO;
89
912000e7 90 if (regno <= PT_MAX_PUT_REG || regno == PT_TRAP) {
865418d8
BH
91 if (regno == PT_MSR)
92 data = (data & MSR_DEBUGCHANGE)
93 | (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
912000e7
BH
94 /* We prevent mucking around with the reserved area of trap
95 * which are used internally by the kernel
96 */
97 if (regno == PT_TRAP)
98 data &= 0xfff0;
865418d8
BH
99 ((unsigned long *)task->thread.regs)[regno] = data;
100 return 0;
101 }
102 return -EIO;
103}
104
105
106static int get_fpregs(void __user *data, struct task_struct *task,
107 int has_fpscr)
108{
109 unsigned int count = has_fpscr ? 33 : 32;
110
111 if (copy_to_user(data, task->thread.fpr, count * sizeof(double)))
112 return -EFAULT;
113 return 0;
114}
115
116static int set_fpregs(void __user *data, struct task_struct *task,
117 int has_fpscr)
118{
119 unsigned int count = has_fpscr ? 33 : 32;
120
121 if (copy_from_user(task->thread.fpr, data, count * sizeof(double)))
122 return -EFAULT;
123 return 0;
124}
125
126
127#ifdef CONFIG_ALTIVEC
128/*
129 * Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
130 * The transfer totals 34 quadword. Quadwords 0-31 contain the
131 * corresponding vector registers. Quadword 32 contains the vscr as the
132 * last word (offset 12) within that quadword. Quadword 33 contains the
133 * vrsave as the first word (offset 0) within the quadword.
134 *
135 * This definition of the VMX state is compatible with the current PPC32
136 * ptrace interface. This allows signal handling and ptrace to use the
137 * same structures. This also simplifies the implementation of a bi-arch
138 * (combined (32- and 64-bit) gdb.
139 */
140
141/*
142 * Get contents of AltiVec register state in task TASK
143 */
144static int get_vrregs(unsigned long __user *data, struct task_struct *task)
145{
146 unsigned long regsize;
147
148 /* copy AltiVec registers VR[0] .. VR[31] */
149 regsize = 32 * sizeof(vector128);
150 if (copy_to_user(data, task->thread.vr, regsize))
151 return -EFAULT;
152 data += (regsize / sizeof(unsigned long));
153
154 /* copy VSCR */
155 regsize = 1 * sizeof(vector128);
156 if (copy_to_user(data, &task->thread.vscr, regsize))
157 return -EFAULT;
158 data += (regsize / sizeof(unsigned long));
159
160 /* copy VRSAVE */
161 if (put_user(task->thread.vrsave, (u32 __user *)data))
162 return -EFAULT;
163
164 return 0;
165}
166
167/*
168 * Write contents of AltiVec register state into task TASK.
169 */
170static int set_vrregs(struct task_struct *task, unsigned long __user *data)
171{
172 unsigned long regsize;
173
174 /* copy AltiVec registers VR[0] .. VR[31] */
175 regsize = 32 * sizeof(vector128);
176 if (copy_from_user(task->thread.vr, data, regsize))
177 return -EFAULT;
178 data += (regsize / sizeof(unsigned long));
179
180 /* copy VSCR */
181 regsize = 1 * sizeof(vector128);
182 if (copy_from_user(&task->thread.vscr, data, regsize))
183 return -EFAULT;
184 data += (regsize / sizeof(unsigned long));
185
186 /* copy VRSAVE */
187 if (get_user(task->thread.vrsave, (u32 __user *)data))
188 return -EFAULT;
189
190 return 0;
191}
192#endif /* CONFIG_ALTIVEC */
193
194#ifdef CONFIG_SPE
195
196/*
197 * For get_evrregs/set_evrregs functions 'data' has the following layout:
198 *
199 * struct {
200 * u32 evr[32];
201 * u64 acc;
202 * u32 spefscr;
203 * }
204 */
205
206/*
207 * Get contents of SPE register state in task TASK.
208 */
209static int get_evrregs(unsigned long *data, struct task_struct *task)
210{
211 int i;
212
213 if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long)))
214 return -EFAULT;
215
216 /* copy SPEFSCR */
217 if (__put_user(task->thread.spefscr, &data[34]))
218 return -EFAULT;
219
220 /* copy SPE registers EVR[0] .. EVR[31] */
221 for (i = 0; i < 32; i++, data++)
222 if (__put_user(task->thread.evr[i], data))
223 return -EFAULT;
224
225 /* copy ACC */
226 if (__put_user64(task->thread.acc, (unsigned long long *)data))
227 return -EFAULT;
228
229 return 0;
230}
231
232/*
233 * Write contents of SPE register state into task TASK.
234 */
235static int set_evrregs(struct task_struct *task, unsigned long *data)
236{
237 int i;
238
239 if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long)))
240 return -EFAULT;
241
242 /* copy SPEFSCR */
243 if (__get_user(task->thread.spefscr, &data[34]))
244 return -EFAULT;
245
246 /* copy SPE registers EVR[0] .. EVR[31] */
247 for (i = 0; i < 32; i++, data++)
248 if (__get_user(task->thread.evr[i], data))
249 return -EFAULT;
250 /* copy ACC */
251 if (__get_user64(task->thread.acc, (unsigned long long*)data))
252 return -EFAULT;
253
254 return 0;
255}
256#endif /* CONFIG_SPE */
257
258
259static void set_single_step(struct task_struct *task)
260{
261 struct pt_regs *regs = task->thread.regs;
262
263 if (regs != NULL) {
264#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
265 task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC;
266 regs->msr |= MSR_DE;
267#else
268 regs->msr |= MSR_SE;
269#endif
270 }
271 set_tsk_thread_flag(task, TIF_SINGLESTEP);
272}
273
274static void clear_single_step(struct task_struct *task)
275{
276 struct pt_regs *regs = task->thread.regs;
277
278 if (regs != NULL) {
279#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
280 task->thread.dbcr0 = 0;
281 regs->msr &= ~MSR_DE;
282#else
283 regs->msr &= ~MSR_SE;
284#endif
285 }
286 clear_tsk_thread_flag(task, TIF_SINGLESTEP);
287}
288
abd06505
BH
289static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
290 unsigned long data)
291{
292 /* We only support one DABR and no IABRS at the moment */
293 if (addr > 0)
294 return -EINVAL;
295
296 /* The bottom 3 bits are flags */
297 if ((data & ~0x7UL) >= TASK_SIZE)
298 return -EIO;
299
300 /* Ensure translation is on */
301 if (data && !(data & DABR_TRANSLATION))
302 return -EIO;
303
304 task->thread.dabr = data;
305 return 0;
306}
abd06505 307
1da177e4
LT
308/*
309 * Called by kernel/ptrace.c when detaching..
310 *
311 * Make sure single step bits etc are not set.
312 */
313void ptrace_disable(struct task_struct *child)
314{
315 /* make sure the single step bit is not set. */
316 clear_single_step(child);
317}
318
e17666ba
BH
319/*
320 * Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
321 * we mark them as obsolete now, they will be removed in a future version
322 */
323static long arch_ptrace_old(struct task_struct *child, long request, long addr,
324 long data)
325{
326 int ret = -EPERM;
327
328 switch(request) {
329 case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
330 int i;
331 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
332 unsigned long __user *tmp = (unsigned long __user *)addr;
333
334 for (i = 0; i < 32; i++) {
335 ret = put_user(*reg, tmp);
336 if (ret)
337 break;
338 reg++;
339 tmp++;
340 }
341 break;
342 }
343
344 case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
345 int i;
346 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
347 unsigned long __user *tmp = (unsigned long __user *)addr;
348
349 for (i = 0; i < 32; i++) {
350 ret = get_user(*reg, tmp);
351 if (ret)
352 break;
353 reg++;
354 tmp++;
355 }
356 break;
357 }
358
359 case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
360 flush_fp_to_thread(child);
361 ret = get_fpregs((void __user *)addr, child, 0);
362 break;
363 }
364
365 case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
366 flush_fp_to_thread(child);
367 ret = set_fpregs((void __user *)addr, child, 0);
368 break;
369 }
370
371 }
372 return ret;
373}
374
481bed45 375long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1da177e4 376{
1da177e4
LT
377 int ret = -EPERM;
378
1da177e4
LT
379 switch (request) {
380 /* when I and D space are separate, these will need to be fixed. */
381 case PTRACE_PEEKTEXT: /* read word at location addr. */
76647323
AD
382 case PTRACE_PEEKDATA:
383 ret = generic_ptrace_peekdata(child, addr, data);
1da177e4 384 break;
1da177e4
LT
385
386 /* read the word at location addr in the USER area. */
1da177e4
LT
387 case PTRACE_PEEKUSR: {
388 unsigned long index, tmp;
389
390 ret = -EIO;
391 /* convert to index and check */
e8a30302 392#ifdef CONFIG_PPC32
1da177e4 393 index = (unsigned long) addr >> 2;
e8a30302
SR
394 if ((addr & 3) || (index > PT_FPSCR)
395 || (child->thread.regs == NULL))
396#else
397 index = (unsigned long) addr >> 3;
398 if ((addr & 7) || (index > PT_FPSCR))
399#endif
1da177e4
LT
400 break;
401
402 CHECK_FULL_REGS(child->thread.regs);
403 if (index < PT_FPR0) {
865418d8 404 tmp = ptrace_get_reg(child, (int) index);
1da177e4 405 } else {
e8a30302 406 flush_fp_to_thread(child);
1da177e4
LT
407 tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
408 }
409 ret = put_user(tmp,(unsigned long __user *) data);
410 break;
411 }
412
413 /* If I and D space are separate, this will have to be fixed. */
414 case PTRACE_POKETEXT: /* write the word at location addr. */
415 case PTRACE_POKEDATA:
416 ret = 0;
e8a30302
SR
417 if (access_process_vm(child, addr, &data, sizeof(data), 1)
418 == sizeof(data))
1da177e4
LT
419 break;
420 ret = -EIO;
421 break;
422
423 /* write the word at location addr in the USER area */
424 case PTRACE_POKEUSR: {
425 unsigned long index;
426
427 ret = -EIO;
428 /* convert to index and check */
e8a30302 429#ifdef CONFIG_PPC32
1da177e4 430 index = (unsigned long) addr >> 2;
e8a30302
SR
431 if ((addr & 3) || (index > PT_FPSCR)
432 || (child->thread.regs == NULL))
433#else
434 index = (unsigned long) addr >> 3;
435 if ((addr & 7) || (index > PT_FPSCR))
436#endif
1da177e4
LT
437 break;
438
439 CHECK_FULL_REGS(child->thread.regs);
1da177e4 440 if (index < PT_FPR0) {
865418d8 441 ret = ptrace_put_reg(child, index, data);
1da177e4 442 } else {
e8a30302 443 flush_fp_to_thread(child);
1da177e4
LT
444 ((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
445 ret = 0;
446 }
447 break;
448 }
449
450 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
451 case PTRACE_CONT: { /* restart after signal. */
452 ret = -EIO;
7ed20e1a 453 if (!valid_signal(data))
1da177e4 454 break;
e8a30302 455 if (request == PTRACE_SYSCALL)
1da177e4 456 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
e8a30302 457 else
1da177e4 458 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
1da177e4
LT
459 child->exit_code = data;
460 /* make sure the single step bit is not set. */
461 clear_single_step(child);
462 wake_up_process(child);
463 ret = 0;
464 break;
465 }
466
467/*
468 * make the child exit. Best I can do is send it a sigkill.
469 * perhaps it should be put in the status that it wants to
470 * exit.
471 */
472 case PTRACE_KILL: {
473 ret = 0;
474 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
475 break;
476 child->exit_code = SIGKILL;
477 /* make sure the single step bit is not set. */
478 clear_single_step(child);
479 wake_up_process(child);
480 break;
481 }
482
483 case PTRACE_SINGLESTEP: { /* set the trap flag. */
484 ret = -EIO;
7ed20e1a 485 if (!valid_signal(data))
1da177e4
LT
486 break;
487 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
488 set_single_step(child);
489 child->exit_code = data;
490 /* give it a chance to run. */
491 wake_up_process(child);
492 ret = 0;
493 break;
494 }
495
e8a30302
SR
496 case PTRACE_GET_DEBUGREG: {
497 ret = -EINVAL;
498 /* We only support one DABR and no IABRS at the moment */
499 if (addr > 0)
500 break;
501 ret = put_user(child->thread.dabr,
502 (unsigned long __user *)data);
503 break;
504 }
505
506 case PTRACE_SET_DEBUGREG:
507 ret = ptrace_set_debugreg(child, addr, data);
508 break;
e8a30302 509
1da177e4
LT
510 case PTRACE_DETACH:
511 ret = ptrace_detach(child, data);
512 break;
513
e17666ba
BH
514#ifdef CONFIG_PPC64
515 case PTRACE_GETREGS64:
516#endif
517 case PTRACE_GETREGS: { /* Get all pt_regs from the child. */
518 int ui;
519 if (!access_ok(VERIFY_WRITE, (void __user *)data,
520 sizeof(struct pt_regs))) {
521 ret = -EIO;
522 break;
523 }
524 ret = 0;
525 for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
865418d8 526 ret |= __put_user(ptrace_get_reg(child, ui),
e17666ba
BH
527 (unsigned long __user *) data);
528 data += sizeof(long);
e8a30302
SR
529 }
530 break;
531 }
532
e17666ba
BH
533#ifdef CONFIG_PPC64
534 case PTRACE_SETREGS64:
535#endif
536 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
537 unsigned long tmp;
538 int ui;
539 if (!access_ok(VERIFY_READ, (void __user *)data,
540 sizeof(struct pt_regs))) {
541 ret = -EIO;
542 break;
543 }
544 ret = 0;
545 for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
546 ret = __get_user(tmp, (unsigned long __user *) data);
e8a30302
SR
547 if (ret)
548 break;
865418d8 549 ptrace_put_reg(child, ui, tmp);
e17666ba 550 data += sizeof(long);
e8a30302
SR
551 }
552 break;
553 }
554
e17666ba 555 case PTRACE_GETFPREGS: { /* Get the child FPU state (FPR0...31 + FPSCR) */
e8a30302 556 flush_fp_to_thread(child);
e17666ba 557 ret = get_fpregs((void __user *)data, child, 1);
e8a30302
SR
558 break;
559 }
560
e17666ba 561 case PTRACE_SETFPREGS: { /* Set the child FPU state (FPR0...31 + FPSCR) */
e8a30302 562 flush_fp_to_thread(child);
e17666ba 563 ret = set_fpregs((void __user *)data, child, 1);
e8a30302
SR
564 break;
565 }
e8a30302 566
1da177e4
LT
567#ifdef CONFIG_ALTIVEC
568 case PTRACE_GETVRREGS:
569 /* Get the child altivec register state. */
e8a30302 570 flush_altivec_to_thread(child);
1da177e4
LT
571 ret = get_vrregs((unsigned long __user *)data, child);
572 break;
573
574 case PTRACE_SETVRREGS:
575 /* Set the child altivec register state. */
e8a30302 576 flush_altivec_to_thread(child);
1da177e4
LT
577 ret = set_vrregs(child, (unsigned long __user *)data);
578 break;
579#endif
580#ifdef CONFIG_SPE
581 case PTRACE_GETEVRREGS:
582 /* Get the child spe register state. */
583 if (child->thread.regs->msr & MSR_SPE)
584 giveup_spe(child);
585 ret = get_evrregs((unsigned long __user *)data, child);
586 break;
587
588 case PTRACE_SETEVRREGS:
589 /* Set the child spe register state. */
590 /* this is to clear the MSR_SPE bit to force a reload
591 * of register state from memory */
592 if (child->thread.regs->msr & MSR_SPE)
593 giveup_spe(child);
594 ret = set_evrregs(child, (unsigned long __user *)data);
595 break;
596#endif
597
e17666ba
BH
598 /* Old reverse args ptrace callss */
599 case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
600 case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
601 case PPC_PTRACE_GETFPREGS: /* Get FPRs 0 - 31. */
602 case PPC_PTRACE_SETFPREGS: /* Get FPRs 0 - 31. */
603 ret = arch_ptrace_old(child, request, addr, data);
604 break;
605
1da177e4
LT
606 default:
607 ret = ptrace_request(child, request, addr, data);
608 break;
609 }
1da177e4
LT
610 return ret;
611}
612
ea9c102c 613static void do_syscall_trace(void)
1da177e4 614{
ea9c102c
DW
615 /* the 0x80 provides a way for the tracing parent to distinguish
616 between a syscall stop and SIGTRAP delivery */
1da177e4
LT
617 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
618 ? 0x80 : 0));
619
620 /*
621 * this isn't the same as continuing with a signal, but it will do
622 * for normal use. strace only continues with a signal if the
623 * stopping signal is not SIGTRAP. -brl
624 */
625 if (current->exit_code) {
626 send_sig(current->exit_code, current, 1);
627 current->exit_code = 0;
628 }
629}
ea9c102c
DW
630
631void do_syscall_trace_enter(struct pt_regs *regs)
632{
e8a30302 633 secure_computing(regs->gpr[0]);
e8a30302 634
ea9c102c
DW
635 if (test_thread_flag(TIF_SYSCALL_TRACE)
636 && (current->ptrace & PT_PTRACED))
637 do_syscall_trace();
638
cfcd1705
DW
639 if (unlikely(current->audit_context)) {
640#ifdef CONFIG_PPC64
641 if (!test_thread_flag(TIF_32BIT))
642 audit_syscall_entry(AUDIT_ARCH_PPC64,
643 regs->gpr[0],
644 regs->gpr[3], regs->gpr[4],
645 regs->gpr[5], regs->gpr[6]);
646 else
e8a30302 647#endif
cfcd1705
DW
648 audit_syscall_entry(AUDIT_ARCH_PPC,
649 regs->gpr[0],
650 regs->gpr[3] & 0xffffffff,
651 regs->gpr[4] & 0xffffffff,
652 regs->gpr[5] & 0xffffffff,
653 regs->gpr[6] & 0xffffffff);
654 }
ea9c102c
DW
655}
656
657void do_syscall_trace_leave(struct pt_regs *regs)
658{
ea9c102c 659 if (unlikely(current->audit_context))
4b9c876a 660 audit_syscall_exit((regs->ccr&0x10000000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
ea9c102c
DW
661 regs->result);
662
e8a30302 663 if ((test_thread_flag(TIF_SYSCALL_TRACE)
1bd79336 664 || test_thread_flag(TIF_SINGLESTEP))
ea9c102c
DW
665 && (current->ptrace & PT_PTRACED))
666 do_syscall_trace();
667}
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