xref: /openbmc/linux/arch/arm64/kernel/ptrace.c (revision d2168146)
1 /*
2  * Based on arch/arm/kernel/ptrace.c
3  *
4  * By Ross Biro 1/23/92
5  * edited by Linus Torvalds
6  * ARM modifications Copyright (C) 2000 Russell King
7  * Copyright (C) 2012 ARM Ltd.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include <linux/compat.h>
23 #include <linux/kernel.h>
24 #include <linux/sched.h>
25 #include <linux/mm.h>
26 #include <linux/smp.h>
27 #include <linux/ptrace.h>
28 #include <linux/user.h>
29 #include <linux/security.h>
30 #include <linux/init.h>
31 #include <linux/signal.h>
32 #include <linux/uaccess.h>
33 #include <linux/perf_event.h>
34 #include <linux/hw_breakpoint.h>
35 #include <linux/regset.h>
36 #include <linux/tracehook.h>
37 #include <linux/elf.h>
38 
39 #include <asm/compat.h>
40 #include <asm/debug-monitors.h>
41 #include <asm/pgtable.h>
42 #include <asm/traps.h>
43 #include <asm/system_misc.h>
44 
45 #define CREATE_TRACE_POINTS
46 #include <trace/events/syscalls.h>
47 
48 /*
49  * TODO: does not yet catch signals sent when the child dies.
50  * in exit.c or in signal.c.
51  */
52 
53 /*
54  * Called by kernel/ptrace.c when detaching..
55  */
56 void ptrace_disable(struct task_struct *child)
57 {
58 }
59 
60 #ifdef CONFIG_HAVE_HW_BREAKPOINT
61 /*
62  * Handle hitting a HW-breakpoint.
63  */
64 static void ptrace_hbptriggered(struct perf_event *bp,
65 				struct perf_sample_data *data,
66 				struct pt_regs *regs)
67 {
68 	struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
69 	siginfo_t info = {
70 		.si_signo	= SIGTRAP,
71 		.si_errno	= 0,
72 		.si_code	= TRAP_HWBKPT,
73 		.si_addr	= (void __user *)(bkpt->trigger),
74 	};
75 
76 #ifdef CONFIG_COMPAT
77 	int i;
78 
79 	if (!is_compat_task())
80 		goto send_sig;
81 
82 	for (i = 0; i < ARM_MAX_BRP; ++i) {
83 		if (current->thread.debug.hbp_break[i] == bp) {
84 			info.si_errno = (i << 1) + 1;
85 			break;
86 		}
87 	}
88 	for (i = ARM_MAX_BRP; i < ARM_MAX_HBP_SLOTS && !bp; ++i) {
89 		if (current->thread.debug.hbp_watch[i] == bp) {
90 			info.si_errno = -((i << 1) + 1);
91 			break;
92 		}
93 	}
94 
95 send_sig:
96 #endif
97 	force_sig_info(SIGTRAP, &info, current);
98 }
99 
100 /*
101  * Unregister breakpoints from this task and reset the pointers in
102  * the thread_struct.
103  */
104 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
105 {
106 	int i;
107 	struct thread_struct *t = &tsk->thread;
108 
109 	for (i = 0; i < ARM_MAX_BRP; i++) {
110 		if (t->debug.hbp_break[i]) {
111 			unregister_hw_breakpoint(t->debug.hbp_break[i]);
112 			t->debug.hbp_break[i] = NULL;
113 		}
114 	}
115 
116 	for (i = 0; i < ARM_MAX_WRP; i++) {
117 		if (t->debug.hbp_watch[i]) {
118 			unregister_hw_breakpoint(t->debug.hbp_watch[i]);
119 			t->debug.hbp_watch[i] = NULL;
120 		}
121 	}
122 }
123 
124 void ptrace_hw_copy_thread(struct task_struct *tsk)
125 {
126 	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
127 }
128 
129 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
130 					       struct task_struct *tsk,
131 					       unsigned long idx)
132 {
133 	struct perf_event *bp = ERR_PTR(-EINVAL);
134 
135 	switch (note_type) {
136 	case NT_ARM_HW_BREAK:
137 		if (idx < ARM_MAX_BRP)
138 			bp = tsk->thread.debug.hbp_break[idx];
139 		break;
140 	case NT_ARM_HW_WATCH:
141 		if (idx < ARM_MAX_WRP)
142 			bp = tsk->thread.debug.hbp_watch[idx];
143 		break;
144 	}
145 
146 	return bp;
147 }
148 
149 static int ptrace_hbp_set_event(unsigned int note_type,
150 				struct task_struct *tsk,
151 				unsigned long idx,
152 				struct perf_event *bp)
153 {
154 	int err = -EINVAL;
155 
156 	switch (note_type) {
157 	case NT_ARM_HW_BREAK:
158 		if (idx < ARM_MAX_BRP) {
159 			tsk->thread.debug.hbp_break[idx] = bp;
160 			err = 0;
161 		}
162 		break;
163 	case NT_ARM_HW_WATCH:
164 		if (idx < ARM_MAX_WRP) {
165 			tsk->thread.debug.hbp_watch[idx] = bp;
166 			err = 0;
167 		}
168 		break;
169 	}
170 
171 	return err;
172 }
173 
174 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
175 					    struct task_struct *tsk,
176 					    unsigned long idx)
177 {
178 	struct perf_event *bp;
179 	struct perf_event_attr attr;
180 	int err, type;
181 
182 	switch (note_type) {
183 	case NT_ARM_HW_BREAK:
184 		type = HW_BREAKPOINT_X;
185 		break;
186 	case NT_ARM_HW_WATCH:
187 		type = HW_BREAKPOINT_RW;
188 		break;
189 	default:
190 		return ERR_PTR(-EINVAL);
191 	}
192 
193 	ptrace_breakpoint_init(&attr);
194 
195 	/*
196 	 * Initialise fields to sane defaults
197 	 * (i.e. values that will pass validation).
198 	 */
199 	attr.bp_addr	= 0;
200 	attr.bp_len	= HW_BREAKPOINT_LEN_4;
201 	attr.bp_type	= type;
202 	attr.disabled	= 1;
203 
204 	bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
205 	if (IS_ERR(bp))
206 		return bp;
207 
208 	err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
209 	if (err)
210 		return ERR_PTR(err);
211 
212 	return bp;
213 }
214 
215 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
216 				     struct arch_hw_breakpoint_ctrl ctrl,
217 				     struct perf_event_attr *attr)
218 {
219 	int err, len, type, disabled = !ctrl.enabled;
220 
221 	attr->disabled = disabled;
222 	if (disabled)
223 		return 0;
224 
225 	err = arch_bp_generic_fields(ctrl, &len, &type);
226 	if (err)
227 		return err;
228 
229 	switch (note_type) {
230 	case NT_ARM_HW_BREAK:
231 		if ((type & HW_BREAKPOINT_X) != type)
232 			return -EINVAL;
233 		break;
234 	case NT_ARM_HW_WATCH:
235 		if ((type & HW_BREAKPOINT_RW) != type)
236 			return -EINVAL;
237 		break;
238 	default:
239 		return -EINVAL;
240 	}
241 
242 	attr->bp_len	= len;
243 	attr->bp_type	= type;
244 
245 	return 0;
246 }
247 
248 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
249 {
250 	u8 num;
251 	u32 reg = 0;
252 
253 	switch (note_type) {
254 	case NT_ARM_HW_BREAK:
255 		num = hw_breakpoint_slots(TYPE_INST);
256 		break;
257 	case NT_ARM_HW_WATCH:
258 		num = hw_breakpoint_slots(TYPE_DATA);
259 		break;
260 	default:
261 		return -EINVAL;
262 	}
263 
264 	reg |= debug_monitors_arch();
265 	reg <<= 8;
266 	reg |= num;
267 
268 	*info = reg;
269 	return 0;
270 }
271 
272 static int ptrace_hbp_get_ctrl(unsigned int note_type,
273 			       struct task_struct *tsk,
274 			       unsigned long idx,
275 			       u32 *ctrl)
276 {
277 	struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
278 
279 	if (IS_ERR(bp))
280 		return PTR_ERR(bp);
281 
282 	*ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
283 	return 0;
284 }
285 
286 static int ptrace_hbp_get_addr(unsigned int note_type,
287 			       struct task_struct *tsk,
288 			       unsigned long idx,
289 			       u64 *addr)
290 {
291 	struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
292 
293 	if (IS_ERR(bp))
294 		return PTR_ERR(bp);
295 
296 	*addr = bp ? bp->attr.bp_addr : 0;
297 	return 0;
298 }
299 
300 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
301 							struct task_struct *tsk,
302 							unsigned long idx)
303 {
304 	struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
305 
306 	if (!bp)
307 		bp = ptrace_hbp_create(note_type, tsk, idx);
308 
309 	return bp;
310 }
311 
312 static int ptrace_hbp_set_ctrl(unsigned int note_type,
313 			       struct task_struct *tsk,
314 			       unsigned long idx,
315 			       u32 uctrl)
316 {
317 	int err;
318 	struct perf_event *bp;
319 	struct perf_event_attr attr;
320 	struct arch_hw_breakpoint_ctrl ctrl;
321 
322 	bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
323 	if (IS_ERR(bp)) {
324 		err = PTR_ERR(bp);
325 		return err;
326 	}
327 
328 	attr = bp->attr;
329 	decode_ctrl_reg(uctrl, &ctrl);
330 	err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
331 	if (err)
332 		return err;
333 
334 	return modify_user_hw_breakpoint(bp, &attr);
335 }
336 
337 static int ptrace_hbp_set_addr(unsigned int note_type,
338 			       struct task_struct *tsk,
339 			       unsigned long idx,
340 			       u64 addr)
341 {
342 	int err;
343 	struct perf_event *bp;
344 	struct perf_event_attr attr;
345 
346 	bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
347 	if (IS_ERR(bp)) {
348 		err = PTR_ERR(bp);
349 		return err;
350 	}
351 
352 	attr = bp->attr;
353 	attr.bp_addr = addr;
354 	err = modify_user_hw_breakpoint(bp, &attr);
355 	return err;
356 }
357 
358 #define PTRACE_HBP_ADDR_SZ	sizeof(u64)
359 #define PTRACE_HBP_CTRL_SZ	sizeof(u32)
360 #define PTRACE_HBP_PAD_SZ	sizeof(u32)
361 
362 static int hw_break_get(struct task_struct *target,
363 			const struct user_regset *regset,
364 			unsigned int pos, unsigned int count,
365 			void *kbuf, void __user *ubuf)
366 {
367 	unsigned int note_type = regset->core_note_type;
368 	int ret, idx = 0, offset, limit;
369 	u32 info, ctrl;
370 	u64 addr;
371 
372 	/* Resource info */
373 	ret = ptrace_hbp_get_resource_info(note_type, &info);
374 	if (ret)
375 		return ret;
376 
377 	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
378 				  sizeof(info));
379 	if (ret)
380 		return ret;
381 
382 	/* Pad */
383 	offset = offsetof(struct user_hwdebug_state, pad);
384 	ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
385 				       offset + PTRACE_HBP_PAD_SZ);
386 	if (ret)
387 		return ret;
388 
389 	/* (address, ctrl) registers */
390 	offset = offsetof(struct user_hwdebug_state, dbg_regs);
391 	limit = regset->n * regset->size;
392 	while (count && offset < limit) {
393 		ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
394 		if (ret)
395 			return ret;
396 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
397 					  offset, offset + PTRACE_HBP_ADDR_SZ);
398 		if (ret)
399 			return ret;
400 		offset += PTRACE_HBP_ADDR_SZ;
401 
402 		ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
403 		if (ret)
404 			return ret;
405 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
406 					  offset, offset + PTRACE_HBP_CTRL_SZ);
407 		if (ret)
408 			return ret;
409 		offset += PTRACE_HBP_CTRL_SZ;
410 
411 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
412 					       offset,
413 					       offset + PTRACE_HBP_PAD_SZ);
414 		if (ret)
415 			return ret;
416 		offset += PTRACE_HBP_PAD_SZ;
417 		idx++;
418 	}
419 
420 	return 0;
421 }
422 
423 static int hw_break_set(struct task_struct *target,
424 			const struct user_regset *regset,
425 			unsigned int pos, unsigned int count,
426 			const void *kbuf, const void __user *ubuf)
427 {
428 	unsigned int note_type = regset->core_note_type;
429 	int ret, idx = 0, offset, limit;
430 	u32 ctrl;
431 	u64 addr;
432 
433 	/* Resource info and pad */
434 	offset = offsetof(struct user_hwdebug_state, dbg_regs);
435 	ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
436 	if (ret)
437 		return ret;
438 
439 	/* (address, ctrl) registers */
440 	limit = regset->n * regset->size;
441 	while (count && offset < limit) {
442 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
443 					 offset, offset + PTRACE_HBP_ADDR_SZ);
444 		if (ret)
445 			return ret;
446 		ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
447 		if (ret)
448 			return ret;
449 		offset += PTRACE_HBP_ADDR_SZ;
450 
451 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
452 					 offset, offset + PTRACE_HBP_CTRL_SZ);
453 		if (ret)
454 			return ret;
455 		ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
456 		if (ret)
457 			return ret;
458 		offset += PTRACE_HBP_CTRL_SZ;
459 
460 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
461 						offset,
462 						offset + PTRACE_HBP_PAD_SZ);
463 		if (ret)
464 			return ret;
465 		offset += PTRACE_HBP_PAD_SZ;
466 		idx++;
467 	}
468 
469 	return 0;
470 }
471 #endif	/* CONFIG_HAVE_HW_BREAKPOINT */
472 
473 static int gpr_get(struct task_struct *target,
474 		   const struct user_regset *regset,
475 		   unsigned int pos, unsigned int count,
476 		   void *kbuf, void __user *ubuf)
477 {
478 	struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
479 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
480 }
481 
482 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
483 		   unsigned int pos, unsigned int count,
484 		   const void *kbuf, const void __user *ubuf)
485 {
486 	int ret;
487 	struct user_pt_regs newregs;
488 
489 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
490 	if (ret)
491 		return ret;
492 
493 	if (!valid_user_regs(&newregs))
494 		return -EINVAL;
495 
496 	task_pt_regs(target)->user_regs = newregs;
497 	return 0;
498 }
499 
500 /*
501  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
502  */
503 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
504 		   unsigned int pos, unsigned int count,
505 		   void *kbuf, void __user *ubuf)
506 {
507 	struct user_fpsimd_state *uregs;
508 	uregs = &target->thread.fpsimd_state.user_fpsimd;
509 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
510 }
511 
512 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
513 		   unsigned int pos, unsigned int count,
514 		   const void *kbuf, const void __user *ubuf)
515 {
516 	int ret;
517 	struct user_fpsimd_state newstate;
518 
519 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
520 	if (ret)
521 		return ret;
522 
523 	target->thread.fpsimd_state.user_fpsimd = newstate;
524 	fpsimd_flush_task_state(target);
525 	return ret;
526 }
527 
528 static int tls_get(struct task_struct *target, const struct user_regset *regset,
529 		   unsigned int pos, unsigned int count,
530 		   void *kbuf, void __user *ubuf)
531 {
532 	unsigned long *tls = &target->thread.tp_value;
533 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
534 }
535 
536 static int tls_set(struct task_struct *target, const struct user_regset *regset,
537 		   unsigned int pos, unsigned int count,
538 		   const void *kbuf, const void __user *ubuf)
539 {
540 	int ret;
541 	unsigned long tls;
542 
543 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
544 	if (ret)
545 		return ret;
546 
547 	target->thread.tp_value = tls;
548 	return ret;
549 }
550 
551 enum aarch64_regset {
552 	REGSET_GPR,
553 	REGSET_FPR,
554 	REGSET_TLS,
555 #ifdef CONFIG_HAVE_HW_BREAKPOINT
556 	REGSET_HW_BREAK,
557 	REGSET_HW_WATCH,
558 #endif
559 };
560 
561 static const struct user_regset aarch64_regsets[] = {
562 	[REGSET_GPR] = {
563 		.core_note_type = NT_PRSTATUS,
564 		.n = sizeof(struct user_pt_regs) / sizeof(u64),
565 		.size = sizeof(u64),
566 		.align = sizeof(u64),
567 		.get = gpr_get,
568 		.set = gpr_set
569 	},
570 	[REGSET_FPR] = {
571 		.core_note_type = NT_PRFPREG,
572 		.n = sizeof(struct user_fpsimd_state) / sizeof(u32),
573 		/*
574 		 * We pretend we have 32-bit registers because the fpsr and
575 		 * fpcr are 32-bits wide.
576 		 */
577 		.size = sizeof(u32),
578 		.align = sizeof(u32),
579 		.get = fpr_get,
580 		.set = fpr_set
581 	},
582 	[REGSET_TLS] = {
583 		.core_note_type = NT_ARM_TLS,
584 		.n = 1,
585 		.size = sizeof(void *),
586 		.align = sizeof(void *),
587 		.get = tls_get,
588 		.set = tls_set,
589 	},
590 #ifdef CONFIG_HAVE_HW_BREAKPOINT
591 	[REGSET_HW_BREAK] = {
592 		.core_note_type = NT_ARM_HW_BREAK,
593 		.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
594 		.size = sizeof(u32),
595 		.align = sizeof(u32),
596 		.get = hw_break_get,
597 		.set = hw_break_set,
598 	},
599 	[REGSET_HW_WATCH] = {
600 		.core_note_type = NT_ARM_HW_WATCH,
601 		.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
602 		.size = sizeof(u32),
603 		.align = sizeof(u32),
604 		.get = hw_break_get,
605 		.set = hw_break_set,
606 	},
607 #endif
608 };
609 
610 static const struct user_regset_view user_aarch64_view = {
611 	.name = "aarch64", .e_machine = EM_AARCH64,
612 	.regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
613 };
614 
615 #ifdef CONFIG_COMPAT
616 #include <linux/compat.h>
617 
618 enum compat_regset {
619 	REGSET_COMPAT_GPR,
620 	REGSET_COMPAT_VFP,
621 };
622 
623 static int compat_gpr_get(struct task_struct *target,
624 			  const struct user_regset *regset,
625 			  unsigned int pos, unsigned int count,
626 			  void *kbuf, void __user *ubuf)
627 {
628 	int ret = 0;
629 	unsigned int i, start, num_regs;
630 
631 	/* Calculate the number of AArch32 registers contained in count */
632 	num_regs = count / regset->size;
633 
634 	/* Convert pos into an register number */
635 	start = pos / regset->size;
636 
637 	if (start + num_regs > regset->n)
638 		return -EIO;
639 
640 	for (i = 0; i < num_regs; ++i) {
641 		unsigned int idx = start + i;
642 		compat_ulong_t reg;
643 
644 		switch (idx) {
645 		case 15:
646 			reg = task_pt_regs(target)->pc;
647 			break;
648 		case 16:
649 			reg = task_pt_regs(target)->pstate;
650 			break;
651 		case 17:
652 			reg = task_pt_regs(target)->orig_x0;
653 			break;
654 		default:
655 			reg = task_pt_regs(target)->regs[idx];
656 		}
657 
658 		if (kbuf) {
659 			memcpy(kbuf, &reg, sizeof(reg));
660 			kbuf += sizeof(reg);
661 		} else {
662 			ret = copy_to_user(ubuf, &reg, sizeof(reg));
663 			if (ret)
664 				break;
665 
666 			ubuf += sizeof(reg);
667 		}
668 	}
669 
670 	return ret;
671 }
672 
673 static int compat_gpr_set(struct task_struct *target,
674 			  const struct user_regset *regset,
675 			  unsigned int pos, unsigned int count,
676 			  const void *kbuf, const void __user *ubuf)
677 {
678 	struct pt_regs newregs;
679 	int ret = 0;
680 	unsigned int i, start, num_regs;
681 
682 	/* Calculate the number of AArch32 registers contained in count */
683 	num_regs = count / regset->size;
684 
685 	/* Convert pos into an register number */
686 	start = pos / regset->size;
687 
688 	if (start + num_regs > regset->n)
689 		return -EIO;
690 
691 	newregs = *task_pt_regs(target);
692 
693 	for (i = 0; i < num_regs; ++i) {
694 		unsigned int idx = start + i;
695 		compat_ulong_t reg;
696 
697 		if (kbuf) {
698 			memcpy(&reg, kbuf, sizeof(reg));
699 			kbuf += sizeof(reg);
700 		} else {
701 			ret = copy_from_user(&reg, ubuf, sizeof(reg));
702 			if (ret)
703 				return ret;
704 
705 			ubuf += sizeof(reg);
706 		}
707 
708 		switch (idx) {
709 		case 15:
710 			newregs.pc = reg;
711 			break;
712 		case 16:
713 			newregs.pstate = reg;
714 			break;
715 		case 17:
716 			newregs.orig_x0 = reg;
717 			break;
718 		default:
719 			newregs.regs[idx] = reg;
720 		}
721 
722 	}
723 
724 	if (valid_user_regs(&newregs.user_regs))
725 		*task_pt_regs(target) = newregs;
726 	else
727 		ret = -EINVAL;
728 
729 	return ret;
730 }
731 
732 static int compat_vfp_get(struct task_struct *target,
733 			  const struct user_regset *regset,
734 			  unsigned int pos, unsigned int count,
735 			  void *kbuf, void __user *ubuf)
736 {
737 	struct user_fpsimd_state *uregs;
738 	compat_ulong_t fpscr;
739 	int ret;
740 
741 	uregs = &target->thread.fpsimd_state.user_fpsimd;
742 
743 	/*
744 	 * The VFP registers are packed into the fpsimd_state, so they all sit
745 	 * nicely together for us. We just need to create the fpscr separately.
746 	 */
747 	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
748 				  VFP_STATE_SIZE - sizeof(compat_ulong_t));
749 
750 	if (count && !ret) {
751 		fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
752 			(uregs->fpcr & VFP_FPSCR_CTRL_MASK);
753 		ret = put_user(fpscr, (compat_ulong_t *)ubuf);
754 	}
755 
756 	return ret;
757 }
758 
759 static int compat_vfp_set(struct task_struct *target,
760 			  const struct user_regset *regset,
761 			  unsigned int pos, unsigned int count,
762 			  const void *kbuf, const void __user *ubuf)
763 {
764 	struct user_fpsimd_state *uregs;
765 	compat_ulong_t fpscr;
766 	int ret;
767 
768 	if (pos + count > VFP_STATE_SIZE)
769 		return -EIO;
770 
771 	uregs = &target->thread.fpsimd_state.user_fpsimd;
772 
773 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
774 				 VFP_STATE_SIZE - sizeof(compat_ulong_t));
775 
776 	if (count && !ret) {
777 		ret = get_user(fpscr, (compat_ulong_t *)ubuf);
778 		uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
779 		uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
780 	}
781 
782 	fpsimd_flush_task_state(target);
783 	return ret;
784 }
785 
786 static const struct user_regset aarch32_regsets[] = {
787 	[REGSET_COMPAT_GPR] = {
788 		.core_note_type = NT_PRSTATUS,
789 		.n = COMPAT_ELF_NGREG,
790 		.size = sizeof(compat_elf_greg_t),
791 		.align = sizeof(compat_elf_greg_t),
792 		.get = compat_gpr_get,
793 		.set = compat_gpr_set
794 	},
795 	[REGSET_COMPAT_VFP] = {
796 		.core_note_type = NT_ARM_VFP,
797 		.n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
798 		.size = sizeof(compat_ulong_t),
799 		.align = sizeof(compat_ulong_t),
800 		.get = compat_vfp_get,
801 		.set = compat_vfp_set
802 	},
803 };
804 
805 static const struct user_regset_view user_aarch32_view = {
806 	.name = "aarch32", .e_machine = EM_ARM,
807 	.regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
808 };
809 
810 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
811 				   compat_ulong_t __user *ret)
812 {
813 	compat_ulong_t tmp;
814 
815 	if (off & 3)
816 		return -EIO;
817 
818 	if (off == COMPAT_PT_TEXT_ADDR)
819 		tmp = tsk->mm->start_code;
820 	else if (off == COMPAT_PT_DATA_ADDR)
821 		tmp = tsk->mm->start_data;
822 	else if (off == COMPAT_PT_TEXT_END_ADDR)
823 		tmp = tsk->mm->end_code;
824 	else if (off < sizeof(compat_elf_gregset_t))
825 		return copy_regset_to_user(tsk, &user_aarch32_view,
826 					   REGSET_COMPAT_GPR, off,
827 					   sizeof(compat_ulong_t), ret);
828 	else if (off >= COMPAT_USER_SZ)
829 		return -EIO;
830 	else
831 		tmp = 0;
832 
833 	return put_user(tmp, ret);
834 }
835 
836 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
837 				    compat_ulong_t val)
838 {
839 	int ret;
840 	mm_segment_t old_fs = get_fs();
841 
842 	if (off & 3 || off >= COMPAT_USER_SZ)
843 		return -EIO;
844 
845 	if (off >= sizeof(compat_elf_gregset_t))
846 		return 0;
847 
848 	set_fs(KERNEL_DS);
849 	ret = copy_regset_from_user(tsk, &user_aarch32_view,
850 				    REGSET_COMPAT_GPR, off,
851 				    sizeof(compat_ulong_t),
852 				    &val);
853 	set_fs(old_fs);
854 
855 	return ret;
856 }
857 
858 #ifdef CONFIG_HAVE_HW_BREAKPOINT
859 
860 /*
861  * Convert a virtual register number into an index for a thread_info
862  * breakpoint array. Breakpoints are identified using positive numbers
863  * whilst watchpoints are negative. The registers are laid out as pairs
864  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
865  * Register 0 is reserved for describing resource information.
866  */
867 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
868 {
869 	return (abs(num) - 1) >> 1;
870 }
871 
872 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
873 {
874 	u8 num_brps, num_wrps, debug_arch, wp_len;
875 	u32 reg = 0;
876 
877 	num_brps	= hw_breakpoint_slots(TYPE_INST);
878 	num_wrps	= hw_breakpoint_slots(TYPE_DATA);
879 
880 	debug_arch	= debug_monitors_arch();
881 	wp_len		= 8;
882 	reg		|= debug_arch;
883 	reg		<<= 8;
884 	reg		|= wp_len;
885 	reg		<<= 8;
886 	reg		|= num_wrps;
887 	reg		<<= 8;
888 	reg		|= num_brps;
889 
890 	*kdata = reg;
891 	return 0;
892 }
893 
894 static int compat_ptrace_hbp_get(unsigned int note_type,
895 				 struct task_struct *tsk,
896 				 compat_long_t num,
897 				 u32 *kdata)
898 {
899 	u64 addr = 0;
900 	u32 ctrl = 0;
901 
902 	int err, idx = compat_ptrace_hbp_num_to_idx(num);;
903 
904 	if (num & 1) {
905 		err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
906 		*kdata = (u32)addr;
907 	} else {
908 		err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
909 		*kdata = ctrl;
910 	}
911 
912 	return err;
913 }
914 
915 static int compat_ptrace_hbp_set(unsigned int note_type,
916 				 struct task_struct *tsk,
917 				 compat_long_t num,
918 				 u32 *kdata)
919 {
920 	u64 addr;
921 	u32 ctrl;
922 
923 	int err, idx = compat_ptrace_hbp_num_to_idx(num);
924 
925 	if (num & 1) {
926 		addr = *kdata;
927 		err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
928 	} else {
929 		ctrl = *kdata;
930 		err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
931 	}
932 
933 	return err;
934 }
935 
936 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
937 				    compat_ulong_t __user *data)
938 {
939 	int ret;
940 	u32 kdata;
941 	mm_segment_t old_fs = get_fs();
942 
943 	set_fs(KERNEL_DS);
944 	/* Watchpoint */
945 	if (num < 0) {
946 		ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
947 	/* Resource info */
948 	} else if (num == 0) {
949 		ret = compat_ptrace_hbp_get_resource_info(&kdata);
950 	/* Breakpoint */
951 	} else {
952 		ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
953 	}
954 	set_fs(old_fs);
955 
956 	if (!ret)
957 		ret = put_user(kdata, data);
958 
959 	return ret;
960 }
961 
962 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
963 				    compat_ulong_t __user *data)
964 {
965 	int ret;
966 	u32 kdata = 0;
967 	mm_segment_t old_fs = get_fs();
968 
969 	if (num == 0)
970 		return 0;
971 
972 	ret = get_user(kdata, data);
973 	if (ret)
974 		return ret;
975 
976 	set_fs(KERNEL_DS);
977 	if (num < 0)
978 		ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
979 	else
980 		ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
981 	set_fs(old_fs);
982 
983 	return ret;
984 }
985 #endif	/* CONFIG_HAVE_HW_BREAKPOINT */
986 
987 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
988 			compat_ulong_t caddr, compat_ulong_t cdata)
989 {
990 	unsigned long addr = caddr;
991 	unsigned long data = cdata;
992 	void __user *datap = compat_ptr(data);
993 	int ret;
994 
995 	switch (request) {
996 		case PTRACE_PEEKUSR:
997 			ret = compat_ptrace_read_user(child, addr, datap);
998 			break;
999 
1000 		case PTRACE_POKEUSR:
1001 			ret = compat_ptrace_write_user(child, addr, data);
1002 			break;
1003 
1004 		case COMPAT_PTRACE_GETREGS:
1005 			ret = copy_regset_to_user(child,
1006 						  &user_aarch32_view,
1007 						  REGSET_COMPAT_GPR,
1008 						  0, sizeof(compat_elf_gregset_t),
1009 						  datap);
1010 			break;
1011 
1012 		case COMPAT_PTRACE_SETREGS:
1013 			ret = copy_regset_from_user(child,
1014 						    &user_aarch32_view,
1015 						    REGSET_COMPAT_GPR,
1016 						    0, sizeof(compat_elf_gregset_t),
1017 						    datap);
1018 			break;
1019 
1020 		case COMPAT_PTRACE_GET_THREAD_AREA:
1021 			ret = put_user((compat_ulong_t)child->thread.tp_value,
1022 				       (compat_ulong_t __user *)datap);
1023 			break;
1024 
1025 		case COMPAT_PTRACE_SET_SYSCALL:
1026 			task_pt_regs(child)->syscallno = data;
1027 			ret = 0;
1028 			break;
1029 
1030 		case COMPAT_PTRACE_GETVFPREGS:
1031 			ret = copy_regset_to_user(child,
1032 						  &user_aarch32_view,
1033 						  REGSET_COMPAT_VFP,
1034 						  0, VFP_STATE_SIZE,
1035 						  datap);
1036 			break;
1037 
1038 		case COMPAT_PTRACE_SETVFPREGS:
1039 			ret = copy_regset_from_user(child,
1040 						    &user_aarch32_view,
1041 						    REGSET_COMPAT_VFP,
1042 						    0, VFP_STATE_SIZE,
1043 						    datap);
1044 			break;
1045 
1046 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1047 		case COMPAT_PTRACE_GETHBPREGS:
1048 			ret = compat_ptrace_gethbpregs(child, addr, datap);
1049 			break;
1050 
1051 		case COMPAT_PTRACE_SETHBPREGS:
1052 			ret = compat_ptrace_sethbpregs(child, addr, datap);
1053 			break;
1054 #endif
1055 
1056 		default:
1057 			ret = compat_ptrace_request(child, request, addr,
1058 						    data);
1059 			break;
1060 	}
1061 
1062 	return ret;
1063 }
1064 #endif /* CONFIG_COMPAT */
1065 
1066 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1067 {
1068 #ifdef CONFIG_COMPAT
1069 	if (is_compat_thread(task_thread_info(task)))
1070 		return &user_aarch32_view;
1071 #endif
1072 	return &user_aarch64_view;
1073 }
1074 
1075 long arch_ptrace(struct task_struct *child, long request,
1076 		 unsigned long addr, unsigned long data)
1077 {
1078 	return ptrace_request(child, request, addr, data);
1079 }
1080 
1081 enum ptrace_syscall_dir {
1082 	PTRACE_SYSCALL_ENTER = 0,
1083 	PTRACE_SYSCALL_EXIT,
1084 };
1085 
1086 static void tracehook_report_syscall(struct pt_regs *regs,
1087 				     enum ptrace_syscall_dir dir)
1088 {
1089 	int regno;
1090 	unsigned long saved_reg;
1091 
1092 	/*
1093 	 * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1094 	 * used to denote syscall entry/exit:
1095 	 */
1096 	regno = (is_compat_task() ? 12 : 7);
1097 	saved_reg = regs->regs[regno];
1098 	regs->regs[regno] = dir;
1099 
1100 	if (dir == PTRACE_SYSCALL_EXIT)
1101 		tracehook_report_syscall_exit(regs, 0);
1102 	else if (tracehook_report_syscall_entry(regs))
1103 		regs->syscallno = ~0UL;
1104 
1105 	regs->regs[regno] = saved_reg;
1106 }
1107 
1108 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1109 {
1110 	if (test_thread_flag(TIF_SYSCALL_TRACE))
1111 		tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1112 
1113 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1114 		trace_sys_enter(regs, regs->syscallno);
1115 
1116 	return regs->syscallno;
1117 }
1118 
1119 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1120 {
1121 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1122 		trace_sys_exit(regs, regs_return_value(regs));
1123 
1124 	if (test_thread_flag(TIF_SYSCALL_TRACE))
1125 		tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1126 }
1127