1/*
2 *  linux/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 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/kernel.h>
13#include <linux/sched.h>
14#include <linux/mm.h>
15#include <linux/elf.h>
16#include <linux/smp.h>
17#include <linux/ptrace.h>
18#include <linux/user.h>
19#include <linux/security.h>
20#include <linux/init.h>
21#include <linux/signal.h>
22#include <linux/uaccess.h>
23#include <linux/perf_event.h>
24#include <linux/hw_breakpoint.h>
25#include <linux/regset.h>
26#include <linux/audit.h>
27#include <linux/tracehook.h>
28#include <linux/unistd.h>
29
30#include <asm/pgtable.h>
31#include <asm/traps.h>
32
33#define CREATE_TRACE_POINTS
34#include <trace/events/syscalls.h>
35
36#define REG_PC	15
37#define REG_PSR	16
38/*
39 * does not yet catch signals sent when the child dies.
40 * in exit.c or in signal.c.
41 */
42
43#if 0
44/*
45 * Breakpoint SWI instruction: SWI &9F0001
46 */
47#define BREAKINST_ARM	0xef9f0001
48#define BREAKINST_THUMB	0xdf00		/* fill this in later */
49#else
50/*
51 * New breakpoints - use an undefined instruction.  The ARM architecture
52 * reference manual guarantees that the following instruction space
53 * will produce an undefined instruction exception on all CPUs:
54 *
55 *  ARM:   xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
56 *  Thumb: 1101 1110 xxxx xxxx
57 */
58#define BREAKINST_ARM	0xe7f001f0
59#define BREAKINST_THUMB	0xde01
60#endif
61
62struct pt_regs_offset {
63	const char *name;
64	int offset;
65};
66
67#define REG_OFFSET_NAME(r) \
68	{.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
69#define REG_OFFSET_END {.name = NULL, .offset = 0}
70
71static const struct pt_regs_offset regoffset_table[] = {
72	REG_OFFSET_NAME(r0),
73	REG_OFFSET_NAME(r1),
74	REG_OFFSET_NAME(r2),
75	REG_OFFSET_NAME(r3),
76	REG_OFFSET_NAME(r4),
77	REG_OFFSET_NAME(r5),
78	REG_OFFSET_NAME(r6),
79	REG_OFFSET_NAME(r7),
80	REG_OFFSET_NAME(r8),
81	REG_OFFSET_NAME(r9),
82	REG_OFFSET_NAME(r10),
83	REG_OFFSET_NAME(fp),
84	REG_OFFSET_NAME(ip),
85	REG_OFFSET_NAME(sp),
86	REG_OFFSET_NAME(lr),
87	REG_OFFSET_NAME(pc),
88	REG_OFFSET_NAME(cpsr),
89	REG_OFFSET_NAME(ORIG_r0),
90	REG_OFFSET_END,
91};
92
93/**
94 * regs_query_register_offset() - query register offset from its name
95 * @name:	the name of a register
96 *
97 * regs_query_register_offset() returns the offset of a register in struct
98 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
99 */
100int regs_query_register_offset(const char *name)
101{
102	const struct pt_regs_offset *roff;
103	for (roff = regoffset_table; roff->name != NULL; roff++)
104		if (!strcmp(roff->name, name))
105			return roff->offset;
106	return -EINVAL;
107}
108
109/**
110 * regs_query_register_name() - query register name from its offset
111 * @offset:	the offset of a register in struct pt_regs.
112 *
113 * regs_query_register_name() returns the name of a register from its
114 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
115 */
116const char *regs_query_register_name(unsigned int offset)
117{
118	const struct pt_regs_offset *roff;
119	for (roff = regoffset_table; roff->name != NULL; roff++)
120		if (roff->offset == offset)
121			return roff->name;
122	return NULL;
123}
124
125/**
126 * regs_within_kernel_stack() - check the address in the stack
127 * @regs:      pt_regs which contains kernel stack pointer.
128 * @addr:      address which is checked.
129 *
130 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
131 * If @addr is within the kernel stack, it returns true. If not, returns false.
132 */
133bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
134{
135	return ((addr & ~(THREAD_SIZE - 1))  ==
136		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
137}
138
139/**
140 * regs_get_kernel_stack_nth() - get Nth entry of the stack
141 * @regs:	pt_regs which contains kernel stack pointer.
142 * @n:		stack entry number.
143 *
144 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
145 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
146 * this returns 0.
147 */
148unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
149{
150	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
151	addr += n;
152	if (regs_within_kernel_stack(regs, (unsigned long)addr))
153		return *addr;
154	else
155		return 0;
156}
157
158/*
159 * this routine will get a word off of the processes privileged stack.
160 * the offset is how far from the base addr as stored in the THREAD.
161 * this routine assumes that all the privileged stacks are in our
162 * data space.
163 */
164static inline long get_user_reg(struct task_struct *task, int offset)
165{
166	return task_pt_regs(task)->uregs[offset];
167}
168
169/*
170 * this routine will put a word on the processes privileged stack.
171 * the offset is how far from the base addr as stored in the THREAD.
172 * this routine assumes that all the privileged stacks are in our
173 * data space.
174 */
175static inline int
176put_user_reg(struct task_struct *task, int offset, long data)
177{
178	struct pt_regs newregs, *regs = task_pt_regs(task);
179	int ret = -EINVAL;
180
181	newregs = *regs;
182	newregs.uregs[offset] = data;
183
184	if (valid_user_regs(&newregs)) {
185		regs->uregs[offset] = data;
186		ret = 0;
187	}
188
189	return ret;
190}
191
192/*
193 * Called by kernel/ptrace.c when detaching..
194 */
195void ptrace_disable(struct task_struct *child)
196{
197	/* Nothing to do. */
198}
199
200/*
201 * Handle hitting a breakpoint.
202 */
203void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
204{
205	siginfo_t info;
206
207	info.si_signo = SIGTRAP;
208	info.si_errno = 0;
209	info.si_code  = TRAP_BRKPT;
210	info.si_addr  = (void __user *)instruction_pointer(regs);
211
212	force_sig_info(SIGTRAP, &info, tsk);
213}
214
215static int break_trap(struct pt_regs *regs, unsigned int instr)
216{
217	ptrace_break(current, regs);
218	return 0;
219}
220
221static struct undef_hook arm_break_hook = {
222	.instr_mask	= 0x0fffffff,
223	.instr_val	= 0x07f001f0,
224	.cpsr_mask	= PSR_T_BIT,
225	.cpsr_val	= 0,
226	.fn		= break_trap,
227};
228
229static struct undef_hook thumb_break_hook = {
230	.instr_mask	= 0xffff,
231	.instr_val	= 0xde01,
232	.cpsr_mask	= PSR_T_BIT,
233	.cpsr_val	= PSR_T_BIT,
234	.fn		= break_trap,
235};
236
237static struct undef_hook thumb2_break_hook = {
238	.instr_mask	= 0xffffffff,
239	.instr_val	= 0xf7f0a000,
240	.cpsr_mask	= PSR_T_BIT,
241	.cpsr_val	= PSR_T_BIT,
242	.fn		= break_trap,
243};
244
245static int __init ptrace_break_init(void)
246{
247	register_undef_hook(&arm_break_hook);
248	register_undef_hook(&thumb_break_hook);
249	register_undef_hook(&thumb2_break_hook);
250	return 0;
251}
252
253core_initcall(ptrace_break_init);
254
255/*
256 * Read the word at offset "off" into the "struct user".  We
257 * actually access the pt_regs stored on the kernel stack.
258 */
259static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
260			    unsigned long __user *ret)
261{
262	unsigned long tmp;
263
264	if (off & 3)
265		return -EIO;
266
267	tmp = 0;
268	if (off == PT_TEXT_ADDR)
269		tmp = tsk->mm->start_code;
270	else if (off == PT_DATA_ADDR)
271		tmp = tsk->mm->start_data;
272	else if (off == PT_TEXT_END_ADDR)
273		tmp = tsk->mm->end_code;
274	else if (off < sizeof(struct pt_regs))
275		tmp = get_user_reg(tsk, off >> 2);
276	else if (off >= sizeof(struct user))
277		return -EIO;
278
279	return put_user(tmp, ret);
280}
281
282/*
283 * Write the word at offset "off" into "struct user".  We
284 * actually access the pt_regs stored on the kernel stack.
285 */
286static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
287			     unsigned long val)
288{
289	if (off & 3 || off >= sizeof(struct user))
290		return -EIO;
291
292	if (off >= sizeof(struct pt_regs))
293		return 0;
294
295	return put_user_reg(tsk, off >> 2, val);
296}
297
298#ifdef CONFIG_IWMMXT
299
300/*
301 * Get the child iWMMXt state.
302 */
303static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
304{
305	struct thread_info *thread = task_thread_info(tsk);
306
307	if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
308		return -ENODATA;
309	iwmmxt_task_disable(thread);  /* force it to ram */
310	return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
311		? -EFAULT : 0;
312}
313
314/*
315 * Set the child iWMMXt state.
316 */
317static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
318{
319	struct thread_info *thread = task_thread_info(tsk);
320
321	if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
322		return -EACCES;
323	iwmmxt_task_release(thread);  /* force a reload */
324	return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
325		? -EFAULT : 0;
326}
327
328#endif
329
330#ifdef CONFIG_CRUNCH
331/*
332 * Get the child Crunch state.
333 */
334static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
335{
336	struct thread_info *thread = task_thread_info(tsk);
337
338	crunch_task_disable(thread);  /* force it to ram */
339	return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
340		? -EFAULT : 0;
341}
342
343/*
344 * Set the child Crunch state.
345 */
346static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
347{
348	struct thread_info *thread = task_thread_info(tsk);
349
350	crunch_task_release(thread);  /* force a reload */
351	return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
352		? -EFAULT : 0;
353}
354#endif
355
356#ifdef CONFIG_HAVE_HW_BREAKPOINT
357/*
358 * Convert a virtual register number into an index for a thread_info
359 * breakpoint array. Breakpoints are identified using positive numbers
360 * whilst watchpoints are negative. The registers are laid out as pairs
361 * of (address, control), each pair mapping to a unique hw_breakpoint struct.
362 * Register 0 is reserved for describing resource information.
363 */
364static int ptrace_hbp_num_to_idx(long num)
365{
366	if (num < 0)
367		num = (ARM_MAX_BRP << 1) - num;
368	return (num - 1) >> 1;
369}
370
371/*
372 * Returns the virtual register number for the address of the
373 * breakpoint at index idx.
374 */
375static long ptrace_hbp_idx_to_num(int idx)
376{
377	long mid = ARM_MAX_BRP << 1;
378	long num = (idx << 1) + 1;
379	return num > mid ? mid - num : num;
380}
381
382/*
383 * Handle hitting a HW-breakpoint.
384 */
385static void ptrace_hbptriggered(struct perf_event *bp,
386				     struct perf_sample_data *data,
387				     struct pt_regs *regs)
388{
389	struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
390	long num;
391	int i;
392	siginfo_t info;
393
394	for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
395		if (current->thread.debug.hbp[i] == bp)
396			break;
397
398	num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
399
400	info.si_signo	= SIGTRAP;
401	info.si_errno	= (int)num;
402	info.si_code	= TRAP_HWBKPT;
403	info.si_addr	= (void __user *)(bkpt->trigger);
404
405	force_sig_info(SIGTRAP, &info, current);
406}
407
408/*
409 * Set ptrace breakpoint pointers to zero for this task.
410 * This is required in order to prevent child processes from unregistering
411 * breakpoints held by their parent.
412 */
413void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
414{
415	memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
416}
417
418/*
419 * Unregister breakpoints from this task and reset the pointers in
420 * the thread_struct.
421 */
422void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
423{
424	int i;
425	struct thread_struct *t = &tsk->thread;
426
427	for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
428		if (t->debug.hbp[i]) {
429			unregister_hw_breakpoint(t->debug.hbp[i]);
430			t->debug.hbp[i] = NULL;
431		}
432	}
433}
434
435static u32 ptrace_get_hbp_resource_info(void)
436{
437	u8 num_brps, num_wrps, debug_arch, wp_len;
438	u32 reg = 0;
439
440	num_brps	= hw_breakpoint_slots(TYPE_INST);
441	num_wrps	= hw_breakpoint_slots(TYPE_DATA);
442	debug_arch	= arch_get_debug_arch();
443	wp_len		= arch_get_max_wp_len();
444
445	reg		|= debug_arch;
446	reg		<<= 8;
447	reg		|= wp_len;
448	reg		<<= 8;
449	reg		|= num_wrps;
450	reg		<<= 8;
451	reg		|= num_brps;
452
453	return reg;
454}
455
456static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
457{
458	struct perf_event_attr attr;
459
460	ptrace_breakpoint_init(&attr);
461
462	/* Initialise fields to sane defaults. */
463	attr.bp_addr	= 0;
464	attr.bp_len	= HW_BREAKPOINT_LEN_4;
465	attr.bp_type	= type;
466	attr.disabled	= 1;
467
468	return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
469					   tsk);
470}
471
472static int ptrace_gethbpregs(struct task_struct *tsk, long num,
473			     unsigned long  __user *data)
474{
475	u32 reg;
476	int idx, ret = 0;
477	struct perf_event *bp;
478	struct arch_hw_breakpoint_ctrl arch_ctrl;
479
480	if (num == 0) {
481		reg = ptrace_get_hbp_resource_info();
482	} else {
483		idx = ptrace_hbp_num_to_idx(num);
484		if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
485			ret = -EINVAL;
486			goto out;
487		}
488
489		bp = tsk->thread.debug.hbp[idx];
490		if (!bp) {
491			reg = 0;
492			goto put;
493		}
494
495		arch_ctrl = counter_arch_bp(bp)->ctrl;
496
497		/*
498		 * Fix up the len because we may have adjusted it
499		 * to compensate for an unaligned address.
500		 */
501		while (!(arch_ctrl.len & 0x1))
502			arch_ctrl.len >>= 1;
503
504		if (num & 0x1)
505			reg = bp->attr.bp_addr;
506		else
507			reg = encode_ctrl_reg(arch_ctrl);
508	}
509
510put:
511	if (put_user(reg, data))
512		ret = -EFAULT;
513
514out:
515	return ret;
516}
517
518static int ptrace_sethbpregs(struct task_struct *tsk, long num,
519			     unsigned long __user *data)
520{
521	int idx, gen_len, gen_type, implied_type, ret = 0;
522	u32 user_val;
523	struct perf_event *bp;
524	struct arch_hw_breakpoint_ctrl ctrl;
525	struct perf_event_attr attr;
526
527	if (num == 0)
528		goto out;
529	else if (num < 0)
530		implied_type = HW_BREAKPOINT_RW;
531	else
532		implied_type = HW_BREAKPOINT_X;
533
534	idx = ptrace_hbp_num_to_idx(num);
535	if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
536		ret = -EINVAL;
537		goto out;
538	}
539
540	if (get_user(user_val, data)) {
541		ret = -EFAULT;
542		goto out;
543	}
544
545	bp = tsk->thread.debug.hbp[idx];
546	if (!bp) {
547		bp = ptrace_hbp_create(tsk, implied_type);
548		if (IS_ERR(bp)) {
549			ret = PTR_ERR(bp);
550			goto out;
551		}
552		tsk->thread.debug.hbp[idx] = bp;
553	}
554
555	attr = bp->attr;
556
557	if (num & 0x1) {
558		/* Address */
559		attr.bp_addr	= user_val;
560	} else {
561		/* Control */
562		decode_ctrl_reg(user_val, &ctrl);
563		ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
564		if (ret)
565			goto out;
566
567		if ((gen_type & implied_type) != gen_type) {
568			ret = -EINVAL;
569			goto out;
570		}
571
572		attr.bp_len	= gen_len;
573		attr.bp_type	= gen_type;
574		attr.disabled	= !ctrl.enabled;
575	}
576
577	ret = modify_user_hw_breakpoint(bp, &attr);
578out:
579	return ret;
580}
581#endif
582
583/* regset get/set implementations */
584
585static int gpr_get(struct task_struct *target,
586		   const struct user_regset *regset,
587		   unsigned int pos, unsigned int count,
588		   void *kbuf, void __user *ubuf)
589{
590	struct pt_regs *regs = task_pt_regs(target);
591
592	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
593				   regs,
594				   0, sizeof(*regs));
595}
596
597static int gpr_set(struct task_struct *target,
598		   const struct user_regset *regset,
599		   unsigned int pos, unsigned int count,
600		   const void *kbuf, const void __user *ubuf)
601{
602	int ret;
603	struct pt_regs newregs;
604
605	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
606				 &newregs,
607				 0, sizeof(newregs));
608	if (ret)
609		return ret;
610
611	if (!valid_user_regs(&newregs))
612		return -EINVAL;
613
614	*task_pt_regs(target) = newregs;
615	return 0;
616}
617
618static int fpa_get(struct task_struct *target,
619		   const struct user_regset *regset,
620		   unsigned int pos, unsigned int count,
621		   void *kbuf, void __user *ubuf)
622{
623	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
624				   &task_thread_info(target)->fpstate,
625				   0, sizeof(struct user_fp));
626}
627
628static int fpa_set(struct task_struct *target,
629		   const struct user_regset *regset,
630		   unsigned int pos, unsigned int count,
631		   const void *kbuf, const void __user *ubuf)
632{
633	struct thread_info *thread = task_thread_info(target);
634
635	thread->used_cp[1] = thread->used_cp[2] = 1;
636
637	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
638		&thread->fpstate,
639		0, sizeof(struct user_fp));
640}
641
642#ifdef CONFIG_VFP
643/*
644 * VFP register get/set implementations.
645 *
646 * With respect to the kernel, struct user_fp is divided into three chunks:
647 * 16 or 32 real VFP registers (d0-d15 or d0-31)
648 *	These are transferred to/from the real registers in the task's
649 *	vfp_hard_struct.  The number of registers depends on the kernel
650 *	configuration.
651 *
652 * 16 or 0 fake VFP registers (d16-d31 or empty)
653 *	i.e., the user_vfp structure has space for 32 registers even if
654 *	the kernel doesn't have them all.
655 *
656 *	vfp_get() reads this chunk as zero where applicable
657 *	vfp_set() ignores this chunk
658 *
659 * 1 word for the FPSCR
660 *
661 * The bounds-checking logic built into user_regset_copyout and friends
662 * means that we can make a simple sequence of calls to map the relevant data
663 * to/from the specified slice of the user regset structure.
664 */
665static int vfp_get(struct task_struct *target,
666		   const struct user_regset *regset,
667		   unsigned int pos, unsigned int count,
668		   void *kbuf, void __user *ubuf)
669{
670	int ret;
671	struct thread_info *thread = task_thread_info(target);
672	struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
673	const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
674	const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
675
676	vfp_sync_hwstate(thread);
677
678	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
679				  &vfp->fpregs,
680				  user_fpregs_offset,
681				  user_fpregs_offset + sizeof(vfp->fpregs));
682	if (ret)
683		return ret;
684
685	ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
686				       user_fpregs_offset + sizeof(vfp->fpregs),
687				       user_fpscr_offset);
688	if (ret)
689		return ret;
690
691	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
692				   &vfp->fpscr,
693				   user_fpscr_offset,
694				   user_fpscr_offset + sizeof(vfp->fpscr));
695}
696
697/*
698 * For vfp_set() a read-modify-write is done on the VFP registers,
699 * in order to avoid writing back a half-modified set of registers on
700 * failure.
701 */
702static int vfp_set(struct task_struct *target,
703			  const struct user_regset *regset,
704			  unsigned int pos, unsigned int count,
705			  const void *kbuf, const void __user *ubuf)
706{
707	int ret;
708	struct thread_info *thread = task_thread_info(target);
709	struct vfp_hard_struct new_vfp;
710	const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
711	const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
712
713	vfp_sync_hwstate(thread);
714	new_vfp = thread->vfpstate.hard;
715
716	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
717				  &new_vfp.fpregs,
718				  user_fpregs_offset,
719				  user_fpregs_offset + sizeof(new_vfp.fpregs));
720	if (ret)
721		return ret;
722
723	ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
724				user_fpregs_offset + sizeof(new_vfp.fpregs),
725				user_fpscr_offset);
726	if (ret)
727		return ret;
728
729	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
730				 &new_vfp.fpscr,
731				 user_fpscr_offset,
732				 user_fpscr_offset + sizeof(new_vfp.fpscr));
733	if (ret)
734		return ret;
735
736	thread->vfpstate.hard = new_vfp;
737	vfp_flush_hwstate(thread);
738
739	return 0;
740}
741#endif /* CONFIG_VFP */
742
743enum arm_regset {
744	REGSET_GPR,
745	REGSET_FPR,
746#ifdef CONFIG_VFP
747	REGSET_VFP,
748#endif
749};
750
751static const struct user_regset arm_regsets[] = {
752	[REGSET_GPR] = {
753		.core_note_type = NT_PRSTATUS,
754		.n = ELF_NGREG,
755		.size = sizeof(u32),
756		.align = sizeof(u32),
757		.get = gpr_get,
758		.set = gpr_set
759	},
760	[REGSET_FPR] = {
761		/*
762		 * For the FPA regs in fpstate, the real fields are a mixture
763		 * of sizes, so pretend that the registers are word-sized:
764		 */
765		.core_note_type = NT_PRFPREG,
766		.n = sizeof(struct user_fp) / sizeof(u32),
767		.size = sizeof(u32),
768		.align = sizeof(u32),
769		.get = fpa_get,
770		.set = fpa_set
771	},
772#ifdef CONFIG_VFP
773	[REGSET_VFP] = {
774		/*
775		 * Pretend that the VFP regs are word-sized, since the FPSCR is
776		 * a single word dangling at the end of struct user_vfp:
777		 */
778		.core_note_type = NT_ARM_VFP,
779		.n = ARM_VFPREGS_SIZE / sizeof(u32),
780		.size = sizeof(u32),
781		.align = sizeof(u32),
782		.get = vfp_get,
783		.set = vfp_set
784	},
785#endif /* CONFIG_VFP */
786};
787
788static const struct user_regset_view user_arm_view = {
789	.name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
790	.regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
791};
792
793const struct user_regset_view *task_user_regset_view(struct task_struct *task)
794{
795	return &user_arm_view;
796}
797
798long arch_ptrace(struct task_struct *child, long request,
799		 unsigned long addr, unsigned long data)
800{
801	int ret;
802	unsigned long __user *datap = (unsigned long __user *) data;
803
804	switch (request) {
805		case PTRACE_PEEKUSR:
806			ret = ptrace_read_user(child, addr, datap);
807			break;
808
809		case PTRACE_POKEUSR:
810			ret = ptrace_write_user(child, addr, data);
811			break;
812
813		case PTRACE_GETREGS:
814			ret = copy_regset_to_user(child,
815						  &user_arm_view, REGSET_GPR,
816						  0, sizeof(struct pt_regs),
817						  datap);
818			break;
819
820		case PTRACE_SETREGS:
821			ret = copy_regset_from_user(child,
822						    &user_arm_view, REGSET_GPR,
823						    0, sizeof(struct pt_regs),
824						    datap);
825			break;
826
827		case PTRACE_GETFPREGS:
828			ret = copy_regset_to_user(child,
829						  &user_arm_view, REGSET_FPR,
830						  0, sizeof(union fp_state),
831						  datap);
832			break;
833
834		case PTRACE_SETFPREGS:
835			ret = copy_regset_from_user(child,
836						    &user_arm_view, REGSET_FPR,
837						    0, sizeof(union fp_state),
838						    datap);
839			break;
840
841#ifdef CONFIG_IWMMXT
842		case PTRACE_GETWMMXREGS:
843			ret = ptrace_getwmmxregs(child, datap);
844			break;
845
846		case PTRACE_SETWMMXREGS:
847			ret = ptrace_setwmmxregs(child, datap);
848			break;
849#endif
850
851		case PTRACE_GET_THREAD_AREA:
852			ret = put_user(task_thread_info(child)->tp_value[0],
853				       datap);
854			break;
855
856		case PTRACE_SET_SYSCALL:
857			task_thread_info(child)->syscall = data;
858			ret = 0;
859			break;
860
861#ifdef CONFIG_CRUNCH
862		case PTRACE_GETCRUNCHREGS:
863			ret = ptrace_getcrunchregs(child, datap);
864			break;
865
866		case PTRACE_SETCRUNCHREGS:
867			ret = ptrace_setcrunchregs(child, datap);
868			break;
869#endif
870
871#ifdef CONFIG_VFP
872		case PTRACE_GETVFPREGS:
873			ret = copy_regset_to_user(child,
874						  &user_arm_view, REGSET_VFP,
875						  0, ARM_VFPREGS_SIZE,
876						  datap);
877			break;
878
879		case PTRACE_SETVFPREGS:
880			ret = copy_regset_from_user(child,
881						    &user_arm_view, REGSET_VFP,
882						    0, ARM_VFPREGS_SIZE,
883						    datap);
884			break;
885#endif
886
887#ifdef CONFIG_HAVE_HW_BREAKPOINT
888		case PTRACE_GETHBPREGS:
889			ret = ptrace_gethbpregs(child, addr,
890						(unsigned long __user *)data);
891			break;
892		case PTRACE_SETHBPREGS:
893			ret = ptrace_sethbpregs(child, addr,
894						(unsigned long __user *)data);
895			break;
896#endif
897
898		default:
899			ret = ptrace_request(child, request, addr, data);
900			break;
901	}
902
903	return ret;
904}
905
906enum ptrace_syscall_dir {
907	PTRACE_SYSCALL_ENTER = 0,
908	PTRACE_SYSCALL_EXIT,
909};
910
911static void tracehook_report_syscall(struct pt_regs *regs,
912				    enum ptrace_syscall_dir dir)
913{
914	unsigned long ip;
915
916	/*
917	 * IP is used to denote syscall entry/exit:
918	 * IP = 0 -> entry, =1 -> exit
919	 */
920	ip = regs->ARM_ip;
921	regs->ARM_ip = dir;
922
923	if (dir == PTRACE_SYSCALL_EXIT)
924		tracehook_report_syscall_exit(regs, 0);
925	else if (tracehook_report_syscall_entry(regs))
926		current_thread_info()->syscall = -1;
927
928	regs->ARM_ip = ip;
929}
930
931asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
932{
933	current_thread_info()->syscall = scno;
934
935	/* Do the secure computing check first; failures should be fast. */
936#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
937	if (secure_computing() == -1)
938		return -1;
939#else
940	/* XXX: remove this once OABI gets fixed */
941	secure_computing_strict(scno);
942#endif
943
944	if (test_thread_flag(TIF_SYSCALL_TRACE))
945		tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
946
947	scno = current_thread_info()->syscall;
948
949	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
950		trace_sys_enter(regs, scno);
951
952	audit_syscall_entry(scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2,
953			    regs->ARM_r3);
954
955	return scno;
956}
957
958asmlinkage void syscall_trace_exit(struct pt_regs *regs)
959{
960	/*
961	 * Audit the syscall before anything else, as a debugger may
962	 * come in and change the current registers.
963	 */
964	audit_syscall_exit(regs);
965
966	/*
967	 * Note that we haven't updated the ->syscall field for the
968	 * current thread. This isn't a problem because it will have
969	 * been set on syscall entry and there hasn't been an opportunity
970	 * for a PTRACE_SET_SYSCALL since then.
971	 */
972	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
973		trace_sys_exit(regs, regs_return_value(regs));
974
975	if (test_thread_flag(TIF_SYSCALL_TRACE))
976		tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
977}
978