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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/smp.h>
16#include <linux/ptrace.h>
17#include <linux/user.h>
18#include <linux/security.h>
19#include <linux/init.h>
20#include <linux/signal.h>
21#include <linux/uaccess.h>
22#include <linux/perf_event.h>
23#include <linux/hw_breakpoint.h>
24#include <linux/regset.h>
25
26#include <asm/pgtable.h>
27#include <asm/system.h>
28#include <asm/traps.h>
29
30#define REG_PC 15
31#define REG_PSR 16
32/*
33 * does not yet catch signals sent when the child dies.
34 * in exit.c or in signal.c.
35 */
36
37#if 0
38/*
39 * Breakpoint SWI instruction: SWI &9F0001
40 */
41#define BREAKINST_ARM 0xef9f0001
42#define BREAKINST_THUMB 0xdf00 /* fill this in later */
43#else
44/*
45 * New breakpoints - use an undefined instruction. The ARM architecture
46 * reference manual guarantees that the following instruction space
47 * will produce an undefined instruction exception on all CPUs:
48 *
49 * ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
50 * Thumb: 1101 1110 xxxx xxxx
51 */
52#define BREAKINST_ARM 0xe7f001f0
53#define BREAKINST_THUMB 0xde01
54#endif
55
56struct pt_regs_offset {
57 const char *name;
58 int offset;
59};
60
61#define REG_OFFSET_NAME(r) \
62 {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
63#define REG_OFFSET_END {.name = NULL, .offset = 0}
64
65static const struct pt_regs_offset regoffset_table[] = {
66 REG_OFFSET_NAME(r0),
67 REG_OFFSET_NAME(r1),
68 REG_OFFSET_NAME(r2),
69 REG_OFFSET_NAME(r3),
70 REG_OFFSET_NAME(r4),
71 REG_OFFSET_NAME(r5),
72 REG_OFFSET_NAME(r6),
73 REG_OFFSET_NAME(r7),
74 REG_OFFSET_NAME(r8),
75 REG_OFFSET_NAME(r9),
76 REG_OFFSET_NAME(r10),
77 REG_OFFSET_NAME(fp),
78 REG_OFFSET_NAME(ip),
79 REG_OFFSET_NAME(sp),
80 REG_OFFSET_NAME(lr),
81 REG_OFFSET_NAME(pc),
82 REG_OFFSET_NAME(cpsr),
83 REG_OFFSET_NAME(ORIG_r0),
84 REG_OFFSET_END,
85};
86
87/**
88 * regs_query_register_offset() - query register offset from its name
89 * @name: the name of a register
90 *
91 * regs_query_register_offset() returns the offset of a register in struct
92 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
93 */
94int regs_query_register_offset(const char *name)
95{
96 const struct pt_regs_offset *roff;
97 for (roff = regoffset_table; roff->name != NULL; roff++)
98 if (!strcmp(roff->name, name))
99 return roff->offset;
100 return -EINVAL;
101}
102
103/**
104 * regs_query_register_name() - query register name from its offset
105 * @offset: the offset of a register in struct pt_regs.
106 *
107 * regs_query_register_name() returns the name of a register from its
108 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
109 */
110const char *regs_query_register_name(unsigned int offset)
111{
112 const struct pt_regs_offset *roff;
113 for (roff = regoffset_table; roff->name != NULL; roff++)
114 if (roff->offset == offset)
115 return roff->name;
116 return NULL;
117}
118
119/**
120 * regs_within_kernel_stack() - check the address in the stack
121 * @regs: pt_regs which contains kernel stack pointer.
122 * @addr: address which is checked.
123 *
124 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
125 * If @addr is within the kernel stack, it returns true. If not, returns false.
126 */
127bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
128{
129 return ((addr & ~(THREAD_SIZE - 1)) ==
130 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
131}
132
133/**
134 * regs_get_kernel_stack_nth() - get Nth entry of the stack
135 * @regs: pt_regs which contains kernel stack pointer.
136 * @n: stack entry number.
137 *
138 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
139 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
140 * this returns 0.
141 */
142unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
143{
144 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
145 addr += n;
146 if (regs_within_kernel_stack(regs, (unsigned long)addr))
147 return *addr;
148 else
149 return 0;
150}
151
152/*
153 * this routine will get a word off of the processes privileged stack.
154 * the offset is how far from the base addr as stored in the THREAD.
155 * this routine assumes that all the privileged stacks are in our
156 * data space.
157 */
158static inline long get_user_reg(struct task_struct *task, int offset)
159{
160 return task_pt_regs(task)->uregs[offset];
161}
162
163/*
164 * this routine will put a word on the processes privileged stack.
165 * the offset is how far from the base addr as stored in the THREAD.
166 * this routine assumes that all the privileged stacks are in our
167 * data space.
168 */
169static inline int
170put_user_reg(struct task_struct *task, int offset, long data)
171{
172 struct pt_regs newregs, *regs = task_pt_regs(task);
173 int ret = -EINVAL;
174
175 newregs = *regs;
176 newregs.uregs[offset] = data;
177
178 if (valid_user_regs(&newregs)) {
179 regs->uregs[offset] = data;
180 ret = 0;
181 }
182
183 return ret;
184}
185
186/*
187 * Called by kernel/ptrace.c when detaching..
188 */
189void ptrace_disable(struct task_struct *child)
190{
191 /* Nothing to do. */
192}
193
194/*
195 * Handle hitting a breakpoint.
196 */
197void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
198{
199 siginfo_t info;
200
201 info.si_signo = SIGTRAP;
202 info.si_errno = 0;
203 info.si_code = TRAP_BRKPT;
204 info.si_addr = (void __user *)instruction_pointer(regs);
205
206 force_sig_info(SIGTRAP, &info, tsk);
207}
208
209static int break_trap(struct pt_regs *regs, unsigned int instr)
210{
211 ptrace_break(current, regs);
212 return 0;
213}
214
215static struct undef_hook arm_break_hook = {
216 .instr_mask = 0x0fffffff,
217 .instr_val = 0x07f001f0,
218 .cpsr_mask = PSR_T_BIT,
219 .cpsr_val = 0,
220 .fn = break_trap,
221};
222
223static struct undef_hook thumb_break_hook = {
224 .instr_mask = 0xffff,
225 .instr_val = 0xde01,
226 .cpsr_mask = PSR_T_BIT,
227 .cpsr_val = PSR_T_BIT,
228 .fn = break_trap,
229};
230
231static struct undef_hook thumb2_break_hook = {
232 .instr_mask = 0xffffffff,
233 .instr_val = 0xf7f0a000,
234 .cpsr_mask = PSR_T_BIT,
235 .cpsr_val = PSR_T_BIT,
236 .fn = break_trap,
237};
238
239static int __init ptrace_break_init(void)
240{
241 register_undef_hook(&arm_break_hook);
242 register_undef_hook(&thumb_break_hook);
243 register_undef_hook(&thumb2_break_hook);
244 return 0;
245}
246
247core_initcall(ptrace_break_init);
248
249/*
250 * Read the word at offset "off" into the "struct user". We
251 * actually access the pt_regs stored on the kernel stack.
252 */
253static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
254 unsigned long __user *ret)
255{
256 unsigned long tmp;
257
258 if (off & 3 || off >= sizeof(struct user))
259 return -EIO;
260
261 tmp = 0;
262 if (off == PT_TEXT_ADDR)
263 tmp = tsk->mm->start_code;
264 else if (off == PT_DATA_ADDR)
265 tmp = tsk->mm->start_data;
266 else if (off == PT_TEXT_END_ADDR)
267 tmp = tsk->mm->end_code;
268 else if (off < sizeof(struct pt_regs))
269 tmp = get_user_reg(tsk, off >> 2);
270
271 return put_user(tmp, ret);
272}
273
274/*
275 * Write the word at offset "off" into "struct user". We
276 * actually access the pt_regs stored on the kernel stack.
277 */
278static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
279 unsigned long val)
280{
281 if (off & 3 || off >= sizeof(struct user))
282 return -EIO;
283
284 if (off >= sizeof(struct pt_regs))
285 return 0;
286
287 return put_user_reg(tsk, off >> 2, val);
288}
289
290#ifdef CONFIG_IWMMXT
291
292/*
293 * Get the child iWMMXt state.
294 */
295static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
296{
297 struct thread_info *thread = task_thread_info(tsk);
298
299 if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
300 return -ENODATA;
301 iwmmxt_task_disable(thread); /* force it to ram */
302 return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
303 ? -EFAULT : 0;
304}
305
306/*
307 * Set the child iWMMXt state.
308 */
309static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
310{
311 struct thread_info *thread = task_thread_info(tsk);
312
313 if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
314 return -EACCES;
315 iwmmxt_task_release(thread); /* force a reload */
316 return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
317 ? -EFAULT : 0;
318}
319
320#endif
321
322#ifdef CONFIG_CRUNCH
323/*
324 * Get the child Crunch state.
325 */
326static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
327{
328 struct thread_info *thread = task_thread_info(tsk);
329
330 crunch_task_disable(thread); /* force it to ram */
331 return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
332 ? -EFAULT : 0;
333}
334
335/*
336 * Set the child Crunch state.
337 */
338static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
339{
340 struct thread_info *thread = task_thread_info(tsk);
341
342 crunch_task_release(thread); /* force a reload */
343 return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
344 ? -EFAULT : 0;
345}
346#endif
347
348#ifdef CONFIG_HAVE_HW_BREAKPOINT
349/*
350 * Convert a virtual register number into an index for a thread_info
351 * breakpoint array. Breakpoints are identified using positive numbers
352 * whilst watchpoints are negative. The registers are laid out as pairs
353 * of (address, control), each pair mapping to a unique hw_breakpoint struct.
354 * Register 0 is reserved for describing resource information.
355 */
356static int ptrace_hbp_num_to_idx(long num)
357{
358 if (num < 0)
359 num = (ARM_MAX_BRP << 1) - num;
360 return (num - 1) >> 1;
361}
362
363/*
364 * Returns the virtual register number for the address of the
365 * breakpoint at index idx.
366 */
367static long ptrace_hbp_idx_to_num(int idx)
368{
369 long mid = ARM_MAX_BRP << 1;
370 long num = (idx << 1) + 1;
371 return num > mid ? mid - num : num;
372}
373
374/*
375 * Handle hitting a HW-breakpoint.
376 */
377static void ptrace_hbptriggered(struct perf_event *bp,
378 struct perf_sample_data *data,
379 struct pt_regs *regs)
380{
381 struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
382 long num;
383 int i;
384 siginfo_t info;
385
386 for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
387 if (current->thread.debug.hbp[i] == bp)
388 break;
389
390 num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
391
392 info.si_signo = SIGTRAP;
393 info.si_errno = (int)num;
394 info.si_code = TRAP_HWBKPT;
395 info.si_addr = (void __user *)(bkpt->trigger);
396
397 force_sig_info(SIGTRAP, &info, current);
398}
399
400/*
401 * Set ptrace breakpoint pointers to zero for this task.
402 * This is required in order to prevent child processes from unregistering
403 * breakpoints held by their parent.
404 */
405void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
406{
407 memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
408}
409
410/*
411 * Unregister breakpoints from this task and reset the pointers in
412 * the thread_struct.
413 */
414void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
415{
416 int i;
417 struct thread_struct *t = &tsk->thread;
418
419 for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
420 if (t->debug.hbp[i]) {
421 unregister_hw_breakpoint(t->debug.hbp[i]);
422 t->debug.hbp[i] = NULL;
423 }
424 }
425}
426
427static u32 ptrace_get_hbp_resource_info(void)
428{
429 u8 num_brps, num_wrps, debug_arch, wp_len;
430 u32 reg = 0;
431
432 num_brps = hw_breakpoint_slots(TYPE_INST);
433 num_wrps = hw_breakpoint_slots(TYPE_DATA);
434 debug_arch = arch_get_debug_arch();
435 wp_len = arch_get_max_wp_len();
436
437 reg |= debug_arch;
438 reg <<= 8;
439 reg |= wp_len;
440 reg <<= 8;
441 reg |= num_wrps;
442 reg <<= 8;
443 reg |= num_brps;
444
445 return reg;
446}
447
448static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
449{
450 struct perf_event_attr attr;
451
452 ptrace_breakpoint_init(&attr);
453
454 /* Initialise fields to sane defaults. */
455 attr.bp_addr = 0;
456 attr.bp_len = HW_BREAKPOINT_LEN_4;
457 attr.bp_type = type;
458 attr.disabled = 1;
459
460 return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
461 tsk);
462}
463
464static int ptrace_gethbpregs(struct task_struct *tsk, long num,
465 unsigned long __user *data)
466{
467 u32 reg;
468 int idx, ret = 0;
469 struct perf_event *bp;
470 struct arch_hw_breakpoint_ctrl arch_ctrl;
471
472 if (num == 0) {
473 reg = ptrace_get_hbp_resource_info();
474 } else {
475 idx = ptrace_hbp_num_to_idx(num);
476 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
477 ret = -EINVAL;
478 goto out;
479 }
480
481 bp = tsk->thread.debug.hbp[idx];
482 if (!bp) {
483 reg = 0;
484 goto put;
485 }
486
487 arch_ctrl = counter_arch_bp(bp)->ctrl;
488
489 /*
490 * Fix up the len because we may have adjusted it
491 * to compensate for an unaligned address.
492 */
493 while (!(arch_ctrl.len & 0x1))
494 arch_ctrl.len >>= 1;
495
496 if (num & 0x1)
497 reg = bp->attr.bp_addr;
498 else
499 reg = encode_ctrl_reg(arch_ctrl);
500 }
501
502put:
503 if (put_user(reg, data))
504 ret = -EFAULT;
505
506out:
507 return ret;
508}
509
510static int ptrace_sethbpregs(struct task_struct *tsk, long num,
511 unsigned long __user *data)
512{
513 int idx, gen_len, gen_type, implied_type, ret = 0;
514 u32 user_val;
515 struct perf_event *bp;
516 struct arch_hw_breakpoint_ctrl ctrl;
517 struct perf_event_attr attr;
518
519 if (num == 0)
520 goto out;
521 else if (num < 0)
522 implied_type = HW_BREAKPOINT_RW;
523 else
524 implied_type = HW_BREAKPOINT_X;
525
526 idx = ptrace_hbp_num_to_idx(num);
527 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
528 ret = -EINVAL;
529 goto out;
530 }
531
532 if (get_user(user_val, data)) {
533 ret = -EFAULT;
534 goto out;
535 }
536
537 bp = tsk->thread.debug.hbp[idx];
538 if (!bp) {
539 bp = ptrace_hbp_create(tsk, implied_type);
540 if (IS_ERR(bp)) {
541 ret = PTR_ERR(bp);
542 goto out;
543 }
544 tsk->thread.debug.hbp[idx] = bp;
545 }
546
547 attr = bp->attr;
548
549 if (num & 0x1) {
550 /* Address */
551 attr.bp_addr = user_val;
552 } else {
553 /* Control */
554 decode_ctrl_reg(user_val, &ctrl);
555 ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
556 if (ret)
557 goto out;
558
559 if ((gen_type & implied_type) != gen_type) {
560 ret = -EINVAL;
561 goto out;
562 }
563
564 attr.bp_len = gen_len;
565 attr.bp_type = gen_type;
566 attr.disabled = !ctrl.enabled;
567 }
568
569 ret = modify_user_hw_breakpoint(bp, &attr);
570out:
571 return ret;
572}
573#endif
574
575/* regset get/set implementations */
576
577static int gpr_get(struct task_struct *target,
578 const struct user_regset *regset,
579 unsigned int pos, unsigned int count,
580 void *kbuf, void __user *ubuf)
581{
582 struct pt_regs *regs = task_pt_regs(target);
583
584 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
585 regs,
586 0, sizeof(*regs));
587}
588
589static int gpr_set(struct task_struct *target,
590 const struct user_regset *regset,
591 unsigned int pos, unsigned int count,
592 const void *kbuf, const void __user *ubuf)
593{
594 int ret;
595 struct pt_regs newregs;
596
597 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
598 &newregs,
599 0, sizeof(newregs));
600 if (ret)
601 return ret;
602
603 if (!valid_user_regs(&newregs))
604 return -EINVAL;
605
606 *task_pt_regs(target) = newregs;
607 return 0;
608}
609
610static int fpa_get(struct task_struct *target,
611 const struct user_regset *regset,
612 unsigned int pos, unsigned int count,
613 void *kbuf, void __user *ubuf)
614{
615 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
616 &task_thread_info(target)->fpstate,
617 0, sizeof(struct user_fp));
618}
619
620static int fpa_set(struct task_struct *target,
621 const struct user_regset *regset,
622 unsigned int pos, unsigned int count,
623 const void *kbuf, const void __user *ubuf)
624{
625 struct thread_info *thread = task_thread_info(target);
626
627 thread->used_cp[1] = thread->used_cp[2] = 1;
628
629 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
630 &thread->fpstate,
631 0, sizeof(struct user_fp));
632}
633
634#ifdef CONFIG_VFP
635/*
636 * VFP register get/set implementations.
637 *
638 * With respect to the kernel, struct user_fp is divided into three chunks:
639 * 16 or 32 real VFP registers (d0-d15 or d0-31)
640 * These are transferred to/from the real registers in the task's
641 * vfp_hard_struct. The number of registers depends on the kernel
642 * configuration.
643 *
644 * 16 or 0 fake VFP registers (d16-d31 or empty)
645 * i.e., the user_vfp structure has space for 32 registers even if
646 * the kernel doesn't have them all.
647 *
648 * vfp_get() reads this chunk as zero where applicable
649 * vfp_set() ignores this chunk
650 *
651 * 1 word for the FPSCR
652 *
653 * The bounds-checking logic built into user_regset_copyout and friends
654 * means that we can make a simple sequence of calls to map the relevant data
655 * to/from the specified slice of the user regset structure.
656 */
657static int vfp_get(struct task_struct *target,
658 const struct user_regset *regset,
659 unsigned int pos, unsigned int count,
660 void *kbuf, void __user *ubuf)
661{
662 int ret;
663 struct thread_info *thread = task_thread_info(target);
664 struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
665 const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
666 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
667
668 vfp_sync_hwstate(thread);
669
670 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
671 &vfp->fpregs,
672 user_fpregs_offset,
673 user_fpregs_offset + sizeof(vfp->fpregs));
674 if (ret)
675 return ret;
676
677 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
678 user_fpregs_offset + sizeof(vfp->fpregs),
679 user_fpscr_offset);
680 if (ret)
681 return ret;
682
683 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
684 &vfp->fpscr,
685 user_fpscr_offset,
686 user_fpscr_offset + sizeof(vfp->fpscr));
687}
688
689/*
690 * For vfp_set() a read-modify-write is done on the VFP registers,
691 * in order to avoid writing back a half-modified set of registers on
692 * failure.
693 */
694static int vfp_set(struct task_struct *target,
695 const struct user_regset *regset,
696 unsigned int pos, unsigned int count,
697 const void *kbuf, const void __user *ubuf)
698{
699 int ret;
700 struct thread_info *thread = task_thread_info(target);
701 struct vfp_hard_struct new_vfp = thread->vfpstate.hard;
702 const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
703 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
704
705 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
706 &new_vfp.fpregs,
707 user_fpregs_offset,
708 user_fpregs_offset + sizeof(new_vfp.fpregs));
709 if (ret)
710 return ret;
711
712 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
713 user_fpregs_offset + sizeof(new_vfp.fpregs),
714 user_fpscr_offset);
715 if (ret)
716 return ret;
717
718 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
719 &new_vfp.fpscr,
720 user_fpscr_offset,
721 user_fpscr_offset + sizeof(new_vfp.fpscr));
722 if (ret)
723 return ret;
724
725 vfp_sync_hwstate(thread);
726 thread->vfpstate.hard = new_vfp;
727 vfp_flush_hwstate(thread);
728
729 return 0;
730}
731#endif /* CONFIG_VFP */
732
733enum arm_regset {
734 REGSET_GPR,
735 REGSET_FPR,
736#ifdef CONFIG_VFP
737 REGSET_VFP,
738#endif
739};
740
741static const struct user_regset arm_regsets[] = {
742 [REGSET_GPR] = {
743 .core_note_type = NT_PRSTATUS,
744 .n = ELF_NGREG,
745 .size = sizeof(u32),
746 .align = sizeof(u32),
747 .get = gpr_get,
748 .set = gpr_set
749 },
750 [REGSET_FPR] = {
751 /*
752 * For the FPA regs in fpstate, the real fields are a mixture
753 * of sizes, so pretend that the registers are word-sized:
754 */
755 .core_note_type = NT_PRFPREG,
756 .n = sizeof(struct user_fp) / sizeof(u32),
757 .size = sizeof(u32),
758 .align = sizeof(u32),
759 .get = fpa_get,
760 .set = fpa_set
761 },
762#ifdef CONFIG_VFP
763 [REGSET_VFP] = {
764 /*
765 * Pretend that the VFP regs are word-sized, since the FPSCR is
766 * a single word dangling at the end of struct user_vfp:
767 */
768 .core_note_type = NT_ARM_VFP,
769 .n = ARM_VFPREGS_SIZE / sizeof(u32),
770 .size = sizeof(u32),
771 .align = sizeof(u32),
772 .get = vfp_get,
773 .set = vfp_set
774 },
775#endif /* CONFIG_VFP */
776};
777
778static const struct user_regset_view user_arm_view = {
779 .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
780 .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
781};
782
783const struct user_regset_view *task_user_regset_view(struct task_struct *task)
784{
785 return &user_arm_view;
786}
787
788long arch_ptrace(struct task_struct *child, long request,
789 unsigned long addr, unsigned long data)
790{
791 int ret;
792 unsigned long __user *datap = (unsigned long __user *) data;
793
794 switch (request) {
795 case PTRACE_PEEKUSR:
796 ret = ptrace_read_user(child, addr, datap);
797 break;
798
799 case PTRACE_POKEUSR:
800 ret = ptrace_write_user(child, addr, data);
801 break;
802
803 case PTRACE_GETREGS:
804 ret = copy_regset_to_user(child,
805 &user_arm_view, REGSET_GPR,
806 0, sizeof(struct pt_regs),
807 datap);
808 break;
809
810 case PTRACE_SETREGS:
811 ret = copy_regset_from_user(child,
812 &user_arm_view, REGSET_GPR,
813 0, sizeof(struct pt_regs),
814 datap);
815 break;
816
817 case PTRACE_GETFPREGS:
818 ret = copy_regset_to_user(child,
819 &user_arm_view, REGSET_FPR,
820 0, sizeof(union fp_state),
821 datap);
822 break;
823
824 case PTRACE_SETFPREGS:
825 ret = copy_regset_from_user(child,
826 &user_arm_view, REGSET_FPR,
827 0, sizeof(union fp_state),
828 datap);
829 break;
830
831#ifdef CONFIG_IWMMXT
832 case PTRACE_GETWMMXREGS:
833 ret = ptrace_getwmmxregs(child, datap);
834 break;
835
836 case PTRACE_SETWMMXREGS:
837 ret = ptrace_setwmmxregs(child, datap);
838 break;
839#endif
840
841 case PTRACE_GET_THREAD_AREA:
842 ret = put_user(task_thread_info(child)->tp_value,
843 datap);
844 break;
845
846 case PTRACE_SET_SYSCALL:
847 task_thread_info(child)->syscall = data;
848 ret = 0;
849 break;
850
851#ifdef CONFIG_CRUNCH
852 case PTRACE_GETCRUNCHREGS:
853 ret = ptrace_getcrunchregs(child, datap);
854 break;
855
856 case PTRACE_SETCRUNCHREGS:
857 ret = ptrace_setcrunchregs(child, datap);
858 break;
859#endif
860
861#ifdef CONFIG_VFP
862 case PTRACE_GETVFPREGS:
863 ret = copy_regset_to_user(child,
864 &user_arm_view, REGSET_VFP,
865 0, ARM_VFPREGS_SIZE,
866 datap);
867 break;
868
869 case PTRACE_SETVFPREGS:
870 ret = copy_regset_from_user(child,
871 &user_arm_view, REGSET_VFP,
872 0, ARM_VFPREGS_SIZE,
873 datap);
874 break;
875#endif
876
877#ifdef CONFIG_HAVE_HW_BREAKPOINT
878 case PTRACE_GETHBPREGS:
879 if (ptrace_get_breakpoints(child) < 0)
880 return -ESRCH;
881
882 ret = ptrace_gethbpregs(child, addr,
883 (unsigned long __user *)data);
884 ptrace_put_breakpoints(child);
885 break;
886 case PTRACE_SETHBPREGS:
887 if (ptrace_get_breakpoints(child) < 0)
888 return -ESRCH;
889
890 ret = ptrace_sethbpregs(child, addr,
891 (unsigned long __user *)data);
892 ptrace_put_breakpoints(child);
893 break;
894#endif
895
896 default:
897 ret = ptrace_request(child, request, addr, data);
898 break;
899 }
900
901 return ret;
902}
903
904asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
905{
906 unsigned long ip;
907
908 if (!test_thread_flag(TIF_SYSCALL_TRACE))
909 return scno;
910 if (!(current->ptrace & PT_PTRACED))
911 return scno;
912
913 /*
914 * Save IP. IP is used to denote syscall entry/exit:
915 * IP = 0 -> entry, = 1 -> exit
916 */
917 ip = regs->ARM_ip;
918 regs->ARM_ip = why;
919
920 current_thread_info()->syscall = scno;
921
922 /* the 0x80 provides a way for the tracing parent to distinguish
923 between a syscall stop and SIGTRAP delivery */
924 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
925 ? 0x80 : 0));
926 /*
927 * this isn't the same as continuing with a signal, but it will do
928 * for normal use. strace only continues with a signal if the
929 * stopping signal is not SIGTRAP. -brl
930 */
931 if (current->exit_code) {
932 send_sig(current->exit_code, current, 1);
933 current->exit_code = 0;
934 }
935 regs->ARM_ip = ip;
936
937 return current_thread_info()->syscall;
938}
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 = *task_pt_regs(target);
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 if (test_thread_flag(TIF_SYSCALL_TRACE))
936 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
937
938 /* Do seccomp after ptrace; syscall may have changed. */
939#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
940 if (secure_computing(NULL) == -1)
941 return -1;
942#else
943 /* XXX: remove this once OABI gets fixed */
944 secure_computing_strict(current_thread_info()->syscall);
945#endif
946
947 /* Tracer or seccomp may have changed syscall. */
948 scno = current_thread_info()->syscall;
949
950 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
951 trace_sys_enter(regs, scno);
952
953 audit_syscall_entry(scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2,
954 regs->ARM_r3);
955
956 return scno;
957}
958
959asmlinkage void syscall_trace_exit(struct pt_regs *regs)
960{
961 /*
962 * Audit the syscall before anything else, as a debugger may
963 * come in and change the current registers.
964 */
965 audit_syscall_exit(regs);
966
967 /*
968 * Note that we haven't updated the ->syscall field for the
969 * current thread. This isn't a problem because it will have
970 * been set on syscall entry and there hasn't been an opportunity
971 * for a PTRACE_SET_SYSCALL since then.
972 */
973 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
974 trace_sys_exit(regs, regs_return_value(regs));
975
976 if (test_thread_flag(TIF_SYSCALL_TRACE))
977 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
978}