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