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