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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/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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/arch/arm/kernel/ptrace.c
4 *
5 * By Ross Biro 1/23/92
6 * edited by Linus Torvalds
7 * ARM modifications Copyright (C) 2000 Russell King
8 */
9#include <linux/kernel.h>
10#include <linux/sched/signal.h>
11#include <linux/sched/task_stack.h>
12#include <linux/mm.h>
13#include <linux/elf.h>
14#include <linux/smp.h>
15#include <linux/ptrace.h>
16#include <linux/user.h>
17#include <linux/security.h>
18#include <linux/init.h>
19#include <linux/signal.h>
20#include <linux/uaccess.h>
21#include <linux/perf_event.h>
22#include <linux/hw_breakpoint.h>
23#include <linux/regset.h>
24#include <linux/audit.h>
25#include <linux/unistd.h>
26
27#include <asm/syscall.h>
28#include <asm/traps.h>
29
30#define CREATE_TRACE_POINTS
31#include <trace/events/syscalls.h>
32
33#define REG_PC 15
34#define REG_PSR 16
35/*
36 * does not yet catch signals sent when the child dies.
37 * in exit.c or in signal.c.
38 */
39
40#if 0
41/*
42 * Breakpoint SWI instruction: SWI &9F0001
43 */
44#define BREAKINST_ARM 0xef9f0001
45#define BREAKINST_THUMB 0xdf00 /* fill this in later */
46#else
47/*
48 * New breakpoints - use an undefined instruction. The ARM architecture
49 * reference manual guarantees that the following instruction space
50 * will produce an undefined instruction exception on all CPUs:
51 *
52 * ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
53 * Thumb: 1101 1110 xxxx xxxx
54 */
55#define BREAKINST_ARM 0xe7f001f0
56#define BREAKINST_THUMB 0xde01
57#endif
58
59struct pt_regs_offset {
60 const char *name;
61 int offset;
62};
63
64#define REG_OFFSET_NAME(r) \
65 {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
66#define REG_OFFSET_END {.name = NULL, .offset = 0}
67
68static const struct pt_regs_offset regoffset_table[] = {
69 REG_OFFSET_NAME(r0),
70 REG_OFFSET_NAME(r1),
71 REG_OFFSET_NAME(r2),
72 REG_OFFSET_NAME(r3),
73 REG_OFFSET_NAME(r4),
74 REG_OFFSET_NAME(r5),
75 REG_OFFSET_NAME(r6),
76 REG_OFFSET_NAME(r7),
77 REG_OFFSET_NAME(r8),
78 REG_OFFSET_NAME(r9),
79 REG_OFFSET_NAME(r10),
80 REG_OFFSET_NAME(fp),
81 REG_OFFSET_NAME(ip),
82 REG_OFFSET_NAME(sp),
83 REG_OFFSET_NAME(lr),
84 REG_OFFSET_NAME(pc),
85 REG_OFFSET_NAME(cpsr),
86 REG_OFFSET_NAME(ORIG_r0),
87 REG_OFFSET_END,
88};
89
90/**
91 * regs_query_register_offset() - query register offset from its name
92 * @name: the name of a register
93 *
94 * regs_query_register_offset() returns the offset of a register in struct
95 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
96 */
97int regs_query_register_offset(const char *name)
98{
99 const struct pt_regs_offset *roff;
100 for (roff = regoffset_table; roff->name != NULL; roff++)
101 if (!strcmp(roff->name, name))
102 return roff->offset;
103 return -EINVAL;
104}
105
106/**
107 * regs_query_register_name() - query register name from its offset
108 * @offset: the offset of a register in struct pt_regs.
109 *
110 * regs_query_register_name() returns the name of a register from its
111 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
112 */
113const char *regs_query_register_name(unsigned int offset)
114{
115 const struct pt_regs_offset *roff;
116 for (roff = regoffset_table; roff->name != NULL; roff++)
117 if (roff->offset == offset)
118 return roff->name;
119 return NULL;
120}
121
122/**
123 * regs_within_kernel_stack() - check the address in the stack
124 * @regs: pt_regs which contains kernel stack pointer.
125 * @addr: address which is checked.
126 *
127 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
128 * If @addr is within the kernel stack, it returns true. If not, returns false.
129 */
130bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
131{
132 return ((addr & ~(THREAD_SIZE - 1)) ==
133 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
134}
135
136/**
137 * regs_get_kernel_stack_nth() - get Nth entry of the stack
138 * @regs: pt_regs which contains kernel stack pointer.
139 * @n: stack entry number.
140 *
141 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
142 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
143 * this returns 0.
144 */
145unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
146{
147 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
148 addr += n;
149 if (regs_within_kernel_stack(regs, (unsigned long)addr))
150 return *addr;
151 else
152 return 0;
153}
154
155/*
156 * this routine will get a word off of the processes privileged stack.
157 * the offset is how far from the base addr as stored in the THREAD.
158 * this routine assumes that all the privileged stacks are in our
159 * data space.
160 */
161static inline long get_user_reg(struct task_struct *task, int offset)
162{
163 return task_pt_regs(task)->uregs[offset];
164}
165
166/*
167 * this routine will put a word on the processes privileged stack.
168 * the offset is how far from the base addr as stored in the THREAD.
169 * this routine assumes that all the privileged stacks are in our
170 * data space.
171 */
172static inline int
173put_user_reg(struct task_struct *task, int offset, long data)
174{
175 struct pt_regs newregs, *regs = task_pt_regs(task);
176 int ret = -EINVAL;
177
178 newregs = *regs;
179 newregs.uregs[offset] = data;
180
181 if (valid_user_regs(&newregs)) {
182 regs->uregs[offset] = data;
183 ret = 0;
184 }
185
186 return ret;
187}
188
189/*
190 * Called by kernel/ptrace.c when detaching..
191 */
192void ptrace_disable(struct task_struct *child)
193{
194 /* Nothing to do. */
195}
196
197/*
198 * Handle hitting a breakpoint.
199 */
200void ptrace_break(struct pt_regs *regs)
201{
202 force_sig_fault(SIGTRAP, TRAP_BRKPT,
203 (void __user *)instruction_pointer(regs));
204}
205
206static int break_trap(struct pt_regs *regs, unsigned int instr)
207{
208 ptrace_break(regs);
209 return 0;
210}
211
212static struct undef_hook arm_break_hook = {
213 .instr_mask = 0x0fffffff,
214 .instr_val = 0x07f001f0,
215 .cpsr_mask = PSR_T_BIT,
216 .cpsr_val = 0,
217 .fn = break_trap,
218};
219
220static struct undef_hook thumb_break_hook = {
221 .instr_mask = 0xffffffff,
222 .instr_val = 0x0000de01,
223 .cpsr_mask = PSR_T_BIT,
224 .cpsr_val = PSR_T_BIT,
225 .fn = break_trap,
226};
227
228static struct undef_hook thumb2_break_hook = {
229 .instr_mask = 0xffffffff,
230 .instr_val = 0xf7f0a000,
231 .cpsr_mask = PSR_T_BIT,
232 .cpsr_val = PSR_T_BIT,
233 .fn = break_trap,
234};
235
236static int __init ptrace_break_init(void)
237{
238 register_undef_hook(&arm_break_hook);
239 register_undef_hook(&thumb_break_hook);
240 register_undef_hook(&thumb2_break_hook);
241 return 0;
242}
243
244core_initcall(ptrace_break_init);
245
246/*
247 * Read the word at offset "off" into the "struct user". We
248 * actually access the pt_regs stored on the kernel stack.
249 */
250static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
251 unsigned long __user *ret)
252{
253 unsigned long tmp;
254
255 if (off & 3)
256 return -EIO;
257
258 tmp = 0;
259 if (off == PT_TEXT_ADDR)
260 tmp = tsk->mm->start_code;
261 else if (off == PT_DATA_ADDR)
262 tmp = tsk->mm->start_data;
263 else if (off == PT_TEXT_END_ADDR)
264 tmp = tsk->mm->end_code;
265 else if (off < sizeof(struct pt_regs))
266 tmp = get_user_reg(tsk, off >> 2);
267 else if (off >= sizeof(struct user))
268 return -EIO;
269
270 return put_user(tmp, ret);
271}
272
273/*
274 * Write the word at offset "off" into "struct user". We
275 * actually access the pt_regs stored on the kernel stack.
276 */
277static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
278 unsigned long val)
279{
280 if (off & 3 || off >= sizeof(struct user))
281 return -EIO;
282
283 if (off >= sizeof(struct pt_regs))
284 return 0;
285
286 return put_user_reg(tsk, off >> 2, val);
287}
288
289#ifdef CONFIG_IWMMXT
290
291/*
292 * Get the child iWMMXt state.
293 */
294static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
295{
296 struct thread_info *thread = task_thread_info(tsk);
297
298 if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
299 return -ENODATA;
300 iwmmxt_task_disable(thread); /* force it to ram */
301 return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
302 ? -EFAULT : 0;
303}
304
305/*
306 * Set the child iWMMXt state.
307 */
308static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
309{
310 struct thread_info *thread = task_thread_info(tsk);
311
312 if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
313 return -EACCES;
314 iwmmxt_task_release(thread); /* force a reload */
315 return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
316 ? -EFAULT : 0;
317}
318
319#endif
320
321#ifdef CONFIG_HAVE_HW_BREAKPOINT
322/*
323 * Convert a virtual register number into an index for a thread_info
324 * breakpoint array. Breakpoints are identified using positive numbers
325 * whilst watchpoints are negative. The registers are laid out as pairs
326 * of (address, control), each pair mapping to a unique hw_breakpoint struct.
327 * Register 0 is reserved for describing resource information.
328 */
329static int ptrace_hbp_num_to_idx(long num)
330{
331 if (num < 0)
332 num = (ARM_MAX_BRP << 1) - num;
333 return (num - 1) >> 1;
334}
335
336/*
337 * Returns the virtual register number for the address of the
338 * breakpoint at index idx.
339 */
340static long ptrace_hbp_idx_to_num(int idx)
341{
342 long mid = ARM_MAX_BRP << 1;
343 long num = (idx << 1) + 1;
344 return num > mid ? mid - num : num;
345}
346
347/*
348 * Handle hitting a HW-breakpoint.
349 */
350static void ptrace_hbptriggered(struct perf_event *bp,
351 struct perf_sample_data *data,
352 struct pt_regs *regs)
353{
354 struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
355 long num;
356 int i;
357
358 for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
359 if (current->thread.debug.hbp[i] == bp)
360 break;
361
362 num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
363
364 force_sig_ptrace_errno_trap((int)num, (void __user *)(bkpt->trigger));
365}
366
367/*
368 * Set ptrace breakpoint pointers to zero for this task.
369 * This is required in order to prevent child processes from unregistering
370 * breakpoints held by their parent.
371 */
372void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
373{
374 memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
375}
376
377/*
378 * Unregister breakpoints from this task and reset the pointers in
379 * the thread_struct.
380 */
381void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
382{
383 int i;
384 struct thread_struct *t = &tsk->thread;
385
386 for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
387 if (t->debug.hbp[i]) {
388 unregister_hw_breakpoint(t->debug.hbp[i]);
389 t->debug.hbp[i] = NULL;
390 }
391 }
392}
393
394static u32 ptrace_get_hbp_resource_info(void)
395{
396 u8 num_brps, num_wrps, debug_arch, wp_len;
397 u32 reg = 0;
398
399 num_brps = hw_breakpoint_slots(TYPE_INST);
400 num_wrps = hw_breakpoint_slots(TYPE_DATA);
401 debug_arch = arch_get_debug_arch();
402 wp_len = arch_get_max_wp_len();
403
404 reg |= debug_arch;
405 reg <<= 8;
406 reg |= wp_len;
407 reg <<= 8;
408 reg |= num_wrps;
409 reg <<= 8;
410 reg |= num_brps;
411
412 return reg;
413}
414
415static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
416{
417 struct perf_event_attr attr;
418
419 ptrace_breakpoint_init(&attr);
420
421 /* Initialise fields to sane defaults. */
422 attr.bp_addr = 0;
423 attr.bp_len = HW_BREAKPOINT_LEN_4;
424 attr.bp_type = type;
425 attr.disabled = 1;
426
427 return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
428 tsk);
429}
430
431static int ptrace_gethbpregs(struct task_struct *tsk, long num,
432 unsigned long __user *data)
433{
434 u32 reg;
435 int idx, ret = 0;
436 struct perf_event *bp;
437 struct arch_hw_breakpoint_ctrl arch_ctrl;
438
439 if (num == 0) {
440 reg = ptrace_get_hbp_resource_info();
441 } else {
442 idx = ptrace_hbp_num_to_idx(num);
443 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
444 ret = -EINVAL;
445 goto out;
446 }
447
448 bp = tsk->thread.debug.hbp[idx];
449 if (!bp) {
450 reg = 0;
451 goto put;
452 }
453
454 arch_ctrl = counter_arch_bp(bp)->ctrl;
455
456 /*
457 * Fix up the len because we may have adjusted it
458 * to compensate for an unaligned address.
459 */
460 while (!(arch_ctrl.len & 0x1))
461 arch_ctrl.len >>= 1;
462
463 if (num & 0x1)
464 reg = bp->attr.bp_addr;
465 else
466 reg = encode_ctrl_reg(arch_ctrl);
467 }
468
469put:
470 if (put_user(reg, data))
471 ret = -EFAULT;
472
473out:
474 return ret;
475}
476
477static int ptrace_sethbpregs(struct task_struct *tsk, long num,
478 unsigned long __user *data)
479{
480 int idx, gen_len, gen_type, implied_type, ret = 0;
481 u32 user_val;
482 struct perf_event *bp;
483 struct arch_hw_breakpoint_ctrl ctrl;
484 struct perf_event_attr attr;
485
486 if (num == 0)
487 goto out;
488 else if (num < 0)
489 implied_type = HW_BREAKPOINT_RW;
490 else
491 implied_type = HW_BREAKPOINT_X;
492
493 idx = ptrace_hbp_num_to_idx(num);
494 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
495 ret = -EINVAL;
496 goto out;
497 }
498
499 if (get_user(user_val, data)) {
500 ret = -EFAULT;
501 goto out;
502 }
503
504 bp = tsk->thread.debug.hbp[idx];
505 if (!bp) {
506 bp = ptrace_hbp_create(tsk, implied_type);
507 if (IS_ERR(bp)) {
508 ret = PTR_ERR(bp);
509 goto out;
510 }
511 tsk->thread.debug.hbp[idx] = bp;
512 }
513
514 attr = bp->attr;
515
516 if (num & 0x1) {
517 /* Address */
518 attr.bp_addr = user_val;
519 } else {
520 /* Control */
521 decode_ctrl_reg(user_val, &ctrl);
522 ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
523 if (ret)
524 goto out;
525
526 if ((gen_type & implied_type) != gen_type) {
527 ret = -EINVAL;
528 goto out;
529 }
530
531 attr.bp_len = gen_len;
532 attr.bp_type = gen_type;
533 attr.disabled = !ctrl.enabled;
534 }
535
536 ret = modify_user_hw_breakpoint(bp, &attr);
537out:
538 return ret;
539}
540#endif
541
542/* regset get/set implementations */
543
544static int gpr_get(struct task_struct *target,
545 const struct user_regset *regset,
546 struct membuf to)
547{
548 return membuf_write(&to, task_pt_regs(target), sizeof(struct pt_regs));
549}
550
551static int gpr_set(struct task_struct *target,
552 const struct user_regset *regset,
553 unsigned int pos, unsigned int count,
554 const void *kbuf, const void __user *ubuf)
555{
556 int ret;
557 struct pt_regs newregs = *task_pt_regs(target);
558
559 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
560 &newregs,
561 0, sizeof(newregs));
562 if (ret)
563 return ret;
564
565 if (!valid_user_regs(&newregs))
566 return -EINVAL;
567
568 *task_pt_regs(target) = newregs;
569 return 0;
570}
571
572static int fpa_get(struct task_struct *target,
573 const struct user_regset *regset,
574 struct membuf to)
575{
576 return membuf_write(&to, &task_thread_info(target)->fpstate,
577 sizeof(struct user_fp));
578}
579
580static int fpa_set(struct task_struct *target,
581 const struct user_regset *regset,
582 unsigned int pos, unsigned int count,
583 const void *kbuf, const void __user *ubuf)
584{
585 struct thread_info *thread = task_thread_info(target);
586
587 thread->used_cp[1] = thread->used_cp[2] = 1;
588
589 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
590 &thread->fpstate,
591 0, sizeof(struct user_fp));
592}
593
594#ifdef CONFIG_VFP
595/*
596 * VFP register get/set implementations.
597 *
598 * With respect to the kernel, struct user_fp is divided into three chunks:
599 * 16 or 32 real VFP registers (d0-d15 or d0-31)
600 * These are transferred to/from the real registers in the task's
601 * vfp_hard_struct. The number of registers depends on the kernel
602 * configuration.
603 *
604 * 16 or 0 fake VFP registers (d16-d31 or empty)
605 * i.e., the user_vfp structure has space for 32 registers even if
606 * the kernel doesn't have them all.
607 *
608 * vfp_get() reads this chunk as zero where applicable
609 * vfp_set() ignores this chunk
610 *
611 * 1 word for the FPSCR
612 */
613static int vfp_get(struct task_struct *target,
614 const struct user_regset *regset,
615 struct membuf to)
616{
617 struct thread_info *thread = task_thread_info(target);
618 struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
619 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
620
621 vfp_sync_hwstate(thread);
622
623 membuf_write(&to, vfp->fpregs, sizeof(vfp->fpregs));
624 membuf_zero(&to, user_fpscr_offset - sizeof(vfp->fpregs));
625 return membuf_store(&to, vfp->fpscr);
626}
627
628/*
629 * For vfp_set() a read-modify-write is done on the VFP registers,
630 * in order to avoid writing back a half-modified set of registers on
631 * failure.
632 */
633static int vfp_set(struct task_struct *target,
634 const struct user_regset *regset,
635 unsigned int pos, unsigned int count,
636 const void *kbuf, const void __user *ubuf)
637{
638 int ret;
639 struct thread_info *thread = task_thread_info(target);
640 struct vfp_hard_struct new_vfp;
641 const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
642 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
643
644 vfp_sync_hwstate(thread);
645 new_vfp = thread->vfpstate.hard;
646
647 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
648 &new_vfp.fpregs,
649 user_fpregs_offset,
650 user_fpregs_offset + sizeof(new_vfp.fpregs));
651 if (ret)
652 return ret;
653
654 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
655 user_fpregs_offset + sizeof(new_vfp.fpregs),
656 user_fpscr_offset);
657
658 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
659 &new_vfp.fpscr,
660 user_fpscr_offset,
661 user_fpscr_offset + sizeof(new_vfp.fpscr));
662 if (ret)
663 return ret;
664
665 thread->vfpstate.hard = new_vfp;
666 vfp_flush_hwstate(thread);
667
668 return 0;
669}
670#endif /* CONFIG_VFP */
671
672enum arm_regset {
673 REGSET_GPR,
674 REGSET_FPR,
675#ifdef CONFIG_VFP
676 REGSET_VFP,
677#endif
678};
679
680static const struct user_regset arm_regsets[] = {
681 [REGSET_GPR] = {
682 .core_note_type = NT_PRSTATUS,
683 .n = ELF_NGREG,
684 .size = sizeof(u32),
685 .align = sizeof(u32),
686 .regset_get = gpr_get,
687 .set = gpr_set
688 },
689 [REGSET_FPR] = {
690 /*
691 * For the FPA regs in fpstate, the real fields are a mixture
692 * of sizes, so pretend that the registers are word-sized:
693 */
694 .core_note_type = NT_PRFPREG,
695 .n = sizeof(struct user_fp) / sizeof(u32),
696 .size = sizeof(u32),
697 .align = sizeof(u32),
698 .regset_get = fpa_get,
699 .set = fpa_set
700 },
701#ifdef CONFIG_VFP
702 [REGSET_VFP] = {
703 /*
704 * Pretend that the VFP regs are word-sized, since the FPSCR is
705 * a single word dangling at the end of struct user_vfp:
706 */
707 .core_note_type = NT_ARM_VFP,
708 .n = ARM_VFPREGS_SIZE / sizeof(u32),
709 .size = sizeof(u32),
710 .align = sizeof(u32),
711 .regset_get = vfp_get,
712 .set = vfp_set
713 },
714#endif /* CONFIG_VFP */
715};
716
717static const struct user_regset_view user_arm_view = {
718 .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
719 .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
720};
721
722const struct user_regset_view *task_user_regset_view(struct task_struct *task)
723{
724 return &user_arm_view;
725}
726
727long arch_ptrace(struct task_struct *child, long request,
728 unsigned long addr, unsigned long data)
729{
730 int ret;
731 unsigned long __user *datap = (unsigned long __user *) data;
732
733 switch (request) {
734 case PTRACE_PEEKUSR:
735 ret = ptrace_read_user(child, addr, datap);
736 break;
737
738 case PTRACE_POKEUSR:
739 ret = ptrace_write_user(child, addr, data);
740 break;
741
742 case PTRACE_GETREGS:
743 ret = copy_regset_to_user(child,
744 &user_arm_view, REGSET_GPR,
745 0, sizeof(struct pt_regs),
746 datap);
747 break;
748
749 case PTRACE_SETREGS:
750 ret = copy_regset_from_user(child,
751 &user_arm_view, REGSET_GPR,
752 0, sizeof(struct pt_regs),
753 datap);
754 break;
755
756 case PTRACE_GETFPREGS:
757 ret = copy_regset_to_user(child,
758 &user_arm_view, REGSET_FPR,
759 0, sizeof(union fp_state),
760 datap);
761 break;
762
763 case PTRACE_SETFPREGS:
764 ret = copy_regset_from_user(child,
765 &user_arm_view, REGSET_FPR,
766 0, sizeof(union fp_state),
767 datap);
768 break;
769
770#ifdef CONFIG_IWMMXT
771 case PTRACE_GETWMMXREGS:
772 ret = ptrace_getwmmxregs(child, datap);
773 break;
774
775 case PTRACE_SETWMMXREGS:
776 ret = ptrace_setwmmxregs(child, datap);
777 break;
778#endif
779
780 case PTRACE_GET_THREAD_AREA:
781 ret = put_user(task_thread_info(child)->tp_value[0],
782 datap);
783 break;
784
785 case PTRACE_SET_SYSCALL:
786 task_thread_info(child)->abi_syscall = data &
787 __NR_SYSCALL_MASK;
788 ret = 0;
789 break;
790
791#ifdef CONFIG_VFP
792 case PTRACE_GETVFPREGS:
793 ret = copy_regset_to_user(child,
794 &user_arm_view, REGSET_VFP,
795 0, ARM_VFPREGS_SIZE,
796 datap);
797 break;
798
799 case PTRACE_SETVFPREGS:
800 ret = copy_regset_from_user(child,
801 &user_arm_view, REGSET_VFP,
802 0, ARM_VFPREGS_SIZE,
803 datap);
804 break;
805#endif
806
807#ifdef CONFIG_HAVE_HW_BREAKPOINT
808 case PTRACE_GETHBPREGS:
809 ret = ptrace_gethbpregs(child, addr,
810 (unsigned long __user *)data);
811 break;
812 case PTRACE_SETHBPREGS:
813 ret = ptrace_sethbpregs(child, addr,
814 (unsigned long __user *)data);
815 break;
816#endif
817
818 default:
819 ret = ptrace_request(child, request, addr, data);
820 break;
821 }
822
823 return ret;
824}
825
826enum ptrace_syscall_dir {
827 PTRACE_SYSCALL_ENTER = 0,
828 PTRACE_SYSCALL_EXIT,
829};
830
831static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
832{
833 unsigned long ip;
834
835 /*
836 * IP is used to denote syscall entry/exit:
837 * IP = 0 -> entry, =1 -> exit
838 */
839 ip = regs->ARM_ip;
840 regs->ARM_ip = dir;
841
842 if (dir == PTRACE_SYSCALL_EXIT)
843 ptrace_report_syscall_exit(regs, 0);
844 else if (ptrace_report_syscall_entry(regs))
845 current_thread_info()->abi_syscall = -1;
846
847 regs->ARM_ip = ip;
848}
849
850asmlinkage int syscall_trace_enter(struct pt_regs *regs)
851{
852 int scno;
853
854 if (test_thread_flag(TIF_SYSCALL_TRACE))
855 report_syscall(regs, PTRACE_SYSCALL_ENTER);
856
857 /* Do seccomp after ptrace; syscall may have changed. */
858#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
859 if (secure_computing() == -1)
860 return -1;
861#else
862 /* XXX: remove this once OABI gets fixed */
863 secure_computing_strict(syscall_get_nr(current, regs));
864#endif
865
866 /* Tracer or seccomp may have changed syscall. */
867 scno = syscall_get_nr(current, regs);
868
869 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
870 trace_sys_enter(regs, scno);
871
872 audit_syscall_entry(scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2,
873 regs->ARM_r3);
874
875 return scno;
876}
877
878asmlinkage void syscall_trace_exit(struct pt_regs *regs)
879{
880 /*
881 * Audit the syscall before anything else, as a debugger may
882 * come in and change the current registers.
883 */
884 audit_syscall_exit(regs);
885
886 /*
887 * Note that we haven't updated the ->syscall field for the
888 * current thread. This isn't a problem because it will have
889 * been set on syscall entry and there hasn't been an opportunity
890 * for a PTRACE_SET_SYSCALL since then.
891 */
892 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
893 trace_sys_exit(regs, regs_return_value(regs));
894
895 if (test_thread_flag(TIF_SYSCALL_TRACE))
896 report_syscall(regs, PTRACE_SYSCALL_EXIT);
897}