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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/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}
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 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
588 &thread->fpstate,
589 0, sizeof(struct user_fp));
590}
591
592#ifdef CONFIG_VFP
593/*
594 * VFP register get/set implementations.
595 *
596 * With respect to the kernel, struct user_fp is divided into three chunks:
597 * 16 or 32 real VFP registers (d0-d15 or d0-31)
598 * These are transferred to/from the real registers in the task's
599 * vfp_hard_struct. The number of registers depends on the kernel
600 * configuration.
601 *
602 * 16 or 0 fake VFP registers (d16-d31 or empty)
603 * i.e., the user_vfp structure has space for 32 registers even if
604 * the kernel doesn't have them all.
605 *
606 * vfp_get() reads this chunk as zero where applicable
607 * vfp_set() ignores this chunk
608 *
609 * 1 word for the FPSCR
610 */
611static int vfp_get(struct task_struct *target,
612 const struct user_regset *regset,
613 struct membuf to)
614{
615 struct thread_info *thread = task_thread_info(target);
616 struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
617 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
618
619 vfp_sync_hwstate(thread);
620
621 membuf_write(&to, vfp->fpregs, sizeof(vfp->fpregs));
622 membuf_zero(&to, user_fpscr_offset - sizeof(vfp->fpregs));
623 return membuf_store(&to, vfp->fpscr);
624}
625
626/*
627 * For vfp_set() a read-modify-write is done on the VFP registers,
628 * in order to avoid writing back a half-modified set of registers on
629 * failure.
630 */
631static int vfp_set(struct task_struct *target,
632 const struct user_regset *regset,
633 unsigned int pos, unsigned int count,
634 const void *kbuf, const void __user *ubuf)
635{
636 int ret;
637 struct thread_info *thread = task_thread_info(target);
638 struct vfp_hard_struct new_vfp;
639 const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
640 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
641
642 vfp_sync_hwstate(thread);
643 new_vfp = thread->vfpstate.hard;
644
645 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
646 &new_vfp.fpregs,
647 user_fpregs_offset,
648 user_fpregs_offset + sizeof(new_vfp.fpregs));
649 if (ret)
650 return ret;
651
652 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
653 user_fpregs_offset + sizeof(new_vfp.fpregs),
654 user_fpscr_offset);
655
656 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
657 &new_vfp.fpscr,
658 user_fpscr_offset,
659 user_fpscr_offset + sizeof(new_vfp.fpscr));
660 if (ret)
661 return ret;
662
663 thread->vfpstate.hard = new_vfp;
664 vfp_flush_hwstate(thread);
665
666 return 0;
667}
668#endif /* CONFIG_VFP */
669
670enum arm_regset {
671 REGSET_GPR,
672 REGSET_FPR,
673#ifdef CONFIG_VFP
674 REGSET_VFP,
675#endif
676};
677
678static const struct user_regset arm_regsets[] = {
679 [REGSET_GPR] = {
680 .core_note_type = NT_PRSTATUS,
681 .n = ELF_NGREG,
682 .size = sizeof(u32),
683 .align = sizeof(u32),
684 .regset_get = gpr_get,
685 .set = gpr_set
686 },
687 [REGSET_FPR] = {
688 /*
689 * For the FPA regs in fpstate, the real fields are a mixture
690 * of sizes, so pretend that the registers are word-sized:
691 */
692 .core_note_type = NT_PRFPREG,
693 .n = sizeof(struct user_fp) / sizeof(u32),
694 .size = sizeof(u32),
695 .align = sizeof(u32),
696 .regset_get = fpa_get,
697 .set = fpa_set
698 },
699#ifdef CONFIG_VFP
700 [REGSET_VFP] = {
701 /*
702 * Pretend that the VFP regs are word-sized, since the FPSCR is
703 * a single word dangling at the end of struct user_vfp:
704 */
705 .core_note_type = NT_ARM_VFP,
706 .n = ARM_VFPREGS_SIZE / sizeof(u32),
707 .size = sizeof(u32),
708 .align = sizeof(u32),
709 .regset_get = vfp_get,
710 .set = vfp_set
711 },
712#endif /* CONFIG_VFP */
713};
714
715static const struct user_regset_view user_arm_view = {
716 .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
717 .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
718};
719
720const struct user_regset_view *task_user_regset_view(struct task_struct *task)
721{
722 return &user_arm_view;
723}
724
725long arch_ptrace(struct task_struct *child, long request,
726 unsigned long addr, unsigned long data)
727{
728 int ret;
729 unsigned long __user *datap = (unsigned long __user *) data;
730
731 switch (request) {
732 case PTRACE_PEEKUSR:
733 ret = ptrace_read_user(child, addr, datap);
734 break;
735
736 case PTRACE_POKEUSR:
737 ret = ptrace_write_user(child, addr, data);
738 break;
739
740 case PTRACE_GETREGS:
741 ret = copy_regset_to_user(child,
742 &user_arm_view, REGSET_GPR,
743 0, sizeof(struct pt_regs),
744 datap);
745 break;
746
747 case PTRACE_SETREGS:
748 ret = copy_regset_from_user(child,
749 &user_arm_view, REGSET_GPR,
750 0, sizeof(struct pt_regs),
751 datap);
752 break;
753
754 case PTRACE_GETFPREGS:
755 ret = copy_regset_to_user(child,
756 &user_arm_view, REGSET_FPR,
757 0, sizeof(union fp_state),
758 datap);
759 break;
760
761 case PTRACE_SETFPREGS:
762 ret = copy_regset_from_user(child,
763 &user_arm_view, REGSET_FPR,
764 0, sizeof(union fp_state),
765 datap);
766 break;
767
768#ifdef CONFIG_IWMMXT
769 case PTRACE_GETWMMXREGS:
770 ret = ptrace_getwmmxregs(child, datap);
771 break;
772
773 case PTRACE_SETWMMXREGS:
774 ret = ptrace_setwmmxregs(child, datap);
775 break;
776#endif
777
778 case PTRACE_GET_THREAD_AREA:
779 ret = put_user(task_thread_info(child)->tp_value[0],
780 datap);
781 break;
782
783 case PTRACE_SET_SYSCALL:
784 if (data != -1)
785 data &= __NR_SYSCALL_MASK;
786 task_thread_info(child)->abi_syscall = data;
787 ret = 0;
788 break;
789
790#ifdef CONFIG_VFP
791 case PTRACE_GETVFPREGS:
792 ret = copy_regset_to_user(child,
793 &user_arm_view, REGSET_VFP,
794 0, ARM_VFPREGS_SIZE,
795 datap);
796 break;
797
798 case PTRACE_SETVFPREGS:
799 ret = copy_regset_from_user(child,
800 &user_arm_view, REGSET_VFP,
801 0, ARM_VFPREGS_SIZE,
802 datap);
803 break;
804#endif
805
806#ifdef CONFIG_HAVE_HW_BREAKPOINT
807 case PTRACE_GETHBPREGS:
808 ret = ptrace_gethbpregs(child, addr,
809 (unsigned long __user *)data);
810 break;
811 case PTRACE_SETHBPREGS:
812 ret = ptrace_sethbpregs(child, addr,
813 (unsigned long __user *)data);
814 break;
815#endif
816
817 default:
818 ret = ptrace_request(child, request, addr, data);
819 break;
820 }
821
822 return ret;
823}
824
825enum ptrace_syscall_dir {
826 PTRACE_SYSCALL_ENTER = 0,
827 PTRACE_SYSCALL_EXIT,
828};
829
830static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
831{
832 unsigned long ip;
833
834 /*
835 * IP is used to denote syscall entry/exit:
836 * IP = 0 -> entry, =1 -> exit
837 */
838 ip = regs->ARM_ip;
839 regs->ARM_ip = dir;
840
841 if (dir == PTRACE_SYSCALL_EXIT)
842 ptrace_report_syscall_exit(regs, 0);
843 else if (ptrace_report_syscall_entry(regs))
844 current_thread_info()->abi_syscall = -1;
845
846 regs->ARM_ip = ip;
847}
848
849asmlinkage int syscall_trace_enter(struct pt_regs *regs)
850{
851 int scno;
852
853 if (test_thread_flag(TIF_SYSCALL_TRACE))
854 report_syscall(regs, PTRACE_SYSCALL_ENTER);
855
856 /* Do seccomp after ptrace; syscall may have changed. */
857#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
858 if (secure_computing() == -1)
859 return -1;
860#else
861 /* XXX: remove this once OABI gets fixed */
862 secure_computing_strict(syscall_get_nr(current, regs));
863#endif
864
865 /* Tracer or seccomp may have changed syscall. */
866 scno = syscall_get_nr(current, regs);
867
868 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
869 trace_sys_enter(regs, scno);
870
871 audit_syscall_entry(scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2,
872 regs->ARM_r3);
873
874 return scno;
875}
876
877asmlinkage void syscall_trace_exit(struct pt_regs *regs)
878{
879 /*
880 * Audit the syscall before anything else, as a debugger may
881 * come in and change the current registers.
882 */
883 audit_syscall_exit(regs);
884
885 /*
886 * Note that we haven't updated the ->syscall field for the
887 * current thread. This isn't a problem because it will have
888 * been set on syscall entry and there hasn't been an opportunity
889 * for a PTRACE_SET_SYSCALL since then.
890 */
891 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
892 trace_sys_exit(regs, regs_return_value(regs));
893
894 if (test_thread_flag(TIF_SYSCALL_TRACE))
895 report_syscall(regs, PTRACE_SYSCALL_EXIT);
896}