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1/*
2 * linux/arch/arm/kernel/ptrace.c
3 *
4 * By Ross Biro 1/23/92
5 * edited by Linus Torvalds
6 * ARM modifications Copyright (C) 2000 Russell King
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/kernel.h>
13#include <linux/sched.h>
14#include <linux/mm.h>
15#include <linux/smp.h>
16#include <linux/ptrace.h>
17#include <linux/user.h>
18#include <linux/security.h>
19#include <linux/init.h>
20#include <linux/signal.h>
21#include <linux/uaccess.h>
22#include <linux/perf_event.h>
23#include <linux/hw_breakpoint.h>
24#include <linux/regset.h>
25
26#include <asm/pgtable.h>
27#include <asm/system.h>
28#include <asm/traps.h>
29
30#define REG_PC 15
31#define REG_PSR 16
32/*
33 * does not yet catch signals sent when the child dies.
34 * in exit.c or in signal.c.
35 */
36
37#if 0
38/*
39 * Breakpoint SWI instruction: SWI &9F0001
40 */
41#define BREAKINST_ARM 0xef9f0001
42#define BREAKINST_THUMB 0xdf00 /* fill this in later */
43#else
44/*
45 * New breakpoints - use an undefined instruction. The ARM architecture
46 * reference manual guarantees that the following instruction space
47 * will produce an undefined instruction exception on all CPUs:
48 *
49 * ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
50 * Thumb: 1101 1110 xxxx xxxx
51 */
52#define BREAKINST_ARM 0xe7f001f0
53#define BREAKINST_THUMB 0xde01
54#endif
55
56struct pt_regs_offset {
57 const char *name;
58 int offset;
59};
60
61#define REG_OFFSET_NAME(r) \
62 {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
63#define REG_OFFSET_END {.name = NULL, .offset = 0}
64
65static const struct pt_regs_offset regoffset_table[] = {
66 REG_OFFSET_NAME(r0),
67 REG_OFFSET_NAME(r1),
68 REG_OFFSET_NAME(r2),
69 REG_OFFSET_NAME(r3),
70 REG_OFFSET_NAME(r4),
71 REG_OFFSET_NAME(r5),
72 REG_OFFSET_NAME(r6),
73 REG_OFFSET_NAME(r7),
74 REG_OFFSET_NAME(r8),
75 REG_OFFSET_NAME(r9),
76 REG_OFFSET_NAME(r10),
77 REG_OFFSET_NAME(fp),
78 REG_OFFSET_NAME(ip),
79 REG_OFFSET_NAME(sp),
80 REG_OFFSET_NAME(lr),
81 REG_OFFSET_NAME(pc),
82 REG_OFFSET_NAME(cpsr),
83 REG_OFFSET_NAME(ORIG_r0),
84 REG_OFFSET_END,
85};
86
87/**
88 * regs_query_register_offset() - query register offset from its name
89 * @name: the name of a register
90 *
91 * regs_query_register_offset() returns the offset of a register in struct
92 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
93 */
94int regs_query_register_offset(const char *name)
95{
96 const struct pt_regs_offset *roff;
97 for (roff = regoffset_table; roff->name != NULL; roff++)
98 if (!strcmp(roff->name, name))
99 return roff->offset;
100 return -EINVAL;
101}
102
103/**
104 * regs_query_register_name() - query register name from its offset
105 * @offset: the offset of a register in struct pt_regs.
106 *
107 * regs_query_register_name() returns the name of a register from its
108 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
109 */
110const char *regs_query_register_name(unsigned int offset)
111{
112 const struct pt_regs_offset *roff;
113 for (roff = regoffset_table; roff->name != NULL; roff++)
114 if (roff->offset == offset)
115 return roff->name;
116 return NULL;
117}
118
119/**
120 * regs_within_kernel_stack() - check the address in the stack
121 * @regs: pt_regs which contains kernel stack pointer.
122 * @addr: address which is checked.
123 *
124 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
125 * If @addr is within the kernel stack, it returns true. If not, returns false.
126 */
127bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
128{
129 return ((addr & ~(THREAD_SIZE - 1)) ==
130 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
131}
132
133/**
134 * regs_get_kernel_stack_nth() - get Nth entry of the stack
135 * @regs: pt_regs which contains kernel stack pointer.
136 * @n: stack entry number.
137 *
138 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
139 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
140 * this returns 0.
141 */
142unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
143{
144 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
145 addr += n;
146 if (regs_within_kernel_stack(regs, (unsigned long)addr))
147 return *addr;
148 else
149 return 0;
150}
151
152/*
153 * this routine will get a word off of the processes privileged stack.
154 * the offset is how far from the base addr as stored in the THREAD.
155 * this routine assumes that all the privileged stacks are in our
156 * data space.
157 */
158static inline long get_user_reg(struct task_struct *task, int offset)
159{
160 return task_pt_regs(task)->uregs[offset];
161}
162
163/*
164 * this routine will put a word on the processes privileged stack.
165 * the offset is how far from the base addr as stored in the THREAD.
166 * this routine assumes that all the privileged stacks are in our
167 * data space.
168 */
169static inline int
170put_user_reg(struct task_struct *task, int offset, long data)
171{
172 struct pt_regs newregs, *regs = task_pt_regs(task);
173 int ret = -EINVAL;
174
175 newregs = *regs;
176 newregs.uregs[offset] = data;
177
178 if (valid_user_regs(&newregs)) {
179 regs->uregs[offset] = data;
180 ret = 0;
181 }
182
183 return ret;
184}
185
186/*
187 * Called by kernel/ptrace.c when detaching..
188 */
189void ptrace_disable(struct task_struct *child)
190{
191 /* Nothing to do. */
192}
193
194/*
195 * Handle hitting a breakpoint.
196 */
197void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
198{
199 siginfo_t info;
200
201 info.si_signo = SIGTRAP;
202 info.si_errno = 0;
203 info.si_code = TRAP_BRKPT;
204 info.si_addr = (void __user *)instruction_pointer(regs);
205
206 force_sig_info(SIGTRAP, &info, tsk);
207}
208
209static int break_trap(struct pt_regs *regs, unsigned int instr)
210{
211 ptrace_break(current, regs);
212 return 0;
213}
214
215static struct undef_hook arm_break_hook = {
216 .instr_mask = 0x0fffffff,
217 .instr_val = 0x07f001f0,
218 .cpsr_mask = PSR_T_BIT,
219 .cpsr_val = 0,
220 .fn = break_trap,
221};
222
223static struct undef_hook thumb_break_hook = {
224 .instr_mask = 0xffff,
225 .instr_val = 0xde01,
226 .cpsr_mask = PSR_T_BIT,
227 .cpsr_val = PSR_T_BIT,
228 .fn = break_trap,
229};
230
231static struct undef_hook thumb2_break_hook = {
232 .instr_mask = 0xffffffff,
233 .instr_val = 0xf7f0a000,
234 .cpsr_mask = PSR_T_BIT,
235 .cpsr_val = PSR_T_BIT,
236 .fn = break_trap,
237};
238
239static int __init ptrace_break_init(void)
240{
241 register_undef_hook(&arm_break_hook);
242 register_undef_hook(&thumb_break_hook);
243 register_undef_hook(&thumb2_break_hook);
244 return 0;
245}
246
247core_initcall(ptrace_break_init);
248
249/*
250 * Read the word at offset "off" into the "struct user". We
251 * actually access the pt_regs stored on the kernel stack.
252 */
253static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
254 unsigned long __user *ret)
255{
256 unsigned long tmp;
257
258 if (off & 3 || off >= sizeof(struct user))
259 return -EIO;
260
261 tmp = 0;
262 if (off == PT_TEXT_ADDR)
263 tmp = tsk->mm->start_code;
264 else if (off == PT_DATA_ADDR)
265 tmp = tsk->mm->start_data;
266 else if (off == PT_TEXT_END_ADDR)
267 tmp = tsk->mm->end_code;
268 else if (off < sizeof(struct pt_regs))
269 tmp = get_user_reg(tsk, off >> 2);
270
271 return put_user(tmp, ret);
272}
273
274/*
275 * Write the word at offset "off" into "struct user". We
276 * actually access the pt_regs stored on the kernel stack.
277 */
278static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
279 unsigned long val)
280{
281 if (off & 3 || off >= sizeof(struct user))
282 return -EIO;
283
284 if (off >= sizeof(struct pt_regs))
285 return 0;
286
287 return put_user_reg(tsk, off >> 2, val);
288}
289
290#ifdef CONFIG_IWMMXT
291
292/*
293 * Get the child iWMMXt state.
294 */
295static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
296{
297 struct thread_info *thread = task_thread_info(tsk);
298
299 if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
300 return -ENODATA;
301 iwmmxt_task_disable(thread); /* force it to ram */
302 return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
303 ? -EFAULT : 0;
304}
305
306/*
307 * Set the child iWMMXt state.
308 */
309static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
310{
311 struct thread_info *thread = task_thread_info(tsk);
312
313 if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
314 return -EACCES;
315 iwmmxt_task_release(thread); /* force a reload */
316 return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
317 ? -EFAULT : 0;
318}
319
320#endif
321
322#ifdef CONFIG_CRUNCH
323/*
324 * Get the child Crunch state.
325 */
326static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
327{
328 struct thread_info *thread = task_thread_info(tsk);
329
330 crunch_task_disable(thread); /* force it to ram */
331 return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
332 ? -EFAULT : 0;
333}
334
335/*
336 * Set the child Crunch state.
337 */
338static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
339{
340 struct thread_info *thread = task_thread_info(tsk);
341
342 crunch_task_release(thread); /* force a reload */
343 return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
344 ? -EFAULT : 0;
345}
346#endif
347
348#ifdef CONFIG_HAVE_HW_BREAKPOINT
349/*
350 * Convert a virtual register number into an index for a thread_info
351 * breakpoint array. Breakpoints are identified using positive numbers
352 * whilst watchpoints are negative. The registers are laid out as pairs
353 * of (address, control), each pair mapping to a unique hw_breakpoint struct.
354 * Register 0 is reserved for describing resource information.
355 */
356static int ptrace_hbp_num_to_idx(long num)
357{
358 if (num < 0)
359 num = (ARM_MAX_BRP << 1) - num;
360 return (num - 1) >> 1;
361}
362
363/*
364 * Returns the virtual register number for the address of the
365 * breakpoint at index idx.
366 */
367static long ptrace_hbp_idx_to_num(int idx)
368{
369 long mid = ARM_MAX_BRP << 1;
370 long num = (idx << 1) + 1;
371 return num > mid ? mid - num : num;
372}
373
374/*
375 * Handle hitting a HW-breakpoint.
376 */
377static void ptrace_hbptriggered(struct perf_event *bp,
378 struct perf_sample_data *data,
379 struct pt_regs *regs)
380{
381 struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
382 long num;
383 int i;
384 siginfo_t info;
385
386 for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
387 if (current->thread.debug.hbp[i] == bp)
388 break;
389
390 num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
391
392 info.si_signo = SIGTRAP;
393 info.si_errno = (int)num;
394 info.si_code = TRAP_HWBKPT;
395 info.si_addr = (void __user *)(bkpt->trigger);
396
397 force_sig_info(SIGTRAP, &info, current);
398}
399
400/*
401 * Set ptrace breakpoint pointers to zero for this task.
402 * This is required in order to prevent child processes from unregistering
403 * breakpoints held by their parent.
404 */
405void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
406{
407 memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
408}
409
410/*
411 * Unregister breakpoints from this task and reset the pointers in
412 * the thread_struct.
413 */
414void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
415{
416 int i;
417 struct thread_struct *t = &tsk->thread;
418
419 for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
420 if (t->debug.hbp[i]) {
421 unregister_hw_breakpoint(t->debug.hbp[i]);
422 t->debug.hbp[i] = NULL;
423 }
424 }
425}
426
427static u32 ptrace_get_hbp_resource_info(void)
428{
429 u8 num_brps, num_wrps, debug_arch, wp_len;
430 u32 reg = 0;
431
432 num_brps = hw_breakpoint_slots(TYPE_INST);
433 num_wrps = hw_breakpoint_slots(TYPE_DATA);
434 debug_arch = arch_get_debug_arch();
435 wp_len = arch_get_max_wp_len();
436
437 reg |= debug_arch;
438 reg <<= 8;
439 reg |= wp_len;
440 reg <<= 8;
441 reg |= num_wrps;
442 reg <<= 8;
443 reg |= num_brps;
444
445 return reg;
446}
447
448static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
449{
450 struct perf_event_attr attr;
451
452 ptrace_breakpoint_init(&attr);
453
454 /* Initialise fields to sane defaults. */
455 attr.bp_addr = 0;
456 attr.bp_len = HW_BREAKPOINT_LEN_4;
457 attr.bp_type = type;
458 attr.disabled = 1;
459
460 return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
461 tsk);
462}
463
464static int ptrace_gethbpregs(struct task_struct *tsk, long num,
465 unsigned long __user *data)
466{
467 u32 reg;
468 int idx, ret = 0;
469 struct perf_event *bp;
470 struct arch_hw_breakpoint_ctrl arch_ctrl;
471
472 if (num == 0) {
473 reg = ptrace_get_hbp_resource_info();
474 } else {
475 idx = ptrace_hbp_num_to_idx(num);
476 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
477 ret = -EINVAL;
478 goto out;
479 }
480
481 bp = tsk->thread.debug.hbp[idx];
482 if (!bp) {
483 reg = 0;
484 goto put;
485 }
486
487 arch_ctrl = counter_arch_bp(bp)->ctrl;
488
489 /*
490 * Fix up the len because we may have adjusted it
491 * to compensate for an unaligned address.
492 */
493 while (!(arch_ctrl.len & 0x1))
494 arch_ctrl.len >>= 1;
495
496 if (num & 0x1)
497 reg = bp->attr.bp_addr;
498 else
499 reg = encode_ctrl_reg(arch_ctrl);
500 }
501
502put:
503 if (put_user(reg, data))
504 ret = -EFAULT;
505
506out:
507 return ret;
508}
509
510static int ptrace_sethbpregs(struct task_struct *tsk, long num,
511 unsigned long __user *data)
512{
513 int idx, gen_len, gen_type, implied_type, ret = 0;
514 u32 user_val;
515 struct perf_event *bp;
516 struct arch_hw_breakpoint_ctrl ctrl;
517 struct perf_event_attr attr;
518
519 if (num == 0)
520 goto out;
521 else if (num < 0)
522 implied_type = HW_BREAKPOINT_RW;
523 else
524 implied_type = HW_BREAKPOINT_X;
525
526 idx = ptrace_hbp_num_to_idx(num);
527 if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
528 ret = -EINVAL;
529 goto out;
530 }
531
532 if (get_user(user_val, data)) {
533 ret = -EFAULT;
534 goto out;
535 }
536
537 bp = tsk->thread.debug.hbp[idx];
538 if (!bp) {
539 bp = ptrace_hbp_create(tsk, implied_type);
540 if (IS_ERR(bp)) {
541 ret = PTR_ERR(bp);
542 goto out;
543 }
544 tsk->thread.debug.hbp[idx] = bp;
545 }
546
547 attr = bp->attr;
548
549 if (num & 0x1) {
550 /* Address */
551 attr.bp_addr = user_val;
552 } else {
553 /* Control */
554 decode_ctrl_reg(user_val, &ctrl);
555 ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
556 if (ret)
557 goto out;
558
559 if ((gen_type & implied_type) != gen_type) {
560 ret = -EINVAL;
561 goto out;
562 }
563
564 attr.bp_len = gen_len;
565 attr.bp_type = gen_type;
566 attr.disabled = !ctrl.enabled;
567 }
568
569 ret = modify_user_hw_breakpoint(bp, &attr);
570out:
571 return ret;
572}
573#endif
574
575/* regset get/set implementations */
576
577static int gpr_get(struct task_struct *target,
578 const struct user_regset *regset,
579 unsigned int pos, unsigned int count,
580 void *kbuf, void __user *ubuf)
581{
582 struct pt_regs *regs = task_pt_regs(target);
583
584 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
585 regs,
586 0, sizeof(*regs));
587}
588
589static int gpr_set(struct task_struct *target,
590 const struct user_regset *regset,
591 unsigned int pos, unsigned int count,
592 const void *kbuf, const void __user *ubuf)
593{
594 int ret;
595 struct pt_regs newregs;
596
597 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
598 &newregs,
599 0, sizeof(newregs));
600 if (ret)
601 return ret;
602
603 if (!valid_user_regs(&newregs))
604 return -EINVAL;
605
606 *task_pt_regs(target) = newregs;
607 return 0;
608}
609
610static int fpa_get(struct task_struct *target,
611 const struct user_regset *regset,
612 unsigned int pos, unsigned int count,
613 void *kbuf, void __user *ubuf)
614{
615 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
616 &task_thread_info(target)->fpstate,
617 0, sizeof(struct user_fp));
618}
619
620static int fpa_set(struct task_struct *target,
621 const struct user_regset *regset,
622 unsigned int pos, unsigned int count,
623 const void *kbuf, const void __user *ubuf)
624{
625 struct thread_info *thread = task_thread_info(target);
626
627 thread->used_cp[1] = thread->used_cp[2] = 1;
628
629 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
630 &thread->fpstate,
631 0, sizeof(struct user_fp));
632}
633
634#ifdef CONFIG_VFP
635/*
636 * VFP register get/set implementations.
637 *
638 * With respect to the kernel, struct user_fp is divided into three chunks:
639 * 16 or 32 real VFP registers (d0-d15 or d0-31)
640 * These are transferred to/from the real registers in the task's
641 * vfp_hard_struct. The number of registers depends on the kernel
642 * configuration.
643 *
644 * 16 or 0 fake VFP registers (d16-d31 or empty)
645 * i.e., the user_vfp structure has space for 32 registers even if
646 * the kernel doesn't have them all.
647 *
648 * vfp_get() reads this chunk as zero where applicable
649 * vfp_set() ignores this chunk
650 *
651 * 1 word for the FPSCR
652 *
653 * The bounds-checking logic built into user_regset_copyout and friends
654 * means that we can make a simple sequence of calls to map the relevant data
655 * to/from the specified slice of the user regset structure.
656 */
657static int vfp_get(struct task_struct *target,
658 const struct user_regset *regset,
659 unsigned int pos, unsigned int count,
660 void *kbuf, void __user *ubuf)
661{
662 int ret;
663 struct thread_info *thread = task_thread_info(target);
664 struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
665 const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
666 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
667
668 vfp_sync_hwstate(thread);
669
670 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
671 &vfp->fpregs,
672 user_fpregs_offset,
673 user_fpregs_offset + sizeof(vfp->fpregs));
674 if (ret)
675 return ret;
676
677 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
678 user_fpregs_offset + sizeof(vfp->fpregs),
679 user_fpscr_offset);
680 if (ret)
681 return ret;
682
683 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
684 &vfp->fpscr,
685 user_fpscr_offset,
686 user_fpscr_offset + sizeof(vfp->fpscr));
687}
688
689/*
690 * For vfp_set() a read-modify-write is done on the VFP registers,
691 * in order to avoid writing back a half-modified set of registers on
692 * failure.
693 */
694static int vfp_set(struct task_struct *target,
695 const struct user_regset *regset,
696 unsigned int pos, unsigned int count,
697 const void *kbuf, const void __user *ubuf)
698{
699 int ret;
700 struct thread_info *thread = task_thread_info(target);
701 struct vfp_hard_struct new_vfp = thread->vfpstate.hard;
702 const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
703 const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
704
705 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
706 &new_vfp.fpregs,
707 user_fpregs_offset,
708 user_fpregs_offset + sizeof(new_vfp.fpregs));
709 if (ret)
710 return ret;
711
712 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
713 user_fpregs_offset + sizeof(new_vfp.fpregs),
714 user_fpscr_offset);
715 if (ret)
716 return ret;
717
718 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
719 &new_vfp.fpscr,
720 user_fpscr_offset,
721 user_fpscr_offset + sizeof(new_vfp.fpscr));
722 if (ret)
723 return ret;
724
725 vfp_sync_hwstate(thread);
726 thread->vfpstate.hard = new_vfp;
727 vfp_flush_hwstate(thread);
728
729 return 0;
730}
731#endif /* CONFIG_VFP */
732
733enum arm_regset {
734 REGSET_GPR,
735 REGSET_FPR,
736#ifdef CONFIG_VFP
737 REGSET_VFP,
738#endif
739};
740
741static const struct user_regset arm_regsets[] = {
742 [REGSET_GPR] = {
743 .core_note_type = NT_PRSTATUS,
744 .n = ELF_NGREG,
745 .size = sizeof(u32),
746 .align = sizeof(u32),
747 .get = gpr_get,
748 .set = gpr_set
749 },
750 [REGSET_FPR] = {
751 /*
752 * For the FPA regs in fpstate, the real fields are a mixture
753 * of sizes, so pretend that the registers are word-sized:
754 */
755 .core_note_type = NT_PRFPREG,
756 .n = sizeof(struct user_fp) / sizeof(u32),
757 .size = sizeof(u32),
758 .align = sizeof(u32),
759 .get = fpa_get,
760 .set = fpa_set
761 },
762#ifdef CONFIG_VFP
763 [REGSET_VFP] = {
764 /*
765 * Pretend that the VFP regs are word-sized, since the FPSCR is
766 * a single word dangling at the end of struct user_vfp:
767 */
768 .core_note_type = NT_ARM_VFP,
769 .n = ARM_VFPREGS_SIZE / sizeof(u32),
770 .size = sizeof(u32),
771 .align = sizeof(u32),
772 .get = vfp_get,
773 .set = vfp_set
774 },
775#endif /* CONFIG_VFP */
776};
777
778static const struct user_regset_view user_arm_view = {
779 .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
780 .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
781};
782
783const struct user_regset_view *task_user_regset_view(struct task_struct *task)
784{
785 return &user_arm_view;
786}
787
788long arch_ptrace(struct task_struct *child, long request,
789 unsigned long addr, unsigned long data)
790{
791 int ret;
792 unsigned long __user *datap = (unsigned long __user *) data;
793
794 switch (request) {
795 case PTRACE_PEEKUSR:
796 ret = ptrace_read_user(child, addr, datap);
797 break;
798
799 case PTRACE_POKEUSR:
800 ret = ptrace_write_user(child, addr, data);
801 break;
802
803 case PTRACE_GETREGS:
804 ret = copy_regset_to_user(child,
805 &user_arm_view, REGSET_GPR,
806 0, sizeof(struct pt_regs),
807 datap);
808 break;
809
810 case PTRACE_SETREGS:
811 ret = copy_regset_from_user(child,
812 &user_arm_view, REGSET_GPR,
813 0, sizeof(struct pt_regs),
814 datap);
815 break;
816
817 case PTRACE_GETFPREGS:
818 ret = copy_regset_to_user(child,
819 &user_arm_view, REGSET_FPR,
820 0, sizeof(union fp_state),
821 datap);
822 break;
823
824 case PTRACE_SETFPREGS:
825 ret = copy_regset_from_user(child,
826 &user_arm_view, REGSET_FPR,
827 0, sizeof(union fp_state),
828 datap);
829 break;
830
831#ifdef CONFIG_IWMMXT
832 case PTRACE_GETWMMXREGS:
833 ret = ptrace_getwmmxregs(child, datap);
834 break;
835
836 case PTRACE_SETWMMXREGS:
837 ret = ptrace_setwmmxregs(child, datap);
838 break;
839#endif
840
841 case PTRACE_GET_THREAD_AREA:
842 ret = put_user(task_thread_info(child)->tp_value,
843 datap);
844 break;
845
846 case PTRACE_SET_SYSCALL:
847 task_thread_info(child)->syscall = data;
848 ret = 0;
849 break;
850
851#ifdef CONFIG_CRUNCH
852 case PTRACE_GETCRUNCHREGS:
853 ret = ptrace_getcrunchregs(child, datap);
854 break;
855
856 case PTRACE_SETCRUNCHREGS:
857 ret = ptrace_setcrunchregs(child, datap);
858 break;
859#endif
860
861#ifdef CONFIG_VFP
862 case PTRACE_GETVFPREGS:
863 ret = copy_regset_to_user(child,
864 &user_arm_view, REGSET_VFP,
865 0, ARM_VFPREGS_SIZE,
866 datap);
867 break;
868
869 case PTRACE_SETVFPREGS:
870 ret = copy_regset_from_user(child,
871 &user_arm_view, REGSET_VFP,
872 0, ARM_VFPREGS_SIZE,
873 datap);
874 break;
875#endif
876
877#ifdef CONFIG_HAVE_HW_BREAKPOINT
878 case PTRACE_GETHBPREGS:
879 if (ptrace_get_breakpoints(child) < 0)
880 return -ESRCH;
881
882 ret = ptrace_gethbpregs(child, addr,
883 (unsigned long __user *)data);
884 ptrace_put_breakpoints(child);
885 break;
886 case PTRACE_SETHBPREGS:
887 if (ptrace_get_breakpoints(child) < 0)
888 return -ESRCH;
889
890 ret = ptrace_sethbpregs(child, addr,
891 (unsigned long __user *)data);
892 ptrace_put_breakpoints(child);
893 break;
894#endif
895
896 default:
897 ret = ptrace_request(child, request, addr, data);
898 break;
899 }
900
901 return ret;
902}
903
904asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
905{
906 unsigned long ip;
907
908 if (!test_thread_flag(TIF_SYSCALL_TRACE))
909 return scno;
910 if (!(current->ptrace & PT_PTRACED))
911 return scno;
912
913 /*
914 * Save IP. IP is used to denote syscall entry/exit:
915 * IP = 0 -> entry, = 1 -> exit
916 */
917 ip = regs->ARM_ip;
918 regs->ARM_ip = why;
919
920 current_thread_info()->syscall = scno;
921
922 /* the 0x80 provides a way for the tracing parent to distinguish
923 between a syscall stop and SIGTRAP delivery */
924 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
925 ? 0x80 : 0));
926 /*
927 * this isn't the same as continuing with a signal, but it will do
928 * for normal use. strace only continues with a signal if the
929 * stopping signal is not SIGTRAP. -brl
930 */
931 if (current->exit_code) {
932 send_sig(current->exit_code, current, 1);
933 current->exit_code = 0;
934 }
935 regs->ARM_ip = ip;
936
937 return current_thread_info()->syscall;
938}
1// 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}