xref: /openbmc/linux/arch/mips/kernel/ptrace.c (revision 1cac4f26)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1992 Ross Biro
7  * Copyright (C) Linus Torvalds
8  * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
9  * Copyright (C) 1996 David S. Miller
10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11  * Copyright (C) 1999 MIPS Technologies, Inc.
12  * Copyright (C) 2000 Ulf Carlsson
13  *
14  * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
15  * binaries.
16  */
17 #include <linux/compiler.h>
18 #include <linux/context_tracking.h>
19 #include <linux/elf.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/sched/task_stack.h>
23 #include <linux/mm.h>
24 #include <linux/errno.h>
25 #include <linux/ptrace.h>
26 #include <linux/regset.h>
27 #include <linux/smp.h>
28 #include <linux/security.h>
29 #include <linux/stddef.h>
30 #include <linux/tracehook.h>
31 #include <linux/audit.h>
32 #include <linux/seccomp.h>
33 #include <linux/ftrace.h>
34 
35 #include <asm/byteorder.h>
36 #include <asm/cpu.h>
37 #include <asm/cpu-info.h>
38 #include <asm/dsp.h>
39 #include <asm/fpu.h>
40 #include <asm/mipsregs.h>
41 #include <asm/mipsmtregs.h>
42 #include <asm/pgtable.h>
43 #include <asm/page.h>
44 #include <asm/processor.h>
45 #include <asm/syscall.h>
46 #include <linux/uaccess.h>
47 #include <asm/bootinfo.h>
48 #include <asm/reg.h>
49 
50 #define CREATE_TRACE_POINTS
51 #include <trace/events/syscalls.h>
52 
53 /*
54  * Called by kernel/ptrace.c when detaching..
55  *
56  * Make sure single step bits etc are not set.
57  */
58 void ptrace_disable(struct task_struct *child)
59 {
60 	/* Don't load the watchpoint registers for the ex-child. */
61 	clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
62 }
63 
64 /*
65  * Read a general register set.	 We always use the 64-bit format, even
66  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
67  * Registers are sign extended to fill the available space.
68  */
69 int ptrace_getregs(struct task_struct *child, struct user_pt_regs __user *data)
70 {
71 	struct pt_regs *regs;
72 	int i;
73 
74 	if (!access_ok(data, 38 * 8))
75 		return -EIO;
76 
77 	regs = task_pt_regs(child);
78 
79 	for (i = 0; i < 32; i++)
80 		__put_user((long)regs->regs[i], (__s64 __user *)&data->regs[i]);
81 	__put_user((long)regs->lo, (__s64 __user *)&data->lo);
82 	__put_user((long)regs->hi, (__s64 __user *)&data->hi);
83 	__put_user((long)regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
84 	__put_user((long)regs->cp0_badvaddr, (__s64 __user *)&data->cp0_badvaddr);
85 	__put_user((long)regs->cp0_status, (__s64 __user *)&data->cp0_status);
86 	__put_user((long)regs->cp0_cause, (__s64 __user *)&data->cp0_cause);
87 
88 	return 0;
89 }
90 
91 /*
92  * Write a general register set.  As for PTRACE_GETREGS, we always use
93  * the 64-bit format.  On a 32-bit kernel only the lower order half
94  * (according to endianness) will be used.
95  */
96 int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
97 {
98 	struct pt_regs *regs;
99 	int i;
100 
101 	if (!access_ok(data, 38 * 8))
102 		return -EIO;
103 
104 	regs = task_pt_regs(child);
105 
106 	for (i = 0; i < 32; i++)
107 		__get_user(regs->regs[i], (__s64 __user *)&data->regs[i]);
108 	__get_user(regs->lo, (__s64 __user *)&data->lo);
109 	__get_user(regs->hi, (__s64 __user *)&data->hi);
110 	__get_user(regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
111 
112 	/* badvaddr, status, and cause may not be written.  */
113 
114 	/* System call number may have been changed */
115 	mips_syscall_update_nr(child, regs);
116 
117 	return 0;
118 }
119 
120 int ptrace_get_watch_regs(struct task_struct *child,
121 			  struct pt_watch_regs __user *addr)
122 {
123 	enum pt_watch_style style;
124 	int i;
125 
126 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
127 		return -EIO;
128 	if (!access_ok(addr, sizeof(struct pt_watch_regs)))
129 		return -EIO;
130 
131 #ifdef CONFIG_32BIT
132 	style = pt_watch_style_mips32;
133 #define WATCH_STYLE mips32
134 #else
135 	style = pt_watch_style_mips64;
136 #define WATCH_STYLE mips64
137 #endif
138 
139 	__put_user(style, &addr->style);
140 	__put_user(boot_cpu_data.watch_reg_use_cnt,
141 		   &addr->WATCH_STYLE.num_valid);
142 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
143 		__put_user(child->thread.watch.mips3264.watchlo[i],
144 			   &addr->WATCH_STYLE.watchlo[i]);
145 		__put_user(child->thread.watch.mips3264.watchhi[i] &
146 				(MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW),
147 			   &addr->WATCH_STYLE.watchhi[i]);
148 		__put_user(boot_cpu_data.watch_reg_masks[i],
149 			   &addr->WATCH_STYLE.watch_masks[i]);
150 	}
151 	for (; i < 8; i++) {
152 		__put_user(0, &addr->WATCH_STYLE.watchlo[i]);
153 		__put_user(0, &addr->WATCH_STYLE.watchhi[i]);
154 		__put_user(0, &addr->WATCH_STYLE.watch_masks[i]);
155 	}
156 
157 	return 0;
158 }
159 
160 int ptrace_set_watch_regs(struct task_struct *child,
161 			  struct pt_watch_regs __user *addr)
162 {
163 	int i;
164 	int watch_active = 0;
165 	unsigned long lt[NUM_WATCH_REGS];
166 	u16 ht[NUM_WATCH_REGS];
167 
168 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
169 		return -EIO;
170 	if (!access_ok(addr, sizeof(struct pt_watch_regs)))
171 		return -EIO;
172 	/* Check the values. */
173 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
174 		__get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]);
175 #ifdef CONFIG_32BIT
176 		if (lt[i] & __UA_LIMIT)
177 			return -EINVAL;
178 #else
179 		if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) {
180 			if (lt[i] & 0xffffffff80000000UL)
181 				return -EINVAL;
182 		} else {
183 			if (lt[i] & __UA_LIMIT)
184 				return -EINVAL;
185 		}
186 #endif
187 		__get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]);
188 		if (ht[i] & ~MIPS_WATCHHI_MASK)
189 			return -EINVAL;
190 	}
191 	/* Install them. */
192 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
193 		if (lt[i] & MIPS_WATCHLO_IRW)
194 			watch_active = 1;
195 		child->thread.watch.mips3264.watchlo[i] = lt[i];
196 		/* Set the G bit. */
197 		child->thread.watch.mips3264.watchhi[i] = ht[i];
198 	}
199 
200 	if (watch_active)
201 		set_tsk_thread_flag(child, TIF_LOAD_WATCH);
202 	else
203 		clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
204 
205 	return 0;
206 }
207 
208 /* regset get/set implementations */
209 
210 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
211 
212 static int gpr32_get(struct task_struct *target,
213 		     const struct user_regset *regset,
214 		     unsigned int pos, unsigned int count,
215 		     void *kbuf, void __user *ubuf)
216 {
217 	struct pt_regs *regs = task_pt_regs(target);
218 	u32 uregs[ELF_NGREG] = {};
219 
220 	mips_dump_regs32(uregs, regs);
221 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
222 				   sizeof(uregs));
223 }
224 
225 static int gpr32_set(struct task_struct *target,
226 		     const struct user_regset *regset,
227 		     unsigned int pos, unsigned int count,
228 		     const void *kbuf, const void __user *ubuf)
229 {
230 	struct pt_regs *regs = task_pt_regs(target);
231 	u32 uregs[ELF_NGREG];
232 	unsigned start, num_regs, i;
233 	int err;
234 
235 	start = pos / sizeof(u32);
236 	num_regs = count / sizeof(u32);
237 
238 	if (start + num_regs > ELF_NGREG)
239 		return -EIO;
240 
241 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
242 				 sizeof(uregs));
243 	if (err)
244 		return err;
245 
246 	for (i = start; i < num_regs; i++) {
247 		/*
248 		 * Cast all values to signed here so that if this is a 64-bit
249 		 * kernel, the supplied 32-bit values will be sign extended.
250 		 */
251 		switch (i) {
252 		case MIPS32_EF_R1 ... MIPS32_EF_R25:
253 			/* k0/k1 are ignored. */
254 		case MIPS32_EF_R28 ... MIPS32_EF_R31:
255 			regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
256 			break;
257 		case MIPS32_EF_LO:
258 			regs->lo = (s32)uregs[i];
259 			break;
260 		case MIPS32_EF_HI:
261 			regs->hi = (s32)uregs[i];
262 			break;
263 		case MIPS32_EF_CP0_EPC:
264 			regs->cp0_epc = (s32)uregs[i];
265 			break;
266 		}
267 	}
268 
269 	/* System call number may have been changed */
270 	mips_syscall_update_nr(target, regs);
271 
272 	return 0;
273 }
274 
275 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
276 
277 #ifdef CONFIG_64BIT
278 
279 static int gpr64_get(struct task_struct *target,
280 		     const struct user_regset *regset,
281 		     unsigned int pos, unsigned int count,
282 		     void *kbuf, void __user *ubuf)
283 {
284 	struct pt_regs *regs = task_pt_regs(target);
285 	u64 uregs[ELF_NGREG] = {};
286 
287 	mips_dump_regs64(uregs, regs);
288 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
289 				   sizeof(uregs));
290 }
291 
292 static int gpr64_set(struct task_struct *target,
293 		     const struct user_regset *regset,
294 		     unsigned int pos, unsigned int count,
295 		     const void *kbuf, const void __user *ubuf)
296 {
297 	struct pt_regs *regs = task_pt_regs(target);
298 	u64 uregs[ELF_NGREG];
299 	unsigned start, num_regs, i;
300 	int err;
301 
302 	start = pos / sizeof(u64);
303 	num_regs = count / sizeof(u64);
304 
305 	if (start + num_regs > ELF_NGREG)
306 		return -EIO;
307 
308 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
309 				 sizeof(uregs));
310 	if (err)
311 		return err;
312 
313 	for (i = start; i < num_regs; i++) {
314 		switch (i) {
315 		case MIPS64_EF_R1 ... MIPS64_EF_R25:
316 			/* k0/k1 are ignored. */
317 		case MIPS64_EF_R28 ... MIPS64_EF_R31:
318 			regs->regs[i - MIPS64_EF_R0] = uregs[i];
319 			break;
320 		case MIPS64_EF_LO:
321 			regs->lo = uregs[i];
322 			break;
323 		case MIPS64_EF_HI:
324 			regs->hi = uregs[i];
325 			break;
326 		case MIPS64_EF_CP0_EPC:
327 			regs->cp0_epc = uregs[i];
328 			break;
329 		}
330 	}
331 
332 	/* System call number may have been changed */
333 	mips_syscall_update_nr(target, regs);
334 
335 	return 0;
336 }
337 
338 #endif /* CONFIG_64BIT */
339 
340 
341 #ifdef CONFIG_MIPS_FP_SUPPORT
342 
343 /*
344  * Poke at FCSR according to its mask.  Set the Cause bits even
345  * if a corresponding Enable bit is set.  This will be noticed at
346  * the time the thread is switched to and SIGFPE thrown accordingly.
347  */
348 static void ptrace_setfcr31(struct task_struct *child, u32 value)
349 {
350 	u32 fcr31;
351 	u32 mask;
352 
353 	fcr31 = child->thread.fpu.fcr31;
354 	mask = boot_cpu_data.fpu_msk31;
355 	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
356 }
357 
358 int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
359 {
360 	int i;
361 
362 	if (!access_ok(data, 33 * 8))
363 		return -EIO;
364 
365 	if (tsk_used_math(child)) {
366 		union fpureg *fregs = get_fpu_regs(child);
367 		for (i = 0; i < 32; i++)
368 			__put_user(get_fpr64(&fregs[i], 0),
369 				   i + (__u64 __user *)data);
370 	} else {
371 		for (i = 0; i < 32; i++)
372 			__put_user((__u64) -1, i + (__u64 __user *) data);
373 	}
374 
375 	__put_user(child->thread.fpu.fcr31, data + 64);
376 	__put_user(boot_cpu_data.fpu_id, data + 65);
377 
378 	return 0;
379 }
380 
381 int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
382 {
383 	union fpureg *fregs;
384 	u64 fpr_val;
385 	u32 value;
386 	int i;
387 
388 	if (!access_ok(data, 33 * 8))
389 		return -EIO;
390 
391 	init_fp_ctx(child);
392 	fregs = get_fpu_regs(child);
393 
394 	for (i = 0; i < 32; i++) {
395 		__get_user(fpr_val, i + (__u64 __user *)data);
396 		set_fpr64(&fregs[i], 0, fpr_val);
397 	}
398 
399 	__get_user(value, data + 64);
400 	ptrace_setfcr31(child, value);
401 
402 	/* FIR may not be written.  */
403 
404 	return 0;
405 }
406 
407 /*
408  * Copy the floating-point context to the supplied NT_PRFPREG buffer,
409  * !CONFIG_CPU_HAS_MSA variant.  FP context's general register slots
410  * correspond 1:1 to buffer slots.  Only general registers are copied.
411  */
412 static int fpr_get_fpa(struct task_struct *target,
413 		       unsigned int *pos, unsigned int *count,
414 		       void **kbuf, void __user **ubuf)
415 {
416 	return user_regset_copyout(pos, count, kbuf, ubuf,
417 				   &target->thread.fpu,
418 				   0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
419 }
420 
421 /*
422  * Copy the floating-point context to the supplied NT_PRFPREG buffer,
423  * CONFIG_CPU_HAS_MSA variant.  Only lower 64 bits of FP context's
424  * general register slots are copied to buffer slots.  Only general
425  * registers are copied.
426  */
427 static int fpr_get_msa(struct task_struct *target,
428 		       unsigned int *pos, unsigned int *count,
429 		       void **kbuf, void __user **ubuf)
430 {
431 	unsigned int i;
432 	u64 fpr_val;
433 	int err;
434 
435 	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
436 	for (i = 0; i < NUM_FPU_REGS; i++) {
437 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
438 		err = user_regset_copyout(pos, count, kbuf, ubuf,
439 					  &fpr_val, i * sizeof(elf_fpreg_t),
440 					  (i + 1) * sizeof(elf_fpreg_t));
441 		if (err)
442 			return err;
443 	}
444 
445 	return 0;
446 }
447 
448 /*
449  * Copy the floating-point context to the supplied NT_PRFPREG buffer.
450  * Choose the appropriate helper for general registers, and then copy
451  * the FCSR and FIR registers separately.
452  */
453 static int fpr_get(struct task_struct *target,
454 		   const struct user_regset *regset,
455 		   unsigned int pos, unsigned int count,
456 		   void *kbuf, void __user *ubuf)
457 {
458 	const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
459 	const int fir_pos = fcr31_pos + sizeof(u32);
460 	int err;
461 
462 	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
463 		err = fpr_get_fpa(target, &pos, &count, &kbuf, &ubuf);
464 	else
465 		err = fpr_get_msa(target, &pos, &count, &kbuf, &ubuf);
466 	if (err)
467 		return err;
468 
469 	err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
470 				  &target->thread.fpu.fcr31,
471 				  fcr31_pos, fcr31_pos + sizeof(u32));
472 	if (err)
473 		return err;
474 
475 	err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
476 				  &boot_cpu_data.fpu_id,
477 				  fir_pos, fir_pos + sizeof(u32));
478 
479 	return err;
480 }
481 
482 /*
483  * Copy the supplied NT_PRFPREG buffer to the floating-point context,
484  * !CONFIG_CPU_HAS_MSA variant.   Buffer slots correspond 1:1 to FP
485  * context's general register slots.  Only general registers are copied.
486  */
487 static int fpr_set_fpa(struct task_struct *target,
488 		       unsigned int *pos, unsigned int *count,
489 		       const void **kbuf, const void __user **ubuf)
490 {
491 	return user_regset_copyin(pos, count, kbuf, ubuf,
492 				  &target->thread.fpu,
493 				  0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
494 }
495 
496 /*
497  * Copy the supplied NT_PRFPREG buffer to the floating-point context,
498  * CONFIG_CPU_HAS_MSA variant.  Buffer slots are copied to lower 64
499  * bits only of FP context's general register slots.  Only general
500  * registers are copied.
501  */
502 static int fpr_set_msa(struct task_struct *target,
503 		       unsigned int *pos, unsigned int *count,
504 		       const void **kbuf, const void __user **ubuf)
505 {
506 	unsigned int i;
507 	u64 fpr_val;
508 	int err;
509 
510 	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
511 	for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) {
512 		err = user_regset_copyin(pos, count, kbuf, ubuf,
513 					 &fpr_val, i * sizeof(elf_fpreg_t),
514 					 (i + 1) * sizeof(elf_fpreg_t));
515 		if (err)
516 			return err;
517 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
518 	}
519 
520 	return 0;
521 }
522 
523 /*
524  * Copy the supplied NT_PRFPREG buffer to the floating-point context.
525  * Choose the appropriate helper for general registers, and then copy
526  * the FCSR register separately.  Ignore the incoming FIR register
527  * contents though, as the register is read-only.
528  *
529  * We optimize for the case where `count % sizeof(elf_fpreg_t) == 0',
530  * which is supposed to have been guaranteed by the kernel before
531  * calling us, e.g. in `ptrace_regset'.  We enforce that requirement,
532  * so that we can safely avoid preinitializing temporaries for
533  * partial register writes.
534  */
535 static int fpr_set(struct task_struct *target,
536 		   const struct user_regset *regset,
537 		   unsigned int pos, unsigned int count,
538 		   const void *kbuf, const void __user *ubuf)
539 {
540 	const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
541 	const int fir_pos = fcr31_pos + sizeof(u32);
542 	u32 fcr31;
543 	int err;
544 
545 	BUG_ON(count % sizeof(elf_fpreg_t));
546 
547 	if (pos + count > sizeof(elf_fpregset_t))
548 		return -EIO;
549 
550 	init_fp_ctx(target);
551 
552 	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
553 		err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf);
554 	else
555 		err = fpr_set_msa(target, &pos, &count, &kbuf, &ubuf);
556 	if (err)
557 		return err;
558 
559 	if (count > 0) {
560 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
561 					 &fcr31,
562 					 fcr31_pos, fcr31_pos + sizeof(u32));
563 		if (err)
564 			return err;
565 
566 		ptrace_setfcr31(target, fcr31);
567 	}
568 
569 	if (count > 0)
570 		err = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
571 						fir_pos,
572 						fir_pos + sizeof(u32));
573 
574 	return err;
575 }
576 
577 /* Copy the FP mode setting to the supplied NT_MIPS_FP_MODE buffer.  */
578 static int fp_mode_get(struct task_struct *target,
579 		       const struct user_regset *regset,
580 		       unsigned int pos, unsigned int count,
581 		       void *kbuf, void __user *ubuf)
582 {
583 	int fp_mode;
584 
585 	fp_mode = mips_get_process_fp_mode(target);
586 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fp_mode, 0,
587 				   sizeof(fp_mode));
588 }
589 
590 /*
591  * Copy the supplied NT_MIPS_FP_MODE buffer to the FP mode setting.
592  *
593  * We optimize for the case where `count % sizeof(int) == 0', which
594  * is supposed to have been guaranteed by the kernel before calling
595  * us, e.g. in `ptrace_regset'.  We enforce that requirement, so
596  * that we can safely avoid preinitializing temporaries for partial
597  * mode writes.
598  */
599 static int fp_mode_set(struct task_struct *target,
600 		       const struct user_regset *regset,
601 		       unsigned int pos, unsigned int count,
602 		       const void *kbuf, const void __user *ubuf)
603 {
604 	int fp_mode;
605 	int err;
606 
607 	BUG_ON(count % sizeof(int));
608 
609 	if (pos + count > sizeof(fp_mode))
610 		return -EIO;
611 
612 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fp_mode, 0,
613 				 sizeof(fp_mode));
614 	if (err)
615 		return err;
616 
617 	if (count > 0)
618 		err = mips_set_process_fp_mode(target, fp_mode);
619 
620 	return err;
621 }
622 
623 #endif /* CONFIG_MIPS_FP_SUPPORT */
624 
625 #ifdef CONFIG_CPU_HAS_MSA
626 
627 struct msa_control_regs {
628 	unsigned int fir;
629 	unsigned int fcsr;
630 	unsigned int msair;
631 	unsigned int msacsr;
632 };
633 
634 static int copy_pad_fprs(struct task_struct *target,
635 			 const struct user_regset *regset,
636 			 unsigned int *ppos, unsigned int *pcount,
637 			 void **pkbuf, void __user **pubuf,
638 			 unsigned int live_sz)
639 {
640 	int i, j, start, start_pad, err;
641 	unsigned long long fill = ~0ull;
642 	unsigned int cp_sz, pad_sz;
643 
644 	cp_sz = min(regset->size, live_sz);
645 	pad_sz = regset->size - cp_sz;
646 	WARN_ON(pad_sz % sizeof(fill));
647 
648 	i = start = err = 0;
649 	for (; i < NUM_FPU_REGS; i++, start += regset->size) {
650 		err |= user_regset_copyout(ppos, pcount, pkbuf, pubuf,
651 					   &target->thread.fpu.fpr[i],
652 					   start, start + cp_sz);
653 
654 		start_pad = start + cp_sz;
655 		for (j = 0; j < (pad_sz / sizeof(fill)); j++) {
656 			err |= user_regset_copyout(ppos, pcount, pkbuf, pubuf,
657 						   &fill, start_pad,
658 						   start_pad + sizeof(fill));
659 			start_pad += sizeof(fill);
660 		}
661 	}
662 
663 	return err;
664 }
665 
666 static int msa_get(struct task_struct *target,
667 		   const struct user_regset *regset,
668 		   unsigned int pos, unsigned int count,
669 		   void *kbuf, void __user *ubuf)
670 {
671 	const unsigned int wr_size = NUM_FPU_REGS * regset->size;
672 	const struct msa_control_regs ctrl_regs = {
673 		.fir = boot_cpu_data.fpu_id,
674 		.fcsr = target->thread.fpu.fcr31,
675 		.msair = boot_cpu_data.msa_id,
676 		.msacsr = target->thread.fpu.msacsr,
677 	};
678 	int err;
679 
680 	if (!tsk_used_math(target)) {
681 		/* The task hasn't used FP or MSA, fill with 0xff */
682 		err = copy_pad_fprs(target, regset, &pos, &count,
683 				    &kbuf, &ubuf, 0);
684 	} else if (!test_tsk_thread_flag(target, TIF_MSA_CTX_LIVE)) {
685 		/* Copy scalar FP context, fill the rest with 0xff */
686 		err = copy_pad_fprs(target, regset, &pos, &count,
687 				    &kbuf, &ubuf, 8);
688 	} else if (sizeof(target->thread.fpu.fpr[0]) == regset->size) {
689 		/* Trivially copy the vector registers */
690 		err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
691 					  &target->thread.fpu.fpr,
692 					  0, wr_size);
693 	} else {
694 		/* Copy as much context as possible, fill the rest with 0xff */
695 		err = copy_pad_fprs(target, regset, &pos, &count,
696 				    &kbuf, &ubuf,
697 				    sizeof(target->thread.fpu.fpr[0]));
698 	}
699 
700 	err |= user_regset_copyout(&pos, &count, &kbuf, &ubuf,
701 				   &ctrl_regs, wr_size,
702 				   wr_size + sizeof(ctrl_regs));
703 	return err;
704 }
705 
706 static int msa_set(struct task_struct *target,
707 		   const struct user_regset *regset,
708 		   unsigned int pos, unsigned int count,
709 		   const void *kbuf, const void __user *ubuf)
710 {
711 	const unsigned int wr_size = NUM_FPU_REGS * regset->size;
712 	struct msa_control_regs ctrl_regs;
713 	unsigned int cp_sz;
714 	int i, err, start;
715 
716 	init_fp_ctx(target);
717 
718 	if (sizeof(target->thread.fpu.fpr[0]) == regset->size) {
719 		/* Trivially copy the vector registers */
720 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
721 					 &target->thread.fpu.fpr,
722 					 0, wr_size);
723 	} else {
724 		/* Copy as much context as possible */
725 		cp_sz = min_t(unsigned int, regset->size,
726 			      sizeof(target->thread.fpu.fpr[0]));
727 
728 		i = start = err = 0;
729 		for (; i < NUM_FPU_REGS; i++, start += regset->size) {
730 			err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
731 						  &target->thread.fpu.fpr[i],
732 						  start, start + cp_sz);
733 		}
734 	}
735 
736 	if (!err)
737 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl_regs,
738 					 wr_size, wr_size + sizeof(ctrl_regs));
739 	if (!err) {
740 		target->thread.fpu.fcr31 = ctrl_regs.fcsr & ~FPU_CSR_ALL_X;
741 		target->thread.fpu.msacsr = ctrl_regs.msacsr & ~MSA_CSR_CAUSEF;
742 	}
743 
744 	return err;
745 }
746 
747 #endif /* CONFIG_CPU_HAS_MSA */
748 
749 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
750 
751 /*
752  * Copy the DSP context to the supplied 32-bit NT_MIPS_DSP buffer.
753  */
754 static int dsp32_get(struct task_struct *target,
755 		     const struct user_regset *regset,
756 		     unsigned int pos, unsigned int count,
757 		     void *kbuf, void __user *ubuf)
758 {
759 	unsigned int start, num_regs, i;
760 	u32 dspregs[NUM_DSP_REGS + 1];
761 
762 	BUG_ON(count % sizeof(u32));
763 
764 	if (!cpu_has_dsp)
765 		return -EIO;
766 
767 	start = pos / sizeof(u32);
768 	num_regs = count / sizeof(u32);
769 
770 	if (start + num_regs > NUM_DSP_REGS + 1)
771 		return -EIO;
772 
773 	for (i = start; i < num_regs; i++)
774 		switch (i) {
775 		case 0 ... NUM_DSP_REGS - 1:
776 			dspregs[i] = target->thread.dsp.dspr[i];
777 			break;
778 		case NUM_DSP_REGS:
779 			dspregs[i] = target->thread.dsp.dspcontrol;
780 			break;
781 		}
782 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, dspregs, 0,
783 				   sizeof(dspregs));
784 }
785 
786 /*
787  * Copy the supplied 32-bit NT_MIPS_DSP buffer to the DSP context.
788  */
789 static int dsp32_set(struct task_struct *target,
790 		     const struct user_regset *regset,
791 		     unsigned int pos, unsigned int count,
792 		     const void *kbuf, const void __user *ubuf)
793 {
794 	unsigned int start, num_regs, i;
795 	u32 dspregs[NUM_DSP_REGS + 1];
796 	int err;
797 
798 	BUG_ON(count % sizeof(u32));
799 
800 	if (!cpu_has_dsp)
801 		return -EIO;
802 
803 	start = pos / sizeof(u32);
804 	num_regs = count / sizeof(u32);
805 
806 	if (start + num_regs > NUM_DSP_REGS + 1)
807 		return -EIO;
808 
809 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, dspregs, 0,
810 				 sizeof(dspregs));
811 	if (err)
812 		return err;
813 
814 	for (i = start; i < num_regs; i++)
815 		switch (i) {
816 		case 0 ... NUM_DSP_REGS - 1:
817 			target->thread.dsp.dspr[i] = (s32)dspregs[i];
818 			break;
819 		case NUM_DSP_REGS:
820 			target->thread.dsp.dspcontrol = (s32)dspregs[i];
821 			break;
822 		}
823 
824 	return 0;
825 }
826 
827 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
828 
829 #ifdef CONFIG_64BIT
830 
831 /*
832  * Copy the DSP context to the supplied 64-bit NT_MIPS_DSP buffer.
833  */
834 static int dsp64_get(struct task_struct *target,
835 		     const struct user_regset *regset,
836 		     unsigned int pos, unsigned int count,
837 		     void *kbuf, void __user *ubuf)
838 {
839 	unsigned int start, num_regs, i;
840 	u64 dspregs[NUM_DSP_REGS + 1];
841 
842 	BUG_ON(count % sizeof(u64));
843 
844 	if (!cpu_has_dsp)
845 		return -EIO;
846 
847 	start = pos / sizeof(u64);
848 	num_regs = count / sizeof(u64);
849 
850 	if (start + num_regs > NUM_DSP_REGS + 1)
851 		return -EIO;
852 
853 	for (i = start; i < num_regs; i++)
854 		switch (i) {
855 		case 0 ... NUM_DSP_REGS - 1:
856 			dspregs[i] = target->thread.dsp.dspr[i];
857 			break;
858 		case NUM_DSP_REGS:
859 			dspregs[i] = target->thread.dsp.dspcontrol;
860 			break;
861 		}
862 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, dspregs, 0,
863 				   sizeof(dspregs));
864 }
865 
866 /*
867  * Copy the supplied 64-bit NT_MIPS_DSP buffer to the DSP context.
868  */
869 static int dsp64_set(struct task_struct *target,
870 		     const struct user_regset *regset,
871 		     unsigned int pos, unsigned int count,
872 		     const void *kbuf, const void __user *ubuf)
873 {
874 	unsigned int start, num_regs, i;
875 	u64 dspregs[NUM_DSP_REGS + 1];
876 	int err;
877 
878 	BUG_ON(count % sizeof(u64));
879 
880 	if (!cpu_has_dsp)
881 		return -EIO;
882 
883 	start = pos / sizeof(u64);
884 	num_regs = count / sizeof(u64);
885 
886 	if (start + num_regs > NUM_DSP_REGS + 1)
887 		return -EIO;
888 
889 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, dspregs, 0,
890 				 sizeof(dspregs));
891 	if (err)
892 		return err;
893 
894 	for (i = start; i < num_regs; i++)
895 		switch (i) {
896 		case 0 ... NUM_DSP_REGS - 1:
897 			target->thread.dsp.dspr[i] = dspregs[i];
898 			break;
899 		case NUM_DSP_REGS:
900 			target->thread.dsp.dspcontrol = dspregs[i];
901 			break;
902 		}
903 
904 	return 0;
905 }
906 
907 #endif /* CONFIG_64BIT */
908 
909 /*
910  * Determine whether the DSP context is present.
911  */
912 static int dsp_active(struct task_struct *target,
913 		      const struct user_regset *regset)
914 {
915 	return cpu_has_dsp ? NUM_DSP_REGS + 1 : -ENODEV;
916 }
917 
918 enum mips_regset {
919 	REGSET_GPR,
920 	REGSET_DSP,
921 #ifdef CONFIG_MIPS_FP_SUPPORT
922 	REGSET_FPR,
923 	REGSET_FP_MODE,
924 #endif
925 #ifdef CONFIG_CPU_HAS_MSA
926 	REGSET_MSA,
927 #endif
928 };
929 
930 struct pt_regs_offset {
931 	const char *name;
932 	int offset;
933 };
934 
935 #define REG_OFFSET_NAME(reg, r) {					\
936 	.name = #reg,							\
937 	.offset = offsetof(struct pt_regs, r)				\
938 }
939 
940 #define REG_OFFSET_END {						\
941 	.name = NULL,							\
942 	.offset = 0							\
943 }
944 
945 static const struct pt_regs_offset regoffset_table[] = {
946 	REG_OFFSET_NAME(r0, regs[0]),
947 	REG_OFFSET_NAME(r1, regs[1]),
948 	REG_OFFSET_NAME(r2, regs[2]),
949 	REG_OFFSET_NAME(r3, regs[3]),
950 	REG_OFFSET_NAME(r4, regs[4]),
951 	REG_OFFSET_NAME(r5, regs[5]),
952 	REG_OFFSET_NAME(r6, regs[6]),
953 	REG_OFFSET_NAME(r7, regs[7]),
954 	REG_OFFSET_NAME(r8, regs[8]),
955 	REG_OFFSET_NAME(r9, regs[9]),
956 	REG_OFFSET_NAME(r10, regs[10]),
957 	REG_OFFSET_NAME(r11, regs[11]),
958 	REG_OFFSET_NAME(r12, regs[12]),
959 	REG_OFFSET_NAME(r13, regs[13]),
960 	REG_OFFSET_NAME(r14, regs[14]),
961 	REG_OFFSET_NAME(r15, regs[15]),
962 	REG_OFFSET_NAME(r16, regs[16]),
963 	REG_OFFSET_NAME(r17, regs[17]),
964 	REG_OFFSET_NAME(r18, regs[18]),
965 	REG_OFFSET_NAME(r19, regs[19]),
966 	REG_OFFSET_NAME(r20, regs[20]),
967 	REG_OFFSET_NAME(r21, regs[21]),
968 	REG_OFFSET_NAME(r22, regs[22]),
969 	REG_OFFSET_NAME(r23, regs[23]),
970 	REG_OFFSET_NAME(r24, regs[24]),
971 	REG_OFFSET_NAME(r25, regs[25]),
972 	REG_OFFSET_NAME(r26, regs[26]),
973 	REG_OFFSET_NAME(r27, regs[27]),
974 	REG_OFFSET_NAME(r28, regs[28]),
975 	REG_OFFSET_NAME(r29, regs[29]),
976 	REG_OFFSET_NAME(r30, regs[30]),
977 	REG_OFFSET_NAME(r31, regs[31]),
978 	REG_OFFSET_NAME(c0_status, cp0_status),
979 	REG_OFFSET_NAME(hi, hi),
980 	REG_OFFSET_NAME(lo, lo),
981 #ifdef CONFIG_CPU_HAS_SMARTMIPS
982 	REG_OFFSET_NAME(acx, acx),
983 #endif
984 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
985 	REG_OFFSET_NAME(c0_cause, cp0_cause),
986 	REG_OFFSET_NAME(c0_epc, cp0_epc),
987 #ifdef CONFIG_CPU_CAVIUM_OCTEON
988 	REG_OFFSET_NAME(mpl0, mpl[0]),
989 	REG_OFFSET_NAME(mpl1, mpl[1]),
990 	REG_OFFSET_NAME(mpl2, mpl[2]),
991 	REG_OFFSET_NAME(mtp0, mtp[0]),
992 	REG_OFFSET_NAME(mtp1, mtp[1]),
993 	REG_OFFSET_NAME(mtp2, mtp[2]),
994 #endif
995 	REG_OFFSET_END,
996 };
997 
998 /**
999  * regs_query_register_offset() - query register offset from its name
1000  * @name:       the name of a register
1001  *
1002  * regs_query_register_offset() returns the offset of a register in struct
1003  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
1004  */
1005 int regs_query_register_offset(const char *name)
1006 {
1007         const struct pt_regs_offset *roff;
1008         for (roff = regoffset_table; roff->name != NULL; roff++)
1009                 if (!strcmp(roff->name, name))
1010                         return roff->offset;
1011         return -EINVAL;
1012 }
1013 
1014 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
1015 
1016 static const struct user_regset mips_regsets[] = {
1017 	[REGSET_GPR] = {
1018 		.core_note_type	= NT_PRSTATUS,
1019 		.n		= ELF_NGREG,
1020 		.size		= sizeof(unsigned int),
1021 		.align		= sizeof(unsigned int),
1022 		.get		= gpr32_get,
1023 		.set		= gpr32_set,
1024 	},
1025 	[REGSET_DSP] = {
1026 		.core_note_type	= NT_MIPS_DSP,
1027 		.n		= NUM_DSP_REGS + 1,
1028 		.size		= sizeof(u32),
1029 		.align		= sizeof(u32),
1030 		.get		= dsp32_get,
1031 		.set		= dsp32_set,
1032 		.active		= dsp_active,
1033 	},
1034 #ifdef CONFIG_MIPS_FP_SUPPORT
1035 	[REGSET_FPR] = {
1036 		.core_note_type	= NT_PRFPREG,
1037 		.n		= ELF_NFPREG,
1038 		.size		= sizeof(elf_fpreg_t),
1039 		.align		= sizeof(elf_fpreg_t),
1040 		.get		= fpr_get,
1041 		.set		= fpr_set,
1042 	},
1043 	[REGSET_FP_MODE] = {
1044 		.core_note_type	= NT_MIPS_FP_MODE,
1045 		.n		= 1,
1046 		.size		= sizeof(int),
1047 		.align		= sizeof(int),
1048 		.get		= fp_mode_get,
1049 		.set		= fp_mode_set,
1050 	},
1051 #endif
1052 #ifdef CONFIG_CPU_HAS_MSA
1053 	[REGSET_MSA] = {
1054 		.core_note_type	= NT_MIPS_MSA,
1055 		.n		= NUM_FPU_REGS + 1,
1056 		.size		= 16,
1057 		.align		= 16,
1058 		.get		= msa_get,
1059 		.set		= msa_set,
1060 	},
1061 #endif
1062 };
1063 
1064 static const struct user_regset_view user_mips_view = {
1065 	.name		= "mips",
1066 	.e_machine	= ELF_ARCH,
1067 	.ei_osabi	= ELF_OSABI,
1068 	.regsets	= mips_regsets,
1069 	.n		= ARRAY_SIZE(mips_regsets),
1070 };
1071 
1072 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
1073 
1074 #ifdef CONFIG_64BIT
1075 
1076 static const struct user_regset mips64_regsets[] = {
1077 	[REGSET_GPR] = {
1078 		.core_note_type	= NT_PRSTATUS,
1079 		.n		= ELF_NGREG,
1080 		.size		= sizeof(unsigned long),
1081 		.align		= sizeof(unsigned long),
1082 		.get		= gpr64_get,
1083 		.set		= gpr64_set,
1084 	},
1085 	[REGSET_DSP] = {
1086 		.core_note_type	= NT_MIPS_DSP,
1087 		.n		= NUM_DSP_REGS + 1,
1088 		.size		= sizeof(u64),
1089 		.align		= sizeof(u64),
1090 		.get		= dsp64_get,
1091 		.set		= dsp64_set,
1092 		.active		= dsp_active,
1093 	},
1094 #ifdef CONFIG_MIPS_FP_SUPPORT
1095 	[REGSET_FP_MODE] = {
1096 		.core_note_type	= NT_MIPS_FP_MODE,
1097 		.n		= 1,
1098 		.size		= sizeof(int),
1099 		.align		= sizeof(int),
1100 		.get		= fp_mode_get,
1101 		.set		= fp_mode_set,
1102 	},
1103 	[REGSET_FPR] = {
1104 		.core_note_type	= NT_PRFPREG,
1105 		.n		= ELF_NFPREG,
1106 		.size		= sizeof(elf_fpreg_t),
1107 		.align		= sizeof(elf_fpreg_t),
1108 		.get		= fpr_get,
1109 		.set		= fpr_set,
1110 	},
1111 #endif
1112 #ifdef CONFIG_CPU_HAS_MSA
1113 	[REGSET_MSA] = {
1114 		.core_note_type	= NT_MIPS_MSA,
1115 		.n		= NUM_FPU_REGS + 1,
1116 		.size		= 16,
1117 		.align		= 16,
1118 		.get		= msa_get,
1119 		.set		= msa_set,
1120 	},
1121 #endif
1122 };
1123 
1124 static const struct user_regset_view user_mips64_view = {
1125 	.name		= "mips64",
1126 	.e_machine	= ELF_ARCH,
1127 	.ei_osabi	= ELF_OSABI,
1128 	.regsets	= mips64_regsets,
1129 	.n		= ARRAY_SIZE(mips64_regsets),
1130 };
1131 
1132 #ifdef CONFIG_MIPS32_N32
1133 
1134 static const struct user_regset_view user_mipsn32_view = {
1135 	.name		= "mipsn32",
1136 	.e_flags	= EF_MIPS_ABI2,
1137 	.e_machine	= ELF_ARCH,
1138 	.ei_osabi	= ELF_OSABI,
1139 	.regsets	= mips64_regsets,
1140 	.n		= ARRAY_SIZE(mips64_regsets),
1141 };
1142 
1143 #endif /* CONFIG_MIPS32_N32 */
1144 
1145 #endif /* CONFIG_64BIT */
1146 
1147 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1148 {
1149 #ifdef CONFIG_32BIT
1150 	return &user_mips_view;
1151 #else
1152 #ifdef CONFIG_MIPS32_O32
1153 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
1154 		return &user_mips_view;
1155 #endif
1156 #ifdef CONFIG_MIPS32_N32
1157 	if (test_tsk_thread_flag(task, TIF_32BIT_ADDR))
1158 		return &user_mipsn32_view;
1159 #endif
1160 	return &user_mips64_view;
1161 #endif
1162 }
1163 
1164 long arch_ptrace(struct task_struct *child, long request,
1165 		 unsigned long addr, unsigned long data)
1166 {
1167 	int ret;
1168 	void __user *addrp = (void __user *) addr;
1169 	void __user *datavp = (void __user *) data;
1170 	unsigned long __user *datalp = (void __user *) data;
1171 
1172 	switch (request) {
1173 	/* when I and D space are separate, these will need to be fixed. */
1174 	case PTRACE_PEEKTEXT: /* read word at location addr. */
1175 	case PTRACE_PEEKDATA:
1176 		ret = generic_ptrace_peekdata(child, addr, data);
1177 		break;
1178 
1179 	/* Read the word at location addr in the USER area. */
1180 	case PTRACE_PEEKUSR: {
1181 		struct pt_regs *regs;
1182 		unsigned long tmp = 0;
1183 
1184 		regs = task_pt_regs(child);
1185 		ret = 0;  /* Default return value. */
1186 
1187 		switch (addr) {
1188 		case 0 ... 31:
1189 			tmp = regs->regs[addr];
1190 			break;
1191 #ifdef CONFIG_MIPS_FP_SUPPORT
1192 		case FPR_BASE ... FPR_BASE + 31: {
1193 			union fpureg *fregs;
1194 
1195 			if (!tsk_used_math(child)) {
1196 				/* FP not yet used */
1197 				tmp = -1;
1198 				break;
1199 			}
1200 			fregs = get_fpu_regs(child);
1201 
1202 #ifdef CONFIG_32BIT
1203 			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
1204 				/*
1205 				 * The odd registers are actually the high
1206 				 * order bits of the values stored in the even
1207 				 * registers.
1208 				 */
1209 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
1210 						addr & 1);
1211 				break;
1212 			}
1213 #endif
1214 			tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
1215 			break;
1216 		}
1217 		case FPC_CSR:
1218 			tmp = child->thread.fpu.fcr31;
1219 			break;
1220 		case FPC_EIR:
1221 			/* implementation / version register */
1222 			tmp = boot_cpu_data.fpu_id;
1223 			break;
1224 #endif
1225 		case PC:
1226 			tmp = regs->cp0_epc;
1227 			break;
1228 		case CAUSE:
1229 			tmp = regs->cp0_cause;
1230 			break;
1231 		case BADVADDR:
1232 			tmp = regs->cp0_badvaddr;
1233 			break;
1234 		case MMHI:
1235 			tmp = regs->hi;
1236 			break;
1237 		case MMLO:
1238 			tmp = regs->lo;
1239 			break;
1240 #ifdef CONFIG_CPU_HAS_SMARTMIPS
1241 		case ACX:
1242 			tmp = regs->acx;
1243 			break;
1244 #endif
1245 		case DSP_BASE ... DSP_BASE + 5: {
1246 			dspreg_t *dregs;
1247 
1248 			if (!cpu_has_dsp) {
1249 				tmp = 0;
1250 				ret = -EIO;
1251 				goto out;
1252 			}
1253 			dregs = __get_dsp_regs(child);
1254 			tmp = dregs[addr - DSP_BASE];
1255 			break;
1256 		}
1257 		case DSP_CONTROL:
1258 			if (!cpu_has_dsp) {
1259 				tmp = 0;
1260 				ret = -EIO;
1261 				goto out;
1262 			}
1263 			tmp = child->thread.dsp.dspcontrol;
1264 			break;
1265 		default:
1266 			tmp = 0;
1267 			ret = -EIO;
1268 			goto out;
1269 		}
1270 		ret = put_user(tmp, datalp);
1271 		break;
1272 	}
1273 
1274 	/* when I and D space are separate, this will have to be fixed. */
1275 	case PTRACE_POKETEXT: /* write the word at location addr. */
1276 	case PTRACE_POKEDATA:
1277 		ret = generic_ptrace_pokedata(child, addr, data);
1278 		break;
1279 
1280 	case PTRACE_POKEUSR: {
1281 		struct pt_regs *regs;
1282 		ret = 0;
1283 		regs = task_pt_regs(child);
1284 
1285 		switch (addr) {
1286 		case 0 ... 31:
1287 			regs->regs[addr] = data;
1288 			/* System call number may have been changed */
1289 			if (addr == 2)
1290 				mips_syscall_update_nr(child, regs);
1291 			else if (addr == 4 &&
1292 				 mips_syscall_is_indirect(child, regs))
1293 				mips_syscall_update_nr(child, regs);
1294 			break;
1295 #ifdef CONFIG_MIPS_FP_SUPPORT
1296 		case FPR_BASE ... FPR_BASE + 31: {
1297 			union fpureg *fregs = get_fpu_regs(child);
1298 
1299 			init_fp_ctx(child);
1300 #ifdef CONFIG_32BIT
1301 			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
1302 				/*
1303 				 * The odd registers are actually the high
1304 				 * order bits of the values stored in the even
1305 				 * registers.
1306 				 */
1307 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
1308 					  addr & 1, data);
1309 				break;
1310 			}
1311 #endif
1312 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
1313 			break;
1314 		}
1315 		case FPC_CSR:
1316 			init_fp_ctx(child);
1317 			ptrace_setfcr31(child, data);
1318 			break;
1319 #endif
1320 		case PC:
1321 			regs->cp0_epc = data;
1322 			break;
1323 		case MMHI:
1324 			regs->hi = data;
1325 			break;
1326 		case MMLO:
1327 			regs->lo = data;
1328 			break;
1329 #ifdef CONFIG_CPU_HAS_SMARTMIPS
1330 		case ACX:
1331 			regs->acx = data;
1332 			break;
1333 #endif
1334 		case DSP_BASE ... DSP_BASE + 5: {
1335 			dspreg_t *dregs;
1336 
1337 			if (!cpu_has_dsp) {
1338 				ret = -EIO;
1339 				break;
1340 			}
1341 
1342 			dregs = __get_dsp_regs(child);
1343 			dregs[addr - DSP_BASE] = data;
1344 			break;
1345 		}
1346 		case DSP_CONTROL:
1347 			if (!cpu_has_dsp) {
1348 				ret = -EIO;
1349 				break;
1350 			}
1351 			child->thread.dsp.dspcontrol = data;
1352 			break;
1353 		default:
1354 			/* The rest are not allowed. */
1355 			ret = -EIO;
1356 			break;
1357 		}
1358 		break;
1359 		}
1360 
1361 	case PTRACE_GETREGS:
1362 		ret = ptrace_getregs(child, datavp);
1363 		break;
1364 
1365 	case PTRACE_SETREGS:
1366 		ret = ptrace_setregs(child, datavp);
1367 		break;
1368 
1369 #ifdef CONFIG_MIPS_FP_SUPPORT
1370 	case PTRACE_GETFPREGS:
1371 		ret = ptrace_getfpregs(child, datavp);
1372 		break;
1373 
1374 	case PTRACE_SETFPREGS:
1375 		ret = ptrace_setfpregs(child, datavp);
1376 		break;
1377 #endif
1378 	case PTRACE_GET_THREAD_AREA:
1379 		ret = put_user(task_thread_info(child)->tp_value, datalp);
1380 		break;
1381 
1382 	case PTRACE_GET_WATCH_REGS:
1383 		ret = ptrace_get_watch_regs(child, addrp);
1384 		break;
1385 
1386 	case PTRACE_SET_WATCH_REGS:
1387 		ret = ptrace_set_watch_regs(child, addrp);
1388 		break;
1389 
1390 	default:
1391 		ret = ptrace_request(child, request, addr, data);
1392 		break;
1393 	}
1394  out:
1395 	return ret;
1396 }
1397 
1398 /*
1399  * Notification of system call entry/exit
1400  * - triggered by current->work.syscall_trace
1401  */
1402 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
1403 {
1404 	user_exit();
1405 
1406 	current_thread_info()->syscall = syscall;
1407 
1408 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
1409 		if (tracehook_report_syscall_entry(regs))
1410 			return -1;
1411 		syscall = current_thread_info()->syscall;
1412 	}
1413 
1414 #ifdef CONFIG_SECCOMP
1415 	if (unlikely(test_thread_flag(TIF_SECCOMP))) {
1416 		int ret, i;
1417 		struct seccomp_data sd;
1418 		unsigned long args[6];
1419 
1420 		sd.nr = syscall;
1421 		sd.arch = syscall_get_arch();
1422 		syscall_get_arguments(current, regs, 0, 6, args);
1423 		for (i = 0; i < 6; i++)
1424 			sd.args[i] = args[i];
1425 		sd.instruction_pointer = KSTK_EIP(current);
1426 
1427 		ret = __secure_computing(&sd);
1428 		if (ret == -1)
1429 			return ret;
1430 		syscall = current_thread_info()->syscall;
1431 	}
1432 #endif
1433 
1434 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1435 		trace_sys_enter(regs, regs->regs[2]);
1436 
1437 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
1438 			    regs->regs[6], regs->regs[7]);
1439 
1440 	/*
1441 	 * Negative syscall numbers are mistaken for rejected syscalls, but
1442 	 * won't have had the return value set appropriately, so we do so now.
1443 	 */
1444 	if (syscall < 0)
1445 		syscall_set_return_value(current, regs, -ENOSYS, 0);
1446 	return syscall;
1447 }
1448 
1449 /*
1450  * Notification of system call entry/exit
1451  * - triggered by current->work.syscall_trace
1452  */
1453 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
1454 {
1455         /*
1456 	 * We may come here right after calling schedule_user()
1457 	 * or do_notify_resume(), in which case we can be in RCU
1458 	 * user mode.
1459 	 */
1460 	user_exit();
1461 
1462 	audit_syscall_exit(regs);
1463 
1464 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1465 		trace_sys_exit(regs, regs_return_value(regs));
1466 
1467 	if (test_thread_flag(TIF_SYSCALL_TRACE))
1468 		tracehook_report_syscall_exit(regs, 0);
1469 
1470 	user_enter();
1471 }
1472