xref: /openbmc/linux/arch/mips/kernel/ptrace.c (revision addee42a)
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/syscall.h>
45 #include <linux/uaccess.h>
46 #include <asm/bootinfo.h>
47 #include <asm/reg.h>
48 
49 #define CREATE_TRACE_POINTS
50 #include <trace/events/syscalls.h>
51 
52 static void init_fp_ctx(struct task_struct *target)
53 {
54 	/* If FP has been used then the target already has context */
55 	if (tsk_used_math(target))
56 		return;
57 
58 	/* Begin with data registers set to all 1s... */
59 	memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));
60 
61 	/* FCSR has been preset by `mips_set_personality_nan'.  */
62 
63 	/*
64 	 * Record that the target has "used" math, such that the context
65 	 * just initialised, and any modifications made by the caller,
66 	 * aren't discarded.
67 	 */
68 	set_stopped_child_used_math(target);
69 }
70 
71 /*
72  * Called by kernel/ptrace.c when detaching..
73  *
74  * Make sure single step bits etc are not set.
75  */
76 void ptrace_disable(struct task_struct *child)
77 {
78 	/* Don't load the watchpoint registers for the ex-child. */
79 	clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
80 }
81 
82 /*
83  * Poke at FCSR according to its mask.  Set the Cause bits even
84  * if a corresponding Enable bit is set.  This will be noticed at
85  * the time the thread is switched to and SIGFPE thrown accordingly.
86  */
87 static void ptrace_setfcr31(struct task_struct *child, u32 value)
88 {
89 	u32 fcr31;
90 	u32 mask;
91 
92 	fcr31 = child->thread.fpu.fcr31;
93 	mask = boot_cpu_data.fpu_msk31;
94 	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
95 }
96 
97 /*
98  * Read a general register set.	 We always use the 64-bit format, even
99  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
100  * Registers are sign extended to fill the available space.
101  */
102 int ptrace_getregs(struct task_struct *child, struct user_pt_regs __user *data)
103 {
104 	struct pt_regs *regs;
105 	int i;
106 
107 	if (!access_ok(VERIFY_WRITE, data, 38 * 8))
108 		return -EIO;
109 
110 	regs = task_pt_regs(child);
111 
112 	for (i = 0; i < 32; i++)
113 		__put_user((long)regs->regs[i], (__s64 __user *)&data->regs[i]);
114 	__put_user((long)regs->lo, (__s64 __user *)&data->lo);
115 	__put_user((long)regs->hi, (__s64 __user *)&data->hi);
116 	__put_user((long)regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
117 	__put_user((long)regs->cp0_badvaddr, (__s64 __user *)&data->cp0_badvaddr);
118 	__put_user((long)regs->cp0_status, (__s64 __user *)&data->cp0_status);
119 	__put_user((long)regs->cp0_cause, (__s64 __user *)&data->cp0_cause);
120 
121 	return 0;
122 }
123 
124 /*
125  * Write a general register set.  As for PTRACE_GETREGS, we always use
126  * the 64-bit format.  On a 32-bit kernel only the lower order half
127  * (according to endianness) will be used.
128  */
129 int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
130 {
131 	struct pt_regs *regs;
132 	int i;
133 
134 	if (!access_ok(VERIFY_READ, data, 38 * 8))
135 		return -EIO;
136 
137 	regs = task_pt_regs(child);
138 
139 	for (i = 0; i < 32; i++)
140 		__get_user(regs->regs[i], (__s64 __user *)&data->regs[i]);
141 	__get_user(regs->lo, (__s64 __user *)&data->lo);
142 	__get_user(regs->hi, (__s64 __user *)&data->hi);
143 	__get_user(regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
144 
145 	/* badvaddr, status, and cause may not be written.  */
146 
147 	/* System call number may have been changed */
148 	mips_syscall_update_nr(child, regs);
149 
150 	return 0;
151 }
152 
153 int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
154 {
155 	int i;
156 
157 	if (!access_ok(VERIFY_WRITE, data, 33 * 8))
158 		return -EIO;
159 
160 	if (tsk_used_math(child)) {
161 		union fpureg *fregs = get_fpu_regs(child);
162 		for (i = 0; i < 32; i++)
163 			__put_user(get_fpr64(&fregs[i], 0),
164 				   i + (__u64 __user *)data);
165 	} else {
166 		for (i = 0; i < 32; i++)
167 			__put_user((__u64) -1, i + (__u64 __user *) data);
168 	}
169 
170 	__put_user(child->thread.fpu.fcr31, data + 64);
171 	__put_user(boot_cpu_data.fpu_id, data + 65);
172 
173 	return 0;
174 }
175 
176 int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
177 {
178 	union fpureg *fregs;
179 	u64 fpr_val;
180 	u32 value;
181 	int i;
182 
183 	if (!access_ok(VERIFY_READ, data, 33 * 8))
184 		return -EIO;
185 
186 	init_fp_ctx(child);
187 	fregs = get_fpu_regs(child);
188 
189 	for (i = 0; i < 32; i++) {
190 		__get_user(fpr_val, i + (__u64 __user *)data);
191 		set_fpr64(&fregs[i], 0, fpr_val);
192 	}
193 
194 	__get_user(value, data + 64);
195 	ptrace_setfcr31(child, value);
196 
197 	/* FIR may not be written.  */
198 
199 	return 0;
200 }
201 
202 int ptrace_get_watch_regs(struct task_struct *child,
203 			  struct pt_watch_regs __user *addr)
204 {
205 	enum pt_watch_style style;
206 	int i;
207 
208 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
209 		return -EIO;
210 	if (!access_ok(VERIFY_WRITE, addr, sizeof(struct pt_watch_regs)))
211 		return -EIO;
212 
213 #ifdef CONFIG_32BIT
214 	style = pt_watch_style_mips32;
215 #define WATCH_STYLE mips32
216 #else
217 	style = pt_watch_style_mips64;
218 #define WATCH_STYLE mips64
219 #endif
220 
221 	__put_user(style, &addr->style);
222 	__put_user(boot_cpu_data.watch_reg_use_cnt,
223 		   &addr->WATCH_STYLE.num_valid);
224 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
225 		__put_user(child->thread.watch.mips3264.watchlo[i],
226 			   &addr->WATCH_STYLE.watchlo[i]);
227 		__put_user(child->thread.watch.mips3264.watchhi[i] &
228 				(MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW),
229 			   &addr->WATCH_STYLE.watchhi[i]);
230 		__put_user(boot_cpu_data.watch_reg_masks[i],
231 			   &addr->WATCH_STYLE.watch_masks[i]);
232 	}
233 	for (; i < 8; i++) {
234 		__put_user(0, &addr->WATCH_STYLE.watchlo[i]);
235 		__put_user(0, &addr->WATCH_STYLE.watchhi[i]);
236 		__put_user(0, &addr->WATCH_STYLE.watch_masks[i]);
237 	}
238 
239 	return 0;
240 }
241 
242 int ptrace_set_watch_regs(struct task_struct *child,
243 			  struct pt_watch_regs __user *addr)
244 {
245 	int i;
246 	int watch_active = 0;
247 	unsigned long lt[NUM_WATCH_REGS];
248 	u16 ht[NUM_WATCH_REGS];
249 
250 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
251 		return -EIO;
252 	if (!access_ok(VERIFY_READ, addr, sizeof(struct pt_watch_regs)))
253 		return -EIO;
254 	/* Check the values. */
255 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
256 		__get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]);
257 #ifdef CONFIG_32BIT
258 		if (lt[i] & __UA_LIMIT)
259 			return -EINVAL;
260 #else
261 		if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) {
262 			if (lt[i] & 0xffffffff80000000UL)
263 				return -EINVAL;
264 		} else {
265 			if (lt[i] & __UA_LIMIT)
266 				return -EINVAL;
267 		}
268 #endif
269 		__get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]);
270 		if (ht[i] & ~MIPS_WATCHHI_MASK)
271 			return -EINVAL;
272 	}
273 	/* Install them. */
274 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
275 		if (lt[i] & MIPS_WATCHLO_IRW)
276 			watch_active = 1;
277 		child->thread.watch.mips3264.watchlo[i] = lt[i];
278 		/* Set the G bit. */
279 		child->thread.watch.mips3264.watchhi[i] = ht[i];
280 	}
281 
282 	if (watch_active)
283 		set_tsk_thread_flag(child, TIF_LOAD_WATCH);
284 	else
285 		clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
286 
287 	return 0;
288 }
289 
290 /* regset get/set implementations */
291 
292 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
293 
294 static int gpr32_get(struct task_struct *target,
295 		     const struct user_regset *regset,
296 		     unsigned int pos, unsigned int count,
297 		     void *kbuf, void __user *ubuf)
298 {
299 	struct pt_regs *regs = task_pt_regs(target);
300 	u32 uregs[ELF_NGREG] = {};
301 
302 	mips_dump_regs32(uregs, regs);
303 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
304 				   sizeof(uregs));
305 }
306 
307 static int gpr32_set(struct task_struct *target,
308 		     const struct user_regset *regset,
309 		     unsigned int pos, unsigned int count,
310 		     const void *kbuf, const void __user *ubuf)
311 {
312 	struct pt_regs *regs = task_pt_regs(target);
313 	u32 uregs[ELF_NGREG];
314 	unsigned start, num_regs, i;
315 	int err;
316 
317 	start = pos / sizeof(u32);
318 	num_regs = count / sizeof(u32);
319 
320 	if (start + num_regs > ELF_NGREG)
321 		return -EIO;
322 
323 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
324 				 sizeof(uregs));
325 	if (err)
326 		return err;
327 
328 	for (i = start; i < num_regs; i++) {
329 		/*
330 		 * Cast all values to signed here so that if this is a 64-bit
331 		 * kernel, the supplied 32-bit values will be sign extended.
332 		 */
333 		switch (i) {
334 		case MIPS32_EF_R1 ... MIPS32_EF_R25:
335 			/* k0/k1 are ignored. */
336 		case MIPS32_EF_R28 ... MIPS32_EF_R31:
337 			regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
338 			break;
339 		case MIPS32_EF_LO:
340 			regs->lo = (s32)uregs[i];
341 			break;
342 		case MIPS32_EF_HI:
343 			regs->hi = (s32)uregs[i];
344 			break;
345 		case MIPS32_EF_CP0_EPC:
346 			regs->cp0_epc = (s32)uregs[i];
347 			break;
348 		}
349 	}
350 
351 	/* System call number may have been changed */
352 	mips_syscall_update_nr(target, regs);
353 
354 	return 0;
355 }
356 
357 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
358 
359 #ifdef CONFIG_64BIT
360 
361 static int gpr64_get(struct task_struct *target,
362 		     const struct user_regset *regset,
363 		     unsigned int pos, unsigned int count,
364 		     void *kbuf, void __user *ubuf)
365 {
366 	struct pt_regs *regs = task_pt_regs(target);
367 	u64 uregs[ELF_NGREG] = {};
368 
369 	mips_dump_regs64(uregs, regs);
370 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
371 				   sizeof(uregs));
372 }
373 
374 static int gpr64_set(struct task_struct *target,
375 		     const struct user_regset *regset,
376 		     unsigned int pos, unsigned int count,
377 		     const void *kbuf, const void __user *ubuf)
378 {
379 	struct pt_regs *regs = task_pt_regs(target);
380 	u64 uregs[ELF_NGREG];
381 	unsigned start, num_regs, i;
382 	int err;
383 
384 	start = pos / sizeof(u64);
385 	num_regs = count / sizeof(u64);
386 
387 	if (start + num_regs > ELF_NGREG)
388 		return -EIO;
389 
390 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
391 				 sizeof(uregs));
392 	if (err)
393 		return err;
394 
395 	for (i = start; i < num_regs; i++) {
396 		switch (i) {
397 		case MIPS64_EF_R1 ... MIPS64_EF_R25:
398 			/* k0/k1 are ignored. */
399 		case MIPS64_EF_R28 ... MIPS64_EF_R31:
400 			regs->regs[i - MIPS64_EF_R0] = uregs[i];
401 			break;
402 		case MIPS64_EF_LO:
403 			regs->lo = uregs[i];
404 			break;
405 		case MIPS64_EF_HI:
406 			regs->hi = uregs[i];
407 			break;
408 		case MIPS64_EF_CP0_EPC:
409 			regs->cp0_epc = uregs[i];
410 			break;
411 		}
412 	}
413 
414 	/* System call number may have been changed */
415 	mips_syscall_update_nr(target, regs);
416 
417 	return 0;
418 }
419 
420 #endif /* CONFIG_64BIT */
421 
422 /*
423  * Copy the floating-point context to the supplied NT_PRFPREG buffer,
424  * !CONFIG_CPU_HAS_MSA variant.  FP context's general register slots
425  * correspond 1:1 to buffer slots.  Only general registers are copied.
426  */
427 static int fpr_get_fpa(struct task_struct *target,
428 		       unsigned int *pos, unsigned int *count,
429 		       void **kbuf, void __user **ubuf)
430 {
431 	return user_regset_copyout(pos, count, kbuf, ubuf,
432 				   &target->thread.fpu,
433 				   0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
434 }
435 
436 /*
437  * Copy the floating-point context to the supplied NT_PRFPREG buffer,
438  * CONFIG_CPU_HAS_MSA variant.  Only lower 64 bits of FP context's
439  * general register slots are copied to buffer slots.  Only general
440  * registers are copied.
441  */
442 static int fpr_get_msa(struct task_struct *target,
443 		       unsigned int *pos, unsigned int *count,
444 		       void **kbuf, void __user **ubuf)
445 {
446 	unsigned int i;
447 	u64 fpr_val;
448 	int err;
449 
450 	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
451 	for (i = 0; i < NUM_FPU_REGS; i++) {
452 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
453 		err = user_regset_copyout(pos, count, kbuf, ubuf,
454 					  &fpr_val, i * sizeof(elf_fpreg_t),
455 					  (i + 1) * sizeof(elf_fpreg_t));
456 		if (err)
457 			return err;
458 	}
459 
460 	return 0;
461 }
462 
463 /*
464  * Copy the floating-point context to the supplied NT_PRFPREG buffer.
465  * Choose the appropriate helper for general registers, and then copy
466  * the FCSR and FIR registers separately.
467  */
468 static int fpr_get(struct task_struct *target,
469 		   const struct user_regset *regset,
470 		   unsigned int pos, unsigned int count,
471 		   void *kbuf, void __user *ubuf)
472 {
473 	const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
474 	const int fir_pos = fcr31_pos + sizeof(u32);
475 	int err;
476 
477 	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
478 		err = fpr_get_fpa(target, &pos, &count, &kbuf, &ubuf);
479 	else
480 		err = fpr_get_msa(target, &pos, &count, &kbuf, &ubuf);
481 	if (err)
482 		return err;
483 
484 	err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
485 				  &target->thread.fpu.fcr31,
486 				  fcr31_pos, fcr31_pos + sizeof(u32));
487 	if (err)
488 		return err;
489 
490 	err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
491 				  &boot_cpu_data.fpu_id,
492 				  fir_pos, fir_pos + sizeof(u32));
493 
494 	return err;
495 }
496 
497 /*
498  * Copy the supplied NT_PRFPREG buffer to the floating-point context,
499  * !CONFIG_CPU_HAS_MSA variant.   Buffer slots correspond 1:1 to FP
500  * context's general register slots.  Only general registers are copied.
501  */
502 static int fpr_set_fpa(struct task_struct *target,
503 		       unsigned int *pos, unsigned int *count,
504 		       const void **kbuf, const void __user **ubuf)
505 {
506 	return user_regset_copyin(pos, count, kbuf, ubuf,
507 				  &target->thread.fpu,
508 				  0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
509 }
510 
511 /*
512  * Copy the supplied NT_PRFPREG buffer to the floating-point context,
513  * CONFIG_CPU_HAS_MSA variant.  Buffer slots are copied to lower 64
514  * bits only of FP context's general register slots.  Only general
515  * registers are copied.
516  */
517 static int fpr_set_msa(struct task_struct *target,
518 		       unsigned int *pos, unsigned int *count,
519 		       const void **kbuf, const void __user **ubuf)
520 {
521 	unsigned int i;
522 	u64 fpr_val;
523 	int err;
524 
525 	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
526 	for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) {
527 		err = user_regset_copyin(pos, count, kbuf, ubuf,
528 					 &fpr_val, i * sizeof(elf_fpreg_t),
529 					 (i + 1) * sizeof(elf_fpreg_t));
530 		if (err)
531 			return err;
532 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
533 	}
534 
535 	return 0;
536 }
537 
538 /*
539  * Copy the supplied NT_PRFPREG buffer to the floating-point context.
540  * Choose the appropriate helper for general registers, and then copy
541  * the FCSR register separately.  Ignore the incoming FIR register
542  * contents though, as the register is read-only.
543  *
544  * We optimize for the case where `count % sizeof(elf_fpreg_t) == 0',
545  * which is supposed to have been guaranteed by the kernel before
546  * calling us, e.g. in `ptrace_regset'.  We enforce that requirement,
547  * so that we can safely avoid preinitializing temporaries for
548  * partial register writes.
549  */
550 static int fpr_set(struct task_struct *target,
551 		   const struct user_regset *regset,
552 		   unsigned int pos, unsigned int count,
553 		   const void *kbuf, const void __user *ubuf)
554 {
555 	const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
556 	const int fir_pos = fcr31_pos + sizeof(u32);
557 	u32 fcr31;
558 	int err;
559 
560 	BUG_ON(count % sizeof(elf_fpreg_t));
561 
562 	if (pos + count > sizeof(elf_fpregset_t))
563 		return -EIO;
564 
565 	init_fp_ctx(target);
566 
567 	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
568 		err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf);
569 	else
570 		err = fpr_set_msa(target, &pos, &count, &kbuf, &ubuf);
571 	if (err)
572 		return err;
573 
574 	if (count > 0) {
575 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
576 					 &fcr31,
577 					 fcr31_pos, fcr31_pos + sizeof(u32));
578 		if (err)
579 			return err;
580 
581 		ptrace_setfcr31(target, fcr31);
582 	}
583 
584 	if (count > 0)
585 		err = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
586 						fir_pos,
587 						fir_pos + sizeof(u32));
588 
589 	return err;
590 }
591 
592 enum mips_regset {
593 	REGSET_GPR,
594 	REGSET_FPR,
595 };
596 
597 struct pt_regs_offset {
598 	const char *name;
599 	int offset;
600 };
601 
602 #define REG_OFFSET_NAME(reg, r) {					\
603 	.name = #reg,							\
604 	.offset = offsetof(struct pt_regs, r)				\
605 }
606 
607 #define REG_OFFSET_END {						\
608 	.name = NULL,							\
609 	.offset = 0							\
610 }
611 
612 static const struct pt_regs_offset regoffset_table[] = {
613 	REG_OFFSET_NAME(r0, regs[0]),
614 	REG_OFFSET_NAME(r1, regs[1]),
615 	REG_OFFSET_NAME(r2, regs[2]),
616 	REG_OFFSET_NAME(r3, regs[3]),
617 	REG_OFFSET_NAME(r4, regs[4]),
618 	REG_OFFSET_NAME(r5, regs[5]),
619 	REG_OFFSET_NAME(r6, regs[6]),
620 	REG_OFFSET_NAME(r7, regs[7]),
621 	REG_OFFSET_NAME(r8, regs[8]),
622 	REG_OFFSET_NAME(r9, regs[9]),
623 	REG_OFFSET_NAME(r10, regs[10]),
624 	REG_OFFSET_NAME(r11, regs[11]),
625 	REG_OFFSET_NAME(r12, regs[12]),
626 	REG_OFFSET_NAME(r13, regs[13]),
627 	REG_OFFSET_NAME(r14, regs[14]),
628 	REG_OFFSET_NAME(r15, regs[15]),
629 	REG_OFFSET_NAME(r16, regs[16]),
630 	REG_OFFSET_NAME(r17, regs[17]),
631 	REG_OFFSET_NAME(r18, regs[18]),
632 	REG_OFFSET_NAME(r19, regs[19]),
633 	REG_OFFSET_NAME(r20, regs[20]),
634 	REG_OFFSET_NAME(r21, regs[21]),
635 	REG_OFFSET_NAME(r22, regs[22]),
636 	REG_OFFSET_NAME(r23, regs[23]),
637 	REG_OFFSET_NAME(r24, regs[24]),
638 	REG_OFFSET_NAME(r25, regs[25]),
639 	REG_OFFSET_NAME(r26, regs[26]),
640 	REG_OFFSET_NAME(r27, regs[27]),
641 	REG_OFFSET_NAME(r28, regs[28]),
642 	REG_OFFSET_NAME(r29, regs[29]),
643 	REG_OFFSET_NAME(r30, regs[30]),
644 	REG_OFFSET_NAME(r31, regs[31]),
645 	REG_OFFSET_NAME(c0_status, cp0_status),
646 	REG_OFFSET_NAME(hi, hi),
647 	REG_OFFSET_NAME(lo, lo),
648 #ifdef CONFIG_CPU_HAS_SMARTMIPS
649 	REG_OFFSET_NAME(acx, acx),
650 #endif
651 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
652 	REG_OFFSET_NAME(c0_cause, cp0_cause),
653 	REG_OFFSET_NAME(c0_epc, cp0_epc),
654 #ifdef CONFIG_CPU_CAVIUM_OCTEON
655 	REG_OFFSET_NAME(mpl0, mpl[0]),
656 	REG_OFFSET_NAME(mpl1, mpl[1]),
657 	REG_OFFSET_NAME(mpl2, mpl[2]),
658 	REG_OFFSET_NAME(mtp0, mtp[0]),
659 	REG_OFFSET_NAME(mtp1, mtp[1]),
660 	REG_OFFSET_NAME(mtp2, mtp[2]),
661 #endif
662 	REG_OFFSET_END,
663 };
664 
665 /**
666  * regs_query_register_offset() - query register offset from its name
667  * @name:       the name of a register
668  *
669  * regs_query_register_offset() returns the offset of a register in struct
670  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
671  */
672 int regs_query_register_offset(const char *name)
673 {
674         const struct pt_regs_offset *roff;
675         for (roff = regoffset_table; roff->name != NULL; roff++)
676                 if (!strcmp(roff->name, name))
677                         return roff->offset;
678         return -EINVAL;
679 }
680 
681 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
682 
683 static const struct user_regset mips_regsets[] = {
684 	[REGSET_GPR] = {
685 		.core_note_type	= NT_PRSTATUS,
686 		.n		= ELF_NGREG,
687 		.size		= sizeof(unsigned int),
688 		.align		= sizeof(unsigned int),
689 		.get		= gpr32_get,
690 		.set		= gpr32_set,
691 	},
692 	[REGSET_FPR] = {
693 		.core_note_type	= NT_PRFPREG,
694 		.n		= ELF_NFPREG,
695 		.size		= sizeof(elf_fpreg_t),
696 		.align		= sizeof(elf_fpreg_t),
697 		.get		= fpr_get,
698 		.set		= fpr_set,
699 	},
700 };
701 
702 static const struct user_regset_view user_mips_view = {
703 	.name		= "mips",
704 	.e_machine	= ELF_ARCH,
705 	.ei_osabi	= ELF_OSABI,
706 	.regsets	= mips_regsets,
707 	.n		= ARRAY_SIZE(mips_regsets),
708 };
709 
710 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
711 
712 #ifdef CONFIG_64BIT
713 
714 static const struct user_regset mips64_regsets[] = {
715 	[REGSET_GPR] = {
716 		.core_note_type	= NT_PRSTATUS,
717 		.n		= ELF_NGREG,
718 		.size		= sizeof(unsigned long),
719 		.align		= sizeof(unsigned long),
720 		.get		= gpr64_get,
721 		.set		= gpr64_set,
722 	},
723 	[REGSET_FPR] = {
724 		.core_note_type	= NT_PRFPREG,
725 		.n		= ELF_NFPREG,
726 		.size		= sizeof(elf_fpreg_t),
727 		.align		= sizeof(elf_fpreg_t),
728 		.get		= fpr_get,
729 		.set		= fpr_set,
730 	},
731 };
732 
733 static const struct user_regset_view user_mips64_view = {
734 	.name		= "mips64",
735 	.e_machine	= ELF_ARCH,
736 	.ei_osabi	= ELF_OSABI,
737 	.regsets	= mips64_regsets,
738 	.n		= ARRAY_SIZE(mips64_regsets),
739 };
740 
741 #ifdef CONFIG_MIPS32_N32
742 
743 static const struct user_regset_view user_mipsn32_view = {
744 	.name		= "mipsn32",
745 	.e_flags	= EF_MIPS_ABI2,
746 	.e_machine	= ELF_ARCH,
747 	.ei_osabi	= ELF_OSABI,
748 	.regsets	= mips64_regsets,
749 	.n		= ARRAY_SIZE(mips64_regsets),
750 };
751 
752 #endif /* CONFIG_MIPS32_N32 */
753 
754 #endif /* CONFIG_64BIT */
755 
756 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
757 {
758 #ifdef CONFIG_32BIT
759 	return &user_mips_view;
760 #else
761 #ifdef CONFIG_MIPS32_O32
762 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
763 		return &user_mips_view;
764 #endif
765 #ifdef CONFIG_MIPS32_N32
766 	if (test_tsk_thread_flag(task, TIF_32BIT_ADDR))
767 		return &user_mipsn32_view;
768 #endif
769 	return &user_mips64_view;
770 #endif
771 }
772 
773 long arch_ptrace(struct task_struct *child, long request,
774 		 unsigned long addr, unsigned long data)
775 {
776 	int ret;
777 	void __user *addrp = (void __user *) addr;
778 	void __user *datavp = (void __user *) data;
779 	unsigned long __user *datalp = (void __user *) data;
780 
781 	switch (request) {
782 	/* when I and D space are separate, these will need to be fixed. */
783 	case PTRACE_PEEKTEXT: /* read word at location addr. */
784 	case PTRACE_PEEKDATA:
785 		ret = generic_ptrace_peekdata(child, addr, data);
786 		break;
787 
788 	/* Read the word at location addr in the USER area. */
789 	case PTRACE_PEEKUSR: {
790 		struct pt_regs *regs;
791 		union fpureg *fregs;
792 		unsigned long tmp = 0;
793 
794 		regs = task_pt_regs(child);
795 		ret = 0;  /* Default return value. */
796 
797 		switch (addr) {
798 		case 0 ... 31:
799 			tmp = regs->regs[addr];
800 			break;
801 		case FPR_BASE ... FPR_BASE + 31:
802 			if (!tsk_used_math(child)) {
803 				/* FP not yet used */
804 				tmp = -1;
805 				break;
806 			}
807 			fregs = get_fpu_regs(child);
808 
809 #ifdef CONFIG_32BIT
810 			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
811 				/*
812 				 * The odd registers are actually the high
813 				 * order bits of the values stored in the even
814 				 * registers - unless we're using r2k_switch.S.
815 				 */
816 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
817 						addr & 1);
818 				break;
819 			}
820 #endif
821 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
822 			break;
823 		case PC:
824 			tmp = regs->cp0_epc;
825 			break;
826 		case CAUSE:
827 			tmp = regs->cp0_cause;
828 			break;
829 		case BADVADDR:
830 			tmp = regs->cp0_badvaddr;
831 			break;
832 		case MMHI:
833 			tmp = regs->hi;
834 			break;
835 		case MMLO:
836 			tmp = regs->lo;
837 			break;
838 #ifdef CONFIG_CPU_HAS_SMARTMIPS
839 		case ACX:
840 			tmp = regs->acx;
841 			break;
842 #endif
843 		case FPC_CSR:
844 			tmp = child->thread.fpu.fcr31;
845 			break;
846 		case FPC_EIR:
847 			/* implementation / version register */
848 			tmp = boot_cpu_data.fpu_id;
849 			break;
850 		case DSP_BASE ... DSP_BASE + 5: {
851 			dspreg_t *dregs;
852 
853 			if (!cpu_has_dsp) {
854 				tmp = 0;
855 				ret = -EIO;
856 				goto out;
857 			}
858 			dregs = __get_dsp_regs(child);
859 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
860 			break;
861 		}
862 		case DSP_CONTROL:
863 			if (!cpu_has_dsp) {
864 				tmp = 0;
865 				ret = -EIO;
866 				goto out;
867 			}
868 			tmp = child->thread.dsp.dspcontrol;
869 			break;
870 		default:
871 			tmp = 0;
872 			ret = -EIO;
873 			goto out;
874 		}
875 		ret = put_user(tmp, datalp);
876 		break;
877 	}
878 
879 	/* when I and D space are separate, this will have to be fixed. */
880 	case PTRACE_POKETEXT: /* write the word at location addr. */
881 	case PTRACE_POKEDATA:
882 		ret = generic_ptrace_pokedata(child, addr, data);
883 		break;
884 
885 	case PTRACE_POKEUSR: {
886 		struct pt_regs *regs;
887 		ret = 0;
888 		regs = task_pt_regs(child);
889 
890 		switch (addr) {
891 		case 0 ... 31:
892 			regs->regs[addr] = data;
893 			/* System call number may have been changed */
894 			if (addr == 2)
895 				mips_syscall_update_nr(child, regs);
896 			else if (addr == 4 &&
897 				 mips_syscall_is_indirect(child, regs))
898 				mips_syscall_update_nr(child, regs);
899 			break;
900 		case FPR_BASE ... FPR_BASE + 31: {
901 			union fpureg *fregs = get_fpu_regs(child);
902 
903 			init_fp_ctx(child);
904 #ifdef CONFIG_32BIT
905 			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
906 				/*
907 				 * The odd registers are actually the high
908 				 * order bits of the values stored in the even
909 				 * registers - unless we're using r2k_switch.S.
910 				 */
911 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
912 					  addr & 1, data);
913 				break;
914 			}
915 #endif
916 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
917 			break;
918 		}
919 		case PC:
920 			regs->cp0_epc = data;
921 			break;
922 		case MMHI:
923 			regs->hi = data;
924 			break;
925 		case MMLO:
926 			regs->lo = data;
927 			break;
928 #ifdef CONFIG_CPU_HAS_SMARTMIPS
929 		case ACX:
930 			regs->acx = data;
931 			break;
932 #endif
933 		case FPC_CSR:
934 			init_fp_ctx(child);
935 			ptrace_setfcr31(child, data);
936 			break;
937 		case DSP_BASE ... DSP_BASE + 5: {
938 			dspreg_t *dregs;
939 
940 			if (!cpu_has_dsp) {
941 				ret = -EIO;
942 				break;
943 			}
944 
945 			dregs = __get_dsp_regs(child);
946 			dregs[addr - DSP_BASE] = data;
947 			break;
948 		}
949 		case DSP_CONTROL:
950 			if (!cpu_has_dsp) {
951 				ret = -EIO;
952 				break;
953 			}
954 			child->thread.dsp.dspcontrol = data;
955 			break;
956 		default:
957 			/* The rest are not allowed. */
958 			ret = -EIO;
959 			break;
960 		}
961 		break;
962 		}
963 
964 	case PTRACE_GETREGS:
965 		ret = ptrace_getregs(child, datavp);
966 		break;
967 
968 	case PTRACE_SETREGS:
969 		ret = ptrace_setregs(child, datavp);
970 		break;
971 
972 	case PTRACE_GETFPREGS:
973 		ret = ptrace_getfpregs(child, datavp);
974 		break;
975 
976 	case PTRACE_SETFPREGS:
977 		ret = ptrace_setfpregs(child, datavp);
978 		break;
979 
980 	case PTRACE_GET_THREAD_AREA:
981 		ret = put_user(task_thread_info(child)->tp_value, datalp);
982 		break;
983 
984 	case PTRACE_GET_WATCH_REGS:
985 		ret = ptrace_get_watch_regs(child, addrp);
986 		break;
987 
988 	case PTRACE_SET_WATCH_REGS:
989 		ret = ptrace_set_watch_regs(child, addrp);
990 		break;
991 
992 	default:
993 		ret = ptrace_request(child, request, addr, data);
994 		break;
995 	}
996  out:
997 	return ret;
998 }
999 
1000 /*
1001  * Notification of system call entry/exit
1002  * - triggered by current->work.syscall_trace
1003  */
1004 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
1005 {
1006 	user_exit();
1007 
1008 	current_thread_info()->syscall = syscall;
1009 
1010 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
1011 		if (tracehook_report_syscall_entry(regs))
1012 			return -1;
1013 		syscall = current_thread_info()->syscall;
1014 	}
1015 
1016 #ifdef CONFIG_SECCOMP
1017 	if (unlikely(test_thread_flag(TIF_SECCOMP))) {
1018 		int ret, i;
1019 		struct seccomp_data sd;
1020 		unsigned long args[6];
1021 
1022 		sd.nr = syscall;
1023 		sd.arch = syscall_get_arch();
1024 		syscall_get_arguments(current, regs, 0, 6, args);
1025 		for (i = 0; i < 6; i++)
1026 			sd.args[i] = args[i];
1027 		sd.instruction_pointer = KSTK_EIP(current);
1028 
1029 		ret = __secure_computing(&sd);
1030 		if (ret == -1)
1031 			return ret;
1032 		syscall = current_thread_info()->syscall;
1033 	}
1034 #endif
1035 
1036 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1037 		trace_sys_enter(regs, regs->regs[2]);
1038 
1039 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
1040 			    regs->regs[6], regs->regs[7]);
1041 
1042 	/*
1043 	 * Negative syscall numbers are mistaken for rejected syscalls, but
1044 	 * won't have had the return value set appropriately, so we do so now.
1045 	 */
1046 	if (syscall < 0)
1047 		syscall_set_return_value(current, regs, -ENOSYS, 0);
1048 	return syscall;
1049 }
1050 
1051 /*
1052  * Notification of system call entry/exit
1053  * - triggered by current->work.syscall_trace
1054  */
1055 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
1056 {
1057         /*
1058 	 * We may come here right after calling schedule_user()
1059 	 * or do_notify_resume(), in which case we can be in RCU
1060 	 * user mode.
1061 	 */
1062 	user_exit();
1063 
1064 	audit_syscall_exit(regs);
1065 
1066 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1067 		trace_sys_exit(regs, regs_return_value(regs));
1068 
1069 	if (test_thread_flag(TIF_SYSCALL_TRACE))
1070 		tracehook_report_syscall_exit(regs, 0);
1071 
1072 	user_enter();
1073 }
1074