xref: /linux/arch/mips/kernel/ptrace.c (revision 4246b92cf9fb32da8d8b060c92d8302797c6fbea)
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 	return 0;
148 }
149 
150 int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
151 {
152 	int i;
153 
154 	if (!access_ok(VERIFY_WRITE, data, 33 * 8))
155 		return -EIO;
156 
157 	if (tsk_used_math(child)) {
158 		union fpureg *fregs = get_fpu_regs(child);
159 		for (i = 0; i < 32; i++)
160 			__put_user(get_fpr64(&fregs[i], 0),
161 				   i + (__u64 __user *)data);
162 	} else {
163 		for (i = 0; i < 32; i++)
164 			__put_user((__u64) -1, i + (__u64 __user *) data);
165 	}
166 
167 	__put_user(child->thread.fpu.fcr31, data + 64);
168 	__put_user(boot_cpu_data.fpu_id, data + 65);
169 
170 	return 0;
171 }
172 
173 int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
174 {
175 	union fpureg *fregs;
176 	u64 fpr_val;
177 	u32 value;
178 	int i;
179 
180 	if (!access_ok(VERIFY_READ, data, 33 * 8))
181 		return -EIO;
182 
183 	init_fp_ctx(child);
184 	fregs = get_fpu_regs(child);
185 
186 	for (i = 0; i < 32; i++) {
187 		__get_user(fpr_val, i + (__u64 __user *)data);
188 		set_fpr64(&fregs[i], 0, fpr_val);
189 	}
190 
191 	__get_user(value, data + 64);
192 	ptrace_setfcr31(child, value);
193 
194 	/* FIR may not be written.  */
195 
196 	return 0;
197 }
198 
199 int ptrace_get_watch_regs(struct task_struct *child,
200 			  struct pt_watch_regs __user *addr)
201 {
202 	enum pt_watch_style style;
203 	int i;
204 
205 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
206 		return -EIO;
207 	if (!access_ok(VERIFY_WRITE, addr, sizeof(struct pt_watch_regs)))
208 		return -EIO;
209 
210 #ifdef CONFIG_32BIT
211 	style = pt_watch_style_mips32;
212 #define WATCH_STYLE mips32
213 #else
214 	style = pt_watch_style_mips64;
215 #define WATCH_STYLE mips64
216 #endif
217 
218 	__put_user(style, &addr->style);
219 	__put_user(boot_cpu_data.watch_reg_use_cnt,
220 		   &addr->WATCH_STYLE.num_valid);
221 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
222 		__put_user(child->thread.watch.mips3264.watchlo[i],
223 			   &addr->WATCH_STYLE.watchlo[i]);
224 		__put_user(child->thread.watch.mips3264.watchhi[i] &
225 				(MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW),
226 			   &addr->WATCH_STYLE.watchhi[i]);
227 		__put_user(boot_cpu_data.watch_reg_masks[i],
228 			   &addr->WATCH_STYLE.watch_masks[i]);
229 	}
230 	for (; i < 8; i++) {
231 		__put_user(0, &addr->WATCH_STYLE.watchlo[i]);
232 		__put_user(0, &addr->WATCH_STYLE.watchhi[i]);
233 		__put_user(0, &addr->WATCH_STYLE.watch_masks[i]);
234 	}
235 
236 	return 0;
237 }
238 
239 int ptrace_set_watch_regs(struct task_struct *child,
240 			  struct pt_watch_regs __user *addr)
241 {
242 	int i;
243 	int watch_active = 0;
244 	unsigned long lt[NUM_WATCH_REGS];
245 	u16 ht[NUM_WATCH_REGS];
246 
247 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
248 		return -EIO;
249 	if (!access_ok(VERIFY_READ, addr, sizeof(struct pt_watch_regs)))
250 		return -EIO;
251 	/* Check the values. */
252 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
253 		__get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]);
254 #ifdef CONFIG_32BIT
255 		if (lt[i] & __UA_LIMIT)
256 			return -EINVAL;
257 #else
258 		if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) {
259 			if (lt[i] & 0xffffffff80000000UL)
260 				return -EINVAL;
261 		} else {
262 			if (lt[i] & __UA_LIMIT)
263 				return -EINVAL;
264 		}
265 #endif
266 		__get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]);
267 		if (ht[i] & ~MIPS_WATCHHI_MASK)
268 			return -EINVAL;
269 	}
270 	/* Install them. */
271 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
272 		if (lt[i] & MIPS_WATCHLO_IRW)
273 			watch_active = 1;
274 		child->thread.watch.mips3264.watchlo[i] = lt[i];
275 		/* Set the G bit. */
276 		child->thread.watch.mips3264.watchhi[i] = ht[i];
277 	}
278 
279 	if (watch_active)
280 		set_tsk_thread_flag(child, TIF_LOAD_WATCH);
281 	else
282 		clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
283 
284 	return 0;
285 }
286 
287 /* regset get/set implementations */
288 
289 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
290 
291 static int gpr32_get(struct task_struct *target,
292 		     const struct user_regset *regset,
293 		     unsigned int pos, unsigned int count,
294 		     void *kbuf, void __user *ubuf)
295 {
296 	struct pt_regs *regs = task_pt_regs(target);
297 	u32 uregs[ELF_NGREG] = {};
298 
299 	mips_dump_regs32(uregs, regs);
300 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
301 				   sizeof(uregs));
302 }
303 
304 static int gpr32_set(struct task_struct *target,
305 		     const struct user_regset *regset,
306 		     unsigned int pos, unsigned int count,
307 		     const void *kbuf, const void __user *ubuf)
308 {
309 	struct pt_regs *regs = task_pt_regs(target);
310 	u32 uregs[ELF_NGREG];
311 	unsigned start, num_regs, i;
312 	int err;
313 
314 	start = pos / sizeof(u32);
315 	num_regs = count / sizeof(u32);
316 
317 	if (start + num_regs > ELF_NGREG)
318 		return -EIO;
319 
320 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
321 				 sizeof(uregs));
322 	if (err)
323 		return err;
324 
325 	for (i = start; i < num_regs; i++) {
326 		/*
327 		 * Cast all values to signed here so that if this is a 64-bit
328 		 * kernel, the supplied 32-bit values will be sign extended.
329 		 */
330 		switch (i) {
331 		case MIPS32_EF_R1 ... MIPS32_EF_R25:
332 			/* k0/k1 are ignored. */
333 		case MIPS32_EF_R28 ... MIPS32_EF_R31:
334 			regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
335 			break;
336 		case MIPS32_EF_LO:
337 			regs->lo = (s32)uregs[i];
338 			break;
339 		case MIPS32_EF_HI:
340 			regs->hi = (s32)uregs[i];
341 			break;
342 		case MIPS32_EF_CP0_EPC:
343 			regs->cp0_epc = (s32)uregs[i];
344 			break;
345 		}
346 	}
347 
348 	return 0;
349 }
350 
351 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
352 
353 #ifdef CONFIG_64BIT
354 
355 static int gpr64_get(struct task_struct *target,
356 		     const struct user_regset *regset,
357 		     unsigned int pos, unsigned int count,
358 		     void *kbuf, void __user *ubuf)
359 {
360 	struct pt_regs *regs = task_pt_regs(target);
361 	u64 uregs[ELF_NGREG] = {};
362 
363 	mips_dump_regs64(uregs, regs);
364 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
365 				   sizeof(uregs));
366 }
367 
368 static int gpr64_set(struct task_struct *target,
369 		     const struct user_regset *regset,
370 		     unsigned int pos, unsigned int count,
371 		     const void *kbuf, const void __user *ubuf)
372 {
373 	struct pt_regs *regs = task_pt_regs(target);
374 	u64 uregs[ELF_NGREG];
375 	unsigned start, num_regs, i;
376 	int err;
377 
378 	start = pos / sizeof(u64);
379 	num_regs = count / sizeof(u64);
380 
381 	if (start + num_regs > ELF_NGREG)
382 		return -EIO;
383 
384 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
385 				 sizeof(uregs));
386 	if (err)
387 		return err;
388 
389 	for (i = start; i < num_regs; i++) {
390 		switch (i) {
391 		case MIPS64_EF_R1 ... MIPS64_EF_R25:
392 			/* k0/k1 are ignored. */
393 		case MIPS64_EF_R28 ... MIPS64_EF_R31:
394 			regs->regs[i - MIPS64_EF_R0] = uregs[i];
395 			break;
396 		case MIPS64_EF_LO:
397 			regs->lo = uregs[i];
398 			break;
399 		case MIPS64_EF_HI:
400 			regs->hi = uregs[i];
401 			break;
402 		case MIPS64_EF_CP0_EPC:
403 			regs->cp0_epc = uregs[i];
404 			break;
405 		}
406 	}
407 
408 	return 0;
409 }
410 
411 #endif /* CONFIG_64BIT */
412 
413 static int fpr_get(struct task_struct *target,
414 		   const struct user_regset *regset,
415 		   unsigned int pos, unsigned int count,
416 		   void *kbuf, void __user *ubuf)
417 {
418 	unsigned i;
419 	int err;
420 	u64 fpr_val;
421 
422 	/* XXX fcr31  */
423 
424 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
425 		return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
426 					   &target->thread.fpu,
427 					   0, sizeof(elf_fpregset_t));
428 
429 	for (i = 0; i < NUM_FPU_REGS; i++) {
430 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
431 		err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
432 					  &fpr_val, i * sizeof(elf_fpreg_t),
433 					  (i + 1) * sizeof(elf_fpreg_t));
434 		if (err)
435 			return err;
436 	}
437 
438 	return 0;
439 }
440 
441 static int fpr_set(struct task_struct *target,
442 		   const struct user_regset *regset,
443 		   unsigned int pos, unsigned int count,
444 		   const void *kbuf, const void __user *ubuf)
445 {
446 	unsigned i;
447 	int err;
448 	u64 fpr_val;
449 
450 	/* XXX fcr31  */
451 
452 	init_fp_ctx(target);
453 
454 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
455 		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
456 					  &target->thread.fpu,
457 					  0, sizeof(elf_fpregset_t));
458 
459 	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
460 	for (i = 0; i < NUM_FPU_REGS && count >= sizeof(elf_fpreg_t); i++) {
461 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
462 					 &fpr_val, i * sizeof(elf_fpreg_t),
463 					 (i + 1) * sizeof(elf_fpreg_t));
464 		if (err)
465 			return err;
466 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
467 	}
468 
469 	return 0;
470 }
471 
472 enum mips_regset {
473 	REGSET_GPR,
474 	REGSET_FPR,
475 };
476 
477 struct pt_regs_offset {
478 	const char *name;
479 	int offset;
480 };
481 
482 #define REG_OFFSET_NAME(reg, r) {					\
483 	.name = #reg,							\
484 	.offset = offsetof(struct pt_regs, r)				\
485 }
486 
487 #define REG_OFFSET_END {						\
488 	.name = NULL,							\
489 	.offset = 0							\
490 }
491 
492 static const struct pt_regs_offset regoffset_table[] = {
493 	REG_OFFSET_NAME(r0, regs[0]),
494 	REG_OFFSET_NAME(r1, regs[1]),
495 	REG_OFFSET_NAME(r2, regs[2]),
496 	REG_OFFSET_NAME(r3, regs[3]),
497 	REG_OFFSET_NAME(r4, regs[4]),
498 	REG_OFFSET_NAME(r5, regs[5]),
499 	REG_OFFSET_NAME(r6, regs[6]),
500 	REG_OFFSET_NAME(r7, regs[7]),
501 	REG_OFFSET_NAME(r8, regs[8]),
502 	REG_OFFSET_NAME(r9, regs[9]),
503 	REG_OFFSET_NAME(r10, regs[10]),
504 	REG_OFFSET_NAME(r11, regs[11]),
505 	REG_OFFSET_NAME(r12, regs[12]),
506 	REG_OFFSET_NAME(r13, regs[13]),
507 	REG_OFFSET_NAME(r14, regs[14]),
508 	REG_OFFSET_NAME(r15, regs[15]),
509 	REG_OFFSET_NAME(r16, regs[16]),
510 	REG_OFFSET_NAME(r17, regs[17]),
511 	REG_OFFSET_NAME(r18, regs[18]),
512 	REG_OFFSET_NAME(r19, regs[19]),
513 	REG_OFFSET_NAME(r20, regs[20]),
514 	REG_OFFSET_NAME(r21, regs[21]),
515 	REG_OFFSET_NAME(r22, regs[22]),
516 	REG_OFFSET_NAME(r23, regs[23]),
517 	REG_OFFSET_NAME(r24, regs[24]),
518 	REG_OFFSET_NAME(r25, regs[25]),
519 	REG_OFFSET_NAME(r26, regs[26]),
520 	REG_OFFSET_NAME(r27, regs[27]),
521 	REG_OFFSET_NAME(r28, regs[28]),
522 	REG_OFFSET_NAME(r29, regs[29]),
523 	REG_OFFSET_NAME(r30, regs[30]),
524 	REG_OFFSET_NAME(r31, regs[31]),
525 	REG_OFFSET_NAME(c0_status, cp0_status),
526 	REG_OFFSET_NAME(hi, hi),
527 	REG_OFFSET_NAME(lo, lo),
528 #ifdef CONFIG_CPU_HAS_SMARTMIPS
529 	REG_OFFSET_NAME(acx, acx),
530 #endif
531 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
532 	REG_OFFSET_NAME(c0_cause, cp0_cause),
533 	REG_OFFSET_NAME(c0_epc, cp0_epc),
534 #ifdef CONFIG_CPU_CAVIUM_OCTEON
535 	REG_OFFSET_NAME(mpl0, mpl[0]),
536 	REG_OFFSET_NAME(mpl1, mpl[1]),
537 	REG_OFFSET_NAME(mpl2, mpl[2]),
538 	REG_OFFSET_NAME(mtp0, mtp[0]),
539 	REG_OFFSET_NAME(mtp1, mtp[1]),
540 	REG_OFFSET_NAME(mtp2, mtp[2]),
541 #endif
542 	REG_OFFSET_END,
543 };
544 
545 /**
546  * regs_query_register_offset() - query register offset from its name
547  * @name:       the name of a register
548  *
549  * regs_query_register_offset() returns the offset of a register in struct
550  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
551  */
552 int regs_query_register_offset(const char *name)
553 {
554         const struct pt_regs_offset *roff;
555         for (roff = regoffset_table; roff->name != NULL; roff++)
556                 if (!strcmp(roff->name, name))
557                         return roff->offset;
558         return -EINVAL;
559 }
560 
561 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
562 
563 static const struct user_regset mips_regsets[] = {
564 	[REGSET_GPR] = {
565 		.core_note_type	= NT_PRSTATUS,
566 		.n		= ELF_NGREG,
567 		.size		= sizeof(unsigned int),
568 		.align		= sizeof(unsigned int),
569 		.get		= gpr32_get,
570 		.set		= gpr32_set,
571 	},
572 	[REGSET_FPR] = {
573 		.core_note_type	= NT_PRFPREG,
574 		.n		= ELF_NFPREG,
575 		.size		= sizeof(elf_fpreg_t),
576 		.align		= sizeof(elf_fpreg_t),
577 		.get		= fpr_get,
578 		.set		= fpr_set,
579 	},
580 };
581 
582 static const struct user_regset_view user_mips_view = {
583 	.name		= "mips",
584 	.e_machine	= ELF_ARCH,
585 	.ei_osabi	= ELF_OSABI,
586 	.regsets	= mips_regsets,
587 	.n		= ARRAY_SIZE(mips_regsets),
588 };
589 
590 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
591 
592 #ifdef CONFIG_64BIT
593 
594 static const struct user_regset mips64_regsets[] = {
595 	[REGSET_GPR] = {
596 		.core_note_type	= NT_PRSTATUS,
597 		.n		= ELF_NGREG,
598 		.size		= sizeof(unsigned long),
599 		.align		= sizeof(unsigned long),
600 		.get		= gpr64_get,
601 		.set		= gpr64_set,
602 	},
603 	[REGSET_FPR] = {
604 		.core_note_type	= NT_PRFPREG,
605 		.n		= ELF_NFPREG,
606 		.size		= sizeof(elf_fpreg_t),
607 		.align		= sizeof(elf_fpreg_t),
608 		.get		= fpr_get,
609 		.set		= fpr_set,
610 	},
611 };
612 
613 static const struct user_regset_view user_mips64_view = {
614 	.name		= "mips64",
615 	.e_machine	= ELF_ARCH,
616 	.ei_osabi	= ELF_OSABI,
617 	.regsets	= mips64_regsets,
618 	.n		= ARRAY_SIZE(mips64_regsets),
619 };
620 
621 #endif /* CONFIG_64BIT */
622 
623 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
624 {
625 #ifdef CONFIG_32BIT
626 	return &user_mips_view;
627 #else
628 #ifdef CONFIG_MIPS32_O32
629 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
630 		return &user_mips_view;
631 #endif
632 	return &user_mips64_view;
633 #endif
634 }
635 
636 long arch_ptrace(struct task_struct *child, long request,
637 		 unsigned long addr, unsigned long data)
638 {
639 	int ret;
640 	void __user *addrp = (void __user *) addr;
641 	void __user *datavp = (void __user *) data;
642 	unsigned long __user *datalp = (void __user *) data;
643 
644 	switch (request) {
645 	/* when I and D space are separate, these will need to be fixed. */
646 	case PTRACE_PEEKTEXT: /* read word at location addr. */
647 	case PTRACE_PEEKDATA:
648 		ret = generic_ptrace_peekdata(child, addr, data);
649 		break;
650 
651 	/* Read the word at location addr in the USER area. */
652 	case PTRACE_PEEKUSR: {
653 		struct pt_regs *regs;
654 		union fpureg *fregs;
655 		unsigned long tmp = 0;
656 
657 		regs = task_pt_regs(child);
658 		ret = 0;  /* Default return value. */
659 
660 		switch (addr) {
661 		case 0 ... 31:
662 			tmp = regs->regs[addr];
663 			break;
664 		case FPR_BASE ... FPR_BASE + 31:
665 			if (!tsk_used_math(child)) {
666 				/* FP not yet used */
667 				tmp = -1;
668 				break;
669 			}
670 			fregs = get_fpu_regs(child);
671 
672 #ifdef CONFIG_32BIT
673 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
674 				/*
675 				 * The odd registers are actually the high
676 				 * order bits of the values stored in the even
677 				 * registers - unless we're using r2k_switch.S.
678 				 */
679 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
680 						addr & 1);
681 				break;
682 			}
683 #endif
684 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
685 			break;
686 		case PC:
687 			tmp = regs->cp0_epc;
688 			break;
689 		case CAUSE:
690 			tmp = regs->cp0_cause;
691 			break;
692 		case BADVADDR:
693 			tmp = regs->cp0_badvaddr;
694 			break;
695 		case MMHI:
696 			tmp = regs->hi;
697 			break;
698 		case MMLO:
699 			tmp = regs->lo;
700 			break;
701 #ifdef CONFIG_CPU_HAS_SMARTMIPS
702 		case ACX:
703 			tmp = regs->acx;
704 			break;
705 #endif
706 		case FPC_CSR:
707 			tmp = child->thread.fpu.fcr31;
708 			break;
709 		case FPC_EIR:
710 			/* implementation / version register */
711 			tmp = boot_cpu_data.fpu_id;
712 			break;
713 		case DSP_BASE ... DSP_BASE + 5: {
714 			dspreg_t *dregs;
715 
716 			if (!cpu_has_dsp) {
717 				tmp = 0;
718 				ret = -EIO;
719 				goto out;
720 			}
721 			dregs = __get_dsp_regs(child);
722 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
723 			break;
724 		}
725 		case DSP_CONTROL:
726 			if (!cpu_has_dsp) {
727 				tmp = 0;
728 				ret = -EIO;
729 				goto out;
730 			}
731 			tmp = child->thread.dsp.dspcontrol;
732 			break;
733 		default:
734 			tmp = 0;
735 			ret = -EIO;
736 			goto out;
737 		}
738 		ret = put_user(tmp, datalp);
739 		break;
740 	}
741 
742 	/* when I and D space are separate, this will have to be fixed. */
743 	case PTRACE_POKETEXT: /* write the word at location addr. */
744 	case PTRACE_POKEDATA:
745 		ret = generic_ptrace_pokedata(child, addr, data);
746 		break;
747 
748 	case PTRACE_POKEUSR: {
749 		struct pt_regs *regs;
750 		ret = 0;
751 		regs = task_pt_regs(child);
752 
753 		switch (addr) {
754 		case 0 ... 31:
755 			regs->regs[addr] = data;
756 			break;
757 		case FPR_BASE ... FPR_BASE + 31: {
758 			union fpureg *fregs = get_fpu_regs(child);
759 
760 			init_fp_ctx(child);
761 #ifdef CONFIG_32BIT
762 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
763 				/*
764 				 * The odd registers are actually the high
765 				 * order bits of the values stored in the even
766 				 * registers - unless we're using r2k_switch.S.
767 				 */
768 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
769 					  addr & 1, data);
770 				break;
771 			}
772 #endif
773 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
774 			break;
775 		}
776 		case PC:
777 			regs->cp0_epc = data;
778 			break;
779 		case MMHI:
780 			regs->hi = data;
781 			break;
782 		case MMLO:
783 			regs->lo = data;
784 			break;
785 #ifdef CONFIG_CPU_HAS_SMARTMIPS
786 		case ACX:
787 			regs->acx = data;
788 			break;
789 #endif
790 		case FPC_CSR:
791 			init_fp_ctx(child);
792 			ptrace_setfcr31(child, data);
793 			break;
794 		case DSP_BASE ... DSP_BASE + 5: {
795 			dspreg_t *dregs;
796 
797 			if (!cpu_has_dsp) {
798 				ret = -EIO;
799 				break;
800 			}
801 
802 			dregs = __get_dsp_regs(child);
803 			dregs[addr - DSP_BASE] = data;
804 			break;
805 		}
806 		case DSP_CONTROL:
807 			if (!cpu_has_dsp) {
808 				ret = -EIO;
809 				break;
810 			}
811 			child->thread.dsp.dspcontrol = data;
812 			break;
813 		default:
814 			/* The rest are not allowed. */
815 			ret = -EIO;
816 			break;
817 		}
818 		break;
819 		}
820 
821 	case PTRACE_GETREGS:
822 		ret = ptrace_getregs(child, datavp);
823 		break;
824 
825 	case PTRACE_SETREGS:
826 		ret = ptrace_setregs(child, datavp);
827 		break;
828 
829 	case PTRACE_GETFPREGS:
830 		ret = ptrace_getfpregs(child, datavp);
831 		break;
832 
833 	case PTRACE_SETFPREGS:
834 		ret = ptrace_setfpregs(child, datavp);
835 		break;
836 
837 	case PTRACE_GET_THREAD_AREA:
838 		ret = put_user(task_thread_info(child)->tp_value, datalp);
839 		break;
840 
841 	case PTRACE_GET_WATCH_REGS:
842 		ret = ptrace_get_watch_regs(child, addrp);
843 		break;
844 
845 	case PTRACE_SET_WATCH_REGS:
846 		ret = ptrace_set_watch_regs(child, addrp);
847 		break;
848 
849 	default:
850 		ret = ptrace_request(child, request, addr, data);
851 		break;
852 	}
853  out:
854 	return ret;
855 }
856 
857 /*
858  * Notification of system call entry/exit
859  * - triggered by current->work.syscall_trace
860  */
861 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
862 {
863 	user_exit();
864 
865 	current_thread_info()->syscall = syscall;
866 
867 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
868 	    tracehook_report_syscall_entry(regs))
869 		return -1;
870 
871 #ifdef CONFIG_SECCOMP
872 	if (unlikely(test_thread_flag(TIF_SECCOMP))) {
873 		int ret, i;
874 		struct seccomp_data sd;
875 		unsigned long args[6];
876 
877 		sd.nr = syscall;
878 		sd.arch = syscall_get_arch();
879 		syscall_get_arguments(current, regs, 0, 6, args);
880 		for (i = 0; i < 6; i++)
881 			sd.args[i] = args[i];
882 		sd.instruction_pointer = KSTK_EIP(current);
883 
884 		ret = __secure_computing(&sd);
885 		if (ret == -1)
886 			return ret;
887 	}
888 #endif
889 
890 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
891 		trace_sys_enter(regs, regs->regs[2]);
892 
893 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
894 			    regs->regs[6], regs->regs[7]);
895 
896 	/*
897 	 * Negative syscall numbers are mistaken for rejected syscalls, but
898 	 * won't have had the return value set appropriately, so we do so now.
899 	 */
900 	if (syscall < 0)
901 		syscall_set_return_value(current, regs, -ENOSYS, 0);
902 	return syscall;
903 }
904 
905 /*
906  * Notification of system call entry/exit
907  * - triggered by current->work.syscall_trace
908  */
909 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
910 {
911         /*
912 	 * We may come here right after calling schedule_user()
913 	 * or do_notify_resume(), in which case we can be in RCU
914 	 * user mode.
915 	 */
916 	user_exit();
917 
918 	audit_syscall_exit(regs);
919 
920 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
921 		trace_sys_exit(regs, regs_return_value(regs));
922 
923 	if (test_thread_flag(TIF_SYSCALL_TRACE))
924 		tracehook_report_syscall_exit(regs, 0);
925 
926 	user_enter();
927 }
928