xref: /linux/arch/mips/kernel/ptrace.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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/mm.h>
23 #include <linux/errno.h>
24 #include <linux/ptrace.h>
25 #include <linux/regset.h>
26 #include <linux/smp.h>
27 #include <linux/security.h>
28 #include <linux/stddef.h>
29 #include <linux/tracehook.h>
30 #include <linux/audit.h>
31 #include <linux/seccomp.h>
32 #include <linux/ftrace.h>
33 
34 #include <asm/byteorder.h>
35 #include <asm/cpu.h>
36 #include <asm/cpu-info.h>
37 #include <asm/dsp.h>
38 #include <asm/fpu.h>
39 #include <asm/mipsregs.h>
40 #include <asm/mipsmtregs.h>
41 #include <asm/pgtable.h>
42 #include <asm/page.h>
43 #include <asm/syscall.h>
44 #include <asm/uaccess.h>
45 #include <asm/bootinfo.h>
46 #include <asm/reg.h>
47 
48 #define CREATE_TRACE_POINTS
49 #include <trace/events/syscalls.h>
50 
51 static void init_fp_ctx(struct task_struct *target)
52 {
53 	/* If FP has been used then the target already has context */
54 	if (tsk_used_math(target))
55 		return;
56 
57 	/* Begin with data registers set to all 1s... */
58 	memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));
59 
60 	/* ...and FCSR zeroed */
61 	target->thread.fpu.fcr31 = 0;
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  * Read a general register set.	 We always use the 64-bit format, even
84  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
85  * Registers are sign extended to fill the available space.
86  */
87 int ptrace_getregs(struct task_struct *child, struct user_pt_regs __user *data)
88 {
89 	struct pt_regs *regs;
90 	int i;
91 
92 	if (!access_ok(VERIFY_WRITE, data, 38 * 8))
93 		return -EIO;
94 
95 	regs = task_pt_regs(child);
96 
97 	for (i = 0; i < 32; i++)
98 		__put_user((long)regs->regs[i], (__s64 __user *)&data->regs[i]);
99 	__put_user((long)regs->lo, (__s64 __user *)&data->lo);
100 	__put_user((long)regs->hi, (__s64 __user *)&data->hi);
101 	__put_user((long)regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
102 	__put_user((long)regs->cp0_badvaddr, (__s64 __user *)&data->cp0_badvaddr);
103 	__put_user((long)regs->cp0_status, (__s64 __user *)&data->cp0_status);
104 	__put_user((long)regs->cp0_cause, (__s64 __user *)&data->cp0_cause);
105 
106 	return 0;
107 }
108 
109 /*
110  * Write a general register set.  As for PTRACE_GETREGS, we always use
111  * the 64-bit format.  On a 32-bit kernel only the lower order half
112  * (according to endianness) will be used.
113  */
114 int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
115 {
116 	struct pt_regs *regs;
117 	int i;
118 
119 	if (!access_ok(VERIFY_READ, data, 38 * 8))
120 		return -EIO;
121 
122 	regs = task_pt_regs(child);
123 
124 	for (i = 0; i < 32; i++)
125 		__get_user(regs->regs[i], (__s64 __user *)&data->regs[i]);
126 	__get_user(regs->lo, (__s64 __user *)&data->lo);
127 	__get_user(regs->hi, (__s64 __user *)&data->hi);
128 	__get_user(regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
129 
130 	/* badvaddr, status, and cause may not be written.  */
131 
132 	return 0;
133 }
134 
135 int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
136 {
137 	int i;
138 
139 	if (!access_ok(VERIFY_WRITE, data, 33 * 8))
140 		return -EIO;
141 
142 	if (tsk_used_math(child)) {
143 		union fpureg *fregs = get_fpu_regs(child);
144 		for (i = 0; i < 32; i++)
145 			__put_user(get_fpr64(&fregs[i], 0),
146 				   i + (__u64 __user *)data);
147 	} else {
148 		for (i = 0; i < 32; i++)
149 			__put_user((__u64) -1, i + (__u64 __user *) data);
150 	}
151 
152 	__put_user(child->thread.fpu.fcr31, data + 64);
153 	__put_user(boot_cpu_data.fpu_id, data + 65);
154 
155 	return 0;
156 }
157 
158 int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
159 {
160 	union fpureg *fregs;
161 	u64 fpr_val;
162 	u32 fcr31;
163 	u32 value;
164 	u32 mask;
165 	int i;
166 
167 	if (!access_ok(VERIFY_READ, data, 33 * 8))
168 		return -EIO;
169 
170 	init_fp_ctx(child);
171 	fregs = get_fpu_regs(child);
172 
173 	for (i = 0; i < 32; i++) {
174 		__get_user(fpr_val, i + (__u64 __user *)data);
175 		set_fpr64(&fregs[i], 0, fpr_val);
176 	}
177 
178 	__get_user(value, data + 64);
179 	fcr31 = child->thread.fpu.fcr31;
180 	mask = boot_cpu_data.fpu_msk31;
181 	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
182 
183 	/* FIR may not be written.  */
184 
185 	return 0;
186 }
187 
188 int ptrace_get_watch_regs(struct task_struct *child,
189 			  struct pt_watch_regs __user *addr)
190 {
191 	enum pt_watch_style style;
192 	int i;
193 
194 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
195 		return -EIO;
196 	if (!access_ok(VERIFY_WRITE, addr, sizeof(struct pt_watch_regs)))
197 		return -EIO;
198 
199 #ifdef CONFIG_32BIT
200 	style = pt_watch_style_mips32;
201 #define WATCH_STYLE mips32
202 #else
203 	style = pt_watch_style_mips64;
204 #define WATCH_STYLE mips64
205 #endif
206 
207 	__put_user(style, &addr->style);
208 	__put_user(boot_cpu_data.watch_reg_use_cnt,
209 		   &addr->WATCH_STYLE.num_valid);
210 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
211 		__put_user(child->thread.watch.mips3264.watchlo[i],
212 			   &addr->WATCH_STYLE.watchlo[i]);
213 		__put_user(child->thread.watch.mips3264.watchhi[i] & 0xfff,
214 			   &addr->WATCH_STYLE.watchhi[i]);
215 		__put_user(boot_cpu_data.watch_reg_masks[i],
216 			   &addr->WATCH_STYLE.watch_masks[i]);
217 	}
218 	for (; i < 8; i++) {
219 		__put_user(0, &addr->WATCH_STYLE.watchlo[i]);
220 		__put_user(0, &addr->WATCH_STYLE.watchhi[i]);
221 		__put_user(0, &addr->WATCH_STYLE.watch_masks[i]);
222 	}
223 
224 	return 0;
225 }
226 
227 int ptrace_set_watch_regs(struct task_struct *child,
228 			  struct pt_watch_regs __user *addr)
229 {
230 	int i;
231 	int watch_active = 0;
232 	unsigned long lt[NUM_WATCH_REGS];
233 	u16 ht[NUM_WATCH_REGS];
234 
235 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
236 		return -EIO;
237 	if (!access_ok(VERIFY_READ, addr, sizeof(struct pt_watch_regs)))
238 		return -EIO;
239 	/* Check the values. */
240 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
241 		__get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]);
242 #ifdef CONFIG_32BIT
243 		if (lt[i] & __UA_LIMIT)
244 			return -EINVAL;
245 #else
246 		if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) {
247 			if (lt[i] & 0xffffffff80000000UL)
248 				return -EINVAL;
249 		} else {
250 			if (lt[i] & __UA_LIMIT)
251 				return -EINVAL;
252 		}
253 #endif
254 		__get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]);
255 		if (ht[i] & ~0xff8)
256 			return -EINVAL;
257 	}
258 	/* Install them. */
259 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
260 		if (lt[i] & 7)
261 			watch_active = 1;
262 		child->thread.watch.mips3264.watchlo[i] = lt[i];
263 		/* Set the G bit. */
264 		child->thread.watch.mips3264.watchhi[i] = ht[i];
265 	}
266 
267 	if (watch_active)
268 		set_tsk_thread_flag(child, TIF_LOAD_WATCH);
269 	else
270 		clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
271 
272 	return 0;
273 }
274 
275 /* regset get/set implementations */
276 
277 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
278 
279 static int gpr32_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 	u32 uregs[ELF_NGREG] = {};
286 	unsigned i;
287 
288 	for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) {
289 		/* k0/k1 are copied as zero. */
290 		if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27)
291 			continue;
292 
293 		uregs[i] = regs->regs[i - MIPS32_EF_R0];
294 	}
295 
296 	uregs[MIPS32_EF_LO] = regs->lo;
297 	uregs[MIPS32_EF_HI] = regs->hi;
298 	uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc;
299 	uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
300 	uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status;
301 	uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause;
302 
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 	return 0;
352 }
353 
354 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
355 
356 #ifdef CONFIG_64BIT
357 
358 static int gpr64_get(struct task_struct *target,
359 		     const struct user_regset *regset,
360 		     unsigned int pos, unsigned int count,
361 		     void *kbuf, void __user *ubuf)
362 {
363 	struct pt_regs *regs = task_pt_regs(target);
364 	u64 uregs[ELF_NGREG] = {};
365 	unsigned i;
366 
367 	for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) {
368 		/* k0/k1 are copied as zero. */
369 		if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27)
370 			continue;
371 
372 		uregs[i] = regs->regs[i - MIPS64_EF_R0];
373 	}
374 
375 	uregs[MIPS64_EF_LO] = regs->lo;
376 	uregs[MIPS64_EF_HI] = regs->hi;
377 	uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc;
378 	uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
379 	uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status;
380 	uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause;
381 
382 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
383 				   sizeof(uregs));
384 }
385 
386 static int gpr64_set(struct task_struct *target,
387 		     const struct user_regset *regset,
388 		     unsigned int pos, unsigned int count,
389 		     const void *kbuf, const void __user *ubuf)
390 {
391 	struct pt_regs *regs = task_pt_regs(target);
392 	u64 uregs[ELF_NGREG];
393 	unsigned start, num_regs, i;
394 	int err;
395 
396 	start = pos / sizeof(u64);
397 	num_regs = count / sizeof(u64);
398 
399 	if (start + num_regs > ELF_NGREG)
400 		return -EIO;
401 
402 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
403 				 sizeof(uregs));
404 	if (err)
405 		return err;
406 
407 	for (i = start; i < num_regs; i++) {
408 		switch (i) {
409 		case MIPS64_EF_R1 ... MIPS64_EF_R25:
410 			/* k0/k1 are ignored. */
411 		case MIPS64_EF_R28 ... MIPS64_EF_R31:
412 			regs->regs[i - MIPS64_EF_R0] = uregs[i];
413 			break;
414 		case MIPS64_EF_LO:
415 			regs->lo = uregs[i];
416 			break;
417 		case MIPS64_EF_HI:
418 			regs->hi = uregs[i];
419 			break;
420 		case MIPS64_EF_CP0_EPC:
421 			regs->cp0_epc = uregs[i];
422 			break;
423 		}
424 	}
425 
426 	return 0;
427 }
428 
429 #endif /* CONFIG_64BIT */
430 
431 static int fpr_get(struct task_struct *target,
432 		   const struct user_regset *regset,
433 		   unsigned int pos, unsigned int count,
434 		   void *kbuf, void __user *ubuf)
435 {
436 	unsigned i;
437 	int err;
438 	u64 fpr_val;
439 
440 	/* XXX fcr31  */
441 
442 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
443 		return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
444 					   &target->thread.fpu,
445 					   0, sizeof(elf_fpregset_t));
446 
447 	for (i = 0; i < NUM_FPU_REGS; i++) {
448 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
449 		err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
450 					  &fpr_val, i * sizeof(elf_fpreg_t),
451 					  (i + 1) * sizeof(elf_fpreg_t));
452 		if (err)
453 			return err;
454 	}
455 
456 	return 0;
457 }
458 
459 static int fpr_set(struct task_struct *target,
460 		   const struct user_regset *regset,
461 		   unsigned int pos, unsigned int count,
462 		   const void *kbuf, const void __user *ubuf)
463 {
464 	unsigned i;
465 	int err;
466 	u64 fpr_val;
467 
468 	/* XXX fcr31  */
469 
470 	init_fp_ctx(target);
471 
472 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
473 		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
474 					  &target->thread.fpu,
475 					  0, sizeof(elf_fpregset_t));
476 
477 	for (i = 0; i < NUM_FPU_REGS; i++) {
478 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
479 					 &fpr_val, i * sizeof(elf_fpreg_t),
480 					 (i + 1) * sizeof(elf_fpreg_t));
481 		if (err)
482 			return err;
483 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
484 	}
485 
486 	return 0;
487 }
488 
489 enum mips_regset {
490 	REGSET_GPR,
491 	REGSET_FPR,
492 };
493 
494 struct pt_regs_offset {
495 	const char *name;
496 	int offset;
497 };
498 
499 #define REG_OFFSET_NAME(reg, r) {					\
500 	.name = #reg,							\
501 	.offset = offsetof(struct pt_regs, r)				\
502 }
503 
504 #define REG_OFFSET_END {						\
505 	.name = NULL,							\
506 	.offset = 0							\
507 }
508 
509 static const struct pt_regs_offset regoffset_table[] = {
510 	REG_OFFSET_NAME(r0, regs[0]),
511 	REG_OFFSET_NAME(r1, regs[1]),
512 	REG_OFFSET_NAME(r2, regs[2]),
513 	REG_OFFSET_NAME(r3, regs[3]),
514 	REG_OFFSET_NAME(r4, regs[4]),
515 	REG_OFFSET_NAME(r5, regs[5]),
516 	REG_OFFSET_NAME(r6, regs[6]),
517 	REG_OFFSET_NAME(r7, regs[7]),
518 	REG_OFFSET_NAME(r8, regs[8]),
519 	REG_OFFSET_NAME(r9, regs[9]),
520 	REG_OFFSET_NAME(r10, regs[10]),
521 	REG_OFFSET_NAME(r11, regs[11]),
522 	REG_OFFSET_NAME(r12, regs[12]),
523 	REG_OFFSET_NAME(r13, regs[13]),
524 	REG_OFFSET_NAME(r14, regs[14]),
525 	REG_OFFSET_NAME(r15, regs[15]),
526 	REG_OFFSET_NAME(r16, regs[16]),
527 	REG_OFFSET_NAME(r17, regs[17]),
528 	REG_OFFSET_NAME(r18, regs[18]),
529 	REG_OFFSET_NAME(r19, regs[19]),
530 	REG_OFFSET_NAME(r20, regs[20]),
531 	REG_OFFSET_NAME(r21, regs[21]),
532 	REG_OFFSET_NAME(r22, regs[22]),
533 	REG_OFFSET_NAME(r23, regs[23]),
534 	REG_OFFSET_NAME(r24, regs[24]),
535 	REG_OFFSET_NAME(r25, regs[25]),
536 	REG_OFFSET_NAME(r26, regs[26]),
537 	REG_OFFSET_NAME(r27, regs[27]),
538 	REG_OFFSET_NAME(r28, regs[28]),
539 	REG_OFFSET_NAME(r29, regs[29]),
540 	REG_OFFSET_NAME(r30, regs[30]),
541 	REG_OFFSET_NAME(r31, regs[31]),
542 	REG_OFFSET_NAME(c0_status, cp0_status),
543 	REG_OFFSET_NAME(hi, hi),
544 	REG_OFFSET_NAME(lo, lo),
545 #ifdef CONFIG_CPU_HAS_SMARTMIPS
546 	REG_OFFSET_NAME(acx, acx),
547 #endif
548 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
549 	REG_OFFSET_NAME(c0_cause, cp0_cause),
550 	REG_OFFSET_NAME(c0_epc, cp0_epc),
551 #ifdef CONFIG_CPU_CAVIUM_OCTEON
552 	REG_OFFSET_NAME(mpl0, mpl[0]),
553 	REG_OFFSET_NAME(mpl1, mpl[1]),
554 	REG_OFFSET_NAME(mpl2, mpl[2]),
555 	REG_OFFSET_NAME(mtp0, mtp[0]),
556 	REG_OFFSET_NAME(mtp1, mtp[1]),
557 	REG_OFFSET_NAME(mtp2, mtp[2]),
558 #endif
559 	REG_OFFSET_END,
560 };
561 
562 /**
563  * regs_query_register_offset() - query register offset from its name
564  * @name:       the name of a register
565  *
566  * regs_query_register_offset() returns the offset of a register in struct
567  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
568  */
569 int regs_query_register_offset(const char *name)
570 {
571         const struct pt_regs_offset *roff;
572         for (roff = regoffset_table; roff->name != NULL; roff++)
573                 if (!strcmp(roff->name, name))
574                         return roff->offset;
575         return -EINVAL;
576 }
577 
578 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
579 
580 static const struct user_regset mips_regsets[] = {
581 	[REGSET_GPR] = {
582 		.core_note_type	= NT_PRSTATUS,
583 		.n		= ELF_NGREG,
584 		.size		= sizeof(unsigned int),
585 		.align		= sizeof(unsigned int),
586 		.get		= gpr32_get,
587 		.set		= gpr32_set,
588 	},
589 	[REGSET_FPR] = {
590 		.core_note_type	= NT_PRFPREG,
591 		.n		= ELF_NFPREG,
592 		.size		= sizeof(elf_fpreg_t),
593 		.align		= sizeof(elf_fpreg_t),
594 		.get		= fpr_get,
595 		.set		= fpr_set,
596 	},
597 };
598 
599 static const struct user_regset_view user_mips_view = {
600 	.name		= "mips",
601 	.e_machine	= ELF_ARCH,
602 	.ei_osabi	= ELF_OSABI,
603 	.regsets	= mips_regsets,
604 	.n		= ARRAY_SIZE(mips_regsets),
605 };
606 
607 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
608 
609 #ifdef CONFIG_64BIT
610 
611 static const struct user_regset mips64_regsets[] = {
612 	[REGSET_GPR] = {
613 		.core_note_type	= NT_PRSTATUS,
614 		.n		= ELF_NGREG,
615 		.size		= sizeof(unsigned long),
616 		.align		= sizeof(unsigned long),
617 		.get		= gpr64_get,
618 		.set		= gpr64_set,
619 	},
620 	[REGSET_FPR] = {
621 		.core_note_type	= NT_PRFPREG,
622 		.n		= ELF_NFPREG,
623 		.size		= sizeof(elf_fpreg_t),
624 		.align		= sizeof(elf_fpreg_t),
625 		.get		= fpr_get,
626 		.set		= fpr_set,
627 	},
628 };
629 
630 static const struct user_regset_view user_mips64_view = {
631 	.name		= "mips64",
632 	.e_machine	= ELF_ARCH,
633 	.ei_osabi	= ELF_OSABI,
634 	.regsets	= mips64_regsets,
635 	.n		= ARRAY_SIZE(mips64_regsets),
636 };
637 
638 #endif /* CONFIG_64BIT */
639 
640 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
641 {
642 #ifdef CONFIG_32BIT
643 	return &user_mips_view;
644 #else
645 #ifdef CONFIG_MIPS32_O32
646 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
647 		return &user_mips_view;
648 #endif
649 	return &user_mips64_view;
650 #endif
651 }
652 
653 long arch_ptrace(struct task_struct *child, long request,
654 		 unsigned long addr, unsigned long data)
655 {
656 	int ret;
657 	void __user *addrp = (void __user *) addr;
658 	void __user *datavp = (void __user *) data;
659 	unsigned long __user *datalp = (void __user *) data;
660 
661 	switch (request) {
662 	/* when I and D space are separate, these will need to be fixed. */
663 	case PTRACE_PEEKTEXT: /* read word at location addr. */
664 	case PTRACE_PEEKDATA:
665 		ret = generic_ptrace_peekdata(child, addr, data);
666 		break;
667 
668 	/* Read the word at location addr in the USER area. */
669 	case PTRACE_PEEKUSR: {
670 		struct pt_regs *regs;
671 		union fpureg *fregs;
672 		unsigned long tmp = 0;
673 
674 		regs = task_pt_regs(child);
675 		ret = 0;  /* Default return value. */
676 
677 		switch (addr) {
678 		case 0 ... 31:
679 			tmp = regs->regs[addr];
680 			break;
681 		case FPR_BASE ... FPR_BASE + 31:
682 			if (!tsk_used_math(child)) {
683 				/* FP not yet used */
684 				tmp = -1;
685 				break;
686 			}
687 			fregs = get_fpu_regs(child);
688 
689 #ifdef CONFIG_32BIT
690 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
691 				/*
692 				 * The odd registers are actually the high
693 				 * order bits of the values stored in the even
694 				 * registers - unless we're using r2k_switch.S.
695 				 */
696 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
697 						addr & 1);
698 				break;
699 			}
700 #endif
701 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
702 			break;
703 		case PC:
704 			tmp = regs->cp0_epc;
705 			break;
706 		case CAUSE:
707 			tmp = regs->cp0_cause;
708 			break;
709 		case BADVADDR:
710 			tmp = regs->cp0_badvaddr;
711 			break;
712 		case MMHI:
713 			tmp = regs->hi;
714 			break;
715 		case MMLO:
716 			tmp = regs->lo;
717 			break;
718 #ifdef CONFIG_CPU_HAS_SMARTMIPS
719 		case ACX:
720 			tmp = regs->acx;
721 			break;
722 #endif
723 		case FPC_CSR:
724 			tmp = child->thread.fpu.fcr31;
725 			break;
726 		case FPC_EIR:
727 			/* implementation / version register */
728 			tmp = boot_cpu_data.fpu_id;
729 			break;
730 		case DSP_BASE ... DSP_BASE + 5: {
731 			dspreg_t *dregs;
732 
733 			if (!cpu_has_dsp) {
734 				tmp = 0;
735 				ret = -EIO;
736 				goto out;
737 			}
738 			dregs = __get_dsp_regs(child);
739 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
740 			break;
741 		}
742 		case DSP_CONTROL:
743 			if (!cpu_has_dsp) {
744 				tmp = 0;
745 				ret = -EIO;
746 				goto out;
747 			}
748 			tmp = child->thread.dsp.dspcontrol;
749 			break;
750 		default:
751 			tmp = 0;
752 			ret = -EIO;
753 			goto out;
754 		}
755 		ret = put_user(tmp, datalp);
756 		break;
757 	}
758 
759 	/* when I and D space are separate, this will have to be fixed. */
760 	case PTRACE_POKETEXT: /* write the word at location addr. */
761 	case PTRACE_POKEDATA:
762 		ret = generic_ptrace_pokedata(child, addr, data);
763 		break;
764 
765 	case PTRACE_POKEUSR: {
766 		struct pt_regs *regs;
767 		ret = 0;
768 		regs = task_pt_regs(child);
769 
770 		switch (addr) {
771 		case 0 ... 31:
772 			regs->regs[addr] = data;
773 			break;
774 		case FPR_BASE ... FPR_BASE + 31: {
775 			union fpureg *fregs = get_fpu_regs(child);
776 
777 			init_fp_ctx(child);
778 #ifdef CONFIG_32BIT
779 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
780 				/*
781 				 * The odd registers are actually the high
782 				 * order bits of the values stored in the even
783 				 * registers - unless we're using r2k_switch.S.
784 				 */
785 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
786 					  addr & 1, data);
787 				break;
788 			}
789 #endif
790 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
791 			break;
792 		}
793 		case PC:
794 			regs->cp0_epc = data;
795 			break;
796 		case MMHI:
797 			regs->hi = data;
798 			break;
799 		case MMLO:
800 			regs->lo = data;
801 			break;
802 #ifdef CONFIG_CPU_HAS_SMARTMIPS
803 		case ACX:
804 			regs->acx = data;
805 			break;
806 #endif
807 		case FPC_CSR:
808 			child->thread.fpu.fcr31 = data & ~FPU_CSR_ALL_X;
809 			break;
810 		case DSP_BASE ... DSP_BASE + 5: {
811 			dspreg_t *dregs;
812 
813 			if (!cpu_has_dsp) {
814 				ret = -EIO;
815 				break;
816 			}
817 
818 			dregs = __get_dsp_regs(child);
819 			dregs[addr - DSP_BASE] = data;
820 			break;
821 		}
822 		case DSP_CONTROL:
823 			if (!cpu_has_dsp) {
824 				ret = -EIO;
825 				break;
826 			}
827 			child->thread.dsp.dspcontrol = data;
828 			break;
829 		default:
830 			/* The rest are not allowed. */
831 			ret = -EIO;
832 			break;
833 		}
834 		break;
835 		}
836 
837 	case PTRACE_GETREGS:
838 		ret = ptrace_getregs(child, datavp);
839 		break;
840 
841 	case PTRACE_SETREGS:
842 		ret = ptrace_setregs(child, datavp);
843 		break;
844 
845 	case PTRACE_GETFPREGS:
846 		ret = ptrace_getfpregs(child, datavp);
847 		break;
848 
849 	case PTRACE_SETFPREGS:
850 		ret = ptrace_setfpregs(child, datavp);
851 		break;
852 
853 	case PTRACE_GET_THREAD_AREA:
854 		ret = put_user(task_thread_info(child)->tp_value, datalp);
855 		break;
856 
857 	case PTRACE_GET_WATCH_REGS:
858 		ret = ptrace_get_watch_regs(child, addrp);
859 		break;
860 
861 	case PTRACE_SET_WATCH_REGS:
862 		ret = ptrace_set_watch_regs(child, addrp);
863 		break;
864 
865 	default:
866 		ret = ptrace_request(child, request, addr, data);
867 		break;
868 	}
869  out:
870 	return ret;
871 }
872 
873 /*
874  * Notification of system call entry/exit
875  * - triggered by current->work.syscall_trace
876  */
877 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
878 {
879 	long ret = 0;
880 	user_exit();
881 
882 	current_thread_info()->syscall = syscall;
883 
884 	if (secure_computing() == -1)
885 		return -1;
886 
887 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
888 	    tracehook_report_syscall_entry(regs))
889 		ret = -1;
890 
891 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
892 		trace_sys_enter(regs, regs->regs[2]);
893 
894 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
895 			    regs->regs[6], regs->regs[7]);
896 	return syscall;
897 }
898 
899 /*
900  * Notification of system call entry/exit
901  * - triggered by current->work.syscall_trace
902  */
903 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
904 {
905         /*
906 	 * We may come here right after calling schedule_user()
907 	 * or do_notify_resume(), in which case we can be in RCU
908 	 * user mode.
909 	 */
910 	user_exit();
911 
912 	audit_syscall_exit(regs);
913 
914 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
915 		trace_sys_exit(regs, regs->regs[2]);
916 
917 	if (test_thread_flag(TIF_SYSCALL_TRACE))
918 		tracehook_report_syscall_exit(regs, 0);
919 
920 	user_enter();
921 }
922