xref: /openbmc/linux/arch/mips/kernel/ptrace.c (revision 4a3fad70)
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 static int fpr_get(struct task_struct *target,
423 		   const struct user_regset *regset,
424 		   unsigned int pos, unsigned int count,
425 		   void *kbuf, void __user *ubuf)
426 {
427 	unsigned i;
428 	int err;
429 	u64 fpr_val;
430 
431 	/* XXX fcr31  */
432 
433 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
434 		return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
435 					   &target->thread.fpu,
436 					   0, sizeof(elf_fpregset_t));
437 
438 	for (i = 0; i < NUM_FPU_REGS; i++) {
439 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
440 		err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
441 					  &fpr_val, i * sizeof(elf_fpreg_t),
442 					  (i + 1) * sizeof(elf_fpreg_t));
443 		if (err)
444 			return err;
445 	}
446 
447 	return 0;
448 }
449 
450 static int fpr_set(struct task_struct *target,
451 		   const struct user_regset *regset,
452 		   unsigned int pos, unsigned int count,
453 		   const void *kbuf, const void __user *ubuf)
454 {
455 	unsigned i;
456 	int err;
457 	u64 fpr_val;
458 
459 	/* XXX fcr31  */
460 
461 	init_fp_ctx(target);
462 
463 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
464 		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
465 					  &target->thread.fpu,
466 					  0, sizeof(elf_fpregset_t));
467 
468 	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
469 	for (i = 0; i < NUM_FPU_REGS && count >= sizeof(elf_fpreg_t); i++) {
470 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
471 					 &fpr_val, i * sizeof(elf_fpreg_t),
472 					 (i + 1) * sizeof(elf_fpreg_t));
473 		if (err)
474 			return err;
475 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
476 	}
477 
478 	return 0;
479 }
480 
481 enum mips_regset {
482 	REGSET_GPR,
483 	REGSET_FPR,
484 };
485 
486 struct pt_regs_offset {
487 	const char *name;
488 	int offset;
489 };
490 
491 #define REG_OFFSET_NAME(reg, r) {					\
492 	.name = #reg,							\
493 	.offset = offsetof(struct pt_regs, r)				\
494 }
495 
496 #define REG_OFFSET_END {						\
497 	.name = NULL,							\
498 	.offset = 0							\
499 }
500 
501 static const struct pt_regs_offset regoffset_table[] = {
502 	REG_OFFSET_NAME(r0, regs[0]),
503 	REG_OFFSET_NAME(r1, regs[1]),
504 	REG_OFFSET_NAME(r2, regs[2]),
505 	REG_OFFSET_NAME(r3, regs[3]),
506 	REG_OFFSET_NAME(r4, regs[4]),
507 	REG_OFFSET_NAME(r5, regs[5]),
508 	REG_OFFSET_NAME(r6, regs[6]),
509 	REG_OFFSET_NAME(r7, regs[7]),
510 	REG_OFFSET_NAME(r8, regs[8]),
511 	REG_OFFSET_NAME(r9, regs[9]),
512 	REG_OFFSET_NAME(r10, regs[10]),
513 	REG_OFFSET_NAME(r11, regs[11]),
514 	REG_OFFSET_NAME(r12, regs[12]),
515 	REG_OFFSET_NAME(r13, regs[13]),
516 	REG_OFFSET_NAME(r14, regs[14]),
517 	REG_OFFSET_NAME(r15, regs[15]),
518 	REG_OFFSET_NAME(r16, regs[16]),
519 	REG_OFFSET_NAME(r17, regs[17]),
520 	REG_OFFSET_NAME(r18, regs[18]),
521 	REG_OFFSET_NAME(r19, regs[19]),
522 	REG_OFFSET_NAME(r20, regs[20]),
523 	REG_OFFSET_NAME(r21, regs[21]),
524 	REG_OFFSET_NAME(r22, regs[22]),
525 	REG_OFFSET_NAME(r23, regs[23]),
526 	REG_OFFSET_NAME(r24, regs[24]),
527 	REG_OFFSET_NAME(r25, regs[25]),
528 	REG_OFFSET_NAME(r26, regs[26]),
529 	REG_OFFSET_NAME(r27, regs[27]),
530 	REG_OFFSET_NAME(r28, regs[28]),
531 	REG_OFFSET_NAME(r29, regs[29]),
532 	REG_OFFSET_NAME(r30, regs[30]),
533 	REG_OFFSET_NAME(r31, regs[31]),
534 	REG_OFFSET_NAME(c0_status, cp0_status),
535 	REG_OFFSET_NAME(hi, hi),
536 	REG_OFFSET_NAME(lo, lo),
537 #ifdef CONFIG_CPU_HAS_SMARTMIPS
538 	REG_OFFSET_NAME(acx, acx),
539 #endif
540 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
541 	REG_OFFSET_NAME(c0_cause, cp0_cause),
542 	REG_OFFSET_NAME(c0_epc, cp0_epc),
543 #ifdef CONFIG_CPU_CAVIUM_OCTEON
544 	REG_OFFSET_NAME(mpl0, mpl[0]),
545 	REG_OFFSET_NAME(mpl1, mpl[1]),
546 	REG_OFFSET_NAME(mpl2, mpl[2]),
547 	REG_OFFSET_NAME(mtp0, mtp[0]),
548 	REG_OFFSET_NAME(mtp1, mtp[1]),
549 	REG_OFFSET_NAME(mtp2, mtp[2]),
550 #endif
551 	REG_OFFSET_END,
552 };
553 
554 /**
555  * regs_query_register_offset() - query register offset from its name
556  * @name:       the name of a register
557  *
558  * regs_query_register_offset() returns the offset of a register in struct
559  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
560  */
561 int regs_query_register_offset(const char *name)
562 {
563         const struct pt_regs_offset *roff;
564         for (roff = regoffset_table; roff->name != NULL; roff++)
565                 if (!strcmp(roff->name, name))
566                         return roff->offset;
567         return -EINVAL;
568 }
569 
570 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
571 
572 static const struct user_regset mips_regsets[] = {
573 	[REGSET_GPR] = {
574 		.core_note_type	= NT_PRSTATUS,
575 		.n		= ELF_NGREG,
576 		.size		= sizeof(unsigned int),
577 		.align		= sizeof(unsigned int),
578 		.get		= gpr32_get,
579 		.set		= gpr32_set,
580 	},
581 	[REGSET_FPR] = {
582 		.core_note_type	= NT_PRFPREG,
583 		.n		= ELF_NFPREG,
584 		.size		= sizeof(elf_fpreg_t),
585 		.align		= sizeof(elf_fpreg_t),
586 		.get		= fpr_get,
587 		.set		= fpr_set,
588 	},
589 };
590 
591 static const struct user_regset_view user_mips_view = {
592 	.name		= "mips",
593 	.e_machine	= ELF_ARCH,
594 	.ei_osabi	= ELF_OSABI,
595 	.regsets	= mips_regsets,
596 	.n		= ARRAY_SIZE(mips_regsets),
597 };
598 
599 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
600 
601 #ifdef CONFIG_64BIT
602 
603 static const struct user_regset mips64_regsets[] = {
604 	[REGSET_GPR] = {
605 		.core_note_type	= NT_PRSTATUS,
606 		.n		= ELF_NGREG,
607 		.size		= sizeof(unsigned long),
608 		.align		= sizeof(unsigned long),
609 		.get		= gpr64_get,
610 		.set		= gpr64_set,
611 	},
612 	[REGSET_FPR] = {
613 		.core_note_type	= NT_PRFPREG,
614 		.n		= ELF_NFPREG,
615 		.size		= sizeof(elf_fpreg_t),
616 		.align		= sizeof(elf_fpreg_t),
617 		.get		= fpr_get,
618 		.set		= fpr_set,
619 	},
620 };
621 
622 static const struct user_regset_view user_mips64_view = {
623 	.name		= "mips64",
624 	.e_machine	= ELF_ARCH,
625 	.ei_osabi	= ELF_OSABI,
626 	.regsets	= mips64_regsets,
627 	.n		= ARRAY_SIZE(mips64_regsets),
628 };
629 
630 #ifdef CONFIG_MIPS32_N32
631 
632 static const struct user_regset_view user_mipsn32_view = {
633 	.name		= "mipsn32",
634 	.e_flags	= EF_MIPS_ABI2,
635 	.e_machine	= ELF_ARCH,
636 	.ei_osabi	= ELF_OSABI,
637 	.regsets	= mips64_regsets,
638 	.n		= ARRAY_SIZE(mips64_regsets),
639 };
640 
641 #endif /* CONFIG_MIPS32_N32 */
642 
643 #endif /* CONFIG_64BIT */
644 
645 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
646 {
647 #ifdef CONFIG_32BIT
648 	return &user_mips_view;
649 #else
650 #ifdef CONFIG_MIPS32_O32
651 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
652 		return &user_mips_view;
653 #endif
654 #ifdef CONFIG_MIPS32_N32
655 	if (test_tsk_thread_flag(task, TIF_32BIT_ADDR))
656 		return &user_mipsn32_view;
657 #endif
658 	return &user_mips64_view;
659 #endif
660 }
661 
662 long arch_ptrace(struct task_struct *child, long request,
663 		 unsigned long addr, unsigned long data)
664 {
665 	int ret;
666 	void __user *addrp = (void __user *) addr;
667 	void __user *datavp = (void __user *) data;
668 	unsigned long __user *datalp = (void __user *) data;
669 
670 	switch (request) {
671 	/* when I and D space are separate, these will need to be fixed. */
672 	case PTRACE_PEEKTEXT: /* read word at location addr. */
673 	case PTRACE_PEEKDATA:
674 		ret = generic_ptrace_peekdata(child, addr, data);
675 		break;
676 
677 	/* Read the word at location addr in the USER area. */
678 	case PTRACE_PEEKUSR: {
679 		struct pt_regs *regs;
680 		union fpureg *fregs;
681 		unsigned long tmp = 0;
682 
683 		regs = task_pt_regs(child);
684 		ret = 0;  /* Default return value. */
685 
686 		switch (addr) {
687 		case 0 ... 31:
688 			tmp = regs->regs[addr];
689 			break;
690 		case FPR_BASE ... FPR_BASE + 31:
691 			if (!tsk_used_math(child)) {
692 				/* FP not yet used */
693 				tmp = -1;
694 				break;
695 			}
696 			fregs = get_fpu_regs(child);
697 
698 #ifdef CONFIG_32BIT
699 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
700 				/*
701 				 * The odd registers are actually the high
702 				 * order bits of the values stored in the even
703 				 * registers - unless we're using r2k_switch.S.
704 				 */
705 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
706 						addr & 1);
707 				break;
708 			}
709 #endif
710 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
711 			break;
712 		case PC:
713 			tmp = regs->cp0_epc;
714 			break;
715 		case CAUSE:
716 			tmp = regs->cp0_cause;
717 			break;
718 		case BADVADDR:
719 			tmp = regs->cp0_badvaddr;
720 			break;
721 		case MMHI:
722 			tmp = regs->hi;
723 			break;
724 		case MMLO:
725 			tmp = regs->lo;
726 			break;
727 #ifdef CONFIG_CPU_HAS_SMARTMIPS
728 		case ACX:
729 			tmp = regs->acx;
730 			break;
731 #endif
732 		case FPC_CSR:
733 			tmp = child->thread.fpu.fcr31;
734 			break;
735 		case FPC_EIR:
736 			/* implementation / version register */
737 			tmp = boot_cpu_data.fpu_id;
738 			break;
739 		case DSP_BASE ... DSP_BASE + 5: {
740 			dspreg_t *dregs;
741 
742 			if (!cpu_has_dsp) {
743 				tmp = 0;
744 				ret = -EIO;
745 				goto out;
746 			}
747 			dregs = __get_dsp_regs(child);
748 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
749 			break;
750 		}
751 		case DSP_CONTROL:
752 			if (!cpu_has_dsp) {
753 				tmp = 0;
754 				ret = -EIO;
755 				goto out;
756 			}
757 			tmp = child->thread.dsp.dspcontrol;
758 			break;
759 		default:
760 			tmp = 0;
761 			ret = -EIO;
762 			goto out;
763 		}
764 		ret = put_user(tmp, datalp);
765 		break;
766 	}
767 
768 	/* when I and D space are separate, this will have to be fixed. */
769 	case PTRACE_POKETEXT: /* write the word at location addr. */
770 	case PTRACE_POKEDATA:
771 		ret = generic_ptrace_pokedata(child, addr, data);
772 		break;
773 
774 	case PTRACE_POKEUSR: {
775 		struct pt_regs *regs;
776 		ret = 0;
777 		regs = task_pt_regs(child);
778 
779 		switch (addr) {
780 		case 0 ... 31:
781 			regs->regs[addr] = data;
782 			/* System call number may have been changed */
783 			if (addr == 2)
784 				mips_syscall_update_nr(child, regs);
785 			else if (addr == 4 &&
786 				 mips_syscall_is_indirect(child, regs))
787 				mips_syscall_update_nr(child, regs);
788 			break;
789 		case FPR_BASE ... FPR_BASE + 31: {
790 			union fpureg *fregs = get_fpu_regs(child);
791 
792 			init_fp_ctx(child);
793 #ifdef CONFIG_32BIT
794 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
795 				/*
796 				 * The odd registers are actually the high
797 				 * order bits of the values stored in the even
798 				 * registers - unless we're using r2k_switch.S.
799 				 */
800 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
801 					  addr & 1, data);
802 				break;
803 			}
804 #endif
805 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
806 			break;
807 		}
808 		case PC:
809 			regs->cp0_epc = data;
810 			break;
811 		case MMHI:
812 			regs->hi = data;
813 			break;
814 		case MMLO:
815 			regs->lo = data;
816 			break;
817 #ifdef CONFIG_CPU_HAS_SMARTMIPS
818 		case ACX:
819 			regs->acx = data;
820 			break;
821 #endif
822 		case FPC_CSR:
823 			init_fp_ctx(child);
824 			ptrace_setfcr31(child, data);
825 			break;
826 		case DSP_BASE ... DSP_BASE + 5: {
827 			dspreg_t *dregs;
828 
829 			if (!cpu_has_dsp) {
830 				ret = -EIO;
831 				break;
832 			}
833 
834 			dregs = __get_dsp_regs(child);
835 			dregs[addr - DSP_BASE] = data;
836 			break;
837 		}
838 		case DSP_CONTROL:
839 			if (!cpu_has_dsp) {
840 				ret = -EIO;
841 				break;
842 			}
843 			child->thread.dsp.dspcontrol = data;
844 			break;
845 		default:
846 			/* The rest are not allowed. */
847 			ret = -EIO;
848 			break;
849 		}
850 		break;
851 		}
852 
853 	case PTRACE_GETREGS:
854 		ret = ptrace_getregs(child, datavp);
855 		break;
856 
857 	case PTRACE_SETREGS:
858 		ret = ptrace_setregs(child, datavp);
859 		break;
860 
861 	case PTRACE_GETFPREGS:
862 		ret = ptrace_getfpregs(child, datavp);
863 		break;
864 
865 	case PTRACE_SETFPREGS:
866 		ret = ptrace_setfpregs(child, datavp);
867 		break;
868 
869 	case PTRACE_GET_THREAD_AREA:
870 		ret = put_user(task_thread_info(child)->tp_value, datalp);
871 		break;
872 
873 	case PTRACE_GET_WATCH_REGS:
874 		ret = ptrace_get_watch_regs(child, addrp);
875 		break;
876 
877 	case PTRACE_SET_WATCH_REGS:
878 		ret = ptrace_set_watch_regs(child, addrp);
879 		break;
880 
881 	default:
882 		ret = ptrace_request(child, request, addr, data);
883 		break;
884 	}
885  out:
886 	return ret;
887 }
888 
889 /*
890  * Notification of system call entry/exit
891  * - triggered by current->work.syscall_trace
892  */
893 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
894 {
895 	user_exit();
896 
897 	current_thread_info()->syscall = syscall;
898 
899 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
900 		if (tracehook_report_syscall_entry(regs))
901 			return -1;
902 		syscall = current_thread_info()->syscall;
903 	}
904 
905 #ifdef CONFIG_SECCOMP
906 	if (unlikely(test_thread_flag(TIF_SECCOMP))) {
907 		int ret, i;
908 		struct seccomp_data sd;
909 		unsigned long args[6];
910 
911 		sd.nr = syscall;
912 		sd.arch = syscall_get_arch();
913 		syscall_get_arguments(current, regs, 0, 6, args);
914 		for (i = 0; i < 6; i++)
915 			sd.args[i] = args[i];
916 		sd.instruction_pointer = KSTK_EIP(current);
917 
918 		ret = __secure_computing(&sd);
919 		if (ret == -1)
920 			return ret;
921 		syscall = current_thread_info()->syscall;
922 	}
923 #endif
924 
925 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
926 		trace_sys_enter(regs, regs->regs[2]);
927 
928 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
929 			    regs->regs[6], regs->regs[7]);
930 
931 	/*
932 	 * Negative syscall numbers are mistaken for rejected syscalls, but
933 	 * won't have had the return value set appropriately, so we do so now.
934 	 */
935 	if (syscall < 0)
936 		syscall_set_return_value(current, regs, -ENOSYS, 0);
937 	return syscall;
938 }
939 
940 /*
941  * Notification of system call entry/exit
942  * - triggered by current->work.syscall_trace
943  */
944 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
945 {
946         /*
947 	 * We may come here right after calling schedule_user()
948 	 * or do_notify_resume(), in which case we can be in RCU
949 	 * user mode.
950 	 */
951 	user_exit();
952 
953 	audit_syscall_exit(regs);
954 
955 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
956 		trace_sys_exit(regs, regs_return_value(regs));
957 
958 	if (test_thread_flag(TIF_SYSCALL_TRACE))
959 		tracehook_report_syscall_exit(regs, 0);
960 
961 	user_enter();
962 }
963