xref: /openbmc/linux/arch/mips/kernel/ptrace.c (revision 174cd4b1)
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 <linux/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 	/* FCSR has been preset by `mips_set_personality_nan'.  */
61 
62 	/*
63 	 * Record that the target has "used" math, such that the context
64 	 * just initialised, and any modifications made by the caller,
65 	 * aren't discarded.
66 	 */
67 	set_stopped_child_used_math(target);
68 }
69 
70 /*
71  * Called by kernel/ptrace.c when detaching..
72  *
73  * Make sure single step bits etc are not set.
74  */
75 void ptrace_disable(struct task_struct *child)
76 {
77 	/* Don't load the watchpoint registers for the ex-child. */
78 	clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
79 }
80 
81 /*
82  * Poke at FCSR according to its mask.  Set the Cause bits even
83  * if a corresponding Enable bit is set.  This will be noticed at
84  * the time the thread is switched to and SIGFPE thrown accordingly.
85  */
86 static void ptrace_setfcr31(struct task_struct *child, u32 value)
87 {
88 	u32 fcr31;
89 	u32 mask;
90 
91 	fcr31 = child->thread.fpu.fcr31;
92 	mask = boot_cpu_data.fpu_msk31;
93 	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
94 }
95 
96 /*
97  * Read a general register set.	 We always use the 64-bit format, even
98  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
99  * Registers are sign extended to fill the available space.
100  */
101 int ptrace_getregs(struct task_struct *child, struct user_pt_regs __user *data)
102 {
103 	struct pt_regs *regs;
104 	int i;
105 
106 	if (!access_ok(VERIFY_WRITE, data, 38 * 8))
107 		return -EIO;
108 
109 	regs = task_pt_regs(child);
110 
111 	for (i = 0; i < 32; i++)
112 		__put_user((long)regs->regs[i], (__s64 __user *)&data->regs[i]);
113 	__put_user((long)regs->lo, (__s64 __user *)&data->lo);
114 	__put_user((long)regs->hi, (__s64 __user *)&data->hi);
115 	__put_user((long)regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
116 	__put_user((long)regs->cp0_badvaddr, (__s64 __user *)&data->cp0_badvaddr);
117 	__put_user((long)regs->cp0_status, (__s64 __user *)&data->cp0_status);
118 	__put_user((long)regs->cp0_cause, (__s64 __user *)&data->cp0_cause);
119 
120 	return 0;
121 }
122 
123 /*
124  * Write a general register set.  As for PTRACE_GETREGS, we always use
125  * the 64-bit format.  On a 32-bit kernel only the lower order half
126  * (according to endianness) will be used.
127  */
128 int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
129 {
130 	struct pt_regs *regs;
131 	int i;
132 
133 	if (!access_ok(VERIFY_READ, data, 38 * 8))
134 		return -EIO;
135 
136 	regs = task_pt_regs(child);
137 
138 	for (i = 0; i < 32; i++)
139 		__get_user(regs->regs[i], (__s64 __user *)&data->regs[i]);
140 	__get_user(regs->lo, (__s64 __user *)&data->lo);
141 	__get_user(regs->hi, (__s64 __user *)&data->hi);
142 	__get_user(regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
143 
144 	/* badvaddr, status, and cause may not be written.  */
145 
146 	return 0;
147 }
148 
149 int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
150 {
151 	int i;
152 
153 	if (!access_ok(VERIFY_WRITE, data, 33 * 8))
154 		return -EIO;
155 
156 	if (tsk_used_math(child)) {
157 		union fpureg *fregs = get_fpu_regs(child);
158 		for (i = 0; i < 32; i++)
159 			__put_user(get_fpr64(&fregs[i], 0),
160 				   i + (__u64 __user *)data);
161 	} else {
162 		for (i = 0; i < 32; i++)
163 			__put_user((__u64) -1, i + (__u64 __user *) data);
164 	}
165 
166 	__put_user(child->thread.fpu.fcr31, data + 64);
167 	__put_user(boot_cpu_data.fpu_id, data + 65);
168 
169 	return 0;
170 }
171 
172 int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
173 {
174 	union fpureg *fregs;
175 	u64 fpr_val;
176 	u32 value;
177 	int i;
178 
179 	if (!access_ok(VERIFY_READ, data, 33 * 8))
180 		return -EIO;
181 
182 	init_fp_ctx(child);
183 	fregs = get_fpu_regs(child);
184 
185 	for (i = 0; i < 32; i++) {
186 		__get_user(fpr_val, i + (__u64 __user *)data);
187 		set_fpr64(&fregs[i], 0, fpr_val);
188 	}
189 
190 	__get_user(value, data + 64);
191 	ptrace_setfcr31(child, value);
192 
193 	/* FIR may not be written.  */
194 
195 	return 0;
196 }
197 
198 int ptrace_get_watch_regs(struct task_struct *child,
199 			  struct pt_watch_regs __user *addr)
200 {
201 	enum pt_watch_style style;
202 	int i;
203 
204 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
205 		return -EIO;
206 	if (!access_ok(VERIFY_WRITE, addr, sizeof(struct pt_watch_regs)))
207 		return -EIO;
208 
209 #ifdef CONFIG_32BIT
210 	style = pt_watch_style_mips32;
211 #define WATCH_STYLE mips32
212 #else
213 	style = pt_watch_style_mips64;
214 #define WATCH_STYLE mips64
215 #endif
216 
217 	__put_user(style, &addr->style);
218 	__put_user(boot_cpu_data.watch_reg_use_cnt,
219 		   &addr->WATCH_STYLE.num_valid);
220 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
221 		__put_user(child->thread.watch.mips3264.watchlo[i],
222 			   &addr->WATCH_STYLE.watchlo[i]);
223 		__put_user(child->thread.watch.mips3264.watchhi[i] &
224 				(MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW),
225 			   &addr->WATCH_STYLE.watchhi[i]);
226 		__put_user(boot_cpu_data.watch_reg_masks[i],
227 			   &addr->WATCH_STYLE.watch_masks[i]);
228 	}
229 	for (; i < 8; i++) {
230 		__put_user(0, &addr->WATCH_STYLE.watchlo[i]);
231 		__put_user(0, &addr->WATCH_STYLE.watchhi[i]);
232 		__put_user(0, &addr->WATCH_STYLE.watch_masks[i]);
233 	}
234 
235 	return 0;
236 }
237 
238 int ptrace_set_watch_regs(struct task_struct *child,
239 			  struct pt_watch_regs __user *addr)
240 {
241 	int i;
242 	int watch_active = 0;
243 	unsigned long lt[NUM_WATCH_REGS];
244 	u16 ht[NUM_WATCH_REGS];
245 
246 	if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
247 		return -EIO;
248 	if (!access_ok(VERIFY_READ, addr, sizeof(struct pt_watch_regs)))
249 		return -EIO;
250 	/* Check the values. */
251 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
252 		__get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]);
253 #ifdef CONFIG_32BIT
254 		if (lt[i] & __UA_LIMIT)
255 			return -EINVAL;
256 #else
257 		if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) {
258 			if (lt[i] & 0xffffffff80000000UL)
259 				return -EINVAL;
260 		} else {
261 			if (lt[i] & __UA_LIMIT)
262 				return -EINVAL;
263 		}
264 #endif
265 		__get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]);
266 		if (ht[i] & ~MIPS_WATCHHI_MASK)
267 			return -EINVAL;
268 	}
269 	/* Install them. */
270 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
271 		if (lt[i] & MIPS_WATCHLO_IRW)
272 			watch_active = 1;
273 		child->thread.watch.mips3264.watchlo[i] = lt[i];
274 		/* Set the G bit. */
275 		child->thread.watch.mips3264.watchhi[i] = ht[i];
276 	}
277 
278 	if (watch_active)
279 		set_tsk_thread_flag(child, TIF_LOAD_WATCH);
280 	else
281 		clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
282 
283 	return 0;
284 }
285 
286 /* regset get/set implementations */
287 
288 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
289 
290 static int gpr32_get(struct task_struct *target,
291 		     const struct user_regset *regset,
292 		     unsigned int pos, unsigned int count,
293 		     void *kbuf, void __user *ubuf)
294 {
295 	struct pt_regs *regs = task_pt_regs(target);
296 	u32 uregs[ELF_NGREG] = {};
297 
298 	mips_dump_regs32(uregs, regs);
299 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
300 				   sizeof(uregs));
301 }
302 
303 static int gpr32_set(struct task_struct *target,
304 		     const struct user_regset *regset,
305 		     unsigned int pos, unsigned int count,
306 		     const void *kbuf, const void __user *ubuf)
307 {
308 	struct pt_regs *regs = task_pt_regs(target);
309 	u32 uregs[ELF_NGREG];
310 	unsigned start, num_regs, i;
311 	int err;
312 
313 	start = pos / sizeof(u32);
314 	num_regs = count / sizeof(u32);
315 
316 	if (start + num_regs > ELF_NGREG)
317 		return -EIO;
318 
319 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
320 				 sizeof(uregs));
321 	if (err)
322 		return err;
323 
324 	for (i = start; i < num_regs; i++) {
325 		/*
326 		 * Cast all values to signed here so that if this is a 64-bit
327 		 * kernel, the supplied 32-bit values will be sign extended.
328 		 */
329 		switch (i) {
330 		case MIPS32_EF_R1 ... MIPS32_EF_R25:
331 			/* k0/k1 are ignored. */
332 		case MIPS32_EF_R28 ... MIPS32_EF_R31:
333 			regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
334 			break;
335 		case MIPS32_EF_LO:
336 			regs->lo = (s32)uregs[i];
337 			break;
338 		case MIPS32_EF_HI:
339 			regs->hi = (s32)uregs[i];
340 			break;
341 		case MIPS32_EF_CP0_EPC:
342 			regs->cp0_epc = (s32)uregs[i];
343 			break;
344 		}
345 	}
346 
347 	return 0;
348 }
349 
350 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
351 
352 #ifdef CONFIG_64BIT
353 
354 static int gpr64_get(struct task_struct *target,
355 		     const struct user_regset *regset,
356 		     unsigned int pos, unsigned int count,
357 		     void *kbuf, void __user *ubuf)
358 {
359 	struct pt_regs *regs = task_pt_regs(target);
360 	u64 uregs[ELF_NGREG] = {};
361 
362 	mips_dump_regs64(uregs, regs);
363 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
364 				   sizeof(uregs));
365 }
366 
367 static int gpr64_set(struct task_struct *target,
368 		     const struct user_regset *regset,
369 		     unsigned int pos, unsigned int count,
370 		     const void *kbuf, const void __user *ubuf)
371 {
372 	struct pt_regs *regs = task_pt_regs(target);
373 	u64 uregs[ELF_NGREG];
374 	unsigned start, num_regs, i;
375 	int err;
376 
377 	start = pos / sizeof(u64);
378 	num_regs = count / sizeof(u64);
379 
380 	if (start + num_regs > ELF_NGREG)
381 		return -EIO;
382 
383 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
384 				 sizeof(uregs));
385 	if (err)
386 		return err;
387 
388 	for (i = start; i < num_regs; i++) {
389 		switch (i) {
390 		case MIPS64_EF_R1 ... MIPS64_EF_R25:
391 			/* k0/k1 are ignored. */
392 		case MIPS64_EF_R28 ... MIPS64_EF_R31:
393 			regs->regs[i - MIPS64_EF_R0] = uregs[i];
394 			break;
395 		case MIPS64_EF_LO:
396 			regs->lo = uregs[i];
397 			break;
398 		case MIPS64_EF_HI:
399 			regs->hi = uregs[i];
400 			break;
401 		case MIPS64_EF_CP0_EPC:
402 			regs->cp0_epc = uregs[i];
403 			break;
404 		}
405 	}
406 
407 	return 0;
408 }
409 
410 #endif /* CONFIG_64BIT */
411 
412 static int fpr_get(struct task_struct *target,
413 		   const struct user_regset *regset,
414 		   unsigned int pos, unsigned int count,
415 		   void *kbuf, void __user *ubuf)
416 {
417 	unsigned i;
418 	int err;
419 	u64 fpr_val;
420 
421 	/* XXX fcr31  */
422 
423 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
424 		return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
425 					   &target->thread.fpu,
426 					   0, sizeof(elf_fpregset_t));
427 
428 	for (i = 0; i < NUM_FPU_REGS; i++) {
429 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
430 		err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
431 					  &fpr_val, i * sizeof(elf_fpreg_t),
432 					  (i + 1) * sizeof(elf_fpreg_t));
433 		if (err)
434 			return err;
435 	}
436 
437 	return 0;
438 }
439 
440 static int fpr_set(struct task_struct *target,
441 		   const struct user_regset *regset,
442 		   unsigned int pos, unsigned int count,
443 		   const void *kbuf, const void __user *ubuf)
444 {
445 	unsigned i;
446 	int err;
447 	u64 fpr_val;
448 
449 	/* XXX fcr31  */
450 
451 	init_fp_ctx(target);
452 
453 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
454 		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
455 					  &target->thread.fpu,
456 					  0, sizeof(elf_fpregset_t));
457 
458 	for (i = 0; i < NUM_FPU_REGS; i++) {
459 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
460 					 &fpr_val, i * sizeof(elf_fpreg_t),
461 					 (i + 1) * sizeof(elf_fpreg_t));
462 		if (err)
463 			return err;
464 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
465 	}
466 
467 	return 0;
468 }
469 
470 enum mips_regset {
471 	REGSET_GPR,
472 	REGSET_FPR,
473 };
474 
475 struct pt_regs_offset {
476 	const char *name;
477 	int offset;
478 };
479 
480 #define REG_OFFSET_NAME(reg, r) {					\
481 	.name = #reg,							\
482 	.offset = offsetof(struct pt_regs, r)				\
483 }
484 
485 #define REG_OFFSET_END {						\
486 	.name = NULL,							\
487 	.offset = 0							\
488 }
489 
490 static const struct pt_regs_offset regoffset_table[] = {
491 	REG_OFFSET_NAME(r0, regs[0]),
492 	REG_OFFSET_NAME(r1, regs[1]),
493 	REG_OFFSET_NAME(r2, regs[2]),
494 	REG_OFFSET_NAME(r3, regs[3]),
495 	REG_OFFSET_NAME(r4, regs[4]),
496 	REG_OFFSET_NAME(r5, regs[5]),
497 	REG_OFFSET_NAME(r6, regs[6]),
498 	REG_OFFSET_NAME(r7, regs[7]),
499 	REG_OFFSET_NAME(r8, regs[8]),
500 	REG_OFFSET_NAME(r9, regs[9]),
501 	REG_OFFSET_NAME(r10, regs[10]),
502 	REG_OFFSET_NAME(r11, regs[11]),
503 	REG_OFFSET_NAME(r12, regs[12]),
504 	REG_OFFSET_NAME(r13, regs[13]),
505 	REG_OFFSET_NAME(r14, regs[14]),
506 	REG_OFFSET_NAME(r15, regs[15]),
507 	REG_OFFSET_NAME(r16, regs[16]),
508 	REG_OFFSET_NAME(r17, regs[17]),
509 	REG_OFFSET_NAME(r18, regs[18]),
510 	REG_OFFSET_NAME(r19, regs[19]),
511 	REG_OFFSET_NAME(r20, regs[20]),
512 	REG_OFFSET_NAME(r21, regs[21]),
513 	REG_OFFSET_NAME(r22, regs[22]),
514 	REG_OFFSET_NAME(r23, regs[23]),
515 	REG_OFFSET_NAME(r24, regs[24]),
516 	REG_OFFSET_NAME(r25, regs[25]),
517 	REG_OFFSET_NAME(r26, regs[26]),
518 	REG_OFFSET_NAME(r27, regs[27]),
519 	REG_OFFSET_NAME(r28, regs[28]),
520 	REG_OFFSET_NAME(r29, regs[29]),
521 	REG_OFFSET_NAME(r30, regs[30]),
522 	REG_OFFSET_NAME(r31, regs[31]),
523 	REG_OFFSET_NAME(c0_status, cp0_status),
524 	REG_OFFSET_NAME(hi, hi),
525 	REG_OFFSET_NAME(lo, lo),
526 #ifdef CONFIG_CPU_HAS_SMARTMIPS
527 	REG_OFFSET_NAME(acx, acx),
528 #endif
529 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
530 	REG_OFFSET_NAME(c0_cause, cp0_cause),
531 	REG_OFFSET_NAME(c0_epc, cp0_epc),
532 #ifdef CONFIG_CPU_CAVIUM_OCTEON
533 	REG_OFFSET_NAME(mpl0, mpl[0]),
534 	REG_OFFSET_NAME(mpl1, mpl[1]),
535 	REG_OFFSET_NAME(mpl2, mpl[2]),
536 	REG_OFFSET_NAME(mtp0, mtp[0]),
537 	REG_OFFSET_NAME(mtp1, mtp[1]),
538 	REG_OFFSET_NAME(mtp2, mtp[2]),
539 #endif
540 	REG_OFFSET_END,
541 };
542 
543 /**
544  * regs_query_register_offset() - query register offset from its name
545  * @name:       the name of a register
546  *
547  * regs_query_register_offset() returns the offset of a register in struct
548  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
549  */
550 int regs_query_register_offset(const char *name)
551 {
552         const struct pt_regs_offset *roff;
553         for (roff = regoffset_table; roff->name != NULL; roff++)
554                 if (!strcmp(roff->name, name))
555                         return roff->offset;
556         return -EINVAL;
557 }
558 
559 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
560 
561 static const struct user_regset mips_regsets[] = {
562 	[REGSET_GPR] = {
563 		.core_note_type	= NT_PRSTATUS,
564 		.n		= ELF_NGREG,
565 		.size		= sizeof(unsigned int),
566 		.align		= sizeof(unsigned int),
567 		.get		= gpr32_get,
568 		.set		= gpr32_set,
569 	},
570 	[REGSET_FPR] = {
571 		.core_note_type	= NT_PRFPREG,
572 		.n		= ELF_NFPREG,
573 		.size		= sizeof(elf_fpreg_t),
574 		.align		= sizeof(elf_fpreg_t),
575 		.get		= fpr_get,
576 		.set		= fpr_set,
577 	},
578 };
579 
580 static const struct user_regset_view user_mips_view = {
581 	.name		= "mips",
582 	.e_machine	= ELF_ARCH,
583 	.ei_osabi	= ELF_OSABI,
584 	.regsets	= mips_regsets,
585 	.n		= ARRAY_SIZE(mips_regsets),
586 };
587 
588 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
589 
590 #ifdef CONFIG_64BIT
591 
592 static const struct user_regset mips64_regsets[] = {
593 	[REGSET_GPR] = {
594 		.core_note_type	= NT_PRSTATUS,
595 		.n		= ELF_NGREG,
596 		.size		= sizeof(unsigned long),
597 		.align		= sizeof(unsigned long),
598 		.get		= gpr64_get,
599 		.set		= gpr64_set,
600 	},
601 	[REGSET_FPR] = {
602 		.core_note_type	= NT_PRFPREG,
603 		.n		= ELF_NFPREG,
604 		.size		= sizeof(elf_fpreg_t),
605 		.align		= sizeof(elf_fpreg_t),
606 		.get		= fpr_get,
607 		.set		= fpr_set,
608 	},
609 };
610 
611 static const struct user_regset_view user_mips64_view = {
612 	.name		= "mips64",
613 	.e_machine	= ELF_ARCH,
614 	.ei_osabi	= ELF_OSABI,
615 	.regsets	= mips64_regsets,
616 	.n		= ARRAY_SIZE(mips64_regsets),
617 };
618 
619 #endif /* CONFIG_64BIT */
620 
621 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
622 {
623 #ifdef CONFIG_32BIT
624 	return &user_mips_view;
625 #else
626 #ifdef CONFIG_MIPS32_O32
627 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
628 		return &user_mips_view;
629 #endif
630 	return &user_mips64_view;
631 #endif
632 }
633 
634 long arch_ptrace(struct task_struct *child, long request,
635 		 unsigned long addr, unsigned long data)
636 {
637 	int ret;
638 	void __user *addrp = (void __user *) addr;
639 	void __user *datavp = (void __user *) data;
640 	unsigned long __user *datalp = (void __user *) data;
641 
642 	switch (request) {
643 	/* when I and D space are separate, these will need to be fixed. */
644 	case PTRACE_PEEKTEXT: /* read word at location addr. */
645 	case PTRACE_PEEKDATA:
646 		ret = generic_ptrace_peekdata(child, addr, data);
647 		break;
648 
649 	/* Read the word at location addr in the USER area. */
650 	case PTRACE_PEEKUSR: {
651 		struct pt_regs *regs;
652 		union fpureg *fregs;
653 		unsigned long tmp = 0;
654 
655 		regs = task_pt_regs(child);
656 		ret = 0;  /* Default return value. */
657 
658 		switch (addr) {
659 		case 0 ... 31:
660 			tmp = regs->regs[addr];
661 			break;
662 		case FPR_BASE ... FPR_BASE + 31:
663 			if (!tsk_used_math(child)) {
664 				/* FP not yet used */
665 				tmp = -1;
666 				break;
667 			}
668 			fregs = get_fpu_regs(child);
669 
670 #ifdef CONFIG_32BIT
671 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
672 				/*
673 				 * The odd registers are actually the high
674 				 * order bits of the values stored in the even
675 				 * registers - unless we're using r2k_switch.S.
676 				 */
677 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
678 						addr & 1);
679 				break;
680 			}
681 #endif
682 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
683 			break;
684 		case PC:
685 			tmp = regs->cp0_epc;
686 			break;
687 		case CAUSE:
688 			tmp = regs->cp0_cause;
689 			break;
690 		case BADVADDR:
691 			tmp = regs->cp0_badvaddr;
692 			break;
693 		case MMHI:
694 			tmp = regs->hi;
695 			break;
696 		case MMLO:
697 			tmp = regs->lo;
698 			break;
699 #ifdef CONFIG_CPU_HAS_SMARTMIPS
700 		case ACX:
701 			tmp = regs->acx;
702 			break;
703 #endif
704 		case FPC_CSR:
705 			tmp = child->thread.fpu.fcr31;
706 			break;
707 		case FPC_EIR:
708 			/* implementation / version register */
709 			tmp = boot_cpu_data.fpu_id;
710 			break;
711 		case DSP_BASE ... DSP_BASE + 5: {
712 			dspreg_t *dregs;
713 
714 			if (!cpu_has_dsp) {
715 				tmp = 0;
716 				ret = -EIO;
717 				goto out;
718 			}
719 			dregs = __get_dsp_regs(child);
720 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
721 			break;
722 		}
723 		case DSP_CONTROL:
724 			if (!cpu_has_dsp) {
725 				tmp = 0;
726 				ret = -EIO;
727 				goto out;
728 			}
729 			tmp = child->thread.dsp.dspcontrol;
730 			break;
731 		default:
732 			tmp = 0;
733 			ret = -EIO;
734 			goto out;
735 		}
736 		ret = put_user(tmp, datalp);
737 		break;
738 	}
739 
740 	/* when I and D space are separate, this will have to be fixed. */
741 	case PTRACE_POKETEXT: /* write the word at location addr. */
742 	case PTRACE_POKEDATA:
743 		ret = generic_ptrace_pokedata(child, addr, data);
744 		break;
745 
746 	case PTRACE_POKEUSR: {
747 		struct pt_regs *regs;
748 		ret = 0;
749 		regs = task_pt_regs(child);
750 
751 		switch (addr) {
752 		case 0 ... 31:
753 			regs->regs[addr] = data;
754 			break;
755 		case FPR_BASE ... FPR_BASE + 31: {
756 			union fpureg *fregs = get_fpu_regs(child);
757 
758 			init_fp_ctx(child);
759 #ifdef CONFIG_32BIT
760 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
761 				/*
762 				 * The odd registers are actually the high
763 				 * order bits of the values stored in the even
764 				 * registers - unless we're using r2k_switch.S.
765 				 */
766 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
767 					  addr & 1, data);
768 				break;
769 			}
770 #endif
771 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
772 			break;
773 		}
774 		case PC:
775 			regs->cp0_epc = data;
776 			break;
777 		case MMHI:
778 			regs->hi = data;
779 			break;
780 		case MMLO:
781 			regs->lo = data;
782 			break;
783 #ifdef CONFIG_CPU_HAS_SMARTMIPS
784 		case ACX:
785 			regs->acx = data;
786 			break;
787 #endif
788 		case FPC_CSR:
789 			init_fp_ctx(child);
790 			ptrace_setfcr31(child, data);
791 			break;
792 		case DSP_BASE ... DSP_BASE + 5: {
793 			dspreg_t *dregs;
794 
795 			if (!cpu_has_dsp) {
796 				ret = -EIO;
797 				break;
798 			}
799 
800 			dregs = __get_dsp_regs(child);
801 			dregs[addr - DSP_BASE] = data;
802 			break;
803 		}
804 		case DSP_CONTROL:
805 			if (!cpu_has_dsp) {
806 				ret = -EIO;
807 				break;
808 			}
809 			child->thread.dsp.dspcontrol = data;
810 			break;
811 		default:
812 			/* The rest are not allowed. */
813 			ret = -EIO;
814 			break;
815 		}
816 		break;
817 		}
818 
819 	case PTRACE_GETREGS:
820 		ret = ptrace_getregs(child, datavp);
821 		break;
822 
823 	case PTRACE_SETREGS:
824 		ret = ptrace_setregs(child, datavp);
825 		break;
826 
827 	case PTRACE_GETFPREGS:
828 		ret = ptrace_getfpregs(child, datavp);
829 		break;
830 
831 	case PTRACE_SETFPREGS:
832 		ret = ptrace_setfpregs(child, datavp);
833 		break;
834 
835 	case PTRACE_GET_THREAD_AREA:
836 		ret = put_user(task_thread_info(child)->tp_value, datalp);
837 		break;
838 
839 	case PTRACE_GET_WATCH_REGS:
840 		ret = ptrace_get_watch_regs(child, addrp);
841 		break;
842 
843 	case PTRACE_SET_WATCH_REGS:
844 		ret = ptrace_set_watch_regs(child, addrp);
845 		break;
846 
847 	default:
848 		ret = ptrace_request(child, request, addr, data);
849 		break;
850 	}
851  out:
852 	return ret;
853 }
854 
855 /*
856  * Notification of system call entry/exit
857  * - triggered by current->work.syscall_trace
858  */
859 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
860 {
861 	user_exit();
862 
863 	current_thread_info()->syscall = syscall;
864 
865 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
866 	    tracehook_report_syscall_entry(regs))
867 		return -1;
868 
869 	if (secure_computing(NULL) == -1)
870 		return -1;
871 
872 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
873 		trace_sys_enter(regs, regs->regs[2]);
874 
875 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
876 			    regs->regs[6], regs->regs[7]);
877 	return syscall;
878 }
879 
880 /*
881  * Notification of system call entry/exit
882  * - triggered by current->work.syscall_trace
883  */
884 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
885 {
886         /*
887 	 * We may come here right after calling schedule_user()
888 	 * or do_notify_resume(), in which case we can be in RCU
889 	 * user mode.
890 	 */
891 	user_exit();
892 
893 	audit_syscall_exit(regs);
894 
895 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
896 		trace_sys_exit(regs, regs->regs[2]);
897 
898 	if (test_thread_flag(TIF_SYSCALL_TRACE))
899 		tracehook_report_syscall_exit(regs, 0);
900 
901 	user_enter();
902 }
903