xref: /openbmc/linux/arch/mips/kernel/ptrace.c (revision 4f6cce39)
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 	for (i = 0; i < NUM_FPU_REGS; i++) {
460 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
461 					 &fpr_val, i * sizeof(elf_fpreg_t),
462 					 (i + 1) * sizeof(elf_fpreg_t));
463 		if (err)
464 			return err;
465 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
466 	}
467 
468 	return 0;
469 }
470 
471 enum mips_regset {
472 	REGSET_GPR,
473 	REGSET_FPR,
474 };
475 
476 struct pt_regs_offset {
477 	const char *name;
478 	int offset;
479 };
480 
481 #define REG_OFFSET_NAME(reg, r) {					\
482 	.name = #reg,							\
483 	.offset = offsetof(struct pt_regs, r)				\
484 }
485 
486 #define REG_OFFSET_END {						\
487 	.name = NULL,							\
488 	.offset = 0							\
489 }
490 
491 static const struct pt_regs_offset regoffset_table[] = {
492 	REG_OFFSET_NAME(r0, regs[0]),
493 	REG_OFFSET_NAME(r1, regs[1]),
494 	REG_OFFSET_NAME(r2, regs[2]),
495 	REG_OFFSET_NAME(r3, regs[3]),
496 	REG_OFFSET_NAME(r4, regs[4]),
497 	REG_OFFSET_NAME(r5, regs[5]),
498 	REG_OFFSET_NAME(r6, regs[6]),
499 	REG_OFFSET_NAME(r7, regs[7]),
500 	REG_OFFSET_NAME(r8, regs[8]),
501 	REG_OFFSET_NAME(r9, regs[9]),
502 	REG_OFFSET_NAME(r10, regs[10]),
503 	REG_OFFSET_NAME(r11, regs[11]),
504 	REG_OFFSET_NAME(r12, regs[12]),
505 	REG_OFFSET_NAME(r13, regs[13]),
506 	REG_OFFSET_NAME(r14, regs[14]),
507 	REG_OFFSET_NAME(r15, regs[15]),
508 	REG_OFFSET_NAME(r16, regs[16]),
509 	REG_OFFSET_NAME(r17, regs[17]),
510 	REG_OFFSET_NAME(r18, regs[18]),
511 	REG_OFFSET_NAME(r19, regs[19]),
512 	REG_OFFSET_NAME(r20, regs[20]),
513 	REG_OFFSET_NAME(r21, regs[21]),
514 	REG_OFFSET_NAME(r22, regs[22]),
515 	REG_OFFSET_NAME(r23, regs[23]),
516 	REG_OFFSET_NAME(r24, regs[24]),
517 	REG_OFFSET_NAME(r25, regs[25]),
518 	REG_OFFSET_NAME(r26, regs[26]),
519 	REG_OFFSET_NAME(r27, regs[27]),
520 	REG_OFFSET_NAME(r28, regs[28]),
521 	REG_OFFSET_NAME(r29, regs[29]),
522 	REG_OFFSET_NAME(r30, regs[30]),
523 	REG_OFFSET_NAME(r31, regs[31]),
524 	REG_OFFSET_NAME(c0_status, cp0_status),
525 	REG_OFFSET_NAME(hi, hi),
526 	REG_OFFSET_NAME(lo, lo),
527 #ifdef CONFIG_CPU_HAS_SMARTMIPS
528 	REG_OFFSET_NAME(acx, acx),
529 #endif
530 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
531 	REG_OFFSET_NAME(c0_cause, cp0_cause),
532 	REG_OFFSET_NAME(c0_epc, cp0_epc),
533 #ifdef CONFIG_CPU_CAVIUM_OCTEON
534 	REG_OFFSET_NAME(mpl0, mpl[0]),
535 	REG_OFFSET_NAME(mpl1, mpl[1]),
536 	REG_OFFSET_NAME(mpl2, mpl[2]),
537 	REG_OFFSET_NAME(mtp0, mtp[0]),
538 	REG_OFFSET_NAME(mtp1, mtp[1]),
539 	REG_OFFSET_NAME(mtp2, mtp[2]),
540 #endif
541 	REG_OFFSET_END,
542 };
543 
544 /**
545  * regs_query_register_offset() - query register offset from its name
546  * @name:       the name of a register
547  *
548  * regs_query_register_offset() returns the offset of a register in struct
549  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
550  */
551 int regs_query_register_offset(const char *name)
552 {
553         const struct pt_regs_offset *roff;
554         for (roff = regoffset_table; roff->name != NULL; roff++)
555                 if (!strcmp(roff->name, name))
556                         return roff->offset;
557         return -EINVAL;
558 }
559 
560 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
561 
562 static const struct user_regset mips_regsets[] = {
563 	[REGSET_GPR] = {
564 		.core_note_type	= NT_PRSTATUS,
565 		.n		= ELF_NGREG,
566 		.size		= sizeof(unsigned int),
567 		.align		= sizeof(unsigned int),
568 		.get		= gpr32_get,
569 		.set		= gpr32_set,
570 	},
571 	[REGSET_FPR] = {
572 		.core_note_type	= NT_PRFPREG,
573 		.n		= ELF_NFPREG,
574 		.size		= sizeof(elf_fpreg_t),
575 		.align		= sizeof(elf_fpreg_t),
576 		.get		= fpr_get,
577 		.set		= fpr_set,
578 	},
579 };
580 
581 static const struct user_regset_view user_mips_view = {
582 	.name		= "mips",
583 	.e_machine	= ELF_ARCH,
584 	.ei_osabi	= ELF_OSABI,
585 	.regsets	= mips_regsets,
586 	.n		= ARRAY_SIZE(mips_regsets),
587 };
588 
589 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
590 
591 #ifdef CONFIG_64BIT
592 
593 static const struct user_regset mips64_regsets[] = {
594 	[REGSET_GPR] = {
595 		.core_note_type	= NT_PRSTATUS,
596 		.n		= ELF_NGREG,
597 		.size		= sizeof(unsigned long),
598 		.align		= sizeof(unsigned long),
599 		.get		= gpr64_get,
600 		.set		= gpr64_set,
601 	},
602 	[REGSET_FPR] = {
603 		.core_note_type	= NT_PRFPREG,
604 		.n		= ELF_NFPREG,
605 		.size		= sizeof(elf_fpreg_t),
606 		.align		= sizeof(elf_fpreg_t),
607 		.get		= fpr_get,
608 		.set		= fpr_set,
609 	},
610 };
611 
612 static const struct user_regset_view user_mips64_view = {
613 	.name		= "mips64",
614 	.e_machine	= ELF_ARCH,
615 	.ei_osabi	= ELF_OSABI,
616 	.regsets	= mips64_regsets,
617 	.n		= ARRAY_SIZE(mips64_regsets),
618 };
619 
620 #endif /* CONFIG_64BIT */
621 
622 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
623 {
624 #ifdef CONFIG_32BIT
625 	return &user_mips_view;
626 #else
627 #ifdef CONFIG_MIPS32_O32
628 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
629 		return &user_mips_view;
630 #endif
631 	return &user_mips64_view;
632 #endif
633 }
634 
635 long arch_ptrace(struct task_struct *child, long request,
636 		 unsigned long addr, unsigned long data)
637 {
638 	int ret;
639 	void __user *addrp = (void __user *) addr;
640 	void __user *datavp = (void __user *) data;
641 	unsigned long __user *datalp = (void __user *) data;
642 
643 	switch (request) {
644 	/* when I and D space are separate, these will need to be fixed. */
645 	case PTRACE_PEEKTEXT: /* read word at location addr. */
646 	case PTRACE_PEEKDATA:
647 		ret = generic_ptrace_peekdata(child, addr, data);
648 		break;
649 
650 	/* Read the word at location addr in the USER area. */
651 	case PTRACE_PEEKUSR: {
652 		struct pt_regs *regs;
653 		union fpureg *fregs;
654 		unsigned long tmp = 0;
655 
656 		regs = task_pt_regs(child);
657 		ret = 0;  /* Default return value. */
658 
659 		switch (addr) {
660 		case 0 ... 31:
661 			tmp = regs->regs[addr];
662 			break;
663 		case FPR_BASE ... FPR_BASE + 31:
664 			if (!tsk_used_math(child)) {
665 				/* FP not yet used */
666 				tmp = -1;
667 				break;
668 			}
669 			fregs = get_fpu_regs(child);
670 
671 #ifdef CONFIG_32BIT
672 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
673 				/*
674 				 * The odd registers are actually the high
675 				 * order bits of the values stored in the even
676 				 * registers - unless we're using r2k_switch.S.
677 				 */
678 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
679 						addr & 1);
680 				break;
681 			}
682 #endif
683 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
684 			break;
685 		case PC:
686 			tmp = regs->cp0_epc;
687 			break;
688 		case CAUSE:
689 			tmp = regs->cp0_cause;
690 			break;
691 		case BADVADDR:
692 			tmp = regs->cp0_badvaddr;
693 			break;
694 		case MMHI:
695 			tmp = regs->hi;
696 			break;
697 		case MMLO:
698 			tmp = regs->lo;
699 			break;
700 #ifdef CONFIG_CPU_HAS_SMARTMIPS
701 		case ACX:
702 			tmp = regs->acx;
703 			break;
704 #endif
705 		case FPC_CSR:
706 			tmp = child->thread.fpu.fcr31;
707 			break;
708 		case FPC_EIR:
709 			/* implementation / version register */
710 			tmp = boot_cpu_data.fpu_id;
711 			break;
712 		case DSP_BASE ... DSP_BASE + 5: {
713 			dspreg_t *dregs;
714 
715 			if (!cpu_has_dsp) {
716 				tmp = 0;
717 				ret = -EIO;
718 				goto out;
719 			}
720 			dregs = __get_dsp_regs(child);
721 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
722 			break;
723 		}
724 		case DSP_CONTROL:
725 			if (!cpu_has_dsp) {
726 				tmp = 0;
727 				ret = -EIO;
728 				goto out;
729 			}
730 			tmp = child->thread.dsp.dspcontrol;
731 			break;
732 		default:
733 			tmp = 0;
734 			ret = -EIO;
735 			goto out;
736 		}
737 		ret = put_user(tmp, datalp);
738 		break;
739 	}
740 
741 	/* when I and D space are separate, this will have to be fixed. */
742 	case PTRACE_POKETEXT: /* write the word at location addr. */
743 	case PTRACE_POKEDATA:
744 		ret = generic_ptrace_pokedata(child, addr, data);
745 		break;
746 
747 	case PTRACE_POKEUSR: {
748 		struct pt_regs *regs;
749 		ret = 0;
750 		regs = task_pt_regs(child);
751 
752 		switch (addr) {
753 		case 0 ... 31:
754 			regs->regs[addr] = data;
755 			break;
756 		case FPR_BASE ... FPR_BASE + 31: {
757 			union fpureg *fregs = get_fpu_regs(child);
758 
759 			init_fp_ctx(child);
760 #ifdef CONFIG_32BIT
761 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
762 				/*
763 				 * The odd registers are actually the high
764 				 * order bits of the values stored in the even
765 				 * registers - unless we're using r2k_switch.S.
766 				 */
767 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
768 					  addr & 1, data);
769 				break;
770 			}
771 #endif
772 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
773 			break;
774 		}
775 		case PC:
776 			regs->cp0_epc = data;
777 			break;
778 		case MMHI:
779 			regs->hi = data;
780 			break;
781 		case MMLO:
782 			regs->lo = data;
783 			break;
784 #ifdef CONFIG_CPU_HAS_SMARTMIPS
785 		case ACX:
786 			regs->acx = data;
787 			break;
788 #endif
789 		case FPC_CSR:
790 			init_fp_ctx(child);
791 			ptrace_setfcr31(child, data);
792 			break;
793 		case DSP_BASE ... DSP_BASE + 5: {
794 			dspreg_t *dregs;
795 
796 			if (!cpu_has_dsp) {
797 				ret = -EIO;
798 				break;
799 			}
800 
801 			dregs = __get_dsp_regs(child);
802 			dregs[addr - DSP_BASE] = data;
803 			break;
804 		}
805 		case DSP_CONTROL:
806 			if (!cpu_has_dsp) {
807 				ret = -EIO;
808 				break;
809 			}
810 			child->thread.dsp.dspcontrol = data;
811 			break;
812 		default:
813 			/* The rest are not allowed. */
814 			ret = -EIO;
815 			break;
816 		}
817 		break;
818 		}
819 
820 	case PTRACE_GETREGS:
821 		ret = ptrace_getregs(child, datavp);
822 		break;
823 
824 	case PTRACE_SETREGS:
825 		ret = ptrace_setregs(child, datavp);
826 		break;
827 
828 	case PTRACE_GETFPREGS:
829 		ret = ptrace_getfpregs(child, datavp);
830 		break;
831 
832 	case PTRACE_SETFPREGS:
833 		ret = ptrace_setfpregs(child, datavp);
834 		break;
835 
836 	case PTRACE_GET_THREAD_AREA:
837 		ret = put_user(task_thread_info(child)->tp_value, datalp);
838 		break;
839 
840 	case PTRACE_GET_WATCH_REGS:
841 		ret = ptrace_get_watch_regs(child, addrp);
842 		break;
843 
844 	case PTRACE_SET_WATCH_REGS:
845 		ret = ptrace_set_watch_regs(child, addrp);
846 		break;
847 
848 	default:
849 		ret = ptrace_request(child, request, addr, data);
850 		break;
851 	}
852  out:
853 	return ret;
854 }
855 
856 /*
857  * Notification of system call entry/exit
858  * - triggered by current->work.syscall_trace
859  */
860 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
861 {
862 	user_exit();
863 
864 	current_thread_info()->syscall = syscall;
865 
866 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
867 	    tracehook_report_syscall_entry(regs))
868 		return -1;
869 
870 	if (secure_computing(NULL) == -1)
871 		return -1;
872 
873 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
874 		trace_sys_enter(regs, regs->regs[2]);
875 
876 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
877 			    regs->regs[6], regs->regs[7]);
878 	return syscall;
879 }
880 
881 /*
882  * Notification of system call entry/exit
883  * - triggered by current->work.syscall_trace
884  */
885 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
886 {
887         /*
888 	 * We may come here right after calling schedule_user()
889 	 * or do_notify_resume(), in which case we can be in RCU
890 	 * user mode.
891 	 */
892 	user_exit();
893 
894 	audit_syscall_exit(regs);
895 
896 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
897 		trace_sys_exit(regs, regs->regs[2]);
898 
899 	if (test_thread_flag(TIF_SYSCALL_TRACE))
900 		tracehook_report_syscall_exit(regs, 0);
901 
902 	user_enter();
903 }
904