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 
init_fp_ctx(struct task_struct * target)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  */
ptrace_disable(struct task_struct * child)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.  Don't set the cause bits as
83  * this is currently not handled correctly in FP context restoration
84  * and will cause an oops if a corresponding enable bit is set.
85  */
ptrace_setfcr31(struct task_struct * child,u32 value)86 static void ptrace_setfcr31(struct task_struct *child, u32 value)
87 {
88 	u32 fcr31;
89 	u32 mask;
90 
91 	value &= ~FPU_CSR_ALL_X;
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  */
ptrace_getregs(struct task_struct * child,struct user_pt_regs __user * data)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  */
ptrace_setregs(struct task_struct * child,struct user_pt_regs __user * data)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 
ptrace_getfpregs(struct task_struct * child,__u32 __user * data)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 
ptrace_setfpregs(struct task_struct * child,__u32 __user * data)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 
ptrace_get_watch_regs(struct task_struct * child,struct pt_watch_regs __user * addr)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] & 0xfff,
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 
ptrace_set_watch_regs(struct task_struct * child,struct pt_watch_regs __user * addr)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] & ~0xff8)
267 			return -EINVAL;
268 	}
269 	/* Install them. */
270 	for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
271 		if (lt[i] & 7)
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 
gpr32_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)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 	unsigned i;
298 
299 	for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) {
300 		/* k0/k1 are copied as zero. */
301 		if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27)
302 			continue;
303 
304 		uregs[i] = regs->regs[i - MIPS32_EF_R0];
305 	}
306 
307 	uregs[MIPS32_EF_LO] = regs->lo;
308 	uregs[MIPS32_EF_HI] = regs->hi;
309 	uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc;
310 	uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
311 	uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status;
312 	uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause;
313 
314 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
315 				   sizeof(uregs));
316 }
317 
gpr32_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)318 static int gpr32_set(struct task_struct *target,
319 		     const struct user_regset *regset,
320 		     unsigned int pos, unsigned int count,
321 		     const void *kbuf, const void __user *ubuf)
322 {
323 	struct pt_regs *regs = task_pt_regs(target);
324 	u32 uregs[ELF_NGREG];
325 	unsigned start, num_regs, i;
326 	int err;
327 
328 	start = pos / sizeof(u32);
329 	num_regs = count / sizeof(u32);
330 
331 	if (start + num_regs > ELF_NGREG)
332 		return -EIO;
333 
334 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
335 				 sizeof(uregs));
336 	if (err)
337 		return err;
338 
339 	for (i = start; i < num_regs; i++) {
340 		/*
341 		 * Cast all values to signed here so that if this is a 64-bit
342 		 * kernel, the supplied 32-bit values will be sign extended.
343 		 */
344 		switch (i) {
345 		case MIPS32_EF_R1 ... MIPS32_EF_R25:
346 			/* k0/k1 are ignored. */
347 		case MIPS32_EF_R28 ... MIPS32_EF_R31:
348 			regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
349 			break;
350 		case MIPS32_EF_LO:
351 			regs->lo = (s32)uregs[i];
352 			break;
353 		case MIPS32_EF_HI:
354 			regs->hi = (s32)uregs[i];
355 			break;
356 		case MIPS32_EF_CP0_EPC:
357 			regs->cp0_epc = (s32)uregs[i];
358 			break;
359 		}
360 	}
361 
362 	return 0;
363 }
364 
365 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
366 
367 #ifdef CONFIG_64BIT
368 
gpr64_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)369 static int gpr64_get(struct task_struct *target,
370 		     const struct user_regset *regset,
371 		     unsigned int pos, unsigned int count,
372 		     void *kbuf, void __user *ubuf)
373 {
374 	struct pt_regs *regs = task_pt_regs(target);
375 	u64 uregs[ELF_NGREG] = {};
376 	unsigned i;
377 
378 	for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) {
379 		/* k0/k1 are copied as zero. */
380 		if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27)
381 			continue;
382 
383 		uregs[i] = regs->regs[i - MIPS64_EF_R0];
384 	}
385 
386 	uregs[MIPS64_EF_LO] = regs->lo;
387 	uregs[MIPS64_EF_HI] = regs->hi;
388 	uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc;
389 	uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
390 	uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status;
391 	uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause;
392 
393 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
394 				   sizeof(uregs));
395 }
396 
gpr64_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)397 static int gpr64_set(struct task_struct *target,
398 		     const struct user_regset *regset,
399 		     unsigned int pos, unsigned int count,
400 		     const void *kbuf, const void __user *ubuf)
401 {
402 	struct pt_regs *regs = task_pt_regs(target);
403 	u64 uregs[ELF_NGREG];
404 	unsigned start, num_regs, i;
405 	int err;
406 
407 	start = pos / sizeof(u64);
408 	num_regs = count / sizeof(u64);
409 
410 	if (start + num_regs > ELF_NGREG)
411 		return -EIO;
412 
413 	err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
414 				 sizeof(uregs));
415 	if (err)
416 		return err;
417 
418 	for (i = start; i < num_regs; i++) {
419 		switch (i) {
420 		case MIPS64_EF_R1 ... MIPS64_EF_R25:
421 			/* k0/k1 are ignored. */
422 		case MIPS64_EF_R28 ... MIPS64_EF_R31:
423 			regs->regs[i - MIPS64_EF_R0] = uregs[i];
424 			break;
425 		case MIPS64_EF_LO:
426 			regs->lo = uregs[i];
427 			break;
428 		case MIPS64_EF_HI:
429 			regs->hi = uregs[i];
430 			break;
431 		case MIPS64_EF_CP0_EPC:
432 			regs->cp0_epc = uregs[i];
433 			break;
434 		}
435 	}
436 
437 	return 0;
438 }
439 
440 #endif /* CONFIG_64BIT */
441 
fpr_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)442 static int fpr_get(struct task_struct *target,
443 		   const struct user_regset *regset,
444 		   unsigned int pos, unsigned int count,
445 		   void *kbuf, void __user *ubuf)
446 {
447 	unsigned i;
448 	int err;
449 	u64 fpr_val;
450 
451 	/* XXX fcr31  */
452 
453 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
454 		return user_regset_copyout(&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 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
460 		err = user_regset_copyout(&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 	}
466 
467 	return 0;
468 }
469 
fpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)470 static int fpr_set(struct task_struct *target,
471 		   const struct user_regset *regset,
472 		   unsigned int pos, unsigned int count,
473 		   const void *kbuf, const void __user *ubuf)
474 {
475 	unsigned i;
476 	int err;
477 	u64 fpr_val;
478 
479 	/* XXX fcr31  */
480 
481 	init_fp_ctx(target);
482 
483 	if (sizeof(target->thread.fpu.fpr[i]) == sizeof(elf_fpreg_t))
484 		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
485 					  &target->thread.fpu,
486 					  0, sizeof(elf_fpregset_t));
487 
488 	for (i = 0; i < NUM_FPU_REGS; i++) {
489 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
490 					 &fpr_val, i * sizeof(elf_fpreg_t),
491 					 (i + 1) * sizeof(elf_fpreg_t));
492 		if (err)
493 			return err;
494 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
495 	}
496 
497 	return 0;
498 }
499 
500 enum mips_regset {
501 	REGSET_GPR,
502 	REGSET_FPR,
503 };
504 
505 struct pt_regs_offset {
506 	const char *name;
507 	int offset;
508 };
509 
510 #define REG_OFFSET_NAME(reg, r) {					\
511 	.name = #reg,							\
512 	.offset = offsetof(struct pt_regs, r)				\
513 }
514 
515 #define REG_OFFSET_END {						\
516 	.name = NULL,							\
517 	.offset = 0							\
518 }
519 
520 static const struct pt_regs_offset regoffset_table[] = {
521 	REG_OFFSET_NAME(r0, regs[0]),
522 	REG_OFFSET_NAME(r1, regs[1]),
523 	REG_OFFSET_NAME(r2, regs[2]),
524 	REG_OFFSET_NAME(r3, regs[3]),
525 	REG_OFFSET_NAME(r4, regs[4]),
526 	REG_OFFSET_NAME(r5, regs[5]),
527 	REG_OFFSET_NAME(r6, regs[6]),
528 	REG_OFFSET_NAME(r7, regs[7]),
529 	REG_OFFSET_NAME(r8, regs[8]),
530 	REG_OFFSET_NAME(r9, regs[9]),
531 	REG_OFFSET_NAME(r10, regs[10]),
532 	REG_OFFSET_NAME(r11, regs[11]),
533 	REG_OFFSET_NAME(r12, regs[12]),
534 	REG_OFFSET_NAME(r13, regs[13]),
535 	REG_OFFSET_NAME(r14, regs[14]),
536 	REG_OFFSET_NAME(r15, regs[15]),
537 	REG_OFFSET_NAME(r16, regs[16]),
538 	REG_OFFSET_NAME(r17, regs[17]),
539 	REG_OFFSET_NAME(r18, regs[18]),
540 	REG_OFFSET_NAME(r19, regs[19]),
541 	REG_OFFSET_NAME(r20, regs[20]),
542 	REG_OFFSET_NAME(r21, regs[21]),
543 	REG_OFFSET_NAME(r22, regs[22]),
544 	REG_OFFSET_NAME(r23, regs[23]),
545 	REG_OFFSET_NAME(r24, regs[24]),
546 	REG_OFFSET_NAME(r25, regs[25]),
547 	REG_OFFSET_NAME(r26, regs[26]),
548 	REG_OFFSET_NAME(r27, regs[27]),
549 	REG_OFFSET_NAME(r28, regs[28]),
550 	REG_OFFSET_NAME(r29, regs[29]),
551 	REG_OFFSET_NAME(r30, regs[30]),
552 	REG_OFFSET_NAME(r31, regs[31]),
553 	REG_OFFSET_NAME(c0_status, cp0_status),
554 	REG_OFFSET_NAME(hi, hi),
555 	REG_OFFSET_NAME(lo, lo),
556 #ifdef CONFIG_CPU_HAS_SMARTMIPS
557 	REG_OFFSET_NAME(acx, acx),
558 #endif
559 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
560 	REG_OFFSET_NAME(c0_cause, cp0_cause),
561 	REG_OFFSET_NAME(c0_epc, cp0_epc),
562 #ifdef CONFIG_MIPS_MT_SMTC
563 	REG_OFFSET_NAME(c0_tcstatus, cp0_tcstatus),
564 #endif
565 #ifdef CONFIG_CPU_CAVIUM_OCTEON
566 	REG_OFFSET_NAME(mpl0, mpl[0]),
567 	REG_OFFSET_NAME(mpl1, mpl[1]),
568 	REG_OFFSET_NAME(mpl2, mpl[2]),
569 	REG_OFFSET_NAME(mtp0, mtp[0]),
570 	REG_OFFSET_NAME(mtp1, mtp[1]),
571 	REG_OFFSET_NAME(mtp2, mtp[2]),
572 #endif
573 	REG_OFFSET_END,
574 };
575 
576 /**
577  * regs_query_register_offset() - query register offset from its name
578  * @name:       the name of a register
579  *
580  * regs_query_register_offset() returns the offset of a register in struct
581  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
582  */
regs_query_register_offset(const char * name)583 int regs_query_register_offset(const char *name)
584 {
585         const struct pt_regs_offset *roff;
586         for (roff = regoffset_table; roff->name != NULL; roff++)
587                 if (!strcmp(roff->name, name))
588                         return roff->offset;
589         return -EINVAL;
590 }
591 
592 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
593 
594 static const struct user_regset mips_regsets[] = {
595 	[REGSET_GPR] = {
596 		.core_note_type	= NT_PRSTATUS,
597 		.n		= ELF_NGREG,
598 		.size		= sizeof(unsigned int),
599 		.align		= sizeof(unsigned int),
600 		.get		= gpr32_get,
601 		.set		= gpr32_set,
602 	},
603 	[REGSET_FPR] = {
604 		.core_note_type	= NT_PRFPREG,
605 		.n		= ELF_NFPREG,
606 		.size		= sizeof(elf_fpreg_t),
607 		.align		= sizeof(elf_fpreg_t),
608 		.get		= fpr_get,
609 		.set		= fpr_set,
610 	},
611 };
612 
613 static const struct user_regset_view user_mips_view = {
614 	.name		= "mips",
615 	.e_machine	= ELF_ARCH,
616 	.ei_osabi	= ELF_OSABI,
617 	.regsets	= mips_regsets,
618 	.n		= ARRAY_SIZE(mips_regsets),
619 };
620 
621 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
622 
623 #ifdef CONFIG_64BIT
624 
625 static const struct user_regset mips64_regsets[] = {
626 	[REGSET_GPR] = {
627 		.core_note_type	= NT_PRSTATUS,
628 		.n		= ELF_NGREG,
629 		.size		= sizeof(unsigned long),
630 		.align		= sizeof(unsigned long),
631 		.get		= gpr64_get,
632 		.set		= gpr64_set,
633 	},
634 	[REGSET_FPR] = {
635 		.core_note_type	= NT_PRFPREG,
636 		.n		= ELF_NFPREG,
637 		.size		= sizeof(elf_fpreg_t),
638 		.align		= sizeof(elf_fpreg_t),
639 		.get		= fpr_get,
640 		.set		= fpr_set,
641 	},
642 };
643 
644 static const struct user_regset_view user_mips64_view = {
645 	.name		= "mips64",
646 	.e_machine	= ELF_ARCH,
647 	.ei_osabi	= ELF_OSABI,
648 	.regsets	= mips64_regsets,
649 	.n		= ARRAY_SIZE(mips64_regsets),
650 };
651 
652 #endif /* CONFIG_64BIT */
653 
task_user_regset_view(struct task_struct * task)654 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
655 {
656 #ifdef CONFIG_32BIT
657 	return &user_mips_view;
658 #else
659 #ifdef CONFIG_MIPS32_O32
660 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
661 		return &user_mips_view;
662 #endif
663 	return &user_mips64_view;
664 #endif
665 }
666 
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)667 long arch_ptrace(struct task_struct *child, long request,
668 		 unsigned long addr, unsigned long data)
669 {
670 	int ret;
671 	void __user *addrp = (void __user *) addr;
672 	void __user *datavp = (void __user *) data;
673 	unsigned long __user *datalp = (void __user *) data;
674 
675 	switch (request) {
676 	/* when I and D space are separate, these will need to be fixed. */
677 	case PTRACE_PEEKTEXT: /* read word at location addr. */
678 	case PTRACE_PEEKDATA:
679 		ret = generic_ptrace_peekdata(child, addr, data);
680 		break;
681 
682 	/* Read the word at location addr in the USER area. */
683 	case PTRACE_PEEKUSR: {
684 		struct pt_regs *regs;
685 		union fpureg *fregs;
686 		unsigned long tmp = 0;
687 
688 		regs = task_pt_regs(child);
689 		ret = 0;  /* Default return value. */
690 
691 		switch (addr) {
692 		case 0 ... 31:
693 			tmp = regs->regs[addr];
694 			break;
695 		case FPR_BASE ... FPR_BASE + 31:
696 			if (!tsk_used_math(child)) {
697 				/* FP not yet used */
698 				tmp = -1;
699 				break;
700 			}
701 			fregs = get_fpu_regs(child);
702 
703 #ifdef CONFIG_32BIT
704 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
705 				/*
706 				 * The odd registers are actually the high
707 				 * order bits of the values stored in the even
708 				 * registers - unless we're using r2k_switch.S.
709 				 */
710 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
711 						addr & 1);
712 				break;
713 			}
714 #endif
715 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
716 			break;
717 		case PC:
718 			tmp = regs->cp0_epc;
719 			break;
720 		case CAUSE:
721 			tmp = regs->cp0_cause;
722 			break;
723 		case BADVADDR:
724 			tmp = regs->cp0_badvaddr;
725 			break;
726 		case MMHI:
727 			tmp = regs->hi;
728 			break;
729 		case MMLO:
730 			tmp = regs->lo;
731 			break;
732 #ifdef CONFIG_CPU_HAS_SMARTMIPS
733 		case ACX:
734 			tmp = regs->acx;
735 			break;
736 #endif
737 		case FPC_CSR:
738 			tmp = child->thread.fpu.fcr31;
739 			break;
740 		case FPC_EIR:
741 			/* implementation / version register */
742 			tmp = boot_cpu_data.fpu_id;
743 			break;
744 		case DSP_BASE ... DSP_BASE + 5: {
745 			dspreg_t *dregs;
746 
747 			if (!cpu_has_dsp) {
748 				tmp = 0;
749 				ret = -EIO;
750 				goto out;
751 			}
752 			dregs = __get_dsp_regs(child);
753 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
754 			break;
755 		}
756 		case DSP_CONTROL:
757 			if (!cpu_has_dsp) {
758 				tmp = 0;
759 				ret = -EIO;
760 				goto out;
761 			}
762 			tmp = child->thread.dsp.dspcontrol;
763 			break;
764 		default:
765 			tmp = 0;
766 			ret = -EIO;
767 			goto out;
768 		}
769 		ret = put_user(tmp, datalp);
770 		break;
771 	}
772 
773 	/* when I and D space are separate, this will have to be fixed. */
774 	case PTRACE_POKETEXT: /* write the word at location addr. */
775 	case PTRACE_POKEDATA:
776 		ret = generic_ptrace_pokedata(child, addr, data);
777 		break;
778 
779 	case PTRACE_POKEUSR: {
780 		struct pt_regs *regs;
781 		ret = 0;
782 		regs = task_pt_regs(child);
783 
784 		switch (addr) {
785 		case 0 ... 31:
786 			regs->regs[addr] = data;
787 			break;
788 		case FPR_BASE ... FPR_BASE + 31: {
789 			union fpureg *fregs = get_fpu_regs(child);
790 
791 			init_fp_ctx(child);
792 #ifdef CONFIG_32BIT
793 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
794 				/*
795 				 * The odd registers are actually the high
796 				 * order bits of the values stored in the even
797 				 * registers - unless we're using r2k_switch.S.
798 				 */
799 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
800 					  addr & 1, data);
801 				break;
802 			}
803 #endif
804 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
805 			break;
806 		}
807 		case PC:
808 			regs->cp0_epc = data;
809 			break;
810 		case MMHI:
811 			regs->hi = data;
812 			break;
813 		case MMLO:
814 			regs->lo = data;
815 			break;
816 #ifdef CONFIG_CPU_HAS_SMARTMIPS
817 		case ACX:
818 			regs->acx = data;
819 			break;
820 #endif
821 		case FPC_CSR:
822 			ptrace_setfcr31(child, data);
823 			break;
824 		case DSP_BASE ... DSP_BASE + 5: {
825 			dspreg_t *dregs;
826 
827 			if (!cpu_has_dsp) {
828 				ret = -EIO;
829 				break;
830 			}
831 
832 			dregs = __get_dsp_regs(child);
833 			dregs[addr - DSP_BASE] = data;
834 			break;
835 		}
836 		case DSP_CONTROL:
837 			if (!cpu_has_dsp) {
838 				ret = -EIO;
839 				break;
840 			}
841 			child->thread.dsp.dspcontrol = data;
842 			break;
843 		default:
844 			/* The rest are not allowed. */
845 			ret = -EIO;
846 			break;
847 		}
848 		break;
849 		}
850 
851 	case PTRACE_GETREGS:
852 		ret = ptrace_getregs(child, datavp);
853 		break;
854 
855 	case PTRACE_SETREGS:
856 		ret = ptrace_setregs(child, datavp);
857 		break;
858 
859 	case PTRACE_GETFPREGS:
860 		ret = ptrace_getfpregs(child, datavp);
861 		break;
862 
863 	case PTRACE_SETFPREGS:
864 		ret = ptrace_setfpregs(child, datavp);
865 		break;
866 
867 	case PTRACE_GET_THREAD_AREA:
868 		ret = put_user(task_thread_info(child)->tp_value, datalp);
869 		break;
870 
871 	case PTRACE_GET_WATCH_REGS:
872 		ret = ptrace_get_watch_regs(child, addrp);
873 		break;
874 
875 	case PTRACE_SET_WATCH_REGS:
876 		ret = ptrace_set_watch_regs(child, addrp);
877 		break;
878 
879 	default:
880 		ret = ptrace_request(child, request, addr, data);
881 		break;
882 	}
883  out:
884 	return ret;
885 }
886 
887 /*
888  * Notification of system call entry/exit
889  * - triggered by current->work.syscall_trace
890  */
syscall_trace_enter(struct pt_regs * regs,long syscall)891 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
892 {
893 	long ret = 0;
894 	user_exit();
895 
896 	current_thread_info()->syscall = syscall;
897 
898 	if (secure_computing() == -1)
899 		return -1;
900 
901 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
902 	    tracehook_report_syscall_entry(regs))
903 		ret = -1;
904 
905 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
906 		trace_sys_enter(regs, regs->regs[2]);
907 
908 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
909 			    regs->regs[6], regs->regs[7]);
910 	return syscall;
911 }
912 
913 /*
914  * Notification of system call entry/exit
915  * - triggered by current->work.syscall_trace
916  */
syscall_trace_leave(struct pt_regs * regs)917 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
918 {
919         /*
920 	 * We may come here right after calling schedule_user()
921 	 * or do_notify_resume(), in which case we can be in RCU
922 	 * user mode.
923 	 */
924 	user_exit();
925 
926 	audit_syscall_exit(regs);
927 
928 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
929 		trace_sys_exit(regs, regs->regs[2]);
930 
931 	if (test_thread_flag(TIF_SYSCALL_TRACE))
932 		tracehook_report_syscall_exit(regs, 0);
933 
934 	user_enter();
935 }
936