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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.  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  */
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 	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  */
ptrace_getregs(struct task_struct * child,struct user_pt_regs __user * data)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  */
ptrace_setregs(struct task_struct * child,struct user_pt_regs __user * data)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 
ptrace_getfpregs(struct task_struct * child,__u32 __user * data)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 
ptrace_setfpregs(struct task_struct * child,__u32 __user * data)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 
ptrace_get_watch_regs(struct task_struct * child,struct pt_watch_regs __user * addr)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 
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] & ~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 
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 
442 /*
443  * Copy the floating-point context to the supplied NT_PRFPREG buffer,
444  * !CONFIG_CPU_HAS_MSA variant.  FP context's general register slots
445  * correspond 1:1 to buffer slots.  Only general registers are copied.
446  */
fpr_get_fpa(struct task_struct * target,unsigned int * pos,unsigned int * count,void ** kbuf,void __user ** ubuf)447 static int fpr_get_fpa(struct task_struct *target,
448 		       unsigned int *pos, unsigned int *count,
449 		       void **kbuf, void __user **ubuf)
450 {
451 	return user_regset_copyout(pos, count, kbuf, ubuf,
452 				   &target->thread.fpu,
453 				   0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
454 }
455 
456 /*
457  * Copy the floating-point context to the supplied NT_PRFPREG buffer,
458  * CONFIG_CPU_HAS_MSA variant.  Only lower 64 bits of FP context's
459  * general register slots are copied to buffer slots.  Only general
460  * registers are copied.
461  */
fpr_get_msa(struct task_struct * target,unsigned int * pos,unsigned int * count,void ** kbuf,void __user ** ubuf)462 static int fpr_get_msa(struct task_struct *target,
463 		       unsigned int *pos, unsigned int *count,
464 		       void **kbuf, void __user **ubuf)
465 {
466 	unsigned int i;
467 	u64 fpr_val;
468 	int err;
469 
470 	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
471 	for (i = 0; i < NUM_FPU_REGS; i++) {
472 		fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
473 		err = user_regset_copyout(pos, count, kbuf, ubuf,
474 					  &fpr_val, i * sizeof(elf_fpreg_t),
475 					  (i + 1) * sizeof(elf_fpreg_t));
476 		if (err)
477 			return err;
478 	}
479 
480 	return 0;
481 }
482 
483 /*
484  * Copy the floating-point context to the supplied NT_PRFPREG buffer.
485  * Choose the appropriate helper for general registers, and then copy
486  * the FCSR register separately.
487  */
fpr_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)488 static int fpr_get(struct task_struct *target,
489 		   const struct user_regset *regset,
490 		   unsigned int pos, unsigned int count,
491 		   void *kbuf, void __user *ubuf)
492 {
493 	const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
494 	int err;
495 
496 	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
497 		err = fpr_get_fpa(target, &pos, &count, &kbuf, &ubuf);
498 	else
499 		err = fpr_get_msa(target, &pos, &count, &kbuf, &ubuf);
500 	if (err)
501 		return err;
502 
503 	err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
504 				  &target->thread.fpu.fcr31,
505 				  fcr31_pos, fcr31_pos + sizeof(u32));
506 
507 	return err;
508 }
509 
510 /*
511  * Copy the supplied NT_PRFPREG buffer to the floating-point context,
512  * !CONFIG_CPU_HAS_MSA variant.   Buffer slots correspond 1:1 to FP
513  * context's general register slots.  Only general registers are copied.
514  */
fpr_set_fpa(struct task_struct * target,unsigned int * pos,unsigned int * count,const void ** kbuf,const void __user ** ubuf)515 static int fpr_set_fpa(struct task_struct *target,
516 		       unsigned int *pos, unsigned int *count,
517 		       const void **kbuf, const void __user **ubuf)
518 {
519 	return user_regset_copyin(pos, count, kbuf, ubuf,
520 				  &target->thread.fpu,
521 				  0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
522 }
523 
524 /*
525  * Copy the supplied NT_PRFPREG buffer to the floating-point context,
526  * CONFIG_CPU_HAS_MSA variant.  Buffer slots are copied to lower 64
527  * bits only of FP context's general register slots.  Only general
528  * registers are copied.
529  */
fpr_set_msa(struct task_struct * target,unsigned int * pos,unsigned int * count,const void ** kbuf,const void __user ** ubuf)530 static int fpr_set_msa(struct task_struct *target,
531 		       unsigned int *pos, unsigned int *count,
532 		       const void **kbuf, const void __user **ubuf)
533 {
534 	unsigned int i;
535 	u64 fpr_val;
536 	int err;
537 
538 	BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
539 	for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) {
540 		err = user_regset_copyin(pos, count, kbuf, ubuf,
541 					 &fpr_val, i * sizeof(elf_fpreg_t),
542 					 (i + 1) * sizeof(elf_fpreg_t));
543 		if (err)
544 			return err;
545 		set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
546 	}
547 
548 	return 0;
549 }
550 
551 /*
552  * Copy the supplied NT_PRFPREG buffer to the floating-point context.
553  * Choose the appropriate helper for general registers, and then copy
554  * the FCSR register separately.
555  *
556  * We optimize for the case where `count % sizeof(elf_fpreg_t) == 0',
557  * which is supposed to have been guaranteed by the kernel before
558  * calling us, e.g. in `ptrace_regset'.  We enforce that requirement,
559  * so that we can safely avoid preinitializing temporaries for
560  * partial register writes.
561  */
fpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)562 static int fpr_set(struct task_struct *target,
563 		   const struct user_regset *regset,
564 		   unsigned int pos, unsigned int count,
565 		   const void *kbuf, const void __user *ubuf)
566 {
567 	const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
568 	u32 fcr31;
569 	int err;
570 
571 	BUG_ON(count % sizeof(elf_fpreg_t));
572 
573 	if (pos + count > sizeof(elf_fpregset_t))
574 		return -EIO;
575 
576 	init_fp_ctx(target);
577 
578 	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
579 		err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf);
580 	else
581 		err = fpr_set_msa(target, &pos, &count, &kbuf, &ubuf);
582 	if (err)
583 		return err;
584 
585 	if (count > 0) {
586 		err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
587 					 &fcr31,
588 					 fcr31_pos, fcr31_pos + sizeof(u32));
589 		if (err)
590 			return err;
591 
592 		ptrace_setfcr31(target, fcr31);
593 	}
594 
595 	return err;
596 }
597 
598 enum mips_regset {
599 	REGSET_GPR,
600 	REGSET_FPR,
601 };
602 
603 struct pt_regs_offset {
604 	const char *name;
605 	int offset;
606 };
607 
608 #define REG_OFFSET_NAME(reg, r) {					\
609 	.name = #reg,							\
610 	.offset = offsetof(struct pt_regs, r)				\
611 }
612 
613 #define REG_OFFSET_END {						\
614 	.name = NULL,							\
615 	.offset = 0							\
616 }
617 
618 static const struct pt_regs_offset regoffset_table[] = {
619 	REG_OFFSET_NAME(r0, regs[0]),
620 	REG_OFFSET_NAME(r1, regs[1]),
621 	REG_OFFSET_NAME(r2, regs[2]),
622 	REG_OFFSET_NAME(r3, regs[3]),
623 	REG_OFFSET_NAME(r4, regs[4]),
624 	REG_OFFSET_NAME(r5, regs[5]),
625 	REG_OFFSET_NAME(r6, regs[6]),
626 	REG_OFFSET_NAME(r7, regs[7]),
627 	REG_OFFSET_NAME(r8, regs[8]),
628 	REG_OFFSET_NAME(r9, regs[9]),
629 	REG_OFFSET_NAME(r10, regs[10]),
630 	REG_OFFSET_NAME(r11, regs[11]),
631 	REG_OFFSET_NAME(r12, regs[12]),
632 	REG_OFFSET_NAME(r13, regs[13]),
633 	REG_OFFSET_NAME(r14, regs[14]),
634 	REG_OFFSET_NAME(r15, regs[15]),
635 	REG_OFFSET_NAME(r16, regs[16]),
636 	REG_OFFSET_NAME(r17, regs[17]),
637 	REG_OFFSET_NAME(r18, regs[18]),
638 	REG_OFFSET_NAME(r19, regs[19]),
639 	REG_OFFSET_NAME(r20, regs[20]),
640 	REG_OFFSET_NAME(r21, regs[21]),
641 	REG_OFFSET_NAME(r22, regs[22]),
642 	REG_OFFSET_NAME(r23, regs[23]),
643 	REG_OFFSET_NAME(r24, regs[24]),
644 	REG_OFFSET_NAME(r25, regs[25]),
645 	REG_OFFSET_NAME(r26, regs[26]),
646 	REG_OFFSET_NAME(r27, regs[27]),
647 	REG_OFFSET_NAME(r28, regs[28]),
648 	REG_OFFSET_NAME(r29, regs[29]),
649 	REG_OFFSET_NAME(r30, regs[30]),
650 	REG_OFFSET_NAME(r31, regs[31]),
651 	REG_OFFSET_NAME(c0_status, cp0_status),
652 	REG_OFFSET_NAME(hi, hi),
653 	REG_OFFSET_NAME(lo, lo),
654 #ifdef CONFIG_CPU_HAS_SMARTMIPS
655 	REG_OFFSET_NAME(acx, acx),
656 #endif
657 	REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
658 	REG_OFFSET_NAME(c0_cause, cp0_cause),
659 	REG_OFFSET_NAME(c0_epc, cp0_epc),
660 #ifdef CONFIG_CPU_CAVIUM_OCTEON
661 	REG_OFFSET_NAME(mpl0, mpl[0]),
662 	REG_OFFSET_NAME(mpl1, mpl[1]),
663 	REG_OFFSET_NAME(mpl2, mpl[2]),
664 	REG_OFFSET_NAME(mtp0, mtp[0]),
665 	REG_OFFSET_NAME(mtp1, mtp[1]),
666 	REG_OFFSET_NAME(mtp2, mtp[2]),
667 #endif
668 	REG_OFFSET_END,
669 };
670 
671 /**
672  * regs_query_register_offset() - query register offset from its name
673  * @name:       the name of a register
674  *
675  * regs_query_register_offset() returns the offset of a register in struct
676  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
677  */
regs_query_register_offset(const char * name)678 int regs_query_register_offset(const char *name)
679 {
680         const struct pt_regs_offset *roff;
681         for (roff = regoffset_table; roff->name != NULL; roff++)
682                 if (!strcmp(roff->name, name))
683                         return roff->offset;
684         return -EINVAL;
685 }
686 
687 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
688 
689 static const struct user_regset mips_regsets[] = {
690 	[REGSET_GPR] = {
691 		.core_note_type	= NT_PRSTATUS,
692 		.n		= ELF_NGREG,
693 		.size		= sizeof(unsigned int),
694 		.align		= sizeof(unsigned int),
695 		.get		= gpr32_get,
696 		.set		= gpr32_set,
697 	},
698 	[REGSET_FPR] = {
699 		.core_note_type	= NT_PRFPREG,
700 		.n		= ELF_NFPREG,
701 		.size		= sizeof(elf_fpreg_t),
702 		.align		= sizeof(elf_fpreg_t),
703 		.get		= fpr_get,
704 		.set		= fpr_set,
705 	},
706 };
707 
708 static const struct user_regset_view user_mips_view = {
709 	.name		= "mips",
710 	.e_machine	= ELF_ARCH,
711 	.ei_osabi	= ELF_OSABI,
712 	.regsets	= mips_regsets,
713 	.n		= ARRAY_SIZE(mips_regsets),
714 };
715 
716 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
717 
718 #ifdef CONFIG_64BIT
719 
720 static const struct user_regset mips64_regsets[] = {
721 	[REGSET_GPR] = {
722 		.core_note_type	= NT_PRSTATUS,
723 		.n		= ELF_NGREG,
724 		.size		= sizeof(unsigned long),
725 		.align		= sizeof(unsigned long),
726 		.get		= gpr64_get,
727 		.set		= gpr64_set,
728 	},
729 	[REGSET_FPR] = {
730 		.core_note_type	= NT_PRFPREG,
731 		.n		= ELF_NFPREG,
732 		.size		= sizeof(elf_fpreg_t),
733 		.align		= sizeof(elf_fpreg_t),
734 		.get		= fpr_get,
735 		.set		= fpr_set,
736 	},
737 };
738 
739 static const struct user_regset_view user_mips64_view = {
740 	.name		= "mips64",
741 	.e_machine	= ELF_ARCH,
742 	.ei_osabi	= ELF_OSABI,
743 	.regsets	= mips64_regsets,
744 	.n		= ARRAY_SIZE(mips64_regsets),
745 };
746 
747 #ifdef CONFIG_MIPS32_N32
748 
749 static const struct user_regset_view user_mipsn32_view = {
750 	.name		= "mipsn32",
751 	.e_flags	= EF_MIPS_ABI2,
752 	.e_machine	= ELF_ARCH,
753 	.ei_osabi	= ELF_OSABI,
754 	.regsets	= mips64_regsets,
755 	.n		= ARRAY_SIZE(mips64_regsets),
756 };
757 
758 #endif /* CONFIG_MIPS32_N32 */
759 
760 #endif /* CONFIG_64BIT */
761 
task_user_regset_view(struct task_struct * task)762 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
763 {
764 #ifdef CONFIG_32BIT
765 	return &user_mips_view;
766 #else
767 #ifdef CONFIG_MIPS32_O32
768 	if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
769 		return &user_mips_view;
770 #endif
771 #ifdef CONFIG_MIPS32_N32
772 	if (test_tsk_thread_flag(task, TIF_32BIT_ADDR))
773 		return &user_mipsn32_view;
774 #endif
775 	return &user_mips64_view;
776 #endif
777 }
778 
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)779 long arch_ptrace(struct task_struct *child, long request,
780 		 unsigned long addr, unsigned long data)
781 {
782 	int ret;
783 	void __user *addrp = (void __user *) addr;
784 	void __user *datavp = (void __user *) data;
785 	unsigned long __user *datalp = (void __user *) data;
786 
787 	switch (request) {
788 	/* when I and D space are separate, these will need to be fixed. */
789 	case PTRACE_PEEKTEXT: /* read word at location addr. */
790 	case PTRACE_PEEKDATA:
791 		ret = generic_ptrace_peekdata(child, addr, data);
792 		break;
793 
794 	/* Read the word at location addr in the USER area. */
795 	case PTRACE_PEEKUSR: {
796 		struct pt_regs *regs;
797 		union fpureg *fregs;
798 		unsigned long tmp = 0;
799 
800 		regs = task_pt_regs(child);
801 		ret = 0;  /* Default return value. */
802 
803 		switch (addr) {
804 		case 0 ... 31:
805 			tmp = regs->regs[addr];
806 			break;
807 		case FPR_BASE ... FPR_BASE + 31:
808 			if (!tsk_used_math(child)) {
809 				/* FP not yet used */
810 				tmp = -1;
811 				break;
812 			}
813 			fregs = get_fpu_regs(child);
814 
815 #ifdef CONFIG_32BIT
816 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
817 				/*
818 				 * The odd registers are actually the high
819 				 * order bits of the values stored in the even
820 				 * registers - unless we're using r2k_switch.S.
821 				 */
822 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
823 						addr & 1);
824 				break;
825 			}
826 #endif
827 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
828 			break;
829 		case PC:
830 			tmp = regs->cp0_epc;
831 			break;
832 		case CAUSE:
833 			tmp = regs->cp0_cause;
834 			break;
835 		case BADVADDR:
836 			tmp = regs->cp0_badvaddr;
837 			break;
838 		case MMHI:
839 			tmp = regs->hi;
840 			break;
841 		case MMLO:
842 			tmp = regs->lo;
843 			break;
844 #ifdef CONFIG_CPU_HAS_SMARTMIPS
845 		case ACX:
846 			tmp = regs->acx;
847 			break;
848 #endif
849 		case FPC_CSR:
850 			tmp = child->thread.fpu.fcr31;
851 			break;
852 		case FPC_EIR:
853 			/* implementation / version register */
854 			tmp = boot_cpu_data.fpu_id;
855 			break;
856 		case DSP_BASE ... DSP_BASE + 5: {
857 			dspreg_t *dregs;
858 
859 			if (!cpu_has_dsp) {
860 				tmp = 0;
861 				ret = -EIO;
862 				goto out;
863 			}
864 			dregs = __get_dsp_regs(child);
865 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
866 			break;
867 		}
868 		case DSP_CONTROL:
869 			if (!cpu_has_dsp) {
870 				tmp = 0;
871 				ret = -EIO;
872 				goto out;
873 			}
874 			tmp = child->thread.dsp.dspcontrol;
875 			break;
876 		default:
877 			tmp = 0;
878 			ret = -EIO;
879 			goto out;
880 		}
881 		ret = put_user(tmp, datalp);
882 		break;
883 	}
884 
885 	/* when I and D space are separate, this will have to be fixed. */
886 	case PTRACE_POKETEXT: /* write the word at location addr. */
887 	case PTRACE_POKEDATA:
888 		ret = generic_ptrace_pokedata(child, addr, data);
889 		break;
890 
891 	case PTRACE_POKEUSR: {
892 		struct pt_regs *regs;
893 		ret = 0;
894 		regs = task_pt_regs(child);
895 
896 		switch (addr) {
897 		case 0 ... 31:
898 			regs->regs[addr] = data;
899 			break;
900 		case FPR_BASE ... FPR_BASE + 31: {
901 			union fpureg *fregs = get_fpu_regs(child);
902 
903 			init_fp_ctx(child);
904 #ifdef CONFIG_32BIT
905 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
906 				/*
907 				 * The odd registers are actually the high
908 				 * order bits of the values stored in the even
909 				 * registers - unless we're using r2k_switch.S.
910 				 */
911 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
912 					  addr & 1, data);
913 				break;
914 			}
915 #endif
916 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
917 			break;
918 		}
919 		case PC:
920 			regs->cp0_epc = data;
921 			break;
922 		case MMHI:
923 			regs->hi = data;
924 			break;
925 		case MMLO:
926 			regs->lo = data;
927 			break;
928 #ifdef CONFIG_CPU_HAS_SMARTMIPS
929 		case ACX:
930 			regs->acx = data;
931 			break;
932 #endif
933 		case FPC_CSR:
934 			init_fp_ctx(child);
935 			ptrace_setfcr31(child, data);
936 			break;
937 		case DSP_BASE ... DSP_BASE + 5: {
938 			dspreg_t *dregs;
939 
940 			if (!cpu_has_dsp) {
941 				ret = -EIO;
942 				break;
943 			}
944 
945 			dregs = __get_dsp_regs(child);
946 			dregs[addr - DSP_BASE] = data;
947 			break;
948 		}
949 		case DSP_CONTROL:
950 			if (!cpu_has_dsp) {
951 				ret = -EIO;
952 				break;
953 			}
954 			child->thread.dsp.dspcontrol = data;
955 			break;
956 		default:
957 			/* The rest are not allowed. */
958 			ret = -EIO;
959 			break;
960 		}
961 		break;
962 		}
963 
964 	case PTRACE_GETREGS:
965 		ret = ptrace_getregs(child, datavp);
966 		break;
967 
968 	case PTRACE_SETREGS:
969 		ret = ptrace_setregs(child, datavp);
970 		break;
971 
972 	case PTRACE_GETFPREGS:
973 		ret = ptrace_getfpregs(child, datavp);
974 		break;
975 
976 	case PTRACE_SETFPREGS:
977 		ret = ptrace_setfpregs(child, datavp);
978 		break;
979 
980 	case PTRACE_GET_THREAD_AREA:
981 		ret = put_user(task_thread_info(child)->tp_value, datalp);
982 		break;
983 
984 	case PTRACE_GET_WATCH_REGS:
985 		ret = ptrace_get_watch_regs(child, addrp);
986 		break;
987 
988 	case PTRACE_SET_WATCH_REGS:
989 		ret = ptrace_set_watch_regs(child, addrp);
990 		break;
991 
992 	default:
993 		ret = ptrace_request(child, request, addr, data);
994 		break;
995 	}
996  out:
997 	return ret;
998 }
999 
1000 /*
1001  * Notification of system call entry/exit
1002  * - triggered by current->work.syscall_trace
1003  */
syscall_trace_enter(struct pt_regs * regs,long syscall)1004 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
1005 {
1006 	user_exit();
1007 
1008 	current_thread_info()->syscall = syscall;
1009 
1010 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
1011 	    tracehook_report_syscall_entry(regs))
1012 		return -1;
1013 
1014 	if (secure_computing(NULL) == -1)
1015 		return -1;
1016 
1017 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1018 		trace_sys_enter(regs, regs->regs[2]);
1019 
1020 	audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
1021 			    regs->regs[6], regs->regs[7]);
1022 	return syscall;
1023 }
1024 
1025 /*
1026  * Notification of system call entry/exit
1027  * - triggered by current->work.syscall_trace
1028  */
syscall_trace_leave(struct pt_regs * regs)1029 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
1030 {
1031         /*
1032 	 * We may come here right after calling schedule_user()
1033 	 * or do_notify_resume(), in which case we can be in RCU
1034 	 * user mode.
1035 	 */
1036 	user_exit();
1037 
1038 	audit_syscall_exit(regs);
1039 
1040 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1041 		trace_sys_exit(regs, regs_return_value(regs));
1042 
1043 	if (test_thread_flag(TIF_SYSCALL_TRACE))
1044 		tracehook_report_syscall_exit(regs, 0);
1045 
1046 	user_enter();
1047 }
1048