xref: /linux/arch/powerpc/lib/sstep.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * Single-step support.
3  *
4  * Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 #include <linux/kernel.h>
12 #include <linux/kprobes.h>
13 #include <linux/ptrace.h>
14 #include <linux/prefetch.h>
15 #include <asm/sstep.h>
16 #include <asm/processor.h>
17 #include <linux/uaccess.h>
18 #include <asm/cpu_has_feature.h>
19 #include <asm/cputable.h>
20 
21 extern char system_call_common[];
22 
23 #ifdef CONFIG_PPC64
24 /* Bits in SRR1 that are copied from MSR */
25 #define MSR_MASK	0xffffffff87c0ffffUL
26 #else
27 #define MSR_MASK	0x87c0ffff
28 #endif
29 
30 /* Bits in XER */
31 #define XER_SO		0x80000000U
32 #define XER_OV		0x40000000U
33 #define XER_CA		0x20000000U
34 
35 #ifdef CONFIG_PPC_FPU
36 /*
37  * Functions in ldstfp.S
38  */
39 extern int do_lfs(int rn, unsigned long ea);
40 extern int do_lfd(int rn, unsigned long ea);
41 extern int do_stfs(int rn, unsigned long ea);
42 extern int do_stfd(int rn, unsigned long ea);
43 extern int do_lvx(int rn, unsigned long ea);
44 extern int do_stvx(int rn, unsigned long ea);
45 extern int do_lxvd2x(int rn, unsigned long ea);
46 extern int do_stxvd2x(int rn, unsigned long ea);
47 #endif
48 
49 /*
50  * Emulate the truncation of 64 bit values in 32-bit mode.
51  */
52 static unsigned long truncate_if_32bit(unsigned long msr, unsigned long val)
53 {
54 #ifdef __powerpc64__
55 	if ((msr & MSR_64BIT) == 0)
56 		val &= 0xffffffffUL;
57 #endif
58 	return val;
59 }
60 
61 /*
62  * Determine whether a conditional branch instruction would branch.
63  */
64 static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs)
65 {
66 	unsigned int bo = (instr >> 21) & 0x1f;
67 	unsigned int bi;
68 
69 	if ((bo & 4) == 0) {
70 		/* decrement counter */
71 		--regs->ctr;
72 		if (((bo >> 1) & 1) ^ (regs->ctr == 0))
73 			return 0;
74 	}
75 	if ((bo & 0x10) == 0) {
76 		/* check bit from CR */
77 		bi = (instr >> 16) & 0x1f;
78 		if (((regs->ccr >> (31 - bi)) & 1) != ((bo >> 3) & 1))
79 			return 0;
80 	}
81 	return 1;
82 }
83 
84 
85 static long __kprobes address_ok(struct pt_regs *regs, unsigned long ea, int nb)
86 {
87 	if (!user_mode(regs))
88 		return 1;
89 	return __access_ok(ea, nb, USER_DS);
90 }
91 
92 /*
93  * Calculate effective address for a D-form instruction
94  */
95 static unsigned long __kprobes dform_ea(unsigned int instr, struct pt_regs *regs)
96 {
97 	int ra;
98 	unsigned long ea;
99 
100 	ra = (instr >> 16) & 0x1f;
101 	ea = (signed short) instr;		/* sign-extend */
102 	if (ra)
103 		ea += regs->gpr[ra];
104 
105 	return truncate_if_32bit(regs->msr, ea);
106 }
107 
108 #ifdef __powerpc64__
109 /*
110  * Calculate effective address for a DS-form instruction
111  */
112 static unsigned long __kprobes dsform_ea(unsigned int instr, struct pt_regs *regs)
113 {
114 	int ra;
115 	unsigned long ea;
116 
117 	ra = (instr >> 16) & 0x1f;
118 	ea = (signed short) (instr & ~3);	/* sign-extend */
119 	if (ra)
120 		ea += regs->gpr[ra];
121 
122 	return truncate_if_32bit(regs->msr, ea);
123 }
124 #endif /* __powerpc64 */
125 
126 /*
127  * Calculate effective address for an X-form instruction
128  */
129 static unsigned long __kprobes xform_ea(unsigned int instr,
130 					struct pt_regs *regs)
131 {
132 	int ra, rb;
133 	unsigned long ea;
134 
135 	ra = (instr >> 16) & 0x1f;
136 	rb = (instr >> 11) & 0x1f;
137 	ea = regs->gpr[rb];
138 	if (ra)
139 		ea += regs->gpr[ra];
140 
141 	return truncate_if_32bit(regs->msr, ea);
142 }
143 
144 /*
145  * Return the largest power of 2, not greater than sizeof(unsigned long),
146  * such that x is a multiple of it.
147  */
148 static inline unsigned long max_align(unsigned long x)
149 {
150 	x |= sizeof(unsigned long);
151 	return x & -x;		/* isolates rightmost bit */
152 }
153 
154 
155 static inline unsigned long byterev_2(unsigned long x)
156 {
157 	return ((x >> 8) & 0xff) | ((x & 0xff) << 8);
158 }
159 
160 static inline unsigned long byterev_4(unsigned long x)
161 {
162 	return ((x >> 24) & 0xff) | ((x >> 8) & 0xff00) |
163 		((x & 0xff00) << 8) | ((x & 0xff) << 24);
164 }
165 
166 #ifdef __powerpc64__
167 static inline unsigned long byterev_8(unsigned long x)
168 {
169 	return (byterev_4(x) << 32) | byterev_4(x >> 32);
170 }
171 #endif
172 
173 static int __kprobes read_mem_aligned(unsigned long *dest, unsigned long ea,
174 				      int nb)
175 {
176 	int err = 0;
177 	unsigned long x = 0;
178 
179 	switch (nb) {
180 	case 1:
181 		err = __get_user(x, (unsigned char __user *) ea);
182 		break;
183 	case 2:
184 		err = __get_user(x, (unsigned short __user *) ea);
185 		break;
186 	case 4:
187 		err = __get_user(x, (unsigned int __user *) ea);
188 		break;
189 #ifdef __powerpc64__
190 	case 8:
191 		err = __get_user(x, (unsigned long __user *) ea);
192 		break;
193 #endif
194 	}
195 	if (!err)
196 		*dest = x;
197 	return err;
198 }
199 
200 static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
201 					int nb, struct pt_regs *regs)
202 {
203 	int err;
204 	unsigned long x, b, c;
205 #ifdef __LITTLE_ENDIAN__
206 	int len = nb; /* save a copy of the length for byte reversal */
207 #endif
208 
209 	/* unaligned, do this in pieces */
210 	x = 0;
211 	for (; nb > 0; nb -= c) {
212 #ifdef __LITTLE_ENDIAN__
213 		c = 1;
214 #endif
215 #ifdef __BIG_ENDIAN__
216 		c = max_align(ea);
217 #endif
218 		if (c > nb)
219 			c = max_align(nb);
220 		err = read_mem_aligned(&b, ea, c);
221 		if (err)
222 			return err;
223 		x = (x << (8 * c)) + b;
224 		ea += c;
225 	}
226 #ifdef __LITTLE_ENDIAN__
227 	switch (len) {
228 	case 2:
229 		*dest = byterev_2(x);
230 		break;
231 	case 4:
232 		*dest = byterev_4(x);
233 		break;
234 #ifdef __powerpc64__
235 	case 8:
236 		*dest = byterev_8(x);
237 		break;
238 #endif
239 	}
240 #endif
241 #ifdef __BIG_ENDIAN__
242 	*dest = x;
243 #endif
244 	return 0;
245 }
246 
247 /*
248  * Read memory at address ea for nb bytes, return 0 for success
249  * or -EFAULT if an error occurred.
250  */
251 static int __kprobes read_mem(unsigned long *dest, unsigned long ea, int nb,
252 			      struct pt_regs *regs)
253 {
254 	if (!address_ok(regs, ea, nb))
255 		return -EFAULT;
256 	if ((ea & (nb - 1)) == 0)
257 		return read_mem_aligned(dest, ea, nb);
258 	return read_mem_unaligned(dest, ea, nb, regs);
259 }
260 
261 static int __kprobes write_mem_aligned(unsigned long val, unsigned long ea,
262 				       int nb)
263 {
264 	int err = 0;
265 
266 	switch (nb) {
267 	case 1:
268 		err = __put_user(val, (unsigned char __user *) ea);
269 		break;
270 	case 2:
271 		err = __put_user(val, (unsigned short __user *) ea);
272 		break;
273 	case 4:
274 		err = __put_user(val, (unsigned int __user *) ea);
275 		break;
276 #ifdef __powerpc64__
277 	case 8:
278 		err = __put_user(val, (unsigned long __user *) ea);
279 		break;
280 #endif
281 	}
282 	return err;
283 }
284 
285 static int __kprobes write_mem_unaligned(unsigned long val, unsigned long ea,
286 					 int nb, struct pt_regs *regs)
287 {
288 	int err;
289 	unsigned long c;
290 
291 #ifdef __LITTLE_ENDIAN__
292 	switch (nb) {
293 	case 2:
294 		val = byterev_2(val);
295 		break;
296 	case 4:
297 		val = byterev_4(val);
298 		break;
299 #ifdef __powerpc64__
300 	case 8:
301 		val = byterev_8(val);
302 		break;
303 #endif
304 	}
305 #endif
306 	/* unaligned or little-endian, do this in pieces */
307 	for (; nb > 0; nb -= c) {
308 #ifdef __LITTLE_ENDIAN__
309 		c = 1;
310 #endif
311 #ifdef __BIG_ENDIAN__
312 		c = max_align(ea);
313 #endif
314 		if (c > nb)
315 			c = max_align(nb);
316 		err = write_mem_aligned(val >> (nb - c) * 8, ea, c);
317 		if (err)
318 			return err;
319 		ea += c;
320 	}
321 	return 0;
322 }
323 
324 /*
325  * Write memory at address ea for nb bytes, return 0 for success
326  * or -EFAULT if an error occurred.
327  */
328 static int __kprobes write_mem(unsigned long val, unsigned long ea, int nb,
329 			       struct pt_regs *regs)
330 {
331 	if (!address_ok(regs, ea, nb))
332 		return -EFAULT;
333 	if ((ea & (nb - 1)) == 0)
334 		return write_mem_aligned(val, ea, nb);
335 	return write_mem_unaligned(val, ea, nb, regs);
336 }
337 
338 #ifdef CONFIG_PPC_FPU
339 /*
340  * Check the address and alignment, and call func to do the actual
341  * load or store.
342  */
343 static int __kprobes do_fp_load(int rn, int (*func)(int, unsigned long),
344 				unsigned long ea, int nb,
345 				struct pt_regs *regs)
346 {
347 	int err;
348 	union {
349 		double dbl;
350 		unsigned long ul[2];
351 		struct {
352 #ifdef __BIG_ENDIAN__
353 			unsigned _pad_;
354 			unsigned word;
355 #endif
356 #ifdef __LITTLE_ENDIAN__
357 			unsigned word;
358 			unsigned _pad_;
359 #endif
360 		} single;
361 	} data;
362 	unsigned long ptr;
363 
364 	if (!address_ok(regs, ea, nb))
365 		return -EFAULT;
366 	if ((ea & 3) == 0)
367 		return (*func)(rn, ea);
368 	ptr = (unsigned long) &data.ul;
369 	if (sizeof(unsigned long) == 8 || nb == 4) {
370 		err = read_mem_unaligned(&data.ul[0], ea, nb, regs);
371 		if (nb == 4)
372 			ptr = (unsigned long)&(data.single.word);
373 	} else {
374 		/* reading a double on 32-bit */
375 		err = read_mem_unaligned(&data.ul[0], ea, 4, regs);
376 		if (!err)
377 			err = read_mem_unaligned(&data.ul[1], ea + 4, 4, regs);
378 	}
379 	if (err)
380 		return err;
381 	return (*func)(rn, ptr);
382 }
383 
384 static int __kprobes do_fp_store(int rn, int (*func)(int, unsigned long),
385 				 unsigned long ea, int nb,
386 				 struct pt_regs *regs)
387 {
388 	int err;
389 	union {
390 		double dbl;
391 		unsigned long ul[2];
392 		struct {
393 #ifdef __BIG_ENDIAN__
394 			unsigned _pad_;
395 			unsigned word;
396 #endif
397 #ifdef __LITTLE_ENDIAN__
398 			unsigned word;
399 			unsigned _pad_;
400 #endif
401 		} single;
402 	} data;
403 	unsigned long ptr;
404 
405 	if (!address_ok(regs, ea, nb))
406 		return -EFAULT;
407 	if ((ea & 3) == 0)
408 		return (*func)(rn, ea);
409 	ptr = (unsigned long) &data.ul[0];
410 	if (sizeof(unsigned long) == 8 || nb == 4) {
411 		if (nb == 4)
412 			ptr = (unsigned long)&(data.single.word);
413 		err = (*func)(rn, ptr);
414 		if (err)
415 			return err;
416 		err = write_mem_unaligned(data.ul[0], ea, nb, regs);
417 	} else {
418 		/* writing a double on 32-bit */
419 		err = (*func)(rn, ptr);
420 		if (err)
421 			return err;
422 		err = write_mem_unaligned(data.ul[0], ea, 4, regs);
423 		if (!err)
424 			err = write_mem_unaligned(data.ul[1], ea + 4, 4, regs);
425 	}
426 	return err;
427 }
428 #endif
429 
430 #ifdef CONFIG_ALTIVEC
431 /* For Altivec/VMX, no need to worry about alignment */
432 static int __kprobes do_vec_load(int rn, int (*func)(int, unsigned long),
433 				 unsigned long ea, struct pt_regs *regs)
434 {
435 	if (!address_ok(regs, ea & ~0xfUL, 16))
436 		return -EFAULT;
437 	return (*func)(rn, ea);
438 }
439 
440 static int __kprobes do_vec_store(int rn, int (*func)(int, unsigned long),
441 				  unsigned long ea, struct pt_regs *regs)
442 {
443 	if (!address_ok(regs, ea & ~0xfUL, 16))
444 		return -EFAULT;
445 	return (*func)(rn, ea);
446 }
447 #endif /* CONFIG_ALTIVEC */
448 
449 #ifdef CONFIG_VSX
450 static int __kprobes do_vsx_load(int rn, int (*func)(int, unsigned long),
451 				 unsigned long ea, struct pt_regs *regs)
452 {
453 	int err;
454 	unsigned long val[2];
455 
456 	if (!address_ok(regs, ea, 16))
457 		return -EFAULT;
458 	if ((ea & 3) == 0)
459 		return (*func)(rn, ea);
460 	err = read_mem_unaligned(&val[0], ea, 8, regs);
461 	if (!err)
462 		err = read_mem_unaligned(&val[1], ea + 8, 8, regs);
463 	if (!err)
464 		err = (*func)(rn, (unsigned long) &val[0]);
465 	return err;
466 }
467 
468 static int __kprobes do_vsx_store(int rn, int (*func)(int, unsigned long),
469 				 unsigned long ea, struct pt_regs *regs)
470 {
471 	int err;
472 	unsigned long val[2];
473 
474 	if (!address_ok(regs, ea, 16))
475 		return -EFAULT;
476 	if ((ea & 3) == 0)
477 		return (*func)(rn, ea);
478 	err = (*func)(rn, (unsigned long) &val[0]);
479 	if (err)
480 		return err;
481 	err = write_mem_unaligned(val[0], ea, 8, regs);
482 	if (!err)
483 		err = write_mem_unaligned(val[1], ea + 8, 8, regs);
484 	return err;
485 }
486 #endif /* CONFIG_VSX */
487 
488 #define __put_user_asmx(x, addr, err, op, cr)		\
489 	__asm__ __volatile__(				\
490 		"1:	" op " %2,0,%3\n"		\
491 		"	mfcr	%1\n"			\
492 		"2:\n"					\
493 		".section .fixup,\"ax\"\n"		\
494 		"3:	li	%0,%4\n"		\
495 		"	b	2b\n"			\
496 		".previous\n"				\
497 		EX_TABLE(1b, 3b)			\
498 		: "=r" (err), "=r" (cr)			\
499 		: "r" (x), "r" (addr), "i" (-EFAULT), "0" (err))
500 
501 #define __get_user_asmx(x, addr, err, op)		\
502 	__asm__ __volatile__(				\
503 		"1:	"op" %1,0,%2\n"			\
504 		"2:\n"					\
505 		".section .fixup,\"ax\"\n"		\
506 		"3:	li	%0,%3\n"		\
507 		"	b	2b\n"			\
508 		".previous\n"				\
509 		EX_TABLE(1b, 3b)			\
510 		: "=r" (err), "=r" (x)			\
511 		: "r" (addr), "i" (-EFAULT), "0" (err))
512 
513 #define __cacheop_user_asmx(addr, err, op)		\
514 	__asm__ __volatile__(				\
515 		"1:	"op" 0,%1\n"			\
516 		"2:\n"					\
517 		".section .fixup,\"ax\"\n"		\
518 		"3:	li	%0,%3\n"		\
519 		"	b	2b\n"			\
520 		".previous\n"				\
521 		EX_TABLE(1b, 3b)			\
522 		: "=r" (err)				\
523 		: "r" (addr), "i" (-EFAULT), "0" (err))
524 
525 static void __kprobes set_cr0(struct pt_regs *regs, int rd)
526 {
527 	long val = regs->gpr[rd];
528 
529 	regs->ccr = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000);
530 #ifdef __powerpc64__
531 	if (!(regs->msr & MSR_64BIT))
532 		val = (int) val;
533 #endif
534 	if (val < 0)
535 		regs->ccr |= 0x80000000;
536 	else if (val > 0)
537 		regs->ccr |= 0x40000000;
538 	else
539 		regs->ccr |= 0x20000000;
540 }
541 
542 static void __kprobes add_with_carry(struct pt_regs *regs, int rd,
543 				     unsigned long val1, unsigned long val2,
544 				     unsigned long carry_in)
545 {
546 	unsigned long val = val1 + val2;
547 
548 	if (carry_in)
549 		++val;
550 	regs->gpr[rd] = val;
551 #ifdef __powerpc64__
552 	if (!(regs->msr & MSR_64BIT)) {
553 		val = (unsigned int) val;
554 		val1 = (unsigned int) val1;
555 	}
556 #endif
557 	if (val < val1 || (carry_in && val == val1))
558 		regs->xer |= XER_CA;
559 	else
560 		regs->xer &= ~XER_CA;
561 }
562 
563 static void __kprobes do_cmp_signed(struct pt_regs *regs, long v1, long v2,
564 				    int crfld)
565 {
566 	unsigned int crval, shift;
567 
568 	crval = (regs->xer >> 31) & 1;		/* get SO bit */
569 	if (v1 < v2)
570 		crval |= 8;
571 	else if (v1 > v2)
572 		crval |= 4;
573 	else
574 		crval |= 2;
575 	shift = (7 - crfld) * 4;
576 	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
577 }
578 
579 static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
580 				      unsigned long v2, int crfld)
581 {
582 	unsigned int crval, shift;
583 
584 	crval = (regs->xer >> 31) & 1;		/* get SO bit */
585 	if (v1 < v2)
586 		crval |= 8;
587 	else if (v1 > v2)
588 		crval |= 4;
589 	else
590 		crval |= 2;
591 	shift = (7 - crfld) * 4;
592 	regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
593 }
594 
595 static int __kprobes trap_compare(long v1, long v2)
596 {
597 	int ret = 0;
598 
599 	if (v1 < v2)
600 		ret |= 0x10;
601 	else if (v1 > v2)
602 		ret |= 0x08;
603 	else
604 		ret |= 0x04;
605 	if ((unsigned long)v1 < (unsigned long)v2)
606 		ret |= 0x02;
607 	else if ((unsigned long)v1 > (unsigned long)v2)
608 		ret |= 0x01;
609 	return ret;
610 }
611 
612 /*
613  * Elements of 32-bit rotate and mask instructions.
614  */
615 #define MASK32(mb, me)	((0xffffffffUL >> (mb)) + \
616 			 ((signed long)-0x80000000L >> (me)) + ((me) >= (mb)))
617 #ifdef __powerpc64__
618 #define MASK64_L(mb)	(~0UL >> (mb))
619 #define MASK64_R(me)	((signed long)-0x8000000000000000L >> (me))
620 #define MASK64(mb, me)	(MASK64_L(mb) + MASK64_R(me) + ((me) >= (mb)))
621 #define DATA32(x)	(((x) & 0xffffffffUL) | (((x) & 0xffffffffUL) << 32))
622 #else
623 #define DATA32(x)	(x)
624 #endif
625 #define ROTATE(x, n)	((n) ? (((x) << (n)) | ((x) >> (8 * sizeof(long) - (n)))) : (x))
626 
627 /*
628  * Decode an instruction, and execute it if that can be done just by
629  * modifying *regs (i.e. integer arithmetic and logical instructions,
630  * branches, and barrier instructions).
631  * Returns 1 if the instruction has been executed, or 0 if not.
632  * Sets *op to indicate what the instruction does.
633  */
634 int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
635 			    unsigned int instr)
636 {
637 	unsigned int opcode, ra, rb, rd, spr, u;
638 	unsigned long int imm;
639 	unsigned long int val, val2;
640 	unsigned int mb, me, sh;
641 	long ival;
642 
643 	op->type = COMPUTE;
644 
645 	opcode = instr >> 26;
646 	switch (opcode) {
647 	case 16:	/* bc */
648 		op->type = BRANCH;
649 		imm = (signed short)(instr & 0xfffc);
650 		if ((instr & 2) == 0)
651 			imm += regs->nip;
652 		regs->nip += 4;
653 		regs->nip = truncate_if_32bit(regs->msr, regs->nip);
654 		if (instr & 1)
655 			regs->link = regs->nip;
656 		if (branch_taken(instr, regs))
657 			regs->nip = truncate_if_32bit(regs->msr, imm);
658 		return 1;
659 #ifdef CONFIG_PPC64
660 	case 17:	/* sc */
661 		if ((instr & 0xfe2) == 2)
662 			op->type = SYSCALL;
663 		else
664 			op->type = UNKNOWN;
665 		return 0;
666 #endif
667 	case 18:	/* b */
668 		op->type = BRANCH;
669 		imm = instr & 0x03fffffc;
670 		if (imm & 0x02000000)
671 			imm -= 0x04000000;
672 		if ((instr & 2) == 0)
673 			imm += regs->nip;
674 		if (instr & 1)
675 			regs->link = truncate_if_32bit(regs->msr, regs->nip + 4);
676 		imm = truncate_if_32bit(regs->msr, imm);
677 		regs->nip = imm;
678 		return 1;
679 	case 19:
680 		switch ((instr >> 1) & 0x3ff) {
681 		case 0:		/* mcrf */
682 			rd = (instr >> 21) & 0x1c;
683 			ra = (instr >> 16) & 0x1c;
684 			val = (regs->ccr >> ra) & 0xf;
685 			regs->ccr = (regs->ccr & ~(0xfUL << rd)) | (val << rd);
686 			goto instr_done;
687 
688 		case 16:	/* bclr */
689 		case 528:	/* bcctr */
690 			op->type = BRANCH;
691 			imm = (instr & 0x400)? regs->ctr: regs->link;
692 			regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
693 			imm = truncate_if_32bit(regs->msr, imm);
694 			if (instr & 1)
695 				regs->link = regs->nip;
696 			if (branch_taken(instr, regs))
697 				regs->nip = imm;
698 			return 1;
699 
700 		case 18:	/* rfid, scary */
701 			if (regs->msr & MSR_PR)
702 				goto priv;
703 			op->type = RFI;
704 			return 0;
705 
706 		case 150:	/* isync */
707 			op->type = BARRIER;
708 			isync();
709 			goto instr_done;
710 
711 		case 33:	/* crnor */
712 		case 129:	/* crandc */
713 		case 193:	/* crxor */
714 		case 225:	/* crnand */
715 		case 257:	/* crand */
716 		case 289:	/* creqv */
717 		case 417:	/* crorc */
718 		case 449:	/* cror */
719 			ra = (instr >> 16) & 0x1f;
720 			rb = (instr >> 11) & 0x1f;
721 			rd = (instr >> 21) & 0x1f;
722 			ra = (regs->ccr >> (31 - ra)) & 1;
723 			rb = (regs->ccr >> (31 - rb)) & 1;
724 			val = (instr >> (6 + ra * 2 + rb)) & 1;
725 			regs->ccr = (regs->ccr & ~(1UL << (31 - rd))) |
726 				(val << (31 - rd));
727 			goto instr_done;
728 		}
729 		break;
730 	case 31:
731 		switch ((instr >> 1) & 0x3ff) {
732 		case 598:	/* sync */
733 			op->type = BARRIER;
734 #ifdef __powerpc64__
735 			switch ((instr >> 21) & 3) {
736 			case 1:		/* lwsync */
737 				asm volatile("lwsync" : : : "memory");
738 				goto instr_done;
739 			case 2:		/* ptesync */
740 				asm volatile("ptesync" : : : "memory");
741 				goto instr_done;
742 			}
743 #endif
744 			mb();
745 			goto instr_done;
746 
747 		case 854:	/* eieio */
748 			op->type = BARRIER;
749 			eieio();
750 			goto instr_done;
751 		}
752 		break;
753 	}
754 
755 	/* Following cases refer to regs->gpr[], so we need all regs */
756 	if (!FULL_REGS(regs))
757 		return 0;
758 
759 	rd = (instr >> 21) & 0x1f;
760 	ra = (instr >> 16) & 0x1f;
761 	rb = (instr >> 11) & 0x1f;
762 
763 	switch (opcode) {
764 #ifdef __powerpc64__
765 	case 2:		/* tdi */
766 		if (rd & trap_compare(regs->gpr[ra], (short) instr))
767 			goto trap;
768 		goto instr_done;
769 #endif
770 	case 3:		/* twi */
771 		if (rd & trap_compare((int)regs->gpr[ra], (short) instr))
772 			goto trap;
773 		goto instr_done;
774 
775 	case 7:		/* mulli */
776 		regs->gpr[rd] = regs->gpr[ra] * (short) instr;
777 		goto instr_done;
778 
779 	case 8:		/* subfic */
780 		imm = (short) instr;
781 		add_with_carry(regs, rd, ~regs->gpr[ra], imm, 1);
782 		goto instr_done;
783 
784 	case 10:	/* cmpli */
785 		imm = (unsigned short) instr;
786 		val = regs->gpr[ra];
787 #ifdef __powerpc64__
788 		if ((rd & 1) == 0)
789 			val = (unsigned int) val;
790 #endif
791 		do_cmp_unsigned(regs, val, imm, rd >> 2);
792 		goto instr_done;
793 
794 	case 11:	/* cmpi */
795 		imm = (short) instr;
796 		val = regs->gpr[ra];
797 #ifdef __powerpc64__
798 		if ((rd & 1) == 0)
799 			val = (int) val;
800 #endif
801 		do_cmp_signed(regs, val, imm, rd >> 2);
802 		goto instr_done;
803 
804 	case 12:	/* addic */
805 		imm = (short) instr;
806 		add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
807 		goto instr_done;
808 
809 	case 13:	/* addic. */
810 		imm = (short) instr;
811 		add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
812 		set_cr0(regs, rd);
813 		goto instr_done;
814 
815 	case 14:	/* addi */
816 		imm = (short) instr;
817 		if (ra)
818 			imm += regs->gpr[ra];
819 		regs->gpr[rd] = imm;
820 		goto instr_done;
821 
822 	case 15:	/* addis */
823 		imm = ((short) instr) << 16;
824 		if (ra)
825 			imm += regs->gpr[ra];
826 		regs->gpr[rd] = imm;
827 		goto instr_done;
828 
829 	case 20:	/* rlwimi */
830 		mb = (instr >> 6) & 0x1f;
831 		me = (instr >> 1) & 0x1f;
832 		val = DATA32(regs->gpr[rd]);
833 		imm = MASK32(mb, me);
834 		regs->gpr[ra] = (regs->gpr[ra] & ~imm) | (ROTATE(val, rb) & imm);
835 		goto logical_done;
836 
837 	case 21:	/* rlwinm */
838 		mb = (instr >> 6) & 0x1f;
839 		me = (instr >> 1) & 0x1f;
840 		val = DATA32(regs->gpr[rd]);
841 		regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
842 		goto logical_done;
843 
844 	case 23:	/* rlwnm */
845 		mb = (instr >> 6) & 0x1f;
846 		me = (instr >> 1) & 0x1f;
847 		rb = regs->gpr[rb] & 0x1f;
848 		val = DATA32(regs->gpr[rd]);
849 		regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
850 		goto logical_done;
851 
852 	case 24:	/* ori */
853 		imm = (unsigned short) instr;
854 		regs->gpr[ra] = regs->gpr[rd] | imm;
855 		goto instr_done;
856 
857 	case 25:	/* oris */
858 		imm = (unsigned short) instr;
859 		regs->gpr[ra] = regs->gpr[rd] | (imm << 16);
860 		goto instr_done;
861 
862 	case 26:	/* xori */
863 		imm = (unsigned short) instr;
864 		regs->gpr[ra] = regs->gpr[rd] ^ imm;
865 		goto instr_done;
866 
867 	case 27:	/* xoris */
868 		imm = (unsigned short) instr;
869 		regs->gpr[ra] = regs->gpr[rd] ^ (imm << 16);
870 		goto instr_done;
871 
872 	case 28:	/* andi. */
873 		imm = (unsigned short) instr;
874 		regs->gpr[ra] = regs->gpr[rd] & imm;
875 		set_cr0(regs, ra);
876 		goto instr_done;
877 
878 	case 29:	/* andis. */
879 		imm = (unsigned short) instr;
880 		regs->gpr[ra] = regs->gpr[rd] & (imm << 16);
881 		set_cr0(regs, ra);
882 		goto instr_done;
883 
884 #ifdef __powerpc64__
885 	case 30:	/* rld* */
886 		mb = ((instr >> 6) & 0x1f) | (instr & 0x20);
887 		val = regs->gpr[rd];
888 		if ((instr & 0x10) == 0) {
889 			sh = rb | ((instr & 2) << 4);
890 			val = ROTATE(val, sh);
891 			switch ((instr >> 2) & 3) {
892 			case 0:		/* rldicl */
893 				regs->gpr[ra] = val & MASK64_L(mb);
894 				goto logical_done;
895 			case 1:		/* rldicr */
896 				regs->gpr[ra] = val & MASK64_R(mb);
897 				goto logical_done;
898 			case 2:		/* rldic */
899 				regs->gpr[ra] = val & MASK64(mb, 63 - sh);
900 				goto logical_done;
901 			case 3:		/* rldimi */
902 				imm = MASK64(mb, 63 - sh);
903 				regs->gpr[ra] = (regs->gpr[ra] & ~imm) |
904 					(val & imm);
905 				goto logical_done;
906 			}
907 		} else {
908 			sh = regs->gpr[rb] & 0x3f;
909 			val = ROTATE(val, sh);
910 			switch ((instr >> 1) & 7) {
911 			case 0:		/* rldcl */
912 				regs->gpr[ra] = val & MASK64_L(mb);
913 				goto logical_done;
914 			case 1:		/* rldcr */
915 				regs->gpr[ra] = val & MASK64_R(mb);
916 				goto logical_done;
917 			}
918 		}
919 #endif
920 	break; /* illegal instruction */
921 
922 	case 31:
923 		switch ((instr >> 1) & 0x3ff) {
924 		case 4:		/* tw */
925 			if (rd == 0x1f ||
926 			    (rd & trap_compare((int)regs->gpr[ra],
927 					       (int)regs->gpr[rb])))
928 				goto trap;
929 			goto instr_done;
930 #ifdef __powerpc64__
931 		case 68:	/* td */
932 			if (rd & trap_compare(regs->gpr[ra], regs->gpr[rb]))
933 				goto trap;
934 			goto instr_done;
935 #endif
936 		case 83:	/* mfmsr */
937 			if (regs->msr & MSR_PR)
938 				goto priv;
939 			op->type = MFMSR;
940 			op->reg = rd;
941 			return 0;
942 		case 146:	/* mtmsr */
943 			if (regs->msr & MSR_PR)
944 				goto priv;
945 			op->type = MTMSR;
946 			op->reg = rd;
947 			op->val = 0xffffffff & ~(MSR_ME | MSR_LE);
948 			return 0;
949 #ifdef CONFIG_PPC64
950 		case 178:	/* mtmsrd */
951 			if (regs->msr & MSR_PR)
952 				goto priv;
953 			op->type = MTMSR;
954 			op->reg = rd;
955 			/* only MSR_EE and MSR_RI get changed if bit 15 set */
956 			/* mtmsrd doesn't change MSR_HV, MSR_ME or MSR_LE */
957 			imm = (instr & 0x10000)? 0x8002: 0xefffffffffffeffeUL;
958 			op->val = imm;
959 			return 0;
960 #endif
961 
962 		case 19:	/* mfcr */
963 			regs->gpr[rd] = regs->ccr;
964 			regs->gpr[rd] &= 0xffffffffUL;
965 			goto instr_done;
966 
967 		case 144:	/* mtcrf */
968 			imm = 0xf0000000UL;
969 			val = regs->gpr[rd];
970 			for (sh = 0; sh < 8; ++sh) {
971 				if (instr & (0x80000 >> sh))
972 					regs->ccr = (regs->ccr & ~imm) |
973 						(val & imm);
974 				imm >>= 4;
975 			}
976 			goto instr_done;
977 
978 		case 339:	/* mfspr */
979 			spr = ((instr >> 16) & 0x1f) | ((instr >> 6) & 0x3e0);
980 			switch (spr) {
981 			case SPRN_XER:	/* mfxer */
982 				regs->gpr[rd] = regs->xer;
983 				regs->gpr[rd] &= 0xffffffffUL;
984 				goto instr_done;
985 			case SPRN_LR:	/* mflr */
986 				regs->gpr[rd] = regs->link;
987 				goto instr_done;
988 			case SPRN_CTR:	/* mfctr */
989 				regs->gpr[rd] = regs->ctr;
990 				goto instr_done;
991 			default:
992 				op->type = MFSPR;
993 				op->reg = rd;
994 				op->spr = spr;
995 				return 0;
996 			}
997 			break;
998 
999 		case 467:	/* mtspr */
1000 			spr = ((instr >> 16) & 0x1f) | ((instr >> 6) & 0x3e0);
1001 			switch (spr) {
1002 			case SPRN_XER:	/* mtxer */
1003 				regs->xer = (regs->gpr[rd] & 0xffffffffUL);
1004 				goto instr_done;
1005 			case SPRN_LR:	/* mtlr */
1006 				regs->link = regs->gpr[rd];
1007 				goto instr_done;
1008 			case SPRN_CTR:	/* mtctr */
1009 				regs->ctr = regs->gpr[rd];
1010 				goto instr_done;
1011 			default:
1012 				op->type = MTSPR;
1013 				op->val = regs->gpr[rd];
1014 				op->spr = spr;
1015 				return 0;
1016 			}
1017 			break;
1018 
1019 /*
1020  * Compare instructions
1021  */
1022 		case 0:	/* cmp */
1023 			val = regs->gpr[ra];
1024 			val2 = regs->gpr[rb];
1025 #ifdef __powerpc64__
1026 			if ((rd & 1) == 0) {
1027 				/* word (32-bit) compare */
1028 				val = (int) val;
1029 				val2 = (int) val2;
1030 			}
1031 #endif
1032 			do_cmp_signed(regs, val, val2, rd >> 2);
1033 			goto instr_done;
1034 
1035 		case 32:	/* cmpl */
1036 			val = regs->gpr[ra];
1037 			val2 = regs->gpr[rb];
1038 #ifdef __powerpc64__
1039 			if ((rd & 1) == 0) {
1040 				/* word (32-bit) compare */
1041 				val = (unsigned int) val;
1042 				val2 = (unsigned int) val2;
1043 			}
1044 #endif
1045 			do_cmp_unsigned(regs, val, val2, rd >> 2);
1046 			goto instr_done;
1047 
1048 /*
1049  * Arithmetic instructions
1050  */
1051 		case 8:	/* subfc */
1052 			add_with_carry(regs, rd, ~regs->gpr[ra],
1053 				       regs->gpr[rb], 1);
1054 			goto arith_done;
1055 #ifdef __powerpc64__
1056 		case 9:	/* mulhdu */
1057 			asm("mulhdu %0,%1,%2" : "=r" (regs->gpr[rd]) :
1058 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1059 			goto arith_done;
1060 #endif
1061 		case 10:	/* addc */
1062 			add_with_carry(regs, rd, regs->gpr[ra],
1063 				       regs->gpr[rb], 0);
1064 			goto arith_done;
1065 
1066 		case 11:	/* mulhwu */
1067 			asm("mulhwu %0,%1,%2" : "=r" (regs->gpr[rd]) :
1068 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1069 			goto arith_done;
1070 
1071 		case 40:	/* subf */
1072 			regs->gpr[rd] = regs->gpr[rb] - regs->gpr[ra];
1073 			goto arith_done;
1074 #ifdef __powerpc64__
1075 		case 73:	/* mulhd */
1076 			asm("mulhd %0,%1,%2" : "=r" (regs->gpr[rd]) :
1077 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1078 			goto arith_done;
1079 #endif
1080 		case 75:	/* mulhw */
1081 			asm("mulhw %0,%1,%2" : "=r" (regs->gpr[rd]) :
1082 			    "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1083 			goto arith_done;
1084 
1085 		case 104:	/* neg */
1086 			regs->gpr[rd] = -regs->gpr[ra];
1087 			goto arith_done;
1088 
1089 		case 136:	/* subfe */
1090 			add_with_carry(regs, rd, ~regs->gpr[ra], regs->gpr[rb],
1091 				       regs->xer & XER_CA);
1092 			goto arith_done;
1093 
1094 		case 138:	/* adde */
1095 			add_with_carry(regs, rd, regs->gpr[ra], regs->gpr[rb],
1096 				       regs->xer & XER_CA);
1097 			goto arith_done;
1098 
1099 		case 200:	/* subfze */
1100 			add_with_carry(regs, rd, ~regs->gpr[ra], 0L,
1101 				       regs->xer & XER_CA);
1102 			goto arith_done;
1103 
1104 		case 202:	/* addze */
1105 			add_with_carry(regs, rd, regs->gpr[ra], 0L,
1106 				       regs->xer & XER_CA);
1107 			goto arith_done;
1108 
1109 		case 232:	/* subfme */
1110 			add_with_carry(regs, rd, ~regs->gpr[ra], -1L,
1111 				       regs->xer & XER_CA);
1112 			goto arith_done;
1113 #ifdef __powerpc64__
1114 		case 233:	/* mulld */
1115 			regs->gpr[rd] = regs->gpr[ra] * regs->gpr[rb];
1116 			goto arith_done;
1117 #endif
1118 		case 234:	/* addme */
1119 			add_with_carry(regs, rd, regs->gpr[ra], -1L,
1120 				       regs->xer & XER_CA);
1121 			goto arith_done;
1122 
1123 		case 235:	/* mullw */
1124 			regs->gpr[rd] = (unsigned int) regs->gpr[ra] *
1125 				(unsigned int) regs->gpr[rb];
1126 			goto arith_done;
1127 
1128 		case 266:	/* add */
1129 			regs->gpr[rd] = regs->gpr[ra] + regs->gpr[rb];
1130 			goto arith_done;
1131 #ifdef __powerpc64__
1132 		case 457:	/* divdu */
1133 			regs->gpr[rd] = regs->gpr[ra] / regs->gpr[rb];
1134 			goto arith_done;
1135 #endif
1136 		case 459:	/* divwu */
1137 			regs->gpr[rd] = (unsigned int) regs->gpr[ra] /
1138 				(unsigned int) regs->gpr[rb];
1139 			goto arith_done;
1140 #ifdef __powerpc64__
1141 		case 489:	/* divd */
1142 			regs->gpr[rd] = (long int) regs->gpr[ra] /
1143 				(long int) regs->gpr[rb];
1144 			goto arith_done;
1145 #endif
1146 		case 491:	/* divw */
1147 			regs->gpr[rd] = (int) regs->gpr[ra] /
1148 				(int) regs->gpr[rb];
1149 			goto arith_done;
1150 
1151 
1152 /*
1153  * Logical instructions
1154  */
1155 		case 26:	/* cntlzw */
1156 			asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) :
1157 			    "r" (regs->gpr[rd]));
1158 			goto logical_done;
1159 #ifdef __powerpc64__
1160 		case 58:	/* cntlzd */
1161 			asm("cntlzd %0,%1" : "=r" (regs->gpr[ra]) :
1162 			    "r" (regs->gpr[rd]));
1163 			goto logical_done;
1164 #endif
1165 		case 28:	/* and */
1166 			regs->gpr[ra] = regs->gpr[rd] & regs->gpr[rb];
1167 			goto logical_done;
1168 
1169 		case 60:	/* andc */
1170 			regs->gpr[ra] = regs->gpr[rd] & ~regs->gpr[rb];
1171 			goto logical_done;
1172 
1173 		case 124:	/* nor */
1174 			regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]);
1175 			goto logical_done;
1176 
1177 		case 284:	/* xor */
1178 			regs->gpr[ra] = ~(regs->gpr[rd] ^ regs->gpr[rb]);
1179 			goto logical_done;
1180 
1181 		case 316:	/* xor */
1182 			regs->gpr[ra] = regs->gpr[rd] ^ regs->gpr[rb];
1183 			goto logical_done;
1184 
1185 		case 412:	/* orc */
1186 			regs->gpr[ra] = regs->gpr[rd] | ~regs->gpr[rb];
1187 			goto logical_done;
1188 
1189 		case 444:	/* or */
1190 			regs->gpr[ra] = regs->gpr[rd] | regs->gpr[rb];
1191 			goto logical_done;
1192 
1193 		case 476:	/* nand */
1194 			regs->gpr[ra] = ~(regs->gpr[rd] & regs->gpr[rb]);
1195 			goto logical_done;
1196 
1197 		case 922:	/* extsh */
1198 			regs->gpr[ra] = (signed short) regs->gpr[rd];
1199 			goto logical_done;
1200 
1201 		case 954:	/* extsb */
1202 			regs->gpr[ra] = (signed char) regs->gpr[rd];
1203 			goto logical_done;
1204 #ifdef __powerpc64__
1205 		case 986:	/* extsw */
1206 			regs->gpr[ra] = (signed int) regs->gpr[rd];
1207 			goto logical_done;
1208 #endif
1209 
1210 /*
1211  * Shift instructions
1212  */
1213 		case 24:	/* slw */
1214 			sh = regs->gpr[rb] & 0x3f;
1215 			if (sh < 32)
1216 				regs->gpr[ra] = (regs->gpr[rd] << sh) & 0xffffffffUL;
1217 			else
1218 				regs->gpr[ra] = 0;
1219 			goto logical_done;
1220 
1221 		case 536:	/* srw */
1222 			sh = regs->gpr[rb] & 0x3f;
1223 			if (sh < 32)
1224 				regs->gpr[ra] = (regs->gpr[rd] & 0xffffffffUL) >> sh;
1225 			else
1226 				regs->gpr[ra] = 0;
1227 			goto logical_done;
1228 
1229 		case 792:	/* sraw */
1230 			sh = regs->gpr[rb] & 0x3f;
1231 			ival = (signed int) regs->gpr[rd];
1232 			regs->gpr[ra] = ival >> (sh < 32 ? sh : 31);
1233 			if (ival < 0 && (sh >= 32 || (ival & ((1ul << sh) - 1)) != 0))
1234 				regs->xer |= XER_CA;
1235 			else
1236 				regs->xer &= ~XER_CA;
1237 			goto logical_done;
1238 
1239 		case 824:	/* srawi */
1240 			sh = rb;
1241 			ival = (signed int) regs->gpr[rd];
1242 			regs->gpr[ra] = ival >> sh;
1243 			if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0)
1244 				regs->xer |= XER_CA;
1245 			else
1246 				regs->xer &= ~XER_CA;
1247 			goto logical_done;
1248 
1249 #ifdef __powerpc64__
1250 		case 27:	/* sld */
1251 			sh = regs->gpr[rb] & 0x7f;
1252 			if (sh < 64)
1253 				regs->gpr[ra] = regs->gpr[rd] << sh;
1254 			else
1255 				regs->gpr[ra] = 0;
1256 			goto logical_done;
1257 
1258 		case 539:	/* srd */
1259 			sh = regs->gpr[rb] & 0x7f;
1260 			if (sh < 64)
1261 				regs->gpr[ra] = regs->gpr[rd] >> sh;
1262 			else
1263 				regs->gpr[ra] = 0;
1264 			goto logical_done;
1265 
1266 		case 794:	/* srad */
1267 			sh = regs->gpr[rb] & 0x7f;
1268 			ival = (signed long int) regs->gpr[rd];
1269 			regs->gpr[ra] = ival >> (sh < 64 ? sh : 63);
1270 			if (ival < 0 && (sh >= 64 || (ival & ((1ul << sh) - 1)) != 0))
1271 				regs->xer |= XER_CA;
1272 			else
1273 				regs->xer &= ~XER_CA;
1274 			goto logical_done;
1275 
1276 		case 826:	/* sradi with sh_5 = 0 */
1277 		case 827:	/* sradi with sh_5 = 1 */
1278 			sh = rb | ((instr & 2) << 4);
1279 			ival = (signed long int) regs->gpr[rd];
1280 			regs->gpr[ra] = ival >> sh;
1281 			if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0)
1282 				regs->xer |= XER_CA;
1283 			else
1284 				regs->xer &= ~XER_CA;
1285 			goto logical_done;
1286 #endif /* __powerpc64__ */
1287 
1288 /*
1289  * Cache instructions
1290  */
1291 		case 54:	/* dcbst */
1292 			op->type = MKOP(CACHEOP, DCBST, 0);
1293 			op->ea = xform_ea(instr, regs);
1294 			return 0;
1295 
1296 		case 86:	/* dcbf */
1297 			op->type = MKOP(CACHEOP, DCBF, 0);
1298 			op->ea = xform_ea(instr, regs);
1299 			return 0;
1300 
1301 		case 246:	/* dcbtst */
1302 			op->type = MKOP(CACHEOP, DCBTST, 0);
1303 			op->ea = xform_ea(instr, regs);
1304 			op->reg = rd;
1305 			return 0;
1306 
1307 		case 278:	/* dcbt */
1308 			op->type = MKOP(CACHEOP, DCBTST, 0);
1309 			op->ea = xform_ea(instr, regs);
1310 			op->reg = rd;
1311 			return 0;
1312 
1313 		case 982:	/* icbi */
1314 			op->type = MKOP(CACHEOP, ICBI, 0);
1315 			op->ea = xform_ea(instr, regs);
1316 			return 0;
1317 		}
1318 		break;
1319 	}
1320 
1321 	/*
1322 	 * Loads and stores.
1323 	 */
1324 	op->type = UNKNOWN;
1325 	op->update_reg = ra;
1326 	op->reg = rd;
1327 	op->val = regs->gpr[rd];
1328 	u = (instr >> 20) & UPDATE;
1329 
1330 	switch (opcode) {
1331 	case 31:
1332 		u = instr & UPDATE;
1333 		op->ea = xform_ea(instr, regs);
1334 		switch ((instr >> 1) & 0x3ff) {
1335 		case 20:	/* lwarx */
1336 			op->type = MKOP(LARX, 0, 4);
1337 			break;
1338 
1339 		case 150:	/* stwcx. */
1340 			op->type = MKOP(STCX, 0, 4);
1341 			break;
1342 
1343 #ifdef __powerpc64__
1344 		case 84:	/* ldarx */
1345 			op->type = MKOP(LARX, 0, 8);
1346 			break;
1347 
1348 		case 214:	/* stdcx. */
1349 			op->type = MKOP(STCX, 0, 8);
1350 			break;
1351 
1352 		case 21:	/* ldx */
1353 		case 53:	/* ldux */
1354 			op->type = MKOP(LOAD, u, 8);
1355 			break;
1356 #endif
1357 
1358 		case 23:	/* lwzx */
1359 		case 55:	/* lwzux */
1360 			op->type = MKOP(LOAD, u, 4);
1361 			break;
1362 
1363 		case 87:	/* lbzx */
1364 		case 119:	/* lbzux */
1365 			op->type = MKOP(LOAD, u, 1);
1366 			break;
1367 
1368 #ifdef CONFIG_ALTIVEC
1369 		case 103:	/* lvx */
1370 		case 359:	/* lvxl */
1371 			if (!(regs->msr & MSR_VEC))
1372 				goto vecunavail;
1373 			op->type = MKOP(LOAD_VMX, 0, 16);
1374 			break;
1375 
1376 		case 231:	/* stvx */
1377 		case 487:	/* stvxl */
1378 			if (!(regs->msr & MSR_VEC))
1379 				goto vecunavail;
1380 			op->type = MKOP(STORE_VMX, 0, 16);
1381 			break;
1382 #endif /* CONFIG_ALTIVEC */
1383 
1384 #ifdef __powerpc64__
1385 		case 149:	/* stdx */
1386 		case 181:	/* stdux */
1387 			op->type = MKOP(STORE, u, 8);
1388 			break;
1389 #endif
1390 
1391 		case 151:	/* stwx */
1392 		case 183:	/* stwux */
1393 			op->type = MKOP(STORE, u, 4);
1394 			break;
1395 
1396 		case 215:	/* stbx */
1397 		case 247:	/* stbux */
1398 			op->type = MKOP(STORE, u, 1);
1399 			break;
1400 
1401 		case 279:	/* lhzx */
1402 		case 311:	/* lhzux */
1403 			op->type = MKOP(LOAD, u, 2);
1404 			break;
1405 
1406 #ifdef __powerpc64__
1407 		case 341:	/* lwax */
1408 		case 373:	/* lwaux */
1409 			op->type = MKOP(LOAD, SIGNEXT | u, 4);
1410 			break;
1411 #endif
1412 
1413 		case 343:	/* lhax */
1414 		case 375:	/* lhaux */
1415 			op->type = MKOP(LOAD, SIGNEXT | u, 2);
1416 			break;
1417 
1418 		case 407:	/* sthx */
1419 		case 439:	/* sthux */
1420 			op->type = MKOP(STORE, u, 2);
1421 			break;
1422 
1423 #ifdef __powerpc64__
1424 		case 532:	/* ldbrx */
1425 			op->type = MKOP(LOAD, BYTEREV, 8);
1426 			break;
1427 
1428 #endif
1429 		case 533:	/* lswx */
1430 			op->type = MKOP(LOAD_MULTI, 0, regs->xer & 0x7f);
1431 			break;
1432 
1433 		case 534:	/* lwbrx */
1434 			op->type = MKOP(LOAD, BYTEREV, 4);
1435 			break;
1436 
1437 		case 597:	/* lswi */
1438 			if (rb == 0)
1439 				rb = 32;	/* # bytes to load */
1440 			op->type = MKOP(LOAD_MULTI, 0, rb);
1441 			op->ea = 0;
1442 			if (ra)
1443 				op->ea = truncate_if_32bit(regs->msr,
1444 							   regs->gpr[ra]);
1445 			break;
1446 
1447 #ifdef CONFIG_PPC_FPU
1448 		case 535:	/* lfsx */
1449 		case 567:	/* lfsux */
1450 			if (!(regs->msr & MSR_FP))
1451 				goto fpunavail;
1452 			op->type = MKOP(LOAD_FP, u, 4);
1453 			break;
1454 
1455 		case 599:	/* lfdx */
1456 		case 631:	/* lfdux */
1457 			if (!(regs->msr & MSR_FP))
1458 				goto fpunavail;
1459 			op->type = MKOP(LOAD_FP, u, 8);
1460 			break;
1461 
1462 		case 663:	/* stfsx */
1463 		case 695:	/* stfsux */
1464 			if (!(regs->msr & MSR_FP))
1465 				goto fpunavail;
1466 			op->type = MKOP(STORE_FP, u, 4);
1467 			break;
1468 
1469 		case 727:	/* stfdx */
1470 		case 759:	/* stfdux */
1471 			if (!(regs->msr & MSR_FP))
1472 				goto fpunavail;
1473 			op->type = MKOP(STORE_FP, u, 8);
1474 			break;
1475 #endif
1476 
1477 #ifdef __powerpc64__
1478 		case 660:	/* stdbrx */
1479 			op->type = MKOP(STORE, BYTEREV, 8);
1480 			op->val = byterev_8(regs->gpr[rd]);
1481 			break;
1482 
1483 #endif
1484 		case 661:	/* stswx */
1485 			op->type = MKOP(STORE_MULTI, 0, regs->xer & 0x7f);
1486 			break;
1487 
1488 		case 662:	/* stwbrx */
1489 			op->type = MKOP(STORE, BYTEREV, 4);
1490 			op->val = byterev_4(regs->gpr[rd]);
1491 			break;
1492 
1493 		case 725:
1494 			if (rb == 0)
1495 				rb = 32;	/* # bytes to store */
1496 			op->type = MKOP(STORE_MULTI, 0, rb);
1497 			op->ea = 0;
1498 			if (ra)
1499 				op->ea = truncate_if_32bit(regs->msr,
1500 							   regs->gpr[ra]);
1501 			break;
1502 
1503 		case 790:	/* lhbrx */
1504 			op->type = MKOP(LOAD, BYTEREV, 2);
1505 			break;
1506 
1507 		case 918:	/* sthbrx */
1508 			op->type = MKOP(STORE, BYTEREV, 2);
1509 			op->val = byterev_2(regs->gpr[rd]);
1510 			break;
1511 
1512 #ifdef CONFIG_VSX
1513 		case 844:	/* lxvd2x */
1514 		case 876:	/* lxvd2ux */
1515 			if (!(regs->msr & MSR_VSX))
1516 				goto vsxunavail;
1517 			op->reg = rd | ((instr & 1) << 5);
1518 			op->type = MKOP(LOAD_VSX, u, 16);
1519 			break;
1520 
1521 		case 972:	/* stxvd2x */
1522 		case 1004:	/* stxvd2ux */
1523 			if (!(regs->msr & MSR_VSX))
1524 				goto vsxunavail;
1525 			op->reg = rd | ((instr & 1) << 5);
1526 			op->type = MKOP(STORE_VSX, u, 16);
1527 			break;
1528 
1529 #endif /* CONFIG_VSX */
1530 		}
1531 		break;
1532 
1533 	case 32:	/* lwz */
1534 	case 33:	/* lwzu */
1535 		op->type = MKOP(LOAD, u, 4);
1536 		op->ea = dform_ea(instr, regs);
1537 		break;
1538 
1539 	case 34:	/* lbz */
1540 	case 35:	/* lbzu */
1541 		op->type = MKOP(LOAD, u, 1);
1542 		op->ea = dform_ea(instr, regs);
1543 		break;
1544 
1545 	case 36:	/* stw */
1546 	case 37:	/* stwu */
1547 		op->type = MKOP(STORE, u, 4);
1548 		op->ea = dform_ea(instr, regs);
1549 		break;
1550 
1551 	case 38:	/* stb */
1552 	case 39:	/* stbu */
1553 		op->type = MKOP(STORE, u, 1);
1554 		op->ea = dform_ea(instr, regs);
1555 		break;
1556 
1557 	case 40:	/* lhz */
1558 	case 41:	/* lhzu */
1559 		op->type = MKOP(LOAD, u, 2);
1560 		op->ea = dform_ea(instr, regs);
1561 		break;
1562 
1563 	case 42:	/* lha */
1564 	case 43:	/* lhau */
1565 		op->type = MKOP(LOAD, SIGNEXT | u, 2);
1566 		op->ea = dform_ea(instr, regs);
1567 		break;
1568 
1569 	case 44:	/* sth */
1570 	case 45:	/* sthu */
1571 		op->type = MKOP(STORE, u, 2);
1572 		op->ea = dform_ea(instr, regs);
1573 		break;
1574 
1575 	case 46:	/* lmw */
1576 		if (ra >= rd)
1577 			break;		/* invalid form, ra in range to load */
1578 		op->type = MKOP(LOAD_MULTI, 0, 4 * (32 - rd));
1579 		op->ea = dform_ea(instr, regs);
1580 		break;
1581 
1582 	case 47:	/* stmw */
1583 		op->type = MKOP(STORE_MULTI, 0, 4 * (32 - rd));
1584 		op->ea = dform_ea(instr, regs);
1585 		break;
1586 
1587 #ifdef CONFIG_PPC_FPU
1588 	case 48:	/* lfs */
1589 	case 49:	/* lfsu */
1590 		if (!(regs->msr & MSR_FP))
1591 			goto fpunavail;
1592 		op->type = MKOP(LOAD_FP, u, 4);
1593 		op->ea = dform_ea(instr, regs);
1594 		break;
1595 
1596 	case 50:	/* lfd */
1597 	case 51:	/* lfdu */
1598 		if (!(regs->msr & MSR_FP))
1599 			goto fpunavail;
1600 		op->type = MKOP(LOAD_FP, u, 8);
1601 		op->ea = dform_ea(instr, regs);
1602 		break;
1603 
1604 	case 52:	/* stfs */
1605 	case 53:	/* stfsu */
1606 		if (!(regs->msr & MSR_FP))
1607 			goto fpunavail;
1608 		op->type = MKOP(STORE_FP, u, 4);
1609 		op->ea = dform_ea(instr, regs);
1610 		break;
1611 
1612 	case 54:	/* stfd */
1613 	case 55:	/* stfdu */
1614 		if (!(regs->msr & MSR_FP))
1615 			goto fpunavail;
1616 		op->type = MKOP(STORE_FP, u, 8);
1617 		op->ea = dform_ea(instr, regs);
1618 		break;
1619 #endif
1620 
1621 #ifdef __powerpc64__
1622 	case 58:	/* ld[u], lwa */
1623 		op->ea = dsform_ea(instr, regs);
1624 		switch (instr & 3) {
1625 		case 0:		/* ld */
1626 			op->type = MKOP(LOAD, 0, 8);
1627 			break;
1628 		case 1:		/* ldu */
1629 			op->type = MKOP(LOAD, UPDATE, 8);
1630 			break;
1631 		case 2:		/* lwa */
1632 			op->type = MKOP(LOAD, SIGNEXT, 4);
1633 			break;
1634 		}
1635 		break;
1636 
1637 	case 62:	/* std[u] */
1638 		op->ea = dsform_ea(instr, regs);
1639 		switch (instr & 3) {
1640 		case 0:		/* std */
1641 			op->type = MKOP(STORE, 0, 8);
1642 			break;
1643 		case 1:		/* stdu */
1644 			op->type = MKOP(STORE, UPDATE, 8);
1645 			break;
1646 		}
1647 		break;
1648 #endif /* __powerpc64__ */
1649 
1650 	}
1651 	return 0;
1652 
1653  logical_done:
1654 	if (instr & 1)
1655 		set_cr0(regs, ra);
1656 	goto instr_done;
1657 
1658  arith_done:
1659 	if (instr & 1)
1660 		set_cr0(regs, rd);
1661 
1662  instr_done:
1663 	regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
1664 	return 1;
1665 
1666  priv:
1667 	op->type = INTERRUPT | 0x700;
1668 	op->val = SRR1_PROGPRIV;
1669 	return 0;
1670 
1671  trap:
1672 	op->type = INTERRUPT | 0x700;
1673 	op->val = SRR1_PROGTRAP;
1674 	return 0;
1675 
1676 #ifdef CONFIG_PPC_FPU
1677  fpunavail:
1678 	op->type = INTERRUPT | 0x800;
1679 	return 0;
1680 #endif
1681 
1682 #ifdef CONFIG_ALTIVEC
1683  vecunavail:
1684 	op->type = INTERRUPT | 0xf20;
1685 	return 0;
1686 #endif
1687 
1688 #ifdef CONFIG_VSX
1689  vsxunavail:
1690 	op->type = INTERRUPT | 0xf40;
1691 	return 0;
1692 #endif
1693 }
1694 EXPORT_SYMBOL_GPL(analyse_instr);
1695 
1696 /*
1697  * For PPC32 we always use stwu with r1 to change the stack pointer.
1698  * So this emulated store may corrupt the exception frame, now we
1699  * have to provide the exception frame trampoline, which is pushed
1700  * below the kprobed function stack. So we only update gpr[1] but
1701  * don't emulate the real store operation. We will do real store
1702  * operation safely in exception return code by checking this flag.
1703  */
1704 static __kprobes int handle_stack_update(unsigned long ea, struct pt_regs *regs)
1705 {
1706 #ifdef CONFIG_PPC32
1707 	/*
1708 	 * Check if we will touch kernel stack overflow
1709 	 */
1710 	if (ea - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) {
1711 		printk(KERN_CRIT "Can't kprobe this since kernel stack would overflow.\n");
1712 		return -EINVAL;
1713 	}
1714 #endif /* CONFIG_PPC32 */
1715 	/*
1716 	 * Check if we already set since that means we'll
1717 	 * lose the previous value.
1718 	 */
1719 	WARN_ON(test_thread_flag(TIF_EMULATE_STACK_STORE));
1720 	set_thread_flag(TIF_EMULATE_STACK_STORE);
1721 	return 0;
1722 }
1723 
1724 static __kprobes void do_signext(unsigned long *valp, int size)
1725 {
1726 	switch (size) {
1727 	case 2:
1728 		*valp = (signed short) *valp;
1729 		break;
1730 	case 4:
1731 		*valp = (signed int) *valp;
1732 		break;
1733 	}
1734 }
1735 
1736 static __kprobes void do_byterev(unsigned long *valp, int size)
1737 {
1738 	switch (size) {
1739 	case 2:
1740 		*valp = byterev_2(*valp);
1741 		break;
1742 	case 4:
1743 		*valp = byterev_4(*valp);
1744 		break;
1745 #ifdef __powerpc64__
1746 	case 8:
1747 		*valp = byterev_8(*valp);
1748 		break;
1749 #endif
1750 	}
1751 }
1752 
1753 /*
1754  * Emulate instructions that cause a transfer of control,
1755  * loads and stores, and a few other instructions.
1756  * Returns 1 if the step was emulated, 0 if not,
1757  * or -1 if the instruction is one that should not be stepped,
1758  * such as an rfid, or a mtmsrd that would clear MSR_RI.
1759  */
1760 int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
1761 {
1762 	struct instruction_op op;
1763 	int r, err, size;
1764 	unsigned long val;
1765 	unsigned int cr;
1766 	int i, rd, nb;
1767 
1768 	r = analyse_instr(&op, regs, instr);
1769 	if (r != 0)
1770 		return r;
1771 
1772 	err = 0;
1773 	size = GETSIZE(op.type);
1774 	switch (op.type & INSTR_TYPE_MASK) {
1775 	case CACHEOP:
1776 		if (!address_ok(regs, op.ea, 8))
1777 			return 0;
1778 		switch (op.type & CACHEOP_MASK) {
1779 		case DCBST:
1780 			__cacheop_user_asmx(op.ea, err, "dcbst");
1781 			break;
1782 		case DCBF:
1783 			__cacheop_user_asmx(op.ea, err, "dcbf");
1784 			break;
1785 		case DCBTST:
1786 			if (op.reg == 0)
1787 				prefetchw((void *) op.ea);
1788 			break;
1789 		case DCBT:
1790 			if (op.reg == 0)
1791 				prefetch((void *) op.ea);
1792 			break;
1793 		case ICBI:
1794 			__cacheop_user_asmx(op.ea, err, "icbi");
1795 			break;
1796 		}
1797 		if (err)
1798 			return 0;
1799 		goto instr_done;
1800 
1801 	case LARX:
1802 		if (op.ea & (size - 1))
1803 			break;		/* can't handle misaligned */
1804 		if (!address_ok(regs, op.ea, size))
1805 			return 0;
1806 		err = 0;
1807 		switch (size) {
1808 		case 4:
1809 			__get_user_asmx(val, op.ea, err, "lwarx");
1810 			break;
1811 #ifdef __powerpc64__
1812 		case 8:
1813 			__get_user_asmx(val, op.ea, err, "ldarx");
1814 			break;
1815 #endif
1816 		default:
1817 			return 0;
1818 		}
1819 		if (!err)
1820 			regs->gpr[op.reg] = val;
1821 		goto ldst_done;
1822 
1823 	case STCX:
1824 		if (op.ea & (size - 1))
1825 			break;		/* can't handle misaligned */
1826 		if (!address_ok(regs, op.ea, size))
1827 			return 0;
1828 		err = 0;
1829 		switch (size) {
1830 		case 4:
1831 			__put_user_asmx(op.val, op.ea, err, "stwcx.", cr);
1832 			break;
1833 #ifdef __powerpc64__
1834 		case 8:
1835 			__put_user_asmx(op.val, op.ea, err, "stdcx.", cr);
1836 			break;
1837 #endif
1838 		default:
1839 			return 0;
1840 		}
1841 		if (!err)
1842 			regs->ccr = (regs->ccr & 0x0fffffff) |
1843 				(cr & 0xe0000000) |
1844 				((regs->xer >> 3) & 0x10000000);
1845 		goto ldst_done;
1846 
1847 	case LOAD:
1848 		err = read_mem(&regs->gpr[op.reg], op.ea, size, regs);
1849 		if (!err) {
1850 			if (op.type & SIGNEXT)
1851 				do_signext(&regs->gpr[op.reg], size);
1852 			if (op.type & BYTEREV)
1853 				do_byterev(&regs->gpr[op.reg], size);
1854 		}
1855 		goto ldst_done;
1856 
1857 #ifdef CONFIG_PPC_FPU
1858 	case LOAD_FP:
1859 		if (size == 4)
1860 			err = do_fp_load(op.reg, do_lfs, op.ea, size, regs);
1861 		else
1862 			err = do_fp_load(op.reg, do_lfd, op.ea, size, regs);
1863 		goto ldst_done;
1864 #endif
1865 #ifdef CONFIG_ALTIVEC
1866 	case LOAD_VMX:
1867 		err = do_vec_load(op.reg, do_lvx, op.ea & ~0xfUL, regs);
1868 		goto ldst_done;
1869 #endif
1870 #ifdef CONFIG_VSX
1871 	case LOAD_VSX:
1872 		err = do_vsx_load(op.reg, do_lxvd2x, op.ea, regs);
1873 		goto ldst_done;
1874 #endif
1875 	case LOAD_MULTI:
1876 		if (regs->msr & MSR_LE)
1877 			return 0;
1878 		rd = op.reg;
1879 		for (i = 0; i < size; i += 4) {
1880 			nb = size - i;
1881 			if (nb > 4)
1882 				nb = 4;
1883 			err = read_mem(&regs->gpr[rd], op.ea, nb, regs);
1884 			if (err)
1885 				return 0;
1886 			if (nb < 4)	/* left-justify last bytes */
1887 				regs->gpr[rd] <<= 32 - 8 * nb;
1888 			op.ea += 4;
1889 			++rd;
1890 		}
1891 		goto instr_done;
1892 
1893 	case STORE:
1894 		if ((op.type & UPDATE) && size == sizeof(long) &&
1895 		    op.reg == 1 && op.update_reg == 1 &&
1896 		    !(regs->msr & MSR_PR) &&
1897 		    op.ea >= regs->gpr[1] - STACK_INT_FRAME_SIZE) {
1898 			err = handle_stack_update(op.ea, regs);
1899 			goto ldst_done;
1900 		}
1901 		err = write_mem(op.val, op.ea, size, regs);
1902 		goto ldst_done;
1903 
1904 #ifdef CONFIG_PPC_FPU
1905 	case STORE_FP:
1906 		if (size == 4)
1907 			err = do_fp_store(op.reg, do_stfs, op.ea, size, regs);
1908 		else
1909 			err = do_fp_store(op.reg, do_stfd, op.ea, size, regs);
1910 		goto ldst_done;
1911 #endif
1912 #ifdef CONFIG_ALTIVEC
1913 	case STORE_VMX:
1914 		err = do_vec_store(op.reg, do_stvx, op.ea & ~0xfUL, regs);
1915 		goto ldst_done;
1916 #endif
1917 #ifdef CONFIG_VSX
1918 	case STORE_VSX:
1919 		err = do_vsx_store(op.reg, do_stxvd2x, op.ea, regs);
1920 		goto ldst_done;
1921 #endif
1922 	case STORE_MULTI:
1923 		if (regs->msr & MSR_LE)
1924 			return 0;
1925 		rd = op.reg;
1926 		for (i = 0; i < size; i += 4) {
1927 			val = regs->gpr[rd];
1928 			nb = size - i;
1929 			if (nb > 4)
1930 				nb = 4;
1931 			else
1932 				val >>= 32 - 8 * nb;
1933 			err = write_mem(val, op.ea, nb, regs);
1934 			if (err)
1935 				return 0;
1936 			op.ea += 4;
1937 			++rd;
1938 		}
1939 		goto instr_done;
1940 
1941 	case MFMSR:
1942 		regs->gpr[op.reg] = regs->msr & MSR_MASK;
1943 		goto instr_done;
1944 
1945 	case MTMSR:
1946 		val = regs->gpr[op.reg];
1947 		if ((val & MSR_RI) == 0)
1948 			/* can't step mtmsr[d] that would clear MSR_RI */
1949 			return -1;
1950 		/* here op.val is the mask of bits to change */
1951 		regs->msr = (regs->msr & ~op.val) | (val & op.val);
1952 		goto instr_done;
1953 
1954 #ifdef CONFIG_PPC64
1955 	case SYSCALL:	/* sc */
1956 		/*
1957 		 * N.B. this uses knowledge about how the syscall
1958 		 * entry code works.  If that is changed, this will
1959 		 * need to be changed also.
1960 		 */
1961 		if (regs->gpr[0] == 0x1ebe &&
1962 		    cpu_has_feature(CPU_FTR_REAL_LE)) {
1963 			regs->msr ^= MSR_LE;
1964 			goto instr_done;
1965 		}
1966 		regs->gpr[9] = regs->gpr[13];
1967 		regs->gpr[10] = MSR_KERNEL;
1968 		regs->gpr[11] = regs->nip + 4;
1969 		regs->gpr[12] = regs->msr & MSR_MASK;
1970 		regs->gpr[13] = (unsigned long) get_paca();
1971 		regs->nip = (unsigned long) &system_call_common;
1972 		regs->msr = MSR_KERNEL;
1973 		return 1;
1974 
1975 	case RFI:
1976 		return -1;
1977 #endif
1978 	}
1979 	return 0;
1980 
1981  ldst_done:
1982 	if (err)
1983 		return 0;
1984 	if (op.type & UPDATE)
1985 		regs->gpr[op.update_reg] = op.ea;
1986 
1987  instr_done:
1988 	regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
1989 	return 1;
1990 }
1991