xref: /linux/arch/x86/mm/pf_in.c (revision 9e9f60108423f18a99c9cc93ef7f23490ecc709b)
1 /*
2  *  Fault Injection Test harness (FI)
3  *  Copyright (C) Intel Crop.
4  *
5  *  This program is free software; you can redistribute it and/or
6  *  modify it under the terms of the GNU General Public License
7  *  as published by the Free Software Foundation; either version 2
8  *  of the License, or (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, write to the Free Software
17  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
18  *  USA.
19  *
20  */
21 
22 /*  Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp
23  *  Copyright by Intel Crop., 2002
24  *  Louis Zhuang (louis.zhuang@intel.com)
25  *
26  *  Bjorn Steinbrink (B.Steinbrink@gmx.de), 2007
27  */
28 
29 #include <linux/module.h>
30 #include <linux/ptrace.h> /* struct pt_regs */
31 #include "pf_in.h"
32 
33 #ifdef __i386__
34 /* IA32 Manual 3, 2-1 */
35 static unsigned char prefix_codes[] = {
36 	0xF0, 0xF2, 0xF3, 0x2E, 0x36, 0x3E, 0x26, 0x64,
37 	0x65, 0x66, 0x67
38 };
39 /* IA32 Manual 3, 3-432*/
40 static unsigned int reg_rop[] = {
41 	0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
42 };
43 static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
44 static unsigned int imm_wop[] = { 0xC6, 0xC7 };
45 /* IA32 Manual 3, 3-432*/
46 static unsigned int rw8[] = { 0x88, 0x8A, 0xC6, 0xAA };
47 static unsigned int rw32[] = {
48 	0x89, 0x8B, 0xC7, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
49 };
50 static unsigned int mw8[] = { 0x88, 0x8A, 0xC6, 0xB60F, 0xBE0F, 0xAA };
51 static unsigned int mw16[] = { 0xB70F, 0xBF0F };
52 static unsigned int mw32[] = { 0x89, 0x8B, 0xC7, 0xAB };
53 static unsigned int mw64[] = {};
54 #else /* not __i386__ */
55 static unsigned char prefix_codes[] = {
56 	0x66, 0x67, 0x2E, 0x3E, 0x26, 0x64, 0x65, 0x36,
57 	0xF0, 0xF3, 0xF2,
58 	/* REX Prefixes */
59 	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
60 	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
61 };
62 /* AMD64 Manual 3, Appendix A*/
63 static unsigned int reg_rop[] = {
64 	0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
65 };
66 static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
67 static unsigned int imm_wop[] = { 0xC6, 0xC7 };
68 static unsigned int rw8[] = { 0xC6, 0x88, 0x8A, 0xAA };
69 static unsigned int rw32[] = {
70 	0xC7, 0x89, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
71 };
72 /* 8 bit only */
73 static unsigned int mw8[] = { 0xC6, 0x88, 0x8A, 0xB60F, 0xBE0F, 0xAA };
74 /* 16 bit only */
75 static unsigned int mw16[] = { 0xB70F, 0xBF0F };
76 /* 16 or 32 bit */
77 static unsigned int mw32[] = { 0xC7 };
78 /* 16, 32 or 64 bit */
79 static unsigned int mw64[] = { 0x89, 0x8B, 0xAB };
80 #endif /* not __i386__ */
81 
82 struct prefix_bits {
83 	unsigned shorted:1;
84 	unsigned enlarged:1;
85 	unsigned rexr:1;
86 	unsigned rex:1;
87 };
88 
89 static int skip_prefix(unsigned char *addr, struct prefix_bits *prf)
90 {
91 	int i;
92 	unsigned char *p = addr;
93 	prf->shorted = 0;
94 	prf->enlarged = 0;
95 	prf->rexr = 0;
96 	prf->rex = 0;
97 
98 restart:
99 	for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) {
100 		if (*p == prefix_codes[i]) {
101 			if (*p == 0x66)
102 				prf->shorted = 1;
103 #ifdef __amd64__
104 			if ((*p & 0xf8) == 0x48)
105 				prf->enlarged = 1;
106 			if ((*p & 0xf4) == 0x44)
107 				prf->rexr = 1;
108 			if ((*p & 0xf0) == 0x40)
109 				prf->rex = 1;
110 #endif
111 			p++;
112 			goto restart;
113 		}
114 	}
115 
116 	return (p - addr);
117 }
118 
119 static int get_opcode(unsigned char *addr, unsigned int *opcode)
120 {
121 	int len;
122 
123 	if (*addr == 0x0F) {
124 		/* 0x0F is extension instruction */
125 		*opcode = *(unsigned short *)addr;
126 		len = 2;
127 	} else {
128 		*opcode = *addr;
129 		len = 1;
130 	}
131 
132 	return len;
133 }
134 
135 #define CHECK_OP_TYPE(opcode, array, type) \
136 	for (i = 0; i < ARRAY_SIZE(array); i++) { \
137 		if (array[i] == opcode) { \
138 			rv = type; \
139 			goto exit; \
140 		} \
141 	}
142 
143 enum reason_type get_ins_type(unsigned long ins_addr)
144 {
145 	unsigned int opcode;
146 	unsigned char *p;
147 	struct prefix_bits prf;
148 	int i;
149 	enum reason_type rv = OTHERS;
150 
151 	p = (unsigned char *)ins_addr;
152 	p += skip_prefix(p, &prf);
153 	p += get_opcode(p, &opcode);
154 
155 	CHECK_OP_TYPE(opcode, reg_rop, REG_READ);
156 	CHECK_OP_TYPE(opcode, reg_wop, REG_WRITE);
157 	CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE);
158 
159 exit:
160 	return rv;
161 }
162 #undef CHECK_OP_TYPE
163 
164 static unsigned int get_ins_reg_width(unsigned long ins_addr)
165 {
166 	unsigned int opcode;
167 	unsigned char *p;
168 	struct prefix_bits prf;
169 	int i;
170 
171 	p = (unsigned char *)ins_addr;
172 	p += skip_prefix(p, &prf);
173 	p += get_opcode(p, &opcode);
174 
175 	for (i = 0; i < ARRAY_SIZE(rw8); i++)
176 		if (rw8[i] == opcode)
177 			return 1;
178 
179 	for (i = 0; i < ARRAY_SIZE(rw32); i++)
180 		if (rw32[i] == opcode)
181 			return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);
182 
183 	printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
184 	return 0;
185 }
186 
187 unsigned int get_ins_mem_width(unsigned long ins_addr)
188 {
189 	unsigned int opcode;
190 	unsigned char *p;
191 	struct prefix_bits prf;
192 	int i;
193 
194 	p = (unsigned char *)ins_addr;
195 	p += skip_prefix(p, &prf);
196 	p += get_opcode(p, &opcode);
197 
198 	for (i = 0; i < ARRAY_SIZE(mw8); i++)
199 		if (mw8[i] == opcode)
200 			return 1;
201 
202 	for (i = 0; i < ARRAY_SIZE(mw16); i++)
203 		if (mw16[i] == opcode)
204 			return 2;
205 
206 	for (i = 0; i < ARRAY_SIZE(mw32); i++)
207 		if (mw32[i] == opcode)
208 			return prf.shorted ? 2 : 4;
209 
210 	for (i = 0; i < ARRAY_SIZE(mw64); i++)
211 		if (mw64[i] == opcode)
212 			return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);
213 
214 	printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
215 	return 0;
216 }
217 
218 /*
219  * Define register ident in mod/rm byte.
220  * Note: these are NOT the same as in ptrace-abi.h.
221  */
222 enum {
223 	arg_AL = 0,
224 	arg_CL = 1,
225 	arg_DL = 2,
226 	arg_BL = 3,
227 	arg_AH = 4,
228 	arg_CH = 5,
229 	arg_DH = 6,
230 	arg_BH = 7,
231 
232 	arg_AX = 0,
233 	arg_CX = 1,
234 	arg_DX = 2,
235 	arg_BX = 3,
236 	arg_SP = 4,
237 	arg_BP = 5,
238 	arg_SI = 6,
239 	arg_DI = 7,
240 #ifdef __amd64__
241 	arg_R8  = 8,
242 	arg_R9  = 9,
243 	arg_R10 = 10,
244 	arg_R11 = 11,
245 	arg_R12 = 12,
246 	arg_R13 = 13,
247 	arg_R14 = 14,
248 	arg_R15 = 15
249 #endif
250 };
251 
252 static unsigned char *get_reg_w8(int no, int rex, struct pt_regs *regs)
253 {
254 	unsigned char *rv = NULL;
255 
256 	switch (no) {
257 	case arg_AL:
258 		rv = (unsigned char *)&regs->ax;
259 		break;
260 	case arg_BL:
261 		rv = (unsigned char *)&regs->bx;
262 		break;
263 	case arg_CL:
264 		rv = (unsigned char *)&regs->cx;
265 		break;
266 	case arg_DL:
267 		rv = (unsigned char *)&regs->dx;
268 		break;
269 #ifdef __amd64__
270 	case arg_R8:
271 		rv = (unsigned char *)&regs->r8;
272 		break;
273 	case arg_R9:
274 		rv = (unsigned char *)&regs->r9;
275 		break;
276 	case arg_R10:
277 		rv = (unsigned char *)&regs->r10;
278 		break;
279 	case arg_R11:
280 		rv = (unsigned char *)&regs->r11;
281 		break;
282 	case arg_R12:
283 		rv = (unsigned char *)&regs->r12;
284 		break;
285 	case arg_R13:
286 		rv = (unsigned char *)&regs->r13;
287 		break;
288 	case arg_R14:
289 		rv = (unsigned char *)&regs->r14;
290 		break;
291 	case arg_R15:
292 		rv = (unsigned char *)&regs->r15;
293 		break;
294 #endif
295 	default:
296 		break;
297 	}
298 
299 	if (rv)
300 		return rv;
301 
302 	if (rex) {
303 		/*
304 		 * If REX prefix exists, access low bytes of SI etc.
305 		 * instead of AH etc.
306 		 */
307 		switch (no) {
308 		case arg_SI:
309 			rv = (unsigned char *)&regs->si;
310 			break;
311 		case arg_DI:
312 			rv = (unsigned char *)&regs->di;
313 			break;
314 		case arg_BP:
315 			rv = (unsigned char *)&regs->bp;
316 			break;
317 		case arg_SP:
318 			rv = (unsigned char *)&regs->sp;
319 			break;
320 		default:
321 			break;
322 		}
323 	} else {
324 		switch (no) {
325 		case arg_AH:
326 			rv = 1 + (unsigned char *)&regs->ax;
327 			break;
328 		case arg_BH:
329 			rv = 1 + (unsigned char *)&regs->bx;
330 			break;
331 		case arg_CH:
332 			rv = 1 + (unsigned char *)&regs->cx;
333 			break;
334 		case arg_DH:
335 			rv = 1 + (unsigned char *)&regs->dx;
336 			break;
337 		default:
338 			break;
339 		}
340 	}
341 
342 	if (!rv)
343 		printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
344 
345 	return rv;
346 }
347 
348 static unsigned long *get_reg_w32(int no, struct pt_regs *regs)
349 {
350 	unsigned long *rv = NULL;
351 
352 	switch (no) {
353 	case arg_AX:
354 		rv = &regs->ax;
355 		break;
356 	case arg_BX:
357 		rv = &regs->bx;
358 		break;
359 	case arg_CX:
360 		rv = &regs->cx;
361 		break;
362 	case arg_DX:
363 		rv = &regs->dx;
364 		break;
365 	case arg_SP:
366 		rv = &regs->sp;
367 		break;
368 	case arg_BP:
369 		rv = &regs->bp;
370 		break;
371 	case arg_SI:
372 		rv = &regs->si;
373 		break;
374 	case arg_DI:
375 		rv = &regs->di;
376 		break;
377 #ifdef __amd64__
378 	case arg_R8:
379 		rv = &regs->r8;
380 		break;
381 	case arg_R9:
382 		rv = &regs->r9;
383 		break;
384 	case arg_R10:
385 		rv = &regs->r10;
386 		break;
387 	case arg_R11:
388 		rv = &regs->r11;
389 		break;
390 	case arg_R12:
391 		rv = &regs->r12;
392 		break;
393 	case arg_R13:
394 		rv = &regs->r13;
395 		break;
396 	case arg_R14:
397 		rv = &regs->r14;
398 		break;
399 	case arg_R15:
400 		rv = &regs->r15;
401 		break;
402 #endif
403 	default:
404 		printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
405 	}
406 
407 	return rv;
408 }
409 
410 unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
411 {
412 	unsigned int opcode;
413 	int reg;
414 	unsigned char *p;
415 	struct prefix_bits prf;
416 	int i;
417 
418 	p = (unsigned char *)ins_addr;
419 	p += skip_prefix(p, &prf);
420 	p += get_opcode(p, &opcode);
421 	for (i = 0; i < ARRAY_SIZE(reg_rop); i++)
422 		if (reg_rop[i] == opcode)
423 			goto do_work;
424 
425 	for (i = 0; i < ARRAY_SIZE(reg_wop); i++)
426 		if (reg_wop[i] == opcode)
427 			goto do_work;
428 
429 	printk(KERN_ERR "mmiotrace: Not a register instruction, opcode "
430 							"0x%02x\n", opcode);
431 	goto err;
432 
433 do_work:
434 	/* for STOS, source register is fixed */
435 	if (opcode == 0xAA || opcode == 0xAB) {
436 		reg = arg_AX;
437 	} else {
438 		unsigned char mod_rm = *p;
439 		reg = ((mod_rm >> 3) & 0x7) | (prf.rexr << 3);
440 	}
441 	switch (get_ins_reg_width(ins_addr)) {
442 	case 1:
443 		return *get_reg_w8(reg, prf.rex, regs);
444 
445 	case 2:
446 		return *(unsigned short *)get_reg_w32(reg, regs);
447 
448 	case 4:
449 		return *(unsigned int *)get_reg_w32(reg, regs);
450 
451 #ifdef __amd64__
452 	case 8:
453 		return *(unsigned long *)get_reg_w32(reg, regs);
454 #endif
455 
456 	default:
457 		printk(KERN_ERR "mmiotrace: Error width# %d\n", reg);
458 	}
459 
460 err:
461 	return 0;
462 }
463 
464 unsigned long get_ins_imm_val(unsigned long ins_addr)
465 {
466 	unsigned int opcode;
467 	unsigned char mod_rm;
468 	unsigned char mod;
469 	unsigned char *p;
470 	struct prefix_bits prf;
471 	int i;
472 
473 	p = (unsigned char *)ins_addr;
474 	p += skip_prefix(p, &prf);
475 	p += get_opcode(p, &opcode);
476 	for (i = 0; i < ARRAY_SIZE(imm_wop); i++)
477 		if (imm_wop[i] == opcode)
478 			goto do_work;
479 
480 	printk(KERN_ERR "mmiotrace: Not an immediate instruction, opcode "
481 							"0x%02x\n", opcode);
482 	goto err;
483 
484 do_work:
485 	mod_rm = *p;
486 	mod = mod_rm >> 6;
487 	p++;
488 	switch (mod) {
489 	case 0:
490 		/* if r/m is 5 we have a 32 disp (IA32 Manual 3, Table 2-2)  */
491 		/* AMD64: XXX Check for address size prefix? */
492 		if ((mod_rm & 0x7) == 0x5)
493 			p += 4;
494 		break;
495 
496 	case 1:
497 		p += 1;
498 		break;
499 
500 	case 2:
501 		p += 4;
502 		break;
503 
504 	case 3:
505 	default:
506 		printk(KERN_ERR "mmiotrace: not a memory access instruction "
507 						"at 0x%lx, rm_mod=0x%02x\n",
508 						ins_addr, mod_rm);
509 	}
510 
511 	switch (get_ins_reg_width(ins_addr)) {
512 	case 1:
513 		return *(unsigned char *)p;
514 
515 	case 2:
516 		return *(unsigned short *)p;
517 
518 	case 4:
519 		return *(unsigned int *)p;
520 
521 #ifdef __amd64__
522 	case 8:
523 		return *(unsigned long *)p;
524 #endif
525 
526 	default:
527 		printk(KERN_ERR "mmiotrace: Error: width.\n");
528 	}
529 
530 err:
531 	return 0;
532 }
533