xref: /openbmc/linux/arch/x86/mm/pf_in.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Fault Injection Test harness (FI)
4  *  Copyright (C) Intel Crop.
5  */
6 
7 /*  Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp
8  *  Copyright by Intel Crop., 2002
9  *  Louis Zhuang (louis.zhuang@intel.com)
10  *
11  *  Bjorn Steinbrink (B.Steinbrink@gmx.de), 2007
12  */
13 
14 #include <linux/ptrace.h> /* struct pt_regs */
15 #include "pf_in.h"
16 
17 #ifdef __i386__
18 /* IA32 Manual 3, 2-1 */
19 static unsigned char prefix_codes[] = {
20 	0xF0, 0xF2, 0xF3, 0x2E, 0x36, 0x3E, 0x26, 0x64,
21 	0x65, 0x66, 0x67
22 };
23 /* IA32 Manual 3, 3-432*/
24 static unsigned int reg_rop[] = {
25 	0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
26 };
27 static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
28 static unsigned int imm_wop[] = { 0xC6, 0xC7 };
29 /* IA32 Manual 3, 3-432*/
30 static unsigned int rw8[] = { 0x88, 0x8A, 0xC6, 0xAA };
31 static unsigned int rw32[] = {
32 	0x89, 0x8B, 0xC7, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
33 };
34 static unsigned int mw8[] = { 0x88, 0x8A, 0xC6, 0xB60F, 0xBE0F, 0xAA };
35 static unsigned int mw16[] = { 0xB70F, 0xBF0F };
36 static unsigned int mw32[] = { 0x89, 0x8B, 0xC7, 0xAB };
37 static unsigned int mw64[] = {};
38 #else /* not __i386__ */
39 static unsigned char prefix_codes[] = {
40 	0x66, 0x67, 0x2E, 0x3E, 0x26, 0x64, 0x65, 0x36,
41 	0xF0, 0xF3, 0xF2,
42 	/* REX Prefixes */
43 	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
44 	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
45 };
46 /* AMD64 Manual 3, Appendix A*/
47 static unsigned int reg_rop[] = {
48 	0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
49 };
50 static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
51 static unsigned int imm_wop[] = { 0xC6, 0xC7 };
52 static unsigned int rw8[] = { 0xC6, 0x88, 0x8A, 0xAA };
53 static unsigned int rw32[] = {
54 	0xC7, 0x89, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
55 };
56 /* 8 bit only */
57 static unsigned int mw8[] = { 0xC6, 0x88, 0x8A, 0xB60F, 0xBE0F, 0xAA };
58 /* 16 bit only */
59 static unsigned int mw16[] = { 0xB70F, 0xBF0F };
60 /* 16 or 32 bit */
61 static unsigned int mw32[] = { 0xC7 };
62 /* 16, 32 or 64 bit */
63 static unsigned int mw64[] = { 0x89, 0x8B, 0xAB };
64 #endif /* not __i386__ */
65 
66 struct prefix_bits {
67 	unsigned shorted:1;
68 	unsigned enlarged:1;
69 	unsigned rexr:1;
70 	unsigned rex:1;
71 };
72 
73 static int skip_prefix(unsigned char *addr, struct prefix_bits *prf)
74 {
75 	int i;
76 	unsigned char *p = addr;
77 	prf->shorted = 0;
78 	prf->enlarged = 0;
79 	prf->rexr = 0;
80 	prf->rex = 0;
81 
82 restart:
83 	for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) {
84 		if (*p == prefix_codes[i]) {
85 			if (*p == 0x66)
86 				prf->shorted = 1;
87 #ifdef __amd64__
88 			if ((*p & 0xf8) == 0x48)
89 				prf->enlarged = 1;
90 			if ((*p & 0xf4) == 0x44)
91 				prf->rexr = 1;
92 			if ((*p & 0xf0) == 0x40)
93 				prf->rex = 1;
94 #endif
95 			p++;
96 			goto restart;
97 		}
98 	}
99 
100 	return (p - addr);
101 }
102 
103 static int get_opcode(unsigned char *addr, unsigned int *opcode)
104 {
105 	int len;
106 
107 	if (*addr == 0x0F) {
108 		/* 0x0F is extension instruction */
109 		*opcode = *(unsigned short *)addr;
110 		len = 2;
111 	} else {
112 		*opcode = *addr;
113 		len = 1;
114 	}
115 
116 	return len;
117 }
118 
119 #define CHECK_OP_TYPE(opcode, array, type) \
120 	for (i = 0; i < ARRAY_SIZE(array); i++) { \
121 		if (array[i] == opcode) { \
122 			rv = type; \
123 			goto exit; \
124 		} \
125 	}
126 
127 enum reason_type get_ins_type(unsigned long ins_addr)
128 {
129 	unsigned int opcode;
130 	unsigned char *p;
131 	struct prefix_bits prf;
132 	int i;
133 	enum reason_type rv = OTHERS;
134 
135 	p = (unsigned char *)ins_addr;
136 	p += skip_prefix(p, &prf);
137 	p += get_opcode(p, &opcode);
138 
139 	CHECK_OP_TYPE(opcode, reg_rop, REG_READ);
140 	CHECK_OP_TYPE(opcode, reg_wop, REG_WRITE);
141 	CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE);
142 
143 exit:
144 	return rv;
145 }
146 #undef CHECK_OP_TYPE
147 
148 static unsigned int get_ins_reg_width(unsigned long ins_addr)
149 {
150 	unsigned int opcode;
151 	unsigned char *p;
152 	struct prefix_bits prf;
153 	int i;
154 
155 	p = (unsigned char *)ins_addr;
156 	p += skip_prefix(p, &prf);
157 	p += get_opcode(p, &opcode);
158 
159 	for (i = 0; i < ARRAY_SIZE(rw8); i++)
160 		if (rw8[i] == opcode)
161 			return 1;
162 
163 	for (i = 0; i < ARRAY_SIZE(rw32); i++)
164 		if (rw32[i] == opcode)
165 			return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);
166 
167 	printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
168 	return 0;
169 }
170 
171 unsigned int get_ins_mem_width(unsigned long ins_addr)
172 {
173 	unsigned int opcode;
174 	unsigned char *p;
175 	struct prefix_bits prf;
176 	int i;
177 
178 	p = (unsigned char *)ins_addr;
179 	p += skip_prefix(p, &prf);
180 	p += get_opcode(p, &opcode);
181 
182 	for (i = 0; i < ARRAY_SIZE(mw8); i++)
183 		if (mw8[i] == opcode)
184 			return 1;
185 
186 	for (i = 0; i < ARRAY_SIZE(mw16); i++)
187 		if (mw16[i] == opcode)
188 			return 2;
189 
190 	for (i = 0; i < ARRAY_SIZE(mw32); i++)
191 		if (mw32[i] == opcode)
192 			return prf.shorted ? 2 : 4;
193 
194 	for (i = 0; i < ARRAY_SIZE(mw64); i++)
195 		if (mw64[i] == opcode)
196 			return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);
197 
198 	printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
199 	return 0;
200 }
201 
202 /*
203  * Define register ident in mod/rm byte.
204  * Note: these are NOT the same as in ptrace-abi.h.
205  */
206 enum {
207 	arg_AL = 0,
208 	arg_CL = 1,
209 	arg_DL = 2,
210 	arg_BL = 3,
211 	arg_AH = 4,
212 	arg_CH = 5,
213 	arg_DH = 6,
214 	arg_BH = 7,
215 
216 	arg_AX = 0,
217 	arg_CX = 1,
218 	arg_DX = 2,
219 	arg_BX = 3,
220 	arg_SP = 4,
221 	arg_BP = 5,
222 	arg_SI = 6,
223 	arg_DI = 7,
224 #ifdef __amd64__
225 	arg_R8  = 8,
226 	arg_R9  = 9,
227 	arg_R10 = 10,
228 	arg_R11 = 11,
229 	arg_R12 = 12,
230 	arg_R13 = 13,
231 	arg_R14 = 14,
232 	arg_R15 = 15
233 #endif
234 };
235 
236 static unsigned char *get_reg_w8(int no, int rex, struct pt_regs *regs)
237 {
238 	unsigned char *rv = NULL;
239 
240 	switch (no) {
241 	case arg_AL:
242 		rv = (unsigned char *)&regs->ax;
243 		break;
244 	case arg_BL:
245 		rv = (unsigned char *)&regs->bx;
246 		break;
247 	case arg_CL:
248 		rv = (unsigned char *)&regs->cx;
249 		break;
250 	case arg_DL:
251 		rv = (unsigned char *)&regs->dx;
252 		break;
253 #ifdef __amd64__
254 	case arg_R8:
255 		rv = (unsigned char *)&regs->r8;
256 		break;
257 	case arg_R9:
258 		rv = (unsigned char *)&regs->r9;
259 		break;
260 	case arg_R10:
261 		rv = (unsigned char *)&regs->r10;
262 		break;
263 	case arg_R11:
264 		rv = (unsigned char *)&regs->r11;
265 		break;
266 	case arg_R12:
267 		rv = (unsigned char *)&regs->r12;
268 		break;
269 	case arg_R13:
270 		rv = (unsigned char *)&regs->r13;
271 		break;
272 	case arg_R14:
273 		rv = (unsigned char *)&regs->r14;
274 		break;
275 	case arg_R15:
276 		rv = (unsigned char *)&regs->r15;
277 		break;
278 #endif
279 	default:
280 		break;
281 	}
282 
283 	if (rv)
284 		return rv;
285 
286 	if (rex) {
287 		/*
288 		 * If REX prefix exists, access low bytes of SI etc.
289 		 * instead of AH etc.
290 		 */
291 		switch (no) {
292 		case arg_SI:
293 			rv = (unsigned char *)&regs->si;
294 			break;
295 		case arg_DI:
296 			rv = (unsigned char *)&regs->di;
297 			break;
298 		case arg_BP:
299 			rv = (unsigned char *)&regs->bp;
300 			break;
301 		case arg_SP:
302 			rv = (unsigned char *)&regs->sp;
303 			break;
304 		default:
305 			break;
306 		}
307 	} else {
308 		switch (no) {
309 		case arg_AH:
310 			rv = 1 + (unsigned char *)&regs->ax;
311 			break;
312 		case arg_BH:
313 			rv = 1 + (unsigned char *)&regs->bx;
314 			break;
315 		case arg_CH:
316 			rv = 1 + (unsigned char *)&regs->cx;
317 			break;
318 		case arg_DH:
319 			rv = 1 + (unsigned char *)&regs->dx;
320 			break;
321 		default:
322 			break;
323 		}
324 	}
325 
326 	if (!rv)
327 		printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
328 
329 	return rv;
330 }
331 
332 static unsigned long *get_reg_w32(int no, struct pt_regs *regs)
333 {
334 	unsigned long *rv = NULL;
335 
336 	switch (no) {
337 	case arg_AX:
338 		rv = &regs->ax;
339 		break;
340 	case arg_BX:
341 		rv = &regs->bx;
342 		break;
343 	case arg_CX:
344 		rv = &regs->cx;
345 		break;
346 	case arg_DX:
347 		rv = &regs->dx;
348 		break;
349 	case arg_SP:
350 		rv = &regs->sp;
351 		break;
352 	case arg_BP:
353 		rv = &regs->bp;
354 		break;
355 	case arg_SI:
356 		rv = &regs->si;
357 		break;
358 	case arg_DI:
359 		rv = &regs->di;
360 		break;
361 #ifdef __amd64__
362 	case arg_R8:
363 		rv = &regs->r8;
364 		break;
365 	case arg_R9:
366 		rv = &regs->r9;
367 		break;
368 	case arg_R10:
369 		rv = &regs->r10;
370 		break;
371 	case arg_R11:
372 		rv = &regs->r11;
373 		break;
374 	case arg_R12:
375 		rv = &regs->r12;
376 		break;
377 	case arg_R13:
378 		rv = &regs->r13;
379 		break;
380 	case arg_R14:
381 		rv = &regs->r14;
382 		break;
383 	case arg_R15:
384 		rv = &regs->r15;
385 		break;
386 #endif
387 	default:
388 		printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
389 	}
390 
391 	return rv;
392 }
393 
394 unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
395 {
396 	unsigned int opcode;
397 	int reg;
398 	unsigned char *p;
399 	struct prefix_bits prf;
400 	int i;
401 
402 	p = (unsigned char *)ins_addr;
403 	p += skip_prefix(p, &prf);
404 	p += get_opcode(p, &opcode);
405 	for (i = 0; i < ARRAY_SIZE(reg_rop); i++)
406 		if (reg_rop[i] == opcode)
407 			goto do_work;
408 
409 	for (i = 0; i < ARRAY_SIZE(reg_wop); i++)
410 		if (reg_wop[i] == opcode)
411 			goto do_work;
412 
413 	printk(KERN_ERR "mmiotrace: Not a register instruction, opcode "
414 							"0x%02x\n", opcode);
415 	goto err;
416 
417 do_work:
418 	/* for STOS, source register is fixed */
419 	if (opcode == 0xAA || opcode == 0xAB) {
420 		reg = arg_AX;
421 	} else {
422 		unsigned char mod_rm = *p;
423 		reg = ((mod_rm >> 3) & 0x7) | (prf.rexr << 3);
424 	}
425 	switch (get_ins_reg_width(ins_addr)) {
426 	case 1:
427 		return *get_reg_w8(reg, prf.rex, regs);
428 
429 	case 2:
430 		return *(unsigned short *)get_reg_w32(reg, regs);
431 
432 	case 4:
433 		return *(unsigned int *)get_reg_w32(reg, regs);
434 
435 #ifdef __amd64__
436 	case 8:
437 		return *(unsigned long *)get_reg_w32(reg, regs);
438 #endif
439 
440 	default:
441 		printk(KERN_ERR "mmiotrace: Error width# %d\n", reg);
442 	}
443 
444 err:
445 	return 0;
446 }
447 
448 unsigned long get_ins_imm_val(unsigned long ins_addr)
449 {
450 	unsigned int opcode;
451 	unsigned char mod_rm;
452 	unsigned char mod;
453 	unsigned char *p;
454 	struct prefix_bits prf;
455 	int i;
456 
457 	p = (unsigned char *)ins_addr;
458 	p += skip_prefix(p, &prf);
459 	p += get_opcode(p, &opcode);
460 	for (i = 0; i < ARRAY_SIZE(imm_wop); i++)
461 		if (imm_wop[i] == opcode)
462 			goto do_work;
463 
464 	printk(KERN_ERR "mmiotrace: Not an immediate instruction, opcode "
465 							"0x%02x\n", opcode);
466 	goto err;
467 
468 do_work:
469 	mod_rm = *p;
470 	mod = mod_rm >> 6;
471 	p++;
472 	switch (mod) {
473 	case 0:
474 		/* if r/m is 5 we have a 32 disp (IA32 Manual 3, Table 2-2)  */
475 		/* AMD64: XXX Check for address size prefix? */
476 		if ((mod_rm & 0x7) == 0x5)
477 			p += 4;
478 		break;
479 
480 	case 1:
481 		p += 1;
482 		break;
483 
484 	case 2:
485 		p += 4;
486 		break;
487 
488 	case 3:
489 	default:
490 		printk(KERN_ERR "mmiotrace: not a memory access instruction "
491 						"at 0x%lx, rm_mod=0x%02x\n",
492 						ins_addr, mod_rm);
493 	}
494 
495 	switch (get_ins_reg_width(ins_addr)) {
496 	case 1:
497 		return *(unsigned char *)p;
498 
499 	case 2:
500 		return *(unsigned short *)p;
501 
502 	case 4:
503 		return *(unsigned int *)p;
504 
505 #ifdef __amd64__
506 	case 8:
507 		return *(unsigned long *)p;
508 #endif
509 
510 	default:
511 		printk(KERN_ERR "mmiotrace: Error: width.\n");
512 	}
513 
514 err:
515 	return 0;
516 }
517