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1 /*
2  * Copyright (C) 2013 Huawei Ltd.
3  * Author: Jiang Liu <liuj97@gmail.com>
4  *
5  * Copyright (C) 2014-2016 Zi Shen Lim <zlim.lnx@gmail.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 #include <linux/bitops.h>
20 #include <linux/bug.h>
21 #include <linux/compiler.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/smp.h>
25 #include <linux/spinlock.h>
26 #include <linux/stop_machine.h>
27 #include <linux/types.h>
28 #include <linux/uaccess.h>
29 
30 #include <asm/cacheflush.h>
31 #include <asm/debug-monitors.h>
32 #include <asm/fixmap.h>
33 #include <asm/insn.h>
34 #include <asm/kprobes.h>
35 
36 #define AARCH64_INSN_SF_BIT	BIT(31)
37 #define AARCH64_INSN_N_BIT	BIT(22)
38 
39 static int aarch64_insn_encoding_class[] = {
40 	AARCH64_INSN_CLS_UNKNOWN,
41 	AARCH64_INSN_CLS_UNKNOWN,
42 	AARCH64_INSN_CLS_UNKNOWN,
43 	AARCH64_INSN_CLS_UNKNOWN,
44 	AARCH64_INSN_CLS_LDST,
45 	AARCH64_INSN_CLS_DP_REG,
46 	AARCH64_INSN_CLS_LDST,
47 	AARCH64_INSN_CLS_DP_FPSIMD,
48 	AARCH64_INSN_CLS_DP_IMM,
49 	AARCH64_INSN_CLS_DP_IMM,
50 	AARCH64_INSN_CLS_BR_SYS,
51 	AARCH64_INSN_CLS_BR_SYS,
52 	AARCH64_INSN_CLS_LDST,
53 	AARCH64_INSN_CLS_DP_REG,
54 	AARCH64_INSN_CLS_LDST,
55 	AARCH64_INSN_CLS_DP_FPSIMD,
56 };
57 
aarch64_get_insn_class(u32 insn)58 enum aarch64_insn_encoding_class __kprobes aarch64_get_insn_class(u32 insn)
59 {
60 	return aarch64_insn_encoding_class[(insn >> 25) & 0xf];
61 }
62 
63 /* NOP is an alias of HINT */
aarch64_insn_is_nop(u32 insn)64 bool __kprobes aarch64_insn_is_nop(u32 insn)
65 {
66 	if (!aarch64_insn_is_hint(insn))
67 		return false;
68 
69 	switch (insn & 0xFE0) {
70 	case AARCH64_INSN_HINT_YIELD:
71 	case AARCH64_INSN_HINT_WFE:
72 	case AARCH64_INSN_HINT_WFI:
73 	case AARCH64_INSN_HINT_SEV:
74 	case AARCH64_INSN_HINT_SEVL:
75 		return false;
76 	default:
77 		return true;
78 	}
79 }
80 
aarch64_insn_is_branch_imm(u32 insn)81 bool aarch64_insn_is_branch_imm(u32 insn)
82 {
83 	return (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn) ||
84 		aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn) ||
85 		aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
86 		aarch64_insn_is_bcond(insn));
87 }
88 
89 static DEFINE_RAW_SPINLOCK(patch_lock);
90 
patch_map(void * addr,int fixmap)91 static void __kprobes *patch_map(void *addr, int fixmap)
92 {
93 	unsigned long uintaddr = (uintptr_t) addr;
94 	bool module = !core_kernel_text(uintaddr);
95 	struct page *page;
96 
97 	if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
98 		page = vmalloc_to_page(addr);
99 	else if (!module)
100 		page = phys_to_page(__pa_symbol(addr));
101 	else
102 		return addr;
103 
104 	BUG_ON(!page);
105 	return (void *)set_fixmap_offset(fixmap, page_to_phys(page) +
106 			(uintaddr & ~PAGE_MASK));
107 }
108 
patch_unmap(int fixmap)109 static void __kprobes patch_unmap(int fixmap)
110 {
111 	clear_fixmap(fixmap);
112 }
113 /*
114  * In ARMv8-A, A64 instructions have a fixed length of 32 bits and are always
115  * little-endian.
116  */
aarch64_insn_read(void * addr,u32 * insnp)117 int __kprobes aarch64_insn_read(void *addr, u32 *insnp)
118 {
119 	int ret;
120 	__le32 val;
121 
122 	ret = probe_kernel_read(&val, addr, AARCH64_INSN_SIZE);
123 	if (!ret)
124 		*insnp = le32_to_cpu(val);
125 
126 	return ret;
127 }
128 
__aarch64_insn_write(void * addr,__le32 insn)129 static int __kprobes __aarch64_insn_write(void *addr, __le32 insn)
130 {
131 	void *waddr = addr;
132 	unsigned long flags = 0;
133 	int ret;
134 
135 	raw_spin_lock_irqsave(&patch_lock, flags);
136 	waddr = patch_map(addr, FIX_TEXT_POKE0);
137 
138 	ret = probe_kernel_write(waddr, &insn, AARCH64_INSN_SIZE);
139 
140 	patch_unmap(FIX_TEXT_POKE0);
141 	raw_spin_unlock_irqrestore(&patch_lock, flags);
142 
143 	return ret;
144 }
145 
aarch64_insn_write(void * addr,u32 insn)146 int __kprobes aarch64_insn_write(void *addr, u32 insn)
147 {
148 	return __aarch64_insn_write(addr, cpu_to_le32(insn));
149 }
150 
__aarch64_insn_hotpatch_safe(u32 insn)151 static bool __kprobes __aarch64_insn_hotpatch_safe(u32 insn)
152 {
153 	if (aarch64_get_insn_class(insn) != AARCH64_INSN_CLS_BR_SYS)
154 		return false;
155 
156 	return	aarch64_insn_is_b(insn) ||
157 		aarch64_insn_is_bl(insn) ||
158 		aarch64_insn_is_svc(insn) ||
159 		aarch64_insn_is_hvc(insn) ||
160 		aarch64_insn_is_smc(insn) ||
161 		aarch64_insn_is_brk(insn) ||
162 		aarch64_insn_is_nop(insn);
163 }
164 
aarch64_insn_uses_literal(u32 insn)165 bool __kprobes aarch64_insn_uses_literal(u32 insn)
166 {
167 	/* ldr/ldrsw (literal), prfm */
168 
169 	return aarch64_insn_is_ldr_lit(insn) ||
170 		aarch64_insn_is_ldrsw_lit(insn) ||
171 		aarch64_insn_is_adr_adrp(insn) ||
172 		aarch64_insn_is_prfm_lit(insn);
173 }
174 
aarch64_insn_is_branch(u32 insn)175 bool __kprobes aarch64_insn_is_branch(u32 insn)
176 {
177 	/* b, bl, cb*, tb*, b.cond, br, blr */
178 
179 	return aarch64_insn_is_b(insn) ||
180 		aarch64_insn_is_bl(insn) ||
181 		aarch64_insn_is_cbz(insn) ||
182 		aarch64_insn_is_cbnz(insn) ||
183 		aarch64_insn_is_tbz(insn) ||
184 		aarch64_insn_is_tbnz(insn) ||
185 		aarch64_insn_is_ret(insn) ||
186 		aarch64_insn_is_br(insn) ||
187 		aarch64_insn_is_blr(insn) ||
188 		aarch64_insn_is_bcond(insn);
189 }
190 
191 /*
192  * ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a
193  * Section B2.6.5 "Concurrent modification and execution of instructions":
194  * Concurrent modification and execution of instructions can lead to the
195  * resulting instruction performing any behavior that can be achieved by
196  * executing any sequence of instructions that can be executed from the
197  * same Exception level, except where the instruction before modification
198  * and the instruction after modification is a B, BL, NOP, BKPT, SVC, HVC,
199  * or SMC instruction.
200  */
aarch64_insn_hotpatch_safe(u32 old_insn,u32 new_insn)201 bool __kprobes aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn)
202 {
203 	return __aarch64_insn_hotpatch_safe(old_insn) &&
204 	       __aarch64_insn_hotpatch_safe(new_insn);
205 }
206 
aarch64_insn_patch_text_nosync(void * addr,u32 insn)207 int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn)
208 {
209 	u32 *tp = addr;
210 	int ret;
211 
212 	/* A64 instructions must be word aligned */
213 	if ((uintptr_t)tp & 0x3)
214 		return -EINVAL;
215 
216 	ret = aarch64_insn_write(tp, insn);
217 	if (ret == 0)
218 		flush_icache_range((uintptr_t)tp,
219 				   (uintptr_t)tp + AARCH64_INSN_SIZE);
220 
221 	return ret;
222 }
223 
224 struct aarch64_insn_patch {
225 	void		**text_addrs;
226 	u32		*new_insns;
227 	int		insn_cnt;
228 	atomic_t	cpu_count;
229 };
230 
aarch64_insn_patch_text_cb(void * arg)231 static int __kprobes aarch64_insn_patch_text_cb(void *arg)
232 {
233 	int i, ret = 0;
234 	struct aarch64_insn_patch *pp = arg;
235 
236 	/* The first CPU becomes master */
237 	if (atomic_inc_return(&pp->cpu_count) == 1) {
238 		for (i = 0; ret == 0 && i < pp->insn_cnt; i++)
239 			ret = aarch64_insn_patch_text_nosync(pp->text_addrs[i],
240 							     pp->new_insns[i]);
241 		/*
242 		 * aarch64_insn_patch_text_nosync() calls flush_icache_range(),
243 		 * which ends with "dsb; isb" pair guaranteeing global
244 		 * visibility.
245 		 */
246 		/* Notify other processors with an additional increment. */
247 		atomic_inc(&pp->cpu_count);
248 	} else {
249 		while (atomic_read(&pp->cpu_count) <= num_online_cpus())
250 			cpu_relax();
251 		isb();
252 	}
253 
254 	return ret;
255 }
256 
257 static
aarch64_insn_patch_text_sync(void * addrs[],u32 insns[],int cnt)258 int __kprobes aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt)
259 {
260 	struct aarch64_insn_patch patch = {
261 		.text_addrs = addrs,
262 		.new_insns = insns,
263 		.insn_cnt = cnt,
264 		.cpu_count = ATOMIC_INIT(0),
265 	};
266 
267 	if (cnt <= 0)
268 		return -EINVAL;
269 
270 	return stop_machine_cpuslocked(aarch64_insn_patch_text_cb, &patch,
271 				       cpu_online_mask);
272 }
273 
aarch64_insn_patch_text(void * addrs[],u32 insns[],int cnt)274 int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt)
275 {
276 	int ret;
277 	u32 insn;
278 
279 	/* Unsafe to patch multiple instructions without synchronizaiton */
280 	if (cnt == 1) {
281 		ret = aarch64_insn_read(addrs[0], &insn);
282 		if (ret)
283 			return ret;
284 
285 		if (aarch64_insn_hotpatch_safe(insn, insns[0])) {
286 			/*
287 			 * ARMv8 architecture doesn't guarantee all CPUs see
288 			 * the new instruction after returning from function
289 			 * aarch64_insn_patch_text_nosync(). So send IPIs to
290 			 * all other CPUs to achieve instruction
291 			 * synchronization.
292 			 */
293 			ret = aarch64_insn_patch_text_nosync(addrs[0], insns[0]);
294 			kick_all_cpus_sync();
295 			return ret;
296 		}
297 	}
298 
299 	return aarch64_insn_patch_text_sync(addrs, insns, cnt);
300 }
301 
aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type,u32 * maskp,int * shiftp)302 static int __kprobes aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type,
303 						u32 *maskp, int *shiftp)
304 {
305 	u32 mask;
306 	int shift;
307 
308 	switch (type) {
309 	case AARCH64_INSN_IMM_26:
310 		mask = BIT(26) - 1;
311 		shift = 0;
312 		break;
313 	case AARCH64_INSN_IMM_19:
314 		mask = BIT(19) - 1;
315 		shift = 5;
316 		break;
317 	case AARCH64_INSN_IMM_16:
318 		mask = BIT(16) - 1;
319 		shift = 5;
320 		break;
321 	case AARCH64_INSN_IMM_14:
322 		mask = BIT(14) - 1;
323 		shift = 5;
324 		break;
325 	case AARCH64_INSN_IMM_12:
326 		mask = BIT(12) - 1;
327 		shift = 10;
328 		break;
329 	case AARCH64_INSN_IMM_9:
330 		mask = BIT(9) - 1;
331 		shift = 12;
332 		break;
333 	case AARCH64_INSN_IMM_7:
334 		mask = BIT(7) - 1;
335 		shift = 15;
336 		break;
337 	case AARCH64_INSN_IMM_6:
338 	case AARCH64_INSN_IMM_S:
339 		mask = BIT(6) - 1;
340 		shift = 10;
341 		break;
342 	case AARCH64_INSN_IMM_R:
343 		mask = BIT(6) - 1;
344 		shift = 16;
345 		break;
346 	default:
347 		return -EINVAL;
348 	}
349 
350 	*maskp = mask;
351 	*shiftp = shift;
352 
353 	return 0;
354 }
355 
356 #define ADR_IMM_HILOSPLIT	2
357 #define ADR_IMM_SIZE		SZ_2M
358 #define ADR_IMM_LOMASK		((1 << ADR_IMM_HILOSPLIT) - 1)
359 #define ADR_IMM_HIMASK		((ADR_IMM_SIZE >> ADR_IMM_HILOSPLIT) - 1)
360 #define ADR_IMM_LOSHIFT		29
361 #define ADR_IMM_HISHIFT		5
362 
aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type,u32 insn)363 u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn)
364 {
365 	u32 immlo, immhi, mask;
366 	int shift;
367 
368 	switch (type) {
369 	case AARCH64_INSN_IMM_ADR:
370 		shift = 0;
371 		immlo = (insn >> ADR_IMM_LOSHIFT) & ADR_IMM_LOMASK;
372 		immhi = (insn >> ADR_IMM_HISHIFT) & ADR_IMM_HIMASK;
373 		insn = (immhi << ADR_IMM_HILOSPLIT) | immlo;
374 		mask = ADR_IMM_SIZE - 1;
375 		break;
376 	default:
377 		if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
378 			pr_err("aarch64_insn_decode_immediate: unknown immediate encoding %d\n",
379 			       type);
380 			return 0;
381 		}
382 	}
383 
384 	return (insn >> shift) & mask;
385 }
386 
aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,u32 insn,u64 imm)387 u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
388 				  u32 insn, u64 imm)
389 {
390 	u32 immlo, immhi, mask;
391 	int shift;
392 
393 	if (insn == AARCH64_BREAK_FAULT)
394 		return AARCH64_BREAK_FAULT;
395 
396 	switch (type) {
397 	case AARCH64_INSN_IMM_ADR:
398 		shift = 0;
399 		immlo = (imm & ADR_IMM_LOMASK) << ADR_IMM_LOSHIFT;
400 		imm >>= ADR_IMM_HILOSPLIT;
401 		immhi = (imm & ADR_IMM_HIMASK) << ADR_IMM_HISHIFT;
402 		imm = immlo | immhi;
403 		mask = ((ADR_IMM_LOMASK << ADR_IMM_LOSHIFT) |
404 			(ADR_IMM_HIMASK << ADR_IMM_HISHIFT));
405 		break;
406 	default:
407 		if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
408 			pr_err("aarch64_insn_encode_immediate: unknown immediate encoding %d\n",
409 			       type);
410 			return AARCH64_BREAK_FAULT;
411 		}
412 	}
413 
414 	/* Update the immediate field. */
415 	insn &= ~(mask << shift);
416 	insn |= (imm & mask) << shift;
417 
418 	return insn;
419 }
420 
aarch64_insn_decode_register(enum aarch64_insn_register_type type,u32 insn)421 u32 aarch64_insn_decode_register(enum aarch64_insn_register_type type,
422 					u32 insn)
423 {
424 	int shift;
425 
426 	switch (type) {
427 	case AARCH64_INSN_REGTYPE_RT:
428 	case AARCH64_INSN_REGTYPE_RD:
429 		shift = 0;
430 		break;
431 	case AARCH64_INSN_REGTYPE_RN:
432 		shift = 5;
433 		break;
434 	case AARCH64_INSN_REGTYPE_RT2:
435 	case AARCH64_INSN_REGTYPE_RA:
436 		shift = 10;
437 		break;
438 	case AARCH64_INSN_REGTYPE_RM:
439 		shift = 16;
440 		break;
441 	default:
442 		pr_err("%s: unknown register type encoding %d\n", __func__,
443 		       type);
444 		return 0;
445 	}
446 
447 	return (insn >> shift) & GENMASK(4, 0);
448 }
449 
aarch64_insn_encode_register(enum aarch64_insn_register_type type,u32 insn,enum aarch64_insn_register reg)450 static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type,
451 					u32 insn,
452 					enum aarch64_insn_register reg)
453 {
454 	int shift;
455 
456 	if (insn == AARCH64_BREAK_FAULT)
457 		return AARCH64_BREAK_FAULT;
458 
459 	if (reg < AARCH64_INSN_REG_0 || reg > AARCH64_INSN_REG_SP) {
460 		pr_err("%s: unknown register encoding %d\n", __func__, reg);
461 		return AARCH64_BREAK_FAULT;
462 	}
463 
464 	switch (type) {
465 	case AARCH64_INSN_REGTYPE_RT:
466 	case AARCH64_INSN_REGTYPE_RD:
467 		shift = 0;
468 		break;
469 	case AARCH64_INSN_REGTYPE_RN:
470 		shift = 5;
471 		break;
472 	case AARCH64_INSN_REGTYPE_RT2:
473 	case AARCH64_INSN_REGTYPE_RA:
474 		shift = 10;
475 		break;
476 	case AARCH64_INSN_REGTYPE_RM:
477 	case AARCH64_INSN_REGTYPE_RS:
478 		shift = 16;
479 		break;
480 	default:
481 		pr_err("%s: unknown register type encoding %d\n", __func__,
482 		       type);
483 		return AARCH64_BREAK_FAULT;
484 	}
485 
486 	insn &= ~(GENMASK(4, 0) << shift);
487 	insn |= reg << shift;
488 
489 	return insn;
490 }
491 
aarch64_insn_encode_ldst_size(enum aarch64_insn_size_type type,u32 insn)492 static u32 aarch64_insn_encode_ldst_size(enum aarch64_insn_size_type type,
493 					 u32 insn)
494 {
495 	u32 size;
496 
497 	switch (type) {
498 	case AARCH64_INSN_SIZE_8:
499 		size = 0;
500 		break;
501 	case AARCH64_INSN_SIZE_16:
502 		size = 1;
503 		break;
504 	case AARCH64_INSN_SIZE_32:
505 		size = 2;
506 		break;
507 	case AARCH64_INSN_SIZE_64:
508 		size = 3;
509 		break;
510 	default:
511 		pr_err("%s: unknown size encoding %d\n", __func__, type);
512 		return AARCH64_BREAK_FAULT;
513 	}
514 
515 	insn &= ~GENMASK(31, 30);
516 	insn |= size << 30;
517 
518 	return insn;
519 }
520 
branch_imm_common(unsigned long pc,unsigned long addr,long range)521 static inline long branch_imm_common(unsigned long pc, unsigned long addr,
522 				     long range)
523 {
524 	long offset;
525 
526 	if ((pc & 0x3) || (addr & 0x3)) {
527 		pr_err("%s: A64 instructions must be word aligned\n", __func__);
528 		return range;
529 	}
530 
531 	offset = ((long)addr - (long)pc);
532 
533 	if (offset < -range || offset >= range) {
534 		pr_err("%s: offset out of range\n", __func__);
535 		return range;
536 	}
537 
538 	return offset;
539 }
540 
aarch64_insn_gen_branch_imm(unsigned long pc,unsigned long addr,enum aarch64_insn_branch_type type)541 u32 __kprobes aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr,
542 					  enum aarch64_insn_branch_type type)
543 {
544 	u32 insn;
545 	long offset;
546 
547 	/*
548 	 * B/BL support [-128M, 128M) offset
549 	 * ARM64 virtual address arrangement guarantees all kernel and module
550 	 * texts are within +/-128M.
551 	 */
552 	offset = branch_imm_common(pc, addr, SZ_128M);
553 	if (offset >= SZ_128M)
554 		return AARCH64_BREAK_FAULT;
555 
556 	switch (type) {
557 	case AARCH64_INSN_BRANCH_LINK:
558 		insn = aarch64_insn_get_bl_value();
559 		break;
560 	case AARCH64_INSN_BRANCH_NOLINK:
561 		insn = aarch64_insn_get_b_value();
562 		break;
563 	default:
564 		pr_err("%s: unknown branch encoding %d\n", __func__, type);
565 		return AARCH64_BREAK_FAULT;
566 	}
567 
568 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
569 					     offset >> 2);
570 }
571 
aarch64_insn_gen_comp_branch_imm(unsigned long pc,unsigned long addr,enum aarch64_insn_register reg,enum aarch64_insn_variant variant,enum aarch64_insn_branch_type type)572 u32 aarch64_insn_gen_comp_branch_imm(unsigned long pc, unsigned long addr,
573 				     enum aarch64_insn_register reg,
574 				     enum aarch64_insn_variant variant,
575 				     enum aarch64_insn_branch_type type)
576 {
577 	u32 insn;
578 	long offset;
579 
580 	offset = branch_imm_common(pc, addr, SZ_1M);
581 	if (offset >= SZ_1M)
582 		return AARCH64_BREAK_FAULT;
583 
584 	switch (type) {
585 	case AARCH64_INSN_BRANCH_COMP_ZERO:
586 		insn = aarch64_insn_get_cbz_value();
587 		break;
588 	case AARCH64_INSN_BRANCH_COMP_NONZERO:
589 		insn = aarch64_insn_get_cbnz_value();
590 		break;
591 	default:
592 		pr_err("%s: unknown branch encoding %d\n", __func__, type);
593 		return AARCH64_BREAK_FAULT;
594 	}
595 
596 	switch (variant) {
597 	case AARCH64_INSN_VARIANT_32BIT:
598 		break;
599 	case AARCH64_INSN_VARIANT_64BIT:
600 		insn |= AARCH64_INSN_SF_BIT;
601 		break;
602 	default:
603 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
604 		return AARCH64_BREAK_FAULT;
605 	}
606 
607 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
608 
609 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
610 					     offset >> 2);
611 }
612 
aarch64_insn_gen_cond_branch_imm(unsigned long pc,unsigned long addr,enum aarch64_insn_condition cond)613 u32 aarch64_insn_gen_cond_branch_imm(unsigned long pc, unsigned long addr,
614 				     enum aarch64_insn_condition cond)
615 {
616 	u32 insn;
617 	long offset;
618 
619 	offset = branch_imm_common(pc, addr, SZ_1M);
620 
621 	insn = aarch64_insn_get_bcond_value();
622 
623 	if (cond < AARCH64_INSN_COND_EQ || cond > AARCH64_INSN_COND_AL) {
624 		pr_err("%s: unknown condition encoding %d\n", __func__, cond);
625 		return AARCH64_BREAK_FAULT;
626 	}
627 	insn |= cond;
628 
629 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
630 					     offset >> 2);
631 }
632 
aarch64_insn_gen_hint(enum aarch64_insn_hint_op op)633 u32 __kprobes aarch64_insn_gen_hint(enum aarch64_insn_hint_op op)
634 {
635 	return aarch64_insn_get_hint_value() | op;
636 }
637 
aarch64_insn_gen_nop(void)638 u32 __kprobes aarch64_insn_gen_nop(void)
639 {
640 	return aarch64_insn_gen_hint(AARCH64_INSN_HINT_NOP);
641 }
642 
aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg,enum aarch64_insn_branch_type type)643 u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg,
644 				enum aarch64_insn_branch_type type)
645 {
646 	u32 insn;
647 
648 	switch (type) {
649 	case AARCH64_INSN_BRANCH_NOLINK:
650 		insn = aarch64_insn_get_br_value();
651 		break;
652 	case AARCH64_INSN_BRANCH_LINK:
653 		insn = aarch64_insn_get_blr_value();
654 		break;
655 	case AARCH64_INSN_BRANCH_RETURN:
656 		insn = aarch64_insn_get_ret_value();
657 		break;
658 	default:
659 		pr_err("%s: unknown branch encoding %d\n", __func__, type);
660 		return AARCH64_BREAK_FAULT;
661 	}
662 
663 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, reg);
664 }
665 
aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg,enum aarch64_insn_register base,enum aarch64_insn_register offset,enum aarch64_insn_size_type size,enum aarch64_insn_ldst_type type)666 u32 aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg,
667 				    enum aarch64_insn_register base,
668 				    enum aarch64_insn_register offset,
669 				    enum aarch64_insn_size_type size,
670 				    enum aarch64_insn_ldst_type type)
671 {
672 	u32 insn;
673 
674 	switch (type) {
675 	case AARCH64_INSN_LDST_LOAD_REG_OFFSET:
676 		insn = aarch64_insn_get_ldr_reg_value();
677 		break;
678 	case AARCH64_INSN_LDST_STORE_REG_OFFSET:
679 		insn = aarch64_insn_get_str_reg_value();
680 		break;
681 	default:
682 		pr_err("%s: unknown load/store encoding %d\n", __func__, type);
683 		return AARCH64_BREAK_FAULT;
684 	}
685 
686 	insn = aarch64_insn_encode_ldst_size(size, insn);
687 
688 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
689 
690 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
691 					    base);
692 
693 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
694 					    offset);
695 }
696 
aarch64_insn_gen_load_store_pair(enum aarch64_insn_register reg1,enum aarch64_insn_register reg2,enum aarch64_insn_register base,int offset,enum aarch64_insn_variant variant,enum aarch64_insn_ldst_type type)697 u32 aarch64_insn_gen_load_store_pair(enum aarch64_insn_register reg1,
698 				     enum aarch64_insn_register reg2,
699 				     enum aarch64_insn_register base,
700 				     int offset,
701 				     enum aarch64_insn_variant variant,
702 				     enum aarch64_insn_ldst_type type)
703 {
704 	u32 insn;
705 	int shift;
706 
707 	switch (type) {
708 	case AARCH64_INSN_LDST_LOAD_PAIR_PRE_INDEX:
709 		insn = aarch64_insn_get_ldp_pre_value();
710 		break;
711 	case AARCH64_INSN_LDST_STORE_PAIR_PRE_INDEX:
712 		insn = aarch64_insn_get_stp_pre_value();
713 		break;
714 	case AARCH64_INSN_LDST_LOAD_PAIR_POST_INDEX:
715 		insn = aarch64_insn_get_ldp_post_value();
716 		break;
717 	case AARCH64_INSN_LDST_STORE_PAIR_POST_INDEX:
718 		insn = aarch64_insn_get_stp_post_value();
719 		break;
720 	default:
721 		pr_err("%s: unknown load/store encoding %d\n", __func__, type);
722 		return AARCH64_BREAK_FAULT;
723 	}
724 
725 	switch (variant) {
726 	case AARCH64_INSN_VARIANT_32BIT:
727 		if ((offset & 0x3) || (offset < -256) || (offset > 252)) {
728 			pr_err("%s: offset must be multiples of 4 in the range of [-256, 252] %d\n",
729 			       __func__, offset);
730 			return AARCH64_BREAK_FAULT;
731 		}
732 		shift = 2;
733 		break;
734 	case AARCH64_INSN_VARIANT_64BIT:
735 		if ((offset & 0x7) || (offset < -512) || (offset > 504)) {
736 			pr_err("%s: offset must be multiples of 8 in the range of [-512, 504] %d\n",
737 			       __func__, offset);
738 			return AARCH64_BREAK_FAULT;
739 		}
740 		shift = 3;
741 		insn |= AARCH64_INSN_SF_BIT;
742 		break;
743 	default:
744 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
745 		return AARCH64_BREAK_FAULT;
746 	}
747 
748 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
749 					    reg1);
750 
751 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT2, insn,
752 					    reg2);
753 
754 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
755 					    base);
756 
757 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_7, insn,
758 					     offset >> shift);
759 }
760 
aarch64_insn_gen_load_store_ex(enum aarch64_insn_register reg,enum aarch64_insn_register base,enum aarch64_insn_register state,enum aarch64_insn_size_type size,enum aarch64_insn_ldst_type type)761 u32 aarch64_insn_gen_load_store_ex(enum aarch64_insn_register reg,
762 				   enum aarch64_insn_register base,
763 				   enum aarch64_insn_register state,
764 				   enum aarch64_insn_size_type size,
765 				   enum aarch64_insn_ldst_type type)
766 {
767 	u32 insn;
768 
769 	switch (type) {
770 	case AARCH64_INSN_LDST_LOAD_EX:
771 		insn = aarch64_insn_get_load_ex_value();
772 		break;
773 	case AARCH64_INSN_LDST_STORE_EX:
774 		insn = aarch64_insn_get_store_ex_value();
775 		break;
776 	default:
777 		pr_err("%s: unknown load/store exclusive encoding %d\n", __func__, type);
778 		return AARCH64_BREAK_FAULT;
779 	}
780 
781 	insn = aarch64_insn_encode_ldst_size(size, insn);
782 
783 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
784 					    reg);
785 
786 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
787 					    base);
788 
789 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT2, insn,
790 					    AARCH64_INSN_REG_ZR);
791 
792 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RS, insn,
793 					    state);
794 }
795 
aarch64_insn_gen_ldadd(enum aarch64_insn_register result,enum aarch64_insn_register address,enum aarch64_insn_register value,enum aarch64_insn_size_type size)796 u32 aarch64_insn_gen_ldadd(enum aarch64_insn_register result,
797 			   enum aarch64_insn_register address,
798 			   enum aarch64_insn_register value,
799 			   enum aarch64_insn_size_type size)
800 {
801 	u32 insn = aarch64_insn_get_ldadd_value();
802 
803 	switch (size) {
804 	case AARCH64_INSN_SIZE_32:
805 	case AARCH64_INSN_SIZE_64:
806 		break;
807 	default:
808 		pr_err("%s: unimplemented size encoding %d\n", __func__, size);
809 		return AARCH64_BREAK_FAULT;
810 	}
811 
812 	insn = aarch64_insn_encode_ldst_size(size, insn);
813 
814 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
815 					    result);
816 
817 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
818 					    address);
819 
820 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RS, insn,
821 					    value);
822 }
823 
aarch64_insn_gen_stadd(enum aarch64_insn_register address,enum aarch64_insn_register value,enum aarch64_insn_size_type size)824 u32 aarch64_insn_gen_stadd(enum aarch64_insn_register address,
825 			   enum aarch64_insn_register value,
826 			   enum aarch64_insn_size_type size)
827 {
828 	/*
829 	 * STADD is simply encoded as an alias for LDADD with XZR as
830 	 * the destination register.
831 	 */
832 	return aarch64_insn_gen_ldadd(AARCH64_INSN_REG_ZR, address,
833 				      value, size);
834 }
835 
aarch64_insn_encode_prfm_imm(enum aarch64_insn_prfm_type type,enum aarch64_insn_prfm_target target,enum aarch64_insn_prfm_policy policy,u32 insn)836 static u32 aarch64_insn_encode_prfm_imm(enum aarch64_insn_prfm_type type,
837 					enum aarch64_insn_prfm_target target,
838 					enum aarch64_insn_prfm_policy policy,
839 					u32 insn)
840 {
841 	u32 imm_type = 0, imm_target = 0, imm_policy = 0;
842 
843 	switch (type) {
844 	case AARCH64_INSN_PRFM_TYPE_PLD:
845 		break;
846 	case AARCH64_INSN_PRFM_TYPE_PLI:
847 		imm_type = BIT(0);
848 		break;
849 	case AARCH64_INSN_PRFM_TYPE_PST:
850 		imm_type = BIT(1);
851 		break;
852 	default:
853 		pr_err("%s: unknown prfm type encoding %d\n", __func__, type);
854 		return AARCH64_BREAK_FAULT;
855 	}
856 
857 	switch (target) {
858 	case AARCH64_INSN_PRFM_TARGET_L1:
859 		break;
860 	case AARCH64_INSN_PRFM_TARGET_L2:
861 		imm_target = BIT(0);
862 		break;
863 	case AARCH64_INSN_PRFM_TARGET_L3:
864 		imm_target = BIT(1);
865 		break;
866 	default:
867 		pr_err("%s: unknown prfm target encoding %d\n", __func__, target);
868 		return AARCH64_BREAK_FAULT;
869 	}
870 
871 	switch (policy) {
872 	case AARCH64_INSN_PRFM_POLICY_KEEP:
873 		break;
874 	case AARCH64_INSN_PRFM_POLICY_STRM:
875 		imm_policy = BIT(0);
876 		break;
877 	default:
878 		pr_err("%s: unknown prfm policy encoding %d\n", __func__, policy);
879 		return AARCH64_BREAK_FAULT;
880 	}
881 
882 	/* In this case, imm5 is encoded into Rt field. */
883 	insn &= ~GENMASK(4, 0);
884 	insn |= imm_policy | (imm_target << 1) | (imm_type << 3);
885 
886 	return insn;
887 }
888 
aarch64_insn_gen_prefetch(enum aarch64_insn_register base,enum aarch64_insn_prfm_type type,enum aarch64_insn_prfm_target target,enum aarch64_insn_prfm_policy policy)889 u32 aarch64_insn_gen_prefetch(enum aarch64_insn_register base,
890 			      enum aarch64_insn_prfm_type type,
891 			      enum aarch64_insn_prfm_target target,
892 			      enum aarch64_insn_prfm_policy policy)
893 {
894 	u32 insn = aarch64_insn_get_prfm_value();
895 
896 	insn = aarch64_insn_encode_ldst_size(AARCH64_INSN_SIZE_64, insn);
897 
898 	insn = aarch64_insn_encode_prfm_imm(type, target, policy, insn);
899 
900 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
901 					    base);
902 
903 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, 0);
904 }
905 
aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst,enum aarch64_insn_register src,int imm,enum aarch64_insn_variant variant,enum aarch64_insn_adsb_type type)906 u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst,
907 				 enum aarch64_insn_register src,
908 				 int imm, enum aarch64_insn_variant variant,
909 				 enum aarch64_insn_adsb_type type)
910 {
911 	u32 insn;
912 
913 	switch (type) {
914 	case AARCH64_INSN_ADSB_ADD:
915 		insn = aarch64_insn_get_add_imm_value();
916 		break;
917 	case AARCH64_INSN_ADSB_SUB:
918 		insn = aarch64_insn_get_sub_imm_value();
919 		break;
920 	case AARCH64_INSN_ADSB_ADD_SETFLAGS:
921 		insn = aarch64_insn_get_adds_imm_value();
922 		break;
923 	case AARCH64_INSN_ADSB_SUB_SETFLAGS:
924 		insn = aarch64_insn_get_subs_imm_value();
925 		break;
926 	default:
927 		pr_err("%s: unknown add/sub encoding %d\n", __func__, type);
928 		return AARCH64_BREAK_FAULT;
929 	}
930 
931 	switch (variant) {
932 	case AARCH64_INSN_VARIANT_32BIT:
933 		break;
934 	case AARCH64_INSN_VARIANT_64BIT:
935 		insn |= AARCH64_INSN_SF_BIT;
936 		break;
937 	default:
938 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
939 		return AARCH64_BREAK_FAULT;
940 	}
941 
942 	if (imm & ~(SZ_4K - 1)) {
943 		pr_err("%s: invalid immediate encoding %d\n", __func__, imm);
944 		return AARCH64_BREAK_FAULT;
945 	}
946 
947 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
948 
949 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
950 
951 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, imm);
952 }
953 
aarch64_insn_gen_bitfield(enum aarch64_insn_register dst,enum aarch64_insn_register src,int immr,int imms,enum aarch64_insn_variant variant,enum aarch64_insn_bitfield_type type)954 u32 aarch64_insn_gen_bitfield(enum aarch64_insn_register dst,
955 			      enum aarch64_insn_register src,
956 			      int immr, int imms,
957 			      enum aarch64_insn_variant variant,
958 			      enum aarch64_insn_bitfield_type type)
959 {
960 	u32 insn;
961 	u32 mask;
962 
963 	switch (type) {
964 	case AARCH64_INSN_BITFIELD_MOVE:
965 		insn = aarch64_insn_get_bfm_value();
966 		break;
967 	case AARCH64_INSN_BITFIELD_MOVE_UNSIGNED:
968 		insn = aarch64_insn_get_ubfm_value();
969 		break;
970 	case AARCH64_INSN_BITFIELD_MOVE_SIGNED:
971 		insn = aarch64_insn_get_sbfm_value();
972 		break;
973 	default:
974 		pr_err("%s: unknown bitfield encoding %d\n", __func__, type);
975 		return AARCH64_BREAK_FAULT;
976 	}
977 
978 	switch (variant) {
979 	case AARCH64_INSN_VARIANT_32BIT:
980 		mask = GENMASK(4, 0);
981 		break;
982 	case AARCH64_INSN_VARIANT_64BIT:
983 		insn |= AARCH64_INSN_SF_BIT | AARCH64_INSN_N_BIT;
984 		mask = GENMASK(5, 0);
985 		break;
986 	default:
987 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
988 		return AARCH64_BREAK_FAULT;
989 	}
990 
991 	if (immr & ~mask) {
992 		pr_err("%s: invalid immr encoding %d\n", __func__, immr);
993 		return AARCH64_BREAK_FAULT;
994 	}
995 	if (imms & ~mask) {
996 		pr_err("%s: invalid imms encoding %d\n", __func__, imms);
997 		return AARCH64_BREAK_FAULT;
998 	}
999 
1000 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1001 
1002 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1003 
1004 	insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_R, insn, immr);
1005 
1006 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, imms);
1007 }
1008 
aarch64_insn_gen_movewide(enum aarch64_insn_register dst,int imm,int shift,enum aarch64_insn_variant variant,enum aarch64_insn_movewide_type type)1009 u32 aarch64_insn_gen_movewide(enum aarch64_insn_register dst,
1010 			      int imm, int shift,
1011 			      enum aarch64_insn_variant variant,
1012 			      enum aarch64_insn_movewide_type type)
1013 {
1014 	u32 insn;
1015 
1016 	switch (type) {
1017 	case AARCH64_INSN_MOVEWIDE_ZERO:
1018 		insn = aarch64_insn_get_movz_value();
1019 		break;
1020 	case AARCH64_INSN_MOVEWIDE_KEEP:
1021 		insn = aarch64_insn_get_movk_value();
1022 		break;
1023 	case AARCH64_INSN_MOVEWIDE_INVERSE:
1024 		insn = aarch64_insn_get_movn_value();
1025 		break;
1026 	default:
1027 		pr_err("%s: unknown movewide encoding %d\n", __func__, type);
1028 		return AARCH64_BREAK_FAULT;
1029 	}
1030 
1031 	if (imm & ~(SZ_64K - 1)) {
1032 		pr_err("%s: invalid immediate encoding %d\n", __func__, imm);
1033 		return AARCH64_BREAK_FAULT;
1034 	}
1035 
1036 	switch (variant) {
1037 	case AARCH64_INSN_VARIANT_32BIT:
1038 		if (shift != 0 && shift != 16) {
1039 			pr_err("%s: invalid shift encoding %d\n", __func__,
1040 			       shift);
1041 			return AARCH64_BREAK_FAULT;
1042 		}
1043 		break;
1044 	case AARCH64_INSN_VARIANT_64BIT:
1045 		insn |= AARCH64_INSN_SF_BIT;
1046 		if (shift != 0 && shift != 16 && shift != 32 && shift != 48) {
1047 			pr_err("%s: invalid shift encoding %d\n", __func__,
1048 			       shift);
1049 			return AARCH64_BREAK_FAULT;
1050 		}
1051 		break;
1052 	default:
1053 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1054 		return AARCH64_BREAK_FAULT;
1055 	}
1056 
1057 	insn |= (shift >> 4) << 21;
1058 
1059 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1060 
1061 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_16, insn, imm);
1062 }
1063 
aarch64_insn_gen_add_sub_shifted_reg(enum aarch64_insn_register dst,enum aarch64_insn_register src,enum aarch64_insn_register reg,int shift,enum aarch64_insn_variant variant,enum aarch64_insn_adsb_type type)1064 u32 aarch64_insn_gen_add_sub_shifted_reg(enum aarch64_insn_register dst,
1065 					 enum aarch64_insn_register src,
1066 					 enum aarch64_insn_register reg,
1067 					 int shift,
1068 					 enum aarch64_insn_variant variant,
1069 					 enum aarch64_insn_adsb_type type)
1070 {
1071 	u32 insn;
1072 
1073 	switch (type) {
1074 	case AARCH64_INSN_ADSB_ADD:
1075 		insn = aarch64_insn_get_add_value();
1076 		break;
1077 	case AARCH64_INSN_ADSB_SUB:
1078 		insn = aarch64_insn_get_sub_value();
1079 		break;
1080 	case AARCH64_INSN_ADSB_ADD_SETFLAGS:
1081 		insn = aarch64_insn_get_adds_value();
1082 		break;
1083 	case AARCH64_INSN_ADSB_SUB_SETFLAGS:
1084 		insn = aarch64_insn_get_subs_value();
1085 		break;
1086 	default:
1087 		pr_err("%s: unknown add/sub encoding %d\n", __func__, type);
1088 		return AARCH64_BREAK_FAULT;
1089 	}
1090 
1091 	switch (variant) {
1092 	case AARCH64_INSN_VARIANT_32BIT:
1093 		if (shift & ~(SZ_32 - 1)) {
1094 			pr_err("%s: invalid shift encoding %d\n", __func__,
1095 			       shift);
1096 			return AARCH64_BREAK_FAULT;
1097 		}
1098 		break;
1099 	case AARCH64_INSN_VARIANT_64BIT:
1100 		insn |= AARCH64_INSN_SF_BIT;
1101 		if (shift & ~(SZ_64 - 1)) {
1102 			pr_err("%s: invalid shift encoding %d\n", __func__,
1103 			       shift);
1104 			return AARCH64_BREAK_FAULT;
1105 		}
1106 		break;
1107 	default:
1108 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1109 		return AARCH64_BREAK_FAULT;
1110 	}
1111 
1112 
1113 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1114 
1115 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1116 
1117 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
1118 
1119 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
1120 }
1121 
aarch64_insn_gen_data1(enum aarch64_insn_register dst,enum aarch64_insn_register src,enum aarch64_insn_variant variant,enum aarch64_insn_data1_type type)1122 u32 aarch64_insn_gen_data1(enum aarch64_insn_register dst,
1123 			   enum aarch64_insn_register src,
1124 			   enum aarch64_insn_variant variant,
1125 			   enum aarch64_insn_data1_type type)
1126 {
1127 	u32 insn;
1128 
1129 	switch (type) {
1130 	case AARCH64_INSN_DATA1_REVERSE_16:
1131 		insn = aarch64_insn_get_rev16_value();
1132 		break;
1133 	case AARCH64_INSN_DATA1_REVERSE_32:
1134 		insn = aarch64_insn_get_rev32_value();
1135 		break;
1136 	case AARCH64_INSN_DATA1_REVERSE_64:
1137 		if (variant != AARCH64_INSN_VARIANT_64BIT) {
1138 			pr_err("%s: invalid variant for reverse64 %d\n",
1139 			       __func__, variant);
1140 			return AARCH64_BREAK_FAULT;
1141 		}
1142 		insn = aarch64_insn_get_rev64_value();
1143 		break;
1144 	default:
1145 		pr_err("%s: unknown data1 encoding %d\n", __func__, type);
1146 		return AARCH64_BREAK_FAULT;
1147 	}
1148 
1149 	switch (variant) {
1150 	case AARCH64_INSN_VARIANT_32BIT:
1151 		break;
1152 	case AARCH64_INSN_VARIANT_64BIT:
1153 		insn |= AARCH64_INSN_SF_BIT;
1154 		break;
1155 	default:
1156 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1157 		return AARCH64_BREAK_FAULT;
1158 	}
1159 
1160 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1161 
1162 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1163 }
1164 
aarch64_insn_gen_data2(enum aarch64_insn_register dst,enum aarch64_insn_register src,enum aarch64_insn_register reg,enum aarch64_insn_variant variant,enum aarch64_insn_data2_type type)1165 u32 aarch64_insn_gen_data2(enum aarch64_insn_register dst,
1166 			   enum aarch64_insn_register src,
1167 			   enum aarch64_insn_register reg,
1168 			   enum aarch64_insn_variant variant,
1169 			   enum aarch64_insn_data2_type type)
1170 {
1171 	u32 insn;
1172 
1173 	switch (type) {
1174 	case AARCH64_INSN_DATA2_UDIV:
1175 		insn = aarch64_insn_get_udiv_value();
1176 		break;
1177 	case AARCH64_INSN_DATA2_SDIV:
1178 		insn = aarch64_insn_get_sdiv_value();
1179 		break;
1180 	case AARCH64_INSN_DATA2_LSLV:
1181 		insn = aarch64_insn_get_lslv_value();
1182 		break;
1183 	case AARCH64_INSN_DATA2_LSRV:
1184 		insn = aarch64_insn_get_lsrv_value();
1185 		break;
1186 	case AARCH64_INSN_DATA2_ASRV:
1187 		insn = aarch64_insn_get_asrv_value();
1188 		break;
1189 	case AARCH64_INSN_DATA2_RORV:
1190 		insn = aarch64_insn_get_rorv_value();
1191 		break;
1192 	default:
1193 		pr_err("%s: unknown data2 encoding %d\n", __func__, type);
1194 		return AARCH64_BREAK_FAULT;
1195 	}
1196 
1197 	switch (variant) {
1198 	case AARCH64_INSN_VARIANT_32BIT:
1199 		break;
1200 	case AARCH64_INSN_VARIANT_64BIT:
1201 		insn |= AARCH64_INSN_SF_BIT;
1202 		break;
1203 	default:
1204 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1205 		return AARCH64_BREAK_FAULT;
1206 	}
1207 
1208 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1209 
1210 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1211 
1212 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
1213 }
1214 
aarch64_insn_gen_data3(enum aarch64_insn_register dst,enum aarch64_insn_register src,enum aarch64_insn_register reg1,enum aarch64_insn_register reg2,enum aarch64_insn_variant variant,enum aarch64_insn_data3_type type)1215 u32 aarch64_insn_gen_data3(enum aarch64_insn_register dst,
1216 			   enum aarch64_insn_register src,
1217 			   enum aarch64_insn_register reg1,
1218 			   enum aarch64_insn_register reg2,
1219 			   enum aarch64_insn_variant variant,
1220 			   enum aarch64_insn_data3_type type)
1221 {
1222 	u32 insn;
1223 
1224 	switch (type) {
1225 	case AARCH64_INSN_DATA3_MADD:
1226 		insn = aarch64_insn_get_madd_value();
1227 		break;
1228 	case AARCH64_INSN_DATA3_MSUB:
1229 		insn = aarch64_insn_get_msub_value();
1230 		break;
1231 	default:
1232 		pr_err("%s: unknown data3 encoding %d\n", __func__, type);
1233 		return AARCH64_BREAK_FAULT;
1234 	}
1235 
1236 	switch (variant) {
1237 	case AARCH64_INSN_VARIANT_32BIT:
1238 		break;
1239 	case AARCH64_INSN_VARIANT_64BIT:
1240 		insn |= AARCH64_INSN_SF_BIT;
1241 		break;
1242 	default:
1243 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1244 		return AARCH64_BREAK_FAULT;
1245 	}
1246 
1247 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1248 
1249 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RA, insn, src);
1250 
1251 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
1252 					    reg1);
1253 
1254 	return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
1255 					    reg2);
1256 }
1257 
aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst,enum aarch64_insn_register src,enum aarch64_insn_register reg,int shift,enum aarch64_insn_variant variant,enum aarch64_insn_logic_type type)1258 u32 aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst,
1259 					 enum aarch64_insn_register src,
1260 					 enum aarch64_insn_register reg,
1261 					 int shift,
1262 					 enum aarch64_insn_variant variant,
1263 					 enum aarch64_insn_logic_type type)
1264 {
1265 	u32 insn;
1266 
1267 	switch (type) {
1268 	case AARCH64_INSN_LOGIC_AND:
1269 		insn = aarch64_insn_get_and_value();
1270 		break;
1271 	case AARCH64_INSN_LOGIC_BIC:
1272 		insn = aarch64_insn_get_bic_value();
1273 		break;
1274 	case AARCH64_INSN_LOGIC_ORR:
1275 		insn = aarch64_insn_get_orr_value();
1276 		break;
1277 	case AARCH64_INSN_LOGIC_ORN:
1278 		insn = aarch64_insn_get_orn_value();
1279 		break;
1280 	case AARCH64_INSN_LOGIC_EOR:
1281 		insn = aarch64_insn_get_eor_value();
1282 		break;
1283 	case AARCH64_INSN_LOGIC_EON:
1284 		insn = aarch64_insn_get_eon_value();
1285 		break;
1286 	case AARCH64_INSN_LOGIC_AND_SETFLAGS:
1287 		insn = aarch64_insn_get_ands_value();
1288 		break;
1289 	case AARCH64_INSN_LOGIC_BIC_SETFLAGS:
1290 		insn = aarch64_insn_get_bics_value();
1291 		break;
1292 	default:
1293 		pr_err("%s: unknown logical encoding %d\n", __func__, type);
1294 		return AARCH64_BREAK_FAULT;
1295 	}
1296 
1297 	switch (variant) {
1298 	case AARCH64_INSN_VARIANT_32BIT:
1299 		if (shift & ~(SZ_32 - 1)) {
1300 			pr_err("%s: invalid shift encoding %d\n", __func__,
1301 			       shift);
1302 			return AARCH64_BREAK_FAULT;
1303 		}
1304 		break;
1305 	case AARCH64_INSN_VARIANT_64BIT:
1306 		insn |= AARCH64_INSN_SF_BIT;
1307 		if (shift & ~(SZ_64 - 1)) {
1308 			pr_err("%s: invalid shift encoding %d\n", __func__,
1309 			       shift);
1310 			return AARCH64_BREAK_FAULT;
1311 		}
1312 		break;
1313 	default:
1314 		pr_err("%s: unknown variant encoding %d\n", __func__, variant);
1315 		return AARCH64_BREAK_FAULT;
1316 	}
1317 
1318 
1319 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
1320 
1321 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
1322 
1323 	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
1324 
1325 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
1326 }
1327 
1328 /*
1329  * Decode the imm field of a branch, and return the byte offset as a
1330  * signed value (so it can be used when computing a new branch
1331  * target).
1332  */
aarch64_get_branch_offset(u32 insn)1333 s32 aarch64_get_branch_offset(u32 insn)
1334 {
1335 	s32 imm;
1336 
1337 	if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn)) {
1338 		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_26, insn);
1339 		return (imm << 6) >> 4;
1340 	}
1341 
1342 	if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
1343 	    aarch64_insn_is_bcond(insn)) {
1344 		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_19, insn);
1345 		return (imm << 13) >> 11;
1346 	}
1347 
1348 	if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn)) {
1349 		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_14, insn);
1350 		return (imm << 18) >> 16;
1351 	}
1352 
1353 	/* Unhandled instruction */
1354 	BUG();
1355 }
1356 
1357 /*
1358  * Encode the displacement of a branch in the imm field and return the
1359  * updated instruction.
1360  */
aarch64_set_branch_offset(u32 insn,s32 offset)1361 u32 aarch64_set_branch_offset(u32 insn, s32 offset)
1362 {
1363 	if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn))
1364 		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
1365 						     offset >> 2);
1366 
1367 	if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
1368 	    aarch64_insn_is_bcond(insn))
1369 		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
1370 						     offset >> 2);
1371 
1372 	if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn))
1373 		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_14, insn,
1374 						     offset >> 2);
1375 
1376 	/* Unhandled instruction */
1377 	BUG();
1378 }
1379 
aarch64_insn_adrp_get_offset(u32 insn)1380 s32 aarch64_insn_adrp_get_offset(u32 insn)
1381 {
1382 	BUG_ON(!aarch64_insn_is_adrp(insn));
1383 	return aarch64_insn_decode_immediate(AARCH64_INSN_IMM_ADR, insn) << 12;
1384 }
1385 
aarch64_insn_adrp_set_offset(u32 insn,s32 offset)1386 u32 aarch64_insn_adrp_set_offset(u32 insn, s32 offset)
1387 {
1388 	BUG_ON(!aarch64_insn_is_adrp(insn));
1389 	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_ADR, insn,
1390 						offset >> 12);
1391 }
1392 
1393 /*
1394  * Extract the Op/CR data from a msr/mrs instruction.
1395  */
aarch64_insn_extract_system_reg(u32 insn)1396 u32 aarch64_insn_extract_system_reg(u32 insn)
1397 {
1398 	return (insn & 0x1FFFE0) >> 5;
1399 }
1400 
aarch32_insn_is_wide(u32 insn)1401 bool aarch32_insn_is_wide(u32 insn)
1402 {
1403 	return insn >= 0xe800;
1404 }
1405 
1406 /*
1407  * Macros/defines for extracting register numbers from instruction.
1408  */
aarch32_insn_extract_reg_num(u32 insn,int offset)1409 u32 aarch32_insn_extract_reg_num(u32 insn, int offset)
1410 {
1411 	return (insn & (0xf << offset)) >> offset;
1412 }
1413 
1414 #define OPC2_MASK	0x7
1415 #define OPC2_OFFSET	5
aarch32_insn_mcr_extract_opc2(u32 insn)1416 u32 aarch32_insn_mcr_extract_opc2(u32 insn)
1417 {
1418 	return (insn & (OPC2_MASK << OPC2_OFFSET)) >> OPC2_OFFSET;
1419 }
1420 
1421 #define CRM_MASK	0xf
aarch32_insn_mcr_extract_crm(u32 insn)1422 u32 aarch32_insn_mcr_extract_crm(u32 insn)
1423 {
1424 	return insn & CRM_MASK;
1425 }
1426 
__check_eq(unsigned long pstate)1427 static bool __kprobes __check_eq(unsigned long pstate)
1428 {
1429 	return (pstate & PSR_Z_BIT) != 0;
1430 }
1431 
__check_ne(unsigned long pstate)1432 static bool __kprobes __check_ne(unsigned long pstate)
1433 {
1434 	return (pstate & PSR_Z_BIT) == 0;
1435 }
1436 
__check_cs(unsigned long pstate)1437 static bool __kprobes __check_cs(unsigned long pstate)
1438 {
1439 	return (pstate & PSR_C_BIT) != 0;
1440 }
1441 
__check_cc(unsigned long pstate)1442 static bool __kprobes __check_cc(unsigned long pstate)
1443 {
1444 	return (pstate & PSR_C_BIT) == 0;
1445 }
1446 
__check_mi(unsigned long pstate)1447 static bool __kprobes __check_mi(unsigned long pstate)
1448 {
1449 	return (pstate & PSR_N_BIT) != 0;
1450 }
1451 
__check_pl(unsigned long pstate)1452 static bool __kprobes __check_pl(unsigned long pstate)
1453 {
1454 	return (pstate & PSR_N_BIT) == 0;
1455 }
1456 
__check_vs(unsigned long pstate)1457 static bool __kprobes __check_vs(unsigned long pstate)
1458 {
1459 	return (pstate & PSR_V_BIT) != 0;
1460 }
1461 
__check_vc(unsigned long pstate)1462 static bool __kprobes __check_vc(unsigned long pstate)
1463 {
1464 	return (pstate & PSR_V_BIT) == 0;
1465 }
1466 
__check_hi(unsigned long pstate)1467 static bool __kprobes __check_hi(unsigned long pstate)
1468 {
1469 	pstate &= ~(pstate >> 1);	/* PSR_C_BIT &= ~PSR_Z_BIT */
1470 	return (pstate & PSR_C_BIT) != 0;
1471 }
1472 
__check_ls(unsigned long pstate)1473 static bool __kprobes __check_ls(unsigned long pstate)
1474 {
1475 	pstate &= ~(pstate >> 1);	/* PSR_C_BIT &= ~PSR_Z_BIT */
1476 	return (pstate & PSR_C_BIT) == 0;
1477 }
1478 
__check_ge(unsigned long pstate)1479 static bool __kprobes __check_ge(unsigned long pstate)
1480 {
1481 	pstate ^= (pstate << 3);	/* PSR_N_BIT ^= PSR_V_BIT */
1482 	return (pstate & PSR_N_BIT) == 0;
1483 }
1484 
__check_lt(unsigned long pstate)1485 static bool __kprobes __check_lt(unsigned long pstate)
1486 {
1487 	pstate ^= (pstate << 3);	/* PSR_N_BIT ^= PSR_V_BIT */
1488 	return (pstate & PSR_N_BIT) != 0;
1489 }
1490 
__check_gt(unsigned long pstate)1491 static bool __kprobes __check_gt(unsigned long pstate)
1492 {
1493 	/*PSR_N_BIT ^= PSR_V_BIT */
1494 	unsigned long temp = pstate ^ (pstate << 3);
1495 
1496 	temp |= (pstate << 1);	/*PSR_N_BIT |= PSR_Z_BIT */
1497 	return (temp & PSR_N_BIT) == 0;
1498 }
1499 
__check_le(unsigned long pstate)1500 static bool __kprobes __check_le(unsigned long pstate)
1501 {
1502 	/*PSR_N_BIT ^= PSR_V_BIT */
1503 	unsigned long temp = pstate ^ (pstate << 3);
1504 
1505 	temp |= (pstate << 1);	/*PSR_N_BIT |= PSR_Z_BIT */
1506 	return (temp & PSR_N_BIT) != 0;
1507 }
1508 
__check_al(unsigned long pstate)1509 static bool __kprobes __check_al(unsigned long pstate)
1510 {
1511 	return true;
1512 }
1513 
1514 /*
1515  * Note that the ARMv8 ARM calls condition code 0b1111 "nv", but states that
1516  * it behaves identically to 0b1110 ("al").
1517  */
1518 pstate_check_t * const aarch32_opcode_cond_checks[16] = {
1519 	__check_eq, __check_ne, __check_cs, __check_cc,
1520 	__check_mi, __check_pl, __check_vs, __check_vc,
1521 	__check_hi, __check_ls, __check_ge, __check_lt,
1522 	__check_gt, __check_le, __check_al, __check_al
1523 };
1524