1 /*
2  * arch/arm/kernel/kprobes-decode.c
3  *
4  * Copyright (C) 2006, 2007 Motorola Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
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 GNU
13  * General Public License for more details.
14  */
15 
16 /*
17  * We do not have hardware single-stepping on ARM, This
18  * effort is further complicated by the ARM not having a
19  * "next PC" register.  Instructions that change the PC
20  * can't be safely single-stepped in a MP environment, so
21  * we have a lot of work to do:
22  *
23  * In the prepare phase:
24  *   *) If it is an instruction that does anything
25  *      with the CPU mode, we reject it for a kprobe.
26  *      (This is out of laziness rather than need.  The
27  *      instructions could be simulated.)
28  *
29  *   *) Otherwise, decode the instruction rewriting its
30  *      registers to take fixed, ordered registers and
31  *      setting a handler for it to run the instruction.
32  *
33  * In the execution phase by an instruction's handler:
34  *
35  *   *) If the PC is written to by the instruction, the
36  *      instruction must be fully simulated in software.
37  *
38  *   *) Otherwise, a modified form of the instruction is
39  *      directly executed.  Its handler calls the
40  *      instruction in insn[0].  In insn[1] is a
41  *      "mov pc, lr" to return.
42  *
43  *      Before calling, load up the reordered registers
44  *      from the original instruction's registers.  If one
45  *      of the original input registers is the PC, compute
46  *      and adjust the appropriate input register.
47  *
48  *	After call completes, copy the output registers to
49  *      the original instruction's original registers.
50  *
51  * We don't use a real breakpoint instruction since that
52  * would have us in the kernel go from SVC mode to SVC
53  * mode losing the link register.  Instead we use an
54  * undefined instruction.  To simplify processing, the
55  * undefined instruction used for kprobes must be reserved
56  * exclusively for kprobes use.
57  *
58  * TODO: ifdef out some instruction decoding based on architecture.
59  */
60 
61 #include <linux/kernel.h>
62 #include <linux/kprobes.h>
63 #include <linux/module.h>
64 
65 #include "kprobes.h"
66 
67 #define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit)))))
68 
69 #define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25)
70 
71 #if  __LINUX_ARM_ARCH__ >= 6
72 #define BLX(reg)	"blx	"reg"		\n\t"
73 #else
74 #define BLX(reg)	"mov	lr, pc		\n\t"	\
75 			"mov	pc, "reg"	\n\t"
76 #endif
77 
78 /*
79  * To avoid the complications of mimicing single-stepping on a
80  * processor without a Next-PC or a single-step mode, and to
81  * avoid having to deal with the side-effects of boosting, we
82  * simulate or emulate (almost) all ARM instructions.
83  *
84  * "Simulation" is where the instruction's behavior is duplicated in
85  * C code.  "Emulation" is where the original instruction is rewritten
86  * and executed, often by altering its registers.
87  *
88  * By having all behavior of the kprobe'd instruction completed before
89  * returning from the kprobe_handler(), all locks (scheduler and
90  * interrupt) can safely be released.  There is no need for secondary
91  * breakpoints, no race with MP or preemptable kernels, nor having to
92  * clean up resources counts at a later time impacting overall system
93  * performance.  By rewriting the instruction, only the minimum registers
94  * need to be loaded and saved back optimizing performance.
95  *
96  * Calling the insnslot_*_rwflags version of a function doesn't hurt
97  * anything even when the CPSR flags aren't updated by the
98  * instruction.  It's just a little slower in return for saving
99  * a little space by not having a duplicate function that doesn't
100  * update the flags.  (The same optimization can be said for
101  * instructions that do or don't perform register writeback)
102  * Also, instructions can either read the flags, only write the
103  * flags, or read and write the flags.  To save combinations
104  * rather than for sheer performance, flag functions just assume
105  * read and write of flags.
106  */
107 
simulate_bbl(struct kprobe * p,struct pt_regs * regs)108 static void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs)
109 {
110 	kprobe_opcode_t insn = p->opcode;
111 	long iaddr = (long)p->addr;
112 	int disp  = branch_displacement(insn);
113 
114 	if (insn & (1 << 24))
115 		regs->ARM_lr = iaddr + 4;
116 
117 	regs->ARM_pc = iaddr + 8 + disp;
118 }
119 
simulate_blx1(struct kprobe * p,struct pt_regs * regs)120 static void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs)
121 {
122 	kprobe_opcode_t insn = p->opcode;
123 	long iaddr = (long)p->addr;
124 	int disp = branch_displacement(insn);
125 
126 	regs->ARM_lr = iaddr + 4;
127 	regs->ARM_pc = iaddr + 8 + disp + ((insn >> 23) & 0x2);
128 	regs->ARM_cpsr |= PSR_T_BIT;
129 }
130 
simulate_blx2bx(struct kprobe * p,struct pt_regs * regs)131 static void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs)
132 {
133 	kprobe_opcode_t insn = p->opcode;
134 	int rm = insn & 0xf;
135 	long rmv = regs->uregs[rm];
136 
137 	if (insn & (1 << 5))
138 		regs->ARM_lr = (long)p->addr + 4;
139 
140 	regs->ARM_pc = rmv & ~0x1;
141 	regs->ARM_cpsr &= ~PSR_T_BIT;
142 	if (rmv & 0x1)
143 		regs->ARM_cpsr |= PSR_T_BIT;
144 }
145 
simulate_mrs(struct kprobe * p,struct pt_regs * regs)146 static void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs)
147 {
148 	kprobe_opcode_t insn = p->opcode;
149 	int rd = (insn >> 12) & 0xf;
150 	unsigned long mask = 0xf8ff03df; /* Mask out execution state */
151 	regs->uregs[rd] = regs->ARM_cpsr & mask;
152 }
153 
simulate_mov_ipsp(struct kprobe * p,struct pt_regs * regs)154 static void __kprobes simulate_mov_ipsp(struct kprobe *p, struct pt_regs *regs)
155 {
156 	regs->uregs[12] = regs->uregs[13];
157 }
158 
159 static void __kprobes
emulate_ldrdstrd(struct kprobe * p,struct pt_regs * regs)160 emulate_ldrdstrd(struct kprobe *p, struct pt_regs *regs)
161 {
162 	kprobe_opcode_t insn = p->opcode;
163 	unsigned long pc = (unsigned long)p->addr + 8;
164 	int rt = (insn >> 12) & 0xf;
165 	int rn = (insn >> 16) & 0xf;
166 	int rm = insn & 0xf;
167 
168 	register unsigned long rtv asm("r0") = regs->uregs[rt];
169 	register unsigned long rt2v asm("r1") = regs->uregs[rt+1];
170 	register unsigned long rnv asm("r2") = (rn == 15) ? pc
171 							  : regs->uregs[rn];
172 	register unsigned long rmv asm("r3") = regs->uregs[rm];
173 
174 	__asm__ __volatile__ (
175 		BLX("%[fn]")
176 		: "=r" (rtv), "=r" (rt2v), "=r" (rnv)
177 		: "0" (rtv), "1" (rt2v), "2" (rnv), "r" (rmv),
178 		  [fn] "r" (p->ainsn.insn_fn)
179 		: "lr", "memory", "cc"
180 	);
181 
182 	regs->uregs[rt] = rtv;
183 	regs->uregs[rt+1] = rt2v;
184 	if (is_writeback(insn))
185 		regs->uregs[rn] = rnv;
186 }
187 
188 static void __kprobes
emulate_ldr(struct kprobe * p,struct pt_regs * regs)189 emulate_ldr(struct kprobe *p, struct pt_regs *regs)
190 {
191 	kprobe_opcode_t insn = p->opcode;
192 	unsigned long pc = (unsigned long)p->addr + 8;
193 	int rt = (insn >> 12) & 0xf;
194 	int rn = (insn >> 16) & 0xf;
195 	int rm = insn & 0xf;
196 
197 	register unsigned long rtv asm("r0");
198 	register unsigned long rnv asm("r2") = (rn == 15) ? pc
199 							  : regs->uregs[rn];
200 	register unsigned long rmv asm("r3") = regs->uregs[rm];
201 
202 	__asm__ __volatile__ (
203 		BLX("%[fn]")
204 		: "=r" (rtv), "=r" (rnv)
205 		: "1" (rnv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn)
206 		: "lr", "memory", "cc"
207 	);
208 
209 	if (rt == 15)
210 		load_write_pc(rtv, regs);
211 	else
212 		regs->uregs[rt] = rtv;
213 
214 	if (is_writeback(insn))
215 		regs->uregs[rn] = rnv;
216 }
217 
218 static void __kprobes
emulate_str(struct kprobe * p,struct pt_regs * regs)219 emulate_str(struct kprobe *p, struct pt_regs *regs)
220 {
221 	kprobe_opcode_t insn = p->opcode;
222 	unsigned long rtpc = (unsigned long)p->addr + str_pc_offset;
223 	unsigned long rnpc = (unsigned long)p->addr + 8;
224 	int rt = (insn >> 12) & 0xf;
225 	int rn = (insn >> 16) & 0xf;
226 	int rm = insn & 0xf;
227 
228 	register unsigned long rtv asm("r0") = (rt == 15) ? rtpc
229 							  : regs->uregs[rt];
230 	register unsigned long rnv asm("r2") = (rn == 15) ? rnpc
231 							  : regs->uregs[rn];
232 	register unsigned long rmv asm("r3") = regs->uregs[rm];
233 
234 	__asm__ __volatile__ (
235 		BLX("%[fn]")
236 		: "=r" (rnv)
237 		: "r" (rtv), "0" (rnv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn)
238 		: "lr", "memory", "cc"
239 	);
240 
241 	if (is_writeback(insn))
242 		regs->uregs[rn] = rnv;
243 }
244 
245 static void __kprobes
emulate_rd12rn16rm0rs8_rwflags(struct kprobe * p,struct pt_regs * regs)246 emulate_rd12rn16rm0rs8_rwflags(struct kprobe *p, struct pt_regs *regs)
247 {
248 	kprobe_opcode_t insn = p->opcode;
249 	unsigned long pc = (unsigned long)p->addr + 8;
250 	int rd = (insn >> 12) & 0xf;
251 	int rn = (insn >> 16) & 0xf;
252 	int rm = insn & 0xf;
253 	int rs = (insn >> 8) & 0xf;
254 
255 	register unsigned long rdv asm("r0") = regs->uregs[rd];
256 	register unsigned long rnv asm("r2") = (rn == 15) ? pc
257 							  : regs->uregs[rn];
258 	register unsigned long rmv asm("r3") = (rm == 15) ? pc
259 							  : regs->uregs[rm];
260 	register unsigned long rsv asm("r1") = regs->uregs[rs];
261 	unsigned long cpsr = regs->ARM_cpsr;
262 
263 	__asm__ __volatile__ (
264 		"msr	cpsr_fs, %[cpsr]	\n\t"
265 		BLX("%[fn]")
266 		"mrs	%[cpsr], cpsr		\n\t"
267 		: "=r" (rdv), [cpsr] "=r" (cpsr)
268 		: "0" (rdv), "r" (rnv), "r" (rmv), "r" (rsv),
269 		  "1" (cpsr), [fn] "r" (p->ainsn.insn_fn)
270 		: "lr", "memory", "cc"
271 	);
272 
273 	if (rd == 15)
274 		alu_write_pc(rdv, regs);
275 	else
276 		regs->uregs[rd] = rdv;
277 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
278 }
279 
280 static void __kprobes
emulate_rd12rn16rm0_rwflags_nopc(struct kprobe * p,struct pt_regs * regs)281 emulate_rd12rn16rm0_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
282 {
283 	kprobe_opcode_t insn = p->opcode;
284 	int rd = (insn >> 12) & 0xf;
285 	int rn = (insn >> 16) & 0xf;
286 	int rm = insn & 0xf;
287 
288 	register unsigned long rdv asm("r0") = regs->uregs[rd];
289 	register unsigned long rnv asm("r2") = regs->uregs[rn];
290 	register unsigned long rmv asm("r3") = regs->uregs[rm];
291 	unsigned long cpsr = regs->ARM_cpsr;
292 
293 	__asm__ __volatile__ (
294 		"msr	cpsr_fs, %[cpsr]	\n\t"
295 		BLX("%[fn]")
296 		"mrs	%[cpsr], cpsr		\n\t"
297 		: "=r" (rdv), [cpsr] "=r" (cpsr)
298 		: "0" (rdv), "r" (rnv), "r" (rmv),
299 		  "1" (cpsr), [fn] "r" (p->ainsn.insn_fn)
300 		: "lr", "memory", "cc"
301 	);
302 
303 	regs->uregs[rd] = rdv;
304 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
305 }
306 
307 static void __kprobes
emulate_rd16rn12rm0rs8_rwflags_nopc(struct kprobe * p,struct pt_regs * regs)308 emulate_rd16rn12rm0rs8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
309 {
310 	kprobe_opcode_t insn = p->opcode;
311 	int rd = (insn >> 16) & 0xf;
312 	int rn = (insn >> 12) & 0xf;
313 	int rm = insn & 0xf;
314 	int rs = (insn >> 8) & 0xf;
315 
316 	register unsigned long rdv asm("r2") = regs->uregs[rd];
317 	register unsigned long rnv asm("r0") = regs->uregs[rn];
318 	register unsigned long rmv asm("r3") = regs->uregs[rm];
319 	register unsigned long rsv asm("r1") = regs->uregs[rs];
320 	unsigned long cpsr = regs->ARM_cpsr;
321 
322 	__asm__ __volatile__ (
323 		"msr	cpsr_fs, %[cpsr]	\n\t"
324 		BLX("%[fn]")
325 		"mrs	%[cpsr], cpsr		\n\t"
326 		: "=r" (rdv), [cpsr] "=r" (cpsr)
327 		: "0" (rdv), "r" (rnv), "r" (rmv), "r" (rsv),
328 		  "1" (cpsr), [fn] "r" (p->ainsn.insn_fn)
329 		: "lr", "memory", "cc"
330 	);
331 
332 	regs->uregs[rd] = rdv;
333 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
334 }
335 
336 static void __kprobes
emulate_rd12rm0_noflags_nopc(struct kprobe * p,struct pt_regs * regs)337 emulate_rd12rm0_noflags_nopc(struct kprobe *p, struct pt_regs *regs)
338 {
339 	kprobe_opcode_t insn = p->opcode;
340 	int rd = (insn >> 12) & 0xf;
341 	int rm = insn & 0xf;
342 
343 	register unsigned long rdv asm("r0") = regs->uregs[rd];
344 	register unsigned long rmv asm("r3") = regs->uregs[rm];
345 
346 	__asm__ __volatile__ (
347 		BLX("%[fn]")
348 		: "=r" (rdv)
349 		: "0" (rdv), "r" (rmv), [fn] "r" (p->ainsn.insn_fn)
350 		: "lr", "memory", "cc"
351 	);
352 
353 	regs->uregs[rd] = rdv;
354 }
355 
356 static void __kprobes
emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(struct kprobe * p,struct pt_regs * regs)357 emulate_rdlo12rdhi16rn0rm8_rwflags_nopc(struct kprobe *p, struct pt_regs *regs)
358 {
359 	kprobe_opcode_t insn = p->opcode;
360 	int rdlo = (insn >> 12) & 0xf;
361 	int rdhi = (insn >> 16) & 0xf;
362 	int rn = insn & 0xf;
363 	int rm = (insn >> 8) & 0xf;
364 
365 	register unsigned long rdlov asm("r0") = regs->uregs[rdlo];
366 	register unsigned long rdhiv asm("r2") = regs->uregs[rdhi];
367 	register unsigned long rnv asm("r3") = regs->uregs[rn];
368 	register unsigned long rmv asm("r1") = regs->uregs[rm];
369 	unsigned long cpsr = regs->ARM_cpsr;
370 
371 	__asm__ __volatile__ (
372 		"msr	cpsr_fs, %[cpsr]	\n\t"
373 		BLX("%[fn]")
374 		"mrs	%[cpsr], cpsr		\n\t"
375 		: "=r" (rdlov), "=r" (rdhiv), [cpsr] "=r" (cpsr)
376 		: "0" (rdlov), "1" (rdhiv), "r" (rnv), "r" (rmv),
377 		  "2" (cpsr), [fn] "r" (p->ainsn.insn_fn)
378 		: "lr", "memory", "cc"
379 	);
380 
381 	regs->uregs[rdlo] = rdlov;
382 	regs->uregs[rdhi] = rdhiv;
383 	regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
384 }
385 
386 /*
387  * For the instruction masking and comparisons in all the "space_*"
388  * functions below, Do _not_ rearrange the order of tests unless
389  * you're very, very sure of what you are doing.  For the sake of
390  * efficiency, the masks for some tests sometimes assume other test
391  * have been done prior to them so the number of patterns to test
392  * for an instruction set can be as broad as possible to reduce the
393  * number of tests needed.
394  */
395 
396 static const union decode_item arm_1111_table[] = {
397 	/* Unconditional instructions					*/
398 
399 	/* memory hint		1111 0100 x001 xxxx xxxx xxxx xxxx xxxx */
400 	/* PLDI (immediate)	1111 0100 x101 xxxx xxxx xxxx xxxx xxxx */
401 	/* PLDW (immediate)	1111 0101 x001 xxxx xxxx xxxx xxxx xxxx */
402 	/* PLD (immediate)	1111 0101 x101 xxxx xxxx xxxx xxxx xxxx */
403 	DECODE_SIMULATE	(0xfe300000, 0xf4100000, kprobe_simulate_nop),
404 
405 	/* memory hint		1111 0110 x001 xxxx xxxx xxxx xxx0 xxxx */
406 	/* PLDI (register)	1111 0110 x101 xxxx xxxx xxxx xxx0 xxxx */
407 	/* PLDW (register)	1111 0111 x001 xxxx xxxx xxxx xxx0 xxxx */
408 	/* PLD (register)	1111 0111 x101 xxxx xxxx xxxx xxx0 xxxx */
409 	DECODE_SIMULATE	(0xfe300010, 0xf6100000, kprobe_simulate_nop),
410 
411 	/* BLX (immediate)	1111 101x xxxx xxxx xxxx xxxx xxxx xxxx */
412 	DECODE_SIMULATE	(0xfe000000, 0xfa000000, simulate_blx1),
413 
414 	/* CPS			1111 0001 0000 xxx0 xxxx xxxx xx0x xxxx */
415 	/* SETEND		1111 0001 0000 0001 xxxx xxxx 0000 xxxx */
416 	/* SRS			1111 100x x1x0 xxxx xxxx xxxx xxxx xxxx */
417 	/* RFE			1111 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
418 
419 	/* Coprocessor instructions... */
420 	/* MCRR2		1111 1100 0100 xxxx xxxx xxxx xxxx xxxx */
421 	/* MRRC2		1111 1100 0101 xxxx xxxx xxxx xxxx xxxx */
422 	/* LDC2			1111 110x xxx1 xxxx xxxx xxxx xxxx xxxx */
423 	/* STC2			1111 110x xxx0 xxxx xxxx xxxx xxxx xxxx */
424 	/* CDP2			1111 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */
425 	/* MCR2			1111 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */
426 	/* MRC2			1111 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */
427 
428 	/* Other unallocated instructions...				*/
429 	DECODE_END
430 };
431 
432 static const union decode_item arm_cccc_0001_0xx0____0xxx_table[] = {
433 	/* Miscellaneous instructions					*/
434 
435 	/* MRS cpsr		cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */
436 	DECODE_SIMULATEX(0x0ff000f0, 0x01000000, simulate_mrs,
437 						 REGS(0, NOPC, 0, 0, 0)),
438 
439 	/* BX			cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */
440 	DECODE_SIMULATE	(0x0ff000f0, 0x01200010, simulate_blx2bx),
441 
442 	/* BLX (register)	cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */
443 	DECODE_SIMULATEX(0x0ff000f0, 0x01200030, simulate_blx2bx,
444 						 REGS(0, 0, 0, 0, NOPC)),
445 
446 	/* CLZ			cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */
447 	DECODE_EMULATEX	(0x0ff000f0, 0x01600010, emulate_rd12rm0_noflags_nopc,
448 						 REGS(0, NOPC, 0, 0, NOPC)),
449 
450 	/* QADD			cccc 0001 0000 xxxx xxxx xxxx 0101 xxxx */
451 	/* QSUB			cccc 0001 0010 xxxx xxxx xxxx 0101 xxxx */
452 	/* QDADD		cccc 0001 0100 xxxx xxxx xxxx 0101 xxxx */
453 	/* QDSUB		cccc 0001 0110 xxxx xxxx xxxx 0101 xxxx */
454 	DECODE_EMULATEX	(0x0f9000f0, 0x01000050, emulate_rd12rn16rm0_rwflags_nopc,
455 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
456 
457 	/* BXJ			cccc 0001 0010 xxxx xxxx xxxx 0010 xxxx */
458 	/* MSR			cccc 0001 0x10 xxxx xxxx xxxx 0000 xxxx */
459 	/* MRS spsr		cccc 0001 0100 xxxx xxxx xxxx 0000 xxxx */
460 	/* BKPT			1110 0001 0010 xxxx xxxx xxxx 0111 xxxx */
461 	/* SMC			cccc 0001 0110 xxxx xxxx xxxx 0111 xxxx */
462 	/* And unallocated instructions...				*/
463 	DECODE_END
464 };
465 
466 static const union decode_item arm_cccc_0001_0xx0____1xx0_table[] = {
467 	/* Halfword multiply and multiply-accumulate			*/
468 
469 	/* SMLALxy		cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */
470 	DECODE_EMULATEX	(0x0ff00090, 0x01400080, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc,
471 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
472 
473 	/* SMULWy		cccc 0001 0010 xxxx xxxx xxxx 1x10 xxxx */
474 	DECODE_OR	(0x0ff000b0, 0x012000a0),
475 	/* SMULxy		cccc 0001 0110 xxxx xxxx xxxx 1xx0 xxxx */
476 	DECODE_EMULATEX	(0x0ff00090, 0x01600080, emulate_rd16rn12rm0rs8_rwflags_nopc,
477 						 REGS(NOPC, 0, NOPC, 0, NOPC)),
478 
479 	/* SMLAxy		cccc 0001 0000 xxxx xxxx xxxx 1xx0 xxxx */
480 	DECODE_OR	(0x0ff00090, 0x01000080),
481 	/* SMLAWy		cccc 0001 0010 xxxx xxxx xxxx 1x00 xxxx */
482 	DECODE_EMULATEX	(0x0ff000b0, 0x01200080, emulate_rd16rn12rm0rs8_rwflags_nopc,
483 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
484 
485 	DECODE_END
486 };
487 
488 static const union decode_item arm_cccc_0000_____1001_table[] = {
489 	/* Multiply and multiply-accumulate				*/
490 
491 	/* MUL			cccc 0000 0000 xxxx xxxx xxxx 1001 xxxx */
492 	/* MULS			cccc 0000 0001 xxxx xxxx xxxx 1001 xxxx */
493 	DECODE_EMULATEX	(0x0fe000f0, 0x00000090, emulate_rd16rn12rm0rs8_rwflags_nopc,
494 						 REGS(NOPC, 0, NOPC, 0, NOPC)),
495 
496 	/* MLA			cccc 0000 0010 xxxx xxxx xxxx 1001 xxxx */
497 	/* MLAS			cccc 0000 0011 xxxx xxxx xxxx 1001 xxxx */
498 	DECODE_OR	(0x0fe000f0, 0x00200090),
499 	/* MLS			cccc 0000 0110 xxxx xxxx xxxx 1001 xxxx */
500 	DECODE_EMULATEX	(0x0ff000f0, 0x00600090, emulate_rd16rn12rm0rs8_rwflags_nopc,
501 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
502 
503 	/* UMAAL		cccc 0000 0100 xxxx xxxx xxxx 1001 xxxx */
504 	DECODE_OR	(0x0ff000f0, 0x00400090),
505 	/* UMULL		cccc 0000 1000 xxxx xxxx xxxx 1001 xxxx */
506 	/* UMULLS		cccc 0000 1001 xxxx xxxx xxxx 1001 xxxx */
507 	/* UMLAL		cccc 0000 1010 xxxx xxxx xxxx 1001 xxxx */
508 	/* UMLALS		cccc 0000 1011 xxxx xxxx xxxx 1001 xxxx */
509 	/* SMULL		cccc 0000 1100 xxxx xxxx xxxx 1001 xxxx */
510 	/* SMULLS		cccc 0000 1101 xxxx xxxx xxxx 1001 xxxx */
511 	/* SMLAL		cccc 0000 1110 xxxx xxxx xxxx 1001 xxxx */
512 	/* SMLALS		cccc 0000 1111 xxxx xxxx xxxx 1001 xxxx */
513 	DECODE_EMULATEX	(0x0f8000f0, 0x00800090, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc,
514 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
515 
516 	DECODE_END
517 };
518 
519 static const union decode_item arm_cccc_0001_____1001_table[] = {
520 	/* Synchronization primitives					*/
521 
522 #if __LINUX_ARM_ARCH__ < 6
523 	/* Deprecated on ARMv6 and may be UNDEFINED on v7		*/
524 	/* SMP/SWPB		cccc 0001 0x00 xxxx xxxx xxxx 1001 xxxx */
525 	DECODE_EMULATEX	(0x0fb000f0, 0x01000090, emulate_rd12rn16rm0_rwflags_nopc,
526 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
527 #endif
528 	/* LDREX/STREX{,D,B,H}	cccc 0001 1xxx xxxx xxxx xxxx 1001 xxxx */
529 	/* And unallocated instructions...				*/
530 	DECODE_END
531 };
532 
533 static const union decode_item arm_cccc_000x_____1xx1_table[] = {
534 	/* Extra load/store instructions				*/
535 
536 	/* STRHT		cccc 0000 xx10 xxxx xxxx xxxx 1011 xxxx */
537 	/* ???			cccc 0000 xx10 xxxx xxxx xxxx 11x1 xxxx */
538 	/* LDRHT		cccc 0000 xx11 xxxx xxxx xxxx 1011 xxxx */
539 	/* LDRSBT		cccc 0000 xx11 xxxx xxxx xxxx 1101 xxxx */
540 	/* LDRSHT		cccc 0000 xx11 xxxx xxxx xxxx 1111 xxxx */
541 	DECODE_REJECT	(0x0f200090, 0x00200090),
542 
543 	/* LDRD/STRD lr,pc,{...	cccc 000x x0x0 xxxx 111x xxxx 1101 xxxx */
544 	DECODE_REJECT	(0x0e10e0d0, 0x0000e0d0),
545 
546 	/* LDRD (register)	cccc 000x x0x0 xxxx xxxx xxxx 1101 xxxx */
547 	/* STRD (register)	cccc 000x x0x0 xxxx xxxx xxxx 1111 xxxx */
548 	DECODE_EMULATEX	(0x0e5000d0, 0x000000d0, emulate_ldrdstrd,
549 						 REGS(NOPCWB, NOPCX, 0, 0, NOPC)),
550 
551 	/* LDRD (immediate)	cccc 000x x1x0 xxxx xxxx xxxx 1101 xxxx */
552 	/* STRD (immediate)	cccc 000x x1x0 xxxx xxxx xxxx 1111 xxxx */
553 	DECODE_EMULATEX	(0x0e5000d0, 0x004000d0, emulate_ldrdstrd,
554 						 REGS(NOPCWB, NOPCX, 0, 0, 0)),
555 
556 	/* STRH (register)	cccc 000x x0x0 xxxx xxxx xxxx 1011 xxxx */
557 	DECODE_EMULATEX	(0x0e5000f0, 0x000000b0, emulate_str,
558 						 REGS(NOPCWB, NOPC, 0, 0, NOPC)),
559 
560 	/* LDRH (register)	cccc 000x x0x1 xxxx xxxx xxxx 1011 xxxx */
561 	/* LDRSB (register)	cccc 000x x0x1 xxxx xxxx xxxx 1101 xxxx */
562 	/* LDRSH (register)	cccc 000x x0x1 xxxx xxxx xxxx 1111 xxxx */
563 	DECODE_EMULATEX	(0x0e500090, 0x00100090, emulate_ldr,
564 						 REGS(NOPCWB, NOPC, 0, 0, NOPC)),
565 
566 	/* STRH (immediate)	cccc 000x x1x0 xxxx xxxx xxxx 1011 xxxx */
567 	DECODE_EMULATEX	(0x0e5000f0, 0x004000b0, emulate_str,
568 						 REGS(NOPCWB, NOPC, 0, 0, 0)),
569 
570 	/* LDRH (immediate)	cccc 000x x1x1 xxxx xxxx xxxx 1011 xxxx */
571 	/* LDRSB (immediate)	cccc 000x x1x1 xxxx xxxx xxxx 1101 xxxx */
572 	/* LDRSH (immediate)	cccc 000x x1x1 xxxx xxxx xxxx 1111 xxxx */
573 	DECODE_EMULATEX	(0x0e500090, 0x00500090, emulate_ldr,
574 						 REGS(NOPCWB, NOPC, 0, 0, 0)),
575 
576 	DECODE_END
577 };
578 
579 static const union decode_item arm_cccc_000x_table[] = {
580 	/* Data-processing (register)					*/
581 
582 	/* <op>S PC, ...	cccc 000x xxx1 xxxx 1111 xxxx xxxx xxxx */
583 	DECODE_REJECT	(0x0e10f000, 0x0010f000),
584 
585 	/* MOV IP, SP		1110 0001 1010 0000 1100 0000 0000 1101 */
586 	DECODE_SIMULATE	(0xffffffff, 0xe1a0c00d, simulate_mov_ipsp),
587 
588 	/* TST (register)	cccc 0001 0001 xxxx xxxx xxxx xxx0 xxxx */
589 	/* TEQ (register)	cccc 0001 0011 xxxx xxxx xxxx xxx0 xxxx */
590 	/* CMP (register)	cccc 0001 0101 xxxx xxxx xxxx xxx0 xxxx */
591 	/* CMN (register)	cccc 0001 0111 xxxx xxxx xxxx xxx0 xxxx */
592 	DECODE_EMULATEX	(0x0f900010, 0x01100000, emulate_rd12rn16rm0rs8_rwflags,
593 						 REGS(ANY, 0, 0, 0, ANY)),
594 
595 	/* MOV (register)	cccc 0001 101x xxxx xxxx xxxx xxx0 xxxx */
596 	/* MVN (register)	cccc 0001 111x xxxx xxxx xxxx xxx0 xxxx */
597 	DECODE_EMULATEX	(0x0fa00010, 0x01a00000, emulate_rd12rn16rm0rs8_rwflags,
598 						 REGS(0, ANY, 0, 0, ANY)),
599 
600 	/* AND (register)	cccc 0000 000x xxxx xxxx xxxx xxx0 xxxx */
601 	/* EOR (register)	cccc 0000 001x xxxx xxxx xxxx xxx0 xxxx */
602 	/* SUB (register)	cccc 0000 010x xxxx xxxx xxxx xxx0 xxxx */
603 	/* RSB (register)	cccc 0000 011x xxxx xxxx xxxx xxx0 xxxx */
604 	/* ADD (register)	cccc 0000 100x xxxx xxxx xxxx xxx0 xxxx */
605 	/* ADC (register)	cccc 0000 101x xxxx xxxx xxxx xxx0 xxxx */
606 	/* SBC (register)	cccc 0000 110x xxxx xxxx xxxx xxx0 xxxx */
607 	/* RSC (register)	cccc 0000 111x xxxx xxxx xxxx xxx0 xxxx */
608 	/* ORR (register)	cccc 0001 100x xxxx xxxx xxxx xxx0 xxxx */
609 	/* BIC (register)	cccc 0001 110x xxxx xxxx xxxx xxx0 xxxx */
610 	DECODE_EMULATEX	(0x0e000010, 0x00000000, emulate_rd12rn16rm0rs8_rwflags,
611 						 REGS(ANY, ANY, 0, 0, ANY)),
612 
613 	/* TST (reg-shift reg)	cccc 0001 0001 xxxx xxxx xxxx 0xx1 xxxx */
614 	/* TEQ (reg-shift reg)	cccc 0001 0011 xxxx xxxx xxxx 0xx1 xxxx */
615 	/* CMP (reg-shift reg)	cccc 0001 0101 xxxx xxxx xxxx 0xx1 xxxx */
616 	/* CMN (reg-shift reg)	cccc 0001 0111 xxxx xxxx xxxx 0xx1 xxxx */
617 	DECODE_EMULATEX	(0x0f900090, 0x01100010, emulate_rd12rn16rm0rs8_rwflags,
618 						 REGS(ANY, 0, NOPC, 0, ANY)),
619 
620 	/* MOV (reg-shift reg)	cccc 0001 101x xxxx xxxx xxxx 0xx1 xxxx */
621 	/* MVN (reg-shift reg)	cccc 0001 111x xxxx xxxx xxxx 0xx1 xxxx */
622 	DECODE_EMULATEX	(0x0fa00090, 0x01a00010, emulate_rd12rn16rm0rs8_rwflags,
623 						 REGS(0, ANY, NOPC, 0, ANY)),
624 
625 	/* AND (reg-shift reg)	cccc 0000 000x xxxx xxxx xxxx 0xx1 xxxx */
626 	/* EOR (reg-shift reg)	cccc 0000 001x xxxx xxxx xxxx 0xx1 xxxx */
627 	/* SUB (reg-shift reg)	cccc 0000 010x xxxx xxxx xxxx 0xx1 xxxx */
628 	/* RSB (reg-shift reg)	cccc 0000 011x xxxx xxxx xxxx 0xx1 xxxx */
629 	/* ADD (reg-shift reg)	cccc 0000 100x xxxx xxxx xxxx 0xx1 xxxx */
630 	/* ADC (reg-shift reg)	cccc 0000 101x xxxx xxxx xxxx 0xx1 xxxx */
631 	/* SBC (reg-shift reg)	cccc 0000 110x xxxx xxxx xxxx 0xx1 xxxx */
632 	/* RSC (reg-shift reg)	cccc 0000 111x xxxx xxxx xxxx 0xx1 xxxx */
633 	/* ORR (reg-shift reg)	cccc 0001 100x xxxx xxxx xxxx 0xx1 xxxx */
634 	/* BIC (reg-shift reg)	cccc 0001 110x xxxx xxxx xxxx 0xx1 xxxx */
635 	DECODE_EMULATEX	(0x0e000090, 0x00000010, emulate_rd12rn16rm0rs8_rwflags,
636 						 REGS(ANY, ANY, NOPC, 0, ANY)),
637 
638 	DECODE_END
639 };
640 
641 static const union decode_item arm_cccc_001x_table[] = {
642 	/* Data-processing (immediate)					*/
643 
644 	/* MOVW			cccc 0011 0000 xxxx xxxx xxxx xxxx xxxx */
645 	/* MOVT			cccc 0011 0100 xxxx xxxx xxxx xxxx xxxx */
646 	DECODE_EMULATEX	(0x0fb00000, 0x03000000, emulate_rd12rm0_noflags_nopc,
647 						 REGS(0, NOPC, 0, 0, 0)),
648 
649 	/* YIELD		cccc 0011 0010 0000 xxxx xxxx 0000 0001 */
650 	DECODE_OR	(0x0fff00ff, 0x03200001),
651 	/* SEV			cccc 0011 0010 0000 xxxx xxxx 0000 0100 */
652 	DECODE_EMULATE	(0x0fff00ff, 0x03200004, kprobe_emulate_none),
653 	/* NOP			cccc 0011 0010 0000 xxxx xxxx 0000 0000 */
654 	/* WFE			cccc 0011 0010 0000 xxxx xxxx 0000 0010 */
655 	/* WFI			cccc 0011 0010 0000 xxxx xxxx 0000 0011 */
656 	DECODE_SIMULATE	(0x0fff00fc, 0x03200000, kprobe_simulate_nop),
657 	/* DBG			cccc 0011 0010 0000 xxxx xxxx ffff xxxx */
658 	/* unallocated hints	cccc 0011 0010 0000 xxxx xxxx xxxx xxxx */
659 	/* MSR (immediate)	cccc 0011 0x10 xxxx xxxx xxxx xxxx xxxx */
660 	DECODE_REJECT	(0x0fb00000, 0x03200000),
661 
662 	/* <op>S PC, ...	cccc 001x xxx1 xxxx 1111 xxxx xxxx xxxx */
663 	DECODE_REJECT	(0x0e10f000, 0x0210f000),
664 
665 	/* TST (immediate)	cccc 0011 0001 xxxx xxxx xxxx xxxx xxxx */
666 	/* TEQ (immediate)	cccc 0011 0011 xxxx xxxx xxxx xxxx xxxx */
667 	/* CMP (immediate)	cccc 0011 0101 xxxx xxxx xxxx xxxx xxxx */
668 	/* CMN (immediate)	cccc 0011 0111 xxxx xxxx xxxx xxxx xxxx */
669 	DECODE_EMULATEX	(0x0f900000, 0x03100000, emulate_rd12rn16rm0rs8_rwflags,
670 						 REGS(ANY, 0, 0, 0, 0)),
671 
672 	/* MOV (immediate)	cccc 0011 101x xxxx xxxx xxxx xxxx xxxx */
673 	/* MVN (immediate)	cccc 0011 111x xxxx xxxx xxxx xxxx xxxx */
674 	DECODE_EMULATEX	(0x0fa00000, 0x03a00000, emulate_rd12rn16rm0rs8_rwflags,
675 						 REGS(0, ANY, 0, 0, 0)),
676 
677 	/* AND (immediate)	cccc 0010 000x xxxx xxxx xxxx xxxx xxxx */
678 	/* EOR (immediate)	cccc 0010 001x xxxx xxxx xxxx xxxx xxxx */
679 	/* SUB (immediate)	cccc 0010 010x xxxx xxxx xxxx xxxx xxxx */
680 	/* RSB (immediate)	cccc 0010 011x xxxx xxxx xxxx xxxx xxxx */
681 	/* ADD (immediate)	cccc 0010 100x xxxx xxxx xxxx xxxx xxxx */
682 	/* ADC (immediate)	cccc 0010 101x xxxx xxxx xxxx xxxx xxxx */
683 	/* SBC (immediate)	cccc 0010 110x xxxx xxxx xxxx xxxx xxxx */
684 	/* RSC (immediate)	cccc 0010 111x xxxx xxxx xxxx xxxx xxxx */
685 	/* ORR (immediate)	cccc 0011 100x xxxx xxxx xxxx xxxx xxxx */
686 	/* BIC (immediate)	cccc 0011 110x xxxx xxxx xxxx xxxx xxxx */
687 	DECODE_EMULATEX	(0x0e000000, 0x02000000, emulate_rd12rn16rm0rs8_rwflags,
688 						 REGS(ANY, ANY, 0, 0, 0)),
689 
690 	DECODE_END
691 };
692 
693 static const union decode_item arm_cccc_0110_____xxx1_table[] = {
694 	/* Media instructions						*/
695 
696 	/* SEL			cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx */
697 	DECODE_EMULATEX	(0x0ff000f0, 0x068000b0, emulate_rd12rn16rm0_rwflags_nopc,
698 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
699 
700 	/* SSAT			cccc 0110 101x xxxx xxxx xxxx xx01 xxxx */
701 	/* USAT			cccc 0110 111x xxxx xxxx xxxx xx01 xxxx */
702 	DECODE_OR(0x0fa00030, 0x06a00010),
703 	/* SSAT16		cccc 0110 1010 xxxx xxxx xxxx 0011 xxxx */
704 	/* USAT16		cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx */
705 	DECODE_EMULATEX	(0x0fb000f0, 0x06a00030, emulate_rd12rn16rm0_rwflags_nopc,
706 						 REGS(0, NOPC, 0, 0, NOPC)),
707 
708 	/* REV			cccc 0110 1011 xxxx xxxx xxxx 0011 xxxx */
709 	/* REV16		cccc 0110 1011 xxxx xxxx xxxx 1011 xxxx */
710 	/* RBIT			cccc 0110 1111 xxxx xxxx xxxx 0011 xxxx */
711 	/* REVSH		cccc 0110 1111 xxxx xxxx xxxx 1011 xxxx */
712 	DECODE_EMULATEX	(0x0fb00070, 0x06b00030, emulate_rd12rm0_noflags_nopc,
713 						 REGS(0, NOPC, 0, 0, NOPC)),
714 
715 	/* ???			cccc 0110 0x00 xxxx xxxx xxxx xxx1 xxxx */
716 	DECODE_REJECT	(0x0fb00010, 0x06000010),
717 	/* ???			cccc 0110 0xxx xxxx xxxx xxxx 1011 xxxx */
718 	DECODE_REJECT	(0x0f8000f0, 0x060000b0),
719 	/* ???			cccc 0110 0xxx xxxx xxxx xxxx 1101 xxxx */
720 	DECODE_REJECT	(0x0f8000f0, 0x060000d0),
721 	/* SADD16		cccc 0110 0001 xxxx xxxx xxxx 0001 xxxx */
722 	/* SADDSUBX		cccc 0110 0001 xxxx xxxx xxxx 0011 xxxx */
723 	/* SSUBADDX		cccc 0110 0001 xxxx xxxx xxxx 0101 xxxx */
724 	/* SSUB16		cccc 0110 0001 xxxx xxxx xxxx 0111 xxxx */
725 	/* SADD8		cccc 0110 0001 xxxx xxxx xxxx 1001 xxxx */
726 	/* SSUB8		cccc 0110 0001 xxxx xxxx xxxx 1111 xxxx */
727 	/* QADD16		cccc 0110 0010 xxxx xxxx xxxx 0001 xxxx */
728 	/* QADDSUBX		cccc 0110 0010 xxxx xxxx xxxx 0011 xxxx */
729 	/* QSUBADDX		cccc 0110 0010 xxxx xxxx xxxx 0101 xxxx */
730 	/* QSUB16		cccc 0110 0010 xxxx xxxx xxxx 0111 xxxx */
731 	/* QADD8		cccc 0110 0010 xxxx xxxx xxxx 1001 xxxx */
732 	/* QSUB8		cccc 0110 0010 xxxx xxxx xxxx 1111 xxxx */
733 	/* SHADD16		cccc 0110 0011 xxxx xxxx xxxx 0001 xxxx */
734 	/* SHADDSUBX		cccc 0110 0011 xxxx xxxx xxxx 0011 xxxx */
735 	/* SHSUBADDX		cccc 0110 0011 xxxx xxxx xxxx 0101 xxxx */
736 	/* SHSUB16		cccc 0110 0011 xxxx xxxx xxxx 0111 xxxx */
737 	/* SHADD8		cccc 0110 0011 xxxx xxxx xxxx 1001 xxxx */
738 	/* SHSUB8		cccc 0110 0011 xxxx xxxx xxxx 1111 xxxx */
739 	/* UADD16		cccc 0110 0101 xxxx xxxx xxxx 0001 xxxx */
740 	/* UADDSUBX		cccc 0110 0101 xxxx xxxx xxxx 0011 xxxx */
741 	/* USUBADDX		cccc 0110 0101 xxxx xxxx xxxx 0101 xxxx */
742 	/* USUB16		cccc 0110 0101 xxxx xxxx xxxx 0111 xxxx */
743 	/* UADD8		cccc 0110 0101 xxxx xxxx xxxx 1001 xxxx */
744 	/* USUB8		cccc 0110 0101 xxxx xxxx xxxx 1111 xxxx */
745 	/* UQADD16		cccc 0110 0110 xxxx xxxx xxxx 0001 xxxx */
746 	/* UQADDSUBX		cccc 0110 0110 xxxx xxxx xxxx 0011 xxxx */
747 	/* UQSUBADDX		cccc 0110 0110 xxxx xxxx xxxx 0101 xxxx */
748 	/* UQSUB16		cccc 0110 0110 xxxx xxxx xxxx 0111 xxxx */
749 	/* UQADD8		cccc 0110 0110 xxxx xxxx xxxx 1001 xxxx */
750 	/* UQSUB8		cccc 0110 0110 xxxx xxxx xxxx 1111 xxxx */
751 	/* UHADD16		cccc 0110 0111 xxxx xxxx xxxx 0001 xxxx */
752 	/* UHADDSUBX		cccc 0110 0111 xxxx xxxx xxxx 0011 xxxx */
753 	/* UHSUBADDX		cccc 0110 0111 xxxx xxxx xxxx 0101 xxxx */
754 	/* UHSUB16		cccc 0110 0111 xxxx xxxx xxxx 0111 xxxx */
755 	/* UHADD8		cccc 0110 0111 xxxx xxxx xxxx 1001 xxxx */
756 	/* UHSUB8		cccc 0110 0111 xxxx xxxx xxxx 1111 xxxx */
757 	DECODE_EMULATEX	(0x0f800010, 0x06000010, emulate_rd12rn16rm0_rwflags_nopc,
758 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
759 
760 	/* PKHBT		cccc 0110 1000 xxxx xxxx xxxx x001 xxxx */
761 	/* PKHTB		cccc 0110 1000 xxxx xxxx xxxx x101 xxxx */
762 	DECODE_EMULATEX	(0x0ff00030, 0x06800010, emulate_rd12rn16rm0_rwflags_nopc,
763 						 REGS(NOPC, NOPC, 0, 0, NOPC)),
764 
765 	/* ???			cccc 0110 1001 xxxx xxxx xxxx 0111 xxxx */
766 	/* ???			cccc 0110 1101 xxxx xxxx xxxx 0111 xxxx */
767 	DECODE_REJECT	(0x0fb000f0, 0x06900070),
768 
769 	/* SXTB16		cccc 0110 1000 1111 xxxx xxxx 0111 xxxx */
770 	/* SXTB			cccc 0110 1010 1111 xxxx xxxx 0111 xxxx */
771 	/* SXTH			cccc 0110 1011 1111 xxxx xxxx 0111 xxxx */
772 	/* UXTB16		cccc 0110 1100 1111 xxxx xxxx 0111 xxxx */
773 	/* UXTB			cccc 0110 1110 1111 xxxx xxxx 0111 xxxx */
774 	/* UXTH			cccc 0110 1111 1111 xxxx xxxx 0111 xxxx */
775 	DECODE_EMULATEX	(0x0f8f00f0, 0x068f0070, emulate_rd12rm0_noflags_nopc,
776 						 REGS(0, NOPC, 0, 0, NOPC)),
777 
778 	/* SXTAB16		cccc 0110 1000 xxxx xxxx xxxx 0111 xxxx */
779 	/* SXTAB		cccc 0110 1010 xxxx xxxx xxxx 0111 xxxx */
780 	/* SXTAH		cccc 0110 1011 xxxx xxxx xxxx 0111 xxxx */
781 	/* UXTAB16		cccc 0110 1100 xxxx xxxx xxxx 0111 xxxx */
782 	/* UXTAB		cccc 0110 1110 xxxx xxxx xxxx 0111 xxxx */
783 	/* UXTAH		cccc 0110 1111 xxxx xxxx xxxx 0111 xxxx */
784 	DECODE_EMULATEX	(0x0f8000f0, 0x06800070, emulate_rd12rn16rm0_rwflags_nopc,
785 						 REGS(NOPCX, NOPC, 0, 0, NOPC)),
786 
787 	DECODE_END
788 };
789 
790 static const union decode_item arm_cccc_0111_____xxx1_table[] = {
791 	/* Media instructions						*/
792 
793 	/* UNDEFINED		cccc 0111 1111 xxxx xxxx xxxx 1111 xxxx */
794 	DECODE_REJECT	(0x0ff000f0, 0x07f000f0),
795 
796 	/* SMLALD		cccc 0111 0100 xxxx xxxx xxxx 00x1 xxxx */
797 	/* SMLSLD		cccc 0111 0100 xxxx xxxx xxxx 01x1 xxxx */
798 	DECODE_EMULATEX	(0x0ff00090, 0x07400010, emulate_rdlo12rdhi16rn0rm8_rwflags_nopc,
799 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
800 
801 	/* SMUAD		cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx */
802 	/* SMUSD		cccc 0111 0000 xxxx 1111 xxxx 01x1 xxxx */
803 	DECODE_OR	(0x0ff0f090, 0x0700f010),
804 	/* SMMUL		cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx */
805 	DECODE_OR	(0x0ff0f0d0, 0x0750f010),
806 	/* USAD8		cccc 0111 1000 xxxx 1111 xxxx 0001 xxxx */
807 	DECODE_EMULATEX	(0x0ff0f0f0, 0x0780f010, emulate_rd16rn12rm0rs8_rwflags_nopc,
808 						 REGS(NOPC, 0, NOPC, 0, NOPC)),
809 
810 	/* SMLAD		cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx */
811 	/* SMLSD		cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx */
812 	DECODE_OR	(0x0ff00090, 0x07000010),
813 	/* SMMLA		cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx */
814 	DECODE_OR	(0x0ff000d0, 0x07500010),
815 	/* USADA8		cccc 0111 1000 xxxx xxxx xxxx 0001 xxxx */
816 	DECODE_EMULATEX	(0x0ff000f0, 0x07800010, emulate_rd16rn12rm0rs8_rwflags_nopc,
817 						 REGS(NOPC, NOPCX, NOPC, 0, NOPC)),
818 
819 	/* SMMLS		cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx */
820 	DECODE_EMULATEX	(0x0ff000d0, 0x075000d0, emulate_rd16rn12rm0rs8_rwflags_nopc,
821 						 REGS(NOPC, NOPC, NOPC, 0, NOPC)),
822 
823 	/* SBFX			cccc 0111 101x xxxx xxxx xxxx x101 xxxx */
824 	/* UBFX			cccc 0111 111x xxxx xxxx xxxx x101 xxxx */
825 	DECODE_EMULATEX	(0x0fa00070, 0x07a00050, emulate_rd12rm0_noflags_nopc,
826 						 REGS(0, NOPC, 0, 0, NOPC)),
827 
828 	/* BFC			cccc 0111 110x xxxx xxxx xxxx x001 1111 */
829 	DECODE_EMULATEX	(0x0fe0007f, 0x07c0001f, emulate_rd12rm0_noflags_nopc,
830 						 REGS(0, NOPC, 0, 0, 0)),
831 
832 	/* BFI			cccc 0111 110x xxxx xxxx xxxx x001 xxxx */
833 	DECODE_EMULATEX	(0x0fe00070, 0x07c00010, emulate_rd12rm0_noflags_nopc,
834 						 REGS(0, NOPC, 0, 0, NOPCX)),
835 
836 	DECODE_END
837 };
838 
839 static const union decode_item arm_cccc_01xx_table[] = {
840 	/* Load/store word and unsigned byte				*/
841 
842 	/* LDRB/STRB pc,[...]	cccc 01xx x0xx xxxx xxxx xxxx xxxx xxxx */
843 	DECODE_REJECT	(0x0c40f000, 0x0440f000),
844 
845 	/* STRT			cccc 01x0 x010 xxxx xxxx xxxx xxxx xxxx */
846 	/* LDRT			cccc 01x0 x011 xxxx xxxx xxxx xxxx xxxx */
847 	/* STRBT		cccc 01x0 x110 xxxx xxxx xxxx xxxx xxxx */
848 	/* LDRBT		cccc 01x0 x111 xxxx xxxx xxxx xxxx xxxx */
849 	DECODE_REJECT	(0x0d200000, 0x04200000),
850 
851 	/* STR (immediate)	cccc 010x x0x0 xxxx xxxx xxxx xxxx xxxx */
852 	/* STRB (immediate)	cccc 010x x1x0 xxxx xxxx xxxx xxxx xxxx */
853 	DECODE_EMULATEX	(0x0e100000, 0x04000000, emulate_str,
854 						 REGS(NOPCWB, ANY, 0, 0, 0)),
855 
856 	/* LDR (immediate)	cccc 010x x0x1 xxxx xxxx xxxx xxxx xxxx */
857 	/* LDRB (immediate)	cccc 010x x1x1 xxxx xxxx xxxx xxxx xxxx */
858 	DECODE_EMULATEX	(0x0e100000, 0x04100000, emulate_ldr,
859 						 REGS(NOPCWB, ANY, 0, 0, 0)),
860 
861 	/* STR (register)	cccc 011x x0x0 xxxx xxxx xxxx xxxx xxxx */
862 	/* STRB (register)	cccc 011x x1x0 xxxx xxxx xxxx xxxx xxxx */
863 	DECODE_EMULATEX	(0x0e100000, 0x06000000, emulate_str,
864 						 REGS(NOPCWB, ANY, 0, 0, NOPC)),
865 
866 	/* LDR (register)	cccc 011x x0x1 xxxx xxxx xxxx xxxx xxxx */
867 	/* LDRB (register)	cccc 011x x1x1 xxxx xxxx xxxx xxxx xxxx */
868 	DECODE_EMULATEX	(0x0e100000, 0x06100000, emulate_ldr,
869 						 REGS(NOPCWB, ANY, 0, 0, NOPC)),
870 
871 	DECODE_END
872 };
873 
874 static const union decode_item arm_cccc_100x_table[] = {
875 	/* Block data transfer instructions				*/
876 
877 	/* LDM			cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
878 	/* STM			cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */
879 	DECODE_CUSTOM	(0x0e400000, 0x08000000, kprobe_decode_ldmstm),
880 
881 	/* STM (user registers)	cccc 100x x1x0 xxxx xxxx xxxx xxxx xxxx */
882 	/* LDM (user registers)	cccc 100x x1x1 xxxx 0xxx xxxx xxxx xxxx */
883 	/* LDM (exception ret)	cccc 100x x1x1 xxxx 1xxx xxxx xxxx xxxx */
884 	DECODE_END
885 };
886 
887 const union decode_item kprobe_decode_arm_table[] = {
888 	/*
889 	 * Unconditional instructions
890 	 *			1111 xxxx xxxx xxxx xxxx xxxx xxxx xxxx
891 	 */
892 	DECODE_TABLE	(0xf0000000, 0xf0000000, arm_1111_table),
893 
894 	/*
895 	 * Miscellaneous instructions
896 	 *			cccc 0001 0xx0 xxxx xxxx xxxx 0xxx xxxx
897 	 */
898 	DECODE_TABLE	(0x0f900080, 0x01000000, arm_cccc_0001_0xx0____0xxx_table),
899 
900 	/*
901 	 * Halfword multiply and multiply-accumulate
902 	 *			cccc 0001 0xx0 xxxx xxxx xxxx 1xx0 xxxx
903 	 */
904 	DECODE_TABLE	(0x0f900090, 0x01000080, arm_cccc_0001_0xx0____1xx0_table),
905 
906 	/*
907 	 * Multiply and multiply-accumulate
908 	 *			cccc 0000 xxxx xxxx xxxx xxxx 1001 xxxx
909 	 */
910 	DECODE_TABLE	(0x0f0000f0, 0x00000090, arm_cccc_0000_____1001_table),
911 
912 	/*
913 	 * Synchronization primitives
914 	 *			cccc 0001 xxxx xxxx xxxx xxxx 1001 xxxx
915 	 */
916 	DECODE_TABLE	(0x0f0000f0, 0x01000090, arm_cccc_0001_____1001_table),
917 
918 	/*
919 	 * Extra load/store instructions
920 	 *			cccc 000x xxxx xxxx xxxx xxxx 1xx1 xxxx
921 	 */
922 	DECODE_TABLE	(0x0e000090, 0x00000090, arm_cccc_000x_____1xx1_table),
923 
924 	/*
925 	 * Data-processing (register)
926 	 *			cccc 000x xxxx xxxx xxxx xxxx xxx0 xxxx
927 	 * Data-processing (register-shifted register)
928 	 *			cccc 000x xxxx xxxx xxxx xxxx 0xx1 xxxx
929 	 */
930 	DECODE_TABLE	(0x0e000000, 0x00000000, arm_cccc_000x_table),
931 
932 	/*
933 	 * Data-processing (immediate)
934 	 *			cccc 001x xxxx xxxx xxxx xxxx xxxx xxxx
935 	 */
936 	DECODE_TABLE	(0x0e000000, 0x02000000, arm_cccc_001x_table),
937 
938 	/*
939 	 * Media instructions
940 	 *			cccc 011x xxxx xxxx xxxx xxxx xxx1 xxxx
941 	 */
942 	DECODE_TABLE	(0x0f000010, 0x06000010, arm_cccc_0110_____xxx1_table),
943 	DECODE_TABLE	(0x0f000010, 0x07000010, arm_cccc_0111_____xxx1_table),
944 
945 	/*
946 	 * Load/store word and unsigned byte
947 	 *			cccc 01xx xxxx xxxx xxxx xxxx xxxx xxxx
948 	 */
949 	DECODE_TABLE	(0x0c000000, 0x04000000, arm_cccc_01xx_table),
950 
951 	/*
952 	 * Block data transfer instructions
953 	 *			cccc 100x xxxx xxxx xxxx xxxx xxxx xxxx
954 	 */
955 	DECODE_TABLE	(0x0e000000, 0x08000000, arm_cccc_100x_table),
956 
957 	/* B			cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */
958 	/* BL			cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */
959 	DECODE_SIMULATE	(0x0e000000, 0x0a000000, simulate_bbl),
960 
961 	/*
962 	 * Supervisor Call, and coprocessor instructions
963 	 */
964 
965 	/* MCRR			cccc 1100 0100 xxxx xxxx xxxx xxxx xxxx */
966 	/* MRRC			cccc 1100 0101 xxxx xxxx xxxx xxxx xxxx */
967 	/* LDC			cccc 110x xxx1 xxxx xxxx xxxx xxxx xxxx */
968 	/* STC			cccc 110x xxx0 xxxx xxxx xxxx xxxx xxxx */
969 	/* CDP			cccc 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */
970 	/* MCR			cccc 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */
971 	/* MRC			cccc 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */
972 	/* SVC			cccc 1111 xxxx xxxx xxxx xxxx xxxx xxxx */
973 	DECODE_REJECT	(0x0c000000, 0x0c000000),
974 
975 	DECODE_END
976 };
977 #ifdef CONFIG_ARM_KPROBES_TEST_MODULE
978 EXPORT_SYMBOL_GPL(kprobe_decode_arm_table);
979 #endif
980 
arm_singlestep(struct kprobe * p,struct pt_regs * regs)981 static void __kprobes arm_singlestep(struct kprobe *p, struct pt_regs *regs)
982 {
983 	regs->ARM_pc += 4;
984 	p->ainsn.insn_handler(p, regs);
985 }
986 
987 /* Return:
988  *   INSN_REJECTED     If instruction is one not allowed to kprobe,
989  *   INSN_GOOD         If instruction is supported and uses instruction slot,
990  *   INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
991  *
992  * For instructions we don't want to kprobe (INSN_REJECTED return result):
993  *   These are generally ones that modify the processor state making
994  *   them "hard" to simulate such as switches processor modes or
995  *   make accesses in alternate modes.  Any of these could be simulated
996  *   if the work was put into it, but low return considering they
997  *   should also be very rare.
998  */
999 enum kprobe_insn __kprobes
arm_kprobe_decode_insn(kprobe_opcode_t insn,struct arch_specific_insn * asi)1000 arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1001 {
1002 	asi->insn_singlestep = arm_singlestep;
1003 	asi->insn_check_cc = kprobe_condition_checks[insn>>28];
1004 	return kprobe_decode_insn(insn, asi, kprobe_decode_arm_table, false);
1005 }
1006