Merge tag 'for-linus-20141102' of git://git.infradead.org/linux-mtd
[deliverable/linux.git] / arch / arm / kernel / kprobes-thumb.c
CommitLineData
24371707
JM
1/*
2 * arch/arm/kernel/kprobes-thumb.c
3 *
4 * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
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
87abef63 11#include <linux/types.h>
24371707 12#include <linux/kernel.h>
87abef63 13#include <linux/ptrace.h>
24371707
JM
14#include <linux/kprobes.h>
15
16#include "kprobes.h"
87abef63 17#include "probes-thumb.h"
eaf4f33f 18
3e6cd394
DL
19/* These emulation encodings are functionally equivalent... */
20#define t32_emulate_rd8rn16rm0ra12_noflags \
21 t32_emulate_rdlo12rdhi8rn16rm0_noflags
22
87abef63
DL
23/* t32 thumb actions */
24
3e6cd394 25static void __kprobes
f145d664 26t32_simulate_table_branch(probes_opcode_t insn,
b4cd605c 27 struct arch_probes_insn *asi, struct pt_regs *regs)
dd212bd3 28{
7579f4b3 29 unsigned long pc = regs->ARM_pc;
dd212bd3
JM
30 int rn = (insn >> 16) & 0xf;
31 int rm = insn & 0xf;
32
33 unsigned long rnv = (rn == 15) ? pc : regs->uregs[rn];
34 unsigned long rmv = regs->uregs[rm];
35 unsigned int halfwords;
36
ce715c77 37 if (insn & 0x10) /* TBH */
dd212bd3 38 halfwords = ((u16 *)rnv)[rmv];
ce715c77 39 else /* TBB */
dd212bd3
JM
40 halfwords = ((u8 *)rnv)[rmv];
41
42 regs->ARM_pc = pc + 2 * halfwords;
43}
44
3e6cd394 45static void __kprobes
f145d664 46t32_simulate_mrs(probes_opcode_t insn,
b4cd605c 47 struct arch_probes_insn *asi, struct pt_regs *regs)
b06f3ee3 48{
b06f3ee3
JM
49 int rd = (insn >> 8) & 0xf;
50 unsigned long mask = 0xf8ff03df; /* Mask out execution state */
51 regs->uregs[rd] = regs->ARM_cpsr & mask;
52}
53
3e6cd394 54static void __kprobes
f145d664 55t32_simulate_cond_branch(probes_opcode_t insn,
b4cd605c 56 struct arch_probes_insn *asi, struct pt_regs *regs)
ce715c77 57{
7579f4b3 58 unsigned long pc = regs->ARM_pc;
ce715c77
JM
59
60 long offset = insn & 0x7ff; /* imm11 */
61 offset += (insn & 0x003f0000) >> 5; /* imm6 */
62 offset += (insn & 0x00002000) << 4; /* J1 */
63 offset += (insn & 0x00000800) << 7; /* J2 */
64 offset -= (insn & 0x04000000) >> 7; /* Apply sign bit */
65
66 regs->ARM_pc = pc + (offset * 2);
67}
68
44a0a59c 69static enum probes_insn __kprobes
b4cd605c 70t32_decode_cond_branch(probes_opcode_t insn, struct arch_probes_insn *asi,
3e6cd394 71 const struct decode_header *d)
ce715c77
JM
72{
73 int cc = (insn >> 22) & 0xf;
f145d664 74 asi->insn_check_cc = probes_condition_checks[cc];
ce715c77
JM
75 asi->insn_handler = t32_simulate_cond_branch;
76 return INSN_GOOD_NO_SLOT;
77}
78
3e6cd394 79static void __kprobes
f145d664 80t32_simulate_branch(probes_opcode_t insn,
b4cd605c 81 struct arch_probes_insn *asi, struct pt_regs *regs)
ce715c77 82{
7579f4b3 83 unsigned long pc = regs->ARM_pc;
ce715c77
JM
84
85 long offset = insn & 0x7ff; /* imm11 */
86 offset += (insn & 0x03ff0000) >> 5; /* imm10 */
87 offset += (insn & 0x00002000) << 9; /* J1 */
88 offset += (insn & 0x00000800) << 10; /* J2 */
89 if (insn & 0x04000000)
90 offset -= 0x00800000; /* Apply sign bit */
91 else
92 offset ^= 0x00600000; /* Invert J1 and J2 */
93
94 if (insn & (1 << 14)) {
95 /* BL or BLX */
7579f4b3 96 regs->ARM_lr = regs->ARM_pc | 1;
ce715c77
JM
97 if (!(insn & (1 << 12))) {
98 /* BLX so switch to ARM mode */
99 regs->ARM_cpsr &= ~PSR_T_BIT;
100 pc &= ~3;
101 }
102 }
103
104 regs->ARM_pc = pc + (offset * 2);
105}
106
3e6cd394 107static void __kprobes
f145d664 108t32_simulate_ldr_literal(probes_opcode_t insn,
b4cd605c 109 struct arch_probes_insn *asi, struct pt_regs *regs)
d691023b 110{
7579f4b3 111 unsigned long addr = regs->ARM_pc & ~3;
d691023b
JM
112 int rt = (insn >> 12) & 0xf;
113 unsigned long rtv;
114
115 long offset = insn & 0xfff;
116 if (insn & 0x00800000)
117 addr += offset;
118 else
119 addr -= offset;
120
121 if (insn & 0x00400000) {
122 /* LDR */
123 rtv = *(unsigned long *)addr;
124 if (rt == 15) {
125 bx_write_pc(rtv, regs);
126 return;
127 }
128 } else if (insn & 0x00200000) {
129 /* LDRH */
130 if (insn & 0x01000000)
131 rtv = *(s16 *)addr;
132 else
133 rtv = *(u16 *)addr;
134 } else {
135 /* LDRB */
136 if (insn & 0x01000000)
137 rtv = *(s8 *)addr;
138 else
139 rtv = *(u8 *)addr;
140 }
141
142 regs->uregs[rt] = rtv;
143}
144
44a0a59c 145static enum probes_insn __kprobes
b4cd605c 146t32_decode_ldmstm(probes_opcode_t insn, struct arch_probes_insn *asi,
3e6cd394 147 const struct decode_header *d)
eaf1d065 148{
44a0a59c 149 enum probes_insn ret = kprobe_decode_ldmstm(insn, asi, d);
eaf1d065
JM
150
151 /* Fixup modified instruction to have halfwords in correct order...*/
888be254
BD
152 insn = __mem_to_opcode_arm(asi->insn[0]);
153 ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(insn >> 16);
154 ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0xffff);
eaf1d065
JM
155
156 return ret;
157}
158
3e6cd394 159static void __kprobes
f145d664 160t32_emulate_ldrdstrd(probes_opcode_t insn,
b4cd605c 161 struct arch_probes_insn *asi, struct pt_regs *regs)
b48354d3 162{
7579f4b3 163 unsigned long pc = regs->ARM_pc & ~3;
b48354d3
JM
164 int rt1 = (insn >> 12) & 0xf;
165 int rt2 = (insn >> 8) & 0xf;
166 int rn = (insn >> 16) & 0xf;
167
168 register unsigned long rt1v asm("r0") = regs->uregs[rt1];
169 register unsigned long rt2v asm("r1") = regs->uregs[rt2];
170 register unsigned long rnv asm("r2") = (rn == 15) ? pc
171 : regs->uregs[rn];
172
173 __asm__ __volatile__ (
174 "blx %[fn]"
175 : "=r" (rt1v), "=r" (rt2v), "=r" (rnv)
7579f4b3 176 : "0" (rt1v), "1" (rt2v), "2" (rnv), [fn] "r" (asi->insn_fn)
b48354d3
JM
177 : "lr", "memory", "cc"
178 );
179
180 if (rn != 15)
181 regs->uregs[rn] = rnv; /* Writeback base register */
182 regs->uregs[rt1] = rt1v;
183 regs->uregs[rt2] = rt2v;
184}
185
3e6cd394 186static void __kprobes
f145d664 187t32_emulate_ldrstr(probes_opcode_t insn,
b4cd605c 188 struct arch_probes_insn *asi, struct pt_regs *regs)
d691023b 189{
d691023b
JM
190 int rt = (insn >> 12) & 0xf;
191 int rn = (insn >> 16) & 0xf;
192 int rm = insn & 0xf;
193
194 register unsigned long rtv asm("r0") = regs->uregs[rt];
195 register unsigned long rnv asm("r2") = regs->uregs[rn];
196 register unsigned long rmv asm("r3") = regs->uregs[rm];
197
198 __asm__ __volatile__ (
199 "blx %[fn]"
200 : "=r" (rtv), "=r" (rnv)
7579f4b3 201 : "0" (rtv), "1" (rnv), "r" (rmv), [fn] "r" (asi->insn_fn)
d691023b
JM
202 : "lr", "memory", "cc"
203 );
204
205 regs->uregs[rn] = rnv; /* Writeback base register */
206 if (rt == 15) /* Can't be true for a STR as they aren't allowed */
207 bx_write_pc(rtv, regs);
208 else
209 regs->uregs[rt] = rtv;
210}
211
3e6cd394 212static void __kprobes
f145d664 213t32_emulate_rd8rn16rm0_rwflags(probes_opcode_t insn,
b4cd605c 214 struct arch_probes_insn *asi, struct pt_regs *regs)
080e0013 215{
080e0013
JM
216 int rd = (insn >> 8) & 0xf;
217 int rn = (insn >> 16) & 0xf;
218 int rm = insn & 0xf;
219
220 register unsigned long rdv asm("r1") = regs->uregs[rd];
221 register unsigned long rnv asm("r2") = regs->uregs[rn];
222 register unsigned long rmv asm("r3") = regs->uregs[rm];
223 unsigned long cpsr = regs->ARM_cpsr;
224
225 __asm__ __volatile__ (
226 "msr cpsr_fs, %[cpsr] \n\t"
227 "blx %[fn] \n\t"
228 "mrs %[cpsr], cpsr \n\t"
229 : "=r" (rdv), [cpsr] "=r" (cpsr)
230 : "0" (rdv), "r" (rnv), "r" (rmv),
7579f4b3 231 "1" (cpsr), [fn] "r" (asi->insn_fn)
080e0013
JM
232 : "lr", "memory", "cc"
233 );
234
235 regs->uregs[rd] = rdv;
236 regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
237}
238
3e6cd394 239static void __kprobes
f145d664 240t32_emulate_rd8pc16_noflags(probes_opcode_t insn,
b4cd605c 241 struct arch_probes_insn *asi, struct pt_regs *regs)
7848786a 242{
7579f4b3 243 unsigned long pc = regs->ARM_pc;
7848786a
JM
244 int rd = (insn >> 8) & 0xf;
245
246 register unsigned long rdv asm("r1") = regs->uregs[rd];
247 register unsigned long rnv asm("r2") = pc & ~3;
248
249 __asm__ __volatile__ (
250 "blx %[fn]"
251 : "=r" (rdv)
7579f4b3 252 : "0" (rdv), "r" (rnv), [fn] "r" (asi->insn_fn)
7848786a
JM
253 : "lr", "memory", "cc"
254 );
255
256 regs->uregs[rd] = rdv;
257}
258
3e6cd394 259static void __kprobes
f145d664 260t32_emulate_rd8rn16_noflags(probes_opcode_t insn,
b4cd605c 261 struct arch_probes_insn *asi, struct pt_regs *regs)
7848786a 262{
7848786a
JM
263 int rd = (insn >> 8) & 0xf;
264 int rn = (insn >> 16) & 0xf;
265
266 register unsigned long rdv asm("r1") = regs->uregs[rd];
267 register unsigned long rnv asm("r2") = regs->uregs[rn];
268
269 __asm__ __volatile__ (
270 "blx %[fn]"
271 : "=r" (rdv)
7579f4b3 272 : "0" (rdv), "r" (rnv), [fn] "r" (asi->insn_fn)
7848786a
JM
273 : "lr", "memory", "cc"
274 );
275
276 regs->uregs[rd] = rdv;
277}
278
3e6cd394 279static void __kprobes
f145d664 280t32_emulate_rdlo12rdhi8rn16rm0_noflags(probes_opcode_t insn,
b4cd605c 281 struct arch_probes_insn *asi,
7579f4b3 282 struct pt_regs *regs)
231fb150 283{
231fb150
JM
284 int rdlo = (insn >> 12) & 0xf;
285 int rdhi = (insn >> 8) & 0xf;
286 int rn = (insn >> 16) & 0xf;
287 int rm = insn & 0xf;
288
289 register unsigned long rdlov asm("r0") = regs->uregs[rdlo];
290 register unsigned long rdhiv asm("r1") = regs->uregs[rdhi];
291 register unsigned long rnv asm("r2") = regs->uregs[rn];
292 register unsigned long rmv asm("r3") = regs->uregs[rm];
293
294 __asm__ __volatile__ (
295 "blx %[fn]"
296 : "=r" (rdlov), "=r" (rdhiv)
297 : "0" (rdlov), "1" (rdhiv), "r" (rnv), "r" (rmv),
7579f4b3 298 [fn] "r" (asi->insn_fn)
231fb150
JM
299 : "lr", "memory", "cc"
300 );
301
302 regs->uregs[rdlo] = rdlov;
303 regs->uregs[rdhi] = rdhiv;
304}
87abef63 305/* t16 thumb actions */
231fb150 306
3e6cd394 307static void __kprobes
f145d664 308t16_simulate_bxblx(probes_opcode_t insn,
b4cd605c 309 struct arch_probes_insn *asi, struct pt_regs *regs)
a9c3c29e 310{
7579f4b3 311 unsigned long pc = regs->ARM_pc + 2;
a9c3c29e
JM
312 int rm = (insn >> 3) & 0xf;
313 unsigned long rmv = (rm == 15) ? pc : regs->uregs[rm];
314
315 if (insn & (1 << 7)) /* BLX ? */
7579f4b3 316 regs->ARM_lr = regs->ARM_pc | 1;
a9c3c29e
JM
317
318 bx_write_pc(rmv, regs);
319}
320
3e6cd394 321static void __kprobes
f145d664 322t16_simulate_ldr_literal(probes_opcode_t insn,
b4cd605c 323 struct arch_probes_insn *asi, struct pt_regs *regs)
f8695142 324{
7579f4b3 325 unsigned long *base = (unsigned long *)((regs->ARM_pc + 2) & ~3);
f8695142
JM
326 long index = insn & 0xff;
327 int rt = (insn >> 8) & 0x7;
328 regs->uregs[rt] = base[index];
329}
330
3e6cd394 331static void __kprobes
f145d664 332t16_simulate_ldrstr_sp_relative(probes_opcode_t insn,
b4cd605c 333 struct arch_probes_insn *asi, struct pt_regs *regs)
f8695142 334{
f8695142
JM
335 unsigned long* base = (unsigned long *)regs->ARM_sp;
336 long index = insn & 0xff;
337 int rt = (insn >> 8) & 0x7;
338 if (insn & 0x800) /* LDR */
339 regs->uregs[rt] = base[index];
340 else /* STR */
341 base[index] = regs->uregs[rt];
342}
343
3e6cd394 344static void __kprobes
f145d664 345t16_simulate_reladr(probes_opcode_t insn,
b4cd605c 346 struct arch_probes_insn *asi, struct pt_regs *regs)
2f335829 347{
2f335829 348 unsigned long base = (insn & 0x800) ? regs->ARM_sp
7579f4b3 349 : ((regs->ARM_pc + 2) & ~3);
2f335829
JM
350 long offset = insn & 0xff;
351 int rt = (insn >> 8) & 0x7;
352 regs->uregs[rt] = base + offset * 4;
353}
354
3e6cd394 355static void __kprobes
f145d664 356t16_simulate_add_sp_imm(probes_opcode_t insn,
b4cd605c 357 struct arch_probes_insn *asi, struct pt_regs *regs)
2f335829 358{
2f335829
JM
359 long imm = insn & 0x7f;
360 if (insn & 0x80) /* SUB */
361 regs->ARM_sp -= imm * 4;
362 else /* ADD */
363 regs->ARM_sp += imm * 4;
364}
365
3e6cd394 366static void __kprobes
f145d664 367t16_simulate_cbz(probes_opcode_t insn,
b4cd605c 368 struct arch_probes_insn *asi, struct pt_regs *regs)
32818f31 369{
32818f31 370 int rn = insn & 0x7;
f145d664 371 probes_opcode_t nonzero = regs->uregs[rn] ? insn : ~insn;
32818f31
JM
372 if (nonzero & 0x800) {
373 long i = insn & 0x200;
374 long imm5 = insn & 0xf8;
7579f4b3 375 unsigned long pc = regs->ARM_pc + 2;
32818f31
JM
376 regs->ARM_pc = pc + (i >> 3) + (imm5 >> 2);
377 }
378}
379
3e6cd394 380static void __kprobes
f145d664 381t16_simulate_it(probes_opcode_t insn,
b4cd605c 382 struct arch_probes_insn *asi, struct pt_regs *regs)
5b94faf8
JM
383{
384 /*
385 * The 8 IT state bits are split into two parts in CPSR:
386 * ITSTATE<1:0> are in CPSR<26:25>
387 * ITSTATE<7:2> are in CPSR<15:10>
388 * The new IT state is in the lower byte of insn.
389 */
5b94faf8
JM
390 unsigned long cpsr = regs->ARM_cpsr;
391 cpsr &= ~PSR_IT_MASK;
392 cpsr |= (insn & 0xfc) << 8;
393 cpsr |= (insn & 0x03) << 25;
394 regs->ARM_cpsr = cpsr;
395}
396
3e6cd394 397static void __kprobes
f145d664 398t16_singlestep_it(probes_opcode_t insn,
b4cd605c 399 struct arch_probes_insn *asi, struct pt_regs *regs)
5b94faf8
JM
400{
401 regs->ARM_pc += 2;
7579f4b3 402 t16_simulate_it(insn, asi, regs);
5b94faf8
JM
403}
404
44a0a59c 405static enum probes_insn __kprobes
b4cd605c 406t16_decode_it(probes_opcode_t insn, struct arch_probes_insn *asi,
3e6cd394 407 const struct decode_header *d)
5b94faf8
JM
408{
409 asi->insn_singlestep = t16_singlestep_it;
410 return INSN_GOOD_NO_SLOT;
411}
412
3e6cd394 413static void __kprobes
f145d664 414t16_simulate_cond_branch(probes_opcode_t insn,
b4cd605c 415 struct arch_probes_insn *asi, struct pt_regs *regs)
396b41f6 416{
7579f4b3 417 unsigned long pc = regs->ARM_pc + 2;
396b41f6
JM
418 long offset = insn & 0x7f;
419 offset -= insn & 0x80; /* Apply sign bit */
420 regs->ARM_pc = pc + (offset * 2);
421}
422
44a0a59c 423static enum probes_insn __kprobes
b4cd605c 424t16_decode_cond_branch(probes_opcode_t insn, struct arch_probes_insn *asi,
3e6cd394 425 const struct decode_header *d)
396b41f6
JM
426{
427 int cc = (insn >> 8) & 0xf;
f145d664 428 asi->insn_check_cc = probes_condition_checks[cc];
396b41f6
JM
429 asi->insn_handler = t16_simulate_cond_branch;
430 return INSN_GOOD_NO_SLOT;
431}
432
3e6cd394 433static void __kprobes
f145d664 434t16_simulate_branch(probes_opcode_t insn,
b4cd605c 435 struct arch_probes_insn *asi, struct pt_regs *regs)
396b41f6 436{
7579f4b3 437 unsigned long pc = regs->ARM_pc + 2;
396b41f6
JM
438 long offset = insn & 0x3ff;
439 offset -= insn & 0x400; /* Apply sign bit */
440 regs->ARM_pc = pc + (offset * 2);
441}
442
02d194f6 443static unsigned long __kprobes
f145d664 444t16_emulate_loregs(probes_opcode_t insn,
b4cd605c 445 struct arch_probes_insn *asi, struct pt_regs *regs)
02d194f6
JM
446{
447 unsigned long oldcpsr = regs->ARM_cpsr;
448 unsigned long newcpsr;
449
450 __asm__ __volatile__ (
451 "msr cpsr_fs, %[oldcpsr] \n\t"
452 "ldmia %[regs], {r0-r7} \n\t"
453 "blx %[fn] \n\t"
454 "stmia %[regs], {r0-r7} \n\t"
455 "mrs %[newcpsr], cpsr \n\t"
456 : [newcpsr] "=r" (newcpsr)
457 : [oldcpsr] "r" (oldcpsr), [regs] "r" (regs),
7579f4b3 458 [fn] "r" (asi->insn_fn)
02d194f6
JM
459 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
460 "lr", "memory", "cc"
461 );
462
463 return (oldcpsr & ~APSR_MASK) | (newcpsr & APSR_MASK);
464}
465
3e6cd394 466static void __kprobes
f145d664 467t16_emulate_loregs_rwflags(probes_opcode_t insn,
b4cd605c 468 struct arch_probes_insn *asi, struct pt_regs *regs)
02d194f6 469{
7579f4b3 470 regs->ARM_cpsr = t16_emulate_loregs(insn, asi, regs);
02d194f6
JM
471}
472
3e6cd394 473static void __kprobes
f145d664 474t16_emulate_loregs_noitrwflags(probes_opcode_t insn,
b4cd605c 475 struct arch_probes_insn *asi, struct pt_regs *regs)
02d194f6 476{
7579f4b3 477 unsigned long cpsr = t16_emulate_loregs(insn, asi, regs);
02d194f6
JM
478 if (!in_it_block(cpsr))
479 regs->ARM_cpsr = cpsr;
480}
481
3e6cd394 482static void __kprobes
f145d664 483t16_emulate_hiregs(probes_opcode_t insn,
b4cd605c 484 struct arch_probes_insn *asi, struct pt_regs *regs)
3b5940e8 485{
7579f4b3 486 unsigned long pc = regs->ARM_pc + 2;
3b5940e8
JM
487 int rdn = (insn & 0x7) | ((insn & 0x80) >> 4);
488 int rm = (insn >> 3) & 0xf;
489
490 register unsigned long rdnv asm("r1");
491 register unsigned long rmv asm("r0");
492 unsigned long cpsr = regs->ARM_cpsr;
493
494 rdnv = (rdn == 15) ? pc : regs->uregs[rdn];
495 rmv = (rm == 15) ? pc : regs->uregs[rm];
496
497 __asm__ __volatile__ (
498 "msr cpsr_fs, %[cpsr] \n\t"
499 "blx %[fn] \n\t"
500 "mrs %[cpsr], cpsr \n\t"
501 : "=r" (rdnv), [cpsr] "=r" (cpsr)
7579f4b3 502 : "0" (rdnv), "r" (rmv), "1" (cpsr), [fn] "r" (asi->insn_fn)
3b5940e8
JM
503 : "lr", "memory", "cc"
504 );
505
506 if (rdn == 15)
507 rdnv &= ~1;
508
509 regs->uregs[rdn] = rdnv;
510 regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
511}
512
44a0a59c 513static enum probes_insn __kprobes
b4cd605c 514t16_decode_hiregs(probes_opcode_t insn, struct arch_probes_insn *asi,
3e6cd394 515 const struct decode_header *d)
3b5940e8
JM
516{
517 insn &= ~0x00ff;
518 insn |= 0x001; /* Set Rdn = R1 and Rm = R0 */
888be254 519 ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(insn);
3b5940e8
JM
520 asi->insn_handler = t16_emulate_hiregs;
521 return INSN_GOOD;
522}
523
3e6cd394 524static void __kprobes
f145d664 525t16_emulate_push(probes_opcode_t insn,
b4cd605c 526 struct arch_probes_insn *asi, struct pt_regs *regs)
fd0c8d8a
JM
527{
528 __asm__ __volatile__ (
529 "ldr r9, [%[regs], #13*4] \n\t"
530 "ldr r8, [%[regs], #14*4] \n\t"
531 "ldmia %[regs], {r0-r7} \n\t"
532 "blx %[fn] \n\t"
533 "str r9, [%[regs], #13*4] \n\t"
534 :
7579f4b3 535 : [regs] "r" (regs), [fn] "r" (asi->insn_fn)
fd0c8d8a
JM
536 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9",
537 "lr", "memory", "cc"
538 );
539}
540
44a0a59c 541static enum probes_insn __kprobes
b4cd605c 542t16_decode_push(probes_opcode_t insn, struct arch_probes_insn *asi,
3e6cd394 543 const struct decode_header *d)
fd0c8d8a
JM
544{
545 /*
546 * To simulate a PUSH we use a Thumb-2 "STMDB R9!, {registers}"
547 * and call it with R9=SP and LR in the register list represented
548 * by R8.
549 */
888be254
BD
550 /* 1st half STMDB R9!,{} */
551 ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(0xe929);
552 /* 2nd half (register list) */
553 ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0x1ff);
fd0c8d8a
JM
554 asi->insn_handler = t16_emulate_push;
555 return INSN_GOOD;
556}
557
3e6cd394 558static void __kprobes
f145d664 559t16_emulate_pop_nopc(probes_opcode_t insn,
b4cd605c 560 struct arch_probes_insn *asi, struct pt_regs *regs)
fd0c8d8a
JM
561{
562 __asm__ __volatile__ (
563 "ldr r9, [%[regs], #13*4] \n\t"
564 "ldmia %[regs], {r0-r7} \n\t"
565 "blx %[fn] \n\t"
566 "stmia %[regs], {r0-r7} \n\t"
567 "str r9, [%[regs], #13*4] \n\t"
568 :
7579f4b3 569 : [regs] "r" (regs), [fn] "r" (asi->insn_fn)
fd0c8d8a
JM
570 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9",
571 "lr", "memory", "cc"
572 );
573}
574
3e6cd394 575static void __kprobes
f145d664 576t16_emulate_pop_pc(probes_opcode_t insn,
b4cd605c 577 struct arch_probes_insn *asi, struct pt_regs *regs)
fd0c8d8a
JM
578{
579 register unsigned long pc asm("r8");
580
581 __asm__ __volatile__ (
582 "ldr r9, [%[regs], #13*4] \n\t"
583 "ldmia %[regs], {r0-r7} \n\t"
584 "blx %[fn] \n\t"
585 "stmia %[regs], {r0-r7} \n\t"
586 "str r9, [%[regs], #13*4] \n\t"
587 : "=r" (pc)
7579f4b3 588 : [regs] "r" (regs), [fn] "r" (asi->insn_fn)
fd0c8d8a
JM
589 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9",
590 "lr", "memory", "cc"
591 );
592
593 bx_write_pc(pc, regs);
594}
595
44a0a59c 596static enum probes_insn __kprobes
b4cd605c 597t16_decode_pop(probes_opcode_t insn, struct arch_probes_insn *asi,
3e6cd394 598 const struct decode_header *d)
fd0c8d8a
JM
599{
600 /*
601 * To simulate a POP we use a Thumb-2 "LDMDB R9!, {registers}"
602 * and call it with R9=SP and PC in the register list represented
603 * by R8.
604 */
888be254
BD
605 /* 1st half LDMIA R9!,{} */
606 ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(0xe8b9);
607 /* 2nd half (register list) */
608 ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0x1ff);
fd0c8d8a
JM
609 asi->insn_handler = insn & 0x100 ? t16_emulate_pop_pc
610 : t16_emulate_pop_nopc;
611 return INSN_GOOD;
612}
3e6cd394
DL
613
614const union decode_action kprobes_t16_actions[NUM_PROBES_T16_ACTIONS] = {
615 [PROBES_T16_ADD_SP] = {.handler = t16_simulate_add_sp_imm},
616 [PROBES_T16_CBZ] = {.handler = t16_simulate_cbz},
617 [PROBES_T16_SIGN_EXTEND] = {.handler = t16_emulate_loregs_rwflags},
618 [PROBES_T16_PUSH] = {.decoder = t16_decode_push},
619 [PROBES_T16_POP] = {.decoder = t16_decode_pop},
eb73ea97
DL
620 [PROBES_T16_SEV] = {.handler = probes_emulate_none},
621 [PROBES_T16_WFE] = {.handler = probes_simulate_nop},
3e6cd394
DL
622 [PROBES_T16_IT] = {.decoder = t16_decode_it},
623 [PROBES_T16_CMP] = {.handler = t16_emulate_loregs_rwflags},
624 [PROBES_T16_ADDSUB] = {.handler = t16_emulate_loregs_noitrwflags},
625 [PROBES_T16_LOGICAL] = {.handler = t16_emulate_loregs_noitrwflags},
626 [PROBES_T16_LDR_LIT] = {.handler = t16_simulate_ldr_literal},
627 [PROBES_T16_BLX] = {.handler = t16_simulate_bxblx},
628 [PROBES_T16_HIREGOPS] = {.decoder = t16_decode_hiregs},
629 [PROBES_T16_LDRHSTRH] = {.handler = t16_emulate_loregs_rwflags},
630 [PROBES_T16_LDRSTR] = {.handler = t16_simulate_ldrstr_sp_relative},
631 [PROBES_T16_ADR] = {.handler = t16_simulate_reladr},
632 [PROBES_T16_LDMSTM] = {.handler = t16_emulate_loregs_rwflags},
633 [PROBES_T16_BRANCH_COND] = {.decoder = t16_decode_cond_branch},
634 [PROBES_T16_BRANCH] = {.handler = t16_simulate_branch},
635};
636
637const union decode_action kprobes_t32_actions[NUM_PROBES_T32_ACTIONS] = {
638 [PROBES_T32_LDMSTM] = {.decoder = t32_decode_ldmstm},
639 [PROBES_T32_LDRDSTRD] = {.handler = t32_emulate_ldrdstrd},
640 [PROBES_T32_TABLE_BRANCH] = {.handler = t32_simulate_table_branch},
641 [PROBES_T32_TST] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
642 [PROBES_T32_MOV] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
643 [PROBES_T32_ADDSUB] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
644 [PROBES_T32_LOGICAL] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
645 [PROBES_T32_CMP] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
646 [PROBES_T32_ADDWSUBW_PC] = {.handler = t32_emulate_rd8pc16_noflags,},
647 [PROBES_T32_ADDWSUBW] = {.handler = t32_emulate_rd8rn16_noflags},
648 [PROBES_T32_MOVW] = {.handler = t32_emulate_rd8rn16_noflags},
649 [PROBES_T32_SAT] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
650 [PROBES_T32_BITFIELD] = {.handler = t32_emulate_rd8rn16_noflags},
eb73ea97
DL
651 [PROBES_T32_SEV] = {.handler = probes_emulate_none},
652 [PROBES_T32_WFE] = {.handler = probes_simulate_nop},
3e6cd394
DL
653 [PROBES_T32_MRS] = {.handler = t32_simulate_mrs},
654 [PROBES_T32_BRANCH_COND] = {.decoder = t32_decode_cond_branch},
655 [PROBES_T32_BRANCH] = {.handler = t32_simulate_branch},
eb73ea97 656 [PROBES_T32_PLDI] = {.handler = probes_simulate_nop},
3e6cd394
DL
657 [PROBES_T32_LDR_LIT] = {.handler = t32_simulate_ldr_literal},
658 [PROBES_T32_LDRSTR] = {.handler = t32_emulate_ldrstr},
659 [PROBES_T32_SIGN_EXTEND] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
660 [PROBES_T32_MEDIA] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
661 [PROBES_T32_REVERSE] = {.handler = t32_emulate_rd8rn16_noflags},
662 [PROBES_T32_MUL_ADD] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
663 [PROBES_T32_MUL_ADD2] = {.handler = t32_emulate_rd8rn16rm0ra12_noflags},
664 [PROBES_T32_MUL_ADD_LONG] = {
665 .handler = t32_emulate_rdlo12rdhi8rn16rm0_noflags},
666};
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