aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/kprobes-arm.c
diff options
context:
space:
mode:
authorJon Medhurst <tixy@yxit.co.uk>2011-07-06 05:49:07 -0400
committerTixy <tixy@medhuaa1.miniserver.com>2011-07-13 13:32:40 -0400
commit691b2ff294a4787f3e54f5bb541570ac74bcb6f4 (patch)
tree77f3452cbd7c20f6bf69ab9c8759720740933b5c /arch/arm/kernel/kprobes-arm.c
parent592201a9f154cdd5db59304d1369e94d8b551803 (diff)
ARM: kprobes: Rename kprobes-decode.c to kprobes-arm.c
This file contains decoding and emulation functions for the ARM instruction set. As we will later be adding a file for Thumb and a file with common decoding functions, this renaming makes things clearer. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm/kernel/kprobes-arm.c')
-rw-r--r--arch/arm/kernel/kprobes-arm.c1670
1 files changed, 1670 insertions, 0 deletions
diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c
new file mode 100644
index 000000000000..15eeff6aea0e
--- /dev/null
+++ b/arch/arm/kernel/kprobes-arm.c
@@ -0,0 +1,1670 @@
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
64#define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit)))))
65
66#define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25)
67
68#define is_r15(insn, bitpos) (((insn) & (0xf << bitpos)) == (0xf << bitpos))
69
70/*
71 * Test if load/store instructions writeback the address register.
72 * if P (bit 24) == 0 or W (bit 21) == 1
73 */
74#define is_writeback(insn) ((insn ^ 0x01000000) & 0x01200000)
75
76#define PSR_fs (PSR_f|PSR_s)
77
78#define KPROBE_RETURN_INSTRUCTION 0xe1a0f00e /* mov pc, lr */
79
80typedef long (insn_0arg_fn_t)(void);
81typedef long (insn_1arg_fn_t)(long);
82typedef long (insn_2arg_fn_t)(long, long);
83typedef long (insn_3arg_fn_t)(long, long, long);
84typedef long (insn_4arg_fn_t)(long, long, long, long);
85typedef long long (insn_llret_0arg_fn_t)(void);
86typedef long long (insn_llret_3arg_fn_t)(long, long, long);
87typedef long long (insn_llret_4arg_fn_t)(long, long, long, long);
88
89union reg_pair {
90 long long dr;
91#ifdef __LITTLE_ENDIAN
92 struct { long r0, r1; };
93#else
94 struct { long r1, r0; };
95#endif
96};
97
98/*
99 * For STR and STM instructions, an ARM core may choose to use either
100 * a +8 or a +12 displacement from the current instruction's address.
101 * Whichever value is chosen for a given core, it must be the same for
102 * both instructions and may not change. This function measures it.
103 */
104
105static int str_pc_offset;
106
107static void __init find_str_pc_offset(void)
108{
109 int addr, scratch, ret;
110
111 __asm__ (
112 "sub %[ret], pc, #4 \n\t"
113 "str pc, %[addr] \n\t"
114 "ldr %[scr], %[addr] \n\t"
115 "sub %[ret], %[scr], %[ret] \n\t"
116 : [ret] "=r" (ret), [scr] "=r" (scratch), [addr] "+m" (addr));
117
118 str_pc_offset = ret;
119}
120
121/*
122 * The insnslot_?arg_r[w]flags() functions below are to keep the
123 * msr -> *fn -> mrs instruction sequences indivisible so that
124 * the state of the CPSR flags aren't inadvertently modified
125 * just before or just after the call.
126 */
127
128static inline long __kprobes
129insnslot_0arg_rflags(long cpsr, insn_0arg_fn_t *fn)
130{
131 register long ret asm("r0");
132
133 __asm__ __volatile__ (
134 "msr cpsr_fs, %[cpsr] \n\t"
135 "mov lr, pc \n\t"
136 "mov pc, %[fn] \n\t"
137 : "=r" (ret)
138 : [cpsr] "r" (cpsr), [fn] "r" (fn)
139 : "lr", "cc"
140 );
141 return ret;
142}
143
144static inline long long __kprobes
145insnslot_llret_0arg_rflags(long cpsr, insn_llret_0arg_fn_t *fn)
146{
147 register long ret0 asm("r0");
148 register long ret1 asm("r1");
149 union reg_pair fnr;
150
151 __asm__ __volatile__ (
152 "msr cpsr_fs, %[cpsr] \n\t"
153 "mov lr, pc \n\t"
154 "mov pc, %[fn] \n\t"
155 : "=r" (ret0), "=r" (ret1)
156 : [cpsr] "r" (cpsr), [fn] "r" (fn)
157 : "lr", "cc"
158 );
159 fnr.r0 = ret0;
160 fnr.r1 = ret1;
161 return fnr.dr;
162}
163
164static inline long __kprobes
165insnslot_1arg_rflags(long r0, long cpsr, insn_1arg_fn_t *fn)
166{
167 register long rr0 asm("r0") = r0;
168 register long ret asm("r0");
169
170 __asm__ __volatile__ (
171 "msr cpsr_fs, %[cpsr] \n\t"
172 "mov lr, pc \n\t"
173 "mov pc, %[fn] \n\t"
174 : "=r" (ret)
175 : "0" (rr0), [cpsr] "r" (cpsr), [fn] "r" (fn)
176 : "lr", "cc"
177 );
178 return ret;
179}
180
181static inline long __kprobes
182insnslot_2arg_rflags(long r0, long r1, long cpsr, insn_2arg_fn_t *fn)
183{
184 register long rr0 asm("r0") = r0;
185 register long rr1 asm("r1") = r1;
186 register long ret asm("r0");
187
188 __asm__ __volatile__ (
189 "msr cpsr_fs, %[cpsr] \n\t"
190 "mov lr, pc \n\t"
191 "mov pc, %[fn] \n\t"
192 : "=r" (ret)
193 : "0" (rr0), "r" (rr1),
194 [cpsr] "r" (cpsr), [fn] "r" (fn)
195 : "lr", "cc"
196 );
197 return ret;
198}
199
200static inline long __kprobes
201insnslot_3arg_rflags(long r0, long r1, long r2, long cpsr, insn_3arg_fn_t *fn)
202{
203 register long rr0 asm("r0") = r0;
204 register long rr1 asm("r1") = r1;
205 register long rr2 asm("r2") = r2;
206 register long ret asm("r0");
207
208 __asm__ __volatile__ (
209 "msr cpsr_fs, %[cpsr] \n\t"
210 "mov lr, pc \n\t"
211 "mov pc, %[fn] \n\t"
212 : "=r" (ret)
213 : "0" (rr0), "r" (rr1), "r" (rr2),
214 [cpsr] "r" (cpsr), [fn] "r" (fn)
215 : "lr", "cc"
216 );
217 return ret;
218}
219
220static inline long long __kprobes
221insnslot_llret_3arg_rflags(long r0, long r1, long r2, long cpsr,
222 insn_llret_3arg_fn_t *fn)
223{
224 register long rr0 asm("r0") = r0;
225 register long rr1 asm("r1") = r1;
226 register long rr2 asm("r2") = r2;
227 register long ret0 asm("r0");
228 register long ret1 asm("r1");
229 union reg_pair fnr;
230
231 __asm__ __volatile__ (
232 "msr cpsr_fs, %[cpsr] \n\t"
233 "mov lr, pc \n\t"
234 "mov pc, %[fn] \n\t"
235 : "=r" (ret0), "=r" (ret1)
236 : "0" (rr0), "r" (rr1), "r" (rr2),
237 [cpsr] "r" (cpsr), [fn] "r" (fn)
238 : "lr", "cc"
239 );
240 fnr.r0 = ret0;
241 fnr.r1 = ret1;
242 return fnr.dr;
243}
244
245static inline long __kprobes
246insnslot_4arg_rflags(long r0, long r1, long r2, long r3, long cpsr,
247 insn_4arg_fn_t *fn)
248{
249 register long rr0 asm("r0") = r0;
250 register long rr1 asm("r1") = r1;
251 register long rr2 asm("r2") = r2;
252 register long rr3 asm("r3") = r3;
253 register long ret asm("r0");
254
255 __asm__ __volatile__ (
256 "msr cpsr_fs, %[cpsr] \n\t"
257 "mov lr, pc \n\t"
258 "mov pc, %[fn] \n\t"
259 : "=r" (ret)
260 : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3),
261 [cpsr] "r" (cpsr), [fn] "r" (fn)
262 : "lr", "cc"
263 );
264 return ret;
265}
266
267static inline long __kprobes
268insnslot_1arg_rwflags(long r0, long *cpsr, insn_1arg_fn_t *fn)
269{
270 register long rr0 asm("r0") = r0;
271 register long ret asm("r0");
272 long oldcpsr = *cpsr;
273 long newcpsr;
274
275 __asm__ __volatile__ (
276 "msr cpsr_fs, %[oldcpsr] \n\t"
277 "mov lr, pc \n\t"
278 "mov pc, %[fn] \n\t"
279 "mrs %[newcpsr], cpsr \n\t"
280 : "=r" (ret), [newcpsr] "=r" (newcpsr)
281 : "0" (rr0), [oldcpsr] "r" (oldcpsr), [fn] "r" (fn)
282 : "lr", "cc"
283 );
284 *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs);
285 return ret;
286}
287
288static inline long __kprobes
289insnslot_2arg_rwflags(long r0, long r1, long *cpsr, insn_2arg_fn_t *fn)
290{
291 register long rr0 asm("r0") = r0;
292 register long rr1 asm("r1") = r1;
293 register long ret asm("r0");
294 long oldcpsr = *cpsr;
295 long newcpsr;
296
297 __asm__ __volatile__ (
298 "msr cpsr_fs, %[oldcpsr] \n\t"
299 "mov lr, pc \n\t"
300 "mov pc, %[fn] \n\t"
301 "mrs %[newcpsr], cpsr \n\t"
302 : "=r" (ret), [newcpsr] "=r" (newcpsr)
303 : "0" (rr0), "r" (rr1), [oldcpsr] "r" (oldcpsr), [fn] "r" (fn)
304 : "lr", "cc"
305 );
306 *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs);
307 return ret;
308}
309
310static inline long __kprobes
311insnslot_3arg_rwflags(long r0, long r1, long r2, long *cpsr,
312 insn_3arg_fn_t *fn)
313{
314 register long rr0 asm("r0") = r0;
315 register long rr1 asm("r1") = r1;
316 register long rr2 asm("r2") = r2;
317 register long ret asm("r0");
318 long oldcpsr = *cpsr;
319 long newcpsr;
320
321 __asm__ __volatile__ (
322 "msr cpsr_fs, %[oldcpsr] \n\t"
323 "mov lr, pc \n\t"
324 "mov pc, %[fn] \n\t"
325 "mrs %[newcpsr], cpsr \n\t"
326 : "=r" (ret), [newcpsr] "=r" (newcpsr)
327 : "0" (rr0), "r" (rr1), "r" (rr2),
328 [oldcpsr] "r" (oldcpsr), [fn] "r" (fn)
329 : "lr", "cc"
330 );
331 *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs);
332 return ret;
333}
334
335static inline long __kprobes
336insnslot_4arg_rwflags(long r0, long r1, long r2, long r3, long *cpsr,
337 insn_4arg_fn_t *fn)
338{
339 register long rr0 asm("r0") = r0;
340 register long rr1 asm("r1") = r1;
341 register long rr2 asm("r2") = r2;
342 register long rr3 asm("r3") = r3;
343 register long ret asm("r0");
344 long oldcpsr = *cpsr;
345 long newcpsr;
346
347 __asm__ __volatile__ (
348 "msr cpsr_fs, %[oldcpsr] \n\t"
349 "mov lr, pc \n\t"
350 "mov pc, %[fn] \n\t"
351 "mrs %[newcpsr], cpsr \n\t"
352 : "=r" (ret), [newcpsr] "=r" (newcpsr)
353 : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3),
354 [oldcpsr] "r" (oldcpsr), [fn] "r" (fn)
355 : "lr", "cc"
356 );
357 *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs);
358 return ret;
359}
360
361static inline long long __kprobes
362insnslot_llret_4arg_rwflags(long r0, long r1, long r2, long r3, long *cpsr,
363 insn_llret_4arg_fn_t *fn)
364{
365 register long rr0 asm("r0") = r0;
366 register long rr1 asm("r1") = r1;
367 register long rr2 asm("r2") = r2;
368 register long rr3 asm("r3") = r3;
369 register long ret0 asm("r0");
370 register long ret1 asm("r1");
371 long oldcpsr = *cpsr;
372 long newcpsr;
373 union reg_pair fnr;
374
375 __asm__ __volatile__ (
376 "msr cpsr_fs, %[oldcpsr] \n\t"
377 "mov lr, pc \n\t"
378 "mov pc, %[fn] \n\t"
379 "mrs %[newcpsr], cpsr \n\t"
380 : "=r" (ret0), "=r" (ret1), [newcpsr] "=r" (newcpsr)
381 : "0" (rr0), "r" (rr1), "r" (rr2), "r" (rr3),
382 [oldcpsr] "r" (oldcpsr), [fn] "r" (fn)
383 : "lr", "cc"
384 );
385 *cpsr = (oldcpsr & ~PSR_fs) | (newcpsr & PSR_fs);
386 fnr.r0 = ret0;
387 fnr.r1 = ret1;
388 return fnr.dr;
389}
390
391/*
392 * To avoid the complications of mimicing single-stepping on a
393 * processor without a Next-PC or a single-step mode, and to
394 * avoid having to deal with the side-effects of boosting, we
395 * simulate or emulate (almost) all ARM instructions.
396 *
397 * "Simulation" is where the instruction's behavior is duplicated in
398 * C code. "Emulation" is where the original instruction is rewritten
399 * and executed, often by altering its registers.
400 *
401 * By having all behavior of the kprobe'd instruction completed before
402 * returning from the kprobe_handler(), all locks (scheduler and
403 * interrupt) can safely be released. There is no need for secondary
404 * breakpoints, no race with MP or preemptable kernels, nor having to
405 * clean up resources counts at a later time impacting overall system
406 * performance. By rewriting the instruction, only the minimum registers
407 * need to be loaded and saved back optimizing performance.
408 *
409 * Calling the insnslot_*_rwflags version of a function doesn't hurt
410 * anything even when the CPSR flags aren't updated by the
411 * instruction. It's just a little slower in return for saving
412 * a little space by not having a duplicate function that doesn't
413 * update the flags. (The same optimization can be said for
414 * instructions that do or don't perform register writeback)
415 * Also, instructions can either read the flags, only write the
416 * flags, or read and write the flags. To save combinations
417 * rather than for sheer performance, flag functions just assume
418 * read and write of flags.
419 */
420
421static void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs)
422{
423 kprobe_opcode_t insn = p->opcode;
424 long iaddr = (long)p->addr;
425 int disp = branch_displacement(insn);
426
427 if (insn & (1 << 24))
428 regs->ARM_lr = iaddr + 4;
429
430 regs->ARM_pc = iaddr + 8 + disp;
431}
432
433static void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs)
434{
435 kprobe_opcode_t insn = p->opcode;
436 long iaddr = (long)p->addr;
437 int disp = branch_displacement(insn);
438
439 regs->ARM_lr = iaddr + 4;
440 regs->ARM_pc = iaddr + 8 + disp + ((insn >> 23) & 0x2);
441 regs->ARM_cpsr |= PSR_T_BIT;
442}
443
444static void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs)
445{
446 kprobe_opcode_t insn = p->opcode;
447 int rm = insn & 0xf;
448 long rmv = regs->uregs[rm];
449
450 if (insn & (1 << 5))
451 regs->ARM_lr = (long)p->addr + 4;
452
453 regs->ARM_pc = rmv & ~0x1;
454 regs->ARM_cpsr &= ~PSR_T_BIT;
455 if (rmv & 0x1)
456 regs->ARM_cpsr |= PSR_T_BIT;
457}
458
459static void __kprobes simulate_mrs(struct kprobe *p, struct pt_regs *regs)
460{
461 kprobe_opcode_t insn = p->opcode;
462 int rd = (insn >> 12) & 0xf;
463 unsigned long mask = 0xf8ff03df; /* Mask out execution state */
464 regs->uregs[rd] = regs->ARM_cpsr & mask;
465}
466
467static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs)
468{
469 kprobe_opcode_t insn = p->opcode;
470 int rn = (insn >> 16) & 0xf;
471 int lbit = insn & (1 << 20);
472 int wbit = insn & (1 << 21);
473 int ubit = insn & (1 << 23);
474 int pbit = insn & (1 << 24);
475 long *addr = (long *)regs->uregs[rn];
476 int reg_bit_vector;
477 int reg_count;
478
479 reg_count = 0;
480 reg_bit_vector = insn & 0xffff;
481 while (reg_bit_vector) {
482 reg_bit_vector &= (reg_bit_vector - 1);
483 ++reg_count;
484 }
485
486 if (!ubit)
487 addr -= reg_count;
488 addr += (!pbit == !ubit);
489
490 reg_bit_vector = insn & 0xffff;
491 while (reg_bit_vector) {
492 int reg = __ffs(reg_bit_vector);
493 reg_bit_vector &= (reg_bit_vector - 1);
494 if (lbit)
495 regs->uregs[reg] = *addr++;
496 else
497 *addr++ = regs->uregs[reg];
498 }
499
500 if (wbit) {
501 if (!ubit)
502 addr -= reg_count;
503 addr -= (!pbit == !ubit);
504 regs->uregs[rn] = (long)addr;
505 }
506}
507
508static void __kprobes simulate_stm1_pc(struct kprobe *p, struct pt_regs *regs)
509{
510 regs->ARM_pc = (long)p->addr + str_pc_offset;
511 simulate_ldm1stm1(p, regs);
512 regs->ARM_pc = (long)p->addr + 4;
513}
514
515static void __kprobes simulate_mov_ipsp(struct kprobe *p, struct pt_regs *regs)
516{
517 regs->uregs[12] = regs->uregs[13];
518}
519
520static void __kprobes emulate_ldrd(struct kprobe *p, struct pt_regs *regs)
521{
522 insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0];
523 kprobe_opcode_t insn = p->opcode;
524 long ppc = (long)p->addr + 8;
525 int rd = (insn >> 12) & 0xf;
526 int rn = (insn >> 16) & 0xf;
527 int rm = insn & 0xf; /* rm may be invalid, don't care. */
528 long rmv = (rm == 15) ? ppc : regs->uregs[rm];
529 long rnv = (rn == 15) ? ppc : regs->uregs[rn];
530
531 /* Not following the C calling convention here, so need asm(). */
532 __asm__ __volatile__ (
533 "ldr r0, %[rn] \n\t"
534 "ldr r1, %[rm] \n\t"
535 "msr cpsr_fs, %[cpsr]\n\t"
536 "mov lr, pc \n\t"
537 "mov pc, %[i_fn] \n\t"
538 "str r0, %[rn] \n\t" /* in case of writeback */
539 "str r2, %[rd0] \n\t"
540 "str r3, %[rd1] \n\t"
541 : [rn] "+m" (rnv),
542 [rd0] "=m" (regs->uregs[rd]),
543 [rd1] "=m" (regs->uregs[rd+1])
544 : [rm] "m" (rmv),
545 [cpsr] "r" (regs->ARM_cpsr),
546 [i_fn] "r" (i_fn)
547 : "r0", "r1", "r2", "r3", "lr", "cc"
548 );
549 if (is_writeback(insn))
550 regs->uregs[rn] = rnv;
551}
552
553static void __kprobes emulate_strd(struct kprobe *p, struct pt_regs *regs)
554{
555 insn_4arg_fn_t *i_fn = (insn_4arg_fn_t *)&p->ainsn.insn[0];
556 kprobe_opcode_t insn = p->opcode;
557 long ppc = (long)p->addr + 8;
558 int rd = (insn >> 12) & 0xf;
559 int rn = (insn >> 16) & 0xf;
560 int rm = insn & 0xf;
561 long rnv = (rn == 15) ? ppc : regs->uregs[rn];
562 /* rm/rmv may be invalid, don't care. */
563 long rmv = (rm == 15) ? ppc : regs->uregs[rm];
564 long rnv_wb;
565
566 rnv_wb = insnslot_4arg_rflags(rnv, rmv, regs->uregs[rd],
567 regs->uregs[rd+1],
568 regs->ARM_cpsr, i_fn);
569 if (is_writeback(insn))
570 regs->uregs[rn] = rnv_wb;
571}
572
573static void __kprobes emulate_ldr(struct kprobe *p, struct pt_regs *regs)
574{
575 insn_llret_3arg_fn_t *i_fn = (insn_llret_3arg_fn_t *)&p->ainsn.insn[0];
576 kprobe_opcode_t insn = p->opcode;
577 long ppc = (long)p->addr + 8;
578 union reg_pair fnr;
579 int rd = (insn >> 12) & 0xf;
580 int rn = (insn >> 16) & 0xf;
581 int rm = insn & 0xf;
582 long rdv;
583 long rnv = (rn == 15) ? ppc : regs->uregs[rn];
584 long rmv = (rm == 15) ? ppc : regs->uregs[rm];
585 long cpsr = regs->ARM_cpsr;
586
587 fnr.dr = insnslot_llret_3arg_rflags(rnv, 0, rmv, cpsr, i_fn);
588 if (rn != 15)
589 regs->uregs[rn] = fnr.r0; /* Save Rn in case of writeback. */
590 rdv = fnr.r1;
591
592 if (rd == 15) {
593#if __LINUX_ARM_ARCH__ >= 5
594 cpsr &= ~PSR_T_BIT;
595 if (rdv & 0x1)
596 cpsr |= PSR_T_BIT;
597 regs->ARM_cpsr = cpsr;
598 rdv &= ~0x1;
599#else
600 rdv &= ~0x2;
601#endif
602 }
603 regs->uregs[rd] = rdv;
604}
605
606static void __kprobes emulate_str(struct kprobe *p, struct pt_regs *regs)
607{
608 insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0];
609 kprobe_opcode_t insn = p->opcode;
610 long iaddr = (long)p->addr;
611 int rd = (insn >> 12) & 0xf;
612 int rn = (insn >> 16) & 0xf;
613 int rm = insn & 0xf;
614 long rdv = (rd == 15) ? iaddr + str_pc_offset : regs->uregs[rd];
615 long rnv = (rn == 15) ? iaddr + 8 : regs->uregs[rn];
616 long rmv = regs->uregs[rm]; /* rm/rmv may be invalid, don't care. */
617 long rnv_wb;
618
619 rnv_wb = insnslot_3arg_rflags(rnv, rdv, rmv, regs->ARM_cpsr, i_fn);
620 if (rn != 15)
621 regs->uregs[rn] = rnv_wb; /* Save Rn in case of writeback. */
622}
623
624static void __kprobes emulate_sat(struct kprobe *p, struct pt_regs *regs)
625{
626 insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0];
627 kprobe_opcode_t insn = p->opcode;
628 int rd = (insn >> 12) & 0xf;
629 int rm = insn & 0xf;
630 long rmv = regs->uregs[rm];
631
632 /* Writes Q flag */
633 regs->uregs[rd] = insnslot_1arg_rwflags(rmv, &regs->ARM_cpsr, i_fn);
634}
635
636static void __kprobes emulate_sel(struct kprobe *p, struct pt_regs *regs)
637{
638 insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0];
639 kprobe_opcode_t insn = p->opcode;
640 int rd = (insn >> 12) & 0xf;
641 int rn = (insn >> 16) & 0xf;
642 int rm = insn & 0xf;
643 long rnv = regs->uregs[rn];
644 long rmv = regs->uregs[rm];
645
646 /* Reads GE bits */
647 regs->uregs[rd] = insnslot_2arg_rflags(rnv, rmv, regs->ARM_cpsr, i_fn);
648}
649
650static void __kprobes emulate_none(struct kprobe *p, struct pt_regs *regs)
651{
652 insn_0arg_fn_t *i_fn = (insn_0arg_fn_t *)&p->ainsn.insn[0];
653
654 insnslot_0arg_rflags(regs->ARM_cpsr, i_fn);
655}
656
657static void __kprobes emulate_nop(struct kprobe *p, struct pt_regs *regs)
658{
659}
660
661static void __kprobes
662emulate_rd12_modify(struct kprobe *p, struct pt_regs *regs)
663{
664 insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0];
665 kprobe_opcode_t insn = p->opcode;
666 int rd = (insn >> 12) & 0xf;
667 long rdv = regs->uregs[rd];
668
669 regs->uregs[rd] = insnslot_1arg_rflags(rdv, regs->ARM_cpsr, i_fn);
670}
671
672static void __kprobes
673emulate_rd12rn0_modify(struct kprobe *p, struct pt_regs *regs)
674{
675 insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0];
676 kprobe_opcode_t insn = p->opcode;
677 int rd = (insn >> 12) & 0xf;
678 int rn = insn & 0xf;
679 long rdv = regs->uregs[rd];
680 long rnv = regs->uregs[rn];
681
682 regs->uregs[rd] = insnslot_2arg_rflags(rdv, rnv, regs->ARM_cpsr, i_fn);
683}
684
685static void __kprobes emulate_rd12rm0(struct kprobe *p, struct pt_regs *regs)
686{
687 insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0];
688 kprobe_opcode_t insn = p->opcode;
689 int rd = (insn >> 12) & 0xf;
690 int rm = insn & 0xf;
691 long rmv = regs->uregs[rm];
692
693 regs->uregs[rd] = insnslot_1arg_rflags(rmv, regs->ARM_cpsr, i_fn);
694}
695
696static void __kprobes
697emulate_rd12rn16rm0_rwflags(struct kprobe *p, struct pt_regs *regs)
698{
699 insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0];
700 kprobe_opcode_t insn = p->opcode;
701 int rd = (insn >> 12) & 0xf;
702 int rn = (insn >> 16) & 0xf;
703 int rm = insn & 0xf;
704 long rnv = regs->uregs[rn];
705 long rmv = regs->uregs[rm];
706
707 regs->uregs[rd] =
708 insnslot_2arg_rwflags(rnv, rmv, &regs->ARM_cpsr, i_fn);
709}
710
711static void __kprobes
712emulate_rd16rn12rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs)
713{
714 insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0];
715 kprobe_opcode_t insn = p->opcode;
716 int rd = (insn >> 16) & 0xf;
717 int rn = (insn >> 12) & 0xf;
718 int rs = (insn >> 8) & 0xf;
719 int rm = insn & 0xf;
720 long rnv = regs->uregs[rn];
721 long rsv = regs->uregs[rs];
722 long rmv = regs->uregs[rm];
723
724 regs->uregs[rd] =
725 insnslot_3arg_rwflags(rnv, rsv, rmv, &regs->ARM_cpsr, i_fn);
726}
727
728static void __kprobes
729emulate_rd16rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs)
730{
731 insn_2arg_fn_t *i_fn = (insn_2arg_fn_t *)&p->ainsn.insn[0];
732 kprobe_opcode_t insn = p->opcode;
733 int rd = (insn >> 16) & 0xf;
734 int rs = (insn >> 8) & 0xf;
735 int rm = insn & 0xf;
736 long rsv = regs->uregs[rs];
737 long rmv = regs->uregs[rm];
738
739 regs->uregs[rd] =
740 insnslot_2arg_rwflags(rsv, rmv, &regs->ARM_cpsr, i_fn);
741}
742
743static void __kprobes
744emulate_rdhi16rdlo12rs8rm0_rwflags(struct kprobe *p, struct pt_regs *regs)
745{
746 insn_llret_4arg_fn_t *i_fn = (insn_llret_4arg_fn_t *)&p->ainsn.insn[0];
747 kprobe_opcode_t insn = p->opcode;
748 union reg_pair fnr;
749 int rdhi = (insn >> 16) & 0xf;
750 int rdlo = (insn >> 12) & 0xf;
751 int rs = (insn >> 8) & 0xf;
752 int rm = insn & 0xf;
753 long rsv = regs->uregs[rs];
754 long rmv = regs->uregs[rm];
755
756 fnr.dr = insnslot_llret_4arg_rwflags(regs->uregs[rdhi],
757 regs->uregs[rdlo], rsv, rmv,
758 &regs->ARM_cpsr, i_fn);
759 regs->uregs[rdhi] = fnr.r0;
760 regs->uregs[rdlo] = fnr.r1;
761}
762
763static void __kprobes
764emulate_alu_imm_rflags(struct kprobe *p, struct pt_regs *regs)
765{
766 insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0];
767 kprobe_opcode_t insn = p->opcode;
768 int rd = (insn >> 12) & 0xf;
769 int rn = (insn >> 16) & 0xf;
770 long rnv = (rn == 15) ? (long)p->addr + 8 : regs->uregs[rn];
771
772 regs->uregs[rd] = insnslot_1arg_rflags(rnv, regs->ARM_cpsr, i_fn);
773}
774
775static void __kprobes
776emulate_alu_imm_rwflags(struct kprobe *p, struct pt_regs *regs)
777{
778 insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0];
779 kprobe_opcode_t insn = p->opcode;
780 int rd = (insn >> 12) & 0xf;
781 int rn = (insn >> 16) & 0xf;
782 long rnv = (rn == 15) ? (long)p->addr + 8 : regs->uregs[rn];
783
784 regs->uregs[rd] = insnslot_1arg_rwflags(rnv, &regs->ARM_cpsr, i_fn);
785}
786
787static void __kprobes
788emulate_alu_tests_imm(struct kprobe *p, struct pt_regs *regs)
789{
790 insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0];
791 kprobe_opcode_t insn = p->opcode;
792 int rn = (insn >> 16) & 0xf;
793 long rnv = (rn == 15) ? (long)p->addr + 8 : regs->uregs[rn];
794
795 insnslot_1arg_rwflags(rnv, &regs->ARM_cpsr, i_fn);
796}
797
798static void __kprobes
799emulate_alu_rflags(struct kprobe *p, struct pt_regs *regs)
800{
801 insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0];
802 kprobe_opcode_t insn = p->opcode;
803 long ppc = (long)p->addr + 8;
804 int rd = (insn >> 12) & 0xf;
805 int rn = (insn >> 16) & 0xf; /* rn/rnv/rs/rsv may be */
806 int rs = (insn >> 8) & 0xf; /* invalid, don't care. */
807 int rm = insn & 0xf;
808 long rnv = (rn == 15) ? ppc : regs->uregs[rn];
809 long rmv = (rm == 15) ? ppc : regs->uregs[rm];
810 long rsv = regs->uregs[rs];
811
812 regs->uregs[rd] =
813 insnslot_3arg_rflags(rnv, rmv, rsv, regs->ARM_cpsr, i_fn);
814}
815
816static void __kprobes
817emulate_alu_rwflags(struct kprobe *p, struct pt_regs *regs)
818{
819 insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0];
820 kprobe_opcode_t insn = p->opcode;
821 long ppc = (long)p->addr + 8;
822 int rd = (insn >> 12) & 0xf;
823 int rn = (insn >> 16) & 0xf; /* rn/rnv/rs/rsv may be */
824 int rs = (insn >> 8) & 0xf; /* invalid, don't care. */
825 int rm = insn & 0xf;
826 long rnv = (rn == 15) ? ppc : regs->uregs[rn];
827 long rmv = (rm == 15) ? ppc : regs->uregs[rm];
828 long rsv = regs->uregs[rs];
829
830 regs->uregs[rd] =
831 insnslot_3arg_rwflags(rnv, rmv, rsv, &regs->ARM_cpsr, i_fn);
832}
833
834static void __kprobes
835emulate_alu_tests(struct kprobe *p, struct pt_regs *regs)
836{
837 insn_3arg_fn_t *i_fn = (insn_3arg_fn_t *)&p->ainsn.insn[0];
838 kprobe_opcode_t insn = p->opcode;
839 long ppc = (long)p->addr + 8;
840 int rn = (insn >> 16) & 0xf;
841 int rs = (insn >> 8) & 0xf; /* rs/rsv may be invalid, don't care. */
842 int rm = insn & 0xf;
843 long rnv = (rn == 15) ? ppc : regs->uregs[rn];
844 long rmv = (rm == 15) ? ppc : regs->uregs[rm];
845 long rsv = regs->uregs[rs];
846
847 insnslot_3arg_rwflags(rnv, rmv, rsv, &regs->ARM_cpsr, i_fn);
848}
849
850static enum kprobe_insn __kprobes
851prep_emulate_ldr_str(kprobe_opcode_t insn, struct arch_specific_insn *asi)
852{
853 int not_imm = (insn & (1 << 26)) ? (insn & (1 << 25))
854 : (~insn & (1 << 22));
855
856 if (is_writeback(insn) && is_r15(insn, 16))
857 return INSN_REJECTED; /* Writeback to PC */
858
859 insn &= 0xfff00fff;
860 insn |= 0x00001000; /* Rn = r0, Rd = r1 */
861 if (not_imm) {
862 insn &= ~0xf;
863 insn |= 2; /* Rm = r2 */
864 }
865 asi->insn[0] = insn;
866 asi->insn_handler = (insn & (1 << 20)) ? emulate_ldr : emulate_str;
867 return INSN_GOOD;
868}
869
870static enum kprobe_insn __kprobes
871prep_emulate_rd12_modify(kprobe_opcode_t insn, struct arch_specific_insn *asi)
872{
873 if (is_r15(insn, 12))
874 return INSN_REJECTED; /* Rd is PC */
875
876 insn &= 0xffff0fff; /* Rd = r0 */
877 asi->insn[0] = insn;
878 asi->insn_handler = emulate_rd12_modify;
879 return INSN_GOOD;
880}
881
882static enum kprobe_insn __kprobes
883prep_emulate_rd12rn0_modify(kprobe_opcode_t insn,
884 struct arch_specific_insn *asi)
885{
886 if (is_r15(insn, 12))
887 return INSN_REJECTED; /* Rd is PC */
888
889 insn &= 0xffff0ff0; /* Rd = r0 */
890 insn |= 0x00000001; /* Rn = r1 */
891 asi->insn[0] = insn;
892 asi->insn_handler = emulate_rd12rn0_modify;
893 return INSN_GOOD;
894}
895
896static enum kprobe_insn __kprobes
897prep_emulate_rd12rm0(kprobe_opcode_t insn, struct arch_specific_insn *asi)
898{
899 if (is_r15(insn, 12))
900 return INSN_REJECTED; /* Rd is PC */
901
902 insn &= 0xffff0ff0; /* Rd = r0, Rm = r0 */
903 asi->insn[0] = insn;
904 asi->insn_handler = emulate_rd12rm0;
905 return INSN_GOOD;
906}
907
908static enum kprobe_insn __kprobes
909prep_emulate_rd12rn16rm0_wflags(kprobe_opcode_t insn,
910 struct arch_specific_insn *asi)
911{
912 if (is_r15(insn, 12))
913 return INSN_REJECTED; /* Rd is PC */
914
915 insn &= 0xfff00ff0; /* Rd = r0, Rn = r0 */
916 insn |= 0x00000001; /* Rm = r1 */
917 asi->insn[0] = insn;
918 asi->insn_handler = emulate_rd12rn16rm0_rwflags;
919 return INSN_GOOD;
920}
921
922static enum kprobe_insn __kprobes
923prep_emulate_rd16rs8rm0_wflags(kprobe_opcode_t insn,
924 struct arch_specific_insn *asi)
925{
926 if (is_r15(insn, 16))
927 return INSN_REJECTED; /* Rd is PC */
928
929 insn &= 0xfff0f0f0; /* Rd = r0, Rs = r0 */
930 insn |= 0x00000001; /* Rm = r1 */
931 asi->insn[0] = insn;
932 asi->insn_handler = emulate_rd16rs8rm0_rwflags;
933 return INSN_GOOD;
934}
935
936static enum kprobe_insn __kprobes
937prep_emulate_rd16rn12rs8rm0_wflags(kprobe_opcode_t insn,
938 struct arch_specific_insn *asi)
939{
940 if (is_r15(insn, 16))
941 return INSN_REJECTED; /* Rd is PC */
942
943 insn &= 0xfff000f0; /* Rd = r0, Rn = r0 */
944 insn |= 0x00000102; /* Rs = r1, Rm = r2 */
945 asi->insn[0] = insn;
946 asi->insn_handler = emulate_rd16rn12rs8rm0_rwflags;
947 return INSN_GOOD;
948}
949
950static enum kprobe_insn __kprobes
951prep_emulate_rdhi16rdlo12rs8rm0_wflags(kprobe_opcode_t insn,
952 struct arch_specific_insn *asi)
953{
954 if (is_r15(insn, 16) || is_r15(insn, 12))
955 return INSN_REJECTED; /* RdHi or RdLo is PC */
956
957 insn &= 0xfff000f0; /* RdHi = r0, RdLo = r1 */
958 insn |= 0x00001203; /* Rs = r2, Rm = r3 */
959 asi->insn[0] = insn;
960 asi->insn_handler = emulate_rdhi16rdlo12rs8rm0_rwflags;
961 return INSN_GOOD;
962}
963
964/*
965 * For the instruction masking and comparisons in all the "space_*"
966 * functions below, Do _not_ rearrange the order of tests unless
967 * you're very, very sure of what you are doing. For the sake of
968 * efficiency, the masks for some tests sometimes assume other test
969 * have been done prior to them so the number of patterns to test
970 * for an instruction set can be as broad as possible to reduce the
971 * number of tests needed.
972 */
973
974static enum kprobe_insn __kprobes
975space_1111(kprobe_opcode_t insn, struct arch_specific_insn *asi)
976{
977 /* memory hint : 1111 0100 x001 xxxx xxxx xxxx xxxx xxxx : */
978 /* PLDI : 1111 0100 x101 xxxx xxxx xxxx xxxx xxxx : */
979 /* PLDW : 1111 0101 x001 xxxx xxxx xxxx xxxx xxxx : */
980 /* PLD : 1111 0101 x101 xxxx xxxx xxxx xxxx xxxx : */
981 if ((insn & 0xfe300000) == 0xf4100000) {
982 asi->insn_handler = emulate_nop;
983 return INSN_GOOD_NO_SLOT;
984 }
985
986 /* BLX(1) : 1111 101x xxxx xxxx xxxx xxxx xxxx xxxx : */
987 if ((insn & 0xfe000000) == 0xfa000000) {
988 asi->insn_handler = simulate_blx1;
989 return INSN_GOOD_NO_SLOT;
990 }
991
992 /* CPS : 1111 0001 0000 xxx0 xxxx xxxx xx0x xxxx */
993 /* SETEND: 1111 0001 0000 0001 xxxx xxxx 0000 xxxx */
994
995 /* SRS : 1111 100x x1x0 xxxx xxxx xxxx xxxx xxxx */
996 /* RFE : 1111 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
997
998 /* Coprocessor instructions... */
999 /* MCRR2 : 1111 1100 0100 xxxx xxxx xxxx xxxx xxxx : (Rd != Rn) */
1000 /* MRRC2 : 1111 1100 0101 xxxx xxxx xxxx xxxx xxxx : (Rd != Rn) */
1001 /* LDC2 : 1111 110x xxx1 xxxx xxxx xxxx xxxx xxxx */
1002 /* STC2 : 1111 110x xxx0 xxxx xxxx xxxx xxxx xxxx */
1003 /* CDP2 : 1111 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */
1004 /* MCR2 : 1111 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */
1005 /* MRC2 : 1111 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */
1006
1007 return INSN_REJECTED;
1008}
1009
1010static enum kprobe_insn __kprobes
1011space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1012{
1013 /* cccc 0001 0xx0 xxxx xxxx xxxx xxxx xxx0 xxxx */
1014 if ((insn & 0x0f900010) == 0x01000000) {
1015
1016 /* MRS cpsr : cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */
1017 if ((insn & 0x0ff000f0) == 0x01000000) {
1018 if (is_r15(insn, 12))
1019 return INSN_REJECTED; /* Rd is PC */
1020 asi->insn_handler = simulate_mrs;
1021 return INSN_GOOD_NO_SLOT;
1022 }
1023
1024 /* SMLALxy : cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */
1025 if ((insn & 0x0ff00090) == 0x01400080)
1026 return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn,
1027 asi);
1028
1029 /* SMULWy : cccc 0001 0010 xxxx xxxx xxxx 1x10 xxxx */
1030 /* SMULxy : cccc 0001 0110 xxxx xxxx xxxx 1xx0 xxxx */
1031 if ((insn & 0x0ff000b0) == 0x012000a0 ||
1032 (insn & 0x0ff00090) == 0x01600080)
1033 return prep_emulate_rd16rs8rm0_wflags(insn, asi);
1034
1035 /* SMLAxy : cccc 0001 0000 xxxx xxxx xxxx 1xx0 xxxx : Q */
1036 /* SMLAWy : cccc 0001 0010 xxxx xxxx xxxx 1x00 xxxx : Q */
1037 if ((insn & 0x0ff00090) == 0x01000080 ||
1038 (insn & 0x0ff000b0) == 0x01200080)
1039 return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi);
1040
1041 /* BXJ : cccc 0001 0010 xxxx xxxx xxxx 0010 xxxx */
1042 /* MSR : cccc 0001 0x10 xxxx xxxx xxxx 0000 xxxx */
1043 /* MRS spsr : cccc 0001 0100 xxxx xxxx xxxx 0000 xxxx */
1044
1045 /* Other instruction encodings aren't yet defined */
1046 return INSN_REJECTED;
1047 }
1048
1049 /* cccc 0001 0xx0 xxxx xxxx xxxx xxxx 0xx1 xxxx */
1050 else if ((insn & 0x0f900090) == 0x01000010) {
1051
1052 /* BLX(2) : cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */
1053 /* BX : cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */
1054 if ((insn & 0x0ff000d0) == 0x01200010) {
1055 if ((insn & 0x0ff000ff) == 0x0120003f)
1056 return INSN_REJECTED; /* BLX pc */
1057 asi->insn_handler = simulate_blx2bx;
1058 return INSN_GOOD_NO_SLOT;
1059 }
1060
1061 /* CLZ : cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */
1062 if ((insn & 0x0ff000f0) == 0x01600010)
1063 return prep_emulate_rd12rm0(insn, asi);
1064
1065 /* QADD : cccc 0001 0000 xxxx xxxx xxxx 0101 xxxx :Q */
1066 /* QSUB : cccc 0001 0010 xxxx xxxx xxxx 0101 xxxx :Q */
1067 /* QDADD : cccc 0001 0100 xxxx xxxx xxxx 0101 xxxx :Q */
1068 /* QDSUB : cccc 0001 0110 xxxx xxxx xxxx 0101 xxxx :Q */
1069 if ((insn & 0x0f9000f0) == 0x01000050)
1070 return prep_emulate_rd12rn16rm0_wflags(insn, asi);
1071
1072 /* BKPT : 1110 0001 0010 xxxx xxxx xxxx 0111 xxxx */
1073 /* SMC : cccc 0001 0110 xxxx xxxx xxxx 0111 xxxx */
1074
1075 /* Other instruction encodings aren't yet defined */
1076 return INSN_REJECTED;
1077 }
1078
1079 /* cccc 0000 xxxx xxxx xxxx xxxx xxxx 1001 xxxx */
1080 else if ((insn & 0x0f0000f0) == 0x00000090) {
1081
1082 /* MUL : cccc 0000 0000 xxxx xxxx xxxx 1001 xxxx : */
1083 /* MULS : cccc 0000 0001 xxxx xxxx xxxx 1001 xxxx :cc */
1084 /* MLA : cccc 0000 0010 xxxx xxxx xxxx 1001 xxxx : */
1085 /* MLAS : cccc 0000 0011 xxxx xxxx xxxx 1001 xxxx :cc */
1086 /* UMAAL : cccc 0000 0100 xxxx xxxx xxxx 1001 xxxx : */
1087 /* undef : cccc 0000 0101 xxxx xxxx xxxx 1001 xxxx : */
1088 /* MLS : cccc 0000 0110 xxxx xxxx xxxx 1001 xxxx : */
1089 /* undef : cccc 0000 0111 xxxx xxxx xxxx 1001 xxxx : */
1090 /* UMULL : cccc 0000 1000 xxxx xxxx xxxx 1001 xxxx : */
1091 /* UMULLS : cccc 0000 1001 xxxx xxxx xxxx 1001 xxxx :cc */
1092 /* UMLAL : cccc 0000 1010 xxxx xxxx xxxx 1001 xxxx : */
1093 /* UMLALS : cccc 0000 1011 xxxx xxxx xxxx 1001 xxxx :cc */
1094 /* SMULL : cccc 0000 1100 xxxx xxxx xxxx 1001 xxxx : */
1095 /* SMULLS : cccc 0000 1101 xxxx xxxx xxxx 1001 xxxx :cc */
1096 /* SMLAL : cccc 0000 1110 xxxx xxxx xxxx 1001 xxxx : */
1097 /* SMLALS : cccc 0000 1111 xxxx xxxx xxxx 1001 xxxx :cc */
1098 if ((insn & 0x00d00000) == 0x00500000)
1099 return INSN_REJECTED;
1100 else if ((insn & 0x00e00000) == 0x00000000)
1101 return prep_emulate_rd16rs8rm0_wflags(insn, asi);
1102 else if ((insn & 0x00a00000) == 0x00200000)
1103 return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi);
1104 else
1105 return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn,
1106 asi);
1107 }
1108
1109 /* cccc 000x xxxx xxxx xxxx xxxx xxxx 1xx1 xxxx */
1110 else if ((insn & 0x0e000090) == 0x00000090) {
1111
1112 /* SWP : cccc 0001 0000 xxxx xxxx xxxx 1001 xxxx */
1113 /* SWPB : cccc 0001 0100 xxxx xxxx xxxx 1001 xxxx */
1114 /* ??? : cccc 0001 0x01 xxxx xxxx xxxx 1001 xxxx */
1115 /* ??? : cccc 0001 0x10 xxxx xxxx xxxx 1001 xxxx */
1116 /* ??? : cccc 0001 0x11 xxxx xxxx xxxx 1001 xxxx */
1117 /* STREX : cccc 0001 1000 xxxx xxxx xxxx 1001 xxxx */
1118 /* LDREX : cccc 0001 1001 xxxx xxxx xxxx 1001 xxxx */
1119 /* STREXD: cccc 0001 1010 xxxx xxxx xxxx 1001 xxxx */
1120 /* LDREXD: cccc 0001 1011 xxxx xxxx xxxx 1001 xxxx */
1121 /* STREXB: cccc 0001 1100 xxxx xxxx xxxx 1001 xxxx */
1122 /* LDREXB: cccc 0001 1101 xxxx xxxx xxxx 1001 xxxx */
1123 /* STREXH: cccc 0001 1110 xxxx xxxx xxxx 1001 xxxx */
1124 /* LDREXH: cccc 0001 1111 xxxx xxxx xxxx 1001 xxxx */
1125
1126 /* LDRD : cccc 000x xxx0 xxxx xxxx xxxx 1101 xxxx */
1127 /* STRD : cccc 000x xxx0 xxxx xxxx xxxx 1111 xxxx */
1128 /* LDRH : cccc 000x xxx1 xxxx xxxx xxxx 1011 xxxx */
1129 /* STRH : cccc 000x xxx0 xxxx xxxx xxxx 1011 xxxx */
1130 /* LDRSB : cccc 000x xxx1 xxxx xxxx xxxx 1101 xxxx */
1131 /* LDRSH : cccc 000x xxx1 xxxx xxxx xxxx 1111 xxxx */
1132 if ((insn & 0x0f0000f0) == 0x01000090) {
1133 if ((insn & 0x0fb000f0) == 0x01000090) {
1134 /* SWP/SWPB */
1135 return prep_emulate_rd12rn16rm0_wflags(insn,
1136 asi);
1137 } else {
1138 /* STREX/LDREX variants and unallocaed space */
1139 return INSN_REJECTED;
1140 }
1141
1142 } else if ((insn & 0x0e1000d0) == 0x00000d0) {
1143 /* STRD/LDRD */
1144 if ((insn & 0x0000e000) == 0x0000e000)
1145 return INSN_REJECTED; /* Rd is LR or PC */
1146 if (is_writeback(insn) && is_r15(insn, 16))
1147 return INSN_REJECTED; /* Writeback to PC */
1148
1149 insn &= 0xfff00fff;
1150 insn |= 0x00002000; /* Rn = r0, Rd = r2 */
1151 if (!(insn & (1 << 22))) {
1152 /* Register index */
1153 insn &= ~0xf;
1154 insn |= 1; /* Rm = r1 */
1155 }
1156 asi->insn[0] = insn;
1157 asi->insn_handler =
1158 (insn & (1 << 5)) ? emulate_strd : emulate_ldrd;
1159 return INSN_GOOD;
1160 }
1161
1162 /* LDRH/STRH/LDRSB/LDRSH */
1163 if (is_r15(insn, 12))
1164 return INSN_REJECTED; /* Rd is PC */
1165 return prep_emulate_ldr_str(insn, asi);
1166 }
1167
1168 /* cccc 000x xxxx xxxx xxxx xxxx xxxx xxxx xxxx */
1169
1170 /*
1171 * ALU op with S bit and Rd == 15 :
1172 * cccc 000x xxx1 xxxx 1111 xxxx xxxx xxxx
1173 */
1174 if ((insn & 0x0e10f000) == 0x0010f000)
1175 return INSN_REJECTED;
1176
1177 /*
1178 * "mov ip, sp" is the most common kprobe'd instruction by far.
1179 * Check and optimize for it explicitly.
1180 */
1181 if (insn == 0xe1a0c00d) {
1182 asi->insn_handler = simulate_mov_ipsp;
1183 return INSN_GOOD_NO_SLOT;
1184 }
1185
1186 /*
1187 * Data processing: Immediate-shift / Register-shift
1188 * ALU op : cccc 000x xxxx xxxx xxxx xxxx xxxx xxxx
1189 * CPY : cccc 0001 1010 xxxx xxxx 0000 0000 xxxx
1190 * MOV : cccc 0001 101x xxxx xxxx xxxx xxxx xxxx
1191 * *S (bit 20) updates condition codes
1192 * ADC/SBC/RSC reads the C flag
1193 */
1194 insn &= 0xfff00ff0; /* Rn = r0, Rd = r0 */
1195 insn |= 0x00000001; /* Rm = r1 */
1196 if (insn & 0x010) {
1197 insn &= 0xfffff0ff; /* register shift */
1198 insn |= 0x00000200; /* Rs = r2 */
1199 }
1200 asi->insn[0] = insn;
1201
1202 if ((insn & 0x0f900000) == 0x01100000) {
1203 /*
1204 * TST : cccc 0001 0001 xxxx xxxx xxxx xxxx xxxx
1205 * TEQ : cccc 0001 0011 xxxx xxxx xxxx xxxx xxxx
1206 * CMP : cccc 0001 0101 xxxx xxxx xxxx xxxx xxxx
1207 * CMN : cccc 0001 0111 xxxx xxxx xxxx xxxx xxxx
1208 */
1209 asi->insn_handler = emulate_alu_tests;
1210 } else {
1211 /* ALU ops which write to Rd */
1212 asi->insn_handler = (insn & (1 << 20)) ? /* S-bit */
1213 emulate_alu_rwflags : emulate_alu_rflags;
1214 }
1215 return INSN_GOOD;
1216}
1217
1218static enum kprobe_insn __kprobes
1219space_cccc_001x(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1220{
1221 /* MOVW : cccc 0011 0000 xxxx xxxx xxxx xxxx xxxx */
1222 /* MOVT : cccc 0011 0100 xxxx xxxx xxxx xxxx xxxx */
1223 if ((insn & 0x0fb00000) == 0x03000000)
1224 return prep_emulate_rd12_modify(insn, asi);
1225
1226 /* hints : cccc 0011 0010 0000 xxxx xxxx xxxx xxxx */
1227 if ((insn & 0x0fff0000) == 0x03200000) {
1228 unsigned op2 = insn & 0x000000ff;
1229 if (op2 == 0x01 || op2 == 0x04) {
1230 /* YIELD : cccc 0011 0010 0000 xxxx xxxx 0000 0001 */
1231 /* SEV : cccc 0011 0010 0000 xxxx xxxx 0000 0100 */
1232 asi->insn[0] = insn;
1233 asi->insn_handler = emulate_none;
1234 return INSN_GOOD;
1235 } else if (op2 <= 0x03) {
1236 /* NOP : cccc 0011 0010 0000 xxxx xxxx 0000 0000 */
1237 /* WFE : cccc 0011 0010 0000 xxxx xxxx 0000 0010 */
1238 /* WFI : cccc 0011 0010 0000 xxxx xxxx 0000 0011 */
1239 /*
1240 * We make WFE and WFI true NOPs to avoid stalls due
1241 * to missing events whilst processing the probe.
1242 */
1243 asi->insn_handler = emulate_nop;
1244 return INSN_GOOD_NO_SLOT;
1245 }
1246 /* For DBG and unallocated hints it's safest to reject them */
1247 return INSN_REJECTED;
1248 }
1249
1250 /*
1251 * MSR : cccc 0011 0x10 xxxx xxxx xxxx xxxx xxxx
1252 * ALU op with S bit and Rd == 15 :
1253 * cccc 001x xxx1 xxxx 1111 xxxx xxxx xxxx
1254 */
1255 if ((insn & 0x0fb00000) == 0x03200000 || /* MSR */
1256 (insn & 0x0e10f000) == 0x0210f000) /* ALU s-bit, R15 */
1257 return INSN_REJECTED;
1258
1259 /*
1260 * Data processing: 32-bit Immediate
1261 * ALU op : cccc 001x xxxx xxxx xxxx xxxx xxxx xxxx
1262 * MOV : cccc 0011 101x xxxx xxxx xxxx xxxx xxxx
1263 * *S (bit 20) updates condition codes
1264 * ADC/SBC/RSC reads the C flag
1265 */
1266 insn &= 0xfff00fff; /* Rn = r0 and Rd = r0 */
1267 asi->insn[0] = insn;
1268
1269 if ((insn & 0x0f900000) == 0x03100000) {
1270 /*
1271 * TST : cccc 0011 0001 xxxx xxxx xxxx xxxx xxxx
1272 * TEQ : cccc 0011 0011 xxxx xxxx xxxx xxxx xxxx
1273 * CMP : cccc 0011 0101 xxxx xxxx xxxx xxxx xxxx
1274 * CMN : cccc 0011 0111 xxxx xxxx xxxx xxxx xxxx
1275 */
1276 asi->insn_handler = emulate_alu_tests_imm;
1277 } else {
1278 /* ALU ops which write to Rd */
1279 asi->insn_handler = (insn & (1 << 20)) ? /* S-bit */
1280 emulate_alu_imm_rwflags : emulate_alu_imm_rflags;
1281 }
1282 return INSN_GOOD;
1283}
1284
1285static enum kprobe_insn __kprobes
1286space_cccc_0110__1(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1287{
1288 /* SEL : cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx GE: !!! */
1289 if ((insn & 0x0ff000f0) == 0x068000b0) {
1290 if (is_r15(insn, 12))
1291 return INSN_REJECTED; /* Rd is PC */
1292 insn &= 0xfff00ff0; /* Rd = r0, Rn = r0 */
1293 insn |= 0x00000001; /* Rm = r1 */
1294 asi->insn[0] = insn;
1295 asi->insn_handler = emulate_sel;
1296 return INSN_GOOD;
1297 }
1298
1299 /* SSAT : cccc 0110 101x xxxx xxxx xxxx xx01 xxxx :Q */
1300 /* USAT : cccc 0110 111x xxxx xxxx xxxx xx01 xxxx :Q */
1301 /* SSAT16 : cccc 0110 1010 xxxx xxxx xxxx 0011 xxxx :Q */
1302 /* USAT16 : cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx :Q */
1303 if ((insn & 0x0fa00030) == 0x06a00010 ||
1304 (insn & 0x0fb000f0) == 0x06a00030) {
1305 if (is_r15(insn, 12))
1306 return INSN_REJECTED; /* Rd is PC */
1307 insn &= 0xffff0ff0; /* Rd = r0, Rm = r0 */
1308 asi->insn[0] = insn;
1309 asi->insn_handler = emulate_sat;
1310 return INSN_GOOD;
1311 }
1312
1313 /* REV : cccc 0110 1011 xxxx xxxx xxxx 0011 xxxx */
1314 /* REV16 : cccc 0110 1011 xxxx xxxx xxxx 1011 xxxx */
1315 /* RBIT : cccc 0110 1111 xxxx xxxx xxxx 0011 xxxx */
1316 /* REVSH : cccc 0110 1111 xxxx xxxx xxxx 1011 xxxx */
1317 if ((insn & 0x0ff00070) == 0x06b00030 ||
1318 (insn & 0x0ff00070) == 0x06f00030)
1319 return prep_emulate_rd12rm0(insn, asi);
1320
1321 /* ??? : cccc 0110 0000 xxxx xxxx xxxx xxx1 xxxx : */
1322 /* SADD16 : cccc 0110 0001 xxxx xxxx xxxx 0001 xxxx :GE */
1323 /* SADDSUBX : cccc 0110 0001 xxxx xxxx xxxx 0011 xxxx :GE */
1324 /* SSUBADDX : cccc 0110 0001 xxxx xxxx xxxx 0101 xxxx :GE */
1325 /* SSUB16 : cccc 0110 0001 xxxx xxxx xxxx 0111 xxxx :GE */
1326 /* SADD8 : cccc 0110 0001 xxxx xxxx xxxx 1001 xxxx :GE */
1327 /* ??? : cccc 0110 0001 xxxx xxxx xxxx 1011 xxxx : */
1328 /* ??? : cccc 0110 0001 xxxx xxxx xxxx 1101 xxxx : */
1329 /* SSUB8 : cccc 0110 0001 xxxx xxxx xxxx 1111 xxxx :GE */
1330 /* QADD16 : cccc 0110 0010 xxxx xxxx xxxx 0001 xxxx : */
1331 /* QADDSUBX : cccc 0110 0010 xxxx xxxx xxxx 0011 xxxx : */
1332 /* QSUBADDX : cccc 0110 0010 xxxx xxxx xxxx 0101 xxxx : */
1333 /* QSUB16 : cccc 0110 0010 xxxx xxxx xxxx 0111 xxxx : */
1334 /* QADD8 : cccc 0110 0010 xxxx xxxx xxxx 1001 xxxx : */
1335 /* ??? : cccc 0110 0010 xxxx xxxx xxxx 1011 xxxx : */
1336 /* ??? : cccc 0110 0010 xxxx xxxx xxxx 1101 xxxx : */
1337 /* QSUB8 : cccc 0110 0010 xxxx xxxx xxxx 1111 xxxx : */
1338 /* SHADD16 : cccc 0110 0011 xxxx xxxx xxxx 0001 xxxx : */
1339 /* SHADDSUBX : cccc 0110 0011 xxxx xxxx xxxx 0011 xxxx : */
1340 /* SHSUBADDX : cccc 0110 0011 xxxx xxxx xxxx 0101 xxxx : */
1341 /* SHSUB16 : cccc 0110 0011 xxxx xxxx xxxx 0111 xxxx : */
1342 /* SHADD8 : cccc 0110 0011 xxxx xxxx xxxx 1001 xxxx : */
1343 /* ??? : cccc 0110 0011 xxxx xxxx xxxx 1011 xxxx : */
1344 /* ??? : cccc 0110 0011 xxxx xxxx xxxx 1101 xxxx : */
1345 /* SHSUB8 : cccc 0110 0011 xxxx xxxx xxxx 1111 xxxx : */
1346 /* ??? : cccc 0110 0100 xxxx xxxx xxxx xxx1 xxxx : */
1347 /* UADD16 : cccc 0110 0101 xxxx xxxx xxxx 0001 xxxx :GE */
1348 /* UADDSUBX : cccc 0110 0101 xxxx xxxx xxxx 0011 xxxx :GE */
1349 /* USUBADDX : cccc 0110 0101 xxxx xxxx xxxx 0101 xxxx :GE */
1350 /* USUB16 : cccc 0110 0101 xxxx xxxx xxxx 0111 xxxx :GE */
1351 /* UADD8 : cccc 0110 0101 xxxx xxxx xxxx 1001 xxxx :GE */
1352 /* ??? : cccc 0110 0101 xxxx xxxx xxxx 1011 xxxx : */
1353 /* ??? : cccc 0110 0101 xxxx xxxx xxxx 1101 xxxx : */
1354 /* USUB8 : cccc 0110 0101 xxxx xxxx xxxx 1111 xxxx :GE */
1355 /* UQADD16 : cccc 0110 0110 xxxx xxxx xxxx 0001 xxxx : */
1356 /* UQADDSUBX : cccc 0110 0110 xxxx xxxx xxxx 0011 xxxx : */
1357 /* UQSUBADDX : cccc 0110 0110 xxxx xxxx xxxx 0101 xxxx : */
1358 /* UQSUB16 : cccc 0110 0110 xxxx xxxx xxxx 0111 xxxx : */
1359 /* UQADD8 : cccc 0110 0110 xxxx xxxx xxxx 1001 xxxx : */
1360 /* ??? : cccc 0110 0110 xxxx xxxx xxxx 1011 xxxx : */
1361 /* ??? : cccc 0110 0110 xxxx xxxx xxxx 1101 xxxx : */
1362 /* UQSUB8 : cccc 0110 0110 xxxx xxxx xxxx 1111 xxxx : */
1363 /* UHADD16 : cccc 0110 0111 xxxx xxxx xxxx 0001 xxxx : */
1364 /* UHADDSUBX : cccc 0110 0111 xxxx xxxx xxxx 0011 xxxx : */
1365 /* UHSUBADDX : cccc 0110 0111 xxxx xxxx xxxx 0101 xxxx : */
1366 /* UHSUB16 : cccc 0110 0111 xxxx xxxx xxxx 0111 xxxx : */
1367 /* UHADD8 : cccc 0110 0111 xxxx xxxx xxxx 1001 xxxx : */
1368 /* ??? : cccc 0110 0111 xxxx xxxx xxxx 1011 xxxx : */
1369 /* ??? : cccc 0110 0111 xxxx xxxx xxxx 1101 xxxx : */
1370 /* UHSUB8 : cccc 0110 0111 xxxx xxxx xxxx 1111 xxxx : */
1371 if ((insn & 0x0f800010) == 0x06000010) {
1372 if ((insn & 0x00300000) == 0x00000000 ||
1373 (insn & 0x000000e0) == 0x000000a0 ||
1374 (insn & 0x000000e0) == 0x000000c0)
1375 return INSN_REJECTED; /* Unallocated space */
1376 return prep_emulate_rd12rn16rm0_wflags(insn, asi);
1377 }
1378
1379 /* PKHBT : cccc 0110 1000 xxxx xxxx xxxx x001 xxxx : */
1380 /* PKHTB : cccc 0110 1000 xxxx xxxx xxxx x101 xxxx : */
1381 if ((insn & 0x0ff00030) == 0x06800010)
1382 return prep_emulate_rd12rn16rm0_wflags(insn, asi);
1383
1384 /* SXTAB16 : cccc 0110 1000 xxxx xxxx xxxx 0111 xxxx : */
1385 /* SXTB16 : cccc 0110 1000 1111 xxxx xxxx 0111 xxxx : */
1386 /* ??? : cccc 0110 1001 xxxx xxxx xxxx 0111 xxxx : */
1387 /* SXTAB : cccc 0110 1010 xxxx xxxx xxxx 0111 xxxx : */
1388 /* SXTB : cccc 0110 1010 1111 xxxx xxxx 0111 xxxx : */
1389 /* SXTAH : cccc 0110 1011 xxxx xxxx xxxx 0111 xxxx : */
1390 /* SXTH : cccc 0110 1011 1111 xxxx xxxx 0111 xxxx : */
1391 /* UXTAB16 : cccc 0110 1100 xxxx xxxx xxxx 0111 xxxx : */
1392 /* UXTB16 : cccc 0110 1100 1111 xxxx xxxx 0111 xxxx : */
1393 /* ??? : cccc 0110 1101 xxxx xxxx xxxx 0111 xxxx : */
1394 /* UXTAB : cccc 0110 1110 xxxx xxxx xxxx 0111 xxxx : */
1395 /* UXTB : cccc 0110 1110 1111 xxxx xxxx 0111 xxxx : */
1396 /* UXTAH : cccc 0110 1111 xxxx xxxx xxxx 0111 xxxx : */
1397 /* UXTH : cccc 0110 1111 1111 xxxx xxxx 0111 xxxx : */
1398 if ((insn & 0x0f8000f0) == 0x06800070) {
1399 if ((insn & 0x00300000) == 0x00100000)
1400 return INSN_REJECTED; /* Unallocated space */
1401
1402 if ((insn & 0x000f0000) == 0x000f0000)
1403 return prep_emulate_rd12rm0(insn, asi);
1404 else
1405 return prep_emulate_rd12rn16rm0_wflags(insn, asi);
1406 }
1407
1408 /* Other instruction encodings aren't yet defined */
1409 return INSN_REJECTED;
1410}
1411
1412static enum kprobe_insn __kprobes
1413space_cccc_0111__1(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1414{
1415 /* Undef : cccc 0111 1111 xxxx xxxx xxxx 1111 xxxx */
1416 if ((insn & 0x0ff000f0) == 0x03f000f0)
1417 return INSN_REJECTED;
1418
1419 /* SMLALD : cccc 0111 0100 xxxx xxxx xxxx 00x1 xxxx */
1420 /* SMLSLD : cccc 0111 0100 xxxx xxxx xxxx 01x1 xxxx */
1421 if ((insn & 0x0ff00090) == 0x07400010)
1422 return prep_emulate_rdhi16rdlo12rs8rm0_wflags(insn, asi);
1423
1424 /* SMLAD : cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx :Q */
1425 /* SMUAD : cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx :Q */
1426 /* SMLSD : cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx :Q */
1427 /* SMUSD : cccc 0111 0000 xxxx 1111 xxxx 01x1 xxxx : */
1428 /* SMMLA : cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx : */
1429 /* SMMUL : cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx : */
1430 /* USADA8 : cccc 0111 1000 xxxx xxxx xxxx 0001 xxxx : */
1431 /* USAD8 : cccc 0111 1000 xxxx 1111 xxxx 0001 xxxx : */
1432 if ((insn & 0x0ff00090) == 0x07000010 ||
1433 (insn & 0x0ff000d0) == 0x07500010 ||
1434 (insn & 0x0ff000f0) == 0x07800010) {
1435
1436 if ((insn & 0x0000f000) == 0x0000f000)
1437 return prep_emulate_rd16rs8rm0_wflags(insn, asi);
1438 else
1439 return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi);
1440 }
1441
1442 /* SMMLS : cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx : */
1443 if ((insn & 0x0ff000d0) == 0x075000d0)
1444 return prep_emulate_rd16rn12rs8rm0_wflags(insn, asi);
1445
1446 /* SBFX : cccc 0111 101x xxxx xxxx xxxx x101 xxxx : */
1447 /* UBFX : cccc 0111 111x xxxx xxxx xxxx x101 xxxx : */
1448 if ((insn & 0x0fa00070) == 0x07a00050)
1449 return prep_emulate_rd12rm0(insn, asi);
1450
1451 /* BFI : cccc 0111 110x xxxx xxxx xxxx x001 xxxx : */
1452 /* BFC : cccc 0111 110x xxxx xxxx xxxx x001 1111 : */
1453 if ((insn & 0x0fe00070) == 0x07c00010) {
1454
1455 if ((insn & 0x0000000f) == 0x0000000f)
1456 return prep_emulate_rd12_modify(insn, asi);
1457 else
1458 return prep_emulate_rd12rn0_modify(insn, asi);
1459 }
1460
1461 return INSN_REJECTED;
1462}
1463
1464static enum kprobe_insn __kprobes
1465space_cccc_01xx(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1466{
1467 /* LDR : cccc 01xx x0x1 xxxx xxxx xxxx xxxx xxxx */
1468 /* LDRB : cccc 01xx x1x1 xxxx xxxx xxxx xxxx xxxx */
1469 /* LDRBT : cccc 01x0 x111 xxxx xxxx xxxx xxxx xxxx */
1470 /* LDRT : cccc 01x0 x011 xxxx xxxx xxxx xxxx xxxx */
1471 /* STR : cccc 01xx x0x0 xxxx xxxx xxxx xxxx xxxx */
1472 /* STRB : cccc 01xx x1x0 xxxx xxxx xxxx xxxx xxxx */
1473 /* STRBT : cccc 01x0 x110 xxxx xxxx xxxx xxxx xxxx */
1474 /* STRT : cccc 01x0 x010 xxxx xxxx xxxx xxxx xxxx */
1475
1476 if ((insn & 0x00500000) == 0x00500000 && is_r15(insn, 12))
1477 return INSN_REJECTED; /* LDRB into PC */
1478
1479 return prep_emulate_ldr_str(insn, asi);
1480}
1481
1482static enum kprobe_insn __kprobes
1483space_cccc_100x(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1484{
1485 /* LDM(2) : cccc 100x x101 xxxx 0xxx xxxx xxxx xxxx */
1486 /* LDM(3) : cccc 100x x1x1 xxxx 1xxx xxxx xxxx xxxx */
1487 if ((insn & 0x0e708000) == 0x85000000 ||
1488 (insn & 0x0e508000) == 0x85010000)
1489 return INSN_REJECTED;
1490
1491 /* LDM(1) : cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
1492 /* STM(1) : cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */
1493 asi->insn_handler = ((insn & 0x108000) == 0x008000) ? /* STM & R15 */
1494 simulate_stm1_pc : simulate_ldm1stm1;
1495 return INSN_GOOD_NO_SLOT;
1496}
1497
1498static enum kprobe_insn __kprobes
1499space_cccc_101x(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1500{
1501 /* B : cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */
1502 /* BL : cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */
1503 asi->insn_handler = simulate_bbl;
1504 return INSN_GOOD_NO_SLOT;
1505}
1506
1507static enum kprobe_insn __kprobes
1508space_cccc_11xx(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1509{
1510 /* Coprocessor instructions... */
1511 /* MCRR : cccc 1100 0100 xxxx xxxx xxxx xxxx xxxx : (Rd!=Rn) */
1512 /* MRRC : cccc 1100 0101 xxxx xxxx xxxx xxxx xxxx : (Rd!=Rn) */
1513 /* LDC : cccc 110x xxx1 xxxx xxxx xxxx xxxx xxxx */
1514 /* STC : cccc 110x xxx0 xxxx xxxx xxxx xxxx xxxx */
1515 /* CDP : cccc 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */
1516 /* MCR : cccc 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */
1517 /* MRC : cccc 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */
1518
1519 /* SVC : cccc 1111 xxxx xxxx xxxx xxxx xxxx xxxx */
1520
1521 return INSN_REJECTED;
1522}
1523
1524static unsigned long __kprobes __check_eq(unsigned long cpsr)
1525{
1526 return cpsr & PSR_Z_BIT;
1527}
1528
1529static unsigned long __kprobes __check_ne(unsigned long cpsr)
1530{
1531 return (~cpsr) & PSR_Z_BIT;
1532}
1533
1534static unsigned long __kprobes __check_cs(unsigned long cpsr)
1535{
1536 return cpsr & PSR_C_BIT;
1537}
1538
1539static unsigned long __kprobes __check_cc(unsigned long cpsr)
1540{
1541 return (~cpsr) & PSR_C_BIT;
1542}
1543
1544static unsigned long __kprobes __check_mi(unsigned long cpsr)
1545{
1546 return cpsr & PSR_N_BIT;
1547}
1548
1549static unsigned long __kprobes __check_pl(unsigned long cpsr)
1550{
1551 return (~cpsr) & PSR_N_BIT;
1552}
1553
1554static unsigned long __kprobes __check_vs(unsigned long cpsr)
1555{
1556 return cpsr & PSR_V_BIT;
1557}
1558
1559static unsigned long __kprobes __check_vc(unsigned long cpsr)
1560{
1561 return (~cpsr) & PSR_V_BIT;
1562}
1563
1564static unsigned long __kprobes __check_hi(unsigned long cpsr)
1565{
1566 cpsr &= ~(cpsr >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */
1567 return cpsr & PSR_C_BIT;
1568}
1569
1570static unsigned long __kprobes __check_ls(unsigned long cpsr)
1571{
1572 cpsr &= ~(cpsr >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */
1573 return (~cpsr) & PSR_C_BIT;
1574}
1575
1576static unsigned long __kprobes __check_ge(unsigned long cpsr)
1577{
1578 cpsr ^= (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */
1579 return (~cpsr) & PSR_N_BIT;
1580}
1581
1582static unsigned long __kprobes __check_lt(unsigned long cpsr)
1583{
1584 cpsr ^= (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */
1585 return cpsr & PSR_N_BIT;
1586}
1587
1588static unsigned long __kprobes __check_gt(unsigned long cpsr)
1589{
1590 unsigned long temp = cpsr ^ (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */
1591 temp |= (cpsr << 1); /* PSR_N_BIT |= PSR_Z_BIT */
1592 return (~temp) & PSR_N_BIT;
1593}
1594
1595static unsigned long __kprobes __check_le(unsigned long cpsr)
1596{
1597 unsigned long temp = cpsr ^ (cpsr << 3); /* PSR_N_BIT ^= PSR_V_BIT */
1598 temp |= (cpsr << 1); /* PSR_N_BIT |= PSR_Z_BIT */
1599 return temp & PSR_N_BIT;
1600}
1601
1602static unsigned long __kprobes __check_al(unsigned long cpsr)
1603{
1604 return true;
1605}
1606
1607static kprobe_check_cc * const condition_checks[16] = {
1608 &__check_eq, &__check_ne, &__check_cs, &__check_cc,
1609 &__check_mi, &__check_pl, &__check_vs, &__check_vc,
1610 &__check_hi, &__check_ls, &__check_ge, &__check_lt,
1611 &__check_gt, &__check_le, &__check_al, &__check_al
1612};
1613
1614/* Return:
1615 * INSN_REJECTED If instruction is one not allowed to kprobe,
1616 * INSN_GOOD If instruction is supported and uses instruction slot,
1617 * INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
1618 *
1619 * For instructions we don't want to kprobe (INSN_REJECTED return result):
1620 * These are generally ones that modify the processor state making
1621 * them "hard" to simulate such as switches processor modes or
1622 * make accesses in alternate modes. Any of these could be simulated
1623 * if the work was put into it, but low return considering they
1624 * should also be very rare.
1625 */
1626enum kprobe_insn __kprobes
1627arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1628{
1629 asi->insn_check_cc = condition_checks[insn>>28];
1630 asi->insn[1] = KPROBE_RETURN_INSTRUCTION;
1631
1632 if ((insn & 0xf0000000) == 0xf0000000)
1633
1634 return space_1111(insn, asi);
1635
1636 else if ((insn & 0x0e000000) == 0x00000000)
1637
1638 return space_cccc_000x(insn, asi);
1639
1640 else if ((insn & 0x0e000000) == 0x02000000)
1641
1642 return space_cccc_001x(insn, asi);
1643
1644 else if ((insn & 0x0f000010) == 0x06000010)
1645
1646 return space_cccc_0110__1(insn, asi);
1647
1648 else if ((insn & 0x0f000010) == 0x07000010)
1649
1650 return space_cccc_0111__1(insn, asi);
1651
1652 else if ((insn & 0x0c000000) == 0x04000000)
1653
1654 return space_cccc_01xx(insn, asi);
1655
1656 else if ((insn & 0x0e000000) == 0x08000000)
1657
1658 return space_cccc_100x(insn, asi);
1659
1660 else if ((insn & 0x0e000000) == 0x0a000000)
1661
1662 return space_cccc_101x(insn, asi);
1663
1664 return space_cccc_11xx(insn, asi);
1665}
1666
1667void __init arm_kprobe_decode_init(void)
1668{
1669 find_str_pc_offset();
1670}
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-25 12:25:51 -0500