Merge tag 'mfd-for-linus-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
[pandora-kernel.git] / arch / arm / probes / decode-arm.c
1 /*
2  *
3  * arch/arm/probes/decode-arm.c
4  *
5  * Some code moved here from arch/arm/kernel/kprobes-arm.c
6  *
7  * Copyright (C) 2006, 2007 Motorola Inc.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  */
18
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/stddef.h>
22 #include <linux/ptrace.h>
23
24 #include "decode.h"
25 #include "decode-arm.h"
26
27 #define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit)))))
28
29 #define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25)
30
31 /*
32  * To avoid the complications of mimicing single-stepping on a
33  * processor without a Next-PC or a single-step mode, and to
34  * avoid having to deal with the side-effects of boosting, we
35  * simulate or emulate (almost) all ARM instructions.
36  *
37  * "Simulation" is where the instruction's behavior is duplicated in
38  * C code.  "Emulation" is where the original instruction is rewritten
39  * and executed, often by altering its registers.
40  *
41  * By having all behavior of the kprobe'd instruction completed before
42  * returning from the kprobe_handler(), all locks (scheduler and
43  * interrupt) can safely be released.  There is no need for secondary
44  * breakpoints, no race with MP or preemptable kernels, nor having to
45  * clean up resources counts at a later time impacting overall system
46  * performance.  By rewriting the instruction, only the minimum registers
47  * need to be loaded and saved back optimizing performance.
48  *
49  * Calling the insnslot_*_rwflags version of a function doesn't hurt
50  * anything even when the CPSR flags aren't updated by the
51  * instruction.  It's just a little slower in return for saving
52  * a little space by not having a duplicate function that doesn't
53  * update the flags.  (The same optimization can be said for
54  * instructions that do or don't perform register writeback)
55  * Also, instructions can either read the flags, only write the
56  * flags, or read and write the flags.  To save combinations
57  * rather than for sheer performance, flag functions just assume
58  * read and write of flags.
59  */
60
61 void __kprobes simulate_bbl(probes_opcode_t insn,
62                 struct arch_probes_insn *asi, struct pt_regs *regs)
63 {
64         long iaddr = (long) regs->ARM_pc - 4;
65         int disp  = branch_displacement(insn);
66
67         if (insn & (1 << 24))
68                 regs->ARM_lr = iaddr + 4;
69
70         regs->ARM_pc = iaddr + 8 + disp;
71 }
72
73 void __kprobes simulate_blx1(probes_opcode_t insn,
74                 struct arch_probes_insn *asi, struct pt_regs *regs)
75 {
76         long iaddr = (long) regs->ARM_pc - 4;
77         int disp = branch_displacement(insn);
78
79         regs->ARM_lr = iaddr + 4;
80         regs->ARM_pc = iaddr + 8 + disp + ((insn >> 23) & 0x2);
81         regs->ARM_cpsr |= PSR_T_BIT;
82 }
83
84 void __kprobes simulate_blx2bx(probes_opcode_t insn,
85                 struct arch_probes_insn *asi, struct pt_regs *regs)
86 {
87         int rm = insn & 0xf;
88         long rmv = regs->uregs[rm];
89
90         if (insn & (1 << 5))
91                 regs->ARM_lr = (long) regs->ARM_pc;
92
93         regs->ARM_pc = rmv & ~0x1;
94         regs->ARM_cpsr &= ~PSR_T_BIT;
95         if (rmv & 0x1)
96                 regs->ARM_cpsr |= PSR_T_BIT;
97 }
98
99 void __kprobes simulate_mrs(probes_opcode_t insn,
100                 struct arch_probes_insn *asi, struct pt_regs *regs)
101 {
102         int rd = (insn >> 12) & 0xf;
103         unsigned long mask = 0xf8ff03df; /* Mask out execution state */
104         regs->uregs[rd] = regs->ARM_cpsr & mask;
105 }
106
107 void __kprobes simulate_mov_ipsp(probes_opcode_t insn,
108                 struct arch_probes_insn *asi, struct pt_regs *regs)
109 {
110         regs->uregs[12] = regs->uregs[13];
111 }
112
113 /*
114  * For the instruction masking and comparisons in all the "space_*"
115  * functions below, Do _not_ rearrange the order of tests unless
116  * you're very, very sure of what you are doing.  For the sake of
117  * efficiency, the masks for some tests sometimes assume other test
118  * have been done prior to them so the number of patterns to test
119  * for an instruction set can be as broad as possible to reduce the
120  * number of tests needed.
121  */
122
123 static const union decode_item arm_1111_table[] = {
124         /* Unconditional instructions                                   */
125
126         /* memory hint          1111 0100 x001 xxxx xxxx xxxx xxxx xxxx */
127         /* PLDI (immediate)     1111 0100 x101 xxxx xxxx xxxx xxxx xxxx */
128         /* PLDW (immediate)     1111 0101 x001 xxxx xxxx xxxx xxxx xxxx */
129         /* PLD (immediate)      1111 0101 x101 xxxx xxxx xxxx xxxx xxxx */
130         DECODE_SIMULATE (0xfe300000, 0xf4100000, PROBES_PRELOAD_IMM),
131
132         /* memory hint          1111 0110 x001 xxxx xxxx xxxx xxx0 xxxx */
133         /* PLDI (register)      1111 0110 x101 xxxx xxxx xxxx xxx0 xxxx */
134         /* PLDW (register)      1111 0111 x001 xxxx xxxx xxxx xxx0 xxxx */
135         /* PLD (register)       1111 0111 x101 xxxx xxxx xxxx xxx0 xxxx */
136         DECODE_SIMULATE (0xfe300010, 0xf6100000, PROBES_PRELOAD_REG),
137
138         /* BLX (immediate)      1111 101x xxxx xxxx xxxx xxxx xxxx xxxx */
139         DECODE_SIMULATE (0xfe000000, 0xfa000000, PROBES_BRANCH_IMM),
140
141         /* CPS                  1111 0001 0000 xxx0 xxxx xxxx xx0x xxxx */
142         /* SETEND               1111 0001 0000 0001 xxxx xxxx 0000 xxxx */
143         /* SRS                  1111 100x x1x0 xxxx xxxx xxxx xxxx xxxx */
144         /* RFE                  1111 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
145
146         /* Coprocessor instructions... */
147         /* MCRR2                1111 1100 0100 xxxx xxxx xxxx xxxx xxxx */
148         /* MRRC2                1111 1100 0101 xxxx xxxx xxxx xxxx xxxx */
149         /* LDC2                 1111 110x xxx1 xxxx xxxx xxxx xxxx xxxx */
150         /* STC2                 1111 110x xxx0 xxxx xxxx xxxx xxxx xxxx */
151         /* CDP2                 1111 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */
152         /* MCR2                 1111 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */
153         /* MRC2                 1111 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */
154
155         /* Other unallocated instructions...                            */
156         DECODE_END
157 };
158
159 static const union decode_item arm_cccc_0001_0xx0____0xxx_table[] = {
160         /* Miscellaneous instructions                                   */
161
162         /* MRS cpsr             cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */
163         DECODE_SIMULATEX(0x0ff000f0, 0x01000000, PROBES_MRS,
164                                                  REGS(0, NOPC, 0, 0, 0)),
165
166         /* BX                   cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */
167         DECODE_SIMULATE (0x0ff000f0, 0x01200010, PROBES_BRANCH_REG),
168
169         /* BLX (register)       cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */
170         DECODE_SIMULATEX(0x0ff000f0, 0x01200030, PROBES_BRANCH_REG,
171                                                  REGS(0, 0, 0, 0, NOPC)),
172
173         /* CLZ                  cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */
174         DECODE_EMULATEX (0x0ff000f0, 0x01600010, PROBES_CLZ,
175                                                  REGS(0, NOPC, 0, 0, NOPC)),
176
177         /* QADD                 cccc 0001 0000 xxxx xxxx xxxx 0101 xxxx */
178         /* QSUB                 cccc 0001 0010 xxxx xxxx xxxx 0101 xxxx */
179         /* QDADD                cccc 0001 0100 xxxx xxxx xxxx 0101 xxxx */
180         /* QDSUB                cccc 0001 0110 xxxx xxxx xxxx 0101 xxxx */
181         DECODE_EMULATEX (0x0f9000f0, 0x01000050, PROBES_SATURATING_ARITHMETIC,
182                                                  REGS(NOPC, NOPC, 0, 0, NOPC)),
183
184         /* BXJ                  cccc 0001 0010 xxxx xxxx xxxx 0010 xxxx */
185         /* MSR                  cccc 0001 0x10 xxxx xxxx xxxx 0000 xxxx */
186         /* MRS spsr             cccc 0001 0100 xxxx xxxx xxxx 0000 xxxx */
187         /* BKPT                 1110 0001 0010 xxxx xxxx xxxx 0111 xxxx */
188         /* SMC                  cccc 0001 0110 xxxx xxxx xxxx 0111 xxxx */
189         /* And unallocated instructions...                              */
190         DECODE_END
191 };
192
193 static const union decode_item arm_cccc_0001_0xx0____1xx0_table[] = {
194         /* Halfword multiply and multiply-accumulate                    */
195
196         /* SMLALxy              cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */
197         DECODE_EMULATEX (0x0ff00090, 0x01400080, PROBES_MUL1,
198                                                  REGS(NOPC, NOPC, NOPC, 0, NOPC)),
199
200         /* SMULWy               cccc 0001 0010 xxxx xxxx xxxx 1x10 xxxx */
201         DECODE_OR       (0x0ff000b0, 0x012000a0),
202         /* SMULxy               cccc 0001 0110 xxxx xxxx xxxx 1xx0 xxxx */
203         DECODE_EMULATEX (0x0ff00090, 0x01600080, PROBES_MUL2,
204                                                  REGS(NOPC, 0, NOPC, 0, NOPC)),
205
206         /* SMLAxy               cccc 0001 0000 xxxx xxxx xxxx 1xx0 xxxx */
207         DECODE_OR       (0x0ff00090, 0x01000080),
208         /* SMLAWy               cccc 0001 0010 xxxx xxxx xxxx 1x00 xxxx */
209         DECODE_EMULATEX (0x0ff000b0, 0x01200080, PROBES_MUL2,
210                                                  REGS(NOPC, NOPC, NOPC, 0, NOPC)),
211
212         DECODE_END
213 };
214
215 static const union decode_item arm_cccc_0000_____1001_table[] = {
216         /* Multiply and multiply-accumulate                             */
217
218         /* MUL                  cccc 0000 0000 xxxx xxxx xxxx 1001 xxxx */
219         /* MULS                 cccc 0000 0001 xxxx xxxx xxxx 1001 xxxx */
220         DECODE_EMULATEX (0x0fe000f0, 0x00000090, PROBES_MUL2,
221                                                  REGS(NOPC, 0, NOPC, 0, NOPC)),
222
223         /* MLA                  cccc 0000 0010 xxxx xxxx xxxx 1001 xxxx */
224         /* MLAS                 cccc 0000 0011 xxxx xxxx xxxx 1001 xxxx */
225         DECODE_OR       (0x0fe000f0, 0x00200090),
226         /* MLS                  cccc 0000 0110 xxxx xxxx xxxx 1001 xxxx */
227         DECODE_EMULATEX (0x0ff000f0, 0x00600090, PROBES_MUL2,
228                                                  REGS(NOPC, NOPC, NOPC, 0, NOPC)),
229
230         /* UMAAL                cccc 0000 0100 xxxx xxxx xxxx 1001 xxxx */
231         DECODE_OR       (0x0ff000f0, 0x00400090),
232         /* UMULL                cccc 0000 1000 xxxx xxxx xxxx 1001 xxxx */
233         /* UMULLS               cccc 0000 1001 xxxx xxxx xxxx 1001 xxxx */
234         /* UMLAL                cccc 0000 1010 xxxx xxxx xxxx 1001 xxxx */
235         /* UMLALS               cccc 0000 1011 xxxx xxxx xxxx 1001 xxxx */
236         /* SMULL                cccc 0000 1100 xxxx xxxx xxxx 1001 xxxx */
237         /* SMULLS               cccc 0000 1101 xxxx xxxx xxxx 1001 xxxx */
238         /* SMLAL                cccc 0000 1110 xxxx xxxx xxxx 1001 xxxx */
239         /* SMLALS               cccc 0000 1111 xxxx xxxx xxxx 1001 xxxx */
240         DECODE_EMULATEX (0x0f8000f0, 0x00800090, PROBES_MUL1,
241                                                  REGS(NOPC, NOPC, NOPC, 0, NOPC)),
242
243         DECODE_END
244 };
245
246 static const union decode_item arm_cccc_0001_____1001_table[] = {
247         /* Synchronization primitives                                   */
248
249 #if __LINUX_ARM_ARCH__ < 6
250         /* Deprecated on ARMv6 and may be UNDEFINED on v7               */
251         /* SMP/SWPB             cccc 0001 0x00 xxxx xxxx xxxx 1001 xxxx */
252         DECODE_EMULATEX (0x0fb000f0, 0x01000090, PROBES_SWP,
253                                                  REGS(NOPC, NOPC, 0, 0, NOPC)),
254 #endif
255         /* LDREX/STREX{,D,B,H}  cccc 0001 1xxx xxxx xxxx xxxx 1001 xxxx */
256         /* And unallocated instructions...                              */
257         DECODE_END
258 };
259
260 static const union decode_item arm_cccc_000x_____1xx1_table[] = {
261         /* Extra load/store instructions                                */
262
263         /* STRHT                cccc 0000 xx10 xxxx xxxx xxxx 1011 xxxx */
264         /* ???                  cccc 0000 xx10 xxxx xxxx xxxx 11x1 xxxx */
265         /* LDRHT                cccc 0000 xx11 xxxx xxxx xxxx 1011 xxxx */
266         /* LDRSBT               cccc 0000 xx11 xxxx xxxx xxxx 1101 xxxx */
267         /* LDRSHT               cccc 0000 xx11 xxxx xxxx xxxx 1111 xxxx */
268         DECODE_REJECT   (0x0f200090, 0x00200090),
269
270         /* LDRD/STRD lr,pc,{... cccc 000x x0x0 xxxx 111x xxxx 1101 xxxx */
271         DECODE_REJECT   (0x0e10e0d0, 0x0000e0d0),
272
273         /* LDRD (register)      cccc 000x x0x0 xxxx xxxx xxxx 1101 xxxx */
274         /* STRD (register)      cccc 000x x0x0 xxxx xxxx xxxx 1111 xxxx */
275         DECODE_EMULATEX (0x0e5000d0, 0x000000d0, PROBES_LDRSTRD,
276                                                  REGS(NOPCWB, NOPCX, 0, 0, NOPC)),
277
278         /* LDRD (immediate)     cccc 000x x1x0 xxxx xxxx xxxx 1101 xxxx */
279         /* STRD (immediate)     cccc 000x x1x0 xxxx xxxx xxxx 1111 xxxx */
280         DECODE_EMULATEX (0x0e5000d0, 0x004000d0, PROBES_LDRSTRD,
281                                                  REGS(NOPCWB, NOPCX, 0, 0, 0)),
282
283         /* STRH (register)      cccc 000x x0x0 xxxx xxxx xxxx 1011 xxxx */
284         DECODE_EMULATEX (0x0e5000f0, 0x000000b0, PROBES_STORE_EXTRA,
285                                                  REGS(NOPCWB, NOPC, 0, 0, NOPC)),
286
287         /* LDRH (register)      cccc 000x x0x1 xxxx xxxx xxxx 1011 xxxx */
288         /* LDRSB (register)     cccc 000x x0x1 xxxx xxxx xxxx 1101 xxxx */
289         /* LDRSH (register)     cccc 000x x0x1 xxxx xxxx xxxx 1111 xxxx */
290         DECODE_EMULATEX (0x0e500090, 0x00100090, PROBES_LOAD_EXTRA,
291                                                  REGS(NOPCWB, NOPC, 0, 0, NOPC)),
292
293         /* STRH (immediate)     cccc 000x x1x0 xxxx xxxx xxxx 1011 xxxx */
294         DECODE_EMULATEX (0x0e5000f0, 0x004000b0, PROBES_STORE_EXTRA,
295                                                  REGS(NOPCWB, NOPC, 0, 0, 0)),
296
297         /* LDRH (immediate)     cccc 000x x1x1 xxxx xxxx xxxx 1011 xxxx */
298         /* LDRSB (immediate)    cccc 000x x1x1 xxxx xxxx xxxx 1101 xxxx */
299         /* LDRSH (immediate)    cccc 000x x1x1 xxxx xxxx xxxx 1111 xxxx */
300         DECODE_EMULATEX (0x0e500090, 0x00500090, PROBES_LOAD_EXTRA,
301                                                  REGS(NOPCWB, NOPC, 0, 0, 0)),
302
303         DECODE_END
304 };
305
306 static const union decode_item arm_cccc_000x_table[] = {
307         /* Data-processing (register)                                   */
308
309         /* <op>S PC, ...        cccc 000x xxx1 xxxx 1111 xxxx xxxx xxxx */
310         DECODE_REJECT   (0x0e10f000, 0x0010f000),
311
312         /* MOV IP, SP           1110 0001 1010 0000 1100 0000 0000 1101 */
313         DECODE_SIMULATE (0xffffffff, 0xe1a0c00d, PROBES_MOV_IP_SP),
314
315         /* TST (register)       cccc 0001 0001 xxxx xxxx xxxx xxx0 xxxx */
316         /* TEQ (register)       cccc 0001 0011 xxxx xxxx xxxx xxx0 xxxx */
317         /* CMP (register)       cccc 0001 0101 xxxx xxxx xxxx xxx0 xxxx */
318         /* CMN (register)       cccc 0001 0111 xxxx xxxx xxxx xxx0 xxxx */
319         DECODE_EMULATEX (0x0f900010, 0x01100000, PROBES_DATA_PROCESSING_REG,
320                                                  REGS(ANY, 0, 0, 0, ANY)),
321
322         /* MOV (register)       cccc 0001 101x xxxx xxxx xxxx xxx0 xxxx */
323         /* MVN (register)       cccc 0001 111x xxxx xxxx xxxx xxx0 xxxx */
324         DECODE_EMULATEX (0x0fa00010, 0x01a00000, PROBES_DATA_PROCESSING_REG,
325                                                  REGS(0, ANY, 0, 0, ANY)),
326
327         /* AND (register)       cccc 0000 000x xxxx xxxx xxxx xxx0 xxxx */
328         /* EOR (register)       cccc 0000 001x xxxx xxxx xxxx xxx0 xxxx */
329         /* SUB (register)       cccc 0000 010x xxxx xxxx xxxx xxx0 xxxx */
330         /* RSB (register)       cccc 0000 011x xxxx xxxx xxxx xxx0 xxxx */
331         /* ADD (register)       cccc 0000 100x xxxx xxxx xxxx xxx0 xxxx */
332         /* ADC (register)       cccc 0000 101x xxxx xxxx xxxx xxx0 xxxx */
333         /* SBC (register)       cccc 0000 110x xxxx xxxx xxxx xxx0 xxxx */
334         /* RSC (register)       cccc 0000 111x xxxx xxxx xxxx xxx0 xxxx */
335         /* ORR (register)       cccc 0001 100x xxxx xxxx xxxx xxx0 xxxx */
336         /* BIC (register)       cccc 0001 110x xxxx xxxx xxxx xxx0 xxxx */
337         DECODE_EMULATEX (0x0e000010, 0x00000000, PROBES_DATA_PROCESSING_REG,
338                                                  REGS(ANY, ANY, 0, 0, ANY)),
339
340         /* TST (reg-shift reg)  cccc 0001 0001 xxxx xxxx xxxx 0xx1 xxxx */
341         /* TEQ (reg-shift reg)  cccc 0001 0011 xxxx xxxx xxxx 0xx1 xxxx */
342         /* CMP (reg-shift reg)  cccc 0001 0101 xxxx xxxx xxxx 0xx1 xxxx */
343         /* CMN (reg-shift reg)  cccc 0001 0111 xxxx xxxx xxxx 0xx1 xxxx */
344         DECODE_EMULATEX (0x0f900090, 0x01100010, PROBES_DATA_PROCESSING_REG,
345                                                  REGS(NOPC, 0, NOPC, 0, NOPC)),
346
347         /* MOV (reg-shift reg)  cccc 0001 101x xxxx xxxx xxxx 0xx1 xxxx */
348         /* MVN (reg-shift reg)  cccc 0001 111x xxxx xxxx xxxx 0xx1 xxxx */
349         DECODE_EMULATEX (0x0fa00090, 0x01a00010, PROBES_DATA_PROCESSING_REG,
350                                                  REGS(0, NOPC, NOPC, 0, NOPC)),
351
352         /* AND (reg-shift reg)  cccc 0000 000x xxxx xxxx xxxx 0xx1 xxxx */
353         /* EOR (reg-shift reg)  cccc 0000 001x xxxx xxxx xxxx 0xx1 xxxx */
354         /* SUB (reg-shift reg)  cccc 0000 010x xxxx xxxx xxxx 0xx1 xxxx */
355         /* RSB (reg-shift reg)  cccc 0000 011x xxxx xxxx xxxx 0xx1 xxxx */
356         /* ADD (reg-shift reg)  cccc 0000 100x xxxx xxxx xxxx 0xx1 xxxx */
357         /* ADC (reg-shift reg)  cccc 0000 101x xxxx xxxx xxxx 0xx1 xxxx */
358         /* SBC (reg-shift reg)  cccc 0000 110x xxxx xxxx xxxx 0xx1 xxxx */
359         /* RSC (reg-shift reg)  cccc 0000 111x xxxx xxxx xxxx 0xx1 xxxx */
360         /* ORR (reg-shift reg)  cccc 0001 100x xxxx xxxx xxxx 0xx1 xxxx */
361         /* BIC (reg-shift reg)  cccc 0001 110x xxxx xxxx xxxx 0xx1 xxxx */
362         DECODE_EMULATEX (0x0e000090, 0x00000010, PROBES_DATA_PROCESSING_REG,
363                                                  REGS(NOPC, NOPC, NOPC, 0, NOPC)),
364
365         DECODE_END
366 };
367
368 static const union decode_item arm_cccc_001x_table[] = {
369         /* Data-processing (immediate)                                  */
370
371         /* MOVW                 cccc 0011 0000 xxxx xxxx xxxx xxxx xxxx */
372         /* MOVT                 cccc 0011 0100 xxxx xxxx xxxx xxxx xxxx */
373         DECODE_EMULATEX (0x0fb00000, 0x03000000, PROBES_MOV_HALFWORD,
374                                                  REGS(0, NOPC, 0, 0, 0)),
375
376         /* YIELD                cccc 0011 0010 0000 xxxx xxxx 0000 0001 */
377         DECODE_OR       (0x0fff00ff, 0x03200001),
378         /* SEV                  cccc 0011 0010 0000 xxxx xxxx 0000 0100 */
379         DECODE_EMULATE  (0x0fff00ff, 0x03200004, PROBES_SEV),
380         /* NOP                  cccc 0011 0010 0000 xxxx xxxx 0000 0000 */
381         /* WFE                  cccc 0011 0010 0000 xxxx xxxx 0000 0010 */
382         /* WFI                  cccc 0011 0010 0000 xxxx xxxx 0000 0011 */
383         DECODE_SIMULATE (0x0fff00fc, 0x03200000, PROBES_WFE),
384         /* DBG                  cccc 0011 0010 0000 xxxx xxxx ffff xxxx */
385         /* unallocated hints    cccc 0011 0010 0000 xxxx xxxx xxxx xxxx */
386         /* MSR (immediate)      cccc 0011 0x10 xxxx xxxx xxxx xxxx xxxx */
387         DECODE_REJECT   (0x0fb00000, 0x03200000),
388
389         /* <op>S PC, ...        cccc 001x xxx1 xxxx 1111 xxxx xxxx xxxx */
390         DECODE_REJECT   (0x0e10f000, 0x0210f000),
391
392         /* TST (immediate)      cccc 0011 0001 xxxx xxxx xxxx xxxx xxxx */
393         /* TEQ (immediate)      cccc 0011 0011 xxxx xxxx xxxx xxxx xxxx */
394         /* CMP (immediate)      cccc 0011 0101 xxxx xxxx xxxx xxxx xxxx */
395         /* CMN (immediate)      cccc 0011 0111 xxxx xxxx xxxx xxxx xxxx */
396         DECODE_EMULATEX (0x0f900000, 0x03100000, PROBES_DATA_PROCESSING_IMM,
397                                                  REGS(ANY, 0, 0, 0, 0)),
398
399         /* MOV (immediate)      cccc 0011 101x xxxx xxxx xxxx xxxx xxxx */
400         /* MVN (immediate)      cccc 0011 111x xxxx xxxx xxxx xxxx xxxx */
401         DECODE_EMULATEX (0x0fa00000, 0x03a00000, PROBES_DATA_PROCESSING_IMM,
402                                                  REGS(0, ANY, 0, 0, 0)),
403
404         /* AND (immediate)      cccc 0010 000x xxxx xxxx xxxx xxxx xxxx */
405         /* EOR (immediate)      cccc 0010 001x xxxx xxxx xxxx xxxx xxxx */
406         /* SUB (immediate)      cccc 0010 010x xxxx xxxx xxxx xxxx xxxx */
407         /* RSB (immediate)      cccc 0010 011x xxxx xxxx xxxx xxxx xxxx */
408         /* ADD (immediate)      cccc 0010 100x xxxx xxxx xxxx xxxx xxxx */
409         /* ADC (immediate)      cccc 0010 101x xxxx xxxx xxxx xxxx xxxx */
410         /* SBC (immediate)      cccc 0010 110x xxxx xxxx xxxx xxxx xxxx */
411         /* RSC (immediate)      cccc 0010 111x xxxx xxxx xxxx xxxx xxxx */
412         /* ORR (immediate)      cccc 0011 100x xxxx xxxx xxxx xxxx xxxx */
413         /* BIC (immediate)      cccc 0011 110x xxxx xxxx xxxx xxxx xxxx */
414         DECODE_EMULATEX (0x0e000000, 0x02000000, PROBES_DATA_PROCESSING_IMM,
415                                                  REGS(ANY, ANY, 0, 0, 0)),
416
417         DECODE_END
418 };
419
420 static const union decode_item arm_cccc_0110_____xxx1_table[] = {
421         /* Media instructions                                           */
422
423         /* SEL                  cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx */
424         DECODE_EMULATEX (0x0ff000f0, 0x068000b0, PROBES_SATURATE,
425                                                  REGS(NOPC, NOPC, 0, 0, NOPC)),
426
427         /* SSAT                 cccc 0110 101x xxxx xxxx xxxx xx01 xxxx */
428         /* USAT                 cccc 0110 111x xxxx xxxx xxxx xx01 xxxx */
429         DECODE_OR(0x0fa00030, 0x06a00010),
430         /* SSAT16               cccc 0110 1010 xxxx xxxx xxxx 0011 xxxx */
431         /* USAT16               cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx */
432         DECODE_EMULATEX (0x0fb000f0, 0x06a00030, PROBES_SATURATE,
433                                                  REGS(0, NOPC, 0, 0, NOPC)),
434
435         /* REV                  cccc 0110 1011 xxxx xxxx xxxx 0011 xxxx */
436         /* REV16                cccc 0110 1011 xxxx xxxx xxxx 1011 xxxx */
437         /* RBIT                 cccc 0110 1111 xxxx xxxx xxxx 0011 xxxx */
438         /* REVSH                cccc 0110 1111 xxxx xxxx xxxx 1011 xxxx */
439         DECODE_EMULATEX (0x0fb00070, 0x06b00030, PROBES_REV,
440                                                  REGS(0, NOPC, 0, 0, NOPC)),
441
442         /* ???                  cccc 0110 0x00 xxxx xxxx xxxx xxx1 xxxx */
443         DECODE_REJECT   (0x0fb00010, 0x06000010),
444         /* ???                  cccc 0110 0xxx xxxx xxxx xxxx 1011 xxxx */
445         DECODE_REJECT   (0x0f8000f0, 0x060000b0),
446         /* ???                  cccc 0110 0xxx xxxx xxxx xxxx 1101 xxxx */
447         DECODE_REJECT   (0x0f8000f0, 0x060000d0),
448         /* SADD16               cccc 0110 0001 xxxx xxxx xxxx 0001 xxxx */
449         /* SADDSUBX             cccc 0110 0001 xxxx xxxx xxxx 0011 xxxx */
450         /* SSUBADDX             cccc 0110 0001 xxxx xxxx xxxx 0101 xxxx */
451         /* SSUB16               cccc 0110 0001 xxxx xxxx xxxx 0111 xxxx */
452         /* SADD8                cccc 0110 0001 xxxx xxxx xxxx 1001 xxxx */
453         /* SSUB8                cccc 0110 0001 xxxx xxxx xxxx 1111 xxxx */
454         /* QADD16               cccc 0110 0010 xxxx xxxx xxxx 0001 xxxx */
455         /* QADDSUBX             cccc 0110 0010 xxxx xxxx xxxx 0011 xxxx */
456         /* QSUBADDX             cccc 0110 0010 xxxx xxxx xxxx 0101 xxxx */
457         /* QSUB16               cccc 0110 0010 xxxx xxxx xxxx 0111 xxxx */
458         /* QADD8                cccc 0110 0010 xxxx xxxx xxxx 1001 xxxx */
459         /* QSUB8                cccc 0110 0010 xxxx xxxx xxxx 1111 xxxx */
460         /* SHADD16              cccc 0110 0011 xxxx xxxx xxxx 0001 xxxx */
461         /* SHADDSUBX            cccc 0110 0011 xxxx xxxx xxxx 0011 xxxx */
462         /* SHSUBADDX            cccc 0110 0011 xxxx xxxx xxxx 0101 xxxx */
463         /* SHSUB16              cccc 0110 0011 xxxx xxxx xxxx 0111 xxxx */
464         /* SHADD8               cccc 0110 0011 xxxx xxxx xxxx 1001 xxxx */
465         /* SHSUB8               cccc 0110 0011 xxxx xxxx xxxx 1111 xxxx */
466         /* UADD16               cccc 0110 0101 xxxx xxxx xxxx 0001 xxxx */
467         /* UADDSUBX             cccc 0110 0101 xxxx xxxx xxxx 0011 xxxx */
468         /* USUBADDX             cccc 0110 0101 xxxx xxxx xxxx 0101 xxxx */
469         /* USUB16               cccc 0110 0101 xxxx xxxx xxxx 0111 xxxx */
470         /* UADD8                cccc 0110 0101 xxxx xxxx xxxx 1001 xxxx */
471         /* USUB8                cccc 0110 0101 xxxx xxxx xxxx 1111 xxxx */
472         /* UQADD16              cccc 0110 0110 xxxx xxxx xxxx 0001 xxxx */
473         /* UQADDSUBX            cccc 0110 0110 xxxx xxxx xxxx 0011 xxxx */
474         /* UQSUBADDX            cccc 0110 0110 xxxx xxxx xxxx 0101 xxxx */
475         /* UQSUB16              cccc 0110 0110 xxxx xxxx xxxx 0111 xxxx */
476         /* UQADD8               cccc 0110 0110 xxxx xxxx xxxx 1001 xxxx */
477         /* UQSUB8               cccc 0110 0110 xxxx xxxx xxxx 1111 xxxx */
478         /* UHADD16              cccc 0110 0111 xxxx xxxx xxxx 0001 xxxx */
479         /* UHADDSUBX            cccc 0110 0111 xxxx xxxx xxxx 0011 xxxx */
480         /* UHSUBADDX            cccc 0110 0111 xxxx xxxx xxxx 0101 xxxx */
481         /* UHSUB16              cccc 0110 0111 xxxx xxxx xxxx 0111 xxxx */
482         /* UHADD8               cccc 0110 0111 xxxx xxxx xxxx 1001 xxxx */
483         /* UHSUB8               cccc 0110 0111 xxxx xxxx xxxx 1111 xxxx */
484         DECODE_EMULATEX (0x0f800010, 0x06000010, PROBES_MMI,
485                                                  REGS(NOPC, NOPC, 0, 0, NOPC)),
486
487         /* PKHBT                cccc 0110 1000 xxxx xxxx xxxx x001 xxxx */
488         /* PKHTB                cccc 0110 1000 xxxx xxxx xxxx x101 xxxx */
489         DECODE_EMULATEX (0x0ff00030, 0x06800010, PROBES_PACK,
490                                                  REGS(NOPC, NOPC, 0, 0, NOPC)),
491
492         /* ???                  cccc 0110 1001 xxxx xxxx xxxx 0111 xxxx */
493         /* ???                  cccc 0110 1101 xxxx xxxx xxxx 0111 xxxx */
494         DECODE_REJECT   (0x0fb000f0, 0x06900070),
495
496         /* SXTB16               cccc 0110 1000 1111 xxxx xxxx 0111 xxxx */
497         /* SXTB                 cccc 0110 1010 1111 xxxx xxxx 0111 xxxx */
498         /* SXTH                 cccc 0110 1011 1111 xxxx xxxx 0111 xxxx */
499         /* UXTB16               cccc 0110 1100 1111 xxxx xxxx 0111 xxxx */
500         /* UXTB                 cccc 0110 1110 1111 xxxx xxxx 0111 xxxx */
501         /* UXTH                 cccc 0110 1111 1111 xxxx xxxx 0111 xxxx */
502         DECODE_EMULATEX (0x0f8f00f0, 0x068f0070, PROBES_EXTEND,
503                                                  REGS(0, NOPC, 0, 0, NOPC)),
504
505         /* SXTAB16              cccc 0110 1000 xxxx xxxx xxxx 0111 xxxx */
506         /* SXTAB                cccc 0110 1010 xxxx xxxx xxxx 0111 xxxx */
507         /* SXTAH                cccc 0110 1011 xxxx xxxx xxxx 0111 xxxx */
508         /* UXTAB16              cccc 0110 1100 xxxx xxxx xxxx 0111 xxxx */
509         /* UXTAB                cccc 0110 1110 xxxx xxxx xxxx 0111 xxxx */
510         /* UXTAH                cccc 0110 1111 xxxx xxxx xxxx 0111 xxxx */
511         DECODE_EMULATEX (0x0f8000f0, 0x06800070, PROBES_EXTEND_ADD,
512                                                  REGS(NOPCX, NOPC, 0, 0, NOPC)),
513
514         DECODE_END
515 };
516
517 static const union decode_item arm_cccc_0111_____xxx1_table[] = {
518         /* Media instructions                                           */
519
520         /* UNDEFINED            cccc 0111 1111 xxxx xxxx xxxx 1111 xxxx */
521         DECODE_REJECT   (0x0ff000f0, 0x07f000f0),
522
523         /* SMLALD               cccc 0111 0100 xxxx xxxx xxxx 00x1 xxxx */
524         /* SMLSLD               cccc 0111 0100 xxxx xxxx xxxx 01x1 xxxx */
525         DECODE_EMULATEX (0x0ff00090, 0x07400010, PROBES_MUL_ADD_LONG,
526                                                  REGS(NOPC, NOPC, NOPC, 0, NOPC)),
527
528         /* SMUAD                cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx */
529         /* SMUSD                cccc 0111 0000 xxxx 1111 xxxx 01x1 xxxx */
530         DECODE_OR       (0x0ff0f090, 0x0700f010),
531         /* SMMUL                cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx */
532         DECODE_OR       (0x0ff0f0d0, 0x0750f010),
533         /* USAD8                cccc 0111 1000 xxxx 1111 xxxx 0001 xxxx */
534         DECODE_EMULATEX (0x0ff0f0f0, 0x0780f010, PROBES_MUL_ADD,
535                                                  REGS(NOPC, 0, NOPC, 0, NOPC)),
536
537         /* SMLAD                cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx */
538         /* SMLSD                cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx */
539         DECODE_OR       (0x0ff00090, 0x07000010),
540         /* SMMLA                cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx */
541         DECODE_OR       (0x0ff000d0, 0x07500010),
542         /* USADA8               cccc 0111 1000 xxxx xxxx xxxx 0001 xxxx */
543         DECODE_EMULATEX (0x0ff000f0, 0x07800010, PROBES_MUL_ADD,
544                                                  REGS(NOPC, NOPCX, NOPC, 0, NOPC)),
545
546         /* SMMLS                cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx */
547         DECODE_EMULATEX (0x0ff000d0, 0x075000d0, PROBES_MUL_ADD,
548                                                  REGS(NOPC, NOPC, NOPC, 0, NOPC)),
549
550         /* SBFX                 cccc 0111 101x xxxx xxxx xxxx x101 xxxx */
551         /* UBFX                 cccc 0111 111x xxxx xxxx xxxx x101 xxxx */
552         DECODE_EMULATEX (0x0fa00070, 0x07a00050, PROBES_BITFIELD,
553                                                  REGS(0, NOPC, 0, 0, NOPC)),
554
555         /* BFC                  cccc 0111 110x xxxx xxxx xxxx x001 1111 */
556         DECODE_EMULATEX (0x0fe0007f, 0x07c0001f, PROBES_BITFIELD,
557                                                  REGS(0, NOPC, 0, 0, 0)),
558
559         /* BFI                  cccc 0111 110x xxxx xxxx xxxx x001 xxxx */
560         DECODE_EMULATEX (0x0fe00070, 0x07c00010, PROBES_BITFIELD,
561                                                  REGS(0, NOPC, 0, 0, NOPCX)),
562
563         DECODE_END
564 };
565
566 static const union decode_item arm_cccc_01xx_table[] = {
567         /* Load/store word and unsigned byte                            */
568
569         /* LDRB/STRB pc,[...]   cccc 01xx x0xx xxxx xxxx xxxx xxxx xxxx */
570         DECODE_REJECT   (0x0c40f000, 0x0440f000),
571
572         /* STRT                 cccc 01x0 x010 xxxx xxxx xxxx xxxx xxxx */
573         /* LDRT                 cccc 01x0 x011 xxxx xxxx xxxx xxxx xxxx */
574         /* STRBT                cccc 01x0 x110 xxxx xxxx xxxx xxxx xxxx */
575         /* LDRBT                cccc 01x0 x111 xxxx xxxx xxxx xxxx xxxx */
576         DECODE_REJECT   (0x0d200000, 0x04200000),
577
578         /* STR (immediate)      cccc 010x x0x0 xxxx xxxx xxxx xxxx xxxx */
579         /* STRB (immediate)     cccc 010x x1x0 xxxx xxxx xxxx xxxx xxxx */
580         DECODE_EMULATEX (0x0e100000, 0x04000000, PROBES_STORE,
581                                                  REGS(NOPCWB, ANY, 0, 0, 0)),
582
583         /* LDR (immediate)      cccc 010x x0x1 xxxx xxxx xxxx xxxx xxxx */
584         /* LDRB (immediate)     cccc 010x x1x1 xxxx xxxx xxxx xxxx xxxx */
585         DECODE_EMULATEX (0x0e100000, 0x04100000, PROBES_LOAD,
586                                                  REGS(NOPCWB, ANY, 0, 0, 0)),
587
588         /* STR (register)       cccc 011x x0x0 xxxx xxxx xxxx xxxx xxxx */
589         /* STRB (register)      cccc 011x x1x0 xxxx xxxx xxxx xxxx xxxx */
590         DECODE_EMULATEX (0x0e100000, 0x06000000, PROBES_STORE,
591                                                  REGS(NOPCWB, ANY, 0, 0, NOPC)),
592
593         /* LDR (register)       cccc 011x x0x1 xxxx xxxx xxxx xxxx xxxx */
594         /* LDRB (register)      cccc 011x x1x1 xxxx xxxx xxxx xxxx xxxx */
595         DECODE_EMULATEX (0x0e100000, 0x06100000, PROBES_LOAD,
596                                                  REGS(NOPCWB, ANY, 0, 0, NOPC)),
597
598         DECODE_END
599 };
600
601 static const union decode_item arm_cccc_100x_table[] = {
602         /* Block data transfer instructions                             */
603
604         /* LDM                  cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
605         /* STM                  cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */
606         DECODE_CUSTOM   (0x0e400000, 0x08000000, PROBES_LDMSTM),
607
608         /* STM (user registers) cccc 100x x1x0 xxxx xxxx xxxx xxxx xxxx */
609         /* LDM (user registers) cccc 100x x1x1 xxxx 0xxx xxxx xxxx xxxx */
610         /* LDM (exception ret)  cccc 100x x1x1 xxxx 1xxx xxxx xxxx xxxx */
611         DECODE_END
612 };
613
614 const union decode_item probes_decode_arm_table[] = {
615         /*
616          * Unconditional instructions
617          *                      1111 xxxx xxxx xxxx xxxx xxxx xxxx xxxx
618          */
619         DECODE_TABLE    (0xf0000000, 0xf0000000, arm_1111_table),
620
621         /*
622          * Miscellaneous instructions
623          *                      cccc 0001 0xx0 xxxx xxxx xxxx 0xxx xxxx
624          */
625         DECODE_TABLE    (0x0f900080, 0x01000000, arm_cccc_0001_0xx0____0xxx_table),
626
627         /*
628          * Halfword multiply and multiply-accumulate
629          *                      cccc 0001 0xx0 xxxx xxxx xxxx 1xx0 xxxx
630          */
631         DECODE_TABLE    (0x0f900090, 0x01000080, arm_cccc_0001_0xx0____1xx0_table),
632
633         /*
634          * Multiply and multiply-accumulate
635          *                      cccc 0000 xxxx xxxx xxxx xxxx 1001 xxxx
636          */
637         DECODE_TABLE    (0x0f0000f0, 0x00000090, arm_cccc_0000_____1001_table),
638
639         /*
640          * Synchronization primitives
641          *                      cccc 0001 xxxx xxxx xxxx xxxx 1001 xxxx
642          */
643         DECODE_TABLE    (0x0f0000f0, 0x01000090, arm_cccc_0001_____1001_table),
644
645         /*
646          * Extra load/store instructions
647          *                      cccc 000x xxxx xxxx xxxx xxxx 1xx1 xxxx
648          */
649         DECODE_TABLE    (0x0e000090, 0x00000090, arm_cccc_000x_____1xx1_table),
650
651         /*
652          * Data-processing (register)
653          *                      cccc 000x xxxx xxxx xxxx xxxx xxx0 xxxx
654          * Data-processing (register-shifted register)
655          *                      cccc 000x xxxx xxxx xxxx xxxx 0xx1 xxxx
656          */
657         DECODE_TABLE    (0x0e000000, 0x00000000, arm_cccc_000x_table),
658
659         /*
660          * Data-processing (immediate)
661          *                      cccc 001x xxxx xxxx xxxx xxxx xxxx xxxx
662          */
663         DECODE_TABLE    (0x0e000000, 0x02000000, arm_cccc_001x_table),
664
665         /*
666          * Media instructions
667          *                      cccc 011x xxxx xxxx xxxx xxxx xxx1 xxxx
668          */
669         DECODE_TABLE    (0x0f000010, 0x06000010, arm_cccc_0110_____xxx1_table),
670         DECODE_TABLE    (0x0f000010, 0x07000010, arm_cccc_0111_____xxx1_table),
671
672         /*
673          * Load/store word and unsigned byte
674          *                      cccc 01xx xxxx xxxx xxxx xxxx xxxx xxxx
675          */
676         DECODE_TABLE    (0x0c000000, 0x04000000, arm_cccc_01xx_table),
677
678         /*
679          * Block data transfer instructions
680          *                      cccc 100x xxxx xxxx xxxx xxxx xxxx xxxx
681          */
682         DECODE_TABLE    (0x0e000000, 0x08000000, arm_cccc_100x_table),
683
684         /* B                    cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */
685         /* BL                   cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */
686         DECODE_SIMULATE (0x0e000000, 0x0a000000, PROBES_BRANCH),
687
688         /*
689          * Supervisor Call, and coprocessor instructions
690          */
691
692         /* MCRR                 cccc 1100 0100 xxxx xxxx xxxx xxxx xxxx */
693         /* MRRC                 cccc 1100 0101 xxxx xxxx xxxx xxxx xxxx */
694         /* LDC                  cccc 110x xxx1 xxxx xxxx xxxx xxxx xxxx */
695         /* STC                  cccc 110x xxx0 xxxx xxxx xxxx xxxx xxxx */
696         /* CDP                  cccc 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */
697         /* MCR                  cccc 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */
698         /* MRC                  cccc 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */
699         /* SVC                  cccc 1111 xxxx xxxx xxxx xxxx xxxx xxxx */
700         DECODE_REJECT   (0x0c000000, 0x0c000000),
701
702         DECODE_END
703 };
704 #ifdef CONFIG_ARM_KPROBES_TEST_MODULE
705 EXPORT_SYMBOL_GPL(probes_decode_arm_table);
706 #endif
707
708 static void __kprobes arm_singlestep(probes_opcode_t insn,
709                 struct arch_probes_insn *asi, struct pt_regs *regs)
710 {
711         regs->ARM_pc += 4;
712         asi->insn_handler(insn, asi, regs);
713 }
714
715 /* Return:
716  *   INSN_REJECTED     If instruction is one not allowed to kprobe,
717  *   INSN_GOOD         If instruction is supported and uses instruction slot,
718  *   INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
719  *
720  * For instructions we don't want to kprobe (INSN_REJECTED return result):
721  *   These are generally ones that modify the processor state making
722  *   them "hard" to simulate such as switches processor modes or
723  *   make accesses in alternate modes.  Any of these could be simulated
724  *   if the work was put into it, but low return considering they
725  *   should also be very rare.
726  */
727 enum probes_insn __kprobes
728 arm_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
729                        bool emulate, const union decode_action *actions,
730                        const struct decode_checker *checkers[])
731 {
732         asi->insn_singlestep = arm_singlestep;
733         asi->insn_check_cc = probes_condition_checks[insn>>28];
734         return probes_decode_insn(insn, asi, probes_decode_arm_table, false,
735                                   emulate, actions, checkers);
736 }