blob: 7884fcb81c26fe1875d88a4a00bde1bbc19cc516 [file] [log] [blame]
Thomas Gleixnerd2912cb2019-06-04 10:11:33 +02001// SPDX-License-Identifier: GPL-2.0-only
Jon Medhurst24371702011-04-19 17:56:58 +01002/*
Wang Nanfca08f32015-01-09 10:19:49 +08003 * arch/arm/probes/kprobes/actions-thumb.c
Jon Medhurst24371702011-04-19 17:56:58 +01004 *
5 * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
Jon Medhurst24371702011-04-19 17:56:58 +01006 */
7
David A. Long87abef62014-03-05 21:06:29 -05008#include <linux/types.h>
Jon Medhurst24371702011-04-19 17:56:58 +01009#include <linux/kernel.h>
David A. Long87abef62014-03-05 21:06:29 -050010#include <linux/ptrace.h>
Jon Medhurst24371702011-04-19 17:56:58 +010011#include <linux/kprobes.h>
12
Wang Nanfca08f32015-01-09 10:19:49 +080013#include "../decode-thumb.h"
14#include "core.h"
Wang Nan6624cf62015-01-05 19:29:21 +080015#include "checkers.h"
Jon Medhursteaf4f33f2011-04-20 19:29:52 +010016
David A. Long3e6cd392014-03-06 18:06:43 -050017/* These emulation encodings are functionally equivalent... */
18#define t32_emulate_rd8rn16rm0ra12_noflags \
19 t32_emulate_rdlo12rdhi8rn16rm0_noflags
20
David A. Long87abef62014-03-05 21:06:29 -050021/* t32 thumb actions */
22
David A. Long3e6cd392014-03-06 18:06:43 -050023static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -050024t32_simulate_table_branch(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -050025 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstdd212bd32011-07-03 14:26:16 +010026{
David A. Long7579f4b32014-03-07 11:19:32 -050027 unsigned long pc = regs->ARM_pc;
Jon Medhurstdd212bd32011-07-03 14:26:16 +010028 int rn = (insn >> 16) & 0xf;
29 int rm = insn & 0xf;
30
31 unsigned long rnv = (rn == 15) ? pc : regs->uregs[rn];
32 unsigned long rmv = regs->uregs[rm];
33 unsigned int halfwords;
34
Jon Medhurstce715c72011-07-03 14:53:45 +010035 if (insn & 0x10) /* TBH */
Jon Medhurstdd212bd32011-07-03 14:26:16 +010036 halfwords = ((u16 *)rnv)[rmv];
Jon Medhurstce715c72011-07-03 14:53:45 +010037 else /* TBB */
Jon Medhurstdd212bd32011-07-03 14:26:16 +010038 halfwords = ((u8 *)rnv)[rmv];
39
40 regs->ARM_pc = pc + 2 * halfwords;
41}
42
David A. Long3e6cd392014-03-06 18:06:43 -050043static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -050044t32_simulate_mrs(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -050045 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstb06f3ee2011-07-03 14:52:18 +010046{
Jon Medhurstb06f3ee2011-07-03 14:52:18 +010047 int rd = (insn >> 8) & 0xf;
48 unsigned long mask = 0xf8ff03df; /* Mask out execution state */
49 regs->uregs[rd] = regs->ARM_cpsr & mask;
50}
51
David A. Long3e6cd392014-03-06 18:06:43 -050052static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -050053t32_simulate_cond_branch(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -050054 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstce715c72011-07-03 14:53:45 +010055{
David A. Long7579f4b32014-03-07 11:19:32 -050056 unsigned long pc = regs->ARM_pc;
Jon Medhurstce715c72011-07-03 14:53:45 +010057
58 long offset = insn & 0x7ff; /* imm11 */
59 offset += (insn & 0x003f0000) >> 5; /* imm6 */
60 offset += (insn & 0x00002000) << 4; /* J1 */
61 offset += (insn & 0x00000800) << 7; /* J2 */
62 offset -= (insn & 0x04000000) >> 7; /* Apply sign bit */
63
64 regs->ARM_pc = pc + (offset * 2);
65}
66
David A. Long44a0a592014-03-05 21:23:42 -050067static enum probes_insn __kprobes
David A. Longb4cd6052014-03-05 21:41:29 -050068t32_decode_cond_branch(probes_opcode_t insn, struct arch_probes_insn *asi,
David A. Long3e6cd392014-03-06 18:06:43 -050069 const struct decode_header *d)
Jon Medhurstce715c72011-07-03 14:53:45 +010070{
71 int cc = (insn >> 22) & 0xf;
David A. Longf145d662014-03-05 21:17:23 -050072 asi->insn_check_cc = probes_condition_checks[cc];
Jon Medhurstce715c72011-07-03 14:53:45 +010073 asi->insn_handler = t32_simulate_cond_branch;
74 return INSN_GOOD_NO_SLOT;
75}
76
David A. Long3e6cd392014-03-06 18:06:43 -050077static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -050078t32_simulate_branch(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -050079 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstce715c72011-07-03 14:53:45 +010080{
David A. Long7579f4b32014-03-07 11:19:32 -050081 unsigned long pc = regs->ARM_pc;
Jon Medhurstce715c72011-07-03 14:53:45 +010082
83 long offset = insn & 0x7ff; /* imm11 */
84 offset += (insn & 0x03ff0000) >> 5; /* imm10 */
85 offset += (insn & 0x00002000) << 9; /* J1 */
86 offset += (insn & 0x00000800) << 10; /* J2 */
87 if (insn & 0x04000000)
88 offset -= 0x00800000; /* Apply sign bit */
89 else
90 offset ^= 0x00600000; /* Invert J1 and J2 */
91
92 if (insn & (1 << 14)) {
93 /* BL or BLX */
David A. Long7579f4b32014-03-07 11:19:32 -050094 regs->ARM_lr = regs->ARM_pc | 1;
Jon Medhurstce715c72011-07-03 14:53:45 +010095 if (!(insn & (1 << 12))) {
96 /* BLX so switch to ARM mode */
97 regs->ARM_cpsr &= ~PSR_T_BIT;
98 pc &= ~3;
99 }
100 }
101
102 regs->ARM_pc = pc + (offset * 2);
103}
104
David A. Long3e6cd392014-03-06 18:06:43 -0500105static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500106t32_simulate_ldr_literal(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500107 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstd6910232011-07-03 15:04:26 +0100108{
David A. Long7579f4b32014-03-07 11:19:32 -0500109 unsigned long addr = regs->ARM_pc & ~3;
Jon Medhurstd6910232011-07-03 15:04:26 +0100110 int rt = (insn >> 12) & 0xf;
111 unsigned long rtv;
112
113 long offset = insn & 0xfff;
114 if (insn & 0x00800000)
115 addr += offset;
116 else
117 addr -= offset;
118
119 if (insn & 0x00400000) {
120 /* LDR */
121 rtv = *(unsigned long *)addr;
122 if (rt == 15) {
123 bx_write_pc(rtv, regs);
124 return;
125 }
126 } else if (insn & 0x00200000) {
127 /* LDRH */
128 if (insn & 0x01000000)
129 rtv = *(s16 *)addr;
130 else
131 rtv = *(u16 *)addr;
132 } else {
133 /* LDRB */
134 if (insn & 0x01000000)
135 rtv = *(s8 *)addr;
136 else
137 rtv = *(u8 *)addr;
138 }
139
140 regs->uregs[rt] = rtv;
141}
142
David A. Long44a0a592014-03-05 21:23:42 -0500143static enum probes_insn __kprobes
David A. Longb4cd6052014-03-05 21:41:29 -0500144t32_decode_ldmstm(probes_opcode_t insn, struct arch_probes_insn *asi,
David A. Long3e6cd392014-03-06 18:06:43 -0500145 const struct decode_header *d)
Jon Medhursteaf1d062011-07-07 08:59:32 +0100146{
David A. Long44a0a592014-03-05 21:23:42 -0500147 enum probes_insn ret = kprobe_decode_ldmstm(insn, asi, d);
Jon Medhursteaf1d062011-07-07 08:59:32 +0100148
149 /* Fixup modified instruction to have halfwords in correct order...*/
Ben Dooks888be252013-11-08 18:29:25 +0000150 insn = __mem_to_opcode_arm(asi->insn[0]);
151 ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(insn >> 16);
152 ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0xffff);
Jon Medhursteaf1d062011-07-07 08:59:32 +0100153
154 return ret;
155}
156
David A. Long3e6cd392014-03-06 18:06:43 -0500157static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500158t32_emulate_ldrdstrd(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500159 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstb48354d2011-07-03 14:23:21 +0100160{
David A. Long7579f4b32014-03-07 11:19:32 -0500161 unsigned long pc = regs->ARM_pc & ~3;
Jon Medhurstb48354d2011-07-03 14:23:21 +0100162 int rt1 = (insn >> 12) & 0xf;
163 int rt2 = (insn >> 8) & 0xf;
164 int rn = (insn >> 16) & 0xf;
165
166 register unsigned long rt1v asm("r0") = regs->uregs[rt1];
167 register unsigned long rt2v asm("r1") = regs->uregs[rt2];
168 register unsigned long rnv asm("r2") = (rn == 15) ? pc
169 : regs->uregs[rn];
170
171 __asm__ __volatile__ (
172 "blx %[fn]"
173 : "=r" (rt1v), "=r" (rt2v), "=r" (rnv)
David A. Long7579f4b32014-03-07 11:19:32 -0500174 : "0" (rt1v), "1" (rt2v), "2" (rnv), [fn] "r" (asi->insn_fn)
Jon Medhurstb48354d2011-07-03 14:23:21 +0100175 : "lr", "memory", "cc"
176 );
177
178 if (rn != 15)
179 regs->uregs[rn] = rnv; /* Writeback base register */
180 regs->uregs[rt1] = rt1v;
181 regs->uregs[rt2] = rt2v;
182}
183
David A. Long3e6cd392014-03-06 18:06:43 -0500184static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500185t32_emulate_ldrstr(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500186 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstd6910232011-07-03 15:04:26 +0100187{
Jon Medhurstd6910232011-07-03 15:04:26 +0100188 int rt = (insn >> 12) & 0xf;
189 int rn = (insn >> 16) & 0xf;
190 int rm = insn & 0xf;
191
192 register unsigned long rtv asm("r0") = regs->uregs[rt];
193 register unsigned long rnv asm("r2") = regs->uregs[rn];
194 register unsigned long rmv asm("r3") = regs->uregs[rm];
195
196 __asm__ __volatile__ (
197 "blx %[fn]"
198 : "=r" (rtv), "=r" (rnv)
David A. Long7579f4b32014-03-07 11:19:32 -0500199 : "0" (rtv), "1" (rnv), "r" (rmv), [fn] "r" (asi->insn_fn)
Jon Medhurstd6910232011-07-03 15:04:26 +0100200 : "lr", "memory", "cc"
201 );
202
203 regs->uregs[rn] = rnv; /* Writeback base register */
204 if (rt == 15) /* Can't be true for a STR as they aren't allowed */
205 bx_write_pc(rtv, regs);
206 else
207 regs->uregs[rt] = rtv;
208}
209
David A. Long3e6cd392014-03-06 18:06:43 -0500210static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500211t32_emulate_rd8rn16rm0_rwflags(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500212 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst080e0012011-07-03 14:31:58 +0100213{
Jon Medhurst080e0012011-07-03 14:31:58 +0100214 int rd = (insn >> 8) & 0xf;
215 int rn = (insn >> 16) & 0xf;
216 int rm = insn & 0xf;
217
218 register unsigned long rdv asm("r1") = regs->uregs[rd];
219 register unsigned long rnv asm("r2") = regs->uregs[rn];
220 register unsigned long rmv asm("r3") = regs->uregs[rm];
221 unsigned long cpsr = regs->ARM_cpsr;
222
223 __asm__ __volatile__ (
224 "msr cpsr_fs, %[cpsr] \n\t"
225 "blx %[fn] \n\t"
226 "mrs %[cpsr], cpsr \n\t"
227 : "=r" (rdv), [cpsr] "=r" (cpsr)
228 : "0" (rdv), "r" (rnv), "r" (rmv),
David A. Long7579f4b32014-03-07 11:19:32 -0500229 "1" (cpsr), [fn] "r" (asi->insn_fn)
Jon Medhurst080e0012011-07-03 14:31:58 +0100230 : "lr", "memory", "cc"
231 );
232
233 regs->uregs[rd] = rdv;
234 regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
235}
236
David A. Long3e6cd392014-03-06 18:06:43 -0500237static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500238t32_emulate_rd8pc16_noflags(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500239 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst78487862011-07-03 14:40:26 +0100240{
David A. Long7579f4b32014-03-07 11:19:32 -0500241 unsigned long pc = regs->ARM_pc;
Jon Medhurst78487862011-07-03 14:40:26 +0100242 int rd = (insn >> 8) & 0xf;
243
244 register unsigned long rdv asm("r1") = regs->uregs[rd];
245 register unsigned long rnv asm("r2") = pc & ~3;
246
247 __asm__ __volatile__ (
248 "blx %[fn]"
249 : "=r" (rdv)
David A. Long7579f4b32014-03-07 11:19:32 -0500250 : "0" (rdv), "r" (rnv), [fn] "r" (asi->insn_fn)
Jon Medhurst78487862011-07-03 14:40:26 +0100251 : "lr", "memory", "cc"
252 );
253
254 regs->uregs[rd] = rdv;
255}
256
David A. Long3e6cd392014-03-06 18:06:43 -0500257static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500258t32_emulate_rd8rn16_noflags(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500259 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst78487862011-07-03 14:40:26 +0100260{
Jon Medhurst78487862011-07-03 14:40:26 +0100261 int rd = (insn >> 8) & 0xf;
262 int rn = (insn >> 16) & 0xf;
263
264 register unsigned long rdv asm("r1") = regs->uregs[rd];
265 register unsigned long rnv asm("r2") = regs->uregs[rn];
266
267 __asm__ __volatile__ (
268 "blx %[fn]"
269 : "=r" (rdv)
David A. Long7579f4b32014-03-07 11:19:32 -0500270 : "0" (rdv), "r" (rnv), [fn] "r" (asi->insn_fn)
Jon Medhurst78487862011-07-03 14:40:26 +0100271 : "lr", "memory", "cc"
272 );
273
274 regs->uregs[rd] = rdv;
275}
276
David A. Long3e6cd392014-03-06 18:06:43 -0500277static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500278t32_emulate_rdlo12rdhi8rn16rm0_noflags(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500279 struct arch_probes_insn *asi,
David A. Long7579f4b32014-03-07 11:19:32 -0500280 struct pt_regs *regs)
Jon Medhurst231fb152011-07-03 15:15:11 +0100281{
Jon Medhurst231fb152011-07-03 15:15:11 +0100282 int rdlo = (insn >> 12) & 0xf;
283 int rdhi = (insn >> 8) & 0xf;
284 int rn = (insn >> 16) & 0xf;
285 int rm = insn & 0xf;
286
287 register unsigned long rdlov asm("r0") = regs->uregs[rdlo];
288 register unsigned long rdhiv asm("r1") = regs->uregs[rdhi];
289 register unsigned long rnv asm("r2") = regs->uregs[rn];
290 register unsigned long rmv asm("r3") = regs->uregs[rm];
291
292 __asm__ __volatile__ (
293 "blx %[fn]"
294 : "=r" (rdlov), "=r" (rdhiv)
295 : "0" (rdlov), "1" (rdhiv), "r" (rnv), "r" (rmv),
David A. Long7579f4b32014-03-07 11:19:32 -0500296 [fn] "r" (asi->insn_fn)
Jon Medhurst231fb152011-07-03 15:15:11 +0100297 : "lr", "memory", "cc"
298 );
299
300 regs->uregs[rdlo] = rdlov;
301 regs->uregs[rdhi] = rdhiv;
302}
David A. Long87abef62014-03-05 21:06:29 -0500303/* t16 thumb actions */
Jon Medhurst231fb152011-07-03 15:15:11 +0100304
David A. Long3e6cd392014-03-06 18:06:43 -0500305static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500306t16_simulate_bxblx(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500307 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhursta9c3c292011-07-02 15:51:03 +0100308{
David A. Long7579f4b32014-03-07 11:19:32 -0500309 unsigned long pc = regs->ARM_pc + 2;
Jon Medhursta9c3c292011-07-02 15:51:03 +0100310 int rm = (insn >> 3) & 0xf;
311 unsigned long rmv = (rm == 15) ? pc : regs->uregs[rm];
312
313 if (insn & (1 << 7)) /* BLX ? */
David A. Long7579f4b32014-03-07 11:19:32 -0500314 regs->ARM_lr = regs->ARM_pc | 1;
Jon Medhursta9c3c292011-07-02 15:51:03 +0100315
316 bx_write_pc(rmv, regs);
317}
318
David A. Long3e6cd392014-03-06 18:06:43 -0500319static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500320t16_simulate_ldr_literal(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500321 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstf8695142011-07-02 16:00:09 +0100322{
David A. Long7579f4b32014-03-07 11:19:32 -0500323 unsigned long *base = (unsigned long *)((regs->ARM_pc + 2) & ~3);
Jon Medhurstf8695142011-07-02 16:00:09 +0100324 long index = insn & 0xff;
325 int rt = (insn >> 8) & 0x7;
326 regs->uregs[rt] = base[index];
327}
328
David A. Long3e6cd392014-03-06 18:06:43 -0500329static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500330t16_simulate_ldrstr_sp_relative(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500331 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstf8695142011-07-02 16:00:09 +0100332{
Jon Medhurstf8695142011-07-02 16:00:09 +0100333 unsigned long* base = (unsigned long *)regs->ARM_sp;
334 long index = insn & 0xff;
335 int rt = (insn >> 8) & 0x7;
336 if (insn & 0x800) /* LDR */
337 regs->uregs[rt] = base[index];
338 else /* STR */
339 base[index] = regs->uregs[rt];
340}
341
David A. Long3e6cd392014-03-06 18:06:43 -0500342static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500343t16_simulate_reladr(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500344 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst2f335822011-07-02 16:05:53 +0100345{
Jon Medhurst2f335822011-07-02 16:05:53 +0100346 unsigned long base = (insn & 0x800) ? regs->ARM_sp
David A. Long7579f4b32014-03-07 11:19:32 -0500347 : ((regs->ARM_pc + 2) & ~3);
Jon Medhurst2f335822011-07-02 16:05:53 +0100348 long offset = insn & 0xff;
349 int rt = (insn >> 8) & 0x7;
350 regs->uregs[rt] = base + offset * 4;
351}
352
David A. Long3e6cd392014-03-06 18:06:43 -0500353static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500354t16_simulate_add_sp_imm(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500355 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst2f335822011-07-02 16:05:53 +0100356{
Jon Medhurst2f335822011-07-02 16:05:53 +0100357 long imm = insn & 0x7f;
358 if (insn & 0x80) /* SUB */
359 regs->ARM_sp -= imm * 4;
360 else /* ADD */
361 regs->ARM_sp += imm * 4;
362}
363
David A. Long3e6cd392014-03-06 18:06:43 -0500364static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500365t16_simulate_cbz(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500366 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst32818f32011-07-02 16:10:44 +0100367{
Jon Medhurst32818f32011-07-02 16:10:44 +0100368 int rn = insn & 0x7;
David A. Longf145d662014-03-05 21:17:23 -0500369 probes_opcode_t nonzero = regs->uregs[rn] ? insn : ~insn;
Jon Medhurst32818f32011-07-02 16:10:44 +0100370 if (nonzero & 0x800) {
371 long i = insn & 0x200;
372 long imm5 = insn & 0xf8;
David A. Long7579f4b32014-03-07 11:19:32 -0500373 unsigned long pc = regs->ARM_pc + 2;
Jon Medhurst32818f32011-07-02 16:10:44 +0100374 regs->ARM_pc = pc + (i >> 3) + (imm5 >> 2);
375 }
376}
377
David A. Long3e6cd392014-03-06 18:06:43 -0500378static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500379t16_simulate_it(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500380 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst5b94faf2011-07-02 16:16:05 +0100381{
382 /*
383 * The 8 IT state bits are split into two parts in CPSR:
384 * ITSTATE<1:0> are in CPSR<26:25>
385 * ITSTATE<7:2> are in CPSR<15:10>
386 * The new IT state is in the lower byte of insn.
387 */
Jon Medhurst5b94faf2011-07-02 16:16:05 +0100388 unsigned long cpsr = regs->ARM_cpsr;
389 cpsr &= ~PSR_IT_MASK;
390 cpsr |= (insn & 0xfc) << 8;
391 cpsr |= (insn & 0x03) << 25;
392 regs->ARM_cpsr = cpsr;
393}
394
David A. Long3e6cd392014-03-06 18:06:43 -0500395static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500396t16_singlestep_it(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500397 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst5b94faf2011-07-02 16:16:05 +0100398{
399 regs->ARM_pc += 2;
David A. Long7579f4b32014-03-07 11:19:32 -0500400 t16_simulate_it(insn, asi, regs);
Jon Medhurst5b94faf2011-07-02 16:16:05 +0100401}
402
David A. Long44a0a592014-03-05 21:23:42 -0500403static enum probes_insn __kprobes
David A. Longb4cd6052014-03-05 21:41:29 -0500404t16_decode_it(probes_opcode_t insn, struct arch_probes_insn *asi,
David A. Long3e6cd392014-03-06 18:06:43 -0500405 const struct decode_header *d)
Jon Medhurst5b94faf2011-07-02 16:16:05 +0100406{
407 asi->insn_singlestep = t16_singlestep_it;
408 return INSN_GOOD_NO_SLOT;
409}
410
David A. Long3e6cd392014-03-06 18:06:43 -0500411static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500412t16_simulate_cond_branch(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500413 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst396b41f2011-07-02 16:30:43 +0100414{
David A. Long7579f4b32014-03-07 11:19:32 -0500415 unsigned long pc = regs->ARM_pc + 2;
Jon Medhurst396b41f2011-07-02 16:30:43 +0100416 long offset = insn & 0x7f;
417 offset -= insn & 0x80; /* Apply sign bit */
418 regs->ARM_pc = pc + (offset * 2);
419}
420
David A. Long44a0a592014-03-05 21:23:42 -0500421static enum probes_insn __kprobes
David A. Longb4cd6052014-03-05 21:41:29 -0500422t16_decode_cond_branch(probes_opcode_t insn, struct arch_probes_insn *asi,
David A. Long3e6cd392014-03-06 18:06:43 -0500423 const struct decode_header *d)
Jon Medhurst396b41f2011-07-02 16:30:43 +0100424{
425 int cc = (insn >> 8) & 0xf;
David A. Longf145d662014-03-05 21:17:23 -0500426 asi->insn_check_cc = probes_condition_checks[cc];
Jon Medhurst396b41f2011-07-02 16:30:43 +0100427 asi->insn_handler = t16_simulate_cond_branch;
428 return INSN_GOOD_NO_SLOT;
429}
430
David A. Long3e6cd392014-03-06 18:06:43 -0500431static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500432t16_simulate_branch(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500433 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst396b41f2011-07-02 16:30:43 +0100434{
David A. Long7579f4b32014-03-07 11:19:32 -0500435 unsigned long pc = regs->ARM_pc + 2;
Jon Medhurst396b41f2011-07-02 16:30:43 +0100436 long offset = insn & 0x3ff;
437 offset -= insn & 0x400; /* Apply sign bit */
438 regs->ARM_pc = pc + (offset * 2);
439}
440
Jon Medhurst02d194f2011-07-02 15:46:05 +0100441static unsigned long __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500442t16_emulate_loregs(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500443 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst02d194f2011-07-02 15:46:05 +0100444{
445 unsigned long oldcpsr = regs->ARM_cpsr;
446 unsigned long newcpsr;
447
448 __asm__ __volatile__ (
449 "msr cpsr_fs, %[oldcpsr] \n\t"
450 "ldmia %[regs], {r0-r7} \n\t"
451 "blx %[fn] \n\t"
452 "stmia %[regs], {r0-r7} \n\t"
453 "mrs %[newcpsr], cpsr \n\t"
454 : [newcpsr] "=r" (newcpsr)
455 : [oldcpsr] "r" (oldcpsr), [regs] "r" (regs),
David A. Long7579f4b32014-03-07 11:19:32 -0500456 [fn] "r" (asi->insn_fn)
Jon Medhurst02d194f2011-07-02 15:46:05 +0100457 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
458 "lr", "memory", "cc"
459 );
460
461 return (oldcpsr & ~APSR_MASK) | (newcpsr & APSR_MASK);
462}
463
David A. Long3e6cd392014-03-06 18:06:43 -0500464static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500465t16_emulate_loregs_rwflags(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500466 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst02d194f2011-07-02 15:46:05 +0100467{
David A. Long7579f4b32014-03-07 11:19:32 -0500468 regs->ARM_cpsr = t16_emulate_loregs(insn, asi, regs);
Jon Medhurst02d194f2011-07-02 15:46:05 +0100469}
470
David A. Long3e6cd392014-03-06 18:06:43 -0500471static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500472t16_emulate_loregs_noitrwflags(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500473 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst02d194f2011-07-02 15:46:05 +0100474{
David A. Long7579f4b32014-03-07 11:19:32 -0500475 unsigned long cpsr = t16_emulate_loregs(insn, asi, regs);
Jon Medhurst02d194f2011-07-02 15:46:05 +0100476 if (!in_it_block(cpsr))
477 regs->ARM_cpsr = cpsr;
478}
479
David A. Long3e6cd392014-03-06 18:06:43 -0500480static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500481t16_emulate_hiregs(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500482 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurst3b5940e2011-07-02 15:54:57 +0100483{
David A. Long7579f4b32014-03-07 11:19:32 -0500484 unsigned long pc = regs->ARM_pc + 2;
Jon Medhurst3b5940e2011-07-02 15:54:57 +0100485 int rdn = (insn & 0x7) | ((insn & 0x80) >> 4);
486 int rm = (insn >> 3) & 0xf;
487
488 register unsigned long rdnv asm("r1");
489 register unsigned long rmv asm("r0");
490 unsigned long cpsr = regs->ARM_cpsr;
491
492 rdnv = (rdn == 15) ? pc : regs->uregs[rdn];
493 rmv = (rm == 15) ? pc : regs->uregs[rm];
494
495 __asm__ __volatile__ (
496 "msr cpsr_fs, %[cpsr] \n\t"
497 "blx %[fn] \n\t"
498 "mrs %[cpsr], cpsr \n\t"
499 : "=r" (rdnv), [cpsr] "=r" (cpsr)
David A. Long7579f4b32014-03-07 11:19:32 -0500500 : "0" (rdnv), "r" (rmv), "1" (cpsr), [fn] "r" (asi->insn_fn)
Jon Medhurst3b5940e2011-07-02 15:54:57 +0100501 : "lr", "memory", "cc"
502 );
503
504 if (rdn == 15)
505 rdnv &= ~1;
506
507 regs->uregs[rdn] = rdnv;
508 regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK);
509}
510
David A. Long44a0a592014-03-05 21:23:42 -0500511static enum probes_insn __kprobes
David A. Longb4cd6052014-03-05 21:41:29 -0500512t16_decode_hiregs(probes_opcode_t insn, struct arch_probes_insn *asi,
David A. Long3e6cd392014-03-06 18:06:43 -0500513 const struct decode_header *d)
Jon Medhurst3b5940e2011-07-02 15:54:57 +0100514{
515 insn &= ~0x00ff;
516 insn |= 0x001; /* Set Rdn = R1 and Rm = R0 */
Ben Dooks888be252013-11-08 18:29:25 +0000517 ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(insn);
Jon Medhurst3b5940e2011-07-02 15:54:57 +0100518 asi->insn_handler = t16_emulate_hiregs;
519 return INSN_GOOD;
520}
521
David A. Long3e6cd392014-03-06 18:06:43 -0500522static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500523t16_emulate_push(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500524 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100525{
526 __asm__ __volatile__ (
527 "ldr r9, [%[regs], #13*4] \n\t"
528 "ldr r8, [%[regs], #14*4] \n\t"
529 "ldmia %[regs], {r0-r7} \n\t"
530 "blx %[fn] \n\t"
531 "str r9, [%[regs], #13*4] \n\t"
532 :
David A. Long7579f4b32014-03-07 11:19:32 -0500533 : [regs] "r" (regs), [fn] "r" (asi->insn_fn)
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100534 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9",
535 "lr", "memory", "cc"
536 );
537}
538
David A. Long44a0a592014-03-05 21:23:42 -0500539static enum probes_insn __kprobes
David A. Longb4cd6052014-03-05 21:41:29 -0500540t16_decode_push(probes_opcode_t insn, struct arch_probes_insn *asi,
David A. Long3e6cd392014-03-06 18:06:43 -0500541 const struct decode_header *d)
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100542{
543 /*
544 * To simulate a PUSH we use a Thumb-2 "STMDB R9!, {registers}"
545 * and call it with R9=SP and LR in the register list represented
546 * by R8.
547 */
Ben Dooks888be252013-11-08 18:29:25 +0000548 /* 1st half STMDB R9!,{} */
549 ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(0xe929);
550 /* 2nd half (register list) */
551 ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0x1ff);
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100552 asi->insn_handler = t16_emulate_push;
553 return INSN_GOOD;
554}
555
David A. Long3e6cd392014-03-06 18:06:43 -0500556static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500557t16_emulate_pop_nopc(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500558 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100559{
560 __asm__ __volatile__ (
561 "ldr r9, [%[regs], #13*4] \n\t"
562 "ldmia %[regs], {r0-r7} \n\t"
563 "blx %[fn] \n\t"
564 "stmia %[regs], {r0-r7} \n\t"
565 "str r9, [%[regs], #13*4] \n\t"
566 :
David A. Long7579f4b32014-03-07 11:19:32 -0500567 : [regs] "r" (regs), [fn] "r" (asi->insn_fn)
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100568 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9",
569 "lr", "memory", "cc"
570 );
571}
572
David A. Long3e6cd392014-03-06 18:06:43 -0500573static void __kprobes
David A. Longf145d662014-03-05 21:17:23 -0500574t16_emulate_pop_pc(probes_opcode_t insn,
David A. Longb4cd6052014-03-05 21:41:29 -0500575 struct arch_probes_insn *asi, struct pt_regs *regs)
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100576{
577 register unsigned long pc asm("r8");
578
579 __asm__ __volatile__ (
580 "ldr r9, [%[regs], #13*4] \n\t"
581 "ldmia %[regs], {r0-r7} \n\t"
582 "blx %[fn] \n\t"
583 "stmia %[regs], {r0-r7} \n\t"
584 "str r9, [%[regs], #13*4] \n\t"
585 : "=r" (pc)
David A. Long7579f4b32014-03-07 11:19:32 -0500586 : [regs] "r" (regs), [fn] "r" (asi->insn_fn)
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100587 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9",
588 "lr", "memory", "cc"
589 );
590
591 bx_write_pc(pc, regs);
592}
593
David A. Long44a0a592014-03-05 21:23:42 -0500594static enum probes_insn __kprobes
David A. Longb4cd6052014-03-05 21:41:29 -0500595t16_decode_pop(probes_opcode_t insn, struct arch_probes_insn *asi,
David A. Long3e6cd392014-03-06 18:06:43 -0500596 const struct decode_header *d)
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100597{
598 /*
599 * To simulate a POP we use a Thumb-2 "LDMDB R9!, {registers}"
600 * and call it with R9=SP and PC in the register list represented
601 * by R8.
602 */
Ben Dooks888be252013-11-08 18:29:25 +0000603 /* 1st half LDMIA R9!,{} */
604 ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(0xe8b9);
605 /* 2nd half (register list) */
606 ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0x1ff);
Jon Medhurstfd0c8d82011-07-02 16:13:29 +0100607 asi->insn_handler = insn & 0x100 ? t16_emulate_pop_pc
608 : t16_emulate_pop_nopc;
609 return INSN_GOOD;
610}
David A. Long3e6cd392014-03-06 18:06:43 -0500611
612const union decode_action kprobes_t16_actions[NUM_PROBES_T16_ACTIONS] = {
613 [PROBES_T16_ADD_SP] = {.handler = t16_simulate_add_sp_imm},
614 [PROBES_T16_CBZ] = {.handler = t16_simulate_cbz},
615 [PROBES_T16_SIGN_EXTEND] = {.handler = t16_emulate_loregs_rwflags},
616 [PROBES_T16_PUSH] = {.decoder = t16_decode_push},
617 [PROBES_T16_POP] = {.decoder = t16_decode_pop},
David A. Longeb73ea92014-03-05 21:20:25 -0500618 [PROBES_T16_SEV] = {.handler = probes_emulate_none},
619 [PROBES_T16_WFE] = {.handler = probes_simulate_nop},
David A. Long3e6cd392014-03-06 18:06:43 -0500620 [PROBES_T16_IT] = {.decoder = t16_decode_it},
621 [PROBES_T16_CMP] = {.handler = t16_emulate_loregs_rwflags},
622 [PROBES_T16_ADDSUB] = {.handler = t16_emulate_loregs_noitrwflags},
623 [PROBES_T16_LOGICAL] = {.handler = t16_emulate_loregs_noitrwflags},
624 [PROBES_T16_LDR_LIT] = {.handler = t16_simulate_ldr_literal},
625 [PROBES_T16_BLX] = {.handler = t16_simulate_bxblx},
626 [PROBES_T16_HIREGOPS] = {.decoder = t16_decode_hiregs},
627 [PROBES_T16_LDRHSTRH] = {.handler = t16_emulate_loregs_rwflags},
628 [PROBES_T16_LDRSTR] = {.handler = t16_simulate_ldrstr_sp_relative},
629 [PROBES_T16_ADR] = {.handler = t16_simulate_reladr},
630 [PROBES_T16_LDMSTM] = {.handler = t16_emulate_loregs_rwflags},
631 [PROBES_T16_BRANCH_COND] = {.decoder = t16_decode_cond_branch},
632 [PROBES_T16_BRANCH] = {.handler = t16_simulate_branch},
633};
634
635const union decode_action kprobes_t32_actions[NUM_PROBES_T32_ACTIONS] = {
636 [PROBES_T32_LDMSTM] = {.decoder = t32_decode_ldmstm},
637 [PROBES_T32_LDRDSTRD] = {.handler = t32_emulate_ldrdstrd},
638 [PROBES_T32_TABLE_BRANCH] = {.handler = t32_simulate_table_branch},
639 [PROBES_T32_TST] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
640 [PROBES_T32_MOV] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
641 [PROBES_T32_ADDSUB] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
642 [PROBES_T32_LOGICAL] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
643 [PROBES_T32_CMP] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
644 [PROBES_T32_ADDWSUBW_PC] = {.handler = t32_emulate_rd8pc16_noflags,},
645 [PROBES_T32_ADDWSUBW] = {.handler = t32_emulate_rd8rn16_noflags},
646 [PROBES_T32_MOVW] = {.handler = t32_emulate_rd8rn16_noflags},
647 [PROBES_T32_SAT] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
648 [PROBES_T32_BITFIELD] = {.handler = t32_emulate_rd8rn16_noflags},
David A. Longeb73ea92014-03-05 21:20:25 -0500649 [PROBES_T32_SEV] = {.handler = probes_emulate_none},
650 [PROBES_T32_WFE] = {.handler = probes_simulate_nop},
David A. Long3e6cd392014-03-06 18:06:43 -0500651 [PROBES_T32_MRS] = {.handler = t32_simulate_mrs},
652 [PROBES_T32_BRANCH_COND] = {.decoder = t32_decode_cond_branch},
653 [PROBES_T32_BRANCH] = {.handler = t32_simulate_branch},
David A. Longeb73ea92014-03-05 21:20:25 -0500654 [PROBES_T32_PLDI] = {.handler = probes_simulate_nop},
David A. Long3e6cd392014-03-06 18:06:43 -0500655 [PROBES_T32_LDR_LIT] = {.handler = t32_simulate_ldr_literal},
656 [PROBES_T32_LDRSTR] = {.handler = t32_emulate_ldrstr},
657 [PROBES_T32_SIGN_EXTEND] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
658 [PROBES_T32_MEDIA] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
659 [PROBES_T32_REVERSE] = {.handler = t32_emulate_rd8rn16_noflags},
660 [PROBES_T32_MUL_ADD] = {.handler = t32_emulate_rd8rn16rm0_rwflags},
661 [PROBES_T32_MUL_ADD2] = {.handler = t32_emulate_rd8rn16rm0ra12_noflags},
662 [PROBES_T32_MUL_ADD_LONG] = {
663 .handler = t32_emulate_rdlo12rdhi8rn16rm0_noflags},
664};
Wang Nan83803d92015-01-05 19:29:18 +0800665
Wang Nan6624cf62015-01-05 19:29:21 +0800666const struct decode_checker *kprobes_t32_checkers[] = {t32_stack_checker, NULL};
667const struct decode_checker *kprobes_t16_checkers[] = {t16_stack_checker, NULL};