Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 1 | /* |
| 2 | * arch/arm/probes/kprobes/actions-thumb.c |
| 3 | * |
| 4 | * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/types.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/ptrace.h> |
| 14 | #include <linux/kprobes.h> |
| 15 | |
| 16 | #include "../decode-thumb.h" |
| 17 | #include "core.h" |
| 18 | #include "checkers.h" |
| 19 | |
| 20 | /* These emulation encodings are functionally equivalent... */ |
| 21 | #define t32_emulate_rd8rn16rm0ra12_noflags \ |
| 22 | t32_emulate_rdlo12rdhi8rn16rm0_noflags |
| 23 | |
| 24 | /* t32 thumb actions */ |
| 25 | |
| 26 | static void __kprobes |
| 27 | t32_simulate_table_branch(probes_opcode_t insn, |
| 28 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 29 | { |
| 30 | unsigned long pc = regs->ARM_pc; |
| 31 | int rn = (insn >> 16) & 0xf; |
| 32 | int rm = insn & 0xf; |
| 33 | |
| 34 | unsigned long rnv = (rn == 15) ? pc : regs->uregs[rn]; |
| 35 | unsigned long rmv = regs->uregs[rm]; |
| 36 | unsigned int halfwords; |
| 37 | |
| 38 | if (insn & 0x10) /* TBH */ |
| 39 | halfwords = ((u16 *)rnv)[rmv]; |
| 40 | else /* TBB */ |
| 41 | halfwords = ((u8 *)rnv)[rmv]; |
| 42 | |
| 43 | regs->ARM_pc = pc + 2 * halfwords; |
| 44 | } |
| 45 | |
| 46 | static void __kprobes |
| 47 | t32_simulate_mrs(probes_opcode_t insn, |
| 48 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 49 | { |
| 50 | int rd = (insn >> 8) & 0xf; |
| 51 | unsigned long mask = 0xf8ff03df; /* Mask out execution state */ |
| 52 | regs->uregs[rd] = regs->ARM_cpsr & mask; |
| 53 | } |
| 54 | |
| 55 | static void __kprobes |
| 56 | t32_simulate_cond_branch(probes_opcode_t insn, |
| 57 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 58 | { |
| 59 | unsigned long pc = regs->ARM_pc; |
| 60 | |
| 61 | long offset = insn & 0x7ff; /* imm11 */ |
| 62 | offset += (insn & 0x003f0000) >> 5; /* imm6 */ |
| 63 | offset += (insn & 0x00002000) << 4; /* J1 */ |
| 64 | offset += (insn & 0x00000800) << 7; /* J2 */ |
| 65 | offset -= (insn & 0x04000000) >> 7; /* Apply sign bit */ |
| 66 | |
| 67 | regs->ARM_pc = pc + (offset * 2); |
| 68 | } |
| 69 | |
| 70 | static enum probes_insn __kprobes |
| 71 | t32_decode_cond_branch(probes_opcode_t insn, struct arch_probes_insn *asi, |
| 72 | const struct decode_header *d) |
| 73 | { |
| 74 | int cc = (insn >> 22) & 0xf; |
| 75 | asi->insn_check_cc = probes_condition_checks[cc]; |
| 76 | asi->insn_handler = t32_simulate_cond_branch; |
| 77 | return INSN_GOOD_NO_SLOT; |
| 78 | } |
| 79 | |
| 80 | static void __kprobes |
| 81 | t32_simulate_branch(probes_opcode_t insn, |
| 82 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 83 | { |
| 84 | unsigned long pc = regs->ARM_pc; |
| 85 | |
| 86 | long offset = insn & 0x7ff; /* imm11 */ |
| 87 | offset += (insn & 0x03ff0000) >> 5; /* imm10 */ |
| 88 | offset += (insn & 0x00002000) << 9; /* J1 */ |
| 89 | offset += (insn & 0x00000800) << 10; /* J2 */ |
| 90 | if (insn & 0x04000000) |
| 91 | offset -= 0x00800000; /* Apply sign bit */ |
| 92 | else |
| 93 | offset ^= 0x00600000; /* Invert J1 and J2 */ |
| 94 | |
| 95 | if (insn & (1 << 14)) { |
| 96 | /* BL or BLX */ |
| 97 | regs->ARM_lr = regs->ARM_pc | 1; |
| 98 | if (!(insn & (1 << 12))) { |
| 99 | /* BLX so switch to ARM mode */ |
| 100 | regs->ARM_cpsr &= ~PSR_T_BIT; |
| 101 | pc &= ~3; |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | regs->ARM_pc = pc + (offset * 2); |
| 106 | } |
| 107 | |
| 108 | static void __kprobes |
| 109 | t32_simulate_ldr_literal(probes_opcode_t insn, |
| 110 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 111 | { |
| 112 | unsigned long addr = regs->ARM_pc & ~3; |
| 113 | int rt = (insn >> 12) & 0xf; |
| 114 | unsigned long rtv; |
| 115 | |
| 116 | long offset = insn & 0xfff; |
| 117 | if (insn & 0x00800000) |
| 118 | addr += offset; |
| 119 | else |
| 120 | addr -= offset; |
| 121 | |
| 122 | if (insn & 0x00400000) { |
| 123 | /* LDR */ |
| 124 | rtv = *(unsigned long *)addr; |
| 125 | if (rt == 15) { |
| 126 | bx_write_pc(rtv, regs); |
| 127 | return; |
| 128 | } |
| 129 | } else if (insn & 0x00200000) { |
| 130 | /* LDRH */ |
| 131 | if (insn & 0x01000000) |
| 132 | rtv = *(s16 *)addr; |
| 133 | else |
| 134 | rtv = *(u16 *)addr; |
| 135 | } else { |
| 136 | /* LDRB */ |
| 137 | if (insn & 0x01000000) |
| 138 | rtv = *(s8 *)addr; |
| 139 | else |
| 140 | rtv = *(u8 *)addr; |
| 141 | } |
| 142 | |
| 143 | regs->uregs[rt] = rtv; |
| 144 | } |
| 145 | |
| 146 | static enum probes_insn __kprobes |
| 147 | t32_decode_ldmstm(probes_opcode_t insn, struct arch_probes_insn *asi, |
| 148 | const struct decode_header *d) |
| 149 | { |
| 150 | enum probes_insn ret = kprobe_decode_ldmstm(insn, asi, d); |
| 151 | |
| 152 | /* Fixup modified instruction to have halfwords in correct order...*/ |
| 153 | insn = __mem_to_opcode_arm(asi->insn[0]); |
| 154 | ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(insn >> 16); |
| 155 | ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0xffff); |
| 156 | |
| 157 | return ret; |
| 158 | } |
| 159 | |
| 160 | static void __kprobes |
| 161 | t32_emulate_ldrdstrd(probes_opcode_t insn, |
| 162 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 163 | { |
| 164 | unsigned long pc = regs->ARM_pc & ~3; |
| 165 | int rt1 = (insn >> 12) & 0xf; |
| 166 | int rt2 = (insn >> 8) & 0xf; |
| 167 | int rn = (insn >> 16) & 0xf; |
| 168 | |
| 169 | register unsigned long rt1v asm("r0") = regs->uregs[rt1]; |
| 170 | register unsigned long rt2v asm("r1") = regs->uregs[rt2]; |
| 171 | register unsigned long rnv asm("r2") = (rn == 15) ? pc |
| 172 | : regs->uregs[rn]; |
| 173 | |
| 174 | __asm__ __volatile__ ( |
| 175 | "blx %[fn]" |
| 176 | : "=r" (rt1v), "=r" (rt2v), "=r" (rnv) |
| 177 | : "0" (rt1v), "1" (rt2v), "2" (rnv), [fn] "r" (asi->insn_fn) |
| 178 | : "lr", "memory", "cc" |
| 179 | ); |
| 180 | |
| 181 | if (rn != 15) |
| 182 | regs->uregs[rn] = rnv; /* Writeback base register */ |
| 183 | regs->uregs[rt1] = rt1v; |
| 184 | regs->uregs[rt2] = rt2v; |
| 185 | } |
| 186 | |
| 187 | static void __kprobes |
| 188 | t32_emulate_ldrstr(probes_opcode_t insn, |
| 189 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 190 | { |
| 191 | int rt = (insn >> 12) & 0xf; |
| 192 | int rn = (insn >> 16) & 0xf; |
| 193 | int rm = insn & 0xf; |
| 194 | |
| 195 | register unsigned long rtv asm("r0") = regs->uregs[rt]; |
| 196 | register unsigned long rnv asm("r2") = regs->uregs[rn]; |
| 197 | register unsigned long rmv asm("r3") = regs->uregs[rm]; |
| 198 | |
| 199 | __asm__ __volatile__ ( |
| 200 | "blx %[fn]" |
| 201 | : "=r" (rtv), "=r" (rnv) |
| 202 | : "0" (rtv), "1" (rnv), "r" (rmv), [fn] "r" (asi->insn_fn) |
| 203 | : "lr", "memory", "cc" |
| 204 | ); |
| 205 | |
| 206 | regs->uregs[rn] = rnv; /* Writeback base register */ |
| 207 | if (rt == 15) /* Can't be true for a STR as they aren't allowed */ |
| 208 | bx_write_pc(rtv, regs); |
| 209 | else |
| 210 | regs->uregs[rt] = rtv; |
| 211 | } |
| 212 | |
| 213 | static void __kprobes |
| 214 | t32_emulate_rd8rn16rm0_rwflags(probes_opcode_t insn, |
| 215 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 216 | { |
| 217 | int rd = (insn >> 8) & 0xf; |
| 218 | int rn = (insn >> 16) & 0xf; |
| 219 | int rm = insn & 0xf; |
| 220 | |
| 221 | register unsigned long rdv asm("r1") = regs->uregs[rd]; |
| 222 | register unsigned long rnv asm("r2") = regs->uregs[rn]; |
| 223 | register unsigned long rmv asm("r3") = regs->uregs[rm]; |
| 224 | unsigned long cpsr = regs->ARM_cpsr; |
| 225 | |
| 226 | __asm__ __volatile__ ( |
| 227 | "msr cpsr_fs, %[cpsr] \n\t" |
| 228 | "blx %[fn] \n\t" |
| 229 | "mrs %[cpsr], cpsr \n\t" |
| 230 | : "=r" (rdv), [cpsr] "=r" (cpsr) |
| 231 | : "0" (rdv), "r" (rnv), "r" (rmv), |
| 232 | "1" (cpsr), [fn] "r" (asi->insn_fn) |
| 233 | : "lr", "memory", "cc" |
| 234 | ); |
| 235 | |
| 236 | regs->uregs[rd] = rdv; |
| 237 | regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK); |
| 238 | } |
| 239 | |
| 240 | static void __kprobes |
| 241 | t32_emulate_rd8pc16_noflags(probes_opcode_t insn, |
| 242 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 243 | { |
| 244 | unsigned long pc = regs->ARM_pc; |
| 245 | int rd = (insn >> 8) & 0xf; |
| 246 | |
| 247 | register unsigned long rdv asm("r1") = regs->uregs[rd]; |
| 248 | register unsigned long rnv asm("r2") = pc & ~3; |
| 249 | |
| 250 | __asm__ __volatile__ ( |
| 251 | "blx %[fn]" |
| 252 | : "=r" (rdv) |
| 253 | : "0" (rdv), "r" (rnv), [fn] "r" (asi->insn_fn) |
| 254 | : "lr", "memory", "cc" |
| 255 | ); |
| 256 | |
| 257 | regs->uregs[rd] = rdv; |
| 258 | } |
| 259 | |
| 260 | static void __kprobes |
| 261 | t32_emulate_rd8rn16_noflags(probes_opcode_t insn, |
| 262 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 263 | { |
| 264 | int rd = (insn >> 8) & 0xf; |
| 265 | int rn = (insn >> 16) & 0xf; |
| 266 | |
| 267 | register unsigned long rdv asm("r1") = regs->uregs[rd]; |
| 268 | register unsigned long rnv asm("r2") = regs->uregs[rn]; |
| 269 | |
| 270 | __asm__ __volatile__ ( |
| 271 | "blx %[fn]" |
| 272 | : "=r" (rdv) |
| 273 | : "0" (rdv), "r" (rnv), [fn] "r" (asi->insn_fn) |
| 274 | : "lr", "memory", "cc" |
| 275 | ); |
| 276 | |
| 277 | regs->uregs[rd] = rdv; |
| 278 | } |
| 279 | |
| 280 | static void __kprobes |
| 281 | t32_emulate_rdlo12rdhi8rn16rm0_noflags(probes_opcode_t insn, |
| 282 | struct arch_probes_insn *asi, |
| 283 | struct pt_regs *regs) |
| 284 | { |
| 285 | int rdlo = (insn >> 12) & 0xf; |
| 286 | int rdhi = (insn >> 8) & 0xf; |
| 287 | int rn = (insn >> 16) & 0xf; |
| 288 | int rm = insn & 0xf; |
| 289 | |
| 290 | register unsigned long rdlov asm("r0") = regs->uregs[rdlo]; |
| 291 | register unsigned long rdhiv asm("r1") = regs->uregs[rdhi]; |
| 292 | register unsigned long rnv asm("r2") = regs->uregs[rn]; |
| 293 | register unsigned long rmv asm("r3") = regs->uregs[rm]; |
| 294 | |
| 295 | __asm__ __volatile__ ( |
| 296 | "blx %[fn]" |
| 297 | : "=r" (rdlov), "=r" (rdhiv) |
| 298 | : "0" (rdlov), "1" (rdhiv), "r" (rnv), "r" (rmv), |
| 299 | [fn] "r" (asi->insn_fn) |
| 300 | : "lr", "memory", "cc" |
| 301 | ); |
| 302 | |
| 303 | regs->uregs[rdlo] = rdlov; |
| 304 | regs->uregs[rdhi] = rdhiv; |
| 305 | } |
| 306 | /* t16 thumb actions */ |
| 307 | |
| 308 | static void __kprobes |
| 309 | t16_simulate_bxblx(probes_opcode_t insn, |
| 310 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 311 | { |
| 312 | unsigned long pc = regs->ARM_pc + 2; |
| 313 | int rm = (insn >> 3) & 0xf; |
| 314 | unsigned long rmv = (rm == 15) ? pc : regs->uregs[rm]; |
| 315 | |
| 316 | if (insn & (1 << 7)) /* BLX ? */ |
| 317 | regs->ARM_lr = regs->ARM_pc | 1; |
| 318 | |
| 319 | bx_write_pc(rmv, regs); |
| 320 | } |
| 321 | |
| 322 | static void __kprobes |
| 323 | t16_simulate_ldr_literal(probes_opcode_t insn, |
| 324 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 325 | { |
| 326 | unsigned long *base = (unsigned long *)((regs->ARM_pc + 2) & ~3); |
| 327 | long index = insn & 0xff; |
| 328 | int rt = (insn >> 8) & 0x7; |
| 329 | regs->uregs[rt] = base[index]; |
| 330 | } |
| 331 | |
| 332 | static void __kprobes |
| 333 | t16_simulate_ldrstr_sp_relative(probes_opcode_t insn, |
| 334 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 335 | { |
| 336 | unsigned long* base = (unsigned long *)regs->ARM_sp; |
| 337 | long index = insn & 0xff; |
| 338 | int rt = (insn >> 8) & 0x7; |
| 339 | if (insn & 0x800) /* LDR */ |
| 340 | regs->uregs[rt] = base[index]; |
| 341 | else /* STR */ |
| 342 | base[index] = regs->uregs[rt]; |
| 343 | } |
| 344 | |
| 345 | static void __kprobes |
| 346 | t16_simulate_reladr(probes_opcode_t insn, |
| 347 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 348 | { |
| 349 | unsigned long base = (insn & 0x800) ? regs->ARM_sp |
| 350 | : ((regs->ARM_pc + 2) & ~3); |
| 351 | long offset = insn & 0xff; |
| 352 | int rt = (insn >> 8) & 0x7; |
| 353 | regs->uregs[rt] = base + offset * 4; |
| 354 | } |
| 355 | |
| 356 | static void __kprobes |
| 357 | t16_simulate_add_sp_imm(probes_opcode_t insn, |
| 358 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 359 | { |
| 360 | long imm = insn & 0x7f; |
| 361 | if (insn & 0x80) /* SUB */ |
| 362 | regs->ARM_sp -= imm * 4; |
| 363 | else /* ADD */ |
| 364 | regs->ARM_sp += imm * 4; |
| 365 | } |
| 366 | |
| 367 | static void __kprobes |
| 368 | t16_simulate_cbz(probes_opcode_t insn, |
| 369 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 370 | { |
| 371 | int rn = insn & 0x7; |
| 372 | probes_opcode_t nonzero = regs->uregs[rn] ? insn : ~insn; |
| 373 | if (nonzero & 0x800) { |
| 374 | long i = insn & 0x200; |
| 375 | long imm5 = insn & 0xf8; |
| 376 | unsigned long pc = regs->ARM_pc + 2; |
| 377 | regs->ARM_pc = pc + (i >> 3) + (imm5 >> 2); |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | static void __kprobes |
| 382 | t16_simulate_it(probes_opcode_t insn, |
| 383 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 384 | { |
| 385 | /* |
| 386 | * The 8 IT state bits are split into two parts in CPSR: |
| 387 | * ITSTATE<1:0> are in CPSR<26:25> |
| 388 | * ITSTATE<7:2> are in CPSR<15:10> |
| 389 | * The new IT state is in the lower byte of insn. |
| 390 | */ |
| 391 | unsigned long cpsr = regs->ARM_cpsr; |
| 392 | cpsr &= ~PSR_IT_MASK; |
| 393 | cpsr |= (insn & 0xfc) << 8; |
| 394 | cpsr |= (insn & 0x03) << 25; |
| 395 | regs->ARM_cpsr = cpsr; |
| 396 | } |
| 397 | |
| 398 | static void __kprobes |
| 399 | t16_singlestep_it(probes_opcode_t insn, |
| 400 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 401 | { |
| 402 | regs->ARM_pc += 2; |
| 403 | t16_simulate_it(insn, asi, regs); |
| 404 | } |
| 405 | |
| 406 | static enum probes_insn __kprobes |
| 407 | t16_decode_it(probes_opcode_t insn, struct arch_probes_insn *asi, |
| 408 | const struct decode_header *d) |
| 409 | { |
| 410 | asi->insn_singlestep = t16_singlestep_it; |
| 411 | return INSN_GOOD_NO_SLOT; |
| 412 | } |
| 413 | |
| 414 | static void __kprobes |
| 415 | t16_simulate_cond_branch(probes_opcode_t insn, |
| 416 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 417 | { |
| 418 | unsigned long pc = regs->ARM_pc + 2; |
| 419 | long offset = insn & 0x7f; |
| 420 | offset -= insn & 0x80; /* Apply sign bit */ |
| 421 | regs->ARM_pc = pc + (offset * 2); |
| 422 | } |
| 423 | |
| 424 | static enum probes_insn __kprobes |
| 425 | t16_decode_cond_branch(probes_opcode_t insn, struct arch_probes_insn *asi, |
| 426 | const struct decode_header *d) |
| 427 | { |
| 428 | int cc = (insn >> 8) & 0xf; |
| 429 | asi->insn_check_cc = probes_condition_checks[cc]; |
| 430 | asi->insn_handler = t16_simulate_cond_branch; |
| 431 | return INSN_GOOD_NO_SLOT; |
| 432 | } |
| 433 | |
| 434 | static void __kprobes |
| 435 | t16_simulate_branch(probes_opcode_t insn, |
| 436 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 437 | { |
| 438 | unsigned long pc = regs->ARM_pc + 2; |
| 439 | long offset = insn & 0x3ff; |
| 440 | offset -= insn & 0x400; /* Apply sign bit */ |
| 441 | regs->ARM_pc = pc + (offset * 2); |
| 442 | } |
| 443 | |
| 444 | static unsigned long __kprobes |
| 445 | t16_emulate_loregs(probes_opcode_t insn, |
| 446 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 447 | { |
| 448 | unsigned long oldcpsr = regs->ARM_cpsr; |
| 449 | unsigned long newcpsr; |
| 450 | |
| 451 | __asm__ __volatile__ ( |
| 452 | "msr cpsr_fs, %[oldcpsr] \n\t" |
| 453 | "ldmia %[regs], {r0-r7} \n\t" |
| 454 | "blx %[fn] \n\t" |
| 455 | "stmia %[regs], {r0-r7} \n\t" |
| 456 | "mrs %[newcpsr], cpsr \n\t" |
| 457 | : [newcpsr] "=r" (newcpsr) |
| 458 | : [oldcpsr] "r" (oldcpsr), [regs] "r" (regs), |
| 459 | [fn] "r" (asi->insn_fn) |
| 460 | : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| 461 | "lr", "memory", "cc" |
| 462 | ); |
| 463 | |
| 464 | return (oldcpsr & ~APSR_MASK) | (newcpsr & APSR_MASK); |
| 465 | } |
| 466 | |
| 467 | static void __kprobes |
| 468 | t16_emulate_loregs_rwflags(probes_opcode_t insn, |
| 469 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 470 | { |
| 471 | regs->ARM_cpsr = t16_emulate_loregs(insn, asi, regs); |
| 472 | } |
| 473 | |
| 474 | static void __kprobes |
| 475 | t16_emulate_loregs_noitrwflags(probes_opcode_t insn, |
| 476 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 477 | { |
| 478 | unsigned long cpsr = t16_emulate_loregs(insn, asi, regs); |
| 479 | if (!in_it_block(cpsr)) |
| 480 | regs->ARM_cpsr = cpsr; |
| 481 | } |
| 482 | |
| 483 | static void __kprobes |
| 484 | t16_emulate_hiregs(probes_opcode_t insn, |
| 485 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 486 | { |
| 487 | unsigned long pc = regs->ARM_pc + 2; |
| 488 | int rdn = (insn & 0x7) | ((insn & 0x80) >> 4); |
| 489 | int rm = (insn >> 3) & 0xf; |
| 490 | |
| 491 | register unsigned long rdnv asm("r1"); |
| 492 | register unsigned long rmv asm("r0"); |
| 493 | unsigned long cpsr = regs->ARM_cpsr; |
| 494 | |
| 495 | rdnv = (rdn == 15) ? pc : regs->uregs[rdn]; |
| 496 | rmv = (rm == 15) ? pc : regs->uregs[rm]; |
| 497 | |
| 498 | __asm__ __volatile__ ( |
| 499 | "msr cpsr_fs, %[cpsr] \n\t" |
| 500 | "blx %[fn] \n\t" |
| 501 | "mrs %[cpsr], cpsr \n\t" |
| 502 | : "=r" (rdnv), [cpsr] "=r" (cpsr) |
| 503 | : "0" (rdnv), "r" (rmv), "1" (cpsr), [fn] "r" (asi->insn_fn) |
| 504 | : "lr", "memory", "cc" |
| 505 | ); |
| 506 | |
| 507 | if (rdn == 15) |
| 508 | rdnv &= ~1; |
| 509 | |
| 510 | regs->uregs[rdn] = rdnv; |
| 511 | regs->ARM_cpsr = (regs->ARM_cpsr & ~APSR_MASK) | (cpsr & APSR_MASK); |
| 512 | } |
| 513 | |
| 514 | static enum probes_insn __kprobes |
| 515 | t16_decode_hiregs(probes_opcode_t insn, struct arch_probes_insn *asi, |
| 516 | const struct decode_header *d) |
| 517 | { |
| 518 | insn &= ~0x00ff; |
| 519 | insn |= 0x001; /* Set Rdn = R1 and Rm = R0 */ |
| 520 | ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(insn); |
| 521 | asi->insn_handler = t16_emulate_hiregs; |
| 522 | return INSN_GOOD; |
| 523 | } |
| 524 | |
| 525 | static void __kprobes |
| 526 | t16_emulate_push(probes_opcode_t insn, |
| 527 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 528 | { |
| 529 | __asm__ __volatile__ ( |
| 530 | "ldr r9, [%[regs], #13*4] \n\t" |
| 531 | "ldr r8, [%[regs], #14*4] \n\t" |
| 532 | "ldmia %[regs], {r0-r7} \n\t" |
| 533 | "blx %[fn] \n\t" |
| 534 | "str r9, [%[regs], #13*4] \n\t" |
| 535 | : |
| 536 | : [regs] "r" (regs), [fn] "r" (asi->insn_fn) |
| 537 | : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", |
| 538 | "lr", "memory", "cc" |
| 539 | ); |
| 540 | } |
| 541 | |
| 542 | static enum probes_insn __kprobes |
| 543 | t16_decode_push(probes_opcode_t insn, struct arch_probes_insn *asi, |
| 544 | const struct decode_header *d) |
| 545 | { |
| 546 | /* |
| 547 | * To simulate a PUSH we use a Thumb-2 "STMDB R9!, {registers}" |
| 548 | * and call it with R9=SP and LR in the register list represented |
| 549 | * by R8. |
| 550 | */ |
| 551 | /* 1st half STMDB R9!,{} */ |
| 552 | ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(0xe929); |
| 553 | /* 2nd half (register list) */ |
| 554 | ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0x1ff); |
| 555 | asi->insn_handler = t16_emulate_push; |
| 556 | return INSN_GOOD; |
| 557 | } |
| 558 | |
| 559 | static void __kprobes |
| 560 | t16_emulate_pop_nopc(probes_opcode_t insn, |
| 561 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 562 | { |
| 563 | __asm__ __volatile__ ( |
| 564 | "ldr r9, [%[regs], #13*4] \n\t" |
| 565 | "ldmia %[regs], {r0-r7} \n\t" |
| 566 | "blx %[fn] \n\t" |
| 567 | "stmia %[regs], {r0-r7} \n\t" |
| 568 | "str r9, [%[regs], #13*4] \n\t" |
| 569 | : |
| 570 | : [regs] "r" (regs), [fn] "r" (asi->insn_fn) |
| 571 | : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9", |
| 572 | "lr", "memory", "cc" |
| 573 | ); |
| 574 | } |
| 575 | |
| 576 | static void __kprobes |
| 577 | t16_emulate_pop_pc(probes_opcode_t insn, |
| 578 | struct arch_probes_insn *asi, struct pt_regs *regs) |
| 579 | { |
| 580 | register unsigned long pc asm("r8"); |
| 581 | |
| 582 | __asm__ __volatile__ ( |
| 583 | "ldr r9, [%[regs], #13*4] \n\t" |
| 584 | "ldmia %[regs], {r0-r7} \n\t" |
| 585 | "blx %[fn] \n\t" |
| 586 | "stmia %[regs], {r0-r7} \n\t" |
| 587 | "str r9, [%[regs], #13*4] \n\t" |
| 588 | : "=r" (pc) |
| 589 | : [regs] "r" (regs), [fn] "r" (asi->insn_fn) |
| 590 | : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r9", |
| 591 | "lr", "memory", "cc" |
| 592 | ); |
| 593 | |
| 594 | bx_write_pc(pc, regs); |
| 595 | } |
| 596 | |
| 597 | static enum probes_insn __kprobes |
| 598 | t16_decode_pop(probes_opcode_t insn, struct arch_probes_insn *asi, |
| 599 | const struct decode_header *d) |
| 600 | { |
| 601 | /* |
| 602 | * To simulate a POP we use a Thumb-2 "LDMDB R9!, {registers}" |
| 603 | * and call it with R9=SP and PC in the register list represented |
| 604 | * by R8. |
| 605 | */ |
| 606 | /* 1st half LDMIA R9!,{} */ |
| 607 | ((u16 *)asi->insn)[0] = __opcode_to_mem_thumb16(0xe8b9); |
| 608 | /* 2nd half (register list) */ |
| 609 | ((u16 *)asi->insn)[1] = __opcode_to_mem_thumb16(insn & 0x1ff); |
| 610 | asi->insn_handler = insn & 0x100 ? t16_emulate_pop_pc |
| 611 | : t16_emulate_pop_nopc; |
| 612 | return INSN_GOOD; |
| 613 | } |
| 614 | |
| 615 | const union decode_action kprobes_t16_actions[NUM_PROBES_T16_ACTIONS] = { |
| 616 | [PROBES_T16_ADD_SP] = {.handler = t16_simulate_add_sp_imm}, |
| 617 | [PROBES_T16_CBZ] = {.handler = t16_simulate_cbz}, |
| 618 | [PROBES_T16_SIGN_EXTEND] = {.handler = t16_emulate_loregs_rwflags}, |
| 619 | [PROBES_T16_PUSH] = {.decoder = t16_decode_push}, |
| 620 | [PROBES_T16_POP] = {.decoder = t16_decode_pop}, |
| 621 | [PROBES_T16_SEV] = {.handler = probes_emulate_none}, |
| 622 | [PROBES_T16_WFE] = {.handler = probes_simulate_nop}, |
| 623 | [PROBES_T16_IT] = {.decoder = t16_decode_it}, |
| 624 | [PROBES_T16_CMP] = {.handler = t16_emulate_loregs_rwflags}, |
| 625 | [PROBES_T16_ADDSUB] = {.handler = t16_emulate_loregs_noitrwflags}, |
| 626 | [PROBES_T16_LOGICAL] = {.handler = t16_emulate_loregs_noitrwflags}, |
| 627 | [PROBES_T16_LDR_LIT] = {.handler = t16_simulate_ldr_literal}, |
| 628 | [PROBES_T16_BLX] = {.handler = t16_simulate_bxblx}, |
| 629 | [PROBES_T16_HIREGOPS] = {.decoder = t16_decode_hiregs}, |
| 630 | [PROBES_T16_LDRHSTRH] = {.handler = t16_emulate_loregs_rwflags}, |
| 631 | [PROBES_T16_LDRSTR] = {.handler = t16_simulate_ldrstr_sp_relative}, |
| 632 | [PROBES_T16_ADR] = {.handler = t16_simulate_reladr}, |
| 633 | [PROBES_T16_LDMSTM] = {.handler = t16_emulate_loregs_rwflags}, |
| 634 | [PROBES_T16_BRANCH_COND] = {.decoder = t16_decode_cond_branch}, |
| 635 | [PROBES_T16_BRANCH] = {.handler = t16_simulate_branch}, |
| 636 | }; |
| 637 | |
| 638 | const union decode_action kprobes_t32_actions[NUM_PROBES_T32_ACTIONS] = { |
| 639 | [PROBES_T32_LDMSTM] = {.decoder = t32_decode_ldmstm}, |
| 640 | [PROBES_T32_LDRDSTRD] = {.handler = t32_emulate_ldrdstrd}, |
| 641 | [PROBES_T32_TABLE_BRANCH] = {.handler = t32_simulate_table_branch}, |
| 642 | [PROBES_T32_TST] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 643 | [PROBES_T32_MOV] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 644 | [PROBES_T32_ADDSUB] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 645 | [PROBES_T32_LOGICAL] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 646 | [PROBES_T32_CMP] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 647 | [PROBES_T32_ADDWSUBW_PC] = {.handler = t32_emulate_rd8pc16_noflags,}, |
| 648 | [PROBES_T32_ADDWSUBW] = {.handler = t32_emulate_rd8rn16_noflags}, |
| 649 | [PROBES_T32_MOVW] = {.handler = t32_emulate_rd8rn16_noflags}, |
| 650 | [PROBES_T32_SAT] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 651 | [PROBES_T32_BITFIELD] = {.handler = t32_emulate_rd8rn16_noflags}, |
| 652 | [PROBES_T32_SEV] = {.handler = probes_emulate_none}, |
| 653 | [PROBES_T32_WFE] = {.handler = probes_simulate_nop}, |
| 654 | [PROBES_T32_MRS] = {.handler = t32_simulate_mrs}, |
| 655 | [PROBES_T32_BRANCH_COND] = {.decoder = t32_decode_cond_branch}, |
| 656 | [PROBES_T32_BRANCH] = {.handler = t32_simulate_branch}, |
| 657 | [PROBES_T32_PLDI] = {.handler = probes_simulate_nop}, |
| 658 | [PROBES_T32_LDR_LIT] = {.handler = t32_simulate_ldr_literal}, |
| 659 | [PROBES_T32_LDRSTR] = {.handler = t32_emulate_ldrstr}, |
| 660 | [PROBES_T32_SIGN_EXTEND] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 661 | [PROBES_T32_MEDIA] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 662 | [PROBES_T32_REVERSE] = {.handler = t32_emulate_rd8rn16_noflags}, |
| 663 | [PROBES_T32_MUL_ADD] = {.handler = t32_emulate_rd8rn16rm0_rwflags}, |
| 664 | [PROBES_T32_MUL_ADD2] = {.handler = t32_emulate_rd8rn16rm0ra12_noflags}, |
| 665 | [PROBES_T32_MUL_ADD_LONG] = { |
| 666 | .handler = t32_emulate_rdlo12rdhi8rn16rm0_noflags}, |
| 667 | }; |
| 668 | |
| 669 | const struct decode_checker *kprobes_t32_checkers[] = {t32_stack_checker, NULL}; |
| 670 | const struct decode_checker *kprobes_t16_checkers[] = {t16_stack_checker, NULL}; |