1 /* 2 * Handle unaligned accesses by emulation. 3 * 4 * This file is subject to the terms and conditions of the GNU General Public 5 * License. See the file "COPYING" in the main directory of this archive 6 * for more details. 7 * 8 * Copyright (C) 1996, 1998, 1999, 2002 by Ralf Baechle 9 * Copyright (C) 1999 Silicon Graphics, Inc. 10 * Copyright (C) 2014 Imagination Technologies Ltd. 11 * 12 * This file contains exception handler for address error exception with the 13 * special capability to execute faulting instructions in software. The 14 * handler does not try to handle the case when the program counter points 15 * to an address not aligned to a word boundary. 16 * 17 * Putting data to unaligned addresses is a bad practice even on Intel where 18 * only the performance is affected. Much worse is that such code is non- 19 * portable. Due to several programs that die on MIPS due to alignment 20 * problems I decided to implement this handler anyway though I originally 21 * didn't intend to do this at all for user code. 22 * 23 * For now I enable fixing of address errors by default to make life easier. 24 * I however intend to disable this somewhen in the future when the alignment 25 * problems with user programs have been fixed. For programmers this is the 26 * right way to go. 27 * 28 * Fixing address errors is a per process option. The option is inherited 29 * across fork(2) and execve(2) calls. If you really want to use the 30 * option in your user programs - I discourage the use of the software 31 * emulation strongly - use the following code in your userland stuff: 32 * 33 * #include <sys/sysmips.h> 34 * 35 * ... 36 * sysmips(MIPS_FIXADE, x); 37 * ... 38 * 39 * The argument x is 0 for disabling software emulation, enabled otherwise. 40 * 41 * Below a little program to play around with this feature. 42 * 43 * #include <stdio.h> 44 * #include <sys/sysmips.h> 45 * 46 * struct foo { 47 * unsigned char bar[8]; 48 * }; 49 * 50 * main(int argc, char *argv[]) 51 * { 52 * struct foo x = {0, 1, 2, 3, 4, 5, 6, 7}; 53 * unsigned int *p = (unsigned int *) (x.bar + 3); 54 * int i; 55 * 56 * if (argc > 1) 57 * sysmips(MIPS_FIXADE, atoi(argv[1])); 58 * 59 * printf("*p = %08lx\n", *p); 60 * 61 * *p = 0xdeadface; 62 * 63 * for(i = 0; i <= 7; i++) 64 * printf("%02x ", x.bar[i]); 65 * printf("\n"); 66 * } 67 * 68 * Coprocessor loads are not supported; I think this case is unimportant 69 * in the practice. 70 * 71 * TODO: Handle ndc (attempted store to doubleword in uncached memory) 72 * exception for the R6000. 73 * A store crossing a page boundary might be executed only partially. 74 * Undo the partial store in this case. 75 */ 76 #include <linux/context_tracking.h> 77 #include <linux/mm.h> 78 #include <linux/signal.h> 79 #include <linux/smp.h> 80 #include <linux/sched.h> 81 #include <linux/debugfs.h> 82 #include <linux/perf_event.h> 83 84 #include <asm/asm.h> 85 #include <asm/branch.h> 86 #include <asm/byteorder.h> 87 #include <asm/cop2.h> 88 #include <asm/debug.h> 89 #include <asm/fpu.h> 90 #include <asm/fpu_emulator.h> 91 #include <asm/inst.h> 92 #include <asm/mmu_context.h> 93 #include <linux/uaccess.h> 94 95 #define STR(x) __STR(x) 96 #define __STR(x) #x 97 98 enum { 99 UNALIGNED_ACTION_QUIET, 100 UNALIGNED_ACTION_SIGNAL, 101 UNALIGNED_ACTION_SHOW, 102 }; 103 #ifdef CONFIG_DEBUG_FS 104 static u32 unaligned_instructions; 105 static u32 unaligned_action; 106 #else 107 #define unaligned_action UNALIGNED_ACTION_QUIET 108 #endif 109 extern void show_registers(struct pt_regs *regs); 110 111 #ifdef __BIG_ENDIAN 112 #define _LoadHW(addr, value, res, type) \ 113 do { \ 114 __asm__ __volatile__ (".set\tnoat\n" \ 115 "1:\t"type##_lb("%0", "0(%2)")"\n" \ 116 "2:\t"type##_lbu("$1", "1(%2)")"\n\t"\ 117 "sll\t%0, 0x8\n\t" \ 118 "or\t%0, $1\n\t" \ 119 "li\t%1, 0\n" \ 120 "3:\t.set\tat\n\t" \ 121 ".insn\n\t" \ 122 ".section\t.fixup,\"ax\"\n\t" \ 123 "4:\tli\t%1, %3\n\t" \ 124 "j\t3b\n\t" \ 125 ".previous\n\t" \ 126 ".section\t__ex_table,\"a\"\n\t" \ 127 STR(PTR)"\t1b, 4b\n\t" \ 128 STR(PTR)"\t2b, 4b\n\t" \ 129 ".previous" \ 130 : "=&r" (value), "=r" (res) \ 131 : "r" (addr), "i" (-EFAULT)); \ 132 } while(0) 133 134 #ifndef CONFIG_CPU_NO_LOAD_STORE_LR 135 #define _LoadW(addr, value, res, type) \ 136 do { \ 137 __asm__ __volatile__ ( \ 138 "1:\t"type##_lwl("%0", "(%2)")"\n" \ 139 "2:\t"type##_lwr("%0", "3(%2)")"\n\t"\ 140 "li\t%1, 0\n" \ 141 "3:\n\t" \ 142 ".insn\n\t" \ 143 ".section\t.fixup,\"ax\"\n\t" \ 144 "4:\tli\t%1, %3\n\t" \ 145 "j\t3b\n\t" \ 146 ".previous\n\t" \ 147 ".section\t__ex_table,\"a\"\n\t" \ 148 STR(PTR)"\t1b, 4b\n\t" \ 149 STR(PTR)"\t2b, 4b\n\t" \ 150 ".previous" \ 151 : "=&r" (value), "=r" (res) \ 152 : "r" (addr), "i" (-EFAULT)); \ 153 } while(0) 154 155 #else /* CONFIG_CPU_NO_LOAD_STORE_LR */ 156 /* For CPUs without lwl instruction */ 157 #define _LoadW(addr, value, res, type) \ 158 do { \ 159 __asm__ __volatile__ ( \ 160 ".set\tpush\n" \ 161 ".set\tnoat\n\t" \ 162 "1:"type##_lb("%0", "0(%2)")"\n\t" \ 163 "2:"type##_lbu("$1", "1(%2)")"\n\t" \ 164 "sll\t%0, 0x8\n\t" \ 165 "or\t%0, $1\n\t" \ 166 "3:"type##_lbu("$1", "2(%2)")"\n\t" \ 167 "sll\t%0, 0x8\n\t" \ 168 "or\t%0, $1\n\t" \ 169 "4:"type##_lbu("$1", "3(%2)")"\n\t" \ 170 "sll\t%0, 0x8\n\t" \ 171 "or\t%0, $1\n\t" \ 172 "li\t%1, 0\n" \ 173 ".set\tpop\n" \ 174 "10:\n\t" \ 175 ".insn\n\t" \ 176 ".section\t.fixup,\"ax\"\n\t" \ 177 "11:\tli\t%1, %3\n\t" \ 178 "j\t10b\n\t" \ 179 ".previous\n\t" \ 180 ".section\t__ex_table,\"a\"\n\t" \ 181 STR(PTR)"\t1b, 11b\n\t" \ 182 STR(PTR)"\t2b, 11b\n\t" \ 183 STR(PTR)"\t3b, 11b\n\t" \ 184 STR(PTR)"\t4b, 11b\n\t" \ 185 ".previous" \ 186 : "=&r" (value), "=r" (res) \ 187 : "r" (addr), "i" (-EFAULT)); \ 188 } while(0) 189 190 #endif /* CONFIG_CPU_NO_LOAD_STORE_LR */ 191 192 #define _LoadHWU(addr, value, res, type) \ 193 do { \ 194 __asm__ __volatile__ ( \ 195 ".set\tnoat\n" \ 196 "1:\t"type##_lbu("%0", "0(%2)")"\n" \ 197 "2:\t"type##_lbu("$1", "1(%2)")"\n\t"\ 198 "sll\t%0, 0x8\n\t" \ 199 "or\t%0, $1\n\t" \ 200 "li\t%1, 0\n" \ 201 "3:\n\t" \ 202 ".insn\n\t" \ 203 ".set\tat\n\t" \ 204 ".section\t.fixup,\"ax\"\n\t" \ 205 "4:\tli\t%1, %3\n\t" \ 206 "j\t3b\n\t" \ 207 ".previous\n\t" \ 208 ".section\t__ex_table,\"a\"\n\t" \ 209 STR(PTR)"\t1b, 4b\n\t" \ 210 STR(PTR)"\t2b, 4b\n\t" \ 211 ".previous" \ 212 : "=&r" (value), "=r" (res) \ 213 : "r" (addr), "i" (-EFAULT)); \ 214 } while(0) 215 216 #ifndef CONFIG_CPU_NO_LOAD_STORE_LR 217 #define _LoadWU(addr, value, res, type) \ 218 do { \ 219 __asm__ __volatile__ ( \ 220 "1:\t"type##_lwl("%0", "(%2)")"\n" \ 221 "2:\t"type##_lwr("%0", "3(%2)")"\n\t"\ 222 "dsll\t%0, %0, 32\n\t" \ 223 "dsrl\t%0, %0, 32\n\t" \ 224 "li\t%1, 0\n" \ 225 "3:\n\t" \ 226 ".insn\n\t" \ 227 "\t.section\t.fixup,\"ax\"\n\t" \ 228 "4:\tli\t%1, %3\n\t" \ 229 "j\t3b\n\t" \ 230 ".previous\n\t" \ 231 ".section\t__ex_table,\"a\"\n\t" \ 232 STR(PTR)"\t1b, 4b\n\t" \ 233 STR(PTR)"\t2b, 4b\n\t" \ 234 ".previous" \ 235 : "=&r" (value), "=r" (res) \ 236 : "r" (addr), "i" (-EFAULT)); \ 237 } while(0) 238 239 #define _LoadDW(addr, value, res) \ 240 do { \ 241 __asm__ __volatile__ ( \ 242 "1:\tldl\t%0, (%2)\n" \ 243 "2:\tldr\t%0, 7(%2)\n\t" \ 244 "li\t%1, 0\n" \ 245 "3:\n\t" \ 246 ".insn\n\t" \ 247 "\t.section\t.fixup,\"ax\"\n\t" \ 248 "4:\tli\t%1, %3\n\t" \ 249 "j\t3b\n\t" \ 250 ".previous\n\t" \ 251 ".section\t__ex_table,\"a\"\n\t" \ 252 STR(PTR)"\t1b, 4b\n\t" \ 253 STR(PTR)"\t2b, 4b\n\t" \ 254 ".previous" \ 255 : "=&r" (value), "=r" (res) \ 256 : "r" (addr), "i" (-EFAULT)); \ 257 } while(0) 258 259 #else /* CONFIG_CPU_NO_LOAD_STORE_LR */ 260 /* For CPUs without lwl and ldl instructions */ 261 #define _LoadWU(addr, value, res, type) \ 262 do { \ 263 __asm__ __volatile__ ( \ 264 ".set\tpush\n\t" \ 265 ".set\tnoat\n\t" \ 266 "1:"type##_lbu("%0", "0(%2)")"\n\t" \ 267 "2:"type##_lbu("$1", "1(%2)")"\n\t" \ 268 "sll\t%0, 0x8\n\t" \ 269 "or\t%0, $1\n\t" \ 270 "3:"type##_lbu("$1", "2(%2)")"\n\t" \ 271 "sll\t%0, 0x8\n\t" \ 272 "or\t%0, $1\n\t" \ 273 "4:"type##_lbu("$1", "3(%2)")"\n\t" \ 274 "sll\t%0, 0x8\n\t" \ 275 "or\t%0, $1\n\t" \ 276 "li\t%1, 0\n" \ 277 ".set\tpop\n" \ 278 "10:\n\t" \ 279 ".insn\n\t" \ 280 ".section\t.fixup,\"ax\"\n\t" \ 281 "11:\tli\t%1, %3\n\t" \ 282 "j\t10b\n\t" \ 283 ".previous\n\t" \ 284 ".section\t__ex_table,\"a\"\n\t" \ 285 STR(PTR)"\t1b, 11b\n\t" \ 286 STR(PTR)"\t2b, 11b\n\t" \ 287 STR(PTR)"\t3b, 11b\n\t" \ 288 STR(PTR)"\t4b, 11b\n\t" \ 289 ".previous" \ 290 : "=&r" (value), "=r" (res) \ 291 : "r" (addr), "i" (-EFAULT)); \ 292 } while(0) 293 294 #define _LoadDW(addr, value, res) \ 295 do { \ 296 __asm__ __volatile__ ( \ 297 ".set\tpush\n\t" \ 298 ".set\tnoat\n\t" \ 299 "1:lb\t%0, 0(%2)\n\t" \ 300 "2:lbu\t $1, 1(%2)\n\t" \ 301 "dsll\t%0, 0x8\n\t" \ 302 "or\t%0, $1\n\t" \ 303 "3:lbu\t$1, 2(%2)\n\t" \ 304 "dsll\t%0, 0x8\n\t" \ 305 "or\t%0, $1\n\t" \ 306 "4:lbu\t$1, 3(%2)\n\t" \ 307 "dsll\t%0, 0x8\n\t" \ 308 "or\t%0, $1\n\t" \ 309 "5:lbu\t$1, 4(%2)\n\t" \ 310 "dsll\t%0, 0x8\n\t" \ 311 "or\t%0, $1\n\t" \ 312 "6:lbu\t$1, 5(%2)\n\t" \ 313 "dsll\t%0, 0x8\n\t" \ 314 "or\t%0, $1\n\t" \ 315 "7:lbu\t$1, 6(%2)\n\t" \ 316 "dsll\t%0, 0x8\n\t" \ 317 "or\t%0, $1\n\t" \ 318 "8:lbu\t$1, 7(%2)\n\t" \ 319 "dsll\t%0, 0x8\n\t" \ 320 "or\t%0, $1\n\t" \ 321 "li\t%1, 0\n" \ 322 ".set\tpop\n\t" \ 323 "10:\n\t" \ 324 ".insn\n\t" \ 325 ".section\t.fixup,\"ax\"\n\t" \ 326 "11:\tli\t%1, %3\n\t" \ 327 "j\t10b\n\t" \ 328 ".previous\n\t" \ 329 ".section\t__ex_table,\"a\"\n\t" \ 330 STR(PTR)"\t1b, 11b\n\t" \ 331 STR(PTR)"\t2b, 11b\n\t" \ 332 STR(PTR)"\t3b, 11b\n\t" \ 333 STR(PTR)"\t4b, 11b\n\t" \ 334 STR(PTR)"\t5b, 11b\n\t" \ 335 STR(PTR)"\t6b, 11b\n\t" \ 336 STR(PTR)"\t7b, 11b\n\t" \ 337 STR(PTR)"\t8b, 11b\n\t" \ 338 ".previous" \ 339 : "=&r" (value), "=r" (res) \ 340 : "r" (addr), "i" (-EFAULT)); \ 341 } while(0) 342 343 #endif /* CONFIG_CPU_NO_LOAD_STORE_LR */ 344 345 346 #define _StoreHW(addr, value, res, type) \ 347 do { \ 348 __asm__ __volatile__ ( \ 349 ".set\tnoat\n" \ 350 "1:\t"type##_sb("%1", "1(%2)")"\n" \ 351 "srl\t$1, %1, 0x8\n" \ 352 "2:\t"type##_sb("$1", "0(%2)")"\n" \ 353 ".set\tat\n\t" \ 354 "li\t%0, 0\n" \ 355 "3:\n\t" \ 356 ".insn\n\t" \ 357 ".section\t.fixup,\"ax\"\n\t" \ 358 "4:\tli\t%0, %3\n\t" \ 359 "j\t3b\n\t" \ 360 ".previous\n\t" \ 361 ".section\t__ex_table,\"a\"\n\t" \ 362 STR(PTR)"\t1b, 4b\n\t" \ 363 STR(PTR)"\t2b, 4b\n\t" \ 364 ".previous" \ 365 : "=r" (res) \ 366 : "r" (value), "r" (addr), "i" (-EFAULT));\ 367 } while(0) 368 369 #ifndef CONFIG_CPU_NO_LOAD_STORE_LR 370 #define _StoreW(addr, value, res, type) \ 371 do { \ 372 __asm__ __volatile__ ( \ 373 "1:\t"type##_swl("%1", "(%2)")"\n" \ 374 "2:\t"type##_swr("%1", "3(%2)")"\n\t"\ 375 "li\t%0, 0\n" \ 376 "3:\n\t" \ 377 ".insn\n\t" \ 378 ".section\t.fixup,\"ax\"\n\t" \ 379 "4:\tli\t%0, %3\n\t" \ 380 "j\t3b\n\t" \ 381 ".previous\n\t" \ 382 ".section\t__ex_table,\"a\"\n\t" \ 383 STR(PTR)"\t1b, 4b\n\t" \ 384 STR(PTR)"\t2b, 4b\n\t" \ 385 ".previous" \ 386 : "=r" (res) \ 387 : "r" (value), "r" (addr), "i" (-EFAULT)); \ 388 } while(0) 389 390 #define _StoreDW(addr, value, res) \ 391 do { \ 392 __asm__ __volatile__ ( \ 393 "1:\tsdl\t%1,(%2)\n" \ 394 "2:\tsdr\t%1, 7(%2)\n\t" \ 395 "li\t%0, 0\n" \ 396 "3:\n\t" \ 397 ".insn\n\t" \ 398 ".section\t.fixup,\"ax\"\n\t" \ 399 "4:\tli\t%0, %3\n\t" \ 400 "j\t3b\n\t" \ 401 ".previous\n\t" \ 402 ".section\t__ex_table,\"a\"\n\t" \ 403 STR(PTR)"\t1b, 4b\n\t" \ 404 STR(PTR)"\t2b, 4b\n\t" \ 405 ".previous" \ 406 : "=r" (res) \ 407 : "r" (value), "r" (addr), "i" (-EFAULT)); \ 408 } while(0) 409 410 #else /* CONFIG_CPU_NO_LOAD_STORE_LR */ 411 #define _StoreW(addr, value, res, type) \ 412 do { \ 413 __asm__ __volatile__ ( \ 414 ".set\tpush\n\t" \ 415 ".set\tnoat\n\t" \ 416 "1:"type##_sb("%1", "3(%2)")"\n\t" \ 417 "srl\t$1, %1, 0x8\n\t" \ 418 "2:"type##_sb("$1", "2(%2)")"\n\t" \ 419 "srl\t$1, $1, 0x8\n\t" \ 420 "3:"type##_sb("$1", "1(%2)")"\n\t" \ 421 "srl\t$1, $1, 0x8\n\t" \ 422 "4:"type##_sb("$1", "0(%2)")"\n\t" \ 423 ".set\tpop\n\t" \ 424 "li\t%0, 0\n" \ 425 "10:\n\t" \ 426 ".insn\n\t" \ 427 ".section\t.fixup,\"ax\"\n\t" \ 428 "11:\tli\t%0, %3\n\t" \ 429 "j\t10b\n\t" \ 430 ".previous\n\t" \ 431 ".section\t__ex_table,\"a\"\n\t" \ 432 STR(PTR)"\t1b, 11b\n\t" \ 433 STR(PTR)"\t2b, 11b\n\t" \ 434 STR(PTR)"\t3b, 11b\n\t" \ 435 STR(PTR)"\t4b, 11b\n\t" \ 436 ".previous" \ 437 : "=&r" (res) \ 438 : "r" (value), "r" (addr), "i" (-EFAULT) \ 439 : "memory"); \ 440 } while(0) 441 442 #define _StoreDW(addr, value, res) \ 443 do { \ 444 __asm__ __volatile__ ( \ 445 ".set\tpush\n\t" \ 446 ".set\tnoat\n\t" \ 447 "1:sb\t%1, 7(%2)\n\t" \ 448 "dsrl\t$1, %1, 0x8\n\t" \ 449 "2:sb\t$1, 6(%2)\n\t" \ 450 "dsrl\t$1, $1, 0x8\n\t" \ 451 "3:sb\t$1, 5(%2)\n\t" \ 452 "dsrl\t$1, $1, 0x8\n\t" \ 453 "4:sb\t$1, 4(%2)\n\t" \ 454 "dsrl\t$1, $1, 0x8\n\t" \ 455 "5:sb\t$1, 3(%2)\n\t" \ 456 "dsrl\t$1, $1, 0x8\n\t" \ 457 "6:sb\t$1, 2(%2)\n\t" \ 458 "dsrl\t$1, $1, 0x8\n\t" \ 459 "7:sb\t$1, 1(%2)\n\t" \ 460 "dsrl\t$1, $1, 0x8\n\t" \ 461 "8:sb\t$1, 0(%2)\n\t" \ 462 "dsrl\t$1, $1, 0x8\n\t" \ 463 ".set\tpop\n\t" \ 464 "li\t%0, 0\n" \ 465 "10:\n\t" \ 466 ".insn\n\t" \ 467 ".section\t.fixup,\"ax\"\n\t" \ 468 "11:\tli\t%0, %3\n\t" \ 469 "j\t10b\n\t" \ 470 ".previous\n\t" \ 471 ".section\t__ex_table,\"a\"\n\t" \ 472 STR(PTR)"\t1b, 11b\n\t" \ 473 STR(PTR)"\t2b, 11b\n\t" \ 474 STR(PTR)"\t3b, 11b\n\t" \ 475 STR(PTR)"\t4b, 11b\n\t" \ 476 STR(PTR)"\t5b, 11b\n\t" \ 477 STR(PTR)"\t6b, 11b\n\t" \ 478 STR(PTR)"\t7b, 11b\n\t" \ 479 STR(PTR)"\t8b, 11b\n\t" \ 480 ".previous" \ 481 : "=&r" (res) \ 482 : "r" (value), "r" (addr), "i" (-EFAULT) \ 483 : "memory"); \ 484 } while(0) 485 486 #endif /* CONFIG_CPU_NO_LOAD_STORE_LR */ 487 488 #else /* __BIG_ENDIAN */ 489 490 #define _LoadHW(addr, value, res, type) \ 491 do { \ 492 __asm__ __volatile__ (".set\tnoat\n" \ 493 "1:\t"type##_lb("%0", "1(%2)")"\n" \ 494 "2:\t"type##_lbu("$1", "0(%2)")"\n\t"\ 495 "sll\t%0, 0x8\n\t" \ 496 "or\t%0, $1\n\t" \ 497 "li\t%1, 0\n" \ 498 "3:\t.set\tat\n\t" \ 499 ".insn\n\t" \ 500 ".section\t.fixup,\"ax\"\n\t" \ 501 "4:\tli\t%1, %3\n\t" \ 502 "j\t3b\n\t" \ 503 ".previous\n\t" \ 504 ".section\t__ex_table,\"a\"\n\t" \ 505 STR(PTR)"\t1b, 4b\n\t" \ 506 STR(PTR)"\t2b, 4b\n\t" \ 507 ".previous" \ 508 : "=&r" (value), "=r" (res) \ 509 : "r" (addr), "i" (-EFAULT)); \ 510 } while(0) 511 512 #ifndef CONFIG_CPU_NO_LOAD_STORE_LR 513 #define _LoadW(addr, value, res, type) \ 514 do { \ 515 __asm__ __volatile__ ( \ 516 "1:\t"type##_lwl("%0", "3(%2)")"\n" \ 517 "2:\t"type##_lwr("%0", "(%2)")"\n\t"\ 518 "li\t%1, 0\n" \ 519 "3:\n\t" \ 520 ".insn\n\t" \ 521 ".section\t.fixup,\"ax\"\n\t" \ 522 "4:\tli\t%1, %3\n\t" \ 523 "j\t3b\n\t" \ 524 ".previous\n\t" \ 525 ".section\t__ex_table,\"a\"\n\t" \ 526 STR(PTR)"\t1b, 4b\n\t" \ 527 STR(PTR)"\t2b, 4b\n\t" \ 528 ".previous" \ 529 : "=&r" (value), "=r" (res) \ 530 : "r" (addr), "i" (-EFAULT)); \ 531 } while(0) 532 533 #else /* CONFIG_CPU_NO_LOAD_STORE_LR */ 534 /* For CPUs without lwl instruction */ 535 #define _LoadW(addr, value, res, type) \ 536 do { \ 537 __asm__ __volatile__ ( \ 538 ".set\tpush\n" \ 539 ".set\tnoat\n\t" \ 540 "1:"type##_lb("%0", "3(%2)")"\n\t" \ 541 "2:"type##_lbu("$1", "2(%2)")"\n\t" \ 542 "sll\t%0, 0x8\n\t" \ 543 "or\t%0, $1\n\t" \ 544 "3:"type##_lbu("$1", "1(%2)")"\n\t" \ 545 "sll\t%0, 0x8\n\t" \ 546 "or\t%0, $1\n\t" \ 547 "4:"type##_lbu("$1", "0(%2)")"\n\t" \ 548 "sll\t%0, 0x8\n\t" \ 549 "or\t%0, $1\n\t" \ 550 "li\t%1, 0\n" \ 551 ".set\tpop\n" \ 552 "10:\n\t" \ 553 ".insn\n\t" \ 554 ".section\t.fixup,\"ax\"\n\t" \ 555 "11:\tli\t%1, %3\n\t" \ 556 "j\t10b\n\t" \ 557 ".previous\n\t" \ 558 ".section\t__ex_table,\"a\"\n\t" \ 559 STR(PTR)"\t1b, 11b\n\t" \ 560 STR(PTR)"\t2b, 11b\n\t" \ 561 STR(PTR)"\t3b, 11b\n\t" \ 562 STR(PTR)"\t4b, 11b\n\t" \ 563 ".previous" \ 564 : "=&r" (value), "=r" (res) \ 565 : "r" (addr), "i" (-EFAULT)); \ 566 } while(0) 567 568 #endif /* CONFIG_CPU_NO_LOAD_STORE_LR */ 569 570 571 #define _LoadHWU(addr, value, res, type) \ 572 do { \ 573 __asm__ __volatile__ ( \ 574 ".set\tnoat\n" \ 575 "1:\t"type##_lbu("%0", "1(%2)")"\n" \ 576 "2:\t"type##_lbu("$1", "0(%2)")"\n\t"\ 577 "sll\t%0, 0x8\n\t" \ 578 "or\t%0, $1\n\t" \ 579 "li\t%1, 0\n" \ 580 "3:\n\t" \ 581 ".insn\n\t" \ 582 ".set\tat\n\t" \ 583 ".section\t.fixup,\"ax\"\n\t" \ 584 "4:\tli\t%1, %3\n\t" \ 585 "j\t3b\n\t" \ 586 ".previous\n\t" \ 587 ".section\t__ex_table,\"a\"\n\t" \ 588 STR(PTR)"\t1b, 4b\n\t" \ 589 STR(PTR)"\t2b, 4b\n\t" \ 590 ".previous" \ 591 : "=&r" (value), "=r" (res) \ 592 : "r" (addr), "i" (-EFAULT)); \ 593 } while(0) 594 595 #ifndef CONFIG_CPU_NO_LOAD_STORE_LR 596 #define _LoadWU(addr, value, res, type) \ 597 do { \ 598 __asm__ __volatile__ ( \ 599 "1:\t"type##_lwl("%0", "3(%2)")"\n" \ 600 "2:\t"type##_lwr("%0", "(%2)")"\n\t"\ 601 "dsll\t%0, %0, 32\n\t" \ 602 "dsrl\t%0, %0, 32\n\t" \ 603 "li\t%1, 0\n" \ 604 "3:\n\t" \ 605 ".insn\n\t" \ 606 "\t.section\t.fixup,\"ax\"\n\t" \ 607 "4:\tli\t%1, %3\n\t" \ 608 "j\t3b\n\t" \ 609 ".previous\n\t" \ 610 ".section\t__ex_table,\"a\"\n\t" \ 611 STR(PTR)"\t1b, 4b\n\t" \ 612 STR(PTR)"\t2b, 4b\n\t" \ 613 ".previous" \ 614 : "=&r" (value), "=r" (res) \ 615 : "r" (addr), "i" (-EFAULT)); \ 616 } while(0) 617 618 #define _LoadDW(addr, value, res) \ 619 do { \ 620 __asm__ __volatile__ ( \ 621 "1:\tldl\t%0, 7(%2)\n" \ 622 "2:\tldr\t%0, (%2)\n\t" \ 623 "li\t%1, 0\n" \ 624 "3:\n\t" \ 625 ".insn\n\t" \ 626 "\t.section\t.fixup,\"ax\"\n\t" \ 627 "4:\tli\t%1, %3\n\t" \ 628 "j\t3b\n\t" \ 629 ".previous\n\t" \ 630 ".section\t__ex_table,\"a\"\n\t" \ 631 STR(PTR)"\t1b, 4b\n\t" \ 632 STR(PTR)"\t2b, 4b\n\t" \ 633 ".previous" \ 634 : "=&r" (value), "=r" (res) \ 635 : "r" (addr), "i" (-EFAULT)); \ 636 } while(0) 637 638 #else /* CONFIG_CPU_NO_LOAD_STORE_LR */ 639 /* For CPUs without lwl and ldl instructions */ 640 #define _LoadWU(addr, value, res, type) \ 641 do { \ 642 __asm__ __volatile__ ( \ 643 ".set\tpush\n\t" \ 644 ".set\tnoat\n\t" \ 645 "1:"type##_lbu("%0", "3(%2)")"\n\t" \ 646 "2:"type##_lbu("$1", "2(%2)")"\n\t" \ 647 "sll\t%0, 0x8\n\t" \ 648 "or\t%0, $1\n\t" \ 649 "3:"type##_lbu("$1", "1(%2)")"\n\t" \ 650 "sll\t%0, 0x8\n\t" \ 651 "or\t%0, $1\n\t" \ 652 "4:"type##_lbu("$1", "0(%2)")"\n\t" \ 653 "sll\t%0, 0x8\n\t" \ 654 "or\t%0, $1\n\t" \ 655 "li\t%1, 0\n" \ 656 ".set\tpop\n" \ 657 "10:\n\t" \ 658 ".insn\n\t" \ 659 ".section\t.fixup,\"ax\"\n\t" \ 660 "11:\tli\t%1, %3\n\t" \ 661 "j\t10b\n\t" \ 662 ".previous\n\t" \ 663 ".section\t__ex_table,\"a\"\n\t" \ 664 STR(PTR)"\t1b, 11b\n\t" \ 665 STR(PTR)"\t2b, 11b\n\t" \ 666 STR(PTR)"\t3b, 11b\n\t" \ 667 STR(PTR)"\t4b, 11b\n\t" \ 668 ".previous" \ 669 : "=&r" (value), "=r" (res) \ 670 : "r" (addr), "i" (-EFAULT)); \ 671 } while(0) 672 673 #define _LoadDW(addr, value, res) \ 674 do { \ 675 __asm__ __volatile__ ( \ 676 ".set\tpush\n\t" \ 677 ".set\tnoat\n\t" \ 678 "1:lb\t%0, 7(%2)\n\t" \ 679 "2:lbu\t$1, 6(%2)\n\t" \ 680 "dsll\t%0, 0x8\n\t" \ 681 "or\t%0, $1\n\t" \ 682 "3:lbu\t$1, 5(%2)\n\t" \ 683 "dsll\t%0, 0x8\n\t" \ 684 "or\t%0, $1\n\t" \ 685 "4:lbu\t$1, 4(%2)\n\t" \ 686 "dsll\t%0, 0x8\n\t" \ 687 "or\t%0, $1\n\t" \ 688 "5:lbu\t$1, 3(%2)\n\t" \ 689 "dsll\t%0, 0x8\n\t" \ 690 "or\t%0, $1\n\t" \ 691 "6:lbu\t$1, 2(%2)\n\t" \ 692 "dsll\t%0, 0x8\n\t" \ 693 "or\t%0, $1\n\t" \ 694 "7:lbu\t$1, 1(%2)\n\t" \ 695 "dsll\t%0, 0x8\n\t" \ 696 "or\t%0, $1\n\t" \ 697 "8:lbu\t$1, 0(%2)\n\t" \ 698 "dsll\t%0, 0x8\n\t" \ 699 "or\t%0, $1\n\t" \ 700 "li\t%1, 0\n" \ 701 ".set\tpop\n\t" \ 702 "10:\n\t" \ 703 ".insn\n\t" \ 704 ".section\t.fixup,\"ax\"\n\t" \ 705 "11:\tli\t%1, %3\n\t" \ 706 "j\t10b\n\t" \ 707 ".previous\n\t" \ 708 ".section\t__ex_table,\"a\"\n\t" \ 709 STR(PTR)"\t1b, 11b\n\t" \ 710 STR(PTR)"\t2b, 11b\n\t" \ 711 STR(PTR)"\t3b, 11b\n\t" \ 712 STR(PTR)"\t4b, 11b\n\t" \ 713 STR(PTR)"\t5b, 11b\n\t" \ 714 STR(PTR)"\t6b, 11b\n\t" \ 715 STR(PTR)"\t7b, 11b\n\t" \ 716 STR(PTR)"\t8b, 11b\n\t" \ 717 ".previous" \ 718 : "=&r" (value), "=r" (res) \ 719 : "r" (addr), "i" (-EFAULT)); \ 720 } while(0) 721 #endif /* CONFIG_CPU_NO_LOAD_STORE_LR */ 722 723 #define _StoreHW(addr, value, res, type) \ 724 do { \ 725 __asm__ __volatile__ ( \ 726 ".set\tnoat\n" \ 727 "1:\t"type##_sb("%1", "0(%2)")"\n" \ 728 "srl\t$1,%1, 0x8\n" \ 729 "2:\t"type##_sb("$1", "1(%2)")"\n" \ 730 ".set\tat\n\t" \ 731 "li\t%0, 0\n" \ 732 "3:\n\t" \ 733 ".insn\n\t" \ 734 ".section\t.fixup,\"ax\"\n\t" \ 735 "4:\tli\t%0, %3\n\t" \ 736 "j\t3b\n\t" \ 737 ".previous\n\t" \ 738 ".section\t__ex_table,\"a\"\n\t" \ 739 STR(PTR)"\t1b, 4b\n\t" \ 740 STR(PTR)"\t2b, 4b\n\t" \ 741 ".previous" \ 742 : "=r" (res) \ 743 : "r" (value), "r" (addr), "i" (-EFAULT));\ 744 } while(0) 745 746 #ifndef CONFIG_CPU_NO_LOAD_STORE_LR 747 #define _StoreW(addr, value, res, type) \ 748 do { \ 749 __asm__ __volatile__ ( \ 750 "1:\t"type##_swl("%1", "3(%2)")"\n" \ 751 "2:\t"type##_swr("%1", "(%2)")"\n\t"\ 752 "li\t%0, 0\n" \ 753 "3:\n\t" \ 754 ".insn\n\t" \ 755 ".section\t.fixup,\"ax\"\n\t" \ 756 "4:\tli\t%0, %3\n\t" \ 757 "j\t3b\n\t" \ 758 ".previous\n\t" \ 759 ".section\t__ex_table,\"a\"\n\t" \ 760 STR(PTR)"\t1b, 4b\n\t" \ 761 STR(PTR)"\t2b, 4b\n\t" \ 762 ".previous" \ 763 : "=r" (res) \ 764 : "r" (value), "r" (addr), "i" (-EFAULT)); \ 765 } while(0) 766 767 #define _StoreDW(addr, value, res) \ 768 do { \ 769 __asm__ __volatile__ ( \ 770 "1:\tsdl\t%1, 7(%2)\n" \ 771 "2:\tsdr\t%1, (%2)\n\t" \ 772 "li\t%0, 0\n" \ 773 "3:\n\t" \ 774 ".insn\n\t" \ 775 ".section\t.fixup,\"ax\"\n\t" \ 776 "4:\tli\t%0, %3\n\t" \ 777 "j\t3b\n\t" \ 778 ".previous\n\t" \ 779 ".section\t__ex_table,\"a\"\n\t" \ 780 STR(PTR)"\t1b, 4b\n\t" \ 781 STR(PTR)"\t2b, 4b\n\t" \ 782 ".previous" \ 783 : "=r" (res) \ 784 : "r" (value), "r" (addr), "i" (-EFAULT)); \ 785 } while(0) 786 787 #else /* CONFIG_CPU_NO_LOAD_STORE_LR */ 788 /* For CPUs without swl and sdl instructions */ 789 #define _StoreW(addr, value, res, type) \ 790 do { \ 791 __asm__ __volatile__ ( \ 792 ".set\tpush\n\t" \ 793 ".set\tnoat\n\t" \ 794 "1:"type##_sb("%1", "0(%2)")"\n\t" \ 795 "srl\t$1, %1, 0x8\n\t" \ 796 "2:"type##_sb("$1", "1(%2)")"\n\t" \ 797 "srl\t$1, $1, 0x8\n\t" \ 798 "3:"type##_sb("$1", "2(%2)")"\n\t" \ 799 "srl\t$1, $1, 0x8\n\t" \ 800 "4:"type##_sb("$1", "3(%2)")"\n\t" \ 801 ".set\tpop\n\t" \ 802 "li\t%0, 0\n" \ 803 "10:\n\t" \ 804 ".insn\n\t" \ 805 ".section\t.fixup,\"ax\"\n\t" \ 806 "11:\tli\t%0, %3\n\t" \ 807 "j\t10b\n\t" \ 808 ".previous\n\t" \ 809 ".section\t__ex_table,\"a\"\n\t" \ 810 STR(PTR)"\t1b, 11b\n\t" \ 811 STR(PTR)"\t2b, 11b\n\t" \ 812 STR(PTR)"\t3b, 11b\n\t" \ 813 STR(PTR)"\t4b, 11b\n\t" \ 814 ".previous" \ 815 : "=&r" (res) \ 816 : "r" (value), "r" (addr), "i" (-EFAULT) \ 817 : "memory"); \ 818 } while(0) 819 820 #define _StoreDW(addr, value, res) \ 821 do { \ 822 __asm__ __volatile__ ( \ 823 ".set\tpush\n\t" \ 824 ".set\tnoat\n\t" \ 825 "1:sb\t%1, 0(%2)\n\t" \ 826 "dsrl\t$1, %1, 0x8\n\t" \ 827 "2:sb\t$1, 1(%2)\n\t" \ 828 "dsrl\t$1, $1, 0x8\n\t" \ 829 "3:sb\t$1, 2(%2)\n\t" \ 830 "dsrl\t$1, $1, 0x8\n\t" \ 831 "4:sb\t$1, 3(%2)\n\t" \ 832 "dsrl\t$1, $1, 0x8\n\t" \ 833 "5:sb\t$1, 4(%2)\n\t" \ 834 "dsrl\t$1, $1, 0x8\n\t" \ 835 "6:sb\t$1, 5(%2)\n\t" \ 836 "dsrl\t$1, $1, 0x8\n\t" \ 837 "7:sb\t$1, 6(%2)\n\t" \ 838 "dsrl\t$1, $1, 0x8\n\t" \ 839 "8:sb\t$1, 7(%2)\n\t" \ 840 "dsrl\t$1, $1, 0x8\n\t" \ 841 ".set\tpop\n\t" \ 842 "li\t%0, 0\n" \ 843 "10:\n\t" \ 844 ".insn\n\t" \ 845 ".section\t.fixup,\"ax\"\n\t" \ 846 "11:\tli\t%0, %3\n\t" \ 847 "j\t10b\n\t" \ 848 ".previous\n\t" \ 849 ".section\t__ex_table,\"a\"\n\t" \ 850 STR(PTR)"\t1b, 11b\n\t" \ 851 STR(PTR)"\t2b, 11b\n\t" \ 852 STR(PTR)"\t3b, 11b\n\t" \ 853 STR(PTR)"\t4b, 11b\n\t" \ 854 STR(PTR)"\t5b, 11b\n\t" \ 855 STR(PTR)"\t6b, 11b\n\t" \ 856 STR(PTR)"\t7b, 11b\n\t" \ 857 STR(PTR)"\t8b, 11b\n\t" \ 858 ".previous" \ 859 : "=&r" (res) \ 860 : "r" (value), "r" (addr), "i" (-EFAULT) \ 861 : "memory"); \ 862 } while(0) 863 864 #endif /* CONFIG_CPU_NO_LOAD_STORE_LR */ 865 #endif 866 867 #define LoadHWU(addr, value, res) _LoadHWU(addr, value, res, kernel) 868 #define LoadHWUE(addr, value, res) _LoadHWU(addr, value, res, user) 869 #define LoadWU(addr, value, res) _LoadWU(addr, value, res, kernel) 870 #define LoadWUE(addr, value, res) _LoadWU(addr, value, res, user) 871 #define LoadHW(addr, value, res) _LoadHW(addr, value, res, kernel) 872 #define LoadHWE(addr, value, res) _LoadHW(addr, value, res, user) 873 #define LoadW(addr, value, res) _LoadW(addr, value, res, kernel) 874 #define LoadWE(addr, value, res) _LoadW(addr, value, res, user) 875 #define LoadDW(addr, value, res) _LoadDW(addr, value, res) 876 877 #define StoreHW(addr, value, res) _StoreHW(addr, value, res, kernel) 878 #define StoreHWE(addr, value, res) _StoreHW(addr, value, res, user) 879 #define StoreW(addr, value, res) _StoreW(addr, value, res, kernel) 880 #define StoreWE(addr, value, res) _StoreW(addr, value, res, user) 881 #define StoreDW(addr, value, res) _StoreDW(addr, value, res) 882 883 static void emulate_load_store_insn(struct pt_regs *regs, 884 void __user *addr, unsigned int __user *pc) 885 { 886 unsigned long origpc, orig31, value; 887 union mips_instruction insn; 888 unsigned int res; 889 #ifdef CONFIG_EVA 890 mm_segment_t seg; 891 #endif 892 origpc = (unsigned long)pc; 893 orig31 = regs->regs[31]; 894 895 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0); 896 897 /* 898 * This load never faults. 899 */ 900 __get_user(insn.word, pc); 901 902 switch (insn.i_format.opcode) { 903 /* 904 * These are instructions that a compiler doesn't generate. We 905 * can assume therefore that the code is MIPS-aware and 906 * really buggy. Emulating these instructions would break the 907 * semantics anyway. 908 */ 909 case ll_op: 910 case lld_op: 911 case sc_op: 912 case scd_op: 913 914 /* 915 * For these instructions the only way to create an address 916 * error is an attempted access to kernel/supervisor address 917 * space. 918 */ 919 case ldl_op: 920 case ldr_op: 921 case lwl_op: 922 case lwr_op: 923 case sdl_op: 924 case sdr_op: 925 case swl_op: 926 case swr_op: 927 case lb_op: 928 case lbu_op: 929 case sb_op: 930 goto sigbus; 931 932 /* 933 * The remaining opcodes are the ones that are really of 934 * interest. 935 */ 936 case spec3_op: 937 if (insn.dsp_format.func == lx_op) { 938 switch (insn.dsp_format.op) { 939 case lwx_op: 940 if (!access_ok(addr, 4)) 941 goto sigbus; 942 LoadW(addr, value, res); 943 if (res) 944 goto fault; 945 compute_return_epc(regs); 946 regs->regs[insn.dsp_format.rd] = value; 947 break; 948 case lhx_op: 949 if (!access_ok(addr, 2)) 950 goto sigbus; 951 LoadHW(addr, value, res); 952 if (res) 953 goto fault; 954 compute_return_epc(regs); 955 regs->regs[insn.dsp_format.rd] = value; 956 break; 957 default: 958 goto sigill; 959 } 960 } 961 #ifdef CONFIG_EVA 962 else { 963 /* 964 * we can land here only from kernel accessing user 965 * memory, so we need to "switch" the address limit to 966 * user space, so that address check can work properly. 967 */ 968 seg = get_fs(); 969 set_fs(USER_DS); 970 switch (insn.spec3_format.func) { 971 case lhe_op: 972 if (!access_ok(addr, 2)) { 973 set_fs(seg); 974 goto sigbus; 975 } 976 LoadHWE(addr, value, res); 977 if (res) { 978 set_fs(seg); 979 goto fault; 980 } 981 compute_return_epc(regs); 982 regs->regs[insn.spec3_format.rt] = value; 983 break; 984 case lwe_op: 985 if (!access_ok(addr, 4)) { 986 set_fs(seg); 987 goto sigbus; 988 } 989 LoadWE(addr, value, res); 990 if (res) { 991 set_fs(seg); 992 goto fault; 993 } 994 compute_return_epc(regs); 995 regs->regs[insn.spec3_format.rt] = value; 996 break; 997 case lhue_op: 998 if (!access_ok(addr, 2)) { 999 set_fs(seg); 1000 goto sigbus; 1001 } 1002 LoadHWUE(addr, value, res); 1003 if (res) { 1004 set_fs(seg); 1005 goto fault; 1006 } 1007 compute_return_epc(regs); 1008 regs->regs[insn.spec3_format.rt] = value; 1009 break; 1010 case she_op: 1011 if (!access_ok(addr, 2)) { 1012 set_fs(seg); 1013 goto sigbus; 1014 } 1015 compute_return_epc(regs); 1016 value = regs->regs[insn.spec3_format.rt]; 1017 StoreHWE(addr, value, res); 1018 if (res) { 1019 set_fs(seg); 1020 goto fault; 1021 } 1022 break; 1023 case swe_op: 1024 if (!access_ok(addr, 4)) { 1025 set_fs(seg); 1026 goto sigbus; 1027 } 1028 compute_return_epc(regs); 1029 value = regs->regs[insn.spec3_format.rt]; 1030 StoreWE(addr, value, res); 1031 if (res) { 1032 set_fs(seg); 1033 goto fault; 1034 } 1035 break; 1036 default: 1037 set_fs(seg); 1038 goto sigill; 1039 } 1040 set_fs(seg); 1041 } 1042 #endif 1043 break; 1044 case lh_op: 1045 if (!access_ok(addr, 2)) 1046 goto sigbus; 1047 1048 if (IS_ENABLED(CONFIG_EVA)) { 1049 if (uaccess_kernel()) 1050 LoadHW(addr, value, res); 1051 else 1052 LoadHWE(addr, value, res); 1053 } else { 1054 LoadHW(addr, value, res); 1055 } 1056 1057 if (res) 1058 goto fault; 1059 compute_return_epc(regs); 1060 regs->regs[insn.i_format.rt] = value; 1061 break; 1062 1063 case lw_op: 1064 if (!access_ok(addr, 4)) 1065 goto sigbus; 1066 1067 if (IS_ENABLED(CONFIG_EVA)) { 1068 if (uaccess_kernel()) 1069 LoadW(addr, value, res); 1070 else 1071 LoadWE(addr, value, res); 1072 } else { 1073 LoadW(addr, value, res); 1074 } 1075 1076 if (res) 1077 goto fault; 1078 compute_return_epc(regs); 1079 regs->regs[insn.i_format.rt] = value; 1080 break; 1081 1082 case lhu_op: 1083 if (!access_ok(addr, 2)) 1084 goto sigbus; 1085 1086 if (IS_ENABLED(CONFIG_EVA)) { 1087 if (uaccess_kernel()) 1088 LoadHWU(addr, value, res); 1089 else 1090 LoadHWUE(addr, value, res); 1091 } else { 1092 LoadHWU(addr, value, res); 1093 } 1094 1095 if (res) 1096 goto fault; 1097 compute_return_epc(regs); 1098 regs->regs[insn.i_format.rt] = value; 1099 break; 1100 1101 case lwu_op: 1102 #ifdef CONFIG_64BIT 1103 /* 1104 * A 32-bit kernel might be running on a 64-bit processor. But 1105 * if we're on a 32-bit processor and an i-cache incoherency 1106 * or race makes us see a 64-bit instruction here the sdl/sdr 1107 * would blow up, so for now we don't handle unaligned 64-bit 1108 * instructions on 32-bit kernels. 1109 */ 1110 if (!access_ok(addr, 4)) 1111 goto sigbus; 1112 1113 LoadWU(addr, value, res); 1114 if (res) 1115 goto fault; 1116 compute_return_epc(regs); 1117 regs->regs[insn.i_format.rt] = value; 1118 break; 1119 #endif /* CONFIG_64BIT */ 1120 1121 /* Cannot handle 64-bit instructions in 32-bit kernel */ 1122 goto sigill; 1123 1124 case ld_op: 1125 #ifdef CONFIG_64BIT 1126 /* 1127 * A 32-bit kernel might be running on a 64-bit processor. But 1128 * if we're on a 32-bit processor and an i-cache incoherency 1129 * or race makes us see a 64-bit instruction here the sdl/sdr 1130 * would blow up, so for now we don't handle unaligned 64-bit 1131 * instructions on 32-bit kernels. 1132 */ 1133 if (!access_ok(addr, 8)) 1134 goto sigbus; 1135 1136 LoadDW(addr, value, res); 1137 if (res) 1138 goto fault; 1139 compute_return_epc(regs); 1140 regs->regs[insn.i_format.rt] = value; 1141 break; 1142 #endif /* CONFIG_64BIT */ 1143 1144 /* Cannot handle 64-bit instructions in 32-bit kernel */ 1145 goto sigill; 1146 1147 case sh_op: 1148 if (!access_ok(addr, 2)) 1149 goto sigbus; 1150 1151 compute_return_epc(regs); 1152 value = regs->regs[insn.i_format.rt]; 1153 1154 if (IS_ENABLED(CONFIG_EVA)) { 1155 if (uaccess_kernel()) 1156 StoreHW(addr, value, res); 1157 else 1158 StoreHWE(addr, value, res); 1159 } else { 1160 StoreHW(addr, value, res); 1161 } 1162 1163 if (res) 1164 goto fault; 1165 break; 1166 1167 case sw_op: 1168 if (!access_ok(addr, 4)) 1169 goto sigbus; 1170 1171 compute_return_epc(regs); 1172 value = regs->regs[insn.i_format.rt]; 1173 1174 if (IS_ENABLED(CONFIG_EVA)) { 1175 if (uaccess_kernel()) 1176 StoreW(addr, value, res); 1177 else 1178 StoreWE(addr, value, res); 1179 } else { 1180 StoreW(addr, value, res); 1181 } 1182 1183 if (res) 1184 goto fault; 1185 break; 1186 1187 case sd_op: 1188 #ifdef CONFIG_64BIT 1189 /* 1190 * A 32-bit kernel might be running on a 64-bit processor. But 1191 * if we're on a 32-bit processor and an i-cache incoherency 1192 * or race makes us see a 64-bit instruction here the sdl/sdr 1193 * would blow up, so for now we don't handle unaligned 64-bit 1194 * instructions on 32-bit kernels. 1195 */ 1196 if (!access_ok(addr, 8)) 1197 goto sigbus; 1198 1199 compute_return_epc(regs); 1200 value = regs->regs[insn.i_format.rt]; 1201 StoreDW(addr, value, res); 1202 if (res) 1203 goto fault; 1204 break; 1205 #endif /* CONFIG_64BIT */ 1206 1207 /* Cannot handle 64-bit instructions in 32-bit kernel */ 1208 goto sigill; 1209 1210 #ifdef CONFIG_MIPS_FP_SUPPORT 1211 1212 case lwc1_op: 1213 case ldc1_op: 1214 case swc1_op: 1215 case sdc1_op: 1216 case cop1x_op: { 1217 void __user *fault_addr = NULL; 1218 1219 die_if_kernel("Unaligned FP access in kernel code", regs); 1220 BUG_ON(!used_math()); 1221 1222 res = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1, 1223 &fault_addr); 1224 own_fpu(1); /* Restore FPU state. */ 1225 1226 /* Signal if something went wrong. */ 1227 process_fpemu_return(res, fault_addr, 0); 1228 1229 if (res == 0) 1230 break; 1231 return; 1232 } 1233 #endif /* CONFIG_MIPS_FP_SUPPORT */ 1234 1235 #ifdef CONFIG_CPU_HAS_MSA 1236 1237 case msa_op: { 1238 unsigned int wd, preempted; 1239 enum msa_2b_fmt df; 1240 union fpureg *fpr; 1241 1242 if (!cpu_has_msa) 1243 goto sigill; 1244 1245 /* 1246 * If we've reached this point then userland should have taken 1247 * the MSA disabled exception & initialised vector context at 1248 * some point in the past. 1249 */ 1250 BUG_ON(!thread_msa_context_live()); 1251 1252 df = insn.msa_mi10_format.df; 1253 wd = insn.msa_mi10_format.wd; 1254 fpr = ¤t->thread.fpu.fpr[wd]; 1255 1256 switch (insn.msa_mi10_format.func) { 1257 case msa_ld_op: 1258 if (!access_ok(addr, sizeof(*fpr))) 1259 goto sigbus; 1260 1261 do { 1262 /* 1263 * If we have live MSA context keep track of 1264 * whether we get preempted in order to avoid 1265 * the register context we load being clobbered 1266 * by the live context as it's saved during 1267 * preemption. If we don't have live context 1268 * then it can't be saved to clobber the value 1269 * we load. 1270 */ 1271 preempted = test_thread_flag(TIF_USEDMSA); 1272 1273 res = __copy_from_user_inatomic(fpr, addr, 1274 sizeof(*fpr)); 1275 if (res) 1276 goto fault; 1277 1278 /* 1279 * Update the hardware register if it is in use 1280 * by the task in this quantum, in order to 1281 * avoid having to save & restore the whole 1282 * vector context. 1283 */ 1284 preempt_disable(); 1285 if (test_thread_flag(TIF_USEDMSA)) { 1286 write_msa_wr(wd, fpr, df); 1287 preempted = 0; 1288 } 1289 preempt_enable(); 1290 } while (preempted); 1291 break; 1292 1293 case msa_st_op: 1294 if (!access_ok(addr, sizeof(*fpr))) 1295 goto sigbus; 1296 1297 /* 1298 * Update from the hardware register if it is in use by 1299 * the task in this quantum, in order to avoid having to 1300 * save & restore the whole vector context. 1301 */ 1302 preempt_disable(); 1303 if (test_thread_flag(TIF_USEDMSA)) 1304 read_msa_wr(wd, fpr, df); 1305 preempt_enable(); 1306 1307 res = __copy_to_user_inatomic(addr, fpr, sizeof(*fpr)); 1308 if (res) 1309 goto fault; 1310 break; 1311 1312 default: 1313 goto sigbus; 1314 } 1315 1316 compute_return_epc(regs); 1317 break; 1318 } 1319 #endif /* CONFIG_CPU_HAS_MSA */ 1320 1321 #ifndef CONFIG_CPU_MIPSR6 1322 /* 1323 * COP2 is available to implementor for application specific use. 1324 * It's up to applications to register a notifier chain and do 1325 * whatever they have to do, including possible sending of signals. 1326 * 1327 * This instruction has been reallocated in Release 6 1328 */ 1329 case lwc2_op: 1330 cu2_notifier_call_chain(CU2_LWC2_OP, regs); 1331 break; 1332 1333 case ldc2_op: 1334 cu2_notifier_call_chain(CU2_LDC2_OP, regs); 1335 break; 1336 1337 case swc2_op: 1338 cu2_notifier_call_chain(CU2_SWC2_OP, regs); 1339 break; 1340 1341 case sdc2_op: 1342 cu2_notifier_call_chain(CU2_SDC2_OP, regs); 1343 break; 1344 #endif 1345 default: 1346 /* 1347 * Pheeee... We encountered an yet unknown instruction or 1348 * cache coherence problem. Die sucker, die ... 1349 */ 1350 goto sigill; 1351 } 1352 1353 #ifdef CONFIG_DEBUG_FS 1354 unaligned_instructions++; 1355 #endif 1356 1357 return; 1358 1359 fault: 1360 /* roll back jump/branch */ 1361 regs->cp0_epc = origpc; 1362 regs->regs[31] = orig31; 1363 /* Did we have an exception handler installed? */ 1364 if (fixup_exception(regs)) 1365 return; 1366 1367 die_if_kernel("Unhandled kernel unaligned access", regs); 1368 force_sig(SIGSEGV); 1369 1370 return; 1371 1372 sigbus: 1373 die_if_kernel("Unhandled kernel unaligned access", regs); 1374 force_sig(SIGBUS); 1375 1376 return; 1377 1378 sigill: 1379 die_if_kernel 1380 ("Unhandled kernel unaligned access or invalid instruction", regs); 1381 force_sig(SIGILL); 1382 } 1383 1384 /* Recode table from 16-bit register notation to 32-bit GPR. */ 1385 const int reg16to32[] = { 16, 17, 2, 3, 4, 5, 6, 7 }; 1386 1387 /* Recode table from 16-bit STORE register notation to 32-bit GPR. */ 1388 static const int reg16to32st[] = { 0, 17, 2, 3, 4, 5, 6, 7 }; 1389 1390 static void emulate_load_store_microMIPS(struct pt_regs *regs, 1391 void __user *addr) 1392 { 1393 unsigned long value; 1394 unsigned int res; 1395 int i; 1396 unsigned int reg = 0, rvar; 1397 unsigned long orig31; 1398 u16 __user *pc16; 1399 u16 halfword; 1400 unsigned int word; 1401 unsigned long origpc, contpc; 1402 union mips_instruction insn; 1403 struct mm_decoded_insn mminsn; 1404 1405 origpc = regs->cp0_epc; 1406 orig31 = regs->regs[31]; 1407 1408 mminsn.micro_mips_mode = 1; 1409 1410 /* 1411 * This load never faults. 1412 */ 1413 pc16 = (unsigned short __user *)msk_isa16_mode(regs->cp0_epc); 1414 __get_user(halfword, pc16); 1415 pc16++; 1416 contpc = regs->cp0_epc + 2; 1417 word = ((unsigned int)halfword << 16); 1418 mminsn.pc_inc = 2; 1419 1420 if (!mm_insn_16bit(halfword)) { 1421 __get_user(halfword, pc16); 1422 pc16++; 1423 contpc = regs->cp0_epc + 4; 1424 mminsn.pc_inc = 4; 1425 word |= halfword; 1426 } 1427 mminsn.insn = word; 1428 1429 if (get_user(halfword, pc16)) 1430 goto fault; 1431 mminsn.next_pc_inc = 2; 1432 word = ((unsigned int)halfword << 16); 1433 1434 if (!mm_insn_16bit(halfword)) { 1435 pc16++; 1436 if (get_user(halfword, pc16)) 1437 goto fault; 1438 mminsn.next_pc_inc = 4; 1439 word |= halfword; 1440 } 1441 mminsn.next_insn = word; 1442 1443 insn = (union mips_instruction)(mminsn.insn); 1444 if (mm_isBranchInstr(regs, mminsn, &contpc)) 1445 insn = (union mips_instruction)(mminsn.next_insn); 1446 1447 /* Parse instruction to find what to do */ 1448 1449 switch (insn.mm_i_format.opcode) { 1450 1451 case mm_pool32a_op: 1452 switch (insn.mm_x_format.func) { 1453 case mm_lwxs_op: 1454 reg = insn.mm_x_format.rd; 1455 goto loadW; 1456 } 1457 1458 goto sigbus; 1459 1460 case mm_pool32b_op: 1461 switch (insn.mm_m_format.func) { 1462 case mm_lwp_func: 1463 reg = insn.mm_m_format.rd; 1464 if (reg == 31) 1465 goto sigbus; 1466 1467 if (!access_ok(addr, 8)) 1468 goto sigbus; 1469 1470 LoadW(addr, value, res); 1471 if (res) 1472 goto fault; 1473 regs->regs[reg] = value; 1474 addr += 4; 1475 LoadW(addr, value, res); 1476 if (res) 1477 goto fault; 1478 regs->regs[reg + 1] = value; 1479 goto success; 1480 1481 case mm_swp_func: 1482 reg = insn.mm_m_format.rd; 1483 if (reg == 31) 1484 goto sigbus; 1485 1486 if (!access_ok(addr, 8)) 1487 goto sigbus; 1488 1489 value = regs->regs[reg]; 1490 StoreW(addr, value, res); 1491 if (res) 1492 goto fault; 1493 addr += 4; 1494 value = regs->regs[reg + 1]; 1495 StoreW(addr, value, res); 1496 if (res) 1497 goto fault; 1498 goto success; 1499 1500 case mm_ldp_func: 1501 #ifdef CONFIG_64BIT 1502 reg = insn.mm_m_format.rd; 1503 if (reg == 31) 1504 goto sigbus; 1505 1506 if (!access_ok(addr, 16)) 1507 goto sigbus; 1508 1509 LoadDW(addr, value, res); 1510 if (res) 1511 goto fault; 1512 regs->regs[reg] = value; 1513 addr += 8; 1514 LoadDW(addr, value, res); 1515 if (res) 1516 goto fault; 1517 regs->regs[reg + 1] = value; 1518 goto success; 1519 #endif /* CONFIG_64BIT */ 1520 1521 goto sigill; 1522 1523 case mm_sdp_func: 1524 #ifdef CONFIG_64BIT 1525 reg = insn.mm_m_format.rd; 1526 if (reg == 31) 1527 goto sigbus; 1528 1529 if (!access_ok(addr, 16)) 1530 goto sigbus; 1531 1532 value = regs->regs[reg]; 1533 StoreDW(addr, value, res); 1534 if (res) 1535 goto fault; 1536 addr += 8; 1537 value = regs->regs[reg + 1]; 1538 StoreDW(addr, value, res); 1539 if (res) 1540 goto fault; 1541 goto success; 1542 #endif /* CONFIG_64BIT */ 1543 1544 goto sigill; 1545 1546 case mm_lwm32_func: 1547 reg = insn.mm_m_format.rd; 1548 rvar = reg & 0xf; 1549 if ((rvar > 9) || !reg) 1550 goto sigill; 1551 if (reg & 0x10) { 1552 if (!access_ok(addr, 4 * (rvar + 1))) 1553 goto sigbus; 1554 } else { 1555 if (!access_ok(addr, 4 * rvar)) 1556 goto sigbus; 1557 } 1558 if (rvar == 9) 1559 rvar = 8; 1560 for (i = 16; rvar; rvar--, i++) { 1561 LoadW(addr, value, res); 1562 if (res) 1563 goto fault; 1564 addr += 4; 1565 regs->regs[i] = value; 1566 } 1567 if ((reg & 0xf) == 9) { 1568 LoadW(addr, value, res); 1569 if (res) 1570 goto fault; 1571 addr += 4; 1572 regs->regs[30] = value; 1573 } 1574 if (reg & 0x10) { 1575 LoadW(addr, value, res); 1576 if (res) 1577 goto fault; 1578 regs->regs[31] = value; 1579 } 1580 goto success; 1581 1582 case mm_swm32_func: 1583 reg = insn.mm_m_format.rd; 1584 rvar = reg & 0xf; 1585 if ((rvar > 9) || !reg) 1586 goto sigill; 1587 if (reg & 0x10) { 1588 if (!access_ok(addr, 4 * (rvar + 1))) 1589 goto sigbus; 1590 } else { 1591 if (!access_ok(addr, 4 * rvar)) 1592 goto sigbus; 1593 } 1594 if (rvar == 9) 1595 rvar = 8; 1596 for (i = 16; rvar; rvar--, i++) { 1597 value = regs->regs[i]; 1598 StoreW(addr, value, res); 1599 if (res) 1600 goto fault; 1601 addr += 4; 1602 } 1603 if ((reg & 0xf) == 9) { 1604 value = regs->regs[30]; 1605 StoreW(addr, value, res); 1606 if (res) 1607 goto fault; 1608 addr += 4; 1609 } 1610 if (reg & 0x10) { 1611 value = regs->regs[31]; 1612 StoreW(addr, value, res); 1613 if (res) 1614 goto fault; 1615 } 1616 goto success; 1617 1618 case mm_ldm_func: 1619 #ifdef CONFIG_64BIT 1620 reg = insn.mm_m_format.rd; 1621 rvar = reg & 0xf; 1622 if ((rvar > 9) || !reg) 1623 goto sigill; 1624 if (reg & 0x10) { 1625 if (!access_ok(addr, 8 * (rvar + 1))) 1626 goto sigbus; 1627 } else { 1628 if (!access_ok(addr, 8 * rvar)) 1629 goto sigbus; 1630 } 1631 if (rvar == 9) 1632 rvar = 8; 1633 1634 for (i = 16; rvar; rvar--, i++) { 1635 LoadDW(addr, value, res); 1636 if (res) 1637 goto fault; 1638 addr += 4; 1639 regs->regs[i] = value; 1640 } 1641 if ((reg & 0xf) == 9) { 1642 LoadDW(addr, value, res); 1643 if (res) 1644 goto fault; 1645 addr += 8; 1646 regs->regs[30] = value; 1647 } 1648 if (reg & 0x10) { 1649 LoadDW(addr, value, res); 1650 if (res) 1651 goto fault; 1652 regs->regs[31] = value; 1653 } 1654 goto success; 1655 #endif /* CONFIG_64BIT */ 1656 1657 goto sigill; 1658 1659 case mm_sdm_func: 1660 #ifdef CONFIG_64BIT 1661 reg = insn.mm_m_format.rd; 1662 rvar = reg & 0xf; 1663 if ((rvar > 9) || !reg) 1664 goto sigill; 1665 if (reg & 0x10) { 1666 if (!access_ok(addr, 8 * (rvar + 1))) 1667 goto sigbus; 1668 } else { 1669 if (!access_ok(addr, 8 * rvar)) 1670 goto sigbus; 1671 } 1672 if (rvar == 9) 1673 rvar = 8; 1674 1675 for (i = 16; rvar; rvar--, i++) { 1676 value = regs->regs[i]; 1677 StoreDW(addr, value, res); 1678 if (res) 1679 goto fault; 1680 addr += 8; 1681 } 1682 if ((reg & 0xf) == 9) { 1683 value = regs->regs[30]; 1684 StoreDW(addr, value, res); 1685 if (res) 1686 goto fault; 1687 addr += 8; 1688 } 1689 if (reg & 0x10) { 1690 value = regs->regs[31]; 1691 StoreDW(addr, value, res); 1692 if (res) 1693 goto fault; 1694 } 1695 goto success; 1696 #endif /* CONFIG_64BIT */ 1697 1698 goto sigill; 1699 1700 /* LWC2, SWC2, LDC2, SDC2 are not serviced */ 1701 } 1702 1703 goto sigbus; 1704 1705 case mm_pool32c_op: 1706 switch (insn.mm_m_format.func) { 1707 case mm_lwu_func: 1708 reg = insn.mm_m_format.rd; 1709 goto loadWU; 1710 } 1711 1712 /* LL,SC,LLD,SCD are not serviced */ 1713 goto sigbus; 1714 1715 #ifdef CONFIG_MIPS_FP_SUPPORT 1716 case mm_pool32f_op: 1717 switch (insn.mm_x_format.func) { 1718 case mm_lwxc1_func: 1719 case mm_swxc1_func: 1720 case mm_ldxc1_func: 1721 case mm_sdxc1_func: 1722 goto fpu_emul; 1723 } 1724 1725 goto sigbus; 1726 1727 case mm_ldc132_op: 1728 case mm_sdc132_op: 1729 case mm_lwc132_op: 1730 case mm_swc132_op: { 1731 void __user *fault_addr = NULL; 1732 1733 fpu_emul: 1734 /* roll back jump/branch */ 1735 regs->cp0_epc = origpc; 1736 regs->regs[31] = orig31; 1737 1738 die_if_kernel("Unaligned FP access in kernel code", regs); 1739 BUG_ON(!used_math()); 1740 BUG_ON(!is_fpu_owner()); 1741 1742 res = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1, 1743 &fault_addr); 1744 own_fpu(1); /* restore FPU state */ 1745 1746 /* If something went wrong, signal */ 1747 process_fpemu_return(res, fault_addr, 0); 1748 1749 if (res == 0) 1750 goto success; 1751 return; 1752 } 1753 #endif /* CONFIG_MIPS_FP_SUPPORT */ 1754 1755 case mm_lh32_op: 1756 reg = insn.mm_i_format.rt; 1757 goto loadHW; 1758 1759 case mm_lhu32_op: 1760 reg = insn.mm_i_format.rt; 1761 goto loadHWU; 1762 1763 case mm_lw32_op: 1764 reg = insn.mm_i_format.rt; 1765 goto loadW; 1766 1767 case mm_sh32_op: 1768 reg = insn.mm_i_format.rt; 1769 goto storeHW; 1770 1771 case mm_sw32_op: 1772 reg = insn.mm_i_format.rt; 1773 goto storeW; 1774 1775 case mm_ld32_op: 1776 reg = insn.mm_i_format.rt; 1777 goto loadDW; 1778 1779 case mm_sd32_op: 1780 reg = insn.mm_i_format.rt; 1781 goto storeDW; 1782 1783 case mm_pool16c_op: 1784 switch (insn.mm16_m_format.func) { 1785 case mm_lwm16_op: 1786 reg = insn.mm16_m_format.rlist; 1787 rvar = reg + 1; 1788 if (!access_ok(addr, 4 * rvar)) 1789 goto sigbus; 1790 1791 for (i = 16; rvar; rvar--, i++) { 1792 LoadW(addr, value, res); 1793 if (res) 1794 goto fault; 1795 addr += 4; 1796 regs->regs[i] = value; 1797 } 1798 LoadW(addr, value, res); 1799 if (res) 1800 goto fault; 1801 regs->regs[31] = value; 1802 1803 goto success; 1804 1805 case mm_swm16_op: 1806 reg = insn.mm16_m_format.rlist; 1807 rvar = reg + 1; 1808 if (!access_ok(addr, 4 * rvar)) 1809 goto sigbus; 1810 1811 for (i = 16; rvar; rvar--, i++) { 1812 value = regs->regs[i]; 1813 StoreW(addr, value, res); 1814 if (res) 1815 goto fault; 1816 addr += 4; 1817 } 1818 value = regs->regs[31]; 1819 StoreW(addr, value, res); 1820 if (res) 1821 goto fault; 1822 1823 goto success; 1824 1825 } 1826 1827 goto sigbus; 1828 1829 case mm_lhu16_op: 1830 reg = reg16to32[insn.mm16_rb_format.rt]; 1831 goto loadHWU; 1832 1833 case mm_lw16_op: 1834 reg = reg16to32[insn.mm16_rb_format.rt]; 1835 goto loadW; 1836 1837 case mm_sh16_op: 1838 reg = reg16to32st[insn.mm16_rb_format.rt]; 1839 goto storeHW; 1840 1841 case mm_sw16_op: 1842 reg = reg16to32st[insn.mm16_rb_format.rt]; 1843 goto storeW; 1844 1845 case mm_lwsp16_op: 1846 reg = insn.mm16_r5_format.rt; 1847 goto loadW; 1848 1849 case mm_swsp16_op: 1850 reg = insn.mm16_r5_format.rt; 1851 goto storeW; 1852 1853 case mm_lwgp16_op: 1854 reg = reg16to32[insn.mm16_r3_format.rt]; 1855 goto loadW; 1856 1857 default: 1858 goto sigill; 1859 } 1860 1861 loadHW: 1862 if (!access_ok(addr, 2)) 1863 goto sigbus; 1864 1865 LoadHW(addr, value, res); 1866 if (res) 1867 goto fault; 1868 regs->regs[reg] = value; 1869 goto success; 1870 1871 loadHWU: 1872 if (!access_ok(addr, 2)) 1873 goto sigbus; 1874 1875 LoadHWU(addr, value, res); 1876 if (res) 1877 goto fault; 1878 regs->regs[reg] = value; 1879 goto success; 1880 1881 loadW: 1882 if (!access_ok(addr, 4)) 1883 goto sigbus; 1884 1885 LoadW(addr, value, res); 1886 if (res) 1887 goto fault; 1888 regs->regs[reg] = value; 1889 goto success; 1890 1891 loadWU: 1892 #ifdef CONFIG_64BIT 1893 /* 1894 * A 32-bit kernel might be running on a 64-bit processor. But 1895 * if we're on a 32-bit processor and an i-cache incoherency 1896 * or race makes us see a 64-bit instruction here the sdl/sdr 1897 * would blow up, so for now we don't handle unaligned 64-bit 1898 * instructions on 32-bit kernels. 1899 */ 1900 if (!access_ok(addr, 4)) 1901 goto sigbus; 1902 1903 LoadWU(addr, value, res); 1904 if (res) 1905 goto fault; 1906 regs->regs[reg] = value; 1907 goto success; 1908 #endif /* CONFIG_64BIT */ 1909 1910 /* Cannot handle 64-bit instructions in 32-bit kernel */ 1911 goto sigill; 1912 1913 loadDW: 1914 #ifdef CONFIG_64BIT 1915 /* 1916 * A 32-bit kernel might be running on a 64-bit processor. But 1917 * if we're on a 32-bit processor and an i-cache incoherency 1918 * or race makes us see a 64-bit instruction here the sdl/sdr 1919 * would blow up, so for now we don't handle unaligned 64-bit 1920 * instructions on 32-bit kernels. 1921 */ 1922 if (!access_ok(addr, 8)) 1923 goto sigbus; 1924 1925 LoadDW(addr, value, res); 1926 if (res) 1927 goto fault; 1928 regs->regs[reg] = value; 1929 goto success; 1930 #endif /* CONFIG_64BIT */ 1931 1932 /* Cannot handle 64-bit instructions in 32-bit kernel */ 1933 goto sigill; 1934 1935 storeHW: 1936 if (!access_ok(addr, 2)) 1937 goto sigbus; 1938 1939 value = regs->regs[reg]; 1940 StoreHW(addr, value, res); 1941 if (res) 1942 goto fault; 1943 goto success; 1944 1945 storeW: 1946 if (!access_ok(addr, 4)) 1947 goto sigbus; 1948 1949 value = regs->regs[reg]; 1950 StoreW(addr, value, res); 1951 if (res) 1952 goto fault; 1953 goto success; 1954 1955 storeDW: 1956 #ifdef CONFIG_64BIT 1957 /* 1958 * A 32-bit kernel might be running on a 64-bit processor. But 1959 * if we're on a 32-bit processor and an i-cache incoherency 1960 * or race makes us see a 64-bit instruction here the sdl/sdr 1961 * would blow up, so for now we don't handle unaligned 64-bit 1962 * instructions on 32-bit kernels. 1963 */ 1964 if (!access_ok(addr, 8)) 1965 goto sigbus; 1966 1967 value = regs->regs[reg]; 1968 StoreDW(addr, value, res); 1969 if (res) 1970 goto fault; 1971 goto success; 1972 #endif /* CONFIG_64BIT */ 1973 1974 /* Cannot handle 64-bit instructions in 32-bit kernel */ 1975 goto sigill; 1976 1977 success: 1978 regs->cp0_epc = contpc; /* advance or branch */ 1979 1980 #ifdef CONFIG_DEBUG_FS 1981 unaligned_instructions++; 1982 #endif 1983 return; 1984 1985 fault: 1986 /* roll back jump/branch */ 1987 regs->cp0_epc = origpc; 1988 regs->regs[31] = orig31; 1989 /* Did we have an exception handler installed? */ 1990 if (fixup_exception(regs)) 1991 return; 1992 1993 die_if_kernel("Unhandled kernel unaligned access", regs); 1994 force_sig(SIGSEGV); 1995 1996 return; 1997 1998 sigbus: 1999 die_if_kernel("Unhandled kernel unaligned access", regs); 2000 force_sig(SIGBUS); 2001 2002 return; 2003 2004 sigill: 2005 die_if_kernel 2006 ("Unhandled kernel unaligned access or invalid instruction", regs); 2007 force_sig(SIGILL); 2008 } 2009 2010 static void emulate_load_store_MIPS16e(struct pt_regs *regs, void __user * addr) 2011 { 2012 unsigned long value; 2013 unsigned int res; 2014 int reg; 2015 unsigned long orig31; 2016 u16 __user *pc16; 2017 unsigned long origpc; 2018 union mips16e_instruction mips16inst, oldinst; 2019 unsigned int opcode; 2020 int extended = 0; 2021 2022 origpc = regs->cp0_epc; 2023 orig31 = regs->regs[31]; 2024 pc16 = (unsigned short __user *)msk_isa16_mode(origpc); 2025 /* 2026 * This load never faults. 2027 */ 2028 __get_user(mips16inst.full, pc16); 2029 oldinst = mips16inst; 2030 2031 /* skip EXTEND instruction */ 2032 if (mips16inst.ri.opcode == MIPS16e_extend_op) { 2033 extended = 1; 2034 pc16++; 2035 __get_user(mips16inst.full, pc16); 2036 } else if (delay_slot(regs)) { 2037 /* skip jump instructions */ 2038 /* JAL/JALX are 32 bits but have OPCODE in first short int */ 2039 if (mips16inst.ri.opcode == MIPS16e_jal_op) 2040 pc16++; 2041 pc16++; 2042 if (get_user(mips16inst.full, pc16)) 2043 goto sigbus; 2044 } 2045 2046 opcode = mips16inst.ri.opcode; 2047 switch (opcode) { 2048 case MIPS16e_i64_op: /* I64 or RI64 instruction */ 2049 switch (mips16inst.i64.func) { /* I64/RI64 func field check */ 2050 case MIPS16e_ldpc_func: 2051 case MIPS16e_ldsp_func: 2052 reg = reg16to32[mips16inst.ri64.ry]; 2053 goto loadDW; 2054 2055 case MIPS16e_sdsp_func: 2056 reg = reg16to32[mips16inst.ri64.ry]; 2057 goto writeDW; 2058 2059 case MIPS16e_sdrasp_func: 2060 reg = 29; /* GPRSP */ 2061 goto writeDW; 2062 } 2063 2064 goto sigbus; 2065 2066 case MIPS16e_swsp_op: 2067 reg = reg16to32[mips16inst.ri.rx]; 2068 if (extended && cpu_has_mips16e2) 2069 switch (mips16inst.ri.imm >> 5) { 2070 case 0: /* SWSP */ 2071 case 1: /* SWGP */ 2072 break; 2073 case 2: /* SHGP */ 2074 opcode = MIPS16e_sh_op; 2075 break; 2076 default: 2077 goto sigbus; 2078 } 2079 break; 2080 2081 case MIPS16e_lwpc_op: 2082 reg = reg16to32[mips16inst.ri.rx]; 2083 break; 2084 2085 case MIPS16e_lwsp_op: 2086 reg = reg16to32[mips16inst.ri.rx]; 2087 if (extended && cpu_has_mips16e2) 2088 switch (mips16inst.ri.imm >> 5) { 2089 case 0: /* LWSP */ 2090 case 1: /* LWGP */ 2091 break; 2092 case 2: /* LHGP */ 2093 opcode = MIPS16e_lh_op; 2094 break; 2095 case 4: /* LHUGP */ 2096 opcode = MIPS16e_lhu_op; 2097 break; 2098 default: 2099 goto sigbus; 2100 } 2101 break; 2102 2103 case MIPS16e_i8_op: 2104 if (mips16inst.i8.func != MIPS16e_swrasp_func) 2105 goto sigbus; 2106 reg = 29; /* GPRSP */ 2107 break; 2108 2109 default: 2110 reg = reg16to32[mips16inst.rri.ry]; 2111 break; 2112 } 2113 2114 switch (opcode) { 2115 2116 case MIPS16e_lb_op: 2117 case MIPS16e_lbu_op: 2118 case MIPS16e_sb_op: 2119 goto sigbus; 2120 2121 case MIPS16e_lh_op: 2122 if (!access_ok(addr, 2)) 2123 goto sigbus; 2124 2125 LoadHW(addr, value, res); 2126 if (res) 2127 goto fault; 2128 MIPS16e_compute_return_epc(regs, &oldinst); 2129 regs->regs[reg] = value; 2130 break; 2131 2132 case MIPS16e_lhu_op: 2133 if (!access_ok(addr, 2)) 2134 goto sigbus; 2135 2136 LoadHWU(addr, value, res); 2137 if (res) 2138 goto fault; 2139 MIPS16e_compute_return_epc(regs, &oldinst); 2140 regs->regs[reg] = value; 2141 break; 2142 2143 case MIPS16e_lw_op: 2144 case MIPS16e_lwpc_op: 2145 case MIPS16e_lwsp_op: 2146 if (!access_ok(addr, 4)) 2147 goto sigbus; 2148 2149 LoadW(addr, value, res); 2150 if (res) 2151 goto fault; 2152 MIPS16e_compute_return_epc(regs, &oldinst); 2153 regs->regs[reg] = value; 2154 break; 2155 2156 case MIPS16e_lwu_op: 2157 #ifdef CONFIG_64BIT 2158 /* 2159 * A 32-bit kernel might be running on a 64-bit processor. But 2160 * if we're on a 32-bit processor and an i-cache incoherency 2161 * or race makes us see a 64-bit instruction here the sdl/sdr 2162 * would blow up, so for now we don't handle unaligned 64-bit 2163 * instructions on 32-bit kernels. 2164 */ 2165 if (!access_ok(addr, 4)) 2166 goto sigbus; 2167 2168 LoadWU(addr, value, res); 2169 if (res) 2170 goto fault; 2171 MIPS16e_compute_return_epc(regs, &oldinst); 2172 regs->regs[reg] = value; 2173 break; 2174 #endif /* CONFIG_64BIT */ 2175 2176 /* Cannot handle 64-bit instructions in 32-bit kernel */ 2177 goto sigill; 2178 2179 case MIPS16e_ld_op: 2180 loadDW: 2181 #ifdef CONFIG_64BIT 2182 /* 2183 * A 32-bit kernel might be running on a 64-bit processor. But 2184 * if we're on a 32-bit processor and an i-cache incoherency 2185 * or race makes us see a 64-bit instruction here the sdl/sdr 2186 * would blow up, so for now we don't handle unaligned 64-bit 2187 * instructions on 32-bit kernels. 2188 */ 2189 if (!access_ok(addr, 8)) 2190 goto sigbus; 2191 2192 LoadDW(addr, value, res); 2193 if (res) 2194 goto fault; 2195 MIPS16e_compute_return_epc(regs, &oldinst); 2196 regs->regs[reg] = value; 2197 break; 2198 #endif /* CONFIG_64BIT */ 2199 2200 /* Cannot handle 64-bit instructions in 32-bit kernel */ 2201 goto sigill; 2202 2203 case MIPS16e_sh_op: 2204 if (!access_ok(addr, 2)) 2205 goto sigbus; 2206 2207 MIPS16e_compute_return_epc(regs, &oldinst); 2208 value = regs->regs[reg]; 2209 StoreHW(addr, value, res); 2210 if (res) 2211 goto fault; 2212 break; 2213 2214 case MIPS16e_sw_op: 2215 case MIPS16e_swsp_op: 2216 case MIPS16e_i8_op: /* actually - MIPS16e_swrasp_func */ 2217 if (!access_ok(addr, 4)) 2218 goto sigbus; 2219 2220 MIPS16e_compute_return_epc(regs, &oldinst); 2221 value = regs->regs[reg]; 2222 StoreW(addr, value, res); 2223 if (res) 2224 goto fault; 2225 break; 2226 2227 case MIPS16e_sd_op: 2228 writeDW: 2229 #ifdef CONFIG_64BIT 2230 /* 2231 * A 32-bit kernel might be running on a 64-bit processor. But 2232 * if we're on a 32-bit processor and an i-cache incoherency 2233 * or race makes us see a 64-bit instruction here the sdl/sdr 2234 * would blow up, so for now we don't handle unaligned 64-bit 2235 * instructions on 32-bit kernels. 2236 */ 2237 if (!access_ok(addr, 8)) 2238 goto sigbus; 2239 2240 MIPS16e_compute_return_epc(regs, &oldinst); 2241 value = regs->regs[reg]; 2242 StoreDW(addr, value, res); 2243 if (res) 2244 goto fault; 2245 break; 2246 #endif /* CONFIG_64BIT */ 2247 2248 /* Cannot handle 64-bit instructions in 32-bit kernel */ 2249 goto sigill; 2250 2251 default: 2252 /* 2253 * Pheeee... We encountered an yet unknown instruction or 2254 * cache coherence problem. Die sucker, die ... 2255 */ 2256 goto sigill; 2257 } 2258 2259 #ifdef CONFIG_DEBUG_FS 2260 unaligned_instructions++; 2261 #endif 2262 2263 return; 2264 2265 fault: 2266 /* roll back jump/branch */ 2267 regs->cp0_epc = origpc; 2268 regs->regs[31] = orig31; 2269 /* Did we have an exception handler installed? */ 2270 if (fixup_exception(regs)) 2271 return; 2272 2273 die_if_kernel("Unhandled kernel unaligned access", regs); 2274 force_sig(SIGSEGV); 2275 2276 return; 2277 2278 sigbus: 2279 die_if_kernel("Unhandled kernel unaligned access", regs); 2280 force_sig(SIGBUS); 2281 2282 return; 2283 2284 sigill: 2285 die_if_kernel 2286 ("Unhandled kernel unaligned access or invalid instruction", regs); 2287 force_sig(SIGILL); 2288 } 2289 2290 asmlinkage void do_ade(struct pt_regs *regs) 2291 { 2292 enum ctx_state prev_state; 2293 unsigned int __user *pc; 2294 mm_segment_t seg; 2295 2296 prev_state = exception_enter(); 2297 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 2298 1, regs, regs->cp0_badvaddr); 2299 /* 2300 * Did we catch a fault trying to load an instruction? 2301 */ 2302 if (regs->cp0_badvaddr == regs->cp0_epc) 2303 goto sigbus; 2304 2305 if (user_mode(regs) && !test_thread_flag(TIF_FIXADE)) 2306 goto sigbus; 2307 if (unaligned_action == UNALIGNED_ACTION_SIGNAL) 2308 goto sigbus; 2309 2310 /* 2311 * Do branch emulation only if we didn't forward the exception. 2312 * This is all so but ugly ... 2313 */ 2314 2315 /* 2316 * Are we running in microMIPS mode? 2317 */ 2318 if (get_isa16_mode(regs->cp0_epc)) { 2319 /* 2320 * Did we catch a fault trying to load an instruction in 2321 * 16-bit mode? 2322 */ 2323 if (regs->cp0_badvaddr == msk_isa16_mode(regs->cp0_epc)) 2324 goto sigbus; 2325 if (unaligned_action == UNALIGNED_ACTION_SHOW) 2326 show_registers(regs); 2327 2328 if (cpu_has_mmips) { 2329 seg = get_fs(); 2330 if (!user_mode(regs)) 2331 set_fs(KERNEL_DS); 2332 emulate_load_store_microMIPS(regs, 2333 (void __user *)regs->cp0_badvaddr); 2334 set_fs(seg); 2335 2336 return; 2337 } 2338 2339 if (cpu_has_mips16) { 2340 seg = get_fs(); 2341 if (!user_mode(regs)) 2342 set_fs(KERNEL_DS); 2343 emulate_load_store_MIPS16e(regs, 2344 (void __user *)regs->cp0_badvaddr); 2345 set_fs(seg); 2346 2347 return; 2348 } 2349 2350 goto sigbus; 2351 } 2352 2353 if (unaligned_action == UNALIGNED_ACTION_SHOW) 2354 show_registers(regs); 2355 pc = (unsigned int __user *)exception_epc(regs); 2356 2357 seg = get_fs(); 2358 if (!user_mode(regs)) 2359 set_fs(KERNEL_DS); 2360 emulate_load_store_insn(regs, (void __user *)regs->cp0_badvaddr, pc); 2361 set_fs(seg); 2362 2363 return; 2364 2365 sigbus: 2366 die_if_kernel("Kernel unaligned instruction access", regs); 2367 force_sig(SIGBUS); 2368 2369 /* 2370 * XXX On return from the signal handler we should advance the epc 2371 */ 2372 exception_exit(prev_state); 2373 } 2374 2375 #ifdef CONFIG_DEBUG_FS 2376 static int __init debugfs_unaligned(void) 2377 { 2378 debugfs_create_u32("unaligned_instructions", S_IRUGO, mips_debugfs_dir, 2379 &unaligned_instructions); 2380 debugfs_create_u32("unaligned_action", S_IRUGO | S_IWUSR, 2381 mips_debugfs_dir, &unaligned_action); 2382 return 0; 2383 } 2384 arch_initcall(debugfs_unaligned); 2385 #endif 2386