1 /* 2 * OpenRISC traps.c 3 * 4 * Linux architectural port borrowing liberally from similar works of 5 * others. All original copyrights apply as per the original source 6 * declaration. 7 * 8 * Modifications for the OpenRISC architecture: 9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> 10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 * 17 * Here we handle the break vectors not used by the system call 18 * mechanism, as well as some general stack/register dumping 19 * things. 20 * 21 */ 22 23 #include <linux/init.h> 24 #include <linux/sched.h> 25 #include <linux/sched/debug.h> 26 #include <linux/sched/task_stack.h> 27 #include <linux/kernel.h> 28 #include <linux/extable.h> 29 #include <linux/kmod.h> 30 #include <linux/string.h> 31 #include <linux/errno.h> 32 #include <linux/ptrace.h> 33 #include <linux/timer.h> 34 #include <linux/mm.h> 35 #include <linux/kallsyms.h> 36 #include <linux/uaccess.h> 37 38 #include <asm/segment.h> 39 #include <asm/io.h> 40 #include <asm/pgtable.h> 41 42 extern char _etext, _stext; 43 44 int kstack_depth_to_print = 0x180; 45 int lwa_flag; 46 unsigned long __user *lwa_addr; 47 48 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p) 49 { 50 return p > (void *)tinfo && p < (void *)tinfo + THREAD_SIZE - 3; 51 } 52 53 void show_trace(struct task_struct *task, unsigned long *stack) 54 { 55 struct thread_info *context; 56 unsigned long addr; 57 58 context = (struct thread_info *) 59 ((unsigned long)stack & (~(THREAD_SIZE - 1))); 60 61 while (valid_stack_ptr(context, stack)) { 62 addr = *stack++; 63 if (__kernel_text_address(addr)) { 64 printk(" [<%08lx>]", addr); 65 print_symbol(" %s", addr); 66 printk("\n"); 67 } 68 } 69 printk(" =======================\n"); 70 } 71 72 /* displays a short stack trace */ 73 void show_stack(struct task_struct *task, unsigned long *esp) 74 { 75 unsigned long addr, *stack; 76 int i; 77 78 if (esp == NULL) 79 esp = (unsigned long *)&esp; 80 81 stack = esp; 82 83 printk("Stack dump [0x%08lx]:\n", (unsigned long)esp); 84 for (i = 0; i < kstack_depth_to_print; i++) { 85 if (kstack_end(stack)) 86 break; 87 if (__get_user(addr, stack)) { 88 /* This message matches "failing address" marked 89 s390 in ksymoops, so lines containing it will 90 not be filtered out by ksymoops. */ 91 printk("Failing address 0x%lx\n", (unsigned long)stack); 92 break; 93 } 94 stack++; 95 96 printk("sp + %02d: 0x%08lx\n", i * 4, addr); 97 } 98 printk("\n"); 99 100 show_trace(task, esp); 101 102 return; 103 } 104 105 void show_trace_task(struct task_struct *tsk) 106 { 107 /* 108 * TODO: SysRq-T trace dump... 109 */ 110 } 111 112 void show_registers(struct pt_regs *regs) 113 { 114 int i; 115 int in_kernel = 1; 116 unsigned long esp; 117 118 esp = (unsigned long)(®s->sp); 119 if (user_mode(regs)) 120 in_kernel = 0; 121 122 printk("CPU #: %d\n" 123 " PC: %08lx SR: %08lx SP: %08lx\n", 124 smp_processor_id(), regs->pc, regs->sr, regs->sp); 125 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n", 126 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]); 127 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n", 128 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]); 129 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n", 130 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]); 131 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n", 132 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]); 133 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n", 134 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]); 135 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n", 136 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]); 137 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n", 138 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]); 139 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n", 140 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]); 141 printk(" RES: %08lx oGPR11: %08lx\n", 142 regs->gpr[11], regs->orig_gpr11); 143 144 printk("Process %s (pid: %d, stackpage=%08lx)\n", 145 current->comm, current->pid, (unsigned long)current); 146 /* 147 * When in-kernel, we also print out the stack and code at the 148 * time of the fault.. 149 */ 150 if (in_kernel) { 151 152 printk("\nStack: "); 153 show_stack(NULL, (unsigned long *)esp); 154 155 printk("\nCode: "); 156 if (regs->pc < PAGE_OFFSET) 157 goto bad; 158 159 for (i = -24; i < 24; i++) { 160 unsigned char c; 161 if (__get_user(c, &((unsigned char *)regs->pc)[i])) { 162 bad: 163 printk(" Bad PC value."); 164 break; 165 } 166 167 if (i == 0) 168 printk("(%02x) ", c); 169 else 170 printk("%02x ", c); 171 } 172 } 173 printk("\n"); 174 } 175 176 void nommu_dump_state(struct pt_regs *regs, 177 unsigned long ea, unsigned long vector) 178 { 179 int i; 180 unsigned long addr, stack = regs->sp; 181 182 printk("\n\r[nommu_dump_state] :: ea %lx, vector %lx\n\r", ea, vector); 183 184 printk("CPU #: %d\n" 185 " PC: %08lx SR: %08lx SP: %08lx\n", 186 0, regs->pc, regs->sr, regs->sp); 187 printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n", 188 0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]); 189 printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n", 190 regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]); 191 printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n", 192 regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]); 193 printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n", 194 regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]); 195 printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n", 196 regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]); 197 printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n", 198 regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]); 199 printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n", 200 regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]); 201 printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n", 202 regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]); 203 printk(" RES: %08lx oGPR11: %08lx\n", 204 regs->gpr[11], regs->orig_gpr11); 205 206 printk("Process %s (pid: %d, stackpage=%08lx)\n", 207 ((struct task_struct *)(__pa(current)))->comm, 208 ((struct task_struct *)(__pa(current)))->pid, 209 (unsigned long)current); 210 211 printk("\nStack: "); 212 printk("Stack dump [0x%08lx]:\n", (unsigned long)stack); 213 for (i = 0; i < kstack_depth_to_print; i++) { 214 if (((long)stack & (THREAD_SIZE - 1)) == 0) 215 break; 216 stack++; 217 218 printk("%lx :: sp + %02d: 0x%08lx\n", stack, i * 4, 219 *((unsigned long *)(__pa(stack)))); 220 } 221 printk("\n"); 222 223 printk("Call Trace: "); 224 i = 1; 225 while (((long)stack & (THREAD_SIZE - 1)) != 0) { 226 addr = *((unsigned long *)__pa(stack)); 227 stack++; 228 229 if (kernel_text_address(addr)) { 230 if (i && ((i % 6) == 0)) 231 printk("\n "); 232 printk(" [<%08lx>]", addr); 233 i++; 234 } 235 } 236 printk("\n"); 237 238 printk("\nCode: "); 239 240 for (i = -24; i < 24; i++) { 241 unsigned char c; 242 c = ((unsigned char *)(__pa(regs->pc)))[i]; 243 244 if (i == 0) 245 printk("(%02x) ", c); 246 else 247 printk("%02x ", c); 248 } 249 printk("\n"); 250 } 251 252 /* This is normally the 'Oops' routine */ 253 void die(const char *str, struct pt_regs *regs, long err) 254 { 255 256 console_verbose(); 257 printk("\n%s#: %04lx\n", str, err & 0xffff); 258 show_registers(regs); 259 #ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION 260 printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n"); 261 262 /* shut down interrupts */ 263 local_irq_disable(); 264 265 __asm__ __volatile__("l.nop 1"); 266 do {} while (1); 267 #endif 268 do_exit(SIGSEGV); 269 } 270 271 /* This is normally the 'Oops' routine */ 272 void die_if_kernel(const char *str, struct pt_regs *regs, long err) 273 { 274 if (user_mode(regs)) 275 return; 276 277 die(str, regs, err); 278 } 279 280 void unhandled_exception(struct pt_regs *regs, int ea, int vector) 281 { 282 printk("Unable to handle exception at EA =0x%x, vector 0x%x", 283 ea, vector); 284 die("Oops", regs, 9); 285 } 286 287 void __init trap_init(void) 288 { 289 /* Nothing needs to be done */ 290 } 291 292 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) 293 { 294 siginfo_t info; 295 memset(&info, 0, sizeof(info)); 296 info.si_signo = SIGTRAP; 297 info.si_code = TRAP_TRACE; 298 info.si_addr = (void *)address; 299 force_sig_info(SIGTRAP, &info, current); 300 301 regs->pc += 4; 302 } 303 304 asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address) 305 { 306 siginfo_t info; 307 308 if (user_mode(regs)) { 309 /* Send a SIGSEGV */ 310 info.si_signo = SIGSEGV; 311 info.si_errno = 0; 312 /* info.si_code has been set above */ 313 info.si_addr = (void *)address; 314 force_sig_info(SIGSEGV, &info, current); 315 } else { 316 printk("KERNEL: Unaligned Access 0x%.8lx\n", address); 317 show_registers(regs); 318 die("Die:", regs, address); 319 } 320 321 } 322 323 asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address) 324 { 325 siginfo_t info; 326 327 if (user_mode(regs)) { 328 /* Send a SIGBUS */ 329 info.si_signo = SIGBUS; 330 info.si_errno = 0; 331 info.si_code = BUS_ADRERR; 332 info.si_addr = (void *)address; 333 force_sig_info(SIGBUS, &info, current); 334 } else { /* Kernel mode */ 335 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address); 336 show_registers(regs); 337 die("Die:", regs, address); 338 } 339 } 340 341 static inline int in_delay_slot(struct pt_regs *regs) 342 { 343 #ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX 344 /* No delay slot flag, do the old way */ 345 unsigned int op, insn; 346 347 insn = *((unsigned int *)regs->pc); 348 op = insn >> 26; 349 switch (op) { 350 case 0x00: /* l.j */ 351 case 0x01: /* l.jal */ 352 case 0x03: /* l.bnf */ 353 case 0x04: /* l.bf */ 354 case 0x11: /* l.jr */ 355 case 0x12: /* l.jalr */ 356 return 1; 357 default: 358 return 0; 359 } 360 #else 361 return regs->sr & SPR_SR_DSX; 362 #endif 363 } 364 365 static inline void adjust_pc(struct pt_regs *regs, unsigned long address) 366 { 367 int displacement; 368 unsigned int rb, op, jmp; 369 370 if (unlikely(in_delay_slot(regs))) { 371 /* In delay slot, instruction at pc is a branch, simulate it */ 372 jmp = *((unsigned int *)regs->pc); 373 374 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27); 375 rb = (jmp & 0x0000ffff) >> 11; 376 op = jmp >> 26; 377 378 switch (op) { 379 case 0x00: /* l.j */ 380 regs->pc += displacement; 381 return; 382 case 0x01: /* l.jal */ 383 regs->pc += displacement; 384 regs->gpr[9] = regs->pc + 8; 385 return; 386 case 0x03: /* l.bnf */ 387 if (regs->sr & SPR_SR_F) 388 regs->pc += 8; 389 else 390 regs->pc += displacement; 391 return; 392 case 0x04: /* l.bf */ 393 if (regs->sr & SPR_SR_F) 394 regs->pc += displacement; 395 else 396 regs->pc += 8; 397 return; 398 case 0x11: /* l.jr */ 399 regs->pc = regs->gpr[rb]; 400 return; 401 case 0x12: /* l.jalr */ 402 regs->pc = regs->gpr[rb]; 403 regs->gpr[9] = regs->pc + 8; 404 return; 405 default: 406 break; 407 } 408 } else { 409 regs->pc += 4; 410 } 411 } 412 413 static inline void simulate_lwa(struct pt_regs *regs, unsigned long address, 414 unsigned int insn) 415 { 416 unsigned int ra, rd; 417 unsigned long value; 418 unsigned long orig_pc; 419 long imm; 420 421 const struct exception_table_entry *entry; 422 423 orig_pc = regs->pc; 424 adjust_pc(regs, address); 425 426 ra = (insn >> 16) & 0x1f; 427 rd = (insn >> 21) & 0x1f; 428 imm = (short)insn; 429 lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm); 430 431 if ((unsigned long)lwa_addr & 0x3) { 432 do_unaligned_access(regs, address); 433 return; 434 } 435 436 if (get_user(value, lwa_addr)) { 437 if (user_mode(regs)) { 438 force_sig(SIGSEGV, current); 439 return; 440 } 441 442 if ((entry = search_exception_tables(orig_pc))) { 443 regs->pc = entry->fixup; 444 return; 445 } 446 447 /* kernel access in kernel space, load it directly */ 448 value = *((unsigned long *)lwa_addr); 449 } 450 451 lwa_flag = 1; 452 regs->gpr[rd] = value; 453 } 454 455 static inline void simulate_swa(struct pt_regs *regs, unsigned long address, 456 unsigned int insn) 457 { 458 unsigned long __user *vaddr; 459 unsigned long orig_pc; 460 unsigned int ra, rb; 461 long imm; 462 463 const struct exception_table_entry *entry; 464 465 orig_pc = regs->pc; 466 adjust_pc(regs, address); 467 468 ra = (insn >> 16) & 0x1f; 469 rb = (insn >> 11) & 0x1f; 470 imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff)); 471 vaddr = (unsigned long __user *)(regs->gpr[ra] + imm); 472 473 if (!lwa_flag || vaddr != lwa_addr) { 474 regs->sr &= ~SPR_SR_F; 475 return; 476 } 477 478 if ((unsigned long)vaddr & 0x3) { 479 do_unaligned_access(regs, address); 480 return; 481 } 482 483 if (put_user(regs->gpr[rb], vaddr)) { 484 if (user_mode(regs)) { 485 force_sig(SIGSEGV, current); 486 return; 487 } 488 489 if ((entry = search_exception_tables(orig_pc))) { 490 regs->pc = entry->fixup; 491 return; 492 } 493 494 /* kernel access in kernel space, store it directly */ 495 *((unsigned long *)vaddr) = regs->gpr[rb]; 496 } 497 498 lwa_flag = 0; 499 regs->sr |= SPR_SR_F; 500 } 501 502 #define INSN_LWA 0x1b 503 #define INSN_SWA 0x33 504 505 asmlinkage void do_illegal_instruction(struct pt_regs *regs, 506 unsigned long address) 507 { 508 siginfo_t info; 509 unsigned int op; 510 unsigned int insn = *((unsigned int *)address); 511 512 op = insn >> 26; 513 514 switch (op) { 515 case INSN_LWA: 516 simulate_lwa(regs, address, insn); 517 return; 518 519 case INSN_SWA: 520 simulate_swa(regs, address, insn); 521 return; 522 523 default: 524 break; 525 } 526 527 if (user_mode(regs)) { 528 /* Send a SIGILL */ 529 info.si_signo = SIGILL; 530 info.si_errno = 0; 531 info.si_code = ILL_ILLOPC; 532 info.si_addr = (void *)address; 533 force_sig_info(SIGBUS, &info, current); 534 } else { /* Kernel mode */ 535 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n", 536 address); 537 show_registers(regs); 538 die("Die:", regs, address); 539 } 540 } 541