arch/openrisc/kernel/traps.c

   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)(&regs->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 }