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