kernel/arch/frv/kernel/traps.c

   1 /* traps.c: high-level exception handler for FR-V
   2  *
   3  * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/sched.h>
  13 #include <linux/signal.h>
  14 #include <linux/kernel.h>
  15 #include <linux/mm.h>
  16 #include <linux/types.h>
  17 #include <linux/user.h>
  18 #include <linux/string.h>
  19 #include <linux/linkage.h>
  20 #include <linux/init.h>
  21 #include <linux/module.h>
  22
  23 #include <asm/asm-offsets.h>
  24 #include <asm/setup.h>
  25 #include <asm/fpu.h>
  26 #include <asm/uaccess.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/siginfo.h>
  29 #include <asm/unaligned.h>
  30
  31 void show_backtrace(struct pt_regs *, unsigned long);
  32
  33 extern asmlinkage void __break_hijack_kernel_event(void);
  34
  35 /*****************************************************************************/
  36 /*
  37  * instruction access error
  38  */
  39 asmlinkage void insn_access_error(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
  40 {
  41         siginfo_t info;
  42
  43         die_if_kernel("-- Insn Access Error --\n"
  44                       "EPCR0 : %08lx\n"
  45                       "ESR0  : %08lx\n",
  46                       epcr0, esr0);
  47
  48         info.si_signo   = SIGSEGV;
  49         info.si_code    = SEGV_ACCERR;
  50         info.si_errno   = 0;
  51         info.si_addr    = (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);
  52
  53         force_sig_info(info.si_signo, &info, current);
  54 } /* end insn_access_error() */
  55
  56 /*****************************************************************************/
  57 /*
  58  * handler for:
  59  * - illegal instruction
  60  * - privileged instruction
  61  * - unsupported trap
  62  * - debug exceptions
  63  */
  64 asmlinkage void illegal_instruction(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
  65 {
  66         siginfo_t info;
  67
  68         die_if_kernel("-- Illegal Instruction --\n"
  69                       "EPCR0 : %08lx\n"
  70                       "ESR0  : %08lx\n"
  71                       "ESFR1 : %08lx\n",
  72                       epcr0, esr0, esfr1);
  73
  74         info.si_errno   = 0;
  75         info.si_addr    = (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);
  76
  77         switch (__frame->tbr & TBR_TT) {
  78         case TBR_TT_ILLEGAL_INSTR:
  79                 info.si_signo   = SIGILL;
  80                 info.si_code    = ILL_ILLOPC;
  81                 break;
  82         case TBR_TT_PRIV_INSTR:
  83                 info.si_signo   = SIGILL;
  84                 info.si_code    = ILL_PRVOPC;
  85                 break;
  86         case TBR_TT_TRAP2 ... TBR_TT_TRAP126:
  87                 info.si_signo   = SIGILL;
  88                 info.si_code    = ILL_ILLTRP;
  89                 break;
  90         /* GDB uses "tira gr0, #1" as a breakpoint instruction.  */
  91         case TBR_TT_TRAP1:
  92         case TBR_TT_BREAK:
  93                 info.si_signo   = SIGTRAP;
  94                 info.si_code    =
  95                         (__frame->__status & REG__STATUS_STEPPED) ? TRAP_TRACE : TRAP_BRKPT;
  96                 break;
  97         }
  98
  99         force_sig_info(info.si_signo, &info, current);
 100 } /* end illegal_instruction() */
 101
 102 /*****************************************************************************/
 103 /*
 104  * handle atomic operations with errors
 105  * - arguments in gr8, gr9, gr10
 106  * - original memory value placed in gr5
 107  * - replacement memory value placed in gr9
 108  */
 109 asmlinkage void atomic_operation(unsigned long esfr1, unsigned long epcr0,
 110                                  unsigned long esr0)
 111 {
 112         static DEFINE_SPINLOCK(atomic_op_lock);
 113         unsigned long x, y, z;
 114         unsigned long __user *p;
 115         mm_segment_t oldfs;
 116         siginfo_t info;
 117         int ret;
 118
 119         y = 0;
 120         z = 0;
 121
 122         oldfs = get_fs();
 123         if (!user_mode(__frame))
 124                 set_fs(KERNEL_DS);
 125
 126         switch (__frame->tbr & TBR_TT) {
 127                 /* TIRA gr0,#120
 128                  * u32 __atomic_user_cmpxchg32(u32 *ptr, u32 test, u32 new)
 129                  */
 130         case TBR_TT_ATOMIC_CMPXCHG32:
 131                 p = (unsigned long __user *) __frame->gr8;
 132                 x = __frame->gr9;
 133                 y = __frame->gr10;
 134
 135                 for (;;) {
 136                         ret = get_user(z, p);
 137                         if (ret < 0)
 138                                 goto error;
 139
 140                         if (z != x)
 141                                 goto done;
 142
 143                         spin_lock_irq(&atomic_op_lock);
 144
 145                         if (__get_user(z, p) == 0) {
 146                                 if (z != x)
 147                                         goto done2;
 148
 149                                 if (__put_user(y, p) == 0)
 150                                         goto done2;
 151                                 goto error2;
 152                         }
 153
 154                         spin_unlock_irq(&atomic_op_lock);
 155                 }
 156
 157                 /* TIRA gr0,#121
 158                  * u32 __atomic_kernel_xchg32(void *v, u32 new)
 159                  */
 160         case TBR_TT_ATOMIC_XCHG32:
 161                 p = (unsigned long __user *) __frame->gr8;
 162                 y = __frame->gr9;
 163
 164                 for (;;) {
 165                         ret = get_user(z, p);
 166                         if (ret < 0)
 167                                 goto error;
 168
 169                         spin_lock_irq(&atomic_op_lock);
 170
 171                         if (__get_user(z, p) == 0) {
 172                                 if (__put_user(y, p) == 0)
 173                                         goto done2;
 174                                 goto error2;
 175                         }
 176
 177                         spin_unlock_irq(&atomic_op_lock);
 178                 }
 179
 180                 /* TIRA gr0,#122
 181                  * ulong __atomic_kernel_XOR_return(ulong i, ulong *v)
 182                  */
 183         case TBR_TT_ATOMIC_XOR:
 184                 p = (unsigned long __user *) __frame->gr8;
 185                 x = __frame->gr9;
 186
 187                 for (;;) {
 188                         ret = get_user(z, p);
 189                         if (ret < 0)
 190                                 goto error;
 191
 192                         spin_lock_irq(&atomic_op_lock);
 193
 194                         if (__get_user(z, p) == 0) {
 195                                 y = x ^ z;
 196                                 if (__put_user(y, p) == 0)
 197                                         goto done2;
 198                                 goto error2;
 199                         }
 200
 201                         spin_unlock_irq(&atomic_op_lock);
 202                 }
 203
 204                 /* TIRA gr0,#123
 205                  * ulong __atomic_kernel_OR_return(ulong i, ulong *v)
 206                  */
 207         case TBR_TT_ATOMIC_OR:
 208                 p = (unsigned long __user *) __frame->gr8;
 209                 x = __frame->gr9;
 210
 211                 for (;;) {
 212                         ret = get_user(z, p);
 213                         if (ret < 0)
 214                                 goto error;
 215
 216                         spin_lock_irq(&atomic_op_lock);
 217
 218                         if (__get_user(z, p) == 0) {
 219                                 y = x ^ z;
 220                                 if (__put_user(y, p) == 0)
 221                                         goto done2;
 222                                 goto error2;
 223                         }
 224
 225                         spin_unlock_irq(&atomic_op_lock);
 226                 }
 227
 228                 /* TIRA gr0,#124
 229                  * ulong __atomic_kernel_AND_return(ulong i, ulong *v)
 230                  */
 231         case TBR_TT_ATOMIC_AND:
 232                 p = (unsigned long __user *) __frame->gr8;
 233                 x = __frame->gr9;
 234
 235                 for (;;) {
 236                         ret = get_user(z, p);
 237                         if (ret < 0)
 238                                 goto error;
 239
 240                         spin_lock_irq(&atomic_op_lock);
 241
 242                         if (__get_user(z, p) == 0) {
 243                                 y = x & z;
 244                                 if (__put_user(y, p) == 0)
 245                                         goto done2;
 246                                 goto error2;
 247                         }
 248
 249                         spin_unlock_irq(&atomic_op_lock);
 250                 }
 251
 252                 /* TIRA gr0,#125
 253                  * int __atomic_user_sub_return(atomic_t *v, int i)
 254                  */
 255         case TBR_TT_ATOMIC_SUB:
 256                 p = (unsigned long __user *) __frame->gr8;
 257                 x = __frame->gr9;
 258
 259                 for (;;) {
 260                         ret = get_user(z, p);
 261                         if (ret < 0)
 262                                 goto error;
 263
 264                         spin_lock_irq(&atomic_op_lock);
 265
 266                         if (__get_user(z, p) == 0) {
 267                                 y = z - x;
 268                                 if (__put_user(y, p) == 0)
 269                                         goto done2;
 270                                 goto error2;
 271                         }
 272
 273                         spin_unlock_irq(&atomic_op_lock);
 274                 }
 275
 276                 /* TIRA gr0,#126
 277                  * int __atomic_user_add_return(atomic_t *v, int i)
 278                  */
 279         case TBR_TT_ATOMIC_ADD:
 280                 p = (unsigned long __user *) __frame->gr8;
 281                 x = __frame->gr9;
 282
 283                 for (;;) {
 284                         ret = get_user(z, p);
 285                         if (ret < 0)
 286                                 goto error;
 287
 288                         spin_lock_irq(&atomic_op_lock);
 289
 290                         if (__get_user(z, p) == 0) {
 291                                 y = z + x;
 292                                 if (__put_user(y, p) == 0)
 293                                         goto done2;
 294                                 goto error2;
 295                         }
 296
 297                         spin_unlock_irq(&atomic_op_lock);
 298                 }
 299
 300         default:
 301                 BUG();
 302         }
 303
 304 done2:
 305         spin_unlock_irq(&atomic_op_lock);
 306 done:
 307         if (!user_mode(__frame))
 308                 set_fs(oldfs);
 309         __frame->gr5 = z;
 310         __frame->gr9 = y;
 311         return;
 312
 313 error2:
 314         spin_unlock_irq(&atomic_op_lock);
 315 error:
 316         if (!user_mode(__frame))
 317                 set_fs(oldfs);
 318         __frame->pc -= 4;
 319
 320         die_if_kernel("-- Atomic Op Error --\n");
 321
 322         info.si_signo   = SIGSEGV;
 323         info.si_code    = SEGV_ACCERR;
 324         info.si_errno   = 0;
 325         info.si_addr    = (void __user *) __frame->pc;
 326
 327         force_sig_info(info.si_signo, &info, current);
 328 }
 329
 330 /*****************************************************************************/
 331 /*
 332  *
 333  */
 334 asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)
 335 {
 336         siginfo_t info;
 337
 338         die_if_kernel("-- Media Exception --\n"
 339                       "MSR0 : %08lx\n"
 340                       "MSR1 : %08lx\n",
 341                       msr0, msr1);
 342
 343         info.si_signo   = SIGFPE;
 344         info.si_code    = FPE_MDAOVF;
 345         info.si_errno   = 0;
 346         info.si_addr    = (void __user *) __frame->pc;
 347
 348         force_sig_info(info.si_signo, &info, current);
 349 } /* end media_exception() */
 350
 351 /*****************************************************************************/
 352 /*
 353  * instruction or data access exception
 354  */
 355 asmlinkage void memory_access_exception(unsigned long esr0,
 356                                         unsigned long ear0,
 357                                         unsigned long epcr0)
 358 {
 359         siginfo_t info;
 360
 361 #ifdef CONFIG_MMU
 362         unsigned long fixup;
 363
 364         fixup = search_exception_table(__frame->pc);
 365         if (fixup) {
 366                 __frame->pc = fixup;
 367                 return;
 368         }
 369 #endif
 370
 371         die_if_kernel("-- Memory Access Exception --\n"
 372                       "ESR0  : %08lx\n"
 373                       "EAR0  : %08lx\n"
 374                       "EPCR0 : %08lx\n",
 375                       esr0, ear0, epcr0);
 376
 377         info.si_signo   = SIGSEGV;
 378         info.si_code    = SEGV_ACCERR;
 379         info.si_errno   = 0;
 380         info.si_addr    = NULL;
 381
 382         if ((esr0 & (ESRx_VALID | ESR0_EAV)) == (ESRx_VALID | ESR0_EAV))
 383                 info.si_addr = (void __user *) ear0;
 384
 385         force_sig_info(info.si_signo, &info, current);
 386
 387 } /* end memory_access_exception() */
 388
 389 /*****************************************************************************/
 390 /*
 391  * data access error
 392  * - double-word data load from CPU control area (0xFExxxxxx)
 393  * - read performed on inactive or self-refreshing SDRAM
 394  * - error notification from slave device
 395  * - misaligned address
 396  * - access to out of bounds memory region
 397  * - user mode accessing privileged memory region
 398  * - write to R/O memory region
 399  */
 400 asmlinkage void data_access_error(unsigned long esfr1, unsigned long esr15, unsigned long ear15)
 401 {
 402         siginfo_t info;
 403
 404         die_if_kernel("-- Data Access Error --\n"
 405                       "ESR15 : %08lx\n"
 406                       "EAR15 : %08lx\n",
 407                       esr15, ear15);
 408
 409         info.si_signo   = SIGSEGV;
 410         info.si_code    = SEGV_ACCERR;
 411         info.si_errno   = 0;
 412         info.si_addr    = (void __user *)
 413                 (((esr15 & (ESRx_VALID|ESR15_EAV)) == (ESRx_VALID|ESR15_EAV)) ? ear15 : 0);
 414
 415         force_sig_info(info.si_signo, &info, current);
 416 } /* end data_access_error() */
 417
 418 /*****************************************************************************/
 419 /*
 420  * data store error - should only happen if accessing inactive or self-refreshing SDRAM
 421  */
 422 asmlinkage void data_store_error(unsigned long esfr1, unsigned long esr15)
 423 {
 424         die_if_kernel("-- Data Store Error --\n"
 425                       "ESR15 : %08lx\n",
 426                       esr15);
 427         BUG();
 428 } /* end data_store_error() */
 429
 430 /*****************************************************************************/
 431 /*
 432  *
 433  */
 434 asmlinkage void division_exception(unsigned long esfr1, unsigned long esr0, unsigned long isr)
 435 {
 436         siginfo_t info;
 437
 438         die_if_kernel("-- Division Exception --\n"
 439                       "ESR0 : %08lx\n"
 440                       "ISR  : %08lx\n",
 441                       esr0, isr);
 442
 443         info.si_signo   = SIGFPE;
 444         info.si_code    = FPE_INTDIV;
 445         info.si_errno   = 0;
 446         info.si_addr    = (void __user *) __frame->pc;
 447
 448         force_sig_info(info.si_signo, &info, current);
 449 } /* end division_exception() */
 450
 451 /*****************************************************************************/
 452 /*
 453  *
 454  */
 455 asmlinkage void compound_exception(unsigned long esfr1,
 456                                    unsigned long esr0, unsigned long esr14, unsigned long esr15,
 457                                    unsigned long msr0, unsigned long msr1)
 458 {
 459         die_if_kernel("-- Compound Exception --\n"
 460                       "ESR0  : %08lx\n"
 461                       "ESR15 : %08lx\n"
 462                       "ESR15 : %08lx\n"
 463                       "MSR0  : %08lx\n"
 464                       "MSR1  : %08lx\n",
 465                       esr0, esr14, esr15, msr0, msr1);
 466         BUG();
 467 } /* end compound_exception() */
 468
 469 void show_stack(struct task_struct *task, unsigned long *sp)
 470 {
 471 }
 472
 473 void show_trace_task(struct task_struct *tsk)
 474 {
 475         printk("CONTEXT: stack=0x%lx frame=0x%p LR=0x%lx RET=0x%lx\n",
 476                tsk->thread.sp, tsk->thread.frame, tsk->thread.lr, tsk->thread.sched_lr);
 477 }
 478
 479 static const char *regnames[] = {
 480         "PSR ", "ISR ", "CCR ", "CCCR",
 481         "LR  ", "LCR ", "PC  ", "_stt",
 482         "sys ", "GR8*", "GNE0", "GNE1",
 483         "IACH", "IACL",
 484         "TBR ", "SP  ", "FP  ", "GR3 ",
 485         "GR4 ", "GR5 ", "GR6 ", "GR7 ",
 486         "GR8 ", "GR9 ", "GR10", "GR11",
 487         "GR12", "GR13", "GR14", "GR15",
 488         "GR16", "GR17", "GR18", "GR19",
 489         "GR20", "GR21", "GR22", "GR23",
 490         "GR24", "GR25", "GR26", "GR27",
 491         "EFRM", "CURR", "GR30", "BFRM"
 492 };
 493
 494 void show_regs(struct pt_regs *regs)
 495 {
 496         unsigned long *reg;
 497         int loop;
 498
 499         printk("\n");
 500         show_regs_print_info(KERN_DEFAULT);
 501
 502         printk("Frame: @%08lx [%s]\n",
 503                (unsigned long) regs,
 504                regs->psr & PSR_S ? "kernel" : "user");
 505
 506         reg = (unsigned long *) regs;
 507         for (loop = 0; loop < NR_PT_REGS; loop++) {
 508                 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
 509
 510                 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
 511                         printk("\n");
 512                 else
 513                         printk(" | ");
 514         }
 515 }
 516
 517 void die_if_kernel(const char *str, ...)
 518 {
 519         char buffer[256];
 520         va_list va;
 521
 522         if (user_mode(__frame))
 523                 return;
 524
 525         va_start(va, str);
 526         vsnprintf(buffer, sizeof(buffer), str, va);
 527         va_end(va);
 528
 529         console_verbose();
 530         printk("\n===================================\n");
 531         printk("%s\n", buffer);
 532         show_backtrace(__frame, 0);
 533
 534         __break_hijack_kernel_event();
 535         do_exit(SIGSEGV);
 536 }
 537
 538 /*****************************************************************************/
 539 /*
 540  * dump the contents of an exception frame
 541  */
 542 static void show_backtrace_regs(struct pt_regs *frame)
 543 {
 544         unsigned long *reg;
 545         int loop;
 546
 547         /* print the registers for this frame */
 548         printk("<-- %s Frame: @%p -->\n",
 549                frame->psr & PSR_S ? "Kernel Mode" : "User Mode",
 550                frame);
 551
 552         reg = (unsigned long *) frame;
 553         for (loop = 0; loop < NR_PT_REGS; loop++) {
 554                 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
 555
 556                 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
 557                         printk("\n");
 558                 else
 559                         printk(" | ");
 560         }
 561
 562         printk("--------\n");
 563 } /* end show_backtrace_regs() */
 564
 565 /*****************************************************************************/
 566 /*
 567  * generate a backtrace of the kernel stack
 568  */
 569 void show_backtrace(struct pt_regs *frame, unsigned long sp)
 570 {
 571         struct pt_regs *frame0;
 572         unsigned long tos = 0, stop = 0, base;
 573         int format;
 574
 575         base = ((((unsigned long) frame) + 8191) & ~8191) - sizeof(struct user_context);
 576         frame0 = (struct pt_regs *) base;
 577
 578         if (sp) {
 579                 tos = sp;
 580                 stop = (unsigned long) frame;
 581         }
 582
 583         printk("\nProcess %s (pid: %d)\n\n", current->comm, current->pid);
 584
 585         for (;;) {
 586                 /* dump stack segment between frames */
 587                 //printk("%08lx -> %08lx\n", tos, stop);
 588                 format = 0;
 589                 while (tos < stop) {
 590                         if (format == 0)
 591                                 printk(" %04lx :", tos & 0xffff);
 592
 593                         printk(" %08lx", *(unsigned long *) tos);
 594
 595                         tos += 4;
 596                         format++;
 597                         if (format == 8) {
 598                                 printk("\n");
 599                                 format = 0;
 600                         }
 601                 }
 602
 603                 if (format > 0)
 604                         printk("\n");
 605
 606                 /* dump frame 0 outside of the loop */
 607                 if (frame == frame0)
 608                         break;
 609
 610                 tos = frame->sp;
 611                 if (((unsigned long) frame) + sizeof(*frame) != tos) {
 612                         printk("-- TOS %08lx does not follow frame %p --\n",
 613                                tos, frame);
 614                         break;
 615                 }
 616
 617                 show_backtrace_regs(frame);
 618
 619                 /* dump the stack between this frame and the next */
 620                 stop = (unsigned long) frame->next_frame;
 621                 if (stop != base &&
 622                     (stop < tos ||
 623                      stop > base ||
 624                      (stop < base && stop + sizeof(*frame) > base) ||
 625                      stop & 3)) {
 626                         printk("-- next_frame %08lx is invalid (range %08lx-%08lx) --\n",
 627                                stop, tos, base);
 628                         break;
 629                 }
 630
 631                 /* move to next frame */
 632                 frame = frame->next_frame;
 633         }
 634
 635         /* we can always dump frame 0, even if the rest of the stack is corrupt */
 636         show_backtrace_regs(frame0);
 637
 638 } /* end show_backtrace() */
 639
 640 /*****************************************************************************/
 641 /*
 642  * initialise traps
 643  */
 644 void __init trap_init (void)
 645 {
 646 } /* end trap_init() */