git.oblomov.eu Git - linux-2.6/blob - 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/system.h>
  27 #include <asm/uaccess.h>
  28 #include <asm/pgtable.h>
  29 #include <asm/siginfo.h>
  30 #include <asm/unaligned.h>
  31
  32 void show_backtrace(struct pt_regs *, unsigned long);
  33
  34 extern asmlinkage void __break_hijack_kernel_event(void);
  35
  36 /*****************************************************************************/
  37 /*
  38  * instruction access error
  39  */
  40 asmlinkage void insn_access_error(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
  41 {
  42         siginfo_t info;
  43
  44         die_if_kernel("-- Insn Access Error --\n"
  45                       "EPCR0 : %08lx\n"
  46                       "ESR0  : %08lx\n",
  47                       epcr0, esr0);
  48
  49         info.si_signo   = SIGSEGV;
  50         info.si_code    = SEGV_ACCERR;
  51         info.si_errno   = 0;
  52         info.si_addr    = (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);
  53
  54         force_sig_info(info.si_signo, &info, current);
  55 } /* end insn_access_error() */
  56
  57 /*****************************************************************************/
  58 /*
  59  * handler for:
  60  * - illegal instruction
  61  * - privileged instruction
  62  * - unsupported trap
  63  * - debug exceptions
  64  */
  65 asmlinkage void illegal_instruction(unsigned long esfr1, unsigned long epcr0, unsigned long esr0)
  66 {
  67         siginfo_t info;
  68
  69         die_if_kernel("-- Illegal Instruction --\n"
  70                       "EPCR0 : %08lx\n"
  71                       "ESR0  : %08lx\n"
  72                       "ESFR1 : %08lx\n",
  73                       epcr0, esr0, esfr1);
  74
  75         info.si_errno   = 0;
  76         info.si_addr    = (void __user *) ((epcr0 & EPCR0_V) ? (epcr0 & EPCR0_PC) : __frame->pc);
  77
  78         switch (__frame->tbr & TBR_TT) {
  79         case TBR_TT_ILLEGAL_INSTR:
  80                 info.si_signo   = SIGILL;
  81                 info.si_code    = ILL_ILLOPC;
  82                 break;
  83         case TBR_TT_PRIV_INSTR:
  84                 info.si_signo   = SIGILL;
  85                 info.si_code    = ILL_PRVOPC;
  86                 break;
  87         case TBR_TT_TRAP2 ... TBR_TT_TRAP126:
  88                 info.si_signo   = SIGILL;
  89                 info.si_code    = ILL_ILLTRP;
  90                 break;
  91         /* GDB uses "tira gr0, #1" as a breakpoint instruction.  */
  92         case TBR_TT_TRAP1:
  93         case TBR_TT_BREAK:
  94                 info.si_signo   = SIGTRAP;
  95                 info.si_code    =
  96                         (__frame->__status & REG__STATUS_STEPPED) ? TRAP_TRACE : TRAP_BRKPT;
  97                 break;
  98         }
  99
 100         force_sig_info(info.si_signo, &info, current);
 101 } /* end illegal_instruction() */
 102
 103 /*****************************************************************************/
 104 /*
 105  * handle atomic operations with errors
 106  * - arguments in gr8, gr9, gr10
 107  * - original memory value placed in gr5
 108  * - replacement memory value placed in gr9
 109  */
 110 asmlinkage void atomic_operation(unsigned long esfr1, unsigned long epcr0,
 111                                  unsigned long esr0)
 112 {
 113         static DEFINE_SPINLOCK(atomic_op_lock);
 114         unsigned long x, y, z;
 115         unsigned long __user *p;
 116         mm_segment_t oldfs;
 117         siginfo_t info;
 118         int ret;
 119
 120         y = 0;
 121         z = 0;
 122
 123         oldfs = get_fs();
 124         if (!user_mode(__frame))
 125                 set_fs(KERNEL_DS);
 126
 127         switch (__frame->tbr & TBR_TT) {
 128                 /* TIRA gr0,#120
 129                  * u32 __atomic_user_cmpxchg32(u32 *ptr, u32 test, u32 new)
 130                  */
 131         case TBR_TT_ATOMIC_CMPXCHG32:
 132                 p = (unsigned long __user *) __frame->gr8;
 133                 x = __frame->gr9;
 134                 y = __frame->gr10;
 135
 136                 for (;;) {
 137                         ret = get_user(z, p);
 138                         if (ret < 0)
 139                                 goto error;
 140
 141                         if (z != x)
 142                                 goto done;
 143
 144                         spin_lock_irq(&atomic_op_lock);
 145
 146                         if (__get_user(z, p) == 0) {
 147                                 if (z != x)
 148                                         goto done2;
 149
 150                                 if (__put_user(y, p) == 0)
 151                                         goto done2;
 152                                 goto error2;
 153                         }
 154
 155                         spin_unlock_irq(&atomic_op_lock);
 156                 }
 157
 158                 /* TIRA gr0,#121
 159                  * u32 __atomic_kernel_xchg32(void *v, u32 new)
 160                  */
 161         case TBR_TT_ATOMIC_XCHG32:
 162                 p = (unsigned long __user *) __frame->gr8;
 163                 y = __frame->gr9;
 164
 165                 for (;;) {
 166                         ret = get_user(z, p);
 167                         if (ret < 0)
 168                                 goto error;
 169
 170                         spin_lock_irq(&atomic_op_lock);
 171
 172                         if (__get_user(z, p) == 0) {
 173                                 if (__put_user(y, p) == 0)
 174                                         goto done2;
 175                                 goto error2;
 176                         }
 177
 178                         spin_unlock_irq(&atomic_op_lock);
 179                 }
 180
 181                 /* TIRA gr0,#122
 182                  * ulong __atomic_kernel_XOR_return(ulong i, ulong *v)
 183                  */
 184         case TBR_TT_ATOMIC_XOR:
 185                 p = (unsigned long __user *) __frame->gr8;
 186                 x = __frame->gr9;
 187
 188                 for (;;) {
 189                         ret = get_user(z, p);
 190                         if (ret < 0)
 191                                 goto error;
 192
 193                         spin_lock_irq(&atomic_op_lock);
 194
 195                         if (__get_user(z, p) == 0) {
 196                                 y = x ^ z;
 197                                 if (__put_user(y, p) == 0)
 198                                         goto done2;
 199                                 goto error2;
 200                         }
 201
 202                         spin_unlock_irq(&atomic_op_lock);
 203                 }
 204
 205                 /* TIRA gr0,#123
 206                  * ulong __atomic_kernel_OR_return(ulong i, ulong *v)
 207                  */
 208         case TBR_TT_ATOMIC_OR:
 209                 p = (unsigned long __user *) __frame->gr8;
 210                 x = __frame->gr9;
 211
 212                 for (;;) {
 213                         ret = get_user(z, p);
 214                         if (ret < 0)
 215                                 goto error;
 216
 217                         spin_lock_irq(&atomic_op_lock);
 218
 219                         if (__get_user(z, p) == 0) {
 220                                 y = x ^ z;
 221                                 if (__put_user(y, p) == 0)
 222                                         goto done2;
 223                                 goto error2;
 224                         }
 225
 226                         spin_unlock_irq(&atomic_op_lock);
 227                 }
 228
 229                 /* TIRA gr0,#124
 230                  * ulong __atomic_kernel_AND_return(ulong i, ulong *v)
 231                  */
 232         case TBR_TT_ATOMIC_AND:
 233                 p = (unsigned long __user *) __frame->gr8;
 234                 x = __frame->gr9;
 235
 236                 for (;;) {
 237                         ret = get_user(z, p);
 238                         if (ret < 0)
 239                                 goto error;
 240
 241                         spin_lock_irq(&atomic_op_lock);
 242
 243                         if (__get_user(z, p) == 0) {
 244                                 y = x & z;
 245                                 if (__put_user(y, p) == 0)
 246                                         goto done2;
 247                                 goto error2;
 248                         }
 249
 250                         spin_unlock_irq(&atomic_op_lock);
 251                 }
 252
 253                 /* TIRA gr0,#125
 254                  * int __atomic_user_sub_return(atomic_t *v, int i)
 255                  */
 256         case TBR_TT_ATOMIC_SUB:
 257                 p = (unsigned long __user *) __frame->gr8;
 258                 x = __frame->gr9;
 259
 260                 for (;;) {
 261                         ret = get_user(z, p);
 262                         if (ret < 0)
 263                                 goto error;
 264
 265                         spin_lock_irq(&atomic_op_lock);
 266
 267                         if (__get_user(z, p) == 0) {
 268                                 y = z - x;
 269                                 if (__put_user(y, p) == 0)
 270                                         goto done2;
 271                                 goto error2;
 272                         }
 273
 274                         spin_unlock_irq(&atomic_op_lock);
 275                 }
 276
 277                 /* TIRA gr0,#126
 278                  * int __atomic_user_add_return(atomic_t *v, int i)
 279                  */
 280         case TBR_TT_ATOMIC_ADD:
 281                 p = (unsigned long __user *) __frame->gr8;
 282                 x = __frame->gr9;
 283
 284                 for (;;) {
 285                         ret = get_user(z, p);
 286                         if (ret < 0)
 287                                 goto error;
 288
 289                         spin_lock_irq(&atomic_op_lock);
 290
 291                         if (__get_user(z, p) == 0) {
 292                                 y = z + x;
 293                                 if (__put_user(y, p) == 0)
 294                                         goto done2;
 295                                 goto error2;
 296                         }
 297
 298                         spin_unlock_irq(&atomic_op_lock);
 299                 }
 300
 301         default:
 302                 BUG();
 303         }
 304
 305 done2:
 306         spin_unlock_irq(&atomic_op_lock);
 307 done:
 308         if (!user_mode(__frame))
 309                 set_fs(oldfs);
 310         __frame->gr5 = z;
 311         __frame->gr9 = y;
 312         return;
 313
 314 error2:
 315         spin_unlock_irq(&atomic_op_lock);
 316 error:
 317         if (!user_mode(__frame))
 318                 set_fs(oldfs);
 319         __frame->pc -= 4;
 320
 321         die_if_kernel("-- Atomic Op Error --\n");
 322
 323         info.si_signo   = SIGSEGV;
 324         info.si_code    = SEGV_ACCERR;
 325         info.si_errno   = 0;
 326         info.si_addr    = (void __user *) __frame->pc;
 327
 328         force_sig_info(info.si_signo, &info, current);
 329 }
 330
 331 /*****************************************************************************/
 332 /*
 333  *
 334  */
 335 asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)
 336 {
 337         siginfo_t info;
 338
 339         die_if_kernel("-- Media Exception --\n"
 340                       "MSR0 : %08lx\n"
 341                       "MSR1 : %08lx\n",
 342                       msr0, msr1);
 343
 344         info.si_signo   = SIGFPE;
 345         info.si_code    = FPE_MDAOVF;
 346         info.si_errno   = 0;
 347         info.si_addr    = (void __user *) __frame->pc;
 348
 349         force_sig_info(info.si_signo, &info, current);
 350 } /* end media_exception() */
 351
 352 /*****************************************************************************/
 353 /*
 354  * instruction or data access exception
 355  */
 356 asmlinkage void memory_access_exception(unsigned long esr0,
 357                                         unsigned long ear0,
 358                                         unsigned long epcr0)
 359 {
 360         siginfo_t info;
 361
 362 #ifdef CONFIG_MMU
 363         unsigned long fixup;
 364
 365         if ((esr0 & ESRx_EC) == ESRx_EC_DATA_ACCESS)
 366                 if (handle_misalignment(esr0, ear0, epcr0) == 0)
 367                         return;
 368
 369         if ((fixup = search_exception_table(__frame->pc)) != 0) {
 370                 __frame->pc = fixup;
 371                 return;
 372         }
 373 #endif
 374
 375         die_if_kernel("-- Memory Access Exception --\n"
 376                       "ESR0  : %08lx\n"
 377                       "EAR0  : %08lx\n"
 378                       "EPCR0 : %08lx\n",
 379                       esr0, ear0, epcr0);
 380
 381         info.si_signo   = SIGSEGV;
 382         info.si_code    = SEGV_ACCERR;
 383         info.si_errno   = 0;
 384         info.si_addr    = NULL;
 385
 386         if ((esr0 & (ESRx_VALID | ESR0_EAV)) == (ESRx_VALID | ESR0_EAV))
 387                 info.si_addr = (void __user *) ear0;
 388
 389         force_sig_info(info.si_signo, &info, current);
 390
 391 } /* end memory_access_exception() */
 392
 393 /*****************************************************************************/
 394 /*
 395  * data access error
 396  * - double-word data load from CPU control area (0xFExxxxxx)
 397  * - read performed on inactive or self-refreshing SDRAM
 398  * - error notification from slave device
 399  * - misaligned address
 400  * - access to out of bounds memory region
 401  * - user mode accessing privileged memory region
 402  * - write to R/O memory region
 403  */
 404 asmlinkage void data_access_error(unsigned long esfr1, unsigned long esr15, unsigned long ear15)
 405 {
 406         siginfo_t info;
 407
 408         die_if_kernel("-- Data Access Error --\n"
 409                       "ESR15 : %08lx\n"
 410                       "EAR15 : %08lx\n",
 411                       esr15, ear15);
 412
 413         info.si_signo   = SIGSEGV;
 414         info.si_code    = SEGV_ACCERR;
 415         info.si_errno   = 0;
 416         info.si_addr    = (void __user *)
 417                 (((esr15 & (ESRx_VALID|ESR15_EAV)) == (ESRx_VALID|ESR15_EAV)) ? ear15 : 0);
 418
 419         force_sig_info(info.si_signo, &info, current);
 420 } /* end data_access_error() */
 421
 422 /*****************************************************************************/
 423 /*
 424  * data store error - should only happen if accessing inactive or self-refreshing SDRAM
 425  */
 426 asmlinkage void data_store_error(unsigned long esfr1, unsigned long esr15)
 427 {
 428         die_if_kernel("-- Data Store Error --\n"
 429                       "ESR15 : %08lx\n",
 430                       esr15);
 431         BUG();
 432 } /* end data_store_error() */
 433
 434 /*****************************************************************************/
 435 /*
 436  *
 437  */
 438 asmlinkage void division_exception(unsigned long esfr1, unsigned long esr0, unsigned long isr)
 439 {
 440         siginfo_t info;
 441
 442         die_if_kernel("-- Division Exception --\n"
 443                       "ESR0 : %08lx\n"
 444                       "ISR  : %08lx\n",
 445                       esr0, isr);
 446
 447         info.si_signo   = SIGFPE;
 448         info.si_code    = FPE_INTDIV;
 449         info.si_errno   = 0;
 450         info.si_addr    = (void __user *) __frame->pc;
 451
 452         force_sig_info(info.si_signo, &info, current);
 453 } /* end division_exception() */
 454
 455 /*****************************************************************************/
 456 /*
 457  *
 458  */
 459 asmlinkage void compound_exception(unsigned long esfr1,
 460                                    unsigned long esr0, unsigned long esr14, unsigned long esr15,
 461                                    unsigned long msr0, unsigned long msr1)
 462 {
 463         die_if_kernel("-- Compound Exception --\n"
 464                       "ESR0  : %08lx\n"
 465                       "ESR15 : %08lx\n"
 466                       "ESR15 : %08lx\n"
 467                       "MSR0  : %08lx\n"
 468                       "MSR1  : %08lx\n",
 469                       esr0, esr14, esr15, msr0, msr1);
 470         BUG();
 471 } /* end compound_exception() */
 472
 473 /*****************************************************************************/
 474 /*
 475  * The architecture-independent backtrace generator
 476  */
 477 void dump_stack(void)
 478 {
 479         show_stack(NULL, NULL);
 480 }
 481
 482 EXPORT_SYMBOL(dump_stack);
 483
 484 void show_stack(struct task_struct *task, unsigned long *sp)
 485 {
 486 }
 487
 488 void show_trace_task(struct task_struct *tsk)
 489 {
 490         printk("CONTEXT: stack=0x%lx frame=0x%p LR=0x%lx RET=0x%lx\n",
 491                tsk->thread.sp, tsk->thread.frame, tsk->thread.lr, tsk->thread.sched_lr);
 492 }
 493
 494 static const char *regnames[] = {
 495         "PSR ", "ISR ", "CCR ", "CCCR",
 496         "LR  ", "LCR ", "PC  ", "_stt",
 497         "sys ", "GR8*", "GNE0", "GNE1",
 498         "IACH", "IACL",
 499         "TBR ", "SP  ", "FP  ", "GR3 ",
 500         "GR4 ", "GR5 ", "GR6 ", "GR7 ",
 501         "GR8 ", "GR9 ", "GR10", "GR11",
 502         "GR12", "GR13", "GR14", "GR15",
 503         "GR16", "GR17", "GR18", "GR19",
 504         "GR20", "GR21", "GR22", "GR23",
 505         "GR24", "GR25", "GR26", "GR27",
 506         "EFRM", "CURR", "GR30", "BFRM"
 507 };
 508
 509 void show_regs(struct pt_regs *regs)
 510 {
 511         unsigned long *reg;
 512         int loop;
 513
 514         printk("\n");
 515
 516         printk("Frame: @%08lx [%s]\n",
 517                (unsigned long) regs,
 518                regs->psr & PSR_S ? "kernel" : "user");
 519
 520         reg = (unsigned long *) regs;
 521         for (loop = 0; loop < NR_PT_REGS; loop++) {
 522                 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
 523
 524                 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
 525                         printk("\n");
 526                 else
 527                         printk(" | ");
 528         }
 529
 530         printk("Process %s (pid: %d)\n", current->comm, current->pid);
 531 }
 532
 533 void die_if_kernel(const char *str, ...)
 534 {
 535         char buffer[256];
 536         va_list va;
 537
 538         if (user_mode(__frame))
 539                 return;
 540
 541         va_start(va, str);
 542         vsprintf(buffer, str, va);
 543         va_end(va);
 544
 545         console_verbose();
 546         printk("\n===================================\n");
 547         printk("%s\n", buffer);
 548         show_backtrace(__frame, 0);
 549
 550         __break_hijack_kernel_event();
 551         do_exit(SIGSEGV);
 552 }
 553
 554 /*****************************************************************************/
 555 /*
 556  * dump the contents of an exception frame
 557  */
 558 static void show_backtrace_regs(struct pt_regs *frame)
 559 {
 560         unsigned long *reg;
 561         int loop;
 562
 563         /* print the registers for this frame */
 564         printk("<-- %s Frame: @%p -->\n",
 565                frame->psr & PSR_S ? "Kernel Mode" : "User Mode",
 566                frame);
 567
 568         reg = (unsigned long *) frame;
 569         for (loop = 0; loop < NR_PT_REGS; loop++) {
 570                 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
 571
 572                 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
 573                         printk("\n");
 574                 else
 575                         printk(" | ");
 576         }
 577
 578         printk("--------\n");
 579 } /* end show_backtrace_regs() */
 580
 581 /*****************************************************************************/
 582 /*
 583  * generate a backtrace of the kernel stack
 584  */
 585 void show_backtrace(struct pt_regs *frame, unsigned long sp)
 586 {
 587         struct pt_regs *frame0;
 588         unsigned long tos = 0, stop = 0, base;
 589         int format;
 590
 591         base = ((((unsigned long) frame) + 8191) & ~8191) - sizeof(struct user_context);
 592         frame0 = (struct pt_regs *) base;
 593
 594         if (sp) {
 595                 tos = sp;
 596                 stop = (unsigned long) frame;
 597         }
 598
 599         printk("\nProcess %s (pid: %d)\n\n", current->comm, current->pid);
 600
 601         for (;;) {
 602                 /* dump stack segment between frames */
 603                 //printk("%08lx -> %08lx\n", tos, stop);
 604                 format = 0;
 605                 while (tos < stop) {
 606                         if (format == 0)
 607                                 printk(" %04lx :", tos & 0xffff);
 608
 609                         printk(" %08lx", *(unsigned long *) tos);
 610
 611                         tos += 4;
 612                         format++;
 613                         if (format == 8) {
 614                                 printk("\n");
 615                                 format = 0;
 616                         }
 617                 }
 618
 619                 if (format > 0)
 620                         printk("\n");
 621
 622                 /* dump frame 0 outside of the loop */
 623                 if (frame == frame0)
 624                         break;
 625
 626                 tos = frame->sp;
 627                 if (((unsigned long) frame) + sizeof(*frame) != tos) {
 628                         printk("-- TOS %08lx does not follow frame %p --\n",
 629                                tos, frame);
 630                         break;
 631                 }
 632
 633                 show_backtrace_regs(frame);
 634
 635                 /* dump the stack between this frame and the next */
 636                 stop = (unsigned long) frame->next_frame;
 637                 if (stop != base &&
 638                     (stop < tos ||
 639                      stop > base ||
 640                      (stop < base && stop + sizeof(*frame) > base) ||
 641                      stop & 3)) {
 642                         printk("-- next_frame %08lx is invalid (range %08lx-%08lx) --\n",
 643                                stop, tos, base);
 644                         break;
 645                 }
 646
 647                 /* move to next frame */
 648                 frame = frame->next_frame;
 649         }
 650
 651         /* we can always dump frame 0, even if the rest of the stack is corrupt */
 652         show_backtrace_regs(frame0);
 653
 654 } /* end show_backtrace() */
 655
 656 /*****************************************************************************/
 657 /*
 658  * initialise traps
 659  */
 660 void __init trap_init (void)
 661 {
 662 } /* end trap_init() */