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 *) ((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 *) ((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, *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 *) __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 *) __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 *) __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 *) __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 *) __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 *) __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 *) __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 *) __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 *) __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         if ((esr0 & ESRx_EC) == ESRx_EC_DATA_ACCESS)
 365                 if (handle_misalignment(esr0, ear0, epcr0) == 0)
 366                         return;
 367
 368         if ((fixup = search_exception_table(__frame->pc)) != 0) {
 369                 __frame->pc = fixup;
 370                 return;
 371         }
 372 #endif
 373
 374         die_if_kernel("-- Memory Access Exception --\n"
 375                       "ESR0  : %08lx\n"
 376                       "EAR0  : %08lx\n"
 377                       "EPCR0 : %08lx\n",
 378                       esr0, ear0, epcr0);
 379
 380         info.si_signo   = SIGSEGV;
 381         info.si_code    = SEGV_ACCERR;
 382         info.si_errno   = 0;
 383         info.si_addr    = NULL;
 384
 385         if ((esr0 & (ESRx_VALID | ESR0_EAV)) == (ESRx_VALID | ESR0_EAV))
 386                 info.si_addr = (void *) ear0;
 387
 388         force_sig_info(info.si_signo, &info, current);
 389
 390 } /* end memory_access_exception() */
 391
 392 /*****************************************************************************/
 393 /*
 394  * data access error
 395  * - double-word data load from CPU control area (0xFExxxxxx)
 396  * - read performed on inactive or self-refreshing SDRAM
 397  * - error notification from slave device
 398  * - misaligned address
 399  * - access to out of bounds memory region
 400  * - user mode accessing privileged memory region
 401  * - write to R/O memory region
 402  */
 403 asmlinkage void data_access_error(unsigned long esfr1, unsigned long esr15, unsigned long ear15)
 404 {
 405         siginfo_t info;
 406
 407         die_if_kernel("-- Data Access Error --\n"
 408                       "ESR15 : %08lx\n"
 409                       "EAR15 : %08lx\n",
 410                       esr15, ear15);
 411
 412         info.si_signo   = SIGSEGV;
 413         info.si_code    = SEGV_ACCERR;
 414         info.si_errno   = 0;
 415         info.si_addr    = (void *)
 416                 (((esr15 & (ESRx_VALID|ESR15_EAV)) == (ESRx_VALID|ESR15_EAV)) ? ear15 : 0);
 417
 418         force_sig_info(info.si_signo, &info, current);
 419 } /* end data_access_error() */
 420
 421 /*****************************************************************************/
 422 /*
 423  * data store error - should only happen if accessing inactive or self-refreshing SDRAM
 424  */
 425 asmlinkage void data_store_error(unsigned long esfr1, unsigned long esr15)
 426 {
 427         die_if_kernel("-- Data Store Error --\n"
 428                       "ESR15 : %08lx\n",
 429                       esr15);
 430         BUG();
 431 } /* end data_store_error() */
 432
 433 /*****************************************************************************/
 434 /*
 435  *
 436  */
 437 asmlinkage void division_exception(unsigned long esfr1, unsigned long esr0, unsigned long isr)
 438 {
 439         siginfo_t info;
 440
 441         die_if_kernel("-- Division Exception --\n"
 442                       "ESR0 : %08lx\n"
 443                       "ISR  : %08lx\n",
 444                       esr0, isr);
 445
 446         info.si_signo   = SIGFPE;
 447         info.si_code    = FPE_INTDIV;
 448         info.si_errno   = 0;
 449         info.si_addr    = (void *) __frame->pc;
 450
 451         force_sig_info(info.si_signo, &info, current);
 452 } /* end division_exception() */
 453
 454 /*****************************************************************************/
 455 /*
 456  *
 457  */
 458 asmlinkage void compound_exception(unsigned long esfr1,
 459                                    unsigned long esr0, unsigned long esr14, unsigned long esr15,
 460                                    unsigned long msr0, unsigned long msr1)
 461 {
 462         die_if_kernel("-- Compound Exception --\n"
 463                       "ESR0  : %08lx\n"
 464                       "ESR15 : %08lx\n"
 465                       "ESR15 : %08lx\n"
 466                       "MSR0  : %08lx\n"
 467                       "MSR1  : %08lx\n",
 468                       esr0, esr14, esr15, msr0, msr1);
 469         BUG();
 470 } /* end compound_exception() */
 471
 472 /*****************************************************************************/
 473 /*
 474  * The architecture-independent backtrace generator
 475  */
 476 void dump_stack(void)
 477 {
 478         show_stack(NULL, NULL);
 479 }
 480
 481 EXPORT_SYMBOL(dump_stack);
 482
 483 void show_stack(struct task_struct *task, unsigned long *sp)
 484 {
 485 }
 486
 487 void show_trace_task(struct task_struct *tsk)
 488 {
 489         printk("CONTEXT: stack=0x%lx frame=0x%p LR=0x%lx RET=0x%lx\n",
 490                tsk->thread.sp, tsk->thread.frame, tsk->thread.lr, tsk->thread.sched_lr);
 491 }
 492
 493 static const char *regnames[] = {
 494         "PSR ", "ISR ", "CCR ", "CCCR",
 495         "LR  ", "LCR ", "PC  ", "_stt",
 496         "sys ", "GR8*", "GNE0", "GNE1",
 497         "IACH", "IACL",
 498         "TBR ", "SP  ", "FP  ", "GR3 ",
 499         "GR4 ", "GR5 ", "GR6 ", "GR7 ",
 500         "GR8 ", "GR9 ", "GR10", "GR11",
 501         "GR12", "GR13", "GR14", "GR15",
 502         "GR16", "GR17", "GR18", "GR19",
 503         "GR20", "GR21", "GR22", "GR23",
 504         "GR24", "GR25", "GR26", "GR27",
 505         "EFRM", "CURR", "GR30", "BFRM"
 506 };
 507
 508 void show_regs(struct pt_regs *regs)
 509 {
 510         unsigned long *reg;
 511         int loop;
 512
 513         printk("\n");
 514
 515         printk("Frame: @%08lx [%s]\n",
 516                (unsigned long) regs,
 517                regs->psr & PSR_S ? "kernel" : "user");
 518
 519         reg = (unsigned long *) regs;
 520         for (loop = 0; loop < NR_PT_REGS; loop++) {
 521                 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
 522
 523                 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
 524                         printk("\n");
 525                 else
 526                         printk(" | ");
 527         }
 528
 529         printk("Process %s (pid: %d)\n", current->comm, current->pid);
 530 }
 531
 532 void die_if_kernel(const char *str, ...)
 533 {
 534         char buffer[256];
 535         va_list va;
 536
 537         if (user_mode(__frame))
 538                 return;
 539
 540         va_start(va, str);
 541         vsprintf(buffer, str, va);
 542         va_end(va);
 543
 544         console_verbose();
 545         printk("\n===================================\n");
 546         printk("%s\n", buffer);
 547         show_backtrace(__frame, 0);
 548
 549         __break_hijack_kernel_event();
 550         do_exit(SIGSEGV);
 551 }
 552
 553 /*****************************************************************************/
 554 /*
 555  * dump the contents of an exception frame
 556  */
 557 static void show_backtrace_regs(struct pt_regs *frame)
 558 {
 559         unsigned long *reg;
 560         int loop;
 561
 562         /* print the registers for this frame */
 563         printk("<-- %s Frame: @%p -->\n",
 564                frame->psr & PSR_S ? "Kernel Mode" : "User Mode",
 565                frame);
 566
 567         reg = (unsigned long *) frame;
 568         for (loop = 0; loop < NR_PT_REGS; loop++) {
 569                 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
 570
 571                 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
 572                         printk("\n");
 573                 else
 574                         printk(" | ");
 575         }
 576
 577         printk("--------\n");
 578 } /* end show_backtrace_regs() */
 579
 580 /*****************************************************************************/
 581 /*
 582  * generate a backtrace of the kernel stack
 583  */
 584 void show_backtrace(struct pt_regs *frame, unsigned long sp)
 585 {
 586         struct pt_regs *frame0;
 587         unsigned long tos = 0, stop = 0, base;
 588         int format;
 589
 590         base = ((((unsigned long) frame) + 8191) & ~8191) - sizeof(struct user_context);
 591         frame0 = (struct pt_regs *) base;
 592
 593         if (sp) {
 594                 tos = sp;
 595                 stop = (unsigned long) frame;
 596         }
 597
 598         printk("\nProcess %s (pid: %d)\n\n", current->comm, current->pid);
 599
 600         for (;;) {
 601                 /* dump stack segment between frames */
 602                 //printk("%08lx -> %08lx\n", tos, stop);
 603                 format = 0;
 604                 while (tos < stop) {
 605                         if (format == 0)
 606                                 printk(" %04lx :", tos & 0xffff);
 607
 608                         printk(" %08lx", *(unsigned long *) tos);
 609
 610                         tos += 4;
 611                         format++;
 612                         if (format == 8) {
 613                                 printk("\n");
 614                                 format = 0;
 615                         }
 616                 }
 617
 618                 if (format > 0)
 619                         printk("\n");
 620
 621                 /* dump frame 0 outside of the loop */
 622                 if (frame == frame0)
 623                         break;
 624
 625                 tos = frame->sp;
 626                 if (((unsigned long) frame) + sizeof(*frame) != tos) {
 627                         printk("-- TOS %08lx does not follow frame %p --\n",
 628                                tos, frame);
 629                         break;
 630                 }
 631
 632                 show_backtrace_regs(frame);
 633
 634                 /* dump the stack between this frame and the next */
 635                 stop = (unsigned long) frame->next_frame;
 636                 if (stop != base &&
 637                     (stop < tos ||
 638                      stop > base ||
 639                      (stop < base && stop + sizeof(*frame) > base) ||
 640                      stop & 3)) {
 641                         printk("-- next_frame %08lx is invalid (range %08lx-%08lx) --\n",
 642                                stop, tos, base);
 643                         break;
 644                 }
 645
 646                 /* move to next frame */
 647                 frame = frame->next_frame;
 648         }
 649
 650         /* we can always dump frame 0, even if the rest of the stack is corrupt */
 651         show_backtrace_regs(frame0);
 652
 653 } /* end show_backtrace() */
 654
 655 /*****************************************************************************/
 656 /*
 657  * initialise traps
 658  */
 659 void __init trap_init (void)
 660 {
 661 } /* end trap_init() */