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