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_PC) ? (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  *
 106  */
 107 asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)
 108 {
 109         siginfo_t info;
 110
 111         die_if_kernel("-- Media Exception --\n"
 112                       "MSR0 : %08lx\n"
 113                       "MSR1 : %08lx\n",
 114                       msr0, msr1);
 115
 116         info.si_signo   = SIGFPE;
 117         info.si_code    = FPE_MDAOVF;
 118         info.si_errno   = 0;
 119         info.si_addr    = (void *) __frame->pc;
 120
 121         force_sig_info(info.si_signo, &info, current);
 122 } /* end media_exception() */
 123
 124 /*****************************************************************************/
 125 /*
 126  * instruction or data access exception
 127  */
 128 asmlinkage void memory_access_exception(unsigned long esr0,
 129                                         unsigned long ear0,
 130                                         unsigned long epcr0)
 131 {
 132         siginfo_t info;
 133
 134 #ifdef CONFIG_MMU
 135         unsigned long fixup;
 136
 137         if ((esr0 & ESRx_EC) == ESRx_EC_DATA_ACCESS)
 138                 if (handle_misalignment(esr0, ear0, epcr0) == 0)
 139                         return;
 140
 141         if ((fixup = search_exception_table(__frame->pc)) != 0) {
 142                 __frame->pc = fixup;
 143                 return;
 144         }
 145 #endif
 146
 147         die_if_kernel("-- Memory Access Exception --\n"
 148                       "ESR0  : %08lx\n"
 149                       "EAR0  : %08lx\n"
 150                       "EPCR0 : %08lx\n",
 151                       esr0, ear0, epcr0);
 152
 153         info.si_signo   = SIGSEGV;
 154         info.si_code    = SEGV_ACCERR;
 155         info.si_errno   = 0;
 156         info.si_addr    = NULL;
 157
 158         if ((esr0 & (ESRx_VALID | ESR0_EAV)) == (ESRx_VALID | ESR0_EAV))
 159                 info.si_addr = (void *) ear0;
 160
 161         force_sig_info(info.si_signo, &info, current);
 162
 163 } /* end memory_access_exception() */
 164
 165 /*****************************************************************************/
 166 /*
 167  * data access error
 168  * - double-word data load from CPU control area (0xFExxxxxx)
 169  * - read performed on inactive or self-refreshing SDRAM
 170  * - error notification from slave device
 171  * - misaligned address
 172  * - access to out of bounds memory region
 173  * - user mode accessing privileged memory region
 174  * - write to R/O memory region
 175  */
 176 asmlinkage void data_access_error(unsigned long esfr1, unsigned long esr15, unsigned long ear15)
 177 {
 178         siginfo_t info;
 179
 180         die_if_kernel("-- Data Access Error --\n"
 181                       "ESR15 : %08lx\n"
 182                       "EAR15 : %08lx\n",
 183                       esr15, ear15);
 184
 185         info.si_signo   = SIGSEGV;
 186         info.si_code    = SEGV_ACCERR;
 187         info.si_errno   = 0;
 188         info.si_addr    = (void *)
 189                 (((esr15 & (ESRx_VALID|ESR15_EAV)) == (ESRx_VALID|ESR15_EAV)) ? ear15 : 0);
 190
 191         force_sig_info(info.si_signo, &info, current);
 192 } /* end data_access_error() */
 193
 194 /*****************************************************************************/
 195 /*
 196  * data store error - should only happen if accessing inactive or self-refreshing SDRAM
 197  */
 198 asmlinkage void data_store_error(unsigned long esfr1, unsigned long esr15)
 199 {
 200         die_if_kernel("-- Data Store Error --\n"
 201                       "ESR15 : %08lx\n",
 202                       esr15);
 203         BUG();
 204 } /* end data_store_error() */
 205
 206 /*****************************************************************************/
 207 /*
 208  *
 209  */
 210 asmlinkage void division_exception(unsigned long esfr1, unsigned long esr0, unsigned long isr)
 211 {
 212         siginfo_t info;
 213
 214         die_if_kernel("-- Division Exception --\n"
 215                       "ESR0 : %08lx\n"
 216                       "ISR  : %08lx\n",
 217                       esr0, isr);
 218
 219         info.si_signo   = SIGFPE;
 220         info.si_code    = FPE_INTDIV;
 221         info.si_errno   = 0;
 222         info.si_addr    = (void *) __frame->pc;
 223
 224         force_sig_info(info.si_signo, &info, current);
 225 } /* end division_exception() */
 226
 227 /*****************************************************************************/
 228 /*
 229  *
 230  */
 231 asmlinkage void compound_exception(unsigned long esfr1,
 232                                    unsigned long esr0, unsigned long esr14, unsigned long esr15,
 233                                    unsigned long msr0, unsigned long msr1)
 234 {
 235         die_if_kernel("-- Compound Exception --\n"
 236                       "ESR0  : %08lx\n"
 237                       "ESR15 : %08lx\n"
 238                       "ESR15 : %08lx\n"
 239                       "MSR0  : %08lx\n"
 240                       "MSR1  : %08lx\n",
 241                       esr0, esr14, esr15, msr0, msr1);
 242         BUG();
 243 } /* end compound_exception() */
 244
 245 /*****************************************************************************/
 246 /*
 247  * The architecture-independent backtrace generator
 248  */
 249 void dump_stack(void)
 250 {
 251         show_stack(NULL, NULL);
 252 }
 253
 254 EXPORT_SYMBOL(dump_stack);
 255
 256 void show_stack(struct task_struct *task, unsigned long *sp)
 257 {
 258 }
 259
 260 void show_trace_task(struct task_struct *tsk)
 261 {
 262         printk("CONTEXT: stack=0x%lx frame=0x%p LR=0x%lx RET=0x%lx\n",
 263                tsk->thread.sp, tsk->thread.frame, tsk->thread.lr, tsk->thread.sched_lr);
 264 }
 265
 266 static const char *regnames[] = {
 267         "PSR ", "ISR ", "CCR ", "CCCR",
 268         "LR  ", "LCR ", "PC  ", "_stt",
 269         "sys ", "GR8*", "GNE0", "GNE1",
 270         "IACH", "IACL",
 271         "TBR ", "SP  ", "FP  ", "GR3 ",
 272         "GR4 ", "GR5 ", "GR6 ", "GR7 ",
 273         "GR8 ", "GR9 ", "GR10", "GR11",
 274         "GR12", "GR13", "GR14", "GR15",
 275         "GR16", "GR17", "GR18", "GR19",
 276         "GR20", "GR21", "GR22", "GR23",
 277         "GR24", "GR25", "GR26", "GR27",
 278         "EFRM", "CURR", "GR30", "BFRM"
 279 };
 280
 281 void show_regs(struct pt_regs *regs)
 282 {
 283         unsigned long *reg;
 284         int loop;
 285
 286         printk("\n");
 287
 288         printk("Frame: @%08lx [%s]\n",
 289                (unsigned long) regs,
 290                regs->psr & PSR_S ? "kernel" : "user");
 291
 292         reg = (unsigned long *) regs;
 293         for (loop = 0; loop < NR_PT_REGS; loop++) {
 294                 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
 295
 296                 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
 297                         printk("\n");
 298                 else
 299                         printk(" | ");
 300         }
 301
 302         printk("Process %s (pid: %d)\n", current->comm, current->pid);
 303 }
 304
 305 void die_if_kernel(const char *str, ...)
 306 {
 307         char buffer[256];
 308         va_list va;
 309
 310         if (user_mode(__frame))
 311                 return;
 312
 313         va_start(va, str);
 314         vsprintf(buffer, str, va);
 315         va_end(va);
 316
 317         console_verbose();
 318         printk("\n===================================\n");
 319         printk("%s\n", buffer);
 320         show_backtrace(__frame, 0);
 321
 322         __break_hijack_kernel_event();
 323         do_exit(SIGSEGV);
 324 }
 325
 326 /*****************************************************************************/
 327 /*
 328  * dump the contents of an exception frame
 329  */
 330 static void show_backtrace_regs(struct pt_regs *frame)
 331 {
 332         unsigned long *reg;
 333         int loop;
 334
 335         /* print the registers for this frame */
 336         printk("<-- %s Frame: @%p -->\n",
 337                frame->psr & PSR_S ? "Kernel Mode" : "User Mode",
 338                frame);
 339
 340         reg = (unsigned long *) frame;
 341         for (loop = 0; loop < NR_PT_REGS; loop++) {
 342                 printk("%s %08lx", regnames[loop + 0], reg[loop + 0]);
 343
 344                 if (loop == NR_PT_REGS - 1 || loop % 5 == 4)
 345                         printk("\n");
 346                 else
 347                         printk(" | ");
 348         }
 349
 350         printk("--------\n");
 351 } /* end show_backtrace_regs() */
 352
 353 /*****************************************************************************/
 354 /*
 355  * generate a backtrace of the kernel stack
 356  */
 357 void show_backtrace(struct pt_regs *frame, unsigned long sp)
 358 {
 359         struct pt_regs *frame0;
 360         unsigned long tos = 0, stop = 0, base;
 361         int format;
 362
 363         base = ((((unsigned long) frame) + 8191) & ~8191) - sizeof(struct user_context);
 364         frame0 = (struct pt_regs *) base;
 365
 366         if (sp) {
 367                 tos = sp;
 368                 stop = (unsigned long) frame;
 369         }
 370
 371         printk("\nProcess %s (pid: %d)\n\n", current->comm, current->pid);
 372
 373         for (;;) {
 374                 /* dump stack segment between frames */
 375                 //printk("%08lx -> %08lx\n", tos, stop);
 376                 format = 0;
 377                 while (tos < stop) {
 378                         if (format == 0)
 379                                 printk(" %04lx :", tos & 0xffff);
 380
 381                         printk(" %08lx", *(unsigned long *) tos);
 382
 383                         tos += 4;
 384                         format++;
 385                         if (format == 8) {
 386                                 printk("\n");
 387                                 format = 0;
 388                         }
 389                 }
 390
 391                 if (format > 0)
 392                         printk("\n");
 393
 394                 /* dump frame 0 outside of the loop */
 395                 if (frame == frame0)
 396                         break;
 397
 398                 tos = frame->sp;
 399                 if (((unsigned long) frame) + sizeof(*frame) != tos) {
 400                         printk("-- TOS %08lx does not follow frame %p --\n",
 401                                tos, frame);
 402                         break;
 403                 }
 404
 405                 show_backtrace_regs(frame);
 406
 407                 /* dump the stack between this frame and the next */
 408                 stop = (unsigned long) frame->next_frame;
 409                 if (stop != base &&
 410                     (stop < tos ||
 411                      stop > base ||
 412                      (stop < base && stop + sizeof(*frame) > base) ||
 413                      stop & 3)) {
 414                         printk("-- next_frame %08lx is invalid (range %08lx-%08lx) --\n",
 415                                stop, tos, base);
 416                         break;
 417                 }
 418
 419                 /* move to next frame */
 420                 frame = frame->next_frame;
 421         }
 422
 423         /* we can always dump frame 0, even if the rest of the stack is corrupt */
 424         show_backtrace_regs(frame0);
 425
 426 } /* end show_backtrace() */
 427
 428 /*****************************************************************************/
 429 /*
 430  * initialise traps
 431  */
 432 void __init trap_init (void)
 433 {
 434 } /* end trap_init() */