arch/avr32/kernel/traps.c

   1 /*
   2  * Copyright (C) 2004-2006 Atmel Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8 #undef DEBUG
   9 #include <linux/sched.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/kallsyms.h>
  13 #include <linux/notifier.h>
  14
  15 #include <asm/traps.h>
  16 #include <asm/sysreg.h>
  17 #include <asm/addrspace.h>
  18 #include <asm/ocd.h>
  19 #include <asm/mmu_context.h>
  20 #include <asm/uaccess.h>
  21
  22 static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
  23 {
  24         unsigned long p;
  25         int i;
  26
  27         printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
  28
  29         for (p = bottom & ~31; p < top; ) {
  30                 printk("%04lx: ", p & 0xffff);
  31
  32                 for (i = 0; i < 8; i++, p += 4) {
  33                         unsigned int val;
  34
  35                         if (p < bottom || p >= top)
  36                                 printk("         ");
  37                         else {
  38                                 if (__get_user(val, (unsigned int __user *)p)) {
  39                                         printk("\n");
  40                                         goto out;
  41                                 }
  42                                 printk("%08x ", val);
  43                         }
  44                 }
  45                 printk("\n");
  46         }
  47
  48 out:
  49         return;
  50 }
  51
  52 #ifdef CONFIG_FRAME_POINTER
  53 static inline void __show_trace(struct task_struct *tsk, unsigned long *sp,
  54                                 struct pt_regs *regs)
  55 {
  56         unsigned long __user *fp;
  57         unsigned long __user *last_fp = NULL;
  58
  59         if (regs) {
  60                 fp = (unsigned long __user *)regs->r7;
  61         } else if (tsk == current) {
  62                 register unsigned long __user *real_fp __asm__("r7");
  63                 fp = real_fp;
  64         } else {
  65                 fp = (unsigned long __user *)tsk->thread.cpu_context.r7;
  66         }
  67
  68         /*
  69          * Walk the stack until (a) we get an exception, (b) the frame
  70          * pointer becomes zero, or (c) the frame pointer gets stuck
  71          * at the same value.
  72          */
  73         while (fp && fp != last_fp) {
  74                 unsigned long lr, new_fp = 0;
  75
  76                 last_fp = fp;
  77                 if (__get_user(lr, fp))
  78                         break;
  79                 if (fp && __get_user(new_fp, fp + 1))
  80                         break;
  81                 fp = (unsigned long __user *)new_fp;
  82
  83                 printk(" [<%08lx>] ", lr);
  84                 print_symbol("%s\n", lr);
  85         }
  86         printk("\n");
  87 }
  88 #else
  89 static inline void __show_trace(struct task_struct *tsk, unsigned long *sp,
  90                                 struct pt_regs *regs)
  91 {
  92         unsigned long addr;
  93
  94         while (!kstack_end(sp)) {
  95                 addr = *sp++;
  96                 if (kernel_text_address(addr)) {
  97                         printk(" [<%08lx>] ", addr);
  98                         print_symbol("%s\n", addr);
  99                 }
 100         }
 101 }
 102 #endif
 103
 104 void show_trace(struct task_struct *tsk, unsigned long *sp,
 105                        struct pt_regs *regs)
 106 {
 107         if (regs &&
 108             (((regs->sr & MODE_MASK) == MODE_EXCEPTION) ||
 109              ((regs->sr & MODE_MASK) == MODE_USER)))
 110                 return;
 111
 112         printk ("Call trace:");
 113 #ifdef CONFIG_KALLSYMS
 114         printk("\n");
 115 #endif
 116
 117         __show_trace(tsk, sp, regs);
 118         printk("\n");
 119 }
 120
 121 void show_stack(struct task_struct *tsk, unsigned long *sp)
 122 {
 123         unsigned long stack;
 124
 125         if (!tsk)
 126                 tsk = current;
 127         if (sp == 0) {
 128                 if (tsk == current) {
 129                         register unsigned long *real_sp __asm__("sp");
 130                         sp = real_sp;
 131                 } else {
 132                         sp = (unsigned long *)tsk->thread.cpu_context.ksp;
 133                 }
 134         }
 135
 136         stack = (unsigned long)sp;
 137         dump_mem("Stack: ", stack,
 138                  THREAD_SIZE + (unsigned long)tsk->thread_info);
 139         show_trace(tsk, sp, NULL);
 140 }
 141
 142 void dump_stack(void)
 143 {
 144         show_stack(NULL, NULL);
 145 }
 146 EXPORT_SYMBOL(dump_stack);
 147
 148 ATOMIC_NOTIFIER_HEAD(avr32_die_chain);
 149
 150 int register_die_notifier(struct notifier_block *nb)
 151 {
 152         pr_debug("register_die_notifier: %p\n", nb);
 153
 154         return atomic_notifier_chain_register(&avr32_die_chain, nb);
 155 }
 156 EXPORT_SYMBOL(register_die_notifier);
 157
 158 int unregister_die_notifier(struct notifier_block *nb)
 159 {
 160         return atomic_notifier_chain_unregister(&avr32_die_chain, nb);
 161 }
 162 EXPORT_SYMBOL(unregister_die_notifier);
 163
 164 static DEFINE_SPINLOCK(die_lock);
 165
 166 void __die(const char *str, struct pt_regs *regs, unsigned long err,
 167            const char *file, const char *func, unsigned long line)
 168 {
 169         struct task_struct *tsk = current;
 170         static int die_counter;
 171
 172         console_verbose();
 173         spin_lock_irq(&die_lock);
 174         bust_spinlocks(1);
 175
 176         printk(KERN_ALERT "%s", str);
 177         if (file && func)
 178                 printk(" in %s:%s, line %ld", file, func, line);
 179         printk("[#%d]:\n", ++die_counter);
 180         print_modules();
 181         show_regs(regs);
 182         printk("Process %s (pid: %d, stack limit = 0x%p)\n",
 183                tsk->comm, tsk->pid, tsk->thread_info + 1);
 184
 185         if (!user_mode(regs) || in_interrupt()) {
 186                 dump_mem("Stack: ", regs->sp,
 187                          THREAD_SIZE + (unsigned long)tsk->thread_info);
 188         }
 189
 190         bust_spinlocks(0);
 191         spin_unlock_irq(&die_lock);
 192         do_exit(SIGSEGV);
 193 }
 194
 195 void __die_if_kernel(const char *str, struct pt_regs *regs, unsigned long err,
 196                      const char *file, const char *func, unsigned long line)
 197 {
 198         if (!user_mode(regs))
 199                 __die(str, regs, err, file, func, line);
 200 }
 201
 202 asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
 203 {
 204 #ifdef CONFIG_SUBARCH_AVR32B
 205         /*
 206          * The exception entry always saves RSR_EX. For NMI, this is
 207          * wrong; it should be RSR_NMI
 208          */
 209         regs->sr = sysreg_read(RSR_NMI);
 210 #endif
 211
 212         printk("NMI taken!!!!\n");
 213         die("NMI", regs, ecr);
 214         BUG();
 215 }
 216
 217 asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
 218 {
 219         printk("Unable to handle critical exception %lu at pc = %08lx!\n",
 220                ecr, regs->pc);
 221         die("Oops", regs, ecr);
 222         BUG();
 223 }
 224
 225 asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
 226 {
 227         siginfo_t info;
 228
 229         die_if_kernel("Oops: Address exception in kernel mode", regs, ecr);
 230
 231 #ifdef DEBUG
 232         if (ecr == ECR_ADDR_ALIGN_X)
 233                 pr_debug("Instruction Address Exception at pc = %08lx\n",
 234                          regs->pc);
 235         else if (ecr == ECR_ADDR_ALIGN_R)
 236                 pr_debug("Data Address Exception (Read) at pc = %08lx\n",
 237                          regs->pc);
 238         else if (ecr == ECR_ADDR_ALIGN_W)
 239                 pr_debug("Data Address Exception (Write) at pc = %08lx\n",
 240                          regs->pc);
 241         else
 242                 BUG();
 243
 244         show_regs(regs);
 245 #endif
 246
 247         info.si_signo = SIGBUS;
 248         info.si_errno = 0;
 249         info.si_code = BUS_ADRALN;
 250         info.si_addr = (void __user *)regs->pc;
 251
 252         force_sig_info(SIGBUS, &info, current);
 253 }
 254
 255 /* This way of handling undefined instructions is stolen from ARM */
 256 static LIST_HEAD(undef_hook);
 257 static spinlock_t undef_lock = SPIN_LOCK_UNLOCKED;
 258
 259 void register_undef_hook(struct undef_hook *hook)
 260 {
 261         spin_lock_irq(&undef_lock);
 262         list_add(&hook->node, &undef_hook);
 263         spin_unlock_irq(&undef_lock);
 264 }
 265
 266 void unregister_undef_hook(struct undef_hook *hook)
 267 {
 268         spin_lock_irq(&undef_lock);
 269         list_del(&hook->node);
 270         spin_unlock_irq(&undef_lock);
 271 }
 272
 273 static int do_cop_absent(u32 insn)
 274 {
 275         int cop_nr;
 276         u32 cpucr;
 277         if ( (insn & 0xfdf00000) == 0xf1900000 )
 278                 /* LDC0 */
 279                 cop_nr = 0;
 280         else
 281                 cop_nr = (insn >> 13) & 0x7;
 282
 283         /* Try enabling the coprocessor */
 284         cpucr = sysreg_read(CPUCR);
 285         cpucr |= (1 << (24 + cop_nr));
 286         sysreg_write(CPUCR, cpucr);
 287
 288         cpucr = sysreg_read(CPUCR);
 289         if ( !(cpucr & (1 << (24 + cop_nr))) ){
 290                 printk("Coprocessor #%i not found!\n", cop_nr);
 291                 return -1;
 292         }
 293
 294         return 0;
 295 }
 296
 297 #ifdef CONFIG_BUG
 298 #ifdef CONFIG_DEBUG_BUGVERBOSE
 299 static inline void do_bug_verbose(struct pt_regs *regs, u32 insn)
 300 {
 301         char *file;
 302         u16 line;
 303         char c;
 304
 305         if (__get_user(line, (u16 __user *)(regs->pc + 2)))
 306                 return;
 307         if (__get_user(file, (char * __user *)(regs->pc + 4))
 308             || (unsigned long)file < PAGE_OFFSET
 309             || __get_user(c, file))
 310                 file = "<bad filename>";
 311
 312         printk(KERN_ALERT "kernel BUG at %s:%d!\n", file, line);
 313 }
 314 #else
 315 static inline void do_bug_verbose(struct pt_regs *regs, u32 insn)
 316 {
 317
 318 }
 319 #endif
 320 #endif
 321
 322 asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
 323 {
 324         u32 insn;
 325         struct undef_hook *hook;
 326         siginfo_t info;
 327         void __user *pc;
 328
 329         if (!user_mode(regs))
 330                 goto kernel_trap;
 331
 332         local_irq_enable();
 333
 334         pc = (void __user *)instruction_pointer(regs);
 335         if (__get_user(insn, (u32 __user *)pc))
 336                 goto invalid_area;
 337
 338         if (ecr == ECR_COPROC_ABSENT) {
 339                 if (do_cop_absent(insn) == 0)
 340                         return;
 341         }
 342
 343         spin_lock_irq(&undef_lock);
 344         list_for_each_entry(hook, &undef_hook, node) {
 345                 if ((insn & hook->insn_mask) == hook->insn_val) {
 346                         if (hook->fn(regs, insn) == 0) {
 347                                 spin_unlock_irq(&undef_lock);
 348                                 return;
 349                         }
 350                 }
 351         }
 352         spin_unlock_irq(&undef_lock);
 353
 354 invalid_area:
 355
 356 #ifdef DEBUG
 357         printk("Illegal instruction at pc = %08lx\n", regs->pc);
 358         if (regs->pc < TASK_SIZE) {
 359                 unsigned long ptbr, pgd, pte, *p;
 360
 361                 ptbr = sysreg_read(PTBR);
 362                 p = (unsigned long *)ptbr;
 363                 pgd = p[regs->pc >> 22];
 364                 p = (unsigned long *)((pgd & 0x1ffff000) | 0x80000000);
 365                 pte = p[(regs->pc >> 12) & 0x3ff];
 366                 printk("page table: 0x%08lx -> 0x%08lx -> 0x%08lx\n", ptbr, pgd, pte);
 367         }
 368 #endif
 369
 370         info.si_signo = SIGILL;
 371         info.si_errno = 0;
 372         info.si_addr = (void __user *)regs->pc;
 373         switch (ecr) {
 374         case ECR_ILLEGAL_OPCODE:
 375         case ECR_UNIMPL_INSTRUCTION:
 376                 info.si_code = ILL_ILLOPC;
 377                 break;
 378         case ECR_PRIVILEGE_VIOLATION:
 379                 info.si_code = ILL_PRVOPC;
 380                 break;
 381         case ECR_COPROC_ABSENT:
 382                 info.si_code = ILL_COPROC;
 383                 break;
 384         default:
 385                 BUG();
 386         }
 387
 388         force_sig_info(SIGILL, &info, current);
 389         return;
 390
 391 kernel_trap:
 392 #ifdef CONFIG_BUG
 393         if (__kernel_text_address(instruction_pointer(regs))) {
 394                 insn = *(u16 *)instruction_pointer(regs);
 395                 if (insn == AVR32_BUG_OPCODE) {
 396                         do_bug_verbose(regs, insn);
 397                         die("Kernel BUG", regs, 0);
 398                         return;
 399                 }
 400         }
 401 #endif
 402
 403         die("Oops: Illegal instruction in kernel code", regs, ecr);
 404 }
 405
 406 asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
 407 {
 408         siginfo_t info;
 409
 410         printk("Floating-point exception at pc = %08lx\n", regs->pc);
 411
 412         /* We have no FPU... */
 413         info.si_signo = SIGILL;
 414         info.si_errno = 0;
 415         info.si_addr = (void __user *)regs->pc;
 416         info.si_code = ILL_COPROC;
 417
 418         force_sig_info(SIGILL, &info, current);
 419 }
 420
 421
 422 void __init trap_init(void)
 423 {
 424
 425 }