linux/arch/m32r/kernel/traps.c
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   1/*
   2 *  linux/arch/m32r/kernel/traps.c
   3 *
   4 *  Copyright (C) 2001, 2002  Hirokazu Takata, Hiroyuki Kondo,
   5 *                            Hitoshi Yamamoto
   6 */
   7
   8/*
   9 * 'traps.c' handles hardware traps and faults after we have saved some
  10 * state in 'entry.S'.
  11 */
  12#include <linux/init.h>
  13#include <linux/kernel.h>
  14#include <linux/kallsyms.h>
  15#include <linux/stddef.h>
  16#include <linux/ptrace.h>
  17#include <linux/mm.h>
  18#include <asm/page.h>
  19#include <asm/processor.h>
  20
  21#include <asm/system.h>
  22#include <asm/uaccess.h>
  23#include <asm/io.h>
  24#include <asm/atomic.h>
  25
  26#include <asm/smp.h>
  27
  28#include <linux/module.h>
  29
  30asmlinkage void alignment_check(void);
  31asmlinkage void ei_handler(void);
  32asmlinkage void rie_handler(void);
  33asmlinkage void debug_trap(void);
  34asmlinkage void cache_flushing_handler(void);
  35asmlinkage void ill_trap(void);
  36
  37#ifdef CONFIG_SMP
  38extern void smp_reschedule_interrupt(void);
  39extern void smp_invalidate_interrupt(void);
  40extern void smp_call_function_interrupt(void);
  41extern void smp_ipi_timer_interrupt(void);
  42extern void smp_flush_cache_all_interrupt(void);
  43extern void smp_call_function_single_interrupt(void);
  44
  45/*
  46 * for Boot AP function
  47 */
  48asm (
  49        "       .section .eit_vector4,\"ax\"    \n"
  50        "       .global _AP_RE                  \n"
  51        "       .global startup_AP              \n"
  52        "_AP_RE:                                \n"
  53        "       .fill 32, 4, 0                  \n"
  54        "_AP_EI: bra    startup_AP              \n"
  55        "       .previous                       \n"
  56);
  57#endif  /* CONFIG_SMP */
  58
  59extern unsigned long    eit_vector[];
  60#define BRA_INSN(func, entry)   \
  61        ((unsigned long)func - (unsigned long)eit_vector - entry*4)/4 \
  62        + 0xff000000UL
  63
  64static void set_eit_vector_entries(void)
  65{
  66        extern void default_eit_handler(void);
  67        extern void system_call(void);
  68        extern void pie_handler(void);
  69        extern void ace_handler(void);
  70        extern void tme_handler(void);
  71        extern void _flush_cache_copyback_all(void);
  72
  73        eit_vector[0] = 0xd0c00001; /* seth r0, 0x01 */
  74        eit_vector[1] = BRA_INSN(default_eit_handler, 1);
  75        eit_vector[4] = 0xd0c00010; /* seth r0, 0x10 */
  76        eit_vector[5] = BRA_INSN(default_eit_handler, 5);
  77        eit_vector[8] = BRA_INSN(rie_handler, 8);
  78        eit_vector[12] = BRA_INSN(alignment_check, 12);
  79        eit_vector[16] = BRA_INSN(ill_trap, 16);
  80        eit_vector[17] = BRA_INSN(debug_trap, 17);
  81        eit_vector[18] = BRA_INSN(system_call, 18);
  82        eit_vector[19] = BRA_INSN(ill_trap, 19);
  83        eit_vector[20] = BRA_INSN(ill_trap, 20);
  84        eit_vector[21] = BRA_INSN(ill_trap, 21);
  85        eit_vector[22] = BRA_INSN(ill_trap, 22);
  86        eit_vector[23] = BRA_INSN(ill_trap, 23);
  87        eit_vector[24] = BRA_INSN(ill_trap, 24);
  88        eit_vector[25] = BRA_INSN(ill_trap, 25);
  89        eit_vector[26] = BRA_INSN(ill_trap, 26);
  90        eit_vector[27] = BRA_INSN(ill_trap, 27);
  91        eit_vector[28] = BRA_INSN(cache_flushing_handler, 28);
  92        eit_vector[29] = BRA_INSN(ill_trap, 29);
  93        eit_vector[30] = BRA_INSN(ill_trap, 30);
  94        eit_vector[31] = BRA_INSN(ill_trap, 31);
  95        eit_vector[32] = BRA_INSN(ei_handler, 32);
  96        eit_vector[64] = BRA_INSN(pie_handler, 64);
  97#ifdef CONFIG_MMU
  98        eit_vector[68] = BRA_INSN(ace_handler, 68);
  99        eit_vector[72] = BRA_INSN(tme_handler, 72);
 100#endif /* CONFIG_MMU */
 101#ifdef CONFIG_SMP
 102        eit_vector[184] = (unsigned long)smp_reschedule_interrupt;
 103        eit_vector[185] = (unsigned long)smp_invalidate_interrupt;
 104        eit_vector[186] = (unsigned long)smp_call_function_interrupt;
 105        eit_vector[187] = (unsigned long)smp_ipi_timer_interrupt;
 106        eit_vector[188] = (unsigned long)smp_flush_cache_all_interrupt;
 107        eit_vector[189] = 0;    /* CPU_BOOT_IPI */
 108        eit_vector[190] = (unsigned long)smp_call_function_single_interrupt;
 109        eit_vector[191] = 0;
 110#endif
 111        _flush_cache_copyback_all();
 112}
 113
 114void __init trap_init(void)
 115{
 116        set_eit_vector_entries();
 117
 118        /*
 119         * Should be a barrier for any external CPU state.
 120         */
 121        cpu_init();
 122}
 123
 124static int kstack_depth_to_print = 24;
 125
 126static void show_trace(struct task_struct *task, unsigned long *stack)
 127{
 128        unsigned long addr;
 129
 130        if (!stack)
 131                stack = (unsigned long*)&stack;
 132
 133        printk("Call Trace: ");
 134        while (!kstack_end(stack)) {
 135                addr = *stack++;
 136                if (__kernel_text_address(addr)) {
 137                        printk("[<%08lx>] ", addr);
 138                        print_symbol("%s\n", addr);
 139                }
 140        }
 141        printk("\n");
 142}
 143
 144void show_stack(struct task_struct *task, unsigned long *sp)
 145{
 146        unsigned long  *stack;
 147        int  i;
 148
 149        /*
 150         * debugging aid: "show_stack(NULL);" prints the
 151         * back trace for this cpu.
 152         */
 153
 154        if(sp==NULL) {
 155                if (task)
 156                        sp = (unsigned long *)task->thread.sp;
 157                else
 158                        sp=(unsigned long*)&sp;
 159        }
 160
 161        stack = sp;
 162        for(i=0; i < kstack_depth_to_print; i++) {
 163                if (kstack_end(stack))
 164                        break;
 165                if (i && ((i % 4) == 0))
 166                        printk("\n       ");
 167                printk("%08lx ", *stack++);
 168        }
 169        printk("\n");
 170        show_trace(task, sp);
 171}
 172
 173void dump_stack(void)
 174{
 175        unsigned long stack;
 176
 177        show_trace(current, &stack);
 178}
 179
 180EXPORT_SYMBOL(dump_stack);
 181
 182static void show_registers(struct pt_regs *regs)
 183{
 184        int i = 0;
 185        int in_kernel = 1;
 186        unsigned long sp;
 187
 188        printk("CPU:    %d\n", smp_processor_id());
 189        show_regs(regs);
 190
 191        sp = (unsigned long) (1+regs);
 192        if (user_mode(regs)) {
 193                in_kernel = 0;
 194                sp = regs->spu;
 195                printk("SPU: %08lx\n", sp);
 196        } else {
 197                printk("SPI: %08lx\n", sp);
 198        }
 199        printk("Process %s (pid: %d, process nr: %d, stackpage=%08lx)",
 200                current->comm, task_pid_nr(current), 0xffff & i, 4096+(unsigned long)current);
 201
 202        /*
 203         * When in-kernel, we also print out the stack and code at the
 204         * time of the fault..
 205         */
 206        if (in_kernel) {
 207                printk("\nStack: ");
 208                show_stack(current, (unsigned long*) sp);
 209
 210                printk("\nCode: ");
 211                if (regs->bpc < PAGE_OFFSET)
 212                        goto bad;
 213
 214                for(i=0;i<20;i++) {
 215                        unsigned char c;
 216                        if (__get_user(c, &((unsigned char*)regs->bpc)[i])) {
 217bad:
 218                                printk(" Bad PC value.");
 219                                break;
 220                        }
 221                        printk("%02x ", c);
 222                }
 223        }
 224        printk("\n");
 225}
 226
 227static DEFINE_SPINLOCK(die_lock);
 228
 229void die(const char * str, struct pt_regs * regs, long err)
 230{
 231        console_verbose();
 232        spin_lock_irq(&die_lock);
 233        bust_spinlocks(1);
 234        printk("%s: %04lx\n", str, err & 0xffff);
 235        show_registers(regs);
 236        bust_spinlocks(0);
 237        spin_unlock_irq(&die_lock);
 238        do_exit(SIGSEGV);
 239}
 240
 241static __inline__ void die_if_kernel(const char * str,
 242        struct pt_regs * regs, long err)
 243{
 244        if (!user_mode(regs))
 245                die(str, regs, err);
 246}
 247
 248static __inline__ void do_trap(int trapnr, int signr, const char * str,
 249        struct pt_regs * regs, long error_code, siginfo_t *info)
 250{
 251        if (user_mode(regs)) {
 252                /* trap_signal */
 253                struct task_struct *tsk = current;
 254                tsk->thread.error_code = error_code;
 255                tsk->thread.trap_no = trapnr;
 256                if (info)
 257                        force_sig_info(signr, info, tsk);
 258                else
 259                        force_sig(signr, tsk);
 260                return;
 261        } else {
 262                /* kernel_trap */
 263                if (!fixup_exception(regs))
 264                        die(str, regs, error_code);
 265                return;
 266        }
 267}
 268
 269#define DO_ERROR(trapnr, signr, str, name) \
 270asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 271{ \
 272        do_trap(trapnr, signr, NULL, regs, error_code, NULL); \
 273}
 274
 275#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
 276asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 277{ \
 278        siginfo_t info; \
 279        info.si_signo = signr; \
 280        info.si_errno = 0; \
 281        info.si_code = sicode; \
 282        info.si_addr = (void __user *)siaddr; \
 283        do_trap(trapnr, signr, str, regs, error_code, &info); \
 284}
 285
 286DO_ERROR( 1, SIGTRAP, "debug trap", debug_trap)
 287DO_ERROR_INFO(0x20, SIGILL,  "reserved instruction ", rie_handler, ILL_ILLOPC, regs->bpc)
 288DO_ERROR_INFO(0x100, SIGILL,  "privileged instruction", pie_handler, ILL_PRVOPC, regs->bpc)
 289DO_ERROR_INFO(-1, SIGILL,  "illegal trap", ill_trap, ILL_ILLTRP, regs->bpc)
 290
 291extern int handle_unaligned_access(unsigned long, struct pt_regs *);
 292
 293/* This code taken from arch/sh/kernel/traps.c */
 294asmlinkage void do_alignment_check(struct pt_regs *regs, long error_code)
 295{
 296        mm_segment_t oldfs;
 297        unsigned long insn;
 298        int tmp;
 299
 300        oldfs = get_fs();
 301
 302        if (user_mode(regs)) {
 303                local_irq_enable();
 304                current->thread.error_code = error_code;
 305                current->thread.trap_no = 0x17;
 306
 307                set_fs(USER_DS);
 308                if (copy_from_user(&insn, (void *)regs->bpc, 4)) {
 309                        set_fs(oldfs);
 310                        goto uspace_segv;
 311                }
 312                tmp = handle_unaligned_access(insn, regs);
 313                set_fs(oldfs);
 314
 315                if (!tmp)
 316                        return;
 317
 318        uspace_segv:
 319                printk(KERN_NOTICE "Killing process \"%s\" due to unaligned "
 320                        "access\n", current->comm);
 321                force_sig(SIGSEGV, current);
 322        } else {
 323                set_fs(KERNEL_DS);
 324                if (copy_from_user(&insn, (void *)regs->bpc, 4)) {
 325                        set_fs(oldfs);
 326                        die("insn faulting in do_address_error", regs, 0);
 327                }
 328                handle_unaligned_access(insn, regs);
 329                set_fs(oldfs);
 330        }
 331}
 332