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