traps.c

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/*
 * OpenRISC traps.c
 *
 * Linux architectural port borrowing liberally from similar works of
 * others.  All original copyrights apply as per the original source
 * declaration.
 *
 * Modifications for the OpenRISC architecture:
 * Copyright (C) 2003 Matjaz Breskvar <[email protected]>
 * Copyright (C) 2010-2011 Jonas Bonn <[email protected]>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 *  Here we handle the break vectors not used by the system call
 *  mechanism, as well as some general stack/register dumping
 *  things.
 *
 */

#include <linux/init.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/kallsyms.h>
#include <asm/uaccess.h>

#include <asm/segment.h>
#include <asm/io.h>
#include <asm/pgtable.h>

extern char _etext, _stext;

int kstack_depth_to_print = 0x180;

static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
{
    return p > (void *)tinfo && p < (void *)tinfo + THREAD_SIZE - 3;
}

void show_trace(struct task_struct *task, unsigned long *stack)
{
    struct thread_info *context;
    unsigned long addr;

    context = (struct thread_info *)
        ((unsigned long)stack & (~(THREAD_SIZE - 1)));

    while (valid_stack_ptr(context, stack)) {
        addr = *stack++;
        if (__kernel_text_address(addr)) {
            printk(" [<%08lx>]", addr);
            print_symbol(" %s", addr);
            printk("\n");
        }
    }
    printk(" =======================\n");
}

/* displays a short stack trace */
void show_stack(struct task_struct *task, unsigned long *esp)
{
    unsigned long addr, *stack;
    int i;

    if (esp == NULL)
        esp = (unsigned long *)&esp;

    stack = esp;

    printk("Stack dump [0x%08lx]:\n", (unsigned long)esp);
    for (i = 0; i < kstack_depth_to_print; i++) {
        if (kstack_end(stack))
            break;
        if (__get_user(addr, stack)) {
            /* This message matches "failing address" marked
               s390 in ksymoops, so lines containing it will
               not be filtered out by ksymoops.  */
            printk("Failing address 0x%lx\n", (unsigned long)stack);
            break;
        }
        stack++;

        printk("sp + %02d: 0x%08lx\n", i * 4, addr);
    }
    printk("\n");

    show_trace(task, esp);

    return;
}

void show_trace_task(struct task_struct *tsk)
{
    /*
     * TODO: SysRq-T trace dump...
     */
}

/*
 * The architecture-independent backtrace generator
 */
void dump_stack(void)
{
    unsigned long stack;

    show_stack(current, &stack);
}
EXPORT_SYMBOL(dump_stack);

void show_registers(struct pt_regs *regs)
{
    int i;
    int in_kernel = 1;
    unsigned long esp;

    esp = (unsigned long)(&regs->sp);
    if (user_mode(regs))
        in_kernel = 0;

    printk("CPU #: %d\n"
           "   PC: %08lx    SR: %08lx    SP: %08lx\n",
           smp_processor_id(), regs->pc, regs->sr, regs->sp);
    printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
           0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
    printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
           regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
    printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
           regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
    printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
           regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
    printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
           regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
    printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
           regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
    printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
           regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
    printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
           regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
    printk("  RES: %08lx oGPR11: %08lx\n",
           regs->gpr[11], regs->orig_gpr11);

    printk("Process %s (pid: %d, stackpage=%08lx)\n",
           current->comm, current->pid, (unsigned long)current);
    /*
     * When in-kernel, we also print out the stack and code at the
     * time of the fault..
     */
    if (in_kernel) {

        printk("\nStack: ");
        show_stack(NULL, (unsigned long *)esp);

        printk("\nCode: ");
        if (regs->pc < PAGE_OFFSET)
            goto bad;

        for (i = -24; i < 24; i++) {
            unsigned char c;
            if (__get_user(c, &((unsigned char *)regs->pc)[i])) {
bad:
                printk(" Bad PC value.");
                break;
            }

            if (i == 0)
                printk("(%02x) ", c);
            else
                printk("%02x ", c);
        }
    }
    printk("\n");
}

void nommu_dump_state(struct pt_regs *regs,
              unsigned long ea, unsigned long vector)
{
    int i;
    unsigned long addr, stack = regs->sp;

    printk("\n\r[nommu_dump_state] :: ea %lx, vector %lx\n\r", ea, vector);

    printk("CPU #: %d\n"
           "   PC: %08lx    SR: %08lx    SP: %08lx\n",
           0, regs->pc, regs->sr, regs->sp);
    printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
           0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
    printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
           regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
    printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
           regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
    printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
           regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
    printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
           regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
    printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
           regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
    printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
           regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
    printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
           regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
    printk("  RES: %08lx oGPR11: %08lx\n",
           regs->gpr[11], regs->orig_gpr11);

    printk("Process %s (pid: %d, stackpage=%08lx)\n",
           ((struct task_struct *)(__pa(current)))->comm,
           ((struct task_struct *)(__pa(current)))->pid,
           (unsigned long)current);

    printk("\nStack: ");
    printk("Stack dump [0x%08lx]:\n", (unsigned long)stack);
    for (i = 0; i < kstack_depth_to_print; i++) {
        if (((long)stack & (THREAD_SIZE - 1)) == 0)
            break;
        stack++;

        printk("%lx :: sp + %02d: 0x%08lx\n", stack, i * 4,
               *((unsigned long *)(__pa(stack))));
    }
    printk("\n");

    printk("Call Trace:   ");
    i = 1;
    while (((long)stack & (THREAD_SIZE - 1)) != 0) {
        addr = *((unsigned long *)__pa(stack));
        stack++;

        if (kernel_text_address(addr)) {
            if (i && ((i % 6) == 0))
                printk("\n ");
            printk(" [<%08lx>]", addr);
            i++;
        }
    }
    printk("\n");

    printk("\nCode: ");

    for (i = -24; i < 24; i++) {
        unsigned char c;
        c = ((unsigned char *)(__pa(regs->pc)))[i];

        if (i == 0)
            printk("(%02x) ", c);
        else
            printk("%02x ", c);
    }
    printk("\n");
}

/* This is normally the 'Oops' routine */
void die(const char *str, struct pt_regs *regs, long err)
{

    console_verbose();
    printk("\n%s#: %04lx\n", str, err & 0xffff);
    show_registers(regs);
#ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
    printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n");

    /* shut down interrupts */
    local_irq_disable();

    __asm__ __volatile__("l.nop   1");
    do {} while (1);
#endif
    do_exit(SIGSEGV);
}

/* This is normally the 'Oops' routine */
void die_if_kernel(const char *str, struct pt_regs *regs, long err)
{
    if (user_mode(regs))
        return;

    die(str, regs, err);
}

void unhandled_exception(struct pt_regs *regs, int ea, int vector)
{
    printk("Unable to handle exception at EA =0x%x, vector 0x%x",
           ea, vector);
    die("Oops", regs, 9);
}

void __init trap_init(void)
{
    /* Nothing needs to be done */
}

asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
{
    siginfo_t info;
    memset(&info, 0, sizeof(info));
    info.si_signo = SIGTRAP;
    info.si_code = TRAP_TRACE;
    info.si_addr = (void *)address;
    force_sig_info(SIGTRAP, &info, current);

    regs->pc += 4;
}

asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)
{
    siginfo_t info;

    if (user_mode(regs)) {
        /* Send a SIGSEGV */
        info.si_signo = SIGSEGV;
        info.si_errno = 0;
        /* info.si_code has been set above */
        info.si_addr = (void *)address;
        force_sig_info(SIGSEGV, &info, current);
    } else {
        printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
        show_registers(regs);
        die("Die:", regs, address);
    }

}

asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address)
{
    siginfo_t info;

    if (user_mode(regs)) {
        /* Send a SIGBUS */
        info.si_signo = SIGBUS;
        info.si_errno = 0;
        info.si_code = BUS_ADRERR;
        info.si_addr = (void *)address;
        force_sig_info(SIGBUS, &info, current);
    } else {        /* Kernel mode */
        printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);
        show_registers(regs);
        die("Die:", regs, address);
    }
}

asmlinkage void do_illegal_instruction(struct pt_regs *regs,
                       unsigned long address)
{
    siginfo_t info;

    if (user_mode(regs)) {
        /* Send a SIGILL */
        info.si_signo = SIGILL;
        info.si_errno = 0;
        info.si_code = ILL_ILLOPC;
        info.si_addr = (void *)address;
        force_sig_info(SIGBUS, &info, current);
    } else {        /* Kernel mode */
        printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",
               address);
        show_registers(regs);
        die("Die:", regs, address);
    }
}