source: mainline/kernel/generic/src/interrupt/interrupt.c@ 515f1b1

/*
 * Copyright (c) 2005 Ondrej Palkovsky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup kernel_generic_interrupt
 * @{
 */
/**
 * @file
 * @brief Interrupt redirector.
 *
 * This file provides means of registering interrupt handlers
 * by kernel functions and calling the handlers when interrupts
 * occur.
 *
 */

#include <assert.h>
#include <interrupt.h>
#include <console/kconsole.h>
#include <console/console.h>
#include <console/cmd.h>
#include <synch/mutex.h>
#include <time/delay.h>
#include <macros.h>
#include <panic.h>
#include <stdio.h>
#include <stdarg.h>
#include <symtab.h>
#include <proc/thread.h>
#include <arch/cycle.h>
#include <arch/stack.h>
#include <str.h>
#include <trace.h>

/*
 * If IVT_ITEMS is zero (e.g. for special/abs32le) we hide completely any
 * access to the exception table array and panic if the function is called
 * at all. It also silences (correct) compiler warnings about possible
 * out-of-bound array access.
 */

exc_table_t exc_table[IVT_ITEMS];
IRQ_SPINLOCK_INITIALIZE(exctbl_lock);

/** Register exception handler
 *
 * @param n       Exception number.
 * @param name    Description.
 * @param hot     Whether the exception is actually handled
 *                in any meaningful way.
 * @param handler New exception handler.
 *
 * @return Previously registered exception handler.
 *
 */
iroutine_t exc_register(unsigned int n, const char *name, bool hot,
    iroutine_t handler)
{
#if (IVT_ITEMS > 0)
        assert(n < IVT_ITEMS);

        irq_spinlock_lock(&exctbl_lock, true);

        iroutine_t old = exc_table[n].handler;
        exc_table[n].handler = handler;
        exc_table[n].name = name;
        exc_table[n].hot = hot;
        exc_table[n].cycles = 0;
        exc_table[n].count = 0;

        irq_spinlock_unlock(&exctbl_lock, true);

        return old;
#else
        panic("No space for any exception handler, cannot register.");
#endif
}

/** Dispatch exception according to exception table
 *
 * Called directly from the assembler code.
 * CPU is interrupts_disable()'d.
 *
 */
_NO_TRACE void exc_dispatch(unsigned int n, istate_t *istate)
{
#if (IVT_ITEMS > 0)
        assert(n < IVT_ITEMS);

        /* Account user cycles */
        if (THREAD)
                thread_update_accounting(true);

        /* Account CPU usage if it woke up from sleep */
        if (CPU && CPU_LOCAL->idle) {
                uint64_t now = get_cycle();
                atomic_time_increment(&CPU->idle_cycles, now - CPU_LOCAL->last_cycle);
                CPU_LOCAL->last_cycle = now;
                CPU_LOCAL->idle = false;
        }

        uint64_t begin_cycle = get_cycle();

#ifdef CONFIG_UDEBUG
        if (THREAD)
                THREAD->udebug.uspace_state = istate;
#endif

        exc_table[n].handler(n + IVT_FIRST, istate);

#ifdef CONFIG_UDEBUG
        if (THREAD)
                THREAD->udebug.uspace_state = NULL;
#endif

        /* This is a safe place to exit exiting thread */
        if ((THREAD) && (THREAD->interrupted) && (istate_from_uspace(istate)))
                thread_exit();

        /* Account exception handling */
        uint64_t end_cycle = get_cycle();

        irq_spinlock_lock(&exctbl_lock, false);
        exc_table[n].cycles += end_cycle - begin_cycle;
        exc_table[n].count++;
        irq_spinlock_unlock(&exctbl_lock, false);

        /* Do not charge THREAD for exception cycles */
        if (THREAD)
                THREAD->last_cycle = end_cycle;
#else
        panic("No space for any exception handler, yet we want to handle some exception.");
#endif
}

/** Default 'null' exception handler
 *
 */
_NO_TRACE static void exc_undef(unsigned int n, istate_t *istate)
{
        fault_if_from_uspace(istate, "Unhandled exception %u.", n);
        panic_badtrap(istate, n, "Unhandled exception %u.", n);
}

static _NO_TRACE void
fault_from_uspace_core(istate_t *istate, const char *fmt, va_list args)
{
        printf("Task %s (%" PRIu64 ") killed due to an exception at "
            "program counter %p.\n", TASK->name, TASK->taskid,
            (void *) istate_get_pc(istate));

        istate_decode(istate);
        stack_trace_istate(istate);

        printf("Kill message: ");
        vprintf(fmt, args);
        printf("\n");

        task_kill_self(true);
}

/** Terminate thread and task after the exception came from userspace.
 *
 */
_NO_TRACE void fault_from_uspace(istate_t *istate, const char *fmt, ...)
{
        va_list args;

        va_start(args, fmt);
        fault_from_uspace_core(istate, fmt, args);
        va_end(args);
}

/** Terminate thread and task if exception came from userspace.
 *
 */
_NO_TRACE void fault_if_from_uspace(istate_t *istate, const char *fmt, ...)
{
        if (!istate_from_uspace(istate))
                return;

        va_list args;
        va_start(args, fmt);
        fault_from_uspace_core(istate, fmt, args);
        va_end(args);
}

/** Get istate structure of a thread.
 *
 * Get pointer to the istate structure at the bottom of the kernel stack.
 *
 * This function can be called in interrupt or user context. In interrupt
 * context the istate structure is created by the low-level exception
 * handler. In user context the istate structure is created by the
 * low-level syscall handler.
 */
istate_t *istate_get(thread_t *thread)
{
        /*
         * The istate structure should be right at the bottom of the kernel
         * memory stack.
         */
        return (istate_t *) &thread->kstack[MEM_STACK_SIZE - sizeof(istate_t)];
}

#ifdef CONFIG_KCONSOLE

static char flag_buf[MAX_CMDLINE + 1];

/** Print all exceptions
 *
 */
_NO_TRACE static int cmd_exc_print(cmd_arg_t *argv)
{
        bool excs_all;

        if (str_cmp(flag_buf, "-a") == 0)
                excs_all = true;
        else if (str_cmp(flag_buf, "") == 0)
                excs_all = false;
        else {
                printf("Unknown argument \"%s\".\n", flag_buf);
                return 1;
        }

#if (IVT_ITEMS > 0)
        unsigned int i;
        unsigned int rows;

        irq_spinlock_lock(&exctbl_lock, true);

#ifdef __32_BITS__
        printf("[exc   ] [description       ] [count   ] [cycles  ]"
            " [handler ] [symbol\n");
        rows = 1;
#endif

#ifdef __64_BITS__
        printf("[exc   ] [description       ] [count   ] [cycles  ]"
            " [handler         ]\n");
        printf("         [symbol\n");
        rows = 2;
#endif

        for (i = 0; i < IVT_ITEMS; i++) {
                if ((!excs_all) && (!exc_table[i].hot))
                        continue;

                uint64_t count;
                char count_suffix;

                order_suffix(exc_table[i].count, &count, &count_suffix);

                uint64_t cycles;
                char cycles_suffix;

                order_suffix(exc_table[i].cycles, &cycles, &cycles_suffix);

                const char *symbol =
                    symtab_fmt_name_lookup((sysarg_t) exc_table[i].handler);

#ifdef __32_BITS__
                printf("%-8u %-20s %9" PRIu64 "%c %9" PRIu64 "%c %10p %s\n",
                    i + IVT_FIRST, exc_table[i].name, count, count_suffix,
                    cycles, cycles_suffix, exc_table[i].handler, symbol);

                PAGING(rows, 1, irq_spinlock_unlock(&exctbl_lock, true),
                    irq_spinlock_lock(&exctbl_lock, true));
#endif

#ifdef __64_BITS__
                printf("%-8u %-20s %9" PRIu64 "%c %9" PRIu64 "%c %18p\n",
                    i + IVT_FIRST, exc_table[i].name, count, count_suffix,
                    cycles, cycles_suffix, exc_table[i].handler);
                printf("         %s\n", symbol);

                PAGING(rows, 2, irq_spinlock_unlock(&exctbl_lock, true),
                    irq_spinlock_lock(&exctbl_lock, true));
#endif
        }

        irq_spinlock_unlock(&exctbl_lock, true);
#else /* (IVT_ITEMS > 0) */

        printf("No exception table%s.\n", excs_all ? " (showing all exceptions)" : "");

#endif /* (IVT_ITEMS > 0) */

        return 1;
}

static cmd_arg_t exc_argv = {
        .type = ARG_TYPE_STRING_OPTIONAL,
        .buffer = flag_buf,
        .len = sizeof(flag_buf)
};

static cmd_info_t exc_info = {
        .name = "exc",
        .description = "Print exception table (use -a for all exceptions).",
        .func = cmd_exc_print,
        .help = NULL,
        .argc = 1,
        .argv = &exc_argv
};

#endif /* CONFIG_KCONSOLE */

/** Initialize generic exception handling support
 *
 */
void exc_init(void)
{
        (void) exc_undef;

#if (IVT_ITEMS > 0)
        unsigned int i;

        for (i = 0; i < IVT_ITEMS; i++)
                exc_register(i, "undef", false, (iroutine_t) exc_undef);
#endif

#ifdef CONFIG_KCONSOLE
        cmd_initialize(&exc_info);
        if (!cmd_register(&exc_info))
                printf("Cannot register command %s\n", exc_info.name);
#endif
}

/** @}
 */