matos/arch/x86/exception.c

#include "exception.h"
#include "cpu_context.h"
#include "idt.h"
#include "interrupt.h"
#include "irq.h"
#include "klibc.h"
#include "kthread.h"
#include "vga.h"

exception_handler exception_handler_array[EXCEPTION_NUM] = {
    NULL,
};

extern vaddr_t exception_handler_wrapper_array[EXCEPTION_NUM];

void exception_handler_wrap(int intr, struct cpu_state *frame)
{
    if (0 > intr || EXCEPTION_NUM <= intr) {
        pr_err("Trying to handle unknow exception %d\n", intr);
        return;
    }

    if (exception_handler_array[intr] != NULL)
        exception_handler_array[intr](frame, intr);
}

int exceptionSetRoutine(int exception, exception_handler handler)
{
    uint32_t flags;
    if ((exception < 0) || exception >= EXCEPTION_NUM)
        return -1;

    disable_IRQs(flags);

    exception_handler_array[exception] = handler;

    idt_set_handler(EXCEPTION_INTERRUPT_BASE_ADDRESS + exception,
                    (unsigned int)exception_handler_wrapper_array[exception], 0);
    restore_IRQs(flags);
    return 0;
}

void print_handler(struct cpu_state *frame, ulong intr)
{
    int intNbInt = intr;
    VGAPrintf(RED, BLACK, 0, VGA_HEIGHT - 1, "EXCEPTION %d %d", intNbInt, intr);
    printf("Exception %d (Err %d) at 0x%x\n", intr, intr,
           cpu_context_get_PC(frame));
    asm("hlt");
}

void pagefault_handler(struct cpu_state *frame, ulong intr)
{
    // A page fault has occurred.
    // The faulting address is stored in the CR2 register.
    uint32_t faulting_address;
    asm volatile("mov %%cr2, %0" : "=r"(faulting_address));

    struct kthread *current = getCurrentThread();
    printf("page fault while in thread %s at 0x%x 0x%x\n", current->name, faulting_address,
           cpu_context_get_PC(frame));
    VGAPrintf(RED, BLACK, 0, VGA_HEIGHT - 1, "PAGE FAULT %d", intr);
    (void)intr;
    for (;;)
        continue;
}

int exceptionSetup()
{
    for (int i = 0; i < EXCEPTION_NUM; i++) {
        exceptionSetRoutine(i, print_handler);
    }
    exceptionSetRoutine(EXCEPTION_PAGE_FAULT, pagefault_handler);
    return 0;
}