// C-Level interrupt/exception handler. NOTE: We are running on the stack
// of the thread that was interrupted!
void irq_handle_exception(int code, uint32 errcode) {
int handled = 0;
// Nested exception?
if (inside_int) {
irq_handler hnd = irq_handlers[EXC_DOUBLE_FAULT];
if (hnd != NULL)
hnd(EXC_DOUBLE_FAULT, irq_srt_addr);
else
irq_dump_regs(code, errcode);
thd_pslist(dbgio_printf);
process_print_list(dbgio_printf);
panic("double fault");
}
inside_int = 1;
// If there's a global handler, call it
if (irq_hnd_global) {
irq_hnd_global(code, irq_srt_addr);
handled = 1;
}
// If there's a handler, call it
{
irq_handler hnd = irq_handlers[code];
if (hnd != NULL) {
hnd(code, irq_srt_addr);
handled = 1;
}
}
// Did it get handled?
if (!handled) {
irq_handler hnd = irq_handlers[EXC_UNHANDLED_EXC];
if (hnd != NULL)
hnd(code, irq_srt_addr);
else
irq_dump_regs(code, errcode);
panic("unhandled IRQ/Exception");
}
inside_int = 0;
}
static void
syscall_handler (struct intr_frame *f)
{
int32_t* esp = (int32_t*)f->esp;
/*
Any parameters passed to syscall will be above ESP, see illustration below.
Number of arguments each syscall expects is in argc[] array above.
syscall number is pointed to by ESP.
--------------------------------------
PHYS_BASE
.................
<param>
<param>
ESP ---> <syscall_number>
--------------------------------------
*/
// verify esp pointer is ok, first parameter: current thread
if(esp == NULL || verify_fix_length(esp, sizeof(esp)) == false){
sys_exit(-1);
}
// esp adress belongs to thread
if(pagedir_get_page(thread_current()->pagedir, esp) == NULL){
sys_exit(-1);
}
// ok syscall nr
int32_t syscall_nr = *esp;
if(syscall_nr < 0 || syscall_nr >= SYS_NUMBER_OF_CALLS){
sys_exit(-1);
}
// Make sure our data is not overwriting PHYS_BASE.
int expected_args = argc[syscall_nr];
unsigned long highest_addr = esp + (expected_args * sizeof(int));
if(highest_addr >= PHYS_BASE){
sys_exit(-1);
}
if(pagedir_get_page(thread_current()->pagedir, highest_addr) == NULL){
sys_exit(-1);
}
/*
int i = 1;
for(; i <= expected_args; i++){
if(verify_fix_length(&esp[i], sizeof(int) ) == false){
sys_exit(-1);
}
}
*/
DEBUG_SYSCALL("# SYSCALL received = %s\n", get_system_call_name(syscall_nr));
switch (syscall_nr)
{
case SYS_HALT:
power_off();
break;
case SYS_EXEC:
{
f->eax = SYS_EXEC_handler(esp);
}
break;
case SYS_WAIT:
{
int child_pid = *(esp + 1);
f->eax = process_wait (child_pid);
break;
}
case SYS_EXIT:
{
if(is_kernel_vaddr(pg_round_up((void*)esp[1]) )){
sys_exit(-1);
}
int exit_status = *(esp + 1);
process_exit(exit_status);
thread_exit();
break;
}
case SYS_PLIST:
process_print_list();
break;
case SYS_CREATE:
{
bool success = false;
char *name = (char*)*(esp + 1);
if(name == NULL){
sys_exit(-1);
}
unsigned initial_size = *(esp + 2);
if(verify_fix_length(esp[1], initial_size) == false){
sys_exit(-1);
}
if(verify_variable_length(esp[1]) == false){
sys_exit(-1);
}
success = filesys_create(name, initial_size);
if(success) {
DEBUG_SYSCALL("#SYS_CREATE - File with name: %s created. \n", name);
} else {
DEBUG_SYSCALL("#SYS_CREATE - filesys_create failed: file named \'%s\' already exists or internal memory allocation failed \n", name);
}
f->eax = success;
break;
}
case SYS_OPEN:
{
char *name = (char*)*(esp + 1);
if(name == NULL){
sys_exit(-1);
}
if(verify_variable_length(esp[1]) == false){
sys_exit(-1);
}
struct file *file;
file = filesys_open(name);
int retVal = -1;
if(file != NULL) {
DEBUG_SYSCALL("# SYS_OPEN - File with name: '%s' created. \n", name);
int fd = flist_add_file(file);
retVal = fd;
} else {
DEBUG_SYSCALL("# SYS_OPEN - filesys_open failed: no file named \'%s\' exists or internal memory allocation failed \n", name);
retVal = -1;
}
f->eax = retVal;
break;
}
case SYS_READ:
{
int retVal = SYS_READ_handler(esp);
f->eax = retVal;
break;
}
case SYS_CLOSE:
{
int retVal = SYS_CLOSE_handler(esp);
f->eax = retVal;
break;
}
case SYS_REMOVE:
{
int retVal = SYS_REMOVE_handler(esp);
f->eax = retVal;
break;
}
case SYS_WRITE:
{
int retVal = SYS_WRITE_handler(esp);
f->eax = retVal;
break;
}
case SYS_SEEK:
{
f->eax = SYS_SEEK_handler(esp);
break;
}
case SYS_TELL:
f->eax = SYS_TELL_handler(esp);
break;
case SYS_FILESIZE:
f->eax = SYS_FILESIZE_handler(esp);
break;
default:
{
DEBUG_SYSCALL ("Executed an unknown system call (nr: %i)!\n", syscall_nr);
DEBUG_SYSCALL ("Stack top + 0: %d\n", esp[0]);
DEBUG_SYSCALL ("Stack top + 1: %d\n", esp[1]);
thread_exit ();
}
}
}
