void release(struct w_spinlock* lk){
if(!is_held(lk))
return;
lk->cpu = 0;
atomic_set(&lk->locked,0);
pop_cli();
}
int sig_handle(void)
{
/* Make sure there is a signal being waited on. */
if(!rproc->sig_queue)
return 0;
/* Not sure if interrupts will mess this up but better be sure */
push_cli();
/* Get the signal from the top of the queue */
struct signal_t* sig = rproc->sig_queue;
void (*sig_handler)(int sig_num) =
rproc->sigactions[sig->signum].sa_handler;
int caught = 0; /* Did we catch the signal? */
int terminated = 0; /* Did we get terminated? */
int stopped = 0; /* Did we get stopped? */
int core = 0; /* Should we dump the core? */
int ignored = 0; /* Was the default action caught and ignored? */
/* Does the user want us to use the default action? */
if(rproc->sigactions[sig->signum].sa_handler == SIG_DFL)
sig->catchable = 0; /* Make signal uncatchable */
switch(rproc->sig_queue->default_action)
{
case SIGDEFAULT_KPANIC:
panic("kernel: Invalid signal handled!\n");
break;
case SIGDEFAULT_TERM:
if(sig->catchable)
{
caught = 1;
} else {
terminated = 1;
}
break;
case SIGDEFAULT_CORE:
if(sig->catchable)
{
caught = 1;
} else {
core = terminated = 1;
}
break;
case SIGDEFAULT_STOP:
if(sig->catchable)
{
caught = 1;
} else {
stopped = 1;
}
break;
case SIGDEFAULT_CONT:
if(sig->catchable)
{
caught = 1;
}
break;
case SIGDEFAULT_IGN:
if(sig->catchable)
{
caught = 1;
}
break;
}
/**
* If the user wants this signal to be ignored, ignore it.
* EXCEPTIONS: if we are terminated, dumped or stopped then
* we must continue with the default action.
*/
if(rproc->sigactions[sig->signum].sa_handler == SIG_IGN)
{
if(!terminated && !stopped && !core)
ignored = 1;
caught = 0;
}
/* Were we able to catch the signal? */
if(caught)
{
/* Do we have a signal stack? */
if(!rproc->sig_stack_start)
{
/* TODO: probably don't use mmap here, this will */
/* change in the future. */
/* Allocate a signal stack */
int pages = SIG_DEFAULT_STACK + SIG_DEFAULT_GUARD;
uint end = (uint)mmap(NULL,
pages * PGSIZE,
PROT_WRITE | PROT_READ,
MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
/* Unmap all guard pages */
int x;
for(x = 0;x < SIG_DEFAULT_GUARD;x++)
{
vm_unmappage(end, rproc->pgdir);
end += PGSIZE;
}
/* Set sig stack start */
rproc->sig_stack_start = end +
(SIG_DEFAULT_STACK * PGSIZE);
}
/* Save the current trap frame if we need to */
if(!rproc->sig_handling)
{
/* We weren't handling a signal until now */
memmove(&rproc->sig_saved,
(char*)rproc->k_stack - sizeof(struct trap_frame),
sizeof(struct trap_frame));
}
pstack_t stack = rproc->sig_stack_start;
/* set the return address to the sig handler */
rproc->tf->eip = (uintptr_t)sig_handler;
vmflags_t dir_flags = VM_DIR_USRP | VM_DIR_READ | VM_DIR_WRIT;
vmflags_t tbl_flags = VM_TBL_USRP | VM_TBL_READ | VM_TBL_WRIT;
/* Push argument (sig) */
stack -= sizeof(int);
vm_memmove((void*)stack, &sig->signum, sizeof(int),
rproc->pgdir, rproc->pgdir,
dir_flags, tbl_flags);
/* (safely) Push our magic return value */
stack -= sizeof(int);
uint32_t mag = SIG_MAGIC;
vm_memmove((void*)stack, &mag, sizeof(int),
rproc->pgdir, rproc->pgdir,
dir_flags, tbl_flags);
/* Update stack pointer */
rproc->tf->esp = stack;
/* We are now actively handling this signal */
rproc->sig_handling = 1;
}
pop_cli();
/* Check to see if we need to dump the core */
if(core)
{
/* Dump memory for gdb analysis */
#ifdef DEBUG
cprintf("%s:%d: CORE DUMPED\n", rproc->name, rproc->pid);
#endif
rproc->status_changed = 1;
rproc->return_code = ((sig->signum & 0xFF) << 0x8) | 0x02;
rproc->state = PROC_ZOMBIE;
wake_parent(rproc);
yield_withlock();
}
/* If we got stopped, we will enter scheduler. */
if(stopped)
{
#ifdef DEBUG
cprintf("%s:%d: process stopped.\n", rproc->name, rproc->pid);
#endif
rproc->status_changed = 1;
rproc->state = PROC_STOPPED;
rproc->return_code = ((sig->signum & 0xFF) << 0x08) | 0x04;
/* Should we wake the parent? */
if(!rproc->orphan && rproc->parent
&& (rproc->parent->wait_options & WUNTRACED))
{
wake_parent(rproc);
}
sig_dequeue(rproc);
yield_withlock();
/* Should we wake our parent now that we've continued */
rproc->status_changed = 1;
if(!rproc->orphan && rproc->parent
&& (rproc->parent->wait_options & WCONTINUED))
{
wake_parent(rproc);
}
}
/* Check to see if we got terminated */
if(terminated)
{
#ifdef DEBUG
cprintf("%s:%d: Process killed by signal. No core dumped.\n",
rproc->name, rproc->pid);
#endif
rproc->status_changed = 1;
rproc->return_code = ((sig->signum & 0xFF) << 0x08) | 0x01;
rproc->state = PROC_ZOMBIE;
wake_parent(rproc);
yield_withlock();
}
if(ignored)
sig_dequeue(rproc);
return 0;
}
