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no recursive interrupts

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rsc 2006-09-07 16:53:16 +00:00
parent 5a71f93301
commit 0b75a8e8be
1 changed files with 34 additions and 31 deletions
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65
trap.c
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@ -18,10 +18,9 @@ tvinit(void)
{ {
int i; int i;
for(i = 0; i < 256; i++){ for(i = 0; i < 256; i++)
SETGATE(idt[i], 1, SEG_KCODE << 3, vectors[i], 0); SETGATE(idt[i], 0, SEG_KCODE << 3, vectors[i], 0);
} SETGATE(idt[T_SYSCALL], 0, SEG_KCODE << 3, vectors[T_SYSCALL], 3);
SETGATE(idt[T_SYSCALL], 1, SEG_KCODE << 3, vectors[T_SYSCALL], 3);
} }
void void
@ -34,9 +33,9 @@ void
trap(struct trapframe *tf) trap(struct trapframe *tf)
{ {
int v = tf->trapno; int v = tf->trapno;
struct proc *cp = curproc[cpu()];
if(v == T_SYSCALL){ if(v == T_SYSCALL){
struct proc *cp = curproc[cpu()];
if(cp->killed) if(cp->killed)
proc_exit(); proc_exit();
cp->tf = tf; cp->tf = tf;
@ -46,9 +45,15 @@ trap(struct trapframe *tf)
return; return;
} }
if(v == (IRQ_OFFSET + IRQ_TIMER)){ // Increment nlock to make sure interrupts stay off
struct proc *cp = curproc[cpu()]; // during interrupt handler. Must decrement before
// returning.
cpus[cpu()].nlock++;
switch(v){
case IRQ_OFFSET + IRQ_TIMER:
lapic_timerintr(); lapic_timerintr();
cpus[cpu()].nlock--;
if(cp){ if(cp){
// Force process exit if it has been killed // Force process exit if it has been killed
// and the interrupt came from user space. // and the interrupt came from user space.
@ -63,36 +68,34 @@ trap(struct trapframe *tf)
yield(); yield();
} }
return; return;
}
if(v == IRQ_OFFSET + IRQ_IDE){ case IRQ_OFFSET + IRQ_IDE:
ide_intr(); ide_intr();
cli(); // prevent a waiting interrupt from overflowing stack
lapic_eoi(); lapic_eoi();
return; break;
}
case IRQ_OFFSET + IRQ_KBD:
if(v == IRQ_OFFSET + IRQ_KBD){
kbd_intr(); kbd_intr();
cli(); // prevent a waiting interrupt from overflowing stack
lapic_eoi(); lapic_eoi();
return; break;
}
case IRQ_OFFSET + IRQ_SPURIOUS:
if(v == IRQ_OFFSET + IRQ_SPURIOUS){
cprintf("spurious interrupt from cpu %d eip %x\n", cpu(), tf->eip); cprintf("spurious interrupt from cpu %d eip %x\n", cpu(), tf->eip);
return; // no eoi for this one. break;
}
default:
if(curproc[cpu()]) { if(curproc[cpu()]) {
// assume process caused unexpected trap, // assume process caused unexpected trap,
// for example by dividing by zero or dereferencing a bad pointer // for example by dividing by zero or dereferencing a bad pointer
cprintf("pid %d: unhandled trap %d on cpu %d eip %x -- kill proc\n", cprintf("pid %d: unhandled trap %d on cpu %d eip %x -- kill proc\n",
curproc[cpu()]->pid, v, cpu(), tf->eip); curproc[cpu()]->pid, v, cpu(), tf->eip);
proc_exit(); proc_exit();
}
// otherwise it's our mistake
cprintf("unexpected trap %d from cpu %d eip %x\n", v, cpu(), tf->eip);
panic("trap");
} }
// otherwise it's our mistake cpus[cpu()].nlock--;
cprintf("unexpected trap %d from cpu %d eip %x\n", v, cpu(), tf->eip);
panic("trap");
} }