diff options
| -rw-r--r-- | trap.c | 38 |
1 files changed, 18 insertions, 20 deletions
@@ -76,29 +76,27 @@ trap(struct trapframe *tf) break; default: - if(cp) { - // Assume process divided by zero or dereferenced null, etc. - cprintf("pid %d %s: trap %d err %d on cpu %d eip %x -- kill proc\n", - cp->pid, cp->name, tf->trapno, tf->err, cpu(), tf->eip); - proc_exit(); + if(cp == 0) { + // Otherwise it's our mistake. + cprintf("unexpected trap %d from cpu %d eip %x\n", + tf->trapno, cpu(), tf->eip); + panic("trap"); } - // Otherwise it's our mistake. - cprintf("unexpected trap %d from cpu %d eip %x\n", - tf->trapno, cpu(), tf->eip); - panic("trap"); + // Assume process divided by zero or dereferenced null, etc. + cprintf("pid %d %s: trap %d err %d on cpu %d eip %x -- kill proc\n", + cp->pid, cp->name, tf->trapno, tf->err, cpu(), tf->eip); + cp->killed = 1; } cpus[cpu()].nlock--; - if(tf->trapno == IRQ_OFFSET + IRQ_TIMER && cp != 0){ - // Force process exit if it has been killed and is in user space. - // (If it is still executing in the kernel, let it keep running - // until it gets to the regular system call return.) - if((tf->cs&3) == DPL_USER && cp->killed) - proc_exit(); + // Force process exit if it has been killed and is in user space. + // (If it is still executing in the kernel, let it keep running + // until it gets to the regular system call return.) + if(cp && cp->killed && (tf->cs&3) == DPL_USER) + proc_exit(); - // Force process to give up CPU and let others run. - // If locks were held with interrupts on, would need to check nlock. - if(cp->state == RUNNING) - yield(); - } + // Force process to give up CPU on clock tick. + // If interrupts were on while locks held, would need to check nlock. + if(cp && cp->state == RUNNING && tf->trapno == IRQ_OFFSET+IRQ_TIMER) + yield(); } |