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authorrsc <rsc>2007-08-28 04:20:13 +0000
committerrsc <rsc>2007-08-28 04:20:13 +0000
commit4c917f6df277025dbec740bfe35456ccb52b164b (patch)
tree01b6640256ca662a2d47f8c4b5d33a6052ca68b1
parent1baead533fe8d10d91b10967ac9c536fa2e41585 (diff)
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do not call proc_exit until lock dropped
-rw-r--r--trap.c38
1 files changed, 18 insertions, 20 deletions
diff --git a/trap.c b/trap.c
index 5955cfc..d60a38a 100644
--- a/trap.c
+++ b/trap.c
@@ -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();
}