ilo-pona/xv6-65oo2
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Activity

do not call proc_exit until lock dropped

Browse source
This commit is contained in:
rsc 2007-08-28 04:20:13 +00:00
parent 1baead533f
commit 4c917f6df2
1 changed files with 18 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

38
trap.c
View file

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