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make trap fit on one page

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rsc 2006-09-08 14:29:58 +00:00
parent 1656b1b232
commit cd12eea3c7
1 changed files with 6 additions and 12 deletions
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18
trap.c
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@ -9,10 +9,8 @@
// Interrupt descriptor table (shared by all CPUs). // Interrupt descriptor table (shared by all CPUs).
struct gatedesc idt[256]; struct gatedesc idt[256];
extern uint vectors[]; // in vectors.S: array of 256 entry pointers extern uint vectors[]; // in vectors.S: array of 256 entry pointers
void void
tvinit(void) tvinit(void)
{ {
@ -46,8 +44,7 @@ trap(struct trapframe *tf)
} }
// Increment nlock to make sure interrupts stay off // Increment nlock to make sure interrupts stay off
// during interrupt handler. Must decrement before // during interrupt handler. Decrement before returning.
// returning.
cpus[cpu()].nlock++; cpus[cpu()].nlock++;
switch(v){ switch(v){
@ -55,11 +52,9 @@ trap(struct trapframe *tf)
lapic_timerintr(); lapic_timerintr();
cpus[cpu()].nlock--; cpus[cpu()].nlock--;
if(cp){ if(cp){
// Force process exit if it has been killed // Force process exit if it has been killed and is in user space.
// and the interrupt came from user space. // (If it is still executing in the kernel, let it keep running
// (If the kernel was executing at time of interrupt, // until it gets to the regular system call return.)
// don't kill the process. Let the process get back
// out to its regular system call return.)
if((tf->cs&3) == 3 && cp->killed) if((tf->cs&3) == 3 && cp->killed)
proc_exit(); proc_exit();
@ -85,14 +80,13 @@ trap(struct trapframe *tf)
default: default:
if(curproc[cpu()]) { if(curproc[cpu()]) {
// assume process caused unexpected trap, // Assume process divided by zero or dereferenced null, etc.
// 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 // Otherwise it's our mistake.
cprintf("unexpected trap %d from cpu %d eip %x\n", v, cpu(), tf->eip); cprintf("unexpected trap %d from cpu %d eip %x\n", v, cpu(), tf->eip);
panic("trap"); panic("trap");
} }