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path: root/drivers/lguest/interrupts_and_traps.c
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Diffstat (limited to 'drivers/lguest/interrupts_and_traps.c')
-rw-r--r--drivers/lguest/interrupts_and_traps.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index 49787e964a0..49aa55577d0 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -195,13 +195,16 @@ static int has_err(unsigned int trap)
/* deliver_trap() returns true if it could deliver the trap. */
int deliver_trap(struct lguest *lg, unsigned int num)
{
- u32 lo = lg->idt[num].a, hi = lg->idt[num].b;
+ /* Trap numbers are always 8 bit, but we set an impossible trap number
+ * for traps inside the Switcher, so check that here. */
+ if (num >= ARRAY_SIZE(lg->idt))
+ return 0;
/* Early on the Guest hasn't set the IDT entries (or maybe it put a
* bogus one in): if we fail here, the Guest will be killed. */
- if (!idt_present(lo, hi))
+ if (!idt_present(lg->idt[num].a, lg->idt[num].b))
return 0;
- set_guest_interrupt(lg, lo, hi, has_err(num));
+ set_guest_interrupt(lg, lg->idt[num].a, lg->idt[num].b, has_err(num));
return 1;
}