KVM: Fix overflow bug in overflow detection code

The expression

   sp - 6 < sp

where sp is a u16 is undefined in C since 'sp - 6' is promoted to int,
and signed overflow is undefined in C.  gcc 4.2 actually warns about it.
Replace with a simpler test.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Eric Sesterhenn / Snakebyte 2007-04-09 16:15:05 +02:00 committed by Avi Kivity
parent 5008fdf5b6
commit 3964994bb5

View file

@ -1182,7 +1182,7 @@ static void inject_rmode_irq(struct kvm_vcpu *vcpu, int irq)
u16 sp = vmcs_readl(GUEST_RSP);
u32 ss_limit = vmcs_read32(GUEST_SS_LIMIT);
if (sp > ss_limit || sp - 6 > sp) {
if (sp > ss_limit || sp < 6 ) {
vcpu_printf(vcpu, "%s: #SS, rsp 0x%lx ss 0x%lx limit 0x%x\n",
__FUNCTION__,
vmcs_readl(GUEST_RSP),