Commit 15bbc1b2 authored Apr 17, 2013 by Marc Zyngier Committed by Linus Torvalds Apr 17, 2013

ARM: KVM: fix unbalanced get_cpu() in access_dcsw



In the very unlikely event where a guest would be foolish enough to
*read* from a write-only cache maintainance register, we end up
with preemption disabled, due to a misplaced get_cpu().

Just move the "is_write" test outside of the critical section.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent fca83168

arch/arm/kvm/coproc.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -79,11 +79,11 @@ static bool access_dcsw(struct kvm_vcpu *vcpu,
		u32 val;
		int cpu;

		cpu = get_cpu();

		if (!p->is_write)
		return read_from_write_only(vcpu, p);

		cpu = get_cpu();

		cpumask_setall(&vcpu->arch.require_dcache_flush);
		cpumask_clear_cpu(cpu, &vcpu->arch.require_dcache_flush);