On Thu, Mar 16, 2017 at 06:24:34PM +0000, Suzuki K Poulose wrote:
> From: Marc Zyngier <marc.zyngier@xxxxxxx>
>
> Add checks to make sure that kvm->mmu_lock is held while calling
> stage2_wp_range. Also avoid explicit checks already done by cond_resched_lock().
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> [ Added assert_spin_locked check ]
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Reviewed-by: Christoffer Dall <cdall@xxxxxxxxxx>
> ---
> arch/arm/kvm/mmu.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
> index 7628ef1..37e67f5 100644
> --- a/arch/arm/kvm/mmu.c
> +++ b/arch/arm/kvm/mmu.c
> @@ -1162,6 +1162,8 @@ static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
> pgd_t *pgd;
> phys_addr_t next;
>
> + assert_spin_locked(&kvm->mmu_lock);
> +
> pgd = kvm->arch.pgd + stage2_pgd_index(addr);
> do {
> /*
> @@ -1171,8 +1173,7 @@ static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
> * CONFIG_LOCKDEP. Additionally, holding the lock too long
> * will also starve other vCPUs.
> */
> - if (need_resched() || spin_needbreak(&kvm->mmu_lock))
> - cond_resched_lock(&kvm->mmu_lock);
> + cond_resched_lock(&kvm->mmu_lock);
>
> next = stage2_pgd_addr_end(addr, end);
> if (stage2_pgd_present(*pgd))
> --
> 2.7.4
>
