From: Christoffer Dall Date: Mon, 5 Dec 2016 09:32:11 +0000 (+0100) Subject: KVM: arm/arm64: timer: Check for properly initialized timer on init X-Git-Tag: rel_imx_4.19.35_1.1.0~13574^2^2~1 X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=8e1a0476f8563cadfa32e9b4fff39c4224553b1e;p=linux.git KVM: arm/arm64: timer: Check for properly initialized timer on init When the arch timer code fails to initialize (for example because the memory mapped timer doesn't work, which is currently seen with the AEM model), then KVM just continues happily with a final result that KVM eventually does a NULL pointer dereference of the uninitialized cycle counter. Check directly for this in the init path and give the user a reasonable error in this case. Cc: Shih-Wei Li Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier --- diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 17b8fa52bf3b..ae95fc0e3214 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -425,6 +425,11 @@ int kvm_timer_hyp_init(void) info = arch_timer_get_kvm_info(); timecounter = &info->timecounter; + if (!timecounter->cc) { + kvm_err("kvm_arch_timer: uninitialized timecounter\n"); + return -ENODEV; + } + if (info->virtual_irq <= 0) { kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n", info->virtual_irq);