| Message ID | 20161205093211.11870-1-christoffer.dall@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/12/16 09:32, Christoffer Dall wrote: > 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 <shihwei@cs.columbia.edu> > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> > --- > virt/kvm/arm/arch_timer.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c > index 27a1f63..5c12f53 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("arch_timer: uninitialized timecounter\n"); For consistency, I'll change the error message to say "kvm_arch_timer", just like the below case. > + return -ENODEV; > + } > + > if (info->virtual_irq <= 0) { > kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n", > info->virtual_irq); > Otherwise looks good to me. I'll queue it now. Thanks, M.
On Tue, Dec 06, 2016 at 11:25:42AM +0000, Marc Zyngier wrote: > On 05/12/16 09:32, Christoffer Dall wrote: > > 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 <shihwei@cs.columbia.edu> > > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> > > --- > > virt/kvm/arm/arch_timer.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c > > index 27a1f63..5c12f53 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("arch_timer: uninitialized timecounter\n"); > > For consistency, I'll change the error message to say "kvm_arch_timer", > just like the below case. > No objections, only problem is that the patch you queued uses kcm_arch_timer ;) > > + return -ENODEV; > > + } > > + > > if (info->virtual_irq <= 0) { > > kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n", > > info->virtual_irq); > > > > Otherwise looks good to me. I'll queue it now. > Thanks, -Christoffer
On 06/12/16 19:56, Christoffer Dall wrote: > On Tue, Dec 06, 2016 at 11:25:42AM +0000, Marc Zyngier wrote: >> On 05/12/16 09:32, Christoffer Dall wrote: >>> 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 <shihwei@cs.columbia.edu> >>> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> >>> --- >>> virt/kvm/arm/arch_timer.c | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c >>> index 27a1f63..5c12f53 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("arch_timer: uninitialized timecounter\n"); >> >> For consistency, I'll change the error message to say "kvm_arch_timer", >> just like the below case. >> > > No objections, only problem is that the patch you queued uses > kcm_arch_timer ;) Yeah, that's the new and upgraded version: Kernel Cryogenic Machine, it freezes time ;-). I'll fix that shortly, thanks for the heads up! M.
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 27a1f63..5c12f53 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("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);
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 <shihwei@cs.columbia.edu> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> --- virt/kvm/arm/arch_timer.c | 5 +++++ 1 file changed, 5 insertions(+)