Il 20/09/2014 01:03, David Matlack ha scritto: > vcpu ioctls can hang the calling thread if issued while a vcpu is > running. If we know ioctl is going to be rejected as invalid anyway, > we can fail before trying to take the vcpu mutex. > > This patch does not change functionality, it just makes invalid ioctls > fail faster. > > Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx> > --- > virt/kvm/kvm_main.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 96ec622..f9234e5 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -52,6 +52,7 @@ > > #include <asm/processor.h> > #include <asm/io.h> > +#include <asm/ioctl.h> > #include <asm/uaccess.h> > #include <asm/pgtable.h> > > @@ -1975,6 +1976,9 @@ static long kvm_vcpu_ioctl(struct file *filp, > if (vcpu->kvm->mm != current->mm) > return -EIO; > > + if (unlikely(_IOC_TYPE(ioctl) != KVMIO)) > + return -EINVAL; > + > #if defined(CONFIG_S390) || defined(CONFIG_PPC) || defined(CONFIG_MIPS) > /* > * Special cases: vcpu ioctls that are asynchronous to vcpu execution, > Thanks, applying this patch. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
