From: Avi Kivity <avi@xxxxxxxxxx> init_fpu() (which is indirectly called by the fpu switching code) assumes it is in process context. Rather than makeing init_fpu() use an atomic allocation, which can cause a task to be killed, make sure the fpu is already initialized when we enter the run loop. KVM-Stable-Tag. Reported-and-tested-by: Kirill A. Shutemov <kas@xxxxxxxxxx> Acked-by: Pekka Enberg <penberg@xxxxxxxxxx> Reviewed-by: Christoph Lameter <cl@xxxxxxxxx> Signed-off-by: Avi Kivity <avi@xxxxxxxxxx> diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 58bb239..e60c38c 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -169,6 +169,7 @@ int init_fpu(struct task_struct *tsk) set_stopped_child_used_math(tsk); return 0; } +EXPORT_SYMBOL_GPL(init_fpu); /* * The xstateregs_active() routine is the same as the fpregs_active() routine, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fa708c9..9dda70d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5376,6 +5376,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) int r; sigset_t sigsaved; + if (!tsk_used_math(current) && init_fpu(current)) + return -ENOMEM; + if (vcpu->sigset_active) sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved); -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
