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| author | Avi Kivity <avi@redhat.com> | 2011-01-11 12:15:54 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-01-12 12:02:26 +0200 |
| commit | e5c301428294cb8925667c9ee39f817c4ab1c2c9 (patch) | |
| tree | 6630b1e95e38287bcda12e40fbbc2d25cf551496 /arch/x86 | |
| parent | 444e863d13373b958ec6b133dcecf140d6c6c2ab (diff) | |
| download | blackbird-op-linux-e5c301428294cb8925667c9ee39f817c4ab1c2c9.tar.gz blackbird-op-linux-e5c301428294cb8925667c9ee39f817c4ab1c2c9.zip | |
KVM: Initialize fpu state in preemptible context
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@openvz.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/i387.c | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 58bb239a2fd7..e60c38cc0eed 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 fa708c9a7437..9dda70dffac1 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); |
