Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7e66f350cfc853043bfa71b281581dd6f92fa347
Commit: 7e66f350cfc853043bfa71b281581dd6f92fa347
Parent: 3090dd7377c7eb5cbe229e2a538f9dc7e5b06814
Author: Avi Kivity <[EMAIL PROTECTED]>
AuthorDate: Wed Aug 15 15:23:34 2007 +0300
Committer: Avi Kivity <[EMAIL PROTECTED]>
CommitDate: Sat Oct 13 10:18:23 2007 +0200
KVM: Close minor race in signal handling
We need to check for signals inside the critical section, otherwise a
signal can be sent which we will not notice. Also move the check
before entry, so that if the signal happens before the first entry,
we exit immediately instead of waiting for something to happen to the
guest.
Signed-off-by: Avi Kivity <[EMAIL PROTECTED]>
---
drivers/kvm/svm.c | 19 ++++++++++---------
drivers/kvm/vmx.c | 23 ++++++++++++-----------
2 files changed, 22 insertions(+), 20 deletions(-)
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index e3c6d89..cc674bf 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1398,11 +1398,19 @@ again:
if (unlikely(r))
return r;
+ clgi();
+
+ if (signal_pending(current)) {
+ stgi();
+ ++vcpu->stat.signal_exits;
+ post_kvm_run_save(svm, kvm_run);
+ kvm_run->exit_reason = KVM_EXIT_INTR;
+ return -EINTR;
+ }
+
if (!vcpu->mmio_read_completed)
do_interrupt_requests(svm, kvm_run);
- clgi();
-
vcpu->guest_mode = 1;
if (vcpu->requests)
if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
@@ -1582,13 +1590,6 @@ again:
r = handle_exit(svm, kvm_run);
if (r > 0) {
- if (signal_pending(current)) {
- ++vcpu->stat.signal_exits;
- post_kvm_run_save(svm, kvm_run);
- kvm_run->exit_reason = KVM_EXIT_INTR;
- return -EINTR;
- }
-
if (dm_request_for_irq_injection(svm, kvm_run)) {
++vcpu->stat.request_irq_exits;
post_kvm_run_save(svm, kvm_run);
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 906d4fa..a9b4cb5 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -2066,9 +2066,6 @@ again:
preempt_disable();
- if (!vcpu->mmio_read_completed)
- do_interrupt_requests(vcpu, kvm_run);
-
vmx_save_host_state(vmx);
kvm_load_guest_fpu(vcpu);
@@ -2079,6 +2076,18 @@ again:
local_irq_disable();
+ if (signal_pending(current)) {
+ local_irq_enable();
+ preempt_enable();
+ r = -EINTR;
+ kvm_run->exit_reason = KVM_EXIT_INTR;
+ ++vcpu->stat.signal_exits;
+ goto out;
+ }
+
+ if (!vcpu->mmio_read_completed)
+ do_interrupt_requests(vcpu, kvm_run);
+
vcpu->guest_mode = 1;
if (vcpu->requests)
if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
@@ -2227,14 +2236,6 @@ again:
r = kvm_handle_exit(kvm_run, vcpu);
if (r > 0) {
- /* Give scheduler a change to reschedule. */
- if (signal_pending(current)) {
- r = -EINTR;
- kvm_run->exit_reason = KVM_EXIT_INTR;
- ++vcpu->stat.signal_exits;
- goto out;
- }
-
if (dm_request_for_irq_injection(vcpu, kvm_run)) {
r = -EINTR;
kvm_run->exit_reason = KVM_EXIT_INTR;
-
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